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+The Project Gutenberg eBook, Aether and Gravitation, by William George
+Hooper
+
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
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+
+Title: Aether and Gravitation
+
+
+Author: William George Hooper
+
+
+
+Release Date: February 22, 2008  [eBook #24667]
+
+Language: English
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+Character set encoding: ISO-8859-1
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+***START OF THE PROJECT GUTENBERG EBOOK AETHER AND GRAVITATION***
+
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+Transcriber's note:
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+      Numbers preceded by a carat character are superscripts
+      (example: 3^2 = 9).
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+
+
+AETHER AND GRAVITATION
+
+by
+
+WILLIAM GEORGE HOOPER, F.S.S.
+
+
+
+
+
+
+
+[Illustration]
+
+
+London
+Chapman and Hall, Ltd.
+1903
+
+
+
+
+INTRODUCTORY NOTES
+
+
+The author in this work endeavours to solve the greatest scientific
+problem that has puzzled scientists for the past two hundred years. The
+question has arisen over and over again, since the discovery of
+universal gravitation by Sir Isaac Newton, as to what is the physical
+cause of the attraction of gravitation.
+
+"Action at a distance" has long ceased to be recognized as a possible
+phenomenon, although up to the present, the medium and method of
+gravitational attraction have not yet been discovered.
+
+It is, however, generally accepted by scientists, that the only possible
+medium which can give rise to the phenomena incidental to, and
+associated with the Law of Gravitation, must be the universal aether,
+which forms the common medium of all phenomena associated with light,
+heat, electricity and magnetism.
+
+It is impossible, however, to reconcile gravitational phenomena with the
+present conception of the universal aether medium, and a new theory is
+therefore demanded, before the long-sought-for explanation will be
+forthcoming.
+
+Professor Glazebrook definitely states the necessity for a new theory in
+his work on J. C. Maxwell, page 221, where he writes: "We are waiting
+for some one to give us a theory of the aether, which shall include the
+facts of electricity and magnetism, luminous radiation, and it may be
+gravitation."
+
+A new theory of the aether is also demanded in view of the recent
+experimental results of Professor Lebedew, and Nichols and Hull of
+America. It is logically impossible to reconcile a frictionless aether,
+with their results relative to the pressure of light waves.
+
+In the following pages of this work the author has endeavoured to
+perfect a theory, which will bring aetherial physics more into harmony
+with modern observation and experiments; and by so doing, believes that
+he has found the key that will unlock the problem not only of the cause
+of universal gravitation, but also other problems of physical science.
+The author has taken Newton's Rules of Philosophy as his guide in the
+making of the new theory, as he believes that if any man knew anything
+of the rules of Philosophy, that man was Sir Isaac Newton. The first
+chapter therefore deals with the generally recognized rules which govern
+philosophical reasoning, the same being three in number; the fundamental
+rule being, that in making any hypothesis, the results of experience as
+obtained by observation and experiments must not be violated.
+
+In applying the rules to the present theory of the aether, he found that
+the theory as at present recognized violated two of the most important
+rules of Philosophy, because, while aether is supposed to be matter, yet
+it failed to fulfil the primary property of all matter, that is, it is
+not subject to the Law of Gravitation. If aether is matter, then, to be
+strictly logical and philosophical, it must possess the properties of
+matter as revealed by observation and experiment.
+
+Those properties are given in Chapter III., where it is shown that they
+are atomicity, heaviness or weight, elasticity, density, inertia, and
+compressibility. To be strictly logical and philosophical, the author
+was compelled to postulate similar properties for the aether, or else
+his hypotheses would contravert the results of all experience.
+
+The application of these properties to the aether will be found in
+Chapter IV., where the author has postulated atomicity, heaviness or
+weight, density, elasticity, inertia, and compressibility for the
+aether, and so brought the theory of the aether into perfect harmony
+with all observation and experiments relative to ordinary matter. It
+will be shown that Clerk Maxwell also definitely affirms the atomicity
+of the aether, while Tyndall and Huyghens also use the term "_particles
+of aether_" over and over again.
+
+Moreover, in view of the most recent researches in electricity made by
+Sir William Crookes and Professor J. J. Thomson, we are compelled to
+accept an atomic basis for electricity, and as Dr. Lodge, in his _Modern
+Views of Electricity_, states that "Aether is made up of positive and
+negative electricity," then, unless we postulate atomicity for the
+aether, we have to suppose that it is possible for a non-atomic body
+(aether) to be made up of atoms or corpuscles, which conclusion is
+absurd, and therefore must be rejected as illogical and unphilosophical.
+
+After postulating atomicity for the aether, we are then able to apply
+the Newtonian Law of Gravitation to it, which distinctly affirms that
+"every particle of matter attracts every other particle," and so we
+arrive at Thomas Young's fourth hypothesis given in the Philosophical
+Transactions of 1802, where he asserts that "All material bodies have an
+attraction for the aetherial medium, by means of which it is
+accumulated within their substance, and for a small distance around them
+in a state of greater density." He adds the significant remark that this
+hypothesis is opposed to that of Newton's. With an atomic and
+gravitative aether it is shown in Chapter IV. how the elasticity,
+density, and inertia of the medium are brought into harmony with all
+observation and experiments.
+
+In the succeeding chapters the new theory is applied to the phenomena of
+heat, light, electricity, and magnetism, and the principles enunciated
+therein are then applied to solar and stellar phenomena.
+
+One of the greatest stumbling-blocks to the discovery of the physical
+cause of gravitation, apart from the unphilosophical theory of the
+aether medium, lies in the fact that apparently the Law of Gravitation
+only recognizes a force of one kind. Dr. Lodge refers to this phase of
+the subject on page 39 of his _Modern Views of Matter_ just published.
+It is here where scientists have failed to solve the problem of
+universal gravitation, as there are _two_ forces at work in the solar
+system and not one; that is, if we are to accept the results of
+up-to-date experiments in relation to radiant light and heat as
+performed by Professor Lebedew, and Nichols and Hull of America. Their
+experiments conclusively prove that light waves exert a pressure upon
+all bodies on which they fall, and by no reasoning can this pressure be
+resolved into an attractive force.
+
+Herschel in his _Lectures on Scientific Subjects_ definitely refers to
+the existence of a repulsive force in the solar system, and asserts that
+it offers the most interesting prospect of any future discovery.
+
+The author has therefore attacked the problem of the cause of
+gravitation, by trying to solve the problem of the cause of the
+_repulsive_ force which has been experimentally demonstrated to exist by
+Professor Lebedew and others.
+
+In his efforts to ascertain the physical cause of the Centrifugal Force,
+he has been assisted by an unknown and original essay written by an
+unknown writer over twenty years ago. That unknown writer was the
+author's father, who wrote an essay on the _Complementary Law of
+Gravitation_, and if it had not been for that essay, the present work
+would never have been attempted.
+
+The main object of the author in Chapters VI., VII., and VIII., is to
+prove beyond the possibility of contradiction, from the phenomena of
+heat, light, and electricity, the existence of _two_ forces in the solar
+system; and by so doing, to bring our philosophy of the aether medium,
+and all gravitational phenomena, into harmony with all observation and
+experiments, which at present is not the case. In seeking to do this he
+found that the new theory of the aether harmonized with views given, by
+Faraday and Clerk Maxwell in relation to electric and magnetic
+phenomena, and by the new theory Maxwell's hypothesis of "Physical Lines
+of Force" receives a definite and physical basis. In Chapter X. the
+author endeavours to show what the Electro-Kinetic energy is, which term
+is used by Clerk Maxwell, the term being brought for the first time into
+harmony with our experience. The Electro-Magnetic Theory of Light also
+receives fresh light from the new theory of an atomic and gravitating
+aether.
+
+In the succeeding chapters the theory is applied to Newton's Laws of
+Motion and Kepler's Laws, and is found to harmonize with all the results
+given by these laws. Such a result is a distinct advance on the
+application of a frictionless aether to solar and stellar phenomena, as
+it is impossible for Kepler's Laws to be reconciled in any way with our
+present theory of the aether.
+
+In the concluding chapter on the unity of the universe, certain views
+are suggested as to the ultimate constitution of all matter, upon an
+aetherial basis, which hypothesis practically resolves itself into an
+electric basis for all matter. It is suggested that aether and
+electricity are one and the same medium, both being a form of matter,
+and both possessing exactly the same properties, viz. atomicity, weight,
+density, elasticity, inertia, and compressibility. This view of matter
+harmonizes with the most "Modern Views of Matter" as suggested by Sir
+Oliver Lodge in his Romanes Lecture 1903.
+
+The author has accepted Newton's way of spelling "_aether_" as given in
+his work on _Optics_, and has given "_aetherial_" the same suffix as
+"material," in order to differentiate the word from "ethereal," which is
+too metaphysical a term for a material medium.
+
+    _Nottingham_,
+        _Sept._ 1903.
+
+
+
+
+CONTENTS
+
+
+                             CHAPTER I
+
+                     PHILOSOPHY OF GRAVITATION
+
+                                                                  PAGE
+ART.   1. GRAVITATION                                                1
+ "     2. CAUSE OF GRAVITATION                                       1
+ "     3. NEWTON'S RULES OF PHILOSOPHY                               3
+ "     4. FIRST RULE OF PHILOSOPHY                                   3
+ "     5. SECOND RULE OF PHILOSOPHY                                  4
+ "     6. THIRD RULE OF PHILOSOPHY                                   7
+ "     7. APPLICATION OF RULES TO GRAVITATION                        9
+ "     8. ANALYSIS OF LAW OF GRAVITATION                             9
+ "     9. PRIMITIVE IMPULSE                                         10
+ "    10. CENTRIPETAL FORCE                                         12
+ "    11. CENTRIFUGAL FORCE                                         13
+ "    12. NEWTON'S LAWS OF MOTION                                   15
+ "    13. FORCE                                                     16
+ "    14. FIRST LAW OF MOTION                                       16
+ "    15. SECOND LAW OF MOTION                                      19
+ "    16. THIRD LAW OF MOTION                                       20
+ "    17. SUMMARY OF CHAPTER                                        22
+
+
+                             CHAPTER II
+
+                PHILOSOPHY OF GRAVITATION--(_continued_)
+
+ART.  18. GRAVITATION ATTRACTION                                    24
+ "    19. UNIVERSALITY OF GRAVITATION                               24
+ "    20. DIRECTION OF THE FORCES                                   26
+ "    21. PROPORTION OF THE FORCES                                  26
+ "    22. LAW OF INVERSE SQUARES                                    27
+ "    23. TERRESTRIAL GRAVITY                                       29
+ "    24. CENTRIFUGAL FORCE                                         30
+ "    25. KEPLER'S LAWS                                             32
+ "    26. FIRST LAW OF KEPLER                                       33
+ "    27. SECOND LAW OF KEPLER                                      36
+ "    28. THIRD LAW OF KEPLER                                       37
+
+
+                             CHAPTER III
+
+                                MATTER
+
+ART.  29. WHAT IS MATTER?                                           40
+ "    30. CONSERVATION OF MATTER                                    42
+ "    31. MATTER IS ATOMIC                                          42
+ "    32. WHAT IS AN ATOM?                                          43
+ "    33. THE ATOMIC THEORY                                         44
+ "    34. KINDS OF ATOMS                                            44
+ "    35. ELEMENTS OF MATTER                                        47
+ "    36. THREE KINDS OF MATTER                                     47
+ "    37. MATTER IS GRAVITATIVE                                     50
+ "    38. MATTER POSSESSES DENSITY                                  51
+ "    39. MATTER POSSESSES ELASTICITY                               51
+ "    40. MATTER POSSESSES INERTIA                                  52
+
+
+                             CHAPTER IV
+
+                               AETHER
+
+ART.  42. AETHER IS MATTER                                          54
+ "    43. AETHER IS UNIVERSAL                                       58
+ "    44. AETHER IS ATOMIC                                          59
+ "    45. AETHER IS GRAVITATIVE                                     64
+ "    46. AETHER POSSESSES DENSITY                                  71
+ "    47. AETHER POSSESSES ELASTICITY                               74
+ "    48. AETHER POSSESSES INERTIA                                  76
+ "    49. AETHER IS IMPRESSIBLE                                     78
+ "    50. AETHER AND ITS MOTIONS                                    80
+
+
+                             CHAPTER V
+
+                              ENERGY
+
+ART.  51. ENERGY                                                    83
+ "    52. CONSERVATION OF ENERGY                                    84
+ "    53. TRANSFORMATION OF ENERGY                                  86
+ "    54. POTENTIAL ENERGY                                          87
+ "    55. KINETIC ENERGY                                            89
+ "    56. ENERGY AND MOTION                                         91
+ "    57. CONSERVATION OF MOTION                                    92
+ "    58. TRANSFORMATION OF MOTION                                  93
+ "    59. MOTION AND WORK                                           95
+
+
+                             CHAPTER VI
+
+                       HEAT, A MODE OF MOTION
+
+ART.  60. HEAT, A MODE OF MOTION                                    98
+ "    61. HEAT AND MATTER                                          100
+ "    62. RADIATION AND ABSORPTION                                 104
+ "    63. HEAT IS A REPULSIVE MOTION                               107
+ "    64. RADIANT HEAT                                             109
+ "    65. DIRECTION OF A RAY OF HEAT                               111
+ "    66. LAW OF INVERSE SQUARES                                   112
+ "    67. FIRST LAW OF THERMODYNAMICS                              114
+ "    68. SECOND LAW OF THERMODYNAMICS                             116
+ "    69. IDENTITY OF HEAT AND LIGHT                               119
+
+
+                            CHAPTER VII
+
+                      LIGHT, A MODE OF MOTION
+
+ART.  70. LIGHT, A MODE OF MOTION                                  122
+ "    71. TRANSVERSE VIBRATION OF LIGHT                            130
+ "    72. REFLECTION AND REFRACTION                                135
+ "    73. THE SOLAR SPECTRUM                                       139
+ "    74. DIRECTION OF A RAY OF LIGHT                              144
+ "    75. INTENSITY OF LIGHT                                       145
+ "    76. VELOCITY OF LIGHT                                        148
+ "    77. DYNAMICAL VALUE OF LIGHT                                 150
+ "    78. ELECTRO-MAGNETIC THEORY OF LIGHT                         155
+
+
+                            CHAPTER VIII
+
+                       AETHER AND ELECTRICITY
+
+ART.  79. ELECTRICITY, A MODE OF MOTION                            162
+ "    80. ELECTRIC FIELD                                           166
+ "    81. ELECTRIC INDUCTION                                       174
+ "    82. ELECTRIC ENERGY                                          179
+ "    83. ELECTRIC RADIATION                                       182
+ "    84. LAW OF INVERSE SQUARES                                   184
+ "    85. SECOND LAW OF ELECTRICITY                                186
+
+
+                             CHAPTER IX
+
+                        AETHER AND MAGNETISM
+
+ART.  86. ELECTRO-MAGNETISM                                        192
+ "    87. THE EARTH A MAGNET                                       195
+ "    88. THE SUN AN ELECTRO-MAGNET                                199
+ "    89. FARADAY'S LINES OF FORCE                                 203
+ "    90. TERRESTRIAL MAGNETISM                                    206
+ "    91. SOLAR MAGNETS                                            211
+ "    92. CAUSE OF ROTATION OF THE EARTH ON ITS AXIS               219
+ "    93. VORTEX MOTION                                            221
+ "    94. RELATIVE MOTION OF AETHER AND MATTER                     224
+ "    95. VIBRATIONS IN THE ELECTRO-MAGNETIC THEORY OF LIGHT       228
+
+
+                             CHAPTER X
+
+                  AETHER AND NEWTON'S LAWS OF MOTION
+
+ART.  96. AETHER AND CENTRIFUGAL FORCE                             232
+ "    97. AETHER AND CENTRIPETAL FORCE                             236
+ "    98. AETHER AND NEWTON'S FIRST LAW OF MOTION                  239
+ "    99. AETHER AND NEWTON'S SECOND LAW OF MOTION                 244
+ "   100. AETHER AND NEWTON'S THIRD LAW OF MOTION                  251
+ "   101. WHY PLANETS REVOLVE FROM WEST TO EAST                    253
+
+
+                             CHAPTER XI
+
+                      AETHER AND KEPLER'S LAWS
+
+ART. 102. AETHER AND KEPLER'S FIRST LAW                            256
+ "   103. AETHER AND KEPLER'S SECOND LAW                           260
+ "   104. AETHER AND KEPLER'S THIRD LAW                            263
+ "   105. ORBITAL MOTION OF PLANETS                                266
+ "   106. ECCENTRICITY OF THE MOON'S ORBIT                         268
+ "   107. THE SUN AND KEPLER'S FIRST LAW                           270
+ "   108. THE SUN AND KEPLER'S SECOND LAW                          274
+ "   109. AETHER AND THE PLANE OF THE ECLIPTIC                     277
+ "   110. AETHER AND THE CENTRIPETAL FORCE                         282
+
+
+                             CHAPTER XII
+
+                          AETHER AND COMETS
+
+ART. 111. WHAT IS A COMET?                                         291
+ "   112. ORBITS OF COMETS                                         293
+ "   113. KINDS OF COMETS                                          296
+ "   114. PARTS OF A COMET                                         298
+ "   115. CENTRIFUGAL FORCE AND COMETS                             300
+ "   116. FORMATION OF TAILS                                       303
+
+
+                            CHAPTER XIII
+
+                       AETHER AND STARRY WORLD
+
+ART. 117. STARRY WORLD                                             306
+ "   118. STARS AND KEPLER'S LAWS                                  309
+ "   119. AETHER AND NEBULAE                                       313
+ "   120. WHAT IS A NEBULA?                                        314
+ "   121. AETHER AND NEBULAR HYPOTHESIS                            317
+ "   122. KINDS OF NEBULAE                                         319
+
+
+                             CHAPTER XIV
+
+                       AETHER AND THE UNIVERSE
+
+ART. 123. THE UNIVERSE                                             323
+ "   124. UNITY OF THE UNIVERSE                                    326
+ "   125. CONSTITUTION OF MATTER                                   334
+ "   126. QUOD ERAT FACIENDUM                                      337
+ "   127. GOD AND THE UNIVERS                                      342
+
+APPENDIX                                                           349
+INDEX                                                              351
+
+
+
+
+                        AETHER AND GRAVITATION
+
+
+
+
+                               CHAPTER I
+
+                       PHILOSOPHY OF GRAVITATION
+
+
+ART. 1. _Gravitation._--In the realm of Science, there exists a Force or
+Law that pervades and influences all Nature, and from the power of
+which, nothing, not even an atom, is free.
+
+It holds together the component parts of each and every individual
+world, and in the world's revolving prevents both its inhabitants and
+its vegetation from being whirled off its surface into space. It exists
+in each and every central sun, and circles round each sun its associated
+system of planets. It rolls each satellite around its primary planet,
+and regulates the comet's mysterious flight into the depths of space,
+while the pendulation of even the remotest star is accomplished by this
+same force. Our own rocking world obeys the same mysterious power, that
+seems to grasp the entire material creation as with the grasp of the
+Infinite.
+
+It exists in, and influences every atom, whose combinations compose and
+constitute the entire material creation, or each and every orb that
+bespangle the blue infinity.
+
+As is readily seen, it weaves as it were around each and all, a
+mysterious network or chain, that binds star to star, and world to
+world, blending all into one entire, vast and complete unity. It decides
+all their orbits and distances, regulates and controls all their
+motions, from the most simple even to the more complex and intricate,
+ultimately producing that wondrous and beauteous order, unity and
+harmony that everywhere pervade and blend all the universe into one
+grand and harmonious whole.
+
+That Law I need hardly say is the Law of Gravitation.
+
+
+ART. 2. _Cause of Gravitation._--Now the question arises, and indeed has
+arisen a thousand times since the discovery of this law by Sir Isaac
+Newton over two hundred years ago, as to what is the physical cause, the
+true explanation of this universal attraction.
+
+MacLaurin in his work on the philosophical discoveries of Sir Isaac
+Newton says: "In all cases when bodies seem to act upon each other at a
+distance, and tend towards one another without any apparent cause
+impelling them, this force has been commonly called Attraction, and this
+term is frequently used by Sir Isaac Newton. But he gives repeated
+caution that he pretends not by the use of this term to define the
+nature of the power, or the manner in which it acts. Nor does he ever
+affirm or insinuate that a body can act upon another body at a distance,
+but by the intervention of other bodies."
+
+The results of modern discovery show that action at a distance, without
+the intervention of any medium, as for example the sun attracting the
+earth, is not the universal condition which governs all so-called
+forces.
+
+It is now recognized that light and heat are both forms of energy, and
+therefore forces, using the term in the same sense that it is applied to
+Gravitation.
+
+Both light and heat are transmitted through space with finite velocity
+through the intervention of a medium, the universal Aether. It is
+therefore only reasonable to suppose, that if one or more particular
+kinds of energy, or forces, require a medium for their transmission, why
+not another force, as for example Gravitation?
+
+Gravitation is an universal force which operates throughout the length
+and breadth of the entire universe, and if there be a medium which is to
+Gravitation, what the Aether is to light and heat, the question at once
+confronts us, as to what are the characteristics, properties, and
+qualities of that universal medium, which is to form the physical basis
+of this universal attraction?
+
+Newton himself suggested that Gravitation was due to an aetherial subtle
+medium, which filled all space.
+
+In his well-known letter to Bentley, Newton writes as follows: "That
+Gravity should be innate, inherent, and essential to matter, so that one
+body can act upon another body at a distance through a vacuum, without
+the mediation of anything else, by and through which their action and
+force may be conveyed from one to another, is to me so great an
+absurdity, that I believe no man who has any philosophical nature or
+competent faculty of thinking can ever fall into it."
+
+We also know from his Queries in his book on _Optics_, that he sought
+for the explanation of Gravitation in the properties of a subtle,
+aetherial medium diffused over the universe.
+
+MacLaurin on this point says: "It appears from his letters to Boyle,
+that this was his opinion early, and if he did not publish his opinion
+sooner, it proceeded from hence only, that he found he was not able from
+experiment and observation to give a satisfactory account of this
+medium, and the manner of its operations in producing the chief
+phenomena of Nature."
+
+Therefore, if we accept Newton's suggestion, and endeavour to trace the
+physical cause of Gravitation in the qualities, properties, and motions
+of this subtle aetherial medium to which he refers, we shall be simply
+working on the lines laid down by Sir Isaac Newton himself.
+
+I wish therefore to premise, that the future pages of this work will
+deal with the hypothesis of this aetherial medium, by which will be
+accounted for, and that on a satisfactory and physical basis, the
+universal Law of Gravitation.
+
+
+ART. 3. _Rules of Philosophy._--In order that we may rightly understand
+the making of any hypothesis, I purpose giving some rules laid down by
+such philosophers as Newton and Herschel, so that we may be guided by
+right principles in the development of this new hypothesis as to the
+cause of Gravitation.
+
+The rules that govern the making of any hypotheses, so far as I can
+discern, may be summed up under the three following heads--
+
+    (1) Simplicity of conception.
+
+    (2) Agreement with experience, observation, and experiment.
+
+    (3) Satisfactorily accounting for, and explaining all phenomena
+        sought to be explained.
+
+
+ART. 4. _1st Rule. Simplicity of Conception._--From this rule we learn
+that the hypothesis must be simple in conception, and simple in its
+fundamental principles, and further, that the same characteristic of
+simplicity must mark each step of its development.
+
+This rule of simplicity is distinctly laid down by Sir Isaac Newton in
+his _Principia_, Book 3, under the heading "Regulae Philosophandi."
+
+In that work he writes: "Natura simplex est, et rerum causis superfluis
+non luxuriat."--"Nature is simple, and does not abound in superfluous
+causes of things."
+
+He further states that: "Not more of the natural causes of things ought
+to be admitted, than those which are true and suffice to explain
+phenomena. In the nature of Philosophy nothing is done in vain, and by
+means of many things, it is done in vain when it can be done by fewer.
+For Nature is simple, and does not abound in superfluous causes."
+
+While again in Rule 3, he adds: "Natura simplex est et sibi semper
+consona."--"Nature is simple, and always agrees with itself."
+
+Whewell also considers simplicity as a fundamental principle of all true
+hypotheses. On this point he writes: "All the hypotheses should tend to
+simplicity and harmony. The new suppositions resolve themselves into the
+old ones, or at least only require some easy modification of the
+hypothesis first assumed. In false theories the contrary is the case."
+
+Thus, it is the very essence of philosophy to build upon a foundation of
+simplicity, combined with the results of experience, observation, and
+experiment. For example, if we desired to form a hypothesis as to the
+cause of day and night, two hypotheses might be assigned as to the
+cause.
+
+First, that the earth revolves on its axis once a day, and so presents
+each part successively to the light and heat of the sun; and second,
+that the sun revolves round the earth once every 24 hours. But such an
+assumption as the latter would involve the revolution of the sun through
+an immense orbit at an enormous velocity, in order for the journey to be
+accomplished in the time. So that it is much simpler to conceive of the
+earth revolving on its axis once every 24 hours, than it is for the sun
+to perform this journey in the same period. Hence the rule of simplicity
+is in favour of day and night being caused by the revolving of the earth
+on its axis. The same rule might be illustrated in many ways; but,
+however illustrated, the principle, according to Newton, always holds
+good that all effects are produced by the simplest causes, and if there
+are apparently two causes to the same phenomenon, then the simpler cause
+is the true and correct one. So that in the making and development of
+any hypotheses of the physical cause of Gravitation, this rule of
+simplicity must always be recognized; and, in conjunction with the other
+rules, we must seek to make our hypotheses, so as to be able to account
+and explain all phenomena sought to be explained.
+
+
+ART. 5. _2nd Rule. Experience._--Newton fully recognized the necessity
+of experience in Philosophy. He saw the absolute necessity of appealing
+to experience, observation, and experiment, both as a basis for
+philosophical reasoning, and further, for the data which were necessary
+to verify particular applications of the hypotheses suggested.
+
+In his Rules of Philosophy, referring to experience as a guide, he says:
+"Hoc est fundamentum philosophiae."--"This is the basis of philosophy."
+
+Herschel, writing on the same subject in his _Natural Philosophy_,
+writes thus with regard to experience: "We have pointed out that the
+great, and indeed the only ultimate source of our knowledge of nature,
+and its laws, is experience. By which I mean, not the experience of one
+man only, or of one generation, but the accumulated experience of all
+mankind in all ages registered in books or recorded in tradition. But
+experience may be acquired in two ways, either first by noticing facts
+as they occur without any attempt to influence the frequency of their
+occurrence, or to vary the circumstances under which they occur. This is
+observation. Second, by putting in action causes and agents over which
+we have no control, and purposely varying their combination, and then
+noticing what effects take place. This is experiment. To these two
+sources we must look as the fountains of all natural science."
+
+Herschel further writes: "Experience once recognized as the fountain of
+all our knowledge of nature, it follows, that in our study of nature and
+its laws, we ought at once to make up our minds to dismiss, as idle
+prejudices, or at least suspend as premature, all preconceived notion of
+what might, or ought to be the order of nature in any proposed case, and
+content ourselves as a plain matter of fact with what is. _To experience
+we refer as the only ground for all physical enquiry._ But before
+experience itself can be used to advantage, there is one preliminary
+step to make which depends wholly upon ourselves."
+
+"It is the _absolute dismissal_ and clearing the mind _of all
+prejudices_ from whatever source arising, and the determination to stand
+or fall by the result of direct appeal to facts in the first instance,
+and to strict logical deduction from them afterwards."
+
+From extracts like these, from such men as Newton and Herschel, it can
+at once be seen that experience, and experience alone, should be the
+chief fountain from whence we draw all our data to form the bases of any
+hypothesis or theory. If the hypothesis formed is contradicted by the
+result of any present or future observation or experiment, then such
+hypothesis will either become untenable, or must be so modified as to
+take in the new fact furnished by that observation and experiment.
+
+It is a _sine quâ non_ of all true philosophy, that philosophy should
+always agree with experience. To the extent that our Philosophy of
+Nature fails to agree with our experience, or with the results of
+observation and experiment, then to that extent it ceases to be
+philosophy. It may be a hypothesis or even a theory, but certainly it is
+not true Philosophy.
+
+Now, in the elaboration and development of the theory as to the physical
+cause of Gravitation, I can premise that nothing will be postulated or
+supposed, unless such supposition can be directly verified by our own
+observation and experiments.
+
+Any theory or hypotheses that are contradicted by our own experience in
+its widest form, will find no place in the development of this work.
+Further, any present accepted theory in relation to any natural
+phenomena, which is controverted by experiment, or observation, will be
+rejected as untenable in the scheme of Natural Philosophy to be
+submitted to the reader.
+
+Whatever else the theory suggested may, or may not be, one thing it
+certainly shall be, and that is, that it shall be strictly based upon
+the Philosophical Rules as given by some of the greatest philosophers
+the world has ever seen. I do not premise that the hypotheses advanced
+will be strictly correct in every detail.
+
+That would be to assume that my experience of all natural phenomena was
+perfect. To the extent that our experience is limited, to that extent
+our hypotheses will be limited and faulty. It would need an Infinite
+mind to form a perfect theory of the philosophy of the universe, because
+only an Infinite mind possesses infinite experience. A finite mind can,
+however, form true philosophical conceptions of natural phenomena, if
+that mind will only follow the guidance of his own experience, and be
+willing to accept the teaching that always arises from the results of
+that experience. In order to do this, however, it must be observed, as
+Herschel points out, that all old prejudices must be put away, and the
+question or problem to be considered must be viewed with an open mind.
+Let me illustrate what I mean. Suppose, for example, that for two
+hundred years, chalk had always been thought to be a mineral, and then,
+owing to the development of the microscope, and to the increased
+magnifying powers of the lenses, it was conclusively demonstrated that
+chalk is made up of the shells and remains of certain organisms that
+lived in the sea ages ago. Would it be philosophical to throw over the
+results of the microscopical research, and, simply because for two
+hundred years chalk had been thought to be a mineral, to argue, and
+still retain the idea that chalk was a mineral?
+
+Such a result would be entirely opposed to all the teaching and
+principles of philosophy. In a similar way, suppose in the development
+of the physical cause of Gravitation, a certain conception of the
+universal Aether has to be put forth in order to account for
+Gravitation, and that that conception is opposed to some of the theories
+which have been held relative to the Aether medium for the past two
+hundred years; but that the conception so advanced is supported by the
+experiments and observation of some of the ablest scientists of the
+present century, would it be philosophical to reject the newer
+conception which harmonized with all experiment and observation, and
+still retain the old conception of the aetherial medium; or, to accept
+the newer conception of that medium, and to reject some of the ideas
+included in the old conception? From a purely philosophic standpoint,
+there can only be one reply, which would be in favour of the newer
+conception, by which our philosophy would be brought into harmony with
+our experience.
+
+This I premise will be done in this work, and the result will be, that
+for the first time, our philosophy of the aetherial medium will agree
+with our experience; and, as the natural result, several outstanding
+problems will be explained on a physical basis, which at the present
+time cannot be satisfactorily explained except from the mathematical
+standpoint.
+
+
+ART. 6. _3rd Rule. Satisfactory explanation of the Phenomena sought to
+be Explained._--The third rule which governs the making of any
+hypothesis is, that the hypothesis formed in accordance with the first
+and second rules shall satisfactorily account for all the phenomena
+sought to be explained.
+
+Newton writes on this point as follows: "No more causes of natural
+things are to be admitted, than such as are true, and sufficient to
+explain the phenomena." While again in his fourth rule he states: "In
+experimental philosophy, propositions collected by induction from
+phenomena are to be regarded as accurately true, or very nearly true,
+notwithstanding any contrary hypothesis, till other phenomena occur by
+which they are made more accurate, or are rendered subject to
+exceptions." _Principia_, Book 3. Herschel in his _Natural Philosophy_
+points out, that one of the chief requirements of any assumed hypothesis
+is, that it shall be sufficient to account for the phenomena to be
+explained, and that it shall be suggested by analogy.
+
+Now the object of this work is to give a physical explanation of the
+cause and working of Gravitation, and to show how, by the properties,
+qualities and motions of the universal Aether, Universal Gravitation may
+be accounted for on a physical basis. So that every phenomenon,
+associated with, or included in the Law of Gravitation, should receive a
+satisfactory physical explanation by the proposed theory.
+
+Thus the physical cause of the centripetal and centrifugal forces should
+receive for the first time a physical explanation.
+
+Newton's Laws of Motion, in so far as they conform to his own Rules of
+Philosophy, should also receive a physical explanation.
+
+Kepler's Laws, which govern the motion of planets in their orbits,
+should also receive a similar physical explanation. Indeed, all
+phenomena which the Law of Gravitation explains from a mathematical
+standpoint, ought to receive a physical explanation by the proposed new
+conception of the Aether medium.
+
+In addition to the outstanding physical cause of Gravitation, there are
+other physical problems that yet remain to be solved; as, for example,
+there is the question as to what is the relative motion of Aether to
+moving matter. Does the Aether move with matter through space as
+suggested by Michelson's and Morley's experiment of America, or does it
+flow freely through all matter, as it is usually thought to do? I
+premise I will give a satisfactory solution of this problem in due
+course.
+
+Again, in relation to the Phenomena of Light, there is still outstanding
+the problem of the physical explanation as to the transverse vibration
+of light. This problem will also be dealt with from the standpoint of
+our new conception of the Aether. Whether it will be as satisfactorily
+solved, as the physical cause of Gravitation, remains to be seen.
+
+Further, there is also the important question yet unsolved, as to what
+Matter is. Lord Kelvin and Dr. Larmor have recently given to the world
+certain conceptions as to the origin of Matter, and I shall endeavour to
+show that such conceptions receive confirmation and support by the
+proposed new conception of the Aether.
+
+Another problem that will be attacked and solved, will be the cause of
+the Permanent Magnetism of the earth, with an answer to some of the
+questions propounded by Professor Schuster at the British Association of
+1892 relative to the magnetism of solar bodies.
+
+There is certainly some physical explanation as to the cause of the
+earth being a magnet, yet up to the present no satisfactory physical
+theory has been given. I premise that the new conception of the Aether,
+to be submitted in the after pages, will satisfactorily account, and
+that on a philosophical basis, for this phenomenon.
+
+Lastly, one of the most interesting discoveries of the present day will
+receive an added confirmation and explanation in the conception of the
+Aether medium to be advanced. I refer to the system of Wireless
+Telegraphy that has been so successfully developed by Signor Marconi,
+and I premise that new light will be thrown on that discovery by the
+suggested theory of the Aether.
+
+Now, if all these problems can be partially or wholly solved by the same
+theory that is advanced to explain the physical cause of Gravitation, it
+needs no further comment to show that that theory is considerably
+strengthened and more firmly established.
+
+For it is a rule in Philosophy, that the more problems any suggested
+theory can solve, the greater are the claims of that theory for
+acceptance by scientists generally. For, if two rival theories can solve
+three and ten physical problems respectively, then, in giving a decision
+as to which is the better theory, the balance of opinion would be
+overwhelming in favour of that theory which could solve the ten
+problems. So that, if in addition to the satisfactory explanation of the
+physical cause of Gravitation, some, if not all of the other problems
+can be solved, as I premise they can, by the same conception of the
+Universal Aether, then it follows our third rule of Philosophy will be
+more than fulfilled, and the theory so advanced will be placed upon such
+a strong foundation, that it can only be overthrown by proving that it
+contradicts the results of some undiscovered phenomena.
+
+
+ART. 7. _Application of Rules to Gravitation._--Let us therefore apply
+Newton's own Rules of Philosophy to the Law of Gravitation, and
+endeavour to find out if the law, as at present understood, fully
+satisfies his own Rules of Philosophy. No one can reasonably object to
+subjecting the Law of Gravitation to the test of those principles which
+he lays down as the fundamental Rules of Philosophy.
+
+If it comes through the ordeal with complete success, that is, if it is
+essentially simple in its conception and development, and if all its
+details are fully in accord with experience, as revealed by observation
+and experiment, then there will be no need to alter any of its
+hypotheses or axioms. If, on the other hand, it violates any of the
+rules as laid down by Newton, then, to that extent, an alteration will
+be necessary, in order that the Law of Gravitation may be brought into
+conformity with his own rules, and our Philosophy made to agree with our
+experience and observation.
+
+
+ART. 8. _Analysis of Law of Gravitation._--In order to accomplish this,
+let us ask ourselves, "What are the component parts of this Law of
+Gravitation?" The Law is not a simple law, but a compound one. It is
+compounded primarily of three parts.
+
+    1st. A Primitive Impulse.
+
+    2nd. A Centripetal Force.
+
+    3rd. A Centrifugal Force.
+
+To these must be added the three Laws of Motion; although they are not
+directly part of the Law of Gravitation, yet they are essential to its
+effectiveness and completion. Without any one of these, the Law of
+Gravitation would fail to account for all the phenomena that it does
+account for.
+
+If there were no Primitive Impulse, then the planets and meteors, sun
+and stars would for ever remain at rest, and the Laws of Motion would
+remain inoperative. If there were no Centripetal Force, then the
+Centrifugal Force would hurl the planets and comets, asteroids or minor
+planets away into the depths of space, never to return to their central
+sun.
+
+If there were no Centrifugal Force, then the Centripetal Force would
+draw all bodies, _i. e._ all planets, etc., to their central sun, and,
+instead of the planets continually revolving round the sun, there would
+be but one immense solitary mass in the centre of the solar system.
+
+If there were no Laws of Motion, with their necessary corollary the
+Parallelogram of Forces, the Primitive Impulse would cease to act, and
+the Law of Gravitation would again fail in its attempt to account for
+those phenomena it does account for.
+
+Thus, as it may easily be seen, Gravitation is a compound Law, depending
+upon at least four hypotheses, and therefore is not essentially a simple
+Force, or Law.
+
+If, therefore, in giving a physical explanation of the cause of
+Gravitation, we can reduce all these four elements of the Law into one
+single physical cause, _i. e._ the Universal Aether, and show how they
+may all be explained and accounted for by the properties, qualities and
+motions of that physical medium, then such a result will be strictly in
+harmony with the first Rule of Philosophy, as laid down by Newton and
+others.
+
+We will, therefore, proceed to consider some of these parts of the Law
+of Gravitation in detail.
+
+
+ART. 9. _Primitive Impulse._--This may be explained as follows. At the
+creating and launching of each world, Newton supposed that there was
+given to each world an impulse or tendency to fly off from the
+controlling centre into space. On this matter MacLaurin writes as
+follows: "If we had engines of sufficient force, bodies might be
+projected from them, so as not only to be carried a vast distance away
+without falling to the earth, but so as to move round the whole earth
+without touching it; and, after returning to the first place, commence a
+new revolution with the same force they first received from the engine;
+and after the second revolution, a third, and thus revolve as a moon or
+satellite round the earth for ever. If this can be effected near the
+earth's surface, it may be done higher in the air, or even as high as
+the moon. By increasing the force or power, a body proportionately
+larger may be thus projected, and by a power sufficiently great, a heavy
+body, not inferior to the moon, might be put in motion, which might
+revolve for ever round the earth. Thus Sir Isaac Newton saw that the
+curvilineal motion of the moon in her orbit, and of a projectile at the
+surface of the earth, were phenomena of the same kind, and might be
+explained from the same principle extended from the earth so as to reach
+the moon, and that the moon was only a greater projectile that received
+its motion in the beginning of things from the Almighty Author of the
+Universe."
+
+Now what I desire to know is, "What is the nature, the mode of
+operation, and, above all, the physical cause of this Primitive
+Impulse?" Is it in its nature and mode of operation a simple Force, or
+Cause? Does it fulfil the condition of Newton's First Rule of
+Philosophy? Permit me to suggest several lines of thought which may be
+made the basis of its analysis.
+
+Astronomers tell us that there are in existence millions of stars, and
+suns, flooding immensity and space with their light and heat.
+
+Now the question I wish to ask regarding Primitive Impulse in relation
+to all these stars is this: "Was the Primitive Impulse imparted to each
+sun, and star, and planet, separately and distinctly?" If so, then there
+must have been just as many Primitive Impulses as there are stars and
+suns and planets, and there would be according to a certain astronomer's
+estimate at least 800,000,000 Primitive Impulses, which assumption is
+altogether opposed to, and violates the First Rule of Philosophy.
+
+If, on the other hand, it is affirmed that they all received their
+motion at one and the same time, then I ask: "What was the physical
+cause and method adopted to communicate the impulse to each one at the
+same time?" If the reply is given, that it was by Universal Gravitation,
+I have two objections to make to such a reply: first, that Gravitation
+is altogether inoperative without the Primitive Impulse, otherwise why
+was it conceived? and secondly, what is the physical cause of
+Gravitation?
+
+Again, scientists inform us that there is every reason for believing,
+that stars and suns are still being formed in the universe, and that
+there are certain distinctive phenomena which go to prove that
+statement. Now, if that be true, and I believe it to be true, I wish to
+ask if the Primitive Impulse as suggested by Newton, is applicable to
+the stars and suns already in process of formation in the various
+nebulae? and, if so, at what point in the star's history or development
+is that Impulse applied?
+
+Personally, I cannot conceive of the Great Creator of all things being
+so lacking in inventive genius, if I may reverently use that term, as to
+necessitate a separate Impulse being given to every separate star, or
+sun, as each one is created or formed during the progress and
+development of the universe of worlds.
+
+I would much rather believe that which I hold to be the correct
+explanation, viz. that He has given to a certain fundamental and
+primordial medium, certain qualities and properties, by, and through
+which are originated and perpetuated, all the motions of the heavenly
+bodies already existent in the universe, or that are ever likely to be
+existent throughout all time.
+
+The question of separate Primitive Impulses for separate bodies becomes
+more and more incongruous and inadmissible, as we consider it in its
+application to such small bodies as meteors and planetoids. Is it not
+contrary to our fundamental principles of Philosophy, that a separate
+Impulse should be necessary for all small bodies that exist in their
+myriads throughout the solar system, not to speak of the universe of
+which that system forms a part? Such a conception as Primitive Impulse,
+to each separate world, is altogether opposed to one's idea of that
+simplicity and beauty which govern the universe at large, and violates
+the first rule of our philosophical reasoning, and for this reason must
+be rejected from the System of Philosophy to be propounded in this work.
+
+
+ART. 10. _Centripetal Force._--Let us now look at the Centripetal Force,
+and ask ourselves what is meant by such a force, and what is its mode of
+action and working. Centripetal Force, strictly, may be defined as that
+force which is always exerted towards the centre of the attracting body.
+
+Taking the earth as an example, Newton points out, that though the
+gravity of bodies arises from their gravitation towards several parts of
+the earth; yet, because this power acts always towards the centre of
+gravity of the earth, it is therefore called the Centripetal Force.
+
+This force, then, is that part of the Law of Gravitation which
+corresponds to the Attraction of Gravitation, and is always exerted in
+that straight line from the body attracted, to the centre of the
+attracting body, which joins the centres of gravity of the two bodies
+concerned.
+
+The combination and effect of the various forces included in the Law of
+Gravitation are illustrated by the familiar illustration of the ball
+whirled round the hand by a piece of string, or the bucket filled with
+water, whirled round in the same way. Let us take the former. A piece of
+string with a ball attached to one of the ends is held firmly by the
+hand. An impulse or motion is imparted to the ball by the hand, that
+motion being continued by the movement from the hand. The first impulse
+given to the ball by the hand represents the Primitive Impulse. The
+tension on the string which holds the ball to its controlling centre
+represents the Centripetal Force, while the opposite force on the
+string, which takes up the Primitive Impulse and continues it, is
+represented by the Centrifugal Force.
+
+The conception of the Centripetal Force is therefore simple, and
+entirely in accordance with our experience as gathered from observation
+and experiments. Both in the spheres of electricity, and magnetism, we
+find a similar force acting, which tends towards the centre of the
+attracting body, and therefore the Centripetal Force satisfies the first
+two Rules of our Philosophy.
+
+Further, it adequately accounts for certain distinctive phenomena which
+occur through the Law of Gravitation, as, for example, the falling of
+bodies to the earth, and therefore is entirely in harmony with all the
+requirements of those principles enunciated by Newton for the successful
+explanation of any phenomena. I need hardly point out, therefore, this
+being so, any physical cause suggested as the explanation of Gravitation
+must deal with the Centripetal Force, and be able to give a physical
+explanation of the mode and manner in which the Centripetal Force
+operates.
+
+The Attraction of Gravitation or the Centripetal Force, however, being,
+as its name implies, simply a drawing or pulling power to a centre, that
+is, a force that is ever and ever only drawing matter to matter, or body
+to body, it could not of, and by itself, accomplish those necessary
+stellar and planetary motions by which are produced that universal
+order, unity and harmony which characterize the universe. It is
+essentially in its operations and influences, a one-sided force, ever
+tending and influencing towards self, and therefore by itself would only
+be a detriment and an evil; and, unless it were accompanied by some
+companion or complementary and counter force, with which it acts in
+union and concert, and which exactly counteracts its pulling power and
+influence, it would soon draw star to star, and world to world, crashing
+and heaping them together in ruinous and dire confusion. So that,
+instead of the infinitude of worlds which now exist, which flash and
+sparkle in the heavens, and in their intricate, elaborate, and mazy
+motions move through the vast infinity like stately armies on the march,
+there would only be one agglomeration of matter, a silent and solitary
+mass existing in the vast abyss of space.
+
+Therefore, as soon as Sir Isaac Newton had discovered and demonstrated
+the existence of the power of Attraction, as represented by the
+Centripetal Force, and its association with the universe at large, there
+was seen at once the necessity of another Force, of an opposite
+character, which would form the companion and complementary force to
+Attraction; a repulsive, repellent force, one tending or repelling from
+a centre, so as to counterbalance the influence of the Centripetal Force
+which ever tends towards the centre.
+
+To fill up the blank, there was conceived to exist what is called a
+Centrifugal Force, that is, literally, a Force acting, and ever acting
+from a centre, and with that Force we will now deal.
+
+
+ART. 11. _Centrifugal Force._--In applying our Rules of Philosophy to
+this Force, if by Centrifugal Force is simply meant that Force which is
+the exact opposite of the Centripetal Force, that is, a Force which acts
+from a centre, instead of to a centre, then such a Force is strictly in
+harmony with, and satisfies all the conditions of the two first Rules of
+Philosophy.
+
+Not only is such a conception simple, but it is also in accordance with
+experience and observation. Professor Hicks in his address to the
+British Association in 1895 said: "What is called Centrifugal Force is
+an apparent bodily Force directed outwards from the centre of curvature
+of the body's path, and having an intensity equal to the distance from
+the centre multiplied by the square of the absolute angular velocity."
+
+In the sphere of magnetism and electricity, the operation of two equal
+and opposite forces prevails. The attractive force of electricity, which
+is exerted to the centre, is always accompanied by the generation and
+development of a repulsive force, it being one of the fundamental rules
+of electricity that equal and opposite quantities of electricity are
+always generated at one and the same time. So that if the Centrifugal
+Force is viewed as being simply the exact opposite of the Centripetal
+Force, it fully satisfies the test when the first two rules laid down by
+Newton are applied to it.
+
+If, on the other hand, Centrifugal Force implies and embodies the idea
+of continuance of the Primitive Impulse, as I believe it is supposed to
+do, then to that extent it is not conformable to the principles of our
+Philosophy, as embodied in the rules given by Newton.
+
+Simply because, while it supposes a source or origin of its activity at
+the first, it goes on to suppose a continuance of that activity, without
+recognizing a continuing source or cause. It only recognizes and
+supposes the one original impulse given at the beginning, to account for
+the cause of the continually existing, and exerted power of the
+Centrifugal Force. I do not for a moment suggest, that the Divine
+Creator of all things, and the Ordainer and Upholder of all powers,
+forces and laws could not, had He chosen to give such a force, have
+given it and for ever operating. With that aspect of the question I have
+nothing to do, and of it nothing to say. I am dealing, and only wish to
+deal, with scientific facts, and scientific teaching from the purely
+philosophical standpoint.
+
+Such an idea of a continuing effect, without a continuing cause, is
+altogether opposed to experience and observation, and is a violation of
+the second Rule of Philosophy.
+
+Look where we will, or at what we will, and not only effects and causes
+are seen on every side, and in every thing, linked together inseparably,
+but wherever, and in whatever phenomena there is found a continuance of
+effect or effects, there is always and without exception found also a
+continuing source or cause.
+
+Wherever Nature, therefore, gives us a continuous effect of any kind or
+sort, she always gives us a continuing cause, that can be both proved
+and demonstrated to exist. Nowhere in Nature, amid all her powers,
+principles and laws, is there to be found an effect without a cause, and
+in all continuing effects, a continuing and perpetuating cause also, and
+that effect exists just as long as the cause exists.
+
+If the effect is perpetual, then the source and cause is perpetual also,
+both in its existence and energy. Hence if the Centrifugal Force
+embodies the idea of continuance of the Primitive Impulse, without
+showing how that Primitive Impulse is continued, then such an idea is an
+anomaly in the universe, is altogether opposed to the teaching of Nature
+and science, and violates the most fundamental principles of our
+Philosophy.
+
+The philosophic explanation, therefore, of the Centrifugal Force, is
+that Force which flows from a centre, and _which is the exact opposite
+and counterpart of the Centripetal Force_. Further, as the Centripetal
+Force is an attractive Force ever attracting to a centre, so the
+Centrifugal Force, being its exact opposite, is a repulsive Force, which
+fulfils all the laws and conditions which govern the Centripetal Force,
+as it is in every phase and aspect the exact opposite, being indeed its
+complement and counterpart.
+
+Any physical explanation of the Law of Gravitation, therefore, must also
+give a satisfactory physical explanation of this Force, and show its
+mode of operation and working. This I premise I will do without the
+faintest shadow of doubt or failure; that is, if we are to accept the
+evidence of some of the most delicate experiments of modern times
+relative to aetherial physics.
+
+
+ART. 12. _Laws of Motion._--One of the most important factors in the
+successful application of the Attraction of Gravitation to the universe
+at large, are the Laws of Motion enunciated by Sir Isaac Newton. These
+are three in number, and are as follows--
+
+1st. Every body continues in its state of rest, or of uniform motion in
+a straight line, except in so far as it may be compelled by impressed
+Forces to change that state.
+
+2nd. Change of motion is proportionate to the impressed Force, and takes
+place in the direction of the straight line in which the Force acts.
+
+3rd. To every action there is always an equal and contrary reaction.
+
+_Corollary._--To these must be added the first Corollary of the three
+laws which is commonly known as the Parallelogram of Forces, which is as
+follows: "That when a body is acted upon by two Forces at the same time,
+it will describe a diagonal, by the motion resulting from their
+composition, in the same time that it would describe the sides of the
+parallelogram."
+
+Now let us apply Newton's Rules of Philosophy to these laws, and see if
+they fulfil the conditions laid down therein.
+
+In the first place, there being three laws necessary to cover all the
+motions involved, there is not that simplicity of conception which is a
+primary factor in the making of any hypothesis. Then it will be observed
+that even after postulating the three laws, Newton was unable to account
+for the elliptic orbits of the planets, until he had added a Corollary
+known as the Parallelogram of Forces.
+
+
+ART. 13. _Force._--The question has arisen also, as to the meaning of
+the term Force which Newton uses. What is a Force, its cause and mode of
+operation? The idea of Force is conveyed to us by our "muscular sense,"
+which gives us the idea of pressure, as for example when we push or pull
+a body along the ground.
+
+We must not, however, limit our idea of Force to that narrow circle. It
+has now been fully established that Sound and Heat, Light, Magnetism,
+and Electricity are Forces, and therefore capable of doing work, as will
+be shown later on. Newton's use of the term Force is therefore somewhat
+vague; he does not definitely say what the Force is which causes the
+change of position, of the body, or of the rate of motion of that body.
+That it is something to do with Gravitation is obvious, but its exact
+nature or character is not revealed.
+
+Since Newton's time we have made an advance in the definition of Force,
+and have come to consider Force as a kind of energy; the application of
+Force being the application of energy. Such terms as Mechanical Force,
+Chemical Force, Vital Force, are therefore out of date, and in their
+place the more definite ideas of energy are substituted. Instead,
+therefore, of getting such terms as Transformation of Forces, we now get
+Transformations of Energy. In the chapter on Energy, I hope to show that
+even that is not a satisfactory solution of the definition of a Force.
+If we are to make our Philosophy agree with our experience, then Force
+is due to motion, and motion alone.
+
+So that Centrifugal Force will imply a motion from the centre;
+Centripetal Force a motion whose effect is ever towards the centre of
+gravity of any body.
+
+
+ART. 14. _First Law of Motion._--This may naturally be divided into two
+parts for the purpose of applying the Rules of Philosophy.
+
+(I) Every body continues in a state of rest, except in so far as it is
+compelled by impressed Forces to change that state. To what extent is
+this statement conformable to our experience and observation? If I place
+a body, as for example a weight, on a table, will it remain in that
+state until it is moved by some other Force? I think that it will so
+remain, and to that extent the law conforms to experiment.
+
+Wider observation, and all experience, also prove the conformity of this
+part of the First Law of Motion to the second Rule of Philosophy, as all
+experience testifies to the fact that a body remains at rest, until some
+other power or force moves it from the position of rest. The application
+of this position of rest to any of the planets is, however, very
+difficult to conceive. MacLaurin, in relation to this fact, states:
+"This perseverance of a body in a state of rest can only take place in
+absolute space, and can then only be intelligible by admitting it." In
+dealing with the physical cause of Gravitation, I hope to be able to
+show that it can not only be admitted as a mathematical proposition, but
+that it can be made intelligible from the physical standpoint.
+
+The second part of the First Law of Motion may be stated as follows:
+"Every body continues in a state of uniform motion in a straight line,
+except in so far as it is compelled by impressed forces to change that
+state."
+
+Now what is the testimony of observation and experiment in regard to
+this part of the First Law of Motion? Let us test the question by the
+results of our experience. If a ball is sent rolling along the ground,
+its motion is gradually reduced until it comes to rest. If the ground is
+very rough indeed, as for example a ploughed field, then its speed will
+be very soon reduced, and the ball quickly comes to a standstill. If,
+however, the ground is smooth and level, like a well-kept cricket-field,
+then the motion of the ball will be reduced more slowly, and it will
+travel further before being brought to rest; while, if the ball is
+thrown along a very smooth surface of ice, it will travel a much longer
+distance before it is finally brought to rest.
+
+Thus we learn, that the more we can get rid of all resistances to the
+motion of any body, the greater distance will the body travel, and the
+less diminution there is in the uniform motion of the body. So that, if
+it were possible to obtain a medium which offered no resistance at all
+to a moving body, then it would be a legitimate inference to infer that
+a body in such a medium, when once set in motion, would move with
+uniform motion for ever. Under such conditions, therefore, this part of
+Newton's First Law of Motion is physically conceivable. The crux of the
+whole matter, therefore, lies in the problem as to whether there is, or
+there is not, in existence, such a thing as a frictionless medium. We
+will therefore consider the problem of the existence of a frictionless
+medium from the philosophical standpoint.
+
+Professor Lodge, in _Modern Views of Electricity_, p. 331, writes: "Now,
+if there is one thing with which the human race has been more conversant
+than another, and concerning which more experience has been
+unconsciously accumulated than about almost anything else that can be
+mentioned, it is the action of one body upon another; the exertion of
+Force by one body on another, the transfer of motion and energy from one
+body to another, any kind of effect, no matter what, which can be
+produced in one body by means of another, whether the bodies be animate
+or inanimate."
+
+"Now I wish to appeal to this mass of experience, and to ask, Is not the
+direct action of one body on another across empty space, and with no
+means of communication whatever, is not this absolutely unthinkable? We
+must not answer the question offhand, but must give it due
+consideration, and we shall find, I think, that wherever one body acts
+on another body by obvious contact, we are satisfied and have a feeling
+that the phenomena is simple and intelligible, and that, whenever one
+body apparently acts on another body at a distance, we are irresistibly
+impelled to look for the connecting medium."
+
+Again, on p. 333 of the same work, he adds: "Remember then, that
+whenever we see a thing being moved, we must look for the rope. It may
+be visible, or it may be invisible, but unless there is either a push or
+a pull, there can be no action."
+
+Now, in relation to celestial phenomena, we are confronted with the fact
+of bodies acting on one another, and yet apparently they do not act upon
+one another by or through a medium, and to that extent according to the
+above extracts, such phenomena are opposed to universal experience.
+Again, we find planets and satellites moving through space with more or
+less uniform speed, and yet apparently there is no physical medium that
+acts upon them with either a push or a pull, as the present conception
+of the Aether is that of a frictionless medium, so that experience in
+its widest form seems altogether opposed to the existence of a
+frictionless medium.
+
+Again, Tait in his _Natural Philosophy_ says: "The greater masses,
+planets and comets moving in a less resisting medium, show less
+indications of resistance. Indeed it cannot be said that observations
+upon any one of these bodies, with the exception of Encke's Comet, has
+demonstrated resistance. The greater masses, planets and comets moving
+in a less resisting medium, show less indications. No motion in Nature
+can take place without meeting resistance due to some if not all of
+these influences. _The analogies of Nature and the ascertained facts of
+physical science forbid us to doubt that every one of them, every star,
+and every body of every kind has its relative motion impeded by the air,
+gas, vapour, medium, or whatever we choose to call the substance
+occupying the space around it_, just as the motion of a rifle-bullet is
+impeded by the resistance of the air."
+
+What is the testimony of our own personal observation and experiments to
+such an impossible entity as a frictionless medium? Can any of the
+readers tell me of any medium, be it solid, liquid, or gaseous, that
+they have ever heard of, or read of, or experimented with, that
+possesses the quality of being frictionless? The answer is unanimously
+in the negative. But a frictionless medium was absolutely imperative to
+the success of the Newtonian aspect of the Law of Gravitation. If the
+Aether had not been frictionless, then the First Law of Motion would
+have been violated, and a body, as for example a planet set in motion,
+would not then have moved with uniform motion, but would have been
+brought to a standstill by the resistance of the Aether. Accepting
+therefore experience as a guide, as we are bound to do if we wish to be
+strictly philosophical, as Newton pointed out, then we are compelled to
+come to the conclusion that there is no such thing in the entire
+universe as a frictionless medium. Such a hypothesis is contrary to all
+laws and rules of Philosophy, and to continue to advocate its claims is
+to remain where we are in relation to the cause of Gravitation, and in
+complete ignorance of the beauty and harmony of the wonderful physical
+mechanism that underlies the whole of the universe. Of course, if
+experience and observation are no guide to Philosophy, then we will let
+imagination run riot, and postulate the most extravagant explanations
+for the varied phenomena of the heavens. With experience of no account,
+we will affirm that the moon is made of green cheese, that the earth is
+flat, that the sun revolves round the moon, and a host of other absurd
+hypotheses that require no correction by experience and observation. But
+there, a truce to such absurd imaginations. Experience is a guide to
+Philosophy, its claims are recognized by the greatest Philosopher the
+world has ever known, and therefore as either experience or a
+frictionless medium has to go, we will part with the frictionless
+medium, and endeavour to make a hypothesis of the Aether that is in
+greater harmony with our Rules of Philosophy.
+
+
+ART. 15. _Second Law of Motion._--The application of Newton's Rules of
+Philosophy to the Second Law of Motion is attended with greater success
+than was the case with his First Law. "Change of motion," he states, "is
+proportionate to the impressed Force, and takes place in the direction
+of the straight line in which the Force acts."
+
+Newton adds this explanation to his Second Law: "If a Force generates
+any motion, a double Force will generate double motion, and a triple
+Force triple motion, whether they are applied simultaneously or
+gradually and successively. And this motion, if the body were already
+moving, is either added to the previous motion, if it is in the same
+direction, or subtracted from it if directly opposed to it, or is
+compounded with the previous motion if the two are inclined at an
+angle."
+
+According to that, a force which presses or pushes with a four-pound
+pressure per square inch, if doubled, would press with a force of eight
+pounds per square inch, which fact agrees with experience. If the force
+is applied gradually, then the change of motion would be gradual; if
+applied suddenly, then the resultant motion would be sudden and violent.
+
+The impressed force, therefore, always produces a definite and
+corresponding effect on any moving body, however that force may be
+originated, and however it may be applied. The effect so produced is
+always a change of motion, or, in present scientific terms, a change of
+momentum in the moving body. If the impressed force is halved, by an
+alteration in the mass of the body which exerts the impressed force,
+then the resultant momentum produced is halved also. If the impressed
+force is doubled, through any alteration in the velocity of the body
+which exerts the force, then the momentum produced in the moving body
+will be doubled also. So that the impressed force is equal to the change
+of momentum in the moving body upon which it is impressed.
+
+When similar forces are impressed upon exactly similar bodies, the
+velocities produced are exactly the same; but, if similar forces act on
+dissimilar bodies, then the velocities produced in the different bodies
+are not the same; yet the total motion produced on all bodies, according
+to the Second Law of Motion, must always be proportionate to the
+impressed force. So that when we compare the effect of similar forces on
+different bodies, we find that there are two factors involved, viz., the
+mass and velocity of the moving body. The product of these two
+quantities is termed the momentum of the body.
+
+When we apply the Second Law of Motion to the theory of aetherial
+dynamics, as suggested in this work, we shall seek to show that Newton's
+Second Law of Motion holds good in its application to the new theory.
+With the present conception of a frictionless Aether, however, it is
+philosophically impossible for the Aether to exert force on any body
+that may exist in it. Because, to the extent that it is frictionless, to
+that extent it ceases to possess mass. If it does possess mass, then it
+cannot be frictionless. Such an assumption violates all the Rules of
+Philosophy.
+
+Yet the Aether is supposed, in some unknown manner, to possess inertia,
+which property is also dependent on mass. If the Aether really possesses
+inertia, then it must possess mass, and possessing mass it ceases to be
+a frictionless medium. So that if it possesses mass, then it can exert
+force the same as any other body, and Newton's Second Law of Motion is
+applicable to it.
+
+
+ART. 16. _Third Law of Motion._--Newton's Third Law of Motion reads as
+follows--
+
+"Action and re-action are equal and opposite, or, to every action there
+is always an equal and contrary re-action." This law is also conformable
+to experience; for, by experiment, it has been proved to hold good for
+electric and magnetic action. As MacLaurin points out, the Third Law of
+Motion may be extended to all sorts of powers that take place in Nature,
+and belongs to attraction and repulsion of all kinds, and must not be
+considered as being arbitrarily introduced by Newton.
+
+The mutual action between any two bodies has, therefore, a double
+action. Thus a piece of stretched string must be conceived as pulling at
+both ends; the pull at the one end being exactly equal and opposite to
+the pull on the other end.
+
+A magnet will attract a piece of iron with a certain force, but it is
+equally true that the iron attracts the magnet with an exactly equal and
+opposite force. We might even extend the application of this Third Law
+to a falling stone in its relation to the earth. Thus, if a stone is
+dropped from a high altitude to the surface of the earth, although the
+motion seems to be all in one direction, yet if the Third Law holds
+good, then the earth is attracted by the stone in exactly an equal, but
+opposite direction, to that in which the earth attracts the stone.
+
+As, however, the mass of the earth is very great compared with that of
+the stone, it follows that the velocity of the stone compared with the
+velocity of the earth, must be very much greater, in order that the
+forces shall be equal.
+
+The application of this Third Rule of Motion to planetary and celestial
+phenomena is therefore philosophical, in that its conception agrees with
+experience and observation.
+
+Thus, while it is true that the sun attracts each of the planets in his
+system, it is equally true that the planets, in their turn, attract the
+sun with an exactly equal and opposite force. But the velocity of motion
+induced by the earth's attractive power upon the sun, would be less than
+the velocity of motion induced by the sun's attractive power upon the
+earth, although the two forces would be equal and opposite, simply
+because force, being a compound quantity, is dependent upon the mass of
+a body as well as upon its velocity.
+
+Not only, however, is it true that the sun and all the planets jointly
+attract each other, but it is equally true that the planets attract each
+other also, with an exactly equal and opposite effect. Indeed, as
+Gravitation is universal, it has to be conceived that there are no two
+bodies existing, but what the Third Law of Motion equally applies to
+those two bodies; so that equality of action and re-action is as
+universal as the Law of Gravitation itself.
+
+In coming to a conclusion with reference to Philosophy and the Laws of
+Motion, I wish to say that I am strongly of the opinion that the day has
+come, or will soon come, when they will pass away and give place to a
+more direct and simple method of working of the great Law of
+Gravitation. I look upon the Laws of Motion as part of the scaffolding
+which has been used to build up the Law of Gravitation. That Law has now
+been erected, and stands firm and secure in its position in the
+universe. Whatever changes may take place in its scaffolding, the Law
+itself will stand out with greater beauty and clearness, if we could but
+see the perfected structure, apart from the props and helps which have
+assisted in its successful erection and completion. As Dr. Larmor said,
+in his address to the British Association, 1900: "There has even
+appeared a disposition to consider that the Newtonian principles, which
+have formed the basis of physical phenomena for nearly two centuries,
+must be replaced in these deeper subjects by a method of more direct
+description of the cause of the phenomena. The question has arisen, as
+to how far the new methods of aetherial physics are to be considered as
+an independent departure; or how far they form the natural development
+of existing dynamical science."
+
+I hope, therefore, to be able in this work to do something towards
+clearing the completed Law from some of the outside props, which have
+long hidden the simplicity, beauty and harmony of the physical working
+of Gravitation from the eyes of those who feign would see its wonderful
+mechanism.
+
+In the elaboration and development, therefore, of the physical cause of
+Gravitation, it will be necessary to conceive a medium, whose properties
+and motions shall be able to account for all the movements of the
+planets, comets, suns and stars that the Laws of Motion now account for.
+Instead, however, of there being several Laws purely and simply
+mathematical in their application, there will be one physical medium,
+which will by its properties and motions account for--and that in a
+satisfactory manner--all the motions of the heavenly bodies. That such a
+medium is required in the scientific world is proved by the statement
+made by Professor Glazebrook, in his work on J. C. Maxwell, page 221,
+where he says: "We are still waiting for some one to give us a theory of
+the Aether, which shall include the facts of electricity and magnetism,
+luminous radiation, and it may be Gravitation."
+
+
+ART. 17. _Summary of the Chapter._--In summing up the contents of this
+chapter, we find therefrom, that there is a Universal Law in existence
+that is known as the Law of Gravitation. The physical cause of this Law,
+however, is unknown; Newton suggesting that it was due to the properties
+of an aetherial medium that pervaded the universe.
+
+To form a right conception of this medium, and to develop the hypotheses
+of the same on strictly philosophical lines, it is essential for us to
+know the rules which govern the making of any hypothesis.
+
+Those rules, according to Newton, and other philosophers, are chiefly
+three in number, and form the very essence of any philosophical
+reasoning. Any departure from those rules will entail partial or entire
+failure in the success of the undertaking.
+
+The application of Newton's rules to parts of the great Law of
+Gravitation show that some of those parts are not fully in harmony with
+the rules which Newton laid down in his _Principia_.
+
+Any physical theory that may be hereafter suggested as the physical
+basis for the Law of Gravitation, must itself not only account for the
+various forces already referred to, but must itself fulfil the Rules of
+Philosophy laid down by Newton. That is to say, the conception of the
+physical medium must be simple in character, its properties and motions
+must agree with all our experience, as given by observation, and
+experiments; and the properties and motions postulated for it must
+satisfactorily account for, and explain all the phenomena that are
+presented to us by the Universal Law of Gravitation.
+
+If all this be done, then from the standpoint of strict philosophical
+reasoning, the physical medium so suggested, and the theory so made,
+will be incapable of being overthrown or disproved.
+
+
+
+
+                              CHAPTER II
+
+                       PHILOSOPHY OF GRAVITATION
+
+
+ART. 18. _Gravitation Attraction._--The Law of Gravitation being a
+compound law, and not a simple law (Art. 8), it is necessary that the
+principles which govern universal attraction should now be considered.
+
+The law which governs Gravitation Attraction may be defined as follows:
+Every particle of matter in the universe attracts every other particle
+with a force whose direction is that of a line joining the centre of
+their masses, whose magnitude is directly as the product of their
+masses, and inversely as the square of the distance between them.
+
+This may be divided into four parts.
+
+    (1) The Universality of Gravitation.
+    (2) The Direction of the Forces involved.
+    (3) The Proportion of these Forces.
+    (4) The Law of Inverse Squares.
+
+The theory of the Aether, therefore, which will be perfected in this
+work, must not only satisfactorily account for the Attraction of
+Gravitation on a strictly philosophical basis, but the laws, governing
+the pressures or tensions of that physical medium, must harmonize with
+each of the parts of the complex Law of Gravitation into which it has
+been resolved.
+
+
+ART. 19. _Universality of the Attractive Force._--The principle upon
+which Universal Attraction rests is found in the words: "Every particle
+of matter in the universe attracts every other particle." It must,
+however, be admitted that this statement has never actually been proved.
+The smallest body that Newton used to prove his Law of Attraction was
+our satellite the moon.
+
+Cavendish, however, in 1798, by a series of experiments, conclusively
+demonstrated that the force of Gravitation existed in small bodies. He
+took two small leaden balls of a certain weight, and fixed them at the
+ends of a rod about six feet long, the rod being suspended by a piece of
+wire in the air. Large leaden balls were then brought near the small
+ones, and great care was taken to see if there were any twist in the
+wire by which they were suspended. It was found that the wire had become
+twisted on the approach of the large leaden balls, and thus he was able
+to prove that every particle of the attracted and attracting body are
+mutually concerned in the Attraction of Gravitation. There is abundant
+evidence of the application of this force in relation to our earth, as
+we shall see later on.
+
+The universality of the Attraction of Gravitation is a fact that has
+been proved in a thousand ways, and a thousand times. All stars and
+suns, and all planets, satellites and comets and nebulae are subject to
+this universal law. Astronomy teaches us that its power extends across
+the vast abysses of space, and that stars situated at distances that
+cannot possibly be measured, are subject to this world-wide law. Some of
+the greatest discoveries in astronomical science were due to the
+operations of this wonderful law, the gravitating influences of certain
+planets indicating their existence, although their discovery had not yet
+been made.
+
+The discovery of Neptune through the mathematical calculations of Le
+Verrier and Mr. Adams in 1846 was the crowning proof of the Law of
+Gravitation. Mr. Adams in England had noticed that the planet Uranus was
+being pulled out of the course by some unknown power, and so set to work
+to calculate the position of the body which thus influenced the motion
+of Uranus in its orbit. He located the position of the supposed
+influencing body strictly by mathematical calculations, and then took
+his results to the Astronomer Royal. Delay, however, occurred in the
+search for the supposed new planet, and nothing was done further in the
+matter for many months. Meanwhile Le Verrier in France, unknown to Mr.
+Adams, had been making similar calculations with reference to the
+perturbations of Uranus, and had arrived at similar results.
+
+These results were sent to the Berlin astronomers, and the heavens were
+searched for the supposed new planet. After a time, the planet was
+discovered in that part of the heavens indicated by Le Verrier, and for
+a time his name stood out as the sole discoverer. Gradually, however,
+the claims of Adams were admitted and recognized, and to-day his claims
+to participate in the honour of the wonderful achievement are generally
+admitted. Thus the discovery of Neptune gave to the Law of Gravitation a
+stability and proof that perhaps it had never received before.
+
+Further evidence of the existence of the universality of the attractive
+force, is to be found in a certain system of stars known as binary
+stars, which revolve around each other, while they gravitate around a
+common centre. Recent researches in astronomy only seek more and more to
+confirm the universality and effectiveness of this grand law, that seems
+to hold the entire universe in its sway.
+
+Any medium, therefore, which is postulated as the physical cause of
+Gravitation, must itself be as universal as Gravitation, in order for it
+to be able to fulfil this condition of universality. We shall find, as
+we proceed, that the only possible medium which can fulfil this
+condition, is the universal Aether, whose qualities and properties are
+already partly known and partly understood.
+
+
+ART. 20. _Direction of the Forces._--The attraction of Gravitation is
+always directed along the straight line which joins the centres of
+masses of the attracting and attracted bodies. Thus, if the earth and
+moon are taken as examples, an imaginary straight line drawn from the
+centre of the earth's mass to the centre of the mass of the moon would
+be the direction in which the gravitative force would be exerted. Now a
+line which joins the central body to its satellite we shall see when we
+come to deal with Kepler's Laws is known as the Radius Vector. Thus the
+path of the attraction between the two bodies is along the Radius
+Vector. It is a singular coincidence that the path of a ray of light
+from the sun also coincides with the Radius Vector, as it is one of the
+laws of light that the path of a ray always follows a straight line.
+
+It must not, however, be assumed, that while the attractive power is
+being exerted along any one straight line joining the centres of two
+bodies, therefore the attractive power is not operative in relation to
+any other part of the space, around the body. If our earth, for example,
+had four moons instead of one, and they were each in different positions
+in relation to the earth, then the law as to the direction of the forces
+would still hold good. We have examples of this in the case of Jupiter
+with his five moons, and Saturn with his eight moons. So that the
+attractive force of Gravitation is again like light, it operates on all
+sides equally at one and the same time. A lamp in the middle of a room
+sends its light waves on every side at one and the same time, so that
+while each ray has for its path a straight line, yet those rays are
+emitted equally on every side. In like manner, though the direction of
+the forces between two attracting bodies is that of a straight line, yet
+the law of universal attraction is equally exerted on every side of the
+planet at one and the same time.
+
+In the theory of the Aether, therefore, to be developed in this work, it
+will have to be demonstrated that the direction of the forces, which are
+originated and transmitted by that physical medium, must philosophically
+fulfil the conditions which govern the direction of the forces, as
+observed in gravitational phenomena.
+
+
+ART. 21. _Proportion of the Forces._--Newton proved that the attraction
+is proportional to the product of the masses of the bodies concerned.
+
+Hence it is that the sun, which is the centre of the solar system, is
+capable of attracting the most remote planets, because the mass of the
+sun is greater than the mass of all the planets put together. Or take
+another illustration. Suppose that the sun and the earth are at equal
+distances from Saturn. Now the sun's mass is about 300,000 times that of
+our earth. Therefore if the earth draws Saturn through a certain
+distance in one second, the sun would draw Saturn through a distance
+which is 300,000 greater than the earth in the same period.
+
+The governing principle, therefore, which decides the proportion of the
+attractive forces between two bodies is mass, and not simply density or
+volume. The mass of a body is a property which remains the same, as long
+as the inertia of the body remains constant. Mass is really a measure of
+the inertia of a body, or that property of a body by which it continues
+in its state of motion or of rest.
+
+Mass is therefore a compound quantity, being equal to volume multiplied
+by density, so that if the volume of any body is halved, the density is
+doubled. Thus, the proportion of the attractive force between any two
+bodies ever remains the same, so long as the masses of the two bodies
+remain the same. Through all the changes of volume and density of any
+body, its attractive force remains constant, as long as the mass remains
+constant; for the simple reason, that as the volume of a body is
+increased, the density is proportionately decreased; or, as the volume
+is decreased, the density is increased.
+
+For example, the volume of the sun as compared with the volume of the
+earth, is about 1,300,000 times greater, but the proportion of the
+attractive forces between the two bodies, is about 324,000 to 1. This
+difference is accounted for by the fact, that the density of the sun is
+about one quarter the mean density of the earth, hence their masses are
+in the proportion of 324,000 to 1. Thus the proportion of the attractive
+forces between any two bodies is dependent upon their masses, and not
+simply upon their volume or density.
+
+
+ART. 22. _Law of Inverse Squares._--The Law of Inverse Squares which is
+applicable to Gravitation is equally true of Sound, Light, Heat and
+Electricity, the Law being that Gravitation acts inversely as the square
+of distance. That is to say, if the distance of any body from the sun,
+for example, be doubled, then the force of Gravitation is diminished to
+one quarter of the intensity which would be exerted on the body in the
+first position.
+
+Thus the further a body is from its controlling centre, the weaker the
+Attraction of Gravitation upon it becomes. Taking therefore Mercury and
+the earth as examples, we find that their mean distances are
+respectively 35,000,000 miles and 92,000,000, which is a proportion of
+about 1 to 2-1/2. So that the intensity of the sun's attraction on the
+earth is about four-twenty-fifths of what it is on Mercury, that being
+the inverse square of the relative distances of the two bodies.
+
+Now the intensity of Light and Heat received by the earth is regulated
+by the same law of inverse squares, so that the earth would receive
+about four-twenty-fifths the intensity of light and heat which Mercury
+receives when they are both at their mean distances.
+
+This law of inverse squares is applicable to every body which acts as a
+gravitating source throughout the whole of the universe, whether that
+body be small or large, and whether it be in the form of meteor,
+satellite, planet, sun or star.
+
+Each satellite, planet or sun exerts an attractive influence upon every
+body that exists, that attractive influence being regulated by the
+masses of the respective bodies, and decreasing inversely as the square
+of the distance from the body viewed as the centre of attraction. So
+that, the further the attracted body is from the attracting body, the
+less is the intensity of the mutual attracting forces, though that
+intensity does not vary simply as the distance, but rather as the square
+of the distance, and that in its inverse ratio. Thus if we take two
+masses of any kind or sort, and place them at various distances as
+represented by the numbers 1, 2, 3, 4, 5, 6, the intensity of the
+attracting forces between the same masses at the relative distances will
+be represented by the numbers 1, 1/4, 1/9, 1/16, 1/25, 1/36, which are
+the inverse squares of the respective numbers representing their
+distances. As we shall see, the same law holds good in relation to heat,
+light and electricity, and indeed to all forms of energy which radiate
+out from a centre equally in all directions.
+
+There is no need to apply Newton's Rules of Philosophy to this
+Attraction of Gravitation, as it has been demonstrated to exist, times
+without number. Moreover its laws are exactly the same as those
+governing the phenomena of sound, light, heat, and electricity, so that
+apart from being proved by actual experiments in relation to the gravity
+of the earth, we have a wider experience of the application of the same
+ruling principles of the law in other departments of science.
+
+The Law of Universal Attraction, which is strictly the Centripetal Force
+of the compound Law of Gravitation, fully satisfies the three governing
+rules of Newton's Philosophy. Not only is it simple in its conception,
+but it is borne out by experience, and adequately accounts for the
+distinctive phenomena which it seeks to explain. By it, astronomical
+observations can be taken with a precision and certainty that defy error
+or failure. The motion of a planet in its orbit can be so perfectly
+calculated, that its position in space in relation to other planets can
+be foretold years in advance. The theory of the Aether, therefore, which
+is to be perfected in this work, must philosophically show that the
+pressures or tensions of that medium, which are postulated as the cause
+of Gravitation Attraction, must themselves fulfil the laws of inverse
+squares, which govern light, heat, electricity and the Attraction of
+Gravitation. I premise that this will be done in the theory of the
+Aether to be submitted to the reader in the after pages of this work.
+
+
+ART. 23. _Terrestrial Gravity._--Before passing from this phase of the
+subject, I should like briefly to look at the question of the Attraction
+of Gravitation from the standpoint of our own earth, as by so doing we
+shall notice some facts regarding the same, hitherto unnoticed, in the
+preceding articles.
+
+Terrestrial Gravity is but a phase of Universal Gravitation. One of the
+most familiar facts and phenomena of everyday life is, that when a body,
+such as a stone or stick or bullet, is thrown or projected into the air,
+it always falls to the earth again. This is due to the attraction of the
+earth and the stone for each other. It has been proved experimentally
+that if a stone and a weight are let fall from a height of 16 feet, they
+would reach the earth in one second of time. Again, a feather, or cork,
+or even a piece of iron would take exactly the same time falling through
+the same space, provided that the feather or cork could be screened from
+the resistance of the air.
+
+The distance, however, through which a body falls in one second varies
+at different parts of the earth's surface, being least at the equator,
+and greatest at the North and South Poles. This is accounted for by the
+fact that the polar diameter is only 7899 miles, while the equatorial
+diameter is 7925 miles, thus the distance from the centre of the earth
+to either pole is about 3950 miles, or 13 miles less than the equatorial
+radius of the earth. Now the force of gravity decreases upwards from the
+earth's surface inversely as the square of the distance from the earth's
+centre of gravity, but decreases downwards simply as the distance from
+the centre decreases. Thus if a ball were taken down 2000 miles, that is
+half the distance to the centre, it would only weigh half-a-pound, while
+if it were taken to the centre of the earth, it would have no weight at
+all; while a pound weight at the equator would not weigh one pound at
+the poles, because it would be nearer the centre of the earth by 13
+miles.
+
+Thus a pound weight is not always a pound weight. It varies as we carry
+it to different parts of the earth's surface, depending upon its
+relation to the centre of the earth for its exact weight. The point
+which I wish to make perfectly clear, as it will be necessary for future
+reference, is, that there is no such thing as weight apart from the
+gravity of the earth; or, if we apply the principle to the solar system,
+there is no gravitating force in that system apart from the gravitating
+force of the central body, the sun, or the planets and other bodies
+which form the solar system.
+
+Let us look at this matter from another standpoint, in order to prove
+this truth and make the same perfectly clear. If a pound weight were put
+in a spring-balance, then at the surface of the earth it would weigh one
+pound. Now, we will suppose that we have taken the weight to a height of
+4000 miles above the surface of the earth, that is exactly double the
+distance from the centre of the earth, the radius of the earth being
+approximately 4000 miles. According to the law of inverse squares, the
+force of Gravitation decreases inversely as the square of the distance.
+The distance having been doubled, the proportion of the forces at the
+two places, _i. e._ the earth's surface and 4000 miles above it, are as
+1 to 1/4.
+
+Thus at a distance of 4000 miles the weight which weighed one pound at
+the earth's surface, now only weighs a quarter of a pound. At a distance
+of 8000 miles, the distance would be trebled, therefore the force of
+Gravitation is one-ninth, and the weight would weigh one-ninth of a
+pound. If we could take the pound weight to the moon, the attractive
+force of the earth would be reduced to 1-3600, as the moon is 240,000
+miles distant, that is sixty times the earth's radius. The square of 60
+is 3600, and if we invert that we get 1-3600, so that the weight which
+weighs a pound at the earth's surface, would only weigh 1-3600 part of a
+pound at the distance of the moon. This again proves, that apart from
+the Attraction of Gravitation, there is no such thing as weight, and
+that the weight so called of any body, such as a planet or satellite,
+increases or decreases as its distance increases or decreases from its
+central attracting body.
+
+
+ART. 24. _Centrifugal Force._--I have already shown in Art. 10 that
+the Centripetal Force and Universal Attraction are one and the same; as
+the Centripetal Force always acts towards the centre, and must therefore
+be in its operation and influence a gravitating or attractive power.
+
+I have also pointed out in the same article, the necessity of another
+force, which is to be the complement, and the counter part of
+Gravitation Attraction. That complement and counter force was conceived
+by Newton, and called by him the Centrifugal Force. The very nature of
+the Centripetal Force demands and necessitates a force which in its mode
+of operation is exactly the opposite of the Centripetal Force. Unless
+there were such a force, a repellent and repulsive force, then instead
+of there being that harmonious working of the universe that now exists,
+there must inevitably be a gradual drawing together of all planets and
+satellites, of all stars and suns, into one vast, solitary, and ruinous
+body.
+
+There are also other phenomena which demand a Centrifugal Force in the
+universe. It is a well-known fact, that there exist between the orbits
+of Jupiter and Mars, what are called planetoids, about 500 in number,
+which are supposed to be the remnants of a broken or shattered world. As
+may be expected from such an accumulation, they present the most
+extraordinary diversities and eccentricities in the orbits that can
+possibly be conceived. They are of all shapes and sizes, and besides
+their orbits round the sun, have orbits among themselves. They are so
+clustered together that their orbits intersect each other at numerous
+points, and when in conjunction are said to suffer great perturbations,
+being pulled great distances this way and that by each other's
+attractive influence. It is further stated that their orbits so
+intersect each other, that if they were imagined to be material rings,
+they would be inseparable, and the whole could be suspended by taking
+any one of them up at random. Here, then, is presented to us a kind or
+order of celestial phenomena for whose well-being and effectual working
+the Centripetal Force or the Attraction of Gravitation cannot possibly
+account. In their case another force is demanded which shall be the
+exact complement and counterpart of the Centripetal Force. There needs
+therefore a force, not an imagined one, simply conceived to fill a want,
+but a real Force, as real and as plainly to be understood as the
+Centripetal Force. A force existing in each world just like the
+Attraction of Gravitation, only the reverse of Gravitation, a repellent,
+repulsive Force, acting in the reverse mode, and way, to universal
+attraction. This Force must be governed by the same rules and laws that
+govern the Centripetal Force, if it is to work in harmony with the same.
+It must be universal in its character, having a proportion of forces
+equal to the product of the masses of the two bodies which are
+concerned, and its path must coincide with the path of gravitational
+attraction, that is, in the straight line which joins the centres of
+gravity of the two bodies. Further, and what is perhaps the most
+important of all, it must act as a repelling or repulsive force which
+shall be in the same proportion in regard to distance, as the law
+governing Centripetal Force, that is, inversely as the square of the
+distance.
+
+Again, and briefly, there are also in existence small bodies called
+meteors, which are said to exist by myriads, which float in space, and
+circle round the sun. They are of all shapes and sizes, from one ounce
+to a ton or even tons, thousands of them coming into contact with our
+earth's atmosphere every year, especially in August and November. All of
+these small bodies have orbits among themselves, and gravitate round one
+another, as they revolve round the sun. Now if the orbits of the
+planetoids be such an entangled mass, what must be the orbits of these
+meteors? What an indescribable, unimaginable mass of labyrinthian
+motions must exist among these myriads of little bodies! How they must
+intersect, cross and intermingle each other's orbits! What attraction
+and counter-attraction they must exert upon each other! Let me ask any
+man to sit down and try to imagine how the present recognized
+Centripetal and Centrifugal Forces can account for the effectual working
+of these meteors. As illustrating the necessity of a real and physical
+Centrifugal Force which is to be the exact counterpart of the
+Centripetal Force, I would call the attention of the reader to
+Herschel's view of this matter. In dealing with the phenomena of comets'
+tails he writes:[1] "Beyond a doubt, the widest and most interesting
+prospect of future discovery, which this study holds out to us, is, that
+distinction between gravitating and levitating matter, that positive and
+irrefutable demonstration in nature of a repulsive force, co-extensive
+with, but enormously more powerful than the attractive force we call
+gravity which the phenomena of their tails afford." I premise that this
+prophecy of Herschel's will be fully demonstrated and proved in the
+succeeding pages of this work. For, in the theory of the Aether that is
+to be afterwards perfected, it will be philosophically proved that the
+physical medium so conceived will satisfactorily account for a force or
+motion from the centre of all bodies; which motions fulfil all the
+conditions required by that Centrifugal Force, which is the complement
+and counterpart of the Attraction of Gravitation. At the present time,
+with the conception of a frictionless Aether, it is impossible to
+harmonize the existence of such a force or motion with our theory of the
+Aether. Yet Professor Lebedew of Moscow, and Nichols and Hull of
+America, have incontrovertibly demonstrated by actual experiments the
+existence of such a force. Therefore it follows, that if our present
+theory of the Aether fails to agree with experimental evidence, such a
+theory must be reconstructed in order that our philosophy may be made to
+agree with our experiments and our experience.
+
+[Footnote 1: _Lectures on Scientific Subjects._]
+
+
+ART. 25. _Kepler's Laws._--A long time before Newton had discovered the
+Law of Gravitation, Kepler had found out that the motions of the planets
+were governed by certain laws, and these came to be known as Kepler's
+Laws.
+
+These laws which were given to the world by Kepler, simply represented
+facts or phenomena which had been discovered by observation, as Kepler
+was unable to account for them, or to give any mathematical basis for
+the same.
+
+On the discovery, however, of Universal Gravitation, Newton saw at once
+that these laws were simply the outcome of the application of the Law of
+Gravitation to the planets, and that they could be accounted for on a
+mathematical basis by the Law of Gravitation, as they seemed to flow
+naturally from that law.
+
+Kepler's Laws are three in number and may be thus stated--
+
+_1st Law._ Each planet revolves round the sun in an elliptic orbit, with
+the sun occupying one of the Foci.
+
+_2nd Law._ In the revolution of a planet round the sun, the Radius Vector
+describes equal areas in equal times.
+
+_3rd Law._ The squares of the periodic times of planets are proportional
+to the cubes of their mean distances.
+
+Now the question arises, whether it is possible to form a theory of the
+Aether which shall satisfactorily and philosophically account for all
+the phenomena associated with Kepler's Laws in their relation to the
+motions of planets, satellites, or other solar bodies? On the present
+conception of the Aether such a result is an absolute impossibility.
+With the theory of the Aether, however, to be submitted to the reader in
+this work, the result is possible and attainable. If, therefore, such a
+result is philosophically proved, as I submit will be done, then we
+shall have greater evidence still that the theory so propounded is a
+more perfect theory than the one at present recognized by scientists
+generally.
+
+
+ART. 26. _Kepler's First Law._--Each planet revolves round the sun in an
+elliptic orbit, the sun occupying one of the Foci.
+
+The ancients thought that the paths of the planets around the sun were
+circular in form, because they held that circular motion was perfect. A
+system of circular orbits for the paths of the planets round the sun
+would be very simple in its conception, and would be full of beauty and
+harmony. But exact calculations reveal to us that the path of a planet
+is not exactly that of a circle, as the distance of a planet from the
+sun in various parts of its orbit is sometimes greater, and sometimes
+less, than its mean distance.
+
+The planet Venus has the nearest approach to a circular orbit, as there
+are only 500,000 miles between the mean, and greatest and least
+distances, but both Mercury and Mars show great differences between
+their greatest and least distances from the sun.
+
+If, therefore, the orbits of a planet are not exactly circular, what is
+their exact shape? Kepler solved this problem, and proved that the exact
+path of a planet round its central body the sun was that of an ellipse,
+or an elongated circle. Thus he gave to the world the first of his
+famous laws which stated that each planet revolves round the sun in an
+orbit which has an elliptic form, the sun occupying one of the Foci.
+
+Not only is the orbit of a planet round the sun elliptic in form, but
+the path of the moon round the earth, or the path of any satellite, as
+for example a satellite of Mars or Jupiter or Saturn, is also that of an
+ellipse, the planet round which it revolves occupying one of the Foci.
+
+It has also been found that certain comets have orbits which cannot be
+distinguished from that of an elongated ellipse, the sun occupying one
+of the Foci.
+
+Now let us apply the Law of Gravitation to Kepler's First Law, and note
+carefully its application.
+
+[Illustration: Fig: 1.]
+
+Let _A_, _B_, _C_, _D_ be an ellipse representing the orbit of the earth,
+and let _S_ represent the sun situated at one of the Foci.
+
+We will suppose that the earth is projected into space at the point _A_,
+then according to the First Law of Motion, it would proceed in a
+straight line in the direction of _A_ _E_, if there were no other force
+acting upon the earth. But it is acted upon by the attraction of the
+sun, that is the Centripetal Force which is exerted along the straight
+line _S_ _A_ (Art. 20), which continues to act upon it according to the
+principle already explained in Arts. 21 and 22.
+
+Now, according to the Second Law of Motion and the Parallelogram of
+Forces, instead of the earth going off at a tangent in the direction of
+_A_ _E_, it will take a mean path in the direction of _A_ _B_, its path
+being curved instead of being a straight line.
+
+If the sun were stationary in space, then the mean distance, that is,
+the length of the imaginary straight line joining the sun _S_ _A_ to the
+earth, would remain unaltered. The Radius Vector _S_ _A_, or the
+straight line referred to, would then be perpendicular to the tangent,
+and the velocity of the earth round the sun would be uniform, its path
+being that of a circle.
+
+The Radius Vector _S_ _A_, however, is not always perpendicular to the
+tangent _F_ _E_, and therefore the velocity of the earth is not always
+uniform in its motion in its orbit, as sometimes it travels at a lesser
+or greater speed than its average speed, which is about 18 miles per
+second.
+
+It has to be remembered that the sun itself is in motion, having a
+velocity through space of about 4-1/2 miles per second, so that, while
+the earth is travelling from _A_ to _B_ the sun is also travelling in
+the direction of _S_ _B_. Thus the orbital velocity of the earth, and the
+orbital velocity of the sun, together with the Centripetal Force or
+universal Gravitation Attraction, are all acting in the same direction
+when the earth is travelling from _A_ to _B_, that is, in the direction
+of the orbit situated at _B_. This point of the orbit is known as the
+perihelion, and at that point the velocity of the earth is at its
+greatest, because the earth is then nearest the sun.
+
+According to Newton, the planet when at _B_ would still have a tendency
+to fly off into space owing to its Centrifugal Force, but it is held in
+check by the Centripetal Force, so that instead of it flying off into
+space, it is whirled round and starts off on its journey away from the
+sun in the direction of _B_, _C_. The sun, however, is still continuing
+its journey in the direction of _S_, _H_, so that not only is the
+increased orbital velocity of the earth, which it obtained at its
+perihelion, urging the earth away from the sun, but the sun itself in
+its advance through space is leaving the earth behind it. The combined
+effect of the two motions, the advancing motion of the sun, and the
+receding motion of the earth, due to its increased orbital velocity,
+drives the earth towards the aphelion, where its distance from the sun
+is greatest, and its orbital velocity is the least.
+
+By the time the planet has arrived at point _C_, its motion through
+space has gradually decreased, and the Centripetal Force begins to
+re-assert itself, with the result that the earth is slowly made to
+proceed towards the point _D_ of the ellipse, at which point its motion
+is the slowest in orbital velocity, only travelling about 16 miles per
+second, while the distance of the earth from the sun is the greatest and
+has increased from 91,000,000 miles at the perihelion to 94,500,000.
+This point of the orbit is known as its aphelion.
+
+After rounding this point, the orbital velocity of the earth begins to
+increase again, owing to the diminishing distance of the earth from the
+sun, which according to the law of inverse squares (Art. 22) gives an
+added intensity to the Centripetal Force.
+
+Thus by the combination of the Laws of Motion and the Law of Gravitation
+discovered by Newton, he was able to satisfactorily account for and
+explain on a mathematical basis, the reason why the earth and all the
+other planets move round the sun in elliptic orbits, according to
+Kepler's First Law.
+
+In the development of the physical cause of gravitation, therefore, the
+same physical medium, which accounts for that law, must also give a
+satisfactory explanation of the first of Kepler's Laws.
+
+
+ART. 27. _Kepler's Second Law._--This law states that the Radius Vector
+describes equal areas in equal times. The Radius Vector is the imaginary
+straight line joining the centres of the sun and the earth or planet.
+While the First Law shows us the kind of path which a planet takes in
+revolving round the sun, the Second Law describes how the velocity of
+the planet varies in different parts of its orbit.
+
+If the earth's orbit were a circle, it can be readily seen that equal
+areas would be traversed in equal times, as the distance from the sun
+would always be the same, so that the Radius Vector being of uniform
+length, the rate of motion would be uniform, and consequently equal
+areas would be traversed in equal times. Take as an illustration the
+earth, which describes its revolution round the sun in 365-1/4 days. Now
+if the orbit of the earth were circular, then equal parts of the earth's
+orbit would be traversed by the Radius Vector in equal times. So that
+with a perfectly circular orbit, one half of the orbit would be
+traversed by the Radius Vector in half a year, one quarter in one
+quarter of a year, one-eighth in one-eighth of a year, and so on; the
+area covered by the Radius Vector being always exactly proportionate to
+the time.
+
+From Kepler's First Law, however, we know that the planet's distance
+does vary from the sun, and therefore the Radius Vector is sometimes
+longer and sometimes shorter than when the earth is at its mean
+distance; the Radius Vector being shortest at the perihelion of the
+orbit, and longest at the aphelion. We learn from Kepler's Second Law
+that when the Radius Vector is shortest, that is, when the planet is
+nearest the sun, it acquires its greatest orbital velocity; and when the
+Radius Vector is longest, that is, when the planet is farthest from the
+sun, the orbital velocity of a planet is the slowest.
+
+Let _A_, _B_, _D_, _C_ represent the elliptic orbit of a planet, with
+_S_ sun at one of the Foci, and let the triangles _A_, _S_, _B_ and _D_,
+_S_, _C_ be triangles of equal area. Then, according to Kepler's Second
+Law, the time taken for the Radius Vector to traverse the area _A_, _S_,
+_B_ is equal to the time that the Radius Vector takes to traverse the
+area _D_, _S_, _C_. So that the planet would take an equal time in going
+from _A_ to _B_ of its orbit, as it would take in going from _D_ to _C_.
+Thus the nearer the planet is to the sun, the greater is its orbital
+velocity, and the farther it is away from the sun the slower is its
+velocity, the velocity being regulated by the distance. The manner in
+which the difference of velocity is accounted for by the Law of
+Gravitation has already been explained in the preceding article. Thus
+Newton proved that Kepler's Second Law was capable of being
+mathematically explained, and accounted for, by the universal Law of
+Gravitation.
+
+[Illustration: Fig: 2.]
+
+If, therefore, a physical cause can be given for Newton's Law of
+Gravitation, then such physical cause must also be able to account for,
+and that on a strictly philosophical basis, the second of Kepler's Laws
+as well as the first.
+
+
+ART. 28. _Kepler's Third Law._--The Third Law of Kepler gives the
+relation between the periodic time of a planet, and its distance from
+the sun. The periodic time of any planet is the time which it takes to
+go once round the sun. Thus the periodic time of the earth is 365-1/4
+days. The periodic time of Venus is 224.7 days, while that of Mars is
+686.9 days.
+
+Kepler had found out that different planets had different periodic
+times; he also found out that the greater the mean distance of the
+planet, the greater was the time which the planet took to perform its
+journey round the sun, and so he set to work to find out the
+relationship of the periodic time to the planet's mean distance.
+
+After many trials and many failures he arrived at the right conclusion,
+and at last discovered the true law which is known as Kepler's Third
+Law, which states that for each and every planet, the squares of their
+periodic times are proportional to the cubes of their mean distances.
+
+For purposes of illustration let us take the earth and the planet Venus
+and compare these two. The periodic time of the earth is 365 days,
+omitting the quarter day. The periodic time of Venus is 224 days
+approximately. Now, according to Kepler's Third Law, the square of 365
+is to the square of 224, as the cube of the earth's mean distance is to
+the cube of Venus's mean distance, which are 92.7 millions of miles and
+67 millions of miles respectively. The problem may be thus stated--
+
+As 365^2: 224^2:: 92.7^3: 67^3:
+
+This worked out gives--
+
+133,225: 50,176: 796,597.982: cube of Venus's mean distance.
+
+So that by Kepler's Third Law, if we have the periodic time of any two
+planets, and the mean distance of either, we can find out the mean
+distance of the other by simple proportion.
+
+In making astronomical calculations, the distances of the planets are
+generally obtained by means of Kepler's Third Law, as the periodic time
+of the planet is a calculation that may be made by astronomers with
+great certainty, and when once the periodic times are found, and the
+mean distance of a planet, as our earth for example, is known, the mean
+distances of all the other planets in the solar system may soon be
+obtained.
+
+In like manner this Third Law of Kepler's is equally applicable to the
+satellites of any planet. For example, when the periodic time of both of
+Mars' satellites, Phobos and Deimos, are known, being about 8 hours and
+30 hours respectively, and the distance of either is known, as Phobos
+with a mean distance of 5800 miles, then the mean distance of Deimos can
+easily be calculated by this law, and is found to be 14,500 miles.
+
+As discovered by Kepler, the Third Law was simply the result of
+observation. He was unable to give any mathematical basis for its
+existence. The Laws as they were given to the world by Kepler were
+simply three great truths which had been discovered by observation. It
+rested with Newton to show how these laws could be accounted for on a
+mathematical basis, and to show how they all sprang from one and the
+same source, namely the universal Law of Gravitation. In his
+_Principia_, he proved that all Kepler's Laws were fully expounded and
+explained by his great discovery of Universal Gravitation.
+
+Now what Newton has done for Kepler's Laws from the mathematical
+standpoint, we propose to do from the physical standpoint. In the
+development of the physical agency or cause of Gravitation, therefore,
+among the phenomena and laws, which have to be satisfactorily accounted
+for on a physical basis, are these three Laws of Kepler's just referred
+to.
+
+So that in addition to the satisfactory explanation of a physical cause
+for the Laws of Motion, and the Centripetal and Centrifugal Forces, the
+hypothesis of a physical cause of Gravitation must fully and
+satisfactorily account for the Laws of Kepler, whose mathematical
+explanation was given by Newton.
+
+Further, and what is as equally important, the explanation so given must
+be strictly in harmony with the Rules of Philosophy as laid down in Art.
+3. That is, the explanation must be simple in character, must not be
+contrary to experience or observation, and must satisfactorily account
+for the laws which the hypothesis of the physical cause of Gravitation
+seeks to explain. This I premise we will do as we pass from stage to
+stage in the development of the theory.
+
+I can safely premise that it will be simple in character and conception,
+that it will be entirely in harmony with all experience and observation,
+and that the physical cause so advanced will give as physical a basis to
+Kepler's Laws as Newton's mathematical calculations gave them a
+mathematical basis.
+
+In summing up, I need hardly point out, that if all that I have premised
+in this and the preceding chapter is accomplished in the after chapters
+of this book, then for the first time since the discovery of Universal
+Gravitation by Sir Isaac Newton, his great discovery will have received
+the long-expected and long-desired physical explanation, that
+explanation and cause being founded on his own Rules of Philosophy given
+in his immortal _Principia_, and for the first time our Philosophy will
+be brought strictly into harmony with our universal experience.
+
+
+
+
+                              CHAPTER III
+
+                                MATTER
+
+
+ART. 29. _What is Matter?_--The law of Universal Attraction states that
+"Every particle of matter attracts every other particle," etc., and the
+question at once arises as to what is meant by the term Matter, what are
+its properties and its constitution? Tait, in his _Natural Philosophy_,
+gives the following as the definition: "Matter is that which can be
+perceived by the senses, or is that which can be acted upon by, or can
+exert force."
+
+It has already been pointed out in Art. 13 that force is due to motion,
+and that wherever we get motion of any kind or sort, there we get
+energy, or what used to be termed force. The consideration of this phase
+of the question will be more fully dealt with in the chapter on Energy
+and Motion. Suffice to say, that all experience teaches us that force is
+the outcome of motion.
+
+Accepting this definition therefore of force, Tait's definition of
+matter will read thus, if brought up to date: "Matter is that which can
+be perceived by the senses, or is that which can be acted upon by
+motion, or which can exert motion."
+
+The common idea that matter can only be that which can be seen or
+actually felt, is not large enough for a definition of Matter. There are
+numbers of things in Nature which cannot either be seen or felt, yet
+which are included in the term Matter. Let us take one or two examples.
+Every one admits that nitrogen and oxygen are matter, yet I venture to
+say that no one has actually seen or felt either of these gases. Both of
+these gases are colourless and invisible, and are both tasteless. You
+may open your mouth and inspire both gases, and yet if they are pure,
+you cannot taste either of them. They are only matter, in the sense that
+they appeal to our sense of force through the motion which they may
+acquire.
+
+Or again, take air, which is a mechanical mixture of several gases. Can
+you see air? If it be free from vapour and smoke, air is invisible, and
+on a clear day you may look for miles across the sea, or from the top of
+a mountain, and yet not have your sight impeded in any way by the
+atmosphere. Neither can it be felt by the sense of touch. Open and shut
+your hand, and see if you can feel the air while you do so. In similar
+ways it may be demonstrated that the air is tasteless. So that it is not
+necessary for us to see, or feel, or taste, or even smell that which we
+term Matter, in order for it to be included in that term. So long as
+that which we term Matter is able to accept motion in any manner from
+any body that is either moving, or in a state of vibration, and not only
+accepts, but also transmits the vibratory, or the kinetic motion so
+called of the moving body, then that which accepts the motion is
+legitimately termed Matter.
+
+It becomes perfectly clear, therefore, why air, aether, oxygen, and
+hydrogen are termed Matter. Because they can be all acted upon by
+motion, and after being so acted upon, they can exert motion upon some
+other body. Heat is a form of motion, and when heat acts upon the air,
+the latter is set in motion, and we have what are commonly known as
+winds. It is unnecessary for me to prove that the motion of winds can be
+transmitted to other matter, as we have numerous examples from our
+observation and experience, in the case of windmills driven by the
+motive power of the winds, and also balloons urged along by the same
+cause; apart from the devastating effect produced in towns and country
+by a hurricane or storm.
+
+The point which I wish to emphasize is, that Matter, strictly defined,
+is that which can be acted upon by motion, such as heat or electricity,
+both being forms of motion, and which can exert the motion so derived
+upon some other body.
+
+Wherever, therefore, in the universe we find any body, whether it be
+solid, liquid or gaseous, or any medium which can be acted upon by
+motion, and after being so acted upon, can exert motion, that body or
+medium may legitimately be included in the term Matter, although it may
+be absolutely invisible to the eyes, or insensible to the sense of
+touch, or taste, or smell. In the same work,[2] Tait states that in the
+physical universe there are but two classes of things, "Matter and
+Energy," and then goes on to give examples of both. He adds that a
+stone, piece of brass, water, air, _aether_, are particles of matter,
+while springs, water-power, wind, waves, heat and electric currents are
+examples of energy associated with Matter.
+
+Now I may add here, that within these two statements is to be found the
+germ of the physical cause of Gravitation, together with the
+satisfactory explanation of all phenomena that the universe reveals to
+us, either by observation or by experiments. I purpose therefore, before
+giving any detailed accounts of that medium which is to form the
+physical basis for the cause of Gravitation, to look at the term Matter
+in all its aspects, in order that we may get a right conception of the
+universe, and of the part that Matter plays in the same.
+
+[Footnote 2: Tait, _Natural Philosophy_.]
+
+
+ART. 30. _Conservation of Matter._--The Theory of the Indestructibility
+of Matter was first introduced by Lavoisier in 1789. This theory may be
+thus summed up; that Matter which fills the universe is unchangeable in
+quantity, so that the total quantity ever remains the same. Changes may
+take place in regard to the state of the Matter, but the sum-total of
+Matter throughout all the changes remains unaltered. Thus when we burn
+coal, it is changed into carbonic acid by combination with the oxygen of
+the atmosphere; when sugar is put into water, it simply passes from the
+solid to the liquid condition. If a piece of iron or steel is allowed to
+rust, the surface of the iron has entered into combination with the
+oxygen and water of the atmosphere, and formed a new substance. So that
+a body may change from solid to liquid, as for example from ice to
+water, or from liquid to a gaseous condition, as from water to steam,
+and probably from a gaseous condition to an aetherial condition as we
+shall see later on, but the sum-total of Matter throughout all these
+changes ever remains the same. Thus, throughout all the physical and
+chemical changes that Matter may undergo in the universe, there is no
+actual loss in weight or quantity. Throughout the whole realm of Nature
+we do not find a single instance of the production of absolutely new
+Matter. We may, and can produce new combinations of the forms of Matter.
+The substance so formed by chemical combination may be different from
+anything that has ever been seen or produced before, but the elements of
+which it is formed must have existed in some other form before its
+production.
+
+This principle is the great underlying principle of all chemical
+investigation and research, and may be proved at any time by means of
+the scales or balance in the laboratory. Lavoisier first made the
+experiment with the scales and proved this truth by actual
+demonstration.
+
+
+ART. 31. _Matter is Atomic._--The hypothesis that Matter is made up of
+infinitely small particles which are termed atoms, was first proposed by
+the Grecian philosophers. This hypothesis has gradually taken definite
+shape, but it remained for Dalton to first put the hypothesis into a
+connected form, and that form is now known as Dalton's Atomic Theory.
+
+According to this theory, an atom of hydrogen was the lightest atom
+known, but comparatively recent researches by Sir W. Crookes have shown
+that there are possibly in existence minute particles which are even
+lighter than an atom of hydrogen. Thus Sir W. Crookes has suggested that
+there are certain particles associated with an atom of hydrogen which
+are 700 times less in weight than the atom itself.
+
+Professor J. J. Thompson has further suggested that if we could divide
+an atom into a thousand parts, and could take one of those parts, we
+should find that this corpuscle, as he has termed it, would be the
+carrier of the charges in an electric current, so that it will be seen
+that we are moving into the direction of the continuity of Matter. Let
+us now look at the question as to what is meant by an atom more fully.
+
+
+ART. 32. _What is an Atom?_--Clerk Maxwell's definition of an atom is,
+"a body that cannot be cut in two." An atom is the smallest part of a
+simple substance which can enter into combination with another element,
+and is incapable of being further subdivided.
+
+An atom of hydrogen is the smallest part of that particular gas which
+can enter into combination with any other element, as oxygen, to form a
+chemical compound as water, which is composed of two atoms of hydrogen
+and one of oxygen.
+
+Further, an atom of any kind or sort, retains its identity and remains
+the same throughout all chemical combinations or physical changes which
+it may undergo. By spectroscopic analysis, it has been ascertained, for
+example, that hydrogen exists in the sun and stars, and the conclusion
+is arrived at in connection therewith, that an atom of hydrogen in any
+sun or star is the same as an atom of hydrogen in our atmosphere, or in
+any of the compounds, as water, in which it is found. Thus it has come
+to be received as an accepted fact, that every atom of any substance, as
+oxygen, nitrogen, and hydrogen, whether they exist in the earth or sun,
+in meteorites or the farthest stars or nebulae, wherever they are found,
+possesses the same identity and the same physical properties.
+
+Atoms attract one another, and this atomic attraction is known as
+affinity. There is not the least possible doubt that affinity is a form
+of universal attraction, except that the affinity of atoms is selective.
+This affinity of atoms for each other gives rise to the combination of
+atoms known as molecules and chemical compounds.
+
+_Size of Atoms._--It has been computed by Lord Kelvin and others, that
+an atom may be as small as 1/50,000,000 of an inch in diameter, so that
+if 50,000,000 of them were put side by side, they would just measure one
+inch in length. Atoms are not all of the same size or weight. An atom of
+oxygen weighs 16 times as much as an atom of hydrogen. It has been
+proved by Kirchhoff and Bunsen, that the 3/1,000,000 part of a
+milligramme of sodium chloride is sufficient to give a yellow colour to
+a gas-jet. Faraday prepared some sheets of gold, so thin that he
+estimated they only measured the 1/100 part of the length of a
+light-wave. We have to remember that each sheet of gold must have
+contained molecules of gold composed of atoms. What must have been the
+size of the atoms therefore of which the sheet was composed?
+
+
+ART. 33. _The Atomic Theory._--The Atomic Theory was revived by Dalton
+in 1804, in order to account for the fact that elements unite in certain
+definite proportions. From that time to the present, the theory has
+grown and developed until at the present time it is looked upon as a
+well-established theory. It is, however, simply a theory, and from the
+very nature of the hypothesis is incapable of proof. No one has ever
+seen an atom of hydrogen or oxygen, or an atom of any solid, liquid, or
+gaseous matter. The Atomic Theory suggests, therefore, that there is a
+limit to the divisibility of matter. All chemical experiments lend
+support to the theory, and by it we are able to give an intelligible and
+easy method of expression to what would otherwise be difficult phenomena
+to explain.
+
+Ancient philosophers were divided on the question of the infinite
+divisibility of matter. The Epicureans were of the opinion that matter
+was incapable of infinite division, and that even if we were able to
+make the smallest possible division, it would be impossible for us to
+reach the smallest particle termed "Atom."
+
+
+ART. 34. _Kinds of Atoms._--Various forms of atoms have been conceived
+by philosophers from time to time, ranging from the Hard Atom, and the
+simple point-centres of Boscovitch, until we come to the more modern
+Vortex Atom of Lord Kelvin, or the Strain Atom of Dr. Larmor, which will
+be looked at separately. Democritus conceived a hard atom as long ago as
+500 B.C., while the notion of a hard atom is not absent from the works
+of Newton himself. We find that Newton suggested that the particles of
+air might be hard spherical bodies, at a distance from one another of
+about nine times their diameter.
+
+The hard atom, however, seems to be refuted by spectroscopic analysis,
+which reveals to us in a manner that has never been revealed before,
+something of the sizes and vibrations of atoms.
+
+From the phenomenon of heat, which is simply matter in motion, we feel
+compelled to accept the fact that an atom is not a hard particle, but
+that it is something which is more closely allied to the Vortex Atom, or
+the Strain Atom of Dr. Larmor.
+
+_Boscovitch Atom._--According to Boscovitch's theory, each atom is
+simply an indivisible point in space capable of motion, and possessing a
+certain mass whereby a certain amount of energy is required to produce a
+certain change of motion. In addition to this, any two atoms could
+attract or repel each other with a force depending upon their distance
+apart. The Law which regulates these forces for all distances greater
+than 1/1000 of an inch is an attraction varying inversely as the square
+of the distance, and a repulsion for less distances.
+
+We have, therefore, to suppose that in place of the hard atom, there is
+merely a geometrical point which can exert attractive or repulsive
+forces to, or from, the central point. So far as external particles are
+concerned, they would behave just the same as a hard atom would do. This
+conception was largely entertained in recent times by Faraday. It is
+more a mathematical explanation than a physical one, but has been found
+convenient in explaining what takes place in the interior of bodies in
+their three states, namely: solid, liquid, and gaseous.
+
+_Lord Kelvin's Vortex Atom._--Another hypothesis which has been
+suggested for the constitution of an atom, is that known as the Vortex
+Atom, which received its birth at the hands of Lord Kelvin. The
+underlying principle of this Vortex Atom is, that matter may be entirely
+due to the rotating parts of a fundamental medium, the Aether, which
+fills all space.
+
+The properties of vortex motion were first mathematically calculated by
+Helmholtz, but it was left to Sir Wm. Thompson, now Lord Kelvin, to give
+a physical idea of the Vortex Atom.
+
+Before entering further into the question of the Vortex Atom, it may be
+as well to explain how vortex smoke rings may be made.
+
+[Illustration: Fig: 3.]
+
+All that is required is a wooden box, about one cubic foot in size, with
+a round hole perforated in one of the sides, and the opposite side
+covered with a piece of linen in place of the wooden side. The bottom of
+the box should then be covered with some strong solution of ammonia, and
+some hydrochloric acid poured into a saucer and put into the box. The
+combination of these two will cause thick clouds to form in the box, and
+if the linen is sharply tapped by the hand, a ring of this cloud will be
+forced through the hole on the opposite side of the box. The ring so
+formed will be circular in shape, and will go sailing through the room
+in which it is made.
+
+When the hole is circular, the rings will be found circular also, but if
+the hole is square, then the rings will be irregular in shape. One
+remarkable characteristic about these rings is, that when two of the rings
+are travelling in the same straight line, the one behind will overtake the
+front one, and while so doing, the diameter of the front one is enlarged,
+while that of the one behind contracts. The front one will also travel
+slower, while the one behind travels faster until it has caught up the
+former, and then the latter, having contracted sufficiently, will pass
+through the diameter of the former as illustrated in the figure. This
+alternation of contraction and expansion is continued as long as the two
+rings move in the same plane and until they are destroyed. When, however,
+the two rings are moving in opposite directions, and meeting each other in
+the same straight line, they will repel one another, instead of attracting
+each other.
+
+Their rate of progress is gradually reduced as they approach together,
+and they begin to expand and enlarge, but they never touch each other.
+Another peculiar feature about the rings consists in the fact, that the
+central core of air in the ring remains the same all the time the ring
+is in motion through the room, so that it has the same core of air at
+the end of its journey as it had when it left the box.
+
+As Lord Kelvin pointed out, if there were no friction of the air, the
+ring once created would rotate for ever. If, therefore, there were such
+a thing as a perfect fluid, and there were vortex rings in it, nothing
+could destroy these rings when once they were created, and this is one
+of the most striking suggestions with reference to the Vortex Atom
+theory of matter. It remains to be seen whether in the universe we have
+such a medium as a perfect fluid.
+
+Sir Wm. Thompson has applied the Vortex Atom theory of matter to the
+Aether, but from mathematical calculation he was unable to arrive at a
+satisfactory conclusion as to the Aether being composed of vortex atoms.
+
+Another remarkable property belonging to these rings, lies in the fact
+that they cannot be cut in two. It will be found that when the knife is
+brought near to them, they seem to recoil from the knife. In that sense,
+it is literally an atom, a thing which cannot be cut in two.
+
+The Vortex Atom has many recommendations in its favour. Many of the most
+important properties of matter are possessed by it, as for example
+indestructibility, elasticity, inertia, compressibility, and its
+incapability to be cut in two. Further, it may be linked with another
+ring, and so give the basis to the combining properties of atomic
+weights.
+
+The Vortex Atom theory is simple in character, as it does not postulate
+any extravagant hypothesis, but makes use of the Aether as the common
+basis for all matter, simply stating that this property of rotation may
+be the basis of all that we call matter. We shall further consider the
+relation of the Vortex Atom to matter, when we deal with the
+constitution of matter and the unity of the universe.
+
+
+ART. 35. _Elements of Matter._--As is well known, modern chemistry has
+succeeded in reducing all the complex forms of matter in Nature into a
+number of simple substances, which are called elements. Of these
+elements about seventy are at present known, some of which, however, are
+very rare. An element therefore is a simple substance which cannot be
+decomposed by any known force or process, as heat or electricity, into
+other elements.
+
+There are, however, only about fourteen of these elements that enter
+largely into the constitution of the earth, the most common being oxygen
+and silicon. By the use of the spectroscope, it has been proved that
+many of these elements, as for example oxygen, hydrogen, sodium and
+calcium, exist in the sun and stars, as well as in the most distant
+nebulae. Most of the elementary bodies are to be found in a gaseous form
+as hydrogen, oxygen, fluorine and chlorine, though it has been found
+possible to liquefy even these gases. Thus we see that matter may be
+roughly divided into three states, viz. solid, liquid, or gaseous.
+
+The condition in which the substance is found depends upon its
+temperature and pressure. An example of matter in its three stages is
+best shown in the case of water, where in the solid condition we have it
+as ice, in the liquid condition as water, and in the gaseous condition
+as steam.
+
+By recent researches it has been found possible to liquefy gases at a
+very low temperature and increased pressure, with the result that now
+nearly all known gases as hydrogen, oxygen, and carbonic acid are to be
+obtained in liquid form. By still more recent experiments made by
+Professor Dewar, it has even become possible to liquefy the air we
+breathe, with the result that at a temperature of about 270 degrees
+below freezing-point and at an increased pressure, the otherwise
+invisible and gaseous air may be changed into a liquid, and poured out
+from one vessel into another in the same way that water can be poured
+out. A vessel, however, at the ordinary temperature into which such
+liquid air is poured, would be so hot compared with the coldness of the
+liquid air, that as soon as the exceedingly cold liquid air came into
+contact with the vessel, the comparatively hot vessel would make the
+liquid air to boil.
+
+
+ART. 36. _Three Divisions of Matter._--Matter has been divided into
+three divisions, viz. solid, liquid, and gaseous. These divisions are
+each known by characteristic qualities, which separate the one division
+from another. At the same time, it is possible for matter to pass from
+one division into another, as for example in the case of water, which
+may exist in solid, liquid, and gaseous form. In view of the recent
+researches of Sir. Wm. Crookes and Professor J. J. Thompson, it is very
+probable that before long we shall have to add a fourth division to
+matter, which we should have to call ultra-gaseous form, or it may
+possibly be the aetherial form. If it should prove to be true that
+Aether is matter, and possesses the essential qualities of matter as
+suggested by Lord Kelvin, then certainly we shall have reached the
+boundary of another great division of matter, and our conception of the
+divisions of matter will have to be enlarged to take in that form, so
+that matter would then be divided into four great divisions, viz. solid,
+liquid, gaseous, and aetherial.
+
+We will now consider the three groups as at present recognized.
+
+_Solid._--Examples of solid bodies are common and familiar, and are
+typified by such things as iron, silver, copper, and lead. The chief
+characteristic of this condition of matter is that its condition or
+state is fixed, and cannot be altered without the expenditure of heat or
+electricity or some other form of energy.
+
+All solid elementary substances, with the exception of carbon, can be
+melted or reduced to a molten condition, although some of them require a
+very high temperature to effect this reduction, as, for example,
+platinum. When a still higher temperature is applied, the metals may be
+vaporized, or reduced from a molten state to that of a vaporous
+condition. In the case of solids, the atoms have not a free path in
+which to move. It must not be thought, however, that the atoms of a
+solid are motionless, as there is nothing absolutely motionless in the
+universe. In the case of the solid, the molecules which compose it,
+preserve their relative position and are linked together in relation to
+each other by the force of Cohesion.
+
+_Liquid._--When matter is in a liquid condition, as, for example, water
+and oil, the condition of its molecules are not so fixed and stable as
+they are in the solid state. The molecules can move freely about one
+another, and their freedom is increased compared with their condition
+when in the solid state.
+
+As already indicated, the reduction of a solid body to a liquid or
+molten state may be effected by heat. When heat is applied to a solid
+body, several results follow, each of which is the outcome of the other.
+
+1. There is an increase of temperature which is due to the increased
+energy of the molecules, through the added heat.
+
+2. There is an enlargement of the volume or size of the body, and if the
+addition of heat be continued, the molecular forces which hold the
+molecules together are broken down, and then the molecules, loosened
+from those forces which in the solid state have bound them together,
+begin to move about with greater freedom, and thus give rise to the
+molten condition of metals, or liquid condition of water. Thus, it is
+the heat which has set the atoms which compose the molecules in motion.
+The atoms of the solid have absorbed the heat, and the heat which has
+thus been absorbed has imparted vibratory energy to the atoms, which
+they did not possess before. Now when a substance is in the liquid
+state, the atoms of that substance have not only a vibratory motion, but
+have also a translatory motion, so that they can move in and out among
+one another. This is proved by the phenomenon of diffusion, where we
+have the case of two different-coloured liquids, for example,
+intermingling with each other, which is conclusive evidence of the
+translatory motion of the atoms in liquids.
+
+_Gaseous._--The third state in which matter is found is the gaseous
+state. In this condition, the particles of matter which form the gas
+have the greatest possible freedom of movement, and are able to move
+about with inconceivable velocity. There is abundant evidence to prove
+that gases consist of particles of matter which are perfectly free, and
+are able to fly about in all directions. The simplest proof is obtained
+by mixing two gases together, as, for example, when any gaseous
+substance is allowed to mix with the air of a room, when we find that
+the particular gas soon mixes itself thoroughly with all the air in the
+room. This process of mixing is known as Diffusion, and the lighter a
+gas is, the more quickly does it diffuse itself. The rate of movement of
+the various particles is varied, by reason of the encounters which each
+particle undergoes from time to time. Through experiments made by Joule,
+he arrived at the conclusion that particles of hydrogen attained a
+velocity of 6055 feet per second at 0° C., which is a velocity much
+greater than that of a cannon-ball. In spite of the enormous velocity
+with which a particle of hydrogen would move, there are such a large
+number of particles in a single cubic inch of space, that no one
+particle has an absolutely free path from the one side of the enclosed
+space to the other. To this constant movement of the individual
+particles is due the elasticity or pressure of gases. The outward
+pressure which they exert on any body which encloses the gas is caused
+by the total effect of the impact of the particles, and is proportional
+to the sum of their masses multiplied into the square of their
+velocities. If we halve the enclosed space, then we should double the
+number of impacts in a given time, so that the number of impacts is
+inversely as the volume of the gas. This is equivalent to the statement,
+that the pressure of a gas varies inversely as its volume, which is
+Boyle and Marriotte's Law.
+
+
+ART. 37. _Matter is Gravitative._--If there is one property which is
+essentially characteristic to all matter, it is that all matter is
+gravitative. To this rule there is no exception, as the universal Law of
+Attraction states that "every particle of matter attracts every other
+particle." Thus, wherever in the whole universe there is a particle of
+matter of any kind or sort, whether such matter be solid, liquid, or
+gaseous, there the force of attraction will be exerted with a force
+proportionate to the mass of the particle, and inversely as the square
+of the distance between the attracted particles.
+
+Gravitation, then, is a property which is essentially inherent in
+matter, and any substance which is termed matter, or fulfils the
+conditions that govern matter, must be gravitative, whatever other
+property it may, or may not, possess. Unless this be so, we should have
+a violation of the universal Law of Gravitation, which would cease at
+once to be a universal law, for instead of reading "every particle of
+matter attracts every other particle," we should have to say that "some
+particles of matter attract some other particles," which would be a
+violation of that universal law which, through the genius of Newton, has
+given to the universe an unity from the philosophical standpoint that it
+did not possess before.
+
+Some matter may, or may not be elastic; it may, or may not be solid, or
+liquid, or gaseous; but there is this fact regarding matter which is
+absolutely undeniable, and that is, "All matter is gravitative."
+
+That this is true of each and all kinds of matter has been proved by
+direct experiment times without number, and the constant application of
+the law to all forms of matter is a fact observable from the phenomena
+incidental to every-day life. Astronomical observation teaches us also,
+that all stars, suns, planets, satellites, and comets are subject to
+this great Law of Gravitation, as indeed they must be if they are
+composed of matter. That they are all composed of exactly similar
+elements of which the earth is composed, has been proved again and again
+by spectroscopic analysis, which teaches that hydrogen, iron, and
+calcium, etc., are to be found in distant stars and nebulae, as they are
+equally to be found in the composition of the earth. Thus throughout the
+wide universe so far as observation and experiment can teach us, we
+learn that without any exception, everything that is termed matter is
+subject to this universal Law of Gravitation.
+
+
+ART. 38. _Matter possesses Density._--Density is that property of matter
+which decides the weight of a body per unit of volume.
+
+The density of any substance may be shown in several ways. It may
+denote, first of all, the number of molecules in a given body. Let us
+take as an illustration, the case of air being forced into a vessel of a
+given size, say one cubic foot capacity. We will suppose that in such a
+vessel there are 1,000,000 molecules. If we pump in a quantity of air
+equal to the amount it contained at first, then it is obvious that we
+have doubled the number of molecules in the same vessel, and therefore
+we say we have doubled the density. Not only so, but the weight of the
+air in the vessel will have been doubled. Looked at from this
+standpoint, density means the number of molecules in unit volume such as
+a cubic inch, or cubic centimetre.
+
+Again, as has already been shown in Art. 35, the different elements have
+different atomic weights. Thus an atom of carbon weighs twelve times as
+much as an atom of hydrogen, that is to say, there are twelve times as
+much matter by weight in an atom of carbon as there is in an atom of
+hydrogen, so that it would take twelve times as many hydrogen atoms to
+weigh a pound as compared with the number of atoms of carbon. This is
+only another way of stating that carbon has twelve times the density of
+hydrogen. If we compare lead and silver with hydrogen in the same way,
+we find that the density is 206 times and 107 times greater than that of
+hydrogen.
+
+Thus, it may be seen, that all matter possesses density, and that that
+density depends partly upon its atomic constitution. If the molecule of
+matter is composed of atoms whose atomic weights are very large compared
+with that of hydrogen, as iron, silver, lead and gold, then the
+molecules will have a much greater density, than a molecule formed of
+oxygen and hydrogen, _i. e._ water. This property of the density of
+matter plays a most important part in the transmission of any kind of
+wave-motion.
+
+
+ART. 39. _Matter possesses Elasticity._--Matter possesses elasticity.
+Elasticity is that property of matter which enables all bodies to resume
+their original shape, when the pressure which has caused the alteration
+of shape has been removed.
+
+For example, suppose an ivory ball be dropped upon a marble table, or
+any other hard surface. It will then rebound, and rise almost to the
+same height from which it was dropped. If the surface upon which it fell
+was first covered with blacklead, a circular spot of lead will be found
+on the ivory ball. From this fact, we arrive at the conclusion that when
+the ball came into contact with the table, at the moment of contact it
+was flattened, and then owing to its elasticity it rebounded into the
+air again.
+
+Now the measure of the elasticity of a body is proportionate to the
+velocity of the wave-motion which it can transmit. A good illustration
+of the transmission of wave-motion may be shown with a number of ivory
+bagatelle or billiard balls. If eight or more of these be put in a row,
+all touching each other, and a single ball be placed about an inch or so
+away from the others in a straight line with them, then when the single
+ball is struck with a cue against the other eight, the motion of the
+single ball is transmitted by each one of the eight successively with
+such rapidity, that the end ball would be set in motion in a quicker
+time than a single ball would take to reach the end ball, if it had been
+free to move along without encountering any opposition.
+
+It is a fact capable of demonstration, that the smaller the particle of
+matter, the greater will be its vibratory motion. Thus the particles of
+air are very, very small, and consequently air is found to be very
+elastic, and allows sound to be transmitted through it with
+comparatively great velocity, some sounds travelling at the rate of over
+1000 feet per second.
+
+A most important factor in determining the propagation of any
+wave-motion, through a gas or solid, is the relationship of the
+elasticity of the gas or solid to its density. Suffice to say, that the
+velocity of any wave-motion is determined by the relation of the
+elasticity to the density. For example, sound, which is a wave-motion of
+the air, can not only be transmitted through gaseous bodies as air, but
+also through liquids and solids. Sound travels faster through solids
+than through liquids, and faster through liquids than through gases. In
+liquids, the relation of the elasticity to density is greater than in
+air, and in solids the relation is greater still. Therefore sound
+travels much faster in liquids than in gases, and faster in solids than
+in liquids.
+
+This is the reason why a train can be heard coming if the ear is put to
+the railway-line, when no indication of its approach is given to the ear
+by the atmosphere. Some examples of the velocities of sound through
+different substances are as follows--
+
+      Gases O. C.             Liquids.                         Solids.
+         FEET                   FEET                            FEET
+
+  Air    1090 per sec.  Water   4708 per sec. (8° C.).   Gold   5717 per sec.
+  Oxygen 1040  "   "    Alcohol 4218  "   "   (20° C.).  Silver 8553  "   "
+
+
+ART. 40. _Matter possesses Inertia._--Inertia is that property of
+matter, by which matter cannot of itself alter, or change its state of
+motion, or of rest.
+
+Newton's first law of motion states that a body at rest remains at rest
+until some force or motion acts upon it. If a stone be dropped from a
+balloon, the stone does not fall because of any property which it
+possesses, but because the force of gravity acts upon it. If it were
+possible to eliminate this force of gravity, then if there were no other
+force which could act upon the stone, it would remain suspended in
+space.
+
+The inertia of a body is equal to the mass of that body, or the amount
+of matter in the body as measured by gravity, so that if a body is
+halved, its inertia will be halved also, and if doubled, its inertia
+will be doubled also. As the inertia of matter opposes all kinds of
+motion, the amount of force required to overcome the inertia of a body
+is proportionate to its mass. So that if the mass of a body is doubled,
+then twice the force would be required to move it, while if the body
+were halved, half the force would suffice to do it.
+
+Inertia is possessed quite as much by a moving body as a body at rest.
+The definition given points this out, as it states that matter cannot of
+itself change its state of motion. If a body therefore is in motion, it
+requires a certain amount of resistance to bring the body to a state of
+rest, or the loss of an equal amount of energy, by friction or
+otherwise, equal to the quantity which it absorbed in order for it to be
+set in motion.
+
+We get numerous examples of this property of the inertia of bodies in
+our daily experience. Many of the accidents that befall people in
+various ways are due to this property of the inertia of matter. A
+cyclist is riding a machine down-hill, and loses control over his
+machine, with the result that he runs into a wall, and is killed. Now
+what has happened? The cyclist has participated in the motion of the
+machine, with the result that when the machine has been suddenly
+stopped, the body has been thrown forward owing to the momentum it had
+acquired.
+
+We are constantly being affected by the property of inertia of matter,
+in tram and train and bus. Whenever any of these are suddenly stopped,
+or suddenly started, we are thrown either backward or forward, owing to
+the body either not having acquired the motion of the train, or, having
+acquired it, is unable to lose its motion as quickly as the train, and
+is therefore thrown forward.
+
+
+
+
+                               CHAPTER IV
+
+                             AETHER IS MATTER
+
+
+ART. 42. _Aether is Matter._--The hypothesis of an Aether which fills
+all space was made in order that scientists might be able to account for
+certain phenomena of Light, which otherwise were difficult to account
+for. Its existence is demanded not only for the phenomena of Light, and
+Heat, but, in view of the comparatively recent researches of Hertz on
+"Electric Waves," of Electricity also.
+
+The Aetherial Medium is generally assumed to be that fundamental medium,
+by means of which possibly all the properties of matter, and all the
+phenomena of motion of the universe are to be explained. Light and Heat
+have been proved to be due to the periodic wave-motion of this universal
+Aether, while from the investigations and researches of such men as
+Clerk Maxwell, Poynting, Thompson and Hertz, it has been proved that
+electro-magnetic phenomena are due to this same medium.
+
+Several different forms of Aether have been postulated by various
+philosophers from time to time, but the only Aether that has survived,
+is that which was first conceived by Huyghens to explain the phenomena
+of Light, though it was Thomas Young who finally succeeded in placing
+the conception of the Aether on a sound basis. Each discovery of science
+has only strengthened the hypothesis and existence of the Aether, the
+latest discovery, that of wireless telegraphy so successfully developed
+by Signor Marconi, being attributed to the electro-magnetic properties
+of this self-same Aether.
+
+It has already been pointed out that Newton endeavoured to account for
+Gravitation by the pressure of the Aether. If, therefore, Gravitation be
+really due to this universal medium it becomes necessary to ask
+ourselves, What are the properties and characteristic qualities of this
+wonderful medium? What then is Aether, and what its properties?
+
+It has already been pointed out in Art. 29 that Aether is matter. Such
+an assumption is strictly in accordance with the Rules of Philosophy,
+quoted in Chap. I.
+
+Not only is this hypothesis a simple one, but it is also in accord with
+all our experience and observation.
+
+It is a simple supposition, because, unless Aether is assumed to be
+matter, then, instead of the universe being composed of two classes of
+things, matter and motion, we have to add a third class, which we call
+Aether. It can be readily seen, that by the introduction of a third
+class into the composition of the universe, such an addition, instead of
+simplifying the constitution of the universe, adds greater complexity to
+the same.
+
+By accepting the hypothesis that Aether is matter, we do away with the
+third class of essentials in the universe, and so reduce the number to
+two classes. If we could go one step further, and prove that instead of
+there being two classes of things in the universe, there was only one
+group, and show that all material things, and all phenomena could come
+under the head of either matter, or motion, then we should have reduced
+the universe to the simplest conception possible. As, however, it is not
+possible, at least in our present state of knowledge, for us to come to
+this fundamental and simple hypothesis of unity for the entire universe,
+we must accept the next simpler solution, and affirm that the universe
+is composed of two classes of things, viz. matter and motion, and this
+as I have already shown is a simpler classification than by putting
+Aether into a class by itself, and therefore is in accord with our first
+Rule of Philosophy.
+
+Again, it is entirely in accord with our second Rule of Philosophy, as
+it in no way violates the results of experiment, experience, or
+observation. Look where we will, or at what we will, whatever we see,
+touch, taste, or smell is termed matter. The burning sun, the glowing
+star, the flying meteor, the glowing comet, the earth, our own island
+home, the towering rock, the wide ocean, the running river, the green
+trees of the forest, the tiny insect, the lordly elephant, all animals,
+plants, and our own physical body, all are composed of matter, either in
+solid, liquid or gaseous form. Therefore when we affirm that Aether is
+matter, the affirmation is strictly in accordance with the elementary
+principles of Philosophy, and in no way violates their rules or laws. To
+affirm that Aether is not matter, is to affirm something contrary to all
+experience, unless it be affirmed that Aether is motion, for which
+assumption the evidence is not nearly so strong or conclusive as that it
+is matter. Therefore the objector to this assumption is himself
+unphilosophical, in that he postulates or supposes that the Aether is a
+medium, with qualities which lie altogether outside the range of our
+experience and observation.
+
+There is a growing conviction in the minds of scientific men, that
+Aether belongs to that group of things which we describe by the term
+matter. Lord Kelvin in giving an address to the British Association,
+1901, on "Clustering of Gravitational Matter in any part of the
+Universe," said: "We are all convinced with our President (Professor
+Rucker) that _Aether is Matter_. Aether we relegate to a distinct
+species of matter which has inertia, rigidity, elasticity,
+compressibility, but not heaviness."
+
+Dr. Larmor in _Aether and Matter_ writes: "Matter must be constituted of
+isolated portions, each of which is of necessity a permanent nucleus
+belonging to the Aether, of some such type as is represented for example
+by a minute vortex ring in a perfect fluid."
+
+Faraday in relation to this subject writes (_Exp. Res._, vol. ii.): "The
+view now stated of the composition of matter would seem to involve the
+conclusion that matter fills all space, or at least all space to which
+Gravitation extends, _including the sun and its system_, for Gravitation
+is a property of matter dependable on a certain Force, and it is this
+Force which constitutes matter." As the Aether fills all space,
+including the solar system, therefore, according to Faraday, "Aether
+must also be Matter."
+
+By the hypothesis that Aether is matter, with all the properties that
+such a hypothesis logically gives to Aether, I venture to premise that
+the third Rule of Philosophy will be fulfilled, and that there is no
+phenomenon of the astronomical world, and no part of the universal Law
+of Gravitation which such a hypothesis will fail to account for on a
+satisfactory physical basis. For the first time a physical explanation
+will be given to Newton's Laws of Motion, at least to those laws which
+are strictly in accordance with the first and second Rules of
+Philosophy. For the first time a physical conception will be given to
+all Kepler's Laws, and what the mathematical Laws of Gravitation have
+done to Kepler's Laws, in giving them a mathematical basis, the simple
+hypothesis that Aether is matter, with all that is logically involved
+therein, will do for the same laws from the physical standpoint. For the
+first time a physical conception will be given to the Centrifugal and
+Centripetal Forces, which are the complement and the counterpart of each
+other, that physical conception being the outcome of the same hypothesis
+that Aether is matter.
+
+In addition to this, light is thrown upon such problems as are referred
+to by Lord Kelvin (_Phil. Mag._, July 1902) in his paper on "Clouds on
+the Undulatory Theory of Light," and further light is given to some
+theories of Electricity advanced by such men as Faraday, Clerk Maxwell,
+and Professor Thompson. I venture to think, therefore, that the
+hypothesis advanced, and the conception put forward that Aether is
+matter, is philosophically correct, and is warranted by the results that
+arise out of such a hypothesis.
+
+It may be thought by some that the hypothesis that I have advanced is
+already conceded, and that the fact that Aether is matter is already
+admitted by scientists and advanced thinkers generally. But such an idea
+is only partly correct. It is already admitted by some of our most
+advanced scientists that Aether is matter, but that admission is only
+carried partially to its logical conclusion.
+
+Lord Kelvin in an address to the British Association, 1901, gave
+utterance to the following remarks on the relation of Aether to Matter:
+"We are convinced with our President (Professor Rucker) that Aether is
+Matter, but we are forced to say that the properties of Matter are not
+to be looked for in Aether, as generally known to us by action resulting
+from force between atoms of Matter and atoms of Aether. _Here I am_
+ILLOGICAL _when I say between Matter and Aether_, as if Aether were not
+Matter. Aether we relegate to a distinct species of Matter which has
+inertia, rigidity, elasticity, compressibility, but NOT HEAVINESS."
+
+From a quotation of this kind, which is from the lips of one of the
+keenest intellects of the present time, I think I am justified when I
+make the statement, that it is not conceded that Aether is matter, with
+all that that concession logically involves. Because, as Lord Kelvin
+points out, though it is admitted that Aether is matter, yet that
+admission is only a qualified admission, and not one which carries with
+it all the properties that essentially belong to matter, or an admission
+which includes the fact that Aether is gravitative, that is, subject to
+Gravitation. To be strictly logical and philosophical, in the statement
+that Aether is matter, it must be conceded not only that Aether is
+subject to such properties as elasticity, inertia, and compressibility,
+but that it is also gravitative or possesses weight. For either Aether
+is matter, or it is not matter.
+
+It cannot be both at one and the same time. Such a conception is
+altogether opposed to that simplicity which is the chief characteristic
+of Nature as pointed out by Newton.
+
+If therefore Aether be matter, then, to be strictly logical and
+philosophical, it must be conceded that Aether is gravitative, as well
+as having the other properties of matter, as elasticity and inertia,
+etc. Unless this is conceded, then we have the anomaly in Nature of
+matter, which is not matter, because it violates the very principles
+which above all others decide what is matter, viz., "That every particle
+of matter attracts every other particle," etc., that is, that it is
+gravitative. Thus by supposing that the Aether is matter, and yet not
+being gravitative, all the Rules of Philosophy are violated, as such a
+hypothesis is opposed to both the first and second Rules of Philosophy,
+and is contrary to all observation and experience. If Aether therefore
+be matter, as is conceded by the most advanced thinkers of the time,
+then it follows that the only logical and philosophical conclusion that
+can be arrived at is, that it is also subject to those properties which
+are the chief characteristics of all matter. These properties may be
+classified as follows: atomicity, gravitation, density, elasticity,
+inertia, and compressibility.
+
+
+ART. 43. _Aether is Universal._--Young in his first Hypothesis on the
+Aether medium states that, "A Luminiferous Aether pervades the Universe
+rare and elastic in a high degree" (_Phil. Tran._, 1802).
+
+As Young points out, this invisible and elastic Aether fills all space
+and floods the universe at large. In it suns blaze, stars shine, worlds
+and planets roll, meteors flash, and comets rush in their mysterious
+flight. In it all material and physical things exist, for it is to them
+not only the primary medium of their existence, but, just as the
+infinite and ever-active energy of the Divine is to the universe in its
+entirety and fulness, the exciting and stimulating spirit of its
+energies and powers, so this aetherial ocean is to the material and
+physical universe, the exciting and stimulating medium of all its
+activities, energies, and powers; and without which, though all material
+and physical things were endowed with the varied capacities of their
+kind or life, yet they could neither exert nor exercise them, nor even
+exhibit the simple activity of motion. Hence everywhere, where material
+and physical things are, there, as the medium of their existence and
+energy, the Aether is; and where the Aether is not, no material or
+physical thing is, or can be. That the Aether is universal is proved by
+the phenomena of light. Light-waves have a velocity of about 186,000
+miles per second. Now the distance of the sun from the earth is about
+92,000,000 of miles, so that light takes about eight minutes and a half
+to travel from the sun to the earth.
+
+A ray of light from the nearest fixed star takes about three and a half
+years to reach the earth, while there are some stars so far away that
+astronomers tell us, that though light travels with so great a velocity,
+yet it would take several thousand years to reach the earth. This fact
+implies that throughout boundless space there is to be found this
+aetherial medium. Thus interplanetary and interstellar space is not
+empty, but is filled with this ever-present, all-pervading Aether; and
+not only so, but every particle of matter in the universe is surrounded
+by this universal Aether, which forms the exciting and stimulating
+medium of all the activities, energies, and motions of all Matter. Thus
+the Aether is both universal and infinite in its extent.
+
+Clerk Maxwell, in his paper on "Action at a Distance" (_Collected
+Works_, by Niven), with reference to the universality of the Aether,
+writes: "The vast interplanetary and interstellar regions will no longer
+be regarded as waste places in the universe, which the Creator has not
+seen fit to fill with the symbols of the manifold order of His Kingdom.
+We shall find them to be full of this wonderful medium, so full, that no
+human power can remove it from the smallest portion of space, or
+produce the slightest flaw in its infinite continuity. It extends
+unbroken from star to star, and when a molecule of hydrogen vibrates in
+the Dog Star, the medium receives the impulses of those vibrations, and
+transmits them to distant worlds. But the medium has other functions
+besides bearing light from world to world, and giving evidence of the
+absolute unity of the material system of the universe. Its minute parts
+may have rotatory as well as vibratory motions, and the axes of rotation
+form those lines of magnetic force which extend in unbroken continuity
+into regions which no eye has seen, and which, by their action on our
+magnets, are telling us in language not yet interpreted what is going on
+in the hidden world from century to century." Now I premise, that in the
+theory of the Aether to be submitted in this work, the physical
+interpretation of this statement of Maxwell's will receive its literal
+fulfilment.
+
+
+ART. 44. _Aether is Atomic._--If there is one fundamental truth which is
+applicable to all matter, it is, that all matter is atomic.
+
+Professor Rucker, in his Presidential Address to the British Association
+of 1901, in dealing with this question, said: "The believer in the
+atomic theory asserts that matter exists in a particular state, that it
+consists of parts which are separate and distinct from one another, and
+as such are capable of independent movement. It is certain that matter
+consists of discrete parts in a state of motion, which can penetrate
+into spaces between the corresponding parts of surrounding bodies. Every
+great advance in chemical knowledge during the last ninety years finds
+its interpretation in Dalton's Atomic Theory."
+
+From such an authority as this, and from the facts which he gave in his
+dealing with the question, we are bound to admit that all matter is
+atomic. That being granted, when the statement is made, therefore, that
+Aether is matter, the only logical conclusion that can be arrived at,
+with reference to the question of the atomicity of the Aether, is, that
+Aether is also atomic. Unless this be conceded, we have the first and
+second rules of our Philosophy violated, as an atomless Aether is
+opposed to that simplicity of conception, which is an essential
+requirement of all hypotheses, and is moreover contrary to that
+presumptive evidence gathered from observation and experiment, which
+teaches us that all matter is atomic. If it be argued, that it is
+impossible to decide upon a question as to the atomicity of the Aether,
+my reply is that the same argument may reasonably be applied to all
+matter. But, as Professor Rucker stated, all the evidence on matter
+points out and supports the theory of its atomicity, and, therefore, the
+only logical and philosophical conclusion is, that Aether is atomic
+also. Again, it may be suggested that we cannot see or touch an atom of
+Aether, and that it is not only invisible, but apparently incapable of
+being made sensible to our senses. In reply to that, as I have already
+shown in Art. 31, that objection can be equally used against an atom of
+hydrogen, or an atom of oxygen. Does any one doubt the existence of the
+hydrogen atom or the atom of oxygen, because it is invisible to the
+sense of sight, or cannot be revealed to the limited sense of touch?
+Certainly not! By the same reasoning, it is just as illogical to deny
+the existence of an atom of Aether because it cannot be seen or felt, as
+it is to deny the existence of an atom of hydrogen or oxygen. An atom of
+Aether reveals itself to the senses in the same way that an atom of
+hydrogen or oxygen does, that is, by the force or energy which it
+exerts. Its vibrations can be manifested to the body in the form of
+heat, while the undulatory motion which the aetherial atoms transmit in
+the form of light, reveal the presence of the aetherial atom to the
+sense of sight. The question at once arises as to what constitutes an
+aetherial atom, what are its properties and motions?
+
+Now, in order for us to enter successfully into this speculative region,
+it is essential that we should, as far as possible, conform to the Rules
+of Philosophy, and endeavour to gain some conception of an aetherial
+atom from the results of experience and observation. In doing this, we
+are at once confronted with the difficulty, that no one has ever seen an
+atom, or analyzed the properties of one. Actual experiment has revealed
+nothing absolutely certain as to the ultimate character of an atom, and
+if this be true of the atoms of matter, then it must also be true of an
+aetherial atom. It would seem at first, therefore, that we have no
+results of experiment, or observation, by which we may be guided in
+formulating a right conception as to the constitution of an aetherial
+atom, and therefore we are thrown simply into the regions of speculation
+as to its constitution and properties.
+
+But I venture to suggest, that there is a method which is strictly
+philosophical in its application, by which we may possibly arrive at a
+clear conception of an aetherial atom. All great discoveries of science
+have been the outcome of applying the principle, that what is true of
+the visible and seen, is true of the invisible and unseen; that what is
+true of the known, is true of the unknown; that the principles and laws
+which govern the small also govern the large and the great. It was thus
+that Newton discovered his great Law of Gravitation, as he was able from
+the falling of an apple, to rise to the application of the same
+principle to our satellite the moon, and this led him on to the
+discovery of the Law of Gravitation.
+
+If, therefore, in Philosophy, the laws governing the small things are
+also applicable to the great things, then the converse equally holds
+good, that the laws governing great things are the reflex of the laws
+which govern the small things. For example, the laws which govern the
+light and heat of the sun are the same which govern the light and heat
+of a candle or a glow-worm; and the laws which govern a planet or world
+are the same as those which govern an atom. Thus a planet or world,
+which is simply an agglomeration of atoms, may reveal to us in its
+motions and laws, what are the motions and laws which govern the atomic
+world.
+
+In looking at the properties and motions of a planet, therefore, as our
+earth for example, we find that a planet is a sphere, or more correctly
+an oblate spheroid; that the earth or planet is a magnet possessing
+polarity, having a north and south pole; that it has rotation on an
+axis, in addition to translation in an orbit, and that it is subject to
+the universal Law of Gravitation.
+
+If, therefore, it holds good in Philosophy, that the small things are
+the index to the greater, and that the laws governing the small things
+also govern the greater, then the converse holds good, that what is true
+of the large is true of the small, and that the laws governing the great
+also govern the small.
+
+So that gathering up those chief properties of the earth to which I have
+already referred, and applying them to an aetherial atom, or any other
+atom if necessary, we arrive at the conclusion that an atom must be
+spherical in shape, must possess rotation, and must have an orbit, must
+possess polarity, and also be subject to the universal Law of
+Gravitation.
+
+Here, then, we have given to us certain data by which we are enabled to
+form our conception of an atom, aetherial or otherwise. The question
+arises, whether, among the forms of atoms which have been devised by
+scientists, any of the atoms so conceived fulfil all, or nearly all of
+these requirements. We have Boscovitch's Atom, the Hard Atom of
+Lucretius, and the more recent conception of the Vortex Atom of Lord
+Kelvin. Of all the hypotheses in regard to the ultimate nature and
+constitution of an atom, the Vortex Theory probably is the one which
+offers to the mind the simplest conception of an aetherial atom.
+
+The Vortex Ring Atom, however, which has been so fully developed by Lord
+Kelvin, hardly fulfils all the requirements of an aetherial atom. In the
+first place it is not spherical in shape, and I hold that to be one of
+the fundamental bases of the aetherial atom. Then, in the next place it
+does not, so far as I can read, possess polarity; that is, it does not
+possess a north and south pole, through being a magnet in the same way
+as the earth is a magnet. We must therefore look for a modification of
+the vortex ring to discover the constitution of our aetherial atom, and
+I venture to think that such a modification is to be found in Professor
+Hill's conception of a Spherical Vortex Atom (_Phil. Trans._, 1894).
+
+In the conception there put forward, and mathematically worked out,
+Professor Hill showed that his spherical vortex atom possessed similar
+properties and characteristics to the vortex rings of Lord Kelvin. So
+that the spherical vortex atom would possess rotation on an axis, and it
+would be a magnet, as I shall prove later on, because it rotates in an
+electro-magnetic medium. It would possess elasticity, compressibility,
+inertia, and, further, would possess a certain amount of mass. That mass
+might be infinitely small, but nevertheless it would possess mass of an
+infinitesimal order.
+
+Further, if we are to be strictly correct, in our analogy between the
+earth and the aetherial atom, its polar diameter must be shorter than
+its equatorial diameter, as that is one of the facts observable
+regarding the shape of our earth, so that the shape of the aetherial
+atom will not be strictly spherical, but its actual shape would be that
+of an oblate spheroid, being flatter at the poles, and bulging out in
+the equatorial regions.
+
+This exact analogy between the earth and an aetherial atom may not at
+present seem of very great importance, but its importance will be seen
+later on, when we come to deal with the phenomena of heat, light, and
+electricity.
+
+Here, then, is our conception of an aetherial atom in the rough, based
+not upon any imaginative hypothesis, but rather upon that strict
+conformity to observation and experience, which is the very groundwork
+of all true Philosophy.
+
+For, after all, what is the earth but an atom on a large scale? In
+comparison with illimitable space, with its infinite distances, that can
+alone be measured by the velocity of light, our own earth is but a speck
+of dust, a very atom that helps to make up the universe, and, as such,
+should teach us the shape and properties of other atoms of which the
+same universe is composed.
+
+We have therefore to conceive of the all-space-pervading Aether as being
+composed of infinitesimal portions of Aether, which are nearly spherical
+in shape, and ever in a state of rotation; this state of rotation
+differentiating the atom of Aether from the free Aether, if such an
+entity exists. So that an atom of Aether would simply be an
+infinitesimal portion of the Aether in a state of rotation.
+
+If, by any means, we could stop the rotation, we should at once destroy
+the atom, in the same way that the smoke vortex ring would cease to be a
+ring, if its rotation were stopped. The cessation of the rotation I,
+however, believe to be impossible. So that even in the ultimate atom of
+that universal medium the Aether, we have an illustration of the
+combination of those two forms which are inseparably connected
+throughout the whole universe, viz. matter and motion, and it is the
+combination of these two that gives to the aetherial atom its form, and
+its very existence, without which it has no life, and ceases to exist.
+
+It may be necessary in the development of this work as we proceed, to
+slightly modify our conception of the aetherial atom, but that
+modification will rather be of a constructive character, than a
+destructive one. There may also be certain objections to meet and
+explain away when we deal with the phenomena of light, heat, and
+electricity, and Gravitation, and the part which the aetherial atom
+plays in those phenomena, but these objections I hope to meet and answer
+as they arise.
+
+The atomicity of the Aether has already been suggested by such
+scientists as Clerk Maxwell, Lord Kelvin, Dr. Larmor, and Professors
+Lodge and J. J. Thompson. Clerk Maxwell, in an article on "Action at a
+Distance,"[3] referring to the atomicity of the Aether, writes: "Its
+minute parts may have rotatory as well as vibratory motions, and the
+axes of rotation may form those lines of magnetic force which extend in
+unbroken continuity into regions which no eye has seen." I premise that
+I will conclusively prove that this statement finds its literal
+fulfilment in the theory of the Aether that will be developed in this
+work.
+
+Lord Kelvin, in several articles on "Vortex Motion" in the Philosophical
+Magazines of recent years, has mathematically dealt with the Aether from
+the atomic standpoint, and has endeavoured to prove that the Aether
+medium is composed of vortex rings, but he was unable to come to any
+satisfactory conclusion. With the theory that Aether is matter, and
+therefore possesses mass, his conception is now brought within the range
+of physical explanation, as well as mathematical calculation.
+
+Dr. Larmor, in his _Aether and Matter_, has successfully applied the
+principle of the atomicity to the Aether, on what is termed the
+"Electron" basis. He states that an electron is nothing more or less
+than "a point singularity in the electro-dynamic and optical Aether." So
+that our aetherial atom is practically synonymous with Dr. Larmor's
+electron. Again, Dr. Larmor, in the same work, states that "the
+atomicity of electricity is coming within the scope of direct
+experiment."[4] But Professor Lodge, in his _Modern Views of
+Electricity_, states that "the Aether is composed of positive and
+negative electricity, the combination of these two forming the Aether
+medium."[5] Now, if the Aether is composed of positive and negative
+electricity, and the atomicity of electricity is coming within the scope
+of direct experiment, it follows as a matter of necessity that the
+atomicity of Aether and the atomicity of electricity are one and the
+same, and therefore the atomicity of Aether is coming within the scope
+of direct experiment. Professor J. J. Thompson, who has also attacked
+the problem of the atomicity of electricity, speaks of "corpuscles"
+which are the actual carriers of the positive and negative electricity,
+in the atoms of the various elements. These corpuscles therefore
+indicate the fact that electricity has an atomic basis.
+
+Now if there is any such identity between Aether and electricity, as
+there undoubtedly is, and electricity has an atomic basis, then the
+atomicity of the Aether follows as a matter of course, otherwise we
+shall have a medium composed of atoms which is itself not atomic, which
+conclusion is absurd and therefore unphilosophical. So that the most
+recent researches into electricity confirm and establish the atomicity
+of the Aether.
+
+[Footnote 3: _Collected Works_, by Niven.]
+
+[Footnote 4: Preface to _Aether and Matter_.]
+
+[Footnote 5: Page 348.]
+
+
+ART. 45. _Aether is Gravitative._--Young, in the _Philosophical Trans._
+of 1802, in regard to this question, states in his Fourth Hypothesis:
+"All material bodies have an attraction for the aetherial medium, by
+means of which it is accumulated within their substance, and for a small
+distance around them, in a state of greater density, but not greater
+elasticity." He adds that "this fourth hypothesis is opposed to that of
+Newton's."
+
+Scientific research has justified the conception of his first three
+hypotheses with respect to the universality, elasticity and vibrations
+of the aetherial medium, but up to the present I am not aware that
+science has accepted his fourth hypothesis.
+
+I propose to show how, from a strictly philosophical and logical
+standpoint, his fourth hypothesis is just as true as his first three
+hypotheses, and that it henceforth passes out of the realm of the
+hypothetical into the realms of fact and science, not only by
+philosophical reasoning, but by actual experiment made by some of the
+most advanced scientists of the present time.
+
+Let us consider the question first from the standpoint of the Rules of
+Philosophy. Our first Rule of Philosophy states, that any hypothesis
+must be simple in connection. Now I put it to any intelligent man, and
+ask him which is the simpler conception of Aether? To affirm that Aether
+is matter, and therefore subject to the properties of matter, as
+elasticity, density, inertia and Gravitation, or to affirm that Aether
+is matter, but while it is subject to some of the properties of matter,
+as elasticity, density and inertia, it is not subject to the very
+property which of all properties is the most fundamental, viz.
+Gravitation. There can, in my opinion, only be one answer to the
+question, so that, when we affirm that Aether is matter, we are
+compelled to affirm, in order to conform to the first Rule of
+Philosophy, that it is gravitative also. Faraday was also of the opinion
+that Aether was subject to the Law of Gravity, for, writing in
+_Experimental Researches_, he states: "The view now stated of the
+constitution of matter, would seem to involve the conclusion, that
+matter fills all space, or at least all space to which Gravitation
+extends, INCLUDING THE SUN AND ITS SYSTEM. For Gravitation is a property
+of matter, dependable on a certain force, and it is this force which
+constitutes matter."
+
+Let us also test the question by our second Rule of Philosophy, and we
+shall find greater evidence still for the statement that Aether is
+gravitative. What do experience and observation teach us with reference
+to matter? As we have already seen (Art. 37), if there is one truth that
+they teach us regarding matter, it is that it is gravitative.
+
+There is not the slightest evidence throughout the universe, as far as
+our observation can lead us to form an opinion, that there is any kind
+of matter which is not subject to the Law of Gravitation. Therefore to
+assume that Aether is matter, and yet not to assume that it is also
+subject to Gravitation, is to assume that which is directly opposed to
+the most fundamental principle of all philosophical teaching and
+scientific research. If Aether be matter, therefore, and yet is not
+gravitative, we shall have an anomaly in an otherwise universal law, as
+we shall have some kind of matter which fails to come within the scope
+of the universal Law of Gravitation.
+
+To be consistent, therefore, we must either cease to call Aether matter,
+or else admit that Aether, like all other matter, is gravitative. It is
+absolutely impossible to be strictly logical and admit that Aether is
+matter, and not to admit that it is subject to the most universal law
+that governs matter, as the Law of Gravitation distinctly states that
+"every particle or atom of matter attracts every other particle." This
+universal law in view of a gravitationless Aether would have to be
+amended to "Some particles of matter attract some other particles." Thus
+the universal Law of Gravitation ceases at once to be a universal law,
+and such a result is opposed to all experience and experiment. Again,
+let us apply our third Rule of Philosophy to this supposed
+gravitationless Aether, and see what the result is.
+
+Our third rule states, that any hypothesis put forward must satisfactorily
+account for the phenomena sought to be explained and accounted for. The
+Aether was conceived in order to explain the phenomena of light, and one
+of the properties it was conceived to possess was elasticity, yet that
+very conception was devoid of the most fundamental property of matter,
+without which there is no elasticity, that is, that it was not atomic.
+
+I have already shown in Art. 44, that Aether is atomic, and therefore
+there is given to the Aether a structure which is capable of exhibiting
+elasticity, inertia, density, and even Gravitation, while at the same
+time, the conception is fully in harmony with philosophical reasoning
+and Newton's Rules of Philosophy.
+
+Let us consider the question whether Aether is, or is not gravitative,
+from another aspect. For several hundred years, the physical cause of
+Gravitation has been outstanding, while the world has held the
+conception that Aether is a gravitationless and frictionless medium. The
+earth has been rolling on in her orbit year in, year out, together with
+all the other planets in their annual march round the sun, and yet
+through all that time no one has been able to suggest, or give any
+satisfactory or adequate physical explanation, as to what moves the
+earth along.
+
+I am fully aware that Newton suggested and proved, that it was because
+of the Law of Gravitation. But I look upon that as a mathematical
+explanation and not as a physical one.
+
+Now I venture to predict this, that on the assumption of a
+gravitationless medium, the physical explanation so longed for will
+always be outstanding, as a gravitationless Aether is synonymous with a
+frictionless medium, and so long as we admit that there is a
+frictionless medium, so long will the physical cause of Gravitation, and
+therefore the physical cause of all the movements of the planets and
+comets, be outstanding and unexplained.
+
+If, however, instead of being illogical in our reasoning, we become
+logical, and affirm that Aether is matter, and because all matter is
+gravitative, therefore Aether is gravitative; and if, instead of being
+unphilosophical, we become philosophical, and affirm that because a
+gravitationless Aether violates both the first and second Rules of
+Philosophy, such a conception must be put away, and in its place a more
+philosophical conception must be forthcoming, which is that Aether is
+gravitative; then, upon such a logical and philosophical basis, I
+venture to premise that the great problem which is still outstanding of
+the cause of Gravitation, will remain outstanding no longer, and the
+physical cause of all the movements of all celestial bodies will be put
+upon a physical basis, in addition to a mathematical one.
+
+If such a result can be arrived at by the logical and philosophical
+conception of a gravitative Aether, then the three Rules of Philosophy
+are fully satisfied, and the assumption of a gravitative Aether is
+warranted on a strictly philosophical basis.
+
+So that Thomas Young is strictly correct from a philosophical standpoint
+in his fourth hypothesis, when he states: "That all material bodies have
+an attraction for the aetherial medium, by means of which it is
+accumulated within their substance and for a small distance around them
+in a state of greater density but not greater elasticity." He is not,
+however, correct when he states that though there is a greater density
+near the body, there is not a greater elasticity, as such an assumption
+is opposed to experiment and observation in relation to perfect gases,
+as I shall show when dealing with the elasticity of the Aether.
+
+Again, in view of the fact that the Aether is atomic, it can now be
+easily understood how it may be subject to Gravitation. The very essence
+of Gravitation is that atoms, or particles, attract each other. If there
+were no particles, or atoms, it is obvious that there would be no
+attraction, and therefore no Gravitation. Wherever, therefore, there are
+to be found atoms of any kind or sort, whether they be atoms of
+hydrogen, oxygen, silver or aetherial atoms, there the Law of
+Gravitation holds good, and attraction between these atoms is to be
+found. In other words, any substance which is atomic, is also
+gravitative. Now Aether is atomic as has been shown, and therefore from
+that standpoint it is also gravitative. It may, however, be objected
+that the assumption of gravitative properties for the Aether is after
+all but a speculation, and that Young's fourth hypothesis was only a
+hypothesis, and that the gravitating properties of the aetherial medium
+have never come within the scope of direct experiment, without which no
+hypothesis can be fully accepted.
+
+If such an argument be advanced against a gravitating Aether, then I
+must differ from those scientists who advance such an objection. My
+contention is that the gravitating properties of the Aether have already
+been made the subject of some of the most refined and delicate
+experiments that have been made during the past few years.
+
+I refer to the experiments of Michelson and Morley of America.
+
+For an outline and explanation of such experiments I must refer the
+reader to the _Phil. Mag._ of December 1887.
+
+Now what is the result of these experiments?
+
+I believe it is almost unanimously conceded by all scientists, that
+their experiments prove that the Aether is carried along by the earth.
+Let us carefully look at this conclusion and see what it implies in
+relation to the question at issue.
+
+If the Aether is carried along by the earth, it necessarily follows that
+there is some governing law or principle which holds it to the earth,
+while the earth moves through space with its velocity of 68,000 miles per
+hour.
+
+Now what is that governing principle or law, which is capable of holding
+such an aetherial atmosphere to its central body? If we wish to be
+strictly philosophical, it is necessary, according to our second Rule of
+Philosophy, that we should not go outside experience and the analogy of
+Nature.
+
+Where is there a similar analogy in Nature to that of the Aether being
+carried along through space by the earth? I know of only one analogy
+which can be used, and that is the analogy of the atmosphere, which is
+also carried along by the earth through space, as it rushes on in its
+orbit round the sun.
+
+That being so, the question arises, what principle or law holds the
+atmosphere to the earth? for, whatever be the law which governs the
+atmosphere, to be consistent with the second Rule of Philosophy, we must
+infer that the same law also holds the Aether in its place. There is
+only one answer to the latter question, and that is the Law of
+Gravitation. If it were not for that law, and the fact that the
+atmosphere is subject to that law, the atmosphere would simply be swept
+off from its central body, the earth, as the latter rushed through space
+with its comparatively enormous velocity.
+
+The only legitimate and philosophical conclusion that we can arrive at,
+therefore, is that the Aether must be carried along with its central
+body, the earth, through being acted upon by the self-same Law of
+Gravitation, and for it to be so acted upon it must obviously be
+gravitative. It would be unphilosophical to suggest that it was held in
+its place by any other force, as that would be introducing a new force
+or law into Nature, contrary to our experience in relation to an exactly
+similar phenomenon of Nature.
+
+We have therefore, it seems to me, direct proof by actual experiment
+that Young's fourth hypothesis was correct, and that not only in
+relation to the atomic world, but also in relation to the planetary
+world, and the stellar world, all bodies exert an attractive influence
+upon the surrounding Aether, by means of which the Aether is accumulated
+near the surfaces of all bodies in a state of greater density, and
+therefore of greater elasticity.
+
+Let us apply this truth to the solar system, and see what we get. If it
+is true that the earth exerts an attractive influence upon the
+surrounding Aether by means of which it is held in its place relatively
+to the earth, then it is equally true that Mercury, Venus, Mars,
+Jupiter, Saturn, Uranus and Neptune also exert gravitating or attractive
+influences upon the surrounding Aether, in the same way that they do
+upon their own atmospheres. So that in their cases also, the surrounding
+Aether is carried along by them through space. Professor Stokes has
+suggested that this is so, in order to account for the aberration of
+light, as we shall see later on.
+
+Not only so, but the sun also would have an attractive power over the
+Aether by means of which its aetherial atmosphere would be carried
+through space, as it moved along in its progress at an estimated rate of
+17,000 or 18,000 miles per hour.
+
+I would like to point out here, that this explanation of the effect of
+the planets' attractive power over the surrounding Aether is only a
+partial one, as there are other effects directly involved in the fact
+that the Aether is subject to the gravitating influence of all
+satellites and planets.
+
+This is not the place, however, to go fuller into the matter, the
+consideration of the subject being taken up in a later chapter.
+
+Thus I have tried to show a gravitating Aether is strictly in accord
+with the three Rules of Philosophy, for it is simple in conception, is
+not contrary to experience, and by it I premise that it is possible to
+explain the physical cause of Gravitation, with all that is involved in
+that law.
+
+Once more, if Aether is gravitative, then every atom and particle in the
+universe, as well as every planet, and sun, and star, exert an
+attractive power over the Aether, so that every atom is enveloped in an
+atmosphere of Aether, in the same way that every planet, and sun, and
+star is enveloped by the aetherial atmosphere.
+
+The Aether, however, while it may flow through the spaces that exist
+between the molecules of bodies, yet is held bound to those molecules in
+the same way, and by exactly the same force, that holds the atmosphere
+to a planet or world.
+
+Further, if the atoms possess different masses or weights, as they do,
+then each atom would possess an aetherial atmosphere proportionate to
+its mass, with the result that an atom of carbon, with its atomic weight
+of 12, ought to possess a denser aetherial atmosphere than an atom of
+hydrogen, and so on right through the atomic scale. I need hardly point
+out that this conception of the Aether in relation to atoms, and
+molecules of bodies, will solve certain problems relating to the density
+of Aether in connection with matter, which problem up to the present
+cannot be solved by the present conception of a frictionless medium.
+
+That problem may be stated as follows: Does the presence of matter
+affect the Aether in any way, so as to load or make it denser? Professor
+Lodge, in _Modern Views of Electricity_, in relation to the density of
+the Aether, writes: "The neighbourhood of gross matter seems to render
+Aether more dense. It is difficult to suppose that it can really
+condense an incompressible fluid, but it may load it, or otherwise
+modify it, so as to produce the effect of increased density."
+
+In view of the fact that Aether is gravitative, the reply is to be found
+in the Law of Gravitation, "Every particle of matter attracts every
+other particle of matter, etc.," and as Aether is matter, it will be
+attracted by the other matter irrespective of whether that matter be in
+the atomic, molecular, or planetary or stellar form. We shall see that
+this is so when we come to deal with the density of the Aether.
+
+It may be objected in relation to this aspect of Aether, that Young also
+asserted that the Aether flows as freely through matter, as the air
+flows through the trees of the forest, and that such a statement
+therefore contradicts his fourth proposition regarding the gravitating
+properties of Aether. A little reflection will, however, put a different
+construction on this objection.
+
+Let us consider the analogy from the standpoint of experience, and see
+what that analogy teaches us. From experience we learn that the air is
+gravitative, but we also learn that it is possible to be moved from
+place to place as winds, and that as such it can move freely between the
+trees of the forest, causing their boughs and leaves to tremble and bend
+beneath its energy and power.
+
+I have yet to learn, however, that while it moves between the trees as
+separate and distinct objects, such a movement militates or destroys its
+gravitating properties.
+
+Does the air cease to be any less gravitative, or subject to the Law of
+Gravity, when it is subject to certain movements, which give rise to
+certain currents as winds? Such an assumption is altogether opposed to
+philosophical reasoning.
+
+Whether the air is stationary or in motion, it is ever subject to the
+great Law of Gravitation, and accepting that as an analogy, the apparent
+contradiction between the oft-quoted simile of Young and his fourth
+hypothesis is at once removed, and from analogy we learn that it is
+quite possible for Aether to move between bodies because of certain
+currents which may be originated by heat, light or electricity, yet at
+the same time the existence of such currents does not violate its
+gravitating tendency.
+
+Young's fourth hypothesis is therefore in perfect harmony with his
+oft-quoted simile, that the Aether flows through the interstices of
+bodies as the wind flows through a group of trees, but like the
+air-currents it does not so flow unless the currents are generated by
+some form of energy, as heat or light, electricity or magnetism.
+
+From these considerations therefore we are compelled to come to the
+conclusion that Aether, like all other matter, is subject to the same
+universal Law of Gravitation. If further evidence of the gravitating
+tendency of the Aether were required, I would refer the reader to Lord
+Kelvin's utterance on this subject.
+
+Lord Kelvin, _Phil. Mag._, November 1899, in relation to the Aether
+writes: "We are accustomed to call Aether imponderable. How do we know
+that it is imponderable? If we had never dealt with air except by our
+senses, air would be imponderable to us, but we know by experiment that
+a vacuum glass tube shows an increased weight when air is allowed to
+flow into it. We have not the slightest reason to believe that Aether is
+imponderable. It is just as likely to be attracted by the sun as air is.
+At all events the _onus of proof rests with those who assert it is
+imponderable_. I think we shall have to modify our ideas of what
+Gravitation is, if we have a mass spreading through space with mutual
+attraction between its parts, without being attracted by other bodies."
+
+We have already seen in the previous article that Faraday was of opinion
+that the Law of Gravitation extended throughout the whole of the solar
+system, and as Aether fills the solar system, then obviously Aether must
+also be subject to the Law of Gravitation.
+
+
+ART. 46. _Aether possesses Density._--That matter possesses density has
+already been shown in Art. 38, and on the hypothesis that Aether is
+matter, Aether must possess density also. This property has already been
+postulated for the Aether, in order to account for certain phenomena in
+connection with the reflection and refraction of light. Young assumed
+different densities for the Aether near bodies owing to its being
+attracted by those bodies (Art. 45). Reflection and refraction of light
+are produced by a change of density of the Aether. It is now generally
+accepted that the optical difference of bodies depends mainly on the
+different densities of Aether in association with those bodies.
+Professor Tyndall, in his _Lectures on Light_, writes on the density of
+the Aether as follows: "The density of the Aether is greater in liquids
+and solids than in gases, and greater in gases than in vacuo. A
+compressing force seems to be exerted on the Aether by the molecules of
+these bodies."
+
+Apart, however, from the atomicity and gravitative properties of the
+Aether, it is difficult to understand how there can be density of the
+medium, and still more difficult to give a satisfactory explanation of
+different degrees of density for the same medium, which some scientists
+assume it to have.
+
+If, however, all that is logically included in the statement that Aether
+is matter, and therefore is atomic and gravitative, is conceded, then,
+from the analogy of our own atmosphere in relation to the earth, the
+density of the Aether, and different degrees of density also, is at once
+put upon a logical and philosophical basis, as it is brought into
+harmony with all experience and observation, and is simple in its
+conception.
+
+On the other hand, an Aether which is not atomic or gravitative cannot
+possess different degrees of density, except by assuming the existence
+of some unknown law of which we have no knowledge, which conception is
+altogether opposed to the fundamental principles of simplicity,
+observation, and experiment as laid down not only by Newton but by every
+true philosopher.
+
+Therefore, that Aether can possess different degrees of density, is only
+the logical outcome of the statement that Aether is matter, seeing that
+such a statement without the shadow of a doubt must at least imply that
+it is gravitative.
+
+I need hardly point out, that it is much more philosophical to be able
+to account for the density of the Aether in a reasonable and
+philosophical manner, than simply to postulate for the Aether certain
+properties and qualities, because certain phenomena demand the existence
+of such properties.
+
+The Aether has been such a hypothetical medium, that it has been easy to
+postulate for it certain properties, if certain phenomena have demanded
+the existence of those properties.
+
+Thus if the Aether were required to be elastic, then elasticity was
+postulated for it; if more elastic, then greater elasticity was added.
+If density were demanded, then density was postulated, and if less or
+more density, less or more density was given to it.
+
+That method of speculation may be satisfactory up to a certain point,
+but no one will admit that such a method is wholly philosophical. It
+will be a far better method to adopt, if, in dealing with the universal
+Aether, we can make it conform to certain recognized laws and
+principles, and from the application of those well-known laws, be able
+to infer the exact constitution of this space-filling Aether medium.
+
+Now the question arises, if Aether is gravitative, what effect has the
+Gravitation of any body, be it an atom, or a meteor or planet, sun or
+star, upon the Aether in which it moves, and which surrounds it?
+
+That we may have some light thrown upon the matter, I would like now to
+take the reader to Newton's _Optics_, in order that he may give us his
+opinion as to this property of density of the Aether. In his nineteenth
+query Newton (_Optics_) asks this question--
+
+"Is not this medium much rarer within the dense bodies of the sun,
+stars, planets and comets than in the empty spaces between them, and in
+passing from them to great distances, doth it not grow denser and denser
+perpetually, and thereby cause the gravity of those great bodies towards
+one another, and of their part towards the bodies, every body
+endeavouring to go from the denser parts of the medium towards the
+rarer?"
+
+Here then we have given to us an indication of what is the possible
+state of things in relation to the gravitation of the Aether, and all
+bodies in solar and stellar space. The only mistake that Newton made,
+was in inverting the right order of comparatively dense and rarer parts
+of the aetherial medium, by putting the rarer parts of the medium near
+to the bodies, and supposing the denser parts to be farther away in
+space.
+
+As a matter of fact, the correct view is exactly the opposite, that is,
+if we are to form our conception by following out those philosophical
+rules that Newton laid down. For either the rules are right, or his
+supposition is right. They cannot both be right, as his supposition is
+contrary to the second Rule of Philosophy, as all experience and
+observation from the analogy of Nature teach us that a medium enveloping
+any body, as planet, star or sun, is densest nearest to the body,
+becoming rarer the further that medium gets away from the central body.
+Let us take for our illustration the best example, that experience and
+observation afford, that of the atmosphere surrounding the earth. The
+analogy is so perfect, that one is almost tempted to believe that the
+atmosphere and the Aether are in some way intimately associated with
+each other. Some years ago Lord Kelvin was of the opinion that the
+Aether was but an extension of the atmosphere, though I am not certain
+whether he holds that view at the present time. Clerk Maxwell, writing
+in the _Phil. Mag._ in May 1861, writes: "I have deduced from this
+result the relation between statical or dynamical electricity, and have
+shown that the elasticity of the magnetic medium in air is the same as
+that of the luminiferous medium, _if these two coexistent, coextensive,
+and equally elastic media are not rather one medium_."
+
+Now for the comparison. Both the atmosphere and Aether are matter. Both
+are atomic, both are gravitative, both possess elasticity, and both
+possess density. The atmosphere also possesses different degrees of
+density, so does the Aether. In the case of the atmosphere, however,
+experience and experiment teach us that the atmosphere is denser nearer
+the earth than farther away.
+
+When we ascend mountains, it is a matter of common knowledge that the
+higher we ascend, that is the further we get from the earth, the rarer
+the atmosphere becomes. When we ascend in balloons, we find that the air
+becomes so rare and so light, that the blood will flow from the nose, on
+account of the reduced pressure exerted on it, the pressure inside the
+body being greater than that outside. Now in accordance with our second
+Rule of Philosophy, if experience is to be any guide at all, then it
+most conclusively teaches us that the Aether being subject to the same
+laws as the atmosphere, the same results inevitably follow. Therefore
+the Aether nearest the earth is denser than any layer immediately above
+it, and that layer denser than the one above it, and so on for great
+distances, with the result that the only conclusion we can come to in
+regard to the density and rarity of Aether in relation to all
+gravitating bodies is, that the densest part of the Aether is nearest to
+them, and the rarest, the farthest away from them. So that while
+Newton's suggestion in his nineteenth query is correct in principle, it
+is incorrect in application to space.
+
+I would like to point out here, that what is true of the earth in
+relation to the density of the surrounding Aether, must also be true,
+according to our second Rule of Philosophy, of every other planet, or
+sun, or star. So that every planet, satellite, every sun or star has its
+atmosphere, if I may so term it, of Aether, which obeys and follows the
+same laws as the earth's atmosphere does.
+
+This is a most important fact, and has a most important bearing upon the
+physical cause of Gravitation as applied to each planet, and sun and
+star, as I shall afterwards show.
+
+I wish now to bring the reader into contact with a Theory of Gravitation
+that was given to the world by Professor Challis of Cambridge, 1872. In
+the _Philosophical Magazine_ of June of that year he writes: "I assume
+that all the active forces of Nature are different modes of pressure
+under different circumstances of a universal elastic Aether, which
+presses always proportionately to its density."
+
+Now what I wish to point out is, that while Prof. Challis admits the
+density of the Aether, and also varying degrees of density, as he states
+that the Aether presses proportionately to the density, he does not show
+how that varying density is accounted for. If there is this varying
+density, then there must be some underlying principle which governs the
+variation in density, and I know of only one principle or law which can
+regulate that variation in density, and that is that Aether is
+gravitative, and being gravitative it not only possesses density, but
+also variations in density.
+
+Thus by admitting that Aether is gravitative, because it is matter, we
+have at once a satisfactory explanation for the density of the Aether
+and also for different degrees of density both in the atomic world, and
+in the planetary and stellar world.
+
+
+ART. 47. _Aether is Elastic._--In Art. 39, matter was shown to be
+elastic, and on the assumption that Aether is matter, the elasticity of
+the Aether, which has been postulated for it by various scientists, can
+be logically and philosophically accounted for.
+
+In view of the transmission of light through space with a definite and
+finite velocity, we are compelled to regard Aether as possessing
+elasticity, similar to that of an elastic solid body.
+
+If we take the analogy of sound, we find that sound is transmitted and
+propagated through matter, by waves of alternate condensation and
+rarefaction, and that transmission is regulated by the relation of the
+density of the medium to its elasticity. Light has been proved to be due
+to the undulatory wave-motions of the Aether, and in order to account
+for the transmission of the wave-motion, it is essential that the Aether
+should possess the property of elasticity.
+
+As Young points out in his First Hypothesis,[6] the Aether possesses
+this property of elasticity, but with the advance of scientific
+knowledge and research, the elasticity of the Aether may be said to have
+passed out of the hypothetical stage, into the state of actual fact and
+experiment. Both McCullagh and Fresnel have assumed this property of
+elasticity for the aetherial medium in order to account for certain
+phenomena of light.
+
+Apart, however, from the atomicity of the Aether, it is exceedingly
+difficult to understand how such a property can belong to it. Atoms are
+exceedingly small particles, possessing the property of elasticity, or
+the power to recover their original shape after distortion or change of
+shape. If the Aether therefore be atomic, as is pointed out in Art. 44,
+it can at once be readily understood how the Aether as a whole can
+possess the property of elasticity. The atoms of the Aether must be
+inconceivably small, as the light-waves travel with the enormous
+velocity of 186,000 miles per second.
+
+What must therefore be the atomic vibration which such a statement
+implies? If, on the other hand, the Aether is assumed to be continuous
+and non-atomic, it must be seen how exceedingly difficult it is to
+account for the elasticity of the Aether, as it seems absolutely
+impossible for a medium which is continuous, and non-atomic, to be able
+to transmit the waves of light with a finite velocity.
+
+Apart, therefore, from atomicity of some kind or other, elasticity of
+the Aether is an assumption philosophically incorrect, as it is contrary
+to that simplicity of conception laid down by Newton, and is also
+contrary to all experience, and thus violates the second Rule of
+Philosophy.
+
+Aether therefore must be said to be perfectly elastic; so perfectly
+elastic, that it is susceptible to the least touch of any natural thing,
+so that even an atom, so small that it cannot be seen with the most
+powerful microscope, yet so elastic is this Aether medium, that the
+least motion or vibration of one of these atoms, though the motion did
+not exceed the 20- or 40-millionth part of an inch, yet even this would
+create in the aetherial ocean, Aether-waves, just as a body moving in
+water creates water-waves, which, radiating from the place of their
+birth, beget and create others, the process continuing until they reach
+the margin of the water in which they were generated. It is precisely
+so with these Aether-waves, when once generated and set in motion. They
+create others, the process being continued and perpetuated; and, unless
+arrested in their course, may continue until they reach the very limits
+and confines of material immensity and space.
+
+It is, perhaps, only necessary to say, regarding the perfection of the
+elasticity of the Aether medium, that though it takes from 40,000 to
+69,000 waves to complete the space of one inch in extent, yet it is done
+with such miraculous rapidity, as to speed the distance of 186,000 miles
+in the short space of a second of time; or, taking the number of
+Aether-waves to complete an inch as 50,000, its elasticity is such that
+it makes 50,000 × 186,000 × 12 × 5280 vibrations in one second of time.
+
+We have already seen in Art. 39, that according to Boyle and Marriotte's
+Law, the velocity of a wave-motion, as sound in the air, is determined
+by the relation of the elasticity of the medium to its density. If the
+temperature of the atmosphere remains the same, then the _elasticity_
+varies in the same proportion as its density.
+
+According to Art. 45, Aether is gravitative, and that fact produces
+different degrees of density in the aetherial atmosphere of an atom or
+planet or meteor, sun or star; that part of the Aether being densest
+nearest the central body, and rarer the further we go away from that
+body.
+
+Now the question at once arises, what is the effect of the increased
+density of the Aether near the body upon the elasticity of the Aether?
+
+From the analogy of sound in air, we arrive at the conclusion that Boyle
+and Marriotte's Law equally applies to the Aether, as it does to the
+atmosphere of any planet. That is, if the temperature of any stratum or
+layer of the Aether remains the same, then the elasticity of the
+aetherial medium in that layer is proportionate to its density, so that
+while the gravitating property of the Aether makes it denser nearest the
+central body, the fact that the elasticity is proportionate to the
+density, does not affect the transmission of any wave-motion.
+
+[Footnote 6: _Phil. Trans._, 1802.]
+
+
+ART. 48. _Aether possesses Inertia._--From Art. 40 we have seen that all
+matter possesses inertia, inertia being that property of matter by which
+it cannot of itself change its state of motion or of rest.
+
+If Aether be matter, therefore, then it must also possess inertia. This
+property of inertia is already postulated for Aether by scientists, and to
+that extent is conformable to the Rules of Philosophy. Professor Tyndall,
+with reference to the inertia of the Aether, writes: "The motion of
+Aether communicated to material substances throws them into motion. It
+must be therefore itself a substance. Aether is a substance endowed with
+inertia, and capable, in accordance with the established laws of motion,
+of imparting its motion to other substances."[7]
+
+Again, Lord Kelvin in his Address to the British Association, 1901, on
+the "Clustering of Gravitational Matter in any part of the Universe,"
+states: "Aether we relegate to a distinct species of matter which has
+inertia, etc." Aether, therefore, according to Tyndall, "is a substance
+or medium endowed with inertia, and capable, in accordance with Newton's
+Laws of Motion, of imparting its motion to other substances."
+
+If, however, the Aether is frictionless, as has generally been supposed,
+then it cannot possess inertia, because to the extent that a body
+possesses inertia, to that extent it is opposed to being frictionless.
+
+Inertia is really the equivalent of mass, or the amount of matter
+measured by gravity, and if Aether possesses mass in any sense at all,
+as it must do if it is matter, then, possessing mass or weight, it must
+offer resistance to any body moving through it, and to that extent
+cannot be frictionless. To suppose that the Aether is frictionless, and
+yet possesses inertia, is to suppose something altogether opposed to all
+the Rules of Philosophy and therefore of experience.
+
+I have already shown that a frictionless medium is opposed to all
+philosophy and experience, and is an anomaly in the universe.
+
+On the strictly philosophical assumption that Aether is matter, and
+therefore atomic and gravitative, the whole question of the inertia of
+the Aether is reduced to one of common experience. It is, at least to my
+mind, difficult to conceive of mass without weight or without atomicity,
+and yet that is the unphilosophical position of the present state of
+science in relation to the Aether. In other words, while the Aether is
+supposed to possess inertia, which is dependent upon mass, as measured
+by gravity, yet it is supposed not to be gravitative, that is, that the
+mass of the Aether has no weight at all, and therefore is not mass,
+which assumption contradicts itself. From Arts. 44 and 45, however, we
+have seen, to be strictly philosophical, that Aether must be atomic and
+also gravitative. It can now be easily understood how it can possess
+inertia like any other matter, and is therefore capable of receiving
+motion from other matter, and also of imparting that motion to other
+matter.
+
+So that, wherever there is motion of any kind in the Aether, either in
+the form of vibratory motion as heat, or undulatory motion as light, or
+rotatory motion as electricity, those motions will affect adjoining
+matter in the same way that the motion of any other moving matter
+affects any body with which it comes into contact.
+
+From the fact that Aether possesses inertia, and is also gravitative, we
+have now to alter our conception of this universal space-filling medium,
+and in place of a frictionless medium, which is incapable of imparting
+motion to any body, we have now to remember henceforth that the Aether
+is matter, which possesses inertia, and therefore has the capacity not
+only of offering resistance to any body moving through it, as a comet or
+meteor, but also of imparting the motion which it may receive in any
+manner to any other matter, as a planet, satellite, or sun, that may be
+floating in it.
+
+With this philosophical view of the Aether, which is entirely in harmony
+with our first and second Rules of Philosophy, we shall be able to give
+a physical explanation of the Law of Gravitation, as we have now a
+physical medium existing in all atomic, solar, and stellar space, which
+can both accept motion, and transmit that motion to other bodies. In
+other words, we have a medium which can both push and pull.
+
+[Footnote 7: _Lectures on Light._]
+
+
+ART. 49. _Aether is Impressible._--Another characteristic property of
+this Aether medium is, that it is as perfectly impressible as it is
+elastic. So perfectly impressible, that it receives, retains, and
+perpetuates for thousands of years, and for distances to human mind
+incalculable, every impression given to it of light, form, colour, tint,
+and shade; and that, too, with a perfect fidelity that nothing mars,
+even to the least and most infinitesimal detail.
+
+Therefore, irrespective of distance, wherever there is matter to arrest
+and reflect the impressions received, there those impressions of light
+(and all that in the luminosity is involved and contained) become
+visible and revealed, and wherever there is power of vision to receive
+and concentrate these Aether- or light-waves, there, not only luminosity
+or light, but all that constitutes and is involved in that luminosity,
+becomes at once visible and seen.
+
+It is by this means we see the colour, tints, shades, and forms of suns
+and planets; of stars, constellations, etc., with all the varied forms,
+configurations, and movements of the celestial phenomena. Each and every
+one, small or great, glittering or blazing, sun or planet, are ever
+creating or generating Aether-waves, and impressing them with all the
+details and particulars of their nature and existence; and these
+Aether-waves ever bear upon their mystic wings the impressions received,
+carrying the information given with lightning speed to the very confines
+and limits of infinite space or the material universe; beyond which
+exists nothing but the ever-living and active energy of the Divine, the
+only unlimited, unbounded, and absolute infinitive.
+
+It is by the interception and concentration of these waves by our
+perceptive powers, aided with the giant powers of the telescope, that we
+obtain the information given, or become cognizant of the nature and
+existence of the varied lights, colours, tints, and shades of the
+celestial bodies.
+
+The vision, assisted by the giant power of the telescope, collects and
+concentrates these Aether-waves into a perfect image of those things
+that gave them birth, and by this means reveals to us the knowledge of
+things afar, their existence, nature, characteristics, properties, and
+powers.
+
+Thus it is we see the solar orb, with its huge fires all aglow, obtain a
+knowledge of its character and powers, see its huge spots, its quivering
+fringe of flame, and high-leaping prominences, or watch its slowly
+revolving form.
+
+Thus we see the planets that around it sweep and roll; swift-footed
+Mercury with his wondrous speed, and dazzling Venus with her silver
+sheen; Mars the god of war with his ruddy glow, and mighty Jupiter with
+his orange hue, and the yellow Saturn with her mysterious rings, the
+blue Uranus, and the more distant Neptune, with all the satellites that
+to it belong.
+
+Then far far away the brilliant Sirius--the Dog Star, Cygnet, Centauri,
+the Great Bear, and a thousand others.
+
+The Pleiades and the twenty millions of suns that form our own galaxy
+and the Milky Way, with all their varied colours, tints, and hues of
+white, golden, orange, ruby, red and blue, green and grey, silver,
+purple and yellow, buff and fawn, emerald and green, lilac and coppery.
+Thus we see the distant Orion, so far away that swift-footed Light, with
+its speed of more than eleven million miles per minute, has to travel
+for more than thirty thousand years before it spans the gulf that
+intervenes between it and us, and brings to us the news of its existence
+there.
+
+Then the spectroscope with its revealing power literally tears asunder
+wave from wave, and reveals the mystic message which each doth bear, of
+the distant things from which they come, of each and every sort and
+kind.
+
+Thus we know, that in the solar fires there ever burn such things as
+hydrogen, oxygen and nitrogen, and also, in a vaporous state, aluminium,
+sodium, iron, magnesium, cobalt, calcium, chromium, copper, manganese,
+zinc, and others.
+
+Thus light-waves are speeding everywhere, and from all material things.
+They come from our own sun, and rush in, and flood the earth's aerial
+veil, the atmosphere; and "Each little atom of matter, like a mirror,
+reflects and re-reflects them as if in sport, buffeting each luminous
+ray from one to another, increasing and amplifying it by an infinity of
+repercussions" (Herschel), and then in their entirety and whole, like a
+huge multi-mirror, so blend and mingle them that they come to earth's
+surface in that soft radiance we call Light, and bathe it as in a sea
+of mellowed glory.
+
+
+ART. 50. _Aether: its Motions._--The question of the exact motions of
+the Aether is a question which has involved the attention of scientific
+men for many years, and which is at the present time receiving the
+attention of some of our most advanced scientists, not only in this
+country but in other countries also.
+
+Whether the Aether in space is at rest, or is moving along with all the
+bodies that float in it, so to speak, is a question of the greatest
+importance to scientists and philosophers generally, as the particular
+character of the motions of the Aether, which are either suggested or
+ascribed to it from the analogies of Nature, are sure to have a most
+important bearing not only on the motions of all the planets and
+satellites, but also upon such questions as the aberration of light, and
+such difficulties as presented by Lord Kelvin in his paper on "Clouds on
+the Undulatory Theory of Light" (_Phil. Mag._, July 1902).
+
+I need hardly point out that the hypothesis that Aether is gravitative,
+is bound to play a most important part in the consideration and
+development of this phase of the study of the universal aetherial
+medium. It is not my intention, however, at this stage of the work to go
+fully into the development of this aspect of the subject.
+
+The application of this principle will be considered at the right time,
+and in the right place. It is, however, generally assumed, that the
+Aether is at rest in space, and that the earth, the planets, and the sun
+and all stars, move through it with varying velocity, although, as Lord
+Kelvin points out, such an assumption is covered with a cloud which up
+to the present is "as dense as ever." Of course, if the Aether be at
+rest, and the planets and other heavenly bodies move through it with
+varying velocity, then the only assumption regarding the Aether is, that
+it is frictionless, but, as I have shown in Art. 45, this is opposed to
+all philosophical reasoning, and therefore to experience and
+observation.
+
+We have, therefore, to postulate for the Aether such motions as shall
+fulfil all the Rules of Philosophy, that is, shall be simple in
+conception, shall be in harmony with our experience and observation, and
+which shall satisfactorily account for the phenomena sought to be
+explained, that is, the universal Law of Gravitation; for it is by the
+properties, combined with the motions of the Aether, that the physical
+cause of Gravitation is alone to be explained.
+
+Let us revert to the question of a stationary Aether for a moment or
+two, and let us ask ourselves, where is the evidence for such an
+assumption? Has the sun ever ceased to shine, or to send its light-waves
+with their enormous velocity speeding through the solar system? So far
+as experience and observation go, I have never read of any record of
+such a fact, or that light-waves have ceased to proceed from the sun and
+fill the solar system with Aether-waves.
+
+Not only is this true of the sun, but it is equally true of every planet
+and satellite, every meteor or comet, every star and sun that exist or
+dwell in this aetherial medium; for, as has already been shown (Art.
+49), every body emits Aether-waves, and these waves spread out in all
+directions in a spherical form.
+
+The truth is, that the universal Aether is in eternal motion, and that
+motion forms the physical life of the universe. If it were possible to
+destroy the motion, then the whole fabric of the universe would fall to
+pieces, and the beauty, order, and harmony of the celestial mechanism
+would be replaced by disorder, confusion, and ultimate ruin. Take any
+analogy of Nature, and see what such an analogy teaches us. Look at any
+planet, sun, or star. Do we find any one of these stationary or at rest?
+Why from the smallest meteorite or satellite, to the largest star that
+shines in the firmament of heaven, there is nothing but motion; each
+satellite, planet, sun, and star moving on and on, ever and ever through
+the countless ages of time until its course is run and its existence
+ended. But rest, never! Such a thing as rest is unknown in the entire
+universe, whether it be in the atomic systems of matter, or the systems
+of stars and suns that form the universe of worlds.
+
+Take another illustration--that of the ocean! Is that ever at rest, with
+its unceasing wave and tidal motion? Has the reader ever stood on the
+shore and seen the ocean when it has been absolutely still, or when the
+tide has ceased to flow? Such a possibility is almost absurd to
+contemplate. The same argument applies to the air with its regular flow
+of winds. Now in regard to the aetherial and universal medium, there are
+just as regular motions as the flowing of the tide round the earth, or
+the revolving of a satellite round a planet, or a planet round the sun.
+
+And what is as important, all the motions can be as satisfactorily
+explained and accounted for from the physical standpoint, as the flow of
+the tide, or the revolution of a planet.
+
+Year in and year out, the motions of the Aether remain the same, governed
+by the same laws and producing the same effects. Age after age, the Aether
+has been moving, producing by its various motions the continuity of that
+beauty, order, and harmony that govern the universe as a whole.
+
+I have already indicated in Art. 45 the effect of Gravitation on the
+Aether surrounding each satellite, or planet, or star, or sun. As each
+satellite, or planet, or star moves through the universal Aether, it
+takes with it its surrounding Aether as indicated in Art. 45, in the
+same way that each planet or sun takes with it its own associated
+atmosphere, which is held in contact with it by the self-same force of
+Gravitation.
+
+In addition to this motion of the aetherial atmosphere through space,
+there are other motions of this same gravitating Aether that have to be
+taken into consideration, before a complete and adequate conception of
+all the motions of the Aether can be arrived at.
+
+I do not intend, however, at this stage to go fully into such motions,
+but rather wish to lead up to them from a consideration of hypotheses
+put forward by such men as Rankine, Challis, Maxwell, Lord Kelvin,
+McCullagh, and Helmholtz, and from a consideration of such hypotheses in
+the realm of heat, light, and electricity to be able to form a
+scientific conception of the proper motions of the Aether, as well as a
+philosophical one.
+
+
+
+
+                               CHAPTER V
+
+                                 ENERGY
+
+
+ART. 51. _Energy._--In the days of Newton, and for a long time afterwards,
+all energy went by the name of "Force." Thus Newton in his Laws of
+Motion refers to the action of forces on stationary or moving bodies,
+and shows how the motion of any body is effected by the impressed force.
+(Art 13.)
+
+As science advanced, and scientific research was carried into the fields
+of heat, light, and electricity, we find that the various forces began
+to be particularized, with the result that such terms as electrical
+force, magnetic force, chemical force, etc., became common and familiar
+terms. As gradually it became known that one particular kind of force
+was the outcome of another kind, there was given to the world such terms
+as the Correlation of Forces (Grove), in which he proved that whenever
+one kind of force appeared as heat or light, it was at the expense of
+another kind of force, as electricity.
+
+Of later years, however, another term has crept into Philosophy, and
+instead of the term Force, which is very indistinct and indefinite in
+character, there appeared the term Energy, although Force and Energy are
+not exactly synonymous terms. Thus electricity, heat, and light are
+forms of energy, and are convertible into one another, in the same way
+that the forces were convertible. Thus we get transformations of energy
+in the same way that we had transformations of force, and conservation
+of energy in the same way that we had conservation of force.
+
+Even the term Energy, however, is being replaced in the present times by
+something more definite and simple, and instead of the term Energy, we
+shall find, in the development of this phase of natural phenomena, that
+that term is being replaced by the simple idea of motion, or modes of
+motion, and that all forms of energy, as light, heat, magnetism, and
+electricity, and even Gravitation itself, are due to motion of some kind
+or other. We will, however, lead up to this truth by looking briefly at
+the term Energy, and see what it implies and embodies.
+
+Energy, therefore, is that property which a body possesses, by which it
+is capable of doing work. Thus our ideas of work give us our conception
+of energy. For example, when a weight is lifted, work is done, and a
+certain amount of energy is expended in the process. Further, the amount
+of work done is proportionate to the weight lifted, and the height to
+which the body is raised. Work is done against resistance, so that
+whenever resistance is overcome, then work is the result. For example,
+suppose one pound is lifted one foot high, in opposition to the force of
+gravity, then work is done, and this amount of work is known as a
+foot-pound.
+
+If a body weighs ten pounds, and is lifted ten feet, the work done is
+equal to ten pounds multiplied by ten feet (10 × 10 equals 100), so that
+one hundred times the amount of work has been done in comparison with
+the lifting of the one pound one foot high.
+
+As all weight is essentially a gravitational measure, depending upon the
+intensity of gravity at the place, then, whenever a body is raised or
+lifted, the work so done is done against the gravity of the earth.
+
+Work is also done, as Newton points out in the first and second laws,
+whenever we apply force to any body, either stationary or already in
+motion. The results of all observation and experiments prove, that
+whenever we have two bodies upon which work is being done, the amount of
+work is determined by the amount of energy transferred from one body to
+the other, and that the actual amount of energy gained by one is equal
+to the amount of energy lost by the other.
+
+Energy is always found in association with matter, so that matter has
+sometimes been termed the Vehicle of Energy. Wherever, therefore, we
+find energy of any kind or sort, there we find matter also, as the two
+are inseparably connected together. Thus, wherever we have heat, we have
+matter in a particular state of motion, generally understood as
+vibratory motion Wherever we have light, which is also a form of energy,
+we also have matter in motion, that is the Aether, in a state of
+periodic wave-motion; and wherever we have electricity, we have again
+matter possibly in a state of rotatory motion, as we shall see later on.
+Energy, therefore, is the power which a body possesses to do work.
+
+
+ART. 52. _Conservation of Energy._--The principle of the Conservation of
+Energy was first enunciated by Mayer in 1842. The principle may be
+defined as follows: The total amount of all the energy, as light, heat,
+electricity and magnetism, Gravitation, etc., in Nature is unchangeable;
+so that, according to this law, the universe possesses a store of energy
+which is unchangeable in quantity throughout all time. The energy may
+pass from one form to another, yet the total amount ever remains the
+same. It is almost unnecessary to say, that this is a principle which,
+like the conservation of matter, is incapable of absolute proof, but its
+assumption has greatly helped scientific thought and speculation from
+time to time. Clerk Maxwell says (_Theory of Heat_) on this point: "The
+total energy of any body is a quantity which can neither be increased
+nor decreased by any mutual action of the bodies, though it may be
+transformed into those forms of which energy is susceptible."
+
+The conservation of energy is inseparably connected with the
+conservation of matter (Art. 30). They cannot be divided, because, if
+energy is only to be found in association with matter, then if the law
+of the conservation of matter falls to the ground, the principle of the
+conservation of energy falls with it. Energy, therefore, like matter,
+cannot be destroyed or created by any process known to man. As there is
+no process known, either in the chemical or in the physical world, by
+which new matter may be created by man, so, in relation to energy of any
+kind or sort, there is no process known by which man can create or even
+destroy the smallest form of energy that exists. If energy appears in
+any body or in any particular form, it is solely because of the loss of
+energy in some other body, or in some other form.
+
+All changes of energy, therefore, are simply changes due to the
+difference in form in which the energy is manifested. At one time it
+will be manifested in the form of light, then of heat, then in
+mechanical motion, and so on. Joule gave us some good illustrations of
+this principle of the conservation of energy. He showed us how
+electricity could be changed into heat, and the heat into work. When
+light, which is a form of energy, is absorbed by any opaque body, it is
+found that the body which has absorbed it has become hotter. The energy
+of light has not been destroyed, but as its energy cannot pass through
+the opaque body, it has been employed in agitating the particles and
+atoms of that body, which becomes hotter in consequence.
+
+Thus from the principle of the conservation of energy, which is in
+operation not only in our planetary world, but throughout the whole of
+the solar and stellar space, and indeed throughout the whole universe,
+we arrive at the conclusion that the total quantity of energy throughout
+the universe is unchangeable. In the evolution and development of
+worlds, and in the destruction of those worlds after long periods of
+time, throughout all the varied manifestations of heat, light,
+electricity, and magnetism, associated with the development and
+destruction of each globe, the sum-total of the energy of the universe
+remains the same. Meteors may rush into the atmosphere of planets, and
+be dissolved into Aether through the friction, comets may be dissolved
+into their component gases as they near the sun, water may be changed
+into vapour by the heat of the summer sun, vegetation may be produced
+from apparently dead matter, and then that vegetation may itself decay
+and return to the dust by which it had been built up, but throughout all
+these processes of birth and death, of evolution and devolution, the
+sum-total of active living energy which is associated with all the
+phenomena, remains unalterable and unchangeable. Such is the teaching of
+the great principle of the Conservation of Energy as enunciated by Mayer
+and Helmholtz.
+
+
+ART. 53. _Transformation of Energy._--One of the chief characteristics
+of energy is, that we can transform it, and it is chiefly of use to us
+because of its capability to be transformed, but in all its
+transformations, the total quantity of energy remains the same. The
+transformation of energy renders it necessary to the existence of all
+life, and to all physical change in the universe. Mayer showed us that
+all energy in the solar system primarily derives its existence from the
+sun, and that all plant life and physical life owe their continued
+existence to the energy which is poured out from the sun upon the
+planetary worlds. So that energy is always flowing from the sun into the
+surrounding space in the form of light, heat, and electricity, the
+medium of its passage being the universal Aether.
+
+This principle of transformation teaches us, that heat may be converted
+into electricity; that light may be converted into heat, or electricity
+may be converted into either heat or light or both. This principle of
+transformation naturally follows from the principle of the conservation
+of energy; because, if energy cannot be destroyed in any way, but is
+made to disappear by any process, it must reappear in some other form,
+and therefore has been transformed from its original state. So that,
+whenever one kind of energy disappears, then it is absolutely necessary,
+according to the principle of conservation of energy, that some other
+kind shall be produced. There cannot be any real loss or destruction.
+
+That leads us to the next point regarding this principle of
+transformation, which is that all transformations of energy take place
+in fixed proportions. When a certain quantity of coal is burned, a
+certain quantity of heat, or thermal energy as it is sometimes called,
+is produced, and the quantity of heat so produced is definitely
+proportionate to the quantity of coal consumed.
+
+If a certain quantity of coal were burned in a perfect steam-engine,
+that is one in which there would be no loss of heat, then also a
+definite amount of mechanical work would be done, which would be
+strictly proportionate to the heat generated by the consumption of the
+coal. So that when coal is put into an engine, the potential energy of
+the coal is transformed into kinetic energy of the steam, and that is
+again transformed into actual mechanical energy of the engine itself, by
+which work is done in driving or pushing or pulling the train along, and
+the amount of work done is proportionate to the coal consumed.
+Illustrations of transformation are common, and may be seen by any
+person living in a large town. Thus at any electrical station or
+electric tram terminus, these transformations of various forms of energy
+are very familiar sights. We have first the transformation of the coal
+in the furnace into heat. This heat converts water into steam, whose
+motion is communicated by proper machinery into a dynamo, the product of
+which is electricity. That electricity is then conveyed along wires, and
+work is done by it, by moving trams along the connected tram system, or
+it may be converted into heat in the carbon filament in the car itself,
+which, if heated enough, will then produce the electric light. So that
+starting from the coal, we have several transformations therefrom into
+the forms of heat, light, motion, and finally mechanical energy, which
+results in Work. The question arises as to what is the law of
+equivalence in regard to the transformation of energy. That is, if we
+have a certain amount of energy of a given sort, how much of any other
+sort can be produced by it? The answer is partly to be found in a
+statement made by Joule in 1843, which practically embodies what is
+known as the first law of Thermo-dynamics, and is as follows: "When
+equal quantities of mechanical effects are produced by any means
+whatever, from purely thermal sources, or lost in purely thermal
+effects, then equal quantities of heat are put out of existence or are
+generated, and for every unit of heat measured by raising a pound of
+water one degree F. in temperature, you have to expend 772 foot-pounds
+of work." From this law we learn that heat may be used to do work, but
+that a certain amount of heat is always used up in the process. It can
+also be demonstrated that electric currents can do work, but to generate
+the currents a certain amount of work must be done.
+
+This equivalence and transformation prevail in all forms of energy,
+whether it be mechanical energy, thermal or heat energy, or electrical
+energy.
+
+
+ART. 54. _Potential Energy._--Energy has been divided into two classes,
+which are termed respectively Potential Energy and Kinetic Energy. We
+will look at the former first.
+
+_Potential Energy_ may be briefly defined as energy of position.
+
+Thus if we lift a body from the ground, the energy which has been
+imparted to it is energy of position, or potential energy. A glacier
+high up the mountain possesses potential energy, because of its
+position. By the mere fact that it is situated high up the mountain, it
+has a capacity for doing work by its descent, and if that descent be
+very sudden, the work done will be destructive work, as it may sweep
+away all houses and villages in its sudden descent. Thus, by the mere
+fact of its elevation, it possesses a power of doing work, which it has
+lost when it has descended. Again, work done in winding up the spring of
+a clock is stored up in the form of potential energy, and gradually runs
+out in the form of motion or kinetic energy.
+
+Potential energy is really the complementary principle of kinetic
+energy. That is to say, the amount of potential energy lost by any body,
+is equal to the amount of kinetic energy gained by the other body, to
+which the energy has been transferred. In the case of a body falling, as
+the potential energy diminishes, the kinetic energy increases, but the
+total amount of the two combined always remains the same. This is well
+illustrated in the case of a swinging pendulum. When a pendulum is at
+the highest point of its swing, its velocity or kinetic energy is zero,
+but at that point its potential energy is greatest. As it descends, the
+potential energy decreases, but the kinetic energy increases. When the
+pendulum is at the lowest point its energy is wholly kinetic, the
+potential energy being zero at that point, while it has sufficient
+kinetic energy to raise it to the highest level again. Throughout the
+cycle of these operations, the sum-total of the two energies always
+remains the same.
+
+Professor Tait points out, in his _Recent Advances in Physical Science_,
+that the available sources of all potential energy may be divided into
+four classes--
+
+    1st. Fuel.
+    2nd. Food of Animals.
+    3rd. Water-power.
+    4th. Tidal Water-power.
+
+All these are different forms of potential energy. Under the head of
+fuel he includes not only wood, coal, but also all forms of matter that
+may be used or burnt up by heat, or dissolved by chemical agencies. Thus
+zinc and lead, which are used in batteries, are merely forms of fuel.
+That potential energy resides in such things as wood and coal is a
+matter of common experience. All our coal-fields are stores of energy,
+which received their energy when in plant form, ages ago, from the sun,
+and this energy is now being used to drive our machinery, to warm our
+houses, and to give light to our homes and our cities. It has been
+calculated that a pound of coal would give out 14,000 heat units, which
+is equal to 11,000,000 foot-pounds of work, which is also equal to the
+amount of work a horse can do in five hours. Again, all food, whether it
+be the food of animals, as vegetables and plants, or of man, as bread,
+meat, etc., are all forms of potential energy, or energy which is stored
+up in matter. All forms of food have a certain amount of energy in them,
+which is used up in the body in building up waste tissue and imparting
+energy to the physical frame.
+
+Again, all forms of water-power, whether it be in the form of the
+flowing river or the tidal motion of the sea, possess a large amount of
+potential energy which may be used up to do mechanical work. They also
+possess kinetic energy, or energy of motion. We find illustrations of
+the possession of potential energy by rivers and tides, in the fact that
+by their fall from a higher to a lower level they may be made to do
+mechanical work, as in the case of the turning of the water-wheel by the
+fall of the water, which motion is communicated to machinery, and
+various forms of work are the result. In Switzerland and America
+advantage is being taken of the energy of falling water to generate
+electricity, by means of which villages and towns are being supplied
+with electric light at a very small cost.
+
+
+ART. 55. _Kinetic Energy._--Kinetic energy may be defined as energy of
+motion, and is the energy which a body possesses in consequence of its
+motion. A body in motion thus possesses kinetic energy, which it must
+impart to some other body before it can be brought to a state of rest.
+The body may be simply an atom, as a vortex atom, but if it be in
+motion, as all atoms are, then it must possess kinetic energy, which may
+be transferred to another atom by collision, or by some other method. As
+has already been pointed out in previous articles, kinetic and potential
+energy are complementary to one another, the sum-total of the two
+combined always remaining the same in any cycle of work, according to
+the principle of the conservation of energy. We get a good example of
+this oscillation from kinetic to potential, and _vice versâ_, in the
+planetary system. When the earth is farthest from the sun, its velocity,
+and consequently its kinetic energy, is at its lowest point; but there
+the potential energy is at its greatest. As the earth turns round in its
+orbit, however, and begins to approach the sun again, its potential
+energy decreases, while its kinetic energy increases with its increased
+velocity. So that by the time it has reached the nearest part of its
+orbit to the sun, its velocity, and consequently its kinetic energy, is
+at a maximum, while the potential energy is at a minimum. Then as the
+earth passes round its perihelion, the kinetic energy is used up in
+assisting the earth to overcome the attraction of the sun. Thus there is
+this oscillation from kinetic to potential, and from potential to
+kinetic, year in and year out, as the earth performs its cycle round its
+central body the sun.
+
+Professor Tait, in the work referred to in the previous Article, gives
+examples of kinetic forms of energy under the following heads--
+
+    1st. Winds.
+    2nd. Currents of Water.
+    3rd. Hot Springs and Volcanoes.
+
+It can be readily seen that winds are a form of energy, as we have
+innumerable instances of the power and energy which they exert.
+Advantage is taken of that kinetic energy by means of windmills, in
+which the energy of the wind is imparted to the revolving sails, and
+thence to the machinery, various forms of mechanical work being the
+result, as, for example, the grinding of corn, or the pumping of water.
+The pressure or energy of winds has even been calculated, the following
+figures being examples--
+
+VELOCITY IN MILES PER HOUR.   FORCE IN LBS. PER SQ. FOOT
+
+           1 mile.               .005 lb. per sq. foot.
+           5  "                  .123  "   "     "
+          10  "                  .496  "   "     "
+          15  "                 1.11   "   "     "
+          20  "                 1.98   "   "     "
+          30  "                 4.5    "   "     "
+          40  "                 7.9    "   "     "
+          50  "                12.5    "   "     "
+
+In the case of currents of water, whether they are in the form of river
+currents or ocean currents, as has already been pointed out in the
+previous article, the question of potential energy, or energy of
+position, is associated with their kinetic energy. Water is taken at a
+certain elevation, and then allowed to fall to a lower level, and in its
+fall from the high level to the lower level, its kinetic energy is used
+to drive mill-wheels, and thus work is done, the kinetic energy of the
+water being transformed into the motion of the machinery. This machinery
+may be used to work a dynamo, and thus electric light may be generated,
+or it may drive an electric motor which may perform all sorts of
+mechanical work. The great underlying principle of either kinetic or
+potential energy rests in the fact, that wherever we have energy of any
+kind or sort, whether it be associated with water, wind, or Aether,
+there we have the capacity to do work, the amount of work depending upon
+the amount of energy that exists in the matter which is the vehicle of
+energy.
+
+In Art. 50 it has been indicated that the Aether possesses several kinds
+of motions. From the sphere of light and heat, we learn that the Aether
+possesses certain motions which are always exerted in a direction from
+the central body, which gives rise to the light- and heat-waves. That
+being so, it conclusively follows that the Aether possesses kinetic
+energy, and therefore, possessing this energy, it also possesses the
+power to do work. It must be remembered we are no longer dealing with a
+frictionless medium, but with a gravitating medium, possessing mass and
+inertia, and, that being so, wherever we have the Aether in motion,
+there we have kinetic energy or the power to do work; and that work will
+correspond to the particular kind of motion which is exerted on any body
+by the aetherial motions, and will be equally subject to Newton's Laws
+of Motion.
+
+
+ART. 56. _Energy and Motion._--An advance, however, as to the meaning of
+the term Energy has been made within recent years, which brings it more
+into harmony with that simplicity of conception, and accordance with
+experience which are the very foundation of all philosophy. Instead of
+the term Energy, there is now being used another term to denote the
+forces which form the life of the universe, and that term is the word
+"Motion."
+
+Professor Poynting says: "All energy is energy of motion" (_British
+Association Report_, 1899).
+
+Thus motion is the fundamental principle of all phenomena. If we analyze
+all forms of energy with which we are familiar, we shall soon find that
+they are only changes of one form of motion into another. Thus we shall
+see that heat is a mode of motion, as has been proved by Tyndall, that
+light is another mode of motion, and that electricity is also a mode of
+motion. I need hardly point out that this advance in our conception of
+energy is strictly in accord with the Rules of Philosophy. First, it is
+simple in conception. When we say that a body possesses energy, whether
+that energy be potential energy or kinetic energy, it does not convey to
+the mind some definite concrete fact, as does the statement that a body
+possesses motion. Every one, whether familiar with scientific teaching
+or not, understands and is familiar with the word Motion, as it is a
+common phenomenon of everyday life and experience. As Energy was simpler
+in conception than Newton's term Force, so Motion is simpler in
+conception than the rather vague and indefinite term Energy; therefore
+when we say that all energy is energy of motion of some kind or sort, we
+state that which is philosophically correct.
+
+It is also in accord with the second Rule of Philosophy, in that it is
+strictly in harmony with experience and observation. Look where we will,
+or at what we will, there we find motion of some kind or other, whether
+it be among the innumerable stars, or in our own solar system, or any
+phenomena on the earth, or even among the world of atoms in their minute
+and atomic systems. Such a thing as absolute rest, or stagnation, is
+unknown in the universe. Wherever there is matter, there we find motion
+of some kind or other. It may be vibratory motion as heat, or wave
+motion as light, or rotatory motion as electricity, but motion of some
+sort is inseparably connected with all matter. So that when we say that
+all energy of the universe is the energy of motion, and motion only, we
+state that which according to the second Rule of Philosophy is
+absolutely correct.
+
+Further, I wish to premise that by the use of the term modes of motion,
+in lieu of energy, the third Rule of Philosophy will be fulfilled. For
+if all phenomena of the universe, whether it be heat, light,
+electricity, be due to different modes of motion, then Gravitation
+should be explained from the physical standpoint by some kind of
+aetherial motion also. This I can safely premise will be done, and in
+the later chapters of this work, Gravitation will be shown to be due to
+the motions of the aetherial medium which floods all space. By so doing,
+all the Rules of Philosophy will be fully satisfied, and Gravitation
+will then be brought into line with all the other forms of motion, as
+heat, light, electricity, and magnetism, which are in themselves modes
+of motion, as will be shown in subsequent articles.
+
+
+ART. 57. _Conservation of Motion._--If it be true that all energy is the
+energy of motion, then the principle of the conservation of energy ought
+also to apply to all the modes of motion, and in its place we should
+then have the principle of the conservation of the various forms of
+motion. This defined would be, that the total amount of all motion in
+the universe, as heat and light, electricity, magnetism, and Gravitation
+also, if that be due to the motion of the Aether, is unalterable and
+unchangeable.
+
+There may be changes from one form of motion to another, from heat to
+light, and light back to heat; heat into electricity, and electricity
+into light or heat; from Gravitation into heat or into light, or even
+into electricity; but the sum-total of the whole remains the same.
+
+Again, as the principle of the conservation of energy is inseparably
+connected with the conservation of matter, so the principle of the
+conservation of all the modes of motion is also inseparably connected
+with the conservation of matter. They cannot be divided, so that
+wherever we get matter of any kind or sort, there we get motion of some
+kind, either in the form of heat, light, or electricity, or those
+aetherial motions which produce those phenomena associated with
+Gravitation.
+
+As matter cannot be destroyed by any known process to man, so motion
+cannot be destroyed either. On the vortex atom theory of matter, this
+principle of the conservation of any mode of motion is perfectly
+intelligible, especially if added to that theory we have Dr. Larmor's
+electron theory as the basis of the vortex atom. An atom in its ultimate
+state is nothing more or less than Aether in rotation, and as Aether is
+matter, we see that on the assumption of this atomic basis, we have even
+in the atomic world an illustration of this conservation of matter and
+motion, as in such an atom we have nothing but matter (_i. e._ Aether)
+and motion. Carrying the idea upwards in the atomic scale, if atoms of
+hydrogen or oxygen are multiples of these vortex atoms, then again we
+have nothing in all the elements, or combination of the elements, but
+matter and motion. Again, as all planets and satellites, suns and stars,
+are but agglomerations of elements, we have still the same two classes
+of things, matter and motion, and so from the most infinitesimal atom in
+existence, up to the most ponderous star that exists in the universe, we
+have running through them all the principle of the conservation of
+motion, which is to matter the source of all its activities, energies,
+and powers. Motion, therefore, might almost be said to be eternal. We
+have heard from time to time of the term perpetual motion. Philosophers
+have from time to time endeavoured to discover some application of this
+perpetual motion, but all efforts in this direction up to the present
+have proved futile. In one sense there is no such thing as perpetual
+motion. In another sense, that is from the standpoint of the
+conservation of all modes of motion, as motion cannot be destroyed, it
+must therefore be perpetual.
+
+It is an absolute impossibility to obtain motion except from some
+antecedent energy, which is itself a form of motion. It would require
+the distinctive fiat of an Almighty Creator to produce motion from
+nothing, and I question whether such a result is obtainable, as I hold
+that if the Creator, at any time in the history of the universe, set any
+substance in motion, the source from which that motion was derived, was
+His own Divine Energy, and in that sense the physical motion was not
+produced from nothing. Such an assumption is altogether opposed to all
+philosophical reasoning and experience. I hope to deal with the question
+either in the last chapter of this book, or in another work.
+
+
+ART. 58. _Transformation of Motion._--Again, if energy be the energy of
+motion, and the principle of the transformations of energy holds good,
+then it is equally true that all modes of motion are also transformable.
+Thus heat is a mode of motion, being due to the vibration of the atoms
+which go to make up any body. Light is also a mode of motion, being due,
+as far as solar light is concerned, to the periodic wave motion of the
+Aether. While electricity, as we shall see later on, is also due to some
+form of rotatory motion. It has already been shown (Art. 54) that light
+can be converted into heat, so that the periodic wave motion of light
+can be transformed into the vibratory motion of heat.
+
+Heat can also be converted into electricity, and if electricity be
+rotatory motion, then the vibratory motion of heat can be transformed
+into the rotatory motion of electricity. Again, as electricity can be
+converted into light, the rotatory motion of electricity can thus be
+transformed into the periodic wave motion of light. Thus through all the
+forms of motion with which we are familiar, we find this principle of
+transformation holds good, so that each form of motion may be directly
+or indirectly transformed into any one of the other kinds. Whenever,
+therefore, one kind of motion disappears, it is absolutely necessary,
+according to the principle of the conservation of motion, that some
+other kind shall be produced. There cannot be any real loss or
+destruction of the motion. It may be transformed, but not lost. By the
+use of proper apparatus, therefore, any form of motion with which we are
+familiar may be converted into another form, and in the process not the
+least quantity of any form of motion is lost. Heat may be changed into
+light, and light into heat; electricity into light, and light into
+electricity; heat into electricity, and electricity into heat. Indeed,
+starting from any one form, any of the other modes of motion may be
+produced, either directly or indirectly, and mechanical effects or work
+may be produced by each and all. Then, again, the order can be reversed,
+as by doing work which is simply applied motion, any of the other modes
+of motion can be produced. Thus heat can be produced by friction, and if
+the friction which is the outcome of muscular energy be continued long
+enough, a light will be the result, in the form of fire. When certain
+forms of work are done, as the turning of the handle of an electrical
+machine, frictional electricity will be produced. So that not only are
+all the modes of motion convertible into work, but work itself can be
+transformed into the modes of motion known as heat, light, electricity,
+and magnetism.
+
+Now, if Gravitation be due to motion of the Aether, and if it is true
+that all modes of motion are convertible, then the application of this
+principle should also hold good in relation to Gravitation. It has been
+demonstrated by Joule and others that Gravitation can be converted into
+heat, light, and electricity. It can be converted first into heat. Joule
+made a number of experiments to ascertain what quantity of heat is
+produced by falling bodies, that is bodies under the influence of
+Gravitation. From experiments he has calculated that if one lb. of water
+falls through a space of 772 feet, it would raise the temperature of
+the water one degree Fahrenheit--that is, the water after its fall will
+be one degree hotter than when it started to fall. Here, then, we have
+the exact equivalence of a certain amount of gravitational motion
+expressed in terms of heat. So that, whenever motion of a falling body
+produced by gravity is arrested, heat is generated, and as heat is a
+mode of motion, it follows that the motion of Gravitation has been
+converted into the motion of heat. Again, the motion of gravity may be
+converted into that of light. This may be demonstrated as follows: Lord
+Kelvin has suggested that the light and heat of the sun are maintained
+by the falling into the sun of meteorites. Now the cause of the falling
+of these meteorites into the sun is the Attraction of Gravitation, and
+therefore if the falling of these meteorites produces light and heat, it
+necessarily follows that the motion of Gravitation, whatever that may be
+due to, is converted into the motion known as light and heat. Thus it
+can be seen that Gravitation, looked at from the standpoint of a mode of
+motion, is itself conformable to the principle of the transformation of
+motion, and this is an indirect argument in favour of the fact that
+Gravitation is itself due to certain motions of the universal Aether.
+
+
+ART. 59. _Motion and Work._--In Art. 52 we have seen that energy is the
+power which a body possesses to do work, the amount of work which a body
+can perform being regulated by the amount of energy which such a body
+possesses. In Art. 57 we have further seen that all energy is the energy
+of motion, and that wherever we have energy of any kind or sort, whether
+it be in the form of light, heat, or electricity, there we have motion
+of some kind or other. That being so, we arrive at the conclusion, that
+wherever in the universe we have motion of any kind or sort, whether it
+be the motion of Aether, or wind, or water, there we have the power of
+doing work, and the work so done will be proportionate to the motion
+which the medium possesses. The amount of work that air in motion can do
+has been measured, as we have already seen (Art. 55) that air which
+moves at the rate of 30 miles per hour exerts a force of 4-1/2 lb. per
+square foot.
+
+The amount of work that water in motion can do has also been measured.
+The carrying and erosive powers of a river depend on the rapidity of its
+currents. It has been calculated that a velocity of three inches per
+second will transport fine clay; eight inches per second coarse sand;
+while three feet per second will transport stones as large as eggs.
+
+If, therefore, air moving at the rate of 30 miles an hour can exert a
+force of 4-1/2 lb. per square foot, what must be the force or pressure
+of aetherial motion, as light-waves for example, which move with a
+velocity of 186,000 miles per second? The amount of work which such an
+aetherial motion can perform has actually been measured by Professor
+Lebedew of Moscow, and will be dealt with in the chapter on "Light, a
+Mode of Motion," when the application of the work done on a body, as a
+planet for example, will also be considered. Work, therefore, can always
+be done by motion against resistance. This is a fundamental principle in
+the sphere of dynamics, which is incontrovertible, as all experience,
+observation, and experiment teach us, that wherever we get motion of any
+kind or sort, there we have the capacity or power to do work. The work
+done may be either in the form of pushing a body along, or pulling a
+body towards a centre. All experience and observation teach us that no
+body moves (whether it be an atom, or moon, or planet, or sun, or star),
+unless some other body or medium, which is in direct contact with the
+moving body, exercises some pressure or pull upon the moving body. The
+action is purely and simply a mechanical one. So that if this be true,
+then the earth and the planets, the sun and stars, comets and meteors,
+are moved through space solely because they are being pushed by some
+medium, or pulled to the centre by the motions of the same medium. If
+this can be proved to be true, then, as can be readily seen, our
+philosophy will then be made to agree with our experience, and the
+second Rule of Philosophy fully satisfied. As has already been pointed
+out, there is no such thing as action at a distance, therefore the Law
+of Gravitation demands a medium for its operation, production, and
+continuity. Newton distinctly points this out in his Letters to Bentley,
+where he says: "That one body should act upon another through empty
+space without the mediation of anything else, by and through which their
+action and pressure may be conveyed from one to another, is to me so
+great an absurdity that I believe no man who has in philosophical
+matters a faculty for thinking can ever fall into it." It has already
+been pointed out (Art. 42), that the only medium which is universal is
+the Aether medium, and we have therefore to look to the motions and
+properties of that medium for the solution of the problem as to the
+physical cause of Gravitation. That such a medium has motions which are
+as regular as the tides of the sea, or the trade winds of the
+atmosphere, will be proved later on, when it will be found that
+Gravitation, with all that that law implies, is due, as Newton and
+Challis suggested, to the pressure, properties, and motions of the
+aetherial medium, which is as universal as Gravitation itself. This
+being so, it is essential that we should set ourselves to find out from
+the analogies of Nature, what are those properties and motions of the
+Aether which give rise to the universal Law of Gravitation. This I
+propose doing by a consideration of three different modes of
+motion--viz. Heat, a mode of motion; Light, a mode of motion; and
+Electricity, a mode of motion. I venture to premise, from a careful
+consideration of these three truths, that we shall be able logically and
+philosophically to arrive at the simple, yet grand truth which reveals
+the physical source of all motion of the universe.
+
+
+
+
+                              CHAPTER VI
+
+                            HEAT IS MOTION
+
+
+ART. 60. _Heat is Motion._--On the phenomena of Heat, Newton in his
+eighteenth query in _Optics_ asks the questions: "Is not the heat of a
+warm room conveyed through the vacuum by the vibrations of a much
+subtler medium than air, and is not the medium the same as that medium
+by which light is reflected and refracted, or by whose vibrations light
+communicates heat to bodies? And do not the vibrations of this medium in
+hot bodies, contribute to the intenseness and duration of their heat?
+And do not hot bodies communicate their heat to contiguous cold ones by
+the vibrations of this medium propagated from them into the cold ones?
+And is not this medium exceedingly more rare and subtle than air, and
+exceedingly more elastic and active?" Thus it can be seen that Newton
+was of the opinion that heat consists in a minute vibratory motion of
+the particles of bodies, and that such motion was communicated through
+what he calls a vacuum by the vibrations of an elastic medium, the
+Aether, which was also concerned in the phenomena of light.
+
+One of the first experimental investigations into the real nature of
+Heat was made in 1798 by Count Rumford.
+
+While he was engaged in boring brass cannon in the arsenal at Munich, he
+was struck with the degree of heat which the brass gun acquired, and
+with the still more intense heat which the metallic chips, which were
+thrown off, possessed. Of the phenomena he says: "The more I meditated
+on these phenomena, the more they appeared to me to be curious and
+interesting. A thorough investigation seemed even to bid fair to give us
+a farther insight into the hidden nature of Heat." Rumford therefore set
+himself to find out by actual experiments what the nature of Heat was.
+For this purpose he constructed a cylinder, and mounted it so that it
+could be made to rotate by horse-power. At the beginning of the
+experiment the thermometer stood at 60° Fahrenheit, and after
+half-an-hour, when the cylinder had made 900 revolutions, the
+temperature was found to be 130° Fahrenheit, so that there had been an
+increase in the temperature of the cylinder of 70° Fahrenheit. The
+experiment was again repeated in another form with similar results.
+Rumford in dealing with the results of his experiments said: "It appears
+to me to be extremely difficult, if not quite impossible, to form any
+distinct idea of anything capable of being excited and communicated, in
+the manner the Heat was excited and communicated, in these experiments,
+except it be Motion."
+
+Only a year later, Davy gave to the world some results of experiments
+which he had performed, by which he had arrived at a similar conclusion
+to that of Rumford, viz. that "Heat is motion of some kind." His
+experiment consisted of rubbing two pieces of ice together, and by so
+doing showed the ice could be melted. He then caused two pieces of metal
+to be rubbed together, keeping them surrounded by ice, and still he
+found that the two pieces of metal when rubbed together, produced heat,
+and melted the ice. He therefore rightly concluded that heat was
+produced by friction, and of the experiment adds: "A motion or vibration
+of the corpuscles of bodies must necessarily be generated by friction.
+Therefore we may reasonably conclude that this motion or vibration is
+Heat. Heat then may be defined as a peculiar motion, probably a
+vibration of the corpuscles of bodies tending to separate them. It may
+with propriety be called a repulsive motion. Now bodies exist in
+different states, and those states depend upon the action of the
+attractive and of the repulsive powers on their corpuscles, or in other
+words, on their different quantities of repulsion and attraction." It
+was not, however, till 1812 that Davy confidently stated that "The
+immediate cause of the phenomena of Heat is motion, and the laws of its
+communication are precisely the same as the laws of the communication of
+motion."
+
+The question therefore confronts us, if heat be motion, what is the
+particular character of that motion? Is it a vibratory motion as Davy
+suggested, or is it similar to the undulatory wave motion of light? I
+need hardly point out, that we have evidence in favour of the hypothesis
+that light is due to some form of periodic wave motion in the Aether,
+the hypothesis being that known as the undulatory theory. We have also
+similar evidence in favour of the hypothesis, that heat is also due to
+some form of motion of the same aetherial medium. Indeed, it can be
+shown that heat possesses all the properties of light, and is subject to
+the same laws, with the exception that it cannot affect the sense of
+sight.
+
+Heat, then, is due to some motion in the universal aetherial medium,
+that not only fills all space, but also forms an atmosphere around every
+atom or particle of matter that exists in the universe, and that motion
+is generally known as a vibratory or backward and forward motion.
+
+Heat, then, may be said to be due to the vibrations of the Aether that
+surrounds all atoms and molecules, and of which those very atoms are
+composed, that is if we accept the aetherial constitution of all matter.
+So that, whenever a body, whether it be an atom or a molecule, or a
+planet or sun or star, is heated in any way whatever, such bodies excite
+waves in the surrounding Aether, and these waves travel through the
+Aether towards us from the heated body with the velocity of light. When
+these waves fall upon any other body, they become more or less absorbed
+by the body on which they fall, and cause corresponding vibratory
+motions in the same, which give rise to the phenomenon of heat in that
+particular body.
+
+It has to be remembered that nothing definite is actually known as to
+the character of this vibratory motion. It is called a vibratory motion
+because it possesses a periodic vibratory movement, but as to its exact
+character, that has not yet been discovered. I hope, however, to
+indicate what the motion is that produces heat before the completion of
+this work.
+
+
+ART. 61. _Heat and Matter._--If it be true that heat is due to the
+vibrations of the aetherial medium, the question now arises, as to how a
+body may become heated, and by so doing be transformed into the three
+stages in which matter is found. We have already seen (Art. 36), that
+matter may be found in three forms, viz. solid, liquid, and gaseous, and
+that all these different forms of matter are composed of minute parts
+called atoms. In the case of the solid, the atoms are held closely
+together by some strong attractive power, termed cohesion; in the case
+of the liquid, the atoms have a greater freedom; while in the gaseous
+form they have a greater freedom of movement than when in either the
+liquid or the solid state. According to Young's Fourth Hypothesis (Art.
+45), we find that all matter, and therefore all atoms have an attraction
+for the Aether, by means of which it is accumulated within their
+substance, and for a small distance around them in a state of greater
+density, and therefore of greater elasticity. In other words, as Aether
+is gravitative, every atom possesses an atmosphere of Aether in the same
+way that the earth has its atmosphere of air; and further, the aetherial
+atmosphere of each atom is densest nearest to the atom, gradually
+getting rarer and rarer the further the atmosphere recedes from the
+nucleus or centre, the elasticity or pressure being always proportionate
+to the density. Professor Challis, in his Dynamical Theory of Light and
+Heat, states that all the forces in Nature are different modes of
+pressure under different circumstances of the universal Aether, and as
+heat is a Force, and therefore a mode of motion, that also must be due
+to some form of pressure due to the vibrations of the Aether.
+
+Professor Challis[8] on this point says: "According to this theory, the
+atoms of any substance are kept in position of equilibrium by attractions
+and repulsions resulting from the dynamical action of the vibrations of
+the Aether which have their origin at the atoms. Each atom is the centre
+of vibration propagated equally from it in all directions, and that part
+of the velocity of the vibration which is accompanied by change of density
+(of the Aether) gives rise to a repulsive action on the surrounding
+atoms. This action is the repulsion of heat, which keeps the individual
+atoms asunder."
+
+With all these facts before us, we are now in a position to account for
+the changes of matter which take place when heat is applied to either
+a solid or a liquid body. We have already seen (Art. 36) that it is by
+the application of heat that matter in its solid form is changed into a
+liquid, and from a liquid into a vaporous or gaseous form. It is now for
+us to endeavour to form a mental picture as to how this is done.
+
+For example, let us take an iron ball, and apply heat to it, either by
+putting it in a furnace or suspending it in some way over an intense
+heat. As the heat, which is vibratory motion of the Aether, begins to be
+absorbed by the iron ball, it sets the atoms which compose the ball in
+motion, urging them to separate, and thus cause the iron ball to expand
+and increase in volume. As greater heat is absorbed, so greater motion
+among the atoms is the result. So that the motion of heat is tending
+all the time to expand the body, while they are held together by the
+attraction of cohesion, whatever that may be. As the heat is further
+increased, the iron ball begins to assume a liquid or molten form, its
+atoms beginning to move about with greater freedom, though held together
+by a decreased attractive power. In this condition we now say that it is
+in the molten state. Now during all this time, what has the Aether been
+doing, or what part has it played in the expansion and changing of the
+solid to a liquid? We have to remember, from Art. 60, that wherever
+there is motion of any kind or sort, there we have a capacity to do
+work, and that the aetherial motion which we term heat is no exception
+to this rule. We are now no longer dealing with a frictionless medium,
+but with a medium which possesses weight, because it is gravitative, and
+consequently possesses inertia also. So that whenever the Aether is set
+in motion by flame or heat, its motion would be transmitted by waves of
+some kind to the iron ball. These periodic waves, acting upon the mass
+of the ball, attack the molecules of the ball and begin to set them in
+motion. It is supposed that they are already in motion, as nothing is
+absolutely cold, and the motion of the aetherial waves imparts a greater
+motion still to the molecules, with the result that the agitation
+becomes greater and greater, until at length the agitation becomes so
+great, that the molecules break away from the power of attraction that
+holds them together, and so begin to move about with greater freedom and
+with greater rapidity. It is this state which we call molten. Now if
+Aether be frictionless, as has hitherto been supposed, and if heat be
+due to the vibratory motions of Aether, the problem confronts us, as to
+how the motion of a frictionless medium can do work in expanding a body,
+and urging the molecules of a body further and further apart. If the
+Aether be frictionless, then the waves of Aether known as aetherial heat
+waves ought to pass between the atoms as water passes through a sieve,
+or wind passes through a forest. Yet it is assumed that the vibratory
+motions of a hot body are caused by vibrations of the periodic waves of
+the Aether, which act upon the molecules of the body; and, in order for
+such an assumption to be consistent with the results, the only possible
+conception that can be accepted of the Aether, is that it is
+gravitative, and consequently possesses mass and inertia, and therefore
+has a capacity not only to accept motion, but also to transmit motion to
+another body, and impart the motion which it has accepted to a colder
+body.
+
+By imparting such motion, it increases the motion of the cold body, and
+gradually changes its state from a solid to a liquid condition. Here,
+then, from the realm of heat we have another argument in favour of the
+fact that Aether is gravitative, and therefore possesses mass and
+inertia.
+
+In the experiment of reducing the iron ball from a liquid state, so to
+speak, to a vaporous condition, we have practically a continuation of
+the same process, only that greater heat or greater aetherial motion is
+required, and whereas in the previous experiment the molecules of the
+ball were acted upon, in this case the atoms are more directly acted
+upon by the Aether waves. In all these processes it suggests itself to
+me that the aetherial atmosphere must take its share in the expansion
+and transformation of the liquid form into a gaseous form, or the solid
+into a liquid form. Taking the analogy of our atmosphere in its relation
+to the earth, we know that when heat is absorbed by it, it expands, the
+result being that a greater pressure is exerted by the expanding
+atmosphere, than would be exerted if it remained at the same temperature
+all the time. If, therefore, each atom has an aetherial atmosphere,
+which is capable of expansion, then the effect of the absorbed aetherial
+motion of the heat waves on each atomic atmosphere must be to expand it,
+and thus there will be a pressure _away from_ the atom, because of the
+increased elasticity acquired by the heated aetherial atmosphere. So
+that the expansion of the liquid is due to the increased elasticity of
+the aetherial atomic atmosphere, which has been expanded by heat, and
+which exerts an increased pressure on neighbouring atoms, thus seeking
+to push them farther away from each other. There are other motions of
+the atoms themselves in addition to this to be considered, but I am now
+seeking to show only the effect of the aetherial atmosphere of each atom
+upon the neighbouring atoms. This would give each atom a larger sphere
+of freedom in which to move, and that state would then be called a
+gaseous and not a liquid one. This assumption of the part which the
+aetherial atmosphere plays in the expansion of a body is therefore in
+agreement with Professor Challis' theory of heat already referred to, in
+which he states that heat gives rise to aetherial vibrations which act
+repulsively on the neighbouring atoms. In further confirmation of the
+existence of these aetherial atmospheres that exist around atoms, I
+would like to draw the attention of the reader to a theory of heat given
+to the world by Rankine, _Phil. Mag._, 1851. His theory is known as the
+"Hypothesis of Molecular Vortices."
+
+He assumed that "each atom of matter consists of a nucleus or central
+point, enveloped by an elastic atmosphere, which is retained in its
+position by attractive forces, and that the elasticity due to heat
+arises from the centrifugal force of those atmospheres revolving or
+oscillating about their nuclei or centres."
+
+Now in this assumption we find that he admits that each atom has an
+atmosphere, such atmosphere evidently being an aetherial one, and in
+that case the hypothesis would agree with the statement in Art. 46, that
+every atom possesses an aetherial atmosphere. He further points out that
+the atmosphere is retained in its position by attractive forces. This is
+also in harmony with the hypothesis given in Art. 45, which proves that
+Aether is gravitative, and therefore the atmosphere of the atom would be
+held in its position by the attractive force of Gravitation, as
+suggested by Young in his Fourth Hypothesis.
+
+Further, he goes on to show that the elasticity of the atomic atmosphere
+is proportionate to its density, which is also in conformity with the
+statement made in Art. 47, and is also in accordance with Boyle's Law.
+Then he goes on to prove that the quantity of heat in a body is measured
+by the molecular revolutions of the vortices.
+
+He does not clearly define the exact character of those molecular
+vortices, but I take it to mean that each atmosphere is in a state of
+revolution around its atomic centre, in the same way that the atmosphere
+of a planet is in a state of revolution around its central body.
+
+Such an assumption is entirely in harmony with experience, as there is
+an analogy for its assumption from the planetary system; and if an atom
+is a world in miniature, as I believe it to be, then the atmosphere of
+the atom ought to revolve around its central nucleus in the same way
+that the atmosphere of a planet revolves around its nucleus or central
+body.
+
+He then deals with temperature, and with the pressure of gases caused by
+heat, showing the relation of elasticity and pressure to temperature in
+a table of results given in the _Phil. Mag._ for 1851. I must refer the
+reader to the paper itself for fuller details. Thus from one of the
+greatest thinkers of modern times we have further testimony to the
+hypothesis that Aether is matter and is therefore gravitative, and
+because of its gravitating tendency, it forms around every atom and
+molecule elastic envelopes or atmospheres, whose pressure is always
+proportionate to their density.
+
+[Footnote:8 _Phil Mag._, 1859.]
+
+
+ART. 62. _Radiation and Absorption._--We have already seen (Art. 31)
+that all matter is made up of atoms and molecules, each of which is
+surrounded by its atmosphere of Aether. By means of the Aether, motion
+in the form of light and heat may be transmitted from one atom and
+molecule to another. The transmission of heat from one body to another
+is termed Radiation, while the acceptance of heat is termed Absorption.
+Tyndall defines Radiation as "the communication of molecular motion from
+the heated body to the Aether in which it is immersed,"[9] and
+Absorption, therefore, would be the acceptance of motion by the body
+from the Aether. So that in Radiation, the atom, molecule, or body parts
+with motion to the Aether, while in Absorption it gains motion from the
+Aether.
+
+Now in order for us to understand this theory of Radiation and
+Absorption, it will be well for us if we look at a similar effect in the
+sphere of music and sound. Let us suppose that we have two tuning-forks
+of the same pitch, placed on a table at a distance of a foot from each
+other. If we set one of the forks vibrating, the waves which it radiates
+through the air will fall upon the other one, and will also set it in
+vibration, because they are of the same period or size as those waves
+which it would itself give off when sounded. Thus while one is losing
+its motion, the other is gaining it, or while one is radiating motion,
+the other is absorbing motion. This can readily be proved by stopping
+the vibration of the first fork, when it will be found that the second
+fork is now giving out a similar note to the first, although it was
+silent at the commencement. Thus we have here an example of radiation
+and absorption of sound, the success of the experiment depending upon
+the fact that both forks shall have the same pitch. Again, it must be
+noted, that if we have two tuning-forks both of which are of the same
+pitch, and both vibrating at the same time, then, while one is radiating
+sound and consequently losing motion to the other, yet at the same time
+it is absorbing motion from the other. Because, if fork A can transfer
+motion to fork B, the latter can equally transfer its motion to fork A,
+and when both are vibrating together, each is the recipient of part of
+the other's motion, while at the same time giving off motion in the form
+of sound waves itself. So that the power of a fork to radiate sound
+waves equals its power to absorb sound waves. If now we apply this
+simile to the atomic and molecular world, we shall be able to form a
+mental picture as to what takes place in radiation and absorption.
+
+All atoms and molecules are ever in a state of ceaseless motion, ever
+moving, never still. All are creating Aether waves which move away with
+the velocity of light. If, in the transmission of the waves by the
+Aether, they fall upon another atom which can emit a wave of similar
+length, in the same way that two tuning-forks emitted sound waves of the
+same length, then the atom upon which the waves strike will be set in
+vibration, as the second tuning-fork was set in vibration by the first.
+We shall look again at the principle of wave motion in the next chapter.
+Further, from the simile of the two forks, which absorb sound at the
+same time that they radiate sound, we learn that an atom or body
+radiates heat waves at the same time that it is absorbing heat waves.
+Suppose that we have two bodies at equal temperatures, it must not be
+thought that the radiation or absorption has ceased, for, according to
+the simile used, they both still continue to vibrate and emit the
+aetherial heat waves; but where we get equality of temperatures, there
+we get equality of radiation and absorption. Before this equality of
+temperatures, however, is reached, the hotter body will radiate more
+heat waves than it absorbs, while the colder body will absorb more heat
+waves than it emits. All bodies, whatever their temperature, are
+incessantly radiating heat waves. This may be proved experimentally with
+proper apparatus, as for example with an instrument known as the
+thermopile. When, however, the total heat waves radiated out by a body
+are less than it absorbs, the body gets gradually colder, and the
+temperature decreases. So long as this is continued, so long will the
+body continue to get colder and colder, until it arrives at the same
+temperature as the surrounding bodies, at which point the total heat
+waves radiated out will equal the total heat waves absorbed, and at that
+point the temperature of the body will remain constant.
+
+This aspect of temperature was first introduced by Prevost of Geneva in
+1792, in an article in which he tried to explain the radiation from a
+cold body. According to his reasoning, a body is not simply regarded as
+radiating heat when its temperature is falling, or absorbing heat when
+it is rising.
+
+What he tried to make clear was, that both radiation and absorption were
+going on at one and the same time; the radiation depending upon the body
+itself, but the absorption depending upon the nature of the body. While
+radiation and absorption are thus reciprocal, which implies that a good
+radiator is a good absorber, and a bad radiator is a bad absorber, it
+does not follow that all bodies radiate and absorb alike.
+
+The capacity of bodies to radiate and to absorb differ considerably. Dr.
+Franklin made several simple experiments to prove the relative powers of
+radiation and absorption with several pieces of cloth. These were put
+out on the snow, and exposed to the heat of the sun. He found that the
+pieces which were dark in colour sank deepest into the snow, while those
+which were lightest in colour sank the least. From this he inferred that
+the darkest pieces were the best absorbers, and therefore the best
+radiators, while the light-coloured cloths were the worst absorbers, and
+therefore the worst radiators.
+
+Radiation, therefore, may be said to be the propagation of a wave motion
+through the Aether; and, as all motion is a source of power or energy,
+we have in the radiation of heat from one body to another by the
+aetherial waves, the transmission of a motive power capable of doing
+work, either internal work as increasing the temperature of the molecule
+or body, or external work as separating the atoms, or driving them
+further apart. It can readily be seen that if the Aether were
+frictionless, as has generally been supposed, the Aether could not have
+any motive power at all, and therefore could not transmit heat from one
+body to another. Professor Tyndall[10] on this point says, referring to
+the cooling of a red-hot ball: "The atoms of the ball oscillate in a
+resisting medium, which accepts their motion and transmits it on all
+sides with inconceivable velocity." Now in the previous quotation given
+in this article from the same authority, he states that the atoms are
+immersed in the Aether. So that evidently in his opinion the Aether and
+the resisting medium are one and the same. So that our assumption of the
+gravitative property of the Aether is perfectly in accord with Professor
+Tyndall's conception of the Aether, in so far as it concerns the
+propagation of heat waves; and, as will be shown later on, heat and
+light waves are due to the same physical agent--that is, the Aether;
+therefore, wherever we get heat and light, there, according to Professor
+Tyndall's statement, we must have a resisting medium, and as Aether
+fills all space, the resisting medium must fill all space. This is
+perfectly in accord with our assumption that the Aether is gravitative
+and possesses inertia--that is, the capacity to receive and to impart
+motion, and being gravitative it possesses mass or weight, which is the
+very quality necessary for the existence of a resisting medium.
+
+[Footnote 9: _Heat, a Mode of Motion._]
+
+[Footnote 10: _Heat, a Mode of Motion._]
+
+
+ART. 63. _Heat is a Repulsive Motion._--Whatever be the particular
+character of the vibratory motion of the Aether termed heat, there is
+one fact regarding the same that is very patent and obvious to all; and
+that is, that the vibratory motion of heat is essentially a repulsive
+motion, or a motion from a centre and not one to a centre.
+
+Professor Davy points this out (Art. 60) where he says of heat, "It may
+with propriety be called a repulsive motion," while Professor Challis
+(Art. 61) states that "Each atom is the centre of vibrations propagated
+from it equally in all directions, which give rise to a repulsive action
+on the surrounding atoms. This action (he adds) is the repulsion of heat
+which keeps the individual atoms asunder."
+
+There have been many experiments undertaken which go to prove that a
+repulsive action between atoms and molecules is produced by heat. It has
+been demonstrated that certain coloured rings, known as Newton's rings,
+change their shape and position when the glasses between which they
+appear are heated, thus indicating the presence of a repulsive power due
+to the increased heat. If we consider the change of state that heat
+induces in matter, as, for example, from solid to a liquid, or liquid to
+a gaseous form, we are compelled to admit that heat possesses an
+expanding and therefore a repulsive motion. It is almost an universal
+law that heat expands and cold contracts, and the greater the heat
+absorbed, the greater the expansion. In the case of a solid being
+converted into a liquid, a much greater heat or repulsive motion is
+required to separate the particles, on account of the power of cohesion
+being greater in the solid than in the liquid. As Professor Tyndall[11]
+states when dealing with the stability of matter from the molecular
+standpoint: "Every atom is held apart from its neighbour by a force of
+repulsion. Why then do not the mutually repellent members of the group
+part company? The reason of this stability is that _two_ forces, the one
+attractive and the other repulsive, are in operation between every two
+atoms, and the position of every atom is determined by the equilibration
+of these two forces. The points at which attraction and repulsion are
+equal to each other is the atom's position of equilibrium. When the
+atoms approach too near each other, repulsion predominates and drives
+them apart; when they recede to too great a distance, attraction
+predominates and draws them together." If, therefore, there are TWO
+forces at work in the atomic world, viz. attraction and repulsion, then
+the question arises, Can that repulsive power be increased in any way,
+and if so, by what means? Such repulsive motion, as experiment and
+experience teach us, can be increased, and such increase may be derived
+from the absorption of heat which gives rise to increased atomic motion,
+and so to increased aetherial motion away from the atom, by which the
+repulsive action of one atom upon another is increased. Thus an atom's
+repulsive power may be increased by heat; the greater the heat absorbed,
+the greater the repulsive power that any atom or body exerts upon a
+neighbouring atom or body. We can therefore understand how it is, that a
+body when changed from a solid to a liquid condition occupies a larger
+space in the latter condition than in the former; or why a body when
+changed from a liquid to a gaseous condition occupies a still larger
+volume in the latter than in its previous condition. The expansion in
+both cases is essentially the result of the increased repulsive motion
+that has been imparted to its atoms or molecules by the increased heat,
+and this increased repulsive power has overcome the attractive power of
+the atoms or molecules, with the result that they have been driven
+further and further apart, until, in the gaseous state, the atoms may
+be very far apart indeed. Wherever, therefore, we have heat of any kind,
+there we have a repulsive motion, such motion being proportionate to the
+heat radiated, that is, the aetherial waves propagated by the body. If,
+therefore, in the atomic world we find a repulsive motion, which is due
+to the vibratory motions of the Aether generated by heat, the question
+now confronts us, as to whether in the solar system, and indeed all
+through the universe, there is not the same repulsive motion from a
+central body due to the wave motions of the Aether termed Heat.
+
+May we not find in the repulsive power of heat in the atomic world, an
+indication of that very power for which we are seeking in the solar
+system--that is, a Centrifugal Force or motion which is the exact
+opposite of the Centripetal Force or attractive power of Gravitation?
+For if heat be a repulsive motion at all, then to be strictly logical it
+must be equally repulsive in relation to large masses, the sun and the
+planets for example, as it is in the atomic world, otherwise we have a
+phenomenon in Nature which contradicts itself, which assumption would be
+contrary to the simplicity which is to govern our philosophy, and also
+contradictory to experience, which is the primary factor of
+philosophical reasoning. Now what are the facts with reference to the
+sun, which is the central body of our solar system, and the source of
+all light and heat in that system? We will look at this aspect of the
+question under the heading of Radiant Heat.
+
+[Footnote 11: _Heat, a Mode of Motion._]
+
+
+ART. 64. _Radiant Heat._--The source of all light and heat, not only of
+our earth, but also of all the other planets, is to be found in the sun.
+We have therefore to deal, not with an atom which is generating heat
+waves on every side, but with a globe about 860,000 miles in diameter,
+and with a circumference of over 2,700,000 miles. This huge orb consists
+of a central body, molten or partly solid, with a temperature so hot
+that it is almost impossible to conceive its intensity. The quantity of
+heat emitted by the sun has been ascertained by Sir John Herschel from
+experiments made at the Cape of Good Hope, and by M. Pouillet in Paris.
+
+Sir John Herschel found that the heating power of the sun when it was
+directly overhead was capable of melting .00754 of an inch of ice per
+minute. According to M. Pouillet the quantity was .00703 of an inch,
+which is equal to about half-an-inch per hour. From these results it has
+been calculated that if the direct heat of the sun were received upon a
+block of ice one mile square, 26,000 tons would be melted per hour by
+the heat which would be absorbed. Again, as Herschel[12] puts it:
+"Supposing a cylinder of ice, 45 miles in diameter, to be continually
+darted into the sun with the velocity of light, the heat given off
+constantly from the sun by radiation would be wholly expended in
+liquefaction on the one hand, while on the other, the actual temperature
+at the sun's surface would undergo no diminution." Sir John Herschel
+further says: "All the heat we enjoy comes from the sun. Imagine the
+heat we should have to endure if the sun were to approach us, or we the
+sun, to a point the one hundred and sixtieth part of the present
+distance. It would not be merely as if 160 suns were shining on us all
+at once, but 160 times 160 suns according to the rule of inverse
+squares--that is, 25,600. Imagine a globe emitting heat 25,600 times
+fiercer than that of an equatorial sunshine at noonday, with the sun
+vertical. In such a heat there is no solid substance we know of which
+would not run like water, boil, or be converted into smoke or vapour."
+
+Lockyer points out that the heat radiated from every square yard of the
+sun's surface is equal to the amount of heat produced by the burning of
+six tons of coal on that area in one hour. Now the surface of the sun
+may be estimated at 2,284,000,000,000 square miles, and there are
+3,097,600 square yards in each square mile; what therefore must be the
+number of tons of coal which must be burnt per hour to represent the
+amount of heat radiated from the sun into space? The approximate result
+may be calculated by multiplication, but the figures arrived at fail to
+give any adequate conception of the actual result.
+
+From these facts it may be seen that the sun has a temperature far
+exceeding any temperature that can be produced on the earth by
+artificial means. All known elements would be transformed into a
+vaporous condition if brought close to the sun's surface. It may readily
+be seen, therefore, that the sun is constantly sending forth an
+incessant flood of radiant heat in all directions, and on every side
+into space. Now if heat be motion, and be primarily due to the vibratory
+motion of Aether, what must be the volume and the intensity of the
+aetherial waves, known as heat waves, generated by the sun? When we
+remember its ponderous mass, with its volume more than 1,200,000 times
+that of our earth, its huge girth of more than 2-1/2 millions of miles,
+and this always aglow with fire the most extensive known--fires so
+intense that they cover its huge form with a quivering fringe of
+flames which leap into space a distance of 80,000 miles, or even
+100,000 miles, or over one-third of the distance of the moon from the
+earth,--remembering all these facts, what must be the volume and
+intensity of the aetherial heat waves which they generate and send upon
+their course into space on all sides! What a very storm of energy and
+power must there be in this aetherial atmosphere which exists around the
+sun's huge form, and with what volume of power must the aetherial heat
+waves speed away from so great a generating source! Some idea as to
+their velocity of motion may be gained by the fact, that these aetherial
+heat waves traverse the distance of 92,000,000 miles between the sun and
+our earth in the short space of 8-1/2 minutes. With such a velocity of
+motion as that, and with the fact before us that all motion is a source
+of energy or power, what must be the energy possessed by these heat
+waves! There must, therefore, be a power in these aetherial heat waves
+which is strictly proportionate to their intensity and flow. So that,
+whenever they come into contact with any body, as a planet, as they flow
+outwards from the sun, they must exert a power upon such a planet which
+is directed _away_ from the sun, and therefore act upon that planet by
+the energy of their motion away from the sun, the source of the
+aetherial heat waves. Therefore, not only in the atomic world is heat a
+repulsive motion, but equally in the solar world, which is but an atomic
+world on a large scale, the same principle prevails, and the effect of
+radiant heat is essentially a repulsive, that is, a centrifugal motion,
+as it is always directed from the central body, the sun.
+
+Further, it can be shown that the repulsive power of heat in the solar
+system has already received the attention of scientists, especially in
+France. This will be seen more fully when we come to deal with the
+phenomena of comets' tails. One remarkable feature about comets' tails
+is, that they are always directed away from the sun, and various
+hypotheses have been advanced to account for that fact. Among them is
+the hypothesis of M. Faye, in which he assumes that there is a repulsive
+force which has its origin in the heat of the sun. This repulsive force
+is not propagated instantaneously, but the velocity of propagation is
+the same as that of a ray of light. By means of this repulsive power due
+to the heat of the sun, M. Faye explains how it is that the tails of
+comets are always turned away from the sun. Here, then, we have an
+indication of the existence of this repulsive force of heat which we are
+considering--a repulsive power which finds its source in the aetherial
+waves, which give rise to the phenomena of Heat, and to which we must
+look for the ultimate source of that repulsive power or Centrifugal
+Force which is to form the complementary power to the attractive force
+of Gravitation.
+
+[Footnote 12: _Lectures on Scientific Subjects._]
+
+
+ART. 65. _Direction of Ray of Heat._--The question as to the path which
+a ray of heat takes may best be attacked by finding out what is the path
+which a ray of light takes in its progress through the Aether. When we
+come to deal with light, we shall find that it has been experimentally
+proved that the path of a ray of light is that of a straight line
+through space; so that if we have any body emitting light, the rays of
+light will proceed from that body in straight lines, with decreasing
+intensity, according to the law of inverse squares, the same as
+Gravitation.
+
+It can readily be shown, that wherever there is light there is heat. For
+example, the radiant heat from the sun proceeds through space along with
+the light from the sun, and when one set of waves, the light waves for
+instance, are intercepted, the heat waves are also intercepted. Or, to
+take another illustration, when the sun is eclipsed, we feel the sun's
+heat as long as any portion of the sun is visible, but as soon as the
+sun is totally eclipsed, then the light waves disappear, and with it the
+heat waves. From this we can readily see, that not only do the heat and
+light waves from the sun proceed in the same straight line, but that
+they also travel at the same rate through space, at the rate of 186,000
+miles per second. Then again the common lens, which is so familiar to
+every one, will prove the same fact by concentrating the rays of light
+to a focus, and by so doing will produce sufficient heat to burn a piece
+of paper, or even set fire to wood. If, therefore, the path of a ray of
+light be that of a straight line, proceeding from the luminous or
+lighted body, and the path of a ray of heat coincides with the path of a
+ray of light, the path of the ray of heat must also be in the direction
+of a straight line from the heated or luminous body, which, as we shall
+see in a subsequent article, also decreases in intensity according to
+the law of inverse squares the same as Gravitation Attraction.
+
+Professor Tyndall, on the direction of a ray of heat,[13] states his
+opinion on the matter as follows: "A wave of Aether starting from a
+radiant point in all directions in a uniform medium constitutes a
+spherical shell, which expands with the velocity of light or of radiant
+heat. A ray of light or a ray of heat is a line perpendicular to the
+wave, and in the case here supposed, the rays would be the radii of the
+spherical shell." From this it can be seen that a ray of light or heat
+corresponds to what is known as the radius vector of a circle (Art. 20),
+and therefore a ray of light and heat takes exactly the same path
+through space (if we consider the sun as the source of the light and
+heat) as the path of the attractive power of Gravitation. Collecting,
+therefore, our results from the preceding articles of this chapter, we
+learn that heat is due to vibrating wave motion of the Aether, and that
+that motion is a motion which is always directed from the central body
+which is the source of the heat; and further, that this motion amounts
+to a repulsive motion acting in an opposite direction to the attractive
+power of gravity or to the centripetal force of Gravitation. What is
+more remarkable still, the path of a ray of heat corresponds with, and
+takes up exactly the same direction through space, whether it be atomic
+space, solar space, or interstellar space, as the attractive force of
+Gravitation.
+
+Looking at the subject from the standpoint of the solar system, with the
+sun as the central body, we see that while we have the sun, which acts
+as the controlling centre of the particular system of planets, holding
+all the planets in their orbits by its attractive power, yet at the same
+time it is also the source of all light and heat. Now heat being due to
+the wave motion of the aetherial medium, such motion being always
+exerted from the central body, we arrive at the only legitimate
+conclusion that can be arrived at, viz. that the sun is also the source
+of a repulsive motion, which motion coincides with the path that the
+attractive power of Gravitation takes, that is, along the radius vector
+of the circle, as shown in Art. 20.
+
+
+ART. 66. _Law of Inverse Squares applied to Heat._--The law of inverse
+squares which governs not only the Law of Gravitation Attraction (Art.
+22), but also electricity and light, is equally applicable to the
+phenomena of heat, so that we say the intensity of heat varies inversely
+as the square of the distance. Thus, if we double the distance of any
+body from the source of heat, the amount of heat which such a body
+receives at the increased distance is one-quarter of the heat compared
+with its original position. If the distance were trebled, then the
+intensity of the heat would be reduced to one-ninth; while if the
+distance were four times as great, the intensity of the heat would only
+be one-sixteenth of what it would receive in its first position. This
+may be proved from experiments as given by Tyndall in his _Heat, a Mode
+of Motion_.
+
+Let us apply the law of inverse squares in relation to heat to the solar
+system, and see what the result gives. In our solar system, we have the
+sun as the central body, the source of all light and heat, with the
+eight planets, Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus,
+Neptune, describing orbits around the central body, and at the same time
+receiving from it the light and heat which the sun is ever pouring
+forth into space. The mean distance of Mercury from the sun is about
+36,000,000 miles, while that of the Earth is about 92,000,000 miles, so
+that reckoning the distance of Mercury as unity, the distance of the
+Earth is a little more than 2-1/2 times that of Mercury from the sun.
+Now the square of 2-1/2 is 25/4, and that inverted gives us 4/25, so
+that according to the law of inverse squares, the intensity of heat at
+the Earth's distance from the sun is 4/25 of what the intensity of heat
+is at the mean distance of Mercury. Again, the mean distance of Mars is
+141,000,000 miles, while the mean distance of Saturn is 884,000,000
+miles, and taking Mars' distance from the sun as unity, the distance of
+Saturn would be represented by 6-1/4. Now the square of 6-1/4 is
+(25/4)^{2} which gives 625/16 and the inverse of that is 16/625, so that
+the intensity of heat at the distance of Saturn's mean distance from the
+sun, in comparison with the intensity of heat at Mars' mean distance,
+would be about 16/625; or in other words, the heat received by Saturn
+would be only 16/625 of the intensity of heat received by the planet
+Mars. In Art. 63 we have seen that heat is a repulsive motion, being a
+wave motion of the Aether which is propagated from the heated and
+central body, which in this case is the sun. Therefore, according to the
+law of inverse squares from the standpoint of heat, we find in the solar
+system a repulsive motion, due to the wave motion of the Aether, which
+is always exerted away from the sun in the same path that the
+centripetal force takes, and which like that force diminishes in
+intensity inversely as the square of the distance. So that, wherever the
+centripetal force, or the attractive force of Gravitation, is diminished
+on account of the increased distance from the sun, the repulsive motion
+due to heat is also diminished in exactly the same proportion and along
+exactly the same path. If at any point in the solar system the
+attractive force is doubled, then according to our repulsive theory of
+heat, and the law of inverse squares, the repulsive motion is also
+doubled. If the attractive force is halved, then the repulsive motion is
+halved also, the repulsive motion being always and at all places exactly
+proportional to the increase or decrease of the attraction of
+Gravitation.
+
+[Footnote 13: _Heat, a Mode of Motion._]
+
+
+ART. 67. _First Law of Thermodynamics._--The Law of Thermodynamics is
+based on two fundamental truths which have reference to the conversion
+of Heat into Work, and Work into Heat. In Art. 54 we have already seen
+that energy in the form of heat, light, electricity and magnetism is
+capable of being converted into other forms of energy, while in Art. 59
+we have seen that Joule gave us the exact relation in foot-pounds
+between heat and work. He showed that when 1 lb. of water fell through
+772 feet its temperature was raised one degree Fahr. Thus the principle
+underlying the first law of thermodynamics states, that whenever work is
+spent in producing heat, the amount of work done is proportionate to the
+quantity of heat generated; and conversely, whenever heat is employed to
+do work, a certain amount of heat is used up, which is the equivalent of
+the work done. This principle is also in accord with the conservation of
+Energy and Motion (Arts. 52 and 57), which assert that whenever energy
+or motion disappears in one form, it is manifested in some other form.
+Thus, from the first law of thermodynamics, we learn that wherever we
+have heat we have the power to do work, and the amount of work so done
+is proportionate to the heat used up. Heat, then, has a capacity to
+perform work, and that power is known as the mechanical equivalent of
+heat. Both Mayer of Germany, and Dr. Joule of Manchester, have worked
+out this problem, and have given us the mechanical value of heat. By
+experiments Mayer found out that a quantity of heat sufficient to raise
+1 lb. of water one degree Fahr. in temperature was able to raise a
+weight 771.4 lb. one foot high. Dr. Joule of Manchester, after making a
+number of experiments which lasted over many years, came to the
+conclusion that the mechanical equivalent of a unit heat was 772
+foot-pounds, a unit of heat being the quantity of heat which would raise
+1 lb. of water one degree Fahr. So that if a 1-lb. weight fell from a
+height of 772 feet, an amount of heat is generated which would raise 1
+lb. of water one degree Fahr.; and conversely, to lift 1 lb. 772 feet
+high, one degree Fahr. of heat would be consumed.
+
+Now if this law of thermodynamics is true, it must not only be true in
+relation to terrestrial heat, or heat produced by artificial means on
+our earth, but it must equally hold good in relation to the solar
+system; and not only the solar system, but equally true throughout all
+the systems of worlds that flood the universe. So that wherever we get
+heat in the universe, in the solar system for example, there, according
+to our first law of thermodynamics, we should have the capacity to do
+work of some kind or other. That work may take either the form of
+expanding a body, as the atmosphere of a planet for example, or it may
+take a mechanical form, that is, actually moving a body by the increased
+pressure due to aetherial heat waves generated by the sun. We have
+already seen in Art. 64, on Radiant Heat, what a store of heat the sun
+has. For thousands and millions of years the sun has been pouring forth
+its heat rays into space, and yet its temperature does not seem to be
+diminished. The great Carboniferous or coal period of past geological
+times is an indication of the heat and light of the sun, which it must
+have radiated out millions of years ago; and year by year, these
+aetherial heat waves are still being poured forth by the sun on every
+side into space, so that no matter where a planet may be in its orbit,
+there it may be the recipient of these aetherial heat waves which break
+upon its surface. Now if there be this quantity of heat existing in the
+sun, and heat according to the first law of thermodynamics has a
+mechanical value, which is that it can push or lift a body through
+space, the question arises, as to what is the mechanical value of this
+heat of the sun? Are we to suppose that if one unit of heat can lift 1
+lb. 772 feet, the millions and millions of units of heat which are
+constantly being poured out of the sun into space are doing no work at
+all? Such an assumption is not only contrary to that simplicity which
+governs our Philosophy, but is entirely opposed to experience, which is
+the very foundation of all philosophical reasoning. If, therefore,
+experience is to be any guide at all, we are compelled to come to the
+conclusion that the heat poured forth into space does do work on the
+bodies, as comets, meteors, planets, upon which the aetherial heat waves
+fall. The problem is, what is the character of the work done? I have
+already indicated part of the work, viz. in the expansion of the
+atmosphere of the planets. Then there is also the reception of the heat
+by the animal and vegetable life of the planet, but these do not account
+for all the motive power of the aetherial waves, which break upon the
+planet or its atmospheres.
+
+The true solution of the first law of thermodynamics, in its relation to
+the solar system, seems to me to be found in the fact already stated in
+Art. 63, viz. that heat is a repulsive motion, and the law of
+thermodynamics confirms that statement, and shows that the work done on
+a planet by the aetherial heat waves is that of pushing it, or urging it
+by their very energy and motion away from their controlling centre, the
+sun. This would practically amount to a repulsive force which had its
+home in the sun, and this conception would bring our Philosophy into
+harmony with our experience, which teaches us that wherever there is
+heat there is the capacity of doing work, the amount of work being
+proportionate to the heat generated and consumed.
+
+
+ART. 68. _Second Law of Thermodynamics._--This law was enunciated by
+Sadi Carnot in 1824, when he wrote an essay on the Motive Power of Heat.
+Previous to the time of Carnot no definite relation seems to have been
+suggested between work and heat; Carnot, however, discovered what were
+those general laws which govern the relation between heat and work. In
+arriving at his conclusion, he based his results on the truth of the
+principle of the conservation of energy already referred to (Art. 52).
+
+Carnot started his reasoning on the assumption that heat was matter, and
+therefore indestructible. The two great truths in relation to heat and
+work, enunciated by Carnot, are known as, first, a Cycle of operations;
+and, secondly, what he termed a Reversible Cycle. In order to be able to
+reason upon the work done by a heat-engine, say a steam-engine for
+example, Carnot stated we must imagine a cycle of operations, by which,
+at the end of such operations, the steam or water is brought back to
+exactly the same state in which it was at its start. He calls this a
+cycle of operations, and of it he says, that only at the conclusion of
+the cycle are we entitled to reason upon the relation between the work
+done and the heat spent in doing it. His other idea of the reversible
+cycle implies that an engine is reversible when, instead of using heat
+and getting work from it, the engine may be driven through the cycle of
+operations the reverse way, that is, by taking in work, it can pump back
+heat to the boiler again. Carnot showed that if you can obtain such a
+reversible engine, it is a perfect engine. All perfect engines, that is
+all reversible engines, will do exactly the same amount of work with the
+same amount of heat, the amount of work being strictly proportionate to
+the amount of heat consumed. I need hardly point out that the reversible
+engine, or the perfect engine of Carnot, is only the ideal one, as there
+is no engine in which all the heat is converted into work, as a great
+deal of the heat is radiated away and not converted into work at all.
+Again, working from the standpoint that heat is matter, Carnot reasoned
+that in the heat-engine the work is performed, not by the actual
+consumption of heat, but by its transportation from a hot body to a cold
+one. Thus, by the fall of heat from a higher to a lower temperature,
+work could be done in the same way that work could be done by allowing
+water to fall from a higher to a lower level. The quantity of water
+which reaches the lower level is exactly the same as that which leaves
+the higher level, as none of the water is destroyed in the fall. He
+argued, therefore, that the work produced by a heat-engine was produced
+in a similar manner, the quantity of heat which reaches the condenser
+being supposed to be equal to that which left the source. Thus the work
+was done by the heat flowing from a hot body to a cold one, and, in
+doing this work, it lost its momentum like falling water, and was
+brought to rest. One of the most important points noted by Carnot is
+the necessity that, in all engines which derive work from heat, there
+must be two bodies at different temperatures, that is, a source and a
+condenser, which correspond to a hot and cold body, so that there may be
+the passage of heat from the hot to the cold body. In order to get work
+out of heat it is absolutely necessary to have a hotter and a colder
+body. From this reasoning we learn, therefore, that work is obtained
+from heat by using up the heat of the hotter body, part of which is
+converted into actual work, while part is absorbed by the colder body.
+So that wherever we have two bodies at different temperatures, according
+to the second law of thermodynamics, there we have the power of doing
+work by the transmission of heat, from the body of higher to the one of
+lower temperature.
+
+That Carnot ultimately came to believe in the dynamical theory of heat,
+is proved by the following passage taken from his notes on the Motive
+Power of Heat: "It would be ridiculous to suppose that it is an emission
+of matter, while the light which accompanies it could only be a
+movement. Could a motion produce matter? No! undoubtedly, it can only
+produce a motion. Heat is then the result of motion. It is plain then
+that it could be produced by the consumption of motive power, and that
+it could produce this power. Heat is then simply motive power, or rather
+motion which has changed its form. It is a movement among the particles
+of bodies. Wherever there is a destruction of motive power, there is at
+the same time production of heat in quantity exactly proportional to the
+quantity of motive power destroyed. Reciprocally, whenever there is
+destruction of heat there is production of motive power."
+
+Let us apply this principle to the solar system, and endeavour to find
+out whether in that system we have, in relation to the heat thereof,
+either a cycle of operations or a reversible cycle. We have again to
+consider the sun as the source of all light and heat in the solar
+system, radiating forth on every side, year by year, the countless units
+of heat which go to form the continuance of all planetary life and
+existence. One of the problems that has confronted scientific men for
+many years is this, Where does the sun get its supply of heat from? When
+we remember the incessant loss of heat which the sun suffers through its
+radiation of heat into space, we are compelled to ask, How is that
+supply maintained, and how has it been kept up through the countless
+ages of the past? Several suggestions have been made, and several
+theories advanced to account for the fact. Mayer, of Germany, suggested
+that the heat is partly maintained by the falling into the sun of
+meteors, which, like comets, pursue a path through the heavens, and are
+subject to the attractive influence of the sun. In the combustion of
+these meteorites, or meteors, he contended there were the means by which
+the light and heat of the sun might be maintained. Whatever theory,
+however, may be suggested as to the maintenance and the source of the
+continuity of the sun's heat, I do not think it has been suggested by
+any scientist that the heat emitted and radiated by the sun is ever
+returned in any way back to the sun from infinite space, whether by
+reflection or by any other method. So far as I can learn, there are no
+facts in connection with the solar system which would lead us to make
+that assumption. On the contrary, experience and experiment teach us
+that radiation implies loss of heat, and that the body, which so
+radiates, ultimately becomes cold, unless its internal heat is kept up
+by some means or other. So that the terms introduced by Carnot in the
+second law of thermodynamics, viz. that of a Cycle of Operations and of
+a Reversible Cycle, do not apply to the solar system, and the solar
+system, viewed from the standpoint of a machine, with the sun as the
+source of the heat, does not represent a perfect engine, that is, all
+the heat is not used up in doing work, some of it being radiated out
+into space. Wherever, however, the heat, that is the aetherial heat
+waves generated by the sun, comes into contact with a planet, as
+Mercury, Venus, or Jupiter, then, in accordance with Carnot's reasoning,
+work is done. Carnot points out that, in order for work to be done, we
+must have a source and a condenser, that is, two bodies at different
+temperatures, a hot body and a cold one. Now these conditions of work
+are satisfactorily fulfilled in the solar system, and as a result work
+is performed. We have the sun with its huge fires, and its intensity of
+heat, representing the source or the hot body, while every planet and
+every meteor and comet, that come under its influence, represent the
+cold body, and between the two work is always going on. That work is
+represented by the repulsive power of heat, which I have already
+indicated, so that, viewed from Carnot's standpoint with relation to the
+motive power of heat, we find that there are in the solar system those
+conditions which govern work, and by which, from a mechanical
+standpoint, work is performed; further, that work takes the form of a
+repulsive power on every planet or other body upon which the aetherial
+heat waves fall. Therefore, from the second law of thermodynamics we
+have another proof of this repulsive power of heat already indicated and
+referred to in Art. 63.
+
+
+ART. 69. _Identity of Heat and Light._--We have seen from the preceding
+articles of this chapter, that heat is due to a periodic wave motion of
+the Aether, and in the succeeding chapter we shall also see that light
+is due to some kind of periodic wave motion in the Aether. So that not
+only heat, but light also, it would appear, is due to certain periodic
+wave motions that are set up in the Aether by the vibrations of hot or
+luminous bodies. The question therefore arises, how many wave motions
+are there in the Aether? Are there different wave motions which in one
+case produce light, and in the other case produce heat, or are light and
+heat both produced by the same set of aetherial waves? The identity of
+light waves with heat waves is manifested by the fact that wherever we
+get light we get heat, as can be proved in many ways. One of the
+simplest proofs is found in the common lens or burning-glass, by which
+the light waves are brought to a focus, and as a result, heat is
+manifested. Although there is this close identity between light and heat
+waves, yet there must be some distinction between the heat and light
+waves, because while light waves affect the eye, heat waves do not.
+There is actually a difference between the two kinds of waves, and that
+difference is one of period or length. It must not, however, be thought
+that there are really two classes or sets of waves in the Aether, one of
+which could be called light waves, and the other heat waves, but rather
+the same wave may be manifested in two different forms because of its
+different wave lengths. In one case the waves may affect the eye, and we
+have the sensation of sight, but in the other case they affect the body,
+and we experience the sensation of warmth. An analogy from the waves of
+sound may make these facts much clearer. We know that sound travels
+about 1100 feet per second. If, therefore, we have a bell which vibrates
+about 1100 times per second, we should have a wave one foot long. If it
+vibrated 100 times per second the waves would be 11 feet long, while if
+it vibrated only 11 times per second, the waves would be 100 feet long.
+Now the impression made upon the ear depends upon the number of
+vibrations the bell makes per second, and from the rate of vibration we
+get the idea of pitch. If the vibrations are very rapid, then we get a
+note of high pitch, and if the vibrations are slow, then we get a note
+of low pitch. A note of high pitch, therefore, will correspond to waves
+of short length, while a low note will correspond to waves of a greater
+length; so that the greater the rapidity with which a sounding bell
+vibrates, the shorter will be the length of the sound waves which it
+generates, and _vice versâ_. The range of the ear however for sound
+waves is limited, so that if the vibrations be too rapid or too slow,
+the ear may not be able to respond to the vibrations, and so no distinct
+impression of the sound will be conveyed to the brain. It need hardly be
+pointed out, that both the very short and long waves are of exactly the
+same character as those of a medium length, which the ear can detect,
+the only difference being one of rapidity. We do not therefore suggest
+that in the case of sound, where the vibrations lie outside the compass
+of the ear, those which lie outside are not sound waves, or that they
+are different from those which lie within the compass of the ear, and
+which the ear can detect. Whether the sound waves are long or short,
+whether they can be detected by the ear or not, we still say that all
+are sound waves, and that all are due to the vibrations of the sounding
+body, which vibrations are transmitted through the air, in waves, that
+fall upon the tympanum or drum of the ear, and set that vibrating, which
+vibrations are transmitted to the auditory nerve and so give rise to the
+sensation of hearing. In a similar manner, every atom and every particle
+of matter, every planet, every sun and star, is constantly in a state of
+vibration, sending off aetherial waves on every side. Nothing in Nature
+is absolutely cold, nothing is absolutely still. Therefore all matter,
+whether in the atomic form, or in the planetary or solar world, is
+constantly generating aetherial waves, which travel from their source or
+origin with the velocity of light. If these aetherial waves so generated
+fall within certain limits, then they affect the eye, and we get the
+sensation of sight. To do this they must vibrate 5000 billion times per
+second, and if they fail to do this, they fail to give rise to the
+sensation of sight. If the aetherial waves fall below this limit, then
+they affect the body, and give rise to the sensation of heat. For it
+must be remembered, that as the ear has a certain compass for sound
+waves, which may vary in different individuals, so the eye has also a
+certain compass for aetherial waves, with the result that some waves may
+be too slow or too rapid to affect the eye, and consequently fail to
+give rise to the sensation of sight. When that is so, the sensation of
+warmth helps us to detect these longer waves, so that the longer waves
+would warm us and make their presence felt in that manner. We shall see
+in the next chapter that there are both shorter and longer waves, which
+may be detected in other ways. From these facts it can be readily seen,
+that we have a common origin for both light and heat, and that they are
+both due to periodic waves in the Aether, and therefore all the laws
+that govern heat should also govern the phenomena of light. Further, if
+heat possesses a dynamical value, and if there be such a truth as the
+motive power of heat, then there ought equally to be a motive power of
+light; and further, if heat possesses a repulsive motion, then because
+of the identity of light and heat, light should equally possess this
+repulsive power, because it is due to similar periodic wave motions in
+the Aether. With regard to the same laws governing both light and heat,
+we shall see that this fact also holds good. We have already seen (Art.
+66) that the intensity of heat is inversely as the square of the
+distance, and we shall also see in the succeeding chapter that the same
+law holds good in relation to light. We have seen (Art. 65) that the
+path of a ray of heat is that of a straight line; we shall see in the
+succeeding chapter that the path of a ray of light is that of a straight
+line also.
+
+Indeed, there is no law applicable to heat which is not applicable to
+light. The law of reflection and refraction of heat equally holds good
+in relation to light; and further, Professor Forbes has shown that heat
+can be polarized in a similar manner to the polarization of light. This
+last fact is considered the most conclusive argument as to the identity
+of light and heat, and proves that the only difference between the two
+is simply the difference corresponding to the difference between a high
+note and a low note in sound. That being so, I hope to be able to show
+that as heat possesses a dynamical value, so light equally possesses a
+dynamical value, and that as heat is a repulsive motion, then light must
+equally possess a similar repulsive motion, that motion always being
+directed from the central body, being caused by the same agency, viz.
+the waves of the Aether, the common source of both light and heat. I
+purpose to address myself to this subject in the following chapter,
+which I have termed Light, a Mode of Motion.
+
+
+
+
+                              CHAPTER VII
+
+                        LIGHT, A MODE OF MOTION
+
+
+ART. 70. _Light, a Mode of Motion._--No subject has in the past received
+greater attention from philosophers and scientists than that involved in
+the question as to "What is Light?" Indeed, it may truthfully be said,
+that even to-day its exact character is not positively known. That it is
+due like heat to some periodic wave motion in the Aether is known, but
+the exact character of that wave motion has yet to be determined. As in
+the case of heat, so in the case of light, there have been two theories
+which have contended with each other for supremacy in endeavouring to
+answer the question as to "What is Light?" Those two theories are known
+as the Emission or Corpuscular Theory, and the Undulatory or Wave
+Theory. The corpuscular theory was introduced and developed by Newton in
+his work on _Optics_, which ranks second only to the _Principia_ as a
+work revealing masterly research and scientific genius. Newton supposed
+that a luminous or lighted body actually emitted minute particles, which
+were shot out from the body with the velocity of light, that is, at the
+rate of 186,000 miles per second. These minute particles he termed
+corpuscles. In the work just referred to regarding this matter, he asks
+the question, "Are not rays of light very small bodies emitted from
+shining substances?" These small particles or corpuscles were supposed
+by him to actually strike the retina of the eye, and so produce the
+sensation of Sight, in the same way that odorous particles entering the
+nostril, come into contact with the olfactory nerves and produce the
+sensation of Smell. In order, however, to account for certain phenomena
+of light, he was compelled to postulate an aetherial medium to fill all
+space, in which his luminous corpuscles travelled, and which would
+excite waves in that medium. In his eighteenth query on this point he
+asks: "Is not the heat of a warm room conveyed through the vacuum by the
+vibration of a much subtler medium than air, and is not this medium the
+same with that medium by which light is reflected or refracted, and by
+whose vibrations light communicates Heat to bodies, and is put into fits
+of easy reflection and easy transmission?" The corpuscular theory,
+however, received its death-blow when, in competition with the wave
+theory of light, as developed by Young, it was found that the latter
+theory satisfactorily accounted for certain phenomena as the refraction
+of light, which the corpuscular theory did not adequately account for.
+Even while Newton was developing his theory, Huyghens, a contemporary of
+Newton, was developing another theory which is now known as the
+undulatory or wave theory. Huyghens drew his conclusions from the
+analogy of sound. He knew that sounds were propagated by waves through
+the air, and from the region of the known, endeavoured to carry the
+principle into the region of the unknown, a strictly philosophical
+method, and one in accordance with the second Rule of Philosophy. He
+supposed that light, therefore, like sound, might be due to wave motion,
+but if it were wave motion, there must have been a medium to propagate
+the waves. In order to account for this wave motion, he supposed all
+space to be filled with a luminiferous Aether, which would be to his
+light waves what air is to sound waves. In this conception he was
+supported by Euler the mathematician, and in 1690 he was able to give a
+satisfactory explanation of the reflection and refraction of light, on
+the hypothesis that light was due to wave motion in the Aether. It was
+not, however, till the advent of Thomas Young, that the undulatory or
+wave theory reached its perfection, and finally overthrew its competitor
+the corpuscular theory. Young made himself thoroughly acquainted with
+wave motion of all kinds, and applied his knowledge and experience to
+the phenomena of light, and from the analogies so obtained, he gradually
+built up the undulatory theory, and gave to it a foundation from which
+it has not yet been moved. Young made use of the same aetherial medium
+in order to propagate the wave motion of light in the same way that
+Huyghens did. From that conception, the Aether has been gradually
+perfected, until we have the conception which has been presented to the
+reader in Chapter IV., in which I have endeavoured to show that this
+aetherial medium is matter, but infinitely more rarefied and infinitely
+more elastic, but notwithstanding its extreme rarefaction and
+elasticity, it possesses inertia, because it is gravitative. It is this
+Aether, then, that is concerned in the propagation of light, and is the
+universal medium which is to light what air is to sound. Young,
+therefore, having applied himself to the wave motion of sound, from such
+researches was able to explain the physical cause of colour, and that
+phenomenon termed interference.
+
+We will therefore look at wave motion, in order to understand the wave
+theory of light.
+
+Now in all wave motion, whether it be water waves or sound waves, that
+which is propagated or conveyed from place to place is energy, or
+motion. If a stone is thrown into water, a series of concentric circles
+of waves are generated, which spread out with increasing size, but
+decreasing power or motion, regularly on all sides. The water, however,
+does not move away from the generating source. There is a motion of the
+water, but it is simply a wave motion, so that the propagation of a wave
+is the propagation of motion, rather than the transference of the actual
+water which constitutes the wave. In the case of sound waves, we have
+again an illustration of the same principle. For example, suppose we
+strike a bell, and so set the particles of that bell in a state of
+vibration. These vibrations give the air in contact with the bell a
+forward movement, and then, owing to the elasticity and inertia of the
+air, a backward movement is set up, with the result that a series of
+waves are set in motion from the bell on every side, which gradually
+diminish in intensity the farther they recede from the generating body.
+According to the wave theory, therefore, we have to picture all heated
+and luminous bodies in a state of vibration, and the atoms of such
+luminous bodies imparting the vibrations to the atoms of the Aether, in
+the same way that the atoms of a bell impart their vibrations to the
+atoms of the air in contact with it. These vibrations are then
+propagated through the Aether in waves, which, entering the eye, impinge
+or strike upon the retina at the back of the eye, and being transmitted
+to the brain give rise to the sensation of sight. It must not be
+forgotten that the waves of Aether, as pointed out in Art. 64 in
+relation to heat, really form spherical shells which radiate out in all
+directions from the central body which gives rise to them. Thus it can
+be seen, that all points in the spherical wave which are at equal
+distances from the vibratory or luminous body, must possess the same
+intensity, and possess equal lighting powers. Light, therefore, like
+heat, is due to a periodic wave motion set up in the Aether by the
+vibrating atomic motion of heated or luminous bodies. It must be also
+noticed, that if we could see the air through which the sound waves are
+passing, we should see that each atom or particle of the atmosphere was
+vibrating to and fro in the direction of propagation. If, however, we
+could see an atom of Aether in vibration, accepting the principle that
+Aether is atomic, we should see that each aetherial atom is not
+vibrating in the direction of propagation, but across the line in which
+the wave is travelling. Thus the vibration of the air is said to be
+longitudinal, but the vibrations of the Aether are transversal. An
+illustration of the transverse motion of a light wave may be obtained by
+taking a rope and imparting to it a series of undulations by shaking it
+up and down, when it will be observed that the wave motion of the rope
+is transverse to the straight line in which it is propagated. The
+physical explanation of the transverse vibration of light will be dealt
+with in a subsequent article.
+
+Now the question suggests itself to our mind, as to what effect the
+atomicity of the Aether has upon the undulatory theory of light. Does it
+establish it upon a firmer basis, or does it in any way destroy its
+truth as a theory? I venture to think that the atomicity of the Aether
+in no sense destroys any part of the undulatory theory of light, but
+rather tends to confirm and establish it upon a logical and
+philosophical basis.
+
+For instance, as has been pointed out in Art. 47, in order for the
+undulatory theory to have any existence at all, it is essential that the
+Aether should possess the property of elasticity. But how the Aether
+possessed the property of elasticity while at the same time it was
+frictionless, and therefore possessed no mass, has been a problem that
+has taxed the ingenuity and resources of scientists for a century past,
+and up to the present is a problem which still remains unsolved. Now,
+however, with our atomic Aether, it is just as easy to conceive Aether
+transmitting a wave as it is for air to transmit sound waves, or water
+to transmit water waves.
+
+Tyndall, in his _Lectures on Light_, seems to have appreciated the
+difficulty, and to avoid confusion, again and again refers to a
+_particle_ of Aether. While Huyghens himself in speculating upon the
+elasticity of the Aether in his _Traité de la Lumière_, 1678, makes a
+suggestion as to its origin, which practically amounts to the fact that
+the aetherial atom which gives rise to this elasticity is the core or
+centre of a vortex ring. Thus it can be seen that the elasticity of the
+Aether, so essential to the undulatory theory, is a problem that cannot
+be solved apart from recognizing the hypothesis of an atomic Aether.
+
+Then, again, in the undulatory theory of light, the density of the
+Aether around molecules of bodies has to be taken into consideration to
+account for such phenomena as the refraction and reflection of light,
+but, as we have seen in Art. 46, such a property as density is
+inconceivable in connection with a medium which is neither atomic and
+possesses no mass. On the assumption, however, of an atomic and
+gravitative Aether, the difficulty is at once solved, and the density of
+the Aether, and different degrees of density are at once placed upon a
+logical and philosophical basis. So that in relation to the elasticity
+and density of the Aether upon which the transmission and reflection of
+wave motion depend, an atomic and gravitative Aether establishes and
+confirms the undulatory theory.
+
+There is also another aspect of the subject that is worthy of notice. I
+refer to the effect of an atomic and gravitative Aether upon Newton's
+corpuscular theory of light. Newton's corpuscular theory failed in not
+being able to account for the relative velocity of light in rare and
+denser media, and if by an atomic Aether in conjunction with the
+undulatory theory, the phenomenon can be accounted for, as I believe it
+can, then our aetherial vortex atoms are analogous to Newton's
+corpuscles. This distinction will, however, have to be made, viz. that
+Newton supposed his luminous corpuscles to be emitted by the luminous
+body, whereas in the conception of our aetherial atoms, we conceive them
+to be stationary relatively in space, and only subject to those
+vibrations and oscillations that give rise to the aetherial waves
+recognized in the undulatory theory.
+
+It would indeed be a consummation to be desired, if, by an atomic
+Aether, it can be proved that Newton's Corpuscular Theory was made to
+harmonize with the Undulatory Theory, and that it can be I am profoundly
+convinced. Professor Preston is also of this view, for in his _Theory of
+Light_, writing on this subject, he says, page 19: "In conclusion, we
+may state that we believe an ingenious exponent of the emission theory,
+by suitably framing his fundamental postulates, might fairly meet all
+the objections that have been raised against it."
+
+We will now apply the hypothesis of an atomic and gravitating Aether to
+Huyghens' principle of wave propagation, and see if this atomicity in
+any way destroys that principle, or whether it simplifies and confirms
+it.
+
+Let us briefly review our conception of the Aether before making the
+application. In the first place, because Aether is gravitative, we
+learned from Art. 45 that it surrounds all bodies in the universe, from
+the smallest atom to the largest sun or star in the firmament of heaven.
+Our sun, then, which is to our system the source of all its light, will
+be surrounded by what are practically spherical aetherial envelopes or
+shells which decrease in density as they recede from the sun (Art. 46).
+These aetherial shells are, according to our conception, made up of
+minute aetherial spherical vortex atoms possessing polarity and rotation
+(Art. 43), and these atoms will be closer together the nearer they are
+to the central body, because of the increased density of the Aether due
+to the attractive influence of the sun. Thus, when a wave motion is set
+up in the Aether around the sun by the intense atomic activity of that
+incandescent body, each atom of that aetherial spherical shell or
+envelope participates in the motion or impulse received, at one and the
+same time, so that the wave is transmitted from envelope to envelope, by
+the elasticity of the aetherial atoms which compose the envelope or
+shell. Thus the light wave is always spherical in form, or nearly so, as
+the rotational and orbital motion of the sun affect the exact shape of
+the aetherial envelope as we shall learn more fully later on.
+
+Further, the wave front always takes the form of a sphere, as the waves
+are radiated out from the luminous body in all directions, and we shall
+learn, in the next article, that the vibrations are always in the wave
+front, that is, take place on the surface of each of these envelopes,
+and these vibrations are also transverse to the propagation of the wave.
+As these aetherial envelopes extend right into space, the wave is
+transmitted from envelope to envelope by means of the aetherial atoms
+with the velocity of 186,000 miles per second, but as each succeeding
+envelope possesses a larger surface than the preceding one, the
+intensity of the light is proportionally decreased. The surface of such
+envelope is always proportionate to the square of the radius, the other
+quantities remaining equal. So that the intensity of the light waves,
+which are coincident with the surface of each spherical envelope, will
+always vary inversely as the square of the distance from the luminous
+body, which agrees with the law of inverse squares that governs light
+and heat.
+
+[Illustration: Fig: 4.]
+
+We have considered the wave motion as a whole, that is, we have viewed
+it from the standpoint of the whole of the aetherial elastic envelope.
+Now we will look at the subject from the atomic standpoint, and see if
+it is in accordance with Huyghens' principle of wave propagation.
+
+We will suppose that an undulatory movement is started by a luminous
+body at point _A_ situated in the Aether, and surrounded by that medium.
+_A_ may represent a part of any luminous body, as the sun or star, while
+_B_ _C_ and _B'_ _C'_ represent a segment of the aetherial envelopes
+already referred to, which exist around the sun. We will further suppose
+that the small dots surrounding the luminous body represent the
+aetherial atoms forming the envelope, which transmit the impulse or
+energy received from the atomic vibrations of the luminous body. As each
+aetherial atom is moved or pushed forwards, each atom directly in
+contact with it accepts and transmits the impulse. But each of these
+atoms stands in relation to those in front of them, as they did in
+relation to the first row of atoms, so to speak, and therefore exert a
+corresponding impulse on the front row.
+
+But the third row stands in relation to the fourth row as the second row
+did to the third, and so on to infinity. Thus each atom being surrounded
+by other atoms may be looked on as the centre of a new wave system, so
+that every particle of the wave system is itself a centre of a new wave
+system which is transmitted in all directions. As these innumerable and
+minute wave systems co-operate with one another, they form a principal
+wave system which is coincident with the surface of the spherical
+envelope, part of which is represented by _B_ _C_. Then if we conceive of
+all the aetherial atoms in part of the principal wave system _B_ _C_, as
+themselves becoming the centre of wave propagation, by their wave
+systems the principal wave will be transmitted further on into space to
+another aetherial envelope _B'_ _C'_, which represents part of another
+principal wave, which again is coincident with the surface of one of the
+spherical aetherial envelopes. So that by the action of the aetherial
+atoms which exist on all sides of the luminous body, the aetherial wave
+can be transmitted from atom to atom in more or less spherical form.
+
+Now let us compare this explanation of the transmission of light by an
+atomic Aether with the celebrated Huyghens' principle which is thus
+enunciated. "When an undulatory movement propagates itself through an
+elastic medium, every _particle_ imitates the movement of the particle
+first excited. But every particle stands in relation to the adjoining
+ones in exactly the same relation that the first particle did to its
+neighbours, and consequently must exert upon those surrounding it,
+exactly the same influence as the first did. Every vibratory particle is
+therefore to be regarded as if it were the originally excited particle
+of the wave system; and as the innumerable and simultaneous elementary
+wave systems co-operate with one another at each instant, we obtain
+exactly that principal wave system by which the elastic medium appears
+at any moment to be moved." Now here, in this statement, we have the
+definite term _particles_ used several times by Huyghens. But in the
+generally accepted theory of the Aether, such a term is unknown and
+unrecognized, with the obvious result that the definite and simple
+statement of Huyghens loses all its simplicity and meaning. Replace,
+however, the non-atomic Aether as at present recognized, by an atomic
+and gravitating Aether, and then Huyghens' exposition or principle
+stands out in all its simplicity and clearness, and finds in an atomic
+Aether its literal fulfilment and complete verification.
+
+In conclusion on this point, viz. that light is a mode of aetherial
+motion, let us endeavour to form a mental picture of our atomic and
+aetherial world. We have to remember that every particle and atom of
+matter in existence are ever vibrating, and by their vibrations are ever
+creating and generating Aether waves in the aetherial medium. These
+waves, begetting others, the process is continued until they are either
+intercepted and brought to rest by other matter, or else speed away
+until they reach the boundary of space.
+
+Now it is scarcely necessary for me to say, that if one atom can create
+and generate these Aether waves, a thousand atoms can create them in
+greater abundance still, and millions of atoms in even still greater
+abundance, and so on in proportion to the quantity or bulk of the matter
+vibrating. Further, as it is with quantity, so will it be with
+intensity, or activity of vibration. The more intensely an atom
+vibrates, the more intense would be the movement of the generated Aether
+waves, and the intensity would be in exact proportion to the intensity
+of the motion of the atoms vibrating. In regard to the power of atomic
+motions or vibrations, those are the greatest and most intense in energy
+or motion, which are produced by combustion or burning. The chemical
+activity by which the burning is brought about arouses and excites the
+atoms of matter subject thereto, into an intensity of motion, thousands,
+it may be millions of times greater than can be produced by any other
+known means. Therefore it can be readily seen, that the Aether waves
+generated by this means will be greater and more abundant, both in their
+volume and intensity, than the Aether waves produced merely by a cold
+body. For example, take a candle at night-time when the light has
+disappeared; look at it and feel it. Though its atoms are all in motion,
+generating Aether waves which are impressed with its own particular form
+and colour, yet it can scarcely be seen even at a short distance; but
+light it, and what a change takes place! We can both see it, and are
+enabled by its light to see other things also. By the power of
+combustion, its atoms have been excited into greater energy or motion,
+generating and speeding Aether waves on every side, and these Aether
+waves being reflected and re-reflected by the atoms of the air, and the
+walls of the house, give light to all that are in the house. I must now
+ask the reader to refer to Art. 64 on Radiant Heat, in order that we may
+recall facts regarding the heat of the sun. Remembering the intensity
+of the heat of the sun as calculated by Herschel and others, and
+remembering that the sun is 1,200,000 times larger in volume than our
+earth, the question naturally suggests itself to our mind, what must be
+the volume and intensity of the light waves as they flow from the sun
+into space? What a storm of fury and of motion must there be within the
+aetherial atmosphere around the sun, and with what volume and power must
+these light waves speed away from so mighty a source! Some idea may be
+gained from the fact that they speed away to the distant Neptune, a
+distance of nearly three thousand millions of miles, and impart to that
+planet the energy of light and heat which to the planet forms the
+physical source of all its life and activities. Thus from the sun, the
+centre of the solar system, there are ever being poured forth into space
+these aetherial light waves. The solar fires are ever glowing, and their
+flames ever burning, robing the solar disc with its quivering fringe, or
+madly leaping on every side to a distance of one hundred thousand miles,
+and by their madness lashing the aetherial atmosphere into fury,
+creating aetherial waves, myriads upon myriads, and sending them with
+lightning speed across the intervening space. As swift-footed messengers
+they come, the bearers of life and beauty to distant planets. They come
+to this our island home in space, these aetherial light waves, like rich
+argosies freighted with the treasures of light, of life, of beauty, and
+of glory, and the transmission of this life and beauty is effected by
+the incessant wave motion generated in the Aether by the central body of
+our solar system, the sun. Let us therefore endeavour to form a mental
+picture of this aetherial wave motion with its transverse vibrations.
+
+
+ART. 71. _Transverse Vibration of Light._--In the previous article we
+saw that the vibration of light was transverse to the line of
+propagation. If we could see the particles of air which are vibrating
+when sound waves are produced, we should find that each particle or atom
+is vibrating backwards and forwards in the direction of propagation.
+
+In the case of an aetherial atom, however, which, according to our own
+theory, participates in the vibration, we have to try to conceive of
+each atom as vibrating across the line of propagation. So that if _A_
+_B_ represents a ray of light proceeding from a luminous body, as the
+sun (Fig. 5), then the vibration must be across the line, as up and down
+and across that line as shown in the figure, each phase of the vibration
+being at right angles to the line of propagation--that is, to _A_ _B_.
+How can we form a physical conception of this phenomenon? There must be
+some physical explanation to it, for if it be an effect there must be a
+cause for its existence and production. Up to the present, however, no
+physical explanation has been forthcoming, so that for over 200 years a
+frictionless medium has failed to account for, or to explain, the
+transverse vibration of light as suggested by Fresnel.
+
+If, therefore, by the hypothesis of an atomic and gravitative Aether, we
+succeed in accomplishing a result that a frictionless Aether has failed
+to accomplish, then the explanation will be a most important factor in
+proving the atomicity and consequent gravitative property of the Aether.
+
+Let us therefore revert to our hypothesis of the Aether as given in Art.
+45. From that we learn, because Aether is atomic, it is also
+gravitative, and therefore forms around every atom and molecule, every
+satellite, planet, sun and star, an aetherial atmosphere--such aetherial
+atmosphere being doubtless proportionate to the mass of the atom or
+molecule or planet as the case may be, in accordance with the Law of
+Gravitation. We shall consider this view of the subject later on.
+
+[Illustration: Fig: 5.]
+
+Thus we learn that every particle of matter, and every body in the
+universe has its aetherial atmosphere so to speak, to which it is held
+bound by the universal Law of Gravitation. In the case of a satellite
+or planet or sun or star, that atmosphere will be more or less spherical
+in shape, decreasing in density as it recedes from the attracting body.
+As we saw in the previous chapter, Tyndall stated that the waves of
+light really formed spherical shells which surrounded the luminous body.
+In the conception of an atomic and gravitating Aether we can form a
+physical conception of these aetherial shells, which can be pictured as
+elastic envelopes, or rather series of envelopes surrounding each
+particle of matter, and also surrounding each satellite, planet, sun,
+and star; each envelope getting gradually less and less dense as the
+distance from the central body is increased.
+
+Now we learn from experiments that the vibration is always in the wave
+front, but the wave front is coincident with the surface of each
+aetherial spherical shell, therefore the vibration must be in, and
+coincide with, the surfaces of the spherical shells that are formed
+around every body in the universe.
+
+We are now, however, dealing specially with one body which is the source
+of light, viz. the sun, and have therefore to picture the sun as being
+surrounded by these aetherial elastic envelopes, which gradually get
+less and less dense as they recede from it. What, therefore, will be the
+effect of the heat of that body as it is poured forth into space? We
+have already learned (Art. 63) of the untold quantity of heat that is
+continually being poured forth into space from the sun with its diameter
+of 856,000 miles, and its circumference of over 2-1/2 million miles.
+What intense activity it must generate in the Aether near its surface!
+and what must be the direct effect of that heat upon the aetherial
+elastic envelopes or shells which surround it?
+
+Perhaps the answer can be best illustrated by a simple experiment. Let
+us take an ordinary toy balloon, with its elastic envelope, and fill it
+moderately full with air, and observe what the effect on it is when we
+put it near the fire. Gradually, as heat is imparted to the air in the
+balloon, the air which is also elastic expands, with the result that the
+envelope of the balloon is extended, and its size enlarged. Now withdraw
+it from the fire and note what happens.
+
+As the air inside gets cold again, the elastic envelope of the balloon
+gradually shrinks, until it has been reduced to its former size. What
+has been taking place during this experiment with regard to the elastic
+envelope and the atoms thereof? May we not say that there has been a
+vibration or oscillation, among the particles which go to make up the
+elastic envelope, that forms the surface of the balloon? Certainly there
+has been some form of motion, and that motion took first the form of an
+expansion, and then contraction of the individual particles; and we have
+only to conceive of this process being repeated quickly and
+continuously, to form a mental picture of what takes place in any
+aetherial elastic envelope or shell that surrounds the sun.
+
+The illustration is not, however, perfect, because we have made the
+source of heat to be outside instead of inside the elastic envelope, as
+is the case with the sun and its aetherial atmosphere or envelope. We
+will therefore slightly modify the experiment, and take two balloons,
+_A_, _B_, one smaller than the other, and put the smaller one _A_ into
+the interior of the larger one, inflating the smaller one, so that it
+can be situated in the middle of the larger one, the latter having twice
+the diameter of the smaller one, as in the diagram (Fig. 6). To the neck
+of the smaller balloon _A_ we will attach an india-rubber tube which
+ends in a closed bulb _C_. We have now the two balloons inflated. Let us
+press the bulb _C_ and notice what happens. The effect will be exactly
+the same as it was when we brought the balloon in contact with the heat
+of the fire in the first experiment--that is, the elastic envelope will
+be again expanded. As soon as we take the pressure from the bulb _C_ the
+envelope, being elastic, seeks to recover its original position, with
+the result that it springs back to its original size. If we pressed the
+bulb _C_ 20 times per minute, we should get 20 vibrations of the
+particles of the envelopes per minute, and if we pressed it 1000 times
+per minute, we should get 1000 vibrations among the particles of the
+elastic envelope, so that the number of vibrations would correspond to
+the number of times we pressed the bulb. Now how did this vibration
+reach the elastic envelope of the balloon _B_ from the balloon _A_?
+
+[Illustration: Fig: 6.]
+
+The reply is, by means of the particles, or atoms of air that exist
+between the two surfaces of the balloons, and that transmission would
+take the form of a wave propagated from particle to particle, so that we
+might put dots on the right side of _A_ to represent the atoms of air
+which transmit the wave from _A_ to _B_.
+
+But the vibration which takes place in the surface of the envelope of
+the outer balloon is _across_ this line of propagation, because as the
+wave proceeds from _A_ to _B_, the elastic envelope expands and
+stretches always _across_ the line of propagation--that is, it stretches
+up and down, left and right, as it is expanded outwards, so that the
+vibration or oscillation of the particles always takes place in the
+surface of the elastic envelope across the line of propagation. Let us
+therefore apply the result of this simple experiment to our solar system
+and the Aether, and see if it can be made to explain the transverse
+vibration of light. Let _A_ represent the sun (Fig. 7) and _B_ an
+aetherial elastic envelope surrounding the sun. In this case we dispense
+with the bulb _C_, as the sun possesses within itself the power to
+generate heat, and so to produce the required expansion of the elastic
+aetherial envelopes _B_, _G_, _H_, etc.
+
+[Illustration: Fig: 7.]
+
+Instead, however, of having air particles between _A_ and _B_, we will
+put in their place our aetherial atoms which we have conceived according
+to Art. 44. These surround the sun, represented by _A_, forming elastic
+spherical shells or envelopes. As the sun radiates its heat into space,
+it urges the aetherial atoms against each other, with the result that
+they transmit the energy from atom to atom, or particle to particle,
+till they come to the elastic aetherial envelopes of _H_, _G_, _B_.
+
+The effect on _B_, or on any other aetherial envelope, is to expand it
+outwardly, and thus set the atoms of which it is composed into
+vibration. The wave, which is now an aetherial wave travelling with a
+velocity of 186,000 miles per second, may be represented by the line _D_
+_E_. But while it is travelling from _D_ to _E_ the same energy is being
+radiated out in all directions, so that a wave reaches the whole surface
+of the elastic envelope _B_ at the same time, with the result that the
+whole of the shell or envelope is set in vibration as it expands
+outwardly.
+
+Thus the vibration is always in the wave front, and the wave front is
+always coincident with the surface of one of these envelopes, and as
+these aetherial envelopes are themselves formed by aetherial atoms, the
+wave is spread outwardly from any central point in a spherical form as
+proved by experiment. Not only, therefore, is the vibration in the wave
+front, but it is always transverse to the line of propagation, for the
+simple reason that the surface of the spherical shell or envelope is
+always at right angles to the radius vector or straight line which joins
+any centre to the surface of a spherical envelope.
+
+As soon as the aetherial atom which forms the spherical aetherial
+envelope has reached the limit of its expansion, it seeks to recover its
+former position because of its elasticity, with the result that the
+whole envelope contracts again, and arrives at its original position in
+space ready to accept motion again and transmit it onwards in the same
+manner as before.
+
+Thus, by the acceptance of an atomic and gravitating Aether, we may form
+a physical conception of one of the greatest problems in optical
+phenomena, viz. the transverse vibration of light which always takes
+place in the wave front, and across the line of propagation. Whether
+this explanation is exactly correct in detail, or not, I am convinced
+that the true physical explanation of the problem is to be found in an
+atomic and gravitating Aether, as hitherto a frictionless Aether has
+failed even to suggest to any scientist how such a transverse vibration
+can take place.
+
+
+ART. 72. _Reflection and Refraction._--A ray or wave of light is said to
+be reflected when it meets with an obstacle which opposes its free
+passage and turns it back. We have illustrations of this law of
+reflection in the case of water waves striking against a breakwater, or
+a sound wave striking against the wall of a room. In either case the
+wave is turned back, and reflection is the result. A ray or a wave of
+light is said to be refracted when, in passing from one medium into
+another, it is turned from the straight path in which it was going
+before it entered the refracting medium. An illustration of the
+refraction of light is to be found in the case of the glass lens, so
+often used to converge the light waves into one focus. We have up to the
+present dealt with only two theories of light, the Corpuscular theory
+and the Undulatory or Wave theory. We have seen how both harmonize with
+Huyghens' principle, and the question arises as to whether both can be
+made to harmonize with the phenomena of reflection and refraction.
+
+In the Corpuscular theory we have luminous particles emitted by luminous
+bodies. These particles we have learned are practically synonymous with
+our aetherial atoms.
+
+In the Wave theory it is impossible to conceive of a wave without
+conceiving of particles which transmit the wave; even Huyghens refers to
+particles of Aether, and so does Tyndall in his _Notes on Light_.
+
+In the Electro-magnetic theory of light we have again to think of atoms,
+which are termed electrons by Dr. Larmor and Sir William Crookes; while
+Professor J. J. Thompson calls them corpuscles.
+
+So that in all three theories we have the same fundamental idea of
+atoms, either expressed or imagined, underlying all the three theories.
+Now what is the property of the Aether on which all reflection and
+refraction is based? Is it not the property of density? Fresnel assumes
+that reflection and refraction of light are dependent upon different
+degrees of density of the Aether associated with any body, and has given
+a mathematical formula, which decides the index of refraction, such
+formula being entirely dependent upon the relative density of the Aether
+in association with the refracting medium.
+
+But with a frictionless medium, it is an absolute impossibility to
+conceive of different degrees of density of the Aether in association
+with matter.
+
+If the Aether does possess different degrees of density which decide the
+refractive index of the substance, then of a certainty there must be
+some law to govern and decide the density, and that law can only be the
+Law of Gravitation.
+
+As Young points out in his Fourth Hypothesis, every particle of matter
+has an attraction for the Aether by which it is accumulated around it
+with greater density. Now on the basis of our conception of a
+gravitative Aether, every atom and molecule, and indeed every body in
+the universe, possess aetherial atmospheres, which possess varying
+degrees of density, the denser layers being nearest to the nucleus of
+the atom or molecule as the case may be, the elasticity of each layer or
+envelope being always proportionate to its density.
+
+When we apply the corpuscular theory to the reflection of light we find
+that it satisfactorily accounts for the phenomenon.
+
+According to Newton's corpuscular theory, each luminous particle travels
+in a straight line through a homogeneous medium. When, however, it comes
+almost into contact with a reflecting surface, which in our case we
+conceive to be a layer of one of the aetherial elastic envelopes
+surrounding the atoms or molecules of the reflecting body, then,
+according to Newton, the light particle is repelled, or reflected by the
+medium; the angle of reflection or repulsion being always equal to the
+angle of incidence. So that the emission theory harmonizes with the wave
+theory in regard to reflection.
+
+When, however, we come to deal with the refraction of light, the
+corpuscular theory apparently breaks down, and it was in relation to
+this phase of the phenomena of light that the undulatory theory
+overthrew the corpuscular theory.
+
+According to the corpuscular theory, when a luminous particle or
+corpuscle is nearing the surface of a denser medium, as glass or water,
+it was attracted by the denser medium, with the result that the velocity
+of the particle in the denser medium was greater than its velocity in
+air. But direct experiments prove exactly the opposite, as it is found
+that when light passes from a rare into a denser medium, the velocity of
+light in the denser or more refracting medium is less than it was in the
+air. Here then was a test to decide the respective merits of the two
+theories. As the undulatory theory was able to give a satisfactory
+explanation of the phenomenon, the corpuscular theory was rejected, and
+the undulatory theory was accepted. Now the question suggests itself, as
+to whether it is possible to reconcile the two theories in relation to
+the refraction of light by our conception of an atomic and gravitative
+Aether. I believe it is possible. Let us look at the case for a moment.
+We have, according to our theory of the Aether, to conceive of all atoms
+and molecules, of all planets and suns and stars, being surrounded by
+aetherial elastic atmospheres, or envelopes, which, like the atmosphere
+in association with the earth, are always the densest nearest the
+nucleus of the atom, getting gradually less and less dense the further
+they recede from the central point. Further, according to our theory,
+with regard to the elasticity or pressure of these elastic envelopes,
+they exert a pressure proportionate to their density. So that the nearer
+the aetherial atmosphere or envelope is to the central point or nucleus
+of the atom, the greater will be the elasticity or pressure.
+
+Now what I wish to call the reader's special attention to is, that the
+pressure in each and every case of the aetherial elastic envelopes which
+surround the central nucleus, is always directed _away from_ the central
+point, and here it seems to me is the solution of the difficulty which
+Newton failed to solve. For when a luminous corpuscle enters any medium,
+assuming it to do so, it would have to overcome the pressure due to the
+increased elasticity of the denser aetherial envelopes, and as the two
+motions, viz. that of the incident ray, and the pressure due to the
+elasticity of the elastic envelope, would be in opposition to each
+other, the result would be that the luminous corpuscle, if it entered
+the medium at all, would be retarded and not accelerated as suggested by
+Newton, and such a result is perfectly in harmony with experiment. So
+that by our theory of an atomic and gravitating Aether, it seems to me
+that it now becomes possible to reconcile the two theories.
+
+There is another difficulty that the emission theory had to contend
+with, and that was, how was it possible for the same surface of any
+substance to reflect and refract a corpuscle at one and the same time?
+Newton overcame this difficulty by suggesting, from the results of his
+observations on certain coloured rings, that each particle had what he
+called certain phases or fits, of easy reflection or refraction, so that
+at certain times they would be refracted, and at other times they would
+be reflected.
+
+Boscovitch has suggested that the fits were due to the fact that each
+luminous corpuscle possessed polarity; which, by rotating, alternately
+offered their different sides to the refractive and reflecting surfaces,
+so that sometimes they would be reflected or repelled, and at other
+times attracted or refracted.
+
+A similar hypothesis has also been suggested by Biot. Now if such a
+hypothesis will satisfactorily account for the fact that the same medium
+will reflect or refract the luminous corpuscles, as the case may be,
+then in our aetherial atom we have the very conditions which would
+satisfy both Boscovitch and Biot's hypothesis. For one of the properties
+that we suggested regarding our aetherial atom was, that it possessed
+rotation like our own earth, and that it also possessed polarity.
+
+The harmonizing of the two theories, therefore, seems to rest upon the
+atomicity or non-atomicity of the Aether.
+
+It is absolutely certain that the electro-magnetic theory of light
+demands the recognition of some form of atomicity for the Aether. For if
+light be really an electro-magnetic phenomena, as has been proved by
+Maxwell and experimentally demonstrated by Hertz, then, in view of the
+fact that the atomicity of electricity is coming within the scope of
+direct experiment as asserted by Dr. Larmor, unless we accept atomicity
+of the Aether in some way, we shall be in the unphilosophical position
+of having the Aether of space not being composed of atoms, while the
+electricity associated with that Aether in some unknown way is composed
+of atoms. In other words, we shall have a non-atomic body composed of
+atoms, which conclusion is absurd. Therefore, from the electro-magnetic
+theory of light, we are again compelled to postulate atoms of some kind
+for the Aether.
+
+If there are electrical atoms in association with the Aether, then they
+must be of two kinds, positive and negative, as it is impossible to find
+positive electricity disassociated from negative. Therefore, from the
+electro-magnetic theory of light we get further evidence of the polarity
+of the aetherial atom, by which Newton's fits of easy reflection or
+refraction may be physically conceived.
+
+I am convinced, that with the hypothesis of an atomic and gravitative
+Aether as suggested by Young in his Fourth Hypothesis, all three
+theories of light in relation to the phenomena of reflection and
+refraction can be harmonized. I wish only to point out the direction in
+which to look for the solution, and must leave it to scientists to work
+out the problem.
+
+
+ART. 73. _The Solar Spectrum._--When a ray or beam of solar light is
+passed through a prism, it is broken up or decomposed into its
+constituent parts. This is called dispersion, and conclusively proves
+that the light from the sun is not a simple, but a compound colour. We
+have illustrations of this decomposition of pure white light in the
+rainbow, where the colours of the sunlight are revealed against the sky
+with clearness and precision. A simple experiment to prove that the
+solar light is a compound one may be made by boring a small hole in a
+shutter, and then allowing the sunlight that passes through the hole to
+fall upon a prism, such as the pendant of a candelabrum. When this is
+done, then on the opposite wall of the room will be seen, not one
+colour, but seven colours, ranged in the following order: Red, Orange,
+Yellow, Green, Blue, Indigo, Violet. This is termed the Visible
+Spectrum.
+
+It may be asked, What is the cause of the various colours in the
+spectrum? We have already seen that light is due to a wave motion of the
+Aether, and it can be demonstrated that the various colours of light are
+due to different wave lengths. Colour is to light what pitch is to
+sound. As has been shown in Art. 62, the pitch of a note depends upon
+the number of air waves which strike upon the tympanum of the ear in a
+given time. The more rapid the vibration, the higher the note. The more
+rapidly a sounding body vibrates, the shorter will be the length of each
+wave. If a violinist wants to produce a note of higher pitch, he presses
+his finger on the string, thereby shortening it, and by so doing
+increases the rapidity of vibration, and raises the pitch of the note.
+Now the colours of the spectrum are to the eye what the notes are to the
+ear. The aetherial waves which produce the red colour are slower in
+their vibrations, and are longer than those which produce the orange
+colour. Those which produce the orange colour are of slower vibrations,
+and longer than those which produce the yellow colour, and so on through
+all the other colours; until we get to the violet and to the
+ultra-violet, or invisible violet rays, which are the most rapid in
+their vibrations, and consequently their wave lengths are the shortest
+of the whole group. It has been ascertained that it takes about 39,000
+waves of red light to measure an inch if placed end to end. Now light
+has a velocity of 186,000 miles per second. If this is reduced to
+inches, we find that there are 11,784,960,000 in that distance. Let us
+therefore multiply this number by 39,000, and we shall then find how
+many waves of red light must enter the eye to produce the sensation of
+red colour. That number is 459,613,440,000,000, so that all these waves
+enter the eye in one second of time, and must strike the retina of the
+eye in order to produce the sensation of redness. In the same way, the
+number of waves that must strike the retina of the eye to produce the
+sensation of violet can be determined. It takes about 57,500 waves of
+violet to measure an inch, so that a violet wave is only 1/57000 part of
+an inch in length. All the other colours of the spectrum which lie
+between the violet and the red waves gradually get longer and longer in
+their wave lengths, and slower and slower in their vibrations, until at
+the red end of the spectrum and beyond it we have the longest waves,
+which are from 1/39000 part of an inch in length to 1/10000 part of an
+inch.
+
+The seven colours seen in the spectrum are called the Visible Spectrum.
+There are, however, rays of light beyond both ends of the spectrum which
+do not affect the optic nerves of the eye, and therefore are invisible
+to sight. The rays in the spectrum which lie beyond the red are termed
+ultra-red rays, while those beyond the violet are called ultra-violet
+rays. It can be proved the former are rich in heating power, while the
+latter possess great chemical power. By means of an instrument known as
+the thermo-electric pile, or thermopile, the various heating power of
+the whole spectrum, visible and invisible, can be determined.
+
+Let us look for a moment at these invisible or dark rays. Strictly
+speaking, all light is invisible, as we cannot see light itself, we can
+only see it by reflection. We have seen that light is due to a wave
+motion in the Aether, but we cannot see that wave motion, neither can we
+see the Aether itself, so that it is not strictly correct to call a ray
+visible or invisible. We have, however, accepted the terms in relation
+to the rays of the spectrum, to distinguish between the invisible or
+obscure rays of the spectrum and the visible rays. It was Sir W.
+Herschel who first discovered the existence of these invisible waves. He
+passed a thermometer through the various colours of the solar spectrum,
+and then noted the temperature of each colour. He did not, however, stop
+at the limit of the visible spectrum, but experimented with his
+thermometer beyond its limits, and then found that beyond the red rays
+there were other rays, the ultra-red rays, which possessed greater
+heating power than any other rays of the spectrum. Thus his experiments
+proved, that side by side with the luminous or light waves, there were
+other rays, which, though they possessed greater heating power, yet were
+not able to excite the optic nerve, and so produce the sensation of
+sight.
+
+From these facts we learn that the solar spectrum may be divided into
+three parts--
+
+1. The red or ultra-red end of the spectrum which possesses the greatest
+heating power.
+
+2. The central part, yellow and green, which is the greatest in luminous
+power or light waves.
+
+3. The violet or ultra-violet end, which possesses great chemical or
+actinic power as it is sometimes termed.
+
+We have already seen (Art. 69) that the same aetherial waves which give
+rise to heat, also give rise to light, and that the only physical
+difference between heat and light is, that the waves which cause the
+phenomena of heat are of slower period, and of greater length, than
+those which cause the phenomena of light. From the solar spectrum we
+learn that there are a third class of Aether waves, which are of more
+rapid vibration, and therefore shorter in length than either the
+aetherial heat waves or the aetherial light waves. As already stated,
+these are called chemical or actinic waves, because they possess a
+greater chemical power than either the heat or the light waves that form
+the central part of the spectrum.
+
+Now this question suggests itself to us in relation to these chemical
+waves. What are these so-called chemical waves that are produced in the
+aetherial medium by the activity and heat of the sun? It must be
+remembered that the aetherial waves which give rise to both light and
+heat, and also these chemical waves, are first set in motion by the sun,
+at least as far as our solar system is concerned. We are perfectly
+conversant with the phenomena and characteristics of both heat and
+light. We are able to exactly determine what their particular effect
+will be on matter, and to describe that effect in a perfectly
+straightforward manner. The same, however, cannot be said of these
+so-called chemical waves that lie chiefly in the violet and ultra-violet
+end of the solar spectrum. What, then, is a chemical wave, its
+particular nature, and its exact properties? That we know it can
+decompose certain compounds, as Carbonic Acid Gas, CO_2, and so give
+rise to chemical decomposition, has been proved by Professor Tyndall and
+others, but I have never yet seen any record of any attempt to find out
+what these chemical waves are. There may have been such attempts made to
+discover their origin and character, but I have not seen any such
+record. I purpose, therefore, to offer an explanation as to the
+character and origin of these chemical or actinic waves, which I hope to
+prove by philosophical reasoning. We have already seen (Arts. 54 and 59)
+that both heat and light are convertible, or can be transformed into
+electricity, so that the same aetherial wave motion which can produce
+light can also produce heat, and that in its turn can produce
+electricity. Thus we learn that there is a very close identity between
+light, heat, and electricity; indeed it can be demonstrated that the
+same aetherial wave motion which produces electricity can produce the
+other two.
+
+Lorentz,[14] in an article on "The Identity of Light Vibrations with
+Electric Currents," states that "the vibrations of light are themselves
+electric currents." Now if this is true, and I believe it to be true, as
+I hope to prove later on from Clerk Maxwell's works, then it necessarily
+follows, that wherever we get aetherial light waves, we must at the
+same time also get aetherial electric waves. If that be so, then in the
+solar spectrum we ought to have revealed to us, not only indications of
+the presence of the heat and light vibrations, but equally so the
+presence of electric waves. This, I believe, is actually the case, and
+the electric waves are the so-called chemical waves in the violet and
+ultra-violet end of the spectrum. I think that we shall find sufficient
+arguments and analogy to support this hypothesis, as we look further
+into the matter. One of the greatest scientists of the past century,
+Clerk Maxwell, has given to the world the genesis of what he termed the
+Electro-Magnetic Theory of Light, in which he proved that light was
+nothing more nor less than an electro-magnetic phenomenon. He pointed out
+that the same Aether which was concerned in the propagation of light and
+heat through space, must therefore be equally concerned in the
+propagation of electric displacements in the free Aether; as he states,
+it would be philosophically wrong to assume that there was one aetherial
+medium for light, and another for electric phenomena. If, therefore,
+there is such a theory as the Electro-Magnetic Theory of Light, and
+there undoubtedly is, as has been proved by the researches of Hertz on
+electric waves, then it follows, either that light waves are themselves
+electric currents, as suggested by Lorentz, or that the light waves are
+directly associated with electric waves in the same way that they are
+associated with heat waves. So that the only difference between them
+would be one of period of vibration and of length, the electric waves of
+the Aether being of greater rapidity and therefore of shorter length
+than either the light or heat waves. The only conclusion, therefore,
+that it seems possible to come to regarding these chemical waves is,
+that they are the electric waves of the spectrum. Thus, in the solar
+spectrum, there are three classes of waves indicated by the various
+colours, and beyond the limits of these colours, viz. (1) Thermal or
+Heat waves in the red or ultra-red end of the spectrum; (2) Luminous or
+Light waves at the middle of the spectrum; and (3) Electric or Chemical
+waves in the violet or ultra-violet end of the spectrum. Now in looking
+at this hypothesis from the standpoint of our Rules of Philosophy, I
+venture to assert that all the three rules are satisfactorily fulfilled,
+and that being so, the hypothesis advanced is philosophically correct.
+In the first place, such a conception that the chemical waves or violet
+waves are really electric waves is simple in its hypothesis, and so
+fulfils our first Rule of Philosophy. It is simple, because it puts in
+the place of unknown chemical waves, a certain kind of aetherial waves
+with whose action we are definitely familiar, and whose origin and
+effect can be satisfactorily accounted for, as proved by Hertz. Chemical
+waves are not simple in conception, because we do not know exactly what
+they are, or how they are originated. Besides, as Newton points out,
+there is nothing superfluous in Nature. If one cause can effect the
+desired end, as electric waves, then another cause as chemical waves is
+superfluous and unnecessary. Further, in our hypothesis of the electric
+character of these chemical waves, we have a solution which
+satisfactorily fulfils the second Rule of our Philosophy. Experience and
+experiment teach us, that there are electric waves constantly being
+generated in a thousand ways. Indeed, it is an absolute impossibility to
+perform the simplest act of ordinary life, as brushing a hat, or wiping
+the boots on a mat, cutting an orange, or any other act of simple
+everyday life, but that these aetherial electric waves are generated.
+But as for these so-called chemical waves, experience has little to say
+about them, and experiment still less. If we decompose water, dividing
+it up into two gases, Oxygen and Hydrogen, we do it by passing a current
+of electricity through the water. If we want to decompose or split up a
+binary compound, as HCl, into its two elements, Hydrogen and Chlorine,
+then we can do it by electricity--that is, by the decomposing action of
+these electric waves. In all these experiments and results we know
+definitely what we are doing, and what the effect will be. There is no
+vagueness about the terms used. When we speak of chemical action we look
+to a definite source for that action, and we do not say that such action
+is produced by chemical waves, but rather by electricity. So that all
+experience teaches us, and all experiments made by such men as Faraday,
+Davy, Maxwell, and Hertz confirm the statement, that these aetherial
+electric currents can accomplish all that the so-called chemical waves
+accomplish, and that being so, the third Rule of our Philosophy is also
+fulfilled, as we have in the aetherial electric waves a satisfactory
+explanation for the fact which we seek to explain, viz. the character
+and origin of the chemical waves that exist in the violet end of the
+spectrum. Thus, we learn, that not only is the sun the source of all
+heat and light, in that it gives rise to the vibrations of the Aether
+which are propagated through it in waves, but that it is also the source
+of all electric waves in the solar system, in that electric currents are
+primarily due to the wave motion set up in the Aether, those electric
+waves also traversing space with the velocity of light.
+
+[Footnote 14: _Phil. Mag._, 1867.]
+
+
+ART. 74. _Direction of Ray of Light._--In Art. 65 it was shown that the
+direction of a ray of heat was that of a straight line from the heated
+or luminous body from which the Aether waves proceeded. We have also
+seen in Art. 69 that the aetherial waves which give rise to the
+phenomena of heat are identical with those that give rise to light, so
+the direction of a ray of light must also be that of a straight line
+proceeding from the luminous body. A ray of light is a line
+perpendicular to the Aether waves which are propagated through space in
+concentric spheres from the luminous body, which, by its atomic
+vibrations, gives rise to the light waves. It must, however, be
+remembered that rays have no physical existence, for it is the waves
+that are propagated, and not the ray, which simply indicates the
+direction that the light takes, this truth being known as the
+rectilineal propagation of light. That light proceeds in straight lines
+may be proved in several ways. For example, we cannot see round corners,
+which would be possible if light took a curved path instead of a
+straight one. A better proof, however, may be obtained by making a small
+hole in the window-shutter, and allowing the sunlight to pass into the
+darkened room. The beam of light which passes into the room will then be
+seen to take a straight course, its presence being revealed by the
+particles of dust that float about the room.
+
+Another conclusive proof that light proceeds in straight lines is to be
+found in the fact, that all images formed on any screen by the rays of
+light after passing through a small hole are inverted. For example,
+suppose we have a window-shutter with a small hole in it, while in the
+garden fronting the window there stands a tree. Now if the rays of light
+which pass from the tree through the hole in the window-shutter are
+allowed to fall upon a screen in the darkened room, it will be found
+that the image is inverted.
+
+This is accounted for by the fact, that the rays cross each other at the
+hole, and proceeding in straight lines, form an inverted picture on the
+screen. It can further be proved, that the path of a ray of light
+through space as it proceeds from the sun is also that of a straight
+line. Whenever there is a solar eclipse we have light so long as we can
+see the smallest part of the sun's surface. The instant, however, that
+we have a total eclipse, at that instant the whole of the light of the
+sun is shut off, and for a brief space there is darkness, until the
+planet which is causing the eclipse has passed on in its orbit and the
+sun's surface reappears again. Now if light did not proceed in straight
+lines, such an event as a total eclipse would be impossible; because, if
+the light proceeded in curved lines instead of straight ones from the
+sun, then even when the planet which causes the eclipse got directly
+between the earth and the sun, the rays of light being curved instead
+of straight would bend round the eclipsing planet, and so would not all
+be intercepted, and thus such an event as a total eclipse would be an
+impossibility. From this we learn, therefore, that the path of a ray of
+light as it proceeds from the sun through space is that of a straight
+line, and that the path corresponds to the radius vector of a circle,
+which is also the path that the centripetal force takes.
+
+Viewing the matter from the standpoint of the solar system, we find the
+sun, which is the centre of that system, exerting an attractive force
+along the radius vector of all the orbits of the planets, with a force
+which decreases in intensity inversely as the square of the distance. At
+the same time, being the source of all light, it is constantly
+propagating into space aetherial light waves with a velocity almost
+inconceivable; which also decrease in exactly the same ratio as the
+attractive power of the sun decreases. If, therefore, it can be shown
+that there is such a truth as the dynamical value of light, in the same
+way that it has been shown that there is a dynamical value of heat, then
+it follows, that not only is the sun the centre of an attractive power
+which proceeds in straight lines, but it is equally the centre of a
+power whose influence and motion are exerted along exactly the same path
+as the centripetal force, but in an opposite direction, that is, away
+from the sun. I hope to be able to show that the aetherial light waves
+do possess such a dynamical value, and if that is accomplished, then not
+only from the realm of heat, but also from the realm of light, we shall
+have conclusive evidence of a power or motion whose influence is
+directed away from the sun, which, therefore, would correspond to a
+centrifugal force--that is, a force or motion directed from a central
+body as the sun.
+
+
+ART. 75. _Intensity of Light._--The intensity of light diminishes with
+the distance from the luminous body, according to the same law that
+governs sound, and heat, and electricity. We have already seen (Art. 67)
+that the intensity of heat diminishes inversely as the square of the
+distance, so that if the same law holds good for light that holds good
+for heat, then, according to the law of the inverse squares, if we
+double the distance from the luminous body, the intensity of light is
+only 1/4 of what it was in its first position. If the distance be
+trebled, then the intensity will be decreased 1/9. This can easily be
+proved by the following experiment: Suppose we have a lighted lamp, and
+at a distance of 1, 2 and 3 feet respectively, we have three square
+surfaces. It can then be demonstrated that the light which falls on the
+square 1 foot away, if allowed to fall upon the square 2 feet away,
+would cover four times the area of the first square; and if allowed to
+fall on the square 3 feet away, it would cover nine times the area.
+Therefore the intensity of the light on the square 2 feet away, covering
+four times the area, would only be 1/4 of what it is on the square 1
+foot away, while the intensity of light on the square 3 feet away, which
+covers nine times the area, would only be 1/9 of the intensity received
+by the first square.
+
+If the difference in the distances therefore be represented by the
+figures 1, 2, and 3 feet respectively, the intensity would be
+represented by the figures 1, 1/4, 1/9. The decrease in the intensity of
+light is really a decrease in motion. The intensity of a note in sound
+depends upon the vibration of the particles of air, while the intensity
+of light also depends upon the vibrations of the aetherial atom.
+
+If, therefore, we get a decrease in the vibration of the aetherial atom,
+the further we get from the luminous body, it can be readily seen that
+the intensity of light really implies a decrease of motion.
+
+Now let us apply the law of inverse squares in relation to light to the
+solar system. We have the sun with its huge form all aglow with fires,
+as the source of all light to the planetary worlds that revolve around
+it. Year in and year out, for many ages past, the sun has been pouring
+out its light into space on every side, lighting up the planets or other
+bodies that revolve round it on that side only which is presented to the
+sun. Thus Mercury, at its distance of about 36,000,000 miles, obtains a
+light from the sun which is of far greater intensity than the light
+which Venus receives, while Venus receives a light of greater intensity
+than the light which the Earth receives, and the Earth receives light of
+greater intensity than any of the planets outside its orbit in the solar
+system, as Mars, Jupiter, Saturn, Uranus, or Neptune. This decrease in
+the intensity of light is according to the inverse square of the
+distance from the central body, the sun. So that if we have one planet
+at twice the distance from the sun, as compared with another planet, the
+intensity of light at that distance will be only 1/4 of the intensity
+received by the nearer planet. This decrease of the intensity of light,
+however, may be compensated for by a difference in the constituents of
+the planets' atmosphere, by means of which it may be possible that the
+outermost planets enjoy climatic conditions similar to our own.
+
+Now we have proved, in the previous chapter, that heat is a repulsive
+motion, and as the same aetherial waves give rise to the phenomena of
+light, then it ought to follow that light has equally a repulsive power
+on the planets with which it comes into contact. If that can be proved,
+and I submit that it can, then from the phenomena of light, we learn
+that there is a force, or rather a motion, ever proceeding from the sun
+in straight lines, as shown in the previous Art., which decreases in
+power or intensity inversely as the square of the distance. So that not
+only is the sun the centre of an attractive Force, the Centripetal
+force, or the attractive Force of Gravity, which proceeds in straight
+lines through space, decreasing in intensity inversely as the square of
+the distance, but at the same time it is also the centre of a motion,
+that is, the aetherial wave motion of light, which takes exactly the
+same path as Gravitation Attraction, and which is subject to exactly the
+same laws. Unlike Gravitation Attraction, however, its power and motion
+is ever directed away from the central body, the sun; and if such motion
+exerts any power on any planet with which it comes into contact, that
+power or motion can only be a repulsive motion in the same way that heat
+is a repulsive motion. Assuming, therefore, that light, through the
+medium of the aetherial waves, does exert this repulsive motion, then,
+according to the law of inverse squares, it can be seen that if a
+planet's distance be doubled, the repelling power of the aetherial light
+waves would be decreased 1/4, while at the same time the attractive
+power of the centripetal force would be decreased 1/4 also. If, on the
+other hand, the planet's distance from the sun be reduced to 1/2 of its
+former distance, then the repelling power of the aetherial light waves
+would be increased four times, but contemporaneously with the increase
+there would be an increase in the attractive power of gravity, which
+would exactly counterbalance the increased repelling power of the light
+waves. So that in assuming that there is this repelling power in the
+light waves, there are thus two forces in existence in the solar system
+(which is a type of all other systems), or rather two motions, as all
+forces resolve themselves into motions of some kind, one motion ever
+tending from the central body, that is, the motion of the aetherial
+light waves, and the other tending to the central body, that is, the
+force of gravity, which we shall see later on is also a motion of the
+Aether, whose influence is ever towards the central body, be it a sun,
+star, or planet. These two motions, therefore, are subject to the same
+law, viz. that their power or intensity is not only directed in straight
+lines from the central body, but their intensity is regulated exactly by
+the same law of inverse squares. If the repelling motion be doubled,
+then the attractive motion or power would be doubled also; if the
+repelling motion be quadrupled or halved, then the attractive force of
+gravity would be quadrupled or halved in the same way, the two forces
+being exactly increased or decreased in the same ratio according to the
+law of inverse squares.
+
+
+ART. 76. _Velocity of Light._--The transmission of light is not
+instantaneous, as it requires time for its propagation through space,
+from the luminous body which gives rise to all light, as the sun for
+example, until it reaches the body which it lights up. The velocity of
+the light waves, however, is so great, that it is almost impossible to
+give any comparative idea of their rate of transmission. The velocity of
+the light waves was first established by Roemer, a Danish astronomer, in
+1675. He ascertained the velocity of light by observations made on the
+satellites of Jupiter. His methods of reasoning can easily be understood
+by reference to the following diagram.
+
+[Illustration: Fig: 8.]
+
+Let _S_ represent the sun, and _A_ and _B_ the orbit of the earth round
+the sun; _C_ _E_ _D_ part of Jupiter's orbit round the sun; while _D_
+_E_ _F_ represents the orbit of Jupiter's satellite. When the earth,
+Jupiter, and the satellite are in a straight line with each other, the
+satellite suffers an eclipse through passing into the shadow thrown by
+Jupiter. Now Roemer found that there was a difference in the time of the
+eclipse when the earth was at _B_, that is, when it was nearest to
+Jupiter, and when it was at _A_, which is that part of the earth's orbit
+furthest away from Jupiter. That difference was accounted for by the
+fact, that when the earth was at _A_ the light had to travel further
+from Jupiter than when the earth was nearest to Jupiter, that is at
+point _B_. Thus, when the earth was nearest to Jupiter, the light had a
+shorter journey to travel than when it was furthest from Jupiter. The
+difference, he found, was about 16 minutes, and he reasoned that this
+difference was caused by the light having to cross the earth's orbit
+from _B_ to _A_, in its longer journey, than when it only had to reach
+the earth at _B_. The mean distance of the earth from the sun, that is,
+the radius of the earth's orbit, is about 92-1/2 million miles, so that
+the diameter of the earth's orbit is about 185,000,000 miles, and if it
+takes about 16 minutes for light to traverse this distance, we find that
+light has a velocity, according to Roemer, of 192,500 miles per second.
+The result, however, arrived at by Roemer was not generally accepted at
+that time, and it was not till 1728 that Bradley discovered what is
+known as the Aberration of Light, and from that discovery proved that
+light was not transmitted instantaneously through space, but that it was
+transmitted with finite velocity; and that that velocity corresponded
+fairly well with the velocity given by Roemer. Bradley, in his
+astronomical observations, noticed that some of the fixed stars, so
+called, did not appear to be really fixed, but that they described small
+circles in the heavens each year. This fact greatly perplexed him, until
+at last he hit upon the true solution by taking into account the motion
+of the earth in its orbit, together with the fact that light had a
+finite velocity. This result showed that the light from the stars
+travelled with the same velocity as that which travelled from Jupiter's
+satellites. The Aberration of Light, as his discovery was termed, may be
+illustrated in the following way--Suppose that you are standing still,
+and that it is raining, the rain descending vertically on the umbrella
+that you hold up to cover you. As soon as you begin to walk, the
+rain-drops will apparently begin to slant, and if the walk is changed
+into a run, the greater apparently will be the slanting direction that
+the rain-drops take. In the same way, the rays of light from a star
+would fall vertically upon the earth if it were motionless, but as the
+earth is moving through space with varying velocity, it gives to the
+rays of light a slanting direction. By calculating the speed of the
+earth, and ascertaining the exact slanting direction of the rays, the
+velocity of light may be ascertained. This Bradley did, and showed that
+it coincided almost with the result arrived at by Roemer. Various other
+means have been adapted to test the results arrived at by these two
+astronomers. Fizeau, in 1849, was able to measure the velocity of light
+by using, not planetary or stellar distances, but by simply using
+distances in the city of Paris; while Foucault, in 1860, devised a
+method of measuring the velocity of light in air or any other medium.
+The results arrived at by these men leave no doubt as to the exact speed
+of light, which may now be reckoned to have a velocity of 186,000 miles,
+or 300,000,000 metres per second. Notwithstanding this great speed at
+which light travels, the nearest stars are so far off that their light
+takes about 3-1/2 years to reach the earth, while scientists tell us
+that some of the most distant stars are so remote, that their light
+takes thousands of years to reach our earth, travelling at the rate of
+186,000 miles per second. From considerations like these we get a dim
+conception of the almost illimitable extent of the universe. Now let us
+try to understand what this rate of motion really means. We have to
+remember that light is caused by wave motions in the Aether, so that we
+have here a wave motion which is travelling through the Aether at the
+enormous rate already quoted. Light takes about 8-1/2 minutes to travel
+from the sun to the earth, a distance of 92,000,000 miles. Our fastest
+trains do not travel 80 miles an hour, and if a train left the sun and
+continued its journey through space at that rate, it would take over 130
+years before it reached our earth, while the light would perform the
+journey in 8-1/2 minutes. We have some idea of the velocity of a train
+travelling at 80 miles an hour; what, however, must be the velocity of a
+wave motion which travels 22,500 times as fast? In Art. 56 we have seen
+that all energy is the energy of motion, and therefore wherever we get
+motion of any kind or sort, there we must have energy accompanying it,
+or the power to do work. We have here, then, a source of energy in the
+aetherial waves known as light waves, with their enormous velocity which
+is almost inconceivable and illimitable. What must be the energy which
+exists in space due to the wave motion of the Aether? We have to
+remember on this point that we are no longer dealing with a frictionless
+medium, but that we are dealing with matter, only in a far more rarefied
+and far more elastic form than ordinary matter, but nevertheless matter
+just as air is considered matter, and, being matter, its very motion
+imparts to the light waves a power and a force which make them capable
+of doing work. The kind of work done will be considered later on, when
+we deal with the dynamical value of light. That we do not feel the power
+and energy of the light waves is due to the well-known fact that their
+power is broken by the activity of the atmospheric particles, each of
+which, in their myriads, is ever moving with great velocity, and
+therefore bombard the light waves, as they endeavour to strike the
+earth. Thus the aetherial light waves are broken up and shattered, and
+fall to the earth not with their full energy or power, but in a blended
+form, or with that reflected energy which we call light. If they were to
+come unbroken and unchecked upon us, and on the earth, in the same way
+that they apparently do upon our satellite the moon, we doubtless should
+experience very different effects of their energy and power due to their
+enormous velocity.
+
+
+ART. 77. _Dynamical Value of Light._--We have already learned (Art. 68)
+that heat possesses a dynamical value, such value being measured by
+Joule, and its equivalent in foot-pounds being exactly ascertained. We
+have further seen (Art. 69, on the identity of light and heat), that the
+same aetherial waves which produce heat are also concerned in the
+production of light. If, therefore, the aetherial waves which give rise
+to heat possess a dynamical action and equivalent, it follows that light
+must also possess a dynamical action and equivalent, and such action
+should be capable of being expressed in terms of foot-pounds. Clerk
+Maxwell has recorded the exact dynamical equivalent of light. On this
+matter he writes:[15] "If in strong sunlight the energy of light which
+falls upon a square foot is 83.4 foot-pounds per second, the mean energy
+of one cubic foot of sunlight is about .0,000,000,882 of a foot-pound,
+and the mean pressure on a square foot is .0,000,000,882 of a pound
+weight." We have here then the exact dynamical equivalent, according to
+Maxwell, of a cubic foot of sunlight near the earth's surface, and of
+the pressure exerted by light on a body with which it comes into
+contact.
+
+Again, Lord Kelvin[16] has measured the exact dynamical equivalent of a
+cubic mile of sunlight, both near the surface of the sun and then near
+the surface of the earth, and in a note adds that the relation of the
+two values is as 46,000 to 1. So that if the dynamical value of a cubic
+mile of sunlight near the earth's surface be represented by unity, then
+the value of a cubic mile of sunlight near the sun's surface would be
+46,000 times greater, while he further adds that it would take 4140
+horse-power every minute, as the amount of work required to generate the
+energy existing in a cubic kilometre of light near the sun, a kilometre
+being equal to about 1093 yards.
+
+Professor Challis[17] stated in 1872 that "Light is to be ranked with
+the physical forces, and its dynamical action is equally to be ascribed
+to the pressure of the Aether." Now I want to put this question to the
+reader: If light possesses this dynamical action, that is, if it
+possesses a motive or driving power, what must be the exact effect of
+the dynamical action of the light waves from the sun upon all the
+planets and meteors that revolve round it? We know that the sun is
+324,000 times the mass of our earth, and that it has a diameter of about
+856,000 miles and a circumference of over two million and a half miles.
+What, therefore, must be the energy of the aetherial light waves that it
+speeds on their way through space on every side? Stokes,[18] in regard
+to the mechanical energy of Light, states that "the amount of energy
+poured forth into space corresponds in round numbers to 12,000
+horse-power per square foot," and that every square foot of the sun's
+surface supplies energy at the above rate. The number of feet in the
+sun's surface can be approximately determined. Roughly, there are
+2,284,000,000 square miles of surface on the sun's huge form, and there
+are 27,878,400 square feet in a mile. By multiplying these two numbers
+we can ascertain the exact number of square feet on the surface of the
+sun. If, therefore, every square foot possesses a mechanical value equal
+to 12,000 horse-power, what must be the mechanical equivalent of the
+sun's radiation of light that it pours forth into space?
+
+I want to call the attention of the reader to another fact, and that is,
+that light always proceeds in straight lines from the sun (Art. 76), and
+therefore if there be any mechanical action in light at all, that action
+must be one which is always directed from the sun in straight lines. Now
+experience universally teaches us, that if a body is pushed, and pushed
+with such a force as has been indicated, then that body not only moves,
+but moves in the direction that the supposed horses would push. I have
+already shown (Art. 76) that the path of light is that of a straight
+line corresponding to the path of the attractive force of gravity;
+therefore these horses must ever push in a direction _from_ the sun
+along the same path that the sun's attractive power takes. In other
+words, the mechanical action of these supposed horses will be a
+repulsive one, that repulsion being due to the dynamical action of the
+light waves upon the body that they come into contact with. If this is
+correct, then not only is heat a repulsive motion, as stated in Art. 63,
+but light is equally the possessor of a repulsive motion, because its
+action is ever directed from the sun. We might continue to follow the
+supposed horses as they continued their course through space, and we
+should find that their energy decreased inversely as the square of the
+distance, partly because the further they proceeded into space the
+larger the area would be they would have to cover, and therefore their
+energy would be decreased proportionately.
+
+Professor Stokes, in the same work[19] already referred to, in
+continuation of the same idea, states: "At the distance of the earth the
+energy received would correspond to about one horse-power for every
+square of 5 feet, on that side of the earth's surface facing the sun,
+supposing the rays to fall perpendicularly." That being so, we can
+exactly calculate in horse-power the energy received from light on that
+side of the earth facing the sun, at its distance of 92,000,000 miles.
+The area of the earth's surface is, roughly, 200,000,000 × 5280 square
+feet, and if the energy received is equal to one horse-power for every 5
+square feet, then the amount of energy received by the earth on that
+side facing the sun would be equal to 200,000,000 × 5280 × 1/2 × 1/5
+horse-power. This power, it must be remembered, is ever directed _away
+from_ the sun, and upon that side of the planet that faces the solar
+orb. So that we have virtually a repulsive force ever directed against
+the earth, estimated by Professor Stokes to be equal to the estimated
+horse-power.
+
+This assumption of the repulsive power of light brings the phenomena of
+light into harmony with that of heat, because we have already seen (Art.
+63) that heat is essentially a repulsive motion, as indicated by Davy,
+Rumford and others; and, as heat and light both have a common origin,
+then light should possess a repulsive power also.
+
+As further proof of this statement, let me again quote from Clerk
+Maxwell. In the quotation already given in this Art. we have seen that
+the pressure of sunlight on a square foot is equal to 83.4 lb. He adds
+the following words to those already quoted: "A flat body exposed to
+sunlight would experience this pressure on its illuminated side only,
+and would therefore be repelled from the side on which the light falls."
+
+Now if more conclusive proof of the correctness of the argument I am
+advancing were required, I do not think it could be given from any
+greater authority than that just quoted. Coming from the pen of one of
+the most brilliant scientists that the past century has known, I venture
+to think the opinion will be received with that due weight which it
+demands.
+
+This statement of Clerk Maxwell's has received, however, definite and
+experimental proof from Professor Lebedew of Moscow University, and by
+Nichols and Hull of America. The former has given, in the _Annalen der
+Physik_ for November 1901, the results of his experiments in relation to
+the pressure of light. The following are the results: He proved, 1st,
+that the incident beam of light exerts pressure both upon an absorbing
+and a reflecting body; 2nd, that the pressure of light is proportionate
+to the amount of incident energy, and is independent of the colour of
+light; 3rd, that the pressure of light corresponds with the forces of
+radiation as calculated by Maxwell.
+
+About the same time, Nichols and Hull of America were engaged upon
+experiments relating to the pressure of light waves, and their results
+were published in the November _Physical Review_, 1901. Thus, from two
+separate and independent sources, Maxwell's equations as to the pressure
+which light waves exert upon any body on which they fall received
+definite experimental confirmation.
+
+The repulsive power of the light waves receives further confirmation from
+that theory known as the electro-magnetic theory, which supposes light to
+be nothing more or less than an electro-magnetic phenomenon; that is to
+say, it is directly or indirectly due to the action of electric currents.
+
+As already indicated, Lorentz was of the opinion that the light waves
+were themselves electric currents, and whether this is the actual fact
+or not, certainly it is true that the electro-magnetic theory of light
+is no mere fable or myth, but that it ranks as one of the most advanced
+and correct hypotheses in regard to light that has ever been given to
+the world. According to that theory, which we shall look at
+subsequently, we find that the aetherial medium is not only the medium
+for the light waves, but that it is also the medium which conveys and
+carries the electric currents through space, and even through all
+matter. Further, from that theory we shall have good reasons for
+assuming that the aetherial light waves are either themselves electric
+currents, or closely identified with them, in the same way that the
+light waves are identified with heat waves. If these facts should be
+found to hold good relative to the identity of aetherial light waves and
+the aetherial electric waves, then it can very readily be seen that such
+a hypothesis gives added weight to the repulsive power of light. One of
+the very commonest facts regarding electricity and its currents is, that
+wherever we get electricity, we not only get attraction, but there is
+always associated with that attractive force a repulsive force, which is
+equal in amount to the attractive force. So that if, wherever we get
+electric currents, we find associated with those currents a repulsive
+force, then, in view of the electro-magnetic theory of light, it should
+also follow that on that hypothesis we ought also to find a repulsive
+power in light. From the dynamical aspect of light on the bases of facts
+given to the world by such men as Professor Stokes, Clerk Maxwell, Lord
+Kelvin, and Professor Lebedew, we are compelled, therefore, to come to
+the conclusion that light does possess such a repulsive force, such
+force being due to the dynamical action of the aetherial light waves.
+
+Thus we learn from the dynamical action of light, that not only is the
+sun the centre of an attractive force, but that it is equally the centre
+of a repellent or repulsive power or motion; which repulsive power
+always follows the path of the radius vector, and diminishes with an
+intensity which is inversely as the square of the distance. What we have
+to ask ourselves therefore is, whether the repulsive power of light is
+the Centrifugal Force that we are trying to discover? In Art. 24 we
+found out what were the necessary characteristics of the Centrifugal
+Force, which is to form the companion law to the attractive law of
+gravity, or the Centripetal Force. We there saw that this centrifugal
+law must be universal in character; that it must coincide with the path
+of the centripetal force; that it must also be subject to the same law
+of intensity, viz. the law of inverse squares; and further, that the
+force must be proportional to the product of the two masses concerned.
+We find in the repulsive power of light three at any rate of these
+conditions fulfilled. Light is universal because Aether is universal.
+It is always subject to the law of inverse squares, and what is more,
+its repelling power coincides exactly with the path which the
+centripetal force takes, that is, the radius vector. We have not,
+however, discovered that light fulfils the remaining necessary
+condition, which is, that the repelling powers of light emitted by any
+two bodies are equal to the product of their masses. So that until this
+is done, it cannot be said that the aetherial light waves form the
+centrifugal force or motion from a central body that we are seeking for.
+But while that may be true, yet if light be not the centrifugal motion,
+it certainly indicates in what direction we are to look for that force,
+and that is to the Aether, whose periodic waves give rise to the
+phenomena of light. For, after all, light is due to aetherial wave
+motion, and, therefore, while light from certain standpoints may be
+conceived to be the cause of other phenomena, yet primarily the real
+cause of all phenomena which are due to light are due to the aetherial
+waves which themselves give rise to the phenomena of light. Thus light
+acts as a guide-post to us, pointing out the direction we should take in
+order to find out the real centrifugal force or motion, and as plainly
+as it possibly can, it indicates to us that the true solution of our
+centrifugal motion that we are seeking for is to be found, and alone
+found, in that universal aetherial medium which, by its vibrations and
+wave motions, gives rise to that which we term Light. In conclusion of
+this point, it may be pointed out that Professor Challis[20] also took
+this view of light, as he distinctly states that "Light is to be ranked
+with the physical forces, and its dynamical action is equally to be
+ascribed to the pressure of the Aether," and then proceeded to show how
+repulsion could be exerted on atoms by the periodic wave motion of the
+Aether.
+
+[Footnote 15: _Magnetism and Electricity._]
+
+[Footnote 16: _Phil. Mag._, 1902.]
+
+[Footnote 17: _Ibid._, 1872.]
+
+[Footnote 18: _Burnet Lectures._]
+
+[Footnote 19: _Burnet Lectures._]
+
+[Footnote 20: _Phil. Mag._, 1872.]
+
+
+ART. 78. _The Electro-Magnetic Theory of Light._--We have seen (Art.
+71) that light is due to a periodic wave motion of the Aether, and we
+have previously seen that heat is also due to a periodic wave motion of
+the Aether. Thus in the phenomena of light and heat, Aether is the
+medium in which the energy of light is stored, and by which it is
+transmitted in its passage from a luminous body, as the sun, until it
+comes into contact with a planet or satellite from which it is
+reflected, thus giving rise to light and heat. When, however, we come to
+deal with electro-magnetic phenomena, which are the results and effects
+produced by electricity and magnetism, we find certain phenomena similar
+to those that we find in relation to light and heat. Thus, when light is
+emitted by a luminous body, a certain amount of energy is given out by
+that body, and if such light is absorbed by another body, the latter
+becomes heated, a clear proof that it has received energy or motion from
+some outside source. From the time it left the luminous body till it
+reached the lighted or absorbing body, it must have existed as energy,
+that is, motion in the Aether. As we have already seen, Newton thought
+that the transference of energy was accomplished by the actual
+transference of certain small corpuscles or atoms given out by the
+luminous body, which conveyed the energy of the one body to the other.
+According to the wave theory of light, however, we find that the
+transference of energy is accomplished by a wave motion in the Aether,
+which is periodic both in time and space, by which wave motion the
+energy is transferred from the luminous to the illuminated body. Now
+every one is familiar with the effects of magnetism and electricity in
+some form or other, and such familiarity teaches that various kinds of
+work may be done by electricity. If an electric current be generated and
+allowed to flow through any circuit, as the ramifications, for example,
+of an electric-tram system, it can readily be seen that by the action of
+the current large masses or bodies as trams may be moved. To generate
+the current requires the expenditure of energy, and for the tram to be
+moved requires the transmission of that energy from the generating
+station till it reaches the body to be moved. By what means is such
+energy transmitted? because if it disappears at one place and reappears
+at another, it must have passed through a medium during the interval. It
+has been demonstrated that the medium which conveys the current from
+place to place is the Aether, so that as light is transmitted through
+space by the Aether, in a similar manner electric currents are
+transmitted through space also by the same medium. The discoverer of
+this great truth was Clerk Maxwell, and it was from the consideration of
+electro-magnetic phenomena that he was able to lay the foundation of
+that theory known as the Electro-Magnetic Theory of Light. In paragraph
+781 of his greatest work[21] he says: "In several parts of this treatise
+an attempt has been made to explain electro-magnetic phenomena by means
+of mechanical action from one body to another by means of a medium
+occupying space between them. The undulatory theory of light also
+assumes the existence of a medium. We have now to show that the
+properties of the electro-magnetic medium are identical with those of
+the luminiferous medium." He then points out that, "to fill all space
+with a new medium, whenever any new phenomenon is to be explained, is by
+no means philosophical"; and further adds, that "If it should be found
+that the velocity of propagation of electro-magnetic disturbances is the
+same as the velocity of light, and this not only in air, but in other
+transparent media, we shall have strong reasons for believing that light
+is an electro-magnetic phenomena." In the wave theory of light we have
+seen (Art. 70), that two properties are necessary to any medium before
+it is capable of transmitting wave motion of any kind. Those two
+properties are elasticity and inertia. Water possesses these properties,
+and so can transmit ocean waves; air also possesses these properties,
+and so can transmit sound waves; and Aether, being matter, also
+possesses these properties (Arts. 47 and 48), and is therefore capable
+of transmitting light waves. The elasticity is essential in order for
+the medium to store up energy, and also to enable it to resume its
+original shape after deformation, while the inertia is necessary in
+order that the medium may transmit the impulse, and oscillate to and fro
+until the impulse received has been passed on. This elasticity and
+inertia may be well illustrated by the bending of a lath or cane. If we
+pull one end down, holding the other end quite still, we shall see that
+the lath oscillates to and fro until gradually it comes to rest. The
+elasticity of the lath allows it to be pulled out of its original
+position, and also enables it to rebound, while its inertia causes it to
+swing back again past its original position. Both combined together
+cause it to swing backwards and forwards till its energy is used up. If
+such a series of springs could be set in motion at equal intervals of
+space and time, we should then have a good illustration of a wave
+motion.
+
+What analogy, may be asked, is there in electro-magnetic phenomena to
+correspond to this elasticity and inertia of the Aether, so essential to
+the propagation of light? Let us look at the familiar illustration of
+charging a Leyden jar. In charging a Leyden jar with electricity a
+certain amount of energy is spent, work is done, and the result is found
+in the electrified state of the jar. That which has actually been
+accomplished is the storing up of energy in the Aether around the jar.
+This storing up of energy is analogous to pulling aside the lath, and is
+the making use of the elasticity of the Aether, in order to produce a
+tendency to recoil. When the jar is discharged, which is analogous to
+letting go the lath, the Aether seeks to recover its former condition by
+discharging the energy it received. In these operations the elasticity
+of the Aether is called into play. After the jar is discharged, however,
+the recoil of the Aether produces a current, and the inertia of the
+current causes it to overshoot its original position, and for an instant
+the charge of the jar is reversed. The current now flows backwards in
+the same way that the lath returned back, and charges the jar as at
+first. This discharging and recharging continue backward and forward, so
+to speak, until all the energy which was originally given to the jar has
+been expended, and it resumes its normal condition. In this experiment
+the elasticity and inertia of the Aether have both been called into
+play, so that we see in this electrical experiment a similar
+illustration of the elasticity and inertia of the Aether, as manifested
+in the undulatory or wave theory of light. The question now arises, what
+are the corresponding properties as given by Maxwell in his
+electro-magnetic theory? In Art. 782 he writes: "In the theory of
+electricity and magnetism adopted in this treatise two forms of energy
+are recognized--the electro-static and the electro-kinetic--and these
+are supposed to have their seat, not merely in the electrified or
+magnetized bodies, but in every part of the surrounding space where
+electric or magnetic force is observed to act. Hence our theory agrees
+with the undulatory theory in assuming the existence of a medium which
+is capable of becoming a receptacle of two forms of energy." Faraday, in
+his _Experimental Researches_, paragraph 3075, in referring to the
+character of magnetic phenomena external to the magnet, writes: "I am
+more inclined to the notion that in the transmission of force there is
+such an action external to the magnet, than that the effects are merely
+attraction and repulsion at a distance. Such a function may be a
+function of the Aether if it should have other uses than simply the
+conveyance of radiations" (light and heat). From this extract we learn
+that Faraday was also of the opinion that the Aether around a magnet or
+any electrified body was directly concerned in the propagation of the
+electric and magnetic forces, these forces according to Maxwell being of
+two kinds. From the illustration of the charging and discharging of the
+Leyden jar, we learn that aetherial electrical waves can be produced by
+electric means, and from the alternate charging and recharging of the
+jar we learn that these aetherial waves travel to and from the jar with
+a periodic wave motion. Here, therefore, we have an aetherial wave
+motion which is produced wholly by electricity, and yet which answers
+our definition of a wave motion of light, in that it is periodic both
+in time and space, and in that aetherial wave motion Maxwell states that
+two forms of energy are called into play, which he calls Electro-Static
+and Electro-Kinetic. These correspond respectively to the elasticity and
+inertia in the older theory of the wave motion of light. It was upon
+this basis that Maxwell built up his electro-magnetic theory. Even this
+theory does not tell us what is the exact character or nature of the
+periodic wave motion of the Aether. All it tells us is, that the
+electro-magnetic wave motion of the Aether is the same in nature and
+character as the wave motion which produces light and heat. Thus it
+shows that light and electricity have a common origin, and proves that
+light is nothing more or less than an electro-magnetic phenomenon.
+Maxwell gave a number of proofs in support of his theory. He showed that
+the velocity of the electro-magnetic waves was almost identical with the
+velocity of light waves, his results being as follows--
+
+  VELOCITY OF ELECTRO-MAGNETIC            VELOCITY OF LIGHT IN
+             WAVES.                         METRES PER SEC.
+
+  Weber      310,740,000 metres per sec.   Fizeau    314,000,000
+  Maxwell    288,000,000   "       "       Foucault  298,360,000
+  Thompson   282,000,000   "       "
+
+
+From these figures it can readily be seen that the velocity of an
+aetherial wave, generated by electric means, is approximately the same
+as an aetherial wave generated by a luminous body. Thus one of the most
+important results of Maxwell's theory was to show that electro-magnetic
+disturbances produced in the Aether by an electrified or magnetic body
+might be propagated through space with a velocity equal to that of
+light.
+
+It was left, however, for Professor Hertz to place the electro-magnetic
+theory of light upon a sure and certain foundation. The results are to
+be found in his work on _Electric Waves_, translated by Professor Jones,
+1893.
+
+In his paper on "The Velocity of Propagation of Electro-dynamic Action,"
+he gave definite and experimental proof of the hitherto theoretical fact
+that the velocity of the electric waves in air was exactly the same as
+that of light, whereas he found that in wires the ratio was not the
+same, being 4 to 7. This was afterwards found out to be an error by some
+experiments made at Geneva, when it was discovered that the propagation
+in wires was the same as in the air. Among his experiments Hertz
+succeeded in producing very short electric waves of 30 centimetres in
+length, that is, about one and one-fifth of an inch. According to
+Maxwell's theory, such a wave ought to behave exactly as a beam of
+ordinary light does. Hertz proved that this was the case, and published
+his proofs in his paper on "Electric Radiation." In that paper he showed
+how such electric radiation was propagated in straight lines, like
+light, and that it could also be refracted and reflected. Thus he gave
+to Maxwell's electro-magnetic theory experimental demonstration, and
+placed it on a solid and immovable foundation. In summing up the results
+of this theory, we learn, therefore, that Hertz has conclusively proved
+that electric and magnetic effects are propagated through the Aether
+which fills all space with the same velocity that light is propagated.
+Further, he has conclusively proved the identity between light and
+electricity, and shown that electric and light radiations are
+essentially one and the same, and that they are both propagated by
+periodic wave motions of the Aether. Further, he has proved that the
+velocity of the propagation of light is the same as that of the
+electro-magnetic waves, and that these waves obey all the laws that
+govern light and heat. We have here, therefore, experimental proof of
+the identity between electricity and light, and in Art. 69 we have also
+proved the identity of light and heat, so that we have now experimental
+proof that light, heat and electricity are all due to the periodic wave
+motions and vibrations of the universal Aether, which not only fills all
+space, but which surrounds every atom and every particle of matter
+throughout the whole universe. Having established, therefore, the
+identity of heat, light and electricity, and having proved that they are
+all due to the periodic wave motions or vibrations of the universal
+Aether, it must follow as a matter of necessity that wherever in
+interplanetary or interstellar space we find light or heat waves we must
+also find electricity. We have already seen that aetherial light waves
+flood all space, both interplanetary and interstellar space, so that in
+view of the identity of the aetherial light waves and aetherial electric
+waves, it follows that the aetherial electric waves flood all space in
+the same way, and at the same time. Wherever, therefore, we find the
+light waves, there we find the electric waves also; and it will be
+impossible to find the one without the other. Thus, throughout all
+space, and indeed throughout the universe, light waves will not be found
+apart from electric waves. They are as incapable of being dissociated as
+are light and heat waves. Now we have already seen (Art. 64), so far as
+the solar system is concerned, that the sun is the generator of all
+light and heat, and that these light waves speed from the sun on every
+side with a velocity of 186,000 miles per second. From the identity of
+light and electric waves, therefore, given to us by the electro-magnetic
+theory of light, it must follow that the sun is equally the source and
+generator of the electric waves. Not only so, but as the light waves
+flood all solar space, these electric waves, being identical with the
+light waves, must flood the solar system also. Thus we learn from
+Maxwell's theory as developed by Hertz, that not only is the sun the
+generator of light and heat waves which are poured forth into space
+continually with a velocity almost inconceivable, but at the same time
+the sun is pouring forth into space electric waves which travel outwards
+in spherical shells in the same way as light waves do, and with a
+similar intensity, as we shall see in the next chapter. Now let me ask
+the reader to ponder over the fact given to us by this electro-magnetic
+theory in its relation to the solar system, and endeavour to find out
+what such an application teaches us. Let it be remembered that we are
+looking for a Centrifugal force or motion, that is, a motion from a
+centre, which is to be the exact counterpart of the Centripetal force,
+_i. e._ motion to a centre; and further, that the Centrifugal motion
+must be a repulsive motion acting in the opposite way to the attractive
+power of the Centripetal force, that is, the attractive power of
+gravity. We have seen (Art. 77) that light possesses a repulsive power.
+We have now only to prove that electricity or the aetherial electric
+waves have a repulsive motion, which will be the easiest of all to
+prove, and then we shall have proved beyond the possibility of
+contradiction, the existence of that repulsive force referred to by
+Herschel in Art. 24, which is to form the complementary and counterpart
+of the attractive power of gravity. If it can be proved that electricity
+does possess such a power, that is, a repulsive power, ever acting from
+a centre, then in view of the identity of light, heat and electricity,
+the correctness of the views we have advanced as to the repulsive power
+of light and heat will be proved beyond the shadow of a doubt, otherwise
+Maxwell's electro-magnetic theory of light is a fable and a myth, and
+Hertz' experiments were never performed. Further, if all
+electro-magnetic phenomena are due to the same aetherial medium which
+gives rise by its wave motions to light, heat and electricity, then we
+shall have discovered a medium which throughout the universe can by its
+wave motions transmit and propagate both repulsions and attractions,
+that is, the aetherial medium which is to be the physical cause of
+Universal Gravitation. In order to further develop and establish this
+point we will now consider the subject of Electricity as a Mode of
+Motion.
+
+[Footnote 21: _Mag. and Elec._]
+
+
+
+
+                              CHAPTER VIII
+
+                         AETHER AND ELECTRICITY
+
+
+ART. 79. _Electricity, a Mode of Motion._--The question as to What is
+Electricity? is one of the greatest problems of modern times. In view of
+the electro-magnetic theory of light, however, science is able to give a
+better definition as to what electricity is, than it was able to do
+previous to the introduction of the theory by Maxwell, and its practical
+establishment by Hertz.
+
+If that theory teaches us anything at all with regard to the nature of
+electricity, it teaches us that electricity is due to certain motions of
+the universal Aether, that not only fills all so-called Space, but
+surrounds all particles and atoms of all Matter.
+
+The question has been asked by various scientists, "Is Aether
+Electricity, or, in other words, are Aether and Electricity one and the
+same?" Let us look at the question from the standpoint of the analogy
+from the phenomena of light and heat. As we have already seen (Art. 61),
+heat is due to a particular kind of motion of the universal Aether,
+generally known as vibratory motion, which motion is communicated to the
+Aether by a luminous or heated body.
+
+So that we learn that heat at any rate has an aetherial basis, as it is
+a particular kind of aetherial motion. From Art. 70 we learn also that
+light is due to an undulatory or wave motion in the Aether; the waves,
+however, in this case being shorter, and of more rapid vibration than
+those waves which give rise to heat.
+
+Thus light and heat both have an aetherial basis, being due to
+vibrations of that medium. From these analogies, therefore, we come to
+the conclusion that electricity and magnetism have an aetherial basis,
+and are also due to certain kinds of motion in the Aether.
+
+That motion may be rotatory motion or vibratory motion, as the case may
+be, but whatever definition we give of electricity, we cannot as yet say
+definitely that Aether is electricity.
+
+We may assume, and indeed prove, that Aether has an electrical and
+magnetic basis, in the same way that it has a thermal or heat basis, or
+a luminiferous or light basis; but while we admit such a hypothesis, we
+cannot admit as yet that Aether and electricity are one and the same
+thing. It is not within the province of this work, however, to prove
+what electricity is, or show the relation of Aether to all the various
+forms of electricity with which we are conversant, but I think I may
+venture to make this statement, that all forms of electricity, whether
+it is electro-static, that is electricity at rest, or current
+electricity, or electro-magnetism, are due to certain forms of motion
+of the universal Aether, in the same way that light and heat are also
+particular forms of motion of the same medium. I need hardly point out
+that it is an absolute impossibility for me to deal with such a subject
+as Electricity in all its details and various aspects in one chapter; so
+that I shall have to assume that the reader is familiar with some of the
+elementary truths of the subject.
+
+At the same time, I will endeavour to make clear most of the technical
+terms used as we proceed. From the Electro-Magnetic theory of light,
+therefore, we learn that Aether has an electrical or electro-magnetic
+basis, so that, wherever we get Aether, there we have the bases and
+conditions which will produce all the phenomena with which we are
+conversant in the sphere of electricity. Given the required motions in
+the Aether necessary to produce any particular form of electricity, then
+that form is produced as soon as the motions of the Aether are generated
+by any charged or electrified body. Produce a circular current in any
+way in the Aether, and you will have a circular current of electricity;
+produce radiations from a radiating body, and you will get electric
+radiations which speed away with the velocity of light.
+
+This phase of the Aether is entirely in harmony with Dr. Larmor's
+Hypothesis of Electrons, which has already been referred to in Art. 44.
+Dr. Larmor in his work indicates that electricity has an atomic basis,
+and further states that "the atomicity of electricity is coming within
+the scope of direct experiment."[22]
+
+Now, if electricity, as I have indicated, be due to certain motions in
+the Aether, then it can easily be seen that postulating atomicity for
+electricity will be the same as postulating atomicity for the Aether.
+Dr. Larmor[23] definitely and clearly states, "that each electron has an
+effective mass of aetherial origin, which forms part, and may be the
+whole, of the mass of matter to which it is attached;" and again points
+out (p. 64) that "an electron is nothing more than a point singularity
+or pole in the electro-dynamic and optical Aether." Thus we see that Dr.
+Larmor's hypothesis as to the atomicity of electricity is a further
+proof of the atomicity of Aether, and is also in harmony with the
+electro-magnetic theory of light.
+
+Now in dealing with electricity as a mode of motion, it will be
+necessary to show that electricity is also a form of energy in the same
+way that heat and light are forms of energy.
+
+If it can be demonstrated that electricity is a form of energy, then it
+can easily be demonstrated that work can be done by it, and that that
+work may take a mechanical form in the same way that the energy of heat
+and light may produce mechanical results. Clerk Maxwell has given us, in
+his greatest work, his conception of the two kinds of energy due to
+electricity and magnetism. On the subject he writes: "In the theory of
+Electricity and Magnetism accepted in this treatise, two forms of energy
+are recognized, the Electro-Static and Electro-Kinetic (paragraphs 630
+and 636), and these are supposed to have their seat not merely in
+electrified or magnetized bodies, but in every part of surrounding
+space, wherever electric or magnetic force is observed to act. Hence our
+theory agrees with the undulatory theory of light in assuming the
+existence of a medium which is capable of becoming susceptible to two
+forms of energy."[24] The question has arisen many times as to what is
+meant by the terms Electro-Static and Electro-Kinetic energy used by
+Maxwell, and various hypotheses have been advanced to explain the same.
+
+Electro-static energy is said to be that phase of electricity in which
+we deal with stresses set up in the Aether by an electrified body at
+rest, whether that body be small or large. It further deals with the
+process of induction, that is, the action of an electrified body upon
+another body, such action taking place through the medium between the
+two bodies. Electro-kinetic energy is the energy due to electricity in
+motion. On this point Maxwell says: "A conducting circuit in which the
+current has been set up has the power of doing work in virtue of the
+current, for it is really and truly energy. It appears, therefore, that
+a system containing an electric current is a seat of energy of some
+kind; and, since we can form no conception of electric current except as
+a kinetic phenomenon, its energy must be kinetic energy, that is to say,
+the energy which a moving body has in virtue of its motion." (Arts. 551
+and 552.)
+
+It is not our purpose to deal with the electro-kinetic form of energy
+referred to by Maxwell in this chapter. We shall deal with that form of
+energy due to electricity in the succeeding chapter. We will consider
+first the effect of the electro-static energy in relation to
+electrified bodies, but I wish it to be distinctly understood, that in
+all the different kinds of electric phenomena manifested, the Aether
+plays the chief part, and without it, none of the phenomena observed
+could be produced; because, what Aether is to light and heat, so it is
+to electricity, being that medium which by its motions propagates and
+gives rise to all electrical phenomena.
+
+This being so, we have now to apply some of the facts taught us by
+electricity, and especially by the electro-magnetic theory of light, to
+our solar system, with the hope that we shall find further evidence of a
+Centrifugal Force which is physical in character, and whose action can
+be traced throughout the whole realm of space. Let us, in starting to
+apply some of the truths already learned, recall some of the facts
+concerning light, its production and its propagation. We recall the fact
+that light is produced by the action of the sun upon the Aether, giving
+rise to waves which speed away from the generating source with a
+velocity of 186,000 miles per second. We further remember that Hertz has
+definitely proved that these light waves are identical with
+electro-magnetic waves, as they ought to be if the Aether possesses an
+electrical basis, as Dr. Larmor and Professor Lodge suggest.
+
+In order that there may be no mistake on this point, let me quote from
+one of Hertz' papers, where, in his conclusion, he says: "The
+experiments described appear to me, at any rate, eminently adapted to
+remove any doubt of the identity of light, radiant heat, and
+electro-magnetic wave motion." Now, what I want to point out regarding
+this fact is this. If the sun gives rise to the aetherial light waves,
+and these light waves are identical with electro-magnetic waves as
+proved by Hertz, then the sun must either be an electrified body or else
+a magnet.
+
+It must be one or the other, because, if it were not, we should then
+have an anomaly in Nature of a body emitting electro-magnetic waves
+which is itself neither electrified nor a magnet. Therefore, according
+to our second Rule of Philosophy, such a body would be incapable of
+giving rise to these waves, as such a result would be contrary to
+universal experience and experiment.
+
+We know that the earth is a magnet, but up to the present it has never
+been proved that the sun is a magnet, although, as I shall show later
+on, Lord Kelvin and others have suggested such a possibility. If we
+assume that the sun is a magnet, our grounds for assumption would not be
+so strong at this point, and our reasons so philosophical, as they are
+if we assume that the sun is an electrified body.
+
+We have philosophical reasoning to prove that the sun is an electrified
+body in the fact that it emits or gives rise to electro-magnetic waves
+in the Aether, and no other hypothesis can be made other than that the
+sun is an electrified body, in order to prove the connection between the
+two.
+
+Thus we affirm that the sun is an electrified body, which like any
+other electrified body is capable of generating electric waves, and
+speeding them through the Aether with similar velocity to that of light.
+Not only so, but, like any other electrified body, it must have its
+electric field and possess the ability to electrify any other body by
+induction, that may happen to be in its electric field, as we shall see
+later on.
+
+Further, being an electrified body, the electric density will be
+greatest near the sun's surface, and this fact fully accords with our
+statement in Art. 45, that Aether is gravitative. As pointed out in that
+Art., if Aether be gravitative, it must be densest nearest to the
+attracting body; and, as Aether has an electric basis, then with the
+denser Aether there must be an increased electric density, which can
+only happen provided the sun is an electrified body.
+
+Sir G. Stokes was also of this opinion, for in his Burnet Lectures on
+Light he writes (p. 212): "There is nothing, therefore, unreasonable
+in supposing that the sun may be a permanently charged body."
+
+So that all the reasoning that has led to this result seems to harmonize
+and confirm each several hypothesis which has been advanced. There can
+be little doubt, therefore, that the sun is an electrified body, and it
+is for us now to carry out this fact to its logical and philosophical
+conclusion, by applying all the truths which circle round it to the
+solar system, when we shall find greater confirmation of the statement
+just advanced than any we have yet adduced.
+
+According to Professor Young of America, the sun is not only an
+electrified body, but is also the abode of living and sentient beings.
+This astronomer has suggested that the sun is the centre of electric
+force, and that converging streams of Electricity are ever flowing to it
+as a centre; but on meeting with the atmosphere they give rise to
+brilliant discharges, which thus gives the appearance of a solid
+incandescent body.
+
+Now, whether this hypothesis is correct or not, it is absolutely
+certain that the sun is an electrified body, as it gives rise to
+electro-magnetic waves in the Aether, as philosophically proved by
+direct experiments.
+
+[Footnote 22: _Aether and Matter_, p. 8.]
+
+[Footnote 23: _Ibid._, p. 64.]
+
+[Footnote 24: _Magnetism and Electricity_, by C. Maxwell, Art. 782.]
+
+
+ART. 80. _Aether and Electric Fields._--Before proceeding to apply some
+of the facts of Electricity to the solar system, let us find out what is
+meant by an Electric Field. An electric field is to an electrified body,
+what a thermal or heat field is to a heated body, or a luminous or
+lighted field is to a luminous body. If a lamp, for example, be lighted,
+its light waves spread out on every side, and extend for a considerable
+distance unless impeded by such obstacles as the wall of a room.
+
+The extent to which the light waves reach and flow might well be called
+the lighted or luminous field, and in that field the effect of the
+aetherial light waves would be manifested and seen.
+
+Now, in a similar manner, when any body is electrified, the electric
+waves spread out on every side of the electrified body, and the extent
+to which the waves spread out form what is known as an electric field.
+
+So that an electric field may be defined as any region or space in which
+electric energy is manifested by means of the aetherial electric waves,
+and across which induction may take place.
+
+[Illustration: Fig: 9.]
+
+Thus, for example, let _E_ be an electrified body (Fig. 9), then it will
+generate electric waves which will speed from the body with a velocity
+equal to that of light. If the body be a sphere, then the waves will be
+spherical in shape, and will proceed from the generating source in the
+shape of concentric spheres as indicated in the figure. Before
+proceeding any further, it is necessary that we should look at the
+electric field from the physical aspect, with a view to discover
+something of what takes place therein. As has already been indicated,
+all electric phenomena are due to motions of the universal Aether.
+
+It was left for Faraday to give us a true conception of an electric
+field, and for Maxwell to perfect that conception and give us a physical
+aspect of the same. Faraday conceived that stretching out from a magnet
+or electrified body through space, that is, through the Aether, were
+what he called "Lines of Force," and that these lines of force indicated
+not only the direction of the magnetic and electric forces, but also
+their intensity or power.
+
+Where the lines of force were closest together, there the electric or
+magnetic energy was the greatest and most intense; and where they were
+the farthest apart, there the field was weakest in energy. An
+illustration of the magnetic lines of force may be obtained by placing a
+piece of paper over a magnet, and then strewing iron filings over the
+same, when it will be seen that the iron filings will arrange themselves
+in certain curved lines, which Faraday called Magnetic Lines of Force.
+In this way Faraday mapped out the lines of force, relative not only to
+single magnets, but also to magnets with poles placed in various
+positions relatively to poles of other magnets.
+
+Now as there are lines of force which reveal the intensity and direction
+of the magnetic energy, so there are lines of force radiating out from
+electrified bodies which reveal the intensity and power of the electric
+field. The electric lines of force are radial, and are shown in the
+figure (Fig. 9) by the straight lines _D_ _F_, _D_ _H_, _D_ _K_.
+
+If an electrified pith ball, for example, be hung up in a room, then the
+lines of force, which extend from the ball, indicate the stress in the
+Aether surrounding the pith ball, so that if a hair be placed across
+these lines of force, any movement of the pith ball will be indicated by
+the motion of the hair.
+
+It was Clerk Maxwell, however, who gave to the world a true physical
+conception of Faraday's Lines of Force, in his paper on "Physical Lines
+of Force."[25]
+
+In the opening words of that paper he writes as follows: "We cannot help
+thinking that in every place where we find these lines of force, some
+physical state or action must exist in sufficient energy to produce the
+actual phenomena." Maxwell then went on to show what these physical
+actions were, which took place in the dielectric--that is, the medium
+surrounding the electrified body which we now know to be the Aether.
+
+This electric field, he pointed out, was "in a state of stress, which
+consisted of pressures or tensions different in different directions at
+the same part of the medium. The relation of these forces were
+threefold, and consisted in the most general type of stress of three
+pressures or tensions in directions at right angles to each other."
+
+Thus, in Maxwell's opinion, the existence of a medium, which by its
+physical character was able to exert energy on material bodies, was one
+of the fundamental hypotheses of his theory as to the physical character
+of Faraday's Lines of Force.
+
+This physical medium was to be capable of certain motions, and both
+electric and magnetic forces were produced by its motions and its
+stresses. Maxwell's conception, however, of the physical lines of force
+was more or less hypothetical, and up to the present, as far as I can
+learn, has not received that authority from science that such a
+hypothesis requires to make it an accepted theory in science.
+
+But what I venture to point out is, that with the view of the aetherial
+medium that is submitted in this work, Maxwell's hypothesis remains a
+hypothesis no longer, and that the hypothetical character of his theory
+ceases to exist. For, by our conception of an atomic and gravitative
+Aether, we are able to see that his physical lines of force are indeed
+physical, and that his brilliant hypothesis now receives a true physical
+foundation which otherwise it would not receive from a frictionless
+Aether.
+
+There is nothing, I venture to predict, in Maxwell's hypothesis which
+cannot be accounted for on a truly physical basis, by the conception of
+the Aether as given in this work. So that when Faraday saw in his mind's
+eye lines of force traversing space, he saw by his imagination that
+which was actually the real state of affairs, and when Maxwell enlarged
+the conception by giving to those lines of force a definite atomic and
+cellular structure, he, too, but anticipated the real nature and
+character of the Aether as given in Chapter IV., which theory is the
+direct outcome of Newton's philosophical rules, and the result of
+discarding everything that is not in accordance with experience and
+observation. Thus the lines of force which exist and surround a magnetic
+or electrified body are as real as ocean currents, or the waves of the
+sea, in that they are the manifestations of the motions of the universal
+Aether, which is as truly matter as air or water.
+
+Let us look at the analogy which exists between the lines of force and
+the gravitative Aether, and we shall see that a gravitative Aether fully
+agrees with the conception of an electric Aether as revealed to us by
+the lines of force in an electric field.
+
+As is well known, the lines of force are closer together in that part of
+the electric field where the intensity of the field is greatest; and the
+intensity of a field being greatest at the surface of an electrified
+body, the lines of force are therefore closer together nearest to the
+surface of such a body than further away.
+
+Now according to Art. 45 Aether is gravitative, therefore the Aether
+nearest the surface of a body is densest, and the aetherial atoms are
+therefore more pressed upon than the layer immediately above it. Such a
+result is exactly what should happen provided that Aether has an
+electric basis, and that Aether is gravitative. For, in Art. 45, we have
+seen that because Aether is gravitative, therefore it must possess
+various degrees of density, being densest nearest the surface of an
+attracting body.
+
+In electricity we find a similar phenomenon which corresponds to
+aetherial density, which is known as Electric Density, by which term is
+meant the amount or quantity of electricity spread over a certain area
+or surface. If we double the quantity of electricity on that given
+surface, then we double the density, and we say that the electric
+density is doubled, while if we halve the quantity of electricity, then
+we say the electric density is halved, and so on.
+
+But this is exactly what happens in the case of aetherial density, as
+proved in Art. 46. We have only to picture the number of aetherial atoms
+being doubled on a given area, and at once the physical conception of
+electric density is furnished, if we remember that Aether has an
+electric basis as suggested by Maxwell and proved by Hertz. Thus we see
+at once why it is the lines of force should be closer together nearer
+the electrified body than farther away.
+
+_Electric Potential._--There is another aspect of the electric field
+that I wish to call the reader's attention to, and that is the Electric
+Potential of such a field.
+
+Electric potential is to electricity what temperature is to heat, or
+pressure is to any medium of different densities. We have already seen,
+according to the laws of thermodynamics, that heat will flow from a
+higher temperature to a lower one, with the result that work is done. In
+the case also of water at two different levels, work can also be done by
+the water flowing from a higher to a lower level.
+
+A similar thing happens in electricity; where we have two conductors or
+two parts of an electrical fluid at different potentials, electricity
+will flow from the place of higher potential, until the potentials are
+equalized, in the same way that the temperature of two bodies at
+different temperatures would be equalized by the flow of heat.
+
+So that electric potential agrees with our conception of a gravitative
+Aether in that, being gravitative, it is denser in those parts nearest
+to the attracting body than farther away, and as the elasticity or
+pressure is proportionate to the density (Art. 47), therefore we learn
+that the electric potential of the Aether, and the thermal condition of
+the Aether, if I may use such a term, both agree and coincide with the
+density and elasticity of the Aether.
+
+Any equipotential surface which represents a particular aetherial
+density, would also correspond with a particular elasticity or pressure
+of the Aether, while it would further correspond with a particular
+temperature, if such a term is applicable to the Aether.
+
+_Equipotential Surfaces._--The fact that in an electric field there are
+different points at different potentials, leads us to the truth that in
+an electric field there are also equipotential surfaces; that is to say,
+there are surfaces where the electric density or the aetherial density
+are equal at all points on such a surface. If, for example, _E_ be an
+electrified body (Fig. 9), and _A_ _A'_, _B_ _B'_, represent equipotential
+surfaces around the body, then all the points on _A_ _A'_ would be of
+equal potential--that is, of equal energy, or pressure.
+
+We have to remember that _A_ _A'_, _B_ _B'_, are sections of a sphere, so
+that when the body as _E_ is a sphere, then the equipotential surfaces
+are spheres also. This agrees with Art. 77, in which we saw that the
+pressure around any body due to aetherial density also possessed
+equipotential surfaces.
+
+It could equally be shown that there were equipotential surfaces so far
+as the phenomena of heat and light are concerned, as these also are
+subject to the same laws. Having now very briefly considered the meaning
+of the Electric Field, Electric Potential, Electric Density, and
+Equipotential Surfaces, we are now in a position to apply these facts to
+our solar system, at least as far as the sun is concerned.
+
+In the foregoing Art. we arrived at the conclusion that the sun was an
+electrified body, therefore, in accordance with all experiment and
+observation, it, too, must have an electric field. Not only must it have
+an electric field; but that field must possess different potentials,
+possessing a higher potential the nearer the field gets to the sun, and
+a lower potential the farther away the field is.
+
+Further, around the sun there must also exist not imaginary but real
+physical lines of force which indicate the electric and magnetic forces,
+and which are made real by the atomic character of the Aether that
+surrounds it; and those lines of force would be closer together the
+nearer they got to the sun on account of the electric density of the
+electric Aether, which coincides with the density of the Aether from the
+gravitative standpoint. There would also be aetherial equipotential
+spheres, or rather oblate spheroids around the sun, as the sun is not
+strictly a sphere, its polar diameter being less than its equatorial
+diameter.
+
+[Illustration: Fig: 10.]
+
+Let us therefore endeavour to picture the sun under these conditions as
+the centre of our solar system. Let _S_ be the sun (Fig. 10), and the
+lines _A_ _A'_, _B_ _B'_, _C_ _C'_, etc. represent Equipotential
+Surfaces, Fig. 11 being a vertical section and Fig. 10 being an
+equatorial section. In Fig. 11 the sections of the equipotential
+surfaces would be vertical, while in Fig. 10 the sections of the
+equipotential surfaces would be horizontal, while the electric lines
+of force would be radial, as all electric radiations take place in
+straight lines, as we shall see was proved by Hertz, later on. We
+will suppose that the sun is stationary, as the question of the
+movement of the sun, both axially and through space, will be
+considered in a subsequent article.
+
+[Illustration: Fig: 11.]
+
+Then the question arises, How far does the sun's electric field extend?
+That is rather a difficult question to answer, but the correct answer
+would be, "As far as the sun's light extends, so far does the sun's
+electric field extend." From the electro-magnetic theory of light we
+know that wherever there are light waves, there are electro-magnetic
+waves, though at the present moment we are only dealing with the
+electric aspect of those waves.
+
+We know that the aetherial light waves reach at least as far as Neptune,
+a distance of 2,750,000,000 miles, therefore we know that the sun's
+electric field must also extend to that distance. How much further in
+space it extends we cannot tell, because the data on which to form a
+basis is inadequate.
+
+[Illustration: Fig: 12.]
+
+Thus we learn that the sun's electric field extends east and west for
+that enormous distance, but we cannot say that it extends the same
+distance north and south. Now why is that? The first reason I should
+give is the well-known experiment of a revolving body, by which we learn
+that when a body is revolving, as the sun for example, the atmosphere
+around it would seek to extend itself east and west, owing to the
+Centrifugal Force so called. But a better reason than that will be found
+from an analogy of a magnetized body. Faraday has shown in his drawings
+illustrating lines of force, that if a spherical body is magnetized, the
+magnetic lines of force extend in circles east and west, but go out into
+space in almost straight lines north, and south as the preceding figure
+shows.
+
+Therefore, accepting Faraday's experiment as the basis for our
+conception of the magnetic lines of force in the sun's electric field,
+we come to the conclusion that the electric field around the sun extends
+east and west, while the lines of force, north and south, are more or
+less radial into space as depicted in the figure.
+
+Throughout the whole of the field, the electric potential, at different
+distances from the sun, would differ in accordance with all experiment
+and observation. The greatest electric potential would therefore be
+nearest the sun's surface, and would be greatest in the equatorial
+regions of the sun, in accordance with a well-known rule which
+determines electric density and electric potential on conductors.
+
+As we proceed from the sun's surface east and west into space, we should
+pass equipotential surfaces of different potentials. Thus the pressure
+on every point of equipotential surfaces would be regulated by the
+electric density of the Aether, which would coincide with the actual
+aetherial density at that point; and as the aetherial density is the
+measure of its elasticity or pressure, so the electric potential would
+correspond with the elasticity or pressure at the same point.
+
+Thus it is possible to map out the electric field east and west by
+ever-increasing and widening circles which would be at lower potential
+the further they receded from the sun. So that by carrying out the
+electro-magnetic theory of light to its logical conclusion, we are able
+to bring the whole of the solar system into line with electric
+phenomena; and, as we proceed, we shall see that all other facts
+relating to electricity, and magnetism also, are equally as applicable
+thereto, otherwise this theory of light must fall to the ground.
+
+That this conception of the universal Aether in its application to solar
+space is not extravagant may be proved from the writings of Prof.
+Tyndall and Clerk Maxwell. Tyndall, writing on the subject of Faraday's
+Lines of Force, says:[26] "The aspect of these curves so fascinated
+Faraday that the greater part of his intellectual life was devoted to
+pondering over them. He invested the space through which they run with a
+kind of materiality, and the probability is that the progress of
+science, by connecting the phenomena of magnetism with the luminiferous
+Aether, will prove these 'Lines of Force,' as Faraday loved to call
+them, to represent a condition of this mysterious substratum of all
+radiant action."
+
+While Clerk Maxwell,[27] writing on "Action at a Distance," says: "These
+Lines of Force _must not be regarded as mere mathematical abstractions_.
+They are the _directions in which the medium is exerting tension like
+that of a rope_, or rather like that of our own muscles." I therefore
+premise, that both these statements will find a literal fulfilment in
+the conception of the Aether advanced and perfected in this work.
+
+[Footnote 25: _Phil. Mag._, 1861.]
+
+[Footnote 26: Tyndall on _Light_.]
+
+[Footnote 27: _Collected Papers_, by Niven.]
+
+
+ART. 81. _Aether and Induction._--We have seen in the preceding Arts.
+that the sun is an electrified body, possessing an electric field, which
+field possesses different intensities at different distances from its
+surfaces.
+
+If such be the case, the question at once confronts us, as to what is
+the effect of such an electrified body with its electric field upon all
+the planets which revolve around it; for, if its electric field extends
+as far as Neptune, then all the planets and meteors, that revolve
+around the sun, must revolve in the sun's electric field.
+
+Such a question can best be answered from the consideration of
+experiments and theories advanced first by Faraday, who gave to the
+world his theory of Induction, which we shall now consider.
+
+Let _A_ be an electrified body (Fig. 13), and _C_ be a body not
+electrified, but situated within the electric field of _A_. Then it can
+be experimentally proved, that _C_ will also become an electrified body
+by induction. As is well known, there are two kinds of electricity,
+Positive and Negative. We will suppose _A_ to be charged with positive
+electricity. Then it can be proved that _C_ will also be charged with
+negative electricity on the half nearest to _A_, while the other half
+will be charged with positive electricity.
+
+[Illustration: Fig: 13.]
+
+Now how has this result been brought about? According to Faraday's
+theory the particles of air, the dielectric, between _A_ and _C_ play a
+most important part in the process. As a matter of fact, each atom or
+particle of air is polarized, as the process of separating the two kinds
+of electricity is termed, so that every atom has one half of it covered
+with positive electricity, and the other half with negative electricity.
+
+For example, let _A_ and _C_ be the same brass balls with the particles
+of air between them, _A_ being the positively charged ball and _C_ the
+unelectrified ball, the shaded parts representing positive electricity
+and the unshaded parts negative electricity.
+
+Then _A_ will act inductively on the unelectrified ball _C_ through the
+medium of the particles of air _d_, _e_, _f_, _g_, _h_. The electrified
+ball _A_ will act first on the layer of particles next to it, attracting
+their negative electricity and repelling the positive according to the
+well-known law that "Unlike electricities attract, like electricities
+repel each other."
+
+The positive electricity in the first layer then acts in the particles
+of the next layer in the same way, and thus the inductive action is
+transmitted through the particles, from layer to layer, until we come to
+the last layer of particles next to the ball _C_.
+
+As the half of each atom or particle nearest to _C_ is positively
+electrified, then the half of the ball _C_ nearest to the layer becomes
+negatively electrified, while the half further away is positively
+electrified. Thus we say that _C_ has become electrified by induction
+through the polarization of the particles of air which lie between the
+two bodies. Faraday on this point says: "Thus induction appears to be
+essentially an action of contiguous particles, through the
+intermediations of which the Electric Force, originating at a certain
+place, is propagated or sustained at a distance, appearing there as a
+Force of the same kind exactly equal in amount, but opposite in its
+direction and tendencies."[28]
+
+While again he states:[29] "Induction appears to consist in a certain
+polarized state of particles into which they are thrown by the
+electrified body sustaining the action, the particles assuming positive
+and negative parts which are symmetrically the lines of Inductive
+Force." Thus in the case of any electrified body, acting on an
+unelectrified body at a distance, it has to be definitely understood
+that _the action at a distance_ is alone communicated and propagated by
+the dielectric or medium which exists between the two bodies. Though in
+the case of Gravitation it has been mathematically assumed, that action
+at a distance is possible, yet experimentally and physically such an
+assumption is philosophically incorrect, as all experience and
+experiment go to prove that there is no such thing as action at a
+distance manifested, except such action is propagated through the
+intervening medium, as stated and proved by Faraday.
+
+In order to bring Gravitation, therefore, into line with our experience,
+it will have to be demonstrated that it, too, is the result of the
+action of the intervening medium, that is, the Aether, which is a result
+we are being led up to.
+
+We have already seen that the sun is an electrified body, possessing an
+electric field, and as all electrified bodies can act on other bodies in
+their field inductively, then a similar result should happen in the
+solar system, that happens in any electrical experiment on induction,
+with the result that all the planets should become electrified bodies by
+induction, such action taking place, as Faraday points out, through the
+medium which divides the sun and the planets, that is, the Aether.
+
+Of course with a frictionless and non-atomic Aether such a result would
+be an impossibility, but with our conception of an atomic and
+gravitative Aether the result is now attainable. We have therefore to
+think of the sun, the centre of the solar system, being an electrified
+body, and for illustration we will suppose it to be a positively charged
+body.
+
+All around the sun is the atomic Aether, which is polarized in the same
+way that the particles of air were polarized; that is, the two kinds of
+electricities in the aetherial atom are separated, the negative being on
+that side nearest to the sun, and the positive on the side further away.
+In this way the whole aetherial medium would be polarized, and any body
+in the field would be electrified by induction, with the result that the
+side nearest the sun would be negatively charged, and the opposite side
+positively charged.
+
+Thus let _S_ (Figs. 10 and 11) be the sun, and the circles represent
+equipotential surfaces, then one half of every surface would be
+negatively electrified and the other half positively electrified, that
+is, assuming the sun to be a positively electrified body.
+
+If _M_ represents Mercury, _V_ represents Venus, and _E_ represents the
+Earth (Fig. 10), then it can readily be seen that all these would be
+negatively electrified on the side facing the sun; and, as they rotate
+on their axes, each part of the planet would be positively and
+negatively electrified once each day.
+
+We are assuming that the medium is at rest, but according to our
+conception in Art. 44, all the aetherial atoms are in rotation on their
+axes, in the same way that the earth rotates on its axis, so that each
+of these aetherial atoms would present different parts of its surface to
+the sun as it rotates on its axis; but, as that does not affect the
+principle of induction, such a fact need not now be fully considered.
+
+Let us now ask, What is the result of all the planets becoming
+electrified bodies in the same way that the sun is an electrified body?
+Arguing from experience, we come to the conclusion that each planet must
+also possess its electric field, which also must have its lines of
+force, its different potentials at different distances, and its
+equipotential surfaces. So that Mercury, Venus, the Earth, Mars,
+Jupiter, Saturn, Uranus, and Neptune all have their electric fields,
+with their own lines of force, and with their equipotential surfaces.
+
+If we carry the analogy further still, then it can also be proved that
+the Earth, and those planets which have moons or satellites, also act
+inductively on their satellites, with the result that they too become
+electrified bodies, with their own smaller electric fields and lines of
+force. This may seem at first sight a little confusing, but the
+confusion will gradually disappear if we will look at it carefully for a
+moment or two. Let us endeavour to picture the solar system from this
+new standpoint, and map out the equipotential surfaces, which this idea
+suggests. Let _S_ represent the sun (Fig. 14), the initials of all the
+planets and satellites representing the various planets; then we get the
+following plan of the solar system with the various equipotential
+surfaces shown by the circular lines.
+
+We are now supposed to be looking down on all the solar system from
+above it, so to speak, so that we should be looking at what we call the
+North Poles of the sun and planets.
+
+[Illustration: Fig: 14.]
+
+Thus we see that the equipotential surfaces around the sun are huge
+circles which stretch out as far as Neptune or even beyond, but within
+those circles we find each of the planets revolving round the sun, each
+with its own equipotential spheres, which are circles also, while around
+the various planets are the satellites, from the moon of our Earth, to
+the two satellites of Mars, five of Jupiter, eight of Saturn, each with
+its own lines of force and electric fields.
+
+Of course we must not forget that all these revolve round the sun, and
+the question may suggest itself to the reader's mind, if such a result
+is possible. I shall prove later on, that according to Maxwell such an
+event is possible, but at present we will consider them stationary.
+
+Now let us see how such a conception compares with our hypothesis of a
+gravitative Aether. If Aether be gravitative, then the sun must have an
+attraction for the Aether, and its aetherial field would stretch out
+into space as far as Neptune at least.
+
+So that it can readily be seen that the aetherial field of the sun's
+attractive power coincides with the electric field which the sun
+possesses as an electrified body. Again, if Aether be gravitative, then
+all the planets must also have an aetherial field, which will be
+co-extensive with their electric field also. The same principle applies
+to each of the satellites, with the result that they too will possess an
+aetherial field which will be equal in extent and limit to their
+electric field.
+
+As the satellites revolve around their primary planet taking their
+electric fields with them, so the planets with their associated
+satellites revolve around the sun taking their electric and aetherial
+fields with them. Thus we get a glimpse, though at this point very
+shadowy and indistinct, of those motions of the universal Aether, which
+help to constitute the harmony, beauty, and order of the universe. We
+have seen, therefore, that as the sun is an electrified body, so all the
+planets and satellites are electrified bodies also, each possessing its
+own field, with all that such a field implies.
+
+We shall find that such a conception is borne out by experience and
+observation, when we come to deal with the Earth as a magnet; because we
+shall afterwards learn that the Earth is an electro-magnet, possessing
+its magnetic field, which is co-existent and equipollent with its
+electric field.
+
+[Footnote 28: _Exp. Res._, 1297, 1298.]
+
+[Footnote 29: Par. 1298.]
+
+
+ART. 82. _Energy of the Field._--We have seen in Art. 79 that every
+electrified body has an electric field. We have further learned, in
+carrying the electro-magnetic theory of light to its logical conclusion,
+that all the planets and satellites together with the sun must be
+electrified bodies, each possessing its electric field.
+
+We have now to determine the effect of such a truth from its dynamical
+aspect upon the bodies within the field, that is to say, we have to
+consider the energy of such electric fields, and endeavour to find out
+the effect of such energy upon other bodies within that field.
+Maxwell,[30] in his introduction to a paper on "The Dynamical Theory of
+the Electro-magnet Field," writes on the matter thus: "It appears
+therefore that certain phenomena in electricity and magnetism lead to
+the same conclusion as those of optics, namely, that there is an
+aetherial medium pervading all bodies and modified only in degree by
+their presence; that the parts of this medium are capable of being set
+in motion by electric currents and magnets; that this motion is
+communicated from one part of the medium to another by forces arising
+from the connection of these parts; that under the action of these
+forces, there is a certain yielding depending upon the elasticity of
+these connections; and that therefore energy in two different forms may
+exist in the medium, the one form being the actual energy of motion of
+its parts, and the other being the potential energy stored up in the
+connections in virtue of their elasticity."
+
+The two forms of energy he gives us in his work on _Magnetism and
+Electricity_, where, in the quotation already given in Art. 79, he
+states them to be electro-static and electro-kinetic energy, while in
+paragraph 792 of the same work he adds: "The intrinsic energy of the
+medium is half electro-static and half electro-kinetic, that is, half is
+due to electricity and half is due to magnetism."
+
+We are, however, only dealing at this point with the electro-static
+energy in the electric field, as we shall deal with the electro-kinetic
+energy in the following chapter.
+
+We have, therefore, to conceive of an electrified body generating
+electric or electro-magnetic waves, which speed away from the generating
+source on every side with the velocity of light. Now we have already
+seen that the aetherial waves which give rise to heat and light possess
+a repulsive power, that is, they exert a pressure on the body with which
+they come into contact.
+
+If, therefore, in the electric field there is this energy manifested as
+proved by Maxwell, and that energy takes partly the form of a pressure
+as stated by Maxwell, then we have in the electro-static energy of the
+electric field, another indication of that centrifugal force for which
+we are looking, and whose existence was so satisfactorily demonstrated
+to Herschel by the phenomena of comets' tails.
+
+That there is this pressure in an electric field was conclusively proved
+by Maxwell, and experimentally demonstrated by Professor Lebedew (Art.
+77). Maxwell distinctly states on this point, "that the combined effect
+of the electro-static and electro-kinetic stresses is a pressure equal
+to 2 P. in the direction of the propagation of the waves," that is, away
+from the electrified or charged body.
+
+He continues: "Thus, if in strong sunlight the energy of light which
+falls on one square foot is 83.4 foot-pounds per second, the mean energy
+in one cubic foot of sunlight is about .0,000,000,882 of a foot-pound,
+and the mean pressure on a square foot is .0,000,000,882 of a pound
+weight. A flat body exposed to sunlight would experience this pressure
+on its illuminated side only, and would therefore be _repelled_ from the
+side on which the light falls."[31]
+
+This pressure only gives the result due to the pressure of one cubic
+foot of sunlight. What must be the pressure, therefore, due to the whole
+of the sunlight received by the flat body from the sun? The total
+pressure, whatever it may be, would be equal to 2 P. according to
+Maxwell, and half of that is due to electricity, and half due to
+magnetism. Now such a result is entirely in harmony with the conception
+of the Aether as given in this work. For, if Aether possess an electric
+basis as suggested by Maxwell, and it is also gravitative as suggested
+in Art. 45, then it must follow, as pointed out in a previous Art., that
+throughout the field there is a varying difference in the potential of
+the field; the potential being regulated by the electric density, that
+density being equivalent to the aetherial density. Further, as the
+elasticity of the medium which regulates the pressure is proportional to
+the density, so the pressure must decrease, as the elasticity
+decreases--that is, as the electric potential decreases, or the electric
+density is diminished. Therefore, if the sun be an electrified body,
+ever generating electro-magnetic waves which speed away from it on every
+side, then, whenever any of these waves come into contact with a planet
+or comet, that planet or comet would be repelled from the sun by the
+pressure of these electro-magnetic waves to which the sun gives rise in
+its electric or electro-magnetic field.
+
+Thus we again come to the conclusion that the sun is not only the centre
+of a centripetal force due to Gravitation, and subject to certain laws,
+whose physical cause is unknown, but it is equally the centre and source
+of a centrifugal force, in that it is an electrified body, and gives
+rise to electric waves which produce a pressure on any body upon which
+they fall, in the sun's electric or aetherial field. It has only to be
+demonstrated, therefore, that this centrifugal force satisfactorily
+fulfils all the laws required as laid down in Art. 24, that is, that its
+course is along the same path as the Centripetal Force of Gravitation,
+that it is subject to the same law of intensity, which is inversely as
+the square of the distance; and further (what is the most important at
+this stage), that the combined effect of the pressure of two bodies is
+equal to the product of their masses, then we shall have discovered that
+which we set out to discover, viz. a complementary force to the
+attractive force of Gravitation.
+
+Unlike the centripetal force, however, the centrifugal force will be
+purely a physical one, due to a purely physical medium, the Aether,
+whose properties and motions can be accounted for on a physical, and not
+on a hypothetical basis.
+
+Further, as the planets are also electrified bodies (Art. 81), they too
+will possess an electric field, and will generate electric waves, which
+will also exert a centrifugal force upon all bodies upon which the waves
+fall. So that, like the sun, the planets are not only the centre of a
+centripetal force, which ever acts towards their centre; but they are
+also the centre of a centrifugal force, due to the aetherial electric
+waves to which they give rise in the Aether.
+
+The application of the same principle may be extended to every satellite
+that exists in the solar system, and indeed to every particle and atom
+of matter that exist throughout the universe, for wherever we find the
+Aether, there we find this centrifugal force, which is due to the
+electric aetherial waves generated by the atom or particle of matter, or
+by any combination of atoms, as a meteor, satellite, planet, sun or
+star.
+
+[Footnote 30: _Collected Papers_, by Niven.]
+
+[Footnote 31: _Magnetism and Electricity_, Arts. 791 and 793.]
+
+
+ART. 83. _Electric Radiation._--We learn, therefore, that the sun,
+together with every planet and satellite in the solar system, is the
+centre of a centrifugal force, which is due to the radiation of electric
+waves by an electrified body. We have now to prove that this force
+fulfils all the laws required, in order for it to become the
+complementary law to the Centripetal Force of Gravitation. We will first
+show that this centrifugal force which proceeds from the electrified
+body is radiated out into space in straight lines with the velocity of
+light and radiant heat.
+
+As we have already seen, it was due to the genius of Hertz to show the
+identity between electric radiation and radiant light and heat. In his
+paper on Electric Radiation he says:[32] "I have succeeded in producing
+distinct rays of electric force, and in carrying out with them the
+elementary experiments which are commonly performed with light and
+radiant heat." We have seen in Arts. 65 and 76 that radiant heat and
+light are propagated in straight lines, so that, according to Maxwell's
+electro-magnetic theory, a ray of electric radiation should also be
+propagated in straight lines.
+
+This Hertz proved, and gave his results in his paper "On the Action of a
+Rectilinear Oscillation upon a Neighbouring Circuit," in which he fully
+demonstrated that when electric action takes place between two charged
+bodies, the electric force is radiated out into space in straight lines
+in the same way that light and radiant heat are radiated. In his paper
+on "The Finite Velocity of Electro-magnetic Actions," he showed that the
+velocity of the electro-magnetic waves was the same as that of light. In
+the summary of this paper (paragraph 3) he states: "There are many
+reasons for believing that the transverse waves of light are
+electro-magnetic waves; a firm foundation for this hypothesis is
+furnished by showing the actual existence in free space of
+electro-magnetic transverse waves which are propagated with a velocity
+akin to light."
+
+Again, in his paper on "Electric Radiation," he not only showed how the
+radiation was propagated in straight lines, like light, but also proved
+that while it was reflected by metals, the electric beam was able to
+pass through doors and stone walls, and adds, "that it was with
+astonishment that one saw the electric beam appear inside a closed room
+after its passage through the door."
+
+Thus Hertz has shown that both electric and magnetic effects are
+propagated through the Aether with finite velocity, and that that
+velocity is exactly the same as the velocity of light. He further proved
+that this propagation takes place in straight lines, in the same way
+that radiant heat and light are propagated. This being so, it is
+necessary for us to apply these truths to the solar system, with a view
+to find out what such a result teaches us.
+
+We have seen in a preceding article, that the sun is an electrified
+body; therefore it, too, must generate these electro-magnetic waves, and
+radiate them into space on every side with the velocity of light. Let us
+try to picture the scene. Let _S_ represent the sun, and the circle
+round it represent the equipotential spheres which exist round the sun.
+(See Figs. 10 and 11.) As the intensity of the electric force is greater
+nearer the sun than further away, these equipotential surfaces will be
+closer nearer the sun than further away.
+
+Then let the straight lines which radiate out from the sun represent the
+path of an electric ray. It can be easily seen that these electric rays
+cut the equipotential surfaces at right angles, as they pass from the
+centre of the sun outwards into space. Now these lines not only
+represent the path which the electric ray takes in its journey through
+space, but exactly coincide with the electric lines of force as
+conceived by Faraday. This great thinker and experimentalist not only
+conceived lines of magnetic forces existing in the dielectric or medium
+between two electrified bodies, which in this case is the Aether, but
+also conceived lines of electric force which started at a conductor, or
+an electrified body, and radiated out into space.
+
+Thus a line of electric force has a definite direction, and always
+starts from an electrified body. If it were possible to move a planet
+along one of these lines of force, its path would be that of a straight
+line. If on the other hand a planet moved at right angles to one of
+these lines of force, that is, along the surface of an equipotential
+sphere, then no work would be done against the electric force, as on
+such a sphere the electric force would be of the same intensity.
+
+So that from Hertz' experiments it can be demonstrated, that if there be
+any electric force existent in the Aether, due to the action of the sun
+upon the Aether, then such a force is directed along the path of a
+straight line into space with the velocity of light, which, as already
+pointed out, is the path taken by a ray of radiant heat and light, and
+coincides with the path taken by the centripetal force.
+
+It has been demonstrated that such electric force is accompanied by a
+repulsive force, or more correctly a pressure, so that here we have
+further evidence of the existence of a centrifugal force which finds its
+generating source in the sun, which is also the centre of the attractive
+force of Gravitation in the solar system.
+
+The application of Hertz' experiments may be made not only to the sun,
+but also to every planet and satellite that exists in space with the
+same result; and, further, may be extended to every particle and atom
+that exists throughout the universe. For, according to Art. 43, we have
+learned that Aether is universal, and we have seen that it is
+gravitative, and have learned from the electro-magnetic theory of light
+that it has an electro-magnetic basis. Therefore, to be thoroughly
+consistent, we must not stop in the application of this principle at any
+point in the whole universe.
+
+Either the whole principle is of universal application, or it ceases to
+be a universal law. Therefore, if there is this centrifugal force
+operating along a straight line from the centre of an electrified body,
+such centrifugal force must be in its application universal, in order to
+be complete, and in order to satisfactorily form the counterpart of the
+centripetal force which is also universal, and operates along the
+straight line joining the centres of gravity of any two bodies.
+
+[Footnote 32: Hertz on _Electric Waves_.]
+
+
+ART. 84. _Law of Inverse Squares._--We have learned therefore from the
+preceding Arts., that the solar system may be looked upon as an electric
+field, with the sun as the electrified body occupying the centre. We
+have also seen that there is a centrifugal force in all electric fields,
+which is due partly to electric waves, and partly to the magnetic waves
+of the Aether.
+
+It will be interesting to find out, what law governs the intensity of
+this force in any part of the field, or at a given distance from the
+central body. We have seen (Art. 66) that the law governing the
+intensity of heat at any distance from the sun, is the law of inverse
+squares. Further, from Art. 75 we have also learned that light is
+subject to the same law of inverse squares, as indeed it should be, if
+it be due to one and the same medium, the Aether.
+
+If, therefore, electricity is also due to certain motions of the
+aetherial medium originated by the action of an electrified body as the
+sun, in the same way that light and heat waves are originated, then it
+ought to follow that the repulsive power of electricity is also subject
+to the same law of inverse squares. As a matter of fact, that is exactly
+the state of affairs, so that we find the intensity of the repulsive power
+in the Aether from any central body, due to the electric waves, or the
+pressure due to the wave motions of the electric Aether, in relation to
+that body, is governed and controlled by the same law that governs light
+and heat.
+
+It may be suggested that such a coincidence is not a very strong
+argument, as all forces emanating from a central body are subject to the
+same law of inverse squares. In reply to that, I should like to point
+out, that even that objection only strengthens the conception of the
+Aether that we are endeavouring to complete. Our contention is, that all
+physical forces, whether they be light, heat, electricity, magnetism or
+Gravitation, are all due to the motions of the aetherial medium; which
+motions may be generated by a heated or luminous or electrified body,
+and are radiated from such a body in waves of concentric spherical form,
+and are all subject to the laws of inverse squares.
+
+So that the fact of the intensity of the centrifugal force due to the
+repulsive power of electricity falling into line with the law governing
+light and heat is, to my mind at any rate, only a clearer proof of the
+one common origin of all the physical forces. The law of inverse squares
+in relation to electricity may be thus stated. The Centrifugal or
+Repulsive Force between two charged electrified bodies acts inversely as
+the square of the distance between them.
+
+This law was proved by Coulomb by means of an instrument known as
+Coulomb's Torsion Balance, and I must refer the reader to any work on
+electricity for a full establishment of this law. Suffice to say, that
+it has been experimentally demonstrated that the law holds good in
+relation to the phenomena of electricity; and, wherever we get the two
+kinds of electricity present in any medium or conductor, owing to the
+polarization of its particles, there we have this law operating in
+relation to the intensity of the repulsions of the two bodies directly
+concerned.
+
+We have already learned that the sun is an electrified body, and from
+that hypothesis we have arrived at the conclusion that the earth and all
+the other planets are electrified bodies. This being so, it naturally
+follows that the intensity of the centrifugal force between any two of
+these bodies, as the sun and the earth for example, or the sun and
+Jupiter, is subject to the law of inverse squares; and that the
+repulsion of the sun and the earth for each other is always regulated by
+their distance, being inversely as the squares of the distance between
+them.
+
+Thus, if the distance between the sun and any planet is reduced to
+one-half, which is an exaggerated view, the intensity of the centrifugal
+force is increased four times; if the distance be doubled the force is
+reduced to four times its former intensity, and so on.
+
+Whatever the distance may be between the sun and any of the planets, if
+that distance be increased or decreased, then the intensity of the
+centrifugal force due to electric waves is increased or decreased in
+accordance with the law of inverse squares. This agrees with the
+centripetal law of Gravitation, as the Attraction of Gravitation is also
+subject to the same law of inverse squares, and, as we have seen (Art.
+83), its path coincides with the path of centrifugal force, as it
+pursues the path represented by the straight lines joining the two
+bodies.
+
+So that, whenever, and wherever, at any point in space in relation to
+the central body, the sun, the intensity of the attractive force is
+increased according to the law of inverse squares by the distance from
+the central body being diminished, at exactly the same time and in
+exactly the same manner, the repulsive force due to aetherial electric
+waves is also increased. If the attractive force is doubled, then the
+repulsive force is doubled. If the attractive force is halved, the
+repulsive force is halved. If the attractive force is lessened
+gradually, then the repulsive force is lessened gradually; and if
+quickly, by the quicker motion of the planet through space, then the
+repulsive motion is also increased with a quicker motion.
+
+Further, like the repulsive power of light and heat, the repulsive power
+of electricity takes exactly the same path as the attractive power of
+Gravitation.
+
+Thus we learn that the sun is the centre of two forces: first, a
+centrifugal force due to the pressure of the aetherial medium which is
+ever directed away from the sun, and which may either be produced by
+electric or thermal or light waves; and second, it is the centre of a
+centripetal force known as the Law of Gravity, whatever that may be due
+to. Further, the centrifugal force is also subject to the same law of
+intensity as the centripetal force, and moreover takes exactly the same
+path which the centripetal force takes.
+
+So that we have only to prove that they both agree in another
+particular, viz. that their power is regulated by the product of their
+masses, and then we shall have discovered a real physical force, which
+is the exact complement and counterpart of the centripetal force due to
+gravity.
+
+
+ART. 85. _Second Law of Electricity. (Product of Masses.)_--We have now
+to prove that the centrifugal force exerted by any electrified body
+operates upon another electrified body in the same proportion and with
+exactly the same force which governs the centripetal force. From Art. 21
+we learn that the centripetal force which is exerted by one body upon
+another is equal to the product of their masses. In order, therefore,
+for any centrifugal force to be the exact counterpart of that force, it
+too must be subject to the same law of proportion, that is, the
+repulsive force between any two bodies must be equal to the product of
+their masses.
+
+We have shown that there is a repulsive force exerted by the Aether from
+the phenomena of heat, light, and electricity, and that that repulsive
+force or energy fulfils every condition required by a centrifugal force
+or motion, with the exception of the part referring to the fact that
+such a force must be proportionate to the product of their masses. What
+we were unable to accomplish, however, from the phenomena of heat or
+light we are now able to accomplish from the phenomena of electricity.
+
+For in the phenomena of electricity we find a law which runs thus: "The
+force of repulsion" (which is the part of electricity we are now dealing
+with) "between two electrified bodies is equal to the quantities of
+electricity with which the body is charged." This law was established
+and proved by Coulomb by means of a delicate instrument known as the
+Torsion Balance, with which he also established the law of inverse
+squares.
+
+It will be seen at a glance that there is a slight difference between
+stating the law of proportion with reference to the centripetal force,
+and the centrifugal force or motion. In the former we state the
+proportion is equal to the product of the masses, while in the latter we
+say that the proportion is equal to the product of the quantities of
+electricity.
+
+In the one case we deal with the mass of the body, whether it be atom,
+molecule, planet or star; in the other case we deal with quantities of
+electricity. At first sight it may seem that there is little, if any,
+connection between the two laws, but a careful reflection of the
+hypotheses laid down with regard to the aetherial medium will show that
+there is not only a close connection between these two laws of
+proportion, but also that the law governing the repulsive power of the
+aetherial electric waves is the direct outcome of the law of proportion
+governing the centripetal force. Let us restate our case in regard to
+the aetherial medium.
+
+We have learned that the Aether is gravitative, and that it also has an
+electro-magnetic basis is proved from Maxwell's electro-magnetic theory
+of light. Let me ask the reader this question therefore. If the Aether
+be gravitative, what must be the rule governing the extent and density
+of the aetherial atmosphere surrounding any planet or sun or other body?
+If the Law of Gravity teaches us anything at all, it distinctly teaches
+us that the gravitating power of any body is regulated by the mass of
+the body, as the law states that the attraction is proportionate to the
+product of the masses. It states nothing about volume or condition of a
+body.
+
+The exact size or state of a body has no direct result bearing on
+gravitation attraction; the underlying principle being that the
+attractive force is dependent on the mass, and only on the mass of a
+body. So that if the volume of any body, whether atom, planet, satellite
+or sun, be doubled, its attractive power remains the same, simply
+because the mass of the whole body remains the same. Mass, we are told
+by mathematicians, is equal to the volume multiplied by the density, and
+whenever we increase the volume of a body we decrease the density, the
+total mass of the body remaining the same.
+
+If the volume be doubled, then the density of the body would be halved,
+and _vice versâ_, but through all the changes of volume and density that
+may arise from the addition of heat or diminution of heat, the total
+mass of a body always remains the same. Looked at from the atomic
+standpoint, taking hydrogen as unity, an atom of oxygen would always
+weigh sixteen times an atom of hydrogen, and this principle applies
+throughout the whole realm of the atomic world. Further, the same
+principle or law, that the mass is equal to the volume multiplied by the
+density, is true of the planetary or even the stellar world. Thus the
+great regulating principle of the attractive force of gravity is mass,
+and not volume, or density, or any other condition.
+
+Now as Aether is subject to the attractive force of gravity, the extent
+of the aetherial field, and the density of the Aether near the surface
+of any body, must be subject to the same law regarding mass. That is,
+the aetherial atmosphere of any atom, or molecule, or satellite, or
+planet, or star is dependent upon the mass of the atom, the molecule, or
+the planet, or the star as the case may be.
+
+Thus an atom of oxygen would have a larger or denser aetherial
+atmosphere than an atom of hydrogen, exactly proportionate to their
+respective masses. A planet whose mass was represented by 1,000,000 tons
+would have twice the quantity of Aether around it, compared to a planet
+weighing only 500,000 tons, and so on, the aetherial atmosphere always
+being proportionate to the mass of the planet, or the satellite, or the
+sun, or the star. The fact which we learn from these considerations is
+that the quantity of Aether, which is attracted by any body, is always
+proportionate to the mass of the body attracting it.
+
+But we have learned from Art. 78 that Aether has an electro-magnetic
+basis, and that the density of the Aether is co-equal with electric
+density, so that the quantity of Aether which is attracted and held
+bound by any body is really equal to the quantity of electricity that
+such a body is covered with, or is charged with. If the quantity of
+Aether around any body is doubled because its mass is doubled, then the
+quantity of electricity is also doubled, but as long as the mass remains
+unaltered, the quantity of electricity held bound by that mass remains
+unaltered also. The area of the mass may be doubled, and in that case
+the density of the electricity would be halved, but as long as the mass
+remained the same, the quantity of electricity would remain the same
+also. So that we learn from this reasoning that the mass of a body, and
+quantities of electricity on that mass, are always proportionate to each
+other, because of the fact that Aether is gravitative, and also has an
+electro-magnetic basis.
+
+If we wanted further evidence of the hypothesis that has just been
+advanced, such evidence is to be found in the hypothesis suggested by
+Faraday as to the electro-chemical equivalents of all elements.
+According to this hypothesis every element has its exact
+electro-chemical equivalent, or definite quantities of electricity are
+to be found in association with each and every particular atom of each
+element. Writing on the subject in his _Exp. Res._, par. 852, he says:
+"The theory of definite electro-chemical action appears to me to touch
+upon the absolute quantity of electricity or electrical power belonging
+to different bodies. Although we know nothing of what an atom is, yet we
+cannot resist forming some idea of a small particle which represents it
+to our mind, and though we cannot say what electricity is, so as to be
+able to say whether it is a particular matter or matters, or mere motion
+of ordinary matter, yet there is immensity of facts which justify us in
+believing that the atoms of matter are in some way endowed or associated
+with electrical powers to which they owe their most striking qualities,
+and amongst them their chemical affinity." Further, in Art. 857, he
+states: "I can have no doubt that, assuming hydrogen as 1, and
+dismissing small fractions for the simplicity of expression, the
+equivalent number or atomic weight of oxygen is 8, of chlorine 36, of
+bromine 78.4, and of lead 103.5, etc., notwithstanding that a high
+authority doubles several of these numbers."
+
+Then, writing upon the definite relationship of these equivalents in
+compounds, he states (Art. 835): "Electro-chemical equivalents are
+always consistent, that is, the same number which represents the
+equivalent of a substance _A_ when it is separating from a substance _B_
+will also represent _A_ when separating from a third substance _C_. Thus
+8 is the electro-chemical equivalent of oxygen, whether separating from
+hydrogen, tin, or lead; and 103.5 is the electro-chemical equivalent of
+lead, whether separating from oxygen, or chlorine, or iodine."
+
+Here, then, from the pen of one of the greatest thinkers and
+experimentalists of modern times we have confirmatory evidence that the
+mass of any body is practically synonymous with the quantity of
+electricity associated with that body. For if the principle is true in
+its application to atoms, it is true in its application to molecules;
+and if it is true in relation to molecules, it is equally true in
+relation to small bodies composed of molecules. And if it holds good in
+relation to small bodies, the principle is equally true in its
+application to larger bodies, as the earth, and therefore is of
+universal application and proves the statement already made, that the
+masses of bodies and quantities of electricity in association with that
+mass are always proportionate to each other.
+
+We are now in a position to compare the proportion of the centripetal
+and centrifugal forces. The attractive power of the former, between two
+bodies, is equal to the product of their masses; the repulsive power of
+the latter is equal to the product of the quantities of electricity
+bound to them, and that, as we have seen, is regulated by the respective
+mass of each body. Let us apply this fact to the solar system and see
+how it works.
+
+Taking the mass of the earth as unity, we find that the mass of the sun
+is 324,000 greater, so that the attractive power of the two bodies would
+be represented by the product of the two numbers; but because the sun is
+that number of times greater, its aetherial and, therefore, its electric
+field would be so many times greater, with the result that the
+proportion of the repulsive forces between the two bodies would be
+exactly the same as the attractive forces between the two bodies, that
+is, if the mean distance remains the same.
+
+In the same way, it can be shown that the attractive forces between the
+earth and Jupiter exactly equal the repulsive forces between the two
+planets at their mean distance, or the attractive forces between any two
+planets or satellites are exactly counterbalanced by the repulsive power
+of the centrifugal force at their mean distances.
+
+Thus the centrifugal force of every body is the exact opposite of its
+centripetal force at their mean distance, because the laws governing the
+centrifugal force are the exact counterpart of the laws governing the
+centripetal force. A comparison of the two will prove this. From Arts.
+20, 21, and 22 we have seen that the centripetal force is exerted along
+the straight lines joining the attracting bodies, that the intensity of
+the attracting body is inversely as the square of the distance, while
+the total force is proportionate to the product of their masses.
+
+From the phenomena of light, heat, and electricity, we learn that the
+centrifugal force due to aetherial pressure is exerted along straight
+lines, that the intensity is inversely as the square of the distance,
+while the total force between two bodies is equal to the product of the
+quantities of electricity, which are regulated by the product of their
+masses.
+
+Thus, if every planet and satellite could be conceived to be motionless
+in space, and these two forces could be set in operation without
+producing rotation or translation in space, which is impossible, then
+every planet and satellite would occupy, by the joint exercise of these
+two forces, the same position in relation to the sun represented by
+their mean distances, as long as the solar system existed as a separate
+system in the realm of aetherial space. We have therefore discovered by
+strict philosophical reasoning, based on Newton's Rules of Philosophy, a
+real tangible centrifugal force existing throughout the universe;
+because it is entirely due to the pressure of an universal Aether, whose
+operation is ever directed from a central body, which force was
+indicated by Herschel, and its existence to his mind was demonstrated by
+the repulsion exhibited in connection with the tails of comets.
+
+We have now to go a step further, and show that the same pressure also
+includes the magnetic phenomena, as indicated by Clerk Maxwell, and that
+magnetic phenomena are also due to the aetherial medium, and then we
+shall have linked together in one common medium the majority of the
+forms of energy, as light, heat, electricity and magnetism, with which
+we are familiar.
+
+If it be demonstrated that these two forces, the centrifugal force and
+the centripetal force, can conjointly account for all the motions of the
+celestial bodies, then we shall have conclusive evidence that one of the
+forces is physical and due to the pressure of a physical medium. After
+that it will be comparatively easy to show that the centripetal force is
+also due to the same aetherial medium, and then we shall have
+accomplished that which we set out to accomplish, viz. the establishment
+of a physical cause for universal Gravitation, which physical cause is
+alone to be found in the pressures, tensions and motions of an universal
+Aether.
+
+
+
+
+                               CHAPTER IX
+
+                          AETHER AND MAGNETISM
+
+
+ART. 86. _Electro-magnetism._--We have now to look at the relation of
+magnetism to electricity, or, in other words, to prove the identity that
+exists between magnetism and electricity. In Art. 78 we have proved the
+identity between electricity and light, so that if we can now prove the
+identity between electricity and magnetism, then, wherever we get
+aetherial light waves, we must also get aetherial electro-magnetic
+waves.
+
+As the light waves due to the vibrations of the Aether are practically
+universal in extent, then it must follow, if the identity of the light
+waves with electro-magnetic waves is established, that the universality
+of electro-magnetic waves is established also, with the natural result,
+that, wherever we get these electro-magnetic waves, there we shall have
+the conditions by which all electro-magnetic phenomena are produced.
+
+Now it can be demonstrated by actual experiment that wherever we get a
+circular current of electricity, there we have magnetic phenomena
+manifested. The two are inseparably connected, and it is impossible to
+obtain the one without the other. For example, suppose we have a wire
+conveying a current of electricity and make it into a coil as in Figure
+15, what is the result? The result is, that the coil of wire has
+actually been converted into a magnet.
+
+It will attract iron filings that are brought near it, and also
+magnetize an iron bar placed in the centre of the coils, and convert
+that into a magnet. Indeed, there is nothing which can be done by an
+ordinary bar magnet which cannot be done by a coiled wire conveying an
+electric current.
+
+From this and similar experiments it can be demonstrated that wherever
+we get a circular current of electricity, there, associated with that
+current, are all the phenomena incidental to and associated with the
+ordinary bar magnet. This leads us to the truth discovered by Ampère,
+that magnetism is nothing more or less than electricity in rotation, or
+that it is due to a whirl of electricity circulating round the molecule
+of any body. From certain experiments which he made in relation to the
+mutual action of two circuits on each other, with currents flowing
+through them, he came to the conclusion that the magnetism of the
+molecule of each magnet is due to electric currents circulating round
+it.
+
+The question arises as to what effect our new theory of the Aether has
+upon Ampère's theory: does it confirm it, or does it destroy it? We have
+learned that every atom has its aetherial atmosphere, so to speak, which
+is bound to the atom by the Law of Gravitation (Art. 45). We have also
+learned that Aether has an electrical basis, as proved by Maxwell and
+Hertz, so that we learn that every atom has really an aetherial electric
+atmosphere in association with it. We have only to conceive of this
+atmosphere being set in rotation either by the rotation of the atom or
+molecule itself, or by outside agencies, and we have at once a physical
+interpretation of Ampère's theory of magnetism in the rotation of electric
+currents around the atom, such currents being due to the circulating or
+rotating motion of the Aether which surrounds the atom or molecule.
+
+[Illustration: Fig: 15.]
+
+Thus we learn from experiment, and from Ampère's theory also, that
+magnetism is directly associated with circulating currents of
+electricity, and that wherever we get currents of electricity
+circulating round any atom or body, there we get all the phenomena
+associated with magnetism. That is to say, we shall have such phenomena
+as magnetic fields, magnetic lines of force, magnetic induction, and the
+production of permanent magnets by electricity.
+
+Further, with reference to the identity of electricity and magnetism,
+Faraday has conclusively proved their relation to each other; and I
+would strongly advise any reader who desires further light on the
+subject to carefully read paragraphs 3265-3269 in his _Experimental
+Researches_, where he will find experiments which place the identity of
+electricity and magnetism beyond the possibility of doubt. In paragraph
+3265 he writes: "The well-known relation of the electric and magnetic
+forces may be thus stated. Let two rings in planes at right angles to
+each other represent them. If a current of electricity be sent round the
+ring _E_ in the direction marked, then lines of magnetic force will be
+produced. As these rings represent the lines of electro-dynamic force
+and of magnetic force respectively, they will serve for a standard of
+comparison."
+
+"I have elsewhere called the electric current or the line of
+electro-dynamic force an axis of power having contrary forces exactly
+equal in amount in contrary directions (517). The line of magnetic force
+may be described in precisely the same terms, and these two axes of power
+considered as right lines are perpendicular to each other," etc.
+
+[Illustration: Fig: 16.]
+
+Again in 3267 he adds: "Like electric currents or lines of force, or
+axes of power when placed side by side attract each other. This is well
+known and well illustrated when wires carrying such currents are placed
+parallel to each other. But like magnetic axes of power or lines of
+force repel each other. The parallel case to that of electric currents
+is given by placing two magnetic needles side by side with like poles in
+the same direction."
+
+Then in 3268 he shows that these effects are not merely contrasts, but
+they are contrasts which coincide when the two axes of power at right
+angles to each other are considered. Then in 3269 he adds: "The mutual
+relation of the magnetic lines of force and the electric axis of power
+has been known since the time of Oersted and Ampère," and further states
+he is of the opinion that "the magnetic lines have a physical existence
+the same as the electric lines," and having that opinion, asks whether
+"the lines have a dynamic condition analogous to the electric axis to
+which they are so closely and inevitably associated, or whether they
+consist in a state of tension of the Aether round the electric axis, and
+may therefore be considered as static in their nature." Thus Faraday
+proved the intimate and close relationship that existed between the
+electric current and the circles which represent the magnetic force in
+association with that current; and, what is more noticeable, he asks
+whether such magnetic results are due to a state of tension in the
+Aether around the axis of the electric current, evidently being of the
+opinion that the Aether played an important part in the phenomena of
+magnetism, as well as in electricity, as other parts of his writings
+abundantly show.
+
+If, therefore, there is this close identity between electricity and
+magnetism, then in view of the fact that all electricity is due to the
+motions of the universal Aether, it must follow that all magnetism is
+also due to motions of the same aetherial medium, which is as universal
+as it is invisible.
+
+What these motions are has already been indicated by previous statements
+in this article, being comprised of circular or rotatory motions of the
+aetherial electric medium about any body, whether that body be an atom,
+planet, or sun or star. Such a conclusion as this is perfectly in
+harmony with Maxwell's electro-magnetic theory of light, as the
+conclusion that he arrived at in that theory was, that the light waves
+were identical in nature and character with electro-magnetic waves
+produced by an electro-magnetic source.
+
+Up to the present we have only dealt with the electric character of
+those waves, and have therefore now to deal with the magnetic character
+of the same. So that throughout the whole realm of space, and indeed
+wherever there is Aether, there we have the conditions which give rise
+to magnetic phenomena, such as those already indicated.
+
+It matters not whether it be in the atomic systems whose combinations
+comprise all material forms of life with which we are familiar, or
+whether it is in the systems of planets that revolve around their
+central sun, or whether it be in the constellations that fill the
+universe, wherever we find the Aether, there we find the conditions in
+that Aether which will produce all the results ordinarily produced by
+magnetism, or with which magnetism is associated, and it is to the
+application of these phenomena to our solar system that we will now turn
+our attention.
+
+
+ART. 87. _The Earth a Magnet._--If there is any fact in relation to a
+planet that holds good, it is that the earth, with which planet we are
+more intimately associated than any other, is a magnet.
+
+This truth was clearly explained by Dr. Gilbert about the year 1600 in
+his work on "De Magnete." Not only has the earth geographical North and
+South poles, but it has also magnetic North and South poles, and indeed
+has all the phenomena incidental to a magnet, such as magnetic dip and
+magnetic lines of force, as we shall see later on.
+
+We know, however, that the earth is simply one of a system of planets,
+which revolves with all the others of that system round its central body
+the sun; and the question arises, whether the earth is the only one out
+of all the planets that is actually a magnet. Suppose it is affirmed
+that the earth is the only planet which is a magnet. On what basis would
+such a statement be made? The only ground for making such a statement
+that I can see is, that we have never lived on Mars or Jupiter or
+Saturn, or any of the other planets, and therefore been unable to
+experiment on them, which reason is totally insufficient and inadequate
+for such a conclusion.
+
+If philosophy simply dealt with the results attained by such limited
+reasoning, then the progress of science would be retarded, and would be
+limited and confined to actual experience obtained on our own planet and
+in relation only to that planet. But philosophy is not satisfied with
+such a narrow and limited outlook, but drawing its conclusions from
+actual experience on our own planet, in accordance with the rules of
+philosophy, it seeks to apply such experience gained to the explanation
+of phenomena of other planets which also revolve round the sun.
+
+By such reasoning we learn that all the other planets have North and
+South geographical poles like our earth, although we have never actually
+trodden on those planets, or discovered the poles. We also learn that
+Mars possesses climatic conditions probably similar to our own earth, as
+there are certain changes on the surface around the poles, which by
+analogy we assume to be caused by increase and decrease of snow during
+the Arctic winter and summer of Mars respectively.
+
+The analogy between our earth and the other planets is very full and
+complete, as the following results show. Our earth has an atmosphere, so
+have all the rest of the planets. The earth revolves on its axis from
+West to East, so do all the rest. The earth possesses two geographical
+poles, so do all the other planets. The earth revolves round the sun in
+an orbit of elliptic form, so do the other planets. The earth fulfils
+all the laws of motion as given by Newton, and all the other planets do
+the same. The earth fulfils all Kepler's laws, and this is also true of
+all the others. Indeed, the only difference apparently that exists at
+present between the earth and all the other planets is, that our earth
+is a magnet, while at present it is not conceded that all the others are
+magnets.
+
+Now such a conclusion I venture to say is altogether opposed to every
+rule of philosophy. For if experience be any guide in philosophy, then
+according to experience and observations made in respect to the only
+planet that we can actually experiment on, it most conclusively follows,
+that not only the earth, but every planet, and indeed every satellite
+that revolves round its primary planet, is a magnet; otherwise the rule
+of philosophy which permits us to formulate hypotheses based on
+experience is entirely violated, and ceases at once to be an universal
+rule.
+
+So that either the earth is not a magnet, or else, being a magnet by our
+second Rule of Philosophy, all the other planets are magnets also. This
+conclusion has already been arrived at by Lord Kelvin, who in writing in
+his _Popular Lectures_[33] on the subject says: "If it is true that
+terrestrial magnetism is a necessary consequence of the magnetism and
+the rotation of the earth, other bodies comparable in these qualities
+with the earth, and comparable also with the earth in respect to
+materials and temperature, such as Venus and Mars, must be magnets,
+comparable in strength with the earth; and they must have poles similar
+to the earth, North and South poles on the North and South sides of the
+equator. It seems probable also that the sun, because of its great mass
+and its rotation in the same direction as the earth's rotation, is a
+magnet, with polarities on the North and South sides of the equator,
+similar to terrestrial North and South magnetic poles." Further, such a
+conclusion is entirely in harmony with the view of the solar system
+revealed in Art. 81, where we saw that each planet was an electrified
+body having its own electric field, with its lines of force, being
+capable of giving rise to all the phenomena associated with electricity.
+So that if we combine that view of the subject with the view that we are
+now coming to, we arrive at the conclusion that each planet and
+satellite, and indeed all bodies that move or revolve in space, are
+electro-magnets giving rise to magnetic waves in the Aether, which
+assumption is fully consistent with the electro-magnetic theory of light.
+
+We must now go one step further and apply a similar line of reasoning to
+the sun, when we shall arrive at exactly the same result that Lord
+Kelvin arrived at, according to the previous extract. All planets
+possess an atmosphere, the sun also possesses an atmosphere. All planets
+revolve on their axes from West to East, so does the sun. All planets
+possess a North and South pole the same as the sun.
+
+The equatorial diameter of every planet is greater than its polar
+diameter, and the same truth applies to the sun. It is hotter at the
+equatorial regions of every planet, and this truth also applies to the
+sun. Now, if the sun agrees with all the planets in these respects, then
+we may philosophically conclude that it agrees with them in another
+respect, viz. that the sun is also a magnet possessing its own magnetic
+field, which is co-equal and co-extensive with its aetherial electrical
+field. We have already seen that the sun is an electrified body,
+possessing its electric field, with its electric lines of force.
+Therefore the sun is also a magnet, or, to speak more correctly, it is
+an electro-magnet, and as such gives rise to electro-magnetic waves.
+
+The conclusion to which we have come, that the sun is an electro-magnet,
+can be arrived at from an altogether different method of reasoning, and
+as that different method of reasoning will tend to confirm the statement
+made, I will just indicate it, and then leave it for fuller development
+in another article.
+
+It is a matter of common knowledge to all students, that the magnetism
+of the earth varies in several important particulars from time to time.
+The magnetic poles of the earth do not always occupy the same place in
+relation to the geographical poles, so that the magnetic force varies as
+regards intensity or magnitude. The reasons of the variations have never
+been satisfactorily accounted for, though various hypotheses have been
+suggested as a solution from time to time.
+
+There is, I believe, only one satisfactory solution to the problem, and
+that is, that the sun is an electro-magnet, and this conclusion may be
+arrived at by strictly adhering to Newton's rules of Philosophy. For we
+have learned that any hypothesis put forward to account for any
+phenomena, must be simple in character, must agree with experience and
+observation, and, lastly, must satisfactorily account for the phenomena
+sought to be explained.
+
+Here then are the variations in time of the magnetic force of the earth,
+the variations in intensity, and in the inclination of the magnetic
+axis, together with other variations. What solution shall we offer to
+such a problem? The only philosophical solution that can be suggested
+lies in the statement that the sun is an electro-magnet. Such statement
+is simple in conception, does not violate our experience or observation,
+as we find a similar revolving body, the earth, which is a magnet; and
+further, such a statement I premise will satisfactorily account for the
+whole of the variations and changes in relation to the magnetic forces
+of the earth. We shall see that this is so when we consider more fully
+the sun as an electro-magnet. Therefore, apart altogether from any
+previous analogies, we can philosophically arrive at the conclusion that
+the sun is an electro-magnet, as well as all the planets.
+
+That being so, it will possess its magnetic field, its magnetic lines of
+force, and be capable of bringing into operation in the solar system all
+the phenomena or effects associated with any ordinary magnet that we may
+experiment with on the earth.
+
+[Footnote 33: _Popular Lectures_, Vol. II.]
+
+
+ART. 88. _The Sun an Electro-magnet._--If the sun is an electro-magnet,
+as stated in the previous article, then it is necessary for us to apply
+the phenomena of magnetism to it in order to ascertain what effect such
+application will have on the solar system as a whole.
+
+[Illustration: Fig: 17.]
+
+The first thing that we will look at is the magnetic field which is
+always associated with every magnet. The magnetic field may be defined
+as that region or space around every magnet in which the magnetic force
+acts or is in operation. An illustration of a magnetic field may easily
+be obtained by taking a bar magnet and bringing near to it a magnetized
+needle, when it will be found that the needle will set itself in various
+positions relative to the magnet, on account of the lines of force which
+exist in the field. Thus let _A_ _B_ (Fig. 17) be a bar magnet with its
+North pole at point _A_ and South pole at point _B_. If a number of
+freely suspended needles be hung above it, as shown in the figure, they
+assume the positions indicated there. It will be seen that at the North
+and South poles the needles hang vertical, while midway between the two
+poles there is no dip of the needle, as it is parallel to the bar
+magnet; while between the place of no dip and the place of vertical dip,
+which is directly over each pole, the dip gradually changes, becoming
+more and more vertical as it gets nearer to the pole. If the bar magnet
+be a strong one, then its magnetic field will be manifested at a great
+distance; and any magnetized needle brought into the field will be,
+affected by the same, and will tend to set itself along the lines of
+force.
+
+As already stated in Art. 80, it was Faraday who originated the term
+"Lines of Force," and gave to the world some idea of the motions of the
+aetherial medium, which plays so important a part in electro-magnetic
+phenomena. A visible manifestation of these lines of force which gather
+round every magnet may be made by strewing iron filings over a piece of
+glass, underneath which are several bar magnets, when it will be found
+that the iron filings will set themselves in well-defined lines or
+curves, which Faraday termed "Lines of Force."
+
+[Illustration: Fig: 18.]
+
+As the bar magnets are placed in different positions, North pole to
+North pole, or North to South, and so on, the iron filings will change
+the figures assumed, indicating in, each case the effect of the lines of
+force of each magnet upon one another. The iron filings strewed over the
+magnet are magnetized by induction, with the result that the North pole
+of one filing attracts the South pole of the next one to it, and this is
+continued along the whole of one line of force, as revealed by the united
+iron filings. Faraday believed in the real physical existence of these
+lines of force, and that belief has been perfected by Clerk Maxwell in two
+papers which he wrote on "Physical Lines of Force," which will be
+considered in another article. We will simply deal with them at present
+as indications of the existence of the magnetic forces in the medium
+surrounding any magnet.
+
+Let us apply these facts to the solar system and see what the
+application yields. We have the sun revolving in the Aether medium
+represented by the circle _S_ in Fig. 19. Then we have the lines of
+force extending in curved lines _E._ and _W._, but in almost straight
+lines North and South. We will suppose the axis of the sun to be
+vertical for the sake of simplicity. It may be asked, how far will these
+lines of force stretch out into space? The reply is that they stretch
+and extend throughout the whole solar system, and far away into the
+depths of space, though with ever-decreasing intensity according to the
+law of inverse squares. Wherever the aetherial light waves are
+manifested, there the electro-magnetic waves, with all that they imply,
+are manifested also. We know that the light waves are existent at least
+as far as Neptune, a distance of 2800 millions of miles, therefore at
+least to that extent the electro-magnetic waves are manifested; and
+wherever the electro-magnetic waves to which the sun has given birth are
+manifested, there we have the existence of the electro-magnetic field,
+which is co-existent and co-extensive with the electric field of the
+sun. Further, wherever we get the magnetic field, there we get the lines
+of force which are as real as air or ocean currents, and are caused, as
+Maxwell indicated (Art. 44), by the motions of the atomic Aether.
+Wherever these lines of force are closest together, there the intensity
+of the magnetic force is at its greatest.
+
+[Illustration: Fig: 19.]
+
+By actual experiment, it can be demonstrated that the lines of force are
+closest together nearest to the magnet, and therefore applying that fact
+to the solar magnetic field, the lines of force should be closest
+together nearest to the surface of the sun, which is exactly what we
+have already learned. For if Aether be gravitative, then it will be
+densest nearest to the sun than further away, and the vortex atoms which
+represent our aetherial atoms will be pressed more closely together near
+to the surface than further away.
+
+We have learned that Aether has an electro-magnetic basis, and it is
+that very fact which gives rise to the existence of these lines of
+force. So that the magnetic phenomena as indicated in the lines of force
+conceived by Faraday harmonize with the fact that the sun is an
+electro-magnet; and that Aether, which has an electro-magnetic basis, is
+also gravitative, with the result that the lines of force are closest
+together nearest the surface of the sun, where the magnetic force is
+greatest in its intensity and power.
+
+Now let us apply the principle of the experiment to the solar system by
+bringing a magnet into a magnetic field, and let us see what the result
+is. We have learned from the experiment, that if a magnet is moved along
+any one of the lines of force the dip of the magnet changes, gradually
+changing from a horizontal to a perpendicular position in accordance
+with its relation to the two poles of the magnet. From the previous
+article we have come to the conclusion that not only is the earth a
+magnet, but that all the other planets are magnets also, so that if any
+of these are brought into the magnetic field of the sun, then the
+magnetic axis of the planet, which corresponds to the needle in our
+experiment, must assume a certain dip in relation to the sun, setting
+itself along those lines of force which are in the immediate
+neighbourhood of the planet.
+
+Let us place the earth, for example, at a distance of 90 millions of
+miles from the sun in the magnetic equator, or that line which exactly
+divides the magnetic field into two equal halves. According to our
+experiment, the magnetic axis will now be exactly parallel with the axis
+of the sun, that is, exactly vertical, pointing North and South, as seen
+in position 1 in Fig. 19. But suppose that the earth is to the North of
+the magnetic equator of the field, what happens then? The result will be
+that the magnetic axis of the earth will dip towards the magnetic North
+pole of the sun (position 2, Fig. 19), while if the earth be to the
+South of the magnetic equator, its axis will dip in the opposite
+direction (position 3), the magnetic axis setting itself in each case
+along the lines of force which exist in the Aether in that region or
+space. Thus it can be seen at a glance, that if the earth changes its
+position at any time in its orbit in relation to the magnetic equator,
+such a change will effect the total dip of the magnetic axis. In other
+words, the magnetic poles which indicate the position of the magnetic
+axis will not occupy the same position in relation to the geographical
+North and South poles, sometimes appearing to the East and sometimes to
+the West, and at other times being coincident with the same as it moves
+to the North or South of the magnetic equator of the sun's
+electro-magnetic field.
+
+We have to remember, also, that the earth is constantly varying its
+distance in relation to the sun, being at a distance of ninety and a
+half millions of miles at its perihelion, or that part of its orbit
+nearest to the sun; while it is ninety-four and a half millions of miles
+at its aphelion, or that part of its orbit furthest away from the sun.
+This implies that as it proceeds from that point in space furthest away
+from the sun, and approaches a point nearer to the sun, it will pass
+into places of greater magnetic intensity, with the result that the
+intensity of the electro-magnetic waves is increased; and the magnetism
+of the earth is accordingly affected by that fact.
+
+When we come to deal with the earth as a magnet more directly, we shall
+see that all the variations of terrestrial magnetism may be
+satisfactorily explained by the fact that the sun is, as we have
+indicated in this article, an electro-magnet, possessing its magnetic
+field with its lines of force, and therefore able to give rise to all
+the phenomena incidental to and associated with any ordinary magnet.
+
+
+ART. 89. _Aether and Faraday's Lines of Force._--We have now to face the
+question of the physical character of the Lines of Force conceived by
+Faraday. We have seen in Fig. 18 illustration of these lines of force,
+which are manifested by the iron filings in the neighbourhood of a
+magnet, and the question suggests itself to the mind, as to what is the
+relation of the Aether to those lines of force? Does the Aether play any
+part in their existence, and if so what?
+
+Faraday was of the opinion that the Aether did play some part in the
+existence of the lines, and that they were no mere hypothetical lines,
+but were caused by the actual physical state or condition of the
+aetherial medium, which existed around every magnet and every
+electrified body. On this point he says, Art. 3263:[34] "To acknowledge
+the action in curved lines seems to me to imply at once that the lines
+have a physical existence. It may be the vibration of the hypothetical
+Aether, or a state of tension of that Aether equivalent to either a
+dynamic or static condition."
+
+Par. 3277: "I conceive that when a magnet is in free space, there is
+such a medium, magnetically speaking, around it. That a vacuum has its
+own magnetic relations of attractions and repulsions is manifest from
+former experimental results (2787). What that surrounding magnetic
+medium deprived of all material substance may be, I cannot tell, perhaps
+the Aether."
+
+It was, however, left for Clerk Maxwell to develop the idea as to their
+physical character, and this he did in his paper on "Physical Lines of
+Force," _Phil. Mag._, 1861. He had previously written a paper on
+"Faraday's Lines of Force," delivered to the Cambridge Phil. Society in
+1855 and 1856, but his more matured conception of Faraday's Lines of
+Force was given in the later article.
+
+What Maxwell did was to conceive a physical theory of electricity and
+magnetism, by which electrified and magnetized bodies could act upon
+each other by means of the stress or strain of some medium, which
+existed in the space surrounding these bodies. Now Faraday looked upon
+electro-static and magnetic induction as always taking place along
+curved lines. These lines may be conceived as atoms or molecules
+starting from the poles of a magnet, and acting on all bodies in the
+electro-magnetic field. These atoms or molecules, joined together in a
+definite manner, tend to shorten in the direction of their length, that
+is to say, there is a tension along the lines of force while at the same
+time they swell out laterally or sideways. Thus there is a tension along
+the lines of force, and a pressure at right angles to them owing to
+their bulging out sideways. Maxwell used as an illustration of the
+tension and pressure, the contraction and thickening of a muscle. As the
+fibres of the muscle contract, and the arm or leg is drawn up, the
+muscle swells in its centre outwardly, and so thickens. Thus there would
+be a tension along the muscle, and a pressure at right angles to it,
+which would cause any body placed on it to move away from it, owing to
+the pressure of the contracted muscle.
+
+In the conception of an aetherial atom (Art. 44) drawn purely from
+observation of the shape of the earth, we came to the conclusion that
+the aetherial atom was a spherical vortex atom, or, to be more correct,
+that it was an oblate spheroid with its polar diameter, so to speak,
+shorter than its equatorial diameter, and further, that the aetherial
+atom possessed polarity.
+
+Now if we can conceive of these aetherial vortex atoms being joined
+together, North pole to South pole, and revolving round their axes, we
+shall then have an exact image of Maxwell's physical conception of
+Faraday's Lines of Force.
+
+We know that when any liquid body is caused to rotate rapidly about its
+axis, it will expand laterally and contract longitudinally in the
+direction of the axis; and it was on this analogy that Maxwell worked
+out his physical conception of the lines of force. Maxwell's fundamental
+idea was, that in a magnetic field there is a rotation of the molecule
+ever going on about the lines of force. For example, let _A_ _B_ be a
+magnet, and _A_ _C_ _B_ be a line of force composed of spherical vortex
+atoms joined end to end, that is, each North pole (assuming the vortex
+atoms to be magnets) being directly associated with the South pole of
+the one next to it, and _vice-versâ_ (Fig. 20).
+
+Thus it can be readily seen that there will be a tension along the line
+of force, while there will be a pressure at right angles to it owing to
+the lateral expansion, partly due to the rotation of the vortex atom,
+and partly due to the attraction of the vortices for each other in the
+direction of the line of force.
+
+Maxwell in his paper says: "It appears therefore that the stress in the
+axis of the line of magnetic force is a tension like that of a rope."
+Further, he adds: "Let us now suppose that the phenomena of magnetism
+depend upon the existence of the tension in the direction of the lines
+of force, combined with a hydrostatic pressure, or in other words, a
+pressure greater in the equatorial than in the axial direction. The next
+question is, What mechanical explanation can we give of these
+inequalities of pressure in a fluid or mobile medium? The explanation
+which most readily occurs to the mind is, that the excess of pressure in
+the equatorial direction arises from the centrifugal force of the
+vortices or eddies in the medium, having their axes in the direction
+parallel to the lines of force." He adds: "A medium of this kind filled
+with molecular vortices, having their axes parallel, differs from an
+ordinary medium in having different pressures in different directions."
+
+[Illustration: Fig: 20.]
+
+He then goes on to develop the idea in relation to different intensities
+of the magnetic field. I must, however, refer the reader to the paper
+itself for fuller details. In his greatest work,[35] writing on this
+subject, he says: "I think we have good evidence for the opinion that
+some phenomenon of rotation is going on in the magnetic field, that this
+rotation is performed by a great number of very small portions of
+matter, each rotating on its own axis, being parallel to the direction
+of the magnetic force, and that the rotations of these different
+vortices are made to depend on one another by means of some kind of
+mechanism."
+
+From the foregoing extracts taken from Maxwell's writings, we learn that
+the constitution of the Aether, as given in Art. 44, exactly coincides
+with, and satisfactorily fulfils the conditions that he lays down with
+reference to his physical conception of the lines of force around a
+magnet or electrified body.
+
+So that the theory of Maxwell is not merely hypothetical, as is
+suggested by scientists, but exactly describes the conditions and state
+of the atomic Aether medium which surrounds all magnets. We have,
+however, seen that the sun is a magnet, and therefore it possesses
+around it on every side, the same as any other magnet, these aetherial
+lines of force composed of infinitesimal vortices, or mere whirling
+points which correspond to an aetherial atom.
+
+These aetherial lines of force stretch out into space on every side of
+the sun, and in fact form concentric magnetic shells around the sun;
+which magnetic shells coincide with the equipotential surfaces of the
+Aether viewed merely from the point of elasticity and density of the
+medium. We learn by experiment, that these lines are closest together
+nearest to the magnet, which fact agrees with the statement that Aether
+is gravitative, and therefore the Aether would be densest nearest the
+sun. That is, the atoms would be pressed closer together, so that the
+lines of force of which these atoms are composed ought also to be closer
+together at the surface of the magnet, which we find by experiment is
+the case. As the sun is an electro-magnet, therefore, it possesses these
+magnetic lines of force on all sides, forming a series of magnetic
+shells. We have now arrived by the aid of Maxwell's theory to a physical
+conception of the Aether from a magnetic standpoint, which fully agrees
+with our physical conception of the Aether which was arrived at by
+purely philosophical reasoning, based on Newton's Rules of Philosophy.
+
+Thus we are able to combine into one whole by our conception that Aether
+is matter, and therefore atomic and gravitative, not only Faraday's
+Lines of Force, but also Maxwell's physical conception of the same,
+apart from the solutions given to the other problems of science by the
+self-same conception, which solutions will be dealt with in their proper
+order.
+
+As further evidence of Maxwell's belief in the physical existence of
+Faraday's Lines of Force, let me again quote from his paper on "Action
+at a Distance,"[36] already referred to in Art. 43. He writes: "Its
+minute parts may have rotatory as well as vibratory motions, and the
+axes of rotation form those lines of Magnetic Force which extend in
+unbroken continuity into regions which no eye has seen.... These lines
+must _not be regarded as mere mathematical abstractions_. They are the
+directions in which the medium is exerting tension like that of a rope,
+or rather like that of our own muscles."
+
+[Footnote 34: _Exp. Res._]
+
+[Footnote 35: _Magnetism and Electricity._]
+
+[Footnote 36: _Collected Works_, by Niven.]
+
+
+ART. 90. _Terrestrial Magnetism._--We have already seen that the earth
+is a magnet, and like any other magnet will therefore possess its
+magnetic field with its magnetic lines of force. The earth's magnetic
+field is co-existent and co-equal with its electric field (Art. 80), and
+that is co-existent with the earth's aetherial atmosphere which is held
+bound to the planet by the force of gravity.
+
+How far the earth's magnetic field reaches, is impossible to say, but we
+know that it extends at least as far as 260,000 miles, the distance of
+the moon; as we find that this satellite of the earth is affected very
+considerably by the electro-magnetic attractive power of the earth. Any
+body which is placed in the earth's magnetic field is affected by the
+lines of force which exist in the magnetic field; for wherever the field
+exists, there the lines of force exist also.
+
+These lines of force, which are associated with the earth, extend
+therefore into space, and any body such as the moon would become a
+magnet, if not already one by the process known as magnetic induction,
+which physical process is well illustrated in the action of a magnet
+upon iron filings strewed over it as in the illustration (Art. 88).
+
+An experiment which well illustrates the inductive power of the earth's
+magnetism, may be made by placing a poker in one of these lines of
+force, whose direction can be found at any part of the earth's surface
+by means of proper instruments. When the poker is so placed, it will be
+seen that it has actually become magnetized by the magnetism of the
+earth, and it is itself able to attract iron filings or small needles.
+These lines of force of the earth are closer together nearest to the
+earth's surface than further away in space, and congregate around the
+North and South magnetic poles, where they are greatest in number in a
+given area, and there the magnetic intensity is the greatest.
+
+Faraday, writing on the terrestrial lines of force, says: "The lines of
+force issue from the earth in the northern and southern parts with
+different but corresponding degrees of inclination, and incline to, and
+coalesce with each other over the equatorial parts. There seems reason
+to believe that the lines of magnetic force which proceed from the earth
+return to it, but in their circuitous course they may extend through
+space to a distance of many diameters of the earth, to tens of thousands
+of miles."[37]
+
+From this extract it will be seen that Faraday was of the opinion that
+the lines of force extended beyond the atmosphere of the earth into the
+Aether, which statement is confirmed by other parts of his writings;
+though he was not able to give any physical explanation of how these
+lines extended beyond the atmosphere on account of the doubtful
+constitution and character of the Aether, although in another part of
+his work he definitively refers to the magnetic character of space.
+
+In writing on the magnetic character of space he says:[38] "From such
+experiments, and also from general observations and knowledge, it seems
+manifest that the lines of magnetic force can traverse pure space, just
+as gravitating force does, and as static electric forces do (1616), and
+therefore space has a magnetic character of its own, and one that we shall
+probably find hereafter to be of the utmost importance in natural
+phenomena." With the view of the Aether presented in this work, viz. that
+Aether is matter, though in an infinitely more rarefied and elastic form,
+we can now see the physical cause of the lines of force with which by his
+imagination he filled all space.
+
+Again, from the conception of the Aether presented to the reader in Art.
+45, we learn that around any body in space there are existing aetherial
+concentric spheres or shells which are equipotential surfaces, or
+surfaces of equal pressure, and that these surfaces coincide with the
+electric equipotential surfaces, as shown in Art. 80.
+
+Not only so, but they coincide with the magnetic shells which the lines
+of force actually form around a circular and globular magnet, as the
+earth. For it must not be forgotten that these lines of force exist
+equally on all sides of the earth, and therefore really form a spherical
+shell, or to speak more correctly an aetherial electro-magnetic shell,
+which is an oblate spheroid in shape, partaking of the shape of the
+earth or other planet which the lines of force surround.
+
+If these shells were divided into two equal halves, the line so dividing
+them would be called the magnetic equator, and on that line any magnet
+would set itself in a horizontal position, so that all round the earth
+on the magnetic equator would correspond to a line of no dip. At the
+magnetic poles, a magnet would set itself vertically, or at an angle of
+90°, and between these two parts, the place of no dip, and that of 90°,
+the dip gradually changes as illustrated in the figure. Again, in
+relation to the magnetism of the earth we find that there are certain
+variations in the magnetic force, which not only influence the dip at
+any place, but also the intensity at that place. The variations in
+Magnetic Force are chiefly three--
+
+    1st. Diurnal Variations.
+    2nd. Annual Variations.
+    3rd. Secular Variations.
+
+Let us look at these three variations from the standpoint of the
+magnetic lines of force which exist around the earth, and around every
+planet. In relation to the variations of the magnetic forces upon the
+surface of the earth, Faraday points out that these variations are
+caused by the action of the sun's rays upon the terrestrial lines of
+force. He uses the following figure to illustrate his meaning. Let _H_
+be the sun, _E_ the earth--
+
+[Illustration: Fig: 21.]
+
+He writes as follows: "If the magnetic and astronomical poles of our
+earth be supposed to be coincident, then North and South poles will also
+represent the North and South magnetic poles, and the different curves
+cutting the earth will sufficiently represent a course of magnetic lines
+as they occur at, or about, the surface of the earth. _H_ represents the
+sun, and _a_ the place immediately underneath it, which is also
+coincident with the magnetic equator. Point _a_ will be a line of no
+dip, while at point _b_ there will be dip. This dip will be increased by
+the action of the sun's rays, because the atmosphere under the influence
+of the sun's rays has expanded the air, and has thus acquired a power to
+affect the lines of magnetic force."
+
+"All the lines passing through the heated and expanded air will, because
+of its being a worse magnetic conductor, tend to open out, and the mass
+of heated air will as a whole assume the condition of diamagnetic
+polarity (2923). The case may be more simply stated for the facility of
+recollection by saying, that the effect of the sun is to raise the
+magnetic circles over the equatorial and neighbouring parts from their
+normal position, in doing which the North and South dip are
+simultaneously affected and increased."
+
+Thus it can readily be seen that every day as the earth turns round on
+its axis, and presents each side of the globe successively to the rays
+of the sun, there should be a gradual change in the intensity of the
+terrestrial magnetism. In Art. 2925, Faraday points out that the maximum
+of dip would be when the sun was at its zenith or directly overhead.
+With reference to the Annual Variation, Faraday points out (2882) that
+if the axis of the earth were perpendicular to the plane of its orbit,
+the intensity and direction of the magnetic forces might be considered
+constant, but (2883) as the axis of the earth's rotation is inclined 23°
+to the plane of the ecliptic, the two hemispheres will become
+alternately warmer and colder than each other, and then a variation in
+the magnetic condition may arise. The consideration of this annual
+variation is further considered by Faraday in the subsequent paragraphs
+to those already quoted, and I must refer the reader to them for fuller
+details; I wish simply to indicate the possible explanation of the
+terrestrial magnetism, in so far as that explanation is in conformity
+with the aspect of the Aether submitted in Chapter IV.
+
+With regard to secular variations Faraday points out (2880) that the
+temperature of the air at the equatorial parts of the earth is greater
+than in latitudes north and south, and as an elevation of temperature
+diminishes the conducting power of magnetism, so the proportion of force
+passing through those parts ought to be less, and that passing through
+the cooler parts, greater, than if the temperature were at the same
+degree over the whole surface of the globe.
+
+Now with our definite conception of the aetherial lines of force
+traversing space, and existing on all sides of the earth, these
+suggestions of Faraday's obtain an increased value in relation to the
+varying intensity of terrestrial magnetism, and will account for the
+variations in a satisfactory manner from the aetherial standpoint, if
+taken in conjunction with the electro-magnetic character of the Aether.
+Of course, what applies to the earth equally applies to all the other
+planets, as they also are magnets according to Art. 87, so that they
+will also possess their magnetic fields, with their own lines of force,
+and their variations in intensity and magnetic dip.
+
+Hitherto we have only considered the problem of the earth and all the
+other planets, as magnets, from the stationary standpoint, and the
+problem faces us as to what effect the movement of the earth and all
+other planets through the Aether will have upon their magnetic fields,
+and their lines of force. Now from Clerk Maxwell's mathematical
+calculations, we learn that the movement of any magnetic body through
+space will practically have no effect upon the relation of the field,
+and the lines of force to the moving magnet; that is to say, the
+magnetic field and the lines of force move with the earth and the
+planets through space, as they journey round the sun with their varying
+velocity. Maxwell has conclusively proved that the mathematical
+equations for moving bodies in relation to their magnetic lines of
+force, and induction, are exactly the same as the equations for
+stationary bodies, and if this be true, then it follows that the
+physical conditions for both stationary and moving bodies are the same.
+
+On this point Maxwell writes: "By its motions this (moving) matter
+carries with it its lines of force, and electricity and magnetism may be
+regarded as free ends of these lines. Hence when both causes act
+together there can be no relative motion of true magnetism with
+reference to surrounding matter," etc.
+
+"Under these circumstances electricity and magnetism move with the
+matter in which they are present as if they were indestructible and
+adhered firmly to the parts thereof." So that from Maxwell's equations
+and statements we learn that the magnetic lines of force around every
+planet, and every satellite in space, move with the planets in their
+orbits round the sun. But as these magnetic lines of force are composed
+of aetherial atoms, as already indicated, it follows that the Aether
+which is associated with each planet and held bound to it by the
+so-called force of gravity moves with the planet also.
+
+This result is entirely consistent with our experience and observation,
+as we shall see later on. We find that the atmosphere, which is also
+gravitative, moves with the earth, and therefore from experience we are
+compelled to arrive at the conclusion that the Aether which is also
+gravitative moves with each planet, and this result is confirmed by
+mathematical calculations given by Clerk Maxwell, and is in perfect
+harmony with the same.
+
+Here then is the key to one of the problems that has been the subject of
+investigation and research for many years past, and one which is at the
+present time occupying the attention of some of our most advanced
+scientists, viz. the relation of the Aether to moving matter.
+
+That problem was solved by Maxwell from an electric and magnetic
+standpoint, and his result was that the Aether, which we now know to be
+the source of all electricity and magnetism, moves with the moving
+matter. What is more, this result has been confirmed by actual
+experiment made by Michelson and Morley in America, which experiment
+conclusively proves that Maxwell's result is physically correct, and
+that the Aether does move through space with its associated planet, and
+therefore its magnetic field and its lines of force move with it because
+of the electro-magnetic character of the Aether.
+
+[Footnote 37: Art. 2850, _Exp. Res._]
+
+[Footnote 38: Art. 2757, _Exp. Res._]
+
+
+ART. 91. _Solar Magnets._--We have now to attack the problem as to the
+cause of all the satellites and planets, together with the sun, being
+electro-magnets. What is the continuing and ever-acting cause which
+makes all planetary bodies, including the sun, their centre, to be
+permanent magnets? According to the Rules of Philosophy there are two
+causes which would be simple in conception, which are suggested by
+experiment and observation, and both causes would satisfactorily account
+for all the planets being magnets.
+
+The first cause suggested to our minds is, that in view of the fact that
+the sun is an electro-magnet, and therefore possesses a magnetic field
+with its aetherial line of force, all the planets may become magnets by
+the process of magnetic induction, which process has already been
+illustrated by the action of the iron filings placed over the magnet.
+Such a hypothesis would fulfil all the Rules of Philosophy, as it would
+be simple in conception, would not violate experience, and would
+satisfactorily account for the fact sought to be explained.
+
+But such a hypothesis would be based upon the assumption that the sun
+was an electro-magnet, and then we should have to find out the cause of
+that fact also. Hence the hypothesis that the planets are magnets,
+because they are situated in the magnetic field of the sun, is not a
+satisfactory solution of the whole problem, as it fails to account for
+the fact that the sun is also an electro-magnet. We must therefore seek
+for another solution of the problem, which, while fulfilling all the
+Rules of Philosophy as laid down in Art. 3, will also account for the
+sun being an electro-magnet, as well as every planet, satellite, meteor,
+or any other body that exists in space. If we can ascertain such a cause
+by philosophical reasoning, then we may say we have satisfactorily
+solved the problem as to the cause of all planetary and stellar bodies
+being electro-magnets.
+
+If, at the same time, we can solve other outstanding problems by the
+solution thus offered, then such solution is more likely to be correct
+than if it simply solved the problem of solar magnetism. The only other
+solution that can possibly present itself to our minds, as to the cause
+of all magnetism in any planet, sun, or star, is the explanation which
+has already been given in Art. 86 on electro-magnetism.
+
+In that article we learned that magnetism was really due to the circular
+motion of an electric current; and that, whenever and wherever we had an
+electric current moving or revolving with a circular motion, there we
+should always have those conditions which would give rise to an
+electro-magnet. As long as the current continued to flow in its circular
+course, so long would there be those conditions which would give rise to
+permanent magnetism.
+
+Now in the solar system we find that there are these magnets, which have
+been in existence for millions of years. We also learn from the
+electro-magnetic theory of light that Aether has an electro-magnetic
+basis, which gives rise to electro-magnetic waves when disturbed, or set
+in motion by any heated or luminous body. It can readily be seen,
+therefore, that we have only to set this electro-magnetic Aether in
+circular motion around any planet or sun, and we have at once a circular
+current of electricity flowing round that planet or sun, which would
+give rise to those conditions by which any body within its influence may
+be formed into a magnet.
+
+Our hypothesis, therefore, to explain the reason why all the planets and
+the sun are magnets, is that the electro-magnetic Aether moves round the
+sun or planet or satellite as the case may be, thus giving rise to
+currents of electricity around the planet or sun, and so forming those
+conditions in the Aether by which the permanency of any planetary or
+stellar magnetism may be maintained and perpetuated.
+
+In other words, to put it plainly and tersely, each aetherial atmosphere
+revolves round the planet, subject to certain limitations, in the same
+way that the aerial atmosphere turns round with the earth, as that
+planet revolves on its axis. At first sight, such an assumption may seem
+impossible, but a little careful consideration will show not only the
+possibility of such a cause, but will establish it, as the only
+reasonable and philosophical explanation for the phenomena we are
+seeking to explain, viz. the electro-magnetism of all celestial bodies.
+
+There is nothing extravagant in this assumption, as we already have a
+similar illustration in the case of the atmosphere which goes round with
+the earth as it revolves on its axis. We have only to extend the same
+principle a little further, viz. to the aetherial atmosphere, and we at
+once get the true physical conception of the hypothesis suggested to
+explain the magnetism of all celestial bodies. We have already learned
+that Maxwell has proved that the equations for moving magnetic bodies
+are the same as those for stationary bodies, from which we came to the
+conclusion that the electric and magnetic field of any planet goes with
+that planet as it revolves on its axis in its journey round the sun.
+
+I would like to ask the reader to try to conceive of any electric or
+magnetic field traversing space in association with any planet or sun
+which is revolving on its axis, while that electric or magnetic field
+does not revolve either partially or wholly with the revolving body. The
+field can only be stationary relatively to the planet or sun, as it
+revolves with the planet or sun on its axis.
+
+There may be, as there doubtless are, conditions governing that
+revolution, as is the case with the atmosphere moving and revolving with
+the planet, but it is an absolute impossibility for Maxwell's equations
+relating to moving magnetic bodies to be carried to their logical
+conclusion, without affirming some such hypothesis as we have affirmed
+in relation to the cause of all solar magnetism.
+
+Let me at once point out, this solution has already been offered by one
+whose name has been referred to several times. I refer to Professor
+Challis. Let us see what he has to say as to the cause of the earth's
+magnetism. In dealing with this subject, and writing in the _Phil.
+Mag._, 1872, par. 42, he states: "With respect to all magnetism which
+has a cosmical origin, the view I now take is that it is due to
+gyrations of the Aether, produced by the impulses which it receives from
+the motions of the constituent atoms of the bodies of the solar system.
+The gyrations may either be immediately generated by the rotations of
+the bodies about their axes, or directly result from disturbances of the
+Aether caused by their motions of translation. This impressed motion
+will be converted into circulatory or gyratory motion. Such circulatory
+motion will necessarily partake of the motion of translation of the
+bodies which generate them, so as to have always the same geometrical
+relation to these bodies provided their motion be uniform."
+
+In paragraph 46 he continues: "From what has been already argued (42),
+the motions impressed on the Aether by the earth in consequence of its
+rotatory or orbital motions result in circulating motions which would be
+steady motions, having always the same geometrical relation to the
+position of the earth's centre."
+
+Again, Ampère and Faraday were also of the opinion that the magnetism of
+the earth was due to the circulation of electric currents round it, for
+in par. 446, _Exp. Res._, Faraday states: "Assuming with Ampère that the
+magnetism of the earth is due to electric currents circulating round it,
+parallel to the equator."
+
+I think it will be seen from these extracts that the hypothesis
+suggested for all planetary and stellar magnetic bodies is thus
+confirmed by Professor Challis, and by Faraday and Ampère. Professor
+Challis in these passages clearly and definitely points out that there
+are circulatory motions in the Aether, which motions are produced by the
+rotation of the earth or other body on its axis, and that these circular
+motions of the aetherial medium always maintain the same geometrical
+shape relative to the earth's centre. So that we have only to combine
+with his hypothesis the electro-magnetic basis of the Aether, and we at
+once get the circulating currents of electricity constantly flowing
+round the heavenly bodies, which produce and give rise to the permanent
+magnetism of those bodies.
+
+If we desired still further confirmation as to the circulating motions of
+the Aether caused by a rotating body, we find it in the writings of
+Herschel, who in relation to this matter asks:[39] "What is the law of
+density of the resisting medium which surrounds the sun? Is it at rest or
+in motion? If the latter, in what direction does it move? Circularly round
+the sun, or traversing space? If circularly, in what plane? Supposing the
+neighbourhood of the sun to be filled with material fluid, it is not
+conceivable that the circulation of the planets in it for ages should not
+have impressed upon it some degree of rotation in their own direction, and
+this may preserve them from the extreme effects of accumulated
+resistance!" Words like these from one of the most searching intellects of
+the last century are well worthy of our consideration, and the suggested
+effect on the Aether caused by the continued rotation of the earth gives
+us the key not only to the problem of celestial magnetism, but also to the
+other outstanding scientific problems.
+
+For example, there is the problem of the relation of moving matter to
+the Aether around it which still remains unsolved. The physical cause of
+the rotation of the earth, and all other celestial bodies upon their
+axes, with unceasing regularity, still remains to be discovered. The
+physical explanation as to the reason why the earth moves round the sun
+in its orbit according to Kepler's Laws, has yet to be determined, and,
+lastly, there is the relation of the magnetic vibration to the electric
+vibration in connection with the electro-magnetic theory of light still
+to be solved.
+
+Now, presuming that all these can be solved by the philosophical
+hypothesis, that the electro-magnetic Aether circulates round each
+planet and sun and star, that revolves in space, then we are justified
+in our conclusion that such is the true cause of all electro-magnetism
+that exists in connection with planetary and stellar bodies. I venture
+to premise that all these problems can be solved by the simple solution
+here given, and will prove that this solution adequately accounts for
+all the other phenomena referred to.
+
+Before proceeding to do this, we will endeavour to prove this hypothesis
+by an altogether different method of reasoning, in order to confirm the
+statements made in this article. Let us therefore endeavour to form a
+complete view of the physical state of the solar system, and for the
+sake of simplicity we will suppose it to be at rest in space. We shall
+deal with the effect of its motion upon its own planetary system, when
+we explain Kepler's Laws.
+
+We have, therefore, the Sun in the centre (see Fig. 14) of the system,
+with Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus, and
+Neptune revolving round the sun at their respective distances, which are
+subject to variations owing to certain causes which can be
+satisfactorily explained. But circulating round the sun, in the same
+direction as the rotation of the sun on its axis, we have the
+electro-magnetic Aether, with its wide-spreading flow and extensive
+electro-magnetic field. In like manner, we have each planet with its
+aetherial electro-magnetic field, which also circulates round each
+planet in the same direction as the planet revolves, that is, from west
+to east, and in the same direction as the sun's electro-magnetic field
+revolves.
+
+Thus we have to picture the whole of the solar system in a state of
+regular and harmonious rotation, while each planet adds to the harmony
+of the rotation by itself rotating in its own aetherial electro-magnetic
+field, while all rotate in the same direction, viz. from west to east.
+
+Of course there are several objections that can be raised to such a
+hypothesis, and those objections will be briefly dealt with in a
+subsequent article, but I venture to think that this hypothesis is the
+true philosophical explanation of a problem which has formed one of the
+greatest outstanding difficulties in regard to the Aether medium for
+many years, that problem being the relative motion of the Aether and
+Matter. Lord Kelvin, in an article in the _Phil. Mag._ for July 1901,
+entitled "Clouds over the Dynamical Theory of Light," refers to this
+very difficulty, and states there are two clouds over the present
+undulatory theory of light, one of which has reference to the difficulty
+of conceiving a body like the earth or any planet rushing through the
+Aether without subjecting the Aether to enormous laceration, and
+concludes by saying that "we must still regard this cloud as very
+dense." Here, then, is the key to the solution of the problem.
+
+The earth does not rush through the Aether, but the Aether being
+gravitative, it is associated with and bound to each planet, and
+accompanies that planet in its journey though space, rotating with it in
+the same way that the atmosphere does, as we shall prove later on.
+
+This conception is fully in accord with our hypothesis as to the
+physical explanation of the cause of the electro-magnetic character of
+all the heavenly bodies, and indeed is the only physical solution that
+can adequately account for all the varied phenomena hitherto unexplained
+in connection with the celestial mechanism.
+
+From the foregoing statements, we are now in a position to consider the
+term Electro-Kinetic Energy, as used by Clerk Maxwell. What does he mean
+by Electro-Kinetic Energy? Let us see what he has to say about the term
+himself.
+
+In par. 636 of his _Magnetism and Electricity_ he writes: "According to
+our hypothesis we assume kinetic energy to exist wherever there is
+magnetic force, that is, in general, in every part of the field. This
+energy exists, therefore, in some kind of motion of the matter in every
+portion of space;" while again, in par. 569, he states: "The electric
+current cannot be conceived except as a kinetic phenomenon." Even
+Faraday speaks of the electric current as "something progressive, and
+not a mere arrangement" (_Exp. Res._ 283).
+
+Then again in par. 552 he writes: "It appears, therefore, that a system
+containing an electric current is a seat of energy of some kind, and,
+since we can form no conception of an electric current except as a
+kinetic phenomenon, its energy must be kinetic energy, that is to say,
+the energy which a moving body has in virtue of its motion."
+
+Here, therefore, according to Clerk Maxwell, the kinetic energy of an
+electro-magnetic field is nothing more or less than the energy which a
+moving body possesses in virtue of its motion. Any other explanation of
+kinetic energy would be opposed to all the Rules of Philosophy; for
+experience in its widest form incontrovertibly proves that all kinetic
+energy is associated, and alone associated, with a moving body;
+therefore in all electro-magnetic fields there is this kinetic energy
+ever being manifested. We have, however, learned that the solar system
+forms a huge electro-magnetic field, traversed by lines of force, as
+Maxwell and Faraday suggested. Therefore, in the solar system, there
+must be this kinetic energy due to the motion of a moving body, which is
+the electro-magnetic Aether.
+
+We have, however, just arrived at the conclusion that in the solar
+system there is ever going on a circulatory or rotatory movement of the
+electro-magnetic Aether forming currents around each electro-magnet. On
+the hypothesis of an atomic and gravitating Aether we have, therefore, a
+medium or body continually circulating, which medium possesses inertia
+and momentum, and it is philosophically possible for such a rotating
+medium to possess kinetic energy. So that our explanation of this term,
+as used by Clerk Maxwell, is, that this kinetic energy is indeed due to
+the momentum of the moving Aether. Such a hypothesis is strictly
+philosophical, and literally fulfils the statements made by Clerk
+Maxwell himself in the paragraphs already referred to.
+
+A remarkable feature about this hypothesis lies in the fact, that it is
+the very hypothesis that Von Helmholtz suggested as the explanation of
+the term. He came to the conclusion that the kinetic energy was due to
+the momentum of the moving Aether. But with a frictionless Aether such a
+hypothesis, although correct, was philosophically untenable. In view of
+the theory of the Aether presented in this work, however, both Clerk
+Maxwell's and Von Helmholtz's statements find their literal and perfect
+fulfilment. So that in an atomic Aether, which is gravitative because
+atomic, and rotatory because it is gravitative, combined with its
+electro-magnetic basis as proved by Hertz, we find for the first time a
+correct philosophical explanation of one of the most puzzling terms used
+by Maxwell in his greatest work on _Magnetism and Electricity_. This
+solution alone ought to stamp the theory of an atomic and gravitating
+electro-magnetic Aether with that authority that is always associated
+with the names of two such great thinkers and experimentalists as those
+just mentioned.
+
+The fact that the Aether is held bound to a planet has already been
+suggested by Sir G. Stokes to account for the aberration of light
+already referred to. In the _Phil. Mag._, July 1845, he writes: "I shall
+suppose that the earth and the planets carry a portion of Aether along
+with them, so that the Aether close to the surface is at rest relatively
+to the earth, while its velocity alters as we recede from its surface,
+till at no great distance it is at rest in space." Sir G. Stokes does
+not, however, say how the Aether is held bound to the earth, and apart
+from an Aether which is gravitative, no satisfactory explanation can be
+given. Further, it is noticeable, that he suggests that the other
+planets also carry part of the Aether associated with them along with
+each planet as it pursues its journey. It would be distinctly
+unphilosophical to assume that the earth was the only planet that
+carried its aetherial field with it. So that by following Sir G. Stokes'
+suggestion, we practically arrive at the same conclusion in relation to
+the motions of the Aether that we have already arrived at from magnetic
+phenomena.
+
+With this view of the case we are now in a position to answer a question
+asked by Professor Schuster at the British Association in 1892. He
+asked, "Is not every large rotating mass a magnet?" and added, "If it
+is, the sun must be a powerful magnet. The comets' tails, which eclipse
+observations show stretching out from the sun in all directions,
+probably consist of electric discharges." Now, in relation to this
+question, the answer is that every rotating body in the Aether is
+undoubtedly an electro-magnet. Thus, not only is the sun an
+electro-magnet, but every planet and satellite, and every meteor that
+rotates in the electro-magnetic Aether, is converted into a magnet,
+partly by that rotation, and partly by the currents induced in the
+Aether by that rotation. We shall also find when we come to deal with
+the phenomena of comets' tails, that Professor Schuster is also right as
+to their cause, and that they are due to electro-magnetic repulsions
+originated in the Aether by the sun, which is an electro-magnet.
+
+[Footnote 39: _Outlines of Astronomy_, Herschel.]
+
+
+ART. 92. _Cause of Rotation of the Earth on its Axis._--If there is one
+fact true in relation to the earth as a planet, it is that the earth
+rotates on its axis every 24 hours. Day in and day out, for centuries
+past, this revolution has taken place as the earth journeys in its
+annual path round the sun.
+
+Not only does the earth rotate on its axis, but every other planet
+rotates on its axis in varying times, as the following table shows--
+
+                  HRS.  MIN.  SEC.
+
+    Mercury        24     5     0
+    Venus          23    24     0
+    The Earth      23    56     4
+    Mars           24    37    23
+    Jupiter         9    55     0
+    Sarturn        10    14    23
+    Uranus          ?
+    Neptune         ?
+
+Further, the sun also rotates on its axis in a period of 26 days. Here,
+then, are certain phenomena in connection with the solar system, for
+which up to the present no explanation as to the physical cause of
+rotation has ever been offered. Surely there is some physical cause, to
+account for such a rotation, and if there be a physical cause, then the
+problem to be solved is--find the physical cause to account for the
+continuous and ever-recurring rotation of all the planets and the sun on
+their axes, which shall be so effective and continual that, year in and
+year out, the rotation of all the planets may be continued as observed.
+In solving this problem we have to revert to our reason why the earth is
+a magnet. In Art. 91 we learned that the earth and all the other
+planets, and indeed all stellar bodies, were electro-magnets, because
+the electro-magnetic Aether was constantly circulating round them.
+
+If, by accepting this explanation, we can at the same time solve the
+problem of the rotation of the planets, and the sun, on their axes, then
+we shall have further evidence that our hypothesis is the correct one.
+Now let me ask, What is the effect of an electric current continually
+circulating round any magnet in the same way that the electro-magnetic
+Aether continually circulates round the earth, which is a magnet?
+
+To find out what the effect is, we must resort to experiment. Professor
+Lodge, in his _Modern Views of Electricity_, shows us the effect of any
+circulating current of electricity revolving round a magnet. In his
+chapter on Electro-Magnetism he writes as follows: "How does a current
+act on a magnetic pole? Two currents attract or repel each other, two
+poles attract or repel each other, but a current and a pole exert a
+mutual force which is neither attraction nor repulsion. It is a rotatory
+force. They tend neither to approach nor to recede, they tend to revolve
+round each other." "A singular action this and at first sight unique"
+(p. 135). "The two things will revolve round each other for ever. This
+affords and has afforded a fine field for the perpetual motionist, and
+if only the current would maintain itself without a sustaining power,
+perpetual motion in fact would be attained."
+
+Faraday has shown by experiment the action of a current on the magnet,
+and _vice versâ_. Faraday, in his description of an electro-magnetic
+apparatus for the exhibition of rotatory motion, shows how the rotation
+of a current round a magnet, and a magnet round a current, may be
+experimentally proved. With the apparatus used he shows that the current
+of electricity may be made to revolve round the pole of the magnet in
+the direction dependent on the pole used, and further, illustrates how
+the magnet may be made to revolve round the current. (Plate 4, Fig. 5,
+_Exp. Res._)
+
+Thus we learn that wherever we have a current constantly circulating
+round a magnet, there we have the conditions by which, according to
+Professor Lodge, perpetual motion may be obtained, that is to say, the
+two will revolve round each other as long as the current is maintained.
+Here then we find in space those very conditions by which perpetual
+motion may be obtained.
+
+We find the electro-magnetic Aether constantly circulating round the
+planetary magnets, with the result that not only will the current
+continue to revolve around the planet, but the planet will continue to
+revolve upon its axis as it revolves round the current. In fact we get
+in space an example of perpetual motion. We know that the rotation of
+the earth on its axis has been in existence for several thousand years,
+and therefore we have a right to assume that it revolved on its axis
+through the untold ages of past geological times as revealed by the
+strata, and rocks of pre-historic ages. Thus the motion must have
+continued, so far as the earth is concerned, at least 100,000,000 years,
+accepting that period as the age of the earth, but no physical reason so
+far as I know has ever been assigned for such continued rotation.
+
+If, therefore, it be true that the joint action of a current and a
+magnet is a rotatory one, then, seeing that in all planetary and stellar
+space we have both these conditions of matter, that is, the
+electro-magnetic aetherial current, constantly circulating round an
+electro-magnet, we have, in space, the conditions by which perpetual
+rotation may be maintained. We have therefore presented to us in that
+joint action, the true cause of the continued rotation of the earth on
+its axis, and therefore of all the planets on their axes, together with
+the sun on its axis; and, if we carry the principle into the stellar
+world, we can philosophically come to the conclusion that the same
+conditions prevail there that prevail in the solar system, with the
+result that we have now a physical cause which fully satisfies all Rules
+of Philosophy to account for certain phenomena which up to the present
+have never yet been accounted for from the physical standpoint. Thus in
+solving the problem of the earth's rotation on its axis, we find greater
+confirmation in the view presented in a previous article as to the
+circulating motion of the electro-magnetic Aether around any and every
+body in space. We shall deal again with the relation of a current and a
+magnet, when we come to the physical explanation of Kepler's Laws.
+
+
+ART. 93. _Vortex Motion._--From Art. 91 we have seen that the
+electro-magnetic Aether possesses a circulating or rotatory motion
+around each central body, and because of this rotatory motion, the body
+is at once converted into a magnet. We have also seen that Professor
+Challis believed in the circulatory or rotatory motion of the Aether, as
+also did Ampère.
+
+Thus we are led back by scientific experiment and philosophical
+reasoning to the conception of vortex motion with which the world was
+familiar in the days of Kepler, Descartes, Huyghens and Bernoulli. There
+is this difference, however, that whereas the vortex motion of those
+philosophers was to displace and do away with Gravitation, the
+circulatory or rotatory Aether suggested by electro-magnetic phenomena
+is to supplement, confirm and establish more firmly than ever the true
+powers and laws of Gravitation Attraction.
+
+Before passing, it will be as well to briefly glance at the conception
+of vortex motion as suggested by Kepler and Descartes and others.
+Whewell on this matter in his _Inductive Sciences_ states that "Kepler
+assumed that a certain force or virtue resided in the sun by which all
+bodies within his influence were carried round him. He illustrated the
+nature of the force in various ways, comparing it to light, and to the
+magnetic power which it resembles in the circumstances of operating at a
+distance, and also of exercising a feebler influence as the distance
+increases." "Another image to which he referred suggested a much more
+conceivable kind of mechanical action by which the celestial motions
+might be produced, viz. a current of fluid matter circulating round the
+sun, and carrying the planets with it like a boat in a stream." Whewell
+adds: "A Vortex fluid constantly whirling round the sun, kept in this
+whirling motion by the sun itself, and carrying the planets round the
+sun by its revolution, as a whirlpool carries straws, could be readily
+understood, and though it appears to have been held by Kepler that this
+current and Vortex were immaterial, he ascribes to it the power of
+overcoming the inertia of bodies, and of putting them and keeping them
+in motion."
+
+Now, as we have seen, the electro-magnetic Aether is not immaterial but
+material, as it is matter possessing mass and inertia, the same as any
+other matter, as Tyndall and Lord Kelvin stated (Chap. IV.). Thus the
+objection to Kepler's immaterial vortices is met and overcome by our
+conception of the Aether (Chap. IV.). Descartes, as Whewell points out,
+asserted, "that a vacuum in any part of the universe is impossible. The
+whole universe must be filled with matter, which must be divided into
+equal angular parts. This matter being in motion, the parts are
+necessarily grounded into a spherical form, and the corners thus rubbed
+off, forming a second or subtle matter. There is besides a third kind of
+matter, of parts more coarse and less fitted for motion. The first part
+makes the luminous bodies as sun and stars, the second part is the
+transparent substance of the skies, and the third part is the material
+of opaque bodies as the earth, planets and comets. We may suppose that
+the motion of these parts takes the form of revolving circular currents
+or vortices. By this means the first matter will be collected to the
+centre of each vortex, while the second or subtle matter surrounds it,
+and by its centrifugal effect constitutes light. The planets are carried
+round the sun by the motion of the vortex, each planet being at such
+distance from the sun as to be in a part of the vortex suitable to its
+solidity and mobility. The satellites are in like manner carried round
+their ordinary planets by subordinate vortices."
+
+It would almost seem from this quotation that we had adopted purely and
+simply Descartes' and Kepler's ideas _in toto_, whereas the truth is
+that the hypothesis of a rotating electro-magnetic Aether has been
+arrived at by following Newton's own Rules of Philosophy, and by
+discarding everything not in harmony with experience and experiment.
+
+Further, Descartes was unable to give, or explain the ellipticity of the
+orbits of planets, and had to assume that there were elliptic vortices.
+When we come to deal with Kepler's Laws, and their physical
+interpretation, the correct solution of this problem will be given from
+a purely experimental and philosophical standpoint, and in a way and
+manner never suggested by Descartes or any other believer in the theory
+of vortices as then known and understood. Indeed there is no objection
+to the theory of vortices, which cannot be satisfactorily explained by a
+rotating electro-magnetic Aether, as we shall see when we deal with
+Newton's Laws of Motion and Kepler's Laws.
+
+Both Liebnitz and Huyghens were believers in the theory of vortices, and
+the fact that Huyghens' undulatory theory of light stands to-day as an
+accepted theory, is conclusive evidence that he was a philosopher of the
+highest order, and his adhesion to the theory of vortices proves that he
+was convinced that there was some truth in it.
+
+It is a result greatly to be desired, therefore, if it can be
+demonstrated, that in the Aether there is this rotatory motion
+continually going on around every planet, satellite, sun or star;
+because it will then join together, in perfect harmony, two great
+theories in relation to celestial phenomena, that contended with each
+other for supremacy for very many years.
+
+It will prove that, after all, men like Kepler, Descartes, Huyghens, and
+Bernoulli had caught glimpses of the great truth which was partly
+revealed by celestial phenomena, and that it was only for lack of data
+that they were unable to successfully compete with Newton's mathematical
+genius, by which he was able to bring his Law of Gravitation safely
+through the conflict with the simpler conception of aetherial vortex
+motion. Of course certain objections will have to be met and answered
+before this aspect of aetherial dynamics can be expected to supplant the
+more cumbrous and somewhat intricate mathematical laws of motion, but I
+shall prove later on, that all these objections can be answered from a
+satisfactory standpoint.
+
+So that if a modified form of aetherial vortex motion can be
+successfully demonstrated to exist in the electro-magnetic Aether, then
+we shall see the conflict that waged about two hundred years ago,
+brought to a satisfactory issue, in the union of the two greatest
+philosophic theories for the explanation of celestial phenomena that the
+world has ever seen.
+
+From that union, therefore, there will then emerge a truer, simpler, and
+yet grander conception of the motions of the universe, which, when
+perfected by abler minds, will be as perfect a theory as human
+intelligence and philosophy can make it. So that, what an atomic and
+gravitative Aether has done for Newton's corpuscular theory of light, in
+showing that it can be united and combined with the undulatory theory,
+and by such combination, for the first time, such phenomena as the
+transverse action of light can be probably demonstrated and explained,
+together with other phenomena relating to reflection and refraction of
+light, the enlarged conception of a rotating electro-magnetic Aether will
+do for the two great theories that vied with each other for supremacy
+for so many years. Thus it will be shown that the philosophers like
+Kepler, Descartes, and Huyghens, the former of whom has stamped his name
+on the three laws that bear his name to-day, and the latter who gave us
+the inception of the very theory that overthrew Newton's theory of
+light, had after all a more or less true philosophic conception of the
+physical mechanism of the solar system and of the universe at large.
+
+
+ART. 94. _Relative Motion of Aether and Matter._--There is hardly any
+subject of greater importance which is engaging the attention of
+scientists at the present time, than the question as to what is the
+relative motion of Matter to the Aether in which it moves.
+
+I venture to premise the successful solution of the problem will be
+accompanied with the greatest advance to science that has been known for
+a long time. The problem to be solved may be stated thus: "Does the
+Aether surrounding a planet or sun or any body in space move with that
+body, or does it allow the body to pass through it?"
+
+Up to the present, opinions on the subject have been varied and
+conflicting. Some scientists hold that the planetary and other bodies in
+space pass through the Aether without disturbing it, while others hold
+that part of the Aether is carried along by the moving planet. Fresnel
+assumed that the surrounding Aether was carried along by the earth, so
+that all relative phenomena would be the same as if the earth were at
+rest. Fizeau, from experiments which he conducted on running water, also
+came to the same conclusion.
+
+With the old idea of a frictionless medium, some of the present accepted
+theories are altogether untenable, because, if Aether is frictionless,
+how can it be carried along with the moving body, unless it is held
+bound to that body? and how can it be held bound to that body if it is
+frictionless?
+
+The whole view of the Aether is, however, changed by the conception of
+the Aether put forward in Chapter IV. Aether is Matter, and being matter
+it is also gravitative, and therefore is just as much subject to the Law
+of Gravitation as any other kind of matter, as Young stated in his
+Fourth Hypothesis (Art. 45).
+
+We will therefore attack the problem of the relative motion of the earth
+and the Aether around it from this new standpoint. In order to be
+strictly philosophical, we must base our hypothesis and conception on
+experience and observation. Where in the whole of planetary phenomena do
+we find similar conditions which exist between the Aether and the earth?
+Such conditions are alone to be found between the atmosphere and the
+earth. The analogy between the atmosphere and the earth, and the Aether
+and the earth is very striking, as the following comparisons will prove.
+
+The atmosphere (when pure) is invisible, so is the Aether. The
+atmosphere is atomic, the Aether is also atomic. Both are subject to the
+same laws of elasticity and density, and both are gravitative, according
+to our conception of the Aether. Now what is the effect of any large
+revolving body on a liquid or gaseous medium surrounding that revolving
+body?
+
+If experience is any guide, we learn that the motion of the revolving
+body is either partially or entirely transmitted to the liquid or
+gaseous medium surrounding such a body. So far as our experience teaches
+us anything, it teaches us that to that rule there is no exception, and
+no experiment can be devised of any body revolving in water or a gaseous
+medium as air, without that body imparting its rotation to the water or
+the air. The atmosphere in relation to the earth is no exception to this
+rule. We know that the earth has an equatorial circumference of about
+24,000 miles, and that it revolves on its axis once every day, so that
+at the equator the surface of the earth is whirling round in space at
+the rate of 1000 miles per hour.
+
+Try to conceive what the result would be if the atmosphere were
+stationary at the earth's surface in the equatorial regions. It would
+mean that any body on its surface would be whirled round at that rate,
+while the atmosphere, being stationary, would exert a power equal to a
+wind travelling at the rate of 1000 miles per hour.
+
+Under the influence of such a hurricane, nothing could exist on the
+surface of the earth at the equator, if the earth revolved on its axis
+and the atmosphere did not participate in that motion. But the
+atmosphere is gravitative, and being gravitative, it is not only held
+bound to the earth as it revolves on its axis in its onward rush through
+space, but accepts the revolving motion of the earth, with the result
+that as the earth revolves on its axis, the atmosphere revolves also.
+
+Thus a balloon at the equator if allowed to rise several hundred feet
+above the surface could remain comparatively stationary if held by a
+rope to overcome its tendency to rise, whereas such an event would be
+impossible if the atmosphere failed to receive only half of the motion
+of the earth's surface, as it would still have a power equal to that of
+a wind blowing at the rate of 500 miles an hour. If, however, we come
+further north, or go further south, then we find that the surface of the
+earth does not have the same velocity as at the equator, with the result
+that the atmosphere has not the same velocity either; consequently it
+would travel slower in the temperate regions than in the equatorial
+regions, and slower still at the poles than in the temperate regions.
+
+We know by experiment what the effect of increased velocity has upon any
+whirling body; it tends to enlarge the body at those parts where the
+velocity is the greatest, the consequence being that the bulging out of
+the atmosphere would be greatest at the equator. We find a similar
+result in the shape of the earth, where the equatorial diameter is
+greater than the polar diameter, because of the centrifugal force being
+greatest in the equatorial regions.
+
+We have, therefore, to apply these facts to the aetherial medium which
+surrounds all planetary and stellar bodies in the same way as the
+atmosphere does; and which, being also gravitative, is equally subject
+to the same laws of motion. We have seen, therefore, that not only does
+the earth revolve on its axis, but that the atmosphere revolves on its
+axis also, and that the velocity of its revolution is greatest in the
+equatorial regions, the atmosphere spreading or bulging out in those
+parts more than in any other part of the earth's surface.
+
+Let us suppose that the atmosphere extends 200 miles above the earth,
+and that there we come to the pure Aether of universal space. In view of
+the fact that Aether is Matter, and therefore gravitative, it is
+reasonable and logical to conclude that exactly the same result follows
+in relation to the atmosphere and the Aether at that height, as follows
+in relation to the earth and the atmosphere 200 miles beneath.
+
+Unless this view is accepted, we should then have our second Rule of
+Philosophy violated, as we should have matter revolving in more rarefied
+matter, and failing to impress upon that rarefied condition of matter
+the motion either partially or wholly which it itself possesses; and
+such a result being contradictory to all experience cannot be admitted
+from a philosophical standpoint.
+
+Therefore, the only solution is, that the rotating atmosphere imparts
+some of its motion to the aetherial atmosphere, which in its turn
+rotates, and that that rotation is governed by exactly the same
+conditions as govern the relation that exists between the earth and the
+atmosphere. Therefore the Aether in space associated with each planet or
+satellite or sun or star, rotates with the rotating body, and that
+rotation imparts to the Aether a greater bulging out in the equatorial
+regions of the aetherial atmosphere than in any other part thereof. It
+is interesting in relation to this point to note Herschel's view of the
+effect of the rotation of any body upon the Aether. In his _Outlines of
+Astronomy_, in a note, p. 358, he states: "Supposing the neighbourhood
+of the sun to be filled with a material fluid; it is not conceivable
+that the circulation of planets in it for ages should not have impressed
+upon it some degree of rotation in their own direction, and this may
+preserve them from the effects of accumulated resistance."
+
+In this way we arrive at the conception of the motions of the Aether
+suggested by Prof. Challis from the magnetic character of the earth,
+which he thought were due to aetherial currents circulating around it,
+and we learn that such physical conception of the Aether fully agrees
+with the explanation of celestial bodies being electro-magnets; because,
+we have only to add to our rotating Aether that which it has been proved
+to possess, viz. an electro-magnetic basis, and we have at once the
+currents of electricity circulating round the earth and other planetary
+or solar bodies, by which is obtained the true explanation of the
+permanent magnetism of all celestial bodies.
+
+Now to some minds unconversant with scientific research and knowledge,
+such a supposition may seem to be incredible, but that incredibility may
+disappear, when I say that the fact that the Aether is bound to the
+earth, and goes along through space with it, has actually been proved by
+some of the most delicate and successful experiments that have been made
+in recent times: experiments of which Lord Kelvin has stated that he can
+find no error or flaw in them. I refer to the scientific experiments of
+Michelson and Morley of America. For full particulars of these
+experiments I must refer the reader to the _American Journal of
+Science_, 1886, vol. 31, or to the _Phil. Mag._, vol. 44.
+
+The conclusion which is arrived at from their experiments is, that the
+Aether is carried along with the earth as it rushes on its journey
+through space. Of course such a result is altogether opposed to the
+ordinary conception of a frictionless medium, and indeed to any
+conception of the Aether except to that submitted in this work, which is
+also in harmony with Young's Fourth Hypothesis (Art. 45).
+
+So that Michelson's and Morley's experiment is a direct experimental
+demonstration of the fact that Aether is gravitative, and because it is
+gravitative, it is carried along with the earth, as that planet journeys
+through space. It further conclusively proves that not only is the
+Aether carried along with the earth, but that the Aether circulates
+round the earth in the same way that the atmosphere circulates round the
+earth.
+
+This result naturally follows from the experiment, because, if it were
+carried along by the earth and yet did not rotate with the atmosphere,
+then we should have a result opposed to all experience and experiment,
+as these teach us that when a body revolves in a medium which is held
+bound to that body by Gravitation, the medium so held bound participates
+in the rotation of the revolving body.
+
+So that in Michelson's and Morley's experiment we have experimental
+evidence of the fact, already stated, that the Aether circulates round the
+earth, and therefore, in view of the electro-magnetic character of the
+Aether, this circulation results in the production of magnetism in all the
+planets, and other bodies around which it circulates.
+
+Thus not only does the Aether circulate round the earth, but it also
+circulates around every other planet, and not only round every other
+planet, but equally so around every sun and star, as stated in Art. 91.
+
+These results are perfectly consistent with philosophical reasoning, and
+any other result would be inconsistent with the analogies presented to
+us by the phenomena of the Aether in relation to our earth as
+ascertained by experiments made by the scientists referred to. Thus for
+the first time the experiment is brought into harmony with our
+Philosophy, which up to the present has not been the case, a result
+which at once stamps the experiment with that validity of truth and fact
+which will ultimately win for it universal acceptance and favour.
+
+We are now in a position to answer some queries regarding the motions of
+the Aether asked by Herschel in his work on _Astronomy_, p. 345. These I
+give with the answers opposite.
+
+
+              QUERIES.             |          ANSWERS.
+                                   |
+  1. What is the law of density    |  The Law of Gravitation
+     of the resisting medium which |  (Art. 45).
+     surrounds the sun?            |
+                                   |
+  2. Is it at rest or in motion?   |  In motion.
+                                   |
+  3. If the latter, in what        |  Rotates round the sun.
+     direction does it move?       |
+                                   |
+  4. Circularly round the sun      |  Both, as it circulates round
+     or traversing space?          |  the sun while that body
+                                   |  traverses space.
+                                   |
+  5. If circularly, in what        |  The plane of the ecliptic.
+     plane?                        |
+
+
+ART. 95. _Physical Explanation of the Vibration in the Electro-Magnetic
+Theory of Light._--In Art. 78 we learned that light was an
+electro-magnetic disturbance in the Aether which was propagated through
+the Aether, with a finite velocity; and from this we gathered that light
+waves were nothing more or less than electro-magnetic waves, which were
+radiated from the sun, out into the Aether on every side.
+
+We were unable, however, at that time to give a definite physical
+conception of the aetherial vibrations, or of the relation of the
+various types of vibration to each other. Since, however, the
+development of the Aether from the electric and magnetic standpoint,
+which has led us up to the fact that the Aether possesses a circulating
+motion round the sun (Art. 91), the solution of the problem appears
+probable. I am of the opinion that the physical conception of the
+various vibrations to each other is now within the region of
+possibility, and in this article I wish to endeavour to give what seems
+to me to be a correct and philosophical explanation of this part of the
+electro-magnetic theory of light, the physical conception of which up to
+the present has not been generally understood.
+
+The explanation may, or may not, be fully complete, but even if it be
+not perfectly correct, I am convinced that it will ultimately lead to a
+satisfactory physical explanation of this part of Maxwell's Theory of
+Light. In forming a conception as to the physical character of the
+vibrations in the electro-magnetic theory, we have to remember that
+there are three distinct vibrations, or motions, concerned in this
+theory.
+
+[Illustration: Fig: 22.]
+
+    1st. There is the direction of propagation.
+
+    2nd. There is the direction of the electric vibration which is
+         at right angles to the direction of propagation.
+
+    3rd. There is the direction of the magnetic vibration or
+         motion which is at right angles to both of the other two.
+
+Now we have seen that the direction of propagation of any aetherial
+light ray, is that of a straight line from the sun corresponding to the
+radius vector (Art. 76). We have also seen that the front of a light
+wave is really that of a spherical shell (Art. 71).
+
+We have also learned that the electric and the magnetic vibrations are
+in the wave front, so that these two vibrations, which are at right
+angles to each other, are to be found on the surface, so to speak, of
+each aetherial spherical shell, that surrounds the sun with
+ever-decreasing density, and ever-decreasing elasticity.
+
+Let us try to picture the actual fact by an illustration. Let _S_ be the
+sun, with concentric spherical aetherial shells surrounding it (Fig.
+22). Then _S_ _A_ and _S_ _C_ will be rays of light being radiated out
+from the sun, and the magnetic and electric vibrations have to be both
+at right angles to the line of propagation and in the wave front; the
+wave front being represented by the circular lines showing the section
+of the concentric shells running north and south.
+
+Now how can we picture these two motions at right angles to each other,
+and yet both at right angles to the line of propagation? First, let us
+take three straight lines and see how this may be done (Fig. 23).
+
+Let _A_ _B_, _A_ _S_ be two straight lines at right angles to each
+other, and _A_ _C_ another straight line at right angles to both. This
+can only be done by making _A_ _C_ perpendicular to the plane of the
+paper, and can be illustrated by supposing that it represents a pencil
+or pen placed upright on the paper, the point of the pencil being at
+point _A_. If this be done, then not only will _A_ _B_ and _A_ _C_ be at
+right angles to each other, but both will be at right angles to _A_ _S_,
+which corresponds to the line of propagation.
+
+[Illustration: Fig: 23.]
+
+Now refer to Fig. 22, and we shall see that the line _A_ _B_ and the
+boundary of the shell will practically correspond. So that any section
+of a spherical wave front will always be at right angles to the ray of
+light. But we have learned from Art. 89 that these sections of the
+aetherial spherical shell are really identical with Faraday's Lines of
+Force, with the result that along any line which stretches from the
+North pole of the sun to the South pole, there will ever be an electric
+vibration, which is put into motion by the elasticity of the aetherial
+vortex atoms. So that on every side of the sun there is ever going on
+this electric vibration, along the lines of force which correspond to a
+section of the aetherial shell, the surface of which really constitutes
+the wave front.
+
+Therefore it can readily be seen, that, as these lines are at right
+angles to the propagation of the ray of light, the electric vibration is
+at right angles to the lines of propagation, and is thus in accordance
+with the result demanded by Maxwell's theory.
+
+We have now to give a physical conception of the magnetic vibration or
+motion of the Aether, and this has to be at right angles to both the
+electric vibration and the line of propagation.
+
+In Art. 91 we have learned that the Aether possesses a rotatory motion, by
+which it rotates round the central body of the solar system, the sun. So
+that if we take any point, for example, in the path of the ray as _S_{1},
+_S_{2}, _S_{3}, and _S_{4}, situated upon some definite equipotential
+surface or lines of force, and if we will imagine those lines to rotate
+round the sun, as the sun rotates on its axis, then in time the points
+will have described half the circle, and will come to the position on the
+right of the sun indicated by the same Nos. _S_{1}, _S_{2}, _S_{3},
+_S_{4}. Thus there has been an aetherial motion at right angles to the
+electric motion, as the Aether circulates round the sun, because this
+motion may be represented as taking place from west to east of the sun,
+while the electric vibration takes place from north to south, or
+transverse to the line of propagation.
+
+We have, however, learned that the Aether has an electro-magnetic basis,
+and therefore the rotation of the Aether gives rise to electro-magnetic
+currents; hence the motion west to east is really the motion of
+electro-magnetic currents which circulate round the sun. As these are at
+right angles to the line of propagation, and we have seen that they are
+at right angles to the electric vibration, it follows that all three are
+at right angles to each other, which is in accordance with the
+requirements as laid down by Maxwell.
+
+We have considered these vibrations, first, from the view of the solar
+system as a whole in its relation to the universal Aether; but the same
+principle holds good if considered from the aetherial atomic standpoint.
+For if we take a line of force, composed as it is of aetherial vortex
+atoms, and suppose them to be rotating, we know that by that rotation
+there will be a tension due to that rotation, and Maxwell has shown this
+tension is due to magnetism, as in his standard work he says: "This
+magnetic force is the effect of the Centrifugal Force of the Vortices."
+
+So that by postulating a rotatory movement for the Aether around the
+sun, as we have done in Art. 92, we have not only solved the problem of
+all planetary and solar magnetism, but we have also solved the problem
+of the relative motion of the Aether and the earth, and also given for
+the first time (though it may be in an incomplete form) a physical
+explanation of that part of the electro-magnetic theory of light, which
+has hitherto been unexplained from the purely physical standpoint.
+
+Such results, therefore, supported as they are by the direct experiment
+of Michelson and Morley of America, justify us in concluding that the
+conception of a rotating Aether is not only philosophically correct, but
+is in actual accord with experimental investigation and research, as
+indeed it ought to be.
+
+
+
+
+                               CHAPTER X
+
+                  AETHER AND NEWTON'S LAWS OF MOTION
+
+
+ART. 96. _Centrifugal Force._--Before proceeding to apply some of the
+principles and laws which govern the electro-magnetic aetherial medium
+to solar and stellar phenomena, it will be as well just to review the
+conception of our new aetherial Centrifugal Force, so that we may form a
+right view of it in its completeness and entirety.
+
+In Art. 11 we premised that there was in existence another force, which
+was the exact opposite of the centripetal force, and that this force was
+the complementary and counterpart of the centripetal force or
+Gravitation Attraction; and further, that this force was due to the
+motion of the universal Aether which filled all space.
+
+In Art. 13 we saw that all force resolved itself into energy of some
+kind, the same being due either to potential energy, _i. e._ energy of
+position, or to kinetic energy, which is the energy belonging to matter
+actually in motion. From Art. 56 we learned that all energy was energy
+of motion, so that all force resolves itself into motion of some kind.
+
+Thus our term Centrifugal Force really implies, and demands, a motion of
+the Aether which is ever directed away from the centre of gravity of any
+body, whether that body be an atom or molecule, satellite or planet, sun
+or star. From the phenomena of heat we have seen that there exists a
+repulsive motion, due to the aetherial medium, which is ever exerted
+from the central body of any atomic, planetary or stellar system, that
+repulsive motion being due to the pressure of the universal Aether,
+which not only surrounds all atoms, but also surrounds all other bodies
+in the universe.
+
+From the phenomena of light we have also seen that the Aether possesses
+a repulsive or centrifugal motion, which is also due to the pressure of
+the same Aether as mathematically proved by Maxwell, and experimentally
+proved by Prof. Lebedew, and Nichols and Hull of America. Further, from
+the phenomena of electricity, we have also seen that there exists this
+centrifugal motion, due to the pressure of the same aetherial medium,
+which pressure is ever directed away from the electrified body, as the
+sun or planets.
+
+So that from these three phases of the universal Aether, that is, from
+its thermal or heat manifestation, its luminiferous or light
+manifestation, and its electro-magnetic manifestation, we get
+irrefutable evidence of the existence of a centrifugal motion, which
+motion is ever directed away from the central body; and the result of
+that motion takes the form of a pressure upon any body with which the
+motion comes into contact.
+
+Again, it was premised, that such a centrifugal force or motion must
+fulfil all the laws which governed the centripetal force or motion.
+
+First, it had to be universal (Art. 19). Second, it had to follow
+exactly the same path as the centripetal force or motion, which was that
+of a straight line joining the centre of gravity of two bodies, as for
+example the earth and the sun (Art. 20). Third, the centrifugal force or
+motion must be equal to the product of the masses, in the same way that
+the centripetal force was governed by such a law (Art. 21). Fourth, its
+intensity was to be governed by the law of inverse squares, the same as
+the centripetal force or Gravitation Attraction was governed (Art. 22).
+
+Now all these conditions are satisfactorily fulfilled, and have been
+shown to be satisfactorily fulfilled, from the phenomena of heat, light,
+and electricity in their relation to the universal Aether. For in Art.
+43 we saw that the Aether was universal, and therefore if the
+centrifugal motion is produced and originated by the Aether, then such
+motions must be as universal as that medium, which under qualifying
+conditions gives rise to these motions.
+
+From Arts. 65 and 76 we have learned that the path of this centrifugal
+motion is that of a straight line, and follows exactly the same path
+that the centripetal force of gravity takes. In Art. 85 we learned that
+the centrifugal force between any two bodies was equal to the product of
+their masses, which is exactly the same as the centripetal force that
+exists between any two bodies; and, lastly, from the phenomena of heat,
+light, and electricity we learned that the intensity of this centrifugal
+motion due to aetherial pressure was inversely as the square of the
+distance, which is the law governing the intensity of its counterpart,
+the centripetal force. Thus we have learned that there is in existence
+throughout universal space, a physical force or motion due to a physical
+medium, the universal Aether, which force or motion is the exact
+opposite of the centripetal force or Gravitation Attraction, which may
+be stated as follows--
+
+Every particle in the universe repels every other particle with a force
+whose direction is in the line joining the centres of gravity of the two
+bodies, and whose magnitude is directly as the product of their masses,
+and inversely as the square of the distance between them, at their mean
+distances.
+
+We shall see that it is by the conjoint working of these two forces, the
+Centripetal and Centrifugal, in combination with other motions of the
+Aether, that the harmonious working of the whole celestial mechanism is
+maintained and perpetuated. In confirmation of the existence of the
+centrifugal force, I should like to draw the attention of the reader to
+certain phenomena relative to the solar system, which phenomena violate
+the centripetal force as at present recognized, and can alone be
+accounted for by the existence of another force or motion existing in
+space, such as the centrifugal motion already proved and demonstrated.
+
+We know that the law governing the centripetal force, or Gravitation
+Attraction, is regulated by the product of the masses of the two
+attracting bodies. So that if there were three bodies in space whose
+masses are respectively represented by 2, 3 and 100, the proportion of
+the attractive force of gravitation between the largest and the other
+two, would be 200 (100 × 2) and 300 (100 × 3) respectively. So that if
+the centripetal force, or the Attraction of Gravitation, is the only
+governing force in the universe, then it naturally follows that the two
+bodies, between which the attractive force is greater, will be closer
+together than the two bodies between which the attractive force is less.
+
+Thus the two bodies, whose product of their masses is represented by
+300, will, according to the Law of Gravitation, be closer together than
+the two bodies, the product of whose masses is represented by only 200.
+Unless this is so, we should have a violation of the Law of Gravitation,
+and it would at once cease to be a law.
+
+Let us therefore apply the centripetal force, or Gravitation Attraction,
+to the solar system, and see how it works out. The law strictly defined
+is given in Art. 18, from which we learn that the attractive force
+between two bodies is as the product of their masses. Now what are the
+masses of some of the bodies in the solar system?
+
+We find that the sun, with its diameter of 865,000 miles, is about
+324,000 times greater in mass than our earth, so that it would take
+about 324,000 bodies of the size and density of our earth to equal a
+body of the size and density of the sun. It has been calculated,
+however, by Von Asten, from observations made on comets by the planet
+Mercury, that the mass of Mercury is about 1/24 of the mass of the
+Earth. Therefore the mass of the sun must exceed the mass of Mercury
+324,000 × 24 = 7,776,000; the exact relation according to Von Asten is
+7,636,440. Again, the planet Jupiter, with its diameter of 85,000 miles
+and its density of 1·38, is only 1/1048 part of the mass of the sun, so
+that it would take about 1048 Jupiters to equal the mass of the sun,
+therefore Jupiter must weigh about 7400 times the mass of Mercury.
+
+If the mass of Mercury, therefore, be represented by 1, the mass of the
+Earth would be represented by 24, the mass of Jupiter by 7400, and the
+mass of the sun by 7,636,400. So that the attractive forces between the
+planets as regards their masses only will be represented numerically as
+follows--
+
+    Sun and Mercury    7,636,400 × 1      =       7,636,400.
+
+    Sun and Earth      7,636,400 × 24     =     190,008,000.
+
+    Sun and Jupiter    7,636,400 × 7,400  =  56,435,360,000.
+
+Thus we see that the attractive force between the sun and the earth
+exceeds 24 times the attractive force between the sun and Mercury, while
+the attractive force of gravity between the sun and Jupiter is 7400
+times greater than the attractive force between the sun and Mercury,
+relative to their masses.
+
+Therefore, according to the Law of Gravity, as regards the masses of
+bodies, Jupiter and the sun should be nearer together than Mercury and
+the sun, because their attractive powers are greater, and the earth and
+the sun should be nearer together than Mercury and the sun, because
+their joint attractive powers are also greater. In the same way it can
+be proved that all the other planets whose masses are greater than
+Mercury ought, according to the Law of Gravity in regard to masses only,
+to be nearer to the sun than what Mercury is, simply because the total
+attractive forces between any two are greater than the attractive force
+between Mercury and the sun.
+
+The respective masses of the planets compared with the sun, taking the
+mass of the sun as unity, are as follows--
+
+    Jupiter  1/1,048  of mass of sun.
+
+    Saturn   1/3,529     "  "
+
+    Neptune  1/18,520    "  "
+
+    Uranus   1/22,020    "  "
+
+    Earth    1/324,439   "  "
+
+    Venus    1/397,000   "  "
+
+    Mars    1/2,994,790  "  "
+
+    Mercury 1/7,636,440  "  "
+
+Therefore, if the total attractive force of gravity is equal to the
+product of the masses of any two bodies, then the planets ought to be in
+the following order in relation to their distance from the sun: Jupiter,
+first, followed by Saturn, Neptune, Uranus, Earth, Venus, Mars and
+Mercury; that being the order in which the attractive power of gravity
+is regulated by their respective masses.
+
+Yet the very opposite is nearly the case, as we find that some of the
+further planets, as Jupiter, Saturn, Uranus and Neptune, possess greater
+masses than any of the nearer planets; so that here we have a distinct
+violation of the Law of Gravitation Attraction, which states that the
+attraction between any two bodies is directly as the product of their
+masses, because we find certain bodies with greater attracting powers
+further away from the sun, than other planets possessing less attracting
+powers, because of their smaller masses. I cannot recall having ever
+read of any explanation which has been given for such an anomaly, and
+indeed this apparent violation admits of no other explanation than the
+conception of the dual character of the so-called Law of Universal
+Gravitation, which includes a repelling or repulsive force or motion,
+such motion being due to the pressure of the universal Aether.
+
+Thus in the light of the centrifugal motion, combined with the fact that
+Aether is gravitative, by which each body possesses an aetherial
+atmosphere and electrical equivalent proportionate to its mass, it can
+be demonstrated within a reasonable limit how it is that such planets as
+Jupiter, Saturn, Uranus, Neptune, possessing aetherial atmospheres and
+electrical equivalents proportionate to their masses, revolve in orbits
+round the sun at much greater distances than Mercury, Venus, the Earth,
+or Mars. This explanation will follow as we consider the Centrifugal
+Force and the Centripetal Force in their relation to Newton's Laws of
+Motion.
+
+
+ART. 97. _Centripetal Force._--We have now to apply the Centripetal
+Force, together with the new Aetherial Centrifugal Force, to the solar
+system, and show that by their conjoint working taken in conjunction
+with the motions of the Aether, all celestial phenomena may be
+satisfactorily explained on a physical basis, in a similar way that
+Newton proved the same result from the mathematical standpoint.
+
+We saw in Art. 10 that the centripetal force was really none other than
+the Attraction of Gravitation, in that it always acted to a centre, and
+in no other way, and therefore by the centripetal force for the present
+we must understand is meant the attractive power of Gravitation.
+
+Afterwards, when it has been demonstrated that the centripetal force and
+the new aetherial centrifugal force can account for all celestial
+phenomena, then we shall be in a position to show what the physical
+cause of the centripetal force is.
+
+Let us again refer to the centripetal force, so that we may see exactly
+what its governing conditions are. In Art. 18 we learned that this force
+might be thus expressed: "Every particle of matter in the universe
+attracts every other particle with a force whose direction is that of a
+line joining their centres of gravity, and whose magnitude is directly
+as the product of their masses, and inversely as the square of the
+distance between them." Now we have seen from the previous Art. that the
+centrifugal force due to the pressure of the Aether medium is the exact
+counterpart of this, in every way, so that if we combine the two, we get
+the complete statement of the universal law which governs all matter,
+and which we may define as follows--
+
+"Every particle in the universe attracts and repels every other
+particle in the universe with a force whose direction is that of a line
+joining their centres of gravity, and whose magnitude is directly as the
+product of their masses, and inversely as the square of the distance
+between them." This complete law, however, only holds good when the two
+forces are in equilibrium.
+
+With this conception of the universal law which governs all matter, the
+harmony and stability of the universe becomes possible from the physical
+standpoint. Apart from this conjoint working of the two forces or
+motions, a physical explanation of Universal Gravitation is impossible,
+as with one force operating only throughout the universe, ultimate
+stability is inconceivable, and the harmony of the spheres might at any
+time be suddenly destroyed.
+
+With this conception of the universal law which governs all matter, the
+great Law of Gravitation is brought into harmony with all experience and
+observation. Look where we will, or at what we will, there we find
+forces possessing a dual character, as we have already seen proved.
+Professor Tyndall, as we have already learned (Art. 63), definitely
+states that the stability of atomic systems is preserved by the
+existence and operation of _two forces, one attractive and the other
+repulsive_, and what is true of the atomic world is equally true of
+solar or stellar worlds. Thus for the first time in this respect, our
+philosophy agrees with our experience, and the true relation of the
+centrifugal force or motion to the centripetal force is made manifest.
+So that, wherever in the solar system the centripetal force or
+Gravitation Attraction operates, there, with exactly equal intensity and
+power, the aetherial centrifugal force operates, at the respective mean
+distances of the planets and satellites, where the two forces are in
+equilibrium.
+
+If it were possible to conceive of a stationary solar system, then, by
+the conjoint working of the two forces, it would be equally possible to
+conceive of perfect stability and harmony existing between the
+respective planets and satellites of that system while stationary.
+
+Such a conception is altogether impossible in the present state of
+Philosophy, as the stability of the system, with the old view of the
+Centrifugal Force, is entirely dependent upon the motions of the
+respective bodies in that system; and if such orbital motions could be
+stayed, then the only physical conception possible would be, that every
+planet and satellite, planetoid and meteor within the attractive force
+of the central body, the sun, would be slowly but surely drawn to a
+fiery death, as they would all ultimately be attracted and swallowed up
+by the sun.
+
+Thus we learn, that while the sun is the centre of a centripetal force,
+which ever operates far and wide throughout space, it is equally the
+centre of a repulsive or centrifugal force or motion which also operates
+co-extensively and co-equally with the former.
+
+Not only so, but every planet and satellite, nay every particle and
+every atom, while it is the centre of a centripetal force, is also the
+centre of a repulsive force, as pointed out by Professor Tyndall, which
+force is due in each and every case to the pressure of the aetherial
+atmosphere which surrounds the atom or molecule, satellite or planet.
+Thus the physical conception of heat in its effect on molecules having a
+repulsive force (Art. 63) is confirmed, and that that force is due to
+the pressure of the Aether is also confirmed by subsequent
+investigations into the phenomena of light and electricity, by which we
+have arrived at our physical conception of the Universal Centrifugal
+Force.
+
+So that we have now a physical conception of the experiment performed by
+Nichols and Hull of America, and by Professor Lebedew of Russia, in
+which they conclusively demonstrated the existence of the pressure of
+aetherial light waves, which proves beyond the possibility of doubt the
+existence of this physical centrifugal force. Every atom and molecule,
+therefore, is the centre of two forces, which co-exist together, and
+every meteor and satellite and every planet is also the centre of the
+same two forces, and this we shall find in its application to planetary
+phenomena will have a most important bearing on the physical conception
+of those phenomena. Thus it is the Aether medium, by its energy of
+motions, that constitutes the companion and complementary force to
+Gravitation Attraction, and which, as we shall see later, is the medium
+which forms the physical basis of that attraction also. It is, then, by
+the combined and harmonious working of these two co-equal, co-existent,
+and co-extensive forces that worlds roll and rush, sweep and swing, move
+and rotate about their respective centres; and, by these two forces
+working in perfect harmony, that that order and stability are produced,
+which everywhere pervade the universe of worlds, and form them in their
+entirety into one grand, ultimate, and harmonious system.
+
+To develop and prove this fact, by explaining their manner and mode of
+working, we shall now proceed to consider Newton's Laws of Motion, and
+their relation to the aetherial medium, and by so doing shall be able to
+show the unmistakable reality and complete efficiency of this physical
+conception of the Aether medium, which forms the physical basis of all
+universal motion and phenomena.
+
+
+ART. 98. _Newton's First Law of Motion._--We will now apply the
+centrifugal and centripetal forces to Newton's Laws of Motion, and
+endeavour to form a physical conception of the same from the aetherial
+standpoint. Before doing so, we must recall some of the statements made
+in Art. 14 with reference to the First Law of Motion.
+
+It will be remembered that we divided the First Law of Motion into two
+parts: 1st, "Every body continues in a state of rest except in so far as
+it is compelled by impressed forces, _i. e._ impulses or motions, to
+change that state." This we saw agreed with our experience, and
+therefore was philosophically correct, and must hold good in its
+application to the centrifugal and centripetal forces of the Aether in
+their effect upon any body in space.
+
+Let us proceed to apply the First Law of Motion to the planetary world.
+We have seen in the previous Art. so far as the distances of the planets
+are concerned in their relation to the sun, that the Law of Gravity is
+violated, and that planetary distance is not regulated by the law
+governing the centripetal force of Gravitation, otherwise the planets
+possessing the largest masses would be nearer to the sun than those
+possessing smaller masses.
+
+The question arises, as to whether there is any law which governs
+planetary distance, by which the distance of any planet was regulated at
+the birth or creation of the solar system. It has been assumed by some
+scientists that planetary density is the regulating factor which
+determines the relative distance of the respective planets from their
+central body, the sun, but such an assumption is not consistent with
+scientific data. For we find that Venus, with a density of 4.81 compared
+with water, occupies a nearer position than the Earth with a density of
+5.66, whereas the reverse should be the case if the density of a planet
+were the deciding factor in regulating a planet's distance.
+
+Again, we find Saturn, which possesses a density of .75, occupying a
+nearer position to the sun than Uranus, which possesses a density of
+1.28; so that here again, if density were the regulating factor which
+decided planetary distance, such a law is violated. According to the
+various densities of the planets, the respective positions of the
+planets in relation to the sun would be as follows: The nearest planet
+would be Mercury, which possesses a density of 6.85. This would be
+followed by the Earth, with a density of 5.66. Then Venus would come
+next, with a density of 4.81, followed by Mars, with a density of 4.01.
+After these we should have Jupiter, whose density is 1.38, with Uranus,
+whose density is 1.28, followed by Neptune possessing a density of 1.15,
+and Saturn would take Neptune's place, as it possesses the least density
+of all, its density being only .75. So that it is manifest, that density
+cannot be the governing condition, as has been proved in the previous
+article.
+
+Now, if all the planets ever formed part of the sun, and they were
+hurled off into space by the centrifugal motion of the Aether, then
+there certainly would be some law which governs the relative distance of
+the various planets; but as far as we can see, there is no such law, as
+a law which is violated ceases to be a law, so that the law of masses or
+densities of a planet, governing their distances, has no place in the
+solar system.
+
+This leads up to the question as to whether the planets ever did form
+part of the sun, as is generally supposed; and, in view of the fact that
+there is no law by which planetary distances are regulated, we are
+compelled to come to the conclusion that each planet and satellite once
+existed in an aetherial condition in space, and that it was by the
+condensation of that Aether, that each planet was formed; and that, at
+its birth, each planet occupied the relative distance from the sun which
+it occupies to-day.
+
+At first sight this may appear startling, but I would ask the reader how
+he can account otherwise for the great irregularity which exists in the
+distances of the planets in their relation to the sun, as every known
+law which governs masses and density seems to be altogether set at
+defiance.
+
+I hope to prove later on, that all matter has an aetherial origin, and
+if that be correct, then the origin of a planet briefly outlined can be
+accepted without violating the results of experience or experiment, and
+to that extent will be philosophically correct.
+
+Dr. Larmor speaks of the aetherial constitution of matter, and refers to
+the views of Faraday and Davy in support of such a theory, while Lord
+Kelvin has referred to the same principle in an article on the
+"Condensation of Gravitational Matter in any part of the Universe"
+(_Phil. Mag._, July 1902). So that if it be possible for Aether to be
+condensed, and so form the nucleus of a planet or satellite, then,
+seeing that the Aether is universal, any planet or satellite or meteor
+may be formed in any part of the solar system; and the process has only
+to be continued, until we have planets of various sizes at various
+distances from the central body, the sun.
+
+Here, therefore, at any rate, is a physical hypothesis which will
+satisfactorily account for all the different distances of the various
+planets. Apart from some such hypothesis, I fail to see how we can
+account for the irregularity that exists between planetary distances,
+when viewed from the standpoint of their masses and their densities.
+
+Further, such a conception is entirely in harmony with the view of the
+dual character of the motions or powers of the aetherial medium, that
+would co-exist with the evolution and development of the planet. For, as
+the planet was evolved and developed from the aetherial medium which
+surrounded it on every side, two motions would be developed and grow
+with it--the centrifugal force or motion, and the centripetal motion of
+the Aether, or the attractive force known as Gravity. Thus, through all
+the growth and development of a planet, these two powers, the
+centripetal force and the centrifugal force, would be co-equal and
+co-existent.
+
+The same truth applies to the sun or any other body in the universe; so
+that, if a planet, as the Earth, was formed in the beginning at its mean
+distance of 92,700,000 miles, then the joint centripetal motions
+produced by the Earth and sun in the Aether, would always equal the
+joint centrifugal motions produced by the same two bodies, simply
+because the two laws are the exact opposite of each other both in regard
+to intensity, distance, and magnitude.
+
+Thus the Earth would always occupy its relative position in relation to
+the sun that it occupies to-day, as long as the two aetherial forces or
+motions, the centripetal and the centrifugal, exist. With this brief
+outline of a planet's history, we are now in a position to form a
+physical picture of the solar system when it first existed in the
+beginning.
+
+We find the sun then occupying its centre. At various distances, we find
+the various planets situated without any regard to their relative masses
+or densities, as the following table shows. (The mass of sun is taken as
+unity.)
+
+                MEAN DISTANCE.    MASS.      DENSITY.
+
+    Mercury       35,900,000   1/7,636,440     6.85
+
+    Venus         67,000,000    1/397,000      4.81
+
+    Earth         92,700,000    1/324,439      5.66
+
+    Mars         141,000,000   1/2,994,790     4.01
+
+    Jupiter      482,000,000     1/1,048       1.38
+
+    Saturn       884,000,000     1/3,529        .75
+
+    Uranus     1,780,000,000     1/22,020      1.28
+
+    Neptune    2,780,000,000     1/18,520      1.15
+
+Now, in order for any of these planets to fulfil Newton's First Law of
+Motion, the sun, which occupies the centre of the solar system, must be
+assumed to have no rotatory or orbital motion of its own; because, so
+long as it has a rotatory motion on its axis, or an orbital motion of
+its own through space, so long will even the first part of Newton's
+First Law of Motion be inapplicable to the solar system.
+
+But if the sun can be assumed to possess at some point in its history no
+orbital motion, or rotatory motion on its axis, then the physical
+interpretation of the first law of motion can be physically conceived,
+and a planet at rest will remain at rest relatively to its central body,
+the sun, for ever.
+
+Let us take the sun and Mercury as an example of the effect of the two
+motions operating in the aetherial medium. We will consider first the
+effect of the centrifugal motion. The sun, with its huge form, occupies
+the centre of the solar system, while Mercury has its mean distance
+about 36,000,000 miles away.
+
+The solar fires are intensely burning, and every atom and every particle
+composing them are excited thereby into the most intense activity, and
+by their energy of motion create myriads upon myriads of waves in the
+surrounding Aether, which flow away on every side with the velocity of
+light.
+
+With such velocity are they generated, that they speed across the
+distance of 36,000,000 miles which exist between Mercury and the sun in
+the short time of about three minutes, and if it were not for the
+aetherial and aerial atmosphere of the planet, would fall upon the
+surface of Mercury with an intensity of heat that would scorch up all
+vegetable life, if any existed thereon.
+
+Now let us for a moment ignore the existence of the centripetal force,
+and then in that light view the influence of the electro-magnetic Aether
+waves upon Mercury. We have seen that when aetherial light waves come
+into contact with any body, they exert a pressure upon that body (Art.
+77), so that under the influence of the centrifugal force only, Mercury
+would be borne away from its central body, the sun, with a power and
+energy of motion entirely dependent upon the intensity of the
+electro-magnetic Aether waves which give rise to the centrifugal force.
+
+Thus Mercury would be carried away from the sun, far far away into the
+depths of space, with ever-decreasing rapidity, the rapidity of its
+motion through space being entirely dependent upon the intensity and
+energy of the Aether waves; and, as that intensity varies inversely as
+the square of the distance from the central body, the sun, so the
+impelling and repelling energy of the Aetherial waves would vary
+inversely as the square of the distance from the central body.
+
+Thus the motion of Mercury or any other planet through space would not
+be uniform, but would gradually decrease, and such a result is perfectly
+in harmony with all experience and experiment in relation to moving
+bodies on this earth.
+
+This effect of the Aetherial electro-magnetic light waves upon a planet
+is in harmony with Newton's nineteenth query in _Optics_, and is indeed
+the physical illustration of that query in its corrected form which we
+have already referred to in Art. 46, where Newton says: "Doth it
+(Aether) not grow denser and denser, etc.; every body endeavouring to go
+from the denser parts of the medium towards the rarer?"
+
+That the Aether does grow denser and denser nearer to a body we have
+already seen in Art. 46, and now we learn that a body, when under the
+influence of the centrifugal force only, would pass from the denser
+parts of a medium to the rarer parts, as suggested by Newton. We will
+now suppose that Mercury has been repelled, by the pressure due to the
+aetherial waves generated by the sun, to the distance of Neptune, a
+distance of 2,780,000,000 miles; and that at this point the centrifugal
+force is cancelled, and in its place is put the centripetal force of
+Gravitation. What will be the effect upon Mercury then? At first sight
+the effect will be exceedingly slight, but slowly, yet surely, the
+attractive power of the sun would begin to make itself manifest, and we
+should find Mercury retracing its path along exactly the same straight
+line that it had taken in its outward journey.
+
+Not only so, but its motion would be accelerated just in the same
+proportion that it had decreased on its outward journey. On and on
+through the intervening space the planet would rush, and if there were
+no centrifugal force in existence, the planet would ultimately rush into
+the central body, the sun, and being swallowed up by it, would maintain
+for a time the heat thereof.
+
+Let us now view the case from the conjoint working of these forces, or
+motions, the centripetal and centrifugal, and we shall see, that under
+certain conditions it is possible to conceive physically of a planet
+being in a state of rest as stated in Newton's First Law of Motion, and
+also remaining in that state of rest, until it is compelled by other
+forces or motions to change that state. Mercury is now situated at its
+mean distance of about 36,000,000 miles. At the same instant let both
+the centrifugal and the centripetal forces or motions be applied to it,
+and to the sun. What is the result of such application? Will the planet
+move nearer the sun, which we are supposing to be perfectly at rest, or
+will it be urged further away? The effect is nil! for the simple reason,
+that when we set in motion the centripetal force of Gravitation, at
+exactly the same time we set in motion an exactly opposite force which
+is the exact complement and counterpart of the other, so that they
+exactly counterbalance each other, and Mercury under the influence of
+both forces still retains its mean position of 36,000,000 miles; and,
+until we either set the sun rotating, or give it a motion of its own
+through space, Mercury would remain at its distance of 36,000,000 miles
+comparatively at rest. The same reasoning may be applied to all the
+other planets, in relation to their mean distances, with the result that
+they too would remain in a comparative state of rest, so long as they
+were only under the influence of the two forces or motions, viz. the
+centrifugal and centripetal.
+
+Each of these, being the exact complement and counterpart of the other,
+when applied together to any planet of any size or mass or density, at
+any distance, fails to affect the distance of that planet in its
+relation to the sun, but simply establishes it in that distance, subject
+to certain regulations dependent upon other motions of the sun, and the
+aetherial medium in which they exist. Thus we learn, that if, in the
+beginning, Mercury were formed at a distance of 36,000,000 miles, it
+would for ever remain at that distance; and the same is true of the
+other planets at their mean distances, no matter what their mass or
+density may be; and that, according to the first law of motion, the
+planet would remain in a state of rest until compelled by other forces
+or motions to change that state, when it would continue moving with
+uniform motion so long as the motive power applied was uniform.
+
+If, however, the motive power applied was not uniform, then the result
+would be an increase or decrease of the planet's motion, just in
+proportion to the increase or decrease of the motive power. This result
+is in perfect harmony with our statement in Art. 15, and is in
+accordance with observation and experience.
+
+
+ART. 99. _Second Law of Motion._--According to Newton's Second Law of
+Motion, "Change of motion is proportional to the impressed force, and
+takes place in the direction in which the force is impressed."
+
+From a consideration of this Law (Art. 15) we saw that the impressed
+force was a compound quantity, being regulated by the mass of the moving
+body which exerted the impressed force, and that it was also
+proportionate to the velocity of the moving body; so that if either of
+these quantities are changed, the total impressed force would be changed
+also.
+
+We have now to show that our aetherial medium agrees with this second
+law of motion in so far as the second law of motion agrees with
+experience and experiments. To do this, we must review our conception of
+the universal Aether, and remember that Aether is matter, and being
+matter, it is atomic and gravitative, possessing density, elasticity,
+inertia, and kinetic energy, the same as any other moving matter.
+
+In this Aether medium we have, according to this conception, something
+that can both push and pull, or exert force upon any body with which it
+comes into contact. Further, the inertia and kinetic energy of the
+Aether at any part of space will be regulated by its mass in that
+particular part, and if its mass is denser in some parts than others,
+that part of the aetherial medium possessing the greatest mass will also
+possess the greatest capacity for impressing force upon any body that
+exists in the medium. Now we have learned from Art. 45 that Aether being
+gravitative, it is denser nearer to the sun, getting gradually less and
+less dense, the further it recedes from the central body, except where
+it is bound or associated to some other planet or satellite, and there
+it gradually gets denser, for the same reason that it is denser nearer
+to the sun. As, therefore, the Aether gets gradually less dense as it
+recedes from the sun, the density of the Aether at the mean distance of
+Mercury, 35,900,000 miles, would not be so great as near the sun's
+surface; while the density of the aetherial medium at the distance of
+Venus, 67,000,000 miles, would be less than the density of the aetherial
+medium at the distance of Mercury. This principle may be applied right
+through the sun's aetherial electro-magnetic field, until we come to the
+mean distance of Neptune, which is 2,780,000,000 miles, and there the
+density of the Aether would be less than at any other part of the
+aetherial electro-magnetic field around the sun.
+
+So that the mass of the Aether at Mercury, which is equal to the number
+of aetherial atoms per unit volume, is greater than the mass at Venus.
+Thus the impressed force which the aetherial medium at the mean distance
+of Mercury can exert upon any body in its neighbourhood, is greater than
+the impressed force which the Aether can exert upon any body at the
+distance of Venus, because of its decreased mass at that distance. In
+the same way it can be proved that the impressed force which the
+electro-magnetic Aether exerts on any body at the distance of Venus, is
+greater than the impressed force which the Aether exerts upon a body at
+the mean distance of the Earth. So that at the respective mean distances
+of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, the
+electro-magnetic Aether, if in motion, would exert less force at each
+of the mean distances of these planets exactly proportionate to the
+decreased mass and decreased velocity of the Aether.
+
+Now what is the motion which the Aether possesses, so far as the sun is
+concerned? because, upon the particular kind of motion which it
+possesses will depend the direction in which the impressed force will be
+exerted according to the second law of motion.
+
+In Art. 98 we supposed the sun and planets to be stationary in the solar
+system, each planet being at its respective mean distance, from which it
+cannot move owing to the equality of the two forces. Now give to the
+central sun from whence the electro-magnetic Aether waves flow, a
+rotatory motion on its own axis, which it really possesses, as it
+rotates on its axis once in every twenty-six days nearly, and this will
+give to the Aether medium a circular or rotatory motion. This circular
+or rotatory motion the Aether has already been proved to possess (Art.
+91, where we learned that all solar magnets were caused by
+electro-magnetic aetherial currents constantly circulating round them).
+So that the Aether will actually possess two motions: 1st, a radial
+motion due to the Aether waves generated by the sun, which are radiated
+out into space with the velocity of light; and 2nd, a circular or
+rotatory motion. This result is in perfect harmony with our hypothesis
+as to the cause of the electro-magnetism of the sun (Art. 91, where we
+saw that solar magnetism was due to electric currents circulating round
+the various planets), and we have proved that the Aether has an
+electro-magnetic basis; thus the rotatory Aether currents and the
+rotatory electro-magnetic currents are due to one and the same medium.
+
+Now what will be the effect of these circular or rotatory Aether
+currents on the bodies situated within their field? It must be
+remembered that we are no longer dealing with a frictionless medium, but
+with a medium which possesses inertia and kinetic energy the same as any
+other moving matter. Therefore, as soon as it is set in motion, it will
+impress its motions upon all planets that come under its control and
+influence, with the result that as the impressed force is ever directed
+in a circular form, the planet will be pushed along through space by the
+moving Aether, and the path it describes will be circular also.
+
+Thus the actual result of the rotatory electro-magnetic Aether currents
+will be, that all dependent and associated planets under their influence
+will be carried by them around the central body which generates the
+Aether currents. So that they will literally and truly have an orbit,
+and the circle they describe will be, in its size and circumference,
+regulated by the mean distance of each planet, which mean distance will
+form the radius of the circular orbit.
+
+Further, as we shall see later, if the sun were always stationary, and
+had no orbital motion of its own, then the orbit of each planet would
+always be circular, each planet always occupying its mean distance from
+the sun, because at that mean distance the centripetal and centrifugal
+forces are equal.
+
+That the actual path of any planet is a circle has been proved by Sir W.
+R. Hamilton. Tait, in his _Natural Philosophy_, on this point writes
+(Art. 38): "The Hodograph for the motion of a planet or comet is always
+a circle, whatever be the form and dimensions of the orbit." This path
+has been termed the Hodograph. So that we have in the circling
+electro-magnetic Aether currents a physical explanation for the
+Hodograph of any planet.
+
+In applying the rotatory Aether currents to the various planets, and in
+endeavouring to find out the quantity of the force impressed upon the
+various planets at their mean distances, by those currents, we have to
+take into consideration, as we have already seen, two facts, viz. the
+mass of the Aether at any point in space, and the velocity of the Aether
+at the same point. We will first take the effect of the difference in
+mass. We have seen that at the distance of Mercury from the sun the
+density of the Aether is greater than at the distance of Venus, and that
+the density at Mars is greater than the aetherial density at the Earth,
+the aetherial density decreasing the further the Aether recedes from the
+sun.
+
+What, therefore, is the effect of the decreased density of the Aether on
+each planet? Even supposing the velocity of the moving Aether is the
+same at the respective mean planetary distances, which it is not, the
+total impressed force at the respective mean planetary distances will
+gradually be decreased upon the various planets, proportionate to the
+decrease in the mass and density of the Aether.
+
+So that on Mercury, which is pushed along by a denser electro-magnetic
+Aether than Venus, the impressed force, according to Newton's Second Law
+of Motion, will be greater than the impressed force exerted by the
+moving electro-magnetic Aether on Venus; and, consequently, Mercury
+should have a greater velocity through space than Venus, due partly to
+the difference of the aetherial mass and density, by which the impressed
+force or motive power that acts upon Mercury is produced.
+
+In the same way, Venus should have a greater velocity through space than
+Mars, and Mars a greater velocity than the Earth. The same principle, when
+applied to the outer planets, equally holds good; with the result, that
+the greater the mean distance, the less the orbital velocity of each
+planet, due partly to the decreased aetherial density at the increased
+distance from the sun. But this is only part of the cause. Not only is
+there a decrease in density of the Aether, as the distance from the sun
+is increased, but there is also a decrease in the velocity of the moving
+Aether, with the result that the Aether at the distance of Mercury,
+possesses a greater angular velocity than at the distance of Venus.
+
+It may be at once asked, How do we know that? Well, Philosophy alone can
+give us the key, and Philosophy tells us to base our theories and
+hypotheses on experience and experiment. Now what does experiment and
+experience teach us as to the effect of a body revolving in any medium
+upon that medium? If experience teaches us anything at all, it teaches
+us that the further away any medium is from the revolving body, the less
+is the angular velocity of that medium at that distance, while the
+nearer the medium is to the revolving body, the greater is the angular
+velocity.
+
+This applies in each and every case, whether the medium is either fluid
+or gaseous, and I will challenge the reader to perform any experiment on
+any solid body rotating in a fluid or gaseous medium, and prove by that
+experiment that the angular velocity of the outermost part of the fluid
+or gaseous medium is equal to the angular velocity of the medium
+directly associated with the body, or even at a short distance from it.
+
+But we have most conclusive evidence of the fact that a solid body does
+not communicate all its rotational surface motion to the medium directly
+in contact with that body in the case of the earth revolving on its
+axis, surrounded by an atmosphere. If the principle held good anywhere
+in relation to a revolving body, viz. that the whole of the rotational
+velocity is communicated to the medium surrounding the body, it should
+certainly hold good at the surface of the body where the two media, the
+solid and gaseous media, meet.
+
+If a solid body fails to impart all its rotational velocity to the
+medium there, then it will certainly fail to impart its full rotational
+velocity to the enveloping medium 100 miles away, and fail still more at
+a distance of 1000, and still more at a distance of 100,000,000, and so
+on proportionate to the distance.
+
+What, then, is the effect of the rotational velocity of the surface of
+the earth on the atmosphere near to it? We know that the velocity of the
+surface of the earth is greatest at the equator, as at that place the
+circumference of the earth is about 25,000 miles, but the further we get
+away from the equator, and the nearer we get to the North and South
+poles, the velocity of the surface decreases, simply because the
+circumference of the earth decreases.
+
+Or, to reverse the statement, the velocity of the surface of the earth
+is least at the poles, but increases the nearer we get to the equator.
+It is also familiar knowledge that there are currents of cold air ever
+moving from the North and South poles to the equatorial regions near the
+surface of the earth. Thus the cold air currents, in passing from the
+North and South poles, are ever passing over surfaces which are
+increasing in velocity as they journey on their way to the equator. This
+of course occurs all round the earth, so that the earth is continually
+revolving in these currents, and if the rotational velocity of the
+surface of the earth were wholly imparted to the air directly over its
+surface, then the currents would be always flowing due North and South.
+
+If, however, the earth fails to impart all its rotational velocity to
+the atmosphere, or the atmosphere fails to pick up the whole of the
+rotational velocity at once, then the result will be that the atmosphere
+as it passes over the surfaces of greatest velocity will lag behind,
+because its rotational velocity will be less than the velocity of the
+earth's surface.
+
+Now this is exactly what does happen in regard to the atmosphere, with
+the result, that instead of getting winds blowing due north and south,
+we get what are known as Trade Winds, which blow north-east in the
+northern hemisphere and south-east in the southern hemisphere. Here then
+we have direct experimental proof on a large scale of the very principle
+I have stated, viz, that a medium surrounding any rotating body does not
+move through the whole of its extent with the same velocity as its does
+at the surface. Thus it can be seen that the velocity of the rotating
+Aether will be greatest at the surface of the sun, but its angular
+velocity will decrease the further the medium recedes from the sun.
+
+The same principle can easily be proved from an electrical standpoint;
+for if we consider the Aether currents as electric currents, no one
+would think of suggesting that the intensity of the currents was the
+same at a distance of several million miles away, as it is near the
+source of the currents, which in this case may be looked upon as the
+sun, because at its surface we have the greatest electric potential
+(Art. 80).
+
+So that we see from this reasoning, that not only is there a decreased
+mass of the Aether at the distance of Venus, compared with Mercury, but
+there is also a decreased velocity in the rotatory electro-magnetic
+Aether currents, with the result that the impressed force exerted upon
+Venus is less than the impressed force exerted upon Mercury, and
+therefore Venus should move slower through space than Mercury, which is
+exactly what happens, as Mercury has an orbital velocity of 29 miles per
+second, while Venus has an orbital velocity of 22 miles per second.
+
+As the angular velocity decreases in proportion as the distance
+increases, it follows that at the respective mean distances not only of
+Venus, but also of Mars, Jupiter, Saturn, Uranus and Neptune, the
+capacity of the Aether to exert its impressed force upon the various
+planets will decrease as the distance increases, with the result that
+the farther a planet is from the sun, the less force will the Aether
+currents exert upon that planet, with the result that its orbital
+velocity should decrease as the distance increases, and this is
+perfectly in accordance with planetary phenomena.
+
+Here, then, we have at once a physical basis for Newton's Second Law of
+Motion, the results of which are entirely in harmony with observation
+and experiment, and whose conception fully satisfies all the Rules of
+Philosophy; as it is simple in conception, fully agrees with observation
+and experiment, and satisfactorily explains the Second Law of Motion
+sought to be explained.
+
+Thus we find that from the physical standpoint, as well as from the
+mathematical standpoint, "Change of motion is proportional to the
+impressed force, and takes place in the direction in which the force is
+impressed," that is, in a circular direction.
+
+We have therefore arrived at exactly the same result that Newton arrived
+at, except that he had to introduce a third factor, viz. the
+Parallelogram of Forces, while we have produced the result by a simpler
+method, which, according to his own rules, is more philosophical, as all
+effects are produced by the simplest causes, as Newton himself stated in
+Rule 1. Thus it is the rotatory electro-magnetic Aether currents that
+urge the planets round the sun; and, as will be shown later, it is the
+same Aether currents in combination with the other motions that give
+rise to the physical cause of Kepler's Laws. It is the electro-magnetic
+Aether currents that produce the regular decrease in the velocity of the
+planets in their orbits, because of the regular decrease of the mass and
+velocity of the Aether currents themselves.
+
+We have now a physical cause as well as a mathematical explanation of
+the decrease of the velocity of a planet in its orbit, which physical
+cause is in perfect harmony with all philosophical rules. The following
+table shows the gradual decrease in the velocity of each planet as the
+various planets recede from the sun--
+
+                   MEAN            PERIOD OF     VELOCITY IN
+                 DISTANCE.        REVOLUTION.    ORBIT PER HOUR.
+
+    Mercury      35,900,000         87.9 days
+
+    Venus        67,000,000        224.7             77.000
+
+    Earth        92,700,000        365.2             66.500
+
+    Mars        141,000,000        686.9             53.000
+
+    Jupiter     482,000,000      4,332.6             28.744
+
+    Saturn      884,000,000     10,759.              21.221
+
+    Uranus    1,780,000,000     30,687.              14.963
+
+    Neptune   2,780,000,000     60,127.              11.958
+
+
+ART. 100. _Aether and Third Law of Motion._--We have seen (Art. 16) that
+action and reaction are equal and opposite, and that it is true of the
+centripetal force in its application to all matter throughout the
+universe. If, therefore, the centrifugal force is the exact opposite of
+the centripetal force, then the Third Law of Motion should equally hold
+good in relation to that force also.
+
+We have, therefore, to form a physical conception of the application of
+the third law of motion, as it relates to the centrifugal force. As we
+have already learned, this force is due to the universal
+electro-magnetic Aether, which being gravitative, surrounds all atoms
+and molecules that may exist throughout the whole universe. It can
+readily be seen, therefore, that if the Aether surrounds every atom and
+molecule, then each atom repels another atom or molecule when the two
+forces are in equilibrium with exactly the same intensity with which the
+atom and molecule attract each other.
+
+But the centrifugal force in each case is due to the pressure of the
+Aether, which presses always proportionately to the density of the
+Aether surrounding the atom or molecules, as suggested by Professor
+Challis.
+
+The mean density, however, of each atomic or molecular atmosphere is
+regulated solely by the mass of the atom or planet, therefore the
+pressure exerted by one atom on another is proportionate to the mass of
+each atom, and to that extent is strictly in accordance with the law
+which governs the proportion of the forces between the two atoms or
+molecules. If, therefore, we have two atoms, A and B, of different
+masses, then it is true that while A exerts a pressure on B, which
+pressure takes the form of a repulsion, at the same time B exerts a
+pressure on A which is equal and opposite in its character and
+intensity, and in each case the pressure is due to the aetherial medium
+which surrounds each atom or molecule.
+
+When the atoms are equal in mass, then the resultant motion produced on
+each atom would be exactly equal, but when the masses vary, the
+resultant motion produced on each atom would vary also, though the
+momentum in each case would be exactly equal and opposite, as momentum
+is a compound term dependent partly upon the mass of the body concerned.
+
+In Art. 16 we saw that when this third law was applied to planetary
+phenomena, not only did the sun attract all the planets, but all the
+planets attracted the sun with equal and opposite forces, and the
+planets also attracted each other with equal and opposite forces. In the
+same way it can be proved, that as the sun repels all the planets by the
+pressure exerted by the aetherial centrifugal force on those planets,
+the planets repel the sun with an exactly equal and opposite force at
+their mean distances. In Newton's conception, however, of the third law
+of motion, there was simply mathematical data to deal with, by which the
+law was shown to apply to the planetary and stellar world. In the case,
+however, of the centrifugal motion, we have a definite physical medium,
+which by its motions produces the pressure on the planets or suns that
+exist in space, which pressure forms the physical centrifugal force that
+forms the counterpart of Gravitation Attraction.
+
+Let us look at this phase of the case in detail, and by so doing help to
+establish and confirm the physical existence of the force or motion
+referred to. We have learned from Chapter IV. that as Aether is
+gravitative, it surrounds all satellites and planets, suns and stars
+that exist in the universe.
+
+We have also learned from Art. 86 that Aether has an electro-magnetic
+basis, as mathematically proved by Maxwell and experimentally proved by
+Hertz. Thus we came to the conclusion that each satellite and planet,
+sun and star, was an electrified body (Art. 81), or an electro-magnet
+(Art. 88), possessing its own electric or electro-magnetic field.
+
+We also learned that in every electro-magnetic field there was a
+pressure which was ever directed away from the body that generated the
+electro-magnetic waves. Now, as every satellite and planet, sun and
+star, is a generator of these waves according to our theory, it follows
+that every satellite and planet, sun and star, is the centre of a
+centrifugal force, which centrifugal force is regulated by the mass of
+the satellite, planet, sun or star which gives rise to the centrifugal
+force or motion.
+
+Now, in relation to all electro-magnetic action, it can be
+experimentally demonstrated, that action and reaction are equal and
+opposite, so that if we have two electrified or magnetized bodies, then
+the joint forces of attraction or repulsion between them are equal and
+opposite. This being so, when we apply the same law of action and
+reaction to the planets' influence on each other, it follows that the
+same law must hold good in relation to them.
+
+So that if we compare the repulsive powers of two planets on each other
+in the solar system, say the Earth and Jupiter, then, according to the
+third law of motion, the repulsive action of Jupiter on the Earth is
+exactly equal and opposite to the repulsive action of the Earth on
+Jupiter. If we compare the Earth and the sun, the repulsive action of
+the sun on the Earth is exactly equal and opposite to the repulsive
+action of the Earth on the sun, that action or force being caused
+directly by the electro-magnetic Aether waves, which are generated by
+each electric, or electro-magnetic body.
+
+Thus, as the third law of motion is true of the centripetal force,
+whether in relation to the atomic world, or in relation to the solar
+system, or even to the universe at large, seeing that the centrifugal
+force is the exact counterpart in every way of the centripetal force,
+exactly fulfilling all the laws which govern it, it follows as a matter
+of absolute necessity that the third law is also applicable to its
+complement or counterpart also, or else it would cease to be the
+complement and counterpart of the centripetal force.
+
+
+ART. 101. _Why Planets revolve from West to East._--In Art. 99 we have
+seen that the revolution of the planets around the sun is produced and
+maintained by the electro-magnetic Aether currents, which are generated
+by the axial motion of that electro-magnetic body. There is, however,
+another effect produced, and another scientific fact which can be
+accounted for by the circulating motions of the Aether medium, viz. that
+the orbital direction of each and all the planets would not only be in
+the same direction, but they would also be in the same direction as the
+sun's rotation on its axis.
+
+So that, whichever way the sun turns upon its axis, that way, and that
+alone, should be the orbital direction of all the planets in which they
+are circled round the sun by the circulating electro-magnetic Aether
+currents. It is the sun's axial motion that partly gives to the Aether
+currents their circling motion, and it is the circling motion of the
+Aether currents that gives rise to the orbital motion of the planets,
+literally carrying them round the sun by their kinetic energy and power.
+
+Therefore, if this be true, whichever way the sun turns upon its axis,
+that will be the direction in which the Aether currents must circle
+round the sun, and in that direction the planets should travel in their
+orbits. As must readily be seen, it is the inevitable result of the
+established working of the electro-magnetic Aether currents. If the sun
+rotated on its axis from east to west, then the electro-magnetic Aether
+currents would also travel in the same direction, from east to west, and
+the planets would then revolve round the sun from east to west.
+
+If the sun, however, rotates on its axis from west to east, then, if
+there are such electro-magnetic Aether currents in existence, as those
+we have already proved to exist, they, too, would travel from west to
+east, and as a natural result the planets, which are carried round the
+sun by the currents, would also possess the same orbital motion, that is
+from west to east.
+
+As is well known, the sun rotates on its axis from west to east,
+therefore the Aether currents also rotate from west to east, with the
+result that the orbital directions of all the planets should also be in
+the same direction, from west to east. Now, as is well known, all the
+planets without exception, Mercury, Venus, the Earth, Mars, Jupiter,
+Saturn, Uranus, and Neptune, all travel round the sun from west to east.
+
+Here, then, we have indisputable evidence of the existence and mode of
+working of the electro-magnetic aetherial currents, whose action alone
+can produce the phenomena with which we are so familiar, and for which
+there must be some physical cause. I am not aware that any reason or
+explanation either mathematical or otherwise has ever been given, or
+even suggested, as to the cause of the phenomena which we have just
+endeavoured to explain.
+
+Indeed, there can be no other physical explanation of the fact, that all
+the planets revolve round the sun in the same direction that the sun
+rotates on its axis, than the one here given, viz. that the cause is to
+be found, and alone found, in the circulating electro-magnetic Aether
+currents which are generated in the Aether by the electro-magnetic body,
+the sun. Again, in order to confirm the existence of these Aether
+currents that exist in space, not only those generated by the sun, but
+also by all the other electro-magnetic bodies, as all the planets (Art.
+88), we will consider the working of the same upon the satellites of
+those planets which possess them.
+
+The Earth we know has one satellite, the moon, Mars has two satellites,
+Phobos and Deimos, Jupiter has five satellites, Saturn has eight
+satellites, while up to the present Uranus has been found to possess
+four, and Neptune one. There is, however, little doubt but that both
+Uranus and Neptune possess more than those already discovered, as it is
+inconceivable that Jupiter and Saturn, which are nearer to the sun,
+should possess a greater number of satellites by which the nights of the
+respective planets are illuminated, while the further planets, which
+need the increased lighting, because of the decreased intensity of the
+aetherial light waves at the increased distance, possess apparently a
+less number of satellites, and therefore less illumination for their
+respective nights.
+
+But what have these satellites to teach us as to the existence of the
+electro-magnetic aetherial currents that circulate round the planets? We
+have to apply a similar course of reasoning to the planets, as we have
+done in the case of the sun. If the sun is an electro-magnetic body, by
+its axial rotation it generates rotating Aether currents, and those
+Aether currents partake of the same rotation as the revolving body, that
+is, from west to east. In a like manner each planet, being an
+electro-magnet, generates electro-magnetic aetherial currents which also
+possess the same rotation as the planetary body which gives rise to
+them.
+
+So that if the planets rotate on their axes from east to west, the
+Aether currents will also rotate from east to west, but if the rotation
+of each planet is from west to east, then the rotation of the Aether
+currents associated with each planet will also be from west to east,
+with the result that each satellite will be carried round its primary
+planet by the circulating Aether currents in exactly the same way as the
+planet rotates on its axis.
+
+Now if this is the case, then we have further evidence of the existence
+of the circulating electro-magnetic Aether currents, not only those
+associated with the sun, but those also associated with each of the
+planets, as explained in Art. 91. It might have been urged in the case
+of the planet's revolution round the sun being in the same direction as
+the sun's axial action, that such a fact was merely a coincidence, but
+such an objection loses its force if it is proved that the same
+principle or truth when applied to other bodies equally holds good. When
+we come to analyze the direction of the satellites round their primary
+planets, we find that each satellite has an orbital motion, or is
+carried round its central and controlling planet by that planet's Aether
+currents in exactly the same direction that the planet rotates on its
+axis, viz. from west to east. So that we have in the orbital direction
+of the satellites, as we have also in the orbital direction of the
+planets, conclusive evidence of the existence and mode of working of the
+Aether and of the electro-magnetic currents generated in that aetherial
+medium by the electro-magnetic bodies which rotate in it.
+
+
+
+
+                               CHAPTER XI
+
+                        AETHER AND KEPLER'S LAWS
+
+
+ART. 102. _Aether and Kepler's First Law._--In Art. 26 we learned that
+according to the First Law of Kepler, each planet revolves round the sun
+in an elliptic orbit, with the sun occupying one of the foci.
+
+We also saw that that elliptic orbit was produced according to Newton by
+the conjoint working of the centripetal and centrifugal forces in
+association with the three Laws of Motion, to which laws had to be added
+a corollary, which is termed the Parallelogram of Forces, before the
+First Law of Kepler could be fulfilled.
+
+In making any hypothesis as to the physical cause of Kepler's Laws, if
+it can be shown that the same aetherial medium that gives rise to the
+centrifugal force, also gives rise to the centripetal force, and that
+the same medium by its rotatory motions also fulfils the three laws of
+motion, and gives a satisfactory physical explanation of all Kepler's
+Laws; then, according to our three Rules of Philosophy, we shall have
+found a physical medium which, by its motions and pressures and
+tensions, can give rise to all the phenomena exhibited in the celestial
+mechanism. Such a physical explanation will be philosophically correct,
+in that it is simple in its conception, is entirely in harmony with
+observation and experiment, and satisfactorily accounts for, and that on
+a physical basis, all the phenomena associated with the whole of the
+celestial mechanism.
+
+We have therefore to apply the motions of the Aether medium to the solar
+system, and by so doing reveal the physical explanation of all Kepler's
+Laws, in the same way that Newton revealed their correctness from the
+mathematical standpoint. Let us review the conception of the solar
+system as given in Art. 99, so that we may be able to proceed from that
+physical conception of a stationary solar system to a moving system.
+
+Thus we see the sun in a stationary system occupying exactly the centre
+of that system. The solar energies are in full play, generating
+electro-magnetic Aether waves which are radiated forth into space with
+the velocity of light. Then, as there is given to the sun a rotatory
+motion on its axis, that rotatory motion imparts to the gravitating
+aetherial medium a circulatory or rotatory motion which spreads out
+through space with ever-increasing intensity.
+
+By their radiating motion the Aether waves would repel all planets from
+their central body, the sun, if they were not counterbalanced by the
+centripetal force; and the two forces, the centrifugal and the
+centripetal forces, find their equilibrium at the mean distance of each
+planet, thus fixing and regulating permanently the distance and orbit of
+each planetary world.
+
+At the same time, the rotatory motion of the electro-magnetic Aether
+currents, according to the second law of motion, would act on the
+planets by their kinetic or moving energy, and so circle them round the
+sun, their controlling centre. As long as the sun was quite stationary,
+while still possessing a rotation on its axis, if such a thing were
+possible, so long would the conception of the ancients be fulfilled, and
+the rotation of all the planets would be strictly circular in form, and
+their orbits would be that of a circle only, as proved by Sir W. R.
+Hamilton (Art. 99).
+
+[Illustration: Fig: 24.]
+
+But, as is well known, the sun itself possesses an orbital motion of its
+own, so that, while all the associated planetary system is revolving
+round it, the sun with all that system is being carried along through
+space in an orbit which is also elliptic in form, as we shall see later
+on.
+
+According to Herschel, the sun is moving towards the constellation of
+Hercules with a velocity of about 18,000 miles per hour, and the problem
+to be faced is, what is the effect of the sun's orbital velocity upon
+the circular motion of the planets? By solving that problem, we shall
+arrive at a physical conception for the first time of Kepler's Laws, and
+shall see that the first of Kepler's Laws is solved simply by giving an
+orbital velocity to any central body, the result of which will be that
+the circular form of any planet's orbit will be changed from the
+circular into one of elliptic form.
+
+Let me ask the reader to perform a very simple experiment to confirm
+this fact. Take a piece of string and a lead pencil, and start to draw a
+circle on a piece of paper (Fig. 24). When, however, one quarter of the
+circle has been drawn, viz. _D_ _F_, move the end of the piece of string
+representing the centre of the circle along the paper, as represented in
+the diagram, from _A_ to _B_. The result will be that the pencil will
+now travel parallel with the moving centre for a time from _F_ to _G_,
+and then, when the centre is brought to rest again, the other part of
+the half ellipse _G_ _H_ may be completed. In the same way, by reversing
+the motion, the other half of the ellipse may be completed. So that it
+is possible for an ellipse to be formed simply by moving the central
+point of a circle, and the motion of that central point will change the
+form of a circle into an ellipse. It is something like this that takes
+place in the planetary world, with this difference, that the central
+point which represents the sun does not return from one focus to
+another, but continues to journey on through space, with the result that
+the orbit of any planet is not strictly an ellipse, as we shall see
+later on. We have, then, the sun occupying the centre of the solar
+system, with all the planets revolving round it. We will take the sun
+and the Earth as examples. Let _S_ in the diagram represent the sun, and
+_E_ the Earth at its mean distance of 92,000,000 miles away (Fig. 25).
+
+[Illustration: Fig: 25.]
+
+The Earth we know is moving with a velocity of about 64,800 miles per
+hour around the sun, or an average velocity of 18 miles per second, so
+that while the Earth is moving 64,800 miles through space to perform the
+half-circle, _E_ _D_ _C_, the sun is also travelling 18,000 miles
+towards the point _D_.
+
+What, therefore, is the effect of this onward movement of the sun
+towards the Earth as it tries to complete the half-circle _E_ _D_ _C_?
+We have seen that the centrifugal force due to the pressure of the
+electro-magnetic Aether waves is exactly equal to the centripetal force
+exerted by the sun on any planet, and if that be so, it can be readily
+seen that as the sun journeys towards the point _D_ of the Earth's
+orbit, it tends to approach nearer and nearer the Earth. Thus the
+intensity of the aetherial pressure owing to the decreased distance will
+be greatly increased, and the effect of the increased pressure of the
+Aether upon the planet will be to push it away from the sun, so that the
+two forces may be equalized, and its mean distance, which is definitely
+fixed, be maintained as far as possible.
+
+The result will be that, instead of the Earth describing the half-circle
+_E_ _D_ _C_, it actually describes the part of the ellipse _E_ _F_ _C_.
+Thus it can be seen that while the sun is travelling through space, it is
+at the same time giving rise to the electro-magnetic Aether waves, which,
+by their repelling power, repel the Earth from the sun in the direction
+that the sun is travelling, and hence the half-circle is elongated into
+that part of the elliptic orbit known as the perihelion, which is that
+part of the orbit where the distance of any planet from the sun is the
+least.
+
+[Illustration: Fig: 26.]
+
+The repelling power of the Aether waves is not, however, sufficient to
+overcome altogether the centripetal force in conjunction with the
+Earth's motion, with the result that when the Earth arrives at _F_, its
+distance is only 91 million miles, that being the least distance between
+the sun and the Earth. We shall see the result of this decreased
+distance when we deal with Kepler's Second Law.
+
+We will now proceed to notice the effect of the sun's orbital velocity
+upon that part of the Earth's orbit which includes the aphelion, or that
+part in which the Earth occupies a position of the greatest distance
+from the sun. Proceeding on the same method of reasoning, if the sun
+were stationary, with the Earth being circled round it by the
+electro-magnetic Aether currents, then the path described by the Earth
+would be that of a circle, being represented by the half-circle _C_ _G_
+_E_ (Fig. 26).
+
+But it has to be remembered that while the Earth is being circled round
+the sun by the rotatory electro-magnetic Aether currents, the sun is
+still travelling on towards _S_ _F_ at the rate of 18,000 miles per
+hour, while the Earth is travelling in almost an opposite direction
+towards _C_ _G_, so that by the time the Earth has got to _G_, which we
+will suppose is one quarter of its ellipse, the sun has travelled
+millions of miles in that time.
+
+Thus it can readily be seen, that by the time the Earth has got to its
+aphelion, it is at its furthest distance from the sun, simply because
+the sun has been travelling onwards through space all the time, while
+the Earth has been receding from it; and as the motion of the Earth has
+been in an opposite direction, the mean distance has been exceeded, and
+instead of the Earth being now at its mean distance from the sun, its
+distance is now 94,500,000 miles. At that part of its orbit, its orbital
+velocity is at a minimum, because the rotating Aether currents have
+there a decreased flow and a decreased mass and density, and therefore
+possess a decreased kinetic energy or motive power.
+
+Thus by the rotating Aether currents working in conjunction with the
+centrifugal and centripetal forces, can be accounted on a physical basis
+the first of Kepler's Laws in a manner which is strictly philosophical,
+as the explanation is simple in conception, does not violate experience
+or experiment, and satisfactorily accounts for, on a physical basis, the
+law which it is required to explain.
+
+If we consider the rotating Aether currents as purely currents of
+electricity, then exactly the same results follow. For, as we shall see
+later, Professor Lodge in his _Modern Views of Electricity_ proves that
+electricity possesses both inertia and momentum, and if electricity
+possesses these properties, then it also possesses the requisite
+properties to enable the currents to propel or push any planet around
+its central body, or a satellite round its primary planet. Therefore the
+same course of reasoning that applies to the rotating Aether currents,
+equally applies to the currents of electricity that circulate round each
+satellite, planet, and sun and star, and by that circulation gives rise
+to the electro-magnetism associated with each body, while at the same
+time they supply the kinetic energy which enables any dependent or
+associated body to be propelled round their controlling centre.
+
+
+ART. 103. _Second Law of Kepler._--According to Kepler's Second Law
+(Art. 27), we learn that the radius vector, which is the imaginary
+straight line joining any planet to the sun, describes, or sweeps over,
+equal areas in equal times. So that, while Kelper's First Law describes
+the path which a planet takes in revolving round the sun, the Second Law
+shows how the velocity of that planet varies in different parts of its
+orbit.
+
+While, however, there is a difference in the velocity of any planet at
+various points in the orbit, there is still a proportion existing
+between its various velocities, in that equal areas are covered in equal
+times. We have now to apply the hypothesis of our rotatory Aether
+currents, in conjunction with the centripetal and centrifugal forces, in
+order to see whether the Second Law of Kepler can be explained on a
+physical basis, in the same way that Newton explained it from the
+mathematical standpoint.
+
+We have again to conceive the sun as the centre of two equal but exactly
+opposite forces, and also possessing a rotatory motion on its axis, with
+the electro-magnetic Aether currents ever circulating round it. If the
+sun were stationary, it will be manifest at once that Kepler's Second
+Law would be literally and strictly fulfilled, for in that case the
+orbit of all the planets would be perfect circles, and the motion of
+planets in their orbits would be perfectly uniform, and therefore equal
+areas would be covered by the radius vector in equal times. Thus any
+quarter of the orbit would be described in exactly a 1/4 of a year, 1/12
+in 1/12 of a year, 1/40 in 1/40 of a year, and so on, the time being
+exactly proportional to the proportion of the area covered by the radius
+vector.
+
+The area covered would always be uniform, because the radius vector
+would always be uniform in length. But, as we have seen in the previous
+article, the distance of a planet from the sun, that is, the length of
+the radius vector, is not uniform, as the Earth is nearer to the sun at
+perihelion, and further away at aphelion, its distance gradually
+changing as it passes from each of these points to the other.
+
+Now what is the effect of the decreased distance upon the circulating or
+rotatory Aether currents? We have already seen (Art. 99) that the closer
+these Aether currents are to the central body, the sun, the greater is
+their velocity and the greater their mass, so that the total impressed
+force which they exert over any planet is greater the nearer that planet
+is to the sun. This is proved by the fact that Mercury has a greater
+orbital velocity than Venus, Venus than the Earth, the Earth than Mars,
+and so on right through the whole of the planetary system. In view of
+these facts, let us again consider the effect of the sun not being
+stationary, but having an orbital velocity of its own through space.
+Thus let the sun be at _S_ and the Earth be at point _D_ of its orbit
+(Fig. 25).
+
+The circulating Aether currents are ever acting upon the Earth, carrying
+it round the sun with them, while at the same time the centripetal force
+is pulling it towards the sun with a certain intensity, but the
+centrifugal force is repelling the Earth with exactly the same
+intensity, and if the sun remained motionless the two forces would
+exactly balance each other, while the Earth would describe the
+half-circle _E_ _D_ _C_. But while the Earth is moving towards the
+point _D_ with a velocity of 64,000 miles per hour, the sun is also
+moving at the velocity of about 18,000 miles per hour towards that
+point.
+
+Thus the repelling power of the radiating electro-magnetic Aether waves
+has to overcome, not only its exact counterpart, the centripetal force,
+but also the onward motion of the sun as it rushes on its course through
+space. This the centrifugal force is unable to do, with the result that
+the distance is gradually lessened, and instead of the Earth describing
+the arc _E_ _D_, it describes the arc _E_ _F_, at which point its
+distance is at the minimum, or about 91 millions of miles.
+
+Or, to put the same fact in another way. When the Earth is at _E_, the
+centripetal force and the orbital velocity of the Earth and the sun are
+acting conjointly, with the result that they overcome the centrifugal
+force, and the distance is gradually decreased. This decreased distance
+means an increased aetherial density and an increased velocity of the
+aetherial currents, with the result, that as the distance is decreased,
+the orbital velocity of the Earth is gradually increased, so that by the
+time the Earth gets to _F_, at its perihelion, it has now acquired its
+greatest orbital velocity, and is carried round the sun by the
+electro-magnetic Aether currents at its maximum velocity.
+
+Now let us look at the Earth being circled round the sun by the
+electro-magnetic Aether currents as it goes on to perform the other half
+of the orbit. In this case we have the orbital motion of the sun and the
+centrifugal force working conjointly, with the result that together they
+overcome the centripetal force, and the Earth is repelled and carried
+beyond its mean distance. Let _S_ represent the sun, the Earth being at
+point _C_ of its orbit, after passing round its perihelion, and at this
+decreased distance it is carried along by the circulating and denser
+Aether with its maximum velocity (Fig. 26).
+
+Now while the Earth is going on to describe the half-circle _C_ _G_ _E_,
+the sun is still pursuing its journey at the rate of about 18,000 miles
+per hour, only this time in a direction away from the Earth. As, however,
+the Earth has not yet regained its mean distance of 92,000,000 miles,
+the centrifugal force is still greater than the centripetal force, so
+that the centrifugal force is urging the planet away from the sun with
+greater intensity than the centripetal force is attracting it, as the
+two forces are only in equilibrium at the mean distance of the Earth.
+
+Thus, as stated, the orbital motion of the sun and the centrifugal
+forces are now working conjointly together, with the result that the
+Earth is repelled gradually further and further from its central body,
+until it reaches its maximum distance of 94,500,000 miles. While,
+however, the distance is gradually being increased, it is passing into a
+part of the Aether possessing not only a decreased mass, but also a
+decreased velocity, with the result that the motive power or kinetic
+energy of the aetherial currents at the increased distance is gradually
+lessened, and as a natural result the velocity of the Earth is also
+decreased; so that by the time the Earth has got to its furthest
+distance from the sun, its orbital velocity is slowest, because of the
+decreased momentum of the aetherial currents.
+
+Thus we can account for the difference of velocity of a planet in its
+orbit by the same electro-magnetic Aether currents working in
+conjunction with the sun's orbital motion, and that upon a strictly
+physical basis. This result is in perfect harmony with Kepler's Second
+Law, which states that equal areas are described by the radius vector in
+equal times. Newton proved that by the Law of Gravitation Attraction he
+could account for this second law, as well as all the others, and as we
+have not destroyed that law, but perfected it by giving it its exact
+complement and counterpart, the same mathematical reasoning that applies
+to the centripetal force must equally apply to the centrifugal force,
+and if it is true that the centripetal force works harmoniously with the
+second of Kepler's Laws, then it is equally true that the centrifugal
+force does also, as the two are inseparably and indisputably united
+together in the atomic Aether. We have, however, a physical basis for
+this centrifugal force, and we have an equal physical basis for the
+centripetal force, as we shall see later, and therefore, by the conjoint
+working of these two forces taken in conjunction with the orbital motion
+of the sun, we have now a physical conception for the first time of
+Kepler's Laws, as well as a mathematical conception, that physical
+conception being derived from the pressure and motions of the universal
+Aether.
+
+
+ART. 104. _Aether and Kepler's Third Law._--In Art. 28 we saw that
+according to the Third Law of Kepler, the square of the periodic time
+was proportionate to the cube of the mean distance of that planet from
+its controlling centre. Newton proved that this Third Law was
+mathematically correct, and that it could be mathematically accounted
+for by the existence and operation of the universal Law of Gravitation.
+As the centrifugal force is the exact opposite of that force in
+intensity, proportion and mode of operation, it follows that
+mathematically the centrifugal force also bears the same relation to the
+Third Law that the centripetal force does.
+
+We have, however, a physical basis for the centrifugal force, and it is
+with the physical conception of this Third Law rather than with its
+mathematical character that we are now dealing. Kepler by his Third Law
+showed that the chief regulating factor in the orbital velocity of a
+planet was its mean distance from the sun.
+
+The great regulator of the velocity of any planet in its orbit is
+simply planetary distance, and planetary distance alone. If there were
+no other law which operated in the solar system than the centripetal
+force, or the attractive force due to gravity, then such factors as mass
+and density of a planet ought to play a most important part in the
+orbital velocity of a planet, as the centripetal force directly
+recognizes the influence of mass, that is, volume and density, but says
+nothing about mean distances. This fact unmistakably points to the
+existence, and demands the operation, of another force, which shall
+explain, and that on a physical as well as a mathematical basis, how it
+is that the mean distance of a planet from any centre regulates the
+orbital velocity of that planet.
+
+The only real and true conception of such a force is to be found in the
+radiating waves and circulating motions of the aetherial medium, which
+waves, like water waves, increase in their radial outflow and extent
+with a regular decreasing intensity, and at the same time decrease in
+their angular velocity as they recede from the sun. With such a regular
+decrease of kinetic energy, there must necessarily be imparted to the
+planets, as their mean distance is increased, a decreased velocity of
+motion, with the natural result, that the further a planet is from the
+sun, the less will be its orbital velocity, and that in a regular and
+uniform proportion as the distance is increased.
+
+Now let us view the matter for a moment in its application to the solar
+system, and by so doing show the simplicity of the explanation, and at
+the same time give added proof to the existence and operation of the
+circulating aetherial currents that exist in space. Let us again picture
+the solar fires burning in all their fierceness and intensity, every
+atom and particle of the sun being thrown thereby into the most intense
+state of activity, and by their energy of motion creating
+electro-magnetic Aether waves in their myriads, which speed away from
+the sun on every side.
+
+Under their influence, all subordinate worlds would be carried away into
+space, were it not for the complementary Law of Gravitation Attraction,
+that is, the centripetal force. But to every planet, by the operation of
+some governing and determining principle, a mean distance has been
+given, and at that mean distance the two forces find their equilibrium;
+and by their conjoint and co-equal working hold each planet at that mean
+distance with a power that cannot be broken. Each power or force may be
+modified under certain conditions, as shown in the two preceding
+articles; but, whether the planet be repelled further away, or attracted
+nearer to the sun, through the onward motion of the sun, the two forces
+ever seek to maintain their equilibrium, and to place the planet at its
+mean position assigned to it in the solar system.
+
+The nearer that mean position is to the sun, the greater is the velocity
+of the aetherial currents which circulate round the sun; and the greater
+their mass, volume for volume, on account of the increasing density of the
+Aether, the nearer it is to the sun. The effect of this increased
+velocity, and the increased mass of the circulating Aether currents, is to
+impart to planets nearest to the sun the greatest orbital velocity; while,
+the greater the distance, the less will be the orbital velocity of the
+planet. That this is exactly in accordance with observation and
+experience may be proved by considering the respective mean distances
+and orbital velocities of the various planets.
+
+Mercury, with a mean distance of 35,900,000 miles, is circled round the
+sun at the enormous rate of about 108,000 miles per hour, accomplishing
+its entire journey in the short period of 88 days. Venus, whose mean
+distance is about 67,000,000 miles, is carried round the sun at the
+reduced rate of 78,000 miles per hour, completing her orbit in the
+increased time of 224 days. Our own Earth, at the still further
+increased mean distance of 92,000,000 miles, performs her journey at the
+reduced velocity of 64,000 miles per hour, accomplishing the journey
+round the sun in a period of 365 days.
+
+Thus, the further we get from the sun, the slower becomes the movement
+of a planet in its orbit, and the longer it takes to complete its
+revolution round its controlling centre. Mars, at the increased distance
+of 141,000,000 miles, possesses a reduced velocity of 54,000 miles per
+hour, and completes its orbit in the increased duration of 686 days. So
+the decrease of velocity goes on, as the planets increase their mean
+distance from the sun, as the following figures show--
+
+                 MEAN DISTANCE.   PERIOD OF   ORBITAL VELOCITY
+                                  REVOLUTION.     PER HOUR.
+
+    Jupiter       482 millions    4,332 days    28,000 miles
+    Saturn        884    "       10,759  "      21,600   "
+    Uranus      1,780    "       30,687  "       1,800   "
+    Neptune     2,780    "       60.127  "         900   "
+
+The relation of this decrease of velocity to the mean distance is
+exactly determined by Kepler's Third Law, in which he states that the
+square of the periodic time is proportionate to the cube of the mean
+distance. That this is true has already been proved in Art. 28.
+
+In conclusion on this point, let me ask the reader to try to conceive
+any other physical explanation for this decrease of orbital velocity as
+the mean distance is increased, than the one given here, namely, the
+decrease in the velocity and mass of the radiating and circulating
+Aether currents, and if such attempt is made, I premise that its only
+result will be utter failure. No other physical conception to account on
+a physical basis for all Kepler's Laws can be given or conceived, than
+that which finds its origin in the universal electro-magnetic Aether,
+which by its pressures, tensions and motions gives rise to all the
+phenomena incidental to, and associated with, planetary and stellar
+phenomena.
+
+Therefore, inasmuch as all the laws of motion, and all Kepler's Laws can
+be accounted for by a gravitating and rotatory Aether medium, those
+facts alone, apart from the explanation of other phenomena associated
+with light and heat, would stamp the circulating Aether medium as the
+physical cause of all the motions and phenomena associated with the
+whole of the celestial mechanism.
+
+
+ART. 105. _Orbital Motions of Satellites and Planets._--According to
+Kepler's First Law, the Earth and all the other planets move round the
+sun in orbits which are in the shape of an ellipse. Not only, however,
+is the first law true of planetary motion, it is equally true of the
+motions of all satellites moving round their primary planets. I wish,
+however, to point out, and prove in an indisputable manner, that
+Kepler's First Law does not sufficiently explain and determine the exact
+orbit of any satellite as it revolves around its primary planet, or even
+of any planet as it revolves around the sun.
+
+Simply because, if any satellite or planet is to perform a perfect
+ellipse as it revolves around its central body, that central body must
+only move for a time and must then come to rest, or partly return in its
+journey in order for a perfect ellipse to be formed, as shown in a
+previous figure. Now we know from observation that such a thing as rest
+in space by any planet, or by the sun, is absolutely unknown in the
+celestial mechanism.
+
+From Art. 92 we learned that the electro-magnetic Aether currents not
+only circulate round the sun, but they also circulate round each planet.
+Thus we found there were electro-magnetic Aether currents circulating
+round each planet, while those planets themselves were circled round the
+sun by the Aether currents generated by the sun; the planetary Aether
+currents in their turn propel the satellites round their primary
+planets. It can easily be seen, therefore, that such phenomena as rest
+and return of a planet in its journey are physical impossibilities, for
+either the circulating Aether currents would have to cease circulating,
+or would have to return upon themselves in some inconceivable manner.
+
+Thus there is ever going on this conjoint motion, so to speak, of the
+sun's aetherial currents which circle all the planets round that body,
+and the planetary aetherial currents which circle all the satellites
+round their central body, and it is the effect of the conjoint working
+of these currents on the planets and satellites to which I wish to call
+the reader's attention.
+
+Let us in starting represent the earth's orbit by a perfect ellipse _A_
+_B_ _C_ _D_, with the sun occupying one of the foci _S_ (Fig. 27). We
+will suppose that the earth is at point _A_ of its orbit and is being
+circled round the sun with uniform velocity. As it is circled round the
+sun by the sun's aetherial currents, at the same time its satellite the
+moon is being circled round the earth by the electro-magnetic Aether
+currents which circulate round that planet. We will represent the orbit of
+the moon by part of a smaller circle _D_ _E_ _F_, and suppose the moon to
+be at point _D_ of that orbit. The mean distance of the moon from the
+earth is about 240,000 miles, so that the diameter of the orbit is 480,000
+miles, therefore the circumference of the orbit is 480,000 × 3.1416, which
+gives us about 1,500,000 miles.
+
+[Illustration: Fig: 27.]
+
+That distance is traversed in about 28 days, so that the moon's average
+velocity in its orbit, as it is circled or pushed round the earth, is
+about 2200 miles per hour. While, therefore, the moon is travelling 2200
+miles, the earth in its journey round the sun has travelled about 64,800
+miles in the same time. So that by the time the moon has travelled half
+its orbit, that is, from _D_ to _F_, which would take about 14 days, the
+earth has also travelled in its orbit 64,800 × 24 × 14 = 21,772,800
+miles, with the result, that instead of the moon arriving at point _F_,
+which it would do if the earth were stationary, it really arrives at a
+point about 21,772,800 miles in front of that point.
+
+In a similar way, while the moon goes on to describe the other half of
+the orbit, the earth still proceeds on its journey, so that at the end
+of 14 days it is again 21,772,800 miles further on, with the result,
+that the centripetal force (by which the moon is attracted to the earth)
+keeps it at the distance of 240,000 miles according to Kepler's Second
+Law as explained in Art. 103.
+
+The moon, therefore, completes its orbit about 21,772,800 miles further
+on than it would do if the earth were stationary. The effect of this
+continual progress of the earth on the moon's orbit as it describes its
+orbit round the sun is seen in the diagram. As the moon revolves round
+the earth thirteen times in one year, it performs thirteen revolutions
+round that planet; but it cannot be said that these orbits are perfect
+ellipses, as the earth is ever being circled round its central body, the
+sun. Even this diagram does not accurately represent the orbital motion
+of the moon through space, as it assumes that the earth returns to the
+same point in space from whence it started. This, however, is incorrect,
+as we have to remember that the sun has also an orbital velocity of
+18,000 miles per hour, so that while the earth has performed one
+revolution in its orbit, the sun has actually progressed through space
+to the extent of 18,000 × 24 × 365 = 157,680,000 miles.
+
+When we come to deal with the sun's motion through space, we shall see
+that this distance only represents a fraction of the sun's orbit, as it
+can be philosophically proved, that if the sun moves at all, it, too,
+obeys Kepler's Laws; and therefore, according to his First Law, it also
+describes and possesses an orbit of its own. So that by the time the
+earth has made its annual revolution round the sun, the whole system has
+been carried 157,680,000 miles through space, and therefore the earth
+does not complete a perfect ellipse, but its orbital motion round the
+sun will be represented by a similar kind of diagram to the one which
+represents the orbital motions of the moon, or any other satellite round
+its central body.
+
+
+ART. 106. _Eccentricity of Orbit of Moon._--From astronomical
+observation we learn, that all the satellites and planets do not possess
+uniformity of motion, as they are carried round their controlling
+centres by the circulating aetherial currents, because the respective
+controlling centres themselves move through space. The result is, that
+the orbit of any satellite or planet is not always of the same size, but
+constantly varies, sometimes having a larger circumference than at other
+times, and sometimes a smaller circumference.
+
+This change in the size of the orbit of a satellite or planet is known
+as the eccentricity of the orbit, which eccentricity is constantly
+changing, being sometimes greater and sometimes less. We will look at
+this truth in its relation to the moon first, and then consider the same
+principle in its relation to the earth and other planets later on. For
+the purpose of illustration, we will consider the earth as being circled
+round the sun by the electro-magnetic Aether currents in a closed orbit,
+_A_ _B_ _C_ _D_, which forms a perfect ellipse, the sun occupying one of
+the foci _S_ (Fig. 28), the earth occupying a position in the orbit
+represented by point _C_, with the moon being circled round the earth by
+that planet's aetherial currents. As we have already seen in Art. 103,
+according to Kepler's Second Law, at this point the earth is furthest
+from the sun, being now at a distance of 94-1/2 millions of miles, and
+therefore its orbital velocity will be slowest at that part of its
+orbit.
+
+If it were absolutely at rest in space, and simply revolving on its own
+axis, then the result would be that the moon would be circled round the
+earth in an orbit _M_ _C_ _F_ which is perfectly circular in form; but, as
+the earth is being carried along slowly through space by the circulating
+Aether currents, this onward movement changes the circular orbit into an
+orbit of elliptic form.
+
+[Illustration: Fig: 28.]
+
+The eccentricity of the moon's orbit when the earth is at its aphelion,
+or furthest from the sun, is now at a minimum, for the simple reason
+that the earth is proceeding slowly through space, owing to the
+decreased kinetic energy of the aetherial currents at the increased
+distance.
+
+So that, at this point of the earth's orbit, the difference between the
+two axes of the moon's orbit will be the least, and its orbit at that
+point will be the nearest approach to that of a circle. But, as we have
+already seen, as soon as the earth leaves this part of its orbit, and
+begins to get nearer to the sun, it passes into a part of the aetherial
+medium possessing greater kinetic energy, with the result that its own
+velocity is accelerated. Now what is the effect of this increased
+acceleration of the earth on the eccentricity of the orbit of the moon?
+
+The earth's rotation on its axis remains unaltered during this
+increasing orbital velocity, consequently the aetherial currents
+generated by the earth will remain uniform, and the moon will still be
+circled round the earth in the same period of about 28 days. But while
+the time of the moon's revolution remains unaltered, the orbit that she
+has to describe is now increased owing to the increased orbital
+velocity of its central body, with the result, that by the time the
+earth gets to that part of its orbit represented by point _D_, it is
+then two millions of miles nearer to the sun than at point _C_, and will
+be circled round the sun by the aetherial currents at a much greater
+rate. Therefore, the eccentricity of the moon's orbit is increased just
+in proportion to the increased velocity of the earth in its orbit round
+the sun. By the time the earth has arrived at point _A_, when it is only
+a distance of about 91 millions of miles from the sun, it reaches the
+minimum distance, and is circled round at the decreased distance with
+its maximum velocity.
+
+At this point, therefore, the eccentricity of the orbit of the moon will
+be at its greatest, and, if one revolution could be represented by an
+ellipse _E_ _G_ _H_, then that ellipse would be more elongated, and the
+difference between the two axes of the moon's orbit would be greater
+than at any other point of the earth's orbit.
+
+Thus it can readily be seen that the eccentricity of the moon's orbit is
+primarily due to the different velocities of the central body, in this
+case the earth, as that body is carried round its central body, the sun.
+Where the earth's motion is slowest, there the eccentricity of the
+moon's orbit will be at a minimum; but where the earth's velocity is
+greatest, there the eccentricity of the moon's orbit will be at a
+maximum.
+
+Between this minimum and maximum velocity of the earth in its orbit
+there is the constant increase or decrease in the eccentricity of the
+orbit of the moon; the eccentricity increasing as the orbital velocity
+of the central body increases, and decreasing as the orbital velocity of
+the earth decreases. A further fact has, however, to be taken into
+consideration, which is that the primary body about which the moon
+revolves is itself subject to the same eccentricity of its orbit, and
+for similar reasons, as we shall see later on. So that when the
+eccentricity of the earth's orbit is at its greatest, then the moon's
+orbit will possess its greatest possible eccentricity, and as the
+eccentricity of the earth's orbit is dependent upon the orbital velocity
+of the sun, so the greatest possible eccentricity of the moon's orbit is
+indirectly connected and associated with the sun's motion through space,
+which motion will now be considered.
+
+
+ART. 107. _The Sun and Kepler's First Law._--We have learned in the
+previous articles that Kepler's Laws not only apply to planetary motion,
+but are equally applicable to the motion of all satellites as they
+revolve round their respective planets.
+
+The question now confronts us, as to whether Kepler's Laws are equally
+true in their application to the sun? Now the sun is one of the host of
+stars that move in the vast infinity of space, and if it can be proved
+that Kepler's Laws hold good in relation to one star, as they do in
+relation to all planets and satellites, then such a result will have a
+most important bearing upon the motions of other stars, and we shall be
+able to determine with some degree of exactness what are the motions and
+orbits by which all the stars in the universe are governed.
+
+Sir Wm. Herschel first attacked the question as to whether the sun, like
+all the other stars, was in motion, and if in motion, what was the shape
+of its orbit, and the laws which governed its orbital velocity.
+
+We know that the sun is the centre of the solar system, and the question
+to be considered is, whether that system is circled round a controlling
+centre while the sun is at rest in space, simply possessing its one
+axial rotation, or whether, like every planet and satellite, it is
+subject to two motions, an axial rotation and an orbital velocity
+through space. Further, if it possesses an orbital velocity through
+space, what is the cause of that orbital velocity?
+
+It was due to the genius of Sir Wm. Herschel to first solve this
+problem, and by careful research he was able to determine that the sun,
+with all its attendant planets, was indeed moving through space.
+
+Not only did he discover this fact, but he also found out the direction
+in which the whole of our solar system was moving, as well as the
+velocity with which the general movement was performed. Herschel proved
+that the onward march of the solar system was in the direction of the
+constellation of Hercules, and that the velocity of the march of this
+system exceeds five miles per second, or 500,000 miles per day.
+
+Thus we learn that the whole of our solar system, comprising the sun,
+with all its planets with their attendant satellites which circle round
+each planet, and the asteroids or minor planets, are bound together by
+the two forces, the centripetal and the centrifugal, while the system as
+a whole is urged on its way by some force or power through the realms of
+space.
+
+What that power is we shall try to find out as we consider the
+application of Kepler's Laws to this onward movement of the sun. If,
+then, the sun is moving through space with this enormous velocity, the
+question arises as to what is the shape of the path or orbit which it
+describes? Sir Wm. Herschel attacked this question from a mathematical
+standpoint, and came to a certain conclusion, as we shall see. We will,
+however, attack the problem solely from the philosophical standpoint, by
+applying to it the Rules of Philosophy given in our first chapter, and
+we will then see whether our result is in harmony with the conclusions
+arrived at by Sir Wm. Herschel.
+
+Now what has experience and observation to tell us regarding the orbit
+which any body moving in space assumes? Take, for example, our moon as
+illustrating the movement of all satellites, and our earth as
+illustrating all planetary motion.
+
+What does observation teach us as to the orbits which these bodies
+describe? If it teaches us anything at all, it teaches us that every
+satellite and planet moves with varying velocity in a varying orbit
+around some central body. So far as our observation goes, then, in
+relation to planetary motion, or the motion of satellites, we learn that
+every body which moves in space fulfils Kepler's First Law, and
+describes an orbit round a central body, that body occupying one of the
+foci.
+
+Thus, wherever we get any body moving in space, if there be any truth in
+philosophy which is based on experiment and observation, that body ought
+also to move in similar elliptic orbits, and be subject to exactly
+similar conditions governing those orbits. But we have learned that the
+sun moves through space with a velocity of about five miles per second,
+therefore it follows, philosophically, that the sun must also move
+around some other central body, and the path of such movement is that of
+an elliptic orbit, with the central body around which it moves occupying
+one of the foci.
+
+In other words, the sun obeys the first of Kepler's Laws, the same as
+all the planets and satellites do. Suppose, for a moment, that it is
+denied that the sun moves in an elliptic orbit! What path would it
+pursue in place of that? Would the path be that of a straight line
+towards the constellation of Hercules? Such an assumption would be
+altogether unphilosophical, as it is contrary to all experience and
+observation, and is therefore untenable.
+
+Before such an assumption can be made, it must be proved that every
+planet and satellite moves in a straight line, and not till that has
+been done can it be assumed that the sun moves in a straight line, or
+indeed in any other path than that stated in the first of Kepler's Laws.
+
+This conclusion is in perfect harmony with the conclusion arrived at by
+Herschel, for in his work on _Astronomy_, in Arts. 292, 295 and 297, he
+points out that the sun's path is elliptic in form, and that Kepler also
+showed the sun fulfilled the first of his laws, and described an orbit
+which was in the shape of an ellipse. We have therefore philosophically
+arrived at the conclusion that the sun moves in an elliptic orbit, and
+to do so it must move round some central body, which is to the sun what
+the sun is to the planets, and what the planets are to the satellites.
+
+It is impossible to conceive of the sun moving in an elliptic orbit,
+and yet not moving around some central body, as we should have a
+celestial phenomenon altogether opposed to all experience and
+observation. For we have already seen that the central body is just as
+important a factor to the elliptic orbit as the planet itself, because,
+without the central body there cannot possibly be any elliptic orbit.
+Where then in the universe is the central body around which the sun
+revolves? What is its distance away from the sun? What is its size?
+These are questions that philosophy alone cannot answer, as there is no
+law, so far as I can see, that regulates the size and distance of the
+central body in proportion to the size and distance of the planets or
+satellites.
+
+If there were, then it would be possible for philosophy to apply such a
+law or rule. That there is a central body around which the sun revolves
+is as true as the fact that there is a central body about which each
+planet revolves, or each satellite revolves, and it remains for the
+practical astronomer, or the mathematician, to endeavour to discover the
+exact part of the heavens in which it is situated, and ascertain its
+distance and possibly its size. What will be the effect of the existence
+of this central body of the sun upon the solar system? One effect will
+be to do away with that isolation that up to the present has apparently
+existed with regard to our solar system and stellar space.
+
+Instead of the solar system being a solitary system that moves through
+space subject to apparently no law, and moved by apparently no physical
+power, that system, through the influence and effect of the aetherial
+currents originated by that central body, will be linked to other parts
+of the universe, and will become a part of one harmonious whole, its
+physical connection being made manifest and plain in the self-same
+electro-magnetic Aether medium that forms the connecting medium between
+the satellites and planets, or the planets and the sun.
+
+Another result will be, that as the sun is a star, we shall be able to
+apply the self-same principles and laws of Kepler to the stellar world
+in exactly the same way that we have done to the solar system. Thus, by
+bringing all stellar phenomena under the influence of Kepler's Laws, we
+shall be able to philosophically give an unity to the universe, and
+show, within rational limits, how such unity may be physically
+conceived, which result will be an advance upon any physical conception
+of the universe hitherto manifested or revealed. Further, by accepting
+the first of Kepler's Laws in relation to the sun, and admitting the
+existence of a central body, we shall be able then to apply the second
+of Kepler's Laws, and by so doing shall be able to give a physical
+explanation of two scientific facts which up to the present have never
+been physically explained, viz. the physical conception of the plane of
+the ecliptic, and a physical explanation of the eccentricity of the
+earth's orbit, which is but the result of the application of Kepler's
+Second Law to the sun's orbital motion around its central body.
+
+
+ART. 108. _The Sun and Kepler's Second Law._--We will now proceed to
+apply the second of Kepler's Laws to the orbital motion of the sun, and,
+in so doing, shall find we are able to give at the same time a physical
+explanation of the eccentricity of the earth's orbit.
+
+In order to obtain a physical conception of the sun's orbital motion
+according to Kepler's First Law, it is essential that we should consider
+the effect of the existence of a central body around which the sun
+revolves; or, to put the matter into another form, we will ask the
+question as to what is the physical cause of the sun revolving round
+that central body?
+
+Let us look at the case for a moment. Here, according to astronomical
+observation, we find a certain phenomenon which takes the form of a huge
+body 865,000 miles in diameter moving through space with a velocity of
+nearly 500,000 miles per day. What then is the physical cause of the
+movement of this large sphere?
+
+Certainly there must be some physical cause, or else we have a violation
+of all experience, which indisputably teaches us that no body moves
+unless it is either pushed or pulled. We have, however, done away with a
+pulling power so far as the cause of the actual revolution of bodies
+around a central body is concerned, and in its place have substituted a
+medium that pushes or carries them round each central body. For over 200
+years the scientific world has accepted a pulling power, that is, an
+attractive power, solely as the cause of the movements of celestial
+bodies, with the result that the physical cause of all the motions of
+planets and satellites has been outstanding and undiscovered.
+
+It would, therefore, be unphilosophical to revert to the old conception
+of a gravitating attractive power as the sole cause of the sun's orbital
+motion through space. If we desire to know what is the cause of its
+revolution round that central body, then we must seek to find the same
+from the result of observation and experience in other directions.
+
+We have learned from Art. 102 that the orbital motion of the moon is
+caused by the electro-magnetic Aether currents that circulate round its
+central body, the earth. By the same means every satellite is circled
+round its central body also. We have also learned from Art. 99 that the
+earth is carried round the sun by the circulating and rotating
+electro-magnetic Aether currents, and that these same currents also form
+the physical cause of the revolution of all the other planets round
+their central body, the sun.
+
+Thus we arrive at the fact that wherever there is a body moving in
+space, it is moving solely because it is pushed along, or carried round
+its controlling centre by the rotating Aether currents. But we have just
+learned that the sun is moving through space, and that it describes an
+elliptic orbit around some central body in accordance with Kepler's
+First Law. So that the only philosophical conclusion that we can
+possibly arrive at in relation to the orbital motion of the sun is, that
+such motion is caused by similar electro-magnetic Aether currents whose
+circulating motion is partly caused by the rotation of that central
+body.
+
+Thus we are led up to the philosophical conclusion, that it is the
+aetherial currents of the central body around which the sun revolves,
+that produce, and alone produce, the onward motion of the sun through
+space. Any other conclusion must be unphilosophical, and therefore
+untenable. We have, therefore, to conceive of the sun's central body
+generating and giving rise to electro-magnetic aetherial currents that
+extend through space to the limits at least of the solar system, and
+these aetherial currents, acting upon the sun's huge form by their
+kinetic energy, carry it with all its associated worlds through infinite
+space.
+
+There is nothing extravagant in this conception, when we remember that
+the solar system has been moving on and on through infinite space year
+after year, and yet it never seems to get appreciably nearer to the
+other stars, but I hope to show the reason of this by strictly
+philosophical reasoning later on. With this conception of the sun in its
+relation to its central body we are now in a position to consider the
+application of Kepler's Second Law upon the sun's orbital motion, and
+its resultant effect upon the orbit of our earth and all the other
+planets.
+
+From Kepler's Second Law we know that equal areas are described by the
+radius vector in equal times, and if the first law of Kepler is at all
+applicable to the sun, then it must follow that if the sun has an orbit,
+and moreover an elliptic orbit as stated by Kepler himself, then, as a
+natural result, the radius vector of the sun must move over equal areas
+in equal times.
+
+The physical explanation of Kepler's Second Law was given in Art. 103,
+and there is no need to traverse the same ground again. It is,
+therefore, true that the sun moves faster in certain parts of its orbit
+than in others, being urged through space at its greatest velocity when
+it is nearest its controlling centre, and slowest when farthest away
+from that controlling centre.
+
+Herschel, in his work on _Astronomy_, states: "The motion of the sun will
+be such that equal areas are thus swept over by the revolving radius
+vector in equal times in whatever part of the circumference of the ellipse
+the sun may be moving." He, however, suggested that the earth forms a
+focus of the sun's ellipse, a suggestion which is unphilosophical, it
+seems to me, as we might equally suggest that the earth revolves round the
+moon, which is contrary to all observation. Thus the sun is not carried
+uniformly through space by the aetherial currents of its central body,
+because it is nearer to that central body at certain times; its velocity
+being regulated by its distance from that body, the same being increased
+as the distance is decreased, and decreased as the distance increases.
+
+Now if this reasoning be correct, and if the sun really moves round a
+central body and is subject to Kepler's Second Law, then that increase
+and decrease of distance will be made manifest in the increase and
+decrease of the eccentricity of the earth's orbit.
+
+So that if the eccentricity of the earth's orbit should vary from
+century to century, then we have conclusive evidence that the sun obeys
+the first and second of Kepler's Laws, and therefore that it revolves
+around a controlling centre of its own. From observation we find that
+this is exactly what is happening, and that at the present time the
+eccentricity of the earth's orbit is gradually diminishing, and in about
+24,000 years the orbit will be very nearly a circle.
+
+Now, from what was stated in Art. 106, we know that the moon's orbit
+will be nearly a circular orbit when the earth is farthest from the sun,
+and that then its orbital velocity is at a minimum.
+
+In order for this result to be produced, the earth must reach that part
+of its orbit known as aphelion, where the distance from its controlling
+centre is greatest, so that the eccentricity of the moon's orbit is
+always an indication of the position of the earth in its relation to the
+sun. When the eccentricity of the moon's orbit is decreasing, the
+earth's distance from the sun is increasing, but when the eccentricity
+of the moon's orbit is increasing, then the earth's distance from the
+sun is decreasing.
+
+Now if we apply this analogy to the eccentricity of the earth's orbit,
+we shall be able to obtain some idea of the relation of the sun to its
+central body. We find then that the eccentricity of the earth's orbit is
+decreasing, therefore, arguing from analogy, we arrive at the conclusion
+that the sun's distance from its controlling centre is increasing, and
+that its orbital velocity is decreasing.
+
+If it be true that in 24,000 years the earth's orbit will be nearly
+circular, then it follows that in 24,000 years the sun will be at that
+part of its orbit corresponding to the aphelion of the orbit of the
+earth, that is, its distance from its controlling centre will then be at
+a maximum. After that the eccentricity of the earth's orbit will begin
+to increase, and will continue to increase for about 40,000 years,
+according to some scientists, which implies that the sun will then have
+started from its aphelion point, so to speak, and will begin its return
+journey towards its central body, gradually getting nearer and nearer.
+As it gets nearer its orbital velocity will be proportionately
+increased, with the result that the eccentricity of the earth's orbit
+will increase also. From a consideration of the movement of the major
+axis of the earth's orbit, which is moving forward at the rate of 11°
+per year, we are told that a whole revolution will be made in 108,000
+years.
+
+We have here, then, an indication of the time that the sun takes to
+revolve round its central body, because the time of the whole revolution
+of the eccentricity of the orbit should correspond with one complete
+revolution of the sun around its central body. So that from a
+consideration of the eccentricity of the earth's orbit, we are not only
+able to demonstrate that the sun satisfactorily fulfils the first and
+second of Kepler's Laws, but, conversely, we are able to give a
+satisfactory physical explanation of the cause of the eccentricity of
+the earth's orbit, which explanation is again primarily to be found in
+the universal Aether medium.
+
+
+ART. 109. _Plane of the Ecliptic and Zodiacal Light._--As already
+pointed out, another phenomenon which can be physically accounted for by
+the sun's orbital motion through space around its central body, is that
+celestial plane known as the Plane of the Ecliptic.
+
+What then is the Plane of the Ecliptic whose physical explanation we are
+to attempt? We know that the moon revolves round the earth as the earth
+revolves round the sun, while the sun is pursuing its way through space.
+It has been found also, that all these motions of these different bodies
+take place on one level, so to speak; that is to say, they do not go up
+or down in space, but straight on.
+
+So straight do they move, that their path has been likened to the level
+of the ocean, on which a ship may sail for thousands of miles, always
+keeping the same level and even course. On some such ocean as this in
+space all the planetary systems and solar systems seem to move, ever
+moving on and on with the same uniformity of level through infinite
+space. Further, this plane of the ecliptic is to the celestial sphere
+what the sea-level is to the earth. The height of a mountain on the
+earth is stated to be so much above the sea-level.
+
+In a similar way astronomers say that a star is a certain height above
+the plane of the ecliptic. What then is the physical explanation of this
+scientific term? We will lead up to it by first considering the effect
+that rotation has upon a liquid body.
+
+It has been demonstrated that if a mass of oil is placed in a
+transparent liquid of the same density, so long as the oil is perfectly
+at rest, its shape will be that of a sphere which will float about in
+the liquid, but as soon as the oil is made to rotate by means of a piece
+of wire, then the spherical shape is changed into that of an oblate
+spheroid.
+
+Further, the faster it is made to rotate, the more it will bulge out, so
+that its equatorial diameter will greatly exceed its polar diameter. The
+same principle may be illustrated by making a hoop to revolve rapidly on
+its axis, when a similar effect of bulging out will be produced.
+
+Now let us apply this principle to the earth with its electro-magnetic
+Aether currents circulating round it, and ask what is the effect of the
+rotation first upon the earth, and then upon the rotating Aether
+currents?
+
+It is a matter of common knowledge that the effect of rotation upon the
+earth when it was in a fluid state was to make its equatorial parts
+bulge out as it rotated, with the result that as it solidified the
+equatorial diameter exceeded the polar diameter by 26 miles.
+
+If, therefore, the result of rotation upon the earth when in its fluid
+state was to make it spread out greater in the equatorial regions than
+in any other part of its surface, what must be the effect of a similar
+rotation upon the rotatory Aether currents? It can easily be seen that
+the rotation of these currents will be to make them spread out into
+space in a region which corresponds to the equatorial regions of the
+earth, so that the rotating Aether currents will be congregated more in
+the equatorial regions of the earth than in any other part of the
+earth's surface. The further also they extend into space the less depth
+they will have, gradually tapering off, as shown in the illustration,
+where _E_ represents the earth and _B_ _C_ the Aether currents (Fig. 29).
+
+Any body, therefore, situated within the sphere of their influence would
+be carried round the earth by the currents, and the currents would be to
+them their governing and controlling level.
+
+So that the moon, which is held bound to the earth by the two opposite
+and equal forces, would always be carried around the earth by those
+electro-magnetic Aether currents, and outside of those currents it could
+not pass. But the earth is only 8000 miles in diameter, therefore if the
+currents gradually tapered off as suggested, by the time the aetherial
+currents reached the distance of the moon, their depth would not exceed
+2000 or 3000 miles.
+
+The diameter of the moon is, however, only 2160 miles, so that the
+rotating Aether currents would practically form an ocean in which the
+moon would swim, and one constant level on which it revolves in space.
+Wherever the earth was carried by the aetherial currents of the sun,
+there the aetherial currents of the earth would carry the moon, its mean
+distance by the conjoint working of the two co-equal forces having been
+permanently fixed.
+
+[Illustration: Fig: 29.]
+
+So that it can be readily seen, as regards the moon, that the earth's
+aetherial currents form the plane on which it revolves around the earth.
+Now in exactly the same way it can be proved that it is the sun's
+aetherial currents which form the plane or level on which all the
+planets revolve or are carried around their central body. We have only
+to enlarge our conception and the same result follows. Instead of
+dealing with a body 8000 miles in diameter, we are now dealing with a
+body 865,000 miles in diameter, and as this huge body is more or less in
+an incandescent state, the aetherial currents will therefore be
+proportionate in intensity and flow to its size and atomic activity.
+
+Instead, therefore, of the aetherial currents which circulate round the
+sun only extending a quarter of a million of miles, their energy and
+flow extend far away into space, even beyond the greatest distance of
+Neptune, a distance of 2,800,000,000 miles. The same truths apply here,
+however, as in the case of the earth and the moon. The aetherial
+currents which circulate round the sun congregate together, and possess
+their greatest depth nearest to the equator, while the further away they
+recede, the less and less depth they possess, with a decreased intensity
+and decreased kinetic energy. These Aether currents will be to all the
+planets, therefore, what the earth's aetherial currents will be to the
+moon, being to them the ocean level on which they alone can move, and by
+which they are carried round their central body.
+
+Thus these currents will form for all the planets the level in infinite
+space upon which they float, and from which they cannot pass. Let us
+further consider the movements of these currents in space, and we shall
+find further confirmation of this fact by so doing. Astronomers tell us
+that it takes light about three and a half years to reach us from the
+nearest star. By calculation, therefore, we find that the nearest star
+to our system is about 205,000,000,000,000 miles away, that being about
+the distance that light travels in three and a half years.
+
+The diameter of the sun is about 865,000 miles, so that the distance of
+the nearest star is 240,000,000 times the diameter of the sun. We could
+therefore put 240,000,000 of our solar systems in the space that exists
+between us and the nearest star. How is it, then, that all the planets
+as they revolve round the sun do not float up and down in the space that
+extends between us and the nearest star?
+
+I can give no other answer, and can see no other possible physical
+explanation than the one already given, which is, that they are bound to
+the sun by the two co-equal forces, the centrifugal and centripetal
+forces, and while so bound are carried round the sun by the
+electro-magnetic aetherial currents which extend out into space. It has
+to be remembered that the aetherial electro-magnetic currents
+circulating round the earth are situated within the aetherial currents
+which circulate round the sun, therefore the plane of the moon's orbit
+will coincide more or less with the plane of the earth's orbit. We have
+now only to go one step further to get our complete conception of the
+plane of the ecliptic.
+
+In Arts. 107 and 108 we learned that the sun was subject to Kepler's 1st
+and 2nd laws, and as a natural result we came to the conclusion that it,
+too, was circled round some central body. We have only to apply a
+similar course of reasoning to the sun and its central body as we have
+to the moon and the earth, and the earth and the sun, and then we arrive
+at our physical conception of the plane of the ecliptic, which is due to
+the aetherial currents that circle round the sun, while that body is
+carried round some other central body.
+
+Thus by the circulating Aether currents, originated and outflowing from
+their respective sources, each source being immutably fixed and bound to
+each other by the two equal and complementary forces, can be accounted
+for, the uniformity of position and plane of the various orbits of the
+various satellites, planets, and the sun, as they move in one great
+plane, termed the Plane of the Ecliptic.
+
+It could not be otherwise than it is, and thus another celestial
+phenomenon can be accounted for on a real tangible basis by accepting
+the existence of those aetherial currents which form the physical basis
+of all the celestial mechanism.
+
+If further evidence were required of the existence of these rotating
+Aether currents round the sun, such evidence is found in that phenomenon
+of the solar system known as the Zodiacal Light, of which up to the
+present no physical explanation has been forthcoming. In the conception
+of the atomic and gravitating Aether which rotates round the sun, I
+venture to premise will be found the physical solution of this
+phenomenon also.
+
+I will refer the reader to an extract taken out of _Outlines of
+Astronomy_, by Herschel (Art. 894), so that we may see what his
+conception of the zodiacal light was, and we will see how far his
+explanation is in conformity with our hypothesis of an atomic,
+gravitating and rotatory Aether medium.
+
+He writes: "We shall conclude this chapter by the mention of two
+phenomena, which to me indicate the existence of some slight degree of
+nebulosity about the sun itself, and even to place it in the list of
+nebulous stars. The first is that called the Zodiacal Light, which may
+be seen any very clear evening soon after sunset, about the months of
+March, April and May, as a cone or lenticularly-shaped light extending
+from the horizon obliquely upwards, and following generally the course
+of the ecliptic, or rather that of the sun's equator. The apparent
+angular distance of its vertex from the sun varies, according to
+circumstances, from 40° to 90°, and the breadth of its base
+perpendicular to its axis from 8° to 30°. It is extremely faint and
+ill-defined, at least in this climate, though better seen in tropical
+regions, but cannot be mistaken for any atmospheric meteor or aurora
+borealis. It is manifestly in the nature of a _lenticularly-formed
+envelope surrounding the sun_, and extending beyond the orbits of
+Mercury and Venus, and nearly, perhaps quite, attaining that of the
+earth, since its vertex has been seen fully 90° from the sun's place in
+a great circle. It may be conjectured to be no other than the _denser
+part_ of that medium which we have some reason to believe resists the
+motions of comets; loaded perhaps with the actual materials of the tails
+of millions of those bodies of which they have been stripped in their
+successive perihelion passage. If its particles have inertia, they must
+necessarily stand with respect to the sun in the relation of separate
+and independent minute planets, each having its own orbit, plane of
+motion, and periodic time."
+
+Let me call the reader's special attention to one or two statements of
+Herschel's given in this extract, in order to see how these statements
+harmonize with the view of the Aether submitted in this work. In the
+first place he states its shape is that of a lenticularly-formed
+envelope surrounding the sun, and extending beyond the orbits of Mercury
+and Venus, and probably to our earth. This harmonizes with the shape of
+the aetherial envelope as given in Art. 70. Then Herschel states it may
+be the denser part of that medium which we have reason to believe
+resists the motions of comets. That is exactly what it is, though
+Herschel failed to show why it should be the denser part of the Aether,
+as we have seen is the case, on account of its being gravitative. I will
+also prove later on, that Herschel was right with regard to the
+resistance of the motion of comets through it. Then he refers to its
+particles probably possessing inertia, as though he had anticipated the
+atomicity of the Aether, and assuming that atomicity, he was compelled
+to postulate inertia also as we have done in Art. 48.
+
+Lastly, he points out that each separate particle must have its own
+plane of motion, its own orbit, and its periodic time. Now this view
+fully coincides with that laid down in this article, where we have
+learned that the rotating Aether has its own plane of motion, that plane
+being the Plane of the Ecliptic, and as every particle or atom has its
+allotted place in the rotating Aether, then, as Herschel points out, the
+particle must have its own orbit, and plane of motion, and also its own
+periodic time. If, therefore, we had desired fuller confirmation of this
+atomic gravitating Aether, we could not have wished for more conclusive
+proof than that given by one of the greatest philosophical astronomers
+of the last century. We shall see later that Herschel also had a clearer
+view of cometary phenomena, and of the forces which played a part in
+those phenomena, than any of his contemporaries, when we deal with the
+origin and motions of all comets. Thus from Herschel we learn that the
+zodiacal light is caused by the atomic, gravitating, and rotatory Aether
+as that aetherial medium revolves round the sun, while at the same time
+every atom of the medium is itself in a state of rotation on its axis,
+as it performs its journey in its own orbit and in its own plane of
+motion.
+
+
+ART. 110. _Centripetal Force._--We have now to consider what is the
+physical cause of that part of the compound Law of Gravitation known as
+the Centripetal Force. As we have already learned (Art. 10), this force
+is really none other than the Attractive Force of Gravitation, in that
+its mode of operation always acts towards the centre of the attracting
+body, and hence was called by Newton the Centripetal Force.
+
+The centripetal force is, however, the exact counterpart and complement
+of the centrifugal force, in the same way that the latter is the exact
+counterpart of the former, as we have already learned that the
+centrifugal force operates along the same path, and that it is subject
+to the same law of proportion, being equal to the product of the masses
+of a body (Art. 85), and further, that its intensity is inversely as the
+square of the distance (Arts. 66, 74 and 84).
+
+We have, however, discovered that the physical cause of the centrifugal
+force is due to the pressure of the electro-magnetic Aether (Art. 96).
+If, therefore, the physical cause of that law which is the complement
+and counterpart of Gravitation Attraction is to be found, and alone
+found, in the pressure and motions of the electro-magnetic Aether, then
+it is only logical and reasonable to infer that the physical cause of
+the Attraction of Gravitation is to be found in the same
+electro-magnetic Aether. That the Attraction of Gravitation is to be
+found in this medium is now an accepted hypothesis among scientists.
+Because, unless the physical cause of Gravitation Attraction is to be
+found in this electro-magnetic Aether, then, in order to account for
+that attraction, we should have to postulate the existence of another
+medium in space, in lieu of the Aether, which would be to the
+centripetal force what the Aether is to the centrifugal force. This
+would be distinctly unphilosophical, as it would be a violation of the
+first two rules of our philosophy, in that it would not be simple in its
+conception, and that such a hypothesis would imply the existence of two
+media which would occupy the same planetary and interstellar space at
+one and the same time, and this is a violation of all experience in its
+widest form.
+
+Therefore the physical cause of Gravitation must be sought for in the
+same medium which gives the physical cause of the companion force, and
+that medium is the electro-magnetic Aether. Professor Preston in his
+_Theory of Light_ is of this opinion. In Art. 327 he writes: "To account
+for the propagation of heat and light, that is, of radiant energy, we
+have postulated the existence of a medium filling all space. But the
+transference of the energy of radiant heat and light is not the only
+evidence we have in favour of the existence of an Aether. Electric,
+magnetic and electro-magnetic phenomena and Gravitation itself point in
+the same direction."
+
+Professor Lodge, in his _Modern Views of Electricity_, is even more
+explicit in his statement of the case. On page 338 he states:
+"Gravitation is explainable by differences of pressure in the medium
+(_i. e._ the Aether) caused by some action between it and matter not
+yet understood." Further, Newton himself suggested that the physical
+cause of Gravitation Attraction was to be found in that aetherial medium
+which pervaded all space.
+
+If, therefore, we attempt to explain the physical cause of Gravitation
+Attraction by the tensions of the universal Aether, we shall not only be
+dealing with the subject from a philosophical standpoint, but we shall
+solve the problem in that direction in which Professors Preston and
+Lodge and other scientists have suggested we are to seek for the
+solution. Professor Curry, in his _Theory of Electricity and Magnetism_,
+page 406, states: "If we regard the luminiferous Aether, as defined by
+Von Helmholtz's equations, as the given medium or transmitter of
+so-called gravitating action, we are then able on the one hand to
+interpret its longitudinal oscillations as gravitational waves
+propagated through space with the given enormous velocity, and on the
+other hand, to form some conception of the mysterious force of
+Gravitation itself, for we can then conceive it as a medium stress
+arising from a certain type of Aether oscillations, its longitudinal
+ones, that pervade entire space."
+
+Now in order for us to lead up to the physical cause of the centripetal
+force, we must recall some of the facts already given with regard to
+planetary and solar space. Thus we have learned that the sun is an
+electro-magnet possessing its own magnetic field, with its lines of
+force (Art. 88). We have also learned that all the planets are
+electro-magnets, each possessing its own field with its lines of force
+(Art. 91).
+
+We have further seen that the cause of all this electro-magnetism is due
+to the fact that electric currents are continually circulating round
+each body, and by their conjoint action with the magnets there are
+produced the electro-magnetic fields that are associated with each body
+in the solar system. From this hypothesis we arrived at the conclusion,
+that wherever there was Aether, there we found electricity, because of
+the electro-magnetic basis which Aether possesses. This result is fully
+confirmed by Maxwell's electro-magnetic theory of light (Art. 78), which
+has been so fully experimentally demonstrated by Hertz. Indeed, in the
+minds of several scientists there is a growing conviction that Aether
+and Electricity are possibly one and the same substance.
+
+Professor Lodge, in the work already referred to, in relation to this
+hypothesis, writes in the preface to that book: "Crudely, one may say
+that as heat is a form of energy, so electricity is a form of Aether, or
+a mode of aetherial manifestation." And again: "A rough and crude
+statement adapted for popular use is that _Electricity and Aether are
+identical_. But that is not all that has to be said, for there are two
+opposite kinds of electricities, and there are not two Aethers. But
+there may be two aspects of one Aether, just as there are two sides to a
+sheet of paper."
+
+As, therefore, we learn that Aether has an electro-magnetic basis, and
+that electricity is a mode of aetherial manifestation, we have therefore
+to consider one of the most fundamental laws of electricity, and note
+its application to solar and planetary space.
+
+It is one of the fundamental laws of electricity, that equal and
+opposite quantities of electricity are always generated at one and the
+same time. Faraday's well-known ice-pail experiment proved this. It is
+an absolute impossibility for one kind of electricity to be generated
+without an equal quantity of the opposite kind being produced, although
+it is not strictly correct to use the term generated or produced in
+relation to electricity, as electricity cannot really be produced by any
+process whatever.
+
+Another way of stating this law is, that the total induced charge on any
+body is always equal and opposite to the inducing charge. So that if we
+look upon the sun as an electrified body (Art. 80) surrounded by the
+aetherial envelopes or shells, then we can conceive of the inductive
+action of the sun upon any planet as taking place along the tubes of
+force in the Aether, which tubes are sections of the spherical envelopes
+that surround it. But this inductive action implies the existence of the
+very law already enunciated, viz. that equal and opposite quantities are
+always generated at one and the same time, and before that law can
+become operative in relation to the Aether, it must be postulated that
+the Aether possesses a dual character, that is, it possesses a positive
+and negative electrical basis.
+
+This view of the Aether has already been developed by Dr. Larmor in his
+Electron Basis of the Aether, as in that hypothesis he postulates both
+positive and negative electrons. In his _Aether and Matter_ he writes,
+page 3: "It assumes that the mass of each sub-atom is proportional to
+the absolute number of electrons, positive and negative, that it
+carries, and that the effective interatomic forces are entirely or
+mainly electric." Further, Professor Lodge on this point writes:[40] "We
+now proceed a step further and analyze the Aether into two constituents,
+two equal opposite constituents, each endowed with inertia and each
+connected to the Aether by elastic ties. The two constituents are called
+positive and negative electricity respectively, and of these two
+electricities we imagine the Aether to be composed." Again, later on, p.
+349 of the same work, he adds: "Is Aether electricity then? I do not say
+so, but that they are connected there can be no doubt. What I have to
+suggest is, _that positive, and negative electricity together may make
+up the Aether_."
+
+Now, accepting this as correct, and I will prove that it is correct later
+on, from experiments performed by Faraday, we can see how the inductive
+action of the sun may be transmitted through space, and how that inductive
+action will effect any body in its electrical field, such inductive action
+always taking place through the polarization of the atomic Aether, and
+taking the form of an attractive power which is exerted towards the
+centre of the attracting body.
+
+Further, this inductive action will be subject to the same laws of
+electricity as the centrifugal force is, which is the repulsive power
+due to the pressure of the Aether. Therefore the inductive action of the
+sun upon any body will, according to the laws of electricity, act
+inversely as the square of the distance (Art. 84), and will be directly
+as the product of the charges on the two attracting bodies, which we
+have seen according to Art. 85 is equal to the product of their masses.
+Not only will this inductive action apply to the sun, but it will
+equally apply to all planets, satellites and stars that exist in the
+heavens, each of these bodies according to Art. 80 being an electrified
+body possessing its electric field and lines of force radiating out into
+space.
+
+Thus we arrive at the conclusion, that each body in the solar system is
+not only the centre of a centrifugal force due to the pressure of the
+electro-magnetic Aether, but that it is also the centre of an attractive
+force due to the existence of the positive and negative elements of the
+Aether, and of their attractive power for each other.
+
+This attractive power is also subject to exactly the same laws that the
+centrifugal force is subject to in regard to intensity, proportion, and
+the direction which it takes. So that we have now two centripetal forces
+existing in space, which exactly correspond with each other, viz.
+Gravitation Attraction and the attraction due to Electrical Induction.
+The cause of one, however, is known, being due to the inductive
+influence of the various electrified bodies that exist in space, which
+inductive influence can be traced through the whole of the atomic Aether
+that exists between the two bodies, whereas the cause of the centripetal
+force or Gravitation Attraction is unknown. According to the Rules of
+Philosophy, therefore, it will be much simpler if we replace our
+Gravitation Attraction, whose cause is unknown, by the inductive power
+of the various bodies, the physical cause of which lies in the
+electro-magnetic Aether, or the dielectric as Faraday called it. In
+other words, we are compelled to come to the conclusion that the
+centripetal force, or Gravitation Attraction so called, is an electrical
+phenomenon, which finds its physical cause in the same universal Aether
+that the centrifugal force does.
+
+Unless this view of the attraction of Gravitation is accepted, we should
+have two forces operating between all bodies, both operating at exactly
+the same time, in exactly the same direction, and with exactly the same
+intensity, and this phenomenon according to Newton would be
+unphilosophical. In Art. 4 we learn that Newton in the first rule states
+that "Nature is simple, and does not abound in superfluous causes of
+things." And again: "In the nature of Philosophy nothing is done in vain;
+and by means of many things, it is done in vain when it can be done by
+fewer." Here then we have apparently two forces which act in the same
+molecular or planetary or interstellar space, at one and the same time.
+Therefore if this be true, Nature does abound in a superfluous cause,
+because we have two forces in existence where one will suffice, and one
+of them therefore exists in vain. So that it will be philosophical if we
+do away with one of the causes, and replace the two causes by only one.
+Now which shall be done away with--the electrical attraction which is due
+to a physical medium, the electro-magnetic Aether, or the Gravitation
+Attraction, that is caused by some virtue of a body of which we have no
+knowledge, which is transmitted through space in a way that we cannot
+understand, and acts upon distant bodies in a manner altogether outside
+our usual experience and observation? There can only be one answer. If
+either of the two forces has to be done away with, it must be the
+mysterious, intangible, unphilosophical attraction of Gravitation, which
+must be replaced by the philosophical and known attraction of electricity,
+which can be traced to a physical medium, the electro-magnetic Aether that
+joins atom to atom, molecule to molecule, satellite to planet, planet to
+sun, and sun to star, and so gives unity to the universe of worlds. From
+philosophical considerations, therefore, we are compelled to come to the
+conclusion that the attraction of gravity and electrical attraction are
+one and the same.
+
+Faraday arrived at this conclusion and performed certain experiments to
+confirm that conclusion, but he was unable to experimentally prove the
+truth. It does not follow, however, that because he failed to
+experimentally establish the connection, therefore the conclusion is
+wrong. In his _Experimental Researches_ he writes, par. 2705, "On the
+possible relation of gravity to electricity":--"First of all, a body
+which was to be allowed to fall, was surrounded by a helix, and then its
+effect in falling sought for." This experiment Faraday states produced
+negative results (par. 2706). "A solid cylinder of copper was introduced
+into the helix, and carefully fastened to it, and this compound
+arrangement was allowed to fall." "The result of this experiment may be
+classified as doubtful. It gave very minute, but remarkable indications
+of a current in the galvanometer, and the probability of these being
+related to gravity appeared the greater, when it was found, in raising
+the helix or core, similar indications of contrary currents appeared."
+In par. 2717 Faraday thus sums up: "Here end my trials for the present.
+The results are negative. They do not shake my strong feeling of the
+existence of a relation between gravity and electricity, though they
+give no proof that such a relation exists." Here then we have expressed
+the strong conviction of the relation that undoubtedly exists between
+gravity and electricity by one of the greatest scientists that has ever
+lived, and I believe that it is a fact that he was engaged upon
+experiments to prove his conviction about the time of his death.
+
+We will now endeavour to trace the action of the Law of Gravitation in
+its compound working, in its application to the atomic Aether that fills
+all space, and by its gravitating property surrounds all bodies situated
+in that space. We are dealing no longer with a frictionless medium,
+which is incapable of accepting and transmitting motion of any kind or
+sort, but we are now dealing with a medium composed of atoms, which can
+give rise to pressures and tensions, or repulsions and attractions from
+any one part of space to another.
+
+If we can prove that an atomic Aether can give rise to these pressures
+and tensions from one body to another, and those pressures and tensions
+harmonize with, and satisfactorily account for, the phenomena sought to
+be explained, then we shall have succeeded in making our philosophy
+agree with our experience, and such a result as action at a distance
+will for ever disappear from the mental conception of all men, as it has
+long disappeared from the pages of philosophical and scientific works,
+though that disappearance was not accompanied with a satisfactory
+solution of the problem.
+
+Let us, therefore, consider these pressures and tensions, or so-called
+repulsions and attractions that exist in this electro-magnetic Aether
+from the atomic standpoint, and by so doing try to realize how it is
+that one body, as the sun, acts upon another body, as the earth, through
+the intervening medium, the Aether. We can either consider it from the
+material standpoint, that is, by considering the Aether as matter, pure
+and simple, or by viewing it from the electrical standpoint, which may
+be considered from Clerk Maxwell's physical conception of an electric
+field. We will briefly consider it from the latter standpoint. Our
+conception of an aetherial atom was that of a spherical vortex atom
+possessing polarity and rotation on an axis. We must, however, make the
+distinction between the two kinds of aetherial atoms that Clerk Maxwell
+first indicated in his paper on Physical Lines of Force, _Phil. Mag._,
+1861, and that Dr. Larmor has worked out in his _Aether and Matter_ from
+the electron standpoint, viz. that the Aether is composed of positive
+and negative electrons. Or we can accept Professor Lodge's theory, that
+Aether is made up of positive and negative electricity. We are compelled
+to accept the hypothesis of two kinds of aetherial or electrical atoms,
+whatever they may be called, in view of the teaching of electricity,
+that positive and negative electricity are always to be found in
+association, and in combination, wherever electricity exists. We have
+proved that electricity is to be found throughout the realm of space
+(Art. 78); therefore in all planetary and stellar regions electricity is
+present. Thus it exists in the so-called space between the sun and
+planets, and between the planets and satellites, forming around them all
+spherical shells, that become less and less dense as they recede from
+the central body. Now it is by the action of these positive and negative
+electrical atoms, that the attraction of one body is transmitted across
+space from the sun to the earth, or from the earth to the sun, or from
+the earth to Jupiter, or from Jupiter to any of the planets, the action
+always taking place along the line joining the centres of gravity of the
+bodies, _i. e._ the radius vector, and with a force equal to the
+quantities of electricity in association with those bodies (Art. 85),
+and with an intensity that always acts inversely as the square of the
+distance. Thus the inductive action of any sun, planet or satellite, or
+any other planet or satellite, can be mentally traced from atom to
+atom, across the intervening space, that is filled with the atomic
+Aether, between any two attracting bodies. So that, if the sun attracts
+the earth, it attracts it by and through the motions and properties of
+the electro-magnetic Aether that is made up of positive and negative
+electricity, and that attraction, being produced by a physical medium
+which is as real and tangible as air or water, is brought into harmony
+with our experience and observation, as no body pushes or pulls another
+body, be it what it may, unless both bodies are joined together by some
+medium which transmits the push or the pull. Professor Lodge, in his
+_Modern Views of Electricity_, has illustrated from an electrical
+standpoint how the pressure and tension in any electrical field may be
+transmitted from particle to particle, or atom to atom. He supposes that
+a positive atom of electricity rotates in one direction while a negative
+atom rotates in the opposite direction. In any electric field these
+atoms are so associated with each other, that when one atom revolves, it
+makes the other to revolve in the opposite direction, with the result,
+that the spin or rotation is transmitted through the medium at a speed
+dependent upon the density of the medium.
+
+For fuller details of the description I must refer the reader to the
+work already referred to. What I wish to call the reader's attention to
+is, that the tension and pressure in this field is not transmitted
+across a vacuum, in some unknown way, but is transmitted solely by a
+physical medium. The action is direct, and is produced, and alone
+produced, continued, and perpetuated by a physical medium which is
+composed of atoms of negative and positive electricity. So that if one
+body _A_ acts upon another body _B_, it acts upon _B_ solely and
+entirely by the action of the atoms which form the magnetic lines of
+force, and the equipotential surfaces around the electrified body, and
+that action can be traced mentally step by step across the intervening
+space that may exist between the two bodies. It is in an exactly similar
+manner, that the Attraction of Gravitation, which we conceive to be the
+same as electrical attraction, is transmitted from body to body in the
+atomic, molecular, planetary or stellar world. In each and every case,
+the pressure and tensions, which are inseparably connected, are
+transmitted by the atoms of the electro-magnetic Aether, that is, by the
+positive and negative atoms of electricity of which, according to
+Professor Lodge and Dr. Larmor, the Aether is composed. So that, if the
+sun acts on the earth, by the centrifugal force, it acts on it solely
+through and by the pressures which are originated in the atomic Aether
+by the central body. If the sun attracts the earth, by the centripetal
+force, that action can also be traced to the tensions that are
+originated among the atoms of the electro-magnetic Aether. There is
+nothing mysterious about the phenomenon in either case, as by accepting
+this view of an atomic Aether with its dual character of positive and
+negative electricity, the action may be traced mentally from point to
+point across the so-called intervening space that exists between any two
+bodies. In each and every case, wherever the centripetal or centrifugal
+force acts, the action is direct, because it is caused by a physical
+medium, which physical medium is in direct contact with each body acted
+upon, and also fills the space between those bodies. With this view of
+the centripetal force of Gravitation, our Philosophy is made to agree
+definitely with our experience, which teaches us beyond contradiction,
+that no body moves, unless it is either pushed or pulled by a physical
+medium. Unless this view of the centripetal force is accepted, we shall
+have to stumble on in darkness as to the physical cause of the
+centripetal force, and mentally accept the unphilosophical proposition,
+that a body can act on another in a way that we cannot understand, and
+by means which lie outside our experience and observation, and this
+hypothesis, as Newton and Herschel pointed out, is distinctly an
+unphilosophical proposition.
+
+[Footnote 40: _Modern Views of Electricity_, p. 221.]
+
+
+
+
+                              CHAPTER XII
+
+                           AETHER AND COMETS
+
+
+ART. 111. _Comets. What are Comets?_--In addition to the planets and
+asteroids which revolve around the sun, there are also other bodies
+termed Comets, which revolve round the solar orb.
+
+Unlike the planets, however, they do not all keep to the plane of the
+ecliptic, but approach to, and recede from the sun at all angles to that
+plane, as well as in that plane itself. Comets are supposed to be huge
+masses of gaseous matter, in a more or less condensed condition. That
+they are not composed of absolutely solid matter is proved by the fact
+that it is possible to see the stars through the gaseous matter of which
+they are composed.
+
+How the gaseous matter of which these comets are formed is originated,
+or how it is formed in solar or stellar space, has, I believe, up to the
+present never been explained, and indeed, with the idea of a
+frictionless Aether, I fail to see how any physical explanation of the
+origin and development of a comet can be satisfactorily given. With the
+conception of the Aether, however, that is put forward in this work,
+viz. that Aether is matter in its most rarefied and attenuated form,
+which can be condensed into a gaseous condition, with such a conception
+of the universal aetherial medium, the origin and development of gaseous
+matter from this Aether becomes a physical possibility.
+
+Lord Kelvin, in the _Philosophical Magazine_, July 1902, on the
+"Clustering of Gravitational Matter in any part of the Universe," has
+already suggested the possibility of the condensation of the Aether, but
+with the old idea of a frictionless Aether, that is, an Aether which
+does not possess mass, such a hypothesis is improbable. Because, if the
+Aether becomes condensed at all, it must be condensed into gaseous and
+solid matter, and all experiments and observation teach us that both
+these forms of matter possess mass and weight.
+
+Therefore, if the frictionless Aether, which possesses no mass and
+weight, is to be condensed into gaseous or solid matter, there must come
+a period in the process of condensation when it must pass out of the
+condition of possessing no mass and no weight, into the condition of
+possessing mass and weight, which assumption is altogether opposed to
+those Rules of Philosophy based upon experiment and observation.
+
+Aether can only pass into a gaseous or solid condition, in which
+condition it will possess mass and weight, on the assumption that in the
+aetherial condition it possesses the same properties, only in a modified
+form, which it possesses after the process of condensation has taken
+place. In a similar way that air can pass out of its gaseous condition
+into a liquid condition, or any gas can pass out of its gaseous into a
+liquid condition, so Aether, on the conception as given in Chapter IV.,
+can pass out of its aetherial and rarefied condition into that form of
+matter which is known as gaseous. We shall deal with this aspect of
+Aether more fully when we come to deal with the Nebular Hypothesis, as
+the same principle underlies that hypothesis as underlies the origin and
+development of comets.
+
+Thus, comets may be formed at any time in interstellar space out of the
+Aether that exists there, provided the conditions of its formation are
+to be found there. Then, as they are gradually formed, they would, like
+any other bodies, come more directly under the influence of any large
+bodies, as the sun, and be attracted by them.
+
+This conception of the origin and development of a comet will also
+account, and that on a logical and philosophical basis, for another fact
+which is associated with cometary phenomena. I refer to the fact of the
+expulsion of gaseous matter out of the head of a comet as it nears the
+sun, which expulsion will be dealt with in the article on "Parts of a
+Comet."
+
+Another problem that might be solved by this conception of a comet lies
+in the question, as to whether comets shine by their own light?
+
+If comets are really formed of condensed Aether, as I believe them to
+be, then, as light is due to a periodic wave motion of the Aether, as
+soon as the Aether (of which the comets' tails, for example, were
+formed) was made to vibrate with that rapidity sufficient to produce
+light waves in the surrounding Aether, the tails would then shine by
+their own light, in exactly the same way that any other body emits light
+waves, as soon as its aetherial vibrations reach the rapidity necessary
+to produce the waves of light, which vibrations would lie between 2000
+to 8000 billions per second.
+
+The number of the comets that exist in the solar system cannot be
+ascertained with any degree of accuracy, but the total probably extends
+into millions. They are of all sizes, from those which possess diameters
+of several miles, to those extending over thousands of miles. They also
+possess orbits, with which we will now deal.
+
+
+ART. 112. _Orbits of Comets._--As has already been pointed out, comets
+perform their journey round the sun, not only in the plane of the
+ecliptic, but also at all angles relatively to that plane. In this
+respect they differ from the orbits of planets and satellites, which
+perform their journey in orbits situated wholly in the plane of the
+ecliptic (Art. 109).
+
+There is another important difference between the orbits of the comets
+and those of the planets. In the case of the latter the orbit is that of
+an ellipse, while in the case of the comet the orbit may be either that
+of a parabola or a hyperbola, which may be looked upon as elongated
+ellipses open at one end. There are, however, some comets whose orbits
+are perfectly elliptical, and whose return may be calculated with a fair
+amount of accuracy.
+
+These are known either as Short Period Comets, as represented by Faye's
+Comet, Encke's and De Vico's; or Long Period Comets, as represented by
+the comets of 1811, 1844, and 1858. In the case of all these, as their
+return to our solar system can be determined, it follows that they must
+revolve around the sun in some sort of a closed orbit, probably that of
+an exceedingly elongated ellipse.
+
+There are, however, other comets which appear once, or it may be several
+times only, and then disappear out of the solar system for ever. Now the
+question arises, as to whether the orbits of the comets which are so
+variable can be explained by the motions of the Aether which we have
+already ascribed to it? We have seen (Art. 109) how it is possible to
+account physically for the plane of the ecliptic from the motions of the
+Aether, and how it is that all the planets move within that plane, but
+here we have a phenomenon of a different kind, as observation distinctly
+teaches us that the comets do not move in, or keep within the plane of
+the ecliptic, but gravitate round the sun at all angles to that plane.
+
+In order for us, therefore, to be able to account, and that on a
+philosophical basis, for this fact, we must revert to our conception of
+the sun in its relation to the solar system. In Art. 88 we learned that
+the sun was an electro-magnet possessing its electro-magnetic field, and
+generating electro-magnetic waves which were radiated forth from it on
+every side. From Art. 89 we learn that an electro-magnetic body
+possesses lines of force, and that these lines of force take various
+directions as they are generated by the body, as proved by Faraday's
+illustrations. Further, a moving electro-magnet, as the sun for example,
+carries its lines of force with it, as proved by Maxwell.
+
+Now these lines of force extend not only east and west, but also north
+and south, as depicted in Fig. 29.
+
+Hitherto we have only dealt with the lines of force proceeding from the
+sun equatorially, which lines form the plane of the ecliptic. We have,
+now, to take into consideration those lines which extend out into space,
+north and south of that plane. These are not so curved as the others, but
+are more inclined to be straight, or less curved, as they are really
+parts of large curves which extend much further outwards into space.
+
+The orbits of the Short or Long Period Comets can be explained by the
+fact that they perform their journey more or less in the plane of the
+ecliptic, though in some cases at a much greater angle than that of any
+of the planets. Provided, however, they remain within the influence of
+the electro-magnetic field of the sun, there is then a physical
+explanation as to their orbital motion round the sun, in a similar way
+to the orbital motion of the planets, though at greater angles to the
+plane of the ecliptic.
+
+For we have to remember, that wherever the electro-magnetic waves of the
+sun's electro-magnetic field extend, there we have also the rotation of
+that field round its central body, though with a continually decreasing
+intensity, as already pointed out. Wherever, therefore, we get rotatory
+Aether currents, due to the rotation of the electro-magnetic field,
+there we get the conditions which would enable any kind of gaseous or
+material body to be circulated round the sun. The case, however, of
+comets which do not return has to be viewed from a different standpoint.
+Here it seems to me we are dealing with masses of condensed Aether that
+come within the inductive influence of the electro-magnetic waves of the
+sun, as that body moves through space with its velocity of about 500,000
+miles per day. We have to conceive of this condensed Aether situated
+north and south of the plane of the ecliptic, and situated probably
+millions of miles away. As the sun moves onward in its journey through
+space, carrying its electro-magnetic field with it, then, by the
+inductive action of the sun, the comet would be attracted by that body,
+and so would be gradually drawn towards it.
+
+Under this inductive influence it would rush towards the sun, until,
+approaching very close to it, it would be repelled by the
+electro-magnetic waves or centrifugal force of that body, and be hurled
+again by their repulsive energy far far away into space to the north or
+south of the plane of the ecliptic. As it was moving away from the syn,
+north or south of the ecliptic, the sun would be moving onwards through
+space in the plane of the ecliptic, which would practically be at right
+angles to the motion of the comet, so that by the time the comet had
+receded far into the depths of space, the sun with its electro-magnetic
+field would have moved on also in a direction at right angles to the
+comet's motion.
+
+The effect of the sun's orbital motion would be, that it would be unable
+to again exert sufficient inductive power upon the comet to bring it
+within its inductive influence once more. For example, suppose there is
+a mass of Aether condensing at point _A_ in interstellar space situated
+some millions of miles north of the plane of the ecliptic, which is
+represented by the straight lines _B_ _C_. The sun is moving in the
+direction towards the part of space represented by point _B_. We will
+suppose that when the sun is near point _C_ the mass of Aether at point
+_A_ is too far away to be appreciably influenced by the inductive action
+of the sun. But as the sun moves towards point _F_, then the condensed
+Aether, which practically forms the body of the comet, will come within
+its influence and be drawn towards the sun, at an angle to the plane of
+the ecliptic.
+
+[Illustration: Fig: 30.]
+
+By the time the body of the comet has reached the sun, it will have
+acquired a momentum which enables it to rush past the sun, and then it
+will be repelled by the electro-magnetic waves in the direction of _F_
+_G_, which is still at an angle to the plane of the ecliptic; but its
+motion, combined with the repulsive power of the electro-magnetic waves,
+is carrying it outside the sphere and influence of the sun's
+electro-magnetic field. At the same time the sun is proceeding onwards
+through space, leaving the comet far behind, so that by the time the
+comet has reached the confines of the solar system, it has either passed
+under the influence of another star, or has become further condensed to
+form a meteor, which begins to circle around the largest and nearest
+body. I do not assert that this hypothesis is strictly correct, but it
+seems to me that only on some such hypothesis can the appearance and
+apparent loss of irregular comets be explained.
+
+
+ART. 113. _Short Period Comets and Long Period Comets._--We have seen in
+the previous article, that some Comets revolve round the sun in closed
+orbits of exceeding great eccentricity, and the return of these may be
+calculated with certainty. There are about two dozen comets which revolve
+around the sun, and which return at intervals lying between three years
+and 76 years.
+
+This class of comets may be divided into two kinds, which are known as
+Short Period Comets and Long Period Comets respectively. The following
+table gives a list of the chief of the Short Period Comets, together
+with some particulars relating to time of revolution, etc.:--
+
+    COMETS.          PERIOD OF         PERIHELION         APHELION
+                    REVOLUTION.         DISTANCE.         DISTANCE.
+
+    Encke's    ...  3-1/4 years.    32,000,000 miles.   387,000,000 miles.
+    De Vico's  ...  5-1/2   "      110,000,000   "      475,000,000   "
+    Biela's    ...  6-1/2   "       82,000,000   "      585,000,000   "
+    D'Arrest's ...  6-1/2   "
+    Faye's     ...  7-1/2   "      192,000,000   "      603,000,000   "
+    Halley's   ... 76-3/4   "       56,000,000   "    3,200,000,000   "
+
+Encke's Comet was discovered by Professor Encke of Berlin, and named
+after him. It revolves in an ellipse of great eccentricity, as proved by
+the fact that when nearest to the sun, it is inside Mercury's orbit, but
+when furthest away from the sun, it passes beyond the orbit of Mars,
+reaching almost to the orbit of Jupiter. One of the most remarkable
+facts about this comet is, that it has done more to establish the
+existence of that resisting medium around the sun, whose existence we
+have demonstrated, than any other comet. Encke found on its periodical
+return that its mean distance was gradually getting less, and in order
+to account for this, he supposed that it was due to the existence of a
+resisting medium which enveloped the sun, and extended some distance
+into space.
+
+This conclusion has been supported in recent years by Von Asten, a
+German mathematician, who has supported the theory of a resisting
+medium. On this point Herschel writes in his _Outlines of Astronomy_,
+Art. 577: "This is evidently the effect which would be produced by a
+resistance experienced by the comet from a very rare aetherial medium
+pervading the regions in which it moves; for such resistance, by
+diminishing its actual velocity, would diminish its centrifugal force.
+Accordingly, this is the solution proposed by Encke, and at present
+generally received."
+
+So that we have in Encke's Comet another proof of the existence of that
+aetherial medium, which is not frictionless, but has the power to oppose
+any body which moves through it, when that body moves in an opposite
+direction to its own motions.
+
+Another Short Period Comet worthy of notice is that of Biela, named
+after M. Biela, its discoverer. This comet had a period of six and a half
+years, and reappeared at several successive intervals until about the
+year 1845, when it seems to have been broken or split up into two parts.
+In December 1845 the comet divided into two parts, which travelled
+parallel to each other for a long distance. During this separation, very
+singular changes were observed to be taking place in both the original
+comet and its offshoot.
+
+Both had a nucleus, and both had tails, which were parallel to each
+other. The comets continued to travel together until the 15th March
+1846, when the new comet began to fade away, until, on the 24th March,
+the old comet only was visible, while in April both had disappeared
+entirely. A similar phenomenon was again observed at its next passage in
+1852, but since then Biela's Comet has entirely disappeared. It is
+suggested by astronomers, that the comet has become condensed, and
+broken up, forming a shoal of meteors.
+
+Support is lent to this theory by the fact that in November 1872, when
+the earth was passing through space and had arrived at that part of its
+orbit which intercepted the orbit of Biela's Comet, instead of the comet
+being seen, the earth came into contact with a swarm of meteors, and
+this is accepted as evidence that Biela's Comet was condensed far away
+in the colder regions of interplanetary space into a more solid form of
+matter, known as meteors. One of the more famous of the short period
+class of comets is that known as Halley's Comet, which has a period of
+about 76 years. This comet has been seen in its return journey to the
+sun about 25 times. It was named after its discoverer, Edmund Halley. He
+was led to identify this comet with that of 1531 and 1607, and thus to
+conclude that it had a period of 75 or 76 years. He therefore predicted
+its reappearance in 1759. As the year approached, its arrival was
+eagerly looked for, to see if the prediction would be verified.
+
+It was thought, however, by a certain astronomer named Clairaut, that
+the larger planets, as Saturn and Jupiter, might interfere with its
+orbital motions, and after careful calculations a difference of 618 days
+was allowed, which brought its anticipated reappearance down to April
+1759. It actually reappeared in March of that year. Its next
+reappearance was fixed to take place about November 1835. The comet
+became visible on 5th August 1835, and continued to be seen till April
+1836, when it again disappeared.
+
+As the reappearance of the comet was calculated by the application of
+the Newtonian Law of Gravitation, such a result only gave added
+confirmation to the application of that law to cometary bodies.
+
+Of the Long Period Comets there are several known. That of 1858 has a
+period, it is thought, of 2000 years. The 1811 comet has a period of
+3000 years, while that of 1844 has a period of over 10,000 years. All
+these comets move in orbits of such great size that their return is
+improbable. One of the characteristic features about Long Period Comets
+is their great brilliancy and size.
+
+The 1858 comet, known as Donati's Comet, was first seen by that
+astronomer at Florence in June. It was invisible, however, to the naked
+eye, as it only appeared through the telescope like a faint cloud of
+light, gradually getting brighter and brighter. Toward the end of August
+it began to show signs of developing a tail, and became visible to the
+eye on August 29th. During September and October it greatly increased in
+size and brilliancy, and was plainly visible in the western heavens.
+After October 10th it was only visible in the southern hemisphere,
+gradually decreasing in brightness. It was seen till March 1859, when it
+disappeared, and will probably not return till the year 3858, as its
+period of revolution is about 2000 years.
+
+Donati's Comet passed between the earth and many stars, which could be
+seen very distinctly through its tail. One of the stars was Arcturus,
+and, though some of the densest parts of the comet passed over it, yet
+the star could be seen all the time, thus conclusively proving that the
+head and tail of a comet are only composed of gaseous matter, probably
+condensed Aether, as suggested in Art. 111.
+
+
+ART. 114. _Parts of a Comet._--A comet may be divided into three parts:
+1st, Nucleus; 2nd, Head or Coma; and 3rd, Tail.
+
+The nucleus is the central part of the head or coma, and is generally
+the brightest part of the whole comet. On the theory that a comet is due
+to the condensation of Aether, the nucleus would represent the first act
+in the process of condensation, as there would have to be some centre of
+condensation, and that centre would be represented by the nucleus.
+Further, the process of condensation would assume a spherical form, as
+the conception of our aetherial atom is that of a sphere or an oblate
+spheroid. As the process of condensation went on, the layers that would
+be produced would form a kind of envelope around the point of
+condensation, with the result that the nucleus would ultimately consist
+of a large mass of gaseous matter, made up of layer upon layer of
+condensed Aether around some central point, which formed the nucleus.
+
+This hypothesis agrees with observed phenomena, because, when we deal
+with the tails of comets, we shall see that the tail is simply formed by
+the reverse process to that of condensation, as in the case of cometary
+tails the gaseous envelopes so formed will be thrown off (either through
+heat generated by friction, or by the increased heat as the comet nears
+the sun), which are then repelled away from the sun by the centrifugal
+force. Herschel,[41] referring to the nucleus, states, paragraph 559:
+"An atmosphere free to expand in all directions would envelop the
+nucleus spherically," while in his Reflection on Halley's Comet, he
+states, Art. 570, "1st, That the matter of the nucleus of a comet is
+powerfully excited and dilated into a vaporous state by the action of
+the sun's rays, escaping in streams and jets at those points of its
+surface which oppose the least resistance. 2nd, That the process chiefly
+takes place in that portion of the nucleus which is turned towards the
+sun, the vapour escaping in that direction. 3rd, That when so emitted,
+it is prevented from proceeding in the direction originally impressed
+upon it, by some force directed _from_ the sun, drifting it back and
+carrying it out to vast distances behind the nucleus forming the tail."
+
+When we come to deal with the question of the formation of the tail, we
+shall find that every reflection made by Herschel is satisfactorily
+fulfilled by the conception of a gravitating and condensing Aether.
+Before considering the tail, however, we will deal with the head or
+coma.
+
+The head or coma is that part of the comet which exists round the
+nucleus. It is less bright than the nucleus, and oftentimes appears as a
+shadowy mass of light. Herschel, in his 4th Reflection, states that "a
+considerable part of the vapour actually produced remains in the
+neighbourhood of the nucleus forming the head or coma." So that the head
+of a comet is simply the vaporised part of the nucleus which is produced
+by the increased heat of the sun, in the same way that water would be
+vaporised by the addition of heat, the vapour in that case being thrown
+off in the form of steam.
+
+This formation of the head is but a continuation of the reversal of the
+process of condensation, which originally gave existence to the mass of
+matter termed the comet. The diameter of this head or coma often extends
+to thousands of miles. The head of the 1811 comet was 540,000 miles in
+diameter, while that of the 1843 was 112,000 miles. As the nucleus is
+formed of a series of envelopes, so the head also consists of a series
+of envelopes.
+
+The comet of 1858 constantly threw off these envelopes, which were first
+expelled _towards_ the sun, and then repelled away _from_ the sun,
+forming the tail. The matter forming the head and the nucleus is
+perfectly transparent, as stars have been seen through the matter which
+forms those parts. Herschel,[42] paragraph 558, states "that whenever
+powerful telescopes have been turned on these bodies, they have not
+failed to dispel the illusion which attributes solidity to that more
+condensed part of the head which appears to the naked eye, though it is
+true that in some a very minute stellar point has been seen indicating
+the existence of a stellar body."
+
+_Tails._--The tail of a comet is that part which flows from the head,
+and is afterwards repelled by the repulsive power of the sun into space.
+We shall deal with this repulsive power, whose existence we have already
+demonstrated, and the part which it plays in the formation of a comet's
+tail, in the next article. The tail of a comet is oftentimes considered
+to be the comet itself, rather than a part of the same, but as the tail
+is the most distinctive feature of a comet, and is the part most visible
+to the naked eye, there has arisen the popular but mistaken idea of
+identity between the tail and the comet itself.
+
+Tails are of all kinds. There are some which are short, while others are
+long. Then we have comets with single tails, or double, and in some
+cases even multiple tails. Occasionally comets appear which have no
+tails at all. The comet of 1744 had six tails, which spread out in the
+shape of a large fan.
+
+One of the most remarkable features of tails is their abnormal length,
+which oftentimes reaches into millions of miles. The comet of 1843 had a
+tail 112,000,000 miles long. Another feature about the tails of comets
+is that they are always directed _away_ from the sun. Up to the present
+I believe no satisfactory explanation has been given of this fact, but
+with the conception of the rotating Aether as given in Art. 94, we shall
+for the first time be able to give a satisfactory physical explanation
+of that phenomenon. In addition to this, the formation of cometary tails
+of all shapes receives a physical explanation, when taken into account
+with the fact that the sun is an electro-magnet, possessing its
+electro-magnetic field, and its lines of force, as described in Art. 88.
+
+[Footnote 41: _Outlines of Astronomy._]
+
+[Footnote 42: _Outlines of Astronomy._]
+
+
+ART. 115. _Centrifugal Force and Comets' Tails._--In order to account
+for the existence of the tails of comets, various repulsive forces have
+been introduced from time to time into the solar system, so that the
+phenomena of cometary tails might be satisfactorily accounted for.
+
+It has been felt by every astronomer that some repulsive force, which
+had its origin in the sun, was absolutely necessary to explain the
+existence of the tails, and as no real force could be demonstrated to
+exist, recourse had to be made to repulsive forces of a more or less
+hypothetical nature. The necessity of this repulsive force is nowhere
+more plainly indicated than by Sir J. Herschel in his _Lectures on
+Scientific Subjects_, where, dealing with the phenomena of comets'
+tails, he writes: "They have furnished us with a proof, amounting to
+demonstration, of the existence of a repulsive force directed from the
+sun, as well as that great and general attractive force which keeps
+planets in their orbits."
+
+In the same work, referring to the comet of 1680, he writes: "This comet
+was perhaps the most magnificent ever seen. It appeared from November
+1680 to March 1681. In its approach to the sun it was not very bright,
+but began to throw out its tail when about as far from the sun as the
+earth. It passed its perihelion on December 8th, and when nearest to the
+sun was only about 1/10 part of the sun's diameter from the surface. No
+wonder it gave evidence of violent excitement, coming from the cold
+region outside planetary space. Already, when arrived even in our
+temperate regions, it began to show signs of internal activity. The head
+had begun to develop and the tail to elongate, till the comet was for a
+time lost sight of. No human eye beheld the wondrous spectacle which it
+must have offered on December 8th. Only _four days_ afterwards, however,
+it was seen again, and the tail, whose direction was reversed, and which
+observe could not possibly be the same tail, its tail had already
+lengthened out to the extent of about 90 millions of miles, so that it
+must have been shot out with immense force in a direction _from_ the
+sun."
+
+The reader will have observed it took from November 10th to December
+8th, or 28 days, to fall to the sun for the same distance, and that with
+all the velocity it had on November 10th to start with. Herschel sums up
+the matter thus: "Beyond a doubt, the widest and most interesting
+prospect of future discovery which their study (comets' tails) holds to
+us, is, that distinction between gravitating and levitating matter, that
+positive and unrefutable demonstration of the existence in nature of a
+repulsive force co-extensive with, but enormously more powerful than the
+attractive force we call gravity, which the phenomena of their tails
+afford."
+
+Thus the philosophic mind of Herschel saw in the existence of cometary
+tails, the irrefutable evidence of the existence of a repulsive force,
+not of a hypothetical character, but as real as the existence of gravity
+itself. Various attempts have been made to define that repulsive force
+which was thus demanded, and the same force has been ascribed by
+scientists to the repulsion due to heat, to light, and also to
+electricity.
+
+Several French scientists have suggested that the repulsive force was
+due to the heat of the sun. M. Roche was one of those who stated that
+the phenomena of cometary tails was due to the repulsive power of heat,
+which found its origin in the heat of the sun. M. Faye, another French
+scientist, states that the repulsive force had its origin in the heat of
+the sun. By a series of experiments he demonstrated that there was a
+repulsive power in all heat waves, which gave his theory that
+experimental support that any theory must possess to make it permanent.
+
+Now in Art. 63 it was shown that heat does possess a repulsive power,
+but that that power is rather due to the electro-magnetic Aether whose
+vibrations produce the heat waves, than to the repulsion of heat; so
+that, indirectly, the assumption of both these French scientists, that
+the repulsive power of heat gave rise to the tails of comets, is
+correct. Then again it has been suggested that the repulsive power is
+produced by the pressure of the light waves. Professor Lebedew suggested
+this after he had experimentally proved that light waves did possess a
+repulsive power (_Annalen der Physik_, November 1901). It can easily be
+seen, as pointed out in Art. 70, that, inasmuch as light is due to the
+vibrations of the Aether, they too possess this repulsive power, and
+therefore Professor Lebedew's suggestion as to the nature of the
+repulsive power is correct, as the real centrifugal force is really due
+to an aetherial pressure.
+
+Whether, therefore, we consider it from the standpoint of heat, or light
+or electricity, it ultimately resolves itself into the same aetherial
+medium which is at once the common source of all these forces. Again, it
+has been suggested that the repulsive power is electrical or
+electro-magnetic, and this view is receiving more support than either of
+the others from modern scientists.
+
+Herschel suggested that the repulsive power was electrical, while
+Bredichin has worked out a very careful theory as to the effect of
+electrical repulsion upon different elements that are found in the
+comets' tails, with a view to explain the different shapes of the tails.
+But whether the force is looked at from the standpoint of heat, light or
+electricity, it ultimately resolves itself into the motions of the
+Aether, which gives rise by its different vibrations and motions to all
+the three forms of energy referred to.
+
+When we also take into account the fact that Aether is gravitative, and
+therefore denser nearer to the sun than further away, and that it is
+also rotating round the central body the sun (Art. 91), then we have at
+once every condition necessary to explain all the various kinds of
+cometary tails, and also for the remarkable fact that the tail is always
+turned away from the sun, which is simply due to the effect of the
+rotating Aether with its outflowing electro-magnetic waves upon the
+gaseous matter of the comet. Thus from the phenomena of comets' tails,
+we have again arrived at the conclusion of the existence of that
+centrifugal force, whose origin and continuity are to be found in the
+electro-magnetic Aether which surrounds the sun, and which by its
+electro-magnetic waves gives rise to pressure on all bodies upon which
+they fall.
+
+
+ART. 116. _Formation of Tails._--With the conception of the formation of
+the comet advanced in Art. 111, viz. that it is nothing more or less
+than Aether in a state of condensation, and remembering the explanation
+given of the parts of the comet, as the nucleus, and head or coma, we
+are now in a position to give a philosophical account of the formation
+of the tails of comets, which will satisfactorily fulfil all the Rules
+of Philosophy. In addition to the facts already referred to in the
+previous articles of this chapter, we must also recall our conception of
+the Aether as given in Chapter IV., remembering that it gets denser
+nearer the sun, and that it is not frictionless; therefore, when a body
+is urged through it, friction is produced, and heat is generated.
+
+We must also remember that the Aether is rotating round the sun as that
+body proceeds through space. We have, therefore, to picture the
+condensed mass of Aether situated out in the cold interstellar space,
+gradually coming under the influence of the sun, as that body rushes on
+its journey through space with a velocity of 500,000 miles per hour.
+
+Slowly, but surely, the mass of condensed Aether begins to respond to
+the attractive power of the sun, and to move through space towards the
+sun. So long as it is moving towards the sun, it is encountering and
+having to overcome the resistance of the Aether.
+
+At first this resistance is very feeble, owing to the decreased density
+of the Aether, but as it proceeds on its journey it is constantly
+passing into denser parts of the aetherial electro-magnetic field around
+the sun. The result is, that as the resistance is increased, so there is
+greater friction between the matter of the comet and the atomic Aether
+in space, and, in consequence, heat is generated.
+
+In addition to the generated heat, the comet is all the while passing
+into regions of greater intensity of heat. In both cases, the effect is
+only manifested on that side of the comet which is approaching the sun;
+for, if there be any friction at all, it will only be on that half of
+the comet which encounters the Aether, so to speak, while the same part
+will receive the added heat, as the distance between the comet and the
+sun is decreased. As can readily be seen therefore, this added heat acts
+only upon the half of the comet which is advancing, and which faces the
+sun, and as the effect of heat is always to vaporise, so the effect on
+the nucleus of the comet is to vaporise the condensed aetherial matter,
+and this vaporised aetherial matter is thrown off in layers which are
+partly spherical in form, the layers always being expelled in the first
+instance _towards_ the sun, on account of that centrifugal motion which
+has its birth in the nucleus of the comet.
+
+This explanation fully establishes and confirms the first and second
+Reflections of Herschel as given in Art. 114, and, moreover, is itself
+established by the very phenomena which comets present in their approach
+to the sun. As soon, however, as the vaporised matter is expelled from
+the nucleus towards the sun, it is met by the centrifugal motion of the
+electro-magnetic Aether which proceeds _from the sun_, and this pressure
+of the aetherial waves on the advancing comet acts as a repelling power,
+literally repelling the vaporised matter from the sun, and thus giving
+rise to the existence of its tail.
+
+This explanation fully confirms the third Reflection of Herschel
+referred to in Art. 114, and is itself also confirmed by actual
+observation. During all this time, however, the comet has been
+approaching the sun with a decreased velocity, for its velocity has been
+minimised by the resistance it has had to overcome in its approach to
+the sun. As soon, however, as it reaches the sun, it is whirled round
+that body by the rotating Aether medium, as the intensity of its
+rotation is greatest nearest the sun, with a velocity which often
+exceeds thousands of miles per hour.
+
+Having passed its perihelion, in view of the physical existence of our
+centrifugal motion, let us now ask ourselves what ought to happen to the
+comet? Previous to its perihelion, the comet's motion and the
+centrifugal motion due to the pressure of the Aether were in opposition,
+but after passing the perihelion, the comet's motion and the centrifugal
+motion will be acting conjointly, with the result that the motion of the
+comet would be accelerated. Now this is exactly what observation teaches
+us does happen in regard to comets, when they have passed their
+perihelion passage.
+
+As Herschel pointed out with reference to the comet of 1680 (Art. 114),
+it took 28 days to fall to the sun, but only took four days to cover the
+_same_ distance, after it had passed the sun and rounded the perihelion.
+So that we have here, as Herschel stated, an irrefutable evidence of the
+existence of the repulsive power whose existence we have demonstrated.
+
+Again, there is another fact which has to be taken into consideration in
+regard to the tails of comets. Observation teaches us that their tails
+are invariably turned _from_ the sun, though why they always are so
+turned away is an unsolved problem, apart from some real or hypothetical
+repulsive power. We have, however, to further remember that the
+electro-magnetic Aether around the sun is ever rotating with that body,
+and carrying with it in its rotation all associated planets and meteors.
+
+This rotation of the Aether plays a most important part in the phenomena
+stated. Whether the comet is approaching the sun, or receding from the
+sun, it is still subject to the influence of this rotatory Aether
+medium. The result will be that the lighter particles of the vaporised
+matter will be acted upon more powerfully than the heavier parts, so
+that even when the comet is receding from the sun, after it has passed
+the perihelion, the lighter parts which go to form the tail will be more
+under the influence of the repelling Aether waves than the heavier
+parts, as the nucleus, as suggested by Bredichin.
+
+Thus the natural result will be that the tail will still be directed
+away from the sun even when it is receding from that body. Gradually,
+however, as the comet recedes, it passes out of the denser Aether, where
+the intensity of motion and vibration are greatest, to those slower
+parts of the sun's aetherial field where they are less intense.
+
+The effect of this is soon made manifest on the tail and head of the
+comet. The process which took place as it approached the sun is now
+exactly reversed, as it is now passing out of a denser into a more
+rarefied medium, where its motions and vibrations are less intense. The
+tail, therefore, appears to be drawn back to the head, while the head
+will itself gradually contract into the nucleus, as it recedes further
+and further into space. If the comet be situated within the plane, or
+nearly the plane of the ecliptic, then it is possible for it to return
+again, and go through the same process, unless it is captured on its
+outward journey by some of the large outer planets, as Jupiter. If,
+however, their planes do not coincide with the plane of the ecliptic,
+then it is very possible that they will not reappear again, but pass on
+to some other stellar system. Thus we can explain on a strictly
+philosophical basis one of the most interesting, and yet one of the most
+mysterious phenomena associated with our solar system, from the simple
+yet truly philosophical assumption that Aether is matter, in conjunction
+with all that that assumption logically involves.
+
+
+
+
+                              CHAPTER XIII
+
+                      AETHER AND STARS AND NEBULAE
+
+
+ART. 117. _The Starry World._--In addition to the planets and comets
+that are found in the heavens, there are other bodies, countless in
+their number, which we know as stars. Who has not looked up into the
+heavens on some clear night, and noticed how the vault of heaven was
+spangled over with points of light, each point representing a huge sun
+that exists in far-off space? For it must be remembered that every star
+is a sun, which, reasoning by analogy, is the centre of a stellar
+system, just in the same way that our sun is the centre of our solar
+system. Like our sun, all stars shine by their own light, and the
+quality of that brilliancy decides the magnitude of the star, the
+magnitude being indicative of the relative brilliancy of a star rather
+than its size. So that stars are divided into groups according to their
+magnitude, the magnitudes ranging from the first to the sixteenth, and
+even beyond. Those of the first magnitude are more brilliant than those
+of the second, those of the second more brilliant than those of the
+third, each magnitude decreasing in relative brilliancy as the number
+which indicates the magnitude increases. There are about sixteen
+different degrees of magnitude, in which are classified the millions of
+stars that exist in infinite space, but only stars up to the sixth
+magnitude are visible to the naked eye, the telescope revealing those
+which lie beyond. The total number of stars visible to the naked eye are
+about 6000, half of which are visible in each hemisphere.
+
+About 20 stars comprise the group of the first magnitude, which include
+all the brightest stars visible, as Sirius, Canopus, Alpha, Arcturus,
+Rigel, and Capella.
+
+Those of the second magnitude number about 65, and include the brighter
+stars to be found in the constellation known as the Great Bear. Stars of
+the third magnitude number about 200, of the fourth magnitude about 400,
+of the fifth magnitude 1100, and of the sixth magnitude about 3200.
+
+With the aid of the telescope about 13,000 stars of the seventh
+magnitude are revealed to us, and 40,000 of the eighth magnitude, while
+of the ninth magnitude over 140,000 are revealed by the telescope. As
+the power of the telescope is increased, so the number revealed is
+increased also, until by the time we have reached stars of the
+fourteenth magnitude, at least 20,000,000 are revealed to us.
+
+If we look into the heavens on a clear moonlight night, we shall further
+see that here and there are groups of stars clustered together. These
+clusters are termed constellations, and are named after some object
+which the arrangement of the stars seemed to suggest. Thus every one is
+familiar with that constellation known as the Great Bear, or the
+"Plough," so called because of its resemblance to a plough.
+
+The brightest stars of each constellation are named after the letters of
+the Greek alphabet, the brightest being called Alpha, the next in
+brilliancy Beta, and so on, right through the Greek alphabet. For
+example, the seven stars in the Great Bear are known as Alpha, Beta,
+Gamma, Delta, Epsilon, Zeta, and Eta.
+
+The constellations are grouped into two divisions, known as the Northern
+and Southern constellations respectively.
+
+The visible Northern constellations are 25 in number, and include the
+following well-known groups--
+
+    Ursa Major          The Great Bear.
+    Ursa Minor          The Little Bear.
+    Draco               The Dragon.
+    Hercules            Hercules.
+    Cygnus              The Swan.
+    Lyra                The Lyre.
+
+The visible Southern constellations are 18 in number, and include such
+groups as--
+
+    Cetus               The Whale.
+    Orion               Orion.
+    Canis Major         The Great Dog.
+    Canis Minor         The Little Dog.
+    Corona Australis    The Southern Crown.
+    Crux Australis      The Southern Cross.
+
+_Variable Stars._--Not only are the stars of different magnitudes, but
+the brilliancy of some of them changes from time to time. This class of
+stars is known as variable stars, and has received the attention of
+modern astronomers for many years, in order that the cause of their
+variation might, if possible, be ascertained. The periods of variation
+differ in length, ranging from a number of days to 60 or 70 years.
+
+One of the most interesting of variable stars is that known as Omicron
+Ceti, whose period of change is about 331 days. Its brilliancy varies
+from one of the second magnitude to one of the tenth.
+
+Beta Persei is another well-known variable star. This star shines as one
+of the second magnitude for 2 days and 13 hours, and then suddenly loses
+its light, and in less than 4 hours becomes a star of the fourth
+magnitude. Its brilliancy then increases again, and in a similar time it
+regains its former brilliancy.
+
+The conclusion that has been arrived at in regard to the cause of the
+variation of these stars is, that in each case the diminution of light
+is due to the existence of dark bodies, probably planets, which revolve
+round the central star.
+
+This hypothesis was confirmed by Professor Vogel about 1889 by means of
+spectroscopic results.
+
+Another interesting fact about stars is that they shine with various
+colours. The colours of stars are as various as the colours of the
+rainbow, and range through the whole spectrum, of red, orange, yellow,
+green, blue, indigo, violet, and white. What is more remarkable is the
+fact that the colours of the stars seem to change through great periods
+of time. If we turn to ancient records we learn that Sirius was red
+then, but is now green, while Capella was also red, but is now pale
+blue.
+
+_Double and Multiple Stars._--Many stars when looked at through powerful
+telescopes are found to be double, triple, quadruple, and even multiple,
+although when looked at by the naked eye, they seem to be single in
+appearance.
+
+An example of a double star is to be found in the constellation of Lyra.
+A moderate telescope reveals this as a double star, while a still more
+powerful telescope reveals the strange fact that each apparently single
+star which forms the double is itself double, so that we have in this
+constellation a system of four stars, in which each pair revolves round
+a point situated between them.
+
+Several thousand double stars are known altogether, while the motions of
+several hundreds of them have been detected with powerful telescopes.
+Some of the double stars are as follows--Zeta Hercules, Eta Coronae
+Borealis, Gamma Coronae Borealis, Beta Cygni, Alpha Centauri.
+
+The colours of some of the double stars are very beautiful. Some are
+yellow and blue; others, yellow and purple, while others are orange and
+green. Some of the double stars are only optical doubles, that is to
+say, they apparently seem close together, while as a matter of fact they
+are immense distances from each other, the apparent doubleness being due
+to the fact that they are more or less in the same line of vision. Real
+double stars, where the component stars are situated close together, are
+known as physical doubles, to distinguish them from the optical doubles.
+
+_Binary Stars._--Another class of double stars are known as Binary
+Stars. This class of stars is composed of two stars which revolve around
+each other in regular orbits, and are among some of the most interesting
+objects in the heavens. About 1000 Binary stars are known altogether.
+Their motions, however, are very slow, and only in a comparatively few
+cases have the dimensions of their orbits been ascertained. Some of the
+Binary stars are Zeta Hercules, which has a period of about 36 years;
+Eta Coronae Borealis, which has a period of 43 years; while the
+brightest star, Sirius, is also a Binary star, with a period of about 50
+years.
+
+_The Milky Way._--The Milky Way is the name given to that band of light
+which stretches across the sky at night-time, and forms a zone or belt
+that completely circles the celestial sphere.
+
+This belt of light has maintained from the earliest ages the same
+relative position among the stars, and, when resolved by powerful
+telescopes, is found to consist entirely of stars scattered by millions
+across the expanse of the heavens.
+
+The whole zone or belt is composed of nothing but stars, whose average
+magnitude, according to Herschel, is about the tenth.
+
+Stars of all magnitudes are, however, found in this zone.
+
+Of the brightest stars, about twelve are found in this region, while the
+majority of stars of the second, third, and fourth magnitudes are also
+found in or near it.
+
+The great majority of star clusters are also found along the course of
+the Milky Way, while many of the irresolvable nebulae seem to congregate
+near the poles of this starry region.
+
+The Milky Way is divided in one part of its course by a stream of stars,
+which seems to branch off as a separate stream, thus dividing it into
+two parts.
+
+All these facts seem to point to the conclusion that the stars of the
+universe, instead of being scattered about haphazard in the space, form
+a ring or layer, of which the thickness is very small compared with its
+length and breadth.
+
+Our own solar system, according to Herschel, occupies a place somewhere
+about the middle of the thickness of the zone, and near the point where
+it divides into two parts.
+
+Recent observations go to show that there is a tendency of the sun's
+apex to drift along the edge of the Milky Way, and this drift seems to
+point to a plane of motion of the sun, nearly coinciding with the plane
+of the Milky Way.
+
+
+ART. 118. _Stars and Kepler's Laws._--We have learned in a previous
+chapter that the sun is the centre of a system which comprises a retinue
+of planets, with their attendant satellites, together with a number of
+asteroids or minor planets, with the addition of meteors and comets to
+complete the system.
+
+Now if the sun is a star, then, according to our First and Second Rules
+of Philosophy, every star ought also to be the centre of a stellar
+system and the centre of two aetherial motions, that is, the Centrifugal
+and Centripetal forces, due to the pressures and tensions of the Aether
+medium. Further, every stellar system would be composed of exactly
+similar bodies to those which compose our solar system, as planets with
+their attendant satellites, together with meteors and comets; the whole
+of the stellar planets being bound to the central body by the
+combination of the two aetherial motions, and kept revolving round the
+central star by the rotating electro-magnetic Aether currents.
+
+Such a hypothesis is entirely philosophical, as it is simple in
+conception, and fully agrees with our experience in relation to the only
+star of which we have any complete knowledge.
+
+It is unthinkable to conceive of a star existing in so-called space, and
+constantly radiating out its light and heat for no purpose at all. All
+Nature teaches us that there is not a single thing in existence but what
+has a definite purpose, and a definite place to fill in the universe.
+Even the aetherial atoms, which form the foundation stones of the
+universe, have their own purpose to fulfil in the glorious scheme of the
+Universe conceived by the Eternal Infinite; and to suppose that a star
+has no purpose to fulfil, no task to perform, is to suppose something
+altogether opposed to the teaching of all Philosophy. Why even man, with
+his finite wisdom, would not be so foolish, so unwise, as to make a
+star, and set it in the firmament of heaven for no purpose at all! Are
+we therefore to suppose that the Divine Creator of all things possesses
+less wisdom than the creatures which He Himself hath made? Such an
+assumption would be a reflection not only on the wisdom of an All Wise
+Being, but would also be a reflection on our own ideas of philosophical
+reasoning.
+
+Therefore the conclusion that we are compelled to come to, in relation
+to the millions of stars that exist in interstellar space, is that every
+star is the centre of a stellar system, and the centre of two aetherial
+motions due to the pressures and tensions of the electro-magnetic
+Aether; while rotating round each star are the ever-circulating
+electro-magnetic Aether currents, which form the medium by which all the
+stellar planets with their attendant satellites are ever made to revolve
+around that central body which supplies them with their light and heat.
+Some such conclusion as this Sir John Herschel arrived at, for in his
+_Treatise of Astronomy_, Art. 592, he writes: "Now for what purpose are
+we to suppose such magnificent bodies scattered through the abyss of
+space? Surely not to illuminate our nights, which an additional moon of
+the 1/1000 part of our own moon would do much better. He must have
+studied astronomy to little purpose who can suppose man to be the only
+object of the Creator's care, or who does not see in the vast and
+wonderful apparatus around us, provisions for other races of animated
+beings. The stars, doubtless, are themselves suns, and may perhaps each
+in its sphere be the presiding centre around which other planets or
+bodies may be circulating."
+
+Further, with reference to the stability of each of these stellar
+systems, it is essential that the existence of a physical centrifugal
+force should be recognized, in order that the unity and harmony of the
+spheres should be maintained.
+
+Professor Challis points this out very conclusively in the _Phil. Mag._
+of 1859, where, writing on this point, he states: "It may also be
+remarked, that if the Law of Gravity be absolute, there is no security
+for the stability of a system of stars, whether the system be a Milky
+Way or a nebulous cluster. For, however small the mutual attraction
+between the constituent bodies may be, in the course of ages it must
+produce a general movement towards the centre or densest region. But the
+form of the Milky Way and of certain nebulae seems to present an utter
+contradiction to any such tendency." With the conception, however, of a
+physical centrifugal force or motion due to the pressure of a physical
+medium, the stability of even the Milky Way may be physically conceived
+and understood.
+
+Again, when we consider the sun as a star, we find that it has two
+motions of its own, one of rotation on an axis, and the other of
+translation in an orbit, such rotation being due to the fact that it is
+a magnet and has ever circulating round it electro-magnetic Aether
+currents (Art. 91). By inference, therefore, we arrive at the fact that
+every star is a magnet, as suggested by Professor Schuster, and
+possesses rotation on an axis, such rotation being due to exactly the
+same cause as produces the rotation of any other planetary or solar body
+(Art. 92). Not only has each star a rotation on its axis, but it must
+also possess translational motion in an orbit, and that orbital motion
+must be due to exactly a similar cause as that which produces the
+orbital motion of the sun. Are there any indications given by
+astronomical observations which lead us to the conclusion that stars do
+possess such orbital motions? The answer is unanimously in the
+affirmative; for, although all the stars and the constellations retain
+apparently the same relative position to each other, yet they are all in
+motion. The actual translational motion of the stars is termed proper
+motion, and has been calculated with more or less success in relation to
+many of the stars nearest to us. There are other motions of the stars
+known as apparent motions, which are easily noted by any observer. These
+apparent motions are due to the rotation of the earth on its axis, and
+its orbital motion round the sun.
+
+Nothing is more certain, however, than that careful astronomical
+observations have revealed the fact that stars have actual orbital
+motions of their own through space. In many cases the orbital velocity
+has been approximately ascertained.
+
+Halley discovered proper motions of certain stars as far back as 1715,
+when he found out, by comparing different observations, that Sirius,
+Arcturus, and Aldebaran had moved during the period which had elapsed
+since the respective observations were taken.
+
+More recent observations tend to confirm the fact that stars have indeed
+proper motions, due to their actual translation through space. It has
+been ascertained, for example, that Arcturus is travelling at least 54
+miles per second.
+
+The proper motion of the stars, however, only gives us an indication of
+their relative motion through so-called space. It does not tell us
+whether the star is apparently receding from the earth, or approaching
+it.
+
+Dr. Vogel has ascertained by a special system of photography in relation
+to the spectra of stars, that Rigel has a velocity away from the earth
+of nearly 39 miles per sec., Aldebaran of 30 miles per sec., and Capella
+of 15 miles per sec., while the Pole star is apparently approaching the
+earth at a rate of nearly 16 miles per sec.
+
+Now if all the stars move through space with varying velocities, as
+spectroscopic and telescopic observations seem to suggest, the question
+naturally confronts us as to what is the particular kind of orbit which
+each star completes? Is the orbit that of an ellipse, or a circle, or a
+parabola?
+
+That it must have some kind of orbit is obvious from the proper motions
+exhibited by the several stars. We have already learned from Arts. 107
+and 108 that the sun possesses an orbit, which orbit fulfils the first
+and second of Kepler's Laws.
+
+If therefore the sun, as representing all stars, is subject to Kepler's
+Laws, then, according to our Second Rule of Philosophy by which we base
+our hypotheses on our experience, we are compelled to come to the
+conclusion that every star which possesses any motion at all through
+space must also be subject to Kepler's Laws, and therefore must each
+possess a controlling centre around which they severally revolve. Kepler
+himself was of the opinion that the stars were subject to the laws which
+go by his name, and this view of the subject was also accepted by Sir
+William Herschel.
+
+Thus from philosophical considerations we affirm that each star, while it
+is itself the centre of a starry system, is also dependent upon and
+associated with some other body, to which it is held bound by the
+electro-magnetic Aether, and around which it is made to revolve by the
+circulating electro-magnetic currents associated with that central body.
+So that by philosophical reasoning we are led to view the whole of the
+innumerable stars that flood interstellar space, not as so many individual
+and isolated units, that have no relation to each other, but rather as
+parts of one great system, which in its entirety may form in its ultimate
+unity one harmonious whole, a universe.
+
+As we come to consider star clusters and nebulae, we shall see how this
+idea of unity seems to be manifested throughout all celestial phenomena.
+
+
+ART. 119. _Aether and Nebulae._--In addition to the host of stars that
+flood the infinite space, there are other celestial bodies that meet the
+gaze of the astronomer as the telescope is turned upon the heavens.
+
+These bodies, which are glowing masses of gaseous matter, are termed
+Nebulae. The word Nebulae signifies a cloud, but they are not clouds in
+the same sense as we apply that term to masses of vapour that exist in
+our own atmosphere. Sir Wm. Herschel did more towards the discovery of
+nebulae than perhaps any other astronomer, either before his time or
+since. His labours in the direction were completed and enlarged by his
+son, Sir John Herschel, who surveyed the Southern heavens in a way that
+had never been accomplished before.
+
+The result of the combined labours of the two Herschels has placed
+information of the nebulae at our disposal which is invaluable. Several
+thousands of different nebulae are now known to us, and as the telescope
+is improved and its powers increased, fresh nebulae are being added to
+the number. Like stars, nebulae vary not only in size, but also in
+colour, shape, and even in the materials of which they are composed.
+They also vary in brightness, the light from some being much fainter
+than the light from others.
+
+It has been estimated by Huggins that the light received from a nebula
+will not exceed the light of a sperm candle looked at from a distance of
+a quarter of a mile. It is thought by some astronomers that the light
+received from a nebula is indicative of the stage of development to
+which it has arrived. Where the light is faint, the nebulae are in their
+first stages of formation, and where it is brighter it is indicative of
+a more advanced stage of development. Thus nebulae may consist of
+nebulous matter in various stages of condensation, but they are not yet
+in that condition which corresponds to the condition supposed to exist
+in our sun.
+
+Nearly all the nebulae lie outside the Milky Way, so that it would seem
+as if in ages past all the nebulae that had ever existed in this starry
+zone had passed out of their nebulous condition and been further
+condensed into suns or stars, as they are called. Astronomical
+observations teach us that there are very few nebulae indeed to be seen
+in this starry highway, the part of the heavens which are richest in
+them lying far beyond the confines of this zone. For many years certain
+aggregations of luminous points in the heavens were supposed to be
+nebulae, but by the aid of more powerful telescopes they have now been
+resolved into clusters of stars. One of these clusters is the cluster in
+Hercules, while another is the great nebula of Orion. In the case of the
+former, situated in the constellation of Hercules, we find a great
+number of very small points of light grouped together in a more or less
+globular form. When looked at through a small telescope, this object
+looks like a nebula, but looked at through Lord Rosse's, or some other
+great telescope, it becomes at once resolved into an immense number of
+separate points of light, each one representing a star, there being
+between one and two thousand altogether in this constellation.
+
+Clusters of stars are usually globular in form, though some are
+irregular in outline. The latter are generally rich in stars, with a
+less condensation of stars towards the centre. Sir Wm. Herschel
+considered the irregular clusters as being in a less advanced stage of
+condensation, as he was of the opinion that all groups ultimately tended
+to clusters which were globular in form. Before dealing with the
+different kinds of true nebulae we will now consider the question as to
+"What are Nebulae?"
+
+
+ART. 120. _What are Nebulae?_--The question which presents itself to the
+mind of all astronomers when they have viewed the wondrous nebulae that
+exist in far-off space is, "What are Nebulae?" This question is so
+closely identified with the question as to "What is Matter?" that the
+solution of the one will give us the key to the solution of the other.
+It is now generally admitted, that nebulae are composed of a glowing
+mass of gaseous matter, that gaseous matter being partly composed of the
+gas Hydrogen. Dr. Huggins in 1864 first made the discovery of the
+existence of Hydrogen in certain nebulae by means of the spectroscope,
+which distinctly revealed certain lines that proved the existence of
+Hydrogen in the nebulae.
+
+In the spectra of some of the nebulae, that of 31 Andromeda, for
+example, there are no dark lines shown, but only a continuous band of
+bright light, which would seem to indicate that there was no glowing
+gaseous matter in that nebula at all. But accepting the fact that the
+nebulae are composed of glowing gaseous matter, the problem confronts us
+as to where this gaseous matter comes from.
+
+If, as spectrum analysis seems to teach us, there are nebulae in various
+stages of formation, there must be a period in their history of
+development when they had an origin. What, then, is the origin of a
+nebula, and what the physical explanation of that origin? From optical
+phenomena we learn that all space is not empty, but filled with the
+Aether which is universal (Art. 42). What is the relation, then, of this
+glowing nebulous matter to this universal Aether? If it be suggested
+that there is no relation, then we are in the unphilosophical position
+of having to admit, either that the nebulous matter of which the nebulae
+are composed never had any origin, or that it had its origin in some
+unknown and still undiscovered medium which exists in space. But both of
+these hypotheses are unphilosophical, as the former is contrary to all
+experience, while the latter is opposed to that simplicity of conception
+by which we only postulate one medium, the Aether, to fill all space.
+
+Thus we are led to the conclusion, that the gaseous matter, be it
+hydrogen or nitrogen, must have some relation to the electro-magnetic
+Aether that is so universal in its extent. Already this relationship has
+been dealt with by one who has done more for the development of
+aetherial physics than any other scientist. Lord Kelvin, in his paper
+"On the Clustering of Gravitational Matter in any part of the
+Universe,"[43] has solved this relationship, though in so doing he has
+had to depart somewhat from the idea of an incompressible Aether. In
+that paper he writes as follows: "If we consider Aether to be matter, we
+postulate that it has rigidity enough for the vibrations of light, but
+we have no right to say that it is absolutely incompressible. We must
+admit that sufficiently great pressure could condense the Aether in a
+given space, allowing the Aether in the surrounding space to come in
+towards the ideal shrinking surface." In another part of the paper,
+dealing with the same question, he writes: "In regions where the density
+was greater than in neighbouring regions, the density would become
+greater still; in places of less density, the density would become less,
+and large regions would quickly become void or nearly void of atoms.
+These large void regions would extend so as to completely surround
+regions of greater density." He then points out, that as soon as this
+density becomes something like the density of the atmosphere, then
+collisions would take place between the particles, and continues: "Each
+collision would give rise to a train of waves in the Aether. These waves
+would carry away energy, spreading it out through the void Aether of
+infinite space. The loss of energy thus taken away from the atoms would
+reduce large condensing clusters to the conditions of a gas in
+equilibrium under the influence of its own gravity, rotating like our
+sun or moving at moderate speed as in spiral nebulae. Gravitational
+condensation would at first produce rise of temperature, followed later
+by cooling, ultimately freezing, giving solid bodies, collision between
+which would produce meteoric stones such as we see them."
+
+Here then we have a definitive relationship between Aether and nebulae
+given to us from one of the keenest intellects of the present time, but
+in order for that relationship to become strictly philosophical, the
+conception of the Aether as advanced in this work must be accepted. For
+with the present conception of a frictionless Aether, such a hypothesis
+is altogether untenable, because it supposes something that is contrary
+to all experience and observation.
+
+On the basis of a condensing frictionless Aether into any kind of solid
+body, be it nebula, meteor, sun or star, we have to suppose that it is
+possible for a medium (the Aether, which is outside the Law of
+Gravitation according to the present theory) to be condensed into a
+body, that is, a nebula or meteor which is subject to the Law of
+Gravitation; and the question arises, at what point in the history of
+its condensation does this frictionless Aether pass out of the condition
+of having no weight, to the condition when it has weight; or, in other
+words, from the condition when it is outside the Law of Gravitation, to
+the condition when it comes under the Law of Gravitation?
+
+No satisfactory solution can possibly be offered to such a problem.
+Therefore one of two results must follow, either that the Aether is not
+frictionless, but possesses weight; or, that the condensation of the
+Aether is not possible. With the theory of Aether presented in this
+work, the whole question receives a simple and philosophical solution.
+As Aether is matter, it is therefore atomic; and being atomic, it is
+subject to the Law of Gravitation; and therefore, possessing mass and
+weight, it can readily pass into other forms of matter, and with such a
+conception Lord Kelvin's hypothesis becomes not only possible but
+probable. So that it is exceedingly probable that nebulae are nothing
+more nor less than condensed Aether, the same as comets were suggested
+to be condensed Aether. It may be asserted that such a hypothesis lacks
+that experimental evidence which is so necessary for its establishment,
+but I hope to show in the last chapter that Faraday has given the world
+that very experimental evidence which will place this hypothesis upon a
+firm and solid foundation, and enable it to pass out of the region of
+the hypothetical into the region of fact and experiment.
+
+According to our hypothesis, therefore, nebulae are simply condensations
+of the electro-magnetic Aether that exists in interstellar space, and
+the various spectra of the different nebulae indicate the stage of
+development to which the process has arrived. Where the spectra are
+bright, and continuous, and free from any dark lines, there we have
+simply the Aether in its very first stage of condensation; and where we
+have the dark lines appearing, such lines indicate a more advanced stage
+to which the process has arrived.
+
+[Footnote 43: _Philosophical Magazine_, July 1902.]
+
+
+ART. 121. _Nebular Hypothesis._--The Nebular Hypothesis was first
+introduced by Kant in his work on the _History of the Earth and Theory
+of the Heavens_.
+
+In that work he attempted to explain the origin of the universe on
+purely mechanical lines. Laplace, a French mathematician, about the same
+time came to similar conclusions as Kant had done, and published his
+views in his work on _Exposition du Système du Monde_, and later on in
+his more famous work the _Mécanique Céleste_.
+
+A feature common to both these theories rested in the fact, that they
+supposed that all material bodies which exist in the universe once
+existed in a nebulous condition, and that they were formed out of this
+nebulous matter. Further, that this nebulous matter gradually condensed,
+and as it condensed, a rotational motion was imparted to them, which
+rotation quickened as the condensation was continued.
+
+Then, as the rotation was accelerated, portions were flung off by the
+centrifugal force, and these portions of nebulous matter gradually
+condensed, forming the various planets of the system. As these
+condensed, they, in their turn, parted with some of their nebulous
+matter through the repulsive energy of the centrifugal force, and these
+secondary parts gave origin to the various satellites that exist round
+the planets.
+
+Now, while the general principle involved in the nebular hypothesis is
+true, yet the conception according to Laplace is not verified by fact,
+as we learn that Uranus and Neptune are still in a state of
+self-luminosity, while their density is the smallest of all the planets.
+From this we should infer that the two outermost planets are the
+youngest planets of our solar system, but according to Laplace's theory,
+they ought to be the oldest, as they would have been flung off first by
+the parent body as it rotated; and therefore, being flung off first,
+should be in a more advanced stage of development than any of the inner
+planets. M. Faye has suggested a remedy for this defect in the theory.
+He supposes that the nebulous matter out of which the planets were
+formed, was not flung off by the central body the sun, but that each
+planet was formed at different centres of condensation within the
+nebular mass that existed in space. This would, undoubtedly, meet the
+difficulty already referred to, and solves the problem as to how the
+various planets were formed at different distances in space.
+
+Further, such a solution is in perfect harmony with all the Rules of
+Philosophy. It is much more simple to conceive of Aether condensing at
+various points in what originally was the solar nebula, than it is to
+conceive of Aether condensing and shrinking towards one central point,
+and yet while condensing and shrinking, portions were flung off into
+space which would form the planet. A greater objection has to be met,
+when we come to deal with the origin of all the meteors and minor
+planets that exist in their numbers in the solar system. In relation to
+their origin, it is much easier to conceive of portions of the Aether
+condensing at different centres of condensation, than to suppose that
+each portion of aetherial matter that originally formed the meteor, or
+asteroid, was flung off as a separate portion from the central body.
+
+With the conception of an atomic and gravitating Aether, the Nebular
+Hypothesis, therefore, for the first time is placed upon a sound and
+philosophical basis, because the condensation of Aether, which is matter
+and possesses mass, admits of the origin of other matter from it which
+also possesses mass, together with other properties, as elasticity,
+density, compressibility and inertia.
+
+When there is added to the atomic Aether the conception of a rotatory
+aetherial atom, as was indicated in Art. 44, we have at once a source
+from whence the rotation of the whole mass may be derived. Thus, as the
+condensation continued, and the nucleus or central part of the body was
+gradually formed, the rotation would be accelerated, because of the
+inherent energy which would exist in the condensed part. Further, as the
+condensation continued, the body so formed would be more or less
+spherical in form, as the conception of our aetherial atom was
+spherical, and when we conceive of the primary point of condensation, we
+have to think of a large number of spherical atoms coming together; and,
+as all the motions of the Aether which give rise to light, heat,
+electricity and magnetism, and which now include gravitation, are
+spherical in their operations, so their effect upon any condensing
+Aether would take a spherical form. Thus such bodies as nebulae, comets,
+asteroids, satellites, planets and suns should possess bodies more or
+less of a spherical form, subject to certain qualifying conditions, as
+rotation and orbital velocity, and this is in harmony with observation
+and experience. For we shall find that even in the case of nebulae, we
+have globular, ring or annular nebulae, and elliptic nebulae, while in
+the case of comets, the nuclei and coma are more or less spherical.
+Further, it is a familiar fact that the shape of all asteroids,
+satellites, planets, and even the sun is spherical or that of an oblate
+spheroid, which latter is simply due to its rotational velocity on its
+axis.
+
+Thus the principle involved in the nebular hypothesis receives its
+confirmation in the atomic and gravitating Aether, and with certain
+modifications of the different hypotheses advanced, is capable of
+uniting all those hypotheses that have ever been put forth in this
+direction into one perfect and harmonious whole.
+
+Again, the condensation of the Aether, composed as it is of its atoms,
+ever in a state of rotation, does away with the Primitive impulse which
+was objected to in Art. 9. For in that article it was shown that the
+conception of a primitive impulse as conceived by Newton was
+unphilosophical, in that its conception was not simple, and failed to
+satisfactorily account for observed phenomena. With the hypothesis,
+however, of a rotatory aetherial atom, we have at once those conditions
+which at any time, in the history of the universe, may give rise to
+those conditions by which a body may be set rotating not only on its
+axis, but also revolving around some central body, as the process of
+condensation is continued.
+
+So that in the primordial and universal electro-magnetic Aether that
+exists in all space, we get those conditions which will not only give
+rise to the phenomena of light, heat, magnetism and electricity, but
+also those properties, qualities and motions by which are produced,
+maintained and perpetuated, the various bodies that exist in the Aether,
+which is at once the physical source and cause of the bodies.
+
+
+ART. 122. _Kinds of Nebulae._--Nebulae may be classified into the
+following groups--
+
+    1. Irregular Nebulae.
+    2. Ring and Elliptical Nebulae.
+    3. Spiral or Whirlpool Nebulae.
+    4. Planetary Nebulae.
+
+_Irregular Nebulae._--Of this class the most conspicuous are those in
+the constellations of Orion and Andromeda. So clearly defined are they,
+that they are oftentimes seen by the naked eye on a clear night, and are
+often mistaken for comets.
+
+The great nebula in Orion is one of the most noticeable objects in the
+heavens. It is noted for its size and brilliancy, and also for the
+successful observation which it has been subjected to from time to time.
+This large nebula is situated in that part of Orion which is occupied by
+several stars known as the Sword Handle. These multiple stars are known
+by the name of Theta. Around these multiple stars is to be seen the
+nebula, as though the multiple stars really were enveloped by the nebula
+extending for a great distance out into space. It is of a faint bluish
+colour, with the central parts possessing the greatest brilliancy. The
+suggestion arises in our mind as to whether the nebulae are in any ways
+indicative of the presence of the electro-magnetic aetherial field that
+each star undoubtedly possesses. We learned in Art. 88 that the sun is
+an electro-magnet, and that it possesses its electro-magnetic field. We
+have also seen in Art. 109 that the zodiacal light, which is to be
+observed in connection with our solar system, is really indicative of
+the presence of that electro-magnetic field, as it rotates round the
+central body. Now, if an observer were situated out in space, where the
+nebula of Orion is situated, and could look at our system with
+telescopes equally as powerful as those we possess, would not our sun
+present an equally nebulous light to them because of the presence of its
+electro-magnetic field?
+
+Conversely, if every star possesses an electro-magnetic aetherial field,
+as they undoubtedly do, then it seems only reasonable to infer that that
+electro-magnetic field possesses a nebulosity which corresponds with our
+zodiacal light. The fact that the spectra of the nebulae are continuous,
+revealing no dark lines, seems to indicate the purity of some of the
+nebulae, and that therefore they are free from all known elements.
+
+So that spectroscopic results seem to confirm this hypothesis, as the
+pure Aether that would surround every star, or multiples of stars, would
+certainly not reveal any dark lines by means of the spectroscope. Such a
+hypothesis, as to the real nature of a nebula, is entirely in harmony
+with the theory of the Aether presented in Chapter IV., because being
+gravitative it will surround each star or multiples of stars, and
+therefore be denser nearest to those stars, and being atomic, there will
+be a certain amount of nebulosity manifested by the denser parts of the
+medium, as is the case in our own solar system.
+
+_Ring or Elliptical Nebulae._--These forms of nebulae are so named from
+their ring-shaped appearance, sometimes being known as Annular Nebulae.
+The elliptical nebulae are usually classed with them, as they are
+supposed to be similar kinds of nebulae looked at edgeways. The best
+known of this class is that found in the constellation of Lyra, and
+known as 57M, which is the number of the star in Messier's catalogue of
+stars. It is small but well-defined, so that it looks more like a flat
+oval solid ring than a nebula.
+
+The central part is not entirely dark, but is filled up with a hazy
+light. Another annular nebula is that situated to the south-west of
+Lambda Scorpii. Sir J. Herschel[44] writes of it thus: "It is a delicate
+but well-defined annulus. The field is crowded with stars, two of which
+are nebulae. A beautiful delicate ring of a faint ghost-like appearance,
+about 40" in diameter, in a field of about 150 stars, of 11 and 12
+magnitude and under."
+
+Of the elliptical nebulae the best known is the one in the constellation
+of Andromeda, which goes by the name of 31M. It is visible on a clear
+night, and can be seen by the naked eye as a hazy light. There are
+several other elliptical nebulae, lying to the north-west of this great
+nebula.
+
+_Planetary Nebulae._--The planetary nebulae represent a number of minute
+objects visible in the heavens. They look like globes of a
+bluish-coloured gas and are sometimes mistaken for small stars. Sir J.
+Herschel writes about them as follows: "Planetary nebulae are very
+extraordinary objects. They have, as their name implies, a resemblance
+to planets, presenting discs, round or slightly oval, some being quite
+sharply defined, terminating in others a little hazy or softened at the
+border. They are comparatively rare objects, not more than 25 having
+been observed, and of these nearly three-quarters are in the southern
+hemisphere. Their disc is circular or slightly elliptic, with sharp,
+clear, and well-defined outline, having exactly the appearance of a
+planet with the exception only of its colour, which is full blue,
+varying somewhat upon green. M. Arago has surmised that they may
+possibly be envelopes shining by reflected light from a solar body
+placed in their centre, invisible to us because of its excessive
+distance."
+
+The suggestion which arises to our mind in view of the atomic and
+gravitating Aether is, that the planetary nebulae are exactly what their
+names imply, that is, nebulous matter around planets. We have already
+learned that each satellite and planet possesses an electro-magnetic
+field, which field takes more or less the shape of a spherical form, so
+that if there are planets existing in the far-off systems in space, as
+we are compelled to believe that there are, then they too would possess
+an electro-magnetic field, which would be composed of spherical
+envelopes surrounding the several planets. These planets would shine by
+reflected light, as suggested by M. Arago.
+
+The possession by the planet of the nebulous matter, which we have
+already suggested is composed of the denser parts of the Aether around
+the planet, would give to the planet a nebulous appearance which would
+satisfactorily account for the term already given. They would indeed be
+what Sir John Herschel suggested they were, viz, planetary nebulae.
+
+_Spiral Nebulae._--The Spiral, or Whirlpool Nebulae, are remarkable
+objects, and were first discovered by Lord Rosse with his six-foot
+telescope. One of the best examples of the spiral nebulae is that known
+as 51M. Small telescopes show this as two clusters, one of them being
+surrounded by a ring, at a distance, which is divided into two parts.
+Lord Rosse, however, found it to be really a spiral nebula, the ring
+running into a series of spiral coils of nebulous matter, the outlying
+parts being connected with the main part by curved bands.
+
+Huggins has found that the spectrum of this nebula is not gaseous. Other
+examples of this class are 99M and 33M. What these spiral or whirlpool
+nebulae are, is unknown, but, on the hypothesis of a condensing and
+gravitating Aether which is in a state of rotation, the spiral nebulae
+can be easily pictured. For, as the condensation goes on, rotation will
+set in, and if we can picture such a phenomenon taking place in a plane
+which is at right angles to the line of vision, then we should have a
+full view of a nebula which would present a spiral form. Indeed, there
+is no phenomenon in connection with nebulae that cannot be physically
+explained by a condensing, gravitating and rotatory Aether; and as
+Aether is universal, the same properties will apply to it in distant
+space as they do in the solar system; and apart from a gravitating and
+rotatory electro-magnetic Aether, the phenomena of our own solar system
+cannot be physically conceived or explained.
+
+Therefore, if such an Aether can explain the phenomena associated with
+our own system, it ought also to explain, and that to the fullest
+extent, all phenomena incidental to and associated with the innumerable
+systems that flood the universe at large.
+
+[Footnote 44: _Outlines of Astronomy._]
+
+
+
+
+                              CHAPTER XIV
+
+                           UNITY OF UNIVERSE
+
+
+ART. 123. _The Universe._--In the preceding chapters we have endeavoured
+to deal with some of the principal phenomena that help to give a
+mechanical conception to the entire Universe.
+
+It now remains for us to show, in this last chapter, how, underlying all
+the physical structure of the Universe, there is one fundamental and
+primordial medium, in which all the forms of matter and motion find
+their ultimate unity.
+
+The Universe literally means one ultimate whole, though that whole may
+be compounded of many parts, the very essence of the term embodying the
+idea of a complete unity which runs throughout its whole physical
+structure.
+
+Apart from some such hypothesis as will be suggested in this chapter,
+that ultimate unity is incapable of a physical or mechanical conception.
+In Art. 29 we learned that the Universe was composed of two classes of
+things, matter and motion, while in Art. 30 we learned that the sum
+total of matter according to the law of the conservation of matter ever
+remains the same; while further, in Art. 53, according to the law of the
+conservation of energy, the sum total of energy ever remains the same.
+We have also learned that the two are indissolubly united, so that
+wherever we found matter, whether that matter was in its atomic,
+molecular, planetary or stellar form, there, as its necessary complement
+and counterpart, was the ever-present and unceasing motion, in one or
+other of its many forms. Thus, throughout the entire Universe, we find
+the same two essentials ever working in unison and harmony.
+
+Nowhere in the realm of infinite space is there such a phenomenon as
+rest or absolute death. The ideal that seems to be the key of the
+Universe, is that continuity of motion which science teaches us is so
+inseparably connected with all matter. Grouped, however, here and there
+throughout the Universe are modifications of this aetherial matter,
+termed molecules, satellites, planets, suns, or stars, which
+modifications are, however, not so real and abiding as the
+electro-magnetic Aether from which they receive their physical origin.
+
+The physical character of the universe is progressive. Even in its
+ultimate unity there is no such thing as stagnation or standing still;
+for, while in some parts of the Universe new stars and suns and planets,
+yea, even new systems are being evolved out of the primordial Aether, in
+other parts of the Universe old stars and suns, with all their attendant
+planets and satellites, are passing on towards that final end, when they
+themselves will be again resolved into the original form of matter from
+which they were first made. This assertion is in perfect harmony not
+only with science, but also with revelation. For even revelation teaches
+us that all the stars shall grow old as doth a garment, and as a vesture
+shall they be folded up (Heb. i. 11), and that (out of their ruins) a
+new heaven and a new earth shall be created and the former shall not be
+remembered (Isaiah lxv. 17).
+
+Thus amid all the modifications of that which is the real physical basis
+of all matter, we find indissolubly associated with each and all of the
+varied forms and modifications certain motions which are analogous to
+each other. In the aetherial atom itself, so infinitesimal in its
+proportions that even our imagination is almost strained in our attempt
+to conceive it, yet even here we have rotation and translation in an
+orbit, such rotation and translation being due to the motions of the
+electro-magnetic Aether. Then in the gaseous forms of matter into which
+these atoms may be condensed, we find the same two essentials, of matter
+and motion, of rotation and translation in an orbit, always working
+harmoniously together, through the motions of the selfsame Aether, which
+gives rise to the attraction and repulsions of the atoms.
+
+Then following the principle into the planetary world, and taking the
+planet Saturn with its ring of satellites as an example, we find again
+the same two factors ever working in unison and in harmony, with their
+incessant rotation and translation in an orbit, forming a complete and
+perfect unity in themselves, such unity being due to the pressures and
+tensions of the Aether combined with its rotatory character. Then going
+a step further, we find a number of planets, with or without satellites,
+all rotating around one central body, that rotation and translation
+again being due to the motions of the rotating electro-magnetic Aether,
+combined with its pressures and tensions.
+
+For millions of years, so far as we can tell, this solar system of ours
+has been moving through space as one complete unit.
+
+Then out in stellar space there are millions of such systems, each
+distinct and perfect in themselves, each of which is made up of exactly
+similar parts to our solar system, these innumerable systems being
+doubtless joined together by the same electro-magnetic Aether, forming
+one larger and grander unity, known as a constellation. Then these
+constellations, increasing in their number, are again joined together,
+and form a still larger unity called a Galaxy; and galaxy being joined
+to galaxy, constellations to constellations, we get such an ocean of
+suns and stars like that known as the Milky Way, the ultimate whole
+revealing in all its beauty and harmony the unison of the two
+essentials of matter and motion. It may even be that all the oceans of
+suns and stars, that exist in far-off space, are joined together by one
+common bond, the universal electro-magnetic Aether by its two
+complementary motions, the centripetal and the centrifugal, the whole
+forming one ultimate unity which we call the Universe, having for its
+centre one common point or central orb, which indeed forms the centre of
+gravity of the entire Universe.
+
+Thus the key to the physical conception of the Universe is to be found,
+and alone found, in that beauty of order, and harmony of motion, which
+are so inseparably associated with the varied forms of matter,
+graduating through a series of units or atoms, each with its dual nature
+complete in itself, through a series of minor entities termed elements,
+which in their aggregations form meteorites, satellites, planets, suns
+and stars, and systems of stars and oceans of suns and stars, until all
+are united into one ultimate unity where all are blended into one
+complete and perfect whole; the whole of the universal fabric being held
+together in its mechanical order and beauty by the electro-magnetic
+Aether. Then in the very centre of the Universe there dwells that
+Supreme Being whom we call God, who is at once the one real fountain and
+source of all the light and life of the Universe itself. For it is His
+universal Spirit that moulds and fashions the plastic matter into the
+many forms which it assumes, and uses the various modes of motion, as
+heat, light, electricity and magnetism, as instruments to build up and
+erect in all their beauty and harmony the innumerable systems that flood
+immensity and space.
+
+For if there be a centre of gravity to an atomic system, and a centre of
+gravity to a planetary system, and a centre of gravity to a solar
+system, then there is also a centre of gravity to a group of systems,
+even to a constellation, or a galaxy; otherwise our philosophy relative
+to the centres of gravity of masses fails in its application to wider
+phenomena of an exactly similar kind.
+
+Thus, if there is a centre of gravity to a galaxy, even to the Milky Way
+itself, then, going one step further, with a faith that laughs at
+scientific data and leaps beyond the narrow bounds of pure reasoning, we
+affirm that there must even be a centre of gravity to the entire
+Universe. Now let me ask the reader, What can be more fitting, more
+appropriate, more reasonable than to infer that the centre of gravity of
+the Universe is to be found in that celestial orb or orbs where the
+throne of God exists and endures, and where ultimately there will be
+congregated together in perfect felicity the spirits of just men made
+perfect, not only from our insignificant planet, but all the spirits of
+all beings from all the planets which in their almost infinite number
+are circled round their central suns by the electro-magnetic Aether? It
+is there, in these bright orbs, with their vision and powers
+spiritualized, quickened and intensified, that all perfected spirits
+shall look out into space, with increasing wonder, upon the birth and
+decay of worlds, the evolution and devolution of planets and systems and
+constellations, and shall watch the continuation and working out of that
+grand and glorious plan, which alone finds its perfection and its
+ultimate fulfilment in the wisdom, and power, and glory of the Eternal
+Spirit of the Living God.
+
+To see if this conception of the Universe is borne out by scientific
+data, we will now address ourselves more particularly to those
+fundamental truths which underlie the unity of the Universe.
+
+
+ART. 124. _The Unity of the Universe._--The Unity of the Universe is a
+dream which has passed before the imagination of many philosophers in
+by-gone times, and has been a fruitful source of speculation to
+old-world, as well as more modern philosophers. The researches of such
+living scientists as Sir William Crookes, Professor J. J. Thomson and
+others, have, however, made this dream come within the range of
+practical research and direct experiment. Professor J. J. Thomson
+believes that it is possible to break off from an atom, a part which is
+only 1/1000 part of the whole, and these infinitesimal parts he has
+called corpuscles, which he considers are the carriers of the electric
+current.
+
+If, therefore, it can be philosophically proved that the hypothesis of
+an atomic, gravitating, and condensing Aether can satisfactorily account
+for the physical existence of all atoms, and therefore of all matter,
+the dream of old-world philosophers will be helped on its way to a
+successful realization.
+
+We have already suggested, that nebulae are formed out of the
+condensation of the electro-magnetic Aether that fills the Universe; and
+as that nebula, according to the Nebular Hypothesis, ultimately resolves
+itself into a sun, or planet, or satellite, as the case may be, it
+follows that the condensation of this electro-magnetic Aether forms the
+basis of all the various elements, as Hydrogen, Nitrogen, Oxygen and the
+other seventy elements of which those bodies are composed. Thus the
+conclusion that we are compelled to come to in regard to the ultimate
+nature of matter, in its primordial condition, is, that all matter which
+exists in its varied forms throughout the entire Universe finds its
+physical origin and source in the universal electro-magnetic Aether,
+which is itself atomic, and possesses all the essential properties of
+matter.
+
+With the conception of the Aether as advanced in this work, this
+hypothesis is perfectly philosophical and logical. For the conception is
+simple, in that it supposes one form of matter to spring out of another
+form, that is, from an aetherial form to gaseous, in a similar manner to
+that in which a gaseous form changes into a liquid form, that is, by
+condensation, or a closer drawing together of the aetherial elastic
+envelopes that surround each atom; each particular gas, as Hydrogen,
+Nitrogen, or Oxygen, representing different quantities of aetherial
+condensations, as will be seen in the next article.
+
+The aetherial constitution of matter has received recognition from the
+hands of such scientists as Lord Kelvin and Dr. Larmor. The latter, in
+his _Aether and Matter_, writes on the subject as follows (page 7):
+"Matter must be constituted of isolated portions, each of which is of
+necessity a permanent nucleus or singularity in and belonging to the
+Aether, of some such type as is represented for example by a minute
+vortex ring in a perfect fluid, or a centre of permanent strain in a
+rotational elastic medium." And again on the same page he adds: "It is
+incumbent on us to recognize an aetherial substratum of matter, in so
+far as this proves conducive to simplicity and logical consistency in
+our scheme of physical relations, and helpful towards the discovery of
+hitherto unnoticed ones."
+
+Dr. Larmor, as has already been pointed out in Art. 44, speaks of his
+aetherial atoms as electrons, which are of two kinds, negative and
+positive, and of these he states (page 97): "Each electron has an
+effective mass of aetherial origin, which forms part, and may be the
+whole of the mass of the matter to which it is attached."
+
+Here, then, we have definite statements as to the hypothesis of all
+matter having a definite aetherial origin. If, therefore, it can be
+proved experimentally that matter does possess this aetherial basis,
+then the hypothesis will pass out of the region of speculation into the
+region of fact and science.
+
+The question, therefore, suggests itself to our mind, as to whether
+among all the experiments that have ever been performed by any
+scientist, there are any which will conclusively confirm and establish
+the hypothesis as to the aetherial origin of all matter. In my opinion
+there are such experiments, which have been given to the world by such
+eminent scientists as Faraday and Sir Humphry Davy. Before, however, the
+value of their experiments can be rightly understood and valued, we
+shall have to ask ourselves another question, and that is, "What is the
+relation of Aether to electricity?" Upon the correct answer to this
+question depends the application of Faraday's experiments to the
+hypothesis of the aetherial constitution of all matter, and therefore of
+the great underlying principle of the unity of the Universe.
+
+Is there any relation therefore between Aether and electricity? If so,
+what is that relation, and to what extent does it hold good? Professor
+Lodge, in his preface to _Modern Views of Electricity_, asks a similar
+question. "Electricity," he states, "has been thought to be a form of
+energy, it has been shown to be a form of Aether. There remains the
+question, What is Aether?"
+
+While again he writes: "A rough and crude statement adopted for popular
+use is that electricity and Aether are identical. But that is not all
+that has to be said, for there are two opposite kinds of electricities,
+and there are not two Aethers. But there may be two aspects of one
+Aether, just as there are two sides to a sheet of paper."
+
+That there is a definite relation between Aether and electricity is as
+certain as there is a definite relation between electricity and light.
+In order to find out how far the relationship and identity between
+Aether and electricity extend we will review our conception of the
+Aether as given in Chapter IV. According to the conception advanced in
+that chapter, on the hypothesis that Aether was matter, we
+philosophically came to the conclusion that Aether was atomic, and
+therefore gravitative. Because it was gravitative, it possessed density,
+and varying degrees of density; and having mass, it possesses the
+property of inertia the same as any other matter; and was also elastic.
+
+We have now to add to these properties that of compressibility, which
+property we have ascribed to it from philosophical considerations when
+dealing with comets, and nebulae, and the origin of planets and
+satellites. Now, if there is any identity between Aether and
+electricity, then it follows that that identity will be more or less
+manifested, as we find electricity possessing more or less of the
+properties which have been ascribed to the electro-magnetic Aether. For,
+if we find two apparently different substances, or entities, possessing
+exactly the same properties, and occupying the same space at one and the
+same time, then the only logical conclusion that we can come to is, that
+these two apparently different substances are not two substances, but
+one.
+
+We have already proved that they both occupy exactly the same space,
+that is, they occupy the planetary and interstellar regions of space,
+and fill indeed the entire Universe. The electro-magnetic theory of
+Light (Art. 78) indisputably proves this. We will therefore find out if
+electricity possesses the properties which have already been ascribed to
+the Aether. The first property, and indeed the fundamental property, of
+Aether is that it is atomic, and upon the atomicity of the medium
+depends the whole of the theory as worked out in relation to heat,
+light, electricity and so-called gravitational phenomena. Is there
+anything about electricity that can suggest the hypothesis that
+electricity is atomic? The answer is unquestionably in the affirmative.
+Many of the greatest scientists of the past and present century have
+believed and worked at the hypothesis of the atomic character of
+electricity, and none more so than Dr. Larmor in his _Aether and Matter_
+and Professor J. J. Thomson.
+
+Now what is Dr. Larmor's opinion as to the atomicity of electricity?
+These are some of his statements quoted in the work. In the very first
+words of his preface he writes:[45] "The following essay was originally
+undertaken mainly as a contribution towards the development of the
+standpoint which considers electricity, as well as the matter, to be
+constituted on an atomic basis." He continues: "Since Faraday's work on
+Electrolysis, the notion of the atomic constitution of electrification
+in its electro-chemical aspect has never been entirely absent." While
+later on he adds: "Thus, for example, the present view of the atomic
+character of electricity, which is at length coming within the scope of
+direct experiment, has been in evidence with gradually increasing
+precision ever since theoretical formulations were attempted on the
+subject."
+
+We are, however, possibly indebted to Professor J. J. Thomson for the
+most direct experimental evidence as to the atomic nature of
+electricity, for, as is well known to scientists, he has discovered what
+he termed corpuscles, in association with electricity, which he makes
+the carriers of the charges involved in electrical phenomena.
+
+Here, then, we have one proof of the identity that exists between Aether
+and electricity, in that while they both fill the same space, they are
+both equally atomic; Dr. Larmor's ultimate atom, as we have already
+seen, being known as positive and negative electrons. Aether, we also
+learned, was gravitative (Art. 45), but we have since learned that
+gravitation is itself an electrical phenomenon, in that both the
+centripetal and centrifugal forces are due to the repulsions and
+attractions or pressure and tension of this electro-magnetic Aether.
+
+So that when we affirm that Aether is gravitative, we do but affirm it
+is subject to the laws of electricity, which govern all electrical
+phenomena, and therefore we might just as truly affirm that electricity
+is gravitative, because such an affirmation is simply another way of
+saying that electricity gives rise to the attractions and repulsions
+incidental to, and associated with, all electrical phenomena. Here,
+again, we have further evidence of the identity that exists between
+Aether and electricity.
+
+Then we learned that Aether possessed density, and also different
+degrees of density, and the question arises as to whether there is
+anything corresponding to this property in electricity. As a matter of
+fact, this very property of density is itself recognized and known to
+all scientists by the term Electric Density, the electric density being
+always proportionate to the charge of electricity on a given area.
+
+We learned also in Art. 79 that aetherial density and electrical density
+were identical in relation to solar and planetary space; so that,
+wherever there was the denser Aether, there was also the denser
+electricity, the density of the one increasing or decreasing exactly in
+the same ratio as the other increased or decreased. From aetherial and
+electrical density, therefore, we have another proof of the close
+identity that exists between Aether and electricity.
+
+Again, we learned (Art. 48) that Aether possessed inertia. Here at
+least, it may be thought, we shall find the first point of difference
+between the two entities. Surely such an intangible, aetherial
+manifestation as electricity cannot possess inertia. Let us see what
+Professor Lodge has to say on the subject. In the chapter on electrical
+inertia he writes (p. 89, par. 365 of _Modern Views of Electricity_): "A
+current does not start instantaneously: it takes a certain time, often
+very short, to rise to its full strength; and when started it tends to
+persist, so that if its circuit be suddenly broken, it refuses to stop
+quite suddenly, and bursts through the introduced insulating partition
+with violence and heat. It is this ram or impetus of the electric
+current which causes the spark seen on breaking a circuit; and the more
+sudden the breakage, the more violent is the spark apt to be. We shall
+understand them better directly; meanwhile they appear to be direct
+consequences of the inertia of electricity; and certainly if electricity
+were a fluid possessing inertia it would behave to a superficial
+observer just in this way."
+
+From these statements we learn then that electricity does possess
+inertia, although there are other phenomena of electricity that would
+destroy the hypothesis. But undoubtedly an electric current possesses
+momentum, and it is philosophically impossible to associate momentum
+with any body that does not possess inertia, as one of the factors of
+momentum implies mass, even though it be a mass of an infinitesimal
+form, and mass is the very essence of the property of inertia (Art. 40).
+
+Dr. Larmor, in the work already referred to, dealing with the subject
+of electric inertia, explains that it is concentrated at the nucleus of
+the electron (p. 230), while on p. 202 he states: "Each electron as it
+is moved by the aetherial displacement belonging to the radiation,
+resists with its own definite inertia."
+
+Apart from this evidence, the philosophical evidence already adduced in
+Chapter X. is altogether in favour of the fact that electricity
+possesses inertia. So that we may say that, though the evidence as to
+the identity of electrical and aetherial inertia is not fully complete,
+the balance of opinion lies in favour of the identity rather than
+otherwise. See _Appendix A_.
+
+It can further be demonstrated that electricity possesses elasticity the
+same as the Aether does. The charge and discharge of a Leyden jar are
+conclusive evidence of the elasticity associated with electrical
+phenomena, while further proof is to be found in the fact that Dr.
+Larmor attributes elasticity to his electrons, such elasticity being of
+a rotational type.
+
+The identity, therefore, that exists between Aether is now almost
+complete. We have now only to prove that both are compressible, and the
+identity is fully established. This will be done by reference to certain
+of Faraday's experiments before the conclusion of this article. As we
+have established, logically, the identity that exists between Aether and
+electricity, the question arises now as to whether they are not one and
+the same medium. If they are not one and the same medium, then we are in
+the distinctly unphilosophical position of having to admit that all
+interplanetary and interstellar space are filled at one and the same
+time by two different media, and such an assumption is directly opposed
+to all observation and experience.
+
+Therefore, to be strictly philosophical, one of these media must be done
+away with, and we may either assert that interplanetary and interstellar
+space is filled with electricity, or else it is filled with Aether, as
+it is much simpler to conceive of space being filled with one medium,
+than it is to suppose it to be filled with two media, which are
+absolutely identical in all their characteristic properties and
+functions. Both can give rise to exactly the same kind of phenomena,
+whether they are the phenomena of heat, light, electricity, or
+magnetism, and even gravitation itself. So that, if Science wishes to be
+distinctly philosophical in her statements in future, it will be
+necessary, it seems to me, to do away either with the Aether, or with
+the electricity, and as the latter is the better known entity, I am of
+the opinion that Science will retain the electric conception of space
+and matter, and do away with the aetherial, as being altogether
+unnecessary. See _Appendix B_.
+
+Thus are we led to the conclusion that electricity is itself a form of
+matter, as indeed it must be if it is atomic, as suggested by Dr. Larmor
+and Professor Thomson.
+
+Professor Lodge, on p. 9 of the work already referred to, states:
+"Electricity in this respect behaves just like a substance;" and again,
+p. 313, he writes: "We cannot assert that it is a form of matter,
+neither can we deny it; on the other hand, we certainly cannot assert
+that it is a form of energy, and I should be disposed to deny it. It may
+be that electricity is an _entity per se, just as matter is an entity
+per se_."
+
+Whether electricity be a form of matter or not, as I believe it
+undoubtedly is, we have arrived at the fact, in view of the identity
+between Aether and electricity, that, wherever the one is present, the
+other is present also. So that if it can be demonstrated by direct
+experiment that matter can be changed into its equivalent quantities of
+electricities, or that equivalent quantities of electricities could
+produce their equivalent forms of matter, then the electrical basis of
+matter, and consequently the aetherial basis of matter, are proved
+beyond contradiction, and we are thus led one step nearer to the
+ultimate unity of the Universe, which unity is to be found in the
+universal electro-magnetic Aether, which is identical with universal
+electricity. For if Aether be the basis of all modes of motion, as heat,
+light, and gravitation, and it is identical with electricity, it follows
+that electricity is equally the basis of all the varied phenomena, and
+if to that we add the constitution of matter itself, then we are within
+sight of the medium in which the ultimate unity of the Universe is to be
+found.
+
+This view of the subject has already been dealt with by a German
+scientist, Professor Vogt, in his book on _The Nature of Electricity and
+Magnetism_, a book, however, which is not translated into English. In
+that work I believe he shows the possibility of all matter having its
+origin in electricity; and if that be so, then that theory is really
+identical with an aetherial basis of matter, seeing that Aether and
+electricity philosophically seem to be one and the same medium. Let us
+therefore turn to Faraday's experiments, and see what they teach us on
+the subject of the electrical basis of matter, and therefore the
+aetherial basis at the same time.
+
+In paragraph 852 of his _Experimental Researches_ Faraday writes: "The
+theory of definite electro-chemical action appears to me to touch upon
+the absolute quantity of electricity, or electrical power, belonging to
+different bodies. Although we know nothing of what an atom is, yet we
+cannot resist forming some idea of a small particle which represents it
+to our mind, and though we cannot say what electricity is, so as to be
+able to say whether it is a particular _matter or matters_, or mere
+motion of ordinary matter, yet there is immensity of facts which justify
+us in believing that the atoms of matter are in some way endowed or
+associated with electrical powers to which they owe their most striking
+qualities, and amongst them their chemical affinity. As soon as we
+perceive, through the teaching of Dalton, that chemical powers are
+(however varied the circumstances in which they are exerted) definite
+for each body, we learn to estimate the relative degree of Force which
+resides in such bodies; and when upon that knowledge comes the fact that
+electricity, which we appear to be capable of loosening from its
+habitation for a while, or conveying from place to place, whilst it
+retains its chemical Force, can be measured out, and being so measured,
+is found to be as definite in its action as any of those portions which,
+remaining associated with the particles of matter, give them their
+chemical relation, we seem to have found a link which connects the
+proportion of that belonging to the particles in their natural state."
+
+Then in paragraph 855 he writes as follows: "It seems a probable and
+almost a natural consequence, that the quantity which passes is the
+equivalent of, and therefore equal to, that of the particles separated,
+_i. e._ that if the electrical power which holds the elements of a grain
+of water in combination (or which makes a grain of oxygen and hydrogen,
+in the right proportions, unite into water when they are made to
+combine) could be thrown into the condition of a current, it would
+exactly equal the current required for the separation of that grain of
+water into its elements again."
+
+Further, in Art. 857, he states, "I can have no doubt that, assuming
+hydrogen as 1, and dismissing small fractions for the simplicity of
+expression, the equivalent number or atomic weight of oxygen is 8, of
+chlorine 36, of bromine 78.4, of lead 103.5, of tin 59, etc.,
+notwithstanding that a very high authority doubles several of these
+numbers." Then, writing upon the definite relationship of
+electro-chemical equivalents, he states, Art. 835: "Electro-chemical
+equivalents are always consistent; _i. e._ the same number which
+represents the equivalent of a substance _A_, when it is separating from
+a substance _B_, will also represent _A_ when separating from a third
+substance _C_. Thus 8 is the electro-chemical equivalent of oxygen,
+whether separating from hydrogen or tin or lead; and 103.5 is the
+electro-chemical equivalent of lead, whether separating from oxygen or
+chlorine or iodine."
+
+So that from Faraday's experiments we learn definitely that the
+electro-chemical equivalents coincide with and agree with the ordinary
+chemical equivalents according to Dalton's theory. From these
+experimental results of Faraday's we therefore learn that Faraday was of
+the opinion that each atom had a definite and certain quantity of
+electricity associated with it; and if this be true, then, in view of
+the identity of Aether with electricity, it follows that each atom must
+have definite and certain quantities of Aether associated with each
+atom. So that through Faraday's experimental researches we are again led
+to the hypothesis enunciated by Lord Kelvin in his paper "On the
+Clustering of Gravitational Matter in any part of the Universe," viz.
+that all matter has an aetherial, that is, an electrical basis, and that
+it is by the condensation of this electricity, and combinations of the
+condensational particles, that all the various elements are formed which
+compose the infinite variety of forms that constitute the entire
+Universe. Here, then, it seems to me, we have the evidence which gives
+to the aetherial Nebular Hypothesis (Art. 121) that experimental
+evidence which places that hypothesis upon a firm and philosophical
+foundation, and conclusively proves that it is possible for Aether out
+in the colder regions of interstellar space to be condensed into masses
+of gaseous matter, which form nebulae, and other masses in the cold
+regions of interplanetary space to condense and form comets and meteors.
+
+[Footnote 45: _Aether and Matter._]
+
+
+ART. 125. _Physical Constitution of Matter._--In Art. 31 we learned that
+all matter was made up of minute parts called atoms. When these atoms
+enter into combination with each other, they form the smallest particles
+of elementary substances as well as compound bodies, these particles or
+bodies being termed molecules.
+
+A molecule, therefore, may consist of any number of atoms of the same
+element, or may be formed of the union of the atoms of two different
+elements. In the preceding article we have learned that the atom of
+hydrogen or carbon, however, is divisible, at least theoretically if not
+experimentally, as we came to the conclusion that all atoms are composed
+of infinitesimal aetherial atoms, which are synonymous with atoms of
+electricity.
+
+Whether we shall ever be able to experimentally prove the existence of
+such an atom remains to be seen, though Dr. Larmor states that the
+atomicity of electricity is coming within the scope of direct
+experiment; while the researches of Professors Crookes and J. J. Thomson
+have undoubtedly given direct evidence of the existence of corpuscles,
+which are part of the atoms of the various elements.
+
+When we try to conceive, however, of the manner in which the various
+elements can be formed from one primary medium, that is, the Aether or
+electricity, we find it difficult to arrive at a simple physical
+conception of the process involved.
+
+We are indebted to Professor J. J. Thomson for what is practically the
+only simple physical conception of the method in which various elements
+may be formed from that medium, which gives unity to the whole of the
+universe. In the Adams Prize Essay of 1883 Professor Thomson indicated a
+theory based on the vortex atom (Art. 43) which satisfactorily accounted
+for the various laws which governed gaseous matter, and also showed how
+the varied chemical combinations might be physically conceived as being
+produced from one primary medium.
+
+In this theory we have to conceive of the vortex atom as possessing a
+hollow core, while in our conception of an aetherial atom (Art. 43) we
+conceived it as being more of a spherical or globular form than
+ring-shaped. We have, then, to consider the atom of any element as being
+composed of a vortex ring of various thickness, the thickness of the
+ring being an indication of its atomic weight.
+
+Each vortex ring must also be conceived as itself being composed of a
+number of aetherial atoms, or atoms of electricity, the number of such
+atoms being proportionate to the respective atomic weights of the
+various elements. Dr. Larmor suggests that a vortex ring may have this
+constitution in his work on _Aether and Matter_.
+
+According to Professor J. J. Thomson, then, any vortex ring, which we
+have supposed to be constituted of aetherial atoms, or atoms of
+electricity, may unite with any other vortex ring, thus producing a
+vortex ring of double density, which would possess double the
+electricity of the unit vortex ring. If we united three vortex rings,
+then the result would be an atom of threefold the density and strength
+of the unit vortex ring.
+
+We might conceive of four or any number of these rings uniting together
+to form a separate element, and then each element would simply be a
+multiple of the unit vortex ring, and so possess regular multiples of
+the atoms of electricity, each multiple representing a distinct element.
+
+We will now let Professor Thomson speak for himself on the matter, and
+will describe the theory in his own words, always keeping in mind the
+hypothesis that the unit vortex ring is itself composed of a definite
+number of atoms of electricity or electrons, as proved by Faraday. See
+_Appendix C_.
+
+In the work already referred to, Professor Thomson states: "We may
+suppose that the union or pairing in this way of two vortex rings of
+different kinds is what takes place, when two elements of which these
+vortex rings are atoms combine chemically; while, if the vortex rings
+are of the same kind, this process is what occurs when atoms combine to
+form molecules. Now let us suppose that the atoms of different chemical
+elements are made up of vortex rings, all of the same strength, but that
+some of these elements consist of only one ring, others of two rings
+linked together, others of three loops, and so on. Then if any of these
+rings combine to form a permanent combination, the strength of all the
+primaries in the system so formed by the combination must be equal."
+
+"Thus an atom of one element may combine with another atom of the same
+kind, to form a molecule of that substance consisting of two atoms.
+Again, three of these atoms may combine, and form a system consisting of
+three primary elements, but the chance of their doing so is small
+compared with the chance of two pairing; so that the number of systems
+of this kind will be small compared with the number of the systems
+consisting only of two atoms. We might have systems of four atoms, but
+the number would be small compared with the number of systems that
+consist of three atoms."
+
+"Now, suppose that an atom of one element is to combine with an atom of
+another. Suppose, to fix our ideas, that the atom consisting of two
+vortex rings linked together, is to combine with an atom consisting of
+one vortex ring; then, since, for the stability of connection, the
+strength of all the primaries which form the components of the compound
+must be equal, the atom consisting of two links must unite with
+molecules containing two atoms of the one with one link. Thus the
+compound formed will be the simplest combination, consisting of one of
+the atoms which consist of two vortex rings linked together with two of
+the atoms consisting of only one vortex ring. Similarly, if an atom
+consisting of three vortex rings linked together were to combine
+directly with atoms consisting of only one vortex ring, the compound
+formed would consist of the three linked atoms with three of the others,
+and so on for all the combinations of atoms formed by any number of
+vortex rings linked together. This suggests that the elements, called by
+the chemists monads, dyads, triads and so on, consist of one, two, etc.
+vortex rings linked together, for then we should know that a dyad could
+not combine with less than two atoms of a monad to form a stable
+compound, or a triad with less than three, and so on, which is just the
+definition of the terms monad, dyad, triad."
+
+"On looking at chemical combination from this point, we expect to find
+that such compounds as Hydrochloric acid, where one atom of Hydrogen has
+only to meet one atom of Chlorine; or water, where one atom of Oxygen
+has only to meet two atoms or a molecule of Hydrogen, would be much more
+easily and quickly formed than a compound such as ammonia gas, to form
+which an atom of Nitrogen has to find itself close to three atoms of
+Hydrogen at once."
+
+"It is the case, I believe, in direct combination, that simple compounds
+are formed more quickly than compound ones. We might call the ratio of
+the number of links in the atom of any element, to the number in the
+atom of Hydrogen, the Valency of the element. Thus the compounds H-CL,
+H-I, H-F, show that the atoms of Chlorine, Iodine, Fluorine have the
+same number of links as the atom of Hydrogen, so that the valency of
+each of these elements is unity. From the compound H_{2}O we infer that
+the atom of Oxygen consists of twice as many links as the atom of
+Hydrogen. The compound H_{2}S indicates that the atoms of Sulphur have
+twice as many links as the atom of Hydrogen."
+
+"The molecules CO_{2} and Marsh Gas have each three primaries
+represented by C-O-O and C-H-H respectively. According to the view we
+have taken, atomicity corresponds to complexity of atomic arrangement,
+and the elements of high atomicity consist of more vortex rings than
+those whose atomicity is low."
+
+"Thus high atomicity corresponds to complicated atomic arrangement, and
+we should expect to find the spectra of bodies of low atomicity much
+simpler than those of high. This seems to be the case, for we find that
+the spectra of Sodium, Potassium, Lithium, Hydrogen, Chlorine, which are
+all monad elements, consist of comparatively few lines."
+
+Here then, on the vortex theory of matter, especially when that vortex
+theory is given an electric basis, as is the case in Dr. Larmor's
+electron theory, we have a thinkable and logical explanation of the
+physical and chemical properties of matter, by which all elements and
+compounds may be formed from the primordial aetherial or electric atom.
+As all Nature is composed of about seventy elements, and it has been
+conclusively demonstrated that an atom of Hydrogen is the same all over
+the universe, no matter whether it exists on this planet, or in some
+distant star or nebula, we arrive at the conclusion that all the other
+elements are exactly the same in their properties and qualities wherever
+they are found. If, therefore, we couple Faraday's experiments and
+results as to the electro-chemical equivalents of all atoms, with this
+theory of Professor J. J. Thomson's, then we are again compelled to come
+to the conclusion that the unity of the universe in all its
+universality, and infinite variety of forms and modes of matter, is to
+be found, and alone found, in the universal Aether, which is co-existent
+and coextensive with electricity.
+
+
+ART. 126. _Quod Erat Faciendum._--Before concluding this work let us
+briefly review the whole of the theory submitted herein to the reader.
+
+That which was to be done consisted primarily in ascertaining the
+physical cause of Gravitation, by which would be accounted for on a
+philosophical basis all the phenomena incidental to and associated with
+the Law of Gravitation. Such phenomena included the physical cause of
+the Centripetal and Centrifugal Forces, the physical cause of Kepler's
+Laws, together with a physical conception of the application of Newton's
+Laws of Motion to all solar and stellar bodies. In addition to this,
+there were other outstanding problems in physics that it was premised
+would receive either a partial or an entire physical explanation. It was
+premised, for example, that the problem of the relative motion of Aether
+and matter would be solved, that the cause of the permanent magnetism of
+the earth would be revealed, and the great problem of the constitution
+of matter attacked, together with the unity of the universe which arose
+from that conception.
+
+In order, however, for any theory to be philosophical in its initial
+stages, the rules of some of the greatest philosophers which govern the
+making of any hypotheses were briefly outlined, and were found to
+resolve themselves into three divisions.
+
+The first rule dealt with the general simplicity of Nature's mode of
+working, and therefore the general simplicity which must govern our
+hypotheses in perfecting any theory as to the cause of all phenomena,
+gravitational or otherwise.
+
+The second rule showed that the only sound basis from whence we could
+derive all our data upon which to speculate and reason, lay in our
+experience of all natural phenomena. Whatever else we might do, or not
+do, it was absolutely necessary, if we wished to be perfectly
+philosophical in our conclusions, that we should not traverse the direct
+results of observations and experiments.
+
+The third rule laid down was the obvious axiom, that the theory so
+perfected by logical reasoning must satisfactorily account for and
+explain all the phenomena sought to be explained.
+
+Now I wish to submit the whole theory as propounded in this work in its
+completion and in its entirety to the reader, and to ask him if the
+Rules of Philosophy have not been adhered to throughout the whole work?
+Can any theory be more simple than the one submitted in this work, by
+which we have endeavoured to account for all, and even more, than was
+premised in the opening chapters?
+
+The very simplicity of the fundamental hypothesis that Aether is matter,
+in all its properties and qualities, has been the chief obstacle to the
+retardation of its earlier discovery.
+
+Any proposition more simple, more easy of comprehension, is, to my mind,
+difficult of conception. Why, children in our homes and schools may be
+taught the truth, and grasp it in its concrete form, and that is the
+highest test of the simplicity of any hypothesis.
+
+Thus the first Rule of Philosophy is satisfied and fulfilled in the
+initial hypothesis, and I venture to affirm that the same simplicity has
+characterized the development of the theory throughout its entire
+progress. Step by step, simple facts and simple truths which are known
+to any ordinary student have been shown to have a wider and more
+universal application than even the writer dreamed of, when he started
+out on his voyage of discovery in philosophical research.
+
+When we consider the second Rule of Philosophy in its application to our
+theory, we find that experience, as revealed by observation and
+experiment, is fulfilled to the minutest detail. The simple hypothesis
+that Aether is matter, fulfils to the very fullest extent all
+requirements demanded by the experience of all the scientists and
+experimentalists that the world has ever known. To assert that Aether is
+not matter is to assert a proposition contrary to all the accumulated
+experience of the past generations. Therefore, if Aether is matter, then
+its fundamental qualities must be those which belong to and are
+associated with all matter, those qualities being atomicity, gravity,
+density, elasticity, inertia, and compressibility.
+
+The objector to this statement is himself violating the chief rule of
+all philosophy, in that he is going contrary to the tenor and teaching
+of his own experience. Then, following out the second rule step by step
+we arrive at the one grand central truth, that electricity is also a
+form of matter, and that all the forces of the entire universe are but
+different modes of motion, different vibrations of the universal
+electro-magnetic Aether; while all the varied bodies that exist are
+themselves but different manifestations in a gaseous, liquid, or solid
+form of the same electro-magnetic substance.
+
+Thus, step by step, we have tried to build up a theory of the physical
+cause of all phenomena, which will satisfactorily account for those
+phenomena, and even for the structure of the universe itself, from the
+mechanical standpoint, and by so doing have fulfilled the third Rule of
+our Philosophy as enunciated by Newton and others.
+
+So that by the conception that Aether is matter, in its primordial
+state, we have more than fulfilled all that was premised should be done.
+
+Thus the long-sought-for and long-expected cause of Gravitation,
+together with the cause of the two complementary forces, is found in the
+simple statement that Aether is matter, with all that is logically
+included therein. Kepler's Laws and Newton's Laws of Motion also receive
+a physical explanation in the same universal electro-magnetic Aether.
+
+In addition to the solution of these problems, the transverse vibrations
+of light has received for the first time a physical conception, and a
+physical explanation, even admitting that that explanation may not be
+perfect in detail.
+
+The origin of the permanent magnetism of the earth has also received a
+physical explanation through the motions of this same electro-magnetic
+Aether, while certain theories in relation to electricity given to the
+world by Ampère, Weber, Faraday, and Clerk Maxwell have found their
+consummation in this atomic electro-magnetic medium.
+
+Further, astronomical hypotheses in relation to comets and nebulae are
+not untouched by the theory of a compressible and condensing atomic
+Aether. Indeed, there is not a phase of natural phenomena which is not
+affected in some way or other by the philosophical result arrived at
+that Aether is matter in its original state. Therefore, we claim,
+however imperfectly it may have been done, that not only have the Rules
+of Philosophy been fulfilled, but that the theory so advanced has
+accomplished more than even we in our wildest imagination hoped and
+dreamed for it.
+
+Look at the problem of the Aether how we may, the advantages of the
+theory of an atomic electro-magnetic Aether far surpass and outweigh the
+advantages of a frictionless medium, which in some unknown way possesses
+mass and inertia, although the conception of such properties themselves
+disproves the existence of such a frictionless medium.
+
+After all, how much of this theory is there which is entirely new or
+absolutely original? Age after age, men have had exactly similar dreams,
+and seen similar visions. In the old Grecian days similar views were
+expressed by their philosophers; and, even in the philosophy of less
+civilized countries, many of the suggested hypotheses found their place
+in a more or less perfect form.
+
+Analyze the whole theory from its initial stages to the last chapter,
+and we shall find, with the exception of one or two features, that every
+hypothesis first had its origin in the mind of some of the greatest
+thinkers and philosophers that the world has ever known.
+
+Take several hypotheses as examples. The hypothesis that Aether is
+atomic was suggested by such men as Newton, Huyghens, Descartes,
+Challis, Clerk Maxwell, and others.
+
+That Aether is gravitative has been suggested by Young, Grove, Faraday,
+and Lord Kelvin. Huyghens, Fresnel, and Young postulated different
+degrees of density for the Aether, while Stokes and McCullagh have
+affirmed and proved different degrees of elasticity of the medium.
+
+The inertia of the medium has received experimental evidence from
+Tyndall, Maxwell, Faraday, Lodge, and others, and its compressibility
+has received the adherence of men like Faraday, Maxwell, and Lord
+Kelvin.
+
+Then, when we come to deal with the causes of the forces involved in
+gravitational phenomena, we find that exactly similar hypotheses in
+regard to the Centrifugal Force have been postulated by Herschel,
+Bredichin, M. Faye, and Lebedew; while Faraday, Gauss and others have
+suggested the close relationship that exists between electrical and
+gravitational phenomena.
+
+The physical explanation of Kepler's Laws was suggested by Kepler
+himself, while Huyghens, Bernoulli, Descartes, and many of their
+contemporaries believed in the existence of some kind of vortices.
+
+The unity of the universe has been a dream of philosophers for
+generations past, and that dream is now crystallized in the definite
+conception of an atomic universal electro-magnetic medium, while the
+electrical basis of matter receives the support of such men as Crookes,
+J. J. Thomson, Larmor and Vogt.
+
+Thus we learn that all the dreams and thoughts, all the hypotheses and
+postulates of old-world as well as present-day philosophers find their
+consummation and ultimate realization in one universal, atomic,
+electro-magnetic medium.
+
+If this fact does not stamp the theory with that authority which is
+undeniably associated with the names of some of the scientists quoted,
+then all the greatest men in the scientific world have lived and toiled,
+thought and dreamed in vain, while the priceless gems of their
+imagination and research are treated as worthless and valueless.
+
+Again, what shall we say of the discoveries of to-day?
+
+What is the key to the greatest scientific discovery of modern times,
+viz. wireless or aetherial telegraphy, which is girdling the earth with
+its mysterious communications? Is not the key to that discovery to be
+found in this universal electro-magnetic medium?
+
+Whence come the X-rays, Rontgen rays, and other light rays with their
+adaptability to human suffering, if they come not from this same
+electro-magnetic medium? their adaptability to human suffering being
+dependent upon the intimate and close relationship that exists between
+the physical body and the electro-magnetic medium.
+
+Where is the key to the principle underlying the gramophone, the
+phonograph and the telephone, if it be not in this self-same atomic and
+easily impressible medium?
+
+Nay! let us go further, and ask ourselves where is the key to be found
+for the many marvellous effects of so-called spirit phenomena? Who can
+read F. W. Myer's _Human Personality and its Survival of Bodily Death_,
+and not feel that we are standing on the threshold of the unseen world?
+
+Already men are asking themselves the meaning of the strange sensations
+which they receive from unseen sources; already men's spirits are
+vibrating in unison with vibrations that come from the unseen world; and
+to-day we see spiritual phenomena as through a glass darkly, and the
+question arises, what is the medium of all this communication, of all
+these vibrations?
+
+Is there no medium at all which forms the medium of communication? To
+assert that would be to assert something opposed to all experience and
+therefore would be unphilosophical.
+
+May not then the theory of an atomic universal electro-magnetic medium
+help us on in our groping and searching after light in this direction?
+Who will uplift the veil? Already we peer almost into the spirit world.
+A little more light, a little more truth, and then there will burst
+forth upon the hearts and minds of men the grandest and most glorious
+truth that Nature can reveal of her Creator, and then men shall come to
+know and understand the place that God holds in the Universe, such truth
+being advanced on its way by an atomic, universal electro-magnetic
+Aether which is as truly matter as our own bodies.
+
+
+ART. 127. _God and the Universe._--To the superficial reader it may
+appear at first sight, that the theory of the Aether suggested in this
+work leaves no place in the Universe for the operations and existence of
+an Infinite and living Spirit, a God. It may be objected, that if all
+matter and all modes of motion find their physical origin in one common
+and primordial medium, the electro-magnetic Aether, where is the
+necessity for the existence of an Eternal and Infinite Spirit?
+
+At first sight there appears some force in the objection, but it loses
+its point when we come to view the Universe from the standpoint of
+spirit phenomena. The purpose of the writer in this work has been to
+deal with natural phenomena only, purely from the philosophical and
+scientific standpoint. Spirit phenomena (which is equally as real and
+obvious as natural phenomena) have no part or place in a work which
+deals with scientific facts and data, but demand and will receive in a
+future work equal consideration and philosophic treatment. A man must
+indeed be lacking in vision who cannot see behind all things the
+evidence of a richer and fuller truth than that which merely lies on the
+surface, or who fails to read and learn the greatest truth that circles
+the Universe in its ultimate unity, which indisputably points to the
+existence of an Eternal and ever-living Spirit, a God. I affirm that
+there is no scientific truth, even including the law of the conservation
+of matter and motion, which has been enunciated in this work, but what
+is reconcilable with the existence of an Eternal and Infinite Spirit;
+and although such a statement may seem a paradox, yet I am convinced
+that before many more years have passed, the reconciliation of natural
+with spiritual phenomena will be an accomplished fact. The fool to-day
+may say in his heart, there is no God, but ere long not only religion,
+but Science herself, shall expose his lack of wisdom and his folly.
+
+For all things derive their existence primarily, with all the energies
+and powers they possess, from God. Look where we will, or at what we
+will, from the smallest atom or molecule up to the most stupendous
+world, or myriads of worlds that roll and sparkle in the blue infinity,
+in each and all we see the indisputable evidence of the existence of a
+mysterious spirit, or power, that controls and governs them. A spirit or
+power that we cannot see, but which is so indisputably evidenced that
+its existence cannot be denied. For example, we see forms of many kinds,
+some of which are simple entities of themselves, while others are
+complex and made up of many parts, but while each part is inseparably
+connected with the other, yet each part is itself distinct from the
+others in nature and substance. The whole combined forms a complete
+mechanism or organism, and, like all mechanisms of human make, not only
+needs a controlling and governing power, but also evidences a maker.
+Even the laws of Nature and modes of motion, whether it be heat, light,
+electricity, or magnetism, are, however, unable of themselves to control
+the mechanism, and therefore prove themselves to be but the servants of
+an infinite Intelligence, a GOD.
+
+Thus, behind and beyond all we see, in every living form, there is the
+evidence of a hidden spirit, which is the governing and controlling and
+sustaining power, and without which the organism ceases to be an
+organism. A spirit which animates the mechanism, and uses its activities
+and powers as it wills for its own purposes and ends. This spirit or
+power we call its life, which gives to the form its existence, together
+with all that it possesses, as its powers, activities, energies and
+productions, for all are but the effects of the hidden life. If this
+mysterious something, termed its life, becomes in any way separated from
+the mechanism or organism, then as a distinct and separate organism it
+ceases to be; and though the mechanism may still exist for a time, yet
+all its powers are gone, while the organism, robbed of its very life,
+begins slowly to decay.
+
+We cannot see this power; we cannot find it We may search for it, rend
+and tear part from part, only to find that it baffles all our skill, and
+laughs at our endeavours to discover the secret of its existence. We
+know that it is there, just as truly as we know that in these forms of
+ours, these living stoves, these perfect mechanisms called our bodies,
+there exists and dwells a spirit, a living, conscious, self-acting and
+controlling power. A spirit which we know is not the mechanism itself,
+and which by experience and observation we know to be distinct from the
+organism. It is this mysterious spirit which controls and governs all
+our acts, that rules and reigns as king of our bodies, and makes the
+physical mechanism, with all its wondrous parts, obey and do its
+bidding. That this is so, that the spirit is distinct from the body, and
+is the controlling and governing principle within us, is evident in a
+thousand ways. If, however, that spirit departs from the mechanism of
+our bodies, then the controlling and governing influence is gone; and
+the mechanism, robbed of its life, ceases to work, ceases to fulfil its
+functions, and ceases to exist in that particular form.
+
+Just as it is with ourselves, so it is with the Universe. For look where
+we will, from the smallest atom to the great aggregation of atoms, as
+our earth, or even to the more stupendous orbs of heaven, the working of
+a secret and mysterious power or spirit meets our gaze. A spirit or
+power that is not the form or the mechanism, but is separate and
+distinct from the mechanism, while at the same time it is inseparably
+connected with each and all. For everything that we see, from an atom to
+the Universe itself, is a perfect mechanism, or complexity of
+mechanisms. The entire Universe is one vast, intricate, and elaborate
+piece of mechanism, beginning with the simple aetherial atom, ranging
+through all the atomic systems, graduating by successive steps through
+compound substances, which, in their aggregations, form meteors,
+satellites, planets, suns, and stars; until the ultimate whole is
+reached, where everything is blended into one vast whole; a perfect,
+infinite, complex mechanism, a Universe.
+
+Now if philosophy teaches anything at all regarding mechanisms of human
+invention, it indisputably teaches that every machine or mechanism that
+has ever been made, implies the existence of a maker, and that the maker
+possessed intelligent attributes, as reason, judgment, perception, and
+imagination. For example, stand before some elaborate machine of human
+invention, as a lace machine, and watch the working of that machine in
+all its details. It is composed of many parts, each of which is perfect
+in itself. Each part may be distinct in nature and purpose, yet each and
+all are inseparably and unitedly connected with each other, and all work
+harmoniously together for the accomplishment of a definite and specific
+end, that is, the production of a lace curtain of exquisite design and
+pattern. As we watch the machine and its workings, we see therein the
+evidence of the existence of a spirit or power that gave it its birth. A
+spirit or mind that made and formed the machine, that constituted,
+arranged, and gave it its governing and controlling power; fitted and
+ordered every part, gave to each part its allotted task, and moulded all
+to the harmonious fulfilment of the definite end and purpose he had in
+view.
+
+Thus in the machine we see evidence of contrivance and design, of method
+and arrangement, of conception, perception and judgment, which are all
+the effects and outflowings of intelligence which belong, and alone
+belong, to mind; and therefore we say, "The machine was made, and there
+was and must have been a maker." So universally is this fact accepted,
+that any one who seriously challenged the statement, or dared to deny
+it, would be at once pitied as insane or laughed at as a fool. Thus all
+experience proves, and philosophy testifies, that wherever we get a
+machine or mechanism of any kind or sort, there must have been a living,
+conscious being or person, who is distinct from and outside of the
+machine. He made it, and therefore must have existed before it, in order
+to make it. Wherever, therefore, we find a mechanism that bears the
+marks of intelligence and design, of judgment, perception and
+conception, it is only logical and philosophical to infer, that such a
+mechanism equally evidences the existence of an intelligent being. The
+more intricate and elaborate the mechanism, the greater the ingenuity
+displayed, the more complex and perfect the design, the more harmonious
+the working, the greater will be the wisdom, the more profound the
+judgment, the keener the perception, the more perfect the understanding,
+and the vaster, nobler, and more sublime the order of Being who
+originated and made it. This being so, according to philosophical
+reasoning, let us glance at the Universe in all its fulness and oneness,
+and we shall see the indisputable evidence of the existence of an
+Infinite Being, who made, controls and governs the infinite Universe.
+
+In the atomic world we get an illustration of the perfect mechanism that
+underlies all atomic systems. Our conception of an aetherial atom was
+based upon the analogy of our own planet, and there is every reason to
+believe that the little world in which all atoms live and move and have
+their being, is analogous to a planetary or solar system, in which we
+find the two essentials of matter and motion ever associated together,
+to form a larger and more complete mechanism. For atoms are not simply
+mere points; they possess real dimensions, with a determinate and fixed
+form, differing in their relative weights, and in the amount of motion
+or force with which each is endowed. The very fact that they possess
+atomic weights which are unalterable throughout the long periods of time
+that mark the history of the Universe, and that they combine in definite
+and fixed proportions, indisputably evidence the fact that they but do
+the bidding of an Eternal and Infinite Spirit, a God. Thus each
+molecule, or atomic system forms a perfect mechanism in itself, with its
+own centre of gravity, and subject to the same laws of repulsion and
+attraction, or pressures and tensions--due to the vibrations and motions
+of the universal electro-magnetic Aether.
+
+In each of the planetary systems we get an illustration of the same
+perfect mechanism, which is indicative of all systems whether large or
+small; each system being characterised by the same beauty of order and
+harmony of motion which are equally characteristic of atomic systems.
+
+Our own solar system, composed as it is of many parts, of thousands of
+meteors and comets, of numbers of satellites and planets, all revolving
+around one common centre, also forms a complete and perfect mechanism in
+itself. For millions and millions of years this perfect mechanism has
+been harmoniously working together in all its parts, as it moves in all
+its unity through the realms of infinite space. Yet through all the
+unknown ages of the past, such a phenomenon as disorder in the working
+of any part of the system is inconceivable and unknown. Out in stellar
+space there are, however, innumerable systems, similar to our own solar
+system, each distinct and perfect in itself; each being made up of
+similar parts, as meteors, comets, satellites, planets, and central sun.
+These systems are, however, united together into one vast aggregation of
+worlds, having one common controlling centre of their own, and by their
+unity form a constellation, a larger and grander mechanism. Throughout
+the whole constellation there is the same order, and harmonious working
+of part with part, that characterise the solar system. Then these
+constellations increasing in their aggregations form a still larger
+complexity of systems, called a Galaxy; and galaxy being added to
+galaxy, constellation to constellation, there is formed by such union,
+an ocean of suns and stars like our own Milky Way, the ultimate whole
+being characterised by the same mechanical order and harmonious working
+that characterise the solar system. It may even be, that there are
+numbers of these oceans of suns and stars existing in infinite space,
+all bound together by one common bond, the universal electro-magnetic
+Aether, and forming one vast ultimate whole, a Universe; with all its
+oceans of suns moving around one central Orb or mass of Orbs called the
+Throne of GOD.
+
+Thus the whole Universe is a mechanism, complete and perfect in every
+detail, and forming a system, so great, so grand, so sublime, so
+magnificent that it puts all mechanisms of human origin to shame and
+scorn. Now, if a mechanism of human invention evidences the existence of
+intelligence and mind, and proves itself to be the production of a
+living, sentient, conscious, and intelligent being, how much more,
+incomparably more, does the Universe with its infinite complexity
+evidence a Maker also; and that Maker must be as infinitely greater in
+wisdom, knowledge, perception and judgment as the Universe is infinitely
+greater in mechanical perfection than any mechanism of human origin.
+
+The Universe is God's teaching in symbol and in type. It is His great
+picture-book, where in living form He has portrayed Himself, and all
+that belongs to Him--His nature, character, wisdom; His greatness,
+glory, and His power. The Universe is a temple, where He sits enshrined
+in the things His own hands have made, and where those who have eyes to
+see, and hearts to learn and understand, may adore and worship Him.
+
+Thus is it true that "the heavens declare the glory of God," _i. e._ the
+character of God, His infinite wisdom, His infinite knowledge, His
+profound judgment, and His eternal righteousness; while the firmament
+showeth His handiwork. "Day unto day uttereth speech, and night unto
+night showeth (His) knowledge."
+
+"The Lord by wisdom hath founded the earth, by understanding hath He
+established the heavens."
+
+"He hath made the earth by His power. He hath established the world by
+His wisdom, and hath stretched out the heavens by His discretion."
+
+"Thou, Lord, in the beginning hast laid the foundations of the earth,
+and the heavens are the work of Thy hands; they shall perish, but Thou
+remainest; and they all shall wax old, as doth a garment; and as a
+vesture shalt Thou fold them up, and they shall be changed; but Thou art
+the same, and Thy years shall not fail."
+
+To prove the validity of these statements from a scientific and
+philosophic standpoint, and to show the harmony that exists between the
+natural and the Divine revelation as given in the Word of God, will form
+the subject of a future work.
+
+
+
+
+                              APPENDIX A
+
+
+According to Sir Oliver Lodge the fact that electricity possesses mass
+or inertia has now passed out of the hypothetical stage into the realm
+of fact and experiment. In his Romanes Lecture recently published, he
+states, page 4: "My first thesis is that an electric charge possesses
+the most fundamental and characteristic property of matter, viz. mass or
+inertia; so that if any one were to speak of a milligramme or an ounce
+or a ton of electricity, though he would certainly be speaking
+inconveniently, he might not necessarily be speaking erroneously."
+
+Now in view of the identity that exists between Aether and electricity,
+as proved by Hertz' experiments, the only logical conclusion that can be
+arrived at is, that Aether must also possess mass and inertia. So that
+the most recent experiments in relation to electricity confirm the
+theory of the Aether presented in this work, viz. that it also possesses
+mass and inertia, otherwise we should have a massless medium being
+composed of electrons which possess mass, and that would be a violation
+of all experience, and therefore an unphilosophical statement.
+
+
+
+
+                              APPENDIX B
+
+
+The hypothesis of electricity being the fundamental basis of all matter
+made in the last chapter on the "Unity of the Universe," receives
+confirmation from Sir Oliver Lodge in his _Modern Views of Matter_,
+where he writes, page 13: "The fundamental ingredient of which, in this
+view, the whole of matter is made up, is nothing more or less than
+electricity, in the form of an aggregate of an equal number of positive
+and negative electric charges. This, when established, will be a
+unification of matter such as has through all the ages been sought; it
+goes further than had been hoped, for the substratum is not an unknown
+and hypothetical protile, but the familiar electric charge."
+
+
+
+
+                              APPENDIX C
+
+
+The hypothesis that all elements have definite quantities of electricity
+in them, or a definite number of electrons, as suggested on page 335,
+receives added weight by the testimony of Sir Oliver Lodge in the work
+already referred to. Writing on the subject, he says: "It is a
+fascinating guess that the electrons constitute the fundamental
+substratum of which all matter is composed. That a grouping of say 700
+electrons, 350 positive and 350 negative, interleaved or interlocked in
+a state of violent motion so as to produce a stable configuration under
+the influence of their centrifugal inertia and their electric forces,
+constitutes an atom of hydrogen. That sixteen times as many, in another
+stable grouping, constitute an atom of oxygen. That some 16,000 of them
+go to form an atom of sodium; about 100,000 an atom of barium; and
+160,000 an atom of radium."
+
+From these extracts, taken from _Modern Views of Matter_, the author
+claims that the theory of the Aether presented to the reader in _Aether
+and Gravitation_ receives added confirmation and support.
+
+
+                        *    *    *    *    *
+
+
+
+
+                                ERRATA
+
+
+The author regrets that Professor J. J. Thomson's name has been
+incorrectly spelled in several places.
+
+
+
+
+                                INDEX
+
+
+Aberration of light, 69, 149, 218
+
+Absorption, 104-6
+
+Acceleration, 239
+
+Actinic rays, 141
+
+Action at a distance, 96, 174, 176
+  and re-action, 20, 251
+
+Adams' discovery of Neptune, 25
+
+Aether is matter, 54-8
+  is atomic, 59-67
+  is gravitative, 64-9
+  density of, 69, 71, 136, 243
+  elasticity of, 74-7
+  inertia of, 76, 330
+  its motions, 80
+  compressibility of, 291, 315
+  waves, 79-80
+
+Aetherial basis of matter, 326
+
+Affinity, chemical, 43
+
+Aldebaran, 312
+
+Aluminium, 79
+
+Ampère, 192
+
+Ampère's theory of magnetism, 193
+
+Andromeda, 314
+
+Annual magnetic variation, 208
+
+Annular nebulae, 320
+
+Aphelion of earth, 36
+
+Arago, M., 321
+
+Arcturus, 312
+
+Areas, Kepler's law of, 36
+
+Asten, Von, 234, 296
+
+Asteroids, 31
+
+Atmosphere, 68, 73, 102, 225
+
+Atom, vortex, 45, 46, 61
+  what it is, 43
+  electron, 63
+  Boscovitch, 61
+  hard, 61
+  size of, 43
+
+Attraction, electrical, 2, 286
+  of gravitation, 13, 24, 31
+  magnetic, 195
+
+
+Balance, Torsion, 187
+
+Bernoulli, 221, 341
+
+Beta Persei, 308
+
+Biela's comet, 296-7
+
+Binary compound, 143
+  stars, 25, 309
+
+Biot, 138
+
+Boscovitch atoms, 44, 138
+
+Boyle and Marriotte's law, 76, 103
+
+Bradley's discovery of aberration, 149
+
+Bredichin on comets' tails, 302
+
+Brilliancy of stars, 307, 309
+
+British Association Report, 57, 59
+
+
+Calcium, 79
+
+Canis major, 307
+  minor, 307
+
+Capella, 312
+
+Carbon, 48
+
+Carboniferous period, 115
+
+Carnot on heat, 116-18
+
+Cassini, 307
+
+Cause and effect, 14
+  of gravitation, 1, 282-9
+
+Cavendish experiment, 24
+
+Centauri, 79
+
+Centre of gravity, 325
+
+Centrifugal force, 9, 13, 15, 30, 236-8
+
+Centripetal force, 9, 12, 282
+
+Cetus, 307
+
+Chalk, 6
+
+Challis, Prof., 74, 96, 100, 107, 151, 155,
+214, 227, 311
+
+Chemistry, 47, 336
+
+Coal, 86, 88
+
+Clairaut, 297
+
+Clusters of stars, 314
+
+Cohesion, 48
+
+Colour, 138
+
+Colours of stars, 308
+  seven primary, 139
+
+Comets, 291
+  attracted by planets, 298
+  condensation of, 292
+
+Comets and meteors, 297
+  short period, 293-4
+  long period, 293-4
+  tails of, 298-9
+  orbits of, 293
+  nucleus of, 298-9
+  coma, 298-9
+
+Compressibility of aether, 291, 315
+
+Condensation of gases, 47
+
+Conservation of matter, 42
+  of energy, 84
+  of motion, 92
+
+Constellations, 307
+
+Corollary, 15
+
+Corona Borealis, 309
+
+Corpuscles, 42, 64, 136
+
+Corpuscular theory of light, 122
+
+Correlation of forces, 83
+
+Coulomb Torsion balance, 185, 187
+
+Crookes, Sir William, 42, 136, 326, 341
+
+Current, electric, 163
+  magnetic, 192
+
+Currents, 90
+
+Curry, Prof., 284
+
+Cycle of operations, 114, 116
+
+Cygnus, 307
+
+
+Dalton's atomic theory, 42
+
+Davy, 99, 107
+
+Day and night, 4
+
+D'Arrest's comet, 296
+
+Deimos, 38
+
+Democritus, 44
+
+Density of matter, 51
+  of aether, 69
+  electric, 170
+  of earth, 242
+  of sun, 27
+  of planets, 242
+
+Descartes, 221-2, 341
+
+Dewar, Prof., 47
+
+Diameter of earth, 29
+  polar, 29
+  equatorial, 29
+  of sun, 280
+  of planets, 29
+
+Dielectric, 168, 175
+
+Diffusion, 49
+
+Dip, magnetic, 199
+
+Distances of stars, 280
+
+Diurnal variations, magnetic, 209
+
+Dog star (Sirius), 306
+
+Donati's comet, 298
+
+Double stars, 308
+
+Draco, 307
+
+Dynamical equivalent of heat, 114
+  value of light, 150
+
+Dynamics, laws of thermo-, 114-18
+
+Dynamo, 87, 90
+
+
+Ear, 120
+
+Earth, mass of, 235, 242
+  a magnet, 196-8
+  size of, 29
+  rotation of, 219
+  orbit of, 276
+  periodic time of, 251
+  gravity of, 29
+  shape of, 29
+  distance from sun, 242, 251
+  velocity in orbit, 251
+
+Eccentricity of orbits, 268, 276
+
+Eclipse, 145, 148
+
+Ecliptic, plane of, 277-9
+
+Elasticity, 46
+  of matter, 51
+  of aether, 74
+
+Electric current, 154
+  potential, 170
+  induction, 175
+  radiation, 182
+  density, 170
+  energy, 179
+  field, 166, 179
+  lines of force, 173
+
+Electricity, 64, 162
+  two kinds of, 175
+  positive, 175
+  negative, 175
+  laws of, 184
+  theories of, 162
+
+Electrons, 136, 163
+
+Electro-static, 158, 164
+  kinetic, 158, 164
+  kinetic energy, 217
+  magnetism, 192-5
+  magnets, 199
+  magnetic theory of light, 229
+  chemical equivalents, 189, 333
+
+Elements of matter, 47
+
+Ellipse, 34
+  Kepler's discovery of, 34
+
+Elliptical nebulae, 320
+
+Emission theory of light, 122
+
+Encke's comet, 293, 296
+  resisting medium, 228
+
+Energy, 83, 84
+  what it is, 83
+  conservation of, 84
+  transformation of, 86
+  potential, 87
+  kinetic, 89, 164
+  radiant, 109
+  electrical, 179
+  and motion, 91
+
+Engine, Carnot's heat, 116
+
+Envelopes of comets, 298
+
+Epicureans, 44
+
+Equal areas, 36
+  times, 36
+
+Equator, N. and S. Poles, 29
+  magnetic, 202
+  terrestrial, 29
+
+Equipotential surfaces, 171
+
+Equivalents, electro-chemical, 189, 333
+
+Euler, 123
+
+Exchanges, theory of, 105
+
+Experience, 4
+
+Experiments of Rumford, 98
+  of Michelson and Morley, 67, 227
+  of Lebedew, 302
+  of Nichols and Hull, 153
+  of Hertz, 165
+  of Faraday, 65, 285
+  of M. Faye, 302
+  of Joule, 114
+
+
+Falling stone, 21, 29
+
+Faraday, 45, 175, 220
+  on matter, 56
+  on Lines of Force, 168, 200, 203-5
+  on magnetic space, 208
+  on gravitation, 287
+  on electricity, 332
+  on induction, 176
+
+Faye, M., 111, 302, 319
+
+Faye's comet, 293, 296
+
+Field, electric, 179
+  magnetic, 199
+
+Fizeau, 149, 224
+
+Fluids, 48
+
+Food, 89
+
+Forbes, 121
+
+Force, 16, 19, 90
+  centrifugal, 9, 13, 236
+  centripetal, 9, 12, 282
+  lines of, 200
+
+Forces, direction of the, 26
+  proportion of the, 26
+
+Foucault, 149
+
+Franklin, 106
+
+Fresnel, 75, 131
+
+Frictionless medium, 17, 131, 136, 224
+
+Fundamental medium, 54
+
+
+Galaxy, 325, 346
+
+Gaseous nebulae, 313
+
+Gases, condensation of, 47
+  liquefaction of, 47
+  kinetic theory of, 49
+
+Glazebrook, Prof., on aether and gravitation, 22
+
+Globular clusters of stars, 314
+
+Gravitation, law of, 61, 65
+  universal, 24
+  intensity of, 27
+  law of proportion, 26
+  cause of, 1, 282
+  and binary stars, 25
+
+Gravity, centre of, 325
+
+Great Bear, 307
+
+Grove, 83
+
+
+Halley's comet, 296-7
+
+Hamilton, Sir W. R., 247
+
+Head of comets, 298
+
+Heat is motion, 98
+  a mode of motion, 107
+  radiant, 109
+  dynamical equivalent of, 116
+  effects of, 107
+  nature of, 98
+  radiation of, 109
+  transformation of, 87
+
+Heat engine, Carnot's, 116
+  of sun, 109
+  and matter, 100
+  and work, 114
+  refraction of, 121
+
+Helmholtz, Von, 45, 86
+
+Hercules, 257, 271, 307
+
+Herschel, Sir J., 3, 4, 7, 226, 228, 281, 299, 301, 310, 321
+  Sir W., 109, 271-2, 313
+
+Hertz, 138, 159, 182
+
+Hicks, Prof., 13
+
+Hodograph of planets, 247
+
+Hot springs, 90
+
+Huggins, 313-14
+
+Huyghens, 54, 123, 125, 128
+
+Hydrogen, 40, 42, 44, 60, 93, 314, 333
+
+Hypotheses, 3, 338
+
+
+Ice, 42
+
+Identity of heat and light, 119
+  light and electricity, 156, 160, 165
+  aether and electricity, 331
+
+Imponderable, 71
+
+Impressed force, 20
+
+Impressible aether, 78
+
+Induction, electric, 174-5
+  magnetic, 199
+  Faraday's theory of, 175
+
+Inertia of matter, 52
+  of aether, 330
+
+Intensity of light, 28, 146
+  of heat, 28, 113
+  of electricity, 184
+  of gravity, 28
+
+Iron, 42
+  expansion by heat, 101
+  contraction by cold, 102
+
+
+Joule, 85, 114
+
+Jupiter, 26, 68
+  mass of, 235
+  satellites of, 149, 178
+  rotation of, 219
+  orbital velocity of, 251, 265
+  size of, 235
+  distance from sun, 242, 251
+  density of, 242
+  and comets, 305
+
+
+Kant, 317
+
+Kelvin, Lord, 43, 71, 77, 80, 95, 216, 227
+  on aether, 56-7
+  on vortex atom, 63
+  on compressible aether, 291, 315
+  on light, 151
+
+Kepler's laws, 32
+  first, 33, 256-9
+  second, 36, 260-2
+  third, 37, 263-5
+  on vortex motion, 221-2
+
+Kinetic energy, 89
+  electro, 217
+
+Kirchhoff, 43
+
+
+Laplace, 317
+  nebular hypothesis, 317
+
+Larmor, Dr., 22, 44, 56, 63, 93, 163
+  on electrons, 284
+  on aetherial physics, 22, 327-9
+
+Lavoisier, 42
+
+Law of gravitation, 24
+  of inverse squares, 27
+
+Laws of electricity, 184
+  of light, 145
+  of heat, 113
+  of motion, 9, 15, 233
+
+Lead, 88, 333
+
+Lebedew, 32, 76, 153
+
+Le Verrier, 25
+  discovery of Neptune, 25
+
+Leyden jar, 157
+
+Liebnitz, 223
+
+Light, 75
+  a mode of motion, 122
+  corpuscular theory of, 123
+  undulatory theory of, 123, 136
+  electro-magnetic theory of, 156
+  path of a ray of, 144
+  intensity of, 145
+  reflection of, 136
+  refraction of, 135
+  aberration of, 149
+  composition of, 139
+  velocity of, 148
+  zodiacal, 277
+  transverse vibration of, 130
+
+Lines of force, electric, 173
+  magnetic, 201-3
+
+Liquefaction of gases, 47
+
+Liquid air, 47
+
+Liquids, 48
+
+Little Bear, 307
+  Dog, 307
+
+Lockyer, 109
+
+Lodge, Dr., 219
+  on aether density, 69
+  on aether, 284, 289, 328, 332
+  on electric inertia, 330
+  on electricity, 64, 69, 284, 285
+  on force, 17
+  on gravitation, 283
+
+Lorentz on light, 154
+
+Lyra, 307
+
+
+MacLaurin, 2, 10, 17
+
+Magnesium, 79
+
+Magnet, 21
+
+Magnets, bar, 199
+  moving, 211
+
+Magnetic axis, 202
+  field, 199
+  lines of force, 200
+  shells, 205
+  equator, 202
+  induction, 199
+  variation, 208
+  molecules of, 193
+  polarity, 194
+
+Magnetism of earth, 207-12
+  of planets, 211
+  cause of solar, 211
+  Ampère's theory of, 193
+
+Mars, 68, 79
+  a magnet, 196
+  rotation of, 219
+  size of, 236
+  orbital velocity of, 251
+  satellites of, 178
+  orbit of, 33
+
+Mass, 27, 53, 187
+  of earth, 235, 242
+  of planets, 235, 242
+  of sun, 190
+
+Matter, elements of, 40
+  properties of, 42, 50
+  and motion, 41, 322
+  conservation of, 42
+  divisibility of, 44
+  four states of, 48
+  aetherial basis of, 48, 333
+  physical constitution of, 334
+
+Maxwell, J. C., 43, 73, 85, 151, 211
+  on physical lines of force, 168, 203-5, 288
+  on aether, 59, 206
+  on magnetism, 205
+  on electro-kinetic energy, 180, 217
+  on aether, 58
+
+Mayer, 84, 86, 114, 118
+
+McCullagh, 75
+
+Mechanical energy, 87
+
+Medium, Descartes on a, 221
+  Kepler on a, 222
+
+Mercury, 68, 79
+  a magnet, 196
+  rotation of, 219
+  eccentricity of orbit, 33
+  mass of, 242
+  orbital velocity of, 251
+
+Meteorites, 95, 118
+
+Meteors, 31, 85, 118
+
+Michelson and Morley, 7, 67
+
+Milky way, 79, 309, 314
+
+Molecules, 44
+
+Momentum, 20
+
+Moon, 61
+
+Motion of stars, 310
+  planetary, 253
+  of sun, 274
+  of aether, 80
+  and work, 95
+  modes of, 92, 122, 163
+  first law of, 15, 16, 239
+  second law of, 19, 244
+  third law of, 20, 251
+
+Multiple stars, 308
+
+
+Natural philosophy, 4
+
+Nebulae and aether, 313
+  structure of, 314
+  spiral, 322
+  annular, 320
+  elliptical, 320
+  planetary, 321
+  spectrum of, 314
+  irregular, 319
+
+Nebular hypothesis, 317
+
+Nebulous stars, 311
+
+Neptune, 68
+  discovery of, 25
+  mass of, 235
+  orbital velocity of, 251, 265
+  distance from sun, 242
+  a magnet, 196
+
+Newton's coloured rings, 107
+  _Optics_,72, 98, 122
+  letter to Bentley, 2, 96
+  Rules of Philosophy, 3
+  _Principia_, 3, 7, 38
+  emission theory, 123
+  law of gravitation, 24
+  atoms, 44
+  on aether, 98
+
+Nichols and Hull, 32, 153
+
+
+Ocean, 81, 90
+
+Operations, cycle of, 114
+
+_Optics_, Newton's, 2, 122
+
+Orbital motions of planets, 266
+
+Orbit of earth, 33
+  of Venus, 33
+
+Orbits of satellites, 34
+  of planets, 33-4, 266
+  moon, 267
+  stars, 310
+  sun, 270
+
+Origin of sun's heat, 95
+
+Orion, 79, 307, 314, 319
+
+Oxygen, 40, 44, 60, 93
+
+
+Parallelogram of forces, 15
+
+Pendulum, 88
+
+Periodic times, 37
+
+Perpetual motion, 93, 220
+
+_Phil. Mag._, 58, 67, 71, 73, 74, 80
+
+_Phil. Trans._, 58, 62, 64, 75
+
+Philosophy, Rules of, 3
+
+Phobos, 38
+
+Physical lines of force, 203-6
+
+Pitch of Sound, 105, 120, 139
+
+Plane of ecliptic, 277-9
+
+Planetoids, 31
+
+Planets, minor, 31
+  origin of, 240
+  orbits of, 33, 266
+  electrified bodies, 177
+  masses of, 242
+  relative distances of, 242
+  orbital velocities of, 251
+  periodic times of, 251
+
+Platinum, 48
+
+Pleiades, 79
+
+Polarization, 176
+
+Potential energy, 87
+
+Potential, electric, 170
+  magnetic, 194
+
+Pouillet, M., 109
+
+Poynting, 91
+
+Pressure, aetherial, 181
+
+Preston, Prof., 283
+
+Prevost, theory of exchanges, 105
+
+Primitive impulse, 9, 10, 12, 319
+
+_Principia_, Newton's, 3, 7, 38-9, 122
+
+Properties of matter, 42
+
+
+Quantity of sun's heat, 109
+
+Query, 18-19
+  _Optics_, 72, 122
+
+
+Radiant heat, 109
+  energy, 115
+
+Radiation, 104
+
+Radius Vector, 26
+
+Rankine, 103
+
+Rays, actinic, 141
+  dark heat, 140
+  infra-red, 141
+  ultra-violet, 140
+  Rontgen, 341
+  X, 341
+
+Rectilinear propagation of light, 144
+  of heat, 111
+
+Reflection, 160
+
+Refraction, 160
+
+Relative motion of aether and matter, 224-6
+
+Resistance to motion, 17
+
+Resisting medium, 228
+
+Reversible cycle, 116, 118
+
+Rings, vortex, 45
+
+Rival theories, 8
+
+Rivers, 89-90
+
+Roemer, and velocity of light, 148
+
+Rotation of earth, 219
+  of planets, 219
+  of sun, 246
+
+Rotatory motion, 93
+
+Rucker, Prof., 59
+
+Rules of Philosophy, 3
+  first, 3
+  second, 4
+  third, 3, 7
+
+Rumford, 98
+
+Running water, 95
+
+
+Satellites of Mars, 38, 178
+  Jupiter, 149, 178
+  Uranus, 254
+  Neptune, 254
+
+Saturn, 26-7, 68
+  mass of, 235, 242
+  orbital velocity of, 251, 265
+  rotation of, 219
+  density of, 242
+  a magnet, 196
+  satellites of, 178
+
+Schuster, Prof., 8, 218, 311
+
+Sirius, 306, 308-9
+
+Sodium, 43
+
+Solar system, motion of, 257, 271
+  spectrum, 79, 139
+  magnetism, 211
+
+Sound, 75
+  waves, 104, 120
+
+Space, interstellar, 310, 313
+
+Spectroscope, 47, 79
+
+Spectrum analysis, 50, 139
+
+Spiral nebulae, 322
+
+Stars, fixed, 58
+  number of, 11, 306
+  binary, 309
+  distances of, 280
+  magnitude of, 306, 309
+  colour of, 79, 308
+  motion of, 310-11
+  nebulous, 320
+  proper motions of, 312
+  variable, 307
+  double, 308
+  clusters of, 314
+  orbits of, 310
+  are magnets, 307
+
+Stokes, Sir G., 69, 152, 218
+
+String, 21
+
+Sun, diameter of, 280
+  constitution of, 79
+  a magnet, 164, 198-9
+  mass of, 190
+  heat of, 109
+  motions of, 270
+  orbital velocity of, 35
+  rotation of, 246
+  centre of two forces, 186
+
+
+Tails of comets, 300, 304
+  straight, 300
+  curved, 301
+  multiple, 300
+
+Tait, Prof., 18, 40-1, 88, 247
+
+Telescope, 79
+
+Temperature, 104-5
+
+Terrestrial magnetism, 207-12
+  gravity, 29
+
+Theory, atomic, 44
+  rules for making, 3
+  undulatory, 123
+  of exchanges, 105
+
+Thermodynamics, first law of, 87, 114
+  second law of, 116
+
+Thomson, J. J., Prof., 43, 326, 335
+
+Tidal water-power, 88
+
+Tides, 89, 96
+
+Torsion balance, 185
+
+Trade winds, 96, 249
+
+Transformation of energy, 86
+  of motion, 93
+
+Transverse vibration of light, 130
+
+Tuning-fork, 104
+
+Tympanum, 120
+
+Tyndall on radiation, 104, 106
+  on light, 71
+  on Lines of Force, 174
+  on aether, 77
+  on atoms, 106
+  on aether waves, 112
+
+
+Ultra-violet rays, 140
+  red rays, 140
+
+Unity of universe, 322-9
+
+Universal gravitation, 24
+  aether, 58
+
+Universe, 313, 322, 347
+
+Uranus, 68
+  mass of, 235
+  density of, 242
+  orbital velocity of, 265
+  a magnet, 196
+
+Ursa Major, 307
+  Minor, 307
+
+
+Vapour, 49
+
+Variation, magnetic, 209-11
+
+Velocity of light, 148
+  of electric waves, 182
+  of heat waves, 148
+  of falling bodies, 21
+  of wave motion, 76
+
+Velocity, angular, 250
+
+Venus, 33, 68, 79
+  a magnet, 197
+  mass of, 235
+  rotation of, 219
+  orbital velocity of, 251
+  periodic time of, 251
+
+Vibration, atomic, 75
+
+Vibrations, transverse, 130
+  longitudinal, 130
+  of sound, 123
+
+Vibratory motion, 91
+
+Vogel, Prof., 308, 312
+
+Vogt, Prof., 332
+
+Volume of sun, 27
+
+Von Asten, 234, 296
+
+Vortex theory, 92, 337
+  motion, 221-4
+  atom, 93, 126, 337
+  rings, 125, 337
+
+Vortices, molecular, 103
+
+
+Water waves, 124
+  currents, power of, 95
+  composition of, 141
+  power, 88
+
+Wave front, 128
+  motion, 124, 160
+
+Wave lengths, 120
+  envelope, 112
+
+Waves, chemical, 141
+  sound, 104, 120, 124
+  light, 126
+  heat, 141
+  electric, 159
+  spherical, 112
+  electro-magnetic, 165
+
+Weight, 29, 69, 84
+  variation of, 29
+  pound, 30
+
+Whewell, 3, 221
+
+Winds, 81, 90
+  energy of, 90
+  trade, 225
+
+Work, 96
+  and energy, 84
+  from heat, 116
+
+
+Young, Thomas, 54, 64, 67, 123
+  on aether, 58
+  fourth hypothesis, 70
+  Prof., of America, on electric space, 166
+
+
+Zinc, 88
+
+Zodiacal light, 277-9
+
+
+              _Richard Clay & Sous, Limited, London & Bungay._
+
+
+
+
+                        Some New Publications
+
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+                              * * * * *
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+                      MR. H. G. WELLS'S NEW WORK.
+
+MANKIND IN THE MAKING. By H. G. WELLS, author of "Anticipations," etc.
+Crown 8vo, _7s. 6d._
+
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+and political questions in a new way and from a new starting-point,
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+
+
+                   DR. ALFRED RUSSEL WALLACE'S NEW BOOK.
+
+MAN'S PLACE IN THE UNIVERSE. A study of the results of scientific
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+"Darwinism," etc., etc. With Diagrams. Demy 8vo, _12s. 6d. net_.
+
+This volume is an amplification and extension of the much-discussed
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+
+In the course of the work the various astronomical and other criticisms
+of the article are considered and replied to.
+
+
+                       A NEW THEORY OF GRAVITATION.
+
+AETHER AND GRAVITATION. By W. G. HOOPER, F.S.S. With Diagrams. Demy 8vo,
+_12s. 6d. net_.
+
+This work seeks to offer an acceptable solution of the greatest
+scientific problem that has puzzled scientists for the past 200 years.
+Ever since the discovery of universal gravitation by Sir Isaac Newton,
+the question has arisen, over and over again, as to what is the physical
+cause of the attraction of gravitation. Is it due, as Newton himself
+suggested, to the properties and qualities of the universal aether, or
+is it due to some still unknown and undiscovered medium?
+
+By the theory propounded in this work, the author has for the first time
+brought aetherial physics into harmony with all observation and
+experiments; so that the inertia, the density, and the elasticity of the
+aether are brought into harmony with all experience by philosophical
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+
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+THE REAL DICKENS LAND. With an outline of Charles Dickens's life. By H.
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+
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+every good reader of his works; but his intimate knowledge of the
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+human being, is not so apparent, because the reader has not the
+necessary knowledge of the places upon which to base an estimate.
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+will appeal to old Carlylean Readers by its careful grouping of
+biographical events around the places with which they are inextricably
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+
+A valuable Carlyle Chronology is appended, together with an Index and
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+
+
+                            HISTORY OF CHINA.
+
+CHINA, PAST AND PRESENT. By E. H. PARKER, Professor of Chinese at the
+Owens College, Manchester; formerly H.B.M. Consul at Kiungchow; Author
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+
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+so that the work may serve as a kind of preface to that enthralling
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+
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+                            IZAAK WALTON.
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+
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+
+                    LONDON: CHAPMAN & HALL, LTD.
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+
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+                        *    *    *    *    *
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+
+
+Transcriber's note:
+
+   ART. 41 is missing from the book.
+
+   In several instances changed S, W, E into italics to be
+   consistent with the rest of the book.
+
+   Page 194: Fixed typographical error for demonstated
+
+   Changed Figure captions so that all are of the form
+   "Fig: number."
+
+   Left unknown/misspelled word protile in appendix b
+
+   Page 148: ... and the Index, The surname of Ole Christensen
+   Rømer is spelled multiple times Roemer and once as Römer in
+   the index. Changed Römer to the English spelling "Roemer."
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+
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+<h1>The Project Gutenberg eBook, Aether and Gravitation, by William George
+Hooper</h1>
+<pre>
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at <a href = "http://www.gutenberg.org">www.gutenberg.org</a></pre>
+<p>Title: Aether and Gravitation</p>
+<p>Author: William George Hooper</p>
+<p>Release Date: February 22, 2008  [eBook #24667]</p>
+<p>Language: English</p>
+<p>Character set encoding: ISO-8859-1</p>
+<p>***START OF THE PROJECT GUTENBERG EBOOK AETHER AND GRAVITATION***</p>
+<p>&nbsp;</p>
+<h3>E-text prepared by Barbara Tozier, Ronnie Sahlberg, Bill Tozier,<br />
+    and the Project Gutenberg Online Distributed Proofreading Team<br />
+    (http://www.pgdp.net)</h3>
+<p>&nbsp;</p>
+<hr class="full" />
+<p>&nbsp;</p>
+<p>&nbsp;</p>
+<p>&nbsp;</p>
+
+<h1>AETHER AND GRAVITATION</h1>
+
+<p><br /><br /><br /><br /><br /><br /><br /></p>
+
+<hr style="width: 65%;" />
+
+
+<h1>AETHER</h1>
+
+<h4>AND</h4>
+
+<h1>GRAVITATION</h1>
+
+<h5>BY</h5>
+
+<h2>WILLIAM GEORGE HOOPER, F.S.S.</h2>
+
+<div class="figcenter" style="width: 200px;">
+<img src="images/003.jpg" width="200" height="330"
+alt="Illustration"
+title="Illustration" />
+</div>
+
+
+<h4>LONDON </h4>
+<h4>CHAPMAN AND HALL, <span class="smcap">Ltd</span>.</h4>
+<h4>1903</h4>
+
+<hr style="width: 65%;" />
+
+<h2>INTRODUCTORY NOTES</h2>
+
+<p>
+The author in this work endeavours to solve the greatest scientific
+problem that has puzzled scientists for the past two hundred years. The
+question has arisen over and over again, since the discovery of
+universal gravitation by Sir Isaac Newton, as to what is the physical
+cause of the attraction of gravitation.
+</p>
+
+<p>
+&ldquo;Action at a distance&rdquo; has long ceased to be recognized as a possible
+phenomenon, although up to the present, the medium and method of
+gravitational attraction have not yet been discovered.
+</p>
+
+<p>
+It is, however, generally accepted by scientists, that the only possible
+medium which can give rise to the phenomena incidental to, and
+associated with the Law of Gravitation, must be the universal aether,
+which forms the common medium of all phenomena associated with light,
+heat, electricity and magnetism.
+</p>
+
+<p>
+It is impossible, however, to reconcile gravitational phenomena with the
+present conception of the universal aether medium, and a new theory is
+therefore demanded, before the long-sought-for explanation will be
+forthcoming.
+</p>
+
+<p>
+Professor Glazebrook definitely states the necessity for a new theory in
+his work on J. C. Maxwell, page 221, where he writes: &ldquo;We are waiting
+for some one to give us a theory of the aether, which shall include the
+facts of electricity and magnetism, luminous radiation, and it may be
+gravitation.&rdquo;
+</p>
+
+<p>
+A new theory of the aether is also demanded in view of the recent
+experimental results of Professor Lebedew, and Nichols and Hull of
+America. It is logically impossible to reconcile a frictionless aether,
+with their results relative to the pressure of light waves.
+</p>
+
+<p>
+In the following pages of this work the author has endeavoured to
+perfect a theory, which will bring aetherial physics more into harmony
+with modern observation and experiments; and by so doing, believes that
+he has found the key that will unlock the problem not only of the cause
+of universal gravitation, but also other problems of physical science.
+The author has taken Newton's Rules of Philosophy as his guide in the
+making of the new theory, as he believes that if any man knew anything
+of the rules of Philosophy, that man was Sir Isaac Newton. The first
+chapter therefore deals with the generally recognized rules which govern
+philosophical reasoning, the same being three in number; the fundamental
+rule being, that in making any hypothesis, the results of experience as
+obtained by observation and experiments must not be violated.
+</p>
+
+<p>
+In applying the rules to the present theory of the aether, he found that
+the theory as at present recognized violated two of the most important
+rules of Philosophy, because, while aether is supposed to be matter, yet
+it failed to fulfil the primary property of all matter, that is, it is
+not subject to the Law of Gravitation. If aether is matter, then, to be
+strictly logical and philosophical, it must possess the properties of
+matter as revealed by observation and experiment.
+</p>
+
+<p>
+Those properties are given in Chapter <a href="#CHAPTER_III">III</a>., where it is shown that they
+are atomicity, heaviness or weight, elasticity, density, inertia, and
+compressibility. To be strictly logical and philosophical, the author
+was compelled to postulate similar properties for the aether, or else
+his hypotheses would contravert the results of all experience.
+</p>
+
+<p>
+The application of these properties to the aether will be found in
+Chapter <a href="#CHAPTER_IV">IV</a>., where the author has postulated atomicity, heaviness or
+weight, density, elasticity, inertia, and compressibility for the
+aether, and so brought the theory of the aether into perfect harmony
+with all observation and experiments relative to ordinary matter. It
+will be shown that Clerk Maxwell also definitely affirms the atomicity
+of the aether, while Tyndall and Huyghens also use the term &ldquo;<i>particles
+of aether</i>&rdquo; over and over again.
+</p>
+
+<p>
+Moreover, in view of the most recent researches in electricity made by
+Sir William Crookes and Professor J. J. Thomson, we are compelled to
+accept an atomic basis for electricity, and as Dr. Lodge, in his <i>Modern
+Views of Electricity</i>, states that &ldquo;Aether is made up of positive and
+negative electricity,&rdquo; then, unless we postulate atomicity for the
+aether, we have to suppose that it is possible for a non-atomic body
+(aether) to be made up of atoms or corpuscles, which conclusion is
+absurd, and therefore must be rejected as illogical and unphilosophical.
+</p>
+
+<p>
+After postulating atomicity for the aether, we are then able to apply
+the Newtonian Law of Gravitation to it, which distinctly affirms that
+&ldquo;every particle of matter attracts every other particle,&rdquo; and so we
+arrive at Thomas Young's fourth hypothesis given in the Philosophical
+Transactions of 1802, where he asserts that &ldquo;All material bodies have an
+attraction for the aetherial medium, by means of which it is
+accumulated within their substance, and for a small distance around them
+in a state of greater density.&rdquo; He adds the significant remark that this
+hypothesis is opposed to that of Newton's. With an atomic and
+gravitative aether it is shown in Chapter <a href="#CHAPTER_IV">IV</a>. how the elasticity,
+density, and inertia of the medium are brought into harmony with all
+observation and experiments.
+</p>
+
+<p>
+In the succeeding chapters the new theory is applied to the phenomena of
+heat, light, electricity, and magnetism, and the principles enunciated
+therein are then applied to solar and stellar phenomena.
+</p>
+
+<p>
+One of the greatest stumbling-blocks to the discovery of the physical
+cause of gravitation, apart from the unphilosophical theory of the
+aether medium, lies in the fact that apparently the Law of Gravitation
+only recognizes a force of one kind. Dr. Lodge refers to this phase of
+the subject on page 39 of his <i>Modern Views of Matter</i> just published.
+It is here where scientists have failed to solve the problem of
+universal gravitation, as there are <i>two</i> forces at work in the solar
+system and not one; that is, if we are to accept the results of
+up-to-date experiments in relation to radiant light and heat as
+performed by Professor Lebedew, and Nichols and Hull of America. Their
+experiments conclusively prove that light waves exert a pressure upon
+all bodies on which they fall, and by no reasoning can this pressure be
+resolved into an attractive force.
+</p>
+
+<p>
+Herschel in his <i>Lectures on Scientific Subjects</i> definitely refers to
+the existence of a repulsive force in the solar system, and asserts that
+it offers the most interesting prospect of any future discovery.
+</p>
+
+<p>
+The author has therefore attacked the problem of the cause of
+gravitation, by trying to solve the problem of the cause of the
+<i>repulsive</i> force which has been experimentally demonstrated to exist by
+Professor Lebedew and others.
+</p>
+
+<p>
+In his efforts to ascertain the physical cause of the Centrifugal Force,
+he has been assisted by an unknown and original essay written by an
+unknown writer over twenty years ago. That unknown writer was the
+author's father, who wrote an essay on the <i>Complementary Law of
+Gravitation</i>, and if it had not been for that essay, the present work
+would never have been attempted.
+</p>
+
+<p>
+The main object of the author in Chapters <a href="#CHAPTER_VI">VI</a>., <a href="#CHAPTER_VII">VII</a>., and <a href="#CHAPTER_VIII">VIII</a>., is to
+prove beyond the possibility of contradiction, from the phenomena of
+heat, light, and electricity, the existence of <i>two</i> forces in the solar
+system; and by so doing, to bring our philosophy of the aether medium,
+and all gravitational phenomena, into harmony with all observation and
+experiments, which at present is not the case. In seeking to do this he
+found that the new theory of the aether harmonized with views given, by
+Faraday and Clerk Maxwell in relation to electric and magnetic
+phenomena, and by the new theory Maxwell's hypothesis of &ldquo;Physical Lines
+of Force&rdquo; receives a definite and physical basis. In Chapter <a href="#CHAPTER_X">X</a>. the
+author endeavours to show what the Electro-Kinetic energy is, which term
+is used by Clerk Maxwell, the term being brought for the first time into
+harmony with our experience. The Electro-Magnetic Theory of Light also
+receives fresh light from the new theory of an atomic and gravitating
+aether.
+</p>
+
+<p>
+In the succeeding chapters the theory is applied to Newton's Laws of
+Motion and Kepler's Laws, and is found to harmonize with all the results
+given by these laws. Such a result is a distinct advance on the
+application of a frictionless aether to solar and stellar phenomena, as
+it is impossible for Kepler's Laws to be reconciled in any way with our
+present theory of the aether.
+</p>
+
+<p>
+In the concluding chapter on the unity of the universe, certain views
+are suggested as to the ultimate constitution of all matter, upon an
+aetherial basis, which hypothesis practically resolves itself into an
+electric basis for all matter. It is suggested that aether and
+electricity are one and the same medium, both being a form of matter,
+and both possessing exactly the same properties, viz. atomicity, weight,
+density, elasticity, inertia, and compressibility. This view of matter
+harmonizes with the most &ldquo;Modern Views of Matter&rdquo; as suggested by Sir
+Oliver Lodge in his Romanes Lecture 1903.
+</p>
+
+<p>
+The author has accepted Newton's way of spelling &ldquo;<i>aether</i>&rdquo; as given in
+his work on <i>Optics</i>, and has given &ldquo;<i>aetherial</i>&rdquo; the same suffix as
+&ldquo;material,&rdquo; in order to differentiate the word from &ldquo;ethereal,&rdquo; which is
+too metaphysical a term for a material medium.
+</p>
+
+<p style="margin-left: 2em;"><i>Nottingham</i>,</p>
+<p style="margin-left: 4em;"><i>Sept</i>. 1903.</p>
+
+<hr style="width: 65%;" />
+
+<h1><a name="TOC" id="TOC"></a>CONTENTS</h1>
+
+<h2><a name="CHAPTER_I_TOC" id="CHAPTER_I_TOC"></a><a href="#CHAPTER_I">CHAPTER I</a></h2>
+
+<h3>PHILOSOPHY OF GRAVITATION</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;">PAGE</th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align: right;"><a href="#ART_1">1</a>.</td><td>GRAVITATION</td><td style="text-align: right;"><a href="#Page_1">1</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_2">2</a>.</td><td>CAUSE OF GRAVITATION</td><td style="text-align: right;"><a href="#Page_1">1</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_3">3</a>.</td><td>NEWTON'S RULES OF PHILOSOPHY</td><td style="text-align: right;"><a href="#Page_3">3</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_4">4</a>.</td><td>FIRST RULE OF PHILOSOPHY</td><td style="text-align: right;"><a href="#Page_3">3</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_5">5</a>.</td><td>SECOND RULE OF PHILOSOPHY</td><td style="text-align: right;"><a href="#Page_4">4</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_6">6</a>.</td><td>THIRD RULE OF PHILOSOPHY</td><td style="text-align: right;"><a href="#Page_7">7</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_7">7</a>.</td><td>APPLICATION OF RULES TO GRAVITATION</td><td style="text-align: right;"><a href="#Page_9">9</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_8">8</a>.</td><td>ANALYSIS OF LAW OF GRAVITATION</td><td style="text-align: right;"><a href="#Page_9">9</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_9">9</a>.</td><td>PRIMITIVE IMPULSE</td><td style="text-align: right;"><a href="#Page_10">10</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_10">10</a>.</td><td>CENTRIPETAL FORCE</td><td style="text-align: right;"><a href="#Page_12">12</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_11">11</a>.</td><td>CENTRIFUGAL FORCE</td><td style="text-align: right;"><a href="#Page_13">13</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_12">12</a>.</td><td>NEWTON'S LAWS OF MOTION</td><td style="text-align: right;"><a href="#Page_15">15</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_13">13</a>.</td><td>FORCE</td><td style="text-align: right;"><a href="#Page_16">16</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_14">14</a>.</td><td>FIRST LAW OF MOTION</td><td style="text-align: right;"><a href="#Page_16">16</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_15">15</a>.</td><td>SECOND LAW OF MOTION</td><td style="text-align: right;"><a href="#Page_19">19</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_16">16</a>.</td><td>THIRD LAW OF MOTION</td><td style="text-align: right;"><a href="#Page_20">20</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align: right;"><a href="#ART_17">17</a>.</td><td>SUMMARY OF CHAPTER</td><td style="text-align: right;"><a href="#Page_22">22</a></td></tr>
+</table>
+
+
+<h2><a name="CHAPTER_II_TOC" id="CHAPTER_II_TOC"></a><a href="#CHAPTER_II">CHAPTER II</a></h2>
+
+<h3>PHILOSOPHY OF GRAVITATION--(<i>continued</i>)</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_18">18</a>.</td><td>GRAVITATION ATTRACTION</td><td style="text-align:right;"><a href="#Page_24">24</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_19">19</a>.</td><td>UNIVERSALITY OF GRAVITATION</td><td style="text-align:right;"><a href="#Page_24">24</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_20">20</a>.</td><td>DIRECTION OF THE FORCES</td><td style="text-align:right;"><a href="#Page_26">26</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_21">21</a>.</td><td>PROPORTION OF THE FORCES</td><td style="text-align:right;"><a href="#Page_26">26</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_22">22</a>.</td><td>LAW OF INVERSE SQUARES</td><td style="text-align:right;"><a href="#Page_27">27</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_23">23</a>.</td><td>TERRESTRIAL GRAVITY</td><td style="text-align:right;"><a href="#Page_29">29</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_24">24</a>.</td><td>CENTRIFUGAL FORCE</td><td style="text-align:right;"><a href="#Page_30">30</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_25">25</a>.</td><td>KEPLER'S LAWS</td><td style="text-align:right;"><a href="#Page_32">32</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_26">26</a>.</td><td>FIRST LAW OF KEPLER</td><td style="text-align:right;"><a href="#Page_33">33</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_27">27</a>.</td><td>SECOND LAW OF KEPLER</td><td style="text-align:right;"><a href="#Page_36">36</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_28">28</a>.</td><td>THIRD LAW OF KEPLER</td><td style="text-align:right;"><a href="#Page_37">37</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_III_TOC" id="CHAPTER_III_TOC"></a><a href="#CHAPTER_III">CHAPTER III</a></h2>
+
+<h3>MATTER</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_29">29</a>.</td><td>WHAT IS MATTER?      </td><td style="text-align:right;"><a href="#Page_40">40</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_30">30</a>.</td><td>CONSERVATION OF MATTER      </td><td style="text-align:right;"><a href="#Page_42">42</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_31">31</a>.</td><td>MATTER IS ATOMIC      </td><td style="text-align:right;"><a href="#Page_42">42</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_32">32</a>.</td><td>WHAT IS AN ATOM?      </td><td style="text-align:right;"><a href="#Page_43">43</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_33">33</a>.</td><td>THE ATOMIC THEORY      </td><td style="text-align:right;"><a href="#Page_44">44</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_34">34</a>.</td><td>KINDS OF ATOMS      </td><td style="text-align:right;"><a href="#Page_44">44</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_35">35</a>.</td><td>ELEMENTS OF MATTER      </td><td style="text-align:right;"><a href="#Page_47">47</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_36">36</a>.</td><td>THREE KINDS OF MATTER      </td><td style="text-align:right;"><a href="#Page_47">47</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_37">37</a>.</td><td>MATTER IS GRAVITATIVE      </td><td style="text-align:right;"><a href="#Page_50">50</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_38">38</a>.</td><td>MATTER POSSESSES DENSITY      </td><td style="text-align:right;"><a href="#Page_51">51</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_39">39</a>.</td><td>MATTER POSSESSES ELASTICITY      </td><td style="text-align:right;"><a href="#Page_51">51</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_40">40</a>.</td><td>MATTER POSSESSES INERTIA      </td><td style="text-align:right;"><a href="#Page_52">52</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_IV_TOC" id="CHAPTER_IV_TOC"></a><a href="#CHAPTER_IV">CHAPTER IV</a></h2>
+
+<h3>AETHER</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_42">42</a>.</td><td>AETHER IS MATTER      </td><td style="text-align:right;"><a href="#Page_54">54</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_43">43</a>.</td><td>AETHER IS UNIVERSAL      </td><td style="text-align:right;"><a href="#Page_58">58</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_44">44</a>.</td><td>AETHER IS ATOMIC      </td><td style="text-align:right;"><a href="#Page_59">59</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_45">45</a>.</td><td>AETHER IS GRAVITATIVE      </td><td style="text-align:right;"><a href="#Page_64">64</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_46">46</a>.</td><td>AETHER POSSESSES DENSITY      </td><td style="text-align:right;"><a href="#Page_71">71</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_47">47</a>.</td><td>AETHER POSSESSES ELASTICITY      </td><td style="text-align:right;"><a href="#Page_74">74</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_48">48</a>.</td><td>AETHER POSSESSES INERTIA      </td><td style="text-align:right;"><a href="#Page_76">76</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_49">49</a>.</td><td>AETHER IS IMPRESSIBLE      </td><td style="text-align:right;"><a href="#Page_78">78</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_50">50</a>.</td><td>AETHER AND ITS MOTIONS      </td><td style="text-align:right;"><a href="#Page_80">80</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_V_TOC" id="CHAPTER_V_TOC"></a><a href="#CHAPTER_V">CHAPTER V</a></h2>
+
+<h3>ENERGY</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_51">51</a>.</td><td>ENERGY      </td><td style="text-align:right;"><a href="#Page_83">83</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_52">52</a>.</td><td>CONSERVATION OF ENERGY      </td><td style="text-align:right;"><a href="#Page_84">84</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_53">53</a>.</td><td>TRANSFORMATION OF ENERGY      </td><td style="text-align:right;"><a href="#Page_86">86</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_54">54</a>.</td><td>POTENTIAL ENERGY      </td><td style="text-align:right;"><a href="#Page_87">87</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_55">55</a>.</td><td>KINETIC ENERGY      </td><td style="text-align:right;"><a href="#Page_89">89</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_56">56</a>.</td><td>ENERGY AND MOTION      </td><td style="text-align:right;"><a href="#Page_91">91</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_57">57</a>.</td><td>CONSERVATION OF MOTION      </td><td style="text-align:right;"><a href="#Page_92">92</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_58">58</a>.</td><td>TRANSFORMATION OF MOTION      </td><td style="text-align:right;"><a href="#Page_93">93</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_59">59</a>.</td><td>MOTION AND WORK      </td><td style="text-align:right;"><a href="#Page_95">95</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_VI_TOC" id="CHAPTER_VI_TOC"></a><a href="#CHAPTER_VI">CHAPTER VI</a></h2>
+
+<h3>HEAT, A MODE OF MOTION</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_60">60</a>.</td><td>HEAT, A MODE OF MOTION      </td><td style="text-align:right;"><a href="#Page_98">98</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_61"> 61</a>.</td><td>HEAT AND MATTER      </td><td style="text-align:right;"><a href="#Page_100">100</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_62"> 62</a>.</td><td>RADIATION AND ABSORPTION      </td><td style="text-align:right;"><a href="#Page_104">104</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_63"> 63</a>.</td><td>HEAT IS A REPULSIVE MOTION      </td><td style="text-align:right;"><a href="#Page_107">107</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_64"> 64</a>.</td><td>RADIANT HEAT      </td><td style="text-align:right;"><a href="#Page_109">109</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_65"> 65</a>.</td><td>DIRECTION OF A RAY OF HEAT      </td><td style="text-align:right;"><a href="#Page_111">111</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_66"> 66</a>.</td><td>LAW OF INVERSE SQUARES      </td><td style="text-align:right;"><a href="#Page_112">112</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_67"> 67</a>.</td><td>FIRST LAW OF THERMODYNAMICS      </td><td style="text-align:right;"><a href="#Page_114">114</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_68"> 68</a>.</td><td>SECOND LAW OF THERMODYNAMICS      </td><td style="text-align:right;"><a href="#Page_116">116</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_69"> 69</a>.</td><td>IDENTITY OF HEAT AND LIGHT      </td><td style="text-align:right;"><a href="#Page_119">119</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_VII_TOC" id="CHAPTER_VII_TOC"></a><a href="#CHAPTER_VII">CHAPTER VII</a></h2>
+
+<h3>LIGHT, A MODE OF MOTION</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_70">70</a>.</td><td>LIGHT, A MODE OF MOTION        </td><td style="text-align:right;"><a href="#Page_122">122</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_71"> 71</a>.</td><td>TRANSVERSE VIBRATION OF LIGHT       </td><td style="text-align:right;"><a href="#Page_130">130</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_72"> 72</a>.</td><td>REFLECTION AND REFRACTION       </td><td style="text-align:right;"><a href="#Page_135">135</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_73"> 73</a>.</td><td>THE SOLAR SPECTRUM       </td><td style="text-align:right;"><a href="#Page_139">139</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_74"> 74</a>.</td><td>DIRECTION OF A RAY OF LIGHT      </td><td style="text-align:right;"><a href="#Page_144">144</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_75"> 75</a>.</td><td>INTENSITY OF LIGHT      </td><td style="text-align:right;"><a href="#Page_145">145</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_76"> 76</a>.</td><td>VELOCITY OF LIGHT      </td><td style="text-align:right;"><a href="#Page_148">148</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_77"> 77</a>.</td><td>DYNAMICAL VALUE OF LIGHT      </td><td style="text-align:right;"><a href="#Page_150">150</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_78"> 78</a>.</td><td>ELECTRO-MAGNETIC THEORY OF LIGHT     </td><td style="text-align:right;"><a href="#Page_155">155</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_VIII_TOC" id="CHAPTER_VIII_TOC"></a><a href="#CHAPTER_VIII">CHAPTER VIII</a></h2>
+
+<h3>AETHER AND ELECTRICITY</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_79">79</a>.</td><td>ELECTRICITY, A MODE OF MOTION       </td><td style="text-align:right;"><a href="#Page_162">162</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_80"> 80</a>.</td><td>ELECTRIC FIELD       </td><td style="text-align:right;"><a href="#Page_166">166</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_81"> 81</a>.</td><td>ELECTRIC INDUCTION       </td><td style="text-align:right;"><a href="#Page_174">174</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_82"> 82</a>.</td><td>ELECTRIC ENERGY       </td><td style="text-align:right;"><a href="#Page_179">179</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_83"> 83</a>.</td><td>ELECTRIC RADIATION       </td><td style="text-align:right;"><a href="#Page_182">182</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_84"> 84</a>.</td><td>LAW OF INVERSE SQUARES       </td><td style="text-align:right;"><a href="#Page_184">184</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_85"> 85</a>.</td><td>SECOND LAW OF ELECTRICITY       </td><td style="text-align:right;"><a href="#Page_186">186</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_IX_TOC" id="CHAPTER_IX_TOC"></a><a href="#CHAPTER_IX">CHAPTER IX</a></h2>
+
+<h3>AETHER AND MAGNETISM</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_86">86</a>.</td><td>ELECTRO-MAGNETISM        </td><td style="text-align:right;"><a href="#Page_192">192</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_87">87</a>.</td><td>THE EARTH A MAGNET          </td><td style="text-align:right;"><a href="#Page_195">195</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_88">88</a>.</td><td>THE SUN AN ELECTRO-MAGNET           </td><td style="text-align:right;"><a href="#Page_199">199</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_89">89</a>.</td><td>FARADAY'S LINES OF FORCE      </td><td style="text-align:right;"><a href="#Page_203">203</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_90">90</a>.</td><td>TERRESTRIAL MAGNETISM      </td><td style="text-align:right;"><a href="#Page_206">206</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_91">91</a>.</td><td>SOLAR MAGNETS        </td><td style="text-align:right;"><a href="#Page_211">211</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_92">92</a>.</td><td>CAUSE OF ROTATION OF THE EARTH ON ITS AXIS      </td><td style="text-align:right;"><a href="#Page_219">219</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_93">93</a>.</td><td>VORTEX MOTION       </td><td style="text-align:right;"><a href="#Page_221">221</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_94">94</a>.</td><td>RELATIVE MOTION OF AETHER AND MATTER       </td><td style="text-align:right;"><a href="#Page_224">224</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_95">95</a>.</td><td>VIBRATIONS IN THE ELECTRO-MAGNETIC THEORY OF LIGHT       </td><td style="text-align:right;"><a href="#Page_228">228</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_X_TOC" id="CHAPTER_X_TOC"></a><a href="#CHAPTER_X">CHAPTER X</a></h2>
+
+<h3>AETHER AND NEWTON'S LAWS OF MOTION</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_96">96</a>.</td><td>AETHER AND CENTRIFUGAL FORCE       </td><td style="text-align:right;"><a href="#Page_232">232</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_97"> 97</a>.</td><td>AETHER AND CENTRIPETAL FORCE       </td><td style="text-align:right;"><a href="#Page_236">236</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_98"> 98</a>.</td><td>AETHER AND NEWTON'S FIRST LAW OF MOTION       </td><td style="text-align:right;"><a href="#Page_239">239</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_99"> 99</a>.</td><td>AETHER AND NEWTON'S SECOND LAW OF MOTION      </td><td style="text-align:right;"><a href="#Page_244">244</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_100"> 100</a>.</td><td>AETHER AND NEWTON'S THIRD LAW OF MOTION      </td><td style="text-align:right;"><a href="#Page_251">251</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_101"> 101</a>.</td><td>WHY PLANETS REVOLVE FROM WEST TO EAST        </td><td style="text-align:right;"><a href="#Page_253">253</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_XI_TOC" id="CHAPTER_XI_TOC"></a><a href="#CHAPTER_XI">CHAPTER XI</a></h2>
+
+<h3>AETHER AND KEPLER'S LAWS</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_102">102</a>.</td><td>AETHER AND KEPLER'S FIRST LAW      </td><td style="text-align:right;"><a href="#Page_256">256</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_103"> 103</a>.</td><td>AETHER AND KEPLER'S SECOND LAW       </td><td style="text-align:right;"><a href="#Page_260">260</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_104"> 104</a>.</td><td>AETHER AND KEPLER'S THIRD LAW       </td><td style="text-align:right;"><a href="#Page_263">263</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_105"> 105</a>.</td><td>ORBITAL MOTION OF PLANETS       </td><td style="text-align:right;"><a href="#Page_266">266</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_106"> 106</a>.</td><td>ECCENTRICITY OF THE MOON'S ORBIT      </td><td style="text-align:right;"><a href="#Page_268">268</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_107"> 107</a>.</td><td>THE SUN AND KEPLER'S FIRST LAW       </td><td style="text-align:right;"><a href="#Page_270">270</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_108"> 108</a>.</td><td>THE SUN AND KEPLER'S SECOND LAW       </td><td style="text-align:right;"><a href="#Page_274">274</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_109"> 109</a>.</td><td>AETHER AND THE PLANE OF THE ECLIPTIC      </td><td style="text-align:right;"><a href="#Page_277">277</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_110"> 110</a>.</td><td>AETHER AND THE CENTRIPETAL FORCE         </td><td style="text-align:right;"><a href="#Page_282">282</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_XII_TOC" id="CHAPTER_XII_TOC"></a><a href="#CHAPTER_XII">CHAPTER XII</a></h2>
+
+<h3>AETHER AND COMETS</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_111">111</a>.</td><td>WHAT IS A COMET?        </td><td style="text-align:right;"><a href="#Page_291">291</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_112"> 112</a>.</td><td>ORBITS OF COMETS        </td><td style="text-align:right;"><a href="#Page_293">293</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_113"> 113</a>.</td><td>KINDS OF COMETS         </td><td style="text-align:right;"><a href="#Page_296">296</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_114"> 114</a>.</td><td>PARTS OF A COMET        </td><td style="text-align:right;"><a href="#Page_298">298</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_115"> 115</a>.</td><td>CENTRIFUGAL FORCE AND COMETS          </td><td style="text-align:right;"><a href="#Page_300">300</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_116"> 116</a>.</td><td>FORMATION OF TAILS         </td><td style="text-align:right;"><a href="#Page_303">303</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_XIII_TOC" id="CHAPTER_XIII_TOC"></a><a href="#CHAPTER_XIII">CHAPTER XIII</a></h2>
+
+<h3>AETHER AND STARRY WORLD</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_117">117</a>.</td><td>STARRY WORLD       </td><td style="text-align:right;"><a href="#Page_306">306</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_118">118</a>.</td><td>STARS AND KEPLER'S LAWS      </td><td style="text-align:right;"><a href="#Page_309">309</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_119">119</a>.</td><td>AETHER AND NEBULAE       </td><td style="text-align:right;"><a href="#Page_313">313</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_120">120</a>.</td><td>WHAT IS A NEBULA?       </td><td style="text-align:right;"><a href="#Page_314">314</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_121">121</a>.</td><td>AETHER AND NEBULAR HYPOTHESIS       </td><td style="text-align:right;"><a href="#Page_317">317</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_122">122</a>.</td><td>KINDS OF NEBULAE       </td><td style="text-align:right;"><a href="#Page_319">319</a></td></tr>
+</table>
+
+<h2><a name="CHAPTER_XIV_TOC" id="CHAPTER_XIV_TOC"></a><a href="#CHAPTER_XIV">CHAPTER XIV</a></h2>
+
+<h3>AETHER AND THE UNIVERSE</h3>
+
+<table summary="CONTENTS.">
+<tr><th style="width: 5%;"></th><th style="width: 5%;"></th><th></th><th style="width: 10%; text-align: right;"></th></tr>
+<tr><td style="text-align: center;">ART.</td><td style="text-align:right;"><a href="#ART_123">123</a>.</td><td>THE UNIVERSE      </td><td style="text-align:right;"><a href="#Page_323">323</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_124"> 124</a>.</td><td>UNITY OF THE UNIVERSE      </td><td style="text-align:right;"><a href="#Page_326">326</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_125"> 125</a>.</td><td>CONSTITUTION OF MATTER      </td><td style="text-align:right;"><a href="#Page_334">334</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_126"> 126</a>.</td><td>QUOD ERAT FACIENDUM      </td><td style="text-align:right;"><a href="#Page_337">337</a></td></tr>
+<tr><td style="text-align: center;">"</td><td style="text-align:right;"><a href="#ART_127"> 127</a>.</td><td>GOD AND THE UNIVERSE    </td><td style="text-align:right;"><a href="#Page_342">342</a></td></tr>
+</table>
+
+<table summary="CONTENTS.">
+<tr><td style="text-align: left;">APPENDIX</td><td style="text-align: right;"><a href="#Page_349">349</a></td></tr>
+<tr><td style="text-align: left;">INDEX</td><td style="text-align: right;"><a href="#Page_351">351</a></td></tr>
+</table>
+
+<hr style="width: 65%;" />
+
+
+<p><span class='pagenum'><a name="Page_1" id="Page_1"></a><a href="#TOC">[1]</a></span></p>
+<h1>AETHER AND GRAVITATION</h1>
+
+<h2><a name="CHAPTER_I" id="CHAPTER_I"></a><a href="#CHAPTER_I_TOC">CHAPTER I</a></h2>
+
+<h3>PHILOSOPHY OF GRAVITATION</h3>
+
+<p>
+<a name='ART_1' id='ART_1'></a><span class='smcap'>Art</span>. 1. <i>Gravitation</i>.--In the realm of Science, there exists a
+Force or Law that pervades and influences all Nature, and from
+the power of which, nothing, not even an atom, is free.
+</p>
+
+<p>
+It holds together the component parts of each and every
+individual world, and in the world's revolving prevents both its
+inhabitants and its vegetation from being whirled off its surface
+into space. It exists in each and every central sun, and circles
+round each sun its associated system of planets. It rolls each
+satellite around its primary planet, and regulates the comet's
+mysterious flight into the depths of space, while the pendulation
+of even the remotest star is accomplished by this same force.
+Our own rocking world obeys the same mysterious power, that
+seems to grasp the entire material creation as with the grasp
+of the Infinite.
+</p>
+
+<p>
+It exists in, and influences every atom, whose combinations
+compose and constitute the entire material creation, or each and
+every orb that bespangle the blue infinity.
+</p>
+
+<p>
+As is readily seen, it weaves as it were around each and all, a
+mysterious network or chain, that binds star to star, and world
+to world, blending all into one entire, vast and complete unity.
+It decides all their orbits and distances, regulates and controls
+all their motions, from the most simple even to the more complex
+and intricate, ultimately producing that wondrous and beauteous
+order, unity and harmony that everywhere pervade and blend
+all the universe into one grand and harmonious whole.
+</p>
+
+<p>
+That Law I need hardly say is the Law of Gravitation.
+</p>
+
+<p>
+<a name='ART_2' id='ART_2'></a><span class='smcap'>Art</span>. 2. <i>Cause of Gravitation</i>.--Now the question arises, and
+indeed has arisen a thousand times since the discovery of this
+law by Sir Isaac Newton over two hundred years ago, as to
+what is the physical cause, the true explanation of this universal
+attraction.
+</p>
+
+<p><span class='pagenum'><a name='Page_2' id='Page_2'></a><a href='#TOC'>[2]</a></span>
+MacLaurin in his work on the philosophical discoveries of Sir
+Isaac Newton says: &ldquo;In all cases when bodies seem to act upon
+each other at a distance, and tend towards one another without
+any apparent cause impelling them, this force has been commonly
+called Attraction, and this term is frequently used by Sir Isaac
+Newton. But he gives repeated caution that he pretends not by
+the use of this term to define the nature of the power, or the
+manner in which it acts. Nor does he ever affirm or insinuate
+that a body can act upon another body at a distance, but by the
+intervention of other bodies.&rdquo;
+</p>
+
+<p>
+The results of modern discovery show that action at a distance,
+without the intervention of any medium, as for example the sun
+attracting the earth, is not the universal condition which governs
+all so-called forces.
+</p>
+
+<p>
+It is now recognized that light and heat are both forms of
+energy, and therefore forces, using the term in the same sense
+that it is applied to Gravitation.
+</p>
+
+<p>
+Both light and heat are transmitted through space with finite
+velocity through the intervention of a medium, the universal
+Aether. It is therefore only reasonable to suppose, that if one or
+more particular kinds of energy, or forces, require a medium
+for their transmission, why not another force, as for example
+Gravitation?
+</p>
+
+<p>
+Gravitation is an universal force which operates throughout
+the length and breadth of the entire universe, and if there be a
+medium which is to Gravitation, what the Aether is to light and
+heat, the question at once confronts us, as to what are the
+characteristics, properties, and qualities of that universal medium,
+which is to form the physical basis of this universal attraction?
+</p>
+
+<p>
+Newton himself suggested that Gravitation was due to an
+aetherial subtle medium, which filled all space.
+</p>
+
+<p>
+In his well-known letter to Bentley, Newton writes as follows:
+&ldquo;That Gravity should be innate, inherent, and essential to
+matter, so that one body can act upon another body at a distance
+through a vacuum, without the mediation of anything else, by
+and through which their action and force may be conveyed from
+one to another, is to me so great an absurdity, that I believe no
+man who has any philosophical nature or competent faculty of
+thinking can ever fall into it.&rdquo;
+</p>
+
+<p>
+We also know from his Queries in his book on <i>Optics</i>, that he
+sought for the explanation of Gravitation in the properties of a
+subtle, aetherial medium diffused over the universe.
+</p>
+
+<p>
+MacLaurin on this point says: &ldquo;It appears from his letters to
+Boyle, that this was his opinion early, and if he did not publish
+his opinion sooner, it proceeded from hence only, that he found
+he was not able from experiment and observation to give a<span class='pagenum'><a name='Page_3' id='Page_3'></a><a href='#TOC'>[3]</a></span>
+satisfactory account of this medium, and the manner of its operations
+in producing the chief phenomena of Nature.&rdquo;
+</p>
+
+<p>
+Therefore, if we accept Newton's suggestion, and endeavour
+to trace the physical cause of Gravitation in the qualities, properties,
+and motions of this subtle aetherial medium to which he
+refers, we shall be simply working on the lines laid down by Sir
+Isaac Newton himself.
+</p>
+
+<p>
+I wish therefore to premise, that the future pages of this work
+will deal with the hypothesis of this aetherial medium, by which
+will be accounted for, and that on a satisfactory and physical
+basis, the universal Law of Gravitation.
+</p>
+
+<p>
+<a name='ART_3' id='ART_3'></a><span class='smcap'>Art</span>. 3. <i>Rules of Philosophy</i>.--In order that we may rightly
+understand the making of any hypothesis, I purpose giving some
+rules laid down by such philosophers as Newton and Herschel,
+so that we may be guided by right principles in the development
+of this new hypothesis as to the cause of Gravitation.
+</p>
+
+<p>
+The rules that govern the making of any hypotheses, so far
+as I can discern, may be summed up under the three following
+heads--
+</p>
+
+<p style='margin-left: 5em;'>(1) Simplicity of conception.</p>
+
+<p style='margin-left: 5em;'>(2) Agreement with experience, observation, and experiment.</p>
+
+<p style='margin-left: 5em;'>(3) Satisfactorily accounting for, and explaining all phenomena
+sought to be explained.</p>
+
+<p>
+<a name='ART_4' id='ART_4'></a><span class='smcap'>Art</span>. 4. <i>1st Rule. Simplicity of Conception</i>.--From this rule
+we learn that the hypothesis must be simple in conception,
+and simple in its fundamental principles, and further, that the
+same characteristic of simplicity must mark each step of its
+development.
+</p>
+
+<p>
+This rule of simplicity is distinctly laid down by Sir Isaac
+Newton in his <i>Principia</i>, Book 3, under the heading &ldquo;Regulae
+Philosophandi.&rdquo;
+</p>
+
+<p>
+In that work he writes: &ldquo;Natura simplex est, et rerum causis
+superfluis non luxuriat.&rdquo;--&ldquo;Nature is simple, and does not abound
+in superfluous causes of things.&rdquo;
+</p>
+
+<p>
+He further states that: &ldquo;Not more of the natural causes of
+things ought to be admitted, than those which are true and
+suffice to explain phenomena. In the nature of Philosophy
+nothing is done in vain, and by means of many things, it is done
+in vain when it can be done by fewer. For Nature is simple,
+and does not abound in superfluous causes.&rdquo;
+</p>
+
+<p>
+While again in Rule 3, he adds: &ldquo;Natura simplex est et
+sibi semper consona.&rdquo;--&ldquo;Nature is simple, and always agrees
+with itself.&rdquo;
+</p>
+
+<p>
+Whewell also considers simplicity as a fundamental principle
+of all true hypotheses. On this point he writes: &ldquo;All the
+hypotheses should tend to simplicity and harmony. The new<span class='pagenum'><a name='Page_4' id='Page_4'></a><a href='#TOC'>[4]</a></span>
+suppositions resolve themselves into the old ones, or at least only
+require some easy modification of the hypothesis first assumed.
+In false theories the contrary is the case.&rdquo;
+</p>
+
+<p>
+Thus, it is the very essence of philosophy to build upon a
+foundation of simplicity, combined with the results of experience,
+observation, and experiment. For example, if we desired to
+form a hypothesis as to the cause of day and night, two
+hypotheses might be assigned as to the cause.
+</p>
+
+<p>
+First, that the earth revolves on its axis once a day, and so
+presents each part successively to the light and heat of the sun;
+and second, that the sun revolves round the earth once every
+24 hours. But such an assumption as the latter would involve
+the revolution of the sun through an immense orbit at an
+enormous velocity, in order for the journey to be accomplished
+in the time. So that it is much simpler to conceive of the earth
+revolving on its axis once every 24 hours, than it is for the sun
+to perform this journey in the same period. Hence the rule of
+simplicity is in favour of day and night being caused by the
+revolving of the earth on its axis. The same rule might be
+illustrated in many ways; but, however illustrated, the principle,
+according to Newton, always holds good that all effects are
+produced by the simplest causes, and if there are apparently two
+causes to the same phenomenon, then the simpler cause is the
+true and correct one. So that in the making and development
+of any hypotheses of the physical cause of Gravitation, this rule
+of simplicity must always be recognized; and, in conjunction
+with the other rules, we must seek to make our hypotheses, so
+as to be able to account and explain all phenomena sought
+to be explained.
+</p>
+
+<p>
+<a name='ART_5' id='ART_5'></a><span class='smcap'>Art</span>. 5. <i>2nd Rule. Experience.</i>--Newton fully recognized the
+necessity of experience in Philosophy. He saw the absolute
+necessity of appealing to experience, observation, and experiment,
+both as a basis for philosophical reasoning, and further,
+for the data which were necessary to verify particular applications
+of the hypotheses suggested.
+</p>
+
+<p>
+In his Rules of Philosophy, referring to experience as a guide,
+he says: &ldquo;Hoc est fundamentum philosophiae.&rdquo;--&ldquo;This is the
+basis of philosophy.&rdquo;
+</p>
+
+<p>
+Herschel, writing on the same subject in his <i>Natural Philosophy</i>,
+writes thus with regard to experience: &ldquo;We have pointed out
+that the great, and indeed the only ultimate source of our knowledge
+of nature, and its laws, is experience. By which I mean,
+not the experience of one man only, or of one generation, but
+the accumulated experience of all mankind in all ages registered
+in books or recorded in tradition. But experience may be
+acquired in two ways, either first by noticing facts as they occur<span class='pagenum'><a name='Page_5' id='Page_5'></a><a href='#TOC'>[5]</a></span>
+without any attempt to influence the frequency of their occurrence,
+or to vary the circumstances under which they occur. This is
+observation. Second, by putting in action causes and agents
+over which we have no control, and purposely varying their combination,
+and then noticing what effects take place. This is
+experiment. To these two sources we must look as the fountains
+of all natural science.&rdquo;
+</p>
+
+<p>
+Herschel further writes: &ldquo;Experience once recognized as the
+fountain of all our knowledge of nature, it follows, that in our
+study of nature and its laws, we ought at once to make up our
+minds to dismiss, as idle prejudices, or at least suspend as premature,
+all preconceived notion of what might, or ought to be
+the order of nature in any proposed case, and content ourselves
+as a plain matter of fact with what is. <i>To experience we refer as
+the only ground for all physical enquiry.</i> But before experience
+itself can be used to advantage, there is one preliminary step to
+make which depends wholly upon ourselves.&rdquo;
+</p>
+
+<p>
+&ldquo;It is the <i>absolute dismissal</i> and clearing the mind <i>of all
+prejudices</i> from whatever source arising, and the determination
+to stand or fall by the result of direct appeal to facts in the first
+instance, and to strict logical deduction from them afterwards.&rdquo;
+</p>
+
+<p>
+From extracts like these, from such men as Newton and
+Herschel, it can at once be seen that experience, and experience
+alone, should be the chief fountain from whence we draw all our
+data to form the bases of any hypothesis or theory. If the
+hypothesis formed is contradicted by the result of any present
+or future observation or experiment, then such hypothesis will
+either become untenable, or must be so modified as to take in
+the new fact furnished by that observation and experiment.
+</p>
+
+<p>
+It is a <i>sine quâ non</i> of all true philosophy, that philosophy
+should always agree with experience. To the extent that our
+Philosophy of Nature fails to agree with our experience, or with
+the results of observation and experiment, then to that extent
+it ceases to be philosophy. It may be a hypothesis or even a
+theory, but certainly it is not true Philosophy.
+</p>
+
+<p>
+Now, in the elaboration and development of the theory as
+to the physical cause of Gravitation, I can premise that nothing
+will be postulated or supposed, unless such supposition can be
+directly verified by our own observation and experiments.
+</p>
+
+<p>
+Any theory or hypotheses that are contradicted by our own
+experience in its widest form, will find no place in the development
+of this work. Further, any present accepted theory in
+relation to any natural phenomena, which is controverted by
+experiment, or observation, will be rejected as untenable in the
+scheme of Natural Philosophy to be submitted to the reader.
+</p>
+
+<p>
+Whatever else the theory suggested may, or may not be, one<span class='pagenum'><a name='Page_6' id='Page_6'></a><a href='#TOC'>[6]</a></span>
+thing it certainly shall be, and that is, that it shall be strictly
+based upon the Philosophical Rules as given by some of the
+greatest philosophers the world has ever seen. I do not premise
+that the hypotheses advanced will be strictly correct in every
+detail.
+</p>
+
+<p>
+That would be to assume that my experience of all natural
+phenomena was perfect. To the extent that our experience is
+limited, to that extent our hypotheses will be limited and faulty.
+It would need an Infinite mind to form a perfect theory of the
+philosophy of the universe, because only an Infinite mind
+possesses infinite experience. A finite mind can, however, form
+true philosophical conceptions of natural phenomena, if that mind
+will only follow the guidance of his own experience, and be
+willing to accept the teaching that always arises from the results
+of that experience. In order to do this, however, it must be
+observed, as Herschel points out, that all old prejudices must be
+put away, and the question or problem to be considered must be
+viewed with an open mind. Let me illustrate what I mean.
+Suppose, for example, that for two hundred years, chalk had
+always been thought to be a mineral, and then, owing to the
+development of the microscope, and to the increased magnifying
+powers of the lenses, it was conclusively demonstrated that chalk
+is made up of the shells and remains of certain organisms that
+lived in the sea ages ago. Would it be philosophical to throw
+over the results of the microscopical research, and, simply
+because for two hundred years chalk had been thought to be
+a mineral, to argue, and still retain the idea that chalk was a
+mineral?
+</p>
+
+<p>
+Such a result would be entirely opposed to all the teaching
+and principles of philosophy. In a similar way, suppose in the
+development of the physical cause of Gravitation, a certain
+conception of the universal Aether has to be put forth in order to
+account for Gravitation, and that that conception is opposed to
+some of the theories which have been held relative to the Aether
+medium for the past two hundred years; but that the conception
+so advanced is supported by the experiments and observation of
+some of the ablest scientists of the present century, would it
+be philosophical to reject the newer conception which harmonized
+with all experiment and observation, and still retain the old
+conception of the aetherial medium; or, to accept the newer
+conception of that medium, and to reject some of the ideas
+included in the old conception? From a purely philosophic
+standpoint, there can only be one reply, which would be in
+favour of the newer conception, by which our philosophy would
+be brought into harmony with our experience.
+</p>
+
+<p>
+This I premise will be done in this work, and the result will<span class='pagenum'><a name='Page_7' id='Page_7'></a><a href='#TOC'>[7]</a></span>
+be, that for the first time, our philosophy of the aetherial medium
+will agree with our experience; and, as the natural result, several
+outstanding problems will be explained on a physical basis, which
+at the present time cannot be satisfactorily explained except from
+the mathematical standpoint.
+</p>
+
+<p>
+<a name='ART_6' id='ART_6'></a><span class='smcap'>Art</span>. 6. <i>3rd Rule. Satisfactory explanation of the Phenomena
+sought to be Explained.</i>--The third rule which governs the making
+of any hypothesis is, that the hypothesis formed in accordance
+with the first and second rules shall satisfactorily account for all
+the phenomena sought to be explained.
+</p>
+
+<p>
+Newton writes on this point as follows: &ldquo;No more causes of
+natural things are to be admitted, than such as are true, and
+sufficient to explain the phenomena.&rdquo; While again in his fourth
+rule he states: &ldquo;In experimental philosophy, propositions
+collected by induction from phenomena are to be regarded as
+accurately true, or very nearly true, notwithstanding any contrary
+hypothesis, till other phenomena occur by which they are made
+more accurate, or are rendered subject to exceptions.&rdquo; <i>Principia</i>,
+Book 3. Herschel in his <i>Natural Philosophy</i> points out,
+that one of the chief requirements of any assumed hypothesis
+is, that it shall be sufficient to account for the phenomena to
+be explained, and that it shall be suggested by analogy.
+</p>
+
+<p>
+Now the object of this work is to give a physical explanation
+of the cause and working of Gravitation, and to show how, by
+the properties, qualities and motions of the universal Aether,
+Universal Gravitation may be accounted for on a physical basis.
+So that every phenomenon, associated with, or included in
+the Law of Gravitation, should receive a satisfactory physical
+explanation by the proposed theory.
+</p>
+
+<p>
+Thus the physical cause of the centripetal and centrifugal
+forces should receive for the first time a physical explanation.
+</p>
+
+<p>
+Newton's Laws of Motion, in so far as they conform to his own
+Rules of Philosophy, should also receive a physical explanation.
+</p>
+
+<p>
+Kepler's Laws, which govern the motion of planets in their
+orbits, should also receive a similar physical explanation. Indeed,
+all phenomena which the Law of Gravitation explains from a
+mathematical standpoint, ought to receive a physical explanation
+by the proposed new conception of the Aether medium.
+</p>
+
+<p>
+In addition to the outstanding physical cause of Gravitation,
+there are other physical problems that yet remain to be solved;
+as, for example, there is the question as to what is the relative
+motion of Aether to moving matter. Does the Aether move
+with matter through space as suggested by Michelson's and
+Morley's experiment of America, or does it flow freely through
+all matter, as it is usually thought to do? I premise I will give
+a satisfactory solution of this problem in due course.<span class='pagenum'><a name='Page_8' id='Page_8'></a><a href='#TOC'>[8]</a></span>
+</p>
+
+<p>
+Again, in relation to the Phenomena of Light, there is still
+outstanding the problem of the physical explanation as to the
+transverse vibration of light. This problem will also be dealt
+with from the standpoint of our new conception of the Aether.
+Whether it will be as satisfactorily solved, as the physical cause
+of Gravitation, remains to be seen.
+</p>
+
+<p>
+Further, there is also the important question yet unsolved, as
+to what Matter is. Lord Kelvin and Dr. Larmor have recently
+given to the world certain conceptions as to the origin of Matter,
+and I shall endeavour to show that such conceptions receive
+confirmation and support by the proposed new conception of
+the Aether.
+</p>
+
+<p>
+Another problem that will be attacked and solved, will be the
+cause of the Permanent Magnetism of the earth, with an answer
+to some of the questions propounded by Professor Schuster at
+the British Association of 1892 relative to the magnetism of solar
+bodies.
+</p>
+
+<p>
+There is certainly some physical explanation as to the cause
+of the earth being a magnet, yet up to the present no satisfactory
+physical theory has been given. I premise that the new conception
+of the Aether, to be submitted in the after pages, will
+satisfactorily account, and that on a philosophical basis, for this
+phenomenon.
+</p>
+
+<p>
+Lastly, one of the most interesting discoveries of the present
+day will receive an added confirmation and explanation in the
+conception of the Aether medium to be advanced. I refer to the
+system of Wireless Telegraphy that has been so successfully
+developed by Signor Marconi, and I premise that new light will
+be thrown on that discovery by the suggested theory of the
+Aether.
+</p>
+
+<p>
+Now, if all these problems can be partially or wholly solved by
+the same theory that is advanced to explain the physical cause
+of Gravitation, it needs no further comment to show that that
+theory is considerably strengthened and more firmly established.
+</p>
+
+<p>
+For it is a rule in Philosophy, that the more problems any
+suggested theory can solve, the greater are the claims of that
+theory for acceptance by scientists generally. For, if two rival
+theories can solve three and ten physical problems respectively,
+then, in giving a decision as to which is the better theory, the
+balance of opinion would be overwhelming in favour of that
+theory which could solve the ten problems. So that, if in addition
+to the satisfactory explanation of the physical cause of Gravitation,
+some, if not all of the other problems can be solved, as
+I premise they can, by the same conception of the Universal
+Aether, then it follows our third rule of Philosophy will be more
+than fulfilled, and the theory so advanced will be placed upon<span class='pagenum'><a name='Page_9' id='Page_9'></a><a href='#TOC'>[9]</a></span>
+such a strong foundation, that it can only be overthrown by
+proving that it contradicts the results of some undiscovered
+phenomena.
+</p>
+
+<p>
+<a name='ART_7' id='ART_7'></a><span class='smcap'>Art</span>. 7. <i>Application of Rules to Gravitation.</i>--Let us therefore
+apply Newton's own Rules of Philosophy to the Law of Gravitation,
+and endeavour to find out if the law, as at present understood,
+fully satisfies his own Rules of Philosophy. No one can
+reasonably object to subjecting the Law of Gravitation to the test
+of those principles which he lays down as the fundamental Rules
+of Philosophy.
+</p>
+
+<p>
+If it comes through the ordeal with complete success, that is,
+if it is essentially simple in its conception and development, and
+if all its details are fully in accord with experience, as revealed
+by observation and experiment, then there will be no need to
+alter any of its hypotheses or axioms. If, on the other hand, it
+violates any of the rules as laid down by Newton, then, to that
+extent, an alteration will be necessary, in order that the Law of
+Gravitation may be brought into conformity with his own rules,
+and our Philosophy made to agree with our experience and
+observation.
+</p>
+
+<p>
+<a name='ART_8' id='ART_8'></a><span class='smcap'>Art</span>. 8. <i>Analysis of Law of Gravitation.</i>--In order to accomplish
+this, let us ask ourselves, &ldquo;What are the component parts
+of this Law of Gravitation?&rdquo; The Law is not a simple law,
+but a compound one. It is compounded primarily of three
+parts.
+</p>
+
+<p style='margin-left: 5em;'>1st. A Primitive Impulse.</p>
+<p style='margin-left: 5em;'>2nd. A Centripetal Force.</p>
+<p style='margin-left: 5em;'>3rd. A Centrifugal Force.</p>
+
+<p>
+To these must be added the three Laws of Motion; although they are not
+directly part of the Law of Gravitation, yet they are essential to its
+effectiveness and completion. Without any one of these, the Law of
+Gravitation would fail to account for all the phenomena that it does
+account for.
+</p>
+
+<p>
+If there were no Primitive Impulse, then the planets and meteors, sun
+and stars would for ever remain at rest, and the Laws of Motion would
+remain inoperative. If there were no Centripetal Force, then the
+Centrifugal Force would hurl the planets and comets, asteroids or minor
+planets away into the depths of space, never to return to their central
+sun.
+</p>
+
+<p>
+If there were no Centrifugal Force, then the Centripetal Force would
+draw all bodies, <i>i. e.</i> all planets, etc., to their central sun, and,
+instead of the planets continually revolving round the sun, there would
+be but one immense solitary mass in the centre of the solar system.
+</p>
+
+<p>
+If there were no Laws of Motion, with their necessary corollary the
+Parallelogram of Forces, the Primitive Impulse would cease to act, and<span class='pagenum'><a name='Page_10' id='Page_10'></a><a href='#TOC'>[10]</a></span>
+the Law of Gravitation would again fail in its attempt to account for
+those phenomena it does account for.
+</p>
+
+<p>
+Thus, as it may easily be seen, Gravitation is a compound Law, depending
+upon at least four hypotheses, and therefore is not essentially a simple
+Force, or Law.
+</p>
+
+<p>
+If, therefore, in giving a physical explanation of the cause of
+Gravitation, we can reduce all these four elements of the Law into one
+single physical cause, <i>i. e.</i> the Universal Aether, and show how they
+may all be explained and accounted for by the properties, qualities and
+motions of that physical medium, then such a result will be strictly in
+harmony with the first Rule of Philosophy, as laid down by Newton and
+others.
+</p>
+
+<p>
+We will, therefore, proceed to consider some of these parts of the Law
+of Gravitation in detail.
+</p>
+
+<p>
+<a name='ART_9' id='ART_9'></a><span class='smcap'>Art</span>. 9. <i>Primitive Impulse.</i>--This may be explained as follows. At the
+creating and launching of each world, Newton supposed that there was
+given to each world an impulse or tendency to fly off from the
+controlling centre into space. On this matter MacLaurin writes as
+follows: &ldquo;If we had engines of sufficient force, bodies might be
+projected from them, so as not only to be carried a vast distance away
+without falling to the earth, but so as to move round the whole earth
+without touching it; and, after returning to the first place, commence a
+new revolution with the same force they first received from the engine;
+and after the second revolution, a third, and thus revolve as a moon or
+satellite round the earth for ever. If this can be effected near the
+earth's surface, it may be done higher in the air, or even as high as
+the moon. By increasing the force or power, a body proportionately
+larger may be thus projected, and by a power sufficiently great, a heavy
+body, not inferior to the moon, might be put in motion, which might
+revolve for ever round the earth. Thus Sir Isaac Newton saw that the
+curvilineal motion of the moon in her orbit, and of a projectile at the
+surface of the earth, were phenomena of the same kind, and might be
+explained from the same principle extended from the earth so as to reach
+the moon, and that the moon was only a greater projectile that received
+its motion in the beginning of things from the Almighty Author of the
+Universe.&rdquo;
+</p>
+
+<p>
+Now what I desire to know is, &ldquo;What is the nature, the mode of
+operation, and, above all, the physical cause of this Primitive
+Impulse?&rdquo; Is it in its nature and mode of operation a simple Force, or
+Cause? Does it fulfil the condition of Newton's First Rule of
+Philosophy? Permit me to suggest several lines of thought which may be
+made the basis of its analysis.
+</p>
+
+<p>
+Astronomers tell us that there are in existence millions of stars, and<span class='pagenum'><a name='Page_11' id='Page_11'></a><a href='#TOC'>[11]</a></span>
+suns, flooding immensity and space with their light and heat.
+</p>
+
+<p>
+Now the question I wish to ask regarding Primitive Impulse in relation
+to all these stars is this: &ldquo;Was the Primitive Impulse imparted to each
+sun, and star, and planet, separately and distinctly?&rdquo; If so, then there
+must have been just as many Primitive Impulses as there are stars and
+suns and planets, and there would be according to a certain astronomer's
+estimate at least 800,000,000 Primitive Impulses, which assumption is
+altogether opposed to, and violates the First Rule of Philosophy.
+</p>
+
+<p>
+If, on the other hand, it is affirmed that they all received their
+motion at one and the same time, then I ask: &ldquo;What was the physical
+cause and method adopted to communicate the impulse to each one at the
+same time?&rdquo; If the reply is given, that it was by Universal Gravitation,
+I have two objections to make to such a reply: first, that Gravitation
+is altogether inoperative without the Primitive Impulse, otherwise why
+was it conceived? and secondly, what is the physical cause of
+Gravitation?
+</p>
+
+<p>
+Again, scientists inform us that there is every reason for believing,
+that stars and suns are still being formed in the universe, and that
+there are certain distinctive phenomena which go to prove that
+statement. Now, if that be true, and I believe it to be true, I wish to
+ask if the Primitive Impulse as suggested by Newton, is applicable to
+the stars and suns already in process of formation in the various
+nebulae? and, if so, at what point in the star's history or development
+is that Impulse applied?
+</p>
+
+<p>
+Personally, I cannot conceive of the Great Creator of all things being
+so lacking in inventive genius, if I may reverently use that term, as to
+necessitate a separate Impulse being given to every separate star, or
+sun, as each one is created or formed during the progress and
+development of the universe of worlds.
+</p>
+
+<p>
+I would much rather believe that which I hold to be the correct
+explanation, viz. that He has given to a certain fundamental and
+primordial medium, certain qualities and properties, by, and through
+which are originated and perpetuated, all the motions of the heavenly
+bodies already existent in the universe, or that are ever likely to be
+existent throughout all time.
+</p>
+
+<p>
+The question of separate Primitive Impulses for separate bodies becomes
+more and more incongruous and inadmissible, as we consider it in its
+application to such small bodies as meteors and planetoids. Is it not
+contrary to our fundamental principles of Philosophy, that a separate
+Impulse should be necessary for all small bodies that exist in their
+myriads throughout the solar system, not to speak of the universe of
+which that system forms a part? Such a conception as Primitive Impulse,
+to each separate world, is altogether opposed to one's idea of that<span class='pagenum'><a name='Page_12' id='Page_12'></a><a href='#TOC'>[12]</a></span>
+simplicity and beauty which govern the universe at large, and violates
+the first rule of our philosophical reasoning, and for this reason must
+be rejected from the System of Philosophy to be propounded in this work.
+</p>
+
+<p>
+<a name='ART_10' id='ART_10'></a><span class='smcap'>Art</span>. 10. <i>Centripetal Force.</i>--Let us now look at the Centripetal Force,
+and ask ourselves what is meant by such a force, and what is its mode of
+action and working. Centripetal Force, strictly, may be defined as that
+force which is always exerted towards the centre of the attracting body.
+</p>
+
+<p>
+Taking the earth as an example, Newton points out, that though the
+gravity of bodies arises from their gravitation towards several parts of
+the earth; yet, because this power acts always towards the centre of
+gravity of the earth, it is therefore called the Centripetal Force.
+</p>
+
+<p>
+This force, then, is that part of the Law of Gravitation which
+corresponds to the Attraction of Gravitation, and is always exerted in
+that straight line from the body attracted, to the centre of the
+attracting body, which joins the centres of gravity of the two bodies
+concerned.
+</p>
+
+<p>
+The combination and effect of the various forces included in the Law of
+Gravitation are illustrated by the familiar illustration of the ball
+whirled round the hand by a piece of string, or the bucket filled with
+water, whirled round in the same way. Let us take the former. A piece of
+string with a ball attached to one of the ends is held firmly by the
+hand. An impulse or motion is imparted to the ball by the hand, that
+motion being continued by the movement from the hand. The first impulse
+given to the ball by the hand represents the Primitive Impulse. The
+tension on the string which holds the ball to its controlling centre
+represents the Centripetal Force, while the opposite force on the
+string, which takes up the Primitive Impulse and continues it, is
+represented by the Centrifugal Force.
+</p>
+
+<p>
+The conception of the Centripetal Force is therefore simple, and
+entirely in accordance with our experience as gathered from observation
+and experiments. Both in the spheres of electricity, and magnetism, we
+find a similar force acting, which tends towards the centre of the
+attracting body, and therefore the Centripetal Force satisfies the first
+two Rules of our Philosophy.
+</p>
+
+<p>
+Further, it adequately accounts for certain distinctive phenomena which
+occur through the Law of Gravitation, as, for example, the falling of
+bodies to the earth, and therefore is entirely in harmony with all the
+requirements of those principles enunciated by Newton for the successful
+explanation of any phenomena. I need hardly point out, therefore, this
+being so, any physical cause suggested as the explanation of Gravitation
+must deal with the Centripetal Force, and be able to give a physical<span class='pagenum'><a name='Page_13' id='Page_13'></a><a href='#TOC'>[13]</a></span>
+explanation of the mode and manner in which the Centripetal Force
+operates.
+</p>
+
+<p>
+The Attraction of Gravitation or the Centripetal Force, however, being,
+as its name implies, simply a drawing or pulling power to a centre, that
+is, a force that is ever and ever only drawing matter to matter, or body
+to body, it could not of, and by itself, accomplish those necessary
+stellar and planetary motions by which are produced that universal
+order, unity and harmony which characterize the universe. It is
+essentially in its operations and influences, a one-sided force, ever
+tending and influencing towards self, and therefore by itself would only
+be a detriment and an evil; and, unless it were accompanied by some
+companion or complementary and counter force, with which it acts in
+union and concert, and which exactly counteracts its pulling power and
+influence, it would soon draw star to star, and world to world, crashing
+and heaping them together in ruinous and dire confusion. So that,
+instead of the infinitude of worlds which now exist, which flash and
+sparkle in the heavens, and in their intricate, elaborate, and mazy
+motions move through the vast infinity like stately armies on the march,
+there would only be one agglomeration of matter, a silent and solitary
+mass existing in the vast abyss of space.
+</p>
+
+<p>
+Therefore, as soon as Sir Isaac Newton had discovered and demonstrated
+the existence of the power of Attraction, as represented by the
+Centripetal Force, and its association with the universe at large, there
+was seen at once the necessity of another Force, of an opposite
+character, which would form the companion and complementary force to
+Attraction; a repulsive, repellent force, one tending or repelling from
+a centre, so as to counterbalance the influence of the Centripetal Force
+which ever tends towards the centre.
+</p>
+
+<p>
+To fill up the blank, there was conceived to exist what is called a
+Centrifugal Force, that is, literally, a Force acting, and ever acting
+from a centre, and with that Force we will now deal.
+</p>
+
+<p>
+<a name='ART_11' id='ART_11'></a><span class='smcap'>Art</span>. 11. <i>Centrifugal Force.</i>--In applying our Rules of Philosophy to
+this Force, if by Centrifugal Force is simply meant that Force which is
+the exact opposite of the Centripetal Force, that is, a Force which acts
+from a centre, instead of to a centre, then such a Force is strictly in
+harmony with, and satisfies all the conditions of the two first Rules of
+Philosophy.
+</p>
+
+<p>
+Not only is such a conception simple, but it is also in accordance with
+experience and observation. Professor Hicks in his address to the
+British Association in 1895 said: &ldquo;What is called Centrifugal Force is
+an apparent bodily Force directed outwards from the centre of curvature
+of the body's path, and having an intensity equal to the distance from<span class='pagenum'><a name='Page_14' id='Page_14'></a><a href='#TOC'>[14]</a></span>
+the centre multiplied by the square of the absolute angular velocity.&rdquo;
+</p>
+
+<p>
+In the sphere of magnetism and electricity, the operation of two equal
+and opposite forces prevails. The attractive force of electricity, which
+is exerted to the centre, is always accompanied by the generation and
+development of a repulsive force, it being one of the fundamental rules
+of electricity that equal and opposite quantities of electricity are
+always generated at one and the same time. So that if the Centrifugal
+Force is viewed as being simply the exact opposite of the Centripetal
+Force, it fully satisfies the test when the first two rules laid down by
+Newton are applied to it.
+</p>
+
+<p>
+If, on the other hand, Centrifugal Force implies and embodies the idea
+of continuance of the Primitive Impulse, as I believe it is supposed to
+do, then to that extent it is not conformable to the principles of our
+Philosophy, as embodied in the rules given by Newton.
+</p>
+
+<p>
+Simply because, while it supposes a source or origin of its activity at
+the first, it goes on to suppose a continuance of that activity, without
+recognizing a continuing source or cause. It only recognizes and
+supposes the one original impulse given at the beginning, to account for
+the cause of the continually existing, and exerted power of the
+Centrifugal Force. I do not for a moment suggest, that the Divine
+Creator of all things, and the Ordainer and Upholder of all powers,
+forces and laws could not, had He chosen to give such a force, have
+given it and for ever operating. With that aspect of the question I have
+nothing to do, and of it nothing to say. I am dealing, and only wish to
+deal, with scientific facts, and scientific teaching from the purely
+philosophical standpoint.
+</p>
+
+<p>
+Such an idea of a continuing effect, without a continuing cause, is
+altogether opposed to experience and observation, and is a violation of
+the second Rule of Philosophy.
+</p>
+
+<p>
+Look where we will, or at what we will, and not only effects and causes
+are seen on every side, and in every thing, linked together inseparably,
+but wherever, and in whatever phenomena there is found a continuance of
+effect or effects, there is always and without exception found also a
+continuing source or cause.
+</p>
+
+<p>
+Wherever Nature, therefore, gives us a continuous effect of any kind or
+sort, she always gives us a continuing cause, that can be both proved
+and demonstrated to exist. Nowhere in Nature, amid all her powers,
+principles and laws, is there to be found an effect without a cause, and
+in all continuing effects, a continuing and perpetuating cause also, and
+that effect exists just as long as the cause exists.
+</p>
+
+<p>
+If the effect is perpetual, then the source and cause is perpetual<span class='pagenum'><a name='Page_15' id='Page_15'></a><a href='#TOC'>[15]</a></span>
+also, both in its existence and energy. Hence if the Centrifugal Force
+embodies the idea of continuance of the Primitive Impulse, without
+showing how that Primitive Impulse is continued, then such an idea is an
+anomaly in the universe, is altogether opposed to the teaching of Nature
+and science, and violates the most fundamental principles of our
+Philosophy.
+</p>
+
+<p>
+The philosophic explanation, therefore, of the Centrifugal Force, is
+that Force which flows from a centre, and <i>which is the exact opposite
+and counterpart of the Centripetal Force</i>. Further, as the Centripetal
+Force is an attractive Force ever attracting to a centre, so the
+Centrifugal Force, being its exact opposite, is a repulsive Force, which
+fulfils all the laws and conditions which govern the Centripetal Force,
+as it is in every phase and aspect the exact opposite, being indeed its
+complement and counterpart.
+</p>
+
+<p>
+Any physical explanation of the Law of Gravitation, therefore, must also
+give a satisfactory physical explanation of this Force, and show its
+mode of operation and working. This I premise I will do without the
+faintest shadow of doubt or failure; that is, if we are to accept the
+evidence of some of the most delicate experiments of modern times
+relative to aetherial physics.
+</p>
+
+<p>
+<a name='ART_12' id='ART_12'></a><span class='smcap'>Art</span>. 12. <i>Laws of Motion.</i>--One of the most important factors in the
+successful application of the Attraction of Gravitation to the universe
+at large, are the Laws of Motion enunciated by Sir Isaac Newton. These
+are three in number, and are as follows--
+</p>
+
+<p>
+1st. Every body continues in its state of rest, or of uniform motion in
+a straight line, except in so far as it may be compelled by impressed
+Forces to change that state.
+</p>
+
+<p>
+2nd. Change of motion is proportionate to the impressed Force, and takes
+place in the direction of the straight line in which the Force acts.
+</p>
+
+<p>
+3rd. To every action there is always an equal and contrary reaction.
+</p>
+
+<p>
+<i>Corollary.</i>--To these must be added the first Corollary of the three
+laws which is commonly known as the Parallelogram of Forces, which is as
+follows: &ldquo;That when a body is acted upon by two Forces at the same time,
+it will describe a diagonal, by the motion resulting from their
+composition, in the same time that it would describe the sides of the
+parallelogram.&rdquo;
+</p>
+
+<p>
+Now let us apply Newton's Rules of Philosophy to these laws, and see if
+they fulfil the conditions laid down therein.
+</p>
+
+<p>
+In the first place, there being three laws necessary to cover all the
+motions involved, there is not that simplicity of conception which is a
+primary factor in the making of any hypothesis. Then it will be observed
+that even after postulating the three laws, Newton was unable to<span class='pagenum'><a name='Page_16' id='Page_16'></a><a href='#TOC'>[16]</a></span>
+account for the elliptic orbits of the planets, until he had added a
+Corollary known as the Parallelogram of Forces.
+</p>
+
+<p>
+<a name='ART_13' id='ART_13'></a><span class='smcap'>Art</span>. 13. <i>Force</i>.--The question has arisen also, as to the meaning of
+the term Force which Newton uses. What is a Force, its cause and mode of
+operation? The idea of Force is conveyed to us by our &ldquo;muscular sense,&rdquo;
+which gives us the idea of pressure, as for example when we push or pull
+a body along the ground.
+</p>
+
+<p>
+We must not, however, limit our idea of Force to that narrow circle. It
+has now been fully established that Sound and Heat, Light, Magnetism,
+and Electricity are Forces, and therefore capable of doing work, as will
+be shown later on. Newton's use of the term Force is therefore somewhat
+vague; he does not definitely say what the Force is which causes the
+change of position, of the body, or of the rate of motion of that body.
+That it is something to do with Gravitation is obvious, but its exact
+nature or character is not revealed.
+</p>
+
+<p>
+Since Newton's time we have made an advance in the definition of Force,
+and have come to consider Force as a kind of energy; the application of
+Force being the application of energy. Such terms as Mechanical Force,
+Chemical Force, Vital Force, are therefore out of date, and in their
+place the more definite ideas of energy are substituted. Instead,
+therefore, of getting such terms as Transformation of Forces, we now get
+Transformations of Energy. In the chapter on Energy, I hope to show that
+even that is not a satisfactory solution of the definition of a Force.
+If we are to make our Philosophy agree with our experience, then Force
+is due to motion, and motion alone.
+</p>
+
+<p>
+So that Centrifugal Force will imply a motion from the centre;
+Centripetal Force a motion whose effect is ever towards the centre of
+gravity of any body.
+</p>
+
+<p>
+<a name='ART_14' id='ART_14'></a><span class='smcap'>Art</span>. 14. <i>First Law of Motion</i>.--This may naturally be divided into two
+parts for the purpose of applying the Rules of Philosophy.
+</p>
+
+<p>
+(I) Every body continues in a state of rest, except in so far as it is
+compelled by impressed Forces to change that state. To what extent is
+this statement conformable to our experience and observation? If I place
+a body, as for example a weight, on a table, will it remain in that
+state until it is moved by some other Force? I think that it will so
+remain, and to that extent the law conforms to experiment.
+</p>
+
+<p>
+Wider observation, and all experience, also prove the conformity of this
+part of the First Law of Motion to the second Rule of Philosophy, as all
+experience testifies to the fact that a body remains at rest, until some
+other power or force moves it from the position of rest. The<span class='pagenum'><a name='Page_17' id='Page_17'></a><a href='#TOC'>[17]</a></span>
+application of this position of rest to any of the planets is, however,
+very difficult to conceive. MacLaurin, in relation to this fact, states:
+&ldquo;This perseverance of a body in a state of rest can only take place in
+absolute space, and can then only be intelligible by admitting it.&rdquo; In
+dealing with the physical cause of Gravitation, I hope to be able to
+show that it can not only be admitted as a mathematical proposition, but
+that it can be made intelligible from the physical standpoint.
+</p>
+
+<p>
+The second part of the First Law of Motion may be stated as follows:
+&ldquo;Every body continues in a state of uniform motion in a straight line,
+except in so far as it is compelled by impressed forces to change that
+state.&rdquo;
+</p>
+
+<p>
+Now what is the testimony of observation and experiment in regard to
+this part of the First Law of Motion? Let us test the question by the
+results of our experience. If a ball is sent rolling along the ground,
+its motion is gradually reduced until it comes to rest. If the ground is
+very rough indeed, as for example a ploughed field, then its speed will
+be very soon reduced, and the ball quickly comes to a standstill. If,
+however, the ground is smooth and level, like a well-kept cricket-field,
+then the motion of the ball will be reduced more slowly, and it will
+travel further before being brought to rest; while, if the ball is
+thrown along a very smooth surface of ice, it will travel a much longer
+distance before it is finally brought to rest.
+</p>
+
+<p>
+Thus we learn, that the more we can get rid of all resistances to the
+motion of any body, the greater distance will the body travel, and the
+less diminution there is in the uniform motion of the body. So that, if
+it were possible to obtain a medium which offered no resistance at all
+to a moving body, then it would be a legitimate inference to infer that
+a body in such a medium, when once set in motion, would move with
+uniform motion for ever. Under such conditions, therefore, this part of
+Newton's First Law of Motion is physically conceivable. The crux of the
+whole matter, therefore, lies in the problem as to whether there is, or
+there is not, in existence, such a thing as a frictionless medium. We
+will therefore consider the problem of the existence of a frictionless
+medium from the philosophical standpoint.
+</p>
+
+<p>
+Professor Lodge, in <i>Modern Views of Electricity</i>, p. 331, writes: &ldquo;Now,
+if there is one thing with which the human race has been more conversant
+than another, and concerning which more experience has been
+unconsciously accumulated than about almost anything else that can be
+mentioned, it is the action of one body upon another; the exertion of
+Force by one body on another, the transfer of motion and energy from one
+body to another, any kind of effect, no matter what, which can be
+produced in one body by means of another, whether the bodies be animate<span class='pagenum'><a name='Page_18' id='Page_18'></a><a href='#TOC'>[18]</a></span>
+or inanimate.&rdquo;
+</p>
+
+<p>
+&ldquo;Now I wish to appeal to this mass of experience, and to ask, Is not the
+direct action of one body on another across empty space, and with no
+means of communication whatever, is not this absolutely unthinkable? We
+must not answer the question offhand, but must give it due
+consideration, and we shall find, I think, that wherever one body acts
+on another body by obvious contact, we are satisfied and have a feeling
+that the phenomena is simple and intelligible, and that, whenever one
+body apparently acts on another body at a distance, we are irresistibly
+impelled to look for the connecting medium.&rdquo;
+</p>
+
+<p>
+Again, on p. 333 of the same work, he adds: &ldquo;Remember then, that
+whenever we see a thing being moved, we must look for the rope. It may
+be visible, or it may be invisible, but unless there is either a push or
+a pull, there can be no action.&rdquo;
+</p>
+
+<p>
+Now, in relation to celestial phenomena, we are confronted with the fact
+of bodies acting on one another, and yet apparently they do not act upon
+one another by or through a medium, and to that extent according to the
+above extracts, such phenomena are opposed to universal experience.
+Again, we find planets and satellites moving through space with more or
+less uniform speed, and yet apparently there is no physical medium that
+acts upon them with either a push or a pull, as the present conception
+of the Aether is that of a frictionless medium, so that experience in
+its widest form seems altogether opposed to the existence of a
+frictionless medium.
+</p>
+
+<p>
+Again, Tait in his <i>Natural Philosophy</i> says: &ldquo;The greater masses,
+planets and comets moving in a less resisting medium, show less
+indications of resistance. Indeed it cannot be said that observations
+upon any one of these bodies, with the exception of Encke's Comet, has
+demonstrated resistance. The greater masses, planets and comets moving
+in a less resisting medium, show less indications. No motion in Nature
+can take place without meeting resistance due to some if not all of
+these influences. <i>The analogies of Nature and the ascertained facts of
+physical science forbid us to doubt that every one of them, every star,
+and every body of every kind has its relative motion impeded by the air,
+gas, vapour, medium, or whatever we choose to call the substance
+occupying the space around it</i>, just as the motion of a rifle-bullet is
+impeded by the resistance of the air.&rdquo;
+</p>
+
+<p>
+What is the testimony of our own personal observation and experiments to
+such an impossible entity as a frictionless medium? Can any of the
+readers tell me of any medium, be it solid, liquid, or gaseous, that
+they have ever heard of, or read of, or experimented with, that
+possesses the quality of being frictionless? The answer is unanimously<span class='pagenum'><a name='Page_19' id='Page_19'></a><a href='#TOC'>[19]</a></span>
+in the negative. But a frictionless medium was absolutely imperative to
+the success of the Newtonian aspect of the Law of Gravitation. If the
+Aether had not been frictionless, then the First Law of Motion would
+have been violated, and a body, as for example a planet set in motion,
+would not then have moved with uniform motion, but would have been
+brought to a standstill by the resistance of the Aether. Accepting
+therefore experience as a guide, as we are bound to do if we wish to be
+strictly philosophical, as Newton pointed out, then we are compelled to
+come to the conclusion that there is no such thing in the entire
+universe as a frictionless medium. Such a hypothesis is contrary to all
+laws and rules of Philosophy, and to continue to advocate its claims is
+to remain where we are in relation to the cause of Gravitation, and in
+complete ignorance of the beauty and harmony of the wonderful physical
+mechanism that underlies the whole of the universe. Of course, if
+experience and observation are no guide to Philosophy, then we will let
+imagination run riot, and postulate the most extravagant explanations
+for the varied phenomena of the heavens. With experience of no account,
+we will affirm that the moon is made of green cheese, that the earth is
+flat, that the sun revolves round the moon, and a host of other absurd
+hypotheses that require no correction by experience and observation. But
+there, a truce to such absurd imaginations. Experience is a guide to
+Philosophy, its claims are recognized by the greatest Philosopher the
+world has ever known, and therefore as either experience or a
+frictionless medium has to go, we will part with the frictionless
+medium, and endeavour to make a hypothesis of the Aether that is in
+greater harmony with our Rules of Philosophy.
+</p>
+
+<p>
+<a name='ART_15' id='ART_15'></a><span class='smcap'>Art</span>. 15. <i>Second Law of Motion</i>.--The application of Newton's Rules of
+Philosophy to the Second Law of Motion is attended with greater success
+than was the case with his First Law. &ldquo;Change of motion,&rdquo; he states, &ldquo;is
+proportionate to the impressed Force, and takes place in the direction
+of the straight line in which the Force acts.&rdquo;
+</p>
+
+<p>
+Newton adds this explanation to his Second Law: &ldquo;If a Force generates
+any motion, a double Force will generate double motion, and a triple
+Force triple motion, whether they are applied simultaneously or
+gradually and successively. And this motion, if the body were already
+moving, is either added to the previous motion, if it is in the same
+direction, or subtracted from it if directly opposed to it, or is
+compounded with the previous motion if the two are inclined at an
+angle.&rdquo;
+</p>
+
+<p>
+According to that, a force which presses or pushes with a four-pound
+pressure per square inch, if doubled, would press with a force of eight
+pounds per square inch, which fact agrees with experience. If the force<span class='pagenum'><a name='Page_20' id='Page_20'></a><a href='#TOC'>[20]</a></span>
+is applied gradually, then the change of motion would be gradual; if
+applied suddenly, then the resultant motion would be sudden and violent.
+</p>
+
+<p>
+The impressed force, therefore, always produces a definite and
+corresponding effect on any moving body, however that force may be
+originated, and however it may be applied. The effect so produced is
+always a change of motion, or, in present scientific terms, a change of
+momentum in the moving body. If the impressed force is halved, by an
+alteration in the mass of the body which exerts the impressed force,
+then the resultant momentum produced is halved also. If the impressed
+force is doubled, through any alteration in the velocity of the body
+which exerts the force, then the momentum produced in the moving body
+will be doubled also. So that the impressed force is equal to the change
+of momentum in the moving body upon which it is impressed.
+</p>
+
+<p>
+When similar forces are impressed upon exactly similar bodies, the
+velocities produced are exactly the same; but, if similar forces act on
+dissimilar bodies, then the velocities produced in the different bodies
+are not the same; yet the total motion produced on all bodies, according
+to the Second Law of Motion, must always be proportionate to the
+impressed force. So that when we compare the effect of similar forces on
+different bodies, we find that there are two factors involved, viz., the
+mass and velocity of the moving body. The product of these two
+quantities is termed the momentum of the body.
+</p>
+
+<p>
+When we apply the Second Law of Motion to the theory of aetherial
+dynamics, as suggested in this work, we shall seek to show that Newton's
+Second Law of Motion holds good in its application to the new theory.
+With the present conception of a frictionless Aether, however, it is
+philosophically impossible for the Aether to exert force on any body
+that may exist in it. Because, to the extent that it is frictionless, to
+that extent it ceases to possess mass. If it does possess mass, then it
+cannot be frictionless. Such an assumption violates all the Rules of
+Philosophy.
+</p>
+
+<p>
+Yet the Aether is supposed, in some unknown manner, to possess inertia,
+which property is also dependent on mass. If the Aether really possesses
+inertia, then it must possess mass, and possessing mass it ceases to be
+a frictionless medium. So that if it possesses mass, then it can exert
+force the same as any other body, and Newton's Second Law of Motion is
+applicable to it.
+</p>
+
+<p>
+<a name='ART_16' id='ART_16'></a><span class='smcap'>Art</span>. 16. <i>Third Law of Motion</i>.--Newton's Third Law of Motion reads as
+follows--
+</p>
+
+<p>
+&ldquo;Action and re-action are equal and opposite, or, to every action there
+is always an equal and contrary re-action.&rdquo; This law is also<span class='pagenum'><a name='Page_21' id='Page_21'></a><a href='#TOC'>[21]</a></span>
+conformable to experience; for, by experiment, it has been proved to
+hold good for electric and magnetic action. As MacLaurin points out, the
+Third Law of Motion may be extended to all sorts of powers that take
+place in Nature, and belongs to attraction and repulsion of all kinds,
+and must not be considered as being arbitrarily introduced by Newton.
+</p>
+
+<p>
+The mutual action between any two bodies has, therefore, a double
+action. Thus a piece of stretched string must be conceived as pulling at
+both ends; the pull at the one end being exactly equal and opposite to
+the pull on the other end.
+</p>
+
+<p>
+A magnet will attract a piece of iron with a certain force, but it is
+equally true that the iron attracts the magnet with an exactly equal and
+opposite force. We might even extend the application of this Third Law
+to a falling stone in its relation to the earth. Thus, if a stone is
+dropped from a high altitude to the surface of the earth, although the
+motion seems to be all in one direction, yet if the Third Law holds
+good, then the earth is attracted by the stone in exactly an equal, but
+opposite direction, to that in which the earth attracts the stone.
+</p>
+
+<p>
+As, however, the mass of the earth is very great compared with that of
+the stone, it follows that the velocity of the stone compared with the
+velocity of the earth, must be very much greater, in order that the
+forces shall be equal.
+</p>
+
+<p>
+The application of this Third Rule of Motion to planetary and celestial
+phenomena is therefore philosophical, in that its conception agrees with
+experience and observation.
+</p>
+
+<p>
+Thus, while it is true that the sun attracts each of the planets in his
+system, it is equally true that the planets, in their turn, attract the
+sun with an exactly equal and opposite force. But the velocity of motion
+induced by the earth's attractive power upon the sun, would be less than
+the velocity of motion induced by the sun's attractive power upon the
+earth, although the two forces would be equal and opposite, simply
+because force, being a compound quantity, is dependent upon the mass of
+a body as well as upon its velocity.
+</p>
+
+<p>
+Not only, however, is it true that the sun and all the planets jointly
+attract each other, but it is equally true that the planets attract each
+other also, with an exactly equal and opposite effect. Indeed, as
+Gravitation is universal, it has to be conceived that there are no two
+bodies existing, but what the Third Law of Motion equally applies to
+those two bodies; so that equality of action and re-action is as
+universal as the Law of Gravitation itself.
+</p>
+
+<p>
+In coming to a conclusion with reference to Philosophy and the Laws of
+Motion, I wish to say that I am strongly of the opinion that the day has
+come, or will soon come, when they will pass away and give place to a
+more direct and simple method of working of the great Law of<span class='pagenum'><a name='Page_22' id='Page_22'></a><a href='#TOC'>[22]</a></span>
+Gravitation. I look upon the Laws of Motion as part of the scaffolding
+which has been used to build up the Law of Gravitation. That Law has now
+been erected, and stands firm and secure in its position in the
+universe. Whatever changes may take place in its scaffolding, the Law
+itself will stand out with greater beauty and clearness, if we could but
+see the perfected structure, apart from the props and helps which have
+assisted in its successful erection and completion. As Dr. Larmor said,
+in his address to the British Association, 1900: &ldquo;There has even
+appeared a disposition to consider that the Newtonian principles, which
+have formed the basis of physical phenomena for nearly two centuries,
+must be replaced in these deeper subjects by a method of more direct
+description of the cause of the phenomena. The question has arisen, as
+to how far the new methods of aetherial physics are to be considered as
+an independent departure; or how far they form the natural development
+of existing dynamical science.&rdquo;
+</p>
+
+<p>
+I hope, therefore, to be able in this work to do something towards
+clearing the completed Law from some of the outside props, which have
+long hidden the simplicity, beauty and harmony of the physical working
+of Gravitation from the eyes of those who feign would see its wonderful
+mechanism.
+</p>
+
+<p>
+In the elaboration and development, therefore, of the physical cause of
+Gravitation, it will be necessary to conceive a medium, whose properties
+and motions shall be able to account for all the movements of the
+planets, comets, suns and stars that the Laws of Motion now account for.
+Instead, however, of there being several Laws purely and simply
+mathematical in their application, there will be one physical medium,
+which will by its properties and motions account for--and that in a
+satisfactory manner--all the motions of the heavenly bodies. That such a
+medium is required in the scientific world is proved by the statement
+made by Professor Glazebrook, in his work on J. C. Maxwell, page 221,
+where he says: &ldquo;We are still waiting for some one to give us a theory of
+the Aether, which shall include the facts of electricity and magnetism,
+luminous radiation, and it may be Gravitation.&rdquo;
+</p>
+
+<p>
+<a name='ART_17' id='ART_17'></a><span class='smcap'>Art</span>. 17. <i>Summary of the Chapter</i>.--In summing up the contents of this
+chapter, we find therefrom, that there is a Universal Law in existence
+that is known as the Law of Gravitation. The physical cause of this Law,
+however, is unknown; Newton suggesting that it was due to the properties
+of an aetherial medium that pervaded the universe.
+</p>
+
+<p>
+To form a right conception of this medium, and to develop the hypotheses
+of the same on strictly philosophical lines, it is essential for us to
+know the rules which govern the making of any hypothesis.<span class='pagenum'><a name='Page_23' id='Page_23'></a><a href='#TOC'>[23]</a></span>
+</p>
+
+<p>
+Those rules,
+according to Newton, and other philosophers, are chiefly three in
+number, and form the very essence of any philosophical reasoning. Any
+departure from those rules will entail partial or entire failure in the
+success of the undertaking.
+</p>
+
+<p>
+The application of Newton's rules to parts of the great Law of
+Gravitation show that some of those parts are not fully in harmony with
+the rules which Newton laid down in his <i>Principia</i>.
+</p>
+
+<p>
+Any physical theory that may be hereafter suggested as the physical
+basis for the Law of Gravitation, must itself not only account for the
+various forces already referred to, but must itself fulfil the Rules of
+Philosophy laid down by Newton. That is to say, the conception of the
+physical medium must be simple in character, its properties and motions
+must agree with all our experience, as given by observation, and
+experiments; and the properties and motions postulated for it must
+satisfactorily account for, and explain all the phenomena that are
+presented to us by the Universal Law of Gravitation.
+</p>
+
+<p>
+If all this be done, then from the standpoint of strict philosophical
+reasoning, the physical medium so suggested, and the theory so made,
+will be incapable of being overthrown or disproved.<span class='pagenum'><a name='Page_24' id='Page_24'></a><a href='#TOC'>[24]</a></span>
+</p>
+
+<h2><a name='CHAPTER_II' id='CHAPTER_II'></a><a href='#CHAPTER_II_TOC'>CHAPTER II</a></h2>
+
+<h3>PHILOSOPHY OF GRAVITATION</h3>
+
+<p>
+<a name='ART_18' id='ART_18'></a><span class='smcap'>Art</span>. 18. <i>Gravitation Attraction</i>.--The Law of Gravitation being a
+compound law, and not a simple law (<a href='#ART_8'>Art. 8</a>), it is necessary that the
+principles which govern universal attraction should now be considered.
+</p>
+
+<p>
+The law which governs Gravitation Attraction may be defined as follows:
+Every particle of matter in the universe attracts every other particle
+with a force whose direction is that of a line joining the centre of
+their masses, whose magnitude is directly as the product of their
+masses, and inversely as the square of the distance between them.
+</p>
+
+<p>
+This may be divided into four parts.
+</p>
+
+<p style='margin-left: 5em;'>(1) The Universality of Gravitation.</p>
+<p style='margin-left: 5em;'>(2) The Direction of the Forces involved.</p>
+<p style='margin-left: 5em;'>(3) The Proportion of these Forces.</p>
+<p style='margin-left: 5em;'>(4) The Law of Inverse Squares.</p>
+
+<p>
+The theory of the Aether, therefore, which will be perfected in this
+work, must not only satisfactorily account for the Attraction of
+Gravitation on a strictly philosophical basis, but the laws, governing
+the pressures or tensions of that physical medium, must harmonize with
+each of the parts of the complex Law of Gravitation into which it has
+been resolved.
+</p>
+
+<p>
+<a name='ART_19' id='ART_19'></a><span class='smcap'>Art</span>. 19. <i>Universality of the Attractive Force</i>.--The principle upon
+which Universal Attraction rests is found in the words: &ldquo;Every particle
+of matter in the universe attracts every other particle.&rdquo; It must,
+however, be admitted that this statement has never actually been proved.
+The smallest body that Newton used to prove his Law of Attraction was
+our satellite the moon.
+</p>
+
+<p>
+Cavendish, however, in 1798, by a series of experiments, conclusively
+demonstrated that the force of Gravitation existed in small bodies. He
+took two small leaden balls of a certain weight, and fixed them at the
+ends of a rod about six feet long, the rod being suspended by a piece of
+wire in the air. Large leaden balls were then brought near the small
+ones, and great care was taken to see if there were any twist in the
+wire by which they were suspended. It was found that the wire had become<span class='pagenum'><a name='Page_25' id='Page_25'></a><a href='#TOC'>[25]</a></span>
+twisted on the approach of the large leaden balls, and thus he was able
+to prove that every particle of the attracted and attracting body are
+mutually concerned in the Attraction of Gravitation. There is abundant
+evidence of the application of this force in relation to our earth, as
+we shall see later on.
+</p>
+
+<p>
+The universality of the Attraction of Gravitation is a fact that has
+been proved in a thousand ways, and a thousand times. All stars and
+suns, and all planets, satellites and comets and nebulae are subject to
+this universal law. Astronomy teaches us that its power extends across
+the vast abysses of space, and that stars situated at distances that
+cannot possibly be measured, are subject to this world-wide law. Some of
+the greatest discoveries in astronomical science were due to the
+operations of this wonderful law, the gravitating influences of certain
+planets indicating their existence, although their discovery had not yet
+been made.
+</p>
+
+<p>
+The discovery of Neptune through the mathematical calculations of Le
+Verrier and Mr. Adams in 1846 was the crowning proof of the Law of
+Gravitation. Mr. Adams in England had noticed that the planet Uranus was
+being pulled out of the course by some unknown power, and so set to work
+to calculate the position of the body which thus influenced the motion
+of Uranus in its orbit. He located the position of the supposed
+influencing body strictly by mathematical calculations, and then took
+his results to the Astronomer Royal. Delay, however, occurred in the
+search for the supposed new planet, and nothing was done further in the
+matter for many months. Meanwhile Le Verrier in France, unknown to Mr.
+Adams, had been making similar calculations with reference to the
+perturbations of Uranus, and had arrived at similar results.
+</p>
+
+<p>
+These results were sent to the Berlin astronomers, and the heavens were
+searched for the supposed new planet. After a time, the planet was
+discovered in that part of the heavens indicated by Le Verrier, and for
+a time his name stood out as the sole discoverer. Gradually, however,
+the claims of Adams were admitted and recognized, and to-day his claims
+to participate in the honour of the wonderful achievement are generally
+admitted. Thus the discovery of Neptune gave to the Law of Gravitation a
+stability and proof that perhaps it had never received before.
+</p>
+
+<p>
+Further evidence of the existence of the universality of the attractive
+force, is to be found in a certain system of stars known as binary
+stars, which revolve around each other, while they gravitate around a
+common centre. Recent researches in astronomy only seek more and more to
+confirm the universality and effectiveness of this grand law, that seems
+to hold the entire universe in its sway.
+</p>
+
+<p>
+Any medium, therefore, which is postulated as the physical cause of<span class='pagenum'><a name='Page_26' id='Page_26'></a><a href='#TOC'>[26]</a></span>
+Gravitation, must itself be as universal as Gravitation, in order for it
+to be able to fulfil this condition of universality. We shall find, as
+we proceed, that the only possible medium which can fulfil this
+condition, is the universal Aether, whose qualities and properties are
+already partly known and partly understood.
+</p>
+
+<p>
+<a name='ART_20' id='ART_20'></a><span class='smcap'>Art</span>. 20. <i>Direction of the Forces</i>.--The attraction of Gravitation is
+always directed along the straight line which joins the centres of
+masses of the attracting and attracted bodies. Thus, if the earth and
+moon are taken as examples, an imaginary straight line drawn from the
+centre of the earth's mass to the centre of the mass of the moon would
+be the direction in which the gravitative force would be exerted. Now a
+line which joins the central body to its satellite we shall see when we
+come to deal with Kepler's Laws is known as the Radius Vector. Thus the
+path of the attraction between the two bodies is along the Radius
+Vector. It is a singular coincidence that the path of a ray of light
+from the sun also coincides with the Radius Vector, as it is one of the
+laws of light that the path of a ray always follows a straight line.
+</p>
+
+<p>
+It must not, however, be assumed, that while the attractive power is
+being exerted along any one straight line joining the centres of two
+bodies, therefore the attractive power is not operative in relation to
+any other part of the space, around the body. If our earth, for example,
+had four moons instead of one, and they were each in different positions
+in relation to the earth, then the law as to the direction of the forces
+would still hold good. We have examples of this in the case of Jupiter
+with his five moons, and Saturn with his eight moons. So that the
+attractive force of Gravitation is again like light, it operates on all
+sides equally at one and the same time. A lamp in the middle of a room
+sends its light waves on every side at one and the same time, so that
+while each ray has for its path a straight line, yet those rays are
+emitted equally on every side. In like manner, though the direction of
+the forces between two attracting bodies is that of a straight line, yet
+the law of universal attraction is equally exerted on every side of the
+planet at one and the same time.
+</p>
+
+<p>
+In the theory of the Aether, therefore, to be developed in this work, it
+will have to be demonstrated that the direction of the forces, which are
+originated and transmitted by that physical medium, must philosophically
+fulfil the conditions which govern the direction of the forces, as
+observed in gravitational phenomena.
+</p>
+
+<p>
+<a name='ART_21' id='ART_21'></a><span class='smcap'>Art</span>. 21. <i>Proportion of the Forces</i>.--Newton proved that the attraction
+is proportional to the product of the masses of the bodies concerned.<span class='pagenum'><a name='Page_27' id='Page_27'></a><a href='#TOC'>[27]</a></span>
+</p>
+
+<p>
+Hence it is that the sun, which is the centre of the solar system, is
+capable of attracting the most remote planets, because the mass of the
+sun is greater than the mass of all the planets put together. Or take
+another illustration. Suppose that the sun and the earth are at equal
+distances from Saturn. Now the sun's mass is about 300,000 times that of
+our earth. Therefore if the earth draws Saturn through a certain
+distance in one second, the sun would draw Saturn through a distance
+which is 300,000 greater than the earth in the same period.
+</p>
+
+<p>
+The governing principle, therefore, which decides the proportion of the
+attractive forces between two bodies is mass, and not simply density or
+volume. The mass of a body is a property which remains the same, as long
+as the inertia of the body remains constant. Mass is really a measure of
+the inertia of a body, or that property of a body by which it continues
+in its state of motion or of rest.
+</p>
+
+<p>
+Mass is therefore a compound quantity, being equal to volume multiplied
+by density, so that if the volume of any body is halved, the density is
+doubled. Thus, the proportion of the attractive force between any two
+bodies ever remains the same, so long as the masses of the two bodies
+remain the same. Through all the changes of volume and density of any
+body, its attractive force remains constant, as long as the mass remains
+constant; for the simple reason, that as the volume of a body is
+increased, the density is proportionately decreased; or, as the volume
+is decreased, the density is increased.
+</p>
+
+<p>
+For example, the volume of the sun as compared with the volume of the
+earth, is about 1,300,000 times greater, but the proportion of the
+attractive forces between the two bodies, is about 324,000 to 1. This
+difference is accounted for by the fact, that the density of the sun is
+about one quarter the mean density of the earth, hence their masses are
+in the proportion of 324,000 to 1. Thus the proportion of the attractive
+forces between any two bodies is dependent upon their masses, and not
+simply upon their volume or density.
+</p>
+
+<p>
+<a name='ART_22' id='ART_22'></a><span class='smcap'>Art</span>. 22. <i>Law of Inverse Squares</i>.--The Law of Inverse Squares which is
+applicable to Gravitation is equally true of Sound, Light, Heat and
+Electricity, the Law being that Gravitation acts inversely as the square
+of distance. That is to say, if the distance of any body from the sun,
+for example, be doubled, then the force of Gravitation is diminished to
+one quarter of the intensity which would be exerted on the body in the
+first position.
+</p>
+
+<p>
+Thus the further a body is from its controlling centre, the weaker the
+Attraction of Gravitation upon it becomes. Taking therefore Mercury and
+the earth as examples, we find that their mean distances are<span class='pagenum'><a name='Page_28' id='Page_28'></a><a href='#TOC'>[28]</a></span>
+respectively 35,000,000 miles and 92,000,000, which is a proportion of
+about 1 to 2-1/2. So that the intensity of the sun's attraction on the
+earth is about four-twenty-fifths of what it is on Mercury, that being
+the inverse square of the relative distances of the two bodies.
+</p>
+
+<p>
+Now the intensity of Light and Heat received by the earth is regulated
+by the same law of inverse squares, so that the earth would receive
+about four-twenty-fifths the intensity of light and heat which Mercury
+receives when they are both at their mean distances.
+</p>
+
+<p>
+This law of inverse squares is applicable to every body which acts as a
+gravitating source throughout the whole of the universe, whether that
+body be small or large, and whether it be in the form of meteor,
+satellite, planet, sun or star.
+</p>
+
+<p>
+Each satellite, planet or sun exerts an attractive influence upon every
+body that exists, that attractive influence being regulated by the
+masses of the respective bodies, and decreasing inversely as the square
+of the distance from the body viewed as the centre of attraction. So
+that, the further the attracted body is from the attracting body, the
+less is the intensity of the mutual attracting forces, though that
+intensity does not vary simply as the distance, but rather as the square
+of the distance, and that in its inverse ratio. Thus if we take two
+masses of any kind or sort, and place them at various distances as
+represented by the numbers 1, 2, 3, 4, 5, 6, the intensity of the
+attracting forces between the same masses at the relative distances will
+be represented by the numbers 1, 1/4, 1/9, 1/16, 1/25, 1/36, which are
+the inverse squares of the respective numbers representing their
+distances. As we shall see, the same law holds good in relation to heat,
+light and electricity, and indeed to all forms of energy which radiate
+out from a centre equally in all directions.
+</p>
+
+<p>
+There is no need to apply Newton's Rules of Philosophy to this
+Attraction of Gravitation, as it has been demonstrated to exist, times
+without number. Moreover its laws are exactly the same as those
+governing the phenomena of sound, light, heat, and electricity, so that
+apart from being proved by actual experiments in relation to the gravity
+of the earth, we have a wider experience of the application of the same
+ruling principles of the law in other departments of science.
+</p>
+
+<p>
+The Law of Universal Attraction, which is strictly the Centripetal Force
+of the compound Law of Gravitation, fully satisfies the three governing
+rules of Newton's Philosophy. Not only is it simple in its conception,
+but it is borne out by experience, and adequately accounts for the
+distinctive phenomena which it seeks to explain. By it, astronomical
+observations can be taken with a precision and certainty that defy error
+or failure. The motion of a planet in its orbit can be so perfectly<span class='pagenum'><a name='Page_29' id='Page_29'></a><a href='#TOC'>[29]</a></span>
+calculated, that its position in space in relation to other planets can
+be foretold years in advance. The theory of the Aether, therefore, which
+is to be perfected in this work, must philosophically show that the
+pressures or tensions of that medium, which are postulated as the cause
+of Gravitation Attraction, must themselves fulfil the laws of inverse
+squares, which govern light, heat, electricity and the Attraction of
+Gravitation. I premise that this will be done in the theory of the
+Aether to be submitted to the reader in the after pages of this work.
+</p>
+
+<p>
+<a name='ART_23' id='ART_23'></a><span class='smcap'>Art</span>. 23. <i>Terrestrial Gravity</i>.--Before passing from this phase of the
+subject, I should like briefly to look at the question of the Attraction
+of Gravitation from the standpoint of our own earth, as by so doing we
+shall notice some facts regarding the same, hitherto unnoticed, in the
+preceding articles.
+</p>
+
+<p>
+Terrestrial Gravity is but a phase of Universal Gravitation. One of the
+most familiar facts and phenomena of everyday life is, that when a body,
+such as a stone or stick or bullet, is thrown or projected into the air,
+it always falls to the earth again. This is due to the attraction of the
+earth and the stone for each other. It has been proved experimentally
+that if a stone and a weight are let fall from a height of 16 feet, they
+would reach the earth in one second of time. Again, a feather, or cork,
+or even a piece of iron would take exactly the same time falling through
+the same space, provided that the feather or cork could be screened from
+the resistance of the air.
+</p>
+
+<p>
+The distance, however, through which a body falls in one second varies
+at different parts of the earth's surface, being least at the equator,
+and greatest at the North and South Poles. This is accounted for by the
+fact that the polar diameter is only 7899 miles, while the equatorial
+diameter is 7925 miles, thus the distance from the centre of the earth
+to either pole is about 3950 miles, or 13 miles less than the equatorial
+radius of the earth. Now the force of gravity decreases upwards from the
+earth's surface inversely as the square of the distance from the earth's
+centre of gravity, but decreases downwards simply as the distance from
+the centre decreases. Thus if a ball were taken down 2000 miles, that is
+half the distance to the centre, it would only weigh half-a-pound, while
+if it were taken to the centre of the earth, it would have no weight at
+all; while a pound weight at the equator would not weigh one pound at
+the poles, because it would be nearer the centre of the earth by 13
+miles.
+</p>
+
+<p>
+Thus a pound weight is not always a pound weight. It varies as we carry
+it to different parts of the earth's surface, depending upon its
+relation to the centre of the earth for its exact weight. The point
+which I wish to make perfectly clear, as it will be necessary for<span class='pagenum'><a name='Page_30' id='Page_30'></a><a href='#TOC'>[30]</a></span>
+future reference, is, that there is no such thing as weight apart from
+the gravity of the earth; or, if we apply the principle to the solar
+system, there is no gravitating force in that system apart from the
+gravitating force of the central body, the sun, or the planets and other
+bodies which form the solar system.
+</p>
+
+<p>
+Let us look at this matter from another standpoint, in order to prove
+this truth and make the same perfectly clear. If a pound weight were put
+in a spring-balance, then at the surface of the earth it would weigh one
+pound. Now, we will suppose that we have taken the weight to a height of
+4000 miles above the surface of the earth, that is exactly double the
+distance from the centre of the earth, the radius of the earth being
+approximately 4000 miles. According to the law of inverse squares, the
+force of Gravitation decreases inversely as the square of the distance.
+The distance having been doubled, the proportion of the forces at the
+two places, <i>i. e.</i> the earth's surface and 4000 miles above it, are as
+1 to 1/4.
+</p>
+
+<p>
+Thus at a distance of 4000 miles the weight which weighed one pound at
+the earth's surface, now only weighs a quarter of a pound. At a distance
+of 8000 miles, the distance would be trebled, therefore the force of
+Gravitation is one-ninth, and the weight would weigh one-ninth of a
+pound. If we could take the pound weight to the moon, the attractive
+force of the earth would be reduced to 1-3600, as the moon is 240,000
+miles distant, that is sixty times the earth's radius. The square of 60
+is 3600, and if we invert that we get 1-3600, so that the weight which
+weighs a pound at the earth's surface, would only weigh 1-3600 part of a
+pound at the distance of the moon. This again proves, that apart from
+the Attraction of Gravitation, there is no such thing as weight, and
+that the weight so called of any body, such as a planet or satellite,
+increases or decreases as its distance increases or decreases from its
+central attracting body.
+</p>
+
+<p>
+<a name='ART_24' id='ART_24'></a><span class='smcap'>Art.</span> 24. <i>Centrifugal Force.</i>--I have already shown in <a href='#ART_10'>Art. 10</a> that
+the Centripetal Force and Universal Attraction are one and the same; as
+the Centripetal Force always acts towards the centre, and must therefore
+be in its operation and influence a gravitating or attractive power.
+</p>
+
+<p>
+I have also pointed out in the same article, the necessity of another
+force, which is to be the complement, and the counter part of
+Gravitation Attraction. That complement and counter force was conceived
+by Newton, and called by him the Centrifugal Force. The very nature of
+the Centripetal Force demands and necessitates a force which in its mode
+of operation is exactly the opposite of the Centripetal Force. Unless
+there were such a force, a repellent and repulsive force, then instead<span class='pagenum'><a name='Page_31' id='Page_31'></a><a href='#TOC'>[31]</a></span>
+of there being that harmonious working of the universe that now exists,
+there must inevitably be a gradual drawing together of all planets and
+satellites, of all stars and suns, into one vast, solitary, and ruinous
+body.
+</p>
+
+<p>
+There are also other phenomena which demand a Centrifugal Force in the
+universe. It is a well-known fact, that there exist between the orbits
+of Jupiter and Mars, what are called planetoids, about 500 in number,
+which are supposed to be the remnants of a broken or shattered world. As
+may be expected from such an accumulation, they present the most
+extraordinary diversities and eccentricities in the orbits that can
+possibly be conceived. They are of all shapes and sizes, and besides
+their orbits round the sun, have orbits among themselves. They are so
+clustered together that their orbits intersect each other at numerous
+points, and when in conjunction are said to suffer great perturbations,
+being pulled great distances this way and that by each other's
+attractive influence. It is further stated that their orbits so
+intersect each other, that if they were imagined to be material rings,
+they would be inseparable, and the whole could be suspended by taking
+any one of them up at random. Here, then, is presented to us a kind or
+order of celestial phenomena for whose well-being and effectual working
+the Centripetal Force or the Attraction of Gravitation cannot possibly
+account. In their case another force is demanded which shall be the
+exact complement and counterpart of the Centripetal Force. There needs
+therefore a force, not an imagined one, simply conceived to fill a want,
+but a real Force, as real and as plainly to be understood as the
+Centripetal Force. A force existing in each world just like the
+Attraction of Gravitation, only the reverse of Gravitation, a repellent,
+repulsive Force, acting in the reverse mode, and way, to universal
+attraction. This Force must be governed by the same rules and laws that
+govern the Centripetal Force, if it is to work in harmony with the same.
+It must be universal in its character, having a proportion of forces
+equal to the product of the masses of the two bodies which are
+concerned, and its path must coincide with the path of gravitational
+attraction, that is, in the straight line which joins the centres of
+gravity of the two bodies. Further, and what is perhaps the most
+important of all, it must act as a repelling or repulsive force which
+shall be in the same proportion in regard to distance, as the law
+governing Centripetal Force, that is, inversely as the square of the
+distance.
+</p>
+
+<p>
+Again, and briefly, there are also in existence small bodies called
+meteors, which are said to exist by myriads, which float in space, and
+circle round the sun. They are of all shapes and sizes, from one ounce
+to a ton or even tons, thousands of them coming into contact with our<span class='pagenum'><a name='Page_32' id='Page_32'></a><a href='#TOC'>[32]</a></span>
+earth's atmosphere every year, especially in August and November. All of
+these small bodies have orbits among themselves, and gravitate round one
+another, as they revolve round the sun. Now if the orbits of the
+planetoids be such an entangled mass, what must be the orbits of these
+meteors? What an indescribable, unimaginable mass of labyrinthian
+motions must exist among these myriads of little bodies! How they must
+intersect, cross and intermingle each other's orbits! What attraction
+and counter-attraction they must exert upon each other! Let me ask any
+man to sit down and try to imagine how the present recognized
+Centripetal and Centrifugal Forces can account for the effectual working
+of these meteors. As illustrating the necessity of a real and physical
+Centrifugal Force which is to be the exact counterpart of the
+Centripetal Force, I would call the attention of the reader to
+Herschel's view of this matter. In dealing with the phenomena of comets'
+tails he writes:<a name='FNanchor_1' id='FNanchor_1'></a><a href='#Footnote_1' class='fnanchor'>[1]</a> &ldquo;Beyond a doubt, the widest and most interesting
+prospect of future discovery, which this study holds out to us, is, that
+distinction between gravitating and levitating matter, that positive and
+irrefutable demonstration in nature of a repulsive force, co-extensive
+with, but enormously more powerful than the attractive force we call
+gravity which the phenomena of their tails afford.&rdquo; I premise that this
+prophecy of Herschel's will be fully demonstrated and proved in the
+succeeding pages of this work. For, in the theory of the Aether that is
+to be afterwards perfected, it will be philosophically proved that the
+physical medium so conceived will satisfactorily account for a force or
+motion from the centre of all bodies; which motions fulfil all the
+conditions required by that Centrifugal Force, which is the complement
+and counterpart of the Attraction of Gravitation. At the present time,
+with the conception of a frictionless Aether, it is impossible to
+harmonize the existence of such a force or motion with our theory of the
+Aether. Yet Professor Lebedew of Moscow, and Nichols and Hull of
+America, have incontrovertibly demonstrated by actual experiments the
+existence of such a force. Therefore it follows, that if our present
+theory of the Aether fails to agree with experimental evidence, such a
+theory must be reconstructed in order that our philosophy may be made to
+agree with our experiments and our experience.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_1' id='Footnote_1'></a><a href='#FNanchor_1'><span class='label'>[1]</span></a><i>Lectures on Scientific Subjects</i>.</p></div>
+
+<p>
+<a name='ART_25' id='ART_25'></a><span class='smcap'>Art</span>. 25. <i>Kepler's Laws</i>.--A long time before Newton had discovered the
+Law of Gravitation, Kepler had found out that the motions of the planets
+were governed by certain laws, and these came to be known as Kepler's
+Laws.
+</p>
+
+<p>
+These laws which were given to the world by Kepler, simply represented<span class='pagenum'><a name='Page_33' id='Page_33'></a><a href='#TOC'>[33]</a></span>
+facts or phenomena which had been discovered by observation, as Kepler
+was unable to account for them, or to give any mathematical basis for the
+same.
+</p>
+
+<p>
+On the discovery, however, of Universal Gravitation, Newton saw at once
+that these laws were simply the outcome of the application of the Law of
+Gravitation to the planets, and that they could be accounted for on a
+mathematical basis by the Law of Gravitation, as they seemed to flow
+naturally from that law.
+</p>
+
+<p>
+Kepler's Laws are three in number and may be thus stated--
+</p>
+
+<p>
+<i>1st Law</i>. Each planet revolves round the sun in an elliptic orbit, with
+the sun occupying one of the Foci.
+</p>
+
+<p>
+<i>2nd Law</i>. In the revolution of a planet round the sun, the Radius
+Vector describes equal areas in equal times.
+</p>
+
+<p>
+<i>3rd Law</i>. The squares of the periodic times of planets are proportional
+to the cubes of their mean distances.
+</p>
+
+<p>
+Now the question arises, whether it is possible to form a theory of the
+Aether which shall satisfactorily and philosophically account for all
+the phenomena associated with Kepler's Laws in their relation to the
+motions of planets, satellites, or other solar bodies? On the present
+conception of the Aether such a result is an absolute impossibility.
+With the theory of the Aether, however, to be submitted to the reader in
+this work, the result is possible and attainable. If, therefore, such a
+result is philosophically proved, as I submit will be done, then we
+shall have greater evidence still that the theory so propounded is a
+more perfect theory than the one at present recognized by scientists
+generally.
+</p>
+
+<p>
+<a name='ART_26' id='ART_26'></a><span class='smcap'>Art</span>. 26. <i>Kepler's First Law</i>.--Each planet revolves round the sun in an
+elliptic orbit, the sun occupying one of the Foci.
+</p>
+
+<p>
+The ancients thought that the paths of the planets around the sun were
+circular in form, because they held that circular motion was perfect. A
+system of circular orbits for the paths of the planets round the sun
+would be very simple in its conception, and would be full of beauty and
+harmony. But exact calculations reveal to us that the path of a planet
+is not exactly that of a circle, as the distance of a planet from the
+sun in various parts of its orbit is sometimes greater, and sometimes
+less, than its mean distance.
+</p>
+
+<p>
+The planet Venus has the nearest approach to a circular orbit, as there
+are only 500,000 miles between the mean, and greatest and least
+distances, but both Mercury and Mars show great differences between
+their greatest and least distances from the sun.
+</p>
+
+<p>
+If, therefore, the orbits of a planet are not exactly circular, what is<span class='pagenum'><a name='Page_34' id='Page_34'></a><a href='#TOC'>[34]</a></span>
+their exact shape? Kepler solved this problem, and proved that the
+exact path of a planet round its central body the sun was that of an
+ellipse, or an elongated circle. Thus he gave to the world the first of
+his famous laws which stated that each planet revolves round the sun in
+an orbit which has an elliptic form, the sun occupying one of the Foci.
+</p>
+
+<p>
+Not only is the orbit of a planet round the sun elliptic in form, but
+the path of the moon round the earth, or the path of any satellite, as
+for example a satellite of Mars or Jupiter or Saturn, is also that of an
+ellipse, the planet round which it revolves occupying one of the Foci.
+</p>
+
+<p>
+It has also been found that certain comets have orbits which cannot be
+distinguished from that of an elongated ellipse, the sun occupying one
+of the Foci.
+</p>
+
+<p>
+Now let us apply the Law of Gravitation to Kepler's First Law, and note
+carefully its application.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/048.jpg' width='400' height='196'
+alt='Fig: 1.'
+title='Fig: 1.' />
+</div>
+
+<p>
+Let <i>A</i>, <i>B</i>, <i>C</i>, <i>D</i> be an ellipse representing the orbit of the earth, and
+let <i>S</i> represent the sun situated at one of the Foci.
+</p>
+
+<p>
+We will suppose that the earth is projected into space at the point <i>A</i>,
+then according to the First Law of Motion, it would proceed in a
+straight line in the direction of <i>A</i> <i>E</i>, if there were no other force
+acting upon the earth. But it is acted upon by the attraction of the
+sun, that is the Centripetal Force which is exerted along the straight
+line <i>S</i> <i>A</i> (<a href='#ART_20'>Art. 20</a>), which continues to act upon it according to the
+principle already explained in <a href='#ART_21'>Arts. 21</a> and <a href='#ART_22'>22</a>.
+</p>
+
+<p>
+Now, according to the Second Law of Motion and the Parallelogram of
+Forces, instead of the earth going off at a tangent in the direction of
+<i>A</i> <i>E</i>, it will take a mean path in the direction of <i>A</i> <i>B</i>, its path
+being curved instead of being a straight line.
+</p>
+
+<p>
+If the sun were stationary in space, then the mean distance, that is,
+the length of the imaginary straight line joining the sun <i>S</i> <i>A</i> to the
+earth, would remain unaltered. The Radius Vector <i>S</i> <i>A</i>, or the straight
+line referred to, would then be perpendicular to the tangent, and the<span class='pagenum'><a name='Page_35' id='Page_35'></a><a href='#TOC'>[35]</a></span>
+velocity of the earth round the sun would be uniform, its path being
+that of a circle.
+</p>
+
+<p>
+The Radius Vector <i>S</i> <i>A</i>, however, is not always perpendicular to the
+tangent <i>F</i> <i>E</i>, and therefore the velocity of the earth is not always
+uniform in its motion in its orbit, as sometimes it travels at a lesser
+or greater speed than its average speed, which is about 18 miles per
+second.
+</p>
+
+<p>
+It has to be remembered that the sun itself is in motion, having a
+velocity through space of about 4-1/2 miles per second, so that, while
+the earth is travelling from <i>A</i> to <i>B</i> the sun is also travelling in
+the direction of <i>S</i> <i>B</i>. Thus the orbital velocity of the earth, and the
+orbital velocity of the sun, together with the Centripetal Force or
+universal Gravitation Attraction, are all acting in the same direction
+when the earth is travelling from <i>A</i> to <i>B</i>, that is, in the direction
+of the orbit situated at <i>B</i>. This point of the orbit is known as the
+perihelion, and at that point the velocity of the earth is at its
+greatest, because the earth is then nearest the sun.
+</p>
+
+<p>
+According to Newton, the planet when at <i>B</i> would still have a tendency
+to fly off into space owing to its Centrifugal Force, but it is held in
+check by the Centripetal Force, so that instead of it flying off into
+space, it is whirled round and starts off on its journey away from the
+sun in the direction of <i>B</i>, <i>C</i>. The sun, however, is still continuing
+its journey in the direction of <i>S</i>, <i>H</i>, so that not only is the
+increased orbital velocity of the earth, which it obtained at its
+perihelion, urging the earth away from the sun, but the sun itself in
+its advance through space is leaving the earth behind it. The combined
+effect of the two motions, the advancing motion of the sun, and the
+receding motion of the earth, due to its increased orbital velocity,
+drives the earth towards the aphelion, where its distance from the sun
+is greatest, and its orbital velocity is the least.
+</p>
+
+<p>
+By the time the planet has arrived at point <i>C</i>, its motion through
+space has gradually decreased, and the Centripetal Force begins to
+re-assert itself, with the result that the earth is slowly made to
+proceed towards the point <i>D</i> of the ellipse, at which point its motion
+is the slowest in orbital velocity, only travelling about 16 miles per
+second, while the distance of the earth from the sun is the greatest and
+has increased from 91,000,000 miles at the perihelion to 94,500,000.
+This point of the orbit is known as its aphelion.
+</p>
+
+<p>
+After rounding this point, the orbital velocity of the earth begins to
+increase again, owing to the diminishing distance of the earth from the
+sun, which according to the law of inverse squares (<a href='#ART_22'>Art. 22</a>) gives an
+added intensity to the Centripetal Force.<span class='pagenum'><a name='Page_36' id='Page_36'></a><a href='#TOC'>[36]</a></span>
+</p>
+
+<p>
+Thus by the combination of
+the Laws of Motion and the Law of Gravitation discovered by Newton, he
+was able to satisfactorily account for and explain on a mathematical
+basis, the reason why the earth and all the other planets move round the
+sun in elliptic orbits, according to Kepler's First Law.
+</p>
+
+<p>
+In the development of the physical cause of gravitation, therefore, the
+same physical medium, which accounts for that law, must also give a
+satisfactory explanation of the first of Kepler's Laws.
+</p>
+
+<p>
+<a name='ART_27' id='ART_27'></a><span class='smcap'>Art</span>. 27. <i>Kepler's Second Law</i>.--This law states that the Radius Vector
+describes equal areas in equal times. The Radius Vector is the imaginary
+straight line joining the centres of the sun and the earth or planet.
+While the First Law shows us the kind of path which a planet takes in
+revolving round the sun, the Second Law describes how the velocity of
+the planet varies in different parts of its orbit.
+</p>
+
+<p>
+If the earth's orbit were a circle, it can be readily seen that equal
+areas would be traversed in equal times, as the distance from the sun
+would always be the same, so that the Radius Vector being of uniform
+length, the rate of motion would be uniform, and consequently equal
+areas would be traversed in equal times. Take as an illustration the
+earth, which describes its revolution round the sun in 365-1/4 days. Now
+if the orbit of the earth were circular, then equal parts of the earth's
+orbit would be traversed by the Radius Vector in equal times. So that
+with a perfectly circular orbit, one half of the orbit would be
+traversed by the Radius Vector in half a year, one quarter in one
+quarter of a year, one-eighth in one-eighth of a year, and so on; the
+area covered by the Radius Vector being always exactly proportionate to
+the time.
+</p>
+
+<p>
+From Kepler's First Law, however, we know that the planet's distance
+does vary from the sun, and therefore the Radius Vector is sometimes
+longer and sometimes shorter than when the earth is at its mean
+distance; the Radius Vector being shortest at the perihelion of the
+orbit, and longest at the aphelion. We learn from Kepler's Second Law
+that when the Radius Vector is shortest, that is, when the planet is
+nearest the sun, it acquires its greatest orbital velocity; and when the
+Radius Vector is longest, that is, when the planet is farthest from the
+sun, the orbital velocity of a planet is the slowest.
+</p>
+
+<p>
+Let <i>A</i>, <i>B</i>, <i>D</i>, <i>C</i> represent the elliptic orbit of a planet, with
+<i>S</i> sun at one of the Foci, and let the triangles <i>A</i>, <i>S</i>, <i>B</i> and <i>D</i>,
+<i>S</i>, <i>C</i> be triangles of equal area. Then, according to Kepler's Second
+Law, the time taken for the Radius Vector to traverse the area <i>A</i>, <i>S</i>,
+<i>B</i> is equal to the time that the Radius Vector takes to traverse the
+area <i>D</i>, <i>S</i>, <i>C</i>. So that the planet would take an<span class='pagenum'><a name='Page_37' id='Page_37'></a><a href='#TOC'>[37]</a></span>
+equal time in going from <i>A</i> to <i>B</i> of its orbit, as it would take in
+going from <i>D</i> to <i>C</i>. Thus the nearer the planet is to the sun, the
+greater is its orbital velocity, and the farther it is away from the sun
+the slower is its velocity, the velocity being regulated by the
+distance. The manner in which the difference of velocity is accounted
+for by the Law of Gravitation has already been explained in the
+preceding article. Thus Newton proved that Kepler's Second Law was
+capable of being mathematically explained, and accounted for, by the
+universal Law of Gravitation.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/051.jpg' width='400' height='197'
+alt='Fig: 2.'
+title='Fig: 2.' />
+</div>
+
+<p>
+If, therefore, a physical cause can be given for Newton's Law of
+Gravitation, then such physical cause must also be able to account for,
+and that on a strictly philosophical basis, the second of Kepler's Laws
+as well as the first.
+</p>
+
+<p>
+<a name='ART_28' id='ART_28'></a><span class='smcap'>Art</span>. 28. <i>Kepler's Third Law</i>.--The Third Law of Kepler gives the
+relation between the periodic time of a planet, and its distance from
+the sun. The periodic time of any planet is the time which it takes to
+go once round the sun. Thus the periodic time of the earth is 365-1/4
+days. The periodic time of Venus is 224.7 days, while that of Mars is
+686.9 days.
+</p>
+
+<p>
+Kepler had found out that different planets had different periodic
+times; he also found out that the greater the mean distance of the
+planet, the greater was the time which the planet took to perform its
+journey round the sun, and so he set to work to find out the
+relationship of the periodic time to the planet's mean distance.
+</p>
+
+<p>
+After many trials and many failures he arrived at the right conclusion,
+and at last discovered the true law which is known as Kepler's Third
+Law, which states that for each and every planet, the squares of their
+periodic times are proportional to the cubes of their mean distances.
+</p>
+
+<p>
+For purposes of illustration let us take the earth and the planet Venus
+and compare these two. The periodic time of the earth is 365 days,
+omitting the quarter day. The periodic time of Venus is 224 days
+approximately. Now, according to Kepler's Third Law, the square of 365<span class='pagenum'><a name='Page_38' id='Page_38'></a><a href='#TOC'>[38]</a></span>
+is to the square of 224, as the cube of the earth's mean distance is to
+the cube of Venus's mean distance, which are 92.7 millions of miles and
+67 millions of miles respectively. The problem may be thus stated--
+</p>
+
+<p>
+As 365<sup>2</sup>: 224<sup>2</sup>:: 92.7<sup>3</sup>: 67<sup>3</sup>:
+</p>
+
+<p>
+This worked out gives--
+</p>
+
+<p>
+133,225: 50,176: 796,597.982: cube of Venus's mean distance.
+</p>
+
+<p>
+So that by Kepler's Third Law, if we have the periodic time of any two
+planets, and the mean distance of either, we can find out the mean
+distance of the other by simple proportion.
+</p>
+
+<p>
+In making astronomical calculations, the distances of the planets are
+generally obtained by means of Kepler's Third Law, as the periodic time
+of the planet is a calculation that may be made by astronomers with
+great certainty, and when once the periodic times are found, and the
+mean distance of a planet, as our earth for example, is known, the mean
+distances of all the other planets in the solar system may soon be
+obtained.
+</p>
+
+<p>
+In like manner this Third Law of Kepler's is equally applicable to the
+satellites of any planet. For example, when the periodic time of both of
+Mars' satellites, Phobos and Deimos, are known, being about 8 hours and
+30 hours respectively, and the distance of either is known, as Phobos
+with a mean distance of 5800 miles, then the mean distance of Deimos can
+easily be calculated by this law, and is found to be 14,500 miles.
+</p>
+
+<p>
+As discovered by Kepler, the Third Law was simply the result of
+observation. He was unable to give any mathematical basis for its
+existence. The Laws as they were given to the world by Kepler were
+simply three great truths which had been discovered by observation. It
+rested with Newton to show how these laws could be accounted for on a
+mathematical basis, and to show how they all sprang from one and the
+same source, namely the universal Law of Gravitation. In his
+<i>Principia</i>, he proved that all Kepler's Laws were fully expounded and
+explained by his great discovery of Universal Gravitation.
+</p>
+
+<p>
+Now what Newton has done for Kepler's Laws from the mathematical
+standpoint, we propose to do from the physical standpoint. In the
+development of the physical agency or cause of Gravitation, therefore,
+among the phenomena and laws, which have to be satisfactorily accounted
+for on a physical basis, are these three Laws of Kepler's just referred
+to.
+</p>
+
+<p>
+So that in addition to the satisfactory explanation of a physical cause
+for the Laws of Motion, and the Centripetal and Centrifugal Forces, the
+hypothesis of a physical cause of Gravitation must fully and
+satisfactorily account for the Laws of Kepler, whose mathematical
+explanation was given by Newton.
+</p>
+
+<p>
+Further, and what is as equally important, the explanation so given<span class='pagenum'><a name='Page_39' id='Page_39'></a><a href='#TOC'>[39]</a></span>
+must be strictly in harmony with the Rules of Philosophy as laid down in
+<a href='#ART_3'>Art. 3</a>. That is, the explanation must be simple in character, must not
+be contrary to experience or observation, and must satisfactorily
+account for the laws which the hypothesis of the physical cause of
+Gravitation seeks to explain. This I premise we will do as we pass from
+stage to stage in the development of the theory.
+</p>
+
+<p>
+I can safely premise that it will be simple in character and conception,
+that it will be entirely in harmony with all experience and observation,
+and that the physical cause so advanced will give as physical a basis to
+Kepler's Laws as Newton's mathematical calculations gave them a
+mathematical basis.
+</p>
+
+<p>
+In summing up, I need hardly point out, that if all that I have premised
+in this and the preceding chapter is accomplished in the after chapters
+of this book, then for the first time since the discovery of Universal
+Gravitation by Sir Isaac Newton, his great discovery will have received
+the long-expected and long-desired physical explanation, that
+explanation and cause being founded on his own Rules of Philosophy given
+in his immortal <i>Principia,</i> and for the first time our Philosophy will
+be brought strictly into harmony with our universal experience.<span class='pagenum'><a name='Page_40' id='Page_40'></a><a href='#TOC'>[40]</a></span>
+</p>
+
+
+<h2><a name='CHAPTER_III' id='CHAPTER_III'></a><a href='#CHAPTER_III_TOC'>CHAPTER III</a></h2>
+
+<h3>MATTER</h3>
+
+<p>
+<a name='ART_29' id='ART_29'></a><span class='smcap'>Art</span>. 29. <i>What is Matter?</i>--The law of Universal Attraction states that
+&ldquo;Every particle of matter attracts every other particle,&rdquo; etc., and the
+question at once arises as to what is meant by the term Matter, what are
+its properties and its constitution? Tait, in his <i>Natural Philosophy</i>,
+gives the following as the definition: &ldquo;Matter is that which can be
+perceived by the senses, or is that which can be acted upon by, or can
+exert force.&rdquo;
+</p>
+
+<p>
+It has already been pointed out in <a href='#ART_13'>Art. 13</a> that force is due to motion,
+and that wherever we get motion of any kind or sort, there we get
+energy, or what used to be termed force. The consideration of this phase
+of the question will be more fully dealt with in the chapter on Energy
+and Motion. Suffice to say, that all experience teaches us that force is
+the outcome of motion.
+</p>
+
+<p>
+Accepting this definition therefore of force, Tait's definition of
+matter will read thus, if brought up to date: &ldquo;Matter is that which can
+be perceived by the senses, or is that which can be acted upon by
+motion, or which can exert motion.&rdquo;
+</p>
+
+<p>
+The common idea that matter can only be that which can be seen or
+actually felt, is not large enough for a definition of Matter. There are
+numbers of things in Nature which cannot either be seen or felt, yet
+which are included in the term Matter. Let us take one or two examples.
+Every one admits that nitrogen and oxygen are matter, yet I venture to
+say that no one has actually seen or felt either of these gases. Both of
+these gases are colourless and invisible, and are both tasteless. You
+may open your mouth and inspire both gases, and yet if they are pure,
+you cannot taste either of them. They are only matter, in the sense that
+they appeal to our sense of force through the motion which they may
+acquire.
+</p>
+
+<p>
+Or again, take air, which is a mechanical mixture of several gases. Can
+you see air? If it be free from vapour and smoke, air is invisible, and
+on a clear day you may look for miles across the sea, or from the top of
+a mountain, and yet not have your sight impeded in any way by the
+atmosphere. Neither can it be felt by the sense of touch. Open and shut<span class='pagenum'><a name='Page_41' id='Page_41'></a><a href='#TOC'>[41]</a></span>
+your hand, and see if you can feel the air while you do so. In similar
+ways it may be demonstrated that the air is tasteless. So that it is not
+necessary for us to see, or feel, or taste, or even smell that which we
+term Matter, in order for it to be included in that term. So long as
+that which we term Matter is able to accept motion in any manner from
+any body that is either moving, or in a state of vibration, and not only
+accepts, but also transmits the vibratory, or the kinetic motion so
+called of the moving body, then that which accepts the motion is
+legitimately termed Matter.
+</p>
+
+<p>
+It becomes perfectly clear, therefore, why air, aether, oxygen, and
+hydrogen are termed Matter. Because they can be all acted upon by
+motion, and after being so acted upon, they can exert motion upon some
+other body. Heat is a form of motion, and when heat acts upon the air,
+the latter is set in motion, and we have what are commonly known as
+winds. It is unnecessary for me to prove that the motion of winds can be
+transmitted to other matter, as we have numerous examples from our
+observation and experience, in the case of windmills driven by the
+motive power of the winds, and also balloons urged along by the same
+cause; apart from the devastating effect produced in towns and country
+by a hurricane or storm.
+</p>
+
+<p>
+The point which I wish to emphasize is, that Matter, strictly defined,
+is that which can be acted upon by motion, such as heat or electricity,
+both being forms of motion, and which can exert the motion so derived
+upon some other body.
+</p>
+
+<p>
+Wherever, therefore, in the universe we find any body, whether it be
+solid, liquid or gaseous, or any medium which can be acted upon by
+motion, and after being so acted upon, can exert motion, that body or
+medium may legitimately be included in the term Matter, although it may
+be absolutely invisible to the eyes, or insensible to the sense of
+touch, or taste, or smell. In the same work,<a name='FNanchor_2' id='FNanchor_2'></a><a href='#Footnote_2' class='fnanchor'>[2]</a>
+ Tait states that in the
+physical universe there are but two classes of things, &ldquo;Matter and
+Energy,&rdquo; and then goes on to give examples of both. He adds that a
+stone, piece of brass, water, air, <i>aether</i>, are particles of matter,
+while springs, water-power, wind, waves, heat and electric currents are
+examples of energy associated with Matter.
+</p>
+
+<p>
+Now I may add here, that within these two statements is to be found the
+germ of the physical cause of Gravitation, together with the
+satisfactory explanation of all phenomena that the universe reveals to
+us, either by observation or by experiments. I purpose therefore, before
+giving any detailed accounts of that medium which is to form the
+physical basis for the cause of Gravitation, to look at the<span class='pagenum'><a name='Page_42' id='Page_42'></a><a href='#TOC'>[42]</a></span>
+term Matter in all its aspects, in order that we may get a right
+conception of the universe, and of the part that Matter plays in the
+same.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_2' id='Footnote_2'></a><a href='#FNanchor_2'><span class='label'>[2]</span></a>
+Tait, <i>Natural Philosophy</i>.
+</p></div>
+
+<p>
+<a name='ART_30' id='ART_30'></a><span class='smcap'>Art</span>. 30. <i>Conservation of Matter</i>.--The Theory of the Indestructibility
+of Matter was first introduced by Lavoisier in 1789. This theory may be
+thus summed up; that Matter which fills the universe is unchangeable in
+quantity, so that the total quantity ever remains the same. Changes may
+take place in regard to the state of the Matter, but the sum-total of
+Matter throughout all the changes remains unaltered. Thus when we burn
+coal, it is changed into carbonic acid by combination with the oxygen of
+the atmosphere; when sugar is put into water, it simply passes from the
+solid to the liquid condition. If a piece of iron or steel is allowed to
+rust, the surface of the iron has entered into combination with the
+oxygen and water of the atmosphere, and formed a new substance. So that
+a body may change from solid to liquid, as for example from ice to
+water, or from liquid to a gaseous condition, as from water to steam,
+and probably from a gaseous condition to an aetherial condition as we
+shall see later on, but the sum-total of Matter throughout all these
+changes ever remains the same. Thus, throughout all the physical and
+chemical changes that Matter may undergo in the universe, there is no
+actual loss in weight or quantity. Throughout the whole realm of Nature
+we do not find a single instance of the production of absolutely new
+Matter. We may, and can produce new combinations of the forms of Matter.
+The substance so formed by chemical combination may be different from
+anything that has ever been seen or produced before, but the elements of
+which it is formed must have existed in some other form before its
+production.
+</p>
+
+<p>
+This principle is the great underlying principle of all chemical
+investigation and research, and may be proved at any time by means of
+the scales or balance in the laboratory. Lavoisier first made the
+experiment with the scales and proved this truth by actual
+demonstration.
+</p>
+
+<p>
+<a name='ART_31' id='ART_31'></a><span class='smcap'>Art</span>. 31. <i>Matter is Atomic</i>.--The hypothesis that Matter is made up of
+infinitely small particles which are termed atoms, was first proposed by
+the Grecian philosophers. This hypothesis has gradually taken definite
+shape, but it remained for Dalton to first put the hypothesis into a
+connected form, and that form is now known as Dalton's Atomic Theory.
+</p>
+
+<p>
+According to this theory, an atom of hydrogen was the lightest atom
+known, but comparatively recent researches by Sir W. Crookes have shown
+that there are possibly in existence minute particles which are even
+lighter than an atom of hydrogen. Thus Sir W. Crookes has suggested that
+there are certain particles associated with an atom of hydrogen which<span class='pagenum'><a name='Page_43' id='Page_43'></a><a href='#TOC'>[43]</a></span>
+are 700 times less in weight than the atom itself.
+</p>
+
+<p>
+Professor J. J. Thompson has further suggested that if we could divide
+an atom into a thousand parts, and could take one of those parts, we
+should find that this corpuscle, as he has termed it, would be the
+carrier of the charges in an electric current, so that it will be seen
+that we are moving into the direction of the continuity of Matter. Let
+us now look at the question as to what is meant by an atom more fully.
+</p>
+
+<p>
+<a name='ART_32' id='ART_32'></a><span class='smcap'>Art</span>. 32. <i>What is an Atom?</i>--Clerk Maxwell's definition of an atom is,
+&ldquo;a body that cannot be cut in two.&rdquo; An atom is the smallest part of a
+simple substance which can enter into combination with another element,
+and is incapable of being further subdivided.
+</p>
+
+<p>
+An atom of hydrogen is the smallest part of that particular gas which
+can enter into combination with any other element, as oxygen, to form a
+chemical compound as water, which is composed of two atoms of hydrogen
+and one of oxygen.
+</p>
+
+<p>
+Further, an atom of any kind or sort, retains its identity and remains
+the same throughout all chemical combinations or physical changes which
+it may undergo. By spectroscopic analysis, it has been ascertained, for
+example, that hydrogen exists in the sun and stars, and the conclusion
+is arrived at in connection therewith, that an atom of hydrogen in any
+sun or star is the same as an atom of hydrogen in our atmosphere, or in
+any of the compounds, as water, in which it is found. Thus it has come
+to be received as an accepted fact, that every atom of any substance, as
+oxygen, nitrogen, and hydrogen, whether they exist in the earth or sun,
+in meteorites or the farthest stars or nebulae, wherever they are found,
+possesses the same identity and the same physical properties.
+</p>
+
+<p>
+Atoms attract one another, and this atomic attraction is known as
+affinity. There is not the least possible doubt that affinity is a form
+of universal attraction, except that the affinity of atoms is selective.
+This affinity of atoms for each other gives rise to the combination of
+atoms known as molecules and chemical compounds.
+</p>
+
+<p>
+<i>Size of Atoms</i>.--It has been computed by Lord Kelvin and others, that
+an atom may be as small as 1/50,000,000 of an inch in diameter, so that
+if 50,000,000 of them were put side by side, they would just measure one
+inch in length. Atoms are not all of the same size or weight. An atom of
+oxygen weighs 16 times as much as an atom of hydrogen. It has been
+proved by Kirchhoff and Bunsen, that the 3/1,000,000 part of a
+milligramme of sodium chloride is sufficient to give a yellow colour to
+a gas-jet. Faraday prepared some sheets of gold, so thin that he<span class='pagenum'><a name='Page_44' id='Page_44'></a><a href='#TOC'>[44]</a></span>
+estimated they only measured the 1/100 part of the length of a
+light-wave. We have to remember that each sheet of gold must have
+contained molecules of gold composed of atoms. What must have been the
+size of the atoms therefore of which the sheet was composed?
+</p>
+
+<p>
+<a name='ART_33' id='ART_33'></a><span class='smcap'>Art</span>. 33. <i>The Atomic Theory</i>.--The Atomic Theory was revived by Dalton
+in 1804, in order to account for the fact that elements unite in certain
+definite proportions. From that time to the present, the theory has
+grown and developed until at the present time it is looked upon as a
+well-established theory. It is, however, simply a theory, and from the
+very nature of the hypothesis is incapable of proof. No one has ever
+seen an atom of hydrogen or oxygen, or an atom of any solid, liquid, or
+gaseous matter. The Atomic Theory suggests, therefore, that there is a
+limit to the divisibility of matter. All chemical experiments lend
+support to the theory, and by it we are able to give an intelligible and
+easy method of expression to what would otherwise be difficult phenomena
+to explain.
+</p>
+
+<p>
+Ancient philosophers were divided on the question of the infinite
+divisibility of matter. The Epicureans were of the opinion that matter
+was incapable of infinite division, and that even if we were able to
+make the smallest possible division, it would be impossible for us to
+reach the smallest particle termed &ldquo;Atom.&rdquo;
+</p>
+
+<p>
+<a name='ART_34' id='ART_34'></a><span class='smcap'>Art</span>. 34. <i>Kinds of Atoms</i>.--Various forms of atoms have been conceived
+by philosophers from time to time, ranging from the Hard Atom, and the
+simple point-centres of Boscovitch, until we come to the more modern
+Vortex Atom of Lord Kelvin, or the Strain Atom of Dr. Larmor, which will
+be looked at separately. Democritus conceived a hard atom as long ago as
+500 B.C., while the notion of a hard atom is not absent from the works
+of Newton himself. We find that Newton suggested that the particles of
+air might be hard spherical bodies, at a distance from one another of
+about nine times their diameter.
+</p>
+
+<p>
+The hard atom, however, seems to be refuted by spectroscopic analysis,
+which reveals to us in a manner that has never been revealed before,
+something of the sizes and vibrations of atoms.
+</p>
+
+<p>
+From the phenomenon of heat, which is simply matter in motion, we feel
+compelled to accept the fact that an atom is not a hard particle, but
+that it is something which is more closely allied to the Vortex Atom, or
+the Strain Atom of Dr. Larmor.
+</p>
+
+<p>
+<i>Boscovitch Atom</i>.--According to Boscovitch's theory, each atom is
+simply an indivisible point in space capable of motion, and possessing a
+certain mass whereby a certain amount of energy is required to produce a
+certain change of motion. In addition to this, any two atoms could
+attract or repel each other with a force depending upon their distance<span class='pagenum'><a name='Page_45' id='Page_45'></a><a href='#TOC'>[45]</a></span>
+apart. The Law which regulates these forces for all distances greater
+than 1/1000 of an inch is an attraction varying inversely as the square
+of the distance, and a repulsion for less distances.
+</p>
+
+<p>
+We have, therefore, to suppose that in place of the hard atom, there is
+merely a geometrical point which can exert attractive or repulsive
+forces to, or from, the central point. So far as external particles are
+concerned, they would behave just the same as a hard atom would do. This
+conception was largely entertained in recent times by Faraday. It is
+more a mathematical explanation than a physical one, but has been found
+convenient in explaining what takes place in the interior of bodies in
+their three states, namely: solid, liquid, and gaseous.
+</p>
+
+<p>
+<i>Lord Kelvin's Vortex Atom</i>.--Another hypothesis which has been
+suggested for the constitution of an atom, is that known as the Vortex
+Atom, which received its birth at the hands of Lord Kelvin. The
+underlying principle of this Vortex Atom is, that matter may be entirely
+due to the rotating parts of a fundamental medium, the Aether, which
+fills all space.
+</p>
+
+<p>
+The properties of vortex motion were first mathematically calculated by
+Helmholtz, but it was left to Sir Wm. Thompson, now Lord Kelvin, to give
+a physical idea of the Vortex Atom.
+</p>
+
+<p>
+Before entering further into the question of the Vortex Atom, it may be
+as well to explain how vortex smoke rings may be made.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/059.jpg' width='400' height='115'
+alt='Fig: 3.'
+title='Fig: 3.' />
+</div>
+
+<p>
+All that is required is a wooden box, about one cubic foot in size, with
+a round hole perforated in one of the sides, and the opposite side
+covered with a piece of linen in place of the wooden side. The bottom of
+the box should then be covered with some strong solution of ammonia, and
+some hydrochloric acid poured into a saucer and put into the box. The
+combination of these two will cause thick clouds to form in the box, and
+if the linen is sharply tapped by the hand, a ring of this cloud will be
+forced through the hole on the opposite side of the box. The ring so
+formed will be circular in shape, and will go sailing through the room
+in which it is made.<span class='pagenum'><a name='Page_46' id='Page_46'></a><a href='#TOC'>[46]</a></span>
+</p>
+
+<p>
+When the hole is circular, the rings will be found
+circular also, but if the hole is square, then the rings will be
+irregular in shape. One remarkable characteristic about these rings is,
+that when two of the rings are travelling in the same straight line, the
+one behind will overtake the front one, and while so doing, the diameter
+of the front one is enlarged, while that of the one behind contracts.
+The front one will also travel slower, while the one behind travels
+faster until it has caught up the former, and then the latter, having
+contracted sufficiently, will pass through the diameter of the former as
+illustrated in the figure. This alternation of contraction and expansion
+is continued as long as the two rings move in the same plane and until
+they are destroyed. When, however, the two rings are moving in opposite
+directions, and meeting each other in the same straight line, they will
+repel one another, instead of attracting each other.
+</p>
+
+<p>
+Their rate of progress is gradually reduced as they approach together,
+and they begin to expand and enlarge, but they never touch each other.
+Another peculiar feature about the rings consists in the fact, that the
+central core of air in the ring remains the same all the time the ring
+is in motion through the room, so that it has the same core of air at
+the end of its journey as it had when it left the box.
+</p>
+
+<p>
+As Lord Kelvin pointed out, if there were no friction of the air, the
+ring once created would rotate for ever. If, therefore, there were such
+a thing as a perfect fluid, and there were vortex rings in it, nothing
+could destroy these rings when once they were created, and this is one
+of the most striking suggestions with reference to the Vortex Atom
+theory of matter. It remains to be seen whether in the universe we have
+such a medium as a perfect fluid.
+</p>
+
+<p>
+Sir Wm. Thompson has applied the Vortex Atom theory of matter to the
+Aether, but from mathematical calculation he was unable to arrive at a
+satisfactory conclusion as to the Aether being composed of vortex atoms.
+</p>
+
+<p>
+Another remarkable property belonging to these rings, lies in the fact
+that they cannot be cut in two. It will be found that when the knife is
+brought near to them, they seem to recoil from the knife. In that sense,
+it is literally an atom, a thing which cannot be cut in two.
+</p>
+
+<p>
+The Vortex Atom has many recommendations in its favour. Many of the most
+important properties of matter are possessed by it, as for example
+indestructibility, elasticity, inertia, compressibility, and its
+incapability to be cut in two. Further, it may be linked with another
+ring, and so give the basis to the combining properties of atomic
+weights.<span class='pagenum'><a name='Page_47' id='Page_47'></a><a href='#TOC'>[47]</a></span>
+</p>
+
+<p>
+The Vortex Atom theory is simple in character, as it does not
+postulate any extravagant hypothesis, but makes use of the Aether as the
+common basis for all matter, simply stating that this property of
+rotation may be the basis of all that we call matter. We shall further
+consider the relation of the Vortex Atom to matter, when we deal with
+the constitution of matter and the unity of the universe.
+</p>
+
+<p>
+<a name='ART_35' id='ART_35'></a><span class='smcap'>Art</span>. 35. <i>Elements of Matter</i>.--As is well known, modern chemistry has
+succeeded in reducing all the complex forms of matter in Nature into a
+number of simple substances, which are called elements. Of these
+elements about seventy are at present known, some of which, however, are
+very rare. An element therefore is a simple substance which cannot be
+decomposed by any known force or process, as heat or electricity, into
+other elements.
+</p>
+
+<p>
+There are, however, only about fourteen of these elements that enter
+largely into the constitution of the earth, the most common being oxygen
+and silicon. By the use of the spectroscope, it has been proved that
+many of these elements, as for example oxygen, hydrogen, sodium and
+calcium, exist in the sun and stars, as well as in the most distant
+nebulae. Most of the elementary bodies are to be found in a gaseous form
+as hydrogen, oxygen, fluorine and chlorine, though it has been found
+possible to liquefy even these gases. Thus we see that matter may be
+roughly divided into three states, viz. solid, liquid, or gaseous.
+</p>
+
+<p>
+The condition in which the substance is found depends upon its
+temperature and pressure. An example of matter in its three stages is
+best shown in the case of water, where in the solid condition we have it
+as ice, in the liquid condition as water, and in the gaseous condition
+as steam.
+</p>
+
+<p>
+By recent researches it has been found possible to liquefy gases at a
+very low temperature and increased pressure, with the result that now
+nearly all known gases as hydrogen, oxygen, and carbonic acid are to be
+obtained in liquid form. By still more recent experiments made by
+Professor Dewar, it has even become possible to liquefy the air we
+breathe, with the result that at a temperature of about 270 degrees
+below freezing-point and at an increased pressure, the otherwise
+invisible and gaseous air may be changed into a liquid, and poured out
+from one vessel into another in the same way that water can be poured
+out. A vessel, however, at the ordinary temperature into which such
+liquid air is poured, would be so hot compared with the coldness of the
+liquid air, that as soon as the exceedingly cold liquid air came into
+contact with the vessel, the comparatively hot vessel would make the
+liquid air to boil.
+</p>
+
+<p>
+<a name='ART_36' id='ART_36'></a><span class='smcap'>Art</span>. 36. <i>Three Divisions of Matter</i>.--Matter has been divided into<span class='pagenum'><a name='Page_48' id='Page_48'></a><a href='#TOC'>[48]</a></span>
+three divisions, viz. solid, liquid, and gaseous. These divisions are
+each known by characteristic qualities, which separate the one division
+from another. At the same time, it is possible for matter to pass from
+one division into another, as for example in the case of water, which
+may exist in solid, liquid, and gaseous form. In view of the recent
+researches of Sir. Wm. Crookes and Professor J. J. Thompson, it is very
+probable that before long we shall have to add a fourth division to
+matter, which we should have to call ultra-gaseous form, or it may
+possibly be the aetherial form. If it should prove to be true that
+Aether is matter, and possesses the essential qualities of matter as
+suggested by Lord Kelvin, then certainly we shall have reached the
+boundary of another great division of matter, and our conception of the
+divisions of matter will have to be enlarged to take in that form, so
+that matter would then be divided into four great divisions, viz. solid,
+liquid, gaseous, and aetherial.
+</p>
+
+<p>
+We will now consider the three groups as at present recognized.
+</p>
+
+<p>
+<i>Solid</i>.--Examples of solid bodies are common and familiar, and are
+typified by such things as iron, silver, copper, and lead. The chief
+characteristic of this condition of matter is that its condition or
+state is fixed, and cannot be altered without the expenditure of heat or
+electricity or some other form of energy.
+</p>
+
+<p>
+All solid elementary substances, with the exception of carbon, can be
+melted or reduced to a molten condition, although some of them require a
+very high temperature to effect this reduction, as, for example,
+platinum. When a still higher temperature is applied, the metals may be
+vaporized, or reduced from a molten state to that of a vaporous
+condition. In the case of solids, the atoms have not a free path in
+which to move. It must not be thought, however, that the atoms of a
+solid are motionless, as there is nothing absolutely motionless in the
+universe. In the case of the solid, the molecules which compose it,
+preserve their relative position and are linked together in relation to
+each other by the force of Cohesion.
+</p>
+
+<p>
+<i>Liquid</i>.--When matter is in a liquid condition, as, for example, water
+and oil, the condition of its molecules are not so fixed and stable as
+they are in the solid state. The molecules can move freely about one
+another, and their freedom is increased compared with their condition
+when in the solid state.
+</p>
+
+<p>
+As already indicated, the reduction of a solid body to a liquid or
+molten state may be effected by heat. When heat is applied to a solid
+body, several results follow, each of which is the outcome of the other.<span class='pagenum'><a name='Page_49' id='Page_49'></a><a href='#TOC'>[49]</a></span>
+</p>
+
+<p>
+1. There is an increase of temperature which is due to the increased
+energy of the molecules, through the added heat.
+</p>
+
+<p>
+2. There is an enlargement of the volume or size of the body, and if the
+addition of heat be continued, the molecular forces which hold the
+molecules together are broken down, and then the molecules, loosened
+from those forces which in the solid state have bound them together,
+begin to move about with greater freedom, and thus give rise to the
+molten condition of metals, or liquid condition of water. Thus, it is
+the heat which has set the atoms which compose the molecules in motion.
+The atoms of the solid have absorbed the heat, and the heat which has
+thus been absorbed has imparted vibratory energy to the atoms, which
+they did not possess before. Now when a substance is in the liquid
+state, the atoms of that substance have not only a vibratory motion, but
+have also a translatory motion, so that they can move in and out among
+one another. This is proved by the phenomenon of diffusion, where we
+have the case of two different-coloured liquids, for example,
+intermingling with each other, which is conclusive evidence of the
+translatory motion of the atoms in liquids.
+</p>
+
+<p>
+<i>Gaseous</i>.--The third state in which matter is found is the gaseous
+state. In this condition, the particles of matter which form the gas
+have the greatest possible freedom of movement, and are able to move
+about with inconceivable velocity. There is abundant evidence to prove
+that gases consist of particles of matter which are perfectly free, and
+are able to fly about in all directions. The simplest proof is obtained
+by mixing two gases together, as, for example, when any gaseous
+substance is allowed to mix with the air of a room, when we find that
+the particular gas soon mixes itself thoroughly with all the air in the
+room. This process of mixing is known as Diffusion, and the lighter a
+gas is, the more quickly does it diffuse itself. The rate of movement of
+the various particles is varied, by reason of the encounters which each
+particle undergoes from time to time. Through experiments made by Joule,
+he arrived at the conclusion that particles of hydrogen attained a
+velocity of 6055 feet per second at 0° C., which is a velocity much
+greater than that of a cannon-ball. In spite of the enormous velocity
+with which a particle of hydrogen would move, there are such a large
+number of particles in a single cubic inch of space, that no one
+particle has an absolutely free path from the one side of the enclosed
+space to the other. To this constant movement of the individual
+particles is due the elasticity or pressure of gases. The outward
+pressure which they exert on any body which encloses the gas is caused
+by the total effect of the impact of the particles, and is proportional
+to the sum of their masses multiplied into the square of their<span class='pagenum'><a name='Page_50' id='Page_50'></a><a href='#TOC'>[50]</a></span>
+velocities. If we halve the enclosed space, then we should double the
+number of impacts in a given time, so that the number of impacts is
+inversely as the volume of the gas. This is equivalent to the statement,
+that the pressure of a gas varies inversely as its volume, which is
+Boyle and Marriotte's Law.
+</p>
+
+<p>
+<a name='ART_37' id='ART_37'></a><span class='smcap'>Art</span>. 37. <i>Matter is Gravitative</i>.--If there is one property which is
+essentially characteristic to all matter, it is that all matter is
+gravitative. To this rule there is no exception, as the universal Law of
+Attraction states that &ldquo;every particle of matter attracts every other
+particle.&rdquo; Thus, wherever in the whole universe there is a particle of
+matter of any kind or sort, whether such matter be solid, liquid, or
+gaseous, there the force of attraction will be exerted with a force
+proportionate to the mass of the particle, and inversely as the square
+of the distance between the attracted particles.
+</p>
+
+<p>
+Gravitation, then, is a property which is essentially inherent in
+matter, and any substance which is termed matter, or fulfils the
+conditions that govern matter, must be gravitative, whatever other
+property it may, or may not, possess. Unless this be so, we should have
+a violation of the universal Law of Gravitation, which would cease at
+once to be a universal law, for instead of reading &ldquo;every particle of
+matter attracts every other particle,&rdquo; we should have to say that &ldquo;some
+particles of matter attract some other particles,&rdquo; which would be a
+violation of that universal law which, through the genius of Newton, has
+given to the universe an unity from the philosophical standpoint that it
+did not possess before.
+</p>
+
+<p>
+Some matter may, or may not be elastic; it may, or may not be solid, or
+liquid, or gaseous; but there is this fact regarding matter which is
+absolutely undeniable, and that is, &ldquo;All matter is gravitative.&rdquo;
+</p>
+
+<p>
+That this is true of each and all kinds of matter has been proved by
+direct experiment times without number, and the constant application of
+the law to all forms of matter is a fact observable from the phenomena
+incidental to every-day life. Astronomical observation teaches us also,
+that all stars, suns, planets, satellites, and comets are subject to
+this great Law of Gravitation, as indeed they must be if they are
+composed of matter. That they are all composed of exactly similar
+elements of which the earth is composed, has been proved again and again
+by spectroscopic analysis, which teaches that hydrogen, iron, and
+calcium, etc., are to be found in distant stars and nebulae, as they are
+equally to be found in the composition of the earth. Thus throughout the
+wide universe so far as observation and experiment can teach us, we
+learn that without any exception, everything that is termed matter is<span class='pagenum'><a name='Page_51' id='Page_51'></a><a href='#TOC'>[51]</a></span>
+subject to this universal Law of Gravitation.
+</p>
+
+<p>
+<a name='ART_38' id='ART_38'></a><span class='smcap'>Art</span>. 38. <i>Matter possesses Density</i>.--Density is that property of matter
+which decides the weight of a body per unit of volume.
+</p>
+
+<p>
+The density of any substance may be shown in several ways. It may
+denote, first of all, the number of molecules in a given body. Let us
+take as an illustration, the case of air being forced into a vessel of a
+given size, say one cubic foot capacity. We will suppose that in such a
+vessel there are 1,000,000 molecules. If we pump in a quantity of air
+equal to the amount it contained at first, then it is obvious that we
+have doubled the number of molecules in the same vessel, and therefore
+we say we have doubled the density. Not only so, but the weight of the
+air in the vessel will have been doubled. Looked at from this
+standpoint, density means the number of molecules in unit volume such as
+a cubic inch, or cubic centimetre.
+</p>
+
+<p>
+Again, as has already been shown in <a href='#ART_35'>Art. 35</a>, the different elements have
+different atomic weights. Thus an atom of carbon weighs twelve times as
+much as an atom of hydrogen, that is to say, there are twelve times as
+much matter by weight in an atom of carbon as there is in an atom of
+hydrogen, so that it would take twelve times as many hydrogen atoms to
+weigh a pound as compared with the number of atoms of carbon. This is
+only another way of stating that carbon has twelve times the density of
+hydrogen. If we compare lead and silver with hydrogen in the same way,
+we find that the density is 206 times and 107 times greater than that of
+hydrogen.
+</p>
+
+<p>
+Thus, it may be seen, that all matter possesses density, and that that
+density depends partly upon its atomic constitution. If the molecule of
+matter is composed of atoms whose atomic weights are very large compared
+with that of hydrogen, as iron, silver, lead and gold, then the
+molecules will have a much greater density, than a molecule formed of
+oxygen and hydrogen, <i>i. e.</i> water. This property of the density of
+matter plays a most important part in the transmission of any kind of
+wave-motion.
+</p>
+
+<p>
+<a name='ART_39' id='ART_39'></a><span class='smcap'>Art</span>. 39. <i>Matter possesses Elasticity</i>.--Matter possesses elasticity.
+Elasticity is that property of matter which enables all bodies to resume
+their original shape, when the pressure which has caused the alteration
+of shape has been removed.
+</p>
+
+<p>
+For example, suppose an ivory ball be dropped upon a marble table, or
+any other hard surface. It will then rebound, and rise almost to the
+same height from which it was dropped. If the surface upon which it fell
+was first covered with blacklead, a circular spot of lead will be found
+on the ivory ball. From this fact, we arrive at the conclusion that when
+the ball came into contact with the table, at the moment of contact it<span class='pagenum'><a name='Page_52' id='Page_52'></a><a href='#TOC'>[52]</a></span>
+was flattened, and then owing to its elasticity it rebounded into the
+air again.
+</p>
+
+<p>
+Now the measure of the elasticity of a body is proportionate to the
+velocity of the wave-motion which it can transmit. A good illustration
+of the transmission of wave-motion may be shown with a number of ivory
+bagatelle or billiard balls. If eight or more of these be put in a row,
+all touching each other, and a single ball be placed about an inch or so
+away from the others in a straight line with them, then when the single
+ball is struck with a cue against the other eight, the motion of the
+single ball is transmitted by each one of the eight successively with
+such rapidity, that the end ball would be set in motion in a quicker
+time than a single ball would take to reach the end ball, if it had been
+free to move along without encountering any opposition.
+</p>
+
+<p>
+It is a fact capable of demonstration, that the smaller the particle of
+matter, the greater will be its vibratory motion. Thus the particles of
+air are very, very small, and consequently air is found to be very
+elastic, and allows sound to be transmitted through it with
+comparatively great velocity, some sounds travelling at the rate of over
+1000 feet per second.
+</p>
+
+<p>
+A most important factor in determining the propagation of any
+wave-motion, through a gas or solid, is the relationship of the
+elasticity of the gas or solid to its density. Suffice to say, that the
+velocity of any wave-motion is determined by the relation of the
+elasticity to the density. For example, sound, which is a wave-motion of
+the air, can not only be transmitted through gaseous bodies as air, but
+also through liquids and solids. Sound travels faster through solids
+than through liquids, and faster through liquids than through gases. In
+liquids, the relation of the elasticity to density is greater than in
+air, and in solids the relation is greater still. Therefore sound
+travels much faster in liquids than in gases, and faster in solids than
+in liquids.
+</p>
+
+<p>
+This is the reason why a train can be heard coming if the ear is put to
+the railway-line, when no indication of its approach is given to the ear
+by the atmosphere. Some examples of the velocities of sound through
+different substances are as follows--
+</p>
+
+<table summary='velocities'>
+<tr><th><span class='smcap'>Gases O. C.<br />feet</span></th><th><span class='smcap'>Liquids.<br />feet</span></th><th><span class='smcap'>Solids<br />feet</span></th></tr>
+
+<tr><td>
+
+<table summary='velocities'>
+<tr><td>Air</td><td>1090</td><td style='text-align: center;'>per</td><td style='text-align: center;'>sec.</td></tr>
+<tr><td>Oxygen</td><td>1040</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+</table>
+
+</td><td>
+
+<table summary='velocities'>
+<tr><td>Water</td><td>4708</td><td style='text-align: center;'>per</td><td style='text-align: center;'>sec.</td><td>(8° C.).</td></tr>
+<tr><td>Alcohol</td><td>4218</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td>(20° C.).</td></tr>
+</table>
+
+</td><td>
+
+<table summary='velocities'>
+<tr><td>Gold</td><td>5717</td><td style='text-align: center;'>per</td><td style='text-align: center;'>sec.</td></tr>
+<tr><td>Silver</td><td>8553</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+</table>
+
+</td></tr>
+
+</table>
+
+
+<p>
+<a name='ART_40' id='ART_40'></a><span class='smcap'>Art</span>. 40. <i>Matter possesses Inertia</i>.--Inertia is that property of
+matter, by which matter cannot of itself alter, or change its state of
+motion, or of rest.
+</p>
+
+<p>
+Newton's first law of motion states that a body at rest remains at rest<span class='pagenum'><a name='Page_53' id='Page_53'></a><a href='#TOC'>[53]</a></span>
+until some force or motion acts upon it. If a stone be dropped from a
+balloon, the stone does not fall because of any property which it
+possesses, but because the force of gravity acts upon it. If it were
+possible to eliminate this force of gravity, then if there were no other
+force which could act upon the stone, it would remain suspended in
+space.
+</p>
+
+<p>
+The inertia of a body is equal to the mass of that body, or the amount
+of matter in the body as measured by gravity, so that if a body is
+halved, its inertia will be halved also, and if doubled, its inertia
+will be doubled also. As the inertia of matter opposes all kinds of
+motion, the amount of force required to overcome the inertia of a body
+is proportionate to its mass. So that if the mass of a body is doubled,
+then twice the force would be required to move it, while if the body
+were halved, half the force would suffice to do it.
+</p>
+
+<p>
+Inertia is possessed quite as much by a moving body as a body at rest.
+The definition given points this out, as it states that matter cannot of
+itself change its state of motion. If a body therefore is in motion, it
+requires a certain amount of resistance to bring the body to a state of
+rest, or the loss of an equal amount of energy, by friction or
+otherwise, equal to the quantity which it absorbed in order for it to be
+set in motion.
+</p>
+
+<p>
+We get numerous examples of this property of the inertia of bodies in
+our daily experience. Many of the accidents that befall people in
+various ways are due to this property of the inertia of matter. A
+cyclist is riding a machine down-hill, and loses control over his
+machine, with the result that he runs into a wall, and is killed. Now
+what has happened? The cyclist has participated in the motion of the
+machine, with the result that when the machine has been suddenly
+stopped, the body has been thrown forward owing to the momentum it had
+acquired.
+</p>
+
+<p>
+We are constantly being affected by the property of inertia of matter,
+in tram and train and bus. Whenever any of these are suddenly stopped,
+or suddenly started, we are thrown either backward or forward, owing to
+the body either not having acquired the motion of the train, or, having
+acquired it, is unable to lose its motion as quickly as the train, and
+is therefore thrown forward.<span class='pagenum'><a name='Page_54' id='Page_54'></a><a href='#TOC'>[54]</a></span>
+</p>
+
+<h2><a name='CHAPTER_IV' id='CHAPTER_IV'></a><a href='#CHAPTER_IV_TOC'>CHAPTER IV</a></h2>
+
+<h3>AETHER IS MATTER</h3>
+
+<p>
+<a name='ART_42' id='ART_42'></a><span class='smcap'>Art</span>. 42. <i>Aether is Matter</i>.--The hypothesis of an Aether which fills
+all space was made in order that scientists might be able to account for
+certain phenomena of Light, which otherwise were difficult to account
+for. Its existence is demanded not only for the phenomena of Light, and
+Heat, but, in view of the comparatively recent researches of Hertz on
+&ldquo;Electric Waves,&rdquo; of Electricity also.
+</p>
+
+<p>
+The Aetherial Medium is generally assumed to be that fundamental medium,
+by means of which possibly all the properties of matter, and all the
+phenomena of motion of the universe are to be explained. Light and Heat
+have been proved to be due to the periodic wave-motion of this universal
+Aether, while from the investigations and researches of such men as
+Clerk Maxwell, Poynting, Thompson and Hertz, it has been proved that
+electro-magnetic phenomena are due to this same medium.
+</p>
+
+<p>
+Several different forms of Aether have been postulated by various
+philosophers from time to time, but the only Aether that has survived,
+is that which was first conceived by Huyghens to explain the phenomena
+of Light, though it was Thomas Young who finally succeeded in placing
+the conception of the Aether on a sound basis. Each discovery of science
+has only strengthened the hypothesis and existence of the Aether, the
+latest discovery, that of wireless telegraphy so successfully developed
+by Signor Marconi, being attributed to the electro-magnetic properties
+of this self-same Aether.
+</p>
+
+<p>
+It has already been pointed out that Newton endeavoured to account for
+Gravitation by the pressure of the Aether. If, therefore, Gravitation be
+really due to this universal medium it becomes necessary to ask
+ourselves, What are the properties and characteristic qualities of this
+wonderful medium? What then is Aether, and what its properties?
+</p>
+
+<p>
+It has already been pointed out in <a href='#ART_29'>Art. 29</a> that Aether is matter. Such
+an assumption is strictly in accordance with the Rules of Philosophy,
+quoted in Chap. I.<span class='pagenum'><a name='Page_55' id='Page_55'></a><a href='#TOC'>[55]</a></span>
+</p>
+
+<p>
+Not only is this hypothesis a simple one, but it is
+also in accord with all our experience and observation.
+</p>
+
+<p>
+It is a simple supposition, because, unless Aether is assumed to be
+matter, then, instead of the universe being composed of two classes of
+things, matter and motion, we have to add a third class, which we call
+Aether. It can be readily seen, that by the introduction of a third
+class into the composition of the universe, such an addition, instead of
+simplifying the constitution of the universe, adds greater complexity to
+the same.
+</p>
+
+<p>
+By accepting the hypothesis that Aether is matter, we do away with the
+third class of essentials in the universe, and so reduce the number to
+two classes. If we could go one step further, and prove that instead of
+there being two classes of things in the universe, there was only one
+group, and show that all material things, and all phenomena could come
+under the head of either matter, or motion, then we should have reduced
+the universe to the simplest conception possible. As, however, it is not
+possible, at least in our present state of knowledge, for us to come to
+this fundamental and simple hypothesis of unity for the entire universe,
+we must accept the next simpler solution, and affirm that the universe
+is composed of two classes of things, viz. matter and motion, and this
+as I have already shown is a simpler classification than by putting
+Aether into a class by itself, and therefore is in accord with our first
+Rule of Philosophy.
+</p>
+
+<p>
+Again, it is entirely in accord with our second Rule of Philosophy, as
+it in no way violates the results of experiment, experience, or
+observation. Look where we will, or at what we will, whatever we see,
+touch, taste, or smell is termed matter. The burning sun, the glowing
+star, the flying meteor, the glowing comet, the earth, our own island
+home, the towering rock, the wide ocean, the running river, the green
+trees of the forest, the tiny insect, the lordly elephant, all animals,
+plants, and our own physical body, all are composed of matter, either in
+solid, liquid or gaseous form. Therefore when we affirm that Aether is
+matter, the affirmation is strictly in accordance with the elementary
+principles of Philosophy, and in no way violates their rules or laws. To
+affirm that Aether is not matter, is to affirm something contrary to all
+experience, unless it be affirmed that Aether is motion, for which
+assumption the evidence is not nearly so strong or conclusive as that it
+is matter. Therefore the objector to this assumption is himself
+unphilosophical, in that he postulates or supposes that the Aether is a
+medium, with qualities which lie altogether outside the range of our
+experience and observation.
+</p>
+
+<p>
+There is a growing conviction in the minds of scientific men, that
+Aether belongs to that group of things which we describe by the term<span class='pagenum'><a name='Page_56' id='Page_56'></a><a href='#TOC'>[56]</a></span>
+matter. Lord Kelvin in giving an address to the British Association,
+1901, on &ldquo;Clustering of Gravitational Matter in any part of the
+Universe,&rdquo; said: &ldquo;We are all convinced with our President (Professor
+Rucker) that <i>Aether is Matter</i>. Aether we relegate to a distinct
+species of matter which has inertia, rigidity, elasticity,
+compressibility, but not heaviness.&rdquo;
+</p>
+
+<p>
+Dr. Larmor in <i>Aether and Matter</i> writes: &ldquo;Matter must be constituted of
+isolated portions, each of which is of necessity a permanent nucleus
+belonging to the Aether, of some such type as is represented for example
+by a minute vortex ring in a perfect fluid.&rdquo;
+</p>
+
+<p>
+Faraday in relation to this subject writes (<i>Exp. Res.</i>, vol. ii.): &ldquo;The
+view now stated of the composition of matter would seem to involve the
+conclusion that matter fills all space, or at least all space to which
+Gravitation extends, <i>including the sun and its system</i>, for Gravitation
+is a property of matter dependable on a certain Force, and it is this
+Force which constitutes matter.&rdquo; As the Aether fills all space,
+including the solar system, therefore, according to Faraday, &ldquo;Aether
+must also be Matter.&rdquo;
+</p>
+
+<p>
+By the hypothesis that Aether is matter, with all the properties that
+such a hypothesis logically gives to Aether, I venture to premise that
+the third Rule of Philosophy will be fulfilled, and that there is no
+phenomenon of the astronomical world, and no part of the universal Law
+of Gravitation which such a hypothesis will fail to account for on a
+satisfactory physical basis. For the first time a physical explanation
+will be given to Newton's Laws of Motion, at least to those laws which
+are strictly in accordance with the first and second Rules of
+Philosophy. For the first time a physical conception will be given to
+all Kepler's Laws, and what the mathematical Laws of Gravitation have
+done to Kepler's Laws, in giving them a mathematical basis, the simple
+hypothesis that Aether is matter, with all that is logically involved
+therein, will do for the same laws from the physical standpoint. For the
+first time a physical conception will be given to the Centrifugal and
+Centripetal Forces, which are the complement and the counterpart of each
+other, that physical conception being the outcome of the same hypothesis
+that Aether is matter.
+</p>
+
+<p>
+In addition to this, light is thrown upon such problems as are referred
+to by Lord Kelvin (<i>Phil. Mag.</i>, July 1902) in his paper on &ldquo;Clouds on
+the Undulatory Theory of Light,&rdquo; and further light is given to some
+theories of Electricity advanced by such men as Faraday, Clerk Maxwell,
+and Professor Thompson. I venture to think, therefore, that the
+hypothesis advanced, and the conception put forward that Aether is
+matter, is philosophically correct, and is warranted by the results that
+arise out of such a hypothesis.<span class='pagenum'><a name='Page_57' id='Page_57'></a><a href='#TOC'>[57]</a></span>
+</p>
+
+<p>
+It may be thought by some that the
+hypothesis that I have advanced is already conceded, and that the fact
+that Aether is matter is already admitted by scientists and advanced
+thinkers generally. But such an idea is only partly correct. It is
+already admitted by some of our most advanced scientists that Aether is
+matter, but that admission is only carried partially to its logical
+conclusion.
+</p>
+
+<p>
+Lord Kelvin in an address to the British Association, 1901, gave
+utterance to the following remarks on the relation of Aether to Matter:
+&ldquo;We are convinced with our President (Professor Rucker) that Aether is
+Matter, but we are forced to say that the properties of Matter are not
+to be looked for in Aether, as generally known to us by action resulting
+from force between atoms of Matter and atoms of Aether. <i>Here I am</i>
+<span class='smcap'>illogical</span> <i>when I say between Matter and Aether</i>, as if Aether were not
+Matter. Aether we relegate to a distinct species of Matter which has
+inertia, rigidity, elasticity, compressibility, but <span class='smcap'>not heaviness</span>.&rdquo;
+</p>
+
+<p>
+From a quotation of this kind, which is from the lips of one of the
+keenest intellects of the present time, I think I am justified when I
+make the statement, that it is not conceded that Aether is matter, with
+all that that concession logically involves. Because, as Lord Kelvin
+points out, though it is admitted that Aether is matter, yet that
+admission is only a qualified admission, and not one which carries with
+it all the properties that essentially belong to matter, or an admission
+which includes the fact that Aether is gravitative, that is, subject to
+Gravitation. To be strictly logical and philosophical, in the statement
+that Aether is matter, it must be conceded not only that Aether is
+subject to such properties as elasticity, inertia, and compressibility,
+but that it is also gravitative or possesses weight. For either Aether
+is matter, or it is not matter.
+</p>
+
+<p>
+It cannot be both at one and the same time. Such a conception is
+altogether opposed to that simplicity which is the chief characteristic
+of Nature as pointed out by Newton.
+</p>
+
+<p>
+If therefore Aether be matter, then, to be strictly logical and
+philosophical, it must be conceded that Aether is gravitative, as well
+as having the other properties of matter, as elasticity and inertia,
+etc. Unless this is conceded, then we have the anomaly in Nature of
+matter, which is not matter, because it violates the very principles
+which above all others decide what is matter, viz., &ldquo;That every particle
+of matter attracts every other particle,&rdquo; etc., that is, that it is
+gravitative. Thus by supposing that the Aether is matter, and yet not
+being gravitative, all the Rules of Philosophy are violated, as such a
+hypothesis is opposed to both the first and second Rules of Philosophy,
+and is contrary to all observation and experience. If Aether therefore<span class='pagenum'><a name='Page_58' id='Page_58'></a><a href='#TOC'>[58]</a></span>
+be matter, as is conceded by the most advanced thinkers of the time,
+then it follows that the only logical and philosophical conclusion that
+can be arrived at is, that it is also subject to those properties which
+are the chief characteristics of all matter. These properties may be
+classified as follows: atomicity, gravitation, density, elasticity,
+inertia, and compressibility.
+</p>
+
+<p>
+<a name='ART_43' id='ART_43'></a><span class='smcap'>Art</span>. 43. <i>Aether is Universal</i>.--Young in his first Hypothesis on the
+Aether medium states that, &ldquo;A Luminiferous Aether pervades the Universe
+rare and elastic in a high degree&rdquo; (<i>Phil. Tran.</i>, 1802).
+</p>
+
+<p>
+As Young points out, this invisible and elastic Aether fills all space
+and floods the universe at large. In it suns blaze, stars shine, worlds
+and planets roll, meteors flash, and comets rush in their mysterious
+flight. In it all material and physical things exist, for it is to them
+not only the primary medium of their existence, but, just as the
+infinite and ever-active energy of the Divine is to the universe in its
+entirety and fulness, the exciting and stimulating spirit of its
+energies and powers, so this aetherial ocean is to the material and
+physical universe, the exciting and stimulating medium of all its
+activities, energies, and powers; and without which, though all material
+and physical things were endowed with the varied capacities of their
+kind or life, yet they could neither exert nor exercise them, nor even
+exhibit the simple activity of motion. Hence everywhere, where material
+and physical things are, there, as the medium of their existence and
+energy, the Aether is; and where the Aether is not, no material or
+physical thing is, or can be. That the Aether is universal is proved by
+the phenomena of light. Light-waves have a velocity of about 186,000
+miles per second. Now the distance of the sun from the earth is about
+92,000,000 of miles, so that light takes about eight minutes and a half
+to travel from the sun to the earth.
+</p>
+
+<p>
+A ray of light from the nearest fixed star takes about three and a half
+years to reach the earth, while there are some stars so far away that
+astronomers tell us, that though light travels with so great a velocity,
+yet it would take several thousand years to reach the earth. This fact
+implies that throughout boundless space there is to be found this
+aetherial medium. Thus interplanetary and interstellar space is not
+empty, but is filled with this ever-present, all-pervading Aether; and
+not only so, but every particle of matter in the universe is surrounded
+by this universal Aether, which forms the exciting and stimulating
+medium of all the activities, energies, and motions of all Matter. Thus
+the Aether is both universal and infinite in its extent.
+</p>
+
+<p>
+Clerk Maxwell, in his paper on &ldquo;Action at a Distance&rdquo; (<i>Collected<span class='pagenum'><a name='Page_59' id='Page_59'></a><a href='#TOC'>[59]</a></span>
+Works</i>, by Niven), with reference to the universality of the Aether,
+writes: &ldquo;The vast interplanetary and interstellar regions will no longer
+be regarded as waste places in the universe, which the Creator has not
+seen fit to fill with the symbols of the manifold order of His Kingdom.
+We shall find them to be full of this wonderful medium, so full, that no
+human power can remove it from the smallest portion of space, or produce
+the slightest flaw in its infinite continuity. It extends unbroken from
+star to star, and when a molecule of hydrogen vibrates in the Dog Star,
+the medium receives the impulses of those vibrations, and transmits them
+to distant worlds. But the medium has other functions besides bearing
+light from world to world, and giving evidence of the absolute unity of
+the material system of the universe. Its minute parts may have rotatory
+as well as vibratory motions, and the axes of rotation form those lines
+of magnetic force which extend in unbroken continuity into regions which
+no eye has seen, and which, by their action on our magnets, are telling
+us in language not yet interpreted what is going on in the hidden world
+from century to century.&rdquo; Now I premise, that in the theory of the
+Aether to be submitted in this work, the physical interpretation of this
+statement of Maxwell's will receive its literal fulfilment.
+</p>
+
+<p>
+<a name='ART_44' id='ART_44'></a><span class='smcap'>Art</span>. 44. <i>Aether is Atomic</i>.--If there is one fundamental truth which is
+applicable to all matter, it is, that all matter is atomic.
+</p>
+
+<p>
+Professor Rucker, in his Presidential Address to the British Association
+of 1901, in dealing with this question, said: &ldquo;The believer in the
+atomic theory asserts that matter exists in a particular state, that it
+consists of parts which are separate and distinct from one another, and
+as such are capable of independent movement. It is certain that matter
+consists of discrete parts in a state of motion, which can penetrate
+into spaces between the corresponding parts of surrounding bodies. Every
+great advance in chemical knowledge during the last ninety years finds
+its interpretation in Dalton's Atomic Theory.&rdquo;
+</p>
+
+<p>
+From such an authority as this, and from the facts which he gave in his
+dealing with the question, we are bound to admit that all matter is
+atomic. That being granted, when the statement is made, therefore, that
+Aether is matter, the only logical conclusion that can be arrived at,
+with reference to the question of the atomicity of the Aether, is, that
+Aether is also atomic. Unless this be conceded, we have the first and
+second rules of our Philosophy violated, as an atomless Aether is
+opposed to that simplicity of conception, which is an essential
+requirement of all hypotheses, and is moreover contrary to that
+presumptive evidence gathered from observation and experiment, which
+teaches us that all matter is atomic. If it be argued, that it is<span class='pagenum'><a name='Page_60' id='Page_60'></a><a href='#TOC'>[60]</a></span>
+impossible to decide upon a question as to the atomicity of the Aether,
+my reply is that the same argument may reasonably be applied to all
+matter. But, as Professor Rucker stated, all the evidence on matter
+points out and supports the theory of its atomicity, and, therefore, the
+only logical and philosophical conclusion is, that Aether is atomic
+also. Again, it may be suggested that we cannot see or touch an atom of
+Aether, and that it is not only invisible, but apparently incapable of
+being made sensible to our senses. In reply to that, as I have already
+shown in <a href='#ART_31'>Art. 31</a>, that objection can be equally used against an atom of
+hydrogen, or an atom of oxygen. Does any one doubt the existence of the
+hydrogen atom or the atom of oxygen, because it is invisible to the
+sense of sight, or cannot be revealed to the limited sense of touch?
+Certainly not! By the same reasoning, it is just as illogical to deny
+the existence of an atom of Aether because it cannot be seen or felt, as
+it is to deny the existence of an atom of hydrogen or oxygen. An atom of
+Aether reveals itself to the senses in the same way that an atom of
+hydrogen or oxygen does, that is, by the force or energy which it
+exerts. Its vibrations can be manifested to the body in the form of
+heat, while the undulatory motion which the aetherial atoms transmit in
+the form of light, reveal the presence of the aetherial atom to the
+sense of sight. The question at once arises as to what constitutes an
+aetherial atom, what are its properties and motions?
+</p>
+
+<p>
+Now, in order for us to enter successfully into this speculative region,
+it is essential that we should, as far as possible, conform to the Rules
+of Philosophy, and endeavour to gain some conception of an aetherial
+atom from the results of experience and observation. In doing this, we
+are at once confronted with the difficulty, that no one has ever seen an
+atom, or analyzed the properties of one. Actual experiment has revealed
+nothing absolutely certain as to the ultimate character of an atom, and
+if this be true of the atoms of matter, then it must also be true of an
+aetherial atom. It would seem at first, therefore, that we have no
+results of experiment, or observation, by which we may be guided in
+formulating a right conception as to the constitution of an aetherial
+atom, and therefore we are thrown simply into the regions of speculation
+as to its constitution and properties.
+</p>
+
+<p>
+But I venture to suggest, that there is a method which is strictly
+philosophical in its application, by which we may possibly arrive at a
+clear conception of an aetherial atom. All great discoveries of science
+have been the outcome of applying the principle, that what is true of
+the visible and seen, is true of the invisible and unseen; that what is
+true of the known, is true of the unknown; that the principles and laws<span class='pagenum'><a name='Page_61' id='Page_61'></a><a href='#TOC'>[61]</a></span>
+which govern the small also govern the large and the great. It was thus
+that Newton discovered his great Law of Gravitation, as he was able from
+the falling of an apple, to rise to the application of the same
+principle to our satellite the moon, and this led him on to the
+discovery of the Law of Gravitation.
+</p>
+
+<p>
+If, therefore, in Philosophy, the laws governing the small things are
+also applicable to the great things, then the converse equally holds
+good, that the laws governing great things are the reflex of the laws
+which govern the small things. For example, the laws which govern the
+light and heat of the sun are the same which govern the light and heat
+of a candle or a glow-worm; and the laws which govern a planet or world
+are the same as those which govern an atom. Thus a planet or world,
+which is simply an agglomeration of atoms, may reveal to us in its
+motions and laws, what are the motions and laws which govern the atomic
+world.
+</p>
+
+<p>
+In looking at the properties and motions of a planet, therefore, as our
+earth for example, we find that a planet is a sphere, or more correctly
+an oblate spheroid; that the earth or planet is a magnet possessing
+polarity, having a north and south pole; that it has rotation on an
+axis, in addition to translation in an orbit, and that it is subject to
+the universal Law of Gravitation.
+</p>
+
+<p>
+If, therefore, it holds good in Philosophy, that the small things are
+the index to the greater, and that the laws governing the small things
+also govern the greater, then the converse holds good, that what is true
+of the large is true of the small, and that the laws governing the great
+also govern the small.
+</p>
+
+<p>
+So that gathering up those chief properties of the earth to which I have
+already referred, and applying them to an aetherial atom, or any other
+atom if necessary, we arrive at the conclusion that an atom must be
+spherical in shape, must possess rotation, and must have an orbit, must
+possess polarity, and also be subject to the universal Law of
+Gravitation.
+</p>
+
+<p>
+Here, then, we have given to us certain data by which we are enabled to
+form our conception of an atom, aetherial or otherwise. The question
+arises, whether, among the forms of atoms which have been devised by
+scientists, any of the atoms so conceived fulfil all, or nearly all of
+these requirements. We have Boscovitch's Atom, the Hard Atom of
+Lucretius, and the more recent conception of the Vortex Atom of Lord
+Kelvin. Of all the hypotheses in regard to the ultimate nature and
+constitution of an atom, the Vortex Theory probably is the one which
+offers to the mind the simplest conception of an aetherial atom.
+</p>
+
+<p>
+The Vortex Ring Atom, however, which has been so fully developed by Lord
+Kelvin, hardly fulfils all the requirements of an aetherial atom. In<span class='pagenum'><a name='Page_62' id='Page_62'></a><a href='#TOC'>[62]</a></span>
+the first place it is not spherical in shape, and I hold that to be one
+of the fundamental bases of the aetherial atom. Then, in the next place
+it does not, so far as I can read, possess polarity; that is, it does
+not possess a north and south pole, through being a magnet in the same
+way as the earth is a magnet. We must therefore look for a modification
+of the vortex ring to discover the constitution of our aetherial atom,
+and I venture to think that such a modification is to be found in
+Professor Hill's conception of a Spherical Vortex Atom (<i>Phil. Trans</i>.,
+1894).
+</p>
+
+<p>
+In the conception there put forward, and mathematically worked out,
+Professor Hill showed that his spherical vortex atom possessed similar
+properties and characteristics to the vortex rings of Lord Kelvin. So
+that the spherical vortex atom would possess rotation on an axis, and it
+would be a magnet, as I shall prove later on, because it rotates in an
+electro-magnetic medium. It would possess elasticity, compressibility,
+inertia, and, further, would possess a certain amount of mass. That mass
+might be infinitely small, but nevertheless it would possess mass of an
+infinitesimal order.
+</p>
+
+<p>
+Further, if we are to be strictly correct, in our analogy between the
+earth and the aetherial atom, its polar diameter must be shorter than
+its equatorial diameter, as that is one of the facts observable
+regarding the shape of our earth, so that the shape of the aetherial
+atom will not be strictly spherical, but its actual shape would be that
+of an oblate spheroid, being flatter at the poles, and bulging out in
+the equatorial regions.
+</p>
+
+<p>
+This exact analogy between the earth and an aetherial atom may not at
+present seem of very great importance, but its importance will be seen
+later on, when we come to deal with the phenomena of heat, light, and
+electricity.
+</p>
+
+<p>
+Here, then, is our conception of an aetherial atom in the rough, based
+not upon any imaginative hypothesis, but rather upon that strict
+conformity to observation and experience, which is the very groundwork
+of all true Philosophy.
+</p>
+
+<p>
+For, after all, what is the earth but an atom on a large scale? In
+comparison with illimitable space, with its infinite distances, that can
+alone be measured by the velocity of light, our own earth is but a speck
+of dust, a very atom that helps to make up the universe, and, as such,
+should teach us the shape and properties of other atoms of which the
+same universe is composed.
+</p>
+
+<p>
+We have therefore to conceive of the all-space-pervading Aether as being
+composed of infinitesimal portions of Aether, which are nearly spherical
+in shape, and ever in a state of rotation; this state of rotation
+differentiating the atom of Aether from the free Aether, if such an
+entity exists. So that an atom of Aether would simply be an<span class='pagenum'><a name='Page_63' id='Page_63'></a><a href='#TOC'>[63]</a></span>
+infinitesimal portion of the Aether in a state of rotation.
+</p>
+
+<p>
+If, by any means, we could stop the rotation, we should at once destroy
+the atom, in the same way that the smoke vortex ring would cease to be a
+ring, if its rotation were stopped. The cessation of the rotation I,
+however, believe to be impossible. So that even in the ultimate atom of
+that universal medium the Aether, we have an illustration of the
+combination of those two forms which are inseparably connected
+throughout the whole universe, viz. matter and motion, and it is the
+combination of these two that gives to the aetherial atom its form, and
+its very existence, without which it has no life, and ceases to exist.
+</p>
+
+<p>
+It may be necessary in the development of this work as we proceed, to
+slightly modify our conception of the aetherial atom, but that
+modification will rather be of a constructive character, than a
+destructive one. There may also be certain objections to meet and
+explain away when we deal with the phenomena of light, heat, and
+electricity, and Gravitation, and the part which the aetherial atom
+plays in those phenomena, but these objections I hope to meet and answer
+as they arise.
+</p>
+
+<p>
+The atomicity of the Aether has already been suggested by such
+scientists as Clerk Maxwell, Lord Kelvin, Dr. Larmor, and Professors
+Lodge and J. J. Thompson. Clerk Maxwell, in an article on &ldquo;Action at a
+Distance,&rdquo;<a name='FNanchor_3' id='FNanchor_3'></a><a href='#Footnote_3' class='fnanchor'>[3]</a>
+ referring to the atomicity of the Aether, writes: &ldquo;Its
+minute parts may have rotatory as well as vibratory motions, and the
+axes of rotation may form those lines of magnetic force which extend in
+unbroken continuity into regions which no eye has seen.&rdquo; I premise that
+I will conclusively prove that this statement finds its literal
+fulfilment in the theory of the Aether that will be developed in this
+work.
+</p>
+
+<p>
+Lord Kelvin, in several articles on &ldquo;Vortex Motion&rdquo; in the Philosophical
+Magazines of recent years, has mathematically dealt with the Aether from
+the atomic standpoint, and has endeavoured to prove that the Aether
+medium is composed of vortex rings, but he was unable to come to any
+satisfactory conclusion. With the theory that Aether is matter, and
+therefore possesses mass, his conception is now brought within the range
+of physical explanation, as well as mathematical calculation.
+</p>
+
+<p>
+Dr. Larmor, in his <i>Aether and Matter</i>, has successfully applied the
+principle of the atomicity to the Aether, on what is termed the
+&ldquo;Electron&rdquo; basis. He states that an electron is nothing more or less
+than &ldquo;a point singularity in the electro-dynamic and optical Aether.&rdquo; So
+that our aetherial atom is practically synonymous with Dr. Larmor's
+electron. Again, Dr. Larmor, in the same work, states that &ldquo;the
+atomicity of electricity is coming within the scope<span class='pagenum'><a name='Page_64' id='Page_64'></a><a href='#TOC'>[64]</a></span>
+of direct experiment.&rdquo;<a name='FNanchor_4' id='FNanchor_4'></a><a href='#Footnote_4' class='fnanchor'>[4]</a>
+ But Professor Lodge, in his <i>Modern Views of
+Electricity</i>, states that &ldquo;the Aether is composed of positive and
+negative electricity, the combination of these two forming the Aether
+medium.&rdquo;<a name='FNanchor_5' id='FNanchor_5'></a><a href='#Footnote_5' class='fnanchor'>[5]</a>
+ Now, if the Aether is composed of positive and negative
+electricity, and the atomicity of electricity is coming within the scope
+of direct experiment, it follows as a matter of necessity that the
+atomicity of Aether and the atomicity of electricity are one and the
+same, and therefore the atomicity of Aether is coming within the scope
+of direct experiment. Professor J. J. Thompson, who has also attacked
+the problem of the atomicity of electricity, speaks of &ldquo;corpuscles&rdquo;
+which are the actual carriers of the positive and negative electricity,
+in the atoms of the various elements. These corpuscles therefore
+indicate the fact that electricity has an atomic basis.
+</p>
+
+<p>
+Now if there is any such identity between Aether and electricity, as
+there undoubtedly is, and electricity has an atomic basis, then the
+atomicity of the Aether follows as a matter of course, otherwise we
+shall have a medium composed of atoms which is itself not atomic, which
+conclusion is absurd and therefore unphilosophical. So that the most
+recent researches into electricity confirm and establish the atomicity
+of the Aether.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_3' id='Footnote_3'></a><a href='#FNanchor_3'><span class='label'>[3]</span></a>
+<i>Collected Works</i>, by Niven.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_4' id='Footnote_4'></a><a href='#FNanchor_4'><span class='label'>[4]</span></a>
+Preface to <i>Aether and Matter</i>.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_5' id='Footnote_5'></a><a href='#FNanchor_5'><span class='label'>[5]</span></a>
+Page 348.
+</p></div>
+
+
+
+<p>
+<a name='ART_45' id='ART_45'></a><span class='smcap'>Art</span>. 45. <i>Aether is Gravitative</i>.--Young, in the <i>Philosophical Trans</i>.
+of 1802, in regard to this question, states in his Fourth Hypothesis:
+&ldquo;All material bodies have an attraction for the aetherial medium, by
+means of which it is accumulated within their substance, and for a small
+distance around them, in a state of greater density, but not greater
+elasticity.&rdquo; He adds that &ldquo;this fourth hypothesis is opposed to that of
+Newton's.&rdquo;
+</p>
+
+<p>
+Scientific research has justified the conception of his first three
+hypotheses with respect to the universality, elasticity and vibrations
+of the aetherial medium, but up to the present I am not aware that
+science has accepted his fourth hypothesis.
+</p>
+
+<p>
+I propose to show how, from a strictly philosophical and logical
+standpoint, his fourth hypothesis is just as true as his first three
+hypotheses, and that it henceforth passes out of the realm of the
+hypothetical into the realms of fact and science, not only by
+philosophical reasoning, but by actual experiment made by some of the
+most advanced scientists of the present time.
+</p>
+
+<p>
+Let us consider the question first from the standpoint of the Rules of
+Philosophy. Our first Rule of Philosophy states, that any hypothesis
+must be simple in connection. Now I put it to any intelligent man, and
+ask him which is the simpler conception of Aether? To affirm that Aether
+is matter, and therefore subject to the properties of matter, as elasticity, density, inertia<span class='pagenum'><a name='Page_65' id='Page_65'></a><a href='#TOC'>[65]</a></span>
+and Gravitation, or to affirm that Aether is matter, but while it is
+subject to some of the properties of matter, as elasticity, density and
+inertia, it is not subject to the very property which of all properties
+is the most fundamental, viz. Gravitation. There can, in my opinion,
+only be one answer to the question, so that, when we affirm that Aether
+is matter, we are compelled to affirm, in order to conform to the first
+Rule of Philosophy, that it is gravitative also. Faraday was also of the
+opinion that Aether was subject to the Law of Gravity, for, writing in
+<i>Experimental Researches</i>, he states: &ldquo;The view now stated of the
+constitution of matter, would seem to involve the conclusion, that
+matter fills all space, or at least all space to which Gravitation
+extends, <span class='smcap'>including the sun and its system</span>. For Gravitation is a property
+of matter, dependable on a certain force, and it is this force which
+constitutes matter.&rdquo;
+</p>
+
+<p>
+Let us also test the question by our second Rule of Philosophy, and we
+shall find greater evidence still for the statement that Aether is
+gravitative. What do experience and observation teach us with reference
+to matter? As we have already seen (<a href='#ART_37'>Art. 37</a>), if there is one truth that
+they teach us regarding matter, it is that it is gravitative.
+</p>
+
+<p>
+There is not the slightest evidence throughout the universe, as far as
+our observation can lead us to form an opinion, that there is any kind
+of matter which is not subject to the Law of Gravitation. Therefore to
+assume that Aether is matter, and yet not to assume that it is also
+subject to Gravitation, is to assume that which is directly opposed to
+the most fundamental principle of all philosophical teaching and
+scientific research. If Aether be matter, therefore, and yet is not
+gravitative, we shall have an anomaly in an otherwise universal law, as
+we shall have some kind of matter which fails to come within the scope
+of the universal Law of Gravitation.
+</p>
+
+<p>
+To be consistent, therefore, we must either cease to call Aether matter,
+or else admit that Aether, like all other matter, is gravitative. It is
+absolutely impossible to be strictly logical and admit that Aether is
+matter, and not to admit that it is subject to the most universal law
+that governs matter, as the Law of Gravitation distinctly states that
+&ldquo;every particle or atom of matter attracts every other particle.&rdquo; This
+universal law in view of a gravitationless Aether would have to be
+amended to &ldquo;Some particles of matter attract some other particles.&rdquo; Thus
+the universal Law of Gravitation ceases at once to be a universal law,
+and such a result is opposed to all experience and experiment. Again,
+let us apply our third Rule of Philosophy to this supposed
+gravitationless Aether, and see what the result is.<span class='pagenum'><a name='Page_66' id='Page_66'></a><a href='#TOC'>[66]</a></span>
+</p>
+
+<p>
+Our third rule
+states, that any hypothesis put forward must satisfactorily account for
+the phenomena sought to be explained and accounted for. The Aether was
+conceived in order to explain the phenomena of light, and one of the
+properties it was conceived to possess was elasticity, yet that very
+conception was devoid of the most fundamental property of matter,
+without which there is no elasticity, that is, that it was not atomic.
+</p>
+
+<p>
+I have already shown in <a href='#ART_44'>Art. 44</a>, that Aether is atomic, and therefore
+there is given to the Aether a structure which is capable of exhibiting
+elasticity, inertia, density, and even Gravitation, while at the same
+time, the conception is fully in harmony with philosophical reasoning
+and Newton's Rules of Philosophy.
+</p>
+
+<p>
+Let us consider the question whether Aether is, or is not gravitative,
+from another aspect. For several hundred years, the physical cause of
+Gravitation has been outstanding, while the world has held the
+conception that Aether is a gravitationless and frictionless medium. The
+earth has been rolling on in her orbit year in, year out, together with
+all the other planets in their annual march round the sun, and yet
+through all that time no one has been able to suggest, or give any
+satisfactory or adequate physical explanation, as to what moves the
+earth along.
+</p>
+
+<p>
+I am fully aware that Newton suggested and proved, that it was because
+of the Law of Gravitation. But I look upon that as a mathematical
+explanation and not as a physical one.
+</p>
+
+<p>
+Now I venture to predict this, that on the assumption of a
+gravitationless medium, the physical explanation so longed for will
+always be outstanding, as a gravitationless Aether is synonymous with a
+frictionless medium, and so long as we admit that there is a
+frictionless medium, so long will the physical cause of Gravitation, and
+therefore the physical cause of all the movements of the planets and
+comets, be outstanding and unexplained.
+</p>
+
+<p>
+If, however, instead of being illogical in our reasoning, we become
+logical, and affirm that Aether is matter, and because all matter is
+gravitative, therefore Aether is gravitative; and if, instead of being
+unphilosophical, we become philosophical, and affirm that because a
+gravitationless Aether violates both the first and second Rules of
+Philosophy, such a conception must be put away, and in its place a more
+philosophical conception must be forthcoming, which is that Aether is
+gravitative; then, upon such a logical and philosophical basis, I
+venture to premise that the great problem which is still outstanding of
+the cause of Gravitation, will remain outstanding no longer, and the
+physical cause of all the movements of all celestial bodies will be put
+upon a physical basis, in addition to a mathematical one.<span class='pagenum'><a name='Page_67' id='Page_67'></a><a href='#TOC'>[67]</a></span>
+</p>
+
+<p>
+If such a
+result can be arrived at by the logical and philosophical conception of
+a gravitative Aether, then the three Rules of Philosophy are fully
+satisfied, and the assumption of a gravitative Aether is warranted on a
+strictly philosophical basis.
+</p>
+
+<p>
+So that Thomas Young is strictly correct from a philosophical standpoint
+in his fourth hypothesis, when he states: &ldquo;That all material bodies have
+an attraction for the aetherial medium, by means of which it is
+accumulated within their substance and for a small distance around them
+in a state of greater density but not greater elasticity.&rdquo; He is not,
+however, correct when he states that though there is a greater density
+near the body, there is not a greater elasticity, as such an assumption
+is opposed to experiment and observation in relation to perfect gases,
+as I shall show when dealing with the elasticity of the Aether.
+</p>
+
+<p>
+Again, in view of the fact that the Aether is atomic, it can now be
+easily understood how it may be subject to Gravitation. The very essence
+of Gravitation is that atoms, or particles, attract each other. If there
+were no particles, or atoms, it is obvious that there would be no
+attraction, and therefore no Gravitation. Wherever, therefore, there are
+to be found atoms of any kind or sort, whether they be atoms of
+hydrogen, oxygen, silver or aetherial atoms, there the Law of
+Gravitation holds good, and attraction between these atoms is to be
+found. In other words, any substance which is atomic, is also
+gravitative. Now Aether is atomic as has been shown, and therefore from
+that standpoint it is also gravitative. It may, however, be objected
+that the assumption of gravitative properties for the Aether is after
+all but a speculation, and that Young's fourth hypothesis was only a
+hypothesis, and that the gravitating properties of the aetherial medium
+have never come within the scope of direct experiment, without which no
+hypothesis can be fully accepted.
+</p>
+
+<p>
+If such an argument be advanced against a gravitating Aether, then I
+must differ from those scientists who advance such an objection. My
+contention is that the gravitating properties of the Aether have already
+been made the subject of some of the most refined and delicate
+experiments that have been made during the past few years.
+</p>
+
+<p>
+I refer to the experiments of Michelson and Morley of America.
+</p>
+
+<p>
+For an outline and explanation of such experiments I must refer the
+reader to the <i>Phil. Mag</i>. of December 1887.
+</p>
+
+<p>
+Now what is the result of these experiments?
+</p>
+
+<p>
+I believe it is almost unanimously conceded by all scientists, that
+their experiments prove that the Aether is carried along by the earth.
+Let us carefully look at this conclusion and see what it implies in
+relation to the question at issue.<span class='pagenum'><a name='Page_68' id='Page_68'></a><a href='#TOC'>[68]</a></span>
+</p>
+
+<p>
+If the Aether is carried along by
+the earth, it necessarily follows that there is some governing law or
+principle which holds it to the earth, while the earth moves through
+space with its velocity of 68,000 miles per hour.
+</p>
+
+<p>
+Now what is that governing principle or law, which is capable of holding
+such an aetherial atmosphere to its central body? If we wish to be
+strictly philosophical, it is necessary, according to our second Rule of
+Philosophy, that we should not go outside experience and the analogy of
+Nature.
+</p>
+
+<p>
+Where is there a similar analogy in Nature to that of the Aether being
+carried along through space by the earth? I know of only one analogy
+which can be used, and that is the analogy of the atmosphere, which is
+also carried along by the earth through space, as it rushes on in its
+orbit round the sun.
+</p>
+
+<p>
+That being so, the question arises, what principle or law holds the
+atmosphere to the earth? for, whatever be the law which governs the
+atmosphere, to be consistent with the second Rule of Philosophy, we must
+infer that the same law also holds the Aether in its place. There is
+only one answer to the latter question, and that is the Law of
+Gravitation. If it were not for that law, and the fact that the
+atmosphere is subject to that law, the atmosphere would simply be swept
+off from its central body, the earth, as the latter rushed through space
+with its comparatively enormous velocity.
+</p>
+
+<p>
+The only legitimate and philosophical conclusion that we can arrive at,
+therefore, is that the Aether must be carried along with its central
+body, the earth, through being acted upon by the self-same Law of
+Gravitation, and for it to be so acted upon it must obviously be
+gravitative. It would be unphilosophical to suggest that it was held in
+its place by any other force, as that would be introducing a new force
+or law into Nature, contrary to our experience in relation to an exactly
+similar phenomenon of Nature.
+</p>
+
+<p>
+We have therefore, it seems to me, direct proof by actual experiment
+that Young's fourth hypothesis was correct, and that not only in
+relation to the atomic world, but also in relation to the planetary
+world, and the stellar world, all bodies exert an attractive influence
+upon the surrounding Aether, by means of which the Aether is accumulated
+near the surfaces of all bodies in a state of greater density, and
+therefore of greater elasticity.
+</p>
+
+<p>
+Let us apply this truth to the solar system, and see what we get. If it
+is true that the earth exerts an attractive influence upon the
+surrounding Aether by means of which it is held in its place relatively
+to the earth, then it is equally true that Mercury, Venus, Mars,
+Jupiter, Saturn, Uranus and Neptune also exert gravitating or attractive
+influences upon the surrounding Aether, in the same way that they do
+upon their own atmospheres. So that in their cases also, the<span class='pagenum'><a name='Page_69' id='Page_69'></a><a href='#TOC'>[69]</a></span>
+surrounding Aether is carried along by them through space. Professor
+Stokes has suggested that this is so, in order to account for the
+aberration of light, as we shall see later on.
+</p>
+
+<p>
+Not only so, but the sun also would have an attractive power over the
+Aether by means of which its aetherial atmosphere would be carried
+through space, as it moved along in its progress at an estimated rate of
+17,000 or 18,000 miles per hour.
+</p>
+
+<p>
+I would like to point out here, that this explanation of the effect of
+the planets' attractive power over the surrounding Aether is only a
+partial one, as there are other effects directly involved in the fact
+that the Aether is subject to the gravitating influence of all
+satellites and planets.
+</p>
+
+<p>
+This is not the place, however, to go fuller into the matter, the
+consideration of the subject being taken up in a later chapter.
+</p>
+
+<p>
+Thus I have tried to show a gravitating Aether is strictly in accord
+with the three Rules of Philosophy, for it is simple in conception, is
+not contrary to experience, and by it I premise that it is possible to
+explain the physical cause of Gravitation, with all that is involved in
+that law.
+</p>
+
+<p>
+Once more, if Aether is gravitative, then every atom and particle in the
+universe, as well as every planet, and sun, and star, exert an
+attractive power over the Aether, so that every atom is enveloped in an
+atmosphere of Aether, in the same way that every planet, and sun, and
+star is enveloped by the aetherial atmosphere.
+</p>
+
+<p>
+The Aether, however, while it may flow through the spaces that exist
+between the molecules of bodies, yet is held bound to those molecules in
+the same way, and by exactly the same force, that holds the atmosphere
+to a planet or world.
+</p>
+
+<p>
+Further, if the atoms possess different masses or weights, as they do,
+then each atom would possess an aetherial atmosphere proportionate to
+its mass, with the result that an atom of carbon, with its atomic weight
+of 12, ought to possess a denser aetherial atmosphere than an atom of
+hydrogen, and so on right through the atomic scale. I need hardly point
+out that this conception of the Aether in relation to atoms, and
+molecules of bodies, will solve certain problems relating to the density
+of Aether in connection with matter, which problem up to the present
+cannot be solved by the present conception of a frictionless medium.
+</p>
+
+<p>
+That problem may be stated as follows: Does the presence of matter
+affect the Aether in any way, so as to load or make it denser? Professor
+Lodge, in <i>Modern Views of Electricity</i>, in relation to the density of
+the Aether, writes: &ldquo;The neighbourhood of gross matter seems to render
+Aether more dense. It is difficult to suppose that it can really
+condense an incompressible fluid, but it may load it, or otherwise<span class='pagenum'><a name='Page_70' id='Page_70'></a><a href='#TOC'>[70]</a></span>
+modify it, so as to produce the effect of increased density.&rdquo;
+</p>
+
+<p>
+In view of the fact that Aether is gravitative, the reply is to be found
+in the Law of Gravitation, &ldquo;Every particle of matter attracts every
+other particle of matter, etc.,&rdquo; and as Aether is matter, it will be
+attracted by the other matter irrespective of whether that matter be in
+the atomic, molecular, or planetary or stellar form. We shall see that
+this is so when we come to deal with the density of the Aether.
+</p>
+
+<p>
+It may be objected in relation to this aspect of Aether, that Young also
+asserted that the Aether flows as freely through matter, as the air
+flows through the trees of the forest, and that such a statement
+therefore contradicts his fourth proposition regarding the gravitating
+properties of Aether. A little reflection will, however, put a different
+construction on this objection.
+</p>
+
+<p>
+Let us consider the analogy from the standpoint of experience, and see
+what that analogy teaches us. From experience we learn that the air is
+gravitative, but we also learn that it is possible to be moved from
+place to place as winds, and that as such it can move freely between the
+trees of the forest, causing their boughs and leaves to tremble and bend
+beneath its energy and power.
+</p>
+
+<p>
+I have yet to learn, however, that while it moves between the trees as
+separate and distinct objects, such a movement militates or destroys its
+gravitating properties.
+</p>
+
+<p>
+Does the air cease to be any less gravitative, or subject to the Law of
+Gravity, when it is subject to certain movements, which give rise to
+certain currents as winds? Such an assumption is altogether opposed to
+philosophical reasoning.
+</p>
+
+<p>
+Whether the air is stationary or in motion, it is ever subject to the
+great Law of Gravitation, and accepting that as an analogy, the apparent
+contradiction between the oft-quoted simile of Young and his fourth
+hypothesis is at once removed, and from analogy we learn that it is
+quite possible for Aether to move between bodies because of certain
+currents which may be originated by heat, light or electricity, yet at
+the same time the existence of such currents does not violate its
+gravitating tendency.
+</p>
+
+<p>
+Young's fourth hypothesis is therefore in perfect harmony with his
+oft-quoted simile, that the Aether flows through the interstices of
+bodies as the wind flows through a group of trees, but like the
+air-currents it does not so flow unless the currents are generated by
+some form of energy, as heat or light, electricity or magnetism.
+</p>
+
+<p>
+From these considerations therefore we are compelled to come to the
+conclusion that Aether, like all other matter, is subject to the same
+universal Law of Gravitation. If further evidence of the gravitating<span class='pagenum'><a name='Page_71' id='Page_71'></a><a href='#TOC'>[71]</a></span>
+tendency of the Aether were required, I would refer the reader to Lord
+Kelvin's utterance on this subject.
+</p>
+
+<p>
+Lord Kelvin, <i>Phil. Mag</i>., November 1899, in relation to the Aether
+writes: &ldquo;We are accustomed to call Aether imponderable. How do we know
+that it is imponderable? If we had never dealt with air except by our
+senses, air would be imponderable to us, but we know by experiment that
+a vacuum glass tube shows an increased weight when air is allowed to
+flow into it. We have not the slightest reason to believe that Aether is
+imponderable. It is just as likely to be attracted by the sun as air is.
+At all events the <i>onus of proof rests with those who assert it is
+imponderable</i>. I think we shall have to modify our ideas of what
+Gravitation is, if we have a mass spreading through space with mutual
+attraction between its parts, without being attracted by other bodies.&rdquo;
+</p>
+
+<p>
+We have already seen in the previous article that Faraday was of opinion
+that the Law of Gravitation extended throughout the whole of the solar
+system, and as Aether fills the solar system, then obviously Aether must
+also be subject to the Law of Gravitation.
+</p>
+
+<p>
+<a name='ART_46' id='ART_46'></a><span class='smcap'>Art</span>. 46. <i>Aether possesses Density</i>.--That matter possesses density has
+already been shown in <a href='#ART_38'>Art. 38</a>, and on the hypothesis that Aether is
+matter, Aether must possess density also. This property has already been
+postulated for the Aether, in order to account for certain phenomena in
+connection with the reflection and refraction of light. Young assumed
+different densities for the Aether near bodies owing to its being
+attracted by those bodies (<a href='#ART_45'>Art. 45</a>). Reflection and refraction of light
+are produced by a change of density of the Aether. It is now generally
+accepted that the optical difference of bodies depends mainly on the
+different densities of Aether in association with those bodies.
+Professor Tyndall, in his <i>Lectures on Light</i>, writes on the density of
+the Aether as follows: &ldquo;The density of the Aether is greater in liquids
+and solids than in gases, and greater in gases than in vacuo. A
+compressing force seems to be exerted on the Aether by the molecules of
+these bodies.&rdquo;
+</p>
+
+<p>
+Apart, however, from the atomicity and gravitative properties of the
+Aether, it is difficult to understand how there can be density of the
+medium, and still more difficult to give a satisfactory explanation of
+different degrees of density for the same medium, which some scientists
+assume it to have.
+</p>
+
+<p>
+If, however, all that is logically included in the statement that Aether
+is matter, and therefore is atomic and gravitative, is conceded, then,
+from the analogy of our own atmosphere in relation to the earth, the
+density of the Aether, and different degrees of density also, is at once
+put upon a logical and philosophical basis, as it is brought into<span class='pagenum'><a name='Page_72' id='Page_72'></a><a href='#TOC'>[72]</a></span>
+harmony with all experience and observation, and is simple in its
+conception.
+</p>
+
+<p>
+On the other hand, an Aether which is not atomic or gravitative cannot
+possess different degrees of density, except by assuming the existence
+of some unknown law of which we have no knowledge, which conception is
+altogether opposed to the fundamental principles of simplicity,
+observation, and experiment as laid down not only by Newton but by every
+true philosopher.
+</p>
+
+<p>
+Therefore, that Aether can possess different degrees of density, is only
+the logical outcome of the statement that Aether is matter, seeing that
+such a statement without the shadow of a doubt must at least imply that
+it is gravitative.
+</p>
+
+<p>
+I need hardly point out, that it is much more philosophical to be able
+to account for the density of the Aether in a reasonable and
+philosophical manner, than simply to postulate for the Aether certain
+properties and qualities, because certain phenomena demand the existence
+of such properties.
+</p>
+
+<p>
+The Aether has been such a hypothetical medium, that it has been easy to
+postulate for it certain properties, if certain phenomena have demanded
+the existence of those properties.
+</p>
+
+<p>
+Thus if the Aether were required to be elastic, then elasticity was
+postulated for it; if more elastic, then greater elasticity was added.
+If density were demanded, then density was postulated, and if less or
+more density, less or more density was given to it.
+</p>
+
+<p>
+That method of speculation may be satisfactory up to a certain point,
+but no one will admit that such a method is wholly philosophical. It
+will be a far better method to adopt, if, in dealing with the universal
+Aether, we can make it conform to certain recognized laws and
+principles, and from the application of those well-known laws, be able
+to infer the exact constitution of this space-filling Aether medium.
+</p>
+
+<p>
+Now the question arises, if Aether is gravitative, what effect has the
+Gravitation of any body, be it an atom, or a meteor or planet, sun or
+star, upon the Aether in which it moves, and which surrounds it?
+</p>
+
+<p>
+That we may have some light thrown upon the matter, I would like now to
+take the reader to Newton's <i>Optics</i>, in order that he may give us his
+opinion as to this property of density of the Aether. In his nineteenth
+query Newton (<i>Optics</i>) asks this question--
+</p>
+
+<p>
+&ldquo;Is not this medium much rarer within the dense bodies of the sun,
+stars, planets and comets than in the empty spaces between them, and in
+passing from them to great distances, doth it not grow denser and denser
+perpetually, and thereby cause the gravity of those great bodies towards
+one another, and of their part towards the bodies, every body<span class='pagenum'><a name='Page_73' id='Page_73'></a><a href='#TOC'>[73]</a></span>
+endeavouring to go from the denser parts of the medium towards the
+rarer?&rdquo;
+</p>
+
+<p>
+Here then we have given to us an indication of what is the possible
+state of things in relation to the gravitation of the Aether, and all
+bodies in solar and stellar space. The only mistake that Newton made,
+was in inverting the right order of comparatively dense and rarer parts
+of the aetherial medium, by putting the rarer parts of the medium near
+to the bodies, and supposing the denser parts to be farther away in
+space.
+</p>
+
+<p>
+As a matter of fact, the correct view is exactly the opposite, that is,
+if we are to form our conception by following out those philosophical
+rules that Newton laid down. For either the rules are right, or his
+supposition is right. They cannot both be right, as his supposition is
+contrary to the second Rule of Philosophy, as all experience and
+observation from the analogy of Nature teach us that a medium enveloping
+any body, as planet, star or sun, is densest nearest to the body,
+becoming rarer the further that medium gets away from the central body.
+Let us take for our illustration the best example, that experience and
+observation afford, that of the atmosphere surrounding the earth. The
+analogy is so perfect, that one is almost tempted to believe that the
+atmosphere and the Aether are in some way intimately associated with
+each other. Some years ago Lord Kelvin was of the opinion that the
+Aether was but an extension of the atmosphere, though I am not certain
+whether he holds that view at the present time. Clerk Maxwell, writing
+in the <i>Phil. Mag.</i> in May 1861, writes: &ldquo;I have deduced from this
+result the relation between statical or dynamical electricity, and have
+shown that the elasticity of the magnetic medium in air is the same as
+that of the luminiferous medium, <i>if these two coexistent, coextensive,
+and equally elastic media are not rather one medium.</i>&rdquo;
+</p>
+
+<p>
+Now for the comparison. Both the atmosphere and Aether are matter. Both
+are atomic, both are gravitative, both possess elasticity, and both
+possess density. The atmosphere also possesses different degrees of
+density, so does the Aether. In the case of the atmosphere, however,
+experience and experiment teach us that the atmosphere is denser nearer
+the earth than farther away.
+</p>
+
+<p>
+When we ascend mountains, it is a matter of common knowledge that the
+higher we ascend, that is the further we get from the earth, the rarer
+the atmosphere becomes. When we ascend in balloons, we find that the air
+becomes so rare and so light, that the blood will flow from the nose, on
+account of the reduced pressure exerted on it, the pressure inside the
+body being greater than that outside. Now in accordance with our second
+Rule of Philosophy, if experience is to be any guide at all, then it<span class='pagenum'><a name='Page_74' id='Page_74'></a><a href='#TOC'>[74]</a></span>
+most conclusively teaches us that the Aether being subject to the same
+laws as the atmosphere, the same results inevitably follow. Therefore
+the Aether nearest the earth is denser than any layer immediately above
+it, and that layer denser than the one above it, and so on for great
+distances, with the result that the only conclusion we can come to in
+regard to the density and rarity of Aether in relation to all
+gravitating bodies is, that the densest part of the Aether is nearest to
+them, and the rarest, the farthest away from them. So that while
+Newton's suggestion in his nineteenth query is correct in principle, it
+is incorrect in application to space.
+</p>
+
+<p>
+I would like to point out here, that what is true of the earth in
+relation to the density of the surrounding Aether, must also be true,
+according to our second Rule of Philosophy, of every other planet, or
+sun, or star. So that every planet, satellite, every sun or star has its
+atmosphere, if I may so term it, of Aether, which obeys and follows the
+same laws as the earth's atmosphere does.
+</p>
+
+<p>
+This is a most important fact, and has a most important bearing upon the
+physical cause of Gravitation as applied to each planet, and sun and
+star, as I shall afterwards show.
+</p>
+
+<p>
+I wish now to bring the reader into contact with a Theory of Gravitation
+that was given to the world by Professor Challis of Cambridge, 1872. In
+the <i>Philosophical Magazine</i> of June of that year he writes: &ldquo;I assume
+that all the active forces of Nature are different modes of pressure
+under different circumstances of a universal elastic Aether, which
+presses always proportionately to its density.&rdquo;
+</p>
+
+<p>
+Now what I wish to point out is, that while Prof. Challis admits the
+density of the Aether, and also varying degrees of density, as he states
+that the Aether presses proportionately to the density, he does not show
+how that varying density is accounted for. If there is this varying
+density, then there must be some underlying principle which governs the
+variation in density, and I know of only one principle or law which can
+regulate that variation in density, and that is that Aether is
+gravitative, and being gravitative it not only possesses density, but
+also variations in density.
+</p>
+
+<p>
+Thus by admitting that Aether is gravitative, because it is matter, we
+have at once a satisfactory explanation for the density of the Aether
+and also for different degrees of density both in the atomic world, and
+in the planetary and stellar world.
+</p>
+
+<p>
+<a name='ART_47' id='ART_47'></a><span class='smcap'>Art</span>. 47. <i>Aether is Elastic</i>.--In <a href='#ART_39'>Art. 39</a>, matter was shown to be
+elastic, and on the assumption that Aether is matter, the elasticity of
+the Aether, which has been postulated for it by various scientists, can
+be logically and philosophically accounted for.<span class='pagenum'><a name='Page_75' id='Page_75'></a><a href='#TOC'>[75]</a></span>
+</p>
+
+<p>
+In view of the
+transmission of light through space with a definite and finite velocity,
+we are compelled to regard Aether as possessing elasticity, similar to
+that of an elastic solid body.
+</p>
+
+<p>
+If we take the analogy of sound, we find that sound is transmitted and
+propagated through matter, by waves of alternate condensation and
+rarefaction, and that transmission is regulated by the relation of the
+density of the medium to its elasticity. Light has been proved to be due
+to the undulatory wave-motions of the Aether, and in order to account
+for the transmission of the wave-motion, it is essential that the Aether
+should possess the property of elasticity.
+</p>
+
+<p>
+As Young points out in his First Hypothesis,<a name='FNanchor_6' id='FNanchor_6'></a><a href='#Footnote_6' class='fnanchor'>[6]</a>
+ the Aether possesses
+this property of elasticity, but with the advance of scientific
+knowledge and research, the elasticity of the Aether may be said to have
+passed out of the hypothetical stage, into the state of actual fact and
+experiment. Both McCullagh and Fresnel have assumed this property of
+elasticity for the aetherial medium in order to account for certain
+phenomena of light.
+</p>
+
+<p>
+Apart, however, from the atomicity of the Aether, it is exceedingly
+difficult to understand how such a property can belong to it. Atoms are
+exceedingly small particles, possessing the property of elasticity, or
+the power to recover their original shape after distortion or change of
+shape. If the Aether therefore be atomic, as is pointed out in <a href='#ART_44'>Art. 44</a>,
+it can at once be readily understood how the Aether as a whole can
+possess the property of elasticity. The atoms of the Aether must be
+inconceivably small, as the light-waves travel with the enormous
+velocity of 186,000 miles per second.
+</p>
+
+<p>
+What must therefore be the atomic vibration which such a statement
+implies? If, on the other hand, the Aether is assumed to be continuous
+and non-atomic, it must be seen how exceedingly difficult it is to
+account for the elasticity of the Aether, as it seems absolutely
+impossible for a medium which is continuous, and non-atomic, to be able
+to transmit the waves of light with a finite velocity.
+</p>
+
+<p>
+Apart, therefore, from atomicity of some kind or other, elasticity of
+the Aether is an assumption philosophically incorrect, as it is contrary
+to that simplicity of conception laid down by Newton, and is also
+contrary to all experience, and thus violates the second Rule of
+Philosophy.
+</p>
+
+<p>
+Aether therefore must be said to be perfectly elastic; so perfectly
+elastic, that it is susceptible to the least touch of any natural thing,
+so that even an atom, so small that it cannot be seen with the most
+powerful microscope, yet so elastic is this Aether medium, that the
+least motion or vibration of one of these atoms, though the motion did<span class='pagenum'><a name='Page_76' id='Page_76'></a><a href='#TOC'>[76]</a></span>
+not exceed the 20- or 40-millionth part of an inch, yet even this would
+create in the aetherial ocean, Aether-waves, just as a body moving in
+water creates water-waves, which, radiating from the place of their
+birth, beget and create others, the process continuing until they reach
+the margin of the water in which they were generated. It is precisely so
+with these Aether-waves, when once generated and set in motion. They
+create others, the process being continued and perpetuated; and, unless
+arrested in their course, may continue until they reach the very limits
+and confines of material immensity and space.
+</p>
+
+<p>
+It is, perhaps, only necessary to say, regarding the perfection of the
+elasticity of the Aether medium, that though it takes from 40,000 to
+69,000 waves to complete the space of one inch in extent, yet it is done
+with such miraculous rapidity, as to speed the distance of 186,000 miles
+in the short space of a second of time; or, taking the number of
+Aether-waves to complete an inch as 50,000, its elasticity is such that
+it makes 50,000 × 186,000 × 12 × 5280 vibrations in one second of time.
+</p>
+
+<p>
+We have already seen in <a href='#ART_39'>Art. 39</a>, that according to Boyle and Marriotte's
+Law, the velocity of a wave-motion, as sound in the air, is determined
+by the relation of the elasticity of the medium to its density. If the
+temperature of the atmosphere remains the same, then the <i>elasticity</i>
+varies in the same proportion as its density.
+</p>
+
+<p>
+According to <a href='#ART_45'>Art. 45</a>, Aether is gravitative, and that fact produces
+different degrees of density in the aetherial atmosphere of an atom or
+planet or meteor, sun or star; that part of the Aether being densest
+nearest the central body, and rarer the further we go away from that
+body.
+</p>
+
+<p>
+Now the question at once arises, what is the effect of the increased
+density of the Aether near the body upon the elasticity of the Aether?
+</p>
+
+<p>
+From the analogy of sound in air, we arrive at the conclusion that Boyle
+and Marriotte's Law equally applies to the Aether, as it does to the
+atmosphere of any planet. That is, if the temperature of any stratum or
+layer of the Aether remains the same, then the elasticity of the
+aetherial medium in that layer is proportionate to its density, so that
+while the gravitating property of the Aether makes it denser nearest the
+central body, the fact that the elasticity is proportionate to the
+density, does not affect the transmission of any wave-motion.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_6' id='Footnote_6'></a><a href='#FNanchor_6'><span class='label'>[6]</span></a>
+<i>Phil. Trans.</i>, 1802.
+</p></div>
+
+
+<p>
+<a name='ART_48' id='ART_48'></a><span class='smcap'>Art</span>. 48. <i>Aether possesses Inertia</i>.--From <a href='#ART_40'>Art. 40</a> we have seen that all
+matter possesses inertia, inertia being that property of matter by which
+it cannot of itself change its state of motion or of rest.<span class='pagenum'><a name='Page_77' id='Page_77'></a><a href='#TOC'>[77]</a></span>
+</p>
+
+<p>
+If Aether be
+matter, therefore, then it must also possess inertia. This property of
+inertia is already postulated for Aether by scientists, and to that
+extent is conformable to the Rules of Philosophy. Professor Tyndall,
+with reference to the inertia of the Aether, writes: &ldquo;The motion of
+Aether communicated to material substances throws them into motion. It
+must be therefore itself a substance. Aether is a substance endowed with
+inertia, and capable, in accordance with the established laws of motion,
+of imparting its motion to other substances.&rdquo;<a name='FNanchor_7' id='FNanchor_7'></a><a href='#Footnote_7' class='fnanchor'>[7]</a>
+
+</p>
+
+<p>
+Again, Lord Kelvin in his Address to the British Association, 1901, on
+the &ldquo;Clustering of Gravitational Matter in any part of the Universe,&rdquo;
+states: &ldquo;Aether we relegate to a distinct species of matter which has
+inertia, etc.&rdquo; Aether, therefore, according to Tyndall, &ldquo;is a substance
+or medium endowed with inertia, and capable, in accordance with Newton's
+Laws of Motion, of imparting its motion to other substances.&rdquo;
+</p>
+
+<p>
+If, however, the Aether is frictionless, as has generally been supposed,
+then it cannot possess inertia, because to the extent that a body
+possesses inertia, to that extent it is opposed to being frictionless.
+</p>
+
+<p>
+Inertia is really the equivalent of mass, or the amount of matter
+measured by gravity, and if Aether possesses mass in any sense at all,
+as it must do if it is matter, then, possessing mass or weight, it must
+offer resistance to any body moving through it, and to that extent
+cannot be frictionless. To suppose that the Aether is frictionless, and
+yet possesses inertia, is to suppose something altogether opposed to all
+the Rules of Philosophy and therefore of experience.
+</p>
+
+<p>
+I have already shown that a frictionless medium is opposed to all
+philosophy and experience, and is an anomaly in the universe.
+</p>
+
+<p>
+On the strictly philosophical assumption that Aether is matter, and
+therefore atomic and gravitative, the whole question of the inertia of
+the Aether is reduced to one of common experience. It is, at least to my
+mind, difficult to conceive of mass without weight or without atomicity,
+and yet that is the unphilosophical position of the present state of
+science in relation to the Aether. In other words, while the Aether is
+supposed to possess inertia, which is dependent upon mass, as measured
+by gravity, yet it is supposed not to be gravitative, that is, that the
+mass of the Aether has no weight at all, and therefore is not mass,
+which assumption contradicts itself. From <a href='#ART_44'>Arts. 44</a> and <a href='#ART_45'>45</a>, however, we
+have seen, to be strictly philosophical, that Aether must be atomic and
+also gravitative. It can now be easily understood how it can possess
+inertia like any other matter, and is therefore<span class='pagenum'><a name='Page_78' id='Page_78'></a><a href='#TOC'>[78]</a></span>
+capable of receiving motion from
+other matter, and also of imparting that motion to other matter.
+</p>
+
+<p>
+So that, wherever there is motion of any kind in the Aether, either in
+the form of vibratory motion as heat, or undulatory motion as light, or
+rotatory motion as electricity, those motions will affect adjoining
+matter in the same way that the motion of any other moving matter
+affects any body with which it comes into contact.
+</p>
+
+<p>
+From the fact that Aether possesses inertia, and is also gravitative, we
+have now to alter our conception of this universal space-filling medium,
+and in place of a frictionless medium, which is incapable of imparting
+motion to any body, we have now to remember henceforth that the Aether
+is matter, which possesses inertia, and therefore has the capacity not
+only of offering resistance to any body moving through it, as a comet or
+meteor, but also of imparting the motion which it may receive in any
+manner to any other matter, as a planet, satellite, or sun, that may be
+floating in it.
+</p>
+
+<p>
+With this philosophical view of the Aether, which is entirely in harmony
+with our first and second Rules of Philosophy, we shall be able to give
+a physical explanation of the Law of Gravitation, as we have now a
+physical medium existing in all atomic, solar, and stellar space, which
+can both accept motion, and transmit that motion to other bodies. In
+other words, we have a medium which can both push and pull.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_7' id='Footnote_7'></a><a href='#FNanchor_7'><span class='label'>[7]</span></a>
+<i>Lectures on Light</i>.
+</p></div>
+
+
+<p>
+<a name='ART_49' id='ART_49'></a><span class='smcap'>Art</span>. 49. <i>Aether is Impressible</i>.--Another characteristic property of
+this Aether medium is, that it is as perfectly impressible as it is
+elastic. So perfectly impressible, that it receives, retains, and
+perpetuates for thousands of years, and for distances to human mind
+incalculable, every impression given to it of light, form, colour, tint,
+and shade; and that, too, with a perfect fidelity that nothing mars,
+even to the least and most infinitesimal detail.
+</p>
+
+<p>
+Therefore, irrespective of distance, wherever there is matter to arrest
+and reflect the impressions received, there those impressions of light
+(and all that in the luminosity is involved and contained) become
+visible and revealed, and wherever there is power of vision to receive
+and concentrate these Aether- or light-waves, there, not only luminosity
+or light, but all that constitutes and is involved in that luminosity,
+becomes at once visible and seen.
+</p>
+
+<p>
+It is by this means we see the colour, tints, shades, and forms of suns
+and planets; of stars, constellations, etc., with all the varied forms,
+configurations, and movements of the celestial phenomena. Each and every
+one, small or great, glittering or blazing, sun or planet, are ever
+creating or generating Aether-waves, and impressing them with all the<span class='pagenum'><a name='Page_79' id='Page_79'></a><a href='#TOC'>[79]</a></span>
+details and particulars of their nature and existence; and these
+Aether-waves ever bear upon their mystic wings the impressions received,
+carrying the information given with lightning speed to the very confines
+and limits of infinite space or the material universe; beyond which
+exists nothing but the ever-living and active energy of the Divine, the
+only unlimited, unbounded, and absolute infinitive.
+</p>
+
+<p>
+It is by the interception and concentration of these waves by our
+perceptive powers, aided with the giant powers of the telescope, that we
+obtain the information given, or become cognizant of the nature and
+existence of the varied lights, colours, tints, and shades of the
+celestial bodies.
+</p>
+
+<p>
+The vision, assisted by the giant power of the telescope, collects and
+concentrates these Aether-waves into a perfect image of those things
+that gave them birth, and by this means reveals to us the knowledge of
+things afar, their existence, nature, characteristics, properties, and
+powers.
+</p>
+
+<p>
+Thus it is we see the solar orb, with its huge fires all aglow, obtain a
+knowledge of its character and powers, see its huge spots, its quivering
+fringe of flame, and high-leaping prominences, or watch its slowly
+revolving form.
+</p>
+
+<p>
+Thus we see the planets that around it sweep and roll; swift-footed
+Mercury with his wondrous speed, and dazzling Venus with her silver
+sheen; Mars the god of war with his ruddy glow, and mighty Jupiter with
+his orange hue, and the yellow Saturn with her mysterious rings, the
+blue Uranus, and the more distant Neptune, with all the satellites that
+to it belong.
+</p>
+
+<p>
+Then far far away the brilliant Sirius--the Dog Star, Cygnet, Centauri,
+the Great Bear, and a thousand others.
+</p>
+
+<p>
+The Pleiades and the twenty millions of suns that form our own galaxy
+and the Milky Way, with all their varied colours, tints, and hues of
+white, golden, orange, ruby, red and blue, green and grey, silver,
+purple and yellow, buff and fawn, emerald and green, lilac and coppery.
+Thus we see the distant Orion, so far away that swift-footed Light, with
+its speed of more than eleven million miles per minute, has to travel
+for more than thirty thousand years before it spans the gulf that
+intervenes between it and us, and brings to us the news of its existence
+there.
+</p>
+
+<p>
+Then the spectroscope with its revealing power literally tears asunder
+wave from wave, and reveals the mystic message which each doth bear, of
+the distant things from which they come, of each and every sort and
+kind.
+</p>
+
+<p>
+Thus we know, that in the solar fires there ever burn such things as
+hydrogen, oxygen and nitrogen, and also, in a vaporous state, aluminium,
+sodium, iron, magnesium, cobalt, calcium, chromium, copper, manganese,
+zinc, and others.<span class='pagenum'><a name='Page_80' id='Page_80'></a><a href='#TOC'>[80]</a></span>
+</p>
+
+<p>
+Thus light-waves are speeding everywhere, and from
+all material things. They come from our own sun, and rush in, and flood
+the earth's aerial veil, the atmosphere; and &ldquo;Each little atom of
+matter, like a mirror, reflects and re-reflects them as if in sport,
+buffeting each luminous ray from one to another, increasing and
+amplifying it by an infinity of repercussions&rdquo; (Herschel), and then in
+their entirety and whole, like a huge multi-mirror, so blend and mingle
+them that they come to earth's surface in that soft radiance we call
+Light, and bathe it as in a sea of mellowed glory.
+</p>
+
+<p>
+<a name='ART_50' id='ART_50'></a><span class='smcap'>Art</span>. 50. <i>Aether: its Motions.</i>--The question of the exact motions of
+the Aether is a question which has involved the attention of scientific
+men for many years, and which is at the present time receiving the
+attention of some of our most advanced scientists, not only in this
+country but in other countries also.
+</p>
+
+<p>
+Whether the Aether in space is at rest, or is moving along with all the
+bodies that float in it, so to speak, is a question of the greatest
+importance to scientists and philosophers generally, as the particular
+character of the motions of the Aether, which are either suggested or
+ascribed to it from the analogies of Nature, are sure to have a most
+important bearing not only on the motions of all the planets and
+satellites, but also upon such questions as the aberration of light, and
+such difficulties as presented by Lord Kelvin in his paper on &ldquo;Clouds on
+the Undulatory Theory of Light&rdquo; (<i>Phil. Mag.</i>, July 1902).
+</p>
+
+<p>
+I need hardly point out that the hypothesis that Aether is gravitative,
+is bound to play a most important part in the consideration and
+development of this phase of the study of the universal aetherial
+medium. It is not my intention, however, at this stage of the work to go
+fully into the development of this aspect of the subject.
+</p>
+
+<p>
+The application of this principle will be considered at the right time,
+and in the right place. It is, however, generally assumed, that the
+Aether is at rest in space, and that the earth, the planets, and the sun
+and all stars, move through it with varying velocity, although, as Lord
+Kelvin points out, such an assumption is covered with a cloud which up
+to the present is &ldquo;as dense as ever.&rdquo; Of course, if the Aether be at
+rest, and the planets and other heavenly bodies move through it with
+varying velocity, then the only assumption regarding the Aether is, that
+it is frictionless, but, as I have shown in <a href='#ART_45'>Art. 45</a>, this is opposed to
+all philosophical reasoning, and therefore to experience and
+observation.
+</p>
+
+<p>
+We have, therefore, to postulate for the Aether such motions as shall
+fulfil all the Rules of Philosophy, that is, shall be simple in
+conception, shall be in harmony with our experience and observation,<span class='pagenum'><a name='Page_81' id='Page_81'></a><a href='#TOC'>[81]</a></span>
+and which shall satisfactorily account for the phenomena sought to be
+explained, that is, the universal Law of Gravitation; for it is by the
+properties, combined with the motions of the Aether, that the physical
+cause of Gravitation is alone to be explained.
+</p>
+
+<p>
+Let us revert to the question of a stationary Aether for a moment or
+two, and let us ask ourselves, where is the evidence for such an
+assumption? Has the sun ever ceased to shine, or to send its light-waves
+with their enormous velocity speeding through the solar system? So far
+as experience and observation go, I have never read of any record of
+such a fact, or that light-waves have ceased to proceed from the sun and
+fill the solar system with Aether-waves.
+</p>
+
+<p>
+Not only is this true of the sun, but it is equally true of every planet
+and satellite, every meteor or comet, every star and sun that exist or
+dwell in this aetherial medium; for, as has already been shown (<a href='#ART_49'>Art. 49</a>), every body emits Aether-waves, and these waves spread out in all
+directions in a spherical form.
+</p>
+
+<p>
+The truth is, that the universal Aether is in eternal motion, and that
+motion forms the physical life of the universe. If it were possible to
+destroy the motion, then the whole fabric of the universe would fall to
+pieces, and the beauty, order, and harmony of the celestial mechanism
+would be replaced by disorder, confusion, and ultimate ruin. Take any
+analogy of Nature, and see what such an analogy teaches us. Look at any
+planet, sun, or star. Do we find any one of these stationary or at rest?
+Why from the smallest meteorite or satellite, to the largest star that
+shines in the firmament of heaven, there is nothing but motion; each
+satellite, planet, sun, and star moving on and on, ever and ever through
+the countless ages of time until its course is run and its existence
+ended. But rest, never! Such a thing as rest is unknown in the entire
+universe, whether it be in the atomic systems of matter, or the systems
+of stars and suns that form the universe of worlds.
+</p>
+
+<p>
+Take another illustration--that of the ocean! Is that ever at rest, with
+its unceasing wave and tidal motion? Has the reader ever stood on the
+shore and seen the ocean when it has been absolutely still, or when the
+tide has ceased to flow? Such a possibility is almost absurd to
+contemplate. The same argument applies to the air with its regular flow
+of winds. Now in regard to the aetherial and universal medium, there are
+just as regular motions as the flowing of the tide round the earth, or
+the revolving of a satellite round a planet, or a planet round the sun.
+</p>
+
+<p>
+And what is as important, all the motions can be as satisfactorily
+explained and accounted for from the physical standpoint, as the flow of
+the tide, or the revolution of a planet.<span class='pagenum'><a name='Page_82' id='Page_82'></a><a href='#TOC'>[82]</a></span>
+</p>
+
+<p>
+Year in and year out, the
+motions of the Aether remain the same, governed by the same laws and
+producing the same effects. Age after age, the Aether has been moving,
+producing by its various motions the continuity of that beauty, order,
+and harmony that govern the universe as a whole.
+</p>
+
+<p>
+I have already indicated in <a href='#ART_45'>Art. 45</a> the effect of Gravitation on the
+Aether surrounding each satellite, or planet, or star, or sun. As each
+satellite, or planet, or star moves through the universal Aether, it
+takes with it its surrounding Aether as indicated in <a href='#ART_45'>Art. 45</a>, in the
+same way that each planet or sun takes with it its own associated
+atmosphere, which is held in contact with it by the self-same force of
+Gravitation.
+</p>
+
+<p>
+In addition to this motion of the aetherial atmosphere through space,
+there are other motions of this same gravitating Aether that have to be
+taken into consideration, before a complete and adequate conception of
+all the motions of the Aether can be arrived at.
+</p>
+
+<p>
+I do not intend, however, at this stage to go fully into such motions,
+but rather wish to lead up to them from a consideration of hypotheses
+put forward by such men as Rankine, Challis, Maxwell, Lord Kelvin,
+McCullagh, and Helmholtz, and from a consideration of such hypotheses in
+the realm of heat, light, and electricity to be able to form a
+scientific conception of the proper motions of the Aether, as well as a
+philosophical one.
+</p>
+
+
+<p><span class='pagenum'><a name='Page_83' id='Page_83'></a><a href='#TOC'>[83]</a></span></p>
+<h2><a name='CHAPTER_V' id='CHAPTER_V'></a><a href='#CHAPTER_V_TOC'>CHAPTER V</a></h2>
+
+<h3>ENERGY</h3>
+
+<p>
+<a name='ART_51' id='ART_51'></a><span class='smcap'>Art</span>. 51. <i>Energy.</i>--In the days of Newton, and for a long time afterwards,
+all energy went by the name of &ldquo;Force.&rdquo; Thus Newton in his Laws of
+Motion refers to the action of forces on stationary or moving bodies,
+and shows how the motion of any body is effected by the impressed force.
+(<a href='#ART_13'>Art. 13</a>.)
+</p>
+
+<p>
+As science advanced, and scientific research was carried into the fields
+of heat, light, and electricity, we find that the various forces began
+to be particularized, with the result that such terms as electrical
+force, magnetic force, chemical force, etc., became common and familiar
+terms. As gradually it became known that one particular kind of force
+was the outcome of another kind, there was given to the world such terms
+as the Correlation of Forces (Grove), in which he proved that whenever
+one kind of force appeared as heat or light, it was at the expense of
+another kind of force, as electricity.
+</p>
+
+<p>
+Of later years, however, another term has crept into Philosophy, and
+instead of the term Force, which is very indistinct and indefinite in
+character, there appeared the term Energy, although Force and Energy are
+not exactly synonymous terms. Thus electricity, heat, and light are
+forms of energy, and are convertible into one another, in the same way
+that the forces were convertible. Thus we get transformations of energy
+in the same way that we had transformations of force, and conservation
+of energy in the same way that we had conservation of force.
+</p>
+
+<p>
+Even the term Energy, however, is being replaced in the present times by
+something more definite and simple, and instead of the term Energy, we
+shall find, in the development of this phase of natural phenomena, that
+that term is being replaced by the simple idea of motion, or modes of
+motion, and that all forms of energy, as light, heat, magnetism, and
+electricity, and even Gravitation itself, are due to motion of some kind
+or other. We will, however, lead up to this truth by looking briefly at
+the term Energy, and see what it implies and embodies.
+</p>
+
+<p>
+Energy, therefore, is that property which a body possesses, by which it
+is capable of doing work. Thus our ideas of work give us our conception<span class='pagenum'><a name='Page_84' id='Page_84'></a><a href='#TOC'>[84]</a></span>
+of energy. For example, when a weight is lifted, work is done, and a
+certain amount of energy is expended in the process. Further, the amount
+of work done is proportionate to the weight lifted, and the height to
+which the body is raised. Work is done against resistance, so that
+whenever resistance is overcome, then work is the result. For example,
+suppose one pound is lifted one foot high, in opposition to the force of
+gravity, then work is done, and this amount of work is known as a
+foot-pound.
+</p>
+
+<p>
+If a body weighs ten pounds, and is lifted ten feet, the work done is
+equal to ten pounds multiplied by ten feet (10 × 10 equals 100), so that
+one hundred times the amount of work has been done in comparison with
+the lifting of the one pound one foot high.
+</p>
+
+<p>
+As all weight is essentially a gravitational measure, depending upon the
+intensity of gravity at the place, then, whenever a body is raised or
+lifted, the work so done is done against the gravity of the earth.
+</p>
+
+<p>
+Work is also done, as Newton points out in the first and second laws,
+whenever we apply force to any body, either stationary or already in
+motion. The results of all observation and experiments prove, that
+whenever we have two bodies upon which work is being done, the amount of
+work is determined by the amount of energy transferred from one body to
+the other, and that the actual amount of energy gained by one is equal
+to the amount of energy lost by the other.
+</p>
+
+<p>
+Energy is always found in association with matter, so that matter has
+sometimes been termed the Vehicle of Energy. Wherever, therefore, we
+find energy of any kind or sort, there we find matter also, as the two
+are inseparably connected together. Thus, wherever we have heat, we have
+matter in a particular state of motion, generally understood as
+vibratory motion Wherever we have light, which is also a form of energy,
+we also have matter in motion, that is the Aether, in a state of
+periodic wave-motion; and wherever we have electricity, we have again
+matter possibly in a state of rotatory motion, as we shall see later on.
+Energy, therefore, is the power which a body possesses to do work.
+</p>
+
+<p>
+<a name='ART_52' id='ART_52'></a><span class='smcap'>Art</span>. 52. <i>Conservation of Energy</i>.--The principle of the Conservation of
+Energy was first enunciated by Mayer in 1842. The principle may be
+defined as follows: The total amount of all the energy, as light, heat,
+electricity and magnetism, Gravitation, etc., in Nature is unchangeable;
+so that, according to this law, the universe possesses a store of energy
+which is unchangeable in quantity throughout all time. The energy may
+pass from one form to another, yet the total amount ever remains the
+same. It is almost unnecessary to say, that this is a principle which,<span class='pagenum'><a name='Page_85' id='Page_85'></a><a href='#TOC'>[85]</a></span>
+like the conservation of matter, is incapable of absolute proof, but
+its assumption has greatly helped scientific thought and speculation
+from time to time. Clerk Maxwell says (<i>Theory of Heat</i>) on this point:
+&ldquo;The total energy of any body is a quantity which can neither be
+increased nor decreased by any mutual action of the bodies, though it
+may be transformed into those forms of which energy is susceptible.&rdquo;
+</p>
+
+<p>
+The conservation of energy is inseparably connected with the
+conservation of matter (<a href='#ART_30'>Art. 30</a>). They cannot be divided, because, if
+energy is only to be found in association with matter, then if the law
+of the conservation of matter falls to the ground, the principle of the
+conservation of energy falls with it. Energy, therefore, like matter,
+cannot be destroyed or created by any process known to man. As there is
+no process known, either in the chemical or in the physical world, by
+which new matter may be created by man, so, in relation to energy of any
+kind or sort, there is no process known by which man can create or even
+destroy the smallest form of energy that exists. If energy appears in
+any body or in any particular form, it is solely because of the loss of
+energy in some other body, or in some other form.
+</p>
+
+<p>
+All changes of energy, therefore, are simply changes due to the
+difference in form in which the energy is manifested. At one time it
+will be manifested in the form of light, then of heat, then in
+mechanical motion, and so on. Joule gave us some good illustrations of
+this principle of the conservation of energy. He showed us how
+electricity could be changed into heat, and the heat into work. When
+light, which is a form of energy, is absorbed by any opaque body, it is
+found that the body which has absorbed it has become hotter. The energy
+of light has not been destroyed, but as its energy cannot pass through
+the opaque body, it has been employed in agitating the particles and
+atoms of that body, which becomes hotter in consequence.
+</p>
+
+<p>
+Thus from the principle of the conservation of energy, which is in
+operation not only in our planetary world, but throughout the whole of
+the solar and stellar space, and indeed throughout the whole universe,
+we arrive at the conclusion that the total quantity of energy throughout
+the universe is unchangeable. In the evolution and development of
+worlds, and in the destruction of those worlds after long periods of
+time, throughout all the varied manifestations of heat, light,
+electricity, and magnetism, associated with the development and
+destruction of each globe, the sum-total of the energy of the universe
+remains the same. Meteors may rush into the atmosphere of planets, and
+be dissolved into Aether through the friction, comets may be dissolved
+into their component gases as they near the sun, water may be changed<span class='pagenum'><a name='Page_86' id='Page_86'></a><a href='#TOC'>[86]</a></span>
+into vapour by the heat of the summer sun, vegetation may be produced
+from apparently dead matter, and then that vegetation may itself decay
+and return to the dust by which it had been built up, but throughout all
+these processes of birth and death, of evolution and devolution, the
+sum-total of active living energy which is associated with all the
+phenomena, remains unalterable and unchangeable. Such is the teaching of
+the great principle of the Conservation of Energy as enunciated by Mayer
+and Helmholtz.
+</p>
+
+<p>
+<a name='ART_53' id='ART_53'></a><span class='smcap'>Art</span>. 53. <i>Transformation of Energy.</i>--One of the chief characteristics
+of energy is, that we can transform it, and it is chiefly of use to us
+because of its capability to be transformed, but in all its
+transformations, the total quantity of energy remains the same. The
+transformation of energy renders it necessary to the existence of all
+life, and to all physical change in the universe. Mayer showed us that
+all energy in the solar system primarily derives its existence from the
+sun, and that all plant life and physical life owe their continued
+existence to the energy which is poured out from the sun upon the
+planetary worlds. So that energy is always flowing from the sun into the
+surrounding space in the form of light, heat, and electricity, the
+medium of its passage being the universal Aether.
+</p>
+
+<p>
+This principle of transformation teaches us, that heat may be converted
+into electricity; that light may be converted into heat, or electricity
+may be converted into either heat or light or both. This principle of
+transformation naturally follows from the principle of the conservation
+of energy; because, if energy cannot be destroyed in any way, but is
+made to disappear by any process, it must reappear in some other form,
+and therefore has been transformed from its original state. So that,
+whenever one kind of energy disappears, then it is absolutely necessary,
+according to the principle of conservation of energy, that some other
+kind shall be produced. There cannot be any real loss or destruction.
+</p>
+
+<p>
+That leads us to the next point regarding this principle of
+transformation, which is that all transformations of energy take place
+in fixed proportions. When a certain quantity of coal is burned, a
+certain quantity of heat, or thermal energy as it is sometimes called,
+is produced, and the quantity of heat so produced is definitely
+proportionate to the quantity of coal consumed.
+</p>
+
+<p>
+If a certain quantity of coal were burned in a perfect steam-engine,
+that is one in which there would be no loss of heat, then also a
+definite amount of mechanical work would be done, which would be
+strictly proportionate to the heat generated by the consumption of the
+coal. So that when coal is put into an engine, the potential energy of
+the coal is transformed into kinetic energy of the steam, and that is<span class='pagenum'><a name='Page_87' id='Page_87'></a><a href='#TOC'>[87]</a></span>
+again transformed into actual mechanical energy of the engine itself, by
+which work is done in driving or pushing or pulling the train along, and
+the amount of work done is proportionate to the coal consumed.
+Illustrations of transformation are common, and may be seen by any
+person living in a large town. Thus at any electrical station or
+electric tram terminus, these transformations of various forms of energy
+are very familiar sights. We have first the transformation of the coal
+in the furnace into heat. This heat converts water into steam, whose
+motion is communicated by proper machinery into a dynamo, the product of
+which is electricity. That electricity is then conveyed along wires, and
+work is done by it, by moving trams along the connected tram system, or
+it may be converted into heat in the carbon filament in the car itself,
+which, if heated enough, will then produce the electric light. So that
+starting from the coal, we have several transformations therefrom into
+the forms of heat, light, motion, and finally mechanical energy, which
+results in Work. The question arises as to what is the law of
+equivalence in regard to the transformation of energy. That is, if we
+have a certain amount of energy of a given sort, how much of any other
+sort can be produced by it? The answer is partly to be found in a
+statement made by Joule in 1843, which practically embodies what is
+known as the first law of Thermo-dynamics, and is as follows: &ldquo;When
+equal quantities of mechanical effects are produced by any means
+whatever, from purely thermal sources, or lost in purely thermal
+effects, then equal quantities of heat are put out of existence or are
+generated, and for every unit of heat measured by raising a pound of
+water one degree F. in temperature, you have to expend 772 foot-pounds
+of work.&rdquo; From this law we learn that heat may be used to do work, but
+that a certain amount of heat is always used up in the process. It can
+also be demonstrated that electric currents can do work, but to generate
+the currents a certain amount of work must be done.
+</p>
+
+<p>
+This equivalence and transformation prevail in all forms of energy,
+whether it be mechanical energy, thermal or heat energy, or electrical
+energy.
+</p>
+
+<p>
+<a name='ART_54' id='ART_54'></a><span class='smcap'>Art</span>. 54. <i>Potential Energy.</i>--Energy has been divided into two classes,
+which are termed respectively Potential Energy and Kinetic Energy. We
+will look at the former first.
+</p>
+
+<p>
+<i>Potential Energy</i> may be briefly defined as energy of position.
+</p>
+
+<p>
+Thus if we lift a body from the ground, the energy which has been
+imparted to it is energy of position, or potential energy. A glacier
+high up the mountain possesses potential energy, because of its
+position. By the mere fact that it is situated high up the mountain, it<span class='pagenum'><a name='Page_88' id='Page_88'></a><a href='#TOC'>[88]</a></span>
+has a capacity for doing work by its descent, and if that descent be
+very sudden, the work done will be destructive work, as it may sweep
+away all houses and villages in its sudden descent. Thus, by the mere
+fact of its elevation, it possesses a power of doing work, which it has
+lost when it has descended. Again, work done in winding up the spring of
+a clock is stored up in the form of potential energy, and gradually runs
+out in the form of motion or kinetic energy.
+</p>
+
+<p>
+Potential energy is really the complementary principle of kinetic
+energy. That is to say, the amount of potential energy lost by any body,
+is equal to the amount of kinetic energy gained by the other body, to
+which the energy has been transferred. In the case of a body falling, as
+the potential energy diminishes, the kinetic energy increases, but the
+total amount of the two combined always remains the same. This is well
+illustrated in the case of a swinging pendulum. When a pendulum is at
+the highest point of its swing, its velocity or kinetic energy is zero,
+but at that point its potential energy is greatest. As it descends, the
+potential energy decreases, but the kinetic energy increases. When the
+pendulum is at the lowest point its energy is wholly kinetic, the
+potential energy being zero at that point, while it has sufficient
+kinetic energy to raise it to the highest level again. Throughout the
+cycle of these operations, the sum-total of the two energies always
+remains the same.
+</p>
+
+<p>
+Professor Tait points out, in his <i>Recent Advances in Physical Science</i>,
+that the available sources of all potential energy may be divided into
+four classes--
+</p>
+
+<p style='margin-left: 5em;'>1st. Fuel.</p>
+<p style='margin-left: 5em;'>2nd. Food of Animals.</p>
+<p style='margin-left: 5em;'>3rd. Water-power.</p>
+<p style='margin-left: 5em;'>4th. Tidal Water-power.</p>
+
+<p>
+All these are different forms of potential energy. Under the head of
+fuel he includes not only wood, coal, but also all forms of matter that
+may be used or burnt up by heat, or dissolved by chemical agencies. Thus
+zinc and lead, which are used in batteries, are merely forms of fuel.
+That potential energy resides in such things as wood and coal is a
+matter of common experience. All our coal-fields are stores of energy,
+which received their energy when in plant form, ages ago, from the sun,
+and this energy is now being used to drive our machinery, to warm our
+houses, and to give light to our homes and our cities. It has been
+calculated that a pound of coal would give out 14,000 heat units, which
+is equal to 11,000,000 foot-pounds of work, which is also equal to the
+amount of work a horse can do in five hours. Again, all food, whether it<span class='pagenum'><a name='Page_89' id='Page_89'></a><a href='#TOC'>[89]</a></span>
+be the food of animals, as vegetables and plants, or of man, as bread,
+meat, etc., are all forms of potential energy, or energy which is stored
+up in matter. All forms of food have a certain amount of energy in them,
+which is used up in the body in building up waste tissue and imparting
+energy to the physical frame.
+</p>
+
+<p>
+Again, all forms of water-power, whether it be in the form of the
+flowing river or the tidal motion of the sea, possess a large amount of
+potential energy which may be used up to do mechanical work. They also
+possess kinetic energy, or energy of motion. We find illustrations of
+the possession of potential energy by rivers and tides, in the fact that
+by their fall from a higher to a lower level they may be made to do
+mechanical work, as in the case of the turning of the water-wheel by the
+fall of the water, which motion is communicated to machinery, and
+various forms of work are the result. In Switzerland and America
+advantage is being taken of the energy of falling water to generate
+electricity, by means of which villages and towns are being supplied
+with electric light at a very small cost.
+</p>
+
+<p>
+<a name='ART_55' id='ART_55'></a><span class='smcap'>Art</span>. 55. <i>Kinetic Energy.</i>--Kinetic energy may be defined as energy of
+motion, and is the energy which a body possesses in consequence of its
+motion. A body in motion thus possesses kinetic energy, which it must
+impart to some other body before it can be brought to a state of rest.
+The body may be simply an atom, as a vortex atom, but if it be in
+motion, as all atoms are, then it must possess kinetic energy, which may
+be transferred to another atom by collision, or by some other method. As
+has already been pointed out in previous articles, kinetic and potential
+energy are complementary to one another, the sum-total of the two
+combined always remaining the same in any cycle of work, according to
+the principle of the conservation of energy. We get a good example of
+this oscillation from kinetic to potential, and <i>vice versâ</i>, in the
+planetary system. When the earth is farthest from the sun, its velocity,
+and consequently its kinetic energy, is at its lowest point; but there
+the potential energy is at its greatest. As the earth turns round in its
+orbit, however, and begins to approach the sun again, its potential
+energy decreases, while its kinetic energy increases with its increased
+velocity. So that by the time it has reached the nearest part of its
+orbit to the sun, its velocity, and consequently its kinetic energy, is
+at a maximum, while the potential energy is at a minimum. Then as the
+earth passes round its perihelion, the kinetic energy is used up in
+assisting the earth to overcome the attraction of the sun. Thus there is
+this oscillation from kinetic to potential, and from potential to
+kinetic, year in and year out, as the earth performs its cycle round its
+central body the sun.<span class='pagenum'><a name='Page_90' id='Page_90'></a><a href='#TOC'>[90]</a></span>
+</p>
+
+<p>
+Professor Tait, in the work referred to in the previous Article, gives
+examples of kinetic forms of energy under the following heads--
+</p>
+
+<p style='margin-left: 5em;'>1st. Winds.</p>
+<p style='margin-left: 5em;'>2nd. Currents of Water.</p>
+<p style='margin-left: 5em;'>3rd. Hot Springs and Volcanoes.</p>
+
+<p>
+It can be readily seen that winds are a form of energy, as we have
+innumerable instances of the power and energy which they exert.
+Advantage is taken of that kinetic energy by means of windmills, in
+which the energy of the wind is imparted to the revolving sails, and
+thence to the machinery, various forms of mechanical work being the
+result, as, for example, the grinding of corn, or the pumping of water.
+The pressure or energy of winds has even been calculated, the following
+figures being examples--
+</p>
+
+<table summary='velocities'>
+<tr><th><span class='smcap'>velocity in miles per hour.</span></th><th><span class='smcap'>force in lbs. per sq. foot</span></th></tr>
+
+<tr><td>
+
+<table summary='subtable1'>
+<tr><td style='text-align: right;'>1</td><td style='text-align: center;'>mile.</td></tr>
+<tr><td style='text-align: right;'>5</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: right;'>10</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: right;'>15</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: right;'>20</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: right;'>30</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: right;'>40</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: right;'>50</td><td style='text-align: center;'>"</td></tr>
+</table>
+
+</td><td>
+
+<table summary='subtable2'>
+<tr><td style='text-align: center;'>.005</td><td style='text-align: center;'>lb.</td><td style='text-align: center;'>per</td><td style='text-align: center;'>sq.</td><td style='text-align: center;'>foot.</td></tr>
+<tr><td style='text-align: center;'>.123</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: center;'>.496</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: center;'>1.11</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: center;'>1.98</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: center;'>4.5</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: center;'>7.9</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+<tr><td style='text-align: center;'>12.5</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td></tr>
+</table>
+
+</td></tr>
+</table>
+
+<p>
+In the case of currents of water, whether they are in the form of river
+currents or ocean currents, as has already been pointed out in the
+previous article, the question of potential energy, or energy of
+position, is associated with their kinetic energy. Water is taken at a
+certain elevation, and then allowed to fall to a lower level, and in its
+fall from the high level to the lower level, its kinetic energy is used
+to drive mill-wheels, and thus work is done, the kinetic energy of the
+water being transformed into the motion of the machinery. This machinery
+may be used to work a dynamo, and thus electric light may be generated,
+or it may drive an electric motor which may perform all sorts of
+mechanical work. The great underlying principle of either kinetic or
+potential energy rests in the fact, that wherever we have energy of any
+kind or sort, whether it be associated with water, wind, or Aether,
+there we have the capacity to do work, the amount of work depending upon
+the amount of energy that exists in the matter which is the vehicle of
+energy.
+</p>
+
+<p>
+In <a href='#ART_50'>Art. 50</a> it has been indicated that the Aether possesses several kinds
+of motions. From the sphere of light and heat, we learn that the Aether
+possesses certain motions which are always exerted in a direction from
+the central body, which gives rise to the light- and heat-waves. That<span class='pagenum'><a name='Page_91' id='Page_91'></a><a href='#TOC'>[91]</a></span>
+being so, it conclusively follows that the Aether possesses kinetic
+energy, and therefore, possessing this energy, it also possesses the
+power to do work. It must be remembered we are no longer dealing with a
+frictionless medium, but with a gravitating medium, possessing mass and
+inertia, and, that being so, wherever we have the Aether in motion,
+there we have kinetic energy or the power to do work; and that work will
+correspond to the particular kind of motion which is exerted on any body
+by the aetherial motions, and will be equally subject to Newton's Laws
+of Motion.
+</p>
+
+<p>
+<a name='ART_56' id='ART_56'></a><span class='smcap'>Art</span>. 56. <i>Energy and Motion.</i>--An advance, however, as to the meaning of
+the term Energy has been made within recent years, which brings it more
+into harmony with that simplicity of conception, and accordance with
+experience which are the very foundation of all philosophy. Instead of
+the term Energy, there is now being used another term to denote the
+forces which form the life of the universe, and that term is the word
+&ldquo;Motion.&rdquo;
+</p>
+
+<p>
+Professor Poynting says: &ldquo;All energy is energy of motion&rdquo; (<i>British
+Association Report</i>, 1899).
+</p>
+
+<p>
+Thus motion is the fundamental principle of all phenomena. If we analyze
+all forms of energy with which we are familiar, we shall soon find that
+they are only changes of one form of motion into another. Thus we shall
+see that heat is a mode of motion, as has been proved by Tyndall, that
+light is another mode of motion, and that electricity is also a mode of
+motion. I need hardly point out that this advance in our conception of
+energy is strictly in accord with the Rules of Philosophy. First, it is
+simple in conception. When we say that a body possesses energy, whether
+that energy be potential energy or kinetic energy, it does not convey to
+the mind some definite concrete fact, as does the statement that a body
+possesses motion. Every one, whether familiar with scientific teaching
+or not, understands and is familiar with the word Motion, as it is a
+common phenomenon of everyday life and experience. As Energy was simpler
+in conception than Newton's term Force, so Motion is simpler in
+conception than the rather vague and indefinite term Energy; therefore
+when we say that all energy is energy of motion of some kind or sort, we
+state that which is philosophically correct.
+</p>
+
+<p>
+It is also in accord with the second Rule of Philosophy, in that it is
+strictly in harmony with experience and observation. Look where we will,
+or at what we will, there we find motion of some kind or other, whether
+it be among the innumerable stars, or in our own solar system, or any
+phenomena on the earth, or even among the world of atoms in their minute
+and atomic systems. Such a thing as absolute rest, or stagnation, is<span class='pagenum'><a name='Page_92' id='Page_92'></a><a href='#TOC'>[92]</a></span>
+unknown in the universe. Wherever there is matter, there we find motion
+of some kind or other. It may be vibratory motion as heat, or wave
+motion as light, or rotatory motion as electricity, but motion of some
+sort is inseparably connected with all matter. So that when we say that
+all energy of the universe is the energy of motion, and motion only, we
+state that which according to the second Rule of Philosophy is
+absolutely correct.
+</p>
+
+<p>
+Further, I wish to premise that by the use of the term modes of motion,
+in lieu of energy, the third Rule of Philosophy will be fulfilled. For
+if all phenomena of the universe, whether it be heat, light,
+electricity, be due to different modes of motion, then Gravitation
+should be explained from the physical standpoint by some kind of
+aetherial motion also. This I can safely premise will be done, and in
+the later chapters of this work, Gravitation will be shown to be due to
+the motions of the aetherial medium which floods all space. By so doing,
+all the Rules of Philosophy will be fully satisfied, and Gravitation
+will then be brought into line with all the other forms of motion, as
+heat, light, electricity, and magnetism, which are in themselves modes
+of motion, as will be shown in subsequent articles.
+</p>
+
+<p>
+<a name='ART_57' id='ART_57'></a><span class='smcap'>Art</span>. 57. <i>Conservation of Motion.</i>--If it be true that all energy is the
+energy of motion, then the principle of the conservation of energy ought
+also to apply to all the modes of motion, and in its place we should
+then have the principle of the conservation of the various forms of
+motion. This defined would be, that the total amount of all motion in
+the universe, as heat and light, electricity, magnetism, and Gravitation
+also, if that be due to the motion of the Aether, is unalterable and
+unchangeable.
+</p>
+
+<p>
+There may be changes from one form of motion to another, from heat to
+light, and light back to heat; heat into electricity, and electricity
+into light or heat; from Gravitation into heat or into light, or even
+into electricity; but the sum-total of the whole remains the same.
+</p>
+
+<p>
+Again, as the principle of the conservation of energy is inseparably
+connected with the conservation of matter, so the principle of the
+conservation of all the modes of motion is also inseparably connected
+with the conservation of matter. They cannot be divided, so that
+wherever we get matter of any kind or sort, there we get motion of some
+kind, either in the form of heat, light, or electricity, or those
+aetherial motions which produce those phenomena associated with
+Gravitation.
+</p>
+
+<p>
+As matter cannot be destroyed by any known process to man, so motion
+cannot be destroyed either. On the vortex atom theory of matter, this
+principle of the conservation of any mode of motion is perfectly
+intelligible, especially if added to that theory we have Dr. Larmor's<span class='pagenum'><a name='Page_93' id='Page_93'></a><a href='#TOC'>[93]</a></span>
+electron theory as the basis of the vortex atom. An atom in its ultimate
+state is nothing more or less than Aether in rotation, and as Aether is
+matter, we see that on the assumption of this atomic basis, we have even
+in the atomic world an illustration of this conservation of matter and
+motion, as in such an atom we have nothing but matter (<i>i. e.</i> Aether)
+and motion. Carrying the idea upwards in the atomic scale, if atoms of
+hydrogen or oxygen are multiples of these vortex atoms, then again we
+have nothing in all the elements, or combination of the elements, but
+matter and motion. Again, as all planets and satellites, suns and stars,
+are but agglomerations of elements, we have still the same two classes
+of things, matter and motion, and so from the most infinitesimal atom in
+existence, up to the most ponderous star that exists in the universe, we
+have running through them all the principle of the conservation of
+motion, which is to matter the source of all its activities, energies,
+and powers. Motion, therefore, might almost be said to be eternal. We
+have heard from time to time of the term perpetual motion. Philosophers
+have from time to time endeavoured to discover some application of this
+perpetual motion, but all efforts in this direction up to the present
+have proved futile. In one sense there is no such thing as perpetual
+motion. In another sense, that is from the standpoint of the
+conservation of all modes of motion, as motion cannot be destroyed, it
+must therefore be perpetual.
+</p>
+
+<p>
+It is an absolute impossibility to obtain motion except from some
+antecedent energy, which is itself a form of motion. It would require
+the distinctive fiat of an Almighty Creator to produce motion from
+nothing, and I question whether such a result is obtainable, as I hold
+that if the Creator, at any time in the history of the universe, set any
+substance in motion, the source from which that motion was derived, was
+His own Divine Energy, and in that sense the physical motion was not
+produced from nothing. Such an assumption is altogether opposed to all
+philosophical reasoning and experience. I hope to deal with the question
+either in the last chapter of this book, or in another work.
+</p>
+
+<p>
+<a name='ART_58' id='ART_58'></a><span class='smcap'>Art</span>. 58. <i>Transformation of Motion.</i>--Again, if energy be the energy of
+motion, and the principle of the transformations of energy holds good,
+then it is equally true that all modes of motion are also transformable.
+Thus heat is a mode of motion, being due to the vibration of the atoms
+which go to make up any body. Light is also a mode of motion, being due,
+as far as solar light is concerned, to the periodic wave motion of the
+Aether. While electricity, as we shall see later on, is also due to some
+form of rotatory motion. It has already been shown (<a href='#ART_54'>Art. 54</a>) that light<span class='pagenum'><a name='Page_94' id='Page_94'></a><a href='#TOC'>[94]</a></span>
+can be converted into heat, so that the periodic wave motion of light
+can be transformed into the vibratory motion of heat.
+</p>
+
+<p>
+Heat can also be converted into electricity, and if electricity be
+rotatory motion, then the vibratory motion of heat can be transformed
+into the rotatory motion of electricity. Again, as electricity can be
+converted into light, the rotatory motion of electricity can thus be
+transformed into the periodic wave motion of light. Thus through all the
+forms of motion with which we are familiar, we find this principle of
+transformation holds good, so that each form of motion may be directly
+or indirectly transformed into any one of the other kinds. Whenever,
+therefore, one kind of motion disappears, it is absolutely necessary,
+according to the principle of the conservation of motion, that some
+other kind shall be produced. There cannot be any real loss or
+destruction of the motion. It may be transformed, but not lost. By the
+use of proper apparatus, therefore, any form of motion with which we are
+familiar may be converted into another form, and in the process not the
+least quantity of any form of motion is lost. Heat may be changed into
+light, and light into heat; electricity into light, and light into
+electricity; heat into electricity, and electricity into heat. Indeed,
+starting from any one form, any of the other modes of motion may be
+produced, either directly or indirectly, and mechanical effects or work
+may be produced by each and all. Then, again, the order can be reversed,
+as by doing work which is simply applied motion, any of the other modes
+of motion can be produced. Thus heat can be produced by friction, and if
+the friction which is the outcome of muscular energy be continued long
+enough, a light will be the result, in the form of fire. When certain
+forms of work are done, as the turning of the handle of an electrical
+machine, frictional electricity will be produced. So that not only are
+all the modes of motion convertible into work, but work itself can be
+transformed into the modes of motion known as heat, light, electricity,
+and magnetism.
+</p>
+
+<p>
+Now, if Gravitation be due to motion of the Aether, and if it is true
+that all modes of motion are convertible, then the application of this
+principle should also hold good in relation to Gravitation. It has been
+demonstrated by Joule and others that Gravitation can be converted into
+heat, light, and electricity. It can be converted first into heat. Joule
+made a number of experiments to ascertain what quantity of heat is
+produced by falling bodies, that is bodies under the influence of
+Gravitation. From experiments he has calculated that if one lb. of water
+falls through a space of 772 feet, it would raise the temperature of<span class='pagenum'><a name='Page_95' id='Page_95'></a><a href='#TOC'>[95]</a></span>
+the water one degree Fahrenheit--that is, the water after its fall will
+be one degree hotter than when it started to fall. Here, then, we have
+the exact equivalence of a certain amount of gravitational motion
+expressed in terms of heat. So that, whenever motion of a falling body
+produced by gravity is arrested, heat is generated, and as heat is a
+mode of motion, it follows that the motion of Gravitation has been
+converted into the motion of heat. Again, the motion of gravity may be
+converted into that of light. This may be demonstrated as follows: Lord
+Kelvin has suggested that the light and heat of the sun are maintained
+by the falling into the sun of meteorites. Now the cause of the falling
+of these meteorites into the sun is the Attraction of Gravitation, and
+therefore if the falling of these meteorites produces light and heat, it
+necessarily follows that the motion of Gravitation, whatever that may be
+due to, is converted into the motion known as light and heat. Thus it
+can be seen that Gravitation, looked at from the standpoint of a mode of
+motion, is itself conformable to the principle of the transformation of
+motion, and this is an indirect argument in favour of the fact that
+Gravitation is itself due to certain motions of the universal Aether.
+</p>
+
+<p>
+<a name='ART_59' id='ART_59'></a><span class='smcap'>Art</span>. 59. <i>Motion and Work.</i>--In <a href='#ART_52'>Art. 52</a> we have seen that energy is the
+power which a body possesses to do work, the amount of work which a body
+can perform being regulated by the amount of energy which such a body
+possesses. In <a href='#ART_57'>Art. 57</a> we have further seen that all energy is the energy
+of motion, and that wherever we have energy of any kind or sort, whether
+it be in the form of light, heat, or electricity, there we have motion
+of some kind or other. That being so, we arrive at the conclusion, that
+wherever in the universe we have motion of any kind or sort, whether it
+be the motion of Aether, or wind, or water, there we have the power of
+doing work, and the work so done will be proportionate to the motion
+which the medium possesses. The amount of work that air in motion can do
+has been measured, as we have already seen (<a href='#ART_55'>Art. 55</a>) that air which
+moves at the rate of 30 miles per hour exerts a force of 4-1/2 lb. per
+square foot.
+</p>
+
+<p>
+The amount of work that water in motion can do has also been measured.
+The carrying and erosive powers of a river depend on the rapidity of its
+currents. It has been calculated that a velocity of three inches per
+second will transport fine clay; eight inches per second coarse sand;
+while three feet per second will transport stones as large as eggs.
+</p>
+
+<p>
+If, therefore, air moving at the rate of 30 miles an hour can exert a
+force of 4-1/2 lb. per square foot, what must be the force or pressure
+of aetherial motion, as light-waves for example, which move with a<span class='pagenum'><a name='Page_96' id='Page_96'></a><a href='#TOC'>[96]</a></span>
+velocity of 186,000 miles per second? The amount of work which such an
+aetherial motion can perform has actually been measured by Professor
+Lebedew of Moscow, and will be dealt with in the chapter on &ldquo;Light, a
+Mode of Motion,&rdquo; when the application of the work done on a body, as a
+planet for example, will also be considered. Work, therefore, can always
+be done by motion against resistance. This is a fundamental principle in
+the sphere of dynamics, which is incontrovertible, as all experience,
+observation, and experiment teach us, that wherever we get motion of any
+kind or sort, there we have the capacity or power to do work. The work
+done may be either in the form of pushing a body along, or pulling a
+body towards a centre. All experience and observation teach us that no
+body moves (whether it be an atom, or moon, or planet, or sun, or star),
+unless some other body or medium, which is in direct contact with the
+moving body, exercises some pressure or pull upon the moving body. The
+action is purely and simply a mechanical one. So that if this be true,
+then the earth and the planets, the sun and stars, comets and meteors,
+are moved through space solely because they are being pushed by some
+medium, or pulled to the centre by the motions of the same medium. If
+this can be proved to be true, then, as can be readily seen, our
+philosophy will then be made to agree with our experience, and the
+second Rule of Philosophy fully satisfied. As has already been pointed
+out, there is no such thing as action at a distance, therefore the Law
+of Gravitation demands a medium for its operation, production, and
+continuity. Newton distinctly points this out in his Letters to Bentley,
+where he says: &ldquo;That one body should act upon another through empty
+space without the mediation of anything else, by and through which their
+action and pressure may be conveyed from one to another, is to me so
+great an absurdity that I believe no man who has in philosophical
+matters a faculty for thinking can ever fall into it.&rdquo; It has already
+been pointed out (<a href='#ART_42'>Art. 42</a>), that the only medium which is universal is
+the Aether medium, and we have therefore to look to the motions and
+properties of that medium for the solution of the problem as to the
+physical cause of Gravitation. That such a medium has motions which are
+as regular as the tides of the sea, or the trade winds of the
+atmosphere, will be proved later on, when it will be found that
+Gravitation, with all that that law implies, is due, as Newton and
+Challis suggested, to the pressure, properties, and motions of the
+aetherial medium, which is as universal as Gravitation itself. This
+being so, it is essential that we should set ourselves to find out from
+the analogies of Nature, what are those properties and motions of the
+Aether which give rise to the universal Law of Gravitation. This I<span class='pagenum'><a name='Page_97' id='Page_97'></a><a href='#TOC'>[97]</a></span>
+propose doing by a consideration of three different modes of
+motion--viz. Heat, a mode of motion; Light, a mode of motion; and
+Electricity, a mode of motion. I venture to premise, from a careful
+consideration of these three truths, that we shall be able logically and
+philosophically to arrive at the simple, yet grand truth which reveals
+the physical source of all motion of the universe.
+</p>
+
+<p><span class='pagenum'><a name='Page_98' id='Page_98'></a><a href='#TOC'>[98]</a></span></p>
+<h2><a name='CHAPTER_VI' id='CHAPTER_VI'></a><a href='#CHAPTER_VI_TOC'>CHAPTER VI</a></h2>
+
+<h3>HEAT IS MOTION</h3>
+
+<p>
+<a name='ART_60' id='ART_60'></a><span class='smcap'>Art</span>. 60. <i>Heat is Motion</i>.--On the phenomena of Heat, Newton in his
+eighteenth query in <i>Optics</i> asks the questions: &ldquo;Is not the heat of a
+warm room conveyed through the vacuum by the vibrations of a much
+subtler medium than air, and is not the medium the same as that medium
+by which light is reflected and refracted, or by whose vibrations light
+communicates heat to bodies? And do not the vibrations of this medium in
+hot bodies, contribute to the intenseness and duration of their heat?
+And do not hot bodies communicate their heat to contiguous cold ones by
+the vibrations of this medium propagated from them into the cold ones?
+And is not this medium exceedingly more rare and subtle than air, and
+exceedingly more elastic and active?&rdquo; Thus it can be seen that Newton
+was of the opinion that heat consists in a minute vibratory motion of
+the particles of bodies, and that such motion was communicated through
+what he calls a vacuum by the vibrations of an elastic medium, the
+Aether, which was also concerned in the phenomena of light.
+</p>
+
+<p>
+One of the first experimental investigations into the real nature of
+Heat was made in 1798 by Count Rumford.
+</p>
+
+<p>
+While he was engaged in boring brass cannon in the arsenal at Munich, he
+was struck with the degree of heat which the brass gun acquired, and
+with the still more intense heat which the metallic chips, which were
+thrown off, possessed. Of the phenomena he says: &ldquo;The more I meditated
+on these phenomena, the more they appeared to me to be curious and
+interesting. A thorough investigation seemed even to bid fair to give us
+a farther insight into the hidden nature of Heat.&rdquo; Rumford therefore set
+himself to find out by actual experiments what the nature of Heat was.
+For this purpose he constructed a cylinder, and mounted it so that it
+could be made to rotate by horse-power. At the beginning of the
+experiment the thermometer stood at 60° Fahrenheit, and after
+half-an-hour, when the cylinder had made 900 revolutions, the
+temperature was found to be 130° Fahrenheit, so that there had been an
+increase in the temperature of the cylinder of 70° Fahrenheit. The
+experiment was again repeated in another form with similar results.<span class='pagenum'><a name='Page_99' id='Page_99'></a><a href='#TOC'>[99]</a></span>
+Rumford in dealing with the results of his experiments said: &ldquo;It appears
+to me to be extremely difficult, if not quite impossible, to form any
+distinct idea of anything capable of being excited and communicated, in
+the manner the Heat was excited and communicated, in these experiments,
+except it be Motion.&rdquo;
+</p>
+
+<p>
+Only a year later, Davy gave to the world some results of experiments
+which he had performed, by which he had arrived at a similar conclusion
+to that of Rumford, viz. that &ldquo;Heat is motion of some kind.&rdquo; His
+experiment consisted of rubbing two pieces of ice together, and by so
+doing showed the ice could be melted. He then caused two pieces of metal
+to be rubbed together, keeping them surrounded by ice, and still he
+found that the two pieces of metal when rubbed together, produced heat,
+and melted the ice. He therefore rightly concluded that heat was
+produced by friction, and of the experiment adds: &ldquo;A motion or vibration
+of the corpuscles of bodies must necessarily be generated by friction.
+Therefore we may reasonably conclude that this motion or vibration is
+Heat. Heat then may be defined as a peculiar motion, probably a
+vibration of the corpuscles of bodies tending to separate them. It may
+with propriety be called a repulsive motion. Now bodies exist in
+different states, and those states depend upon the action of the
+attractive and of the repulsive powers on their corpuscles, or in other
+words, on their different quantities of repulsion and attraction.&rdquo; It
+was not, however, till 1812 that Davy confidently stated that &ldquo;The
+immediate cause of the phenomena of Heat is motion, and the laws of its
+communication are precisely the same as the laws of the communication of
+motion.&rdquo;
+</p>
+
+<p>
+The question therefore confronts us, if heat be motion, what is the
+particular character of that motion? Is it a vibratory motion as Davy
+suggested, or is it similar to the undulatory wave motion of light? I
+need hardly point out, that we have evidence in favour of the hypothesis
+that light is due to some form of periodic wave motion in the Aether,
+the hypothesis being that known as the undulatory theory. We have also
+similar evidence in favour of the hypothesis, that heat is also due to
+some form of motion of the same aetherial medium. Indeed, it can be
+shown that heat possesses all the properties of light, and is subject to
+the same laws, with the exception that it cannot affect the sense of
+sight.
+</p>
+
+<p>
+Heat, then, is due to some motion in the universal aetherial medium,
+that not only fills all space, but also forms an atmosphere around every
+atom or particle of matter that exists in the universe, and that motion
+is generally known as a vibratory or backward and forward motion.
+</p>
+
+<p>
+Heat, then, may be said to be due to the vibrations of the Aether that<span class='pagenum'><a name='Page_100' id='Page_100'></a><a href='#TOC'>[100]</a></span>
+surrounds all atoms and molecules, and of which those very atoms are
+composed, that is if we accept the aetherial constitution of all matter.
+So that, whenever a body, whether it be an atom or a molecule, or a
+planet or sun or star, is heated in any way whatever, such bodies excite
+waves in the surrounding Aether, and these waves travel through the
+Aether towards us from the heated body with the velocity of light. When
+these waves fall upon any other body, they become more or less absorbed
+by the body on which they fall, and cause corresponding vibratory
+motions in the same, which give rise to the phenomenon of heat in that
+particular body.
+</p>
+
+<p>
+It has to be remembered that nothing definite is actually known as to
+the character of this vibratory motion. It is called a vibratory motion
+because it possesses a periodic vibratory movement, but as to its exact
+character, that has not yet been discovered. I hope, however, to
+indicate what the motion is that produces heat before the completion of
+this work.
+</p>
+
+<p>
+<a name='ART_61' id='ART_61'></a><span class='smcap'>Art</span>. 61. <i>Heat and Matter</i>.--If it be true that heat is due to the
+vibrations of the aetherial medium, the question now arises, as to how a
+body may become heated, and by so doing be transformed into the three
+stages in which matter is found. We have already seen (<a href='#ART_36'>Art. 36</a>), that
+matter may be found in three forms, viz. solid, liquid, and gaseous, and
+that all these different forms of matter are composed of minute parts
+called atoms. In the case of the solid, the atoms are held closely
+together by some strong attractive power, termed cohesion; in the case
+of the liquid, the atoms have a greater freedom; while in the gaseous
+form they have a greater freedom of movement than when in either the
+liquid or the solid state. According to Young's Fourth Hypothesis (<a href='#ART_45'>Art. 45</a>), we find that all matter, and therefore all atoms have an attraction
+for the Aether, by means of which it is accumulated within their
+substance, and for a small distance around them in a state of greater
+density, and therefore of greater elasticity. In other words, as Aether
+is gravitative, every atom possesses an atmosphere of Aether in the same
+way that the earth has its atmosphere of air; and further, the aetherial
+atmosphere of each atom is densest nearest to the atom, gradually
+getting rarer and rarer the further the atmosphere recedes from the
+nucleus or centre, the elasticity or pressure being always proportionate
+to the density. Professor Challis, in his Dynamical Theory of Light and
+Heat, states that all the forces in Nature are different modes of
+pressure under different circumstances of the universal Aether, and as
+heat is a Force, and therefore a mode of motion, that also must be due
+to some form of pressure due to the vibrations of the Aether.<span class='pagenum'><a name='Page_101' id='Page_101'></a><a href='#TOC'>[101]</a></span>
+</p>
+
+<p>
+Professor
+Challis<a name='FNanchor_8' id='FNanchor_8'></a><a href='#Footnote_8' class='fnanchor'>[8]</a>
+ on this point says: &ldquo;According to this theory, the atoms of
+any substance are kept in position of equilibrium by attractions and
+repulsions resulting from the dynamical action of the vibrations of the
+Aether which have their origin at the atoms. Each atom is the centre of
+vibration propagated equally from it in all directions, and that part of
+the velocity of the vibration which is accompanied by change of density
+(of the Aether) gives rise to a repulsive action on the surrounding
+atoms. This action is the repulsion of heat, which keeps the individual
+atoms asunder.&rdquo;
+</p>
+
+<p>
+With all these facts before us, we are now in a position to account for
+the changes of matter which take place when heat is applied to either
+a solid or a liquid body. We have already seen (<a href='#ART_36'>Art. 36</a>) that it is by
+the application of heat that matter in its solid form is changed into a
+liquid, and from a liquid into a vaporous or gaseous form. It is now for
+us to endeavour to form a mental picture as to how this is done.
+</p>
+
+<p>
+For example, let us take an iron ball, and apply heat to it, either by
+putting it in a furnace or suspending it in some way over an intense
+heat. As the heat, which is vibratory motion of the Aether, begins to be
+absorbed by the iron ball, it sets the atoms which compose the ball in
+motion, urging them to separate, and thus cause the iron ball to expand
+and increase in volume. As greater heat is absorbed, so greater motion
+among the atoms is the result. So that the motion of heat is tending all
+the time to expand the body, while they are held together by the
+attraction of cohesion, whatever that may be. As the heat is further
+increased, the iron ball begins to assume a liquid or molten form, its
+atoms beginning to move about with greater freedom, though held together
+by a decreased attractive power. In this condition we now say that it is
+in the molten state. Now during all this time, what has the Aether been
+doing, or what part has it played in the expansion and changing of the
+solid to a liquid? We have to remember, from <a href='#ART_60'>Art. 60</a>, that wherever
+there is motion of any kind or sort, there we have a capacity to do
+work, and that the aetherial motion which we term heat is no exception
+to this rule. We are now no longer dealing with a frictionless medium,
+but with a medium which possesses weight, because it is gravitative, and
+consequently possesses inertia also. So that whenever the Aether is set
+in motion by flame or heat, its motion would be transmitted by waves of
+some kind to the iron ball. These periodic waves, acting upon the mass
+of the ball, attack the molecules of the ball and begin to set them in
+motion. It is supposed that they are already in motion, as nothing is<span class='pagenum'><a name='Page_102' id='Page_102'></a><a href='#TOC'>[102]</a></span>
+absolutely cold, and the motion of the aetherial
+waves imparts a greater motion still to the molecules, with the result
+that the agitation becomes greater and greater, until at length the
+agitation becomes so great, that the molecules break away from the power
+of attraction that holds them together, and so begin to move about with
+greater freedom and with greater rapidity. It is this state which we
+call molten. Now if Aether be frictionless, as has hitherto been
+supposed, and if heat be due to the vibratory motions of Aether, the
+problem confronts us, as to how the motion of a frictionless medium can
+do work in expanding a body, and urging the molecules of a body further
+and further apart. If the Aether be frictionless, then the waves of
+Aether known as aetherial heat waves ought to pass between the atoms as
+water passes through a sieve, or wind passes through a forest. Yet it is
+assumed that the vibratory motions of a hot body are caused by
+vibrations of the periodic waves of the Aether, which act upon the
+molecules of the body; and, in order for such an assumption to be
+consistent with the results, the only possible conception that can be
+accepted of the Aether, is that it is gravitative, and consequently
+possesses mass and inertia, and therefore has a capacity not only to
+accept motion, but also to transmit motion to another body, and impart
+the motion which it has accepted to a colder body.
+</p>
+
+<p>
+By imparting such motion, it increases the motion of the cold body, and
+gradually changes its state from a solid to a liquid condition. Here,
+then, from the realm of heat we have another argument in favour of the
+fact that Aether is gravitative, and therefore possesses mass and
+inertia.
+</p>
+
+<p>
+In the experiment of reducing the iron ball from a liquid state, so to
+speak, to a vaporous condition, we have practically a continuation of
+the same process, only that greater heat or greater aetherial motion is
+required, and whereas in the previous experiment the molecules of the
+ball were acted upon, in this case the atoms are more directly acted
+upon by the Aether waves. In all these processes it suggests itself to
+me that the aetherial atmosphere must take its share in the expansion
+and transformation of the liquid form into a gaseous form, or the solid
+into a liquid form. Taking the analogy of our atmosphere in its relation
+to the earth, we know that when heat is absorbed by it, it expands, the
+result being that a greater pressure is exerted by the expanding
+atmosphere, than would be exerted if it remained at the same temperature
+all the time. If, therefore, each atom has an aetherial atmosphere,
+which is capable of expansion, then the effect of the absorbed aetherial
+motion of the heat waves on each atomic atmosphere must be to expand it,
+and thus there will be a pressure <i>away from</i> the atom, because of the
+increased elasticity acquired by the heated aetherial atmosphere. So<span class='pagenum'><a name='Page_103' id='Page_103'></a><a href='#TOC'>[103]</a></span>
+that the expansion of the liquid is due to the increased elasticity of
+the aetherial atomic atmosphere, which has been expanded by heat, and
+which exerts an increased pressure on neighbouring atoms, thus seeking
+to push them farther away from each other. There are other motions of
+the atoms themselves in addition to this to be considered, but I am now
+seeking to show only the effect of the aetherial atmosphere of each atom
+upon the neighbouring atoms. This would give each atom a larger sphere
+of freedom in which to move, and that state would then be called a
+gaseous and not a liquid one. This assumption of the part which the
+aetherial atmosphere plays in the expansion of a body is therefore in
+agreement with Professor Challis' theory of heat already referred to, in
+which he states that heat gives rise to aetherial vibrations which act
+repulsively on the neighbouring atoms. In further confirmation of the
+existence of these aetherial atmospheres that exist around atoms, I
+would like to draw the attention of the reader to a theory of heat given
+to the world by Rankine, <i>Phil. Mag</i>., 1851. His theory is known as the
+&ldquo;Hypothesis of Molecular Vortices.&rdquo;
+</p>
+
+<p>
+He assumed that &ldquo;each atom of matter consists of a nucleus or central
+point, enveloped by an elastic atmosphere, which is retained in its
+position by attractive forces, and that the elasticity due to heat
+arises from the centrifugal force of those atmospheres revolving or
+oscillating about their nuclei or centres.&rdquo;
+</p>
+
+<p>
+Now in this assumption we find that he admits that each atom has an
+atmosphere, such atmosphere evidently being an aetherial one, and in
+that case the hypothesis would agree with the statement in <a href='#ART_46'>Art. 46</a>, that
+every atom possesses an aetherial atmosphere. He further points out that
+the atmosphere is retained in its position by attractive forces. This is
+also in harmony with the hypothesis given in <a href='#ART_45'>Art. 45</a>, which proves that
+Aether is gravitative, and therefore the atmosphere of the atom would be
+held in its position by the attractive force of Gravitation, as
+suggested by Young in his Fourth Hypothesis.
+</p>
+
+<p>
+Further, he goes on to show that the elasticity of the atomic atmosphere
+is proportionate to its density, which is also in conformity with the
+statement made in <a href='#ART_47'>Art. 47</a>, and is also in accordance with Boyle's Law.
+Then he goes on to prove that the quantity of heat in a body is measured
+by the molecular revolutions of the vortices.
+</p>
+
+<p>
+He does not clearly define the exact character of those molecular
+vortices, but I take it to mean that each atmosphere is in a state of
+revolution around its atomic centre, in the same way that the atmosphere
+of a planet is in a state of revolution around its central body.
+</p>
+
+<p>
+Such an assumption is entirely in harmony with experience, as there is<span class='pagenum'><a name='Page_104' id='Page_104'></a><a href='#TOC'>[104]</a></span>
+an analogy for its assumption from the planetary system; and if an atom
+is a world in miniature, as I believe it to be, then the atmosphere of
+the atom ought to revolve around its central nucleus in the same way
+that the atmosphere of a planet revolves around its nucleus or central
+body.
+</p>
+
+<p>
+He then deals with temperature, and with the pressure of gases caused by
+heat, showing the relation of elasticity and pressure to temperature in
+a table of results given in the <i>Phil. Mag</i>. for 1851. I must refer the
+reader to the paper itself for fuller details. Thus from one of the
+greatest thinkers of modern times we have further testimony to the
+hypothesis that Aether is matter and is therefore gravitative, and
+because of its gravitating tendency, it forms around every atom and
+molecule elastic envelopes or atmospheres, whose pressure is always
+proportionate to their density.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_8' id='Footnote_8'></a><a href='#FNanchor_8'><span class='label'>[8]</span></a>
+<i>Phil Mag</i>., 1859.
+</p></div>
+
+
+<p>
+<a name='ART_62' id='ART_62'></a><span class='smcap'>Art</span>. 62. <i>Radiation and Absorption</i>.--We have already seen (<a href='#ART_31'>Art. 31</a>)
+that all matter is made up of atoms and molecules, each of which is
+surrounded by its atmosphere of Aether. By means of the Aether, motion
+in the form of light and heat may be transmitted from one atom and
+molecule to another. The transmission of heat from one body to another
+is termed Radiation, while the acceptance of heat is termed Absorption.
+Tyndall defines Radiation as &ldquo;the communication of molecular motion from
+the heated body to the Aether in which it is immersed,&rdquo;<a name='FNanchor_9' id='FNanchor_9'></a><a href='#Footnote_9' class='fnanchor'>[9]</a>
+ and
+Absorption, therefore, would be the acceptance of motion by the body
+from the Aether. So that in Radiation, the atom, molecule, or body parts
+with motion to the Aether, while in Absorption it gains motion from the
+Aether.
+</p>
+
+<p>
+Now in order for us to understand this theory of Radiation and
+Absorption, it will be well for us if we look at a similar effect in the
+sphere of music and sound. Let us suppose that we have two tuning-forks
+of the same pitch, placed on a table at a distance of a foot from each
+other. If we set one of the forks vibrating, the waves which it radiates
+through the air will fall upon the other one, and will also set it in
+vibration, because they are of the same period or size as those waves
+which it would itself give off when sounded. Thus while one is losing
+its motion, the other is gaining it, or while one is radiating motion,
+the other is absorbing motion. This can readily be proved by stopping
+the vibration of the first fork, when it will be found that the second
+fork is now giving out a similar note to the first, although it was
+silent at the commencement. Thus we have here an example of radiation
+and absorption of sound, the success of the experiment depending upon
+the fact that both forks shall have the same pitch. Again, it must be
+noted, that if we have two tuning-forks both of which are of the same<span class='pagenum'><a name='Page_105' id='Page_105'></a><a href='#TOC'>[105]</a></span>
+pitch, and both vibrating at the same time, then, while one is radiating
+sound and consequently losing motion to the other, yet at the same time
+it is absorbing motion from the other. Because, if fork A can transfer
+motion to fork B, the latter can equally transfer its motion to fork A,
+and when both are vibrating together, each is the recipient of part of
+the other's motion, while at the same time giving off motion in the form
+of sound waves itself. So that the power of a fork to radiate sound
+waves equals its power to absorb sound waves. If now we apply this
+simile to the atomic and molecular world, we shall be able to form a
+mental picture as to what takes place in radiation and absorption.
+</p>
+
+<p>
+All atoms and molecules are ever in a state of ceaseless motion, ever
+moving, never still. All are creating Aether waves which move away with
+the velocity of light. If, in the transmission of the waves by the
+Aether, they fall upon another atom which can emit a wave of similar
+length, in the same way that two tuning-forks emitted sound waves of the
+same length, then the atom upon which the waves strike will be set in
+vibration, as the second tuning-fork was set in vibration by the first.
+We shall look again at the principle of wave motion in the next chapter.
+Further, from the simile of the two forks, which absorb sound at the
+same time that they radiate sound, we learn that an atom or body
+radiates heat waves at the same time that it is absorbing heat waves.
+Suppose that we have two bodies at equal temperatures, it must not be
+thought that the radiation or absorption has ceased, for, according to
+the simile used, they both still continue to vibrate and emit the
+aetherial heat waves; but where we get equality of temperatures, there
+we get equality of radiation and absorption. Before this equality of
+temperatures, however, is reached, the hotter body will radiate more
+heat waves than it absorbs, while the colder body will absorb more heat
+waves than it emits. All bodies, whatever their temperature, are
+incessantly radiating heat waves. This may be proved experimentally with
+proper apparatus, as for example with an instrument known as the
+thermopile. When, however, the total heat waves radiated out by a body
+are less than it absorbs, the body gets gradually colder, and the
+temperature decreases. So long as this is continued, so long will the
+body continue to get colder and colder, until it arrives at the same
+temperature as the surrounding bodies, at which point the total heat
+waves radiated out will equal the total heat waves absorbed, and at that
+point the temperature of the body will remain constant.
+</p>
+
+<p>
+This aspect of temperature was first introduced by Prevost of Geneva in
+1792, in an article in which he tried to explain the radiation from a
+cold body. According to his reasoning, a body is not simply regarded as<span class='pagenum'><a name='Page_106' id='Page_106'></a><a href='#TOC'>[106]</a></span>
+radiating heat when its temperature is falling, or absorbing heat when
+it is rising.
+</p>
+
+<p>
+What he tried to make clear was, that both radiation and absorption were
+going on at one and the same time; the radiation depending upon the body
+itself, but the absorption depending upon the nature of the body. While
+radiation and absorption are thus reciprocal, which implies that a good
+radiator is a good absorber, and a bad radiator is a bad absorber, it
+does not follow that all bodies radiate and absorb alike.
+</p>
+
+<p>
+The capacity of bodies to radiate and to absorb differ considerably. Dr.
+Franklin made several simple experiments to prove the relative powers of
+radiation and absorption with several pieces of cloth. These were put
+out on the snow, and exposed to the heat of the sun. He found that the
+pieces which were dark in colour sank deepest into the snow, while those
+which were lightest in colour sank the least. From this he inferred that
+the darkest pieces were the best absorbers, and therefore the best
+radiators, while the light-coloured cloths were the worst absorbers, and
+therefore the worst radiators.
+</p>
+
+<p>
+Radiation, therefore, may be said to be the propagation of a wave motion
+through the Aether; and, as all motion is a source of power or energy,
+we have in the radiation of heat from one body to another by the
+aetherial waves, the transmission of a motive power capable of doing
+work, either internal work as increasing the temperature of the molecule
+or body, or external work as separating the atoms, or driving them
+further apart. It can readily be seen that if the Aether were
+frictionless, as has generally been supposed, the Aether could not have
+any motive power at all, and therefore could not transmit heat from one
+body to another. Professor Tyndall[2] on this point says, referring to
+the cooling of a red-hot ball: &ldquo;The atoms of the ball oscillate in a
+resisting medium, which accepts their motion and transmits it on all
+sides with inconceivable velocity.&rdquo; Now in the previous quotation given
+in this article from the same authority, he states that the atoms are
+immersed in the Aether. So that evidently in his opinion the Aether and
+the resisting medium are one and the same. So that our assumption of the
+gravitative property of the Aether is perfectly in accord with Professor
+Tyndall's conception of the Aether, in so far as it concerns the
+propagation of heat waves; and, as will be shown later on, heat and
+light waves are due to the same physical agent--that is, the Aether;
+therefore, wherever we get heat and light, there, according to Professor
+Tyndall's statement, we must have a resisting medium, and as Aether
+fills all space, the resisting medium must fill all<span class='pagenum'><a name='Page_107' id='Page_107'></a><a href='#TOC'>[107]</a></span>
+space. This is perfectly in accord with our assumption that the Aether
+is gravitative and possesses inertia--that is, the capacity to receive
+and to impart motion, and being gravitative it possesses mass or weight,
+which is the very quality necessary for the existence of a resisting
+medium.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_9' id='Footnote_9'></a><a href='#FNanchor_9'><span class='label'>[9]</span></a>
+<i>Heat, a Mode of Motion</i>.
+</p></div>
+
+
+<p>
+<a name='ART_63' id='ART_63'></a><span class='smcap'>Art</span>. 63. <i>Heat is a Repulsive Motion</i>.--Whatever be the particular
+character of the vibratory motion of the Aether termed heat, there is
+one fact regarding the same that is very patent and obvious to all; and
+that is, that the vibratory motion of heat is essentially a repulsive
+motion, or a motion from a centre and not one to a centre.
+</p>
+
+<p>
+Professor Davy points this out (<a href='#ART_60'>Art. 60</a>) where he says of heat, &ldquo;It may
+with propriety be called a repulsive motion,&rdquo; while Professor Challis
+(<a href='#ART_61'>Art. 61</a>) states that &ldquo;Each atom is the centre of vibrations propagated
+from it equally in all directions, which give rise to a repulsive action
+on the surrounding atoms. This action (he adds) is the repulsion of heat
+which keeps the individual atoms asunder.&rdquo;
+</p>
+
+<p>
+There have been many experiments undertaken which go to prove that a
+repulsive action between atoms and molecules is produced by heat. It has
+been demonstrated that certain coloured rings, known as Newton's rings,
+change their shape and position when the glasses between which they
+appear are heated, thus indicating the presence of a repulsive power due
+to the increased heat. If we consider the change of state that heat
+induces in matter, as, for example, from solid to a liquid, or liquid to
+a gaseous form, we are compelled to admit that heat possesses an
+expanding and therefore a repulsive motion. It is almost an universal
+law that heat expands and cold contracts, and the greater the heat
+absorbed, the greater the expansion. In the case of a solid being
+converted into a liquid, a much greater heat or repulsive motion is
+required to separate the particles, on account of the power of cohesion
+being greater in the solid than in the liquid. As Professor Tyndall<a name='FNanchor_10' id='FNanchor_10'></a><a href='#Footnote_10' class='fnanchor'>[10]</a>
+
+states when dealing with the stability of matter from the molecular
+standpoint: &ldquo;Every atom is held apart from its neighbour by a force of
+repulsion. Why then do not the mutually repellent members of the group
+part company? The reason of this stability is that <i>two</i> forces, the one
+attractive and the other repulsive, are in operation between every two
+atoms, and the position of every atom is determined by the equilibration
+of these two forces. The points at which attraction and repulsion are
+equal to each other is the atom's position of equilibrium. When the
+atoms approach too near each other, repulsion<span class='pagenum'><a name='Page_108' id='Page_108'></a><a href='#TOC'>[108]</a></span>
+predominates and drives them apart; when they recede to too great a
+distance, attraction predominates and draws them together.&rdquo; If,
+therefore, there are TWO forces at work in the atomic world, viz.
+attraction and repulsion, then the question arises, Can that repulsive
+power be increased in any way, and if so, by what means? Such repulsive
+motion, as experiment and experience teach us, can be increased, and
+such increase may be derived from the absorption of heat which gives
+rise to increased atomic motion, and so to increased aetherial motion
+away from the atom, by which the repulsive action of one atom upon
+another is increased. Thus an atom's repulsive power may be increased by
+heat; the greater the heat absorbed, the greater the repulsive power
+that any atom or body exerts upon a neighbouring atom or body. We can
+therefore understand how it is, that a body when changed from a solid to
+a liquid condition occupies a larger space in the latter condition than
+in the former; or why a body when changed from a liquid to a gaseous
+condition occupies a still larger volume in the latter than in its
+previous condition. The expansion in both cases is essentially the
+result of the increased repulsive motion that has been imparted to its
+atoms or molecules by the increased heat, and this increased repulsive
+power has overcome the attractive power of the atoms or molecules, with
+the result that they have been driven further and further apart, until,
+in the gaseous state, the atoms may be very far apart indeed. Wherever,
+therefore, we have heat of any kind, there we have a repulsive motion,
+such motion being proportionate to the heat radiated, that is, the
+aetherial waves propagated by the body. If, therefore, in the atomic
+world we find a repulsive motion, which is due to the vibratory motions
+of the Aether generated by heat, the question now confronts us, as to
+whether in the solar system, and indeed all through the universe, there
+is not the same repulsive motion from a central body due to the wave
+motions of the Aether termed Heat.
+</p>
+
+<p>
+May we not find in the repulsive power of heat in the atomic world, an
+indication of that very power for which we are seeking in the solar
+system--that is, a Centrifugal Force or motion which is the exact
+opposite of the Centripetal Force or attractive power of Gravitation?
+For if heat be a repulsive motion at all, then to be strictly logical it
+must be equally repulsive in relation to large masses, the sun and the
+planets for example, as it is in the atomic world, otherwise we have a
+phenomenon in Nature which contradicts itself, which assumption would be
+contrary to the simplicity which is to govern our philosophy, and also
+contradictory to experience, which is the primary factor of
+philosophical reasoning. Now what are the facts with reference to the<span class='pagenum'><a name='Page_109' id='Page_109'></a><a href='#TOC'>[109]</a></span>
+sun, which is the central body of our solar system, and the source of
+all light and heat in that system? We will look at this aspect of the
+question under the heading of Radiant Heat.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_10' id='Footnote_10'></a><a href='#FNanchor_10'><span class='label'>[10]</span></a>
+<i>Heat, a Mode of Motion</i>.
+</p></div>
+
+
+
+<p>
+<a name='ART_64' id='ART_64'></a><span class='smcap'>Art</span>. 64. <i>Radiant Heat</i>.--The source of all light and heat, not only of
+our earth, but also of all the other planets, is to be found in the sun.
+We have therefore to deal, not with an atom which is generating heat
+waves on every side, but with a globe about 860,000 miles in diameter,
+and with a circumference of over 2,700,000 miles. This huge orb consists
+of a central body, molten or partly solid, with a temperature so hot
+that it is almost impossible to conceive its intensity. The quantity of
+heat emitted by the sun has been ascertained by Sir John Herschel from
+experiments made at the Cape of Good Hope, and by M. Pouillet in Paris.
+</p>
+
+<p>
+Sir John Herschel found that the heating power of the sun when it was
+directly overhead was capable of melting .00754 of an inch of ice per
+minute. According to M. Pouillet the quantity was .00703 of an inch,
+which is equal to about half-an-inch per hour. From these results it has
+been calculated that if the direct heat of the sun were received upon a
+block of ice one mile square, 26,000 tons would be melted per hour by
+the heat which would be absorbed. Again, as Herschel<a name='FNanchor_11' id='FNanchor_11'></a><a href='#Footnote_11' class='fnanchor'>[11]</a>
+ puts it:
+&ldquo;Supposing a cylinder of ice, 45 miles in diameter, to be continually
+darted into the sun with the velocity of light, the heat given off
+constantly from the sun by radiation would be wholly expended in
+liquefaction on the one hand, while on the other, the actual temperature
+at the sun's surface would undergo no diminution.&rdquo; Sir John Herschel
+further says: &ldquo;All the heat we enjoy comes from the sun. Imagine the
+heat we should have to endure if the sun were to approach us, or we the
+sun, to a point the one hundred and sixtieth part of the present
+distance. It would not be merely as if 160 suns were shining on us all
+at once, but 160 times 160 suns according to the rule of inverse
+squares--that is, 25,600. Imagine a globe emitting heat 25,600 times
+fiercer than that of an equatorial sunshine at noonday, with the sun
+vertical. In such a heat there is no solid substance we know of which
+would not run like water, boil, or be converted into smoke or vapour.&rdquo;
+</p>
+
+<p>
+Lockyer points out that the heat radiated from every square yard of the
+sun's surface is equal to the amount of heat produced by the burning of
+six tons of coal on that area in one hour. Now the surface of the sun
+may be estimated at 2,284,000,000,000 square miles, and there are
+3,097,600 square yards in each square mile; what therefore must be the
+number of tons of coal which must be burnt<span class='pagenum'><a name='Page_110' id='Page_110'></a><a href='#TOC'>[110]</a></span>
+per hour to represent the amount of heat radiated from the sun into
+space? The approximate result may be calculated by multiplication, but
+the figures arrived at fail to give any adequate conception of the
+actual result.
+</p>
+
+<p>
+From these facts it may be seen that the sun has a temperature far
+exceeding any temperature that can be produced on the earth by
+artificial means. All known elements would be transformed into a
+vaporous condition if brought close to the sun's surface. It may readily
+be seen, therefore, that the sun is constantly sending forth an
+incessant flood of radiant heat in all directions, and on every side
+into space. Now if heat be motion, and be primarily due to the vibratory
+motion of Aether, what must be the volume and the intensity of the
+aetherial waves, known as heat waves, generated by the sun? When we
+remember its ponderous mass, with its volume more than 1,200,000 times
+that of our earth, its huge girth of more than 2-1/2 millions of miles,
+and this always aglow with fire the most extensive known--fires so
+intense that they cover its huge form with a quivering fringe of flames
+which leap into space a distance of 80,000 miles, or even 100,000 miles,
+or over one-third of the distance of the moon from the
+earth,--remembering all these facts, what must be the volume and
+intensity of the aetherial heat waves which they generate and send upon
+their course into space on all sides! What a very storm of energy and
+power must there be in this aetherial atmosphere which exists around the
+sun's huge form, and with what volume of power must the aetherial heat
+waves speed away from so great a generating source! Some idea as to
+their velocity of motion may be gained by the fact, that these aetherial
+heat waves traverse the distance of 92,000,000 miles between the sun and
+our earth in the short space of 8-1/2 minutes. With such a velocity of
+motion as that, and with the fact before us that all motion is a source
+of energy or power, what must be the energy possessed by these heat
+waves! There must, therefore, be a power in these aetherial heat waves
+which is strictly proportionate to their intensity and flow. So that,
+whenever they come into contact with any body, as a planet, as they flow
+outwards from the sun, they must exert a power upon such a planet which
+is directed <i>away</i> from the sun, and therefore act upon that planet by
+the energy of their motion away from the sun, the source of the
+aetherial heat waves. Therefore, not only in the atomic world is heat a
+repulsive motion, but equally in the solar world, which is but an atomic
+world on a large scale, the same principle prevails, and the effect of
+radiant heat is essentially a repulsive, that is, a centrifugal motion,
+as it is always directed from the central body, the sun.<span class='pagenum'><a name='Page_111' id='Page_111'></a><a href='#TOC'>[111]</a></span>
+</p>
+
+<p>
+Further, it
+can be shown that the repulsive power of heat in the solar system has
+already received the attention of scientists, especially in France. This
+will be seen more fully when we come to deal with the phenomena of
+comets' tails. One remarkable feature about comets' tails is, that they
+are always directed away from the sun, and various hypotheses have been
+advanced to account for that fact. Among them is the hypothesis of M.
+Faye, in which he assumes that there is a repulsive force which has its
+origin in the heat of the sun. This repulsive force is not propagated
+instantaneously, but the velocity of propagation is the same as that of
+a ray of light. By means of this repulsive power due to the heat of the
+sun, M. Faye explains how it is that the tails of comets are always
+turned away from the sun. Here, then, we have an indication of the
+existence of this repulsive force of heat which we are considering--a
+repulsive power which finds its source in the aetherial waves, which
+give rise to the phenomena of Heat, and to which we must look for the
+ultimate source of that repulsive power or Centrifugal Force which is to
+form the complementary power to the attractive force of Gravitation.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_11' id='Footnote_11'></a><a href='#FNanchor_11'><span class='label'>[11]</span></a>
+<i>Lectures on Scientific Subjects.</i>
+</p></div>
+
+
+<p>
+<a name='ART_65' id='ART_65'></a><span class='smcap'>Art</span>. 65. <i>Direction of Ray of Heat</i>.--The question as to the path which
+a ray of heat takes may best be attacked by finding out what is the path
+which a ray of light takes in its progress through the Aether. When we
+come to deal with light, we shall find that it has been experimentally
+proved that the path of a ray of light is that of a straight line
+through space; so that if we have any body emitting light, the rays of
+light will proceed from that body in straight lines, with decreasing
+intensity, according to the law of inverse squares, the same as
+Gravitation.
+</p>
+
+<p>
+It can readily be shown, that wherever there is light there is heat. For
+example, the radiant heat from the sun proceeds through space along with
+the light from the sun, and when one set of waves, the light waves for
+instance, are intercepted, the heat waves are also intercepted. Or, to
+take another illustration, when the sun is eclipsed, we feel the sun's
+heat as long as any portion of the sun is visible, but as soon as the
+sun is totally eclipsed, then the light waves disappear, and with it the
+heat waves. From this we can readily see, that not only do the heat and
+light waves from the sun proceed in the same straight line, but that
+they also travel at the same rate through space, at the rate of 186,000
+miles per second. Then again the common lens, which is so familiar to
+every one, will prove the same fact by concentrating the rays of light
+to a focus, and by so doing will produce sufficient heat to burn a piece
+of paper, or even set fire to wood. If, therefore, the path of a ray of
+light be that of a straight line, proceeding from the luminous or
+lighted body, and the path of a ray of heat coincides with the path of<span class='pagenum'><a name='Page_112' id='Page_112'></a><a href='#TOC'>[112]</a></span>
+a ray of light, the path of the ray of heat must also be in the
+direction of a straight line from the heated or luminous body, which, as
+we shall see in a subsequent article, also decreases in intensity
+according to the law of inverse squares the same as Gravitation
+Attraction.
+</p>
+
+<p>
+Professor Tyndall, on the direction of a ray of heat,<a name='FNanchor_12' id='FNanchor_12'></a><a href='#Footnote_12' class='fnanchor'>[12]</a>
+ states his
+opinion on the matter as follows: &ldquo;A wave of Aether starting from a
+radiant point in all directions in a uniform medium constitutes a
+spherical shell, which expands with the velocity of light or of radiant
+heat. A ray of light or a ray of heat is a line perpendicular to the
+wave, and in the case here supposed, the rays would be the radii of the
+spherical shell.&rdquo; From this it can be seen that a ray of light or heat
+corresponds to what is known as the radius vector of a circle (<a href='#ART_20'>Art. 20</a>),
+and therefore a ray of light and heat takes exactly the same path
+through space (if we consider the sun as the source of the light and
+heat) as the path of the attractive power of Gravitation. Collecting,
+therefore, our results from the preceding articles of this chapter, we
+learn that heat is due to vibrating wave motion of the Aether, and that
+that motion is a motion which is always directed from the central body
+which is the source of the heat; and further, that this motion amounts
+to a repulsive motion acting in an opposite direction to the attractive
+power of gravity or to the centripetal force of Gravitation. What is
+more remarkable still, the path of a ray of heat corresponds with, and
+takes up exactly the same direction through space, whether it be atomic
+space, solar space, or interstellar space, as the attractive force of
+Gravitation.
+</p>
+
+<p>
+Looking at the subject from the standpoint of the solar system, with the
+sun as the central body, we see that while we have the sun, which acts
+as the controlling centre of the particular system of planets, holding
+all the planets in their orbits by its attractive power, yet at the same
+time it is also the source of all light and heat. Now heat being due to
+the wave motion of the aetherial medium, such motion being always
+exerted from the central body, we arrive at the only legitimate
+conclusion that can be arrived at, viz. that the sun is also the source
+of a repulsive motion, which motion coincides with the path that the
+attractive power of Gravitation takes, that is, along the radius vector
+of the circle, as shown in <a href='#ART_20'>Art. 20</a>.
+</p>
+
+<p>
+<a name='ART_66' id='ART_66'></a><span class='smcap'>Art</span>. 66. <i>Law of Inverse Squares applied to Heat</i>.--The law of inverse
+squares which governs not only the Law of Gravitation Attraction (<a href='#ART_22'>Art. 22</a>), but also electricity and light, is equally applicable to the phenomena of<span class='pagenum'><a name='Page_113' id='Page_113'></a><a href='#TOC'>[113]</a></span>
+heat, so that we say the intensity of heat varies inversely as the
+square of the distance. Thus, if we double the distance of any body from
+the source of heat, the amount of heat which such a body receives at the
+increased distance is one-quarter of the heat compared with its original
+position. If the distance were trebled, then the intensity of the heat
+would be reduced to one-ninth; while if the distance were four times as
+great, the intensity of the heat would only be one-sixteenth of what it
+would receive in its first position. This may be proved from experiments
+as given by Tyndall in his <i>Heat, a Mode of Motion</i>.
+</p>
+
+<p>
+Let us apply the law of inverse squares in relation to heat to the solar
+system, and see what the result gives. In our solar system, we have the
+sun as the central body, the source of all light and heat, with the
+eight planets, Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus,
+Neptune, describing orbits around the central body, and at the same time
+receiving from it the light and heat which the sun is ever pouring forth
+into space. The mean distance of Mercury from the sun is about
+36,000,000 miles, while that of the Earth is about 92,000,000 miles, so
+that reckoning the distance of Mercury as unity, the distance of the
+Earth is a little more than 2-1/2 times that of Mercury from the sun.
+Now the square of 2-1/2 is 25/4, and that inverted gives us 4/25, so
+that according to the law of inverse squares, the intensity of heat at
+the Earth's distance from the sun is 4/25 of what the intensity of heat
+is at the mean distance of Mercury. Again, the mean distance of Mars is
+141,000,000 miles, while the mean distance of Saturn is 884,000,000
+miles, and taking Mars' distance from the sun as unity, the distance of
+Saturn would be represented by 6-1/4. Now the square of 6-1/4 is
+(25/4)<sup>2</sup> which gives 625/16 and the inverse of that is 16/625, so that
+the intensity of heat at the distance of Saturn's mean distance from the
+sun, in comparison with the intensity of heat at Mars' mean distance,
+would be about 16/625; or in other words, the heat received by Saturn
+would be only 16/625 of the intensity of heat received by the planet
+Mars. In <a href='#ART_63'>Art. 63</a> we have seen that heat is a repulsive motion, being a
+wave motion of the Aether which is propagated from the heated and
+central body, which in this case is the sun. Therefore, according to the
+law of inverse squares from the standpoint of heat, we find in the solar
+system a repulsive motion, due to the wave motion of the Aether, which
+is always exerted away from the sun in the same path that the
+centripetal force takes, and which like that force diminishes in
+intensity inversely as the square of the distance. So that, wherever the
+centripetal force, or the attractive force of Gravitation, is diminished
+on account of the increased distance from the sun, the repulsive motion<span class='pagenum'><a name='Page_114' id='Page_114'></a><a href='#TOC'>[114]</a></span>
+due to heat is also diminished in exactly the same proportion and along
+exactly the same path. If at any point in the solar system the
+attractive force is doubled, then according to our repulsive theory of
+heat, and the law of inverse squares, the repulsive motion is also
+doubled. If the attractive force is halved, then the repulsive motion is
+halved also, the repulsive motion being always and at all places exactly
+proportional to the increase or decrease of the attraction of
+Gravitation.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_12' id='Footnote_12'></a><a href='#FNanchor_12'><span class='label'>[12]</span></a>
+<i>Heat, a Mode of Motion</i>.
+</p></div>
+
+
+<p>
+<a name='ART_67' id='ART_67'></a><span class='smcap'>Art</span>. 67. <i>First Law of Thermodynamics</i>.--The Law of Thermodynamics is
+based on two fundamental truths which have reference to the conversion
+of Heat into Work, and Work into Heat. In <a href='#ART_54'>Art. 54</a> we have already seen
+that energy in the form of heat, light, electricity and magnetism is
+capable of being converted into other forms of energy, while in <a href='#ART_59'>Art. 59</a>
+we have seen that Joule gave us the exact relation in foot-pounds
+between heat and work. He showed that when 1 lb. of water fell through
+772 feet its temperature was raised one degree Fahr. Thus the principle
+underlying the first law of thermodynamics states, that whenever work is
+spent in producing heat, the amount of work done is proportionate to the
+quantity of heat generated; and conversely, whenever heat is employed to
+do work, a certain amount of heat is used up, which is the equivalent of
+the work done. This principle is also in accord with the conservation of
+Energy and Motion (<a href='#ART_52'>Arts. 52</a> and <a href='#ART_57'>57</a>), which assert that whenever energy
+or motion disappears in one form, it is manifested in some other form.
+Thus, from the first law of thermodynamics, we learn that wherever we
+have heat we have the power to do work, and the amount of work so done
+is proportionate to the heat used up. Heat, then, has a capacity to
+perform work, and that power is known as the mechanical equivalent of
+heat. Both Mayer of Germany, and Dr. Joule of Manchester, have worked
+out this problem, and have given us the mechanical value of heat. By
+experiments Mayer found out that a quantity of heat sufficient to raise
+1 lb. of water one degree Fahr. in temperature was able to raise a
+weight 771.4 lb. one foot high. Dr. Joule of Manchester, after making a
+number of experiments which lasted over many years, came to the
+conclusion that the mechanical equivalent of a unit heat was 772
+foot-pounds, a unit of heat being the quantity of heat which would raise
+1 lb. of water one degree Fahr. So that if a 1-lb. weight fell from a
+height of 772 feet, an amount of heat is generated which would raise 1
+lb. of water one degree Fahr.; and conversely, to lift 1 lb. 772 feet
+high, one degree Fahr. of heat would be consumed.
+</p>
+
+<p>
+Now if this law of thermodynamics is true, it must not only be true in<span class='pagenum'><a name='Page_115' id='Page_115'></a><a href='#TOC'>[115]</a></span>
+relation to terrestrial heat, or heat produced by artificial means on
+our earth, but it must equally hold good in relation to the solar
+system; and not only the solar system, but equally true throughout all
+the systems of worlds that flood the universe. So that wherever we get
+heat in the universe, in the solar system for example, there, according
+to our first law of thermodynamics, we should have the capacity to do
+work of some kind or other. That work may take either the form of
+expanding a body, as the atmosphere of a planet for example, or it may
+take a mechanical form, that is, actually moving a body by the increased
+pressure due to aetherial heat waves generated by the sun. We have
+already seen in <a href='#ART_64'>Art. 64</a>, on Radiant Heat, what a store of heat the sun
+has. For thousands and millions of years the sun has been pouring forth
+its heat rays into space, and yet its temperature does not seem to be
+diminished. The great Carboniferous or coal period of past geological
+times is an indication of the heat and light of the sun, which it must
+have radiated out millions of years ago; and year by year, these
+aetherial heat waves are still being poured forth by the sun on every
+side into space, so that no matter where a planet may be in its orbit,
+there it may be the recipient of these aetherial heat waves which break
+upon its surface. Now if there be this quantity of heat existing in the
+sun, and heat according to the first law of thermodynamics has a
+mechanical value, which is that it can push or lift a body through
+space, the question arises, as to what is the mechanical value of this
+heat of the sun? Are we to suppose that if one unit of heat can lift 1
+lb. 772 feet, the millions and millions of units of heat which are
+constantly being poured out of the sun into space are doing no work at
+all? Such an assumption is not only contrary to that simplicity which
+governs our Philosophy, but is entirely opposed to experience, which is
+the very foundation of all philosophical reasoning. If, therefore,
+experience is to be any guide at all, we are compelled to come to the
+conclusion that the heat poured forth into space does do work on the
+bodies, as comets, meteors, planets, upon which the aetherial heat waves
+fall. The problem is, what is the character of the work done? I have
+already indicated part of the work, viz. in the expansion of the
+atmosphere of the planets. Then there is also the reception of the heat
+by the animal and vegetable life of the planet, but these do not account
+for all the motive power of the aetherial waves, which break upon the
+planet or its atmospheres.
+</p>
+
+<p>
+The true solution of the first law of thermodynamics, in its relation to
+the solar system, seems to me to be found in the fact already stated in
+<a href='#ART_63'>Art. 63</a>, viz. that heat is a repulsive motion, and the law of<span class='pagenum'><a name='Page_116' id='Page_116'></a><a href='#TOC'>[116]</a></span>
+thermodynamics confirms that statement, and shows that the work done on
+a planet by the aetherial heat waves is that of pushing it, or urging it
+by their very energy and motion away from their controlling centre, the
+sun. This would practically amount to a repulsive force which had its
+home in the sun, and this conception would bring our Philosophy into
+harmony with our experience, which teaches us that wherever there is
+heat there is the capacity of doing work, the amount of work being
+proportionate to the heat generated and consumed.
+</p>
+
+<p>
+<a name='ART_68' id='ART_68'></a><span class='smcap'>Art</span>. 68. <i>Second Law of Thermodynamics</i>.--This law was enunciated by
+Sadi Carnot in 1824, when he wrote an essay on the Motive Power of Heat.
+Previous to the time of Carnot no definite relation seems to have been
+suggested between work and heat; Carnot, however, discovered what were
+those general laws which govern the relation between heat and work. In
+arriving at his conclusion, he based his results on the truth of the
+principle of the conservation of energy already referred to (<a href='#ART_52'>Art. 52</a>).
+</p>
+
+<p>
+Carnot started his reasoning on the assumption that heat was matter, and
+therefore indestructible. The two great truths in relation to heat and
+work, enunciated by Carnot, are known as, first, a Cycle of operations;
+and, secondly, what he termed a Reversible Cycle. In order to be able to
+reason upon the work done by a heat-engine, say a steam-engine for
+example, Carnot stated we must imagine a cycle of operations, by which,
+at the end of such operations, the steam or water is brought back to
+exactly the same state in which it was at its start. He calls this a
+cycle of operations, and of it he says, that only at the conclusion of
+the cycle are we entitled to reason upon the relation between the work
+done and the heat spent in doing it. His other idea of the reversible
+cycle implies that an engine is reversible when, instead of using heat
+and getting work from it, the engine may be driven through the cycle of
+operations the reverse way, that is, by taking in work, it can pump back
+heat to the boiler again. Carnot showed that if you can obtain such a
+reversible engine, it is a perfect engine. All perfect engines, that is
+all reversible engines, will do exactly the same amount of work with the
+same amount of heat, the amount of work being strictly proportionate to
+the amount of heat consumed. I need hardly point out that the reversible
+engine, or the perfect engine of Carnot, is only the ideal one, as there
+is no engine in which all the heat is converted into work, as a great
+deal of the heat is radiated away and not converted into work at all.
+Again, working from the standpoint that heat is matter, Carnot reasoned
+that in the heat-engine the work is performed, not by the actual<span class='pagenum'><a name='Page_117' id='Page_117'></a><a href='#TOC'>[117]</a></span>
+consumption of heat, but by its transportation from a hot body to a cold
+one. Thus, by the fall of heat from a higher to a lower temperature,
+work could be done in the same way that work could be done by allowing
+water to fall from a higher to a lower level. The quantity of water
+which reaches the lower level is exactly the same as that which leaves
+the higher level, as none of the water is destroyed in the fall. He
+argued, therefore, that the work produced by a heat-engine was produced
+in a similar manner, the quantity of heat which reaches the condenser
+being supposed to be equal to that which left the source. Thus the work
+was done by the heat flowing from a hot body to a cold one, and, in
+doing this work, it lost its momentum like falling water, and was
+brought to rest. One of the most important points noted by Carnot is the
+necessity that, in all engines which derive work from heat, there must
+be two bodies at different temperatures, that is, a source and a
+condenser, which correspond to a hot and cold body, so that there may be
+the passage of heat from the hot to the cold body. In order to get work
+out of heat it is absolutely necessary to have a hotter and a colder
+body. From this reasoning we learn, therefore, that work is obtained
+from heat by using up the heat of the hotter body, part of which is
+converted into actual work, while part is absorbed by the colder body.
+So that wherever we have two bodies at different temperatures, according
+to the second law of thermodynamics, there we have the power of doing
+work by the transmission of heat, from the body of higher to the one of
+lower temperature.
+</p>
+
+<p>
+That Carnot ultimately came to believe in the dynamical theory of heat,
+is proved by the following passage taken from his notes on the Motive
+Power of Heat: &ldquo;It would be ridiculous to suppose that it is an emission
+of matter, while the light which accompanies it could only be a
+movement. Could a motion produce matter? No! undoubtedly, it can only
+produce a motion. Heat is then the result of motion. It is plain then
+that it could be produced by the consumption of motive power, and that
+it could produce this power. Heat is then simply motive power, or rather
+motion which has changed its form. It is a movement among the particles
+of bodies. Wherever there is a destruction of motive power, there is at
+the same time production of heat in quantity exactly proportional to the
+quantity of motive power destroyed. Reciprocally, whenever there is
+destruction of heat there is production of motive power.&rdquo;
+</p>
+
+<p>
+Let us apply this principle to the solar system, and endeavour to find
+out whether in that system we have, in relation to the heat thereof,
+either a cycle of operations or a reversible cycle. We have again to
+consider the sun as the source of all light and heat in the solar<span class='pagenum'><a name='Page_118' id='Page_118'></a><a href='#TOC'>[118]</a></span>
+system, radiating forth on every side, year by year, the countless units
+of heat which go to form the continuance of all planetary life and
+existence. One of the problems that has confronted scientific men for
+many years is this, Where does the sun get its supply of heat from? When
+we remember the incessant loss of heat which the sun suffers through its
+radiation of heat into space, we are compelled to ask, How is that
+supply maintained, and how has it been kept up through the countless
+ages of the past? Several suggestions have been made, and several
+theories advanced to account for the fact. Mayer, of Germany, suggested
+that the heat is partly maintained by the falling into the sun of
+meteors, which, like comets, pursue a path through the heavens, and are
+subject to the attractive influence of the sun. In the combustion of
+these meteorites, or meteors, he contended there were the means by which
+the light and heat of the sun might be maintained. Whatever theory,
+however, may be suggested as to the maintenance and the source of the
+continuity of the sun's heat, I do not think it has been suggested by
+any scientist that the heat emitted and radiated by the sun is ever
+returned in any way back to the sun from infinite space, whether by
+reflection or by any other method. So far as I can learn, there are no
+facts in connection with the solar system which would lead us to make
+that assumption. On the contrary, experience and experiment teach us
+that radiation implies loss of heat, and that the body, which so
+radiates, ultimately becomes cold, unless its internal heat is kept up
+by some means or other. So that the terms introduced by Carnot in the
+second law of thermodynamics, viz. that of a Cycle of Operations and of
+a Reversible Cycle, do not apply to the solar system, and the solar
+system, viewed from the standpoint of a machine, with the sun as the
+source of the heat, does not represent a perfect engine, that is, all
+the heat is not used up in doing work, some of it being radiated out
+into space. Wherever, however, the heat, that is the aetherial heat
+waves generated by the sun, comes into contact with a planet, as
+Mercury, Venus, or Jupiter, then, in accordance with Carnot's reasoning,
+work is done. Carnot points out that, in order for work to be done, we
+must have a source and a condenser, that is, two bodies at different
+temperatures, a hot body and a cold one. Now these conditions of work
+are satisfactorily fulfilled in the solar system, and as a result work
+is performed. We have the sun with its huge fires, and its intensity of
+heat, representing the source or the hot body, while every planet and
+every meteor and comet, that come under its influence, represent the
+cold body, and between the two work is always going on. That work is
+represented by the repulsive power of heat, which I have already<span class='pagenum'><a name='Page_119' id='Page_119'></a><a href='#TOC'>[119]</a></span>
+indicated, so that, viewed from Carnot's standpoint with relation to the
+motive power of heat, we find that there are in the solar system those
+conditions which govern work, and by which, from a mechanical
+standpoint, work is performed; further, that work takes the form of a
+repulsive power on every planet or other body upon which the aetherial
+heat waves fall. Therefore, from the second law of thermodynamics we
+have another proof of this repulsive power of heat already indicated and
+referred to in <a href='#ART_63'>Art. 63</a>.
+</p>
+
+<p>
+<a name='ART_69' id='ART_69'></a><span class='smcap'>Art</span>. 69. <i>Identity of Heat and Light</i>.--We have seen from the preceding
+articles of this chapter, that heat is due to a periodic wave motion of
+the Aether, and in the succeeding chapter we shall also see that light
+is due to some kind of periodic wave motion in the Aether. So that not
+only heat, but light also, it would appear, is due to certain periodic
+wave motions that are set up in the Aether by the vibrations of hot or
+luminous bodies. The question therefore arises, how many wave motions
+are there in the Aether? Are there different wave motions which in one
+case produce light, and in the other case produce heat, or are light and
+heat both produced by the same set of aetherial waves? The identity of
+light waves with heat waves is manifested by the fact that wherever we
+get light we get heat, as can be proved in many ways. One of the
+simplest proofs is found in the common lens or burning-glass, by which
+the light waves are brought to a focus, and as a result, heat is
+manifested. Although there is this close identity between light and heat
+waves, yet there must be some distinction between the heat and light
+waves, because while light waves affect the eye, heat waves do not.
+There is actually a difference between the two kinds of waves, and that
+difference is one of period or length. It must not, however, be thought
+that there are really two classes or sets of waves in the Aether, one of
+which could be called light waves, and the other heat waves, but rather
+the same wave may be manifested in two different forms because of its
+different wave lengths. In one case the waves may affect the eye, and we
+have the sensation of sight, but in the other case they affect the body,
+and we experience the sensation of warmth. An analogy from the waves of
+sound may make these facts much clearer. We know that sound travels
+about 1100 feet per second. If, therefore, we have a bell which vibrates
+about 1100 times per second, we should have a wave one foot long. If it
+vibrated 100 times per second the waves would be 11 feet long, while if
+it vibrated only 11 times per second, the waves would be 100 feet long.
+Now the impression made upon the ear depends upon the number of
+vibrations the bell makes per second, and from the rate of vibration we
+get the idea of pitch. If the vibrations are very rapid, then we get a<span class='pagenum'><a name='Page_120' id='Page_120'></a><a href='#TOC'>[120]</a></span>
+note of high pitch, and if the vibrations are slow, then we get a note
+of low pitch. A note of high pitch, therefore, will correspond to waves
+of short length, while a low note will correspond to waves of a greater
+length; so that the greater the rapidity with which a sounding bell
+vibrates, the shorter will be the length of the sound waves which it
+generates, and <i>vice versâ</i>. The range of the ear however for sound
+waves is limited, so that if the vibrations be too rapid or too slow,
+the ear may not be able to respond to the vibrations, and so no distinct
+impression of the sound will be conveyed to the brain. It need hardly be
+pointed out, that both the very short and long waves are of exactly the
+same character as those of a medium length, which the ear can detect,
+the only difference being one of rapidity. We do not therefore suggest
+that in the case of sound, where the vibrations lie outside the compass
+of the ear, those which lie outside are not sound waves, or that they
+are different from those which lie within the compass of the ear, and
+which the ear can detect. Whether the sound waves are long or short,
+whether they can be detected by the ear or not, we still say that all
+are sound waves, and that all are due to the vibrations of the sounding
+body, which vibrations are transmitted through the air, in waves, that
+fall upon the tympanum or drum of the ear, and set that vibrating, which
+vibrations are transmitted to the auditory nerve and so give rise to the
+sensation of hearing. In a similar manner, every atom and every particle
+of matter, every planet, every sun and star, is constantly in a state of
+vibration, sending off aetherial waves on every side. Nothing in Nature
+is absolutely cold, nothing is absolutely still. Therefore all matter,
+whether in the atomic form, or in the planetary or solar world, is
+constantly generating aetherial waves, which travel from their source or
+origin with the velocity of light. If these aetherial waves so generated
+fall within certain limits, then they affect the eye, and we get the
+sensation of sight. To do this they must vibrate 5000 billion times per
+second, and if they fail to do this, they fail to give rise to the
+sensation of sight. If the aetherial waves fall below this limit, then
+they affect the body, and give rise to the sensation of heat. For it
+must be remembered, that as the ear has a certain compass for sound
+waves, which may vary in different individuals, so the eye has also a
+certain compass for aetherial waves, with the result that some waves may
+be too slow or too rapid to affect the eye, and consequently fail to
+give rise to the sensation of sight. When that is so, the sensation of
+warmth helps us to detect these longer waves, so that the longer waves
+would warm us and make their presence felt in that manner. We shall see
+in the next chapter that there are both shorter and longer waves, which<span class='pagenum'><a name='Page_121' id='Page_121'></a><a href='#TOC'>[121]</a></span>
+may be detected in other ways. From these facts it can be readily seen,
+that we have a common origin for both light and heat, and that they are
+both due to periodic waves in the Aether, and therefore all the laws
+that govern heat should also govern the phenomena of light. Further, if
+heat possesses a dynamical value, and if there be such a truth as the
+motive power of heat, then there ought equally to be a motive power of
+light; and further, if heat possesses a repulsive motion, then because
+of the identity of light and heat, light should equally possess this
+repulsive power, because it is due to similar periodic wave motions in
+the Aether. With regard to the same laws governing both light and heat,
+we shall see that this fact also holds good. We have already seen (<a href='#ART_66'>Art. 66</a>) that the intensity of heat is inversely as the square of the
+distance, and we shall also see in the succeeding chapter that the same
+law holds good in relation to light. We have seen (<a href='#ART_65'>Art. 65</a>) that the
+path of a ray of heat is that of a straight line; we shall see in the
+succeeding chapter that the path of a ray of light is that of a straight
+line also.
+</p>
+
+<p>
+Indeed, there is no law applicable to heat which is not applicable to
+light. The law of reflection and refraction of heat equally holds good
+in relation to light; and further, Professor Forbes has shown that heat
+can be polarized in a similar manner to the polarization of light. This
+last fact is considered the most conclusive argument as to the identity
+of light and heat, and proves that the only difference between the two
+is simply the difference corresponding to the difference between a high
+note and a low note in sound. That being so, I hope to be able to show
+that as heat possesses a dynamical value, so light equally possesses a
+dynamical value, and that as heat is a repulsive motion, then light must
+equally possess a similar repulsive motion, that motion always being
+directed from the central body, being caused by the same agency, viz.
+the waves of the Aether, the common source of both light and heat. I
+purpose to address myself to this subject in the following chapter,
+which I have termed Light, a Mode of Motion.
+</p>
+
+
+<p><span class='pagenum'><a name='Page_122' id='Page_122'></a><a href='#TOC'>[122]</a></span></p>
+<h2><a name='CHAPTER_VII' id='CHAPTER_VII'></a><a href='#CHAPTER_VII_TOC'>CHAPTER VII</a></h2>
+
+<h3>LIGHT, A MODE OF MOTION</h3>
+
+<p>
+<a name='ART_70' id='ART_70'></a><span class='smcap'>Art</span>. 70. <i>Light, a Mode of Motion</i>.--No subject has in the past received
+greater attention from philosophers and scientists than that involved in
+the question as to &ldquo;What is Light?&rdquo; Indeed, it may truthfully be said,
+that even to-day its exact character is not positively known. That it is
+due like heat to some periodic wave motion in the Aether is known, but
+the exact character of that wave motion has yet to be determined. As in
+the case of heat, so in the case of light, there have been two theories
+which have contended with each other for supremacy in endeavouring to
+answer the question as to &ldquo;What is Light?&rdquo; Those two theories are known
+as the Emission or Corpuscular Theory, and the Undulatory or Wave
+Theory. The corpuscular theory was introduced and developed by Newton in
+his work on <i>Optics</i>, which ranks second only to the <i>Principia</i> as a
+work revealing masterly research and scientific genius. Newton supposed
+that a luminous or lighted body actually emitted minute particles, which
+were shot out from the body with the velocity of light, that is, at the
+rate of 186,000 miles per second. These minute particles he termed
+corpuscles. In the work just referred to regarding this matter, he asks
+the question, &ldquo;Are not rays of light very small bodies emitted from
+shining substances?&rdquo; These small particles or corpuscles were supposed
+by him to actually strike the retina of the eye, and so produce the
+sensation of Sight, in the same way that odorous particles entering the
+nostril, come into contact with the olfactory nerves and produce the
+sensation of Smell. In order, however, to account for certain phenomena
+of light, he was compelled to postulate an aetherial medium to fill all
+space, in which his luminous corpuscles travelled, and which would
+excite waves in that medium. In his eighteenth query on this point he
+asks: &ldquo;Is not the heat of a warm room conveyed through the vacuum by the
+vibration of a much subtler medium than air, and is not this medium the
+same with that medium by which light is reflected or refracted, and by
+whose vibrations light communicates Heat to bodies, and is put into fits
+of easy reflection and easy transmission?&rdquo; The corpuscular theory,
+however, received its death-blow when, in competition with the wave<span class='pagenum'><a name='Page_123' id='Page_123'></a><a href='#TOC'>[123]</a></span>
+theory of light, as developed by Young, it was found that the latter
+theory satisfactorily accounted for certain phenomena as the refraction
+of light, which the corpuscular theory did not adequately account for.
+Even while Newton was developing his theory, Huyghens, a contemporary of
+Newton, was developing another theory which is now known as the
+undulatory or wave theory. Huyghens drew his conclusions from the
+analogy of sound. He knew that sounds were propagated by waves through
+the air, and from the region of the known, endeavoured to carry the
+principle into the region of the unknown, a strictly philosophical
+method, and one in accordance with the second Rule of Philosophy. He
+supposed that light, therefore, like sound, might be due to wave motion,
+but if it were wave motion, there must have been a medium to propagate
+the waves. In order to account for this wave motion, he supposed all
+space to be filled with a luminiferous Aether, which would be to his
+light waves what air is to sound waves. In this conception he was
+supported by Euler the mathematician, and in 1690 he was able to give a
+satisfactory explanation of the reflection and refraction of light, on
+the hypothesis that light was due to wave motion in the Aether. It was
+not, however, till the advent of Thomas Young, that the undulatory or
+wave theory reached its perfection, and finally overthrew its competitor
+the corpuscular theory. Young made himself thoroughly acquainted with
+wave motion of all kinds, and applied his knowledge and experience to
+the phenomena of light, and from the analogies so obtained, he gradually
+built up the undulatory theory, and gave to it a foundation from which
+it has not yet been moved. Young made use of the same aetherial medium
+in order to propagate the wave motion of light in the same way that
+Huyghens did. From that conception, the Aether has been gradually
+perfected, until we have the conception which has been presented to the
+reader in Chapter <a href='#CHAPTER_IV'>IV</a>., in which I have endeavoured to show that this
+aetherial medium is matter, but infinitely more rarefied and infinitely
+more elastic, but notwithstanding its extreme rarefaction and
+elasticity, it possesses inertia, because it is gravitative. It is this
+Aether, then, that is concerned in the propagation of light, and is the
+universal medium which is to light what air is to sound. Young,
+therefore, having applied himself to the wave motion of sound, from such
+researches was able to explain the physical cause of colour, and that
+phenomenon termed interference.
+</p>
+
+<p>
+We will therefore look at wave motion, in order to understand the wave
+theory of light.
+</p>
+
+<p>
+Now in all wave motion, whether it be water waves or sound waves, that
+which is propagated or conveyed from place to place is energy, or<span class='pagenum'><a name='Page_124' id='Page_124'></a><a href='#TOC'>[124]</a></span>
+motion. If a stone is thrown into water, a series of concentric circles
+of waves are generated, which spread out with increasing size, but
+decreasing power or motion, regularly on all sides. The water, however,
+does not move away from the generating source. There is a motion of the
+water, but it is simply a wave motion, so that the propagation of a wave
+is the propagation of motion, rather than the transference of the actual
+water which constitutes the wave. In the case of sound waves, we have
+again an illustration of the same principle. For example, suppose we
+strike a bell, and so set the particles of that bell in a state of
+vibration. These vibrations give the air in contact with the bell a
+forward movement, and then, owing to the elasticity and inertia of the
+air, a backward movement is set up, with the result that a series of
+waves are set in motion from the bell on every side, which gradually
+diminish in intensity the farther they recede from the generating body.
+According to the wave theory, therefore, we have to picture all heated
+and luminous bodies in a state of vibration, and the atoms of such
+luminous bodies imparting the vibrations to the atoms of the Aether, in
+the same way that the atoms of a bell impart their vibrations to the
+atoms of the air in contact with it. These vibrations are then
+propagated through the Aether in waves, which, entering the eye, impinge
+or strike upon the retina at the back of the eye, and being transmitted
+to the brain give rise to the sensation of sight. It must not be
+forgotten that the waves of Aether, as pointed out in <a href='#ART_64'>Art. 64</a> in
+relation to heat, really form spherical shells which radiate out in all
+directions from the central body which gives rise to them. Thus it can
+be seen, that all points in the spherical wave which are at equal
+distances from the vibratory or luminous body, must possess the same
+intensity, and possess equal lighting powers. Light, therefore, like
+heat, is due to a periodic wave motion set up in the Aether by the
+vibrating atomic motion of heated or luminous bodies. It must be also
+noticed, that if we could see the air through which the sound waves are
+passing, we should see that each atom or particle of the atmosphere was
+vibrating to and fro in the direction of propagation. If, however, we
+could see an atom of Aether in vibration, accepting the principle that
+Aether is atomic, we should see that each aetherial atom is not
+vibrating in the direction of propagation, but across the line in which
+the wave is travelling. Thus the vibration of the air is said to be
+longitudinal, but the vibrations of the Aether are transversal. An
+illustration of the transverse motion of a light wave may be obtained by
+taking a rope and imparting to it a series of undulations by shaking it
+up and down, when it will be observed that the wave motion of the rope
+is transverse to the straight line in which it is propagated. The<span class='pagenum'><a name='Page_125' id='Page_125'></a><a href='#TOC'>[125]</a></span>
+physical explanation of the transverse vibration of light will be dealt
+with in a subsequent article.
+</p>
+
+<p>
+Now the question suggests itself to our mind, as to what effect the
+atomicity of the Aether has upon the undulatory theory of light. Does it
+establish it upon a firmer basis, or does it in any way destroy its
+truth as a theory? I venture to think that the atomicity of the Aether
+in no sense destroys any part of the undulatory theory of light, but
+rather tends to confirm and establish it upon a logical and
+philosophical basis.
+</p>
+
+<p>
+For instance, as has been pointed out in <a href='#ART_47'>Art. 47</a>, in order for the
+undulatory theory to have any existence at all, it is essential that the
+Aether should possess the property of elasticity. But how the Aether
+possessed the property of elasticity while at the same time it was
+frictionless, and therefore possessed no mass, has been a problem that
+has taxed the ingenuity and resources of scientists for a century past,
+and up to the present is a problem which still remains unsolved. Now,
+however, with our atomic Aether, it is just as easy to conceive Aether
+transmitting a wave as it is for air to transmit sound waves, or water
+to transmit water waves.
+</p>
+
+<p>
+Tyndall, in his <i>Lectures on Light</i>, seems to have appreciated the
+difficulty, and to avoid confusion, again and again refers to a
+<i>particle</i> of Aether. While Huyghens himself in speculating upon the
+elasticity of the Aether in his <i>Traité de la Lumière</i>, 1678, makes a
+suggestion as to its origin, which practically amounts to the fact that
+the aetherial atom which gives rise to this elasticity is the core or
+centre of a vortex ring. Thus it can be seen that the elasticity of the
+Aether, so essential to the undulatory theory, is a problem that cannot
+be solved apart from recognizing the hypothesis of an atomic Aether.
+</p>
+
+<p>
+Then, again, in the undulatory theory of light, the density of the
+Aether around molecules of bodies has to be taken into consideration to
+account for such phenomena as the refraction and reflection of light,
+but, as we have seen in <a href='#ART_46'>Art. 46</a>, such a property as density is
+inconceivable in connection with a medium which is neither atomic and
+possesses no mass. On the assumption, however, of an atomic and
+gravitative Aether, the difficulty is at once solved, and the density of
+the Aether, and different degrees of density are at once placed upon a
+logical and philosophical basis. So that in relation to the elasticity
+and density of the Aether upon which the transmission and reflection of
+wave motion depend, an atomic and gravitative Aether establishes and
+confirms the undulatory theory.
+</p>
+
+<p>
+There is also another aspect of the subject that is worthy of notice. I
+refer to the effect of an atomic and gravitative Aether upon Newton's<span class='pagenum'><a name='Page_126' id='Page_126'></a><a href='#TOC'>[126]</a></span>
+corpuscular theory of light. Newton's corpuscular theory failed in not
+being able to account for the relative velocity of light in rare and
+denser media, and if by an atomic Aether in conjunction with the
+undulatory theory, the phenomenon can be accounted for, as I believe it
+can, then our aetherial vortex atoms are analogous to Newton's
+corpuscles. This distinction will, however, have to be made, viz. that
+Newton supposed his luminous corpuscles to be emitted by the luminous
+body, whereas in the conception of our aetherial atoms, we conceive them
+to be stationary relatively in space, and only subject to those
+vibrations and oscillations that give rise to the aetherial waves
+recognized in the undulatory theory.
+</p>
+
+<p>
+It would indeed be a consummation to be desired, if, by an atomic
+Aether, it can be proved that Newton's Corpuscular Theory was made to
+harmonize with the Undulatory Theory, and that it can be I am profoundly
+convinced. Professor Preston is also of this view, for in his <i>Theory of
+Light</i>, writing on this subject, he says, page 19: &ldquo;In conclusion, we
+may state that we believe an ingenious exponent of the emission theory,
+by suitably framing his fundamental postulates, might fairly meet all
+the objections that have been raised against it.&rdquo;
+</p>
+
+<p>
+We will now apply the hypothesis of an atomic and gravitating Aether to
+Huyghens' principle of wave propagation, and see if this atomicity in
+any way destroys that principle, or whether it simplifies and confirms
+it.
+</p>
+
+<p>
+Let us briefly review our conception of the Aether before making the
+application. In the first place, because Aether is gravitative, we
+learned from <a href='#ART_45'>Art. 45</a> that it surrounds all bodies in the universe, from
+the smallest atom to the largest sun or star in the firmament of heaven.
+Our sun, then, which is to our system the source of all its light, will
+be surrounded by what are practically spherical aetherial envelopes or
+shells which decrease in density as they recede from the sun (<a href='#ART_46'>Art. 46</a>).
+These aetherial shells are, according to our conception, made up of
+minute aetherial spherical vortex atoms possessing polarity and rotation
+(<a href='#ART_43'>Art. 43</a>), and these atoms will be closer together the nearer they are
+to the central body, because of the increased density of the Aether due
+to the attractive influence of the sun. Thus, when a wave motion is set
+up in the Aether around the sun by the intense atomic activity of that
+incandescent body, each atom of that aetherial spherical shell or
+envelope participates in the motion or impulse received, at one and the
+same time, so that the wave is transmitted from envelope to envelope, by
+the elasticity of the aetherial atoms which compose the envelope or
+shell. Thus the light wave is always spherical in form, or nearly so, as
+the rotational and orbital motion of the sun affect the exact shape of<span class='pagenum'><a name='Page_127' id='Page_127'></a><a href='#TOC'>[127]</a></span>
+the aetherial envelope as we shall learn more fully later on.
+</p>
+
+<p>
+Further, the wave front always takes the form of a sphere, as the waves
+are radiated out from the luminous body in all directions, and we shall
+learn, in the next article, that the vibrations are always in the wave
+front, that is, take place on the surface of each of these envelopes,
+and these vibrations are also transverse to the propagation of the wave.
+As these aetherial envelopes extend right into space, the wave is
+transmitted from envelope to envelope by means of the aetherial atoms
+with the velocity of 186,000 miles per second, but as each succeeding
+envelope possesses a larger surface than the preceding one, the
+intensity of the light is proportionally decreased. The surface of such
+envelope is always proportionate to the square of the radius, the other
+quantities remaining equal. So that the intensity of the light waves,
+which are coincident with the
+surface of each spherical envelope, will always vary inversely as the
+square of the distance from the luminous body, which agrees with the law
+of inverse squares that governs light and heat.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/141.jpg' width='400' height='183'
+alt='Fig: 4.'
+title='Fig: 4.' />
+</div>
+
+<p>
+We have considered the wave motion as a whole, that is, we have viewed
+it from the standpoint of the whole of the aetherial elastic envelope.
+Now we will look at the subject from the atomic standpoint, and see if
+it is in accordance with Huyghens' principle of wave propagation.
+</p>
+
+<p>
+We will suppose that an undulatory movement is started by a luminous
+body at point <i>A</i> situated in the Aether, and surrounded by that medium.
+<i>A</i> may represent a part of any luminous body, as the sun or star, while
+<i>B C</i> and <i>B' C'</i> represent a segment of the aetherial envelopes already
+referred to, which exist around the sun. We will further suppose that
+the small dots surrounding the luminous body represent the aetherial
+atoms forming the envelope, which transmit the impulse or energy
+received from the atomic vibrations of the luminous body. As each
+aetherial atom is moved or pushed forwards, each atom directly in<span class='pagenum'><a name='Page_128' id='Page_128'></a><a href='#TOC'>[128]</a></span>
+contact with it accepts and transmits the impulse. But each of these
+atoms stands in relation to those in front of them, as they did in
+relation to the first row of atoms, so to speak, and therefore exert a
+corresponding impulse on the front row.
+</p>
+
+<p>
+But the third row stands in relation to the fourth row as the second row
+did to the third, and so on to infinity. Thus each atom being surrounded
+by other atoms may be looked on as the centre of a new wave system, so
+that every particle of the wave system is itself a centre of a new wave
+system which is transmitted in all directions. As these innumerable and
+minute wave systems co-operate with one another, they form a principal
+wave system which is coincident with the surface of the spherical
+envelope, part of which is represented by <i>B C</i>. Then if we conceive of
+all the aetherial atoms in part of the principal wave system <i>B C</i>, as
+themselves becoming the centre of wave propagation, by their wave
+systems the principal wave will be transmitted further on into space to
+another aetherial envelope <i>B' C</i>', which represents part of another
+principal wave, which again is coincident with the surface of one of the
+spherical aetherial envelopes. So that by the action of the aetherial
+atoms which exist on all sides of the luminous body, the aetherial wave
+can be transmitted from atom to atom in more or less spherical form.
+</p>
+
+<p>
+Now let us compare this explanation of the transmission of light by an
+atomic Aether with the celebrated Huyghens' principle which is thus
+enunciated. &ldquo;When an undulatory movement propagates itself through an
+elastic medium, every <i>particle</i> imitates the movement of the particle
+first excited. But every particle stands in relation to the adjoining
+ones in exactly the same relation that the first particle did to its
+neighbours, and consequently must exert upon those surrounding it,
+exactly the same influence as the first did. Every vibratory particle is
+therefore to be regarded as if it were the originally excited particle
+of the wave system; and as the innumerable and simultaneous elementary
+wave systems co-operate with one another at each instant, we obtain
+exactly that principal wave system by which the elastic medium appears
+at any moment to be moved.&rdquo; Now here, in this statement, we have the
+definite term <i>particles</i> used several times by Huyghens. But in the
+generally accepted theory of the Aether, such a term is unknown and
+unrecognized, with the obvious result that the definite and simple
+statement of Huyghens loses all its simplicity and meaning. Replace,
+however, the non-atomic Aether as at present recognized, by an atomic
+and gravitating Aether, and then Huyghens' exposition or principle
+stands out in all its simplicity and clearness, and finds in an atomic<span class='pagenum'><a name='Page_129' id='Page_129'></a><a href='#TOC'>[129]</a></span>
+Aether its literal fulfilment and complete verification.
+</p>
+
+<p>
+In conclusion on this point, viz. that light is a mode of aetherial
+motion, let us endeavour to form a mental picture of our atomic and
+aetherial world. We have to remember that every particle and atom of
+matter in existence are ever vibrating, and by their vibrations are ever
+creating and generating Aether waves in the aetherial medium. These
+waves, begetting others, the process is continued until they are either
+intercepted and brought to rest by other matter, or else speed away
+until they reach the boundary of space.
+</p>
+
+<p>
+Now it is scarcely necessary for me to say, that if one atom can create
+and generate these Aether waves, a thousand atoms can create them in
+greater abundance still, and millions of atoms in even still greater
+abundance, and so on in proportion to the quantity or bulk of the matter
+vibrating. Further, as it is with quantity, so will it be with
+intensity, or activity of vibration. The more intensely an atom
+vibrates, the more intense would be the movement of the generated Aether
+waves, and the intensity would be in exact proportion to the intensity
+of the motion of the atoms vibrating. In regard to the power of atomic
+motions or vibrations, those are the greatest and most intense in energy
+or motion, which are produced by combustion or burning. The chemical
+activity by which the burning is brought about arouses and excites the
+atoms of matter subject thereto, into an intensity of motion, thousands,
+it may be millions of times greater than can be produced by any other
+known means. Therefore it can be readily seen, that the Aether waves
+generated by this means will be greater and more abundant, both in their
+volume and intensity, than the Aether waves produced merely by a cold
+body. For example, take a candle at night-time when the light has
+disappeared; look at it and feel it. Though its atoms are all in motion,
+generating Aether waves which are impressed with its own particular form
+and colour, yet it can scarcely be seen even at a short distance; but
+light it, and what a change takes place! We can both see it, and are
+enabled by its light to see other things also. By the power of
+combustion, its atoms have been excited into greater energy or motion,
+generating and speeding Aether waves on every side, and these Aether
+waves being reflected and re-reflected by the atoms of the air, and the
+walls of the house, give light to all that are in the house. I must now
+ask the reader to refer to <a href='#ART_64'>Art. 64</a> on Radiant Heat, in order that we may
+recall facts regarding the heat of the sun. Remembering the intensity of
+the heat of the sun as calculated by Herschel and others, and
+remembering that the sun is 1,200,000 times larger in volume than our<span class='pagenum'><a name='Page_130' id='Page_130'></a><a href='#TOC'>[130]</a></span>
+earth, the question naturally suggests itself to our mind, what must be
+the volume and intensity of the light waves as they flow from the sun
+into space? What a storm of fury and of motion must there be within the
+aetherial atmosphere around the sun, and with what volume and power must
+these light waves speed away from so mighty a source! Some idea may be
+gained from the fact that they speed away to the distant Neptune, a
+distance of nearly three thousand millions of miles, and impart to that
+planet the energy of light and heat which to the planet forms the
+physical source of all its life and activities. Thus from the sun, the
+centre of the solar system, there are ever being poured forth into space
+these aetherial light waves. The solar fires are ever glowing, and their
+flames ever burning, robing the solar disc with its quivering fringe, or
+madly leaping on every side to a distance of one hundred thousand miles,
+and by their madness lashing the aetherial atmosphere into fury,
+creating aetherial waves, myriads upon myriads, and sending them with
+lightning speed across the intervening space. As swift-footed messengers
+they come, the bearers of life and beauty to distant planets. They come
+to this our island home in space, these aetherial light waves, like rich
+argosies freighted with the treasures of light, of life, of beauty, and
+of glory, and the transmission of this life and beauty is effected by
+the incessant wave motion generated in the Aether by the central body of
+our solar system, the sun. Let us therefore endeavour to form a mental
+picture of this aetherial wave motion with its transverse vibrations.
+</p>
+
+<p>
+<a name='ART_71' id='ART_71'></a><span class='smcap'>Art</span>. 71. <i>Transverse Vibration of Light</i>.--In the previous article we
+saw that the vibration of light was transverse to the line of
+propagation. If we could see the particles of air which are vibrating
+when sound waves are produced, we should find that each particle or atom
+is vibrating backwards and forwards in the direction of propagation.
+</p>
+
+<p>
+In the case of an aetherial atom, however, which, according to our own
+theory, participates in the vibration, we have to try to conceive of
+each atom as vibrating across the line of propagation. So that if <i>A B</i>
+represents a ray of light proceeding from a luminous body, as the sun
+(Fig. 5), then the vibration must be across the line, as up and down and
+across that line as shown in the figure, each phase of the vibration
+being at right angles to the line of propagation--that is, to <i>A B</i>. How
+can we form a physical conception of this phenomenon? There must be some
+physical explanation to it, for if it be an effect there must be a cause
+for its existence and production. Up to the present, however, no
+physical explanation has been forthcoming, so that for over 200 years a
+frictionless medium has failed to account for, or to explain, the<span class='pagenum'><a name='Page_131' id='Page_131'></a><a href='#TOC'>[131]</a></span>
+transverse vibration of light as suggested by Fresnel.
+</p>
+
+<p>
+If, therefore, by the hypothesis of an atomic and gravitative Aether, we
+succeed in accomplishing a result that a frictionless Aether has failed
+to accomplish, then the explanation will be a most important factor in
+proving the atomicity and consequent gravitative property of the Aether.
+</p>
+
+<p>
+Let us therefore revert to our hypothesis of the Aether as given in <a href='#ART_45'>Art. 45</a>. From that we learn, because Aether is atomic, it is also
+gravitative, and therefore forms around every atom and molecule, every
+satellite, planet, sun and star, an aetherial
+atmosphere--such aetherial atmosphere being doubtless proportionate to
+the mass of the atom or molecule or planet as the case may be, in
+accordance with the Law of Gravitation. We shall consider this view of
+the subject later on.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/145.jpg' width='400' height='313'
+alt='Fig: 5.'
+title='Fig: 5.' />
+</div>
+
+<p>
+Thus we learn that every particle of matter, and every body in the
+universe has its aetherial atmosphere so to speak, to which it is held
+bound by the universal Law of Gravitation. In the case of a satellite or
+planet or sun or star, that atmosphere will be more or less spherical in
+shape, decreasing in density as it recedes from the attracting body. As
+we saw in the previous chapter, Tyndall stated that the waves of light
+really formed spherical shells which surrounded the luminous body. In
+the conception of an atomic and gravitating Aether we can form a
+physical conception of these aetherial shells, which can be pictured as<span class='pagenum'><a name='Page_132' id='Page_132'></a><a href='#TOC'>[132]</a></span>
+elastic envelopes, or rather series of envelopes surrounding each
+particle of matter, and also surrounding each satellite, planet, sun,
+and star; each envelope getting gradually less and less dense as the
+distance from the central body is increased.
+</p>
+
+<p>
+Now we learn from experiments that the vibration is always in the wave
+front, but the wave front is coincident with the surface of each
+aetherial spherical shell, therefore the vibration must be in, and
+coincide with, the surfaces of the spherical shells that are formed
+around every body in the universe.
+</p>
+
+<p>
+We are now, however, dealing specially with one body which is the source
+of light, viz. the sun, and have therefore to picture the sun as being
+surrounded by these aetherial elastic envelopes, which gradually get
+less and less dense as they recede from it. What, therefore, will be the
+effect of the heat of that body as it is poured forth into space? We
+have already learned (<a href='#ART_63'>Art. 63</a>) of the untold quantity of heat that is
+continually being poured forth into space from the sun with its diameter
+of 856,000 miles, and its circumference of over 2-1/2 million miles.
+What intense activity it must generate in the Aether near its surface!
+and what must be the direct effect of that heat upon the aetherial
+elastic envelopes or shells which surround it?
+</p>
+
+<p>
+Perhaps the answer can be best illustrated by a simple experiment. Let
+us take an ordinary toy balloon, with its elastic envelope, and fill it
+moderately full with air, and observe what the effect on it is when we
+put it near the fire. Gradually, as heat is imparted to the air in the
+balloon, the air which is also elastic expands, with the result that the
+envelope of the balloon is extended, and its size enlarged. Now withdraw
+it from the fire and note what happens.
+</p>
+
+<p>
+As the air inside gets cold again, the elastic envelope of the balloon
+gradually shrinks, until it has been reduced to its former size. What
+has been taking place during this experiment with regard to the elastic
+envelope and the atoms thereof? May we not say that there has been a
+vibration or oscillation, among the particles which go to make up the
+elastic envelope, that forms the surface of the balloon? Certainly there
+has been some form of motion, and that motion took first the form of an
+expansion, and then contraction of the individual particles; and we have
+only to conceive of this process being repeated quickly and
+continuously, to form a mental picture of what takes place in any
+aetherial elastic envelope or shell that surrounds the sun.
+</p>
+
+<p>
+The illustration is not, however, perfect, because we have made the
+source of heat to be outside instead of inside the elastic envelope, as
+is the case with the sun and its aetherial atmosphere or envelope. We<span class='pagenum'><a name='Page_133' id='Page_133'></a><a href='#TOC'>[133]</a></span>
+will therefore slightly modify the experiment, and take two balloons,
+<i>A, B</i>, one smaller than the other, and put the smaller one <i>A</i> into the
+interior of the larger one, inflating the smaller one, so that it can be
+situated in the middle of the larger one, the latter having twice the
+diameter of the smaller one, as in the diagram (Fig. 6). To the neck of
+the smaller balloon <i>A</i> we will attach an india-rubber tube which ends
+in a closed bulb <i>C</i>. We have now the two balloons inflated. Let us
+press the bulb <i>C</i> and notice what happens. The effect will be exactly
+the same as it was when we brought the balloon in contact with the heat
+of the fire in the first experiment--that is, the elastic envelope will
+be again expanded. As soon as we take the pressure from the bulb <i>C</i> the
+envelope, being elastic, seeks to recover its original position, with
+the result that it springs back to its original size. If we pressed the
+bulb <i>C</i> 20 times per minute, we should get 20 vibrations of the
+particles of the envelopes per minute, and if we pressed it 1000 times
+per minute, we should get 1000 vibrations among the particles of the
+elastic envelope, so that the number of vibrations would correspond to
+the number of times we pressed the bulb. Now how did this vibration
+reach the elastic envelope of the balloon <i>B</i> from the balloon <i>A</i>?
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/147.jpg' width='400' height='334'
+alt='Fig: 6.'
+title='Fig: 6.' />
+</div>
+
+<p>
+The reply is, by means of the particles, or atoms of air that exist
+between the two surfaces of the balloons, and that transmission would
+take the form of a wave propagated from particle to particle, so that we
+might put dots on the right side of <i>A</i> to represent the atoms of air
+which transmit the wave from <i>A</i> to <i>B</i>.
+</p>
+
+<p>
+But the vibration which takes place in the surface of the envelope of
+the outer balloon is <i>across</i> this line of propagation, because as the
+wave proceeds from <i>A</i> to <i>B</i>, the elastic envelope expands and<span class='pagenum'><a name='Page_134' id='Page_134'></a><a href='#TOC'>[134]</a></span>
+stretches always <i>across</i> the line of propagation--that is, it stretches
+up and down, left and right, as it is expanded outwards, so that the
+vibration or oscillation of the particles always takes place in the
+surface of the elastic envelope across the line of propagation. Let us
+therefore apply the result of this simple experiment to our solar system
+and the Aether, and see if it can be made to explain the transverse
+vibration of light. Let <i>A</i> represent the sun (Fig. 7) and <i>B</i> an
+aetherial elastic envelope surrounding the sun. In this case we dispense
+with the bulb <i>C</i>, as the sun possesses within itself the power to
+generate heat, and so to produce the required expansion of the elastic
+aetherial envelopes <i>B, G, H</i>, etc.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/148.jpg' width='400' height='275'
+alt='Fig: 7.'
+title='Fig: 7.' />
+</div>
+
+<p>
+Instead, however, of having air particles between <i>A</i> and <i>B</i>, we will
+put in their place our aetherial atoms which we have conceived according
+to <a href='#ART_44'>Art. 44</a>. These surround the sun, represented by <i>A</i>, forming elastic
+spherical shells or envelopes. As the sun radiates its heat into space,
+it urges the aetherial atoms against each other, with the result that
+they transmit the energy from atom to atom, or particle to particle,
+till they come to the elastic aetherial envelopes of <i>H, G, B</i>.
+</p>
+
+<p>
+The effect on <i>B</i>, or on any other aetherial envelope, is to expand it
+outwardly, and thus set the atoms of which it is composed into
+vibration. The wave, which is now an aetherial wave travelling with a
+velocity of 186,000 miles per second, may be represented by the line <i>D
+E</i>. But while it is travelling from <i>D</i> to <i>E</i> the same energy is being
+radiated out in all directions, so that a wave reaches the whole surface
+of the elastic envelope <i>B</i> at the same time, with the result that the
+whole of the shell or envelope is set in vibration as it expands
+outwardly.
+</p>
+
+<p>
+Thus the vibration is always in the wave front, and the wave front is
+always coincident with the surface of one of these envelopes, and as<span class='pagenum'><a name='Page_135' id='Page_135'></a><a href='#TOC'>[135]</a></span>
+these aetherial envelopes are themselves formed by aetherial atoms, the
+wave is spread outwardly from any central point in a spherical form as
+proved by experiment. Not only, therefore, is the vibration in the wave
+front, but it is always transverse to the line of propagation, for the
+simple reason that the surface of the spherical shell or envelope is
+always at right angles to the radius vector or straight line which joins
+any centre to the surface of a spherical envelope.
+</p>
+
+<p>
+As soon as the aetherial atom which forms the spherical aetherial
+envelope has reached the limit of its expansion, it seeks to recover its
+former position because of its elasticity, with the result that the
+whole envelope contracts again, and arrives at its original position in
+space ready to accept motion again and transmit it onwards in the same
+manner as before.
+</p>
+
+<p>
+Thus, by the acceptance of an atomic and gravitating Aether, we may form
+a physical conception of one of the greatest problems in optical
+phenomena, viz. the transverse vibration of light which always takes
+place in the wave front, and across the line of propagation. Whether
+this explanation is exactly correct in detail, or not, I am convinced
+that the true physical explanation of the problem is to be found in an
+atomic and gravitating Aether, as hitherto a frictionless Aether has
+failed even to suggest to any scientist how such a transverse vibration
+can take place.
+</p>
+
+<p>
+<a name='ART_72' id='ART_72'></a><span class='smcap'>Art</span>. 72. <i>Reflection and Refraction</i>.--A ray or wave of light is said to
+be reflected when it meets with an obstacle which opposes its free
+passage and turns it back. We have illustrations of this law of
+reflection in the case of water waves striking against a breakwater, or
+a sound wave striking against the wall of a room. In either case the
+wave is turned back, and reflection is the result. A ray or a wave of
+light is said to be refracted when, in passing from one medium into
+another, it is turned from the straight path in which it was going
+before it entered the refracting medium. An illustration of the
+refraction of light is to be found in the case of the glass lens, so
+often used to converge the light waves into one focus. We have up to the
+present dealt with only two theories of light, the Corpuscular theory
+and the Undulatory or Wave theory. We have seen how both harmonize with
+Huyghens' principle, and the question arises as to whether both can be
+made to harmonize with the phenomena of reflection and refraction.
+</p>
+
+<p>
+In the Corpuscular theory we have luminous particles emitted by luminous
+bodies. These particles we have learned are practically synonymous with
+our aetherial atoms.
+</p>
+
+<p>
+In the Wave theory it is impossible to conceive of a wave without
+conceiving of particles which transmit the wave; even Huyghens refers<span class='pagenum'><a name='Page_136' id='Page_136'></a><a href='#TOC'>[136]</a></span>
+to particles of Aether, and so does Tyndall in his <i>Notes on Light</i>.
+</p>
+
+<p>
+In the Electro-magnetic theory of light we have again to think of atoms,
+which are termed electrons by Dr. Larmor and Sir William Crookes; while
+Professor J. J. Thompson calls them corpuscles.
+</p>
+
+<p>
+So that in all three theories we have the same fundamental idea of
+atoms, either expressed or imagined, underlying all the three theories.
+Now what is the property of the Aether on which all reflection and
+refraction is based? Is it not the property of density? Fresnel assumes
+that reflection and refraction of light are dependent upon different
+degrees of density of the Aether associated with any body, and has given
+a mathematical formula, which decides the index of refraction, such
+formula being entirely dependent upon the relative density of the Aether
+in association with the refracting medium.
+</p>
+
+<p>
+But with a frictionless medium, it is an absolute impossibility to
+conceive of different degrees of density of the Aether in association
+with matter.
+</p>
+
+<p>
+If the Aether does possess different degrees of density which decide the
+refractive index of the substance, then of a certainty there must be
+some law to govern and decide the density, and that law can only be the
+Law of Gravitation.
+</p>
+
+<p>
+As Young points out in his Fourth Hypothesis, every particle of matter
+has an attraction for the Aether by which it is accumulated around it
+with greater density. Now on the basis of our conception of a
+gravitative Aether, every atom and molecule, and indeed every body in
+the universe, possess aetherial atmospheres, which possess varying
+degrees of density, the denser layers being nearest to the nucleus of
+the atom or molecule as the case may be, the elasticity of each layer or
+envelope being always proportionate to its density.
+</p>
+
+<p>
+When we apply the corpuscular theory to the reflection of light we find
+that it satisfactorily accounts for the phenomenon.
+</p>
+
+<p>
+According to Newton's corpuscular theory, each luminous particle travels
+in a straight line through a homogeneous medium. When, however, it comes
+almost into contact with a reflecting surface, which in our case we
+conceive to be a layer of one of the aetherial elastic envelopes
+surrounding the atoms or molecules of the reflecting body, then,
+according to Newton, the light particle is repelled, or reflected by the
+medium; the angle of reflection or repulsion being always equal to the
+angle of incidence. So that the emission theory harmonizes with the wave
+theory in regard to reflection.
+</p>
+
+<p>
+When, however, we come to deal with the refraction of light, the
+corpuscular theory apparently breaks down, and it was in relation to<span class='pagenum'><a name='Page_137' id='Page_137'></a><a href='#TOC'>[137]</a></span>
+this phase of the phenomena of light that the undulatory theory
+overthrew the corpuscular theory.
+</p>
+
+<p>
+According to the corpuscular theory, when a luminous particle or
+corpuscle is nearing the surface of a denser medium, as glass or water,
+it was attracted by the denser medium, with the result that the velocity
+of the particle in the denser medium was greater than its velocity in
+air. But direct experiments prove exactly the opposite, as it is found
+that when light passes from a rare into a denser medium, the velocity of
+light in the denser or more refracting medium is less than it was in the
+air. Here then was a test to decide the respective merits of the two
+theories. As the undulatory theory was able to give a satisfactory
+explanation of the phenomenon, the corpuscular theory was rejected, and
+the undulatory theory was accepted. Now the question suggests itself, as
+to whether it is possible to reconcile the two theories in relation to
+the refraction of light by our conception of an atomic and gravitative
+Aether. I believe it is possible. Let us look at the case for a moment.
+We have, according to our theory of the Aether, to conceive of all atoms
+and molecules, of all planets and suns and stars, being surrounded by
+aetherial elastic atmospheres, or envelopes, which, like the atmosphere
+in association with the earth, are always the densest nearest the
+nucleus of the atom, getting gradually less and less dense the further
+they recede from the central point. Further, according to our theory,
+with regard to the elasticity or pressure of these elastic envelopes,
+they exert a pressure proportionate to their density. So that the nearer
+the aetherial atmosphere or envelope is to the central point or nucleus
+of the atom, the greater will be the elasticity or pressure.
+</p>
+
+<p>
+Now what I wish to call the reader's special attention to is, that the
+pressure in each and every case of the aetherial elastic envelopes which
+surround the central nucleus, is always directed <i>away from</i> the central
+point, and here it seems to me is the solution of the difficulty which
+Newton failed to solve. For when a luminous corpuscle enters any medium,
+assuming it to do so, it would have to overcome the pressure due to the
+increased elasticity of the denser aetherial envelopes, and as the two
+motions, viz. that of the incident ray, and the pressure due to the
+elasticity of the elastic envelope, would be in opposition to each
+other, the result would be that the luminous corpuscle, if it entered
+the medium at all, would be retarded and not accelerated as suggested by
+Newton, and such a result is perfectly in harmony with experiment. So
+that by our theory of an atomic and gravitating Aether, it seems to me
+that it now becomes possible to reconcile the two theories.
+</p>
+
+<p>
+There is another difficulty that the emission theory had to contend<span class='pagenum'><a name='Page_138' id='Page_138'></a><a href='#TOC'>[138]</a></span>
+with, and that was, how was it possible for the same surface of any
+substance to reflect and refract a corpuscle at one and the same time?
+Newton overcame this difficulty by suggesting, from the results of his
+observations on certain coloured rings, that each particle had what he
+called certain phases or fits, of easy reflection or refraction, so that
+at certain times they would be refracted, and at other times they would
+be reflected.
+</p>
+
+<p>
+Boscovitch has suggested that the fits were due to the fact that each
+luminous corpuscle possessed polarity; which, by rotating, alternately
+offered their different sides to the refractive and reflecting surfaces,
+so that sometimes they would be reflected or repelled, and at other
+times attracted or refracted.
+</p>
+
+<p>
+A similar hypothesis has also been suggested by Biot. Now if such a
+hypothesis will satisfactorily account for the fact that the same medium
+will reflect or refract the luminous corpuscles, as the case may be,
+then in our aetherial atom we have the very conditions which would
+satisfy both Boscovitch and Biot's hypothesis. For one of the properties
+that we suggested regarding our aetherial atom was, that it possessed
+rotation like our own earth, and that it also possessed polarity.
+</p>
+
+<p>
+The harmonizing of the two theories, therefore, seems to rest upon the
+atomicity or non-atomicity of the Aether.
+</p>
+
+<p>
+It is absolutely certain that the electro-magnetic theory of light
+demands the recognition of some form of atomicity for the Aether. For if
+light be really an electro-magnetic phenomena, as has been proved by
+Maxwell and experimentally demonstrated by Hertz, then, in view of the
+fact that the atomicity of electricity is coming within the scope of
+direct experiment as asserted by Dr. Larmor, unless we accept atomicity
+of the Aether in some way, we shall be in the unphilosophical position
+of having the Aether of space not being composed of atoms, while the
+electricity associated with that Aether in some unknown way is composed
+of atoms. In other words, we shall have a non-atomic body composed of
+atoms, which conclusion is absurd. Therefore, from the electro-magnetic
+theory of light, we are again compelled to postulate atoms of some kind
+for the Aether.
+</p>
+
+<p>
+If there are electrical atoms in association with the Aether, then they
+must be of two kinds, positive and negative, as it is impossible to find
+positive electricity disassociated from negative. Therefore, from the
+electro-magnetic theory of light we get further evidence of the polarity
+of the aetherial atom, by which Newton's fits of easy reflection or
+refraction may be physically conceived.
+</p>
+
+<p>
+I am convinced, that with the hypothesis of an atomic and gravitative
+Aether as suggested by Young in his Fourth Hypothesis, all three
+theories of light in relation to the phenomena of reflection and
+refraction can be harmonized. I wish only to point out the direction in<span class='pagenum'><a name='Page_139' id='Page_139'></a><a href='#TOC'>[139]</a></span>
+which to look for the solution, and must leave it to scientists to work
+out the problem.
+</p>
+
+<p>
+<a name='ART_73' id='ART_73'></a><span class='smcap'>Art</span>. 73. <i>The Solar Spectrum</i>.--When a ray or beam of solar light is
+passed through a prism, it is broken up or decomposed into its
+constituent parts. This is called dispersion, and conclusively proves
+that the light from the sun is not a simple, but a compound colour. We
+have illustrations of this decomposition of pure white light in the
+rainbow, where the colours of the sunlight are revealed against the sky
+with clearness and precision. A simple experiment to prove that the
+solar light is a compound one may be made by boring a small hole in a
+shutter, and then allowing the sunlight that passes through the hole to
+fall upon a prism, such as the pendant of a candelabrum. When this is
+done, then on the opposite wall of the room will be seen, not one
+colour, but seven colours, ranged in the following order: Red, Orange,
+Yellow, Green, Blue, Indigo, Violet. This is termed the Visible
+Spectrum.
+</p>
+
+<p>
+It may be asked, What is the cause of the various colours in the
+spectrum? We have already seen that light is due to a wave motion of the
+Aether, and it can be demonstrated that the various colours of light are
+due to different wave lengths. Colour is to light what pitch is to
+sound. As has been shown in <a href='#ART_62'>Art. 62</a>, the pitch of a note depends upon
+the number of air waves which strike upon the tympanum of the ear in a
+given time. The more rapid the vibration, the higher the note. The more
+rapidly a sounding body vibrates, the shorter will be the length of each
+wave. If a violinist wants to produce a note of higher pitch, he presses
+his finger on the string, thereby shortening it, and by so doing
+increases the rapidity of vibration, and raises the pitch of the note.
+Now the colours of the spectrum are to the eye what the notes are to the
+ear. The aetherial waves which produce the red colour are slower in
+their vibrations, and are longer than those which produce the orange
+colour. Those which produce the orange colour are of slower vibrations,
+and longer than those which produce the yellow colour, and so on through
+all the other colours; until we get to the violet and to the
+ultra-violet, or invisible violet rays, which are the most rapid in
+their vibrations, and consequently their wave lengths are the shortest
+of the whole group. It has been ascertained that it takes about 39,000
+waves of red light to measure an inch if placed end to end. Now light
+has a velocity of 186,000 miles per second. If this is reduced to
+inches, we find that there are 11,784,960,000 in that distance. Let us
+therefore multiply this number by 39,000, and we shall then find how
+many waves of red light must enter the eye to produce the sensation of
+red colour. That number is 459,613,440,000,000, so that all these waves<span class='pagenum'><a name='Page_140' id='Page_140'></a><a href='#TOC'>[140]</a></span>
+enter the eye in one second of time, and must strike the retina of the
+eye in order to produce the sensation of redness. In the same way, the
+number of waves that must strike the retina of the eye to produce the
+sensation of violet can be determined. It takes about 57,500 waves of
+violet to measure an inch, so that a violet wave is only 1/57000 part of
+an inch in length. All the other colours of the spectrum which lie
+between the violet and the red waves gradually get longer and longer in
+their wave lengths, and slower and slower in their vibrations, until at
+the red end of the spectrum and beyond it we have the longest waves,
+which are from 1/39000 part of an inch in length to 1/10000 part of an
+inch.
+</p>
+
+<p>
+The seven colours seen in the spectrum are called the Visible Spectrum.
+There are, however, rays of light beyond both ends of the spectrum which
+do not affect the optic nerves of the eye, and therefore are invisible
+to sight. The rays in the spectrum which lie beyond the red are termed
+ultra-red rays, while those beyond the violet are called ultra-violet
+rays. It can be proved the former are rich in heating power, while the
+latter possess great chemical power. By means of an instrument known as
+the thermo-electric pile, or thermopile, the various heating power of
+the whole spectrum, visible and invisible, can be determined.
+</p>
+
+<p>
+Let us look for a moment at these invisible or dark rays. Strictly
+speaking, all light is invisible, as we cannot see light itself, we can
+only see it by reflection. We have seen that light is due to a wave
+motion in the Aether, but we cannot see that wave motion, neither can we
+see the Aether itself, so that it is not strictly correct to call a ray
+visible or invisible. We have, however, accepted the terms in relation
+to the rays of the spectrum, to distinguish between the invisible or
+obscure rays of the spectrum and the visible rays. It was Sir W.
+Herschel who first discovered the existence of these invisible waves. He
+passed a thermometer through the various colours of the solar spectrum,
+and then noted the temperature of each colour. He did not, however, stop
+at the limit of the visible spectrum, but experimented with his
+thermometer beyond its limits, and then found that beyond the red rays
+there were other rays, the ultra-red rays, which possessed greater
+heating power than any other rays of the spectrum. Thus his experiments
+proved, that side by side with the luminous or light waves, there were
+other rays, which, though they possessed greater heating power, yet were
+not able to excite the optic nerve, and so produce the sensation of
+sight.
+</p>
+
+<p>
+From these facts we learn that the solar spectrum may be divided into
+three parts--<span class='pagenum'><a name='Page_141' id='Page_141'></a><a href='#TOC'>[141]</a></span>
+</p>
+
+<p>
+1. The red or ultra-red end of the spectrum which possesses
+the greatest heating power.
+</p>
+
+<p>
+2. The central part, yellow and green, which is the greatest in luminous
+power or light waves.
+</p>
+
+<p>
+3. The violet or ultra-violet end, which possesses great chemical or
+actinic power as it is sometimes termed.
+</p>
+
+<p>
+We have already seen (<a href='#ART_69'>Art. 69</a>) that the same aetherial waves which give
+rise to heat, also give rise to light, and that the only physical
+difference between heat and light is, that the waves which cause the
+phenomena of heat are of slower period, and of greater length, than
+those which cause the phenomena of light. From the solar spectrum we
+learn that there are a third class of Aether waves, which are of more
+rapid vibration, and therefore shorter in length than either the
+aetherial heat waves or the aetherial light waves. As already stated,
+these are called chemical or actinic waves, because they possess a
+greater chemical power than either the heat or the light waves that form
+the central part of the spectrum.
+</p>
+
+<p>
+Now this question suggests itself to us in relation to these chemical
+waves. What are these so-called chemical waves that are produced in the
+aetherial medium by the activity and heat of the sun? It must be
+remembered that the aetherial waves which give rise to both light and
+heat, and also these chemical waves, are first set in motion by the sun,
+at least as far as our solar system is concerned. We are perfectly
+conversant with the phenomena and characteristics of both heat and
+light. We are able to exactly determine what their particular effect
+will be on matter, and to describe that effect in a perfectly
+straightforward manner. The same, however, cannot be said of these
+so-called chemical waves that lie chiefly in the violet and ultra-violet
+end of the solar spectrum. What, then, is a chemical wave, its
+particular nature, and its exact properties? That we know it can
+decompose certain compounds, as Carbonic Acid Gas, CO<sub>2</sub>, and so give
+rise to chemical decomposition, has been proved by Professor Tyndall and
+others, but I have never yet seen any record of any attempt to find out
+what these chemical waves are. There may have been such attempts made to
+discover their origin and character, but I have not seen any such
+record. I purpose, therefore, to offer an explanation as to the
+character and origin of these chemical or actinic waves, which I hope to
+prove by philosophical reasoning. We have already seen (<a href='#ART_54'>Arts. 54</a> and <a href='#ART_59'>59</a>)
+that both heat and light are convertible, or can be transformed into
+electricity, so that the same aetherial wave motion which can produce
+light can also produce heat, and that in its turn can produce
+electricity. Thus we learn that there is a very close identity between
+light, heat, and electricity; indeed it can be demonstrated that the<span class='pagenum'><a name='Page_142' id='Page_142'></a><a href='#TOC'>[142]</a></span>
+same aetherial wave motion which produces electricity can produce the
+other two.
+</p>
+
+<p>
+Lorentz,<a name='FNanchor_13' id='FNanchor_13'></a><a href='#Footnote_13' class='fnanchor'>[13]</a> in an article on &ldquo;The Identity of Light Vibrations with
+Electric Currents,&rdquo; states that &ldquo;the vibrations of light are themselves
+electric currents.&rdquo; Now if this is true, and I believe it to be true, as
+I hope to prove later on from Clerk Maxwell's works, then it necessarily
+follows, that wherever we get aetherial light waves, we must at the same
+time also get aetherial electric waves. If that be so, then in the solar
+spectrum we ought to have revealed to us, not only indications of the
+presence of the heat and light vibrations, but equally so the presence
+of electric waves. This, I believe, is actually the case, and the
+electric waves are the so-called chemical waves in the violet and
+ultra-violet end of the spectrum. I think that we shall find sufficient
+arguments and analogy to support this hypothesis, as we look further
+into the matter. One of the greatest scientists of the past century,
+Clerk Maxwell, has given to the world the genesis of what he termed the
+Electro-Magnetic Theory of Light, in which he proved that light was
+nothing more nor less than an electro-magnetic phenomenon. He pointed out
+that the same Aether which was concerned in the propagation of light and
+heat through space, must therefore be equally concerned in the
+propagation of electric displacements in the free Aether; as he states,
+it would be philosophically wrong to assume that there was one aetherial
+medium for light, and another for electric phenomena. If, therefore,
+there is such a theory as the Electro-Magnetic Theory of Light, and
+there undoubtedly is, as has been proved by the researches of Hertz on
+electric waves, then it follows, either that light waves are themselves
+electric currents, as suggested by Lorentz, or that the light waves are
+directly associated with electric waves in the same way that they are
+associated with heat waves. So that the only difference between them
+would be one of period of vibration and of length, the electric waves of
+the Aether being of greater rapidity and therefore of shorter length
+than either the light or heat waves. The only conclusion, therefore,
+that it seems possible to come to regarding these chemical waves is,
+that they are the electric waves of the spectrum. Thus, in the solar
+spectrum, there are three classes of waves indicated by the various
+colours, and beyond the limits of these colours, viz. (1) Thermal or
+Heat waves in the red or ultra-red end of the spectrum; (2) Luminous or
+Light waves at the middle of the spectrum; and (3) Electric or Chemical
+waves in the violet or ultra-violet end of the spectrum. Now in looking
+at this hypothesis from the standpoint of our Rules of Philosophy, I venture<span class='pagenum'><a name='Page_143' id='Page_143'></a><a href='#TOC'>[143]</a></span>
+to assert that all the three rules are satisfactorily fulfilled, and
+that being so, the hypothesis advanced is philosophically correct. In
+the first place, such a conception that the chemical waves or violet
+waves are really electric waves is simple in its hypothesis, and so
+fulfils our first Rule of Philosophy. It is simple, because it puts in
+the place of unknown chemical waves, a certain kind of aetherial waves
+with whose action we are definitely familiar, and whose origin and
+effect can be satisfactorily accounted for, as proved by Hertz. Chemical
+waves are not simple in conception, because we do not know exactly what
+they are, or how they are originated. Besides, as Newton points out,
+there is nothing superfluous in Nature. If one cause can effect the
+desired end, as electric waves, then another cause as chemical waves is
+superfluous and unnecessary. Further, in our hypothesis of the electric
+character of these chemical waves, we have a solution which
+satisfactorily fulfils the second Rule of our Philosophy. Experience and
+experiment teach us, that there are electric waves constantly being
+generated in a thousand ways. Indeed, it is an absolute impossibility to
+perform the simplest act of ordinary life, as brushing a hat, or wiping
+the boots on a mat, cutting an orange, or any other act of simple
+everyday life, but that these aetherial electric waves are generated.
+But as for these so-called chemical waves, experience has little to say
+about them, and experiment still less. If we decompose water, dividing
+it up into two gases, Oxygen and Hydrogen, we do it by passing a current
+of electricity through the water. If we want to decompose or split up a
+binary compound, as HCl, into its two elements, Hydrogen and Chlorine,
+then we can do it by electricity--that is, by the decomposing action of
+these electric waves. In all these experiments and results we know
+definitely what we are doing, and what the effect will be. There is no
+vagueness about the terms used. When we speak of chemical action we look
+to a definite source for that action, and we do not say that such action
+is produced by chemical waves, but rather by electricity. So that all
+experience teaches us, and all experiments made by such men as Faraday,
+Davy, Maxwell, and Hertz confirm the statement, that these aetherial
+electric currents can accomplish all that the so-called chemical waves
+accomplish, and that being so, the third Rule of our Philosophy is also
+fulfilled, as we have in the aetherial electric waves a satisfactory
+explanation for the fact which we seek to explain, viz. the character
+and origin of the chemical waves that exist in the violet end of the
+spectrum. Thus, we learn, that not only is the sun the source of all
+heat and light, in that it gives rise to the vibrations of the Aether
+which are propagated through it in waves, but that it is also the<span class='pagenum'><a name='Page_144' id='Page_144'></a><a href='#TOC'>[144]</a></span>
+source of all electric waves in the solar system, in that electric
+currents are primarily due to the wave motion set up in the Aether,
+those electric waves also traversing space with the velocity of light.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_13' id='Footnote_13'></a><a href='#FNanchor_13'><span class='label'>[13]</span></a>
+<i>Phil. Mag</i>., 1867.
+</p></div>
+
+
+<p>
+<a name='ART_74' id='ART_74'></a><span class='smcap'>Art</span>. 74. <i>Direction of Ray of Light</i>.--In <a href='#ART_65'>Art. 65</a> it was shown that the
+direction of a ray of heat was that of a straight line from the heated
+or luminous body from which the Aether waves proceeded. We have also
+seen in <a href='#ART_69'>Art. 69</a> that the aetherial waves which give rise to the
+phenomena of heat are identical with those that give rise to light, so
+the direction of a ray of light must also be that of a straight line
+proceeding from the luminous body. A ray of light is a line
+perpendicular to the Aether waves which are propagated through space in
+concentric spheres from the luminous body, which, by its atomic
+vibrations, gives rise to the light waves. It must, however, be
+remembered that rays have no physical existence, for it is the waves
+that are propagated, and not the ray, which simply indicates the
+direction that the light takes, this truth being known as the
+rectilineal propagation of light. That light proceeds in straight lines
+may be proved in several ways. For example, we cannot see round corners,
+which would be possible if light took a curved path instead of a
+straight one. A better proof, however, may be obtained by making a small
+hole in the window-shutter, and allowing the sunlight to pass into the
+darkened room. The beam of light which passes into the room will then be
+seen to take a straight course, its presence being revealed by the
+particles of dust that float about the room.
+</p>
+
+<p>
+Another conclusive proof that light proceeds in straight lines is to be
+found in the fact, that all images formed on any screen by the rays of
+light after passing through a small hole are inverted. For example,
+suppose we have a window-shutter with a small hole in it, while in the
+garden fronting the window there stands a tree. Now if the rays of light
+which pass from the tree through the hole in the window-shutter are
+allowed to fall upon a screen in the darkened room, it will be found
+that the image is inverted.
+</p>
+
+<p>
+This is accounted for by the fact, that the rays cross each other at the
+hole, and proceeding in straight lines, form an inverted picture on the
+screen. It can further be proved, that the path of a ray of light
+through space as it proceeds from the sun is also that of a straight
+line. Whenever there is a solar eclipse we have light so long as we can
+see the smallest part of the sun's surface. The instant, however, that
+we have a total eclipse, at that instant the whole of the light of the
+sun is shut off, and for a brief space there is darkness, until the
+planet which is causing the eclipse has passed on in its orbit and the<span class='pagenum'><a name='Page_145' id='Page_145'></a><a href='#TOC'>[145]</a></span>
+sun's surface reappears again. Now if light did not proceed in
+straight lines, such an event as a total eclipse would be impossible;
+because, if the light proceeded in curved lines instead of straight ones
+from the sun, then even when the planet which causes the eclipse got
+directly between the earth and the sun, the rays of light being curved
+instead of straight would bend round the eclipsing planet, and so would
+not all be intercepted, and thus such an event as a total eclipse would
+be an impossibility. From this we learn, therefore, that the path of a
+ray of light as it proceeds from the sun through space is that of a
+straight line, and that the path corresponds to the radius vector of a
+circle, which is also the path that the centripetal force takes.
+</p>
+
+<p>
+Viewing the matter from the standpoint of the solar system, we find the
+sun, which is the centre of that system, exerting an attractive force
+along the radius vector of all the orbits of the planets, with a force
+which decreases in intensity inversely as the square of the distance. At
+the same time, being the source of all light, it is constantly
+propagating into space aetherial light waves with a velocity almost
+inconceivable; which also decrease in exactly the same ratio as the
+attractive power of the sun decreases. If, therefore, it can be shown
+that there is such a truth as the dynamical value of light, in the same
+way that it has been shown that there is a dynamical value of heat, then
+it follows, that not only is the sun the centre of an attractive power
+which proceeds in straight lines, but it is equally the centre of a
+power whose influence and motion are exerted along exactly the same path
+as the centripetal force, but in an opposite direction, that is, away
+from the sun. I hope to be able to show that the aetherial light waves
+do possess such a dynamical value, and if that is accomplished, then not
+only from the realm of heat, but also from the realm of light, we shall
+have conclusive evidence of a power or motion whose influence is
+directed away from the sun, which, therefore, would correspond to a
+centrifugal force--that is, a force or motion directed from a central
+body as the sun.
+</p>
+
+<p>
+<a name='ART_75' id='ART_75'></a><span class='smcap'>Art</span>. 75. <i>Intensity of Light</i>.--The intensity of light diminishes with
+the distance from the luminous body, according to the same law that
+governs sound, and heat, and electricity. We have already seen (<a href='#ART_67'>Art. 67</a>)
+that the intensity of heat diminishes inversely as the square of the
+distance, so that if the same law holds good for light that holds good
+for heat, then, according to the law of the inverse squares, if we
+double the distance from the luminous body, the intensity of light is
+only 1/4 of what it was in its first position. If the distance be
+trebled, then the intensity will be decreased 1/9. This can easily be
+proved by the following experiment: Suppose we have a lighted lamp, and<span class='pagenum'><a name='Page_146' id='Page_146'></a><a href='#TOC'>[146]</a></span>
+at a distance of 1, 2 and 3 feet respectively, we have three square
+surfaces. It can then be demonstrated that the light which falls on the
+square 1 foot away, if allowed to fall upon the square 2 feet away,
+would cover four times the area of the first square; and if allowed to
+fall on the square 3 feet away, it would cover nine times the area.
+Therefore the intensity of the light on the square 2 feet away, covering
+four times the area, would only be 1/4 of what it is on the square 1
+foot away, while the intensity of light on the square 3 feet away, which
+covers nine times the area, would only be 1/9 of the intensity received
+by the first square.
+</p>
+
+<p>
+If the difference in the distances therefore be represented by the
+figures 1, 2, and 3 feet respectively, the intensity would be
+represented by the figures 1, 1/4, 1/9. The decrease in the intensity of
+light is really a decrease in motion. The intensity of a note in sound
+depends upon the vibration of the particles of air, while the intensity
+of light also depends upon the vibrations of the aetherial atom.
+</p>
+
+<p>
+If, therefore, we get a decrease in the vibration of the aetherial atom,
+the further we get from the luminous body, it can be readily seen that
+the intensity of light really implies a decrease of motion.
+</p>
+
+<p>
+Now let us apply the law of inverse squares in relation to light to the
+solar system. We have the sun with its huge form all aglow with fires,
+as the source of all light to the planetary worlds that revolve around
+it. Year in and year out, for many ages past, the sun has been pouring
+out its light into space on every side, lighting up the planets or other
+bodies that revolve round it on that side only which is presented to the
+sun. Thus Mercury, at its distance of about 36,000,000 miles, obtains a
+light from the sun which is of far greater intensity than the light
+which Venus receives, while Venus receives a light of greater intensity
+than the light which the Earth receives, and the Earth receives light of
+greater intensity than any of the planets outside its orbit in the solar
+system, as Mars, Jupiter, Saturn, Uranus, or Neptune. This decrease in
+the intensity of light is according to the inverse square of the
+distance from the central body, the sun. So that if we have one planet
+at twice the distance from the sun, as compared with another planet, the
+intensity of light at that distance will be only 1/4 of the intensity
+received by the nearer planet. This decrease of the intensity of light,
+however, may be compensated for by a difference in the constituents of
+the planets' atmosphere, by means of which it may be possible that the
+outermost planets enjoy climatic conditions similar to our own.<span class='pagenum'><a name='Page_147' id='Page_147'></a><a href='#TOC'>[147]</a></span>
+</p>
+
+<p>
+Now we
+have proved, in the previous chapter, that heat is a repulsive motion,
+and as the same aetherial waves give rise to the phenomena of light,
+then it ought to follow that light has equally a repulsive power on the
+planets with which it comes into contact. If that can be proved, and I
+submit that it can, then from the phenomena of light, we learn that
+there is a force, or rather a motion, ever proceeding from the sun in
+straight lines, as shown in the previous Art., which decreases in power
+or intensity inversely as the square of the distance. So that not only
+<i>is</i> the sun the centre of an attractive Force, the Centripetal force,
+or the attractive Force of Gravity, which proceeds in straight lines
+through space, decreasing in intensity inversely as the square of the
+distance, but at the same time it is also the centre of a motion, that
+is, the aetherial wave motion of light, which takes exactly the same
+path as Gravitation Attraction, and which is subject to exactly the same
+laws. Unlike Gravitation Attraction, however, its power and motion is
+ever directed away from the central body, the sun; and if such motion
+exerts any power on any planet with which it comes into contact, that
+power or motion can only be a repulsive motion in the same way that heat
+is a repulsive motion. Assuming, therefore, that light, through the
+medium of the aetherial waves, does exert this repulsive motion, then,
+according to the law of inverse squares, it can be seen that if a
+planet's distance be doubled, the repelling power of the aetherial light
+waves would be decreased 1/4, while at the same time the attractive
+power of the centripetal force would be decreased 1/4 also. If, on the
+other hand, the planet's distance from the sun be reduced to 1/2 of its
+former distance, then the repelling power of the aetherial light waves
+would be increased four times, but contemporaneously with the increase
+there would be an increase in the attractive power of gravity, which
+would exactly counterbalance the increased repelling power of the light
+waves. So that in assuming that there is this repelling power in the
+light waves, there are thus two forces in existence in the solar system
+(which is a type of all other systems), or rather two motions, as all
+forces resolve themselves into motions of some kind, one motion ever
+tending from the central body, that is, the motion of the aetherial
+light waves, and the other tending to the central body, that is, the
+force of gravity, which we shall see later on is also a motion of the
+Aether, whose influence is ever towards the central body, be it a sun,
+star, or planet. These two motions, therefore, are subject to the same
+law, viz. that their power or intensity is not only directed in straight
+lines from the central body, but their intensity is regulated exactly by
+the same law of inverse squares. If the repelling motion be doubled,
+then the attractive motion or power would be doubled also; if the<span class='pagenum'><a name='Page_148' id='Page_148'></a><a href='#TOC'>[148]</a></span>
+repelling motion be quadrupled or halved, then the attractive force of
+gravity would be quadrupled or halved in the same way, the two forces
+being exactly increased or decreased in the same ratio according to the
+law of inverse squares.
+</p>
+
+<p>
+<a name='ART_76' id='ART_76'></a><span class='smcap'>Art</span>. 76. <i>Velocity of Light</i>.--The transmission of light is not
+instantaneous, as it requires time for its propagation through space,
+from the luminous body which gives rise to all light, as the sun for
+example, until it reaches the body which it lights up. The velocity of
+the light waves, however, is so great, that it is almost impossible to
+give any comparative idea of their rate of transmission. The velocity of
+the light waves was first established by Roemer, a Danish astronomer, in
+1675. He ascertained the velocity of light by observations made on the
+satellites of Jupiter. His methods of reasoning can easily be understood
+by reference to the following diagram.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/162.jpg' width='400' height='120'
+alt='Fig: 8.'
+title='Fig: 8.' />
+</div>
+
+<p>
+Let <i>S</i> represent the sun, and <i>A</i> and <i>B</i> the orbit of the earth round
+the sun; <i>C E D</i> part of Jupiter's orbit round the sun; while <i>D E F</i>
+represents the orbit of Jupiter's satellite. When the earth, Jupiter,
+and the satellite are in a straight line with each other, the satellite
+suffers an eclipse through passing into the shadow thrown by Jupiter.
+Now Roemer found that there was a difference in the time of the eclipse
+when the earth was at <i>B</i>, that is, when it was nearest to Jupiter, and
+when it was at <i>A</i>, which is that part of the earth's orbit furthest
+away from Jupiter. That difference was accounted for by the fact, that
+when the earth was at <i>A</i> the light had to travel further from Jupiter
+than when the earth was nearest to Jupiter, that is at point <i>B</i>. Thus,
+when the earth was nearest to Jupiter, the light had a shorter journey
+to travel than when it was furthest from Jupiter. The difference, he
+found, was about 16 minutes, and he reasoned that this difference was
+caused by the light having to cross the earth's orbit from <i>B</i> to <i>A</i>,
+in its longer journey, than when it only had to reach the earth at <i>B</i>.<span class='pagenum'><a name='Page_149' id='Page_149'></a><a href='#TOC'>[149]</a></span>
+The mean distance of the earth from the sun, that is, the radius of the
+earth's orbit, is about 92-1/2 million miles, so that the diameter of
+the earth's orbit is about 185,000,000 miles, and if it takes about 16
+minutes for light to traverse this distance, we find that light has a
+velocity, according to Roemer, of 192,500 miles per second. The result,
+however, arrived at by Roemer was not generally accepted at that time,
+and it was not till 1728 that Bradley discovered what is known as the
+Aberration of Light, and from that discovery proved that light was not
+transmitted instantaneously through space, but that it was transmitted
+with finite velocity; and that that velocity corresponded fairly well
+with the velocity given by Roemer. Bradley, in his astronomical
+observations, noticed that some of the fixed stars, so called, did not
+appear to be really fixed, but that they described small circles in the
+heavens each year. This fact greatly perplexed him, until at last he hit
+upon the true solution by taking into account the motion of the earth in
+its orbit, together with the fact that light had a finite velocity. This
+result showed that the light from the stars travelled with the same
+velocity as that which travelled from Jupiter's satellites. The
+Aberration of Light, as his discovery was termed, may be illustrated in
+the following way--Suppose that you are standing still, and that it is
+raining, the rain descending vertically on the umbrella that you hold up
+to cover you. As soon as you begin to walk, the rain-drops will
+apparently begin to slant, and if the walk is changed into a run, the
+greater apparently will be the slanting direction that the rain-drops
+take. In the same way, the rays of light from a star would fall
+vertically upon the earth if it were motionless, but as the earth is
+moving through space with varying velocity, it gives to the rays of
+light a slanting direction. By calculating the speed of the earth, and
+ascertaining the exact slanting direction of the rays, the velocity of
+light may be ascertained. This Bradley did, and showed that it coincided
+almost with the result arrived at by Roemer. Various other means have
+been adapted to test the results arrived at by these two astronomers.
+Fizeau, in 1849, was able to measure the velocity of light by using, not
+planetary or stellar distances, but by simply using distances in the
+city of Paris; while Foucault, in 1860, devised a method of measuring
+the velocity of light in air or any other medium. The results arrived at
+by these men leave no doubt as to the exact speed of light, which may
+now be reckoned to have a velocity of 186,000 miles, or 300,000,000
+metres per second. Notwithstanding this great speed at which light
+travels, the nearest stars are so far off that their light takes about
+3-1/2 years to reach the earth, while scientists tell us that some of
+the most distant stars are so remote, that their light takes thousands<span class='pagenum'><a name='Page_150' id='Page_150'></a><a href='#TOC'>[150]</a></span>
+of years to reach our earth, travelling at the rate of 186,000 miles per
+second. From considerations like these we get a dim conception of the
+almost illimitable extent of the universe. Now let us try to understand
+what this rate of motion really means. We have to remember that light is
+caused by wave motions in the Aether, so that we have here a wave motion
+which is travelling through the Aether at the enormous rate already
+quoted. Light takes about 8-1/2 minutes to travel from the sun to the
+earth, a distance of 92,000,000 miles. Our fastest trains do not travel
+80 miles an hour, and if a train left the sun and continued its journey
+through space at that rate, it would take over 130 years before it
+reached our earth, while the light would perform the journey in 8-1/2
+minutes. We have some idea of the velocity of a train travelling at 80
+miles an hour; what, however, must be the velocity of a wave motion
+which travels 22,500 times as fast? In <a href='#ART_56'>Art. 56</a> we have seen that all
+energy is the energy of motion, and therefore wherever we get motion of
+any kind or sort, there we must have energy accompanying it, or the
+power to do work. We have here, then, a source of energy in the
+aetherial waves known as light waves, with their enormous velocity which
+is almost inconceivable and illimitable. What must be the energy which
+exists in space due to the wave motion of the Aether? We have to
+remember on this point that we are no longer dealing with a frictionless
+medium, but that we are dealing with matter, only in a far more rarefied
+and far more elastic form than ordinary matter, but nevertheless matter
+just as air is considered matter, and, being matter, its very motion
+imparts to the light waves a power and a force which make them capable
+of doing work. The kind of work done will be considered later on, when
+we deal with the dynamical value of light. That we do not feel the power
+and energy of the light waves is due to the well-known fact that their
+power is broken by the activity of the atmospheric particles, each of
+which, in their myriads, is ever moving with great velocity, and
+therefore bombard the light waves, as they endeavour to strike the
+earth. Thus the aetherial light waves are broken up and shattered, and
+fall to the earth not with their full energy or power, but in a blended
+form, or with that reflected energy which we call light. If they were to
+come unbroken and unchecked upon us, and on the earth, in the same way
+that they apparently do upon our satellite the moon, we doubtless should
+experience very different effects of their energy and power due to their
+enormous velocity.
+</p>
+
+<p>
+<a name='ART_77' id='ART_77'></a><span class='smcap'>Art</span>. 77. <i>Dynamical Value of Light</i>.--We have already learned (<a href='#ART_68'>Art. 68</a>)
+that heat possesses a dynamical value, such value being measured by
+Joule, and its equivalent in foot-pounds being exactly ascertained. We<span class='pagenum'><a name='Page_151' id='Page_151'></a><a href='#TOC'>[151]</a></span>
+have further seen (<a href='#ART_69'>Art. 69</a>, on the identity of light and heat), that the
+same aetherial waves which produce heat are also concerned in the
+production of light. If, therefore, the aetherial waves which give rise
+to heat possess a dynamical action and equivalent, it follows that light
+must also possess a dynamical action and equivalent, and such action
+should be capable of being expressed in terms of foot-pounds. Clerk
+Maxwell has recorded the exact dynamical equivalent of light. On this
+matter he writes:<a name='FNanchor_14' id='FNanchor_14'></a><a href='#Footnote_14' class='fnanchor'>[14]</a>
+ &ldquo;If in strong sunlight the energy of light which
+falls upon a square foot is 83.4 foot-pounds per second, the mean energy
+of one cubic foot of sunlight is about .0,000,000,882 of a foot-pound,
+and the mean pressure on a square foot is .0,000,000,882 of a pound
+weight.&rdquo; We have here then the exact dynamical equivalent, according to
+Maxwell, of a cubic foot of sunlight near the earth's surface, and of
+the pressure exerted by light on a body with which it comes into
+contact.
+</p>
+
+<p>
+Again, Lord Kelvin<a name='FNanchor_15' id='FNanchor_15'></a><a href='#Footnote_15' class='fnanchor'>[15]</a>
+ has measured the exact dynamical equivalent of a
+cubic mile of sunlight, both near the surface of the sun and then near
+the surface of the earth, and in a note adds that the relation of the
+two values is as 46,000 to 1. So that if the dynamical value of a cubic
+mile of sunlight near the earth's surface be represented by unity, then
+the value of a cubic mile of sunlight near the sun's surface would be
+46,000 times greater, while he further adds that it would take 4140
+horse-power every minute, as the amount of work required to generate the
+energy existing in a cubic kilometre of light near the sun, a kilometre
+being equal to about 1093 yards.
+</p>
+
+<p>
+Professor Challis<a name='FNanchor_16' id='FNanchor_16'></a><a href='#Footnote_16' class='fnanchor'>[16]</a>
+ stated in 1872 that &ldquo;Light is to be ranked with the
+physical forces, and its dynamical action is equally to be ascribed to
+the pressure of the Aether.&rdquo; Now I want to put this question to the
+reader: If light possesses this dynamical action, that is, if it
+possesses a motive or driving power, what must be the exact effect of
+the dynamical action of the light waves from the sun upon all the
+planets and meteors that revolve round it? We know that the sun is
+324,000 times the mass of our earth, and that it has a diameter of about
+856,000 miles and a circumference of over two million and a half miles.
+What, therefore, must be the energy of the aetherial light waves that it
+speeds on their way through space on every side? Stokes,<a name='FNanchor_17' id='FNanchor_17'></a><a href='#Footnote_17' class='fnanchor'>[17]</a>
+ in regard to
+the mechanical energy of Light, states that &ldquo;the amount of energy poured
+forth into space corresponds in round numbers to 12,000 horse-power per
+square foot,&rdquo; and that every square foot of<span class='pagenum'><a name='Page_152' id='Page_152'></a><a href='#TOC'>[152]</a></span>
+the sun's surface supplies energy at the above rate. The number of feet
+in the sun's surface can be approximately determined. Roughly, there are
+2,284,000,000 square miles of surface on the sun's huge form, and there
+are 27,878,400 square feet in a mile. By multiplying these two numbers
+we can ascertain the exact number of square feet on the surface of the
+sun. If, therefore, every square foot possesses a mechanical value equal
+to 12,000 horse-power, what must be the mechanical equivalent of the
+sun's radiation of light that it pours forth into space?
+</p>
+
+<p>
+I want to call the attention of the reader to another fact, and that is,
+that light always proceeds in straight lines from the sun (<a href='#ART_76'>Art. 76</a>), and
+therefore if there be any mechanical action in light at all, that action
+must be one which is always directed from the sun in straight lines. Now
+experience universally teaches us, that if a body is pushed, and pushed
+with such a force as has been indicated, then that body not only moves,
+but moves in the direction that the supposed horses would push. I have
+already shown (<a href='#ART_76'>Art. 76</a>) that the path of light is that of a straight
+line corresponding to the path of the attractive force of gravity;
+therefore these horses must ever push in a direction <i>from</i> the sun
+along the same path that the sun's attractive power takes. In other
+words, the mechanical action of these supposed horses will be a
+repulsive one, that repulsion being due to the dynamical action of the
+light waves upon the body that they come into contact with. If this is
+correct, then not only is heat a repulsive motion, as stated in <a href='#ART_63'>Art. 63</a>,
+but light is equally the possessor of a repulsive motion, because its
+action is ever directed from the sun. We might continue to follow the
+supposed horses as they continued their course through space, and we
+should find that their energy decreased inversely as the square of the
+distance, partly because the further they proceeded into space the
+larger the area would be they would have to cover, and therefore their
+energy would be decreased proportionately.
+</p>
+
+<p>
+Professor Stokes, in the same work<a name='FNanchor_18' id='FNanchor_18'></a><a href='#Footnote_18' class='fnanchor'>[18]</a>
+ already referred to, in
+continuation of the same idea, states: &ldquo;At the distance of the earth the
+energy received would correspond to about one horse-power for every
+square of 5 feet, on that side of the earth's surface facing the sun,
+supposing the rays to fall perpendicularly.&rdquo; That being so, we can
+exactly calculate in horse-power the energy received from light on that
+side of the earth facing the sun, at its distance of 92,000,000 miles.
+The area of the earth's surface is, roughly, 200,000,000 × 5280 square
+feet, and if the energy received is equal to one horse-power for every 5 square feet, then the amount<span class='pagenum'><a name='Page_153' id='Page_153'></a><a href='#TOC'>[153]</a></span>
+of energy received by the earth on that side facing the sun would be
+equal to 200,000,000 × 5280 × 1/2 × 1/5 horse-power. This power, it must
+be remembered, is ever directed <i>away from</i> the sun, and upon that side
+of the planet that faces the solar orb. So that we have virtually a
+repulsive force ever directed against the earth, estimated by Professor
+Stokes to be equal to the estimated horse-power.
+</p>
+
+<p>
+This assumption of the repulsive power of light brings the phenomena of
+light into harmony with that of heat, because we have already seen (<a href='#ART_63'>Art. 63</a>) that heat is essentially a repulsive motion, as indicated by Davy,
+Rumford and others; and, as heat and light both have a common origin,
+then light should possess a repulsive power also.
+</p>
+
+<p>
+As further proof of this statement, let me again quote from Clerk
+Maxwell. In the quotation already given in this Art. we have seen that
+the pressure of sunlight on a square foot is equal to 83.4 lb. He adds
+the following words to those already quoted: &ldquo;A flat body exposed to
+sunlight would experience this pressure on its illuminated side only,
+and would therefore be repelled from the side on which the light falls.&rdquo;
+</p>
+
+<p>
+Now if more conclusive proof of the correctness of the argument I am
+advancing were required, I do not think it could be given from any
+greater authority than that just quoted. Coming from the pen of one of
+the most brilliant scientists that the past century has known, I venture
+to think the opinion will be received with that due weight which it
+demands.
+</p>
+
+<p>
+This statement of Clerk Maxwell's has received, however, definite and
+experimental proof from Professor Lebedew of Moscow University, and by
+Nichols and Hull of America. The former has given, in the <i>Annalen der
+Physik</i> for November 1901, the results of his experiments in relation to
+the pressure of light. The following are the results: He proved, 1st,
+that the incident beam of light exerts pressure both upon an absorbing
+and a reflecting body; 2nd, that the pressure of light is proportionate
+to the amount of incident energy, and is independent of the colour of
+light; 3rd, that the pressure of light corresponds with the forces of
+radiation as calculated by Maxwell.
+</p>
+
+<p>
+About the same time, Nichols and Hull of America were engaged upon
+experiments relating to the pressure of light waves, and their results
+were published in the November <i>Physical Review</i>, 1901. Thus, from two
+separate and independent sources, Maxwell's equations as to the pressure
+which light waves exert upon any body on which they fall received
+definite experimental confirmation.<span class='pagenum'><a name='Page_154' id='Page_154'></a><a href='#TOC'>[154]</a></span>
+</p>
+
+<p>
+The repulsive power of the light
+waves receives further confirmation from that theory known as the
+electro-magnetic theory, which supposes light to be nothing more or less
+than an electro-magnetic phenomenon; that is to say, it is directly or
+indirectly due to the action of electric currents.
+</p>
+
+<p>
+As already indicated, Lorentz was of the opinion that the light waves
+were themselves electric currents, and whether this is the actual fact
+or not, certainly it is true that the electro-magnetic theory of light
+is no mere fable or myth, but that it ranks as one of the most advanced
+and correct hypotheses in regard to light that has ever been given to
+the world. According to that theory, which we shall look at
+subsequently, we find that the aetherial medium is not only the medium
+for the light waves, but that it is also the medium which conveys and
+carries the electric currents through space, and even through all
+matter. Further, from that theory we shall have good reasons for
+assuming that the aetherial light waves are either themselves electric
+currents, or closely identified with them, in the same way that the
+light waves are identified with heat waves. If these facts should be
+found to hold good relative to the identity of aetherial light waves and
+the aetherial electric waves, then it can very readily be seen that such
+a hypothesis gives added weight to the repulsive power of light. One of
+the very commonest facts regarding electricity and its currents is, that
+wherever we get electricity, we not only get attraction, but there is
+always associated with that attractive force a repulsive force, which is
+equal in amount to the attractive force. So that if, wherever we get
+electric currents, we find associated with those currents a repulsive
+force, then, in view of the electro-magnetic theory of light, it should
+also follow that on that hypothesis we ought also to find a repulsive
+power in light. From the dynamical aspect of light on the bases of facts
+given to the world by such men as Professor Stokes, Clerk Maxwell, Lord
+Kelvin, and Professor Lebedew, we are compelled, therefore, to come to
+the conclusion that light does possess such a repulsive force, such
+force being due to the dynamical action of the aetherial light waves.
+</p>
+
+<p>
+Thus we learn from the dynamical action of light, that not only is the
+sun the centre of an attractive force, but that it is equally the centre
+of a repellent or repulsive power or motion; which repulsive power
+always follows the path of the radius vector, and diminishes with an
+intensity which is inversely as the square of the distance. What we have
+to ask ourselves therefore is, whether the repulsive power of light is
+the Centrifugal Force that we are trying to discover? In <a href='#ART_24'>Art. 24</a> we
+found out what were the necessary characteristics of the Centrifugal<span class='pagenum'><a name='Page_155' id='Page_155'></a><a href='#TOC'>[155]</a></span>
+Force, which is to form the companion law to the attractive law of
+gravity, or the Centripetal Force. We there saw that this centrifugal
+law must be universal in character; that it must coincide with the path
+of the centripetal force; that it must also be subject to the same law
+of intensity, viz. the law of inverse squares; and further, that the
+force must be proportional to the product of the two masses concerned.
+We find in the repulsive power of light three at any rate of these
+conditions fulfilled. Light is universal because Aether is universal. It
+is always subject to the law of inverse squares, and what is more, its
+repelling power coincides exactly with the path which the centripetal
+force takes, that is, the radius vector. We have not, however,
+discovered that light fulfils the remaining necessary condition, which
+is, that the repelling powers of light emitted by any two bodies are
+equal to the product of their masses. So that until this is done, it
+cannot be said that the aetherial light waves form the centrifugal force
+or motion from a central body that we are seeking for. But while that
+may be true, yet if light be not the centrifugal motion, it certainly
+indicates in what direction we are to look for that force, and that is
+to the Aether, whose periodic waves give rise to the phenomena of light.
+For, after all, light is due to aetherial wave motion, and, therefore,
+while light from certain standpoints may be conceived to be the cause of
+other phenomena, yet primarily the real cause of all phenomena which are
+due to light are due to the aetherial waves which themselves give rise
+to the phenomena of light. Thus light acts as a guide-post to us,
+pointing out the direction we should take in order to find out the real
+centrifugal force or motion, and as plainly as it possibly can, it
+indicates to us that the true solution of our centrifugal motion that we
+are seeking for is to be found, and alone found, in that universal
+aetherial medium which, by its vibrations and wave motions, gives rise
+to that which we term Light. In conclusion of this point, it may be
+pointed out that Professor Challis<a name='FNanchor_19' id='FNanchor_19'></a><a href='#Footnote_19' class='fnanchor'>[19]</a>
+ also took this view of light, as
+he distinctly states that &ldquo;Light is to be ranked with the physical
+forces, and its dynamical action is equally to be ascribed to the
+pressure of the Aether,&rdquo; and then proceeded to show how repulsion could
+be exerted on atoms by the periodic wave motion of the Aether.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_14' id='Footnote_14'></a><a href='#FNanchor_14'><span class='label'>[14]</span></a>
+<i>Magnetism and Electricity.</i>
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_15' id='Footnote_15'></a><a href='#FNanchor_15'><span class='label'>[15]</span></a>
+<i>Phil. Mag.</i>, 1902.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_16' id='Footnote_16'></a><a href='#FNanchor_16'><span class='label'>[16]</span></a>
+<i>Ibid.</i>, 1872.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_17' id='Footnote_17'></a><a href='#FNanchor_17'><span class='label'>[17]</span></a>
+<i>Burnet Lectures.</i>
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_18' id='Footnote_18'></a><a href='#FNanchor_18'><span class='label'>[18]</span></a>
+<i>Burnet Lectures.</i>
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_19' id='Footnote_19'></a><a href='#FNanchor_19'><span class='label'>[19]</span></a>
+<i>Phil. Mag.</i>, 1872.
+</p></div>
+
+
+
+<p>
+<a name='ART_78' id='ART_78'></a><span class='smcap'>Art</span>. 78. <i>The Electro-Magnetic Theory of Light</i>.--We have seen (<a href='#ART_71'>Art. 71</a>)
+that light is due to a periodic wave motion of the Aether, and we have
+previously seen that heat is also due to a periodic wave motion of the
+Aether. Thus in the phenomena of light and heat, Aether is the medium in
+which the energy of light is stored, and by which it is<span class='pagenum'><a name='Page_156' id='Page_156'></a><a href='#TOC'>[156]</a></span>
+transmitted in its passage from a luminous body, as the sun, until it
+comes into contact with a planet or satellite from which it is
+reflected, thus giving rise to light and heat. When, however, we come to
+deal with electro-magnetic phenomena, which are the results and effects
+produced by electricity and magnetism, we find certain phenomena similar
+to those that we find in relation to light and heat. Thus, when light is
+emitted by a luminous body, a certain amount of energy is given out by
+that body, and if such light is absorbed by another body, the latter
+becomes heated, a clear proof that it has received energy or motion from
+some outside source. From the time it left the luminous body till it
+reached the lighted or absorbing body, it must have existed as energy,
+that is, motion in the Aether. As we have already seen, Newton thought
+that the transference of energy was accomplished by the actual
+transference of certain small corpuscles or atoms given out by the
+luminous body, which conveyed the energy of the one body to the other.
+According to the wave theory of light, however, we find that the
+transference of energy is accomplished by a wave motion in the Aether,
+which is periodic both in time and space, by which wave motion the
+energy is transferred from the luminous to the illuminated body. Now
+every one is familiar with the effects of magnetism and electricity in
+some form or other, and such familiarity teaches that various kinds of
+work may be done by electricity. If an electric current be generated and
+allowed to flow through any circuit, as the ramifications, for example,
+of an electric-tram system, it can readily be seen that by the action of
+the current large masses or bodies as trams may be moved. To generate
+the current requires the expenditure of energy, and for the tram to be
+moved requires the transmission of that energy from the generating
+station till it reaches the body to be moved. By what means is such
+energy transmitted? because if it disappears at one place and reappears
+at another, it must have passed through a medium during the interval. It
+has been demonstrated that the medium which conveys the current from
+place to place is the Aether, so that as light is transmitted through
+space by the Aether, in a similar manner electric currents are
+transmitted through space also by the same medium. The discoverer of
+this great truth was Clerk Maxwell, and it was from the consideration of
+electro-magnetic phenomena that he was able to lay the foundation of
+that theory known as the Electro-Magnetic Theory of Light. In paragraph
+781 of his greatest work<a name='FNanchor_20' id='FNanchor_20'></a><a href='#Footnote_20' class='fnanchor'>[20]</a>
+ he says: &ldquo;In several parts of this treatise
+an attempt has been made to explain electro-magnetic phenomena by means
+of mechanical action<span class='pagenum'><a name='Page_157' id='Page_157'></a><a href='#TOC'>[157]</a></span>
+from one body to another by means of a medium occupying space between
+them. The undulatory theory of light also assumes the existence of a
+medium. We have now to show that the properties of the electro-magnetic
+medium are identical with those of the luminiferous medium.&rdquo; He then
+points out that, &ldquo;to fill all space with a new medium, whenever any new
+phenomenon is to be explained, is by no means philosophical&rdquo;; and
+further adds, that &ldquo;If it should be found that the velocity of
+propagation of electro-magnetic disturbances is the same as the velocity
+of light, and this not only in air, but in other transparent media, we
+shall have strong reasons for believing that light is an
+electro-magnetic phenomena.&rdquo; In the wave theory of light we have seen
+(<a href='#ART_70'>Art. 70</a>), that two properties are necessary to any medium before it is
+capable of transmitting wave motion of any kind. Those two properties
+are elasticity and inertia. Water possesses these properties, and so can
+transmit ocean waves; air also possesses these properties, and so can
+transmit sound waves; and Aether, being matter, also possesses these
+properties (<a href='#ART_47'>Arts. 47</a> and <a href='#ART_48'>48</a>), and is therefore capable of transmitting
+light waves. The elasticity is essential in order for the medium to
+store up energy, and also to enable it to resume its original shape
+after deformation, while the inertia is necessary in order that the
+medium may transmit the impulse, and oscillate to and fro until the
+impulse received has been passed on. This elasticity and inertia may be
+well illustrated by the bending of a lath or cane. If we pull one end
+down, holding the other end quite still, we shall see that the lath
+oscillates to and fro until gradually it comes to rest. The elasticity
+of the lath allows it to be pulled out of its original position, and
+also enables it to rebound, while its inertia causes it to swing back
+again past its original position. Both combined together cause it to
+swing backwards and forwards till its energy is used up. If such a
+series of springs could be set in motion at equal intervals of space and
+time, we should then have a good illustration of a wave motion.
+</p>
+
+<p>
+What analogy, may be asked, is there in electro-magnetic phenomena to
+correspond to this elasticity and inertia of the Aether, so essential to
+the propagation of light? Let us look at the familiar illustration of
+charging a Leyden jar. In charging a Leyden jar with electricity a
+certain amount of energy is spent, work is done, and the result is found
+in the electrified state of the jar. That which has actually been
+accomplished is the storing up of energy in the Aether around the jar.
+This storing up of energy is analogous to pulling aside the lath, and is
+the making use of the elasticity of the Aether, in order to produce a
+tendency to recoil. When the jar is discharged, which is analogous to<span class='pagenum'><a name='Page_158' id='Page_158'></a><a href='#TOC'>[158]</a></span>
+letting go the lath, the Aether seeks to recover its former condition by
+discharging the energy it received. In these operations the elasticity
+of the Aether is called into play. After the jar is discharged, however,
+the recoil of the Aether produces a current, and the inertia of the
+current causes it to overshoot its original position, and for an instant
+the charge of the jar is reversed. The current now flows backwards in
+the same way that the lath returned back, and charges the jar as at
+first. This discharging and recharging continue backward and forward, so
+to speak, until all the energy which was originally given to the jar has
+been expended, and it resumes its normal condition. In this experiment
+the elasticity and inertia of the Aether have both been called into
+play, so that we see in this electrical experiment a similar
+illustration of the elasticity and inertia of the Aether, as manifested
+in the undulatory or wave theory of light. The question now arises, what
+are the corresponding properties as given by Maxwell in his
+electro-magnetic theory? In Art. 782 he writes: &ldquo;In the theory of
+electricity and magnetism adopted in this treatise two forms of energy
+are recognized--the electro-static and the electro-kinetic--and these
+are supposed to have their seat, not merely in the electrified or
+magnetized bodies, but in every part of the surrounding space where
+electric or magnetic force is observed to act. Hence our theory agrees
+with the undulatory theory in assuming the existence of a medium which
+is capable of becoming a receptacle of two forms of energy.&rdquo; Faraday, in
+his <i>Experimental Researches</i>, paragraph 3075, in referring to the
+character of magnetic phenomena external to the magnet, writes: &ldquo;I am
+more inclined to the notion that in the transmission of force there is
+such an action external to the magnet, than that the effects are merely
+attraction and repulsion at a distance. Such a function may be a
+function of the Aether if it should have other uses than simply the
+conveyance of radiations&rdquo; (light and heat). From this extract we learn
+that Faraday was also of the opinion that the Aether around a magnet or
+any electrified body was directly concerned in the propagation of the
+electric and magnetic forces, these forces according to Maxwell being of
+two kinds. From the illustration of the charging and discharging of the
+Leyden jar, we learn that aetherial electrical waves can be produced by
+electric means, and from the alternate charging and recharging of the
+jar we learn that these aetherial waves travel to and from the jar with
+a periodic wave motion. Here, therefore, we have an aetherial wave
+motion which is produced wholly by electricity, and yet which answers
+our definition of a wave motion of light, in that it is periodic both in
+time and space, and in that aetherial wave motion Maxwell states that
+two forms of energy are called into play, which he calls Electro-Static<span class='pagenum'><a name='Page_159' id='Page_159'></a><a href='#TOC'>[159]</a></span>
+and Electro-Kinetic. These correspond respectively to the elasticity and
+inertia in the older theory of the wave motion of light. It was upon
+this basis that Maxwell built up his electro-magnetic theory. Even this
+theory does not tell us what is the exact character or nature of the
+periodic wave motion of the Aether. All it tells us is, that the
+electro-magnetic wave motion of the Aether is the same in nature and
+character as the wave motion which produces light and heat. Thus it
+shows that light and electricity have a common origin, and proves that
+light is nothing more or less than an electro-magnetic phenomenon.
+Maxwell gave a number of proofs in support of his theory. He showed that
+the velocity of the electro-magnetic waves was almost identical with the
+velocity of light waves, his results being as follows--
+</p>
+
+<table summary='velocities'>
+
+<tr><th colspan='4'><span class='smcap'>velocity of electro-magnetic<br />waves.</span></th><th colspan='2'><span class='smcap'>velocity of light in<br />metres per sec.</span></th></tr>
+
+<tr><td style='text-align: left;'>Weber</td><td style='text-align: right;'>310,740,000</td><td style='text-align: center;'>metres</td><td style='text-align: center;'>per sec.</td><td style='text-align: left;'>Fizeau</td><td style='text-align: right;'>314,000,000</td></tr>
+
+<tr><td style='text-align: left;'>Maxwell</td><td style='text-align: right;'>288,000,000</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: left;'>Foucault</td><td style='text-align: right;'>298,360,000</td></tr>
+
+<tr><td style='text-align: left;'>Thompson</td><td style='text-align: right;'>282,000,000</td><td style='text-align: center;'>"</td><td style='text-align: center;'>"</td><td style='text-align: left;'></td><td style='text-align: right;'></td></tr>
+
+</table>
+
+
+<p>
+From these figures it can readily be seen that the velocity of an
+aetherial wave, generated by electric means, is approximately the same
+as an aetherial wave generated by a luminous body. Thus one of the most
+important results of Maxwell's theory was to show that electro-magnetic
+disturbances produced in the Aether by an electrified or magnetic body
+might be propagated through space with a velocity equal to that of
+light.
+</p>
+
+<p>
+It was left, however, for Professor Hertz to place the electro-magnetic
+theory of light upon a sure and certain foundation. The results are to
+be found in his work on <i>Electric Waves,</i> translated by Professor Jones,
+1893.
+</p>
+
+<p>
+In his paper on &ldquo;The Velocity of Propagation of Electro-dynamic Action,&rdquo;
+he gave definite and experimental proof of the hitherto theoretical fact
+that the velocity of the electric waves in air was exactly the same as
+that of light, whereas he found that in wires the ratio was not the
+same, being 4 to 7. This was afterwards found out to be an error by some
+experiments made at Geneva, when it was discovered that the propagation
+in wires was the same as in the air. Among his experiments Hertz
+succeeded in producing very short electric waves of 30 centimetres in
+length, that is, about one and one-fifth of an inch. According to
+Maxwell's theory, such a wave ought to behave exactly as a beam of
+ordinary light does. Hertz proved that this was the case, and published
+his proofs in his paper on &ldquo;Electric Radiation.&rdquo; In that paper he showed
+how such electric radiation was propagated in straight lines, like
+light, and that it could also be refracted and reflected. Thus he gave<span class='pagenum'><a name='Page_160' id='Page_160'></a><a href='#TOC'>[160]</a></span>
+to Maxwell's electro-magnetic theory experimental demonstration, and
+placed it on a solid and immovable foundation. In summing up the results
+of this theory, we learn, therefore, that Hertz has conclusively proved
+that electric and magnetic effects are propagated through the Aether
+which fills all space with the same velocity that light is propagated.
+Further, he has conclusively proved the identity between light and
+electricity, and shown that electric and light radiations are
+essentially one and the same, and that they are both propagated by
+periodic wave motions of the Aether. Further, he has proved that the
+velocity of the propagation of light is the same as that of the
+electro-magnetic waves, and that these waves obey all the laws that
+govern light and heat. We have here, therefore, experimental proof of
+the identity between electricity and light, and in <a href='#ART_69'>Art. 69</a> we have also
+proved the identity of light and heat, so that we have now experimental
+proof that light, heat and electricity are all due to the periodic wave
+motions and vibrations of the universal Aether, which not only fills all
+space, but which surrounds every atom and every particle of matter
+throughout the whole universe. Having established, therefore, the
+identity of heat, light and electricity, and having proved that they are
+all due to the periodic wave motions or vibrations of the universal
+Aether, it must follow as a matter of necessity that wherever in
+interplanetary or interstellar space we find light or heat waves we must
+also find electricity. We have already seen that aetherial light waves
+flood all space, both interplanetary and interstellar space, so that in
+view of the identity of the aetherial light waves and aetherial electric
+waves, it follows that the aetherial electric waves flood all space in
+the same way, and at the same time. Wherever, therefore, we find the
+light waves, there we find the electric waves also; and it will be
+impossible to find the one without the other. Thus, throughout all
+space, and indeed throughout the universe, light waves will not be found
+apart from electric waves. They are as incapable of being dissociated as
+are light and heat waves. Now we have already seen (<a href='#ART_64'>Art. 64</a>), so far as
+the solar system is concerned, that the sun is the generator of all
+light and heat, and that these light waves speed from the sun on every
+side with a velocity of 186,000 miles per second. From the identity of
+light and electric waves, therefore, given to us by the electro-magnetic
+theory of light, it must follow that the sun is equally the source and
+generator of the electric waves. Not only so, but as the light waves
+flood all solar space, these electric waves, being identical with the
+light waves, must flood the solar system also. Thus we learn from
+Maxwell's theory as developed by Hertz, that not only is the sun the<span class='pagenum'><a name='Page_161' id='Page_161'></a><a href='#TOC'>[161]</a></span>
+generator of light and heat waves which are poured forth into space
+continually with a velocity almost inconceivable, but at the same time
+the sun is pouring forth into space electric waves which travel outwards
+in spherical shells in the same way as light waves do, and with a
+similar intensity, as we shall see in the next chapter. Now let me ask
+the reader to ponder over the fact given to us by this electro-magnetic
+theory in its relation to the solar system, and endeavour to find out
+what such an application teaches us. Let it be remembered that we are
+looking for a Centrifugal force or motion, that is, a motion from a
+centre, which is to be the exact counterpart of the Centripetal force,
+<i>i. e</i>. motion to a centre; and further, that the Centrifugal motion
+must be a repulsive motion acting in the opposite way to the attractive
+power of the Centripetal force, that is, the attractive power of
+gravity. We have seen (<a href='#ART_77'>Art. 77</a>) that light possesses a repulsive power.
+We have now only to prove that electricity or the aetherial electric
+waves have a repulsive motion, which will be the easiest of all to
+prove, and then we shall have proved beyond the possibility of
+contradiction, the existence of that repulsive force referred to by
+Herschel in <a href='#ART_24'>Art. 24</a>, which is to form the complementary and counterpart
+of the attractive power of gravity. If it can be proved that electricity
+does possess such a power, that is, a repulsive power, ever acting from
+a centre, then in view of the identity of light, heat and electricity,
+the correctness of the views we have advanced as to the repulsive power
+of light and heat will be proved beyond the shadow of a doubt, otherwise
+Maxwell's electro-magnetic theory of light is a fable and a myth, and
+Hertz' experiments were never performed. Further, if all
+electro-magnetic phenomena are due to the same aetherial medium which
+gives rise by its wave motions to light, heat and electricity, then we
+shall have discovered a medium which throughout the universe can by its
+wave motions transmit and propagate both repulsions and attractions,
+that is, the aetherial medium which is to be the physical cause of
+Universal Gravitation. In order to further develop and establish this
+point we will now consider the subject of Electricity as a Mode of
+Motion.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_20' id='Footnote_20'></a><a href='#FNanchor_20'><span class='label'>[20]</span></a>
+<i>Mag. and Elec.</i>
+</p></div>
+
+
+<p><span class='pagenum'><a name='Page_162' id='Page_162'></a><a href='#TOC'>[162]</a></span></p>
+<h2><a name='CHAPTER_VIII' id='CHAPTER_VIII'></a><a href='#CHAPTER_VIII_TOC'>CHAPTER VIII</a></h2>
+
+<h3>AETHER AND ELECTRICITY</h3>
+
+
+<p>
+<a name='ART_79' id='ART_79'></a><span class='smcap'>Art</span>. 79. <i>Electricity, a Mode of Motion</i>.--The question as to What is
+Electricity? is one of the greatest problems of modern times. In view of
+the electro-magnetic theory of light, however, science is able to give a
+better definition as to what electricity is, than it was able to do
+previous to the introduction of the theory by Maxwell, and its practical
+establishment by Hertz.
+</p>
+
+<p>
+If that theory teaches us anything at all with regard to the nature of
+electricity, it teaches us that electricity is due to certain motions of
+the universal Aether, that not only fills all so-called Space, but
+surrounds all particles and atoms of all Matter.
+</p>
+
+<p>
+The question has been asked by various scientists, &ldquo;Is Aether
+Electricity, or, in other words, are Aether and Electricity one and the
+same?&rdquo; Let us look at the question from the standpoint of the analogy
+from the phenomena of light and heat. As we have already seen (<a href='#ART_61'>Art. 61</a>),
+heat is due to a particular kind of motion of the universal Aether,
+generally known as vibratory motion, which motion is communicated to the
+Aether by a luminous or heated body.
+</p>
+
+<p>
+So that we learn that heat at any rate has an aetherial basis, as it is
+a particular kind of aetherial motion. From <a href='#ART_70'>Art. 70</a> we learn also that
+light is due to an undulatory or wave motion in the Aether; the waves,
+however, in this case being shorter, and of more rapid vibration than
+those waves which give rise to heat.
+</p>
+
+<p>
+Thus light and heat both have an aetherial basis, being due to
+vibrations of that medium. From these analogies, therefore, we come to
+the conclusion that electricity and magnetism have an aetherial basis,
+and are also due to certain kinds of motion in the Aether.
+</p>
+
+<p>
+That motion may be rotatory motion or vibratory motion, as the case may
+be, but whatever definition we give of electricity, we cannot as yet say
+definitely that Aether is electricity.
+</p>
+
+<p>
+We may assume, and indeed prove, that Aether has an electrical and
+magnetic basis, in the same way that it has a thermal or heat basis, or
+a luminiferous or light basis; but while we admit such a hypothesis, we<span class='pagenum'><a name='Page_163' id='Page_163'></a><a href='#TOC'>[163]</a></span>
+cannot admit as yet that Aether and electricity are one and the same
+thing. It is not within the province of this work, however, to prove
+what electricity is, or show the relation of Aether to all the various
+forms of electricity with which we are conversant, but I think I may
+venture to make this statement, that all forms of electricity, whether
+it is electro-static, that is electricity at rest, or current
+electricity, or electro-magnetism, are due to certain forms of motion of
+the universal Aether, in the same way that light and heat are also
+particular forms of motion of the same medium. I need hardly point out
+that it is an absolute impossibility for me to deal with such a subject
+as Electricity in all its details and various aspects in one chapter; so
+that I shall have to assume that the reader is familiar with some of the
+elementary truths of the subject.
+</p>
+
+<p>
+At the same time, I will endeavour to make clear most of the technical
+terms used as we proceed. From the Electro-Magnetic theory of light,
+therefore, we learn that Aether has an electrical or electro-magnetic
+basis, so that, wherever we get Aether, there we have the bases and
+conditions which will produce all the phenomena with which we are
+conversant in the sphere of electricity. Given the required motions in
+the Aether necessary to produce any particular form of electricity, then
+that form is produced as soon as the motions of the Aether are generated
+by any charged or electrified body. Produce a circular current in any
+way in the Aether, and you will have a circular current of electricity;
+produce radiations from a radiating body, and you will get electric
+radiations which speed away with the velocity of light.
+</p>
+
+<p>
+This phase of the Aether is entirely in harmony with Dr. Larmor's
+Hypothesis of Electrons, which has already been referred to in <a href='#ART_44'>Art. 44</a>.
+Dr. Larmor in his work indicates that electricity has an atomic basis,
+and further states that &ldquo;the atomicity of electricity is coming within
+the scope of direct experiment.&rdquo;<a name='FNanchor_21' id='FNanchor_21'></a><a href='#Footnote_21' class='fnanchor'>[21]</a>
+
+</p>
+
+<p>
+Now, if electricity, as I have indicated, be due to certain motions in
+the Aether, then it can easily be seen that postulating atomicity for
+electricity will be the same as postulating atomicity for the Aether.
+Dr. Larmor<a name='FNanchor_22' id='FNanchor_22'></a><a href='#Footnote_22' class='fnanchor'>[22]</a>
+ definitely and clearly states, &ldquo;that each electron has an
+effective mass of aetherial origin, which forms part, and may be the
+whole, of the mass of matter to which it is attached;&rdquo; and again points
+out (p. 64) that &ldquo;an electron is nothing more than a point singularity
+or pole in the electro-dynamic and optical Aether.&rdquo; Thus we see that Dr.
+Larmor's hypothesis as to the atomicity of electricity is a further
+proof of the atomicity of Aether, and is also in<span class='pagenum'><a name='Page_164' id='Page_164'></a><a href='#TOC'>[164]</a></span>
+harmony with the electro-magnetic theory of light.
+</p>
+
+<p>
+Now in dealing with electricity as a mode of motion, it will be
+necessary to show that electricity is also a form of energy in the same
+way that heat and light are forms of energy.
+</p>
+
+<p>
+If it can be demonstrated that electricity is a form of energy, then it
+can easily be demonstrated that work can be done by it, and that that
+work may take a mechanical form in the same way that the energy of heat
+and light may produce mechanical results. Clerk Maxwell has given us, in
+his greatest work, his conception of the two kinds of energy due to
+electricity and magnetism. On the subject he writes: &ldquo;In the theory of
+Electricity and Magnetism accepted in this treatise, two forms of energy
+are recognized, the Electro-Static and Electro-Kinetic (paragraphs 630
+and 636), and these are supposed to have their seat not merely in
+electrified or magnetized bodies, but in every part of surrounding
+space, wherever electric or magnetic force is observed to act. Hence our
+theory agrees with the undulatory theory of light in assuming the
+existence of a medium which is capable of becoming susceptible to two
+forms of energy.&rdquo;<a name='FNanchor_23' id='FNanchor_23'></a><a href='#Footnote_23' class='fnanchor'>[23]</a>
+ The question has arisen many times as to what is
+meant by the terms Electro-Static and Electro-Kinetic energy used by
+Maxwell, and various hypotheses have been advanced to explain the same.
+</p>
+
+<p>
+Electro-static energy is said to be that phase of electricity in which
+we deal with stresses set up in the Aether by an electrified body at
+rest, whether that body be small or large. It further deals with the
+process of induction, that is, the action of an electrified body upon
+another body, such action taking place through the medium between the
+two bodies. Electro-kinetic energy is the energy due to electricity in
+motion. On this point Maxwell says: &ldquo;A conducting circuit in which the
+current has been set up has the power of doing work in virtue of the
+current, for it is really and truly energy. It appears, therefore, that
+a system containing an electric current is a seat of energy of some
+kind; and, since we can form no conception of electric current except as
+a kinetic phenomenon, its energy must be kinetic energy, that is to say,
+the energy which a moving body has in virtue of its motion.&rdquo; (Arts. 551
+and 552.)
+</p>
+
+<p>
+It is not our purpose to deal with the electro-kinetic form of energy
+referred to by Maxwell in this chapter. We shall deal with that form of
+energy due to electricity in the succeeding chapter. We will consider
+first the effect of the electro-static energy in relation to electrified
+bodies, but I wish it to be distinctly understood, that in all the
+different kinds of electric phenomena manifested, the Aether plays the chief part, and without it,<span class='pagenum'><a name='Page_165' id='Page_165'></a><a href='#TOC'>[165]</a></span>
+none of the phenomena observed could be produced; because, what Aether
+is to light and heat, so it is to electricity, being that medium which
+by its motions propagates and gives rise to all electrical phenomena.
+</p>
+
+<p>
+This being so, we have now to apply some of the facts taught us by
+electricity, and especially by the electro-magnetic theory of light, to
+our solar system, with the hope that we shall find further evidence of a
+Centrifugal Force which is physical in character, and whose action can
+be traced throughout the whole realm of space. Let us, in starting to
+apply some of the truths already learned, recall some of the facts
+concerning light, its production and its propagation. We recall the fact
+that light is produced by the action of the sun upon the Aether, giving
+rise to waves which speed away from the generating source with a
+velocity of 186,000 miles per second. We further remember that Hertz has
+definitely proved that these light waves are identical with
+electro-magnetic waves, as they ought to be if the Aether possesses an
+electrical basis, as Dr. Larmor and Professor Lodge suggest.
+</p>
+
+<p>
+In order that there may be no mistake on this point, let me quote from
+one of Hertz' papers, where, in his conclusion, he says: &ldquo;The
+experiments described appear to me, at any rate, eminently adapted to
+remove any doubt of the identity of light, radiant heat, and
+electro-magnetic wave motion.&rdquo; Now, what I want to point out regarding
+this fact is this. If the sun gives rise to the aetherial light waves,
+and these light waves are identical with electro-magnetic waves as
+proved by Hertz, then the sun must either be an electrified body or else
+a magnet.
+</p>
+
+<p>
+It must be one or the other, because, if it were not, we should then
+have an anomaly in Nature of a body emitting electro-magnetic waves
+which is itself neither electrified nor a magnet. Therefore, according
+to our second Rule of Philosophy, such a body would be incapable of
+giving rise to these waves, as such a result would be contrary to
+universal experience and experiment.
+</p>
+
+<p>
+We know that the earth is a magnet, but up to the present it has never
+been proved that the sun is a magnet, although, as I shall show later
+on, Lord Kelvin and others have suggested such a possibility. If we
+assume that the sun is a magnet, our grounds for assumption would not be
+so strong at this point, and our reasons so philosophical, as they are
+if we assume that the sun is an electrified body.
+</p>
+
+<p>
+We have philosophical reasoning to prove that the sun is an electrified
+body in the fact that it emits or gives rise to electro-magnetic waves
+in the Aether, and no other hypothesis can be made other than that the<span class='pagenum'><a name='Page_166' id='Page_166'></a><a href='#TOC'>[166]</a></span>
+sun is an electrified body, in order to prove the connection between the
+two.
+</p>
+
+<p>
+Thus we affirm that the sun is an electrified body, which like any
+other electrified body is capable of generating electric waves, and
+speeding them through the Aether with similar velocity to that of light.
+Not only so, but, like any other electrified body, it must have its
+electric field and possess the ability to electrify any other body by
+induction, that may happen to be in its electric field, as we shall see
+later on.
+</p>
+
+<p>
+Further, being an electrified body, the electric density will be
+greatest near the sun's surface, and this fact fully accords with our
+statement in <a href='#ART_45'>Art. 45</a>, that Aether is gravitative. As pointed out in that
+Art., if Aether be gravitative, it must be densest nearest to the
+attracting body; and, as Aether has an electric basis, then with the
+denser Aether there must be an increased electric density, which can
+only happen provided the sun is an electrified body.
+</p>
+
+<p>
+Sir G. Stokes was also of this opinion, for in his Burnet Lectures on
+Light he writes (p. 212): &ldquo;There is nothing, therefore, unreasonable
+in supposing that the sun may be a permanently charged body.&rdquo;
+</p>
+
+<p>
+So that all the reasoning that has led to this result seems to harmonize
+and confirm each several hypothesis which has been advanced. There can
+be little doubt, therefore, that the sun is an electrified body, and it
+is for us now to carry out this fact to its logical and philosophical
+conclusion, by applying all the truths which circle round it to the
+solar system, when we shall find greater confirmation of the statement
+just advanced than any we have yet adduced.
+</p>
+
+<p>
+According to Professor Young of America, the sun is not only an
+electrified body, but is also the abode of living and sentient beings.
+This astronomer has suggested that the sun is the centre of electric
+force, and that converging streams of Electricity are ever flowing to it
+as a centre; but on meeting with the atmosphere they give rise to
+brilliant discharges, which thus gives the appearance of a solid
+incandescent body.
+</p>
+
+<p>
+Now, whether this hypothesis is correct or not, it is absolutely
+certain that the sun is an electrified body, as it gives rise to
+electro-magnetic waves in the Aether, as philosophically proved by
+direct experiments.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_21' id='Footnote_21'></a><a href='#FNanchor_21'><span class='label'>[21]</span></a>
+<i>Aether and Matter</i>, p. 8.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_22' id='Footnote_22'></a><a href='#FNanchor_22'><span class='label'>[22]</span></a>
+<i>Ibid.</i>, p. 64.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_23' id='Footnote_23'></a><a href='#FNanchor_23'><span class='label'>[23]</span></a>
+<i>Magnetism and Electricity</i>, by C. Maxwell, Art. 782.
+</p></div>
+
+
+
+
+<p>
+<a name='ART_80' id='ART_80'></a><span class='smcap'>Art</span>. 80. <i>Aether and Electric Fields</i>.--Before proceeding to apply some
+of the facts of Electricity to the solar system, let us find out what is
+meant by an Electric Field. An electric field is to an electrified body,
+what a thermal or heat field is to a heated body, or a luminous or
+lighted field is to a luminous body. If a lamp, for example, be lighted,
+its light waves spread out on every side, and extend for a considerable<span class='pagenum'><a name='Page_167' id='Page_167'></a><a href='#TOC'>[167]</a></span>
+distance unless impeded by such obstacles as the wall of a room.
+</p>
+
+<p>
+The extent to which the light waves reach and flow might well be called
+the lighted or luminous field, and in that field the effect of the
+aetherial light waves would be manifested and seen.
+</p>
+
+<p>
+Now, in a similar manner, when any body is electrified, the electric
+waves spread out on every side of the electrified body, and the extent
+to which the waves spread out form what is known as an electric field.
+</p>
+
+<p>
+So that an electric field may be defined as any region or space in which
+electric energy is manifested by means of the aetherial electric waves,
+and across which induction may take place.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/181.jpg' width='400' height='387'
+alt='Fig: 9.'
+title='Fig: 9.' />
+</div>
+
+<p>
+Thus, for example, let <i>E</i> be an electrified body (Fig. 9), then it will
+generate electric waves which will speed from the body with a velocity
+equal to that of light. If the body be a sphere, then the waves will be
+spherical in shape, and will proceed from the generating source in the
+shape of concentric spheres as indicated in the figure. Before
+proceeding any further, it is necessary that we should look at the
+electric field from the physical aspect, with a view to discover
+something of what takes place therein. As has already been indicated,
+all electric phenomena are due to motions of the universal Aether.
+</p>
+
+<p>
+It was left for Faraday to give us a true conception of an electric
+field, and for Maxwell to perfect that conception and give us a<span class='pagenum'><a name='Page_168' id='Page_168'></a><a href='#TOC'>[168]</a></span>
+physical aspect of the same. Faraday conceived that stretching out from
+a magnet or electrified body through space, that is, through the Aether,
+were what he called &ldquo;Lines of Force,&rdquo; and that these lines of force
+indicated not only the direction of the magnetic and electric forces,
+but also their intensity or power.
+</p>
+
+<p>
+Where the lines of force were closest together, there the electric or
+magnetic energy was the greatest and most intense; and where they were
+the farthest apart, there the field was weakest in energy. An
+illustration of the magnetic lines of force may be obtained by placing a
+piece of paper over a magnet, and then strewing iron filings over the
+same, when it will be seen that the iron filings will arrange themselves
+in certain curved lines, which Faraday called Magnetic Lines of Force.
+In this way Faraday mapped out the lines of force, relative not only to
+single magnets, but also to magnets with poles placed in various
+positions relatively to poles of other magnets.
+</p>
+
+<p>
+Now as there are lines of force which reveal the intensity and direction
+of the magnetic energy, so there are lines of force radiating out from
+electrified bodies which reveal the intensity and power of the electric
+field. The electric lines of force are radial, and are shown in the
+figure (Fig. 9) by the straight lines <i>D F, D H, D K</i>.
+</p>
+
+<p>
+If an electrified pith ball, for example, be hung up in a room, then the
+lines of force, which extend from the ball, indicate the stress in the
+Aether surrounding the pith ball, so that if a hair be placed across
+these lines of force, any movement of the pith ball will be indicated by
+the motion of the hair.
+</p>
+
+<p>
+It was Clerk Maxwell, however, who gave to the world a true physical
+conception of Faraday's Lines of Force, in his paper on &ldquo;Physical Lines
+of Force.&rdquo;<a name='FNanchor_24' id='FNanchor_24'></a><a href='#Footnote_24' class='fnanchor'>[24]</a>
+
+</p>
+
+<p>
+In the opening words of that paper he writes as follows: &ldquo;We cannot help
+thinking that in every place where we find these lines of force, some
+physical state or action must exist in sufficient energy to produce the
+actual phenomena.&rdquo; Maxwell then went on to show what these physical
+actions were, which took place in the dielectric--that is, the medium
+surrounding the electrified body which we now know to be the Aether.
+</p>
+
+<p>
+This electric field, he pointed out, was &ldquo;in a state of stress, which
+consisted of pressures or tensions different in different directions at
+the same part of the medium. The relation of these forces were
+threefold, and consisted in the most general type of stress of three
+pressures or tensions in directions at right angles to each other.&rdquo;<span class='pagenum'><a name='Page_169' id='Page_169'></a><a href='#TOC'>[169]</a></span>
+</p>
+
+<p>
+Thus, in Maxwell's opinion, the
+existence of a medium, which by its physical character was able to exert
+energy on material bodies, was one of the fundamental hypotheses of his
+theory as to the physical character of Faraday's Lines of Force.
+</p>
+
+<p>
+This physical medium was to be capable of certain motions, and both
+electric and magnetic forces were produced by its motions and its
+stresses. Maxwell's conception, however, of the physical lines of force
+was more or less hypothetical, and up to the present, as far as I can
+learn, has not received that authority from science that such a
+hypothesis requires to make it an accepted theory in science.
+</p>
+
+<p>
+But what I venture to point out is, that with the view of the aetherial
+medium that is submitted in this work, Maxwell's hypothesis remains a
+hypothesis no longer, and that the hypothetical character of his theory
+ceases to exist. For, by our conception of an atomic and gravitative
+Aether, we are able to see that his physical lines of force are indeed
+physical, and that his brilliant hypothesis now receives a true physical
+foundation which otherwise it would not receive from a frictionless
+Aether.
+</p>
+
+<p>
+There is nothing, I venture to predict, in Maxwell's hypothesis which
+cannot be accounted for on a truly physical basis, by the conception of
+the Aether as given in this work. So that when Faraday saw in his mind's
+eye lines of force traversing space, he saw by his imagination that
+which was actually the real state of affairs, and when Maxwell enlarged
+the conception by giving to those lines of force a definite atomic and
+cellular structure, he, too, but anticipated the real nature and
+character of the Aether as given in Chapter <a href='#CHAPTER_IV'>IV</a>., which theory is the
+direct outcome of Newton's philosophical rules, and the result of
+discarding everything that is not in accordance with experience and
+observation. Thus the lines of force which exist and surround a magnetic
+or electrified body are as real as ocean currents, or the waves of the
+sea, in that they are the manifestations of the motions of the universal
+Aether, which is as truly matter as air or water.
+</p>
+
+<p>
+Let us look at the analogy which exists between the lines of force and
+the gravitative Aether, and we shall see that a gravitative Aether fully
+agrees with the conception of an electric Aether as revealed to us by
+the lines of force in an electric field.
+</p>
+
+<p>
+As is well known, the lines of force are closer together in that part of
+the electric field where the intensity of the field is greatest; and the
+intensity of a field being greatest at the surface of an electrified
+body, the lines of force are therefore closer together nearest to the
+surface of such a body than further away.
+</p>
+
+<p>
+Now according to <a href='#ART_45'>Art. 45</a> Aether is gravitative, therefore the Aether<span class='pagenum'><a name='Page_170' id='Page_170'></a><a href='#TOC'>[170]</a></span>
+nearest the surface of a body is densest, and the aetherial atoms are
+therefore more pressed upon than the layer immediately above it. Such a
+result is exactly what should happen provided that Aether has an
+electric basis, and that Aether is gravitative. For, in <a href='#ART_45'>Art. 45</a>, we have
+seen that because Aether is gravitative, therefore it must possess
+various degrees of density, being densest nearest the surface of an
+attracting body.
+</p>
+
+<p>
+In electricity we find a similar phenomenon which corresponds to
+aetherial density, which is known as Electric Density, by which term is
+meant the amount or quantity of electricity spread over a certain area
+or surface. If we double the quantity of electricity on that given
+surface, then we double the density, and we say that the electric
+density is doubled, while if we halve the quantity of electricity, then
+we say the electric density is halved, and so on.
+</p>
+
+<p>
+But this is exactly what happens in the case of aetherial density, as
+proved in <a href='#ART_46'>Art. 46</a>. We have only to picture the number of aetherial atoms
+being doubled on a given area, and at once the physical conception of
+electric density is furnished, if we remember that Aether has an
+electric basis as suggested by Maxwell and proved by Hertz. Thus we see
+at once why it is the lines of force should be closer together nearer
+the electrified body than farther away.
+</p>
+
+<p>
+<i>Electric Potential</i>.--There is another aspect of the electric field
+that I wish to call the reader's attention to, and that is the Electric
+Potential of such a field.
+</p>
+
+<p>
+Electric potential is to electricity what temperature is to heat, or
+pressure is to any medium of different densities. We have already seen,
+according to the laws of thermodynamics, that heat will flow from a
+higher temperature to a lower one, with the result that work is done. In
+the case also of water at two different levels, work can also be done by
+the water flowing from a higher to a lower level.
+</p>
+
+<p>
+A similar thing happens in electricity; where we have two conductors or
+two parts of an electrical fluid at different potentials, electricity
+will flow from the place of higher potential, until the potentials are
+equalized, in the same way that the temperature of two bodies at
+different temperatures would be equalized by the flow of heat.
+</p>
+
+<p>
+So that electric potential agrees with our conception of a gravitative
+Aether in that, being gravitative, it is denser in those parts nearest
+to the attracting body than farther away, and as the elasticity or
+pressure is proportionate to the density (<a href='#ART_47'>Art. 47</a>), therefore we learn
+that the electric potential of the Aether, and the thermal condition of
+the Aether, if I may use such a term, both agree and coincide with the<span class='pagenum'><a name='Page_171' id='Page_171'></a><a href='#TOC'>[171]</a></span>
+density and elasticity of the Aether.
+</p>
+
+<p>
+Any equipotential surface which represents a particular aetherial
+density, would also correspond with a particular elasticity or pressure
+of the Aether, while it would further correspond with a particular
+temperature, if such a term is applicable to the Aether.
+</p>
+
+<p>
+<i>Equipotential Surfaces</i>.--The fact that in an electric field there are
+different points at different potentials, leads us to the truth that in
+an electric field there are also equipotential surfaces; that is to say,
+there are surfaces where the electric density or the aetherial density
+are equal at all points on such a surface. If, for example, <i>E</i> be an
+electrified body (Fig. 9), and <i>A A'</i>, <i>B B'</i>, represent equipotential
+surfaces around the body, then all the points on <i>A A</i>' would be of
+equal potential--that is, of equal energy, or pressure.
+</p>
+
+<p>
+We have to remember that <i>A A'</i>, <i>B B'</i>, are sections of a sphere, so
+that when the body as <i>E</i> is a sphere, then the equipotential surfaces
+are spheres also. This agrees with <a href='#ART_77'>Art. 77</a>, in which we saw that the
+pressure around any body due to aetherial density also possessed
+equipotential surfaces.
+</p>
+
+<p>
+It could equally be shown that there were equipotential surfaces so far
+as the phenomena of heat and light are concerned, as these also are
+subject to the same laws. Having now very briefly considered the meaning
+of the Electric Field, Electric Potential, Electric Density, and
+Equipotential Surfaces, we are now in a position to apply these facts to
+our solar system, at least as far as the sun is concerned.
+</p>
+
+<p>
+In the foregoing Art. we arrived at the conclusion that the sun was an
+electrified body, therefore, in accordance with all experiment and
+observation, it, too, must have an electric field. Not only must it have
+an electric field; but that field must possess different potentials,
+possessing a higher potential the nearer the field gets to the sun, and
+a lower potential the farther away the field is.
+</p>
+
+<p>
+Further, around the sun there must also exist not imaginary but real
+physical lines of force which indicate the electric and magnetic forces,
+and which are made real by the atomic character of the Aether that
+surrounds it; and those lines of force would be closer together the
+nearer they got to the sun on account of the electric density of the
+electric Aether, which coincides with the density of the Aether from the
+gravitative standpoint. There would also be aetherial equipotential
+spheres, or rather oblate spheroids around the sun, as the sun is not
+strictly a sphere, its polar diameter being less than its equatorial
+diameter.<span class='pagenum'><a name='Page_172' id='Page_172'></a><a href='#TOC'>[172]</a></span>
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/186a.jpg' width='400' height='252'
+alt='Fig: 10.'
+title='Fig: 10.' />
+</div>
+
+<p>
+Let us therefore endeavour to picture the sun under these
+conditions as the centre of our solar system. Let <i>S</i> be the sun
+(Fig. 10), and the lines <i>A A'</i>, <i>B B'</i>, <i>C C'</i>, etc. represent
+Equipotential Surfaces, Fig. 11 being a vertical section and Fig. 10
+being an equatorial section. In Fig. 11 the sections of the
+equipotential surfaces would be vertical, while in Fig. 10 the sections
+of the equipotential surfaces would be horizontal, while the electric
+lines of force would be radial, as all electric radiations take place in
+straight lines, as we shall see was proved by Hertz, later on. We will
+suppose that the sun is stationary, as the question of the movement of
+the sun, both axially and through space, will be considered in a
+subsequent article.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/186b.jpg' width='400' height='245'
+alt='Fig: 11.'
+title='Fig: 11.' />
+</div>
+
+<p>
+Then the question arises, How far does the sun's electric field extend?
+That is rather a difficult question to answer, but the correct answer
+would be, &ldquo;As far as the sun's light extends, so far does the sun's
+electric field extend.&rdquo; From the electro-magnetic theory of light we
+know that wherever there are light waves, there are electro-magnetic
+waves, though at the present moment we are only dealing with the<span class='pagenum'><a name='Page_173' id='Page_173'></a><a href='#TOC'>[173]</a></span>
+electric aspect of those waves.
+</p>
+
+<p>
+We know that the aetherial light waves reach at least as far as Neptune,
+a distance of 2,750,000,000 miles, therefore we know that the sun's
+electric field must also extend to that distance. How much further in
+space it extends we cannot tell, because the data on which to form a
+basis is inadequate.
+</p>
+
+<p>
+Thus we learn that the sun's electric field extends east and west for
+that enormous distance, but we cannot say that it extends the same
+distance north and south. Now why is that? The first reason I should
+give is the well-known experiment of a revolving body, by which we learn
+that when a body is revolving, as the sun for example, the atmosphere
+around it would seek to extend itself east and west, owing to the
+Centrifugal Force so called. But a better reason than that will be found
+from an analogy of a magnetized body. Faraday has shown in his drawings
+illustrating lines of force, that if a spherical body is magnetized, the
+magnetic lines of force extend in circles east and west, but go out into
+space in almost straight lines north, and south as the preceding figure
+shows.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/187.jpg' width='400' height='328'
+alt='Fig: 12.'
+title='Fig: 12.' />
+</div>
+
+<p>
+Therefore, accepting Faraday's experiment as the basis for our
+conception of the magnetic lines of force in the sun's electric field,
+we come to the conclusion that the electric field around the sun extends
+east and west, while the lines of force, north and south, are more or
+less radial into space as depicted in the figure.
+</p>
+
+<p>
+Throughout the whole of the field, the electric potential, at different
+distances from the sun, would differ in accordance with all experiment
+and observation. The greatest electric potential would therefore be
+nearest the sun's surface, and would be greatest in the equatorial
+regions of the sun, in accordance with a well-known rule which<span class='pagenum'><a name='Page_174' id='Page_174'></a><a href='#TOC'>[174]</a></span>
+determines electric density and electric potential on conductors.
+</p>
+
+<p>
+As we proceed from the sun's surface east and west into space, we should
+pass equipotential surfaces of different potentials. Thus the pressure
+on every point of equipotential surfaces would be regulated by the
+electric density of the Aether, which would coincide with the actual
+aetherial density at that point; and as the aetherial density is the
+measure of its elasticity or pressure, so the electric potential would
+correspond with the elasticity or pressure at the same point.
+</p>
+
+<p>
+Thus it is possible to map out the electric field east and west by
+ever-increasing and widening circles which would be at lower potential
+the further they receded from the sun. So that by carrying out the
+electro-magnetic theory of light to its logical conclusion, we are able
+to bring the whole of the solar system into line with electric
+phenomena; and, as we proceed, we shall see that all other facts
+relating to electricity, and magnetism also, are equally as applicable
+thereto, otherwise this theory of light must fall to the ground.
+</p>
+
+<p>
+That this conception of the universal Aether in its application to solar
+space is not extravagant may be proved from the writings of Prof.
+Tyndall and Clerk Maxwell. Tyndall, writing on the subject of Faraday's
+Lines of Force, says:<a name='FNanchor_25' id='FNanchor_25'></a><a href='#Footnote_25' class='fnanchor'>[25]</a>
+ &ldquo;The aspect of these curves so fascinated
+Faraday that the greater part of his intellectual life was devoted to
+pondering over them. He invested the space through which they run with a
+kind of materiality, and the probability is that the progress of
+science, by connecting the phenomena of magnetism with the luminiferous
+Aether, will prove these 'Lines of Force,' as Faraday loved to call
+them, to represent a condition of this mysterious substratum of all
+radiant action.&rdquo;
+</p>
+
+<p>
+While Clerk Maxwell,<a name='FNanchor_26' id='FNanchor_26'></a><a href='#Footnote_26' class='fnanchor'>[26]</a>
+ writing on &ldquo;Action at a Distance,&rdquo; says: &ldquo;These
+Lines of Force <i>must not be regarded as mere mathematical abstractions</i>.
+They are the <i>directions in which the medium is exerting tension like
+that of a rope</i>, or rather like that of our own muscles.&rdquo; I therefore
+premise, that both these statements will find a literal fulfilment in
+the conception of the Aether advanced and perfected in this work.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_24' id='Footnote_24'></a><a href='#FNanchor_24'><span class='label'>[24]</span></a>
+<i>Phil. Mag.</i>, 1861.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_25' id='Footnote_25'></a><a href='#FNanchor_25'><span class='label'>[25]</span></a>
+Tyndall on <i>Light</i>.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_26' id='Footnote_26'></a><a href='#FNanchor_26'><span class='label'>[26]</span></a>
+<i>Collected Papers</i>, by Niven.
+</p></div>
+
+
+
+
+<p>
+<a name='ART_81' id='ART_81'></a><span class='smcap'>Art</span>. 81. <i>Aether and Induction</i>.--We have seen in the preceding Arts.
+that the sun is an electrified body, possessing an electric field, which
+field possesses different intensities at different distances from its
+surfaces.
+</p>
+
+<p>
+If such be the case, the question at once confronts us, as to what is
+the effect of such an electrified body with its electric<span class='pagenum'><a name='Page_175' id='Page_175'></a><a href='#TOC'>[175]</a></span>
+field upon all the planets
+which revolve around it; for, if its electric field extends as far as
+Neptune, then all the planets and meteors, that revolve around the sun,
+must revolve in the sun's electric field.
+</p>
+
+<p>
+Such a question can best be answered from the consideration of
+experiments and theories advanced first by Faraday, who gave to the
+world his theory of Induction, which we shall now consider.
+</p>
+
+<p>
+Let <i>A</i> be an electrified body (Fig. 13), and <i>C</i> be a body not
+electrified, but situated within the electric field of <i>A</i>. Then it can
+be experimentally proved, that <i>C</i> will also become an electrified body
+by induction. As is well known, there are two kinds of electricity,
+Positive and Negative. We will suppose <i>A</i> to be charged with positive
+electricity. Then it can be proved that <i>C</i> will also be charged with
+negative electricity on the half nearest to <i>A</i>, while the other half
+will be charged with positive electricity.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/189.jpg' width='400' height='123'
+alt='Fig: 13.'
+title='Fig: 13.' />
+</div>
+
+<p>
+Now how has this result been brought about? According to Faraday's
+theory the particles of air, the dielectric, between <i>A</i> and <i>C</i> play a
+most important part in the process. As a matter of fact, each atom or
+particle of air is polarized, as the process of separating the two kinds
+of electricity is termed, so that every atom has one half of it covered
+with positive electricity, and the other half with negative electricity.
+</p>
+
+<p>
+For example, let <i>A</i> and <i>C</i> be the same brass balls with the particles
+of air between them, <i>A</i> being the positively charged ball and <i>C</i> the
+unelectrified ball, the shaded parts representing positive electricity
+and the unshaded parts negative electricity.
+</p>
+
+<p>
+Then <i>A</i> will act inductively on the unelectrified ball <i>C</i> through the
+medium of the particles of air <i>d, e, f, g, h</i>. The electrified ball <i>A</i>
+will act first on the layer of particles next to it, attracting their
+negative electricity and repelling the positive according to the
+well-known law that &ldquo;Unlike electricities attract, like electricities
+repel each other.&rdquo;
+</p>
+
+<p>
+The positive electricity in the first layer then acts in the particles
+of the next layer in the same way, and thus the inductive action is<span class='pagenum'><a name='Page_176' id='Page_176'></a><a href='#TOC'>[176]</a></span>
+transmitted through the particles, from layer to layer, until we come to
+the last layer of particles next to the ball <i>C</i>.
+</p>
+
+<p>
+As the half of each atom or particle nearest to <i>C</i> is positively
+electrified, then the half of the ball <i>C</i> nearest to the layer becomes
+negatively electrified, while the half further away is positively
+electrified. Thus we say that <i>C</i> has become electrified by induction
+through the polarization of the particles of air which lie between the
+two bodies. Faraday on this point says: &ldquo;Thus induction appears to be
+essentially an action of contiguous particles, through the
+intermediations of which the Electric Force, originating at a certain
+place, is propagated or sustained at a distance, appearing there as a
+Force of the same kind exactly equal in amount, but opposite in its
+direction and tendencies.&rdquo;<a name='FNanchor_27' id='FNanchor_27'></a><a href='#Footnote_27' class='fnanchor'>[27]</a>
+
+</p>
+
+<p>
+While again he states:<a name='FNanchor_28' id='FNanchor_28'></a><a href='#Footnote_28' class='fnanchor'>[28]</a>
+ &ldquo;Induction appears to consist in a certain
+polarized state of particles into which they are thrown by the
+electrified body sustaining the action, the particles assuming positive
+and negative parts which are symmetrically the lines of Inductive
+Force.&rdquo; Thus in the case of any electrified body, acting on an
+unelectrified body at a distance, it has to be definitely understood
+that <i>the action at a distance</i> is alone communicated and propagated by
+the dielectric or medium which exists between the two bodies. Though in
+the case of Gravitation it has been mathematically assumed, that action
+at a distance is possible, yet experimentally and physically such an
+assumption is philosophically incorrect, as all experience and
+experiment go to prove that there is no such thing as action at a
+distance manifested, except such action is propagated through the
+intervening medium, as stated and proved by Faraday.
+</p>
+
+<p>
+In order to bring Gravitation, therefore, into line with our experience,
+it will have to be demonstrated that it, too, is the result of the
+action of the intervening medium, that is, the Aether, which is a result
+we are being led up to.
+</p>
+
+<p>
+We have already seen that the sun is an electrified body, possessing an
+electric field, and as all electrified bodies can act on other bodies in
+their field inductively, then a similar result should happen in the
+solar system, that happens in any electrical experiment on induction,
+with the result that all the planets should become electrified bodies by
+induction, such action taking place, as Faraday points out, through the
+medium which divides the sun and the planets, that is, the Aether.
+</p>
+
+<p>
+Of course with a frictionless and non-atomic Aether such a<span class='pagenum'><a name='Page_177' id='Page_177'></a><a href='#TOC'>[177]</a></span>
+result would be an impossibility, but with our
+conception of an atomic and gravitative Aether the result is now
+attainable. We have therefore to think of the sun, the centre of the
+solar system, being an electrified body, and for illustration we will
+suppose it to be a positively charged body.
+</p>
+
+<p>
+All around the sun is the atomic Aether, which is polarized in the same
+way that the particles of air were polarized; that is, the two kinds of
+electricities in the aetherial atom are separated, the negative being on
+that side nearest to the sun, and the positive on the side further away.
+In this way the whole aetherial medium would be polarized, and any body
+in the field would be electrified by induction, with the result that the
+side nearest the sun would be negatively charged, and the opposite side
+positively charged.
+</p>
+
+<p>
+Thus let <i>S</i> (Figs. 10 and 11) be the sun, and the circles represent
+equipotential surfaces, then one half of every surface would be
+negatively electrified and the other half positively electrified, that
+is, assuming the sun to be a positively electrified body.
+</p>
+
+<p>
+If <i>M</i> represents Mercury, <i>V</i> represents Venus, and <i>E</i> represents the
+Earth (Fig. 10), then it can readily be seen that all these would be
+negatively electrified on the side facing the sun; and, as they rotate
+on their axes, each part of the planet would be positively and
+negatively electrified once each day.
+</p>
+
+<p>
+We are assuming that the medium is at rest, but according to our
+conception in <a href='#ART_44'>Art. 44</a>, all the aetherial atoms are in rotation on their
+axes, in the same way that the earth rotates on its axis, so that each
+of these aetherial atoms would present different parts of its surface to
+the sun as it rotates on its axis; but, as that does not affect the
+principle of induction, such a fact need not now be fully considered.
+</p>
+
+<p>
+Let us now ask, What is the result of all the planets becoming
+electrified bodies in the same way that the sun is an electrified body?
+Arguing from experience, we come to the conclusion that each planet must
+also possess its electric field, which also must have its lines of
+force, its different potentials at different distances, and its
+equipotential surfaces. So that Mercury, Venus, the Earth, Mars,
+Jupiter, Saturn, Uranus, and Neptune all have their electric fields,
+with their own lines of force, and with their equipotential surfaces.
+</p>
+
+<p>
+If we carry the analogy further still, then it can also be proved that
+the Earth, and those planets which have moons or satellites, also act
+inductively on their satellites, with the result that they too become
+electrified bodies, with their own smaller electric fields and lines of
+force. This may seem at first sight a little confusing, but the
+confusion will gradually disappear if we will look at it carefully for a
+moment or two. Let us endeavour to picture the solar system from this<span class='pagenum'><a name='Page_178' id='Page_178'></a><a href='#TOC'>[178]</a></span>
+new standpoint, and map out the equipotential surfaces, which this idea
+suggests. Let <i>S</i> represent the sun (Fig. 14), the initials of all the
+planets and satellites representing the various planets; then we get the
+following plan of the solar system with the various equipotential
+surfaces shown by the circular lines.
+</p>
+
+<p>
+We are now supposed to be looking down on all the solar system from
+above it, so to speak, so that we should be looking at what we call the
+North Poles of the sun and planets.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/192.jpg' width='400' height='323'
+alt='Fig: 14.'
+title='Fig: 14.' />
+</div>
+
+<p>
+Thus we see that the equipotential surfaces around the sun are huge
+circles which stretch out as far as Neptune or even beyond, but within
+those circles we find each of the planets revolving round the sun, each
+with its own equipotential spheres, which are circles also, while around
+the various planets are the satellites, from the moon of our Earth, to
+the two satellites of Mars, five of Jupiter, eight of Saturn, each with
+its own lines of force and electric fields.
+</p>
+
+<p>
+Of course we must not forget that all these revolve round the sun, and
+the question may suggest itself to the reader's mind, if such a result
+is possible. I shall prove later on, that according to Maxwell such an<span class='pagenum'><a name='Page_179' id='Page_179'></a><a href='#TOC'>[179]</a></span>
+event is possible, but at present we will consider them stationary.
+</p>
+
+<p>
+Now let us see how such a conception compares with our hypothesis of a
+gravitative Aether. If Aether be gravitative, then the sun must have an
+attraction for the Aether, and its aetherial field would stretch out
+into space as far as Neptune at least.
+</p>
+
+<p>
+So that it can readily be seen that the aetherial field of the sun's
+attractive power coincides with the electric field which the sun
+possesses as an electrified body. Again, if Aether be gravitative, then
+all the planets must also have an aetherial field, which will be
+co-extensive with their electric field also. The same principle applies
+to each of the satellites, with the result that they too will possess an
+aetherial field which will be equal in extent and limit to their
+electric field.
+</p>
+
+<p>
+As the satellites revolve around their primary planet taking their
+electric fields with them, so the planets with their associated
+satellites revolve around the sun taking their electric and aetherial
+fields with them. Thus we get a glimpse, though at this point very
+shadowy and indistinct, of those motions of the universal Aether, which
+help to constitute the harmony, beauty, and order of the universe. We
+have seen, therefore, that as the sun is an electrified body, so all the
+planets and satellites are electrified bodies also, each possessing its
+own field, with all that such a field implies.
+</p>
+
+<p>
+We shall find that such a conception is borne out by experience and
+observation, when we come to deal with the Earth as a magnet; because we
+shall afterwards learn that the Earth is an electro-magnet, possessing
+its magnetic field, which is co-existent and equipollent with its
+electric field.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_27' id='Footnote_27'></a><a href='#FNanchor_27'><span class='label'>[27]</span></a>
+<i>Exp. Res</i>., 1297, 1298.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_28' id='Footnote_28'></a><a href='#FNanchor_28'><span class='label'>[28]</span></a>
+Par. 1298.
+</p></div>
+
+
+
+
+<p>
+<a name='ART_82' id='ART_82'></a><span class='smcap'>Art</span>. 82. <i>Energy of the Field</i>.--We have seen in <a href='#ART_79'>Art. 79</a> that every
+electrified body has an electric field. We have further learned, in
+carrying the electro-magnetic theory of light to its logical conclusion,
+that all the planets and satellites together with the sun must be
+electrified bodies, each possessing its electric field.
+</p>
+
+<p>
+We have now to determine the effect of such a truth from its dynamical
+aspect upon the bodies within the field, that is to say, we have to
+consider the energy of such electric fields, and endeavour to find out
+the effect of such energy upon other bodies within that field.
+Maxwell,<a name='FNanchor_29' id='FNanchor_29'></a><a href='#Footnote_29' class='fnanchor'>[29]</a>
+ in his introduction to a paper on &ldquo;The Dynamical Theory of
+the Electro-magnet Field,&rdquo; writes on the matter thus: &ldquo;It appears
+therefore that certain phenomena in electricity and magnetism lead to
+the same conclusion as those of optics, namely, that there is an
+aetherial medium pervading all bodies and modified only in degree by their<span class='pagenum'><a name='Page_180' id='Page_180'></a><a href='#TOC'>[180]</a></span>
+presence; that the parts of this
+medium are capable of being set in motion by electric currents and
+magnets; that this motion is communicated from one part of the medium to
+another by forces arising from the connection of these parts; that under
+the action of these forces, there is a certain yielding depending upon
+the elasticity of these connections; and that therefore energy in two
+different forms may exist in the medium, the one form being the actual
+energy of motion of its parts, and the other being the potential energy
+stored up in the connections in virtue of their elasticity.&rdquo;
+</p>
+
+<p>
+The two forms of energy he gives us in his work on <i>Magnetism and
+Electricity</i>, where, in the quotation already given in <a href='#ART_79'>Art. 79</a>, he
+states them to be electro-static and electro-kinetic energy, while in
+paragraph 792 of the same work he adds: &ldquo;The intrinsic energy of the
+medium is half electro-static and half electro-kinetic, that is, half is
+due to electricity and half is due to magnetism.&rdquo;
+</p>
+
+<p>
+We are, however, only dealing at this point with the electro-static
+energy in the electric field, as we shall deal with the electro-kinetic
+energy in the following chapter.
+</p>
+
+<p>
+We have, therefore, to conceive of an electrified body generating
+electric or electro-magnetic waves, which speed away from the generating
+source on every side with the velocity of light. Now we have already
+seen that the aetherial waves which give rise to heat and light possess
+a repulsive power, that is, they exert a pressure on the body with which
+they come into contact.
+</p>
+
+<p>
+If, therefore, in the electric field there is this energy manifested as
+proved by Maxwell, and that energy takes partly the form of a pressure
+as stated by Maxwell, then we have in the electro-static energy of the
+electric field, another indication of that centrifugal force for which
+we are looking, and whose existence was so satisfactorily demonstrated
+to Herschel by the phenomena of comets' tails.
+</p>
+
+<p>
+That there is this pressure in an electric field was conclusively proved
+by Maxwell, and experimentally demonstrated by Professor Lebedew (<a href='#ART_77'>Art. 77</a>. Maxwell distinctly states on this point, &ldquo;that the combined effect
+of the electro-static and electro-kinetic stresses is a pressure equal
+to 2 P. in the direction of the propagation of the waves,&rdquo; that is, away
+from the electrified or charged body.
+</p>
+
+<p>
+He continues: &ldquo;Thus, if in strong sunlight the energy of light which
+falls on one square foot is 83.4 foot-pounds per second, the mean energy
+in one cubic foot of sunlight is about .0,000,000,882 of a foot-pound,
+and the mean pressure on a square foot is .0,000,000,882 of a pound
+weight. A flat body exposed to sunlight would experience this pressure<span class='pagenum'><a name='Page_181' id='Page_181'></a><a href='#TOC'>[181]</a></span>
+on its illuminated side only, and would therefore be <i>repelled</i> from the
+side on which the light falls.&rdquo;<a name='FNanchor_30' id='FNanchor_30'></a><a href='#Footnote_30' class='fnanchor'>[30]</a>
+
+</p>
+
+<p>
+This pressure only gives the result due to the pressure of one cubic
+foot of sunlight. What must be the pressure, therefore, due to the whole
+of the sunlight received by the flat body from the sun? The total
+pressure, whatever it may be, would be equal to 2 P. according to
+Maxwell, and half of that is due to electricity, and half due to
+magnetism. Now such a result is entirely in harmony with the conception
+of the Aether as given in this work. For, if Aether possess an electric
+basis as suggested by Maxwell, and it is also gravitative as suggested
+in <a href='#ART_45'>Art. 45</a>, then it must follow, as pointed out in a previous Art., that
+throughout the field there is a varying difference in the potential of
+the field; the potential being regulated by the electric density, that
+density being equivalent to the aetherial density. Further, as the
+elasticity of the medium which regulates the pressure is proportional to
+the density, so the pressure must decrease, as the elasticity
+decreases--that is, as the electric potential decreases, or the electric
+density is diminished. Therefore, if the sun be an electrified body,
+ever generating electro-magnetic waves which speed away from it on every
+side, then, whenever any of these waves come into contact with a planet
+or comet, that planet or comet would be repelled from the sun by the
+pressure of these electro-magnetic waves to which the sun gives rise in
+its electric or electro-magnetic field.
+</p>
+
+<p>
+Thus we again come to the conclusion that the sun is not only the centre
+of a centripetal force due to Gravitation, and subject to certain laws,
+whose physical cause is unknown, but it is equally the centre and source
+of a centrifugal force, in that it is an electrified body, and gives
+rise to electric waves which produce a pressure on any body upon which
+they fall, in the sun's electric or aetherial field. It has only to be
+demonstrated, therefore, that this centrifugal force satisfactorily
+fulfils all the laws required as laid down in <a href='#ART_24'>Art. 24</a>, that is, that its
+course is along the same path as the Centripetal Force of Gravitation,
+that it is subject to the same law of intensity, which is inversely as
+the square of the distance; and further (what is the most important at
+this stage), that the combined effect of the pressure of two bodies is
+equal to the product of their masses, then we shall have discovered that
+which we set out to discover, viz. a complementary force to the
+attractive force of Gravitation.
+</p>
+
+<p>
+Unlike the centripetal force, however, the centrifugal force will be
+purely a physical one, due to a purely physical medium, the<span class='pagenum'><a name='Page_182' id='Page_182'></a><a href='#TOC'>[182]</a></span>
+Aether, whose properties and motions can be accounted for on a physical,
+and not on a hypothetical basis.
+</p>
+
+<p>
+Further, as the planets are also electrified bodies (<a href='#ART_81'>Art. 81</a>), they too
+will possess an electric field, and will generate electric waves, which
+will also exert a centrifugal force upon all bodies upon which the waves
+fall. So that, like the sun, the planets are not only the centre of a
+centripetal force, which ever acts towards their centre; but they are
+also the centre of a centrifugal force, due to the aetherial electric
+waves to which they give rise in the Aether.
+</p>
+
+<p>
+The application of the same principle may be extended to every satellite
+that exists in the solar system, and indeed to every particle and atom
+of matter that exist throughout the universe, for wherever we find the
+Aether, there we find this centrifugal force, which is due to the
+electric aetherial waves generated by the atom or particle of matter, or
+by any combination of atoms, as a meteor, satellite, planet, sun or
+star.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_29' id='Footnote_29'></a><a href='#FNanchor_29'><span class='label'>[29]</span></a>
+<i>Collected Papers</i>, by Niven.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_30' id='Footnote_30'></a><a href='#FNanchor_30'><span class='label'>[30]</span></a>
+<i>Magnetism and Electricity</i>, Arts. 791 and 793.
+</p></div>
+
+
+
+
+<p>
+<a name='ART_83' id='ART_83'></a><span class='smcap'>Art</span>. 83. <i>Electric Radiation</i>.--We learn, therefore, that the sun,
+together with every planet and satellite in the solar system, is the
+centre of a centrifugal force, which is due to the radiation of electric
+waves by an electrified body. We have now to prove that this force
+fulfils all the laws required, in order for it to become the
+complementary law to the Centripetal Force of Gravitation. We will first
+show that this centrifugal force which proceeds from the electrified
+body is radiated out into space in straight lines with the velocity of
+light and radiant heat.
+</p>
+
+<p>
+As we have already seen, it was due to the genius of Hertz to show the
+identity between electric radiation and radiant light and heat. In his
+paper on Electric Radiation he says:<a name='FNanchor_31' id='FNanchor_31'></a><a href='#Footnote_31' class='fnanchor'>[31]</a>
+ &ldquo;I have succeeded in producing
+distinct rays of electric force, and in carrying out with them the
+elementary experiments which are commonly performed with light and
+radiant heat.&rdquo; We have seen in <a href='#ART_65'>Arts. 65</a> and <a href='#ART_76'>76</a> that radiant heat and
+light are propagated in straight lines, so that, according to Maxwell's
+electro-magnetic theory, a ray of electric radiation should also be
+propagated in straight lines.
+</p>
+
+<p>
+This Hertz proved, and gave his results in his paper &ldquo;On the Action of a
+Rectilinear Oscillation upon a Neighbouring Circuit,&rdquo; in which he fully
+demonstrated that when electric action takes place between two charged
+bodies, the electric force is radiated out into space in straight lines
+in the same way that light and radiant heat are radiated. In his paper
+on &ldquo;The Finite Velocity of Electro-magnetic Actions,&rdquo; he showed that the
+velocity of the electro-magnetic waves was the same as that of light. In
+the summary of this paper<span class='pagenum'><a name='Page_183' id='Page_183'></a><a href='#TOC'>[183]</a></span>
+(paragraph 3) he states: &ldquo;There are many reasons for believing that the
+transverse waves of light are electro-magnetic waves; a firm foundation
+for this hypothesis is furnished by showing the actual existence in free
+space of electro-magnetic transverse waves which are propagated with a
+velocity akin to light.&rdquo;
+</p>
+
+<p>
+Again, in his paper on &ldquo;Electric Radiation,&rdquo; he not only showed how the
+radiation was propagated in straight lines, like light, but also proved
+that while it was reflected by metals, the electric beam was able to
+pass through doors and stone walls, and adds, &ldquo;that it was with
+astonishment that one saw the electric beam appear inside a closed room
+after its passage through the door.&rdquo;
+</p>
+
+<p>
+Thus Hertz has shown that both electric and magnetic effects are
+propagated through the Aether with finite velocity, and that that
+velocity is exactly the same as the velocity of light. He further proved
+that this propagation takes place in straight lines, in the same way
+that radiant heat and light are propagated. This being so, it is
+necessary for us to apply these truths to the solar system, with a view
+to find out what such a result teaches us.
+</p>
+
+<p>
+We have seen in a preceding article, that the sun is an electrified
+body; therefore it, too, must generate these electro-magnetic waves, and
+radiate them into space on every side with the velocity of light. Let us
+try to picture the scene. Let <i>S</i> represent the sun, and the circle
+round it represent the equipotential spheres which exist round the sun.
+(See Figs. 10 and 11.) As the intensity of the electric force is greater
+nearer the sun than further away, these equipotential surfaces will be
+closer nearer the sun than further away.
+</p>
+
+<p>
+Then let the straight lines which radiate out from the sun represent the
+path of an electric ray. It can be easily seen that these electric rays
+cut the equipotential surfaces at right angles, as they pass from the
+centre of the sun outwards into space. Now these lines not only
+represent the path which the electric ray takes in its journey through
+space, but exactly coincide with the electric lines of force as
+conceived by Faraday. This great thinker and experimentalist not only
+conceived lines of magnetic forces existing in the dielectric or medium
+between two electrified bodies, which in this case is the Aether, but
+also conceived lines of electric force which started at a conductor, or
+an electrified body, and radiated out into space.
+</p>
+
+<p>
+Thus a line of electric force has a definite direction, and always
+starts from an electrified body. If it were possible to move a planet
+along one of these lines of force, its path would be that of a straight
+line. If on the other hand a planet moved at right angles to one of
+these lines of force, that is, along the surface of an equipotential
+sphere, then no work would be done against the electric force, as on<span class='pagenum'><a name='Page_184' id='Page_184'></a><a href='#TOC'>[184]</a></span>
+such a sphere the electric force would be of the same intensity.
+</p>
+
+<p>
+So that from Hertz' experiments it can be demonstrated, that if there be
+any electric force existent in the Aether, due to the action of the sun
+upon the Aether, then such a force is directed along the path of a
+straight line into space with the velocity of light, which, as already
+pointed out, is the path taken by a ray of radiant heat and light, and
+coincides with the path taken by the centripetal force.
+</p>
+
+<p>
+It has been demonstrated that such electric force is accompanied by a
+repulsive force, or more correctly a pressure, so that here we have
+further evidence of the existence of a centrifugal force which finds its
+generating source in the sun, which is also the centre of the attractive
+force of Gravitation in the solar system.
+</p>
+
+<p>
+The application of Hertz' experiments may be made not only to the sun,
+but also to every planet and satellite that exists in space with the
+same result; and, further, may be extended to every particle and atom
+that exists throughout the universe. For, according to <a href='#ART_43'>Art. 43</a>, we have
+learned that Aether is universal, and we have seen that it is
+gravitative, and have learned from the electro-magnetic theory of light
+that it has an electro-magnetic basis. Therefore, to be thoroughly
+consistent, we must not stop in the application of this principle at any
+point in the whole universe.
+</p>
+
+<p>
+Either the whole principle is of universal application, or it ceases to
+be a universal law. Therefore, if there is this centrifugal force
+operating along a straight line from the centre of an electrified body,
+such centrifugal force must be in its application universal, in order to
+be complete, and in order to satisfactorily form the counterpart of the
+centripetal force which is also universal, and operates along the
+straight line joining the centres of gravity of any two bodies.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_31' id='Footnote_31'></a><a href='#FNanchor_31'><span class='label'>[31]</span></a>
+Hertz on <i>Electric Waves</i>.
+</p></div>
+
+
+<p>
+<a name='ART_84' id='ART_84'></a><span class='smcap'>Art</span>. 84. <i>Law of Inverse Squares</i>.--We have learned therefore from the
+preceding Arts., that the solar system may be looked upon as an electric
+field, with the sun as the electrified body occupying the centre. We
+have also seen that there is a centrifugal force in all electric fields,
+which is due partly to electric waves, and partly to the magnetic waves
+of the Aether.
+</p>
+
+<p>
+It will be interesting to find out, what law governs the intensity of
+this force in any part of the field, or at a given distance from the
+central body. We have seen (<a href='#ART_66'>Art. 66</a>) that the law governing the
+intensity of heat at any distance from the sun, is the law of inverse
+squares. Further, from <a href='#ART_75'>Art. 75</a> we have also learned that light is
+subject to the same law of inverse squares, as indeed it should be, if
+it be due to one and the same medium, the Aether.<span class='pagenum'><a name='Page_185' id='Page_185'></a><a href='#TOC'>[185]</a></span>
+</p>
+
+<p>
+If, therefore,
+electricity is also due to certain motions of the aetherial medium
+originated by the action of an electrified body as the sun, in the same
+way that light and heat waves are originated, then it ought to follow
+that the repulsive power of electricity is also subject to the same law
+of inverse squares. As a matter of fact, that is exactly the state of
+affairs, so that we find the intensity of the repulsive power in the
+Aether from any central body, due to the electric waves, or the pressure
+due to the wave motions of the electric Aether, in relation to that
+body, is governed and controlled by the same law that governs light and
+heat.
+</p>
+
+<p>
+It may be suggested that such a coincidence is not a very strong
+argument, as all forces emanating from a central body are subject to the
+same law of inverse squares. In reply to that, I should like to point
+out, that even that objection only strengthens the conception of the
+Aether that we are endeavouring to complete. Our contention is, that all
+physical forces, whether they be light, heat, electricity, magnetism or
+Gravitation, are all due to the motions of the aetherial medium; which
+motions may be generated by a heated or luminous or electrified body,
+and are radiated from such a body in waves of concentric spherical form,
+and are all subject to the laws of inverse squares.
+</p>
+
+<p>
+So that the fact of the intensity of the centrifugal force due to the
+repulsive power of electricity falling into line with the law governing
+light and heat is, to my mind at any rate, only a clearer proof of the
+one common origin of all the physical forces. The law of inverse squares
+in relation to electricity may be thus stated. The Centrifugal or
+Repulsive Force between two charged electrified bodies acts inversely as
+the square of the distance between them.
+</p>
+
+<p>
+This law was proved by Coulomb by means of an instrument known as
+Coulomb's Torsion Balance, and I must refer the reader to any work on
+electricity for a full establishment of this law. Suffice to say, that
+it has been experimentally demonstrated that the law holds good in
+relation to the phenomena of electricity; and, wherever we get the two
+kinds of electricity present in any medium or conductor, owing to the
+polarization of its particles, there we have this law operating in
+relation to the intensity of the repulsions of the two bodies directly
+concerned.
+</p>
+
+<p>
+We have already learned that the sun is an electrified body, and from
+that hypothesis we have arrived at the conclusion that the earth and all
+the other planets are electrified bodies. This being so, it naturally
+follows that the intensity of the centrifugal force between any two of
+these bodies, as the sun and the earth for example, or the sun and
+Jupiter, is subject to the law of inverse squares; and that the
+repulsion of the sun and the earth for each other is always regulated<span class='pagenum'><a name='Page_186' id='Page_186'></a><a href='#TOC'>[186]</a></span>
+by their distance, being inversely as the squares of the distance
+between them.
+</p>
+
+<p>
+Thus, if the distance between the sun and any planet is reduced to
+one-half, which is an exaggerated view, the intensity of the centrifugal
+force is increased four times; if the distance be doubled the force is
+reduced to four times its former intensity, and so on.
+</p>
+
+<p>
+Whatever the distance may be between the sun and any of the planets, if
+that distance be increased or decreased, then the intensity of the
+centrifugal force due to electric waves is increased or decreased in
+accordance with the law of inverse squares. This agrees with the
+centripetal law of Gravitation, as the Attraction of Gravitation is also
+subject to the same law of inverse squares, and, as we have seen (<a href='#ART_83'>Art. 83</a>), its path coincides with the path of centrifugal force, as it
+pursues the path represented by the straight lines joining the two
+bodies.
+</p>
+
+<p>
+So that, whenever, and wherever, at any point in space in relation to
+the central body, the sun, the intensity of the attractive force is
+increased according to the law of inverse squares by the distance from
+the central body being diminished, at exactly the same time and in
+exactly the same manner, the repulsive force due to aetherial electric
+waves is also increased. If the attractive force is doubled, then the
+repulsive force is doubled. If the attractive force is halved, the
+repulsive force is halved. If the attractive force is lessened
+gradually, then the repulsive force is lessened gradually; and if
+quickly, by the quicker motion of the planet through space, then the
+repulsive motion is also increased with a quicker motion.
+</p>
+
+<p>
+Further, like the repulsive power of light and heat, the repulsive power
+of electricity takes exactly the same path as the attractive power of
+Gravitation.
+</p>
+
+<p>
+Thus we learn that the sun is the centre of two forces: first, a
+centrifugal force due to the pressure of the aetherial medium which is
+ever directed away from the sun, and which may either be produced by
+electric or thermal or light waves; and second, it is the centre of a
+centripetal force known as the Law of Gravity, whatever that may be due
+to. Further, the centrifugal force is also subject to the same law of
+intensity as the centripetal force, and moreover takes exactly the same
+path which the centripetal force takes.
+</p>
+
+<p>
+So that we have only to prove that they both agree in another
+particular, viz. that their power is regulated by the product of their
+masses, and then we shall have discovered a real physical force, which
+is the exact complement and counterpart of the centripetal force due to
+gravity.
+</p>
+
+<p>
+<a name='ART_85' id='ART_85'></a><span class='smcap'>Art</span>. 85. <i>Second Law of Electricity. (Product of Masses</i>.)--We have now<span class='pagenum'><a name='Page_187' id='Page_187'></a><a href='#TOC'>[187]</a></span>
+to prove that the centrifugal force exerted by any electrified body
+operates upon another electrified body in the same proportion and with
+exactly the same force which governs the centripetal force. From <a href='#ART_21'>Art. 21</a>
+we learn that the centripetal force which is exerted by one body upon
+another is equal to the product of their masses. In order, therefore,
+for any centrifugal force to be the exact counterpart of that force, it
+too must be subject to the same law of proportion, that is, the
+repulsive force between any two bodies must be equal to the product of
+their masses.
+</p>
+
+<p>
+We have shown that there is a repulsive force exerted by the Aether from
+the phenomena of heat, light, and electricity, and that that repulsive
+force or energy fulfils every condition required by a centrifugal force
+or motion, with the exception of the part referring to the fact that
+such a force must be proportionate to the product of their masses. What
+we were unable to accomplish, however, from the phenomena of heat or
+light we are now able to accomplish from the phenomena of electricity
+</p>
+
+<p>
+For in the phenomena of electricity we find a law which runs thus: &ldquo;The
+force of repulsion&rdquo; (which is the part of electricity we are now dealing
+with) &ldquo;between two electrified bodies is equal to the quantities of
+electricity with which the body is charged.&rdquo; This law was established
+and proved by Coulomb by means of a delicate instrument known as the
+Torsion Balance, with which he also established the law of inverse
+squares.
+</p>
+
+<p>
+It will be seen at a glance that there is a slight difference between
+stating the law of proportion with reference to the centripetal force,
+and the centrifugal force or motion. In the former we state the
+proportion is equal to the product of the masses, while in the latter we
+say that the proportion is equal to the product of the quantities of
+electricity.
+</p>
+
+<p>
+In the one case we deal with the mass of the body, whether it be atom,
+molecule, planet or star; in the other case we deal with quantities of
+electricity. At first sight it may seem that there is little, if any,
+connection between the two laws, but a careful reflection of the
+hypotheses laid down with regard to the aetherial medium will show that
+there is not only a close connection between these two laws of
+proportion, but also that the law governing the repulsive power of the
+aetherial electric waves is the direct outcome of the law of proportion
+governing the centripetal force. Let us restate our case in regard to
+the aetherial medium.
+</p>
+
+<p>
+We have learned that the Aether is gravitative, and that it also has an
+electro-magnetic basis is proved from Maxwell's electro-magnetic theory
+of light. Let me ask the reader this question therefore. If the Aether<span class='pagenum'><a name='Page_188' id='Page_188'></a><a href='#TOC'>[188]</a></span>
+be gravitative, what must be the rule governing the extent and density
+of the aetherial atmosphere surrounding any planet or sun or other body?
+If the Law of Gravity teaches us anything at all, it distinctly teaches
+us that the gravitating power of any body is regulated by the mass of
+the body, as the law states that the attraction is proportionate to the
+product of the masses. It states nothing about volume or condition of a
+body.
+</p>
+
+<p>
+The exact size or state of a body has no direct result bearing on
+gravitation attraction; the underlying principle being that the
+attractive force is dependent on the mass, and only on the mass of a
+body. So that if the volume of any body, whether atom, planet, satellite
+or sun, be doubled, its attractive power remains the same, simply
+because the mass of the whole body remains the same. Mass, we are told
+by mathematicians, is equal to the volume multiplied by the density, and
+whenever we increase the volume of a body we decrease the density, the
+total mass of the body remaining the same.
+</p>
+
+<p>
+If the volume be doubled, then the density of the body would be halved,
+and <i>vice versâ</i>, but through all the changes of volume and density that
+may arise from the addition of heat or diminution of heat, the total
+mass of a body always remains the same. Looked at from the atomic
+standpoint, taking hydrogen as unity, an atom of oxygen would always
+weigh sixteen times an atom of hydrogen, and this principle applies
+throughout the whole realm of the atomic world. Further, the same
+principle or law, that the mass is equal to the volume multiplied by the
+density, is true of the planetary or even the stellar world. Thus the
+great regulating principle of the attractive force of gravity is mass,
+and not volume, or density, or any other condition.
+</p>
+
+<p>
+Now as Aether is subject to the attractive force of gravity, the extent
+of the aetherial field, and the density of the Aether near the surface
+of any body, must be subject to the same law regarding mass. That is,
+the aetherial atmosphere of any atom, or molecule, or satellite, or
+planet, or star is dependent upon the mass of the atom, the molecule, or
+the planet, or the star as the case may be.
+</p>
+
+<p>
+Thus an atom of oxygen would have a larger or denser aetherial
+atmosphere than an atom of hydrogen, exactly proportionate to their
+respective masses. A planet whose mass was represented by 1,000,000 tons
+would have twice the quantity of Aether around it, compared to a planet
+weighing only 500,000 tons, and so on, the aetherial atmosphere always
+being proportionate to the mass of the planet, or the satellite, or the
+sun, or the star. The fact which we learn from these considerations is<span class='pagenum'><a name='Page_189' id='Page_189'></a><a href='#TOC'>[189]</a></span>
+that the quantity of Aether, which is attracted by any body, is always
+proportionate to the mass of the body attracting it.
+</p>
+
+<p>
+But we have learned from <a href='#ART_78'>Art. 78</a> that Aether has an electro-magnetic
+basis, and that the density of the Aether is co-equal with electric
+density, so that the quantity of Aether which is attracted and held
+bound by any body is really equal to the quantity of electricity that
+such a body is covered with, or is charged with. If the quantity of
+Aether around any body is doubled because its mass is doubled, then the
+quantity of electricity is also doubled, but as long as the mass remains
+unaltered, the quantity of electricity held bound by that mass remains
+unaltered also. The area of the mass may be doubled, and in that case
+the density of the electricity would be halved, but as long as the mass
+remained the same, the quantity of electricity would remain the same
+also. So that we learn from this reasoning that the mass of a body, and
+quantities of electricity on that mass, are always proportionate to each
+other, because of the fact that Aether is gravitative, and also has an
+electro-magnetic basis.
+</p>
+
+<p>
+If we wanted further evidence of the hypothesis that has just been
+advanced, such evidence is to be found in the hypothesis suggested by
+Faraday as to the electro-chemical equivalents of all elements.
+According to this hypothesis every element has its exact
+electro-chemical equivalent, or definite quantities of electricity are
+to be found in association with each and every particular atom of each
+element. Writing on the subject in his <i>Exp. Res.</i>, par. 852, he says:
+&ldquo;The theory of definite electro-chemical action appears to me to touch
+upon the absolute quantity of electricity or electrical power belonging
+to different bodies. Although we know nothing of what an atom is, yet we
+cannot resist forming some idea of a small particle which represents it
+to our mind, and though we cannot say what electricity is, so as to be
+able to say whether it is a particular matter or matters, or mere motion
+of ordinary matter, yet there is immensity of facts which justify us in
+believing that the atoms of matter are in some way endowed or associated
+with electrical powers to which they owe their most striking qualities,
+and amongst them their chemical affinity.&rdquo; Further, in Art. 857, he
+states: &ldquo;I can have no doubt that, assuming hydrogen as 1, and
+dismissing small fractions for the simplicity of expression, the
+equivalent number or atomic weight of oxygen is 8, of chlorine 36, of
+bromine 78.4, and of lead 103.5, etc., notwithstanding that a high
+authority doubles several of these numbers.&rdquo;
+</p>
+
+<p>
+Then, writing upon the definite relationship of these equivalents in
+compounds, he states (Art. 835): &ldquo;Electro-chemical equivalents are<span class='pagenum'><a name='Page_190' id='Page_190'></a><a href='#TOC'>[190]</a></span>
+always consistent, that is, the same number which represents the
+equivalent of a substance <i>A</i> when it is separating from a substance <i>B</i>
+will also represent <i>A</i> when separating from a third substance <i>C</i>. Thus
+8 is the electro-chemical equivalent of oxygen, whether separating from
+hydrogen, tin, or lead; and 103.5 is the electro-chemical equivalent of
+lead, whether separating from oxygen, or chlorine, or iodine.&rdquo;
+</p>
+
+<p>
+Here, then, from the pen of one of the greatest thinkers and
+experimentalists of modern times we have confirmatory evidence that the
+mass of any body is practically synonymous with the quantity of
+electricity associated with that body. For if the principle is true in
+its application to atoms, it is true in its application to molecules;
+and if it is true in relation to molecules, it is equally true in
+relation to small bodies composed of molecules. And if it holds good in
+relation to small bodies, the principle is equally true in its
+application to larger bodies, as the earth, and therefore is of
+universal application and proves the statement already made, that the
+masses of bodies and quantities of electricity in association with that
+mass are always proportionate to each other.
+</p>
+
+<p>
+We are now in a position to compare the proportion of the centripetal
+and centrifugal forces. The attractive power of the former, between two
+bodies, is equal to the product of their masses; the repulsive power of
+the latter is equal to the product of the quantities of electricity
+bound to them, and that, as we have seen, is regulated by the respective
+mass of each body. Let us apply this fact to the solar system and see
+how it works.
+</p>
+
+<p>
+Taking the mass of the earth as unity, we find that the mass of the sun
+is 324,000 greater, so that the attractive power of the two bodies would
+be represented by the product of the two numbers; but because the sun is
+that number of times greater, its aetherial and, therefore, its electric
+field would be so many times greater, with the result that the
+proportion of the repulsive forces between the two bodies would be
+exactly the same as the attractive forces between the two bodies, that
+is, if the mean distance remains the same.
+</p>
+
+<p>
+In the same way, it can be shown that the attractive forces between the
+earth and Jupiter exactly equal the repulsive forces between the two
+planets at their mean distance, or the attractive forces between any two
+planets or satellites are exactly counterbalanced by the repulsive power
+of the centrifugal force at their mean distances.
+</p>
+
+<p>
+Thus the centrifugal force of every body is the exact opposite of its
+centripetal force at their mean distance, because the laws governing the
+centrifugal force are the exact counterpart of the laws governing the
+centripetal force. A comparison of the two will prove this. From <a href='#ART_20'>Arts. 20</a>, <a href='#ART_21'>21</a>, and <a href='#ART_22'>Art. 22</a> we have seen that the centripetal force is exerted along<span class='pagenum'><a name='Page_191' id='Page_191'></a><a href='#TOC'>[191]</a></span>
+the straight lines joining the attracting bodies, that the intensity of
+the attracting body is inversely as the square of the distance, while
+the total force is proportionate to the product of their masses.
+</p>
+
+<p>
+From the phenomena of light, heat, and electricity, we learn that the
+centrifugal force due to aetherial pressure is exerted along straight
+lines, that the intensity is inversely as the square of the distance,
+while the total force between two bodies is equal to the product of the
+quantities of electricity, which are regulated by the product of their
+masses.
+</p>
+
+<p>
+Thus, if every planet and satellite could be conceived to be motionless
+in space, and these two forces could be set in operation without
+producing rotation or translation in space, which is impossible, then
+every planet and satellite would occupy, by the joint exercise of these
+two forces, the same position in relation to the sun represented by
+their mean distances, as long as the solar system existed as a separate
+system in the realm of aetherial space. We have therefore discovered by
+strict philosophical reasoning, based on Newton's Rules of Philosophy, a
+real tangible centrifugal force existing throughout the universe;
+because it is entirely due to the pressure of an universal Aether, whose
+operation is ever directed from a central body, which force was
+indicated by Herschel, and its existence to his mind was demonstrated by
+the repulsion exhibited in connection with the tails of comets.
+</p>
+
+<p>
+We have now to go a step further, and show that the same pressure also
+includes the magnetic phenomena, as indicated by Clerk Maxwell, and that
+magnetic phenomena are also due to the aetherial medium, and then we
+shall have linked together in one common medium the majority of the
+forms of energy, as light, heat, electricity and magnetism, with which
+we are familiar.
+</p>
+
+<p>
+If it be demonstrated that these two forces, the centrifugal force and
+the centripetal force, can conjointly account for all the motions of the
+celestial bodies, then we shall have conclusive evidence that one of the
+forces is physical and due to the pressure of a physical medium. After
+that it will be comparatively easy to show that the centripetal force is
+also due to the same aetherial medium, and then we shall have
+accomplished that which we set out to accomplish, viz. the establishment
+of a physical cause for universal Gravitation, which physical cause is
+alone to be found in the pressures, tensions and motions of an universal
+Aether.
+</p>
+
+<p><span class='pagenum'><a name='Page_192' id='Page_192'></a><a href='#TOC'>[192]</a></span></p>
+<h2><a name='CHAPTER_IX' id='CHAPTER_IX'></a><a href='#CHAPTER_IX_TOC'>CHAPTER IX</a></h2>
+
+<h3>AETHER AND MAGNETISM</h3>
+
+<p>
+<a name='ART_86' id='ART_86'></a><span class='smcap'>Art</span>. 86. <i>Electro-magnetism</i>.--We have now to look at the relation of
+magnetism to electricity, or, in other words, to prove the identity that
+exists between magnetism and electricity. In <a href='#ART_78'>Art. 78</a> we have proved the
+identity between electricity and light, so that if we can now prove the
+identity between electricity and magnetism, then, wherever we get
+aetherial light waves, we must also get aetherial electro-magnetic
+waves.
+</p>
+
+<p>
+As the light waves due to the vibrations of the Aether are practically
+universal in extent, then it must follow, if the identity of the light
+waves with electro-magnetic waves is established, that the universality
+of electro-magnetic waves is established also, with the natural result,
+that, wherever we get these electro-magnetic waves, there we shall have
+the conditions by which all electro-magnetic phenomena are produced.
+</p>
+
+<p>
+Now it can be demonstrated by actual experiment that wherever we get a
+circular current of electricity, there we have magnetic phenomena
+manifested. The two are inseparably connected, and it is impossible to
+obtain the one without the other. For example, suppose we have a wire
+conveying a current of electricity and make it into a coil as in Figure
+15, what is the result? The result is, that the coil of wire has
+actually been converted into a magnet.
+</p>
+
+<p>
+It will attract iron filings that are brought near it, and also
+magnetize an iron bar placed in the centre of the coils, and convert
+that into a magnet. Indeed, there is nothing which can be done by an
+ordinary bar magnet which cannot be done by a coiled wire conveying an
+electric current.
+</p>
+
+<p>
+From this and similar experiments it can be demonstrated that wherever
+we get a circular current of electricity, there, associated with that
+current, are all the phenomena incidental to and associated with the
+ordinary bar magnet. This leads us to the truth discovered by Ampère,
+that magnetism is nothing more or less than electricity in rotation, or
+that it is due to a whirl of electricity circulating round the molecule
+of any body. From certain experiments which he made in relation to the
+mutual action of two circuits on each other, with currents flowing<span class='pagenum'><a name='Page_193' id='Page_193'></a><a href='#TOC'>[193]</a></span>
+through them, he came to the conclusion that the magnetism of the
+molecule of each magnet is due to electric currents circulating round
+it.
+</p>
+
+<p>
+The question arises as to what effect our new theory of the Aether has
+upon Ampère's theory: does it confirm it, or does it destroy it? We have
+learned that every atom has its aetherial atmosphere, so to speak, which
+is bound to the atom by the Law of Gravitation (<a href='#ART_45'>Art. 45</a>). We have also
+learned that Aether has an electrical basis, as proved by Maxwell and
+Hertz, so that we learn that every atom has really an aetherial electric
+atmosphere in association with it. We have only to conceive of this
+atmosphere being set in rotation either by the rotation of the atom or
+molecule itself, or by outside agencies, and we have at
+once a physical interpretation of Ampère's theory of magnetism in the
+rotation of electric currents around the atom, such currents being due
+to the circulating or rotating motion of the Aether which surrounds the
+atom or molecule.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/207.jpg' width='400' height='395'
+alt='Fig: 15.'
+title='Fig: 15.' />
+</div>
+
+<p>
+Thus we learn from experiment, and from Ampère's theory also, that
+magnetism is directly associated with circulating currents of
+electricity, and that wherever we get currents of electricity
+circulating round any atom or body, there we get all the phenomena
+associated with magnetism. That is to say, we shall have such phenomena
+as magnetic fields, magnetic lines of force, magnetic induction, and the
+production of permanent magnets by electricity.
+</p>
+
+<p>
+Further, with reference to the identity of electricity and magnetism,
+Faraday has conclusively proved their relation to each other; and I
+would strongly advise any reader who desires further light on the
+subject to carefully read paragraphs 3265-3269 in his <i>Experimental<span class='pagenum'><a name='Page_194' id='Page_194'></a><a href='#TOC'>[194]</a></span>
+Researches</i>, where he will find experiments which place the identity of
+electricity and magnetism beyond the possibility of doubt. In paragraph
+3265 he writes: &ldquo;The well-known relation of the electric and magnetic
+forces may be thus stated. Let two rings in planes at right angles to
+each other represent them. If a current of electricity be sent round the
+ring <i>E</i> in the direction marked, then lines of magnetic force will be
+produced. As these rings represent the lines of electro-dynamic force
+and of magnetic force respectively, they will serve for a standard of
+comparison.&rdquo;
+</p>
+
+<p>
+&ldquo;I have elsewhere called the electric current or the line of
+electro-dynamic force an axis of power having contrary forces exactly
+equal in amount in contrary directions (517). The line of magnetic force
+may be described in precisely the same terms,
+and these two axes of power considered as right lines are perpendicular
+to each other,&rdquo; etc.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/208.jpg' width='400' height='298'
+alt='Fig: 16.'
+title='Fig: 16.' />
+</div>
+
+<p>
+Again in 3267 he adds: &ldquo;Like electric currents or lines of force, or
+axes of power when placed side by side attract each other. This is well
+known and well illustrated when wires carrying such currents are placed
+parallel to each other. But like magnetic axes of power or lines of
+force repel each other. The parallel case to that of electric currents
+is given by placing two magnetic needles side by side with like poles in
+the same direction.&rdquo;
+</p>
+
+<p>
+Then in 3268 he shows that these effects are not merely contrasts, but
+they are contrasts which coincide when the two axes of power at right
+angles to each other are considered. Then in 3269 he adds: &ldquo;The mutual
+relation of the magnetic lines of force and the electric axis of power
+has been known since the time of Oersted and Ampère,&rdquo; and further states
+he is of the opinion that &ldquo;the magnetic lines have a physical existence<span class='pagenum'><a name='Page_195' id='Page_195'></a><a href='#TOC'>[195]</a></span>
+the same as the electric lines,&rdquo; and having that opinion, asks whether
+&ldquo;the lines have a dynamic condition analogous to the electric axis to
+which they are so closely and inevitably associated, or whether they
+consist in a state of tension of the Aether round the electric axis, and
+may therefore be considered as static in their nature.&rdquo; Thus Faraday
+proved the intimate and close relationship that existed between the
+electric current and the circles which represent the magnetic force in
+association with that current; and, what is more noticeable, he asks
+whether such magnetic results are due to a state of tension in the
+Aether around the axis of the electric current, evidently being of the
+opinion that the Aether played an important part in the phenomena of
+magnetism, as well as in electricity, as other parts of his writings
+abundantly show.
+</p>
+
+<p>
+If, therefore, there is this close identity between electricity and
+magnetism, then in view of the fact that all electricity is due to the
+motions of the universal Aether, it must follow that all magnetism is
+also due to motions of the same aetherial medium, which is as universal
+as it is invisible.
+</p>
+
+<p>
+What these motions are has already been indicated by previous statements
+in this article, being comprised of circular or rotatory motions of the
+aetherial electric medium about any body, whether that body be an atom,
+planet, or sun or star. Such a conclusion as this is perfectly in
+harmony with Maxwell's electro-magnetic theory of light, as the
+conclusion that he arrived at in that theory was, that the light waves
+were identical in nature and character with electro-magnetic waves
+produced by an electro-magnetic source.
+</p>
+
+<p>
+Up to the present we have only dealt with the electric character of
+those waves, and have therefore now to deal with the magnetic character
+of the same. So that throughout the whole realm of space, and indeed
+wherever there is Aether, there we have the conditions which give rise
+to magnetic phenomena, such as those already indicated.
+</p>
+
+<p>
+It matters not whether it be in the atomic systems whose combinations
+comprise all material forms of life with which we are familiar, or
+whether it is in the systems of planets that revolve around their
+central sun, or whether it be in the constellations that fill the
+universe, wherever we find the Aether, there we find the conditions in
+that Aether which will produce all the results ordinarily produced by
+magnetism, or with which magnetism is associated, and it is to the
+application of these phenomena to our solar system that we will now turn
+our attention.
+</p>
+
+<p>
+<a name='ART_87' id='ART_87'></a><span class='smcap'>Art</span>. 87. <i>The Earth a Magnet</i>.--If there is any fact in relation to a
+planet that holds good, it is that the earth, with which planet we are<span class='pagenum'><a name='Page_196' id='Page_196'></a><a href='#TOC'>[196]</a></span>
+more intimately associated than any other, is a magnet.
+</p>
+
+<p>
+This truth was clearly explained by Dr. Gilbert about the year 1600 in
+his work on &ldquo;De Magnete.&rdquo; Not only has the earth geographical North and
+South poles, but it has also magnetic North and South poles, and indeed
+has all the phenomena incidental to a magnet, such as magnetic dip and
+magnetic lines of force, as we shall see later on.
+</p>
+
+<p>
+We know, however, that the earth is simply one of a system of planets,
+which revolves with all the others of that system round its central body
+the sun; and the question arises, whether the earth is the only one out
+of all the planets that is actually a magnet. Suppose it is affirmed
+that the earth is the only planet which is a magnet. On what basis would
+such a statement be made? The only ground for making such a statement
+that I can see is, that we have never lived on Mars or Jupiter or
+Saturn, or any of the other planets, and therefore been unable to
+experiment on them, which reason is totally insufficient and inadequate
+for such a conclusion.
+</p>
+
+<p>
+If philosophy simply dealt with the results attained by such limited
+reasoning, then the progress of science would be retarded, and would be
+limited and confined to actual experience obtained on our own planet and
+in relation only to that planet. But philosophy is not satisfied with
+such a narrow and limited outlook, but drawing its conclusions from
+actual experience on our own planet, in accordance with the rules of
+philosophy, it seeks to apply such experience gained to the explanation
+of phenomena of other planets which also revolve round the sun.
+</p>
+
+<p>
+By such reasoning we learn that all the other planets have North and
+South geographical poles like our earth, although we have never actually
+trodden on those planets, or discovered the poles. We also learn that
+Mars possesses climatic conditions probably similar to our own earth, as
+there are certain changes on the surface around the poles, which by
+analogy we assume to be caused by increase and decrease of snow during
+the Arctic winter and summer of Mars respectively.
+</p>
+
+<p>
+The analogy between our earth and the other planets is very full and
+complete, as the following results show. Our earth has an atmosphere, so
+have all the rest of the planets. The earth revolves on its axis from
+West to East, so do all the rest. The earth possesses two geographical
+poles, so do all the other planets. The earth revolves round the sun in
+an orbit of elliptic form, so do the other planets. The earth fulfils
+all the laws of motion as given by Newton, and all the other planets do
+the same. The earth fulfils all Kepler's laws, and this is also true of
+all the others. Indeed, the only difference apparently that exists at<span class='pagenum'><a name='Page_197' id='Page_197'></a><a href='#TOC'>[197]</a></span>
+present between the earth and all the other planets is, that our earth
+is a magnet, while at present it is not conceded that all the others are
+magnets.
+</p>
+
+<p>
+Now such a conclusion I venture to say is altogether opposed to every
+rule of philosophy. For if experience be any guide in philosophy, then
+according to experience and observations made in respect to the only
+planet that we can actually experiment on, it most conclusively follows,
+that not only the earth, but every planet, and indeed every satellite
+that revolves round its primary planet, is a magnet; otherwise the rule
+of philosophy which permits us to formulate hypotheses based on
+experience is entirely violated, and ceases at once to be an universal
+rule.
+</p>
+
+<p>
+So that either the earth is not a magnet, or else, being a magnet by our
+second Rule of Philosophy, all the other planets are magnets also. This
+conclusion has already been arrived at by Lord Kelvin, who in writing in
+his <i>Popular Lectures</i><a name='FNanchor_32' id='FNanchor_32'></a><a href='#Footnote_32' class='fnanchor'>[32]</a>
+ on the subject says: &ldquo;If it is true that
+terrestrial magnetism is a necessary consequence of the magnetism and
+the rotation of the earth, other bodies comparable in these qualities
+with the earth, and comparable also with the earth in respect to
+materials and temperature, such as Venus and Mars, must be magnets,
+comparable in strength with the earth; and they must have poles similar
+to the earth, North and South poles on the North and South sides of the
+equator. It seems probable also that the sun, because of its great mass
+and its rotation in the same direction as the earth's rotation, is a
+magnet, with polarities on the North and South sides of the equator,
+similar to terrestrial North and South magnetic poles.&rdquo; Further, such a
+conclusion is entirely in harmony with the view of the solar system
+revealed in <a href='#ART_81'>Art. 81</a>, where we saw that each planet was an electrified
+body having its own electric field, with its lines of force, being
+capable of giving rise to all the phenomena associated with electricity.
+So that if we combine that view of the subject with the view that we are
+now coming to, we arrive at the conclusion that each planet and
+satellite, and indeed all bodies that move or revolve in space, are
+electro-magnets giving rise to magnetic waves in the Aether, which
+assumption is fully consistent with the electro-magnetic theory of light.
+</p>
+
+<p>
+We must now go one step further and apply a similar line of reasoning to
+the sun, when we shall arrive at exactly the same result that Lord
+Kelvin arrived at, according to the previous extract. All planets
+possess an atmosphere, the sun also possesses an atmosphere. All planets
+revolve on their axes from West to East, so does the sun. All planets
+possess a North and South pole the same as the sun.<span class='pagenum'><a name='Page_198' id='Page_198'></a><a href='#TOC'>[198]</a></span>
+</p>
+
+<p>
+The equatorial diameter of
+every planet is greater than its polar diameter, and the same truth
+applies to the sun. It is hotter at the equatorial regions of every
+planet, and this truth also applies to the sun. Now, if the sun agrees
+with all the planets in these respects, then we may philosophically
+conclude that it agrees with them in another respect, viz. that the sun
+is also a magnet possessing its own magnetic field, which is co-equal
+and co-extensive with its aetherial electrical field. We have already
+seen that the sun is an electrified body, possessing its electric field,
+with its electric lines of force. Therefore the sun is also a magnet,
+or, to speak more correctly, it is an electro-magnet, and as such gives
+rise to electro-magnetic waves.
+</p>
+
+<p>
+The conclusion to which we have come, that the sun is an electro-magnet,
+can be arrived at from an altogether different method of reasoning, and
+as that different method of reasoning will tend to confirm the statement
+made, I will just indicate it, and then leave it for fuller development
+in another article.
+</p>
+
+<p>
+It is a matter of common knowledge to all students, that the magnetism
+of the earth varies in several important particulars from time to time.
+The magnetic poles of the earth do not always occupy the same place in
+relation to the geographical poles, so that the magnetic force varies as
+regards intensity or magnitude. The reasons of the variations have never
+been satisfactorily accounted for, though various hypotheses have been
+suggested as a solution from time to time.
+</p>
+
+<p>
+There is, I believe, only one satisfactory solution to the problem, and
+that is, that the sun is an electro-magnet, and this conclusion may be
+arrived at by strictly adhering to Newton's rules of Philosophy. For we
+have learned that any hypothesis put forward to account for any
+phenomena, must be simple in character, must agree with experience and
+observation, and, lastly, must satisfactorily account for the phenomena
+sought to be explained.
+</p>
+
+<p>
+Here then are the variations in time of the magnetic force of the earth,
+the variations in intensity, and in the inclination of the magnetic
+axis, together with other variations. What solution shall we offer to
+such a problem? The only philosophical solution that can be suggested
+lies in the statement that the sun is an electro-magnet. Such statement
+is simple in conception, does not violate our experience or observation,
+as we find a similar revolving body, the earth, which is a magnet; and
+further, such a statement I premise will satisfactorily account for the
+whole of the variations and changes in relation to the magnetic forces
+of the earth. We shall see that this is so when we consider more fully
+the sun as an electro-magnet. Therefore, apart altogether from any
+previous analogies, we can philosophically arrive at the conclusion<span class='pagenum'><a name='Page_199' id='Page_199'></a><a href='#TOC'>[199]</a></span>
+that the sun is an electro-magnet, as well as all the planets.
+</p>
+
+<p>
+That being so, it will possess its magnetic field, its magnetic lines of
+force, and be capable of bringing into operation in the solar system all
+the phenomena or effects associated with any ordinary magnet that we may
+experiment with on the earth.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_32' id='Footnote_32'></a><a href='#FNanchor_32'><span class='label'>[32]</span></a>
+<i>Popular Lectures</i>, Vol. II.
+</p></div>
+
+
+<p>
+<a name='ART_88' id='ART_88'></a><span class='smcap'>Art</span>. 88. <i>The Sun an Electro-magnet</i>.--If the sun is an electro-magnet,
+as stated in the previous article, then it is necessary for us to apply
+the phenomena of magnetism to it in order to ascertain what effect such
+application will have on the solar system as a whole.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/213.jpg' width='400' height='246'
+alt='Fig: 17.'
+title='Fig: 17.' />
+</div>
+
+<p>
+The first thing that we will look at is the magnetic field which is
+always associated with every magnet. The magnetic field may be defined
+as that region or space around every magnet in which the magnetic force
+acts or is in operation. An illustration of a magnetic field may easily
+be obtained by taking
+a bar magnet and bringing near to it a magnetized needle, when it will
+be found that the needle will set itself in various positions relative
+to the magnet, on account of the lines of force which exist in the
+field. Thus let <i>A B</i> (Fig. 17) be a bar magnet with its North pole at
+point <i>A</i> and South pole at point <i>B</i>. If a number of freely suspendedneedles be hung above it, as shown in the figure, they assume the
+positions indicated there. It will be seen that at the North and South
+poles the needles hang vertical, while midway between the two poles
+there is no dip of the needle, as it is parallel to the bar magnet;
+while between the place of no dip and the place of vertical dip, which
+is directly over each pole, the dip gradually changes, becoming more and
+more vertical as it gets nearer to the pole. If the bar magnet be a
+strong one, then its magnetic field will be manifested at a great
+distance; and any magnetized needle brought into the field will be,
+affected by the same, and will tend to set itself along the lines of
+force.<span class='pagenum'><a name='Page_200' id='Page_200'></a><a href='#TOC'>[200]</a></span>
+</p>
+
+<p>
+As already stated in <a href='#ART_80'>Art. 80</a>, it was Faraday who originated the
+term &ldquo;Lines of Force,&rdquo; and gave to the world some idea of the motions of
+the aetherial medium, which plays so important a part in
+electro-magnetic phenomena. A visible manifestation of these lines of
+force which gather round every magnet may be made by strewing iron
+filings over a piece of glass, underneath which are several bar magnets,
+when it will be found that the iron filings will set themselves in
+well-defined lines or curves, which Faraday termed &ldquo;Lines of Force.&rdquo;
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/214.jpg' width='400' height='164'
+alt='Fig: 18.'
+title='Fig: 18.' />
+</div>
+
+<p>
+As the bar magnets are placed in different positions, North pole to
+North pole, or North to South, and so on, the iron filings will change
+the figures assumed, indicating in, each case the effect of the lines of
+force of each magnet upon one another. The iron filings strewed over the
+magnet are magnetized by induction, with the result that the North pole
+of one filing attracts the South pole of the next one to it, and this is
+continued
+along the whole of one line of force, as revealed by the united iron
+filings. Faraday believed in the real physical existence of these lines
+of force, and that belief has been perfected by Clerk Maxwell in two
+papers which he wrote on &ldquo;Physical Lines of Force,&rdquo; which will be
+considered in another article. We will simply deal with them at present
+as indications of the existence of the magnetic forces in the medium
+surrounding any magnet.
+</p>
+
+<p>
+Let us apply these facts to the solar system and see what the
+application yields. We have the sun revolving in the Aether medium
+represented by the circle <i>S</i> in Fig. 19. Then we have the lines of
+force extending in curved lines <i>E</i>. and <i>W</i>., but in almost straight
+lines North and South. We will suppose the axis of the sun to be
+vertical for the sake of simplicity. It may be asked, how far will these
+lines of force stretch out into space? The reply is that they stretch
+and extend throughout the whole solar system, and far away into the
+depths of space, though with ever-decreasing intensity according to the
+law of inverse squares. Wherever the aetherial light waves are
+manifested, there the electro-magnetic waves, with all that they imply,<span class='pagenum'><a name='Page_201' id='Page_201'></a><a href='#TOC'>[201]</a></span>
+are manifested also. We know that the light waves are existent at least
+as far as Neptune, a distance of 2800 millions of miles, therefore at
+least to that extent the electro-magnetic waves are manifested; and
+wherever the electro-magnetic waves to which the sun has given birth are
+manifested, there we have the existence of the electro-magnetic field,
+which is co-existent and co-extensive with the electric field of the
+sun. Further, wherever we get the magnetic field, there we get the lines
+of force which are as real as air or ocean currents, and are caused, as
+Maxwell indicated (<a href='#ART_44'>Art. 44</a>), by the motions of the atomic Aether.
+Wherever these lines of force are closest together, there the intensity
+of the magnetic force is at its greatest.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/215.jpg' width='400' height='183'
+alt='Fig: 19.'
+title='Fig: 19.' />
+</div>
+
+<p>
+By actual experiment, it can be demonstrated that the lines of force are
+closest together nearest to the magnet, and therefore
+applying that fact to the solar magnetic field, the lines of force
+should be closest together nearest to the surface of the sun, which is
+exactly what we have already learned. For if Aether be gravitative, then
+it will be densest nearest to the sun than further away, and the vortex
+atoms which represent our aetherial atoms will be pressed more closely
+together near to the surface than further away.
+</p>
+
+<p>
+We have learned that Aether has an electro-magnetic basis, and it is
+that very fact which gives rise to the existence of these lines of
+force. So that the magnetic phenomena as indicated in the lines of force
+conceived by Faraday harmonize with the fact that the sun is an
+electro-magnet; and that Aether, which has an electro-magnetic basis, is
+also gravitative, with the result that the lines of force are closest
+together nearest the surface of the sun, where the magnetic force is
+greatest in its intensity and power.<span class='pagenum'><a name='Page_202' id='Page_202'></a><a href='#TOC'>[202]</a></span>
+</p>
+
+<p>
+Now let us apply the principle of
+the experiment to the solar system by bringing a magnet into a magnetic
+field, and let us see what the result is. We have learned from the
+experiment, that if a magnet is moved along any one of the lines of
+force the dip of the magnet changes, gradually changing from a
+horizontal to a perpendicular position in accordance with its relation
+to the two poles of the magnet. From the previous article we have come
+to the conclusion that not only is the earth a magnet, but that all the
+other planets are magnets also, so that if any of these are brought into
+the magnetic field of the sun, then the magnetic axis of the planet,
+which corresponds to the needle in our experiment, must assume a certain
+dip in relation to the sun, setting itself along those lines of force
+which are in the immediate neighbourhood of the planet.
+</p>
+
+<p>
+Let us place the earth, for example, at a distance of 90 millions of
+miles from the sun in the magnetic equator, or that line which exactly
+divides the magnetic field into two equal halves. According to our
+experiment, the magnetic axis will now be exactly parallel with the axis
+of the sun, that is, exactly vertical, pointing North and South, as seen
+in position 1 in Fig. 19. But suppose that the earth is to the North of
+the magnetic equator of the field, what happens then? The result will be
+that the magnetic axis of the earth will dip towards the magnetic North
+pole of the sun (position 2, Fig. 19), while if the earth be to the
+South of the magnetic equator, its axis will dip in the opposite
+direction (position 3), the magnetic axis setting itself in each case
+along the lines of force which exist in the Aether in that region or
+space. Thus it can be seen at a glance, that if the earth changes its
+position at any time in its orbit in relation to the magnetic equator,
+such a change will effect the total dip of the magnetic axis. In other
+words, the magnetic poles which indicate the position of the magnetic
+axis will not occupy the same position in relation to the geographical
+North and South poles, sometimes appearing to the East and sometimes to
+the West, and at other times being coincident with the same as it moves
+to the North or South of the magnetic equator of the sun's
+electro-magnetic field.
+</p>
+
+<p>
+We have to remember, also, that the earth is constantly varying its
+distance in relation to the sun, being at a distance of ninety and a
+half millions of miles at its perihelion, or that part of its orbit
+nearest to the sun; while it is ninety-four and a half millions of miles
+at its aphelion, or that part of its orbit furthest away from the sun.
+This implies that as it proceeds from that point in space furthest away
+from the sun, and approaches a point nearer to the sun, it will pass
+into places of greater magnetic intensity, with the result that the
+intensity of the electro-magnetic waves is increased; and the magnetism<span class='pagenum'><a name='Page_203' id='Page_203'></a><a href='#TOC'>[203]</a></span>
+of the earth is accordingly affected by that fact.
+</p>
+
+<p>
+When we come to deal with the earth as a magnet more directly, we shall
+see that all the variations of terrestrial magnetism may be
+satisfactorily explained by the fact that the sun is, as we have
+indicated in this article, an electro-magnet, possessing its magnetic
+field with its lines of force, and therefore able to give rise to all
+the phenomena incidental to and associated with any ordinary magnet.
+</p>
+
+<p>
+<a name='ART_89' id='ART_89'></a><span class='smcap'>Art</span>. 89. <i>Aether and Faraday's Lines of Force</i>.--We have now to face the
+question of the physical character of the Lines of Force conceived by
+Faraday. We have seen in Fig. 18 illustration of these lines of force,
+which are manifested by the iron filings in the neighbourhood of a
+magnet, and the question suggests itself to the mind, as to what is the
+relation of the Aether to those lines of force? Does the Aether play any
+part in their existence, and if so what?
+</p>
+
+<p>
+Faraday was of the opinion that the Aether did play some part in the
+existence of the lines, and that they were no mere hypothetical lines,
+but were caused by the actual physical state or condition of the
+aetherial medium, which existed around every magnet and every
+electrified body. On this point he says, Art. 3263:<a name='FNanchor_33' id='FNanchor_33'></a><a href='#Footnote_33' class='fnanchor'>[33]</a>
+ &ldquo;To acknowledge
+the action in curved lines seems to me to imply at once that the lines
+have a physical existence. It may be the vibration of the hypothetical
+Aether, or a state of tension of that Aether equivalent to either a
+dynamic or static condition.&rdquo;
+</p>
+
+<p>
+Par. 3277: &ldquo;I conceive that when a magnet is in free space, there is
+such a medium, magnetically speaking, around it. That a vacuum has its
+own magnetic relations of attractions and repulsions is manifest from
+former experimental results (2787). What that surrounding magnetic
+medium deprived of all material substance may be, I cannot tell, perhaps
+the Aether.&rdquo;
+</p>
+
+<p>
+It was, however, left for Clerk Maxwell to develop the idea as to their
+physical character, and this he did in his paper on &ldquo;Physical Lines of
+Force,&rdquo; <i>Phil. Mag</i>., 1861. He had previously written a paper on
+&ldquo;Faraday's Lines of Force,&rdquo; delivered to the Cambridge Phil. Society in
+1855 and 1856, but his more matured conception of Faraday's Lines of
+Force was given in the later article.
+</p>
+
+<p>
+What Maxwell did was to conceive a physical theory of electricity and
+magnetism, by which electrified and magnetized bodies could act upon
+each other by means of the stress or strain of some medium, which
+existed in the space surrounding these bodies. Now Faraday looked upon<span class='pagenum'><a name='Page_204' id='Page_204'></a><a href='#TOC'>[204]</a></span>
+electro-static and magnetic induction as always taking place along
+curved lines. These lines may be conceived as atoms or molecules
+starting from the poles of a magnet, and acting on all bodies in the
+electro-magnetic field. These atoms or molecules, joined together in a
+definite manner, tend to shorten in the direction of their length, that
+is to say, there is a tension along the lines of force while at the same
+time they swell out laterally or sideways. Thus there is a tension along
+the lines of force, and a pressure at right angles to them owing to
+their bulging out sideways. Maxwell used as an illustration of the
+tension and pressure, the contraction and thickening of a muscle. As the
+fibres of the muscle contract, and the arm or leg is drawn up, the
+muscle swells in its centre outwardly, and so thickens. Thus there would
+be a tension along the muscle, and a pressure at right angles to it,
+which would cause any body placed on it to move away from it, owing to
+the pressure of the contracted muscle.
+</p>
+
+<p>
+In the conception of an aetherial atom (<a href='#ART_44'>Art. 44</a>) drawn purely from
+observation of the shape of the earth, we came to the conclusion that
+the aetherial atom was a spherical vortex atom, or, to be more correct,
+that it was an oblate spheroid with its polar diameter, so to speak,
+shorter than its equatorial diameter, and further, that the aetherial
+atom possessed polarity.
+</p>
+
+<p>
+Now if we can conceive of these aetherial vortex atoms being joined
+together, North pole to South pole, and revolving round their axes, we
+shall then have an exact image of Maxwell's physical conception of
+Faraday's Lines of Force.
+</p>
+
+<p>
+We know that when any liquid body is caused to rotate rapidly about its
+axis, it will expand laterally and contract longitudinally in the
+direction of the axis; and it was on this analogy that Maxwell worked
+out his physical conception of the lines of force. Maxwell's fundamental
+idea was, that in a magnetic field there is a rotation of the molecule
+ever going on about the lines of force. For example, let <i>A B</i> be a
+magnet, and <i>A C B</i> be a line of force composed of spherical vortex
+atoms joined end to end, that is, each North pole (assuming the vortex
+atoms to be magnets) being directly associated with the South pole of
+the one next to it, and <i>vice-versâ</i> (Fig. 20).
+</p>
+
+<p>
+Thus it can be readily seen that there will be a tension along the line
+of force, while there will be a pressure at right angles to it owing to
+the lateral expansion, partly due to the rotation of the vortex atom,
+and partly due to the attraction of the vortices for each other in the
+direction of the line of force.
+</p>
+
+<p>
+Maxwell in his paper says: &ldquo;It appears therefore that the stress in the
+axis of the line of magnetic force is a tension like that of a rope.&rdquo;
+Further, he adds: &ldquo;Let us now suppose that the phenomena of magnetism<span class='pagenum'><a name='Page_205' id='Page_205'></a><a href='#TOC'>[205]</a></span>
+depend upon the existence of the tension in the direction of the lines
+of force, combined with a hydrostatic pressure, or in other words, a
+pressure greater in the equatorial than in the axial direction. The next
+question is, What mechanical explanation can we give of these
+inequalities of pressure in a fluid or mobile medium? The explanation
+which most readily occurs to the mind is, that the excess of pressure in
+the equatorial direction arises from the centrifugal force of the
+vortices or eddies in the medium, having their axes in the direction
+parallel to the lines of force.&rdquo; He adds: &ldquo;A medium of this kind filled
+with molecular vortices, having their axes parallel, differs from an
+ordinary medium in having different pressures in different directions.&rdquo;
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/219.jpg' width='400' height='368'
+alt='Fig: 20.'
+title='Fig: 20.' />
+</div>
+
+<p>
+He then goes on to develop the idea in relation to different intensities
+of the magnetic field. I must, however, refer the
+reader to the paper itself for fuller details. In his greatest work,<a name='FNanchor_34' id='FNanchor_34'></a><a href='#Footnote_34' class='fnanchor'>[34]</a>
+
+writing on this subject, he says: &ldquo;I think we have good evidence for the
+opinion that some phenomenon of rotation is going on in the magnetic
+field, that this rotation is performed by a great number of very small
+portions of matter, each rotating on its own axis, being parallel to the
+direction of the magnetic force, and that the rotations of these
+different vortices are made to depend on one another by means of some
+kind of mechanism.&rdquo;
+</p>
+
+<p>
+From the foregoing extracts taken from Maxwell's writings, we learn that
+the constitution of the Aether, as given in <a href='#ART_44'>Art. 44</a>, exactly coincides
+with, and satisfactorily fulfils the conditions that he lays down with
+reference to his physical conception of the lines of force around a
+magnet or electrified body.
+</p>
+
+<p>
+So that the theory of Maxwell is not merely hypothetical, as is
+suggested by scientists, but exactly describes the conditions and<span class='pagenum'><a name='Page_206' id='Page_206'></a><a href='#TOC'>[206]</a></span>
+state of the atomic
+Aether medium which surrounds all magnets. We have, however, seen that
+the sun is a magnet, and therefore it possesses around it on every side,
+the same as any other magnet, these aetherial lines of force composed of
+infinitesimal vortices, or mere whirling points which correspond to an
+aetherial atom.
+</p>
+
+<p>
+These aetherial lines of force stretch out into space on every side of
+the sun, and in fact form concentric magnetic shells around the sun;
+which magnetic shells coincide with the equipotential surfaces of the
+Aether viewed merely from the point of elasticity and density of the
+medium. We learn by experiment, that these lines are closest together
+nearest to the magnet, which fact agrees with the statement that Aether
+is gravitative, and therefore the Aether would be densest nearest the
+sun. That is, the atoms would be pressed closer together, so that the
+lines of force of which these atoms are composed ought also to be closer
+together at the surface of the magnet, which we find by experiment is
+the case. As the sun is an electro-magnet, therefore, it possesses these
+magnetic lines of force on all sides, forming a series of magnetic
+shells. We have now arrived by the aid of Maxwell's theory to a physical
+conception of the Aether from a magnetic standpoint, which fully agrees
+with our physical conception of the Aether which was arrived at by
+purely philosophical reasoning, based on Newton's Rules of Philosophy.
+</p>
+
+<p>
+Thus we are able to combine into one whole by our conception that Aether
+is matter, and therefore atomic and gravitative, not only Faraday's
+Lines of Force, but also Maxwell's physical conception of the same,
+apart from the solutions given to the other problems of science by the
+self-same conception, which solutions will be dealt with in their proper
+order.
+</p>
+
+<p>
+As further evidence of Maxwell's belief in the physical existence of
+Faraday's Lines of Force, let me again quote from his paper on &ldquo;Action
+at a Distance,&ldquo;<a name='FNanchor_35' id='FNanchor_35'></a><a href='#Footnote_35' class='fnanchor'>[35]</a>
+ already referred to in <a href='#ART_43'>Art. 43</a>. He writes: &ldquo;Its
+minute parts may have rotatory as well as vibratory motions, and the
+axes of rotation form those lines of Magnetic Force which extend in
+unbroken continuity into regions which no eye has seen.... These lines
+must <i>not be regarded as mere mathematical abstractions</i>. They are the
+directions in which the medium is exerting tension like that of a rope,
+or rather like that of our own muscles.&ldquo;
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_33' id='Footnote_33'></a><a href='#FNanchor_33'><span class='label'>[33]</span></a>
+<i>Exp. Res</i>.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_34' id='Footnote_34'></a><a href='#FNanchor_34'><span class='label'>[34]</span></a>
+<i>Magnetism and Electricity</i>.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_35' id='Footnote_35'></a><a href='#FNanchor_35'><span class='label'>[35]</span></a>
+<i>Collected Works</i>, by Niven.
+</p></div>
+
+
+
+
+
+<p>
+<a name='ART_90' id='ART_90'></a><span class='smcap'>Art</span>. 90. <i>Terrestrial Magnetism</i>.--We have already seen that the earth
+is a magnet, and like any other magnet will therefore possess its
+magnetic field with its magnetic lines of force. The earth's magnetic
+field is co-existent and co-equal with its<span class='pagenum'><a name='Page_207' id='Page_207'></a><a href='#TOC'>[207]</a></span>
+electric field (<a href='#ART_80'>Art. 80</a>),
+and that is co-existent with the earth's aetherial atmosphere which is
+held bound to the planet by the force of gravity.
+</p>
+
+<p>
+How far the earth's magnetic field reaches, is impossible to say, but we
+know that it extends at least as far as 260,000 miles, the distance of
+the moon; as we find that this satellite of the earth is affected very
+considerably by the electro-magnetic attractive power of the earth. Any
+body which is placed in the earth's magnetic field is affected by the
+lines of force which exist in the magnetic field; for wherever the field
+exists, there the lines of force exist also.
+</p>
+
+<p>
+These lines of force, which are associated with the earth, extend
+therefore into space, and any body such as the moon would become a
+magnet, if not already one by the process known as magnetic induction,
+which physical process is well illustrated in the action of a magnet
+upon iron filings strewed over it as in the illustration (<a href='#ART_88'>Art. 88</a>).
+</p>
+
+<p>
+An experiment which well illustrates the inductive power of the earth's
+magnetism, may be made by placing a poker in one of these lines of
+force, whose direction can be found at any part of the earth's surface
+by means of proper instruments. When the poker is so placed, it will be
+seen that it has actually become magnetized by the magnetism of the
+earth, and it is itself able to attract iron filings or small needles.
+These lines of force of the earth are closer together nearest to the
+earth's surface than further away in space, and congregate around the
+North and South magnetic poles, where they are greatest in number in a
+given area, and there the magnetic intensity is the greatest.
+</p>
+
+<p>
+Faraday, writing on the terrestrial lines of force, says: &ldquo;The lines of
+force issue from the earth in the northern and southern parts with
+different but corresponding degrees of inclination, and incline to, and
+coalesce with each other over the equatorial parts. There seems reason
+to believe that the lines of magnetic force which proceed from the earth
+return to it, but in their circuitous course they may extend through
+space to a distance of many diameters of the earth, to tens of thousands
+of miles.&ldquo;<a name='FNanchor_36' id='FNanchor_36'></a><a href='#Footnote_36' class='fnanchor'>[36]</a>
+
+</p>
+
+<p>
+From this extract it will be seen that Faraday was of the opinion that
+the lines of force extended beyond the atmosphere of the earth into the
+Aether, which statement is confirmed by other parts of his writings;
+though he was not able to give any physical explanation of how these
+lines extended beyond the atmosphere on account of the doubtful
+constitution and character of the Aether, although in another part of
+his work he definitively refers to the magnetic character of space.<span class='pagenum'><a name='Page_208' id='Page_208'></a><a href='#TOC'>[208]</a></span>
+</p>
+
+<p>
+In writing on the magnetic
+character of space he says:<a name='FNanchor_37' id='FNanchor_37'></a><a href='#Footnote_37' class='fnanchor'>[37]</a>
+ &ldquo;From such experiments, and also from
+general observations and knowledge, it seems manifest that the lines of
+magnetic force can traverse pure space, just as gravitating force does,
+and as static electric forces do (1616), and therefore space has a
+magnetic character of its own, and one that we shall probably find
+hereafter to be of the utmost importance in natural phenomena.&ldquo; With the
+view of the Aether presented in this work, viz. that Aether is matter,
+though in an infinitely more rarefied and elastic form, we can now see
+the physical cause of the lines of force with which by his imagination
+he filled all space.
+</p>
+
+<p>
+Again, from the conception of the Aether presented to the reader in <a href='#ART_45'>Art. 45</a>, we learn that around any body in space there are existing aetherial
+concentric spheres or shells which are equipotential surfaces, or
+surfaces of equal pressure, and that these surfaces coincide with the
+electric equipotential surfaces, as shown in <a href='#ART_80'>Art. 80</a>.
+</p>
+
+<p>
+Not only so, but they coincide with the magnetic shells which the lines
+of force actually form around a circular and globular magnet, as the
+earth. For it must not be forgotten that these lines of force exist
+equally on all sides of the earth, and therefore really form a spherical
+shell, or to speak more correctly an aetherial electro-magnetic shell,
+which is an oblate spheroid in shape, partaking of the shape of the
+earth or other planet which the lines of force surround.
+</p>
+
+<p>
+If these shells were divided into two equal halves, the line so dividing
+them would be called the magnetic equator, and on that line any magnet
+would set itself in a horizontal position, so that all round the earth
+on the magnetic equator would correspond to a line of no dip. At the
+magnetic poles, a magnet would set itself vertically, or at an angle of
+90°, and between these two parts, the place of no dip, and that of 90°,
+the dip gradually changes as illustrated in the figure. Again, in
+relation to the magnetism of the earth we find that there are certain
+variations in the magnetic force, which not only influence the dip at
+any place, but also the intensity at that place. The variations in
+Magnetic Force are chiefly three--
+</p>
+
+<p style='margin-left: 5em;'>1st. Diurnal Variations.</p>
+<p style='margin-left: 5em;'>2nd. Annual Variations.</p>
+<p style='margin-left: 5em;'>3rd. Secular Variations.</p>
+
+
+<p>
+Let us look at these three variations from the standpoint of the
+magnetic lines of force which exist around the earth, and around every
+planet. In relation to the variations of the magnetic forces upon the
+surface of the earth, Faraday points<span class='pagenum'><a name='Page_209' id='Page_209'></a><a href='#TOC'>[209]</a></span>
+out that these variations are
+caused by the action of the sun's rays upon the terrestrial lines of
+force. He uses the following figure to illustrate his meaning. Let <i>H</i>
+be the sun, <i>E</i> the earth--
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/223.jpg' width='400' height='501'
+alt='Fig: 21.'
+title='Fig: 21.' />
+</div>
+
+<p>
+He writes as follows: &ldquo;If the magnetic and astronomical poles of our
+earth be supposed to be coincident, then North and South poles will also
+represent the North and South magnetic poles, and the different curves
+cutting the earth will sufficiently represent a course of magnetic lines
+as they occur at, or about, the surface of the earth. <i>H</i> represents the
+sun, and <i>a</i> the place immediately underneath it, which is also
+coincident with the magnetic equator. Point <i>a</i> will be a line of no
+dip, while at point <i>b</i> there will be dip. This dip will be increased by
+the action of the sun's rays, because the atmosphere under the influence
+of the sun's rays has expanded the air, and has thus acquired a power to
+affect the lines of magnetic force.&ldquo;
+</p>
+
+<p>
+&ldquo;All the lines passing through the heated and expanded air will, because
+of its being a worse magnetic conductor, tend to open out, and the mass
+of heated air will as a whole assume the condition of diamagnetic
+polarity (2923). The case may be more simply stated for the facility of
+recollection by saying, that the effect of the sun is to raise the
+magnetic circles over the equatorial and neighbouring parts from their
+normal position, in doing which the North and South dip are
+simultaneously affected and increased.&ldquo;
+</p>
+
+<p>
+Thus it can readily be seen that every day as the earth turns round on
+its axis, and presents each side of the globe successively to the rays<span class='pagenum'><a name='Page_210' id='Page_210'></a><a href='#TOC'>[210]</a></span>
+of the sun, there should be a gradual change in the intensity of the
+terrestrial magnetism. In Art. 2925, Faraday points out that the maximum
+of dip would be when the sun was at its zenith or directly overhead.
+With reference to the Annual Variation, Faraday points out (2882) that
+if the axis of the earth were perpendicular to the plane of its orbit,
+the intensity and direction of the magnetic forces might be considered
+constant, but (2883) as the axis of the earth's rotation is inclined 23°
+to the plane of the ecliptic, the two hemispheres will become
+alternately warmer and colder than each other, and then a variation in
+the magnetic condition may arise. The consideration of this annual
+variation is further considered by Faraday in the subsequent paragraphs
+to those already quoted, and I must refer the reader to them for fuller
+details; I wish simply to indicate the possible explanation of the
+terrestrial magnetism, in so far as that explanation is in conformity
+with the aspect of the Aether submitted in Chapter <a href='#CHAPTER_IV'>IV</a>.
+</p>
+
+<p>
+With regard to secular variations Faraday points out (2880) that the
+temperature of the air at the equatorial parts of the earth is greater
+than in latitudes north and south, and as an elevation of temperature
+diminishes the conducting power of magnetism, so the proportion of force
+passing through those parts ought to be less, and that passing through
+the cooler parts, greater, than if the temperature were at the same
+degree over the whole surface of the globe.
+</p>
+
+<p>
+Now with our definite conception of the aetherial lines of force
+traversing space, and existing on all sides of the earth, these
+suggestions of Faraday's obtain an increased value in relation to the
+varying intensity of terrestrial magnetism, and will account for the
+variations in a satisfactory manner from the aetherial standpoint, if
+taken in conjunction with the electro-magnetic character of the Aether.
+Of course, what applies to the earth equally applies to all the other
+planets, as they also are magnets according to <a href='#ART_87'>Art. 87</a>, so that they
+will also possess their magnetic fields, with their own lines of force,
+and their variations in intensity and magnetic dip.
+</p>
+
+<p>
+Hitherto we have only considered the problem of the earth and all the
+other planets, as magnets, from the stationary standpoint, and the
+problem faces us as to what effect the movement of the earth and all
+other planets through the Aether will have upon their magnetic fields,
+and their lines of force. Now from Clerk Maxwell's mathematical
+calculations, we learn that the movement of any magnetic body through
+space will practically have no effect upon the relation of the field,
+and the lines of force to the moving magnet; that is to say, the
+magnetic field and the lines of force move with the earth and the
+planets through space, as they journey round the sun with their varying<span class='pagenum'><a name='Page_211' id='Page_211'></a><a href='#TOC'>[211]</a></span>
+velocity. Maxwell has conclusively proved that the mathematical
+equations for moving bodies in relation to their magnetic lines of
+force, and induction, are exactly the same as the equations for
+stationary bodies, and if this be true, then it follows that the
+physical conditions for both stationary and moving bodies are the same.
+</p>
+
+<p>
+On this point Maxwell writes: &ldquo;By its motions this (moving) matter
+carries with it its lines of force, and electricity and magnetism may be
+regarded as free ends of these lines. Hence when both causes act
+together there can be no relative motion of true magnetism with
+reference to surrounding matter,&ldquo; etc.
+</p>
+
+<p>
+&ldquo;Under these circumstances electricity and magnetism move with the
+matter in which they are present as if they were indestructible and
+adhered firmly to the parts thereof.&ldquo; So that from Maxwell's equations
+and statements we learn that the magnetic lines of force around every
+planet, and every satellite in space, move with the planets in their
+orbits round the sun. But as these magnetic lines of force are composed
+of aetherial atoms, as already indicated, it follows that the Aether
+which is associated with each planet and held bound to it by the
+so-called force of gravity moves with the planet also.
+</p>
+
+<p>
+This result is entirely consistent with our experience and observation,
+as we shall see later on. We find that the atmosphere, which is also
+gravitative, moves with the earth, and therefore from experience we are
+compelled to arrive at the conclusion that the Aether which is also
+gravitative moves with each planet, and this result is confirmed by
+mathematical calculations given by Clerk Maxwell, and is in perfect
+harmony with the same.
+</p>
+
+<p>
+Here then is the key to one of the problems that has been the subject of
+investigation and research for many years past, and one which is at the
+present time occupying the attention of some of our most advanced
+scientists, viz. the relation of the Aether to moving matter.
+</p>
+
+<p>
+That problem was solved by Maxwell from an electric and magnetic
+standpoint, and his result was that the Aether, which we now know to be
+the source of all electricity and magnetism, moves with the moving
+matter. What is more, this result has been confirmed by actual
+experiment made by Michelson and Morley in America, which experiment
+conclusively proves that Maxwell's result is physically correct, and
+that the Aether does move through space with its associated planet, and
+therefore its magnetic field and its lines of force move with it because
+of the electro-magnetic character of the Aether.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_36' id='Footnote_36'></a><a href='#FNanchor_36'><span class='label'>[36]</span></a>
+Art. 2850, <i>Exp. Res</i>.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_37' id='Footnote_37'></a><a href='#FNanchor_37'><span class='label'>[37]</span></a>
+Art. 2757, <i>Exp. Res</i>.
+</p></div>
+
+
+<p>
+<a name='ART_91' id='ART_91'></a><span class='smcap'>Art</span>. 91. <i>Solar Magnets</i>.--We have now to attack the problem as to the
+cause of all the satellites and planets, together with the sun, being<span class='pagenum'><a name='Page_212' id='Page_212'></a><a href='#TOC'>[212]</a></span>
+electro-magnets. What is the continuing and ever-acting cause which
+makes all planetary bodies, including the sun, their centre, to be
+permanent magnets? According to the Rules of Philosophy there are two
+causes which would be simple in conception, which are suggested by
+experiment and observation, and both causes would satisfactorily account
+for all the planets being magnets.
+</p>
+
+<p>
+The first cause suggested to our minds is, that in view of the fact that
+the sun is an electro-magnet, and therefore possesses a magnetic field
+with its aetherial line of force, all the planets may become magnets by
+the process of magnetic induction, which process has already been
+illustrated by the action of the iron filings placed over the magnet.
+Such a hypothesis would fulfil all the Rules of Philosophy, as it would
+be simple in conception, would not violate experience, and would
+satisfactorily account for the fact sought to be explained.
+</p>
+
+<p>
+But such a hypothesis would be based upon the assumption that the sun
+was an electro-magnet, and then we should have to find out the cause of
+that fact also. Hence the hypothesis that the planets are magnets,
+because they are situated in the magnetic field of the sun, is not a
+satisfactory solution of the whole problem, as it fails to account for
+the fact that the sun is also an electro-magnet. We must therefore seek
+for another solution of the problem, which, while fulfilling all the
+Rules of Philosophy as laid down in <a href='#ART_3'>Art. 3</a>, will also account for the
+sun being an electro-magnet, as well as every planet, satellite, meteor,
+or any other body that exists in space. If we can ascertain such a cause
+by philosophical reasoning, then we may say we have satisfactorily
+solved the problem as to the cause of all planetary and stellar bodies
+being electro-magnets.
+</p>
+
+<p>
+If, at the same time, we can solve other outstanding problems by the
+solution thus offered, then such solution is more likely to be correct
+than if it simply solved the problem of solar magnetism. The only other
+solution that can possibly present itself to our minds, as to the cause
+of all magnetism in any planet, sun, or star, is the explanation which
+has already been given in <a href='#ART_86'>Art. 86</a> on electro-magnetism.
+</p>
+
+<p>
+In that article we learned that magnetism was really due to the circular
+motion of an electric current; and that, whenever and wherever we had an
+electric current moving or revolving with a circular motion, there we
+should always have those conditions which would give rise to an
+electro-magnet. As long as the current continued to flow in its circular
+course, so long would there be those conditions which would give rise to
+permanent magnetism.
+</p>
+
+<p>
+Now in the solar system we find that there are these magnets, which<span class='pagenum'><a name='Page_213' id='Page_213'></a><a href='#TOC'>[213]</a></span>
+have been in existence for millions of years. We also learn from the
+electro-magnetic theory of light that Aether has an electro-magnetic
+basis, which gives rise to electro-magnetic waves when disturbed, or set
+in motion by any heated or luminous body. It can readily be seen,
+therefore, that we have only to set this electro-magnetic Aether in
+circular motion around any planet or sun, and we have at once a circular
+current of electricity flowing round that planet or sun, which would
+give rise to those conditions by which any body within its influence may
+be formed into a magnet.
+</p>
+
+<p>
+Our hypothesis, therefore, to explain the reason why all the planets and
+the sun are magnets, is that the electro-magnetic Aether moves round the
+sun or planet or satellite as the case may be, thus giving rise to
+currents of electricity around the planet or sun, and so forming those
+conditions in the Aether by which the permanency of any planetary or
+stellar magnetism may be maintained and perpetuated.
+</p>
+
+<p>
+In other words, to put it plainly and tersely, each aetherial atmosphere
+revolves round the planet, subject to certain limitations, in the same
+way that the aerial atmosphere turns round with the earth, as that
+planet revolves on its axis. At first sight, such an assumption may seem
+impossible, but a little careful consideration will show not only the
+possibility of such a cause, but will establish it, as the only
+reasonable and philosophical explanation for the phenomena we are
+seeking to explain, viz. the electro-magnetism of all celestial bodies.
+</p>
+
+<p>
+There is nothing extravagant in this assumption, as we already have a
+similar illustration in the case of the atmosphere which goes round with
+the earth as it revolves on its axis. We have only to extend the same
+principle a little further, viz. to the aetherial atmosphere, and we at
+once get the true physical conception of the hypothesis suggested to
+explain the magnetism of all celestial bodies. We have already learned
+that Maxwell has proved that the equations for moving magnetic bodies
+are the same as those for stationary bodies, from which we came to the
+conclusion that the electric and magnetic field of any planet goes with
+that planet as it revolves on its axis in its journey round the sun.
+</p>
+
+<p>
+I would like to ask the reader to try to conceive of any electric or
+magnetic field traversing space in association with any planet or sun
+which is revolving on its axis, while that electric or magnetic field
+does not revolve either partially or wholly with the revolving body. The
+field can only be stationary relatively to the planet or sun, as it
+revolves with the planet or sun on its axis.
+</p>
+
+<p>
+There may be, as there doubtless are, conditions governing that<span class='pagenum'><a name='Page_214' id='Page_214'></a><a href='#TOC'>[214]</a></span>
+revolution, as is the case with the atmosphere moving and revolving with
+the planet, but it is an absolute impossibility for Maxwell's equations
+relating to moving magnetic bodies to be carried to their logical
+conclusion, without affirming some such hypothesis as we have affirmed
+in relation to the cause of all solar magnetism.
+</p>
+
+<p>
+Let me at once point out, this solution has already been offered by one
+whose name has been referred to several times. I refer to Professor
+Challis. Let us see what he has to say as to the cause of the earth's
+magnetism. In dealing with this subject, and writing in the <i>Phil.
+Mag</i>., 1872, par. 42, he states: &ldquo;With respect to all magnetism which
+has a cosmical origin, the view I now take is that it is due to
+gyrations of the Aether, produced by the impulses which it receives from
+the motions of the constituent atoms of the bodies of the solar system.
+The gyrations may either be immediately generated by the rotations of
+the bodies about their axes, or directly result from disturbances of the
+Aether caused by their motions of translation. This impressed motion
+will be converted into circulatory or gyratory motion. Such circulatory
+motion will necessarily partake of the motion of translation of the
+bodies which generate them, so as to have always the same geometrical
+relation to these bodies provided their motion be uniform.&ldquo;
+</p>
+
+<p>
+In paragraph 46 he continues: &ldquo;From what has been already argued (42),
+the motions impressed on the Aether by the earth in consequence of its
+rotatory or orbital motions result in circulating motions which would be
+steady motions, having always the same geometrical relation to the
+position of the earth's centre.&ldquo;
+</p>
+
+<p>
+Again, Ampère and Faraday were also of the opinion that the magnetism of
+the earth was due to the circulation of electric currents round it, for
+in par. 446, <i>Exp. Res</i>., Faraday states: &ldquo;Assuming with Ampère that the
+magnetism of the earth is due to electric currents circulating round it,
+parallel to the equator.&ldquo;
+</p>
+
+<p>
+I think it will be seen from these extracts that the hypothesis
+suggested for all planetary and stellar magnetic bodies is thus
+confirmed by Professor Challis, and by Faraday and Ampère. Professor
+Challis in these passages clearly and definitely points out that there
+are circulatory motions in the Aether, which motions are produced by the
+rotation of the earth or other body on its axis, and that these circular
+motions of the aetherial medium always maintain the same geometrical
+shape relative to the earth's centre. So that we have only to combine
+with his hypothesis the electro-magnetic basis of the Aether, and we at
+once get the circulating currents of electricity constantly flowing
+round the heavenly bodies, which produce and give rise to the permanent
+magnetism of those bodies.<span class='pagenum'><a name='Page_215' id='Page_215'></a><a href='#TOC'>[215]</a></span>
+</p>
+
+<p>
+If we desired still further confirmation as
+to the circulating motions of the Aether caused by a rotating body, we
+find it in the writings of Herschel, who in relation to this matter
+asks:<a name='FNanchor_38' id='FNanchor_38'></a><a href='#Footnote_38' class='fnanchor'>[38]</a>
+ &ldquo;What is the law of density of the resisting medium which
+surrounds the sun? Is it at rest or in motion? If the latter, in what
+direction does it move? Circularly round the sun, or traversing space?
+If circularly, in what plane? Supposing the neighbourhood of the sun to
+be filled with material fluid, it is not conceivable that the
+circulation of the planets in it for ages should not have impressed upon
+it some degree of rotation in their own direction, and this may preserve
+them from the extreme effects of accumulated resistance!&ldquo; Words like
+these from one of the most searching intellects of the last century are
+well worthy of our consideration, and the suggested effect on the Aether
+caused by the continued rotation of the earth gives us the key not only
+to the problem of celestial magnetism, but also to the other outstanding
+scientific problems.
+</p>
+
+<p>
+For example, there is the problem of the relation of moving matter to
+the Aether around it which still remains unsolved. The physical cause of
+the rotation of the earth, and all other celestial bodies upon their
+axes, with unceasing regularity, still remains to be discovered. The
+physical explanation as to the reason why the earth moves round the sun
+in its orbit according to Kepler's Laws, has yet to be determined, and,
+lastly, there is the relation of the magnetic vibration to the electric
+vibration in connection with the electro-magnetic theory of light still
+to be solved.
+</p>
+
+<p>
+Now, presuming that all these can be solved by the philosophical
+hypothesis, that the electro-magnetic Aether circulates round each
+planet and sun and star, that revolves in space, then we are justified
+in our conclusion that such is the true cause of all electro-magnetism
+that exists in connection with planetary and stellar bodies. I venture
+to premise that all these problems can be solved by the simple solution
+here given, and will prove that this solution adequately accounts for
+all the other phenomena referred to.
+</p>
+
+<p>
+Before proceeding to do this, we will endeavour to prove this hypothesis
+by an altogether different method of reasoning, in order to confirm the
+statements made in this article. Let us therefore endeavour to form a
+complete view of the physical state of the solar system, and for the
+sake of simplicity we will suppose it to be at rest in space. We shall
+deal with the effect of its motion upon its own planetary system, when
+we explain Kepler's Laws.<span class='pagenum'><a name='Page_216' id='Page_216'></a><a href='#TOC'>[216]</a></span>
+</p>
+
+<p>
+We have, therefore,
+the Sun in the centre (see Fig. 14) of the system, with Mercury, Venus,
+the Earth, Mars, Jupiter, Saturn, Uranus, and Neptune revolving round
+the sun at their respective distances, which are subject to variations
+owing to certain causes which can be satisfactorily explained. But
+circulating round the sun, in the same direction as the rotation of the
+sun on its axis, we have the electro-magnetic Aether, with its
+wide-spreading flow and extensive electro-magnetic field. In like
+manner, we have each planet with its aetherial electro-magnetic field,
+which also circulates round each planet in the same direction as the
+planet revolves, that is, from west to east, and in the same direction
+as the sun's electro-magnetic field revolves.
+</p>
+
+<p>
+Thus we have to picture the whole of the solar system in a state of
+regular and harmonious rotation, while each planet adds to the harmony
+of the rotation by itself rotating in its own aetherial electro-magnetic
+field, while all rotate in the same direction, viz. from west to east.
+</p>
+
+<p>
+Of course there are several objections that can be raised to such a
+hypothesis, and those objections will be briefly dealt with in a
+subsequent article, but I venture to think that this hypothesis is the
+true philosophical explanation of a problem which has formed one of the
+greatest outstanding difficulties in regard to the Aether medium for
+many years, that problem being the relative motion of the Aether and
+Matter. Lord Kelvin, in an article in the <i>Phil. Mag</i>. for July 1901,
+entitled &ldquo;Clouds over the Dynamical Theory of Light,&ldquo; refers to this
+very difficulty, and states there are two clouds over the present
+undulatory theory of light, one of which has reference to the difficulty
+of conceiving a body like the earth or any planet rushing through the
+Aether without subjecting the Aether to enormous laceration, and
+concludes by saying that &ldquo;we must still regard this cloud as very
+dense.&ldquo; Here, then, is the key to the solution of the problem.
+</p>
+
+<p>
+The earth does not rush through the Aether, but the Aether being
+gravitative, it is associated with and bound to each planet, and
+accompanies that planet in its journey though space, rotating with it in
+the same way that the atmosphere does, as we shall prove later on.
+</p>
+
+<p>
+This conception is fully in accord with our hypothesis as to the
+physical explanation of the cause of the electro-magnetic character of
+all the heavenly bodies, and indeed is the only physical solution that
+can adequately account for all the varied phenomena hitherto unexplained
+in connection with the celestial mechanism.
+</p>
+
+<p>
+From the foregoing statements, we are now in a position to consider the
+term Electro-Kinetic Energy, as used by Clerk Maxwell. What does he<span class='pagenum'><a name='Page_217' id='Page_217'></a><a href='#TOC'>[217]</a></span>
+mean by Electro-Kinetic Energy? Let us see what he has to say about the
+term himself.
+</p>
+
+<p>
+In par. 636 of his <i>Magnetism and Electricity</i> he writes: &ldquo;According to
+our hypothesis we assume kinetic energy to exist wherever there is
+magnetic force, that is, in general, in every part of the field. This
+energy exists, therefore, in some kind of motion of the matter in every
+portion of space;&ldquo; while again, in par. 569, he states: &ldquo;The electric
+current cannot be conceived except as a kinetic phenomenon.&ldquo; Even
+Faraday speaks of the electric current as &ldquo;something progressive, and
+not a mere arrangement&ldquo; (<i>Exp. Res</i>. 283).
+</p>
+
+<p>
+Then again in par. 552 he writes: &ldquo;It appears, therefore, that a system
+containing an electric current is a seat of energy of some kind, and,
+since we can form no conception of an electric current except as a
+kinetic phenomenon, its energy must be kinetic energy, that is to say,
+the energy which a moving body has in virtue of its motion.&ldquo;
+</p>
+
+<p>
+Here, therefore, according to Clerk Maxwell, the kinetic energy of an
+electro-magnetic field is nothing more or less than the energy which a
+moving body possesses in virtue of its motion. Any other explanation of
+kinetic energy would be opposed to all the Rules of Philosophy; for
+experience in its widest form incontrovertibly proves that all kinetic
+energy is associated, and alone associated, with a moving body;
+therefore in all electro-magnetic fields there is this kinetic energy
+ever being manifested. We have, however, learned that the solar system
+forms a huge electro-magnetic field, traversed by lines of force, as
+Maxwell and Faraday suggested. Therefore, in the solar system, there
+must be this kinetic energy due to the motion of a moving body, which is
+the electro-magnetic Aether.
+</p>
+
+<p>
+We have, however, just arrived at the conclusion that in the solar
+system there is ever going on a circulatory or rotatory movement of the
+electro-magnetic Aether forming currents around each electro-magnet. On
+the hypothesis of an atomic and gravitating Aether we have, therefore, a
+medium or body continually circulating, which medium possesses inertia
+and momentum, and it is philosophically possible for such a rotating
+medium to possess kinetic energy. So that our explanation of this term,
+as used by Clerk Maxwell, is, that this kinetic energy is indeed due to
+the momentum of the moving Aether. Such a hypothesis is strictly
+philosophical, and literally fulfils the statements made by Clerk
+Maxwell himself in the paragraphs already referred to.
+</p>
+
+<p>
+A remarkable feature about this hypothesis lies in the fact, that it is
+the very hypothesis that Von Helmholtz suggested as the explanation of
+the term. He came to the conclusion that the kinetic energy was due to<span class='pagenum'><a name='Page_218' id='Page_218'></a><a href='#TOC'>[218]</a></span>
+the momentum of the moving Aether. But with a frictionless Aether such a
+hypothesis, although correct, was philosophically untenable. In view of
+the theory of the Aether presented in this work, however, both Clerk
+Maxwell's and Von Helmholtz's statements find their literal and perfect
+fulfilment. So that in an atomic Aether, which is gravitative because
+atomic, and rotatory because it is gravitative, combined with its
+electro-magnetic basis as proved by Hertz, we find for the first time a
+correct philosophical explanation of one of the most puzzling terms used
+by Maxwell in his greatest work on <i>Magnetism and Electricity</i>. This
+solution alone ought to stamp the theory of an atomic and gravitating
+electro-magnetic Aether with that authority that is always associated
+with the names of two such great thinkers and experimentalists as those
+just mentioned.
+</p>
+
+<p>
+The fact that the Aether is held bound to a planet has already been
+suggested by Sir G. Stokes to account for the aberration of light
+already referred to. In the <i>Phil. Mag</i>., July 1845, he writes: &ldquo;I shall
+suppose that the earth and the planets carry a portion of Aether along
+with them, so that the Aether close to the surface is at rest relatively
+to the earth, while its velocity alters as we recede from its surface,
+till at no great distance it is at rest in space.&ldquo; Sir G. Stokes does
+not, however, say how the Aether is held bound to the earth, and apart
+from an Aether which is gravitative, no satisfactory explanation can be
+given. Further, it is noticeable, that he suggests that the other
+planets also carry part of the Aether associated with them along with
+each planet as it pursues its journey. It would be distinctly
+unphilosophical to assume that the earth was the only planet that
+carried its aetherial field with it. So that by following Sir G. Stokes'
+suggestion, we practically arrive at the same conclusion in relation to
+the motions of the Aether that we have already arrived at from magnetic
+phenomena.
+</p>
+
+<p>
+With this view of the case we are now in a position to answer a question
+asked by Professor Schuster at the British Association in 1892. He
+asked, &ldquo;Is not every large rotating mass a magnet?&ldquo; and added, &ldquo;If it
+is, the sun must be a powerful magnet. The comets' tails, which eclipse
+observations show stretching out from the sun in all directions,
+probably consist of electric discharges.&ldquo; Now, in relation to this
+question, the answer is that every rotating body in the Aether is
+undoubtedly an electro-magnet. Thus, not only is the sun an
+electro-magnet, but every planet and satellite, and every meteor that
+rotates in the electro-magnetic Aether, is converted into a magnet,
+partly by that rotation, and partly by the currents induced in the
+Aether by that rotation. We shall also find when we come to deal with<span class='pagenum'><a name='Page_219' id='Page_219'></a><a href='#TOC'>[219]</a></span>
+the phenomena of comets' tails, that Professor Schuster is also right as
+to their cause, and that they are due to electro-magnetic repulsions
+originated in the Aether by the sun, which is an electro-magnet.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_38' id='Footnote_38'></a><a href='#FNanchor_38'><span class='label'>[38]</span></a>
+<i>Outlines of Astronomy</i>, Herschel.
+</p></div>
+
+
+<p>
+<a name='ART_92' id='ART_92'></a><span class='smcap'>Art</span>. 92. <i>Cause of Rotation of the Earth on its Axis</i>.--If there is one
+fact true in relation to the earth as a planet, it is that the earth
+rotates on its axis every 24 hours. Day in and day out, for centuries
+past, this revolution has taken place as the earth journeys in its
+annual path round the sun.
+</p>
+
+<p>
+Not only does the earth rotate on its axis, but every other planet
+rotates on its axis in varying times, as the following table shows--
+</p>
+
+<table summary='subtable2'>
+<tr><th style='width: 10%; text-align: left;'></th><th style='width: 10%; text-align: right;'><span class='smcap'>hrs.</span></th><th style='width: 10%; text-align: right;'><span class='smcap'>min.</span></th><th style='width: 10%; text-align: right;'><span class='smcap'>sec.</span></th><th></th></tr>
+<tr><td>Mercury</td><td style='text-align: right;'>24</td><td style='text-align: right;'>5</td><td style='text-align: right;'>0</td></tr>
+<tr><td>Venus</td><td style='text-align: right;'>23</td><td style='text-align: right;'>24</td><td style='text-align: right;'>0</td></tr>
+<tr><td>The Earth</td><td style='text-align: right;'>23</td><td style='text-align: right;'>56</td><td style='text-align: right;'>4</td></tr>
+<tr><td>Mars</td><td style='text-align: right;'>24</td><td style='text-align: right;'>37</td><td style='text-align: right;'>23</td></tr>
+<tr><td>Jupiter</td><td style='text-align: right;'>9</td><td style='text-align: right;'>55</td><td style='text-align: right;'>0</td></tr>
+<tr><td>Sarturn</td><td style='text-align: right;'>10</td><td style='text-align: right;'>14</td><td style='text-align: right;'>23</td></tr>
+<tr><td>Uranus</td><td style='text-align: right;'>?</td><td></td><td></td></tr>
+<tr><td>Neptune</td><td style='text-align: right;'>?</td><td></td><td></td></tr>
+</table>
+
+<p>
+Further, the sun also rotates on its axis in a period of 26 days. Here,
+then, are certain phenomena in connection with the solar system, for
+which up to the present no explanation as to the physical cause of
+rotation has ever been offered. Surely there is some physical cause, to
+account for such a rotation, and if there be a physical cause, then the
+problem to be solved is--find the physical cause to account for the
+continuous and ever-recurring rotation of all the planets and the sun on
+their axes, which shall be so effective and continual that, year in and
+year out, the rotation of all the planets may be continued as observed.
+In solving this problem we have to revert to our reason why the earth is
+a magnet. In <a href='#ART_91'>Art. 91</a> we learned that the earth and all the other
+planets, and indeed all stellar bodies, were electro-magnets, because
+the electro-magnetic Aether was constantly circulating round them.
+</p>
+
+<p>
+If, by accepting this explanation, we can at the same time solve the
+problem of the rotation of the planets, and the sun, on their axes, then
+we shall have further evidence that our hypothesis is the correct one.
+Now let me ask, What is the effect of an electric current continually
+circulating round any magnet in the same way that the electro-magnetic
+Aether continually circulates round the earth, which is a magnet?
+</p>
+
+<p>
+To find out what the effect is, we must resort to experiment. Professor
+Lodge, in his <i>Modern Views of Electricity</i>, shows us the effect of any
+circulating current of electricity revolving round a magnet. In his<span class='pagenum'><a name='Page_220' id='Page_220'></a><a href='#TOC'>[220]</a></span>
+chapter on Electro-Magnetism he writes as follows: &ldquo;How does a current
+act on a magnetic pole? Two currents attract or repel each other, two
+poles attract or repel each other, but a current and a pole exert a
+mutual force which is neither attraction nor repulsion. It is a rotatory
+force. They tend neither to approach nor to recede, they tend to revolve
+round each other.&ldquo; &ldquo;A singular action this and at first sight unique&ldquo;
+(p. 135). &ldquo;The two things will revolve round each other for ever. This
+affords and has afforded a fine field for the perpetual motionist, and
+if only the current would maintain itself without a sustaining power,
+perpetual motion in fact would be attained.&ldquo;
+</p>
+
+<p>
+Faraday has shown by experiment the action of a current on the magnet,
+and <i>vice versâ</i>. Faraday, in his description of an electro-magnetic
+apparatus for the exhibition of rotatory motion, shows how the rotation
+of a current round a magnet, and a magnet round a current, may be
+experimentally proved. With the apparatus used he shows that the current
+of electricity may be made to revolve round the pole of the magnet in
+the direction dependent on the pole used, and further, illustrates how
+the magnet may be made to revolve round the current. (Plate 4, Fig. 5,
+<i>Exp. Res.</i>)
+</p>
+
+<p>
+Thus we learn that wherever we have a current constantly circulating
+round a magnet, there we have the conditions by which, according to
+Professor Lodge, perpetual motion may be obtained, that is to say, the
+two will revolve round each other as long as the current is maintained.
+Here then we find in space those very conditions by which perpetual
+motion may be obtained.
+</p>
+
+<p>
+We find the electro-magnetic Aether constantly circulating round the
+planetary magnets, with the result that not only will the current
+continue to revolve around the planet, but the planet will continue to
+revolve upon its axis as it revolves round the current. In fact we get
+in space an example of perpetual motion. We know that the rotation of
+the earth on its axis has been in existence for several thousand years,
+and therefore we have a right to assume that it revolved on its axis
+through the untold ages of past geological times as revealed by the
+strata, and rocks of pre-historic ages. Thus the motion must have
+continued, so far as the earth is concerned, at least 100,000,000 years,
+accepting that period as the age of the earth, but no physical reason so
+far as I know has ever been assigned for such continued rotation.
+</p>
+
+<p>
+If, therefore, it be true that the joint action of a current and a
+magnet is a rotatory one, then, seeing that in all planetary and stellar
+space we have both these conditions of matter, that is, the<span class='pagenum'><a name='Page_221' id='Page_221'></a><a href='#TOC'>[221]</a></span>
+electro-magnetic aetherial current, constantly circulating round an
+electro-magnet, we have, in space, the conditions by which perpetual
+rotation may be maintained. We have therefore presented to us in that
+joint action, the true cause of the continued rotation of the earth on
+its axis, and therefore of all the planets on their axes, together with
+the sun on its axis; and, if we carry the principle into the stellar
+world, we can philosophically come to the conclusion that the same
+conditions prevail there that prevail in the solar system, with the
+result that we have now a physical cause which fully satisfies all Rules
+of Philosophy to account for certain phenomena which up to the present
+have never yet been accounted for from the physical standpoint. Thus in
+solving the problem of the earth's rotation on its axis, we find greater
+confirmation in the view presented in a previous article as to the
+circulating motion of the electro-magnetic Aether around any and every
+body in space. We shall deal again with the relation of a current and a
+magnet, when we come to the physical explanation of Kepler's Laws.
+</p>
+
+<p>
+<a name='ART_93' id='ART_93'></a><span class='smcap'>Art</span>. 93. <i>Vortex Motion</i>.--From <a href='#ART_91'>Art. 91</a> we have seen that the
+electro-magnetic Aether possesses a circulating or rotatory motion
+around each central body, and because of this rotatory motion, the body
+is at once converted into a magnet. We have also seen that Professor
+Challis believed in the circulatory or rotatory motion of the Aether, as
+also did Ampère.
+</p>
+
+<p>
+Thus we are led back by scientific experiment and philosophical
+reasoning to the conception of vortex motion with which the world was
+familiar in the days of Kepler, Descartes, Huyghens and Bernoulli. There
+is this difference, however, that whereas the vortex motion of those
+philosophers was to displace and do away with Gravitation, the
+circulatory or rotatory Aether suggested by electro-magnetic phenomena
+is to supplement, confirm and establish more firmly than ever the true
+powers and laws of Gravitation Attraction.
+</p>
+
+<p>
+Before passing, it will be as well to briefly glance at the conception
+of vortex motion as suggested by Kepler and Descartes and others.
+Whewell on this matter in his <i>Inductive Sciences</i> states that &ldquo;Kepler
+assumed that a certain force or virtue resided in the sun by which all
+bodies within his influence were carried round him. He illustrated the
+nature of the force in various ways, comparing it to light, and to the
+magnetic power which it resembles in the circumstances of operating at a
+distance, and also of exercising a feebler influence as the distance
+increases.&ldquo; &ldquo;Another image to which he referred suggested a much more
+conceivable kind of mechanical action by which the celestial motions
+might be produced, viz. a current of fluid matter circulating round the
+sun, and carrying the planets with it like a boat in a stream.&ldquo; Whewell<span class='pagenum'><a name='Page_222' id='Page_222'></a><a href='#TOC'>[222]</a></span>
+adds: &ldquo;A Vortex fluid constantly whirling round the sun, kept in this
+whirling motion by the sun itself, and carrying the planets round the
+sun by its revolution, as a whirlpool carries straws, could be readily
+understood, and though it appears to have been held by Kepler that this
+current and Vortex were immaterial, he ascribes to it the power of
+overcoming the inertia of bodies, and of putting them and keeping them
+in motion.&ldquo;
+</p>
+
+<p>
+Now, as we have seen, the electro-magnetic Aether is not immaterial but
+material, as it is matter possessing mass and inertia, the same as any
+other matter, as Tyndall and Lord Kelvin stated (Chap. IV.). Thus the
+objection to Kepler's immaterial vortices is met and overcome by our
+conception of the Aether (Chap. IV.). Descartes, as Whewell points out,
+asserted, &ldquo;that a vacuum in any part of the universe is impossible. The
+whole universe must be filled with matter, which must be divided into
+equal angular parts. This matter being in motion, the parts are
+necessarily grounded into a spherical form, and the corners thus rubbed
+off, forming a second or subtle matter. There is besides a third kind of
+matter, of parts more coarse and less fitted for motion. The first part
+makes the luminous bodies as sun and stars, the second part is the
+transparent substance of the skies, and the third part is the material
+of opaque bodies as the earth, planets and comets. We may suppose that
+the motion of these parts takes the form of revolving circular currents
+or vortices. By this means the first matter will be collected to the
+centre of each vortex, while the second or subtle matter surrounds it,
+and by its centrifugal effect constitutes light. The planets are carried
+round the sun by the motion of the vortex, each planet being at such
+distance from the sun as to be in a part of the vortex suitable to its
+solidity and mobility. The satellites are in like manner carried round
+their ordinary planets by subordinate vortices.&ldquo;
+</p>
+
+<p>
+It would almost seem from this quotation that we had adopted purely and
+simply Descartes' and Kepler's ideas <i>in toto</i>, whereas the truth is
+that the hypothesis of a rotating electro-magnetic Aether has been
+arrived at by following Newton's own Rules of Philosophy, and by
+discarding everything not in harmony with experience and experiment.
+</p>
+
+<p>
+Further, Descartes was unable to give, or explain the ellipticity of the
+orbits of planets, and had to assume that there were elliptic vortices.
+When we come to deal with Kepler's Laws, and their physical
+interpretation, the correct solution of this problem will be given from
+a purely experimental and philosophical standpoint, and in a way and
+manner never suggested by Descartes or any other believer in the theory
+of vortices as then known and understood. Indeed there is no objection<span class='pagenum'><a name='Page_223' id='Page_223'></a><a href='#TOC'>[223]</a></span>
+to the theory of vortices, which cannot be satisfactorily explained by a
+rotating electro-magnetic Aether, as we shall see when we deal with
+Newton's Laws of Motion and Kepler's Laws.
+</p>
+
+<p>
+Both Liebnitz and Huyghens were believers in the theory of vortices, and
+the fact that Huyghens' undulatory theory of light stands to-day as an
+accepted theory, is conclusive evidence that he was a philosopher of the
+highest order, and his adhesion to the theory of vortices proves that he
+was convinced that there was some truth in it.
+</p>
+
+<p>
+It is a result greatly to be desired, therefore, if it can be
+demonstrated, that in the Aether there is this rotatory motion
+continually going on around every planet, satellite, sun or star;
+because it will then join together, in perfect harmony, two great
+theories in relation to celestial phenomena, that contended with each
+other for supremacy for very many years.
+</p>
+
+<p>
+It will prove that, after all, men like Kepler, Descartes, Huyghens, and
+Bernoulli had caught glimpses of the great truth which was partly
+revealed by celestial phenomena, and that it was only for lack of data
+that they were unable to successfully compete with Newton's mathematical
+genius, by which he was able to bring his Law of Gravitation safely
+through the conflict with the simpler conception of aetherial vortex
+motion. Of course certain objections will have to be met and answered
+before this aspect of aetherial dynamics can be expected to supplant the
+more cumbrous and somewhat intricate mathematical laws of motion, but I
+shall prove later on, that all these objections can be answered from a
+satisfactory standpoint.
+</p>
+
+<p>
+So that if a modified form of aetherial vortex motion can be
+successfully demonstrated to exist in the electro-magnetic Aether, then
+we shall see the conflict that waged about two hundred years ago,
+brought to a satisfactory issue, in the union of the two greatest
+philosophic theories for the explanation of celestial phenomena that the
+world has ever seen.
+</p>
+
+<p>
+From that union, therefore, there will then emerge a truer, simpler, and
+yet grander conception of the motions of the universe, which, when
+perfected by abler minds, will be as perfect a theory as human
+intelligence and philosophy can make it. So that, what an atomic and
+gravitative Aether has done for Newton's corpuscular theory of light, in
+showing that it can be united and combined with the undulatory theory,
+and by such combination, for the first time, such phenomena as the
+transverse action of light can be probably demonstrated and explained,
+together with other phenomena relating to reflection and refraction of
+light, the enlarged conception of a rotating electro-magnetic Aether will
+do for the two great theories that vied with each other for supremacy<span class='pagenum'><a name='Page_224' id='Page_224'></a><a href='#TOC'>[224]</a></span>
+for so many years. Thus it will be shown that the philosophers like
+Kepler, Descartes, and Huyghens, the former of whom has stamped his name
+on the three laws that bear his name to-day, and the latter who gave us
+the inception of the very theory that overthrew Newton's theory of
+light, had after all a more or less true philosophic conception of the
+physical mechanism of the solar system and of the universe at large.
+</p>
+
+<p>
+<a name='ART_94' id='ART_94'></a><span class='smcap'>Art</span>. 94. <i>Relative Motion of Aether and Matter</i>.--There is hardly any
+subject of greater importance which is engaging the attention of
+scientists at the present time, than the question as to what is the
+relative motion of Matter to the Aether in which it moves.
+</p>
+
+<p>
+I venture to premise the successful solution of the problem will be
+accompanied with the greatest advance to science that has been known for
+a long time. The problem to be solved may be stated thus: &ldquo;Does the
+Aether surrounding a planet or sun or any body in space move with that
+body, or does it allow the body to pass through it?&ldquo;
+</p>
+
+<p>
+Up to the present, opinions on the subject have been varied and
+conflicting. Some scientists hold that the planetary and other bodies in
+space pass through the Aether without disturbing it, while others hold
+that part of the Aether is carried along by the moving planet. Fresnel
+assumed that the surrounding Aether was carried along by the earth, so
+that all relative phenomena would be the same as if the earth were at
+rest. Fizeau, from experiments which he conducted on running water, also
+came to the same conclusion.
+</p>
+
+<p>
+With the old idea of a frictionless medium, some of the present accepted
+theories are altogether untenable, because, if Aether is frictionless,
+how can it be carried along with the moving body, unless it is held
+bound to that body? and how can it be held bound to that body if it is
+frictionless?
+</p>
+
+<p>
+The whole view of the Aether is, however, changed by the conception of
+the Aether put forward in Chapter <a href='#CHAPTER_IV'>IV</a>. Aether is Matter, and being matter
+it is also gravitative, and therefore is just as much subject to the Law
+of Gravitation as any other kind of matter, as Young stated in his
+Fourth Hypothesis (<a href='#ART_45'>Art. 45</a>).
+</p>
+
+<p>
+We will therefore attack the problem of the relative motion of the earth
+and the Aether around it from this new standpoint. In order to be
+strictly philosophical, we must base our hypothesis and conception on
+experience and observation. Where in the whole of planetary phenomena do
+we find similar conditions which exist between the Aether and the earth?
+Such conditions are alone to be found between the atmosphere and the
+earth. The analogy between the atmosphere and the earth, and the Aether<span class='pagenum'><a name='Page_225' id='Page_225'></a><a href='#TOC'>[225]</a></span>
+and the earth is very striking, as the following comparisons will prove.
+</p>
+
+<p>
+The atmosphere (when pure) is invisible, so is the Aether. The
+atmosphere is atomic, the Aether is also atomic. Both are subject to the
+same laws of elasticity and density, and both are gravitative, according
+to our conception of the Aether. Now what is the effect of any large
+revolving body on a liquid or gaseous medium surrounding that revolving
+body?
+</p>
+
+<p>
+If experience is any guide, we learn that the motion of the revolving
+body is either partially or entirely transmitted to the liquid or
+gaseous medium surrounding such a body. So far as our experience teaches
+us anything, it teaches us that to that rule there is no exception, and
+no experiment can be devised of any body revolving in water or a gaseous
+medium as air, without that body imparting its rotation to the water or
+the air. The atmosphere in relation to the earth is no exception to this
+rule. We know that the earth has an equatorial circumference of about
+24,000 miles, and that it revolves on its axis once every day, so that
+at the equator the surface of the earth is whirling round in space at
+the rate of 1000 miles per hour.
+</p>
+
+<p>
+Try to conceive what the result would be if the atmosphere were
+stationary at the earth's surface in the equatorial regions. It would
+mean that any body on its surface would be whirled round at that rate,
+while the atmosphere, being stationary, would exert a power equal to a
+wind travelling at the rate of 1000 miles per hour.
+</p>
+
+<p>
+Under the influence of such a hurricane, nothing could exist on the
+surface of the earth at the equator, if the earth revolved on its axis
+and the atmosphere did not participate in that motion. But the
+atmosphere is gravitative, and being gravitative, it is not only held
+bound to the earth as it revolves on its axis in its onward rush through
+space, but accepts the revolving motion of the earth, with the result
+that as the earth revolves on its axis, the atmosphere revolves also.
+</p>
+
+<p>
+Thus a balloon at the equator if allowed to rise several hundred feet
+above the surface could remain comparatively stationary if held by a
+rope to overcome its tendency to rise, whereas such an event would be
+impossible if the atmosphere failed to receive only half of the motion
+of the earth's surface, as it would still have a power equal to that of
+a wind blowing at the rate of 500 miles an hour. If, however, we come
+further north, or go further south, then we find that the surface of the
+earth does not have the same velocity as at the equator, with the result
+that the atmosphere has not the same velocity either; consequently it
+would travel slower in the temperate regions than in the equatorial<span class='pagenum'><a name='Page_226' id='Page_226'></a><a href='#TOC'>[226]</a></span>
+regions, and slower still at the poles than in the temperate regions.
+</p>
+
+<p>
+We know by experiment what the effect of increased velocity has upon any
+whirling body; it tends to enlarge the body at those parts where the
+velocity is the greatest, the consequence being that the bulging out of
+the atmosphere would be greatest at the equator. We find a similar
+result in the shape of the earth, where the equatorial diameter is
+greater than the polar diameter, because of the centrifugal force being
+greatest in the equatorial regions.
+</p>
+
+<p>
+We have, therefore, to apply these facts to the aetherial medium which
+surrounds all planetary and stellar bodies in the same way as the
+atmosphere does; and which, being also gravitative, is equally subject
+to the same laws of motion. We have seen, therefore, that not only does
+the earth revolve on its axis, but that the atmosphere revolves on its
+axis also, and that the velocity of its revolution is greatest in the
+equatorial regions, the atmosphere spreading or bulging out in those
+parts more than in any other part of the earth's surface.
+</p>
+
+<p>
+Let us suppose that the atmosphere extends 200 miles above the earth,
+and that there we come to the pure Aether of universal space. In view of
+the fact that Aether is Matter, and therefore gravitative, it is
+reasonable and logical to conclude that exactly the same result follows
+in relation to the atmosphere and the Aether at that height, as follows
+in relation to the earth and the atmosphere 200 miles beneath.
+</p>
+
+<p>
+Unless this view is accepted, we should then have our second Rule of
+Philosophy violated, as we should have matter revolving in more rarefied
+matter, and failing to impress upon that rarefied condition of matter
+the motion either partially or wholly which it itself possesses; and
+such a result being contradictory to all experience cannot be admitted
+from a philosophical standpoint.
+</p>
+
+<p>
+Therefore, the only solution is, that the rotating atmosphere imparts
+some of its motion to the aetherial atmosphere, which in its turn
+rotates, and that that rotation is governed by exactly the same
+conditions as govern the relation that exists between the earth and the
+atmosphere. Therefore the Aether in space associated with each planet or
+satellite or sun or star, rotates with the rotating body, and that
+rotation imparts to the Aether a greater bulging out in the equatorial
+regions of the aetherial atmosphere than in any other part thereof. It
+is interesting in relation to this point to note Herschel's view of the
+effect of the rotation of any body upon the Aether. In his <i>Outlines of
+Astronomy</i>, in a note, p. 358, he states: &ldquo;Supposing the neighbourhood
+of the sun to be filled with a material fluid; it is not conceivable
+that the circulation of planets in it for ages should not have<span class='pagenum'><a name='Page_227' id='Page_227'></a><a href='#TOC'>[227]</a></span>
+impressed upon it some degree of rotation in their own direction, and
+this may preserve them from the effects of accumulated resistance.&ldquo;
+</p>
+
+<p>
+In this way we arrive at the conception of the motions of the Aether
+suggested by Prof. Challis from the magnetic character of the earth,
+which he thought were due to aetherial currents circulating around it,
+and we learn that such physical conception of the Aether fully agrees
+with the explanation of celestial bodies being electro-magnets; because,
+we have only to add to our rotating Aether that which it has been proved
+to possess, viz. an electro-magnetic basis, and we have at once the
+currents of electricity circulating round the earth and other planetary
+or solar bodies, by which is obtained the true explanation of the
+permanent magnetism of all celestial bodies.
+</p>
+
+<p>
+Now to some minds unconversant with scientific research and knowledge,
+such a supposition may seem to be incredible, but that incredibility may
+disappear, when I say that the fact that the Aether is bound to the
+earth, and goes along through space with it, has actually been proved by
+some of the most delicate and successful experiments that have been made
+in recent times: experiments of which Lord Kelvin has stated that he can
+find no error or flaw in them. I refer to the scientific experiments of
+Michelson and Morley of America. For full particulars of these
+experiments I must refer the reader to the <i>American Journal of
+Science</i>, 1886, vol. 31, or to the <i>Phil. Mag</i>., vol. 44.
+</p>
+
+<p>
+The conclusion which is arrived at from their experiments is, that the
+Aether is carried along with the earth as it rushes on its journey
+through space. Of course such a result is altogether opposed to the
+ordinary conception of a frictionless medium, and indeed to any
+conception of the Aether except to that submitted in this work, which is
+also in harmony with Young's Fourth Hypothesis (<a href='#ART_45'>Art. 45</a>).
+</p>
+
+<p>
+So that Michelson's and Morley's experiment is a direct experimental
+demonstration of the fact that Aether is gravitative, and because it is
+gravitative, it is carried along with the earth, as that planet journeys
+through space. It further conclusively proves that not only is the
+Aether carried along with the earth, but that the Aether circulates
+round the earth in the same way that the atmosphere circulates round the
+earth.
+</p>
+
+<p>
+This result naturally follows from the experiment, because, if it were
+carried along by the earth and yet did not rotate with the atmosphere,
+then we should have a result opposed to all experience and experiment,
+as these teach us that when a body revolves in a medium which is held
+bound to that body by Gravitation, the medium so held bound participates
+in the rotation of the revolving body.<span class='pagenum'><a name='Page_228' id='Page_228'></a><a href='#TOC'>[228]</a></span>
+</p>
+
+<p>
+So that in Michelson's and
+Morley's experiment we have experimental evidence of the fact, already
+stated, that the Aether circulates round the earth, and therefore, in
+view of the electro-magnetic character of the Aether, this circulation
+results in the production of magnetism in all the planets, and other
+bodies around which it circulates.
+</p>
+
+<p>
+Thus not only does the Aether circulate round the earth, but it also
+circulates around every other planet, and not only round every other
+planet, but equally so around every sun and star, as stated in <a href='#ART_91'>Art. 91</a>.
+</p>
+
+<p>
+These results are perfectly consistent with philosophical reasoning, and
+any other result would be inconsistent with the analogies presented to
+us by the phenomena of the Aether in relation to our earth as
+ascertained by experiments made by the scientists referred to. Thus for
+the first time the experiment is brought into harmony with our
+Philosophy, which up to the present has not been the case, a result
+which at once stamps the experiment with that validity of truth and fact
+which will ultimately win for it universal acceptance and favour.
+</p>
+
+<p>
+We are now in a position to answer some queries regarding the motions of
+the Aether asked by Herschel in his work on <i>Astronomy</i>, p. 345. These I
+give with the answers opposite.
+</p>
+
+<table summary='questions'>
+<tr><th style='width:30%; text-align: center;'><span class='smcap'>QUERIES.</span></th><th style='width: 20%; text-align: center;'><span class='smcap'>ANSWERS.</span></th><th></th></tr>
+
+<tr><td style='text-align: left;'>1. What is the law of density<br />&nbsp;&nbsp;&nbsp;&nbsp;of the resisting medium which<br />&nbsp;&nbsp;&nbsp;&nbsp;surrounds the sun?</td><td style='text-align: left;'>The Law of Gravitation<br />(<a href='#ART_45'>Art. 45</a>).</td></tr>
+
+<tr><td style='text-align: left;'>2. Is it at rest or in motion?</td><td style='text-align: left;'>In motion.</td></tr>
+
+<tr><td style='text-align: left;'>3. If the latter, in what<br />&nbsp;&nbsp;&nbsp;&nbsp;direction does it move?</td><td style='text-align: left;'>Rotates round the sun.</td></tr>
+
+<tr><td style='text-align: left;'>4. Circularly round the sun<br />&nbsp;&nbsp;&nbsp;&nbsp;or traversing space?</td><td style='text-align: left;'>Both, as it circulates round<br />the sun while that body<br />traverses space.</td></tr>
+
+<tr><td style='text-align: left;'>5. If circularly, in what<br />&nbsp;&nbsp;&nbsp;&nbsp;plane?</td><td style='text-align: left;'>The plane of the ecliptic.</td></tr>
+</table>
+
+<p>
+<a name='ART_95' id='ART_95'></a><span class='smcap'>Art</span>. 95. <i>Physical Explanation of the Vibration in the Electro-Magnetic
+Theory of Light</i>.--In <a href='#ART_78'>Art. 78</a> we learned that light was an
+electro-magnetic disturbance in the Aether which was propagated through
+the Aether, with a finite velocity; and from this we gathered that light
+waves were nothing more or less than electro-magnetic waves, which were
+radiated from the sun, out into the Aether on every side.
+</p>
+
+<p>
+We were unable, however, at that time to give a definite physical
+conception of the aetherial vibrations, or of the relation of the
+various types of vibration to each other. Since, however, the<span class='pagenum'><a name='Page_229' id='Page_229'></a><a href='#TOC'>[229]</a></span>
+development of the Aether from the electric and magnetic standpoint,
+which has led us up to the fact that the Aether possesses a circulating
+motion round the sun (<a href='#ART_91'>Art. 91</a>), the solution of the problem appears
+probable. I am of the opinion that the physical conception of the
+various vibrations to each other is now within the region of
+possibility, and in this article I wish to endeavour to give what seems
+to me to be a correct and philosophical explanation of this part of the
+electro-magnetic theory of light, the physical conception of which up to
+the present has not been generally understood.
+</p>
+
+<p>
+The explanation may, or may not, be fully complete, but even if it be
+not perfectly correct, I am convinced that it will ultimately lead to a
+satisfactory physical explanation of this part of Maxwell's Theory of
+Light. In forming a conception as to the physical character of the
+vibrations in the electro-magnetic theory, we have to remember that
+there are three distinct vibrations, or motions, concerned in this
+theory.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/229.jpg' width='400' height='162'
+alt='Fig: 22.'
+title='Fig: 22.' />
+</div>
+
+<p style='margin-left: 5em;'>1st. There is the direction of propagation.</p>
+
+<p style='margin-left: 5em;'>2nd. There is the direction of the electric
+vibration which is at right angles to the direction of propagation.</p>
+
+<p style='margin-left: 5em;'>3rd. There is the direction of the magnetic
+vibration or motion which is at right angles to both of the other two.</p>
+
+
+<p>
+Now we have seen that the direction of propagation of any aetherial
+light ray, is that of a straight line from the sun corresponding to the
+radius vector (<a href='#ART_76'>Art. 76</a>). We have also seen that the front of a light
+wave is really that of a spherical shell (<a href='#ART_71'>Art. 71</a>).
+</p>
+
+<p>
+We have also learned that the electric and the magnetic vibrations are
+in the wave front, so that these two vibrations, which are at right
+angles to each other, are to be found on the surface, so to speak, of
+each aetherial spherical shell, that surrounds the sun with
+ever-decreasing density, and ever-decreasing elasticity.
+</p>
+
+<p>
+Let us try to picture the actual fact by an illustration. Let <i>S</i> be the
+sun, with concentric spherical aetherial shells surrounding it (Fig.
+22). Then <i>S</i> <i>A</i> and <i>S</i> <i>C</i> will be rays of light being radiated out from
+the sun, and the magnetic and electric vibrations have to be both at<span class='pagenum'><a name='Page_230' id='Page_230'></a><a href='#TOC'>[230]</a></span>
+right angles to the line of propagation and in the wave front; the wave
+front being represented by the circular lines showing the section of the
+concentric shells running north and south.
+</p>
+
+<p>
+Now how can we picture these two motions at right angles to each other,
+and yet both at right angles to the line of propagation? First, let us
+take three straight lines and see how this may be done (Fig. 23).
+</p>
+
+<p>
+Let <i>A</i> <i>B</i>, <i>A</i> <i>S</i> be two straight lines at right angles to each other, and
+<i>A</i> <i>C</i> another straight line at right angles to both. This can only be
+done by making <i>A</i> <i>C</i> perpendicular to the plane of the paper, and can be
+illustrated by supposing that it represents a pencil or pen placed
+upright on the paper, the point of the pencil being at point <i>A</i>. If
+this be done, then not only will <i>A</i> <i>B</i> and <i>A</i> <i>C</i> be at right angles to
+each other, but both will be at right angles to <i>A</i> <i>S</i>, which corresponds
+to the line of propagation.
+</p>
+
+<p>
+Now refer to Fig. 22, and we shall see that the line <i>A</i> <i>B</i> and the
+boundary of the shell will practically correspond. So that
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/230.jpg' width='400' height='272'
+alt='Fig: 23.'
+title='Fig: 23.' />
+</div>
+
+<p>
+any section of a spherical wave front will always be at right angles to
+the ray of light. But we have learned from <a href='#ART_89'>Art. 89</a> that these sections
+of the aetherial spherical shell are really identical with Faraday's
+Lines of Force, with the result that along any line which stretches from
+the North pole of the sun to the South pole, there will ever be an
+electric vibration, which is put into motion by the elasticity of the
+aetherial vortex atoms. So that on every side of the sun there is ever
+going on this electric vibration, along the lines of force which
+correspond to a section of the aetherial shell, the surface of which
+really constitutes the wave front.
+</p>
+
+
+
+<p>
+Therefore it can readily be seen, that, as these lines are at right
+angles to the propagation of the ray of light, the electric vibration is
+at right angles to the lines of propagation, and is thus in accordance
+with the result demanded by Maxwell's theory.
+</p>
+
+<p>
+We have now to give a physical conception of the magnetic vibration or
+motion of the Aether, and this has to be at right angles to both the
+electric vibration and the line of propagation.<span class='pagenum'><a name='Page_231' id='Page_231'></a><a href='#TOC'>[231]</a></span>
+</p>
+
+<p>
+In <a href='#ART_91'>Art. 91</a> we have
+learned that the Aether possesses a rotatory motion, by which it rotates
+round the central body of the solar system, the sun. So that if we take
+any point, for example, in the path of the ray as <i>S</i><sub>1</sub>, <i>S</i><sub>2</sub>, <i>S</i><sub>3</sub>,
+and <i>S</i><sub>4</sub>, situated upon some definite equipotential surface or lines of
+force, and if we will imagine those lines to rotate round the sun, as
+the sun rotates on its axis, then in time the points will have described
+half the circle, and will come to the position on the right of the sun
+indicated by the same Nos. <i>S</i><sub>1</sub>, <i>S</i><sub>2</sub>, <i>S</i><sub>3</sub>, <i>S</i><sub>4</sub>. Thus there has
+been an aetherial motion at right angles to the electric motion, as the
+Aether circulates round the sun, because this motion may be represented
+as taking place from west to east of the sun, while the electric
+vibration takes place from north to south, or transverse to the line of
+propagation.
+</p>
+
+<p>
+We have, however, learned that the Aether has an electro-magnetic basis,
+and therefore the rotation of the Aether gives rise to electro-magnetic
+currents; hence the motion west to east is really the motion of
+electro-magnetic currents which circulate round the sun. As these are at
+right angles to the line of propagation, and we have seen that they are
+at right angles to the electric vibration, it follows that all three are
+at right angles to each other, which is in accordance with the
+requirements as laid down by Maxwell.
+</p>
+
+<p>
+We have considered these vibrations, first, from the view of the solar
+system as a whole in its relation to the universal Aether; but the same
+principle holds good if considered from the aetherial atomic standpoint.
+For if we take a line of force, composed as it is of aetherial vortex
+atoms, and suppose them to be rotating, we know that by that rotation
+there will be a tension due to that rotation, and Maxwell has shown this
+tension is due to magnetism, as in his standard work he says: &ldquo;This
+magnetic force is the effect of the Centrifugal Force of the Vortices.&ldquo;
+</p>
+
+<p>
+So that by postulating a rotatory movement for the Aether around the
+sun, as we have done in <a href='#ART_92'>Art. 92</a>, we have not only solved the problem of
+all planetary and solar magnetism, but we have also solved the problem
+of the relative motion of the Aether and the earth, and also given for
+the first time (though it may be in an incomplete form) a physical
+explanation of that part of the electro-magnetic theory of light, which
+has hitherto been unexplained from the purely physical standpoint.
+</p>
+
+<p>
+Such results, therefore, supported as they are by the direct experiment
+of Michelson and Morley of America, justify us in concluding that the
+conception of a rotating Aether is not only philosophically correct, but
+is in actual accord with experimental investigation and research, as
+indeed it ought to be.
+</p>
+
+<p><span class='pagenum'><a name='Page_232' id='Page_232'></a><a href='#TOC'>[232]</a></span></p>
+<h2><a name='CHAPTER_X' id='CHAPTER_X'></a><a href='#CHAPTER_X_TOC'>CHAPTER X</a></h2>
+
+<h3>AETHER AND NEWTON'S LAWS OF MOTION</h3>
+
+
+<p>
+<a name='ART_96' id='ART_96'></a><span class='smcap'>Art</span>. 96. <i>Centrifugal Force</i>.--Before proceeding to apply some of the
+principles and laws which govern the electro-magnetic aetherial medium
+to solar and stellar phenomena, it will be as well just to review the
+conception of our new aetherial Centrifugal Force, so that we may form a
+right view of it in its completeness and entirety.
+</p>
+
+<p>
+In <a href='#ART_11'>Art. 11</a> we premised that there was in existence another force, which
+was the exact opposite of the centripetal force, and that this force was
+the complementary and counterpart of the centripetal force or
+Gravitation Attraction; and further, that this force was due to the
+motion of the universal Aether which filled all space.
+</p>
+
+<p>
+In <a href='#ART_13'>Art. 13</a> we saw that all force resolved itself into energy of some
+kind, the same being due either to potential energy, <i>i. e.</i> energy of
+position, or to kinetic energy, which is the energy belonging to matter
+actually in motion. From <a href='#ART_56'>Art. 56</a> we learned that all energy was energy
+of motion, so that all force resolves itself into motion of some kind.
+</p>
+
+<p>
+Thus our term Centrifugal Force really implies, and demands, a motion of
+the Aether which is ever directed away from the centre of gravity of any
+body, whether that body be an atom or molecule, satellite or planet, sun
+or star. From the phenomena of heat we have seen that there exists a
+repulsive motion, due to the aetherial medium, which is ever exerted
+from the central body of any atomic, planetary or stellar system, that
+repulsive motion being due to the pressure of the universal Aether,
+which not only surrounds all atoms, but also surrounds all other bodies
+in the universe.
+</p>
+
+<p>
+From the phenomena of light we have also seen that the Aether possesses
+a repulsive or centrifugal motion, which is also due to the pressure of
+the same Aether as mathematically proved by Maxwell, and experimentally
+proved by Prof. Lebedew, and Nichols and Hull of America. Further, from
+the phenomena of electricity, we have also seen that there exists this
+centrifugal motion, due to the pressure of the same aetherial medium,
+which pressure is ever directed away from the electrified body, as the<span class='pagenum'><a name='Page_233' id='Page_233'></a><a href='#TOC'>[233]</a></span>
+sun or planets.
+</p>
+
+<p>
+So that from these three phases of the universal Aether, that is, from
+its thermal or heat manifestation, its luminiferous or light
+manifestation, and its electro-magnetic manifestation, we get
+irrefutable evidence of the existence of a centrifugal motion, which
+motion is ever directed away from the central body; and the result of
+that motion takes the form of a pressure upon any body with which the
+motion comes into contact.
+</p>
+
+<p>
+Again, it was premised, that such a centrifugal force or motion must
+fulfil all the laws which governed the centripetal force or motion.
+</p>
+
+<p>
+First, it had to be universal (<a href='#ART_19'>Art. 19</a>). Second, it had to follow
+exactly the same path as the centripetal force or motion, which was that
+of a straight line joining the centre of gravity of two bodies, as for
+example the earth and the sun (<a href='#ART_20'>Art. 20</a>). Third, the centrifugal force or
+motion must be equal to the product of the masses, in the same way that
+the centripetal force was governed by such a law (<a href='#ART_21'>Art. 21</a>). Fourth, its
+intensity was to be governed by the law of inverse squares, the same as
+the centripetal force or Gravitation Attraction was governed (<a href='#ART_22'>Art. 22</a>).
+</p>
+
+<p>
+Now all these conditions are satisfactorily fulfilled, and have been
+shown to be satisfactorily fulfilled, from the phenomena of heat, light,
+and electricity in their relation to the universal Aether. For in <a href='#ART_43'>Art. 43</a> we saw that the Aether was universal, and therefore if the
+centrifugal motion is produced and originated by the Aether, then such
+motions must be as universal as that medium, which under qualifying
+conditions gives rise to these motions.
+</p>
+
+<p>
+From <a href='#ART_65'>Arts. 65</a> and <a href='#ART_76'>Art. 76</a> we have learned that the path of this centrifugal
+motion is that of a straight line, and follows exactly the same path
+that the centripetal force of gravity takes. In <a href='#ART_85'>Art. 85</a> we learned that
+the centrifugal force between any two bodies was equal to the product of
+their masses, which is exactly the same as the centripetal force that
+exists between any two bodies; and, lastly, from the phenomena of heat,
+light, and electricity we learned that the intensity of this centrifugal
+motion due to aetherial pressure was inversely as the square of the
+distance, which is the law governing the intensity of its counterpart,
+the centripetal force. Thus we have learned that there is in existence
+throughout universal space, a physical force or motion due to a physical
+medium, the universal Aether, which force or motion is the exact
+opposite of the centripetal force or Gravitation Attraction, which may
+be stated as follows--
+</p>
+
+<p>
+Every particle in the universe repels every other particle with a force<span class='pagenum'><a name='Page_234' id='Page_234'></a><a href='#TOC'>[234]</a></span>
+whose direction is in the line joining the centres of gravity of the two
+bodies, and whose magnitude is directly as the product of their masses,
+and inversely as the square of the distance between them, at their mean
+distances.
+</p>
+
+<p>
+We shall see that it is by the conjoint working of these two forces, the
+Centripetal and Centrifugal, in combination with other motions of the
+Aether, that the harmonious working of the whole celestial mechanism is
+maintained and perpetuated. In confirmation of the existence of the
+centrifugal force, I should like to draw the attention of the reader to
+certain phenomena relative to the solar system, which phenomena violate
+the centripetal force as at present recognized, and can alone be
+accounted for by the existence of another force or motion existing in
+space, such as the centrifugal motion already proved and demonstrated.
+</p>
+
+<p>
+We know that the law governing the centripetal force, or Gravitation
+Attraction, is regulated by the product of the masses of the two
+attracting bodies. So that if there were three bodies in space whose
+masses are respectively represented by 2, 3 and 100, the proportion of
+the attractive force of gravitation between the largest and the other
+two, would be 200 (100 × 2) and 300 (100 × 3) respectively. So that if
+the centripetal force, or the Attraction of Gravitation, is the only
+governing force in the universe, then it naturally follows that the two
+bodies, between which the attractive force is greater, will be closer
+together than the two bodies between which the attractive force is less.
+</p>
+
+<p>
+Thus the two bodies, whose product of their masses is represented by
+300, will, according to the Law of Gravitation, be closer together than
+the two bodies, the product of whose masses is represented by only 200.
+Unless this is so, we should have a violation of the Law of Gravitation,
+and it would at once cease to be a law.
+</p>
+
+<p>
+Let us therefore apply the centripetal force, or Gravitation Attraction,
+to the solar system, and see how it works out. The law strictly defined
+is given in <a href='#ART_18'>Art. 18</a>, from which we learn that the attractive force
+between two bodies is as the product of their masses. Now what are the
+masses of some of the bodies in the solar system?
+</p>
+
+<p>
+We find that the sun, with its diameter of 865,000 miles, is about
+324,000 times greater in mass than our earth, so that it would take
+about 324,000 bodies of the size and density of our earth to equal a
+body of the size and density of the sun. It has been calculated,
+however, by Von Asten, from observations made on comets by the planet
+Mercury, that the mass of Mercury is about 1/24 of the mass of the
+Earth. Therefore the mass of the sun must exceed the mass of Mercury
+324,000 × 24 = 7,776,000; the exact relation according to Von Asten is
+7,636,440. Again, the planet Jupiter, with its diameter of 85,000 miles<span class='pagenum'><a name='Page_235' id='Page_235'></a><a href='#TOC'>[235]</a></span>
+and its density of 1.38, is only 1/1048 part of the mass of the sun, so
+that it would take about 1048 Jupiters to equal the mass of the sun,
+therefore Jupiter must weigh about 7400 times the mass of Mercury.
+</p>
+
+<p>
+If the mass of Mercury, therefore, be represented by 1, the mass of the
+Earth would be represented by 24, the mass of Jupiter by 7400, and the
+mass of the sun by 7,636,400. So that the attractive forces between the
+planets as regards their masses only will be represented numerically as
+follows--
+</p>
+
+<table summary='attractive_forces'>
+<tr><th></th><th></th><th></th><th></th><th></th></tr>
+<tr><td style='width:20%; text-align: left;'>Sun and Mercury</td><td style='width:20%; text-align: left;'>7,636,400 × 1</td><td style='width:5%; text-align: center;'>=</td><td style='width:20%; text-align: right;'>7,636,400.</td></tr>
+
+<tr><td style='width:20%; text-align: left;'>Sun and Earth</td><td style='width:20%; text-align: left;'>7,636,400 × 24</td><td style='width:5%; text-align: center;'>=</td><td style='width:20%; text-align: right;'>190,008,000.</td></tr>
+
+<tr><td style='width:20%; text-align: left;'>Sun and Jupiter</td><td style='width:20%; text-align: left;'>7,636,400 × 7,400</td><td style='width:5%; text-align: center;'>=</td><td style='width:20%; text-align: right;'>56,435,360,000.</td></tr>
+</table>
+
+
+<p>
+Thus we see that the attractive force between the sun and the earth
+exceeds 24 times the attractive force between the sun and Mercury, while
+the attractive force of gravity between the sun and Jupiter is 7400
+times greater than the attractive force between the sun and Mercury,
+relative to their masses.
+</p>
+
+<p>
+Therefore, according to the Law of Gravity, as regards the masses of
+bodies, Jupiter and the sun should be nearer together than Mercury and
+the sun, because their attractive powers are greater, and the earth and
+the sun should be nearer together than Mercury and the sun, because
+their joint attractive powers are also greater. In the same way it can
+be proved that all the other planets whose masses are greater than
+Mercury ought, according to the Law of Gravity in regard to masses only,
+to be nearer to the sun than what Mercury is, simply because the total
+attractive forces between any two are greater than the attractive force
+between Mercury and the sun.
+</p>
+
+<p>
+The respective masses of the planets compared with the sun, taking the
+mass of the sun as unity, are as follows--
+</p>
+
+<table summary='planetary_masses'>
+<tr><th style='width:20%; text-align: left;'></th><th style='width:20%; text-align: center;'></th><th style='width:20%; text-align: center;'></th><th></th></tr>
+<tr><td>Jupiter</td><td>1/1,048</td><td style='text-align: center;'>of mass of sun.</td></tr>
+<tr><td>Saturn</td><td>1/3,529</td><td style='text-align: center;'>"&nbsp;&nbsp;&nbsp;&nbsp;"</td></tr>
+<tr><td>Neptune</td><td>1/18,520</td><td style='text-align: center;'>"&nbsp;&nbsp;&nbsp;&nbsp;"</td></tr>
+<tr><td>Uranus</td><td>1/22,020</td><td style='text-align: center;'>"&nbsp;&nbsp;&nbsp;&nbsp;"</td></tr>
+<tr><td>Earth</td><td>1/324,439</td><td style='text-align: center;'>"&nbsp;&nbsp;&nbsp;&nbsp;"</td></tr>
+<tr><td>Venus</td><td>1/397,000</td><td style='text-align: center;'>"&nbsp;&nbsp;&nbsp;&nbsp;"</td></tr>
+<tr><td>Mars</td><td>1/2,994,790</td><td style='text-align: center;'>"&nbsp;&nbsp;&nbsp;&nbsp;"</td></tr>
+<tr><td>Mercury</td><td>1/7,636,440</td><td style='text-align: center;'>"&nbsp;&nbsp;&nbsp;&nbsp;"</td></tr>
+</table>
+
+<p><span class='pagenum'><a name='Page_236' id='Page_236'></a><a href='#TOC'>[236]</a></span></p>
+
+<p>
+Therefore, if the total attractive force of gravity is equal to
+the product of the masses of any two bodies, then the planets
+ought to be in the following order in relation to their distance
+from the sun: Jupiter, first, followed by Saturn, Neptune, Uranus,
+Earth, Venus, Mars and Mercury; that being the order in which
+the attractive power of gravity is regulated by their respective
+masses.
+</p>
+
+<p>
+Yet the very opposite is nearly the case, as we find that some
+of the further planets, as Jupiter, Saturn, Uranus and Neptune,
+possess greater masses than any of the nearer planets; so that
+here we have a distinct violation of the Law of Gravitation Attraction,
+which states that the attraction between any two bodies is
+directly as the product of their masses, because we find certain
+bodies with greater attracting powers further away from the sun,
+than other planets possessing less attracting powers, because of
+their smaller masses. I cannot recall having ever read of any
+explanation which has been given for such an anomaly, and
+indeed this apparent violation admits of no other explanation
+than the conception of the dual character of the so-called Law of
+Universal Gravitation, which includes a repelling or repulsive
+force or motion, such motion being due to the pressure of the
+universal Aether.
+</p>
+
+<p>
+Thus in the light of the centrifugal motion, combined with the
+fact that Aether is gravitative, by which each body possesses an
+aetherial atmosphere and electrical equivalent proportionate to
+its mass, it can be demonstrated within a reasonable limit how it
+is that such planets as Jupiter, Saturn, Uranus, Neptune, possessing
+aetherial atmospheres and electrical equivalents proportionate
+to their masses, revolve in orbits round the sun at much greater
+distances than Mercury, Venus, the Earth, or Mars. This
+explanation will follow as we consider the Centrifugal Force
+and the Centripetal Force in their relation to Newton's Laws of
+Motion.
+</p>
+
+<p>
+<a name='ART_97' id='ART_97'></a><span class='smcap'>Art</span>. 97. <i>Centripetal Force</i>.--We have now to apply the
+Centripetal Force, together with the new Aetherial Centrifugal
+Force, to the solar system, and show that by their conjoint working
+taken in conjunction with the motions of the Aether, all
+celestial phenomena may be satisfactorily explained on a physical
+basis, in a similar way that Newton proved the same result from
+the mathematical standpoint.
+</p>
+
+<p>
+We saw in <a href='#ART_10'>Art. 10</a> that the centripetal force was really none<span class='pagenum'><a name='Page_237' id='Page_237'></a><a href='#TOC'>[237]</a></span>
+other than the Attraction of Gravitation, in that it always acted
+to a centre, and in no other way, and therefore by the centripetal
+force for the present we must understand is meant the attractive
+power of Gravitation.
+</p>
+
+<p>
+Afterwards, when it has been demonstrated that the centripetal
+force and the new aetherial centrifugal force can account for
+all celestial phenomena, then we shall be in a position to show
+what the physical cause of the centripetal force is.
+</p>
+
+<p>
+Let us again refer to the centripetal force, so that we may
+see exactly what its governing conditions are. In <a href='#ART_18'>Art. 18</a> we
+learned that this force might be thus expressed: &ldquo;Every particle
+of matter in the universe attracts every other particle with a force
+whose direction is that of a line joining their centres of gravity,
+and whose magnitude is directly as the product of their masses,
+and inversely as the square of the distance between them.&rdquo; Now
+we have seen from the previous Art. that the centrifugal force
+due to the pressure of the Aether medium is the exact counterpart
+of this, in every way, so that if we combine the two, we get
+the complete statement of the universal law which governs all
+matter, and which we may define as follows--
+</p>
+
+<p>
+&ldquo;Every particle in the universe attracts and repels every other
+particle in the universe with a force whose direction is that of a
+line joining their centres of gravity, and whose magnitude is
+directly as the product of their masses, and inversely as the square
+of the distance between them.&rdquo; This complete law, however,
+only holds good when the two forces are in equilibrium.
+</p>
+
+<p>
+With this conception of the universal law which governs all
+matter, the harmony and stability of the universe becomes
+possible from the physical standpoint. Apart from this conjoint
+working of the two forces or motions, a physical explanation of
+Universal Gravitation is impossible, as with one force operating
+only throughout the universe, ultimate stability is inconceivable,
+and the harmony of the spheres might at any time be suddenly
+destroyed.
+</p>
+
+<p>
+With this conception of the universal law which governs all
+matter, the great Law of Gravitation is brought into harmony
+with all experience and observation. Look where we will, or at
+what we will, there we find forces possessing a dual character, as
+we have already seen proved. Professor Tyndall, as we have
+already learned (<a href='#ART_63'>Art. 63</a>), definitely states that the stability of
+atomic systems is preserved by the existence and operation of
+<i>two forces, one attractive and the other repulsive</i>, and what is true
+of the atomic world is equally true of solar or stellar worlds.
+Thus for the first time in this respect, our philosophy agrees
+with our experience, and the true relation of the centrifugal
+force or motion to the centripetal force is made manifest. So<span class='pagenum'><a name='Page_238' id='Page_238'></a><a href='#TOC'>[238]</a></span>
+that, wherever in the solar system the centripetal force or
+Gravitation Attraction operates, there, with exactly equal intensity
+and power, the aetherial centrifugal force operates, at the
+respective mean distances of the planets and satellites, where
+the two forces are in equilibrium.
+</p>
+
+<p>
+If it were possible to conceive of a stationary solar system,
+then, by the conjoint working of the two forces, it would be
+equally possible to conceive of perfect stability and harmony
+existing between the respective planets and satellites of that
+system while stationary.
+</p>
+
+<p>
+Such a conception is altogether impossible in the present state
+of Philosophy, as the stability of the system, with the old view of
+the Centrifugal Force, is entirely dependent upon the motions of
+the respective bodies in that system; and if such orbital motions
+could be stayed, then the only physical conception possible would
+be, that every planet and satellite, planetoid and meteor within
+the attractive force of the central body, the sun, would be slowly
+but surely drawn to a fiery death, as they would all ultimately
+be attracted and swallowed up by the sun.
+</p>
+
+<p>
+Thus we learn, that while the sun is the centre of a centripetal
+force, which ever operates far and wide throughout space, it is
+equally the centre of a repulsive or centrifugal force or motion
+which also operates co-extensively and co-equally with the
+former.
+</p>
+
+<p>
+Not only so, but every planet and satellite, nay every particle
+and every atom, while it is the centre of a centripetal force, is
+also the centre of a repulsive force, as pointed out by Professor
+Tyndall, which force is due in each and every case to the pressure
+of the aetherial atmosphere which surrounds the atom or
+molecule, satellite or planet. Thus the physical conception of
+heat in its effect on molecules having a repulsive force (<a href='#ART_63'>Art. 63</a>)
+is confirmed, and that that force is due to the pressure of the
+Aether is also confirmed by subsequent investigations into the
+phenomena of light and electricity, by which we have arrived at
+our physical conception of the Universal Centrifugal Force.
+</p>
+
+<p>
+So that we have now a physical conception of the experiment
+performed by Nichols and Hull of America, and by Professor
+Lebedew of Russia, in which they conclusively demonstrated the
+existence of the pressure of aetherial light waves, which proves
+beyond the possibility of doubt the existence of this physical
+centrifugal force. Every atom and molecule, therefore, is the
+centre of two forces, which co-exist together, and every meteor
+and satellite and every planet is also the centre of the same two
+forces, and this we shall find in its application to planetary
+phenomena will have a most important bearing on the physical
+conception of those phenomena. Thus it is the Aether medium,<span class='pagenum'><a name='Page_239' id='Page_239'></a><a href='#TOC'>[239]</a></span>
+by its energy of motions, that constitutes the companion and
+complementary force to Gravitation Attraction, and which, as we
+shall see later, is the medium which forms the physical basis of
+that attraction also. It is, then, by the combined and harmonious
+working of these two co-equal, co-existent, and co-extensive
+forces that worlds roll and rush, sweep and swing, move and
+rotate about their respective centres; and, by these two forces
+working in perfect harmony, that that order and stability are
+produced, which everywhere pervade the universe of worlds,
+and form them in their entirety into one grand, ultimate, and
+harmonious system.
+</p>
+
+<p>
+To develop and prove this fact, by explaining their manner
+and mode of working, we shall now proceed to consider Newton's
+Laws of Motion, and their relation to the aetherial medium, and
+by so doing shall be able to show the unmistakable reality and
+complete efficiency of this physical conception of the Aether
+medium, which forms the physical basis of all universal motion
+and phenomena.
+</p>
+
+
+<p>
+<a name='ART_98' id='ART_98'></a><span class='smcap'>Art</span>. 98. <i>Newton's First Law of Motion.</i>--We will now apply
+the centrifugal and centripetal forces to Newton's Laws of
+Motion, and endeavour to form a physical conception of the
+same from the aetherial standpoint. Before doing so, we must
+recall some of the statements made in <a href='#ART_14'>Art. 14</a> with reference to
+the First Law of Motion.
+</p>
+
+<p>
+It will be remembered that we divided the First Law of Motion
+into two parts: 1st, &ldquo;Every body continues in a state of rest
+except in so far as it is compelled by impressed forces, <i>i. e.</i>
+impulses or motions, to change that state.&rdquo; This we saw agreed
+with our experience, and therefore was philosophically correct,
+and must hold good in its application to the centrifugal and
+centripetal forces of the Aether in their effect upon any body
+in space.
+</p>
+
+<p>
+Let us proceed to apply the First Law of Motion to the
+planetary world. We have seen in the previous Art. so far
+as the distances of the planets are concerned in their relation
+to the sun, that the Law of Gravity is violated, and that planetary
+distance is not regulated by the law governing the centripetal
+force of Gravitation, otherwise the planets possessing the largest
+masses would be nearer to the sun than those possessing smaller
+masses.
+</p>
+
+<p>
+The question arises, as to whether there is any law which
+governs planetary distance, by which the distance of any planet
+was regulated at the birth or creation of the solar system. It
+has been assumed by some scientists that planetary density is
+the regulating factor which determines the relative distance of
+the respective planets from their central body, the sun, but such<span class='pagenum'><a name='Page_240' id='Page_240'></a><a href='#TOC'>[240]</a></span>
+an assumption is not consistent with scientific data. For we
+find that Venus, with a density of 4.81 compared with water,
+occupies a nearer position than the Earth with a density of 5.66,
+whereas the reverse should be the case if the density of a planet
+were the deciding factor in regulating a planet's distance.
+</p>
+
+<p>
+Again, we find Saturn, which possesses a density of .75,
+occupying a nearer position to the sun than Uranus, which
+possesses a density of 1.28; so that here again, if density were
+the regulating factor which decided planetary distance, such a
+law is violated. According to the various densities of the planets,
+the respective positions of the planets in relation to the sun would
+be as follows: The nearest planet would be Mercury, which
+possesses a density of 6.85. This would be followed by the
+Earth, with a density of 5.66. Then Venus would come next,
+with a density of 4.81, followed by Mars, with a density of 4.01.
+After these we should have Jupiter, whose density is 1.38, with
+Uranus, whose density is 1.28, followed by Neptune possessing a
+density of 1.15, and Saturn would take Neptune's place, as it
+possesses the least density of all, its density being only .75. So
+that it is manifest, that density cannot be the governing condition,
+as has been proved in the previous article.
+</p>
+
+<p>
+Now, if all the planets ever formed part of the sun, and they
+were hurled off into space by the centrifugal motion of the
+Aether, then there certainly would be some law which governs
+the relative distance of the various planets; but as far as we
+can see, there is no such law, as a law which is violated ceases
+to be a law, so that the law of masses or densities of a planet,
+governing their distances, has no place in the solar system.
+</p>
+
+<p>
+This leads up to the question as to whether the planets ever
+did form part of the sun, as is generally supposed; and, in view
+of the fact that there is no law by which planetary distances are
+regulated, we are compelled to come to the conclusion that each
+planet and satellite once existed in an aetherial condition in
+space, and that it was by the condensation of that Aether, that
+each planet was formed; and that, at its birth, each planet
+occupied the relative distance from the sun which it occupies
+to-day.
+</p>
+
+<p>
+At first sight this may appear startling, but I would ask the
+reader how he can account otherwise for the great irregularity
+which exists in the distances of the planets in their relation to
+the sun, as every known law which governs masses and density
+seems to be altogether set at defiance.
+</p>
+
+<p>
+I hope to prove later on, that all matter has an aetherial origin,
+and if that be correct, then the origin of a planet briefly outlined
+can be accepted without violating the results of experience
+or experiment, and to that extent will be philosophically correct.<span class='pagenum'><a name='Page_241' id='Page_241'></a><a href='#TOC'>[241]</a></span>
+</p>
+
+<p>
+Dr. Larmor speaks of the aetherial constitution of matter, and
+refers to the views of Faraday and Davy in support of such a
+theory, while Lord Kelvin has referred to the same principle in
+an article on the &ldquo;Condensation of Gravitational Matter in any
+part of the Universe&rdquo; (<i>Phil. Mag</i>., July 1902). So that if it be
+possible for Aether to be condensed, and so form the nucleus of
+a planet or satellite, then, seeing that the Aether is universal, any
+planet or satellite or meteor may be formed in any part of the
+solar system; and the process has only to be continued, until we
+have planets of various sizes at various distances from the central
+body, the sun.
+</p>
+
+<p>
+Here, therefore, at any rate, is a physical hypothesis which will
+satisfactorily account for all the different distances of the various
+planets. Apart from some such hypothesis, I fail to see how we
+can account for the irregularity that exists between planetary
+distances, when viewed from the standpoint of their masses and
+their densities.
+</p>
+
+<p>
+Further, such a conception is entirely in harmony with the
+view of the dual character of the motions or powers of the
+aetherial medium, that would co-exist with the evolution and
+development of the planet. For, as the planet was evolved and
+developed from the aetherial medium which surrounded it on
+every side, two motions would be developed and grow with it--the
+centrifugal force or motion, and the centripetal motion of the
+Aether, or the attractive force known as Gravity. Thus, through
+all the growth and development of a planet, these two powers,
+the centripetal force and the centrifugal force, would be co-equal
+and co-existent.
+</p>
+
+<p>
+The same truth applies to the sun or any other body in the
+universe; so that, if a planet, as the Earth, was formed in the
+beginning at its mean distance of 92,700,000 miles, then the
+joint centripetal motions produced by the Earth and sun in
+the Aether, would always equal the joint centrifugal motions
+produced by the same two bodies, simply because the two laws
+are the exact opposite of each other both in regard to intensity,
+distance, and magnitude.
+</p>
+
+<p>
+Thus the Earth would always occupy its relative position in
+relation to the sun that it occupies to-day, as long as the two
+aetherial forces or motions, the centripetal and the centrifugal,
+exist. With this brief outline of a planet's history, we are now
+in a position to form a physical picture of the solar system when
+it first existed in the beginning.
+</p>
+
+<p>
+We find the sun then occupying its centre. At various
+distances, we find the various planets situated without any
+regard to their relative masses or densities, as the following
+table shows. (The mass of sun is taken as unity.)<span class='pagenum'><a name='Page_242' id='Page_242'></a><a href='#TOC'>[242]</a></span>
+</p>
+
+<table summary='planetary_masses'>
+
+<tr><th style='width:10%; text-align: left;'></th><th style='width:20%; text-align: right;'><span class='smcap'>mean distance.</span></th><th style='width:5%;'></th><th style='width:20%; text-align: left;'><span class='smcap'>mass.</span></th><th style='width:10%; text-align: right;'><span class='smcap'>density.</span></th><th></th></tr>
+
+
+<tr><td style='text-align: left;'>Mercury</td><td style='text-align: right;'>35,900,000</td><td></td><td style='text-align: left;'>1/7,636,440</td><td style='text-align: right;'>6.85</td></tr>
+
+<tr><td style='text-align: left;'>Venus</td><td style='text-align: right;'>67,000,000</td><td></td><td style='text-align: left;'>1/397,000</td><td style='text-align: right;'>4.81</td></tr>
+
+<tr><td style='text-align: left;'>Earth</td><td style='text-align: right;'>92,700,000</td><td></td><td style='text-align: left;'>1/324,439</td><td style='text-align: right;'>5.66</td></tr>
+
+<tr><td style='text-align: left;'>Mars</td><td style='text-align: right;'>141,000,000</td><td></td><td style='text-align: left;'>1/2,994,790</td><td style='text-align: right;'>4.01</td></tr>
+
+<tr><td style='text-align: left;'>Jupiter</td><td style='text-align: right;'>482,000,000</td><td></td><td style='text-align: left;'>1/1,048</td><td style='text-align: right;'>1.38</td></tr>
+
+<tr><td style='text-align: left;'>Saturn</td><td style='text-align: right;'>884,000,000</td><td></td><td style='text-align: left;'>1/3,529</td><td style='text-align: right;'>.75</td></tr>
+
+<tr><td style='text-align: left;'>Uranus</td><td style='text-align: right;'>1,780,000,000</td><td></td><td style='text-align: left;'>1/22,020</td><td style='text-align: right;'>1.28</td></tr>
+
+<tr><td style='text-align: left;'>Neptune</td><td style='text-align: right;'>2,780,000,000</td><td></td><td style='text-align: left;'>1/18,520</td><td style='text-align: right;'>1.15</td></tr>
+</table>
+
+<p>
+Now, in order for any of these planets to fulfil Newton's First Law of
+Motion, the sun, which occupies the centre of the solar system, must be
+assumed to have no rotatory or orbital motion of its own; because, so
+long as it has a rotatory motion on its axis, or an orbital motion of
+its own through space, so long will even the first part of Newton's
+First Law of Motion be inapplicable to the solar system.
+</p>
+
+<p>
+But if the sun can be assumed to possess at some point in its history no
+orbital motion, or rotatory motion on its axis, then the physical
+interpretation of the first law of motion can be physically conceived,
+and a planet at rest will remain at rest relatively to its central body,
+the sun, for ever.
+</p>
+
+<p>
+Let us take the sun and Mercury as an example of the effect of the two
+motions operating in the aetherial medium. We will consider first the
+effect of the centrifugal motion. The sun, with its huge form, occupies
+the centre of the solar system, while Mercury has its mean distance
+about 36,000,000 miles away.
+</p>
+
+<p>
+The solar fires are intensely burning, and every atom and every particle
+composing them are excited thereby into the most intense activity, and
+by their energy of motion create myriads upon myriads of waves in the
+surrounding Aether, which flow away on every side with the velocity of
+light.
+</p>
+
+<p>
+With such velocity are they generated, that they speed across the
+distance of 36,000,000 miles which exist between Mercury and the sun in
+the short time of about three minutes, and if it were not for the
+aetherial and aerial atmosphere of the planet, would fall upon the
+surface of Mercury with an intensity of heat that would scorch up all
+vegetable life, if any existed thereon.
+</p>
+
+<p>
+Now let us for a moment ignore the existence of the centripetal force,
+and then in that light view the influence of the electro-magnetic Aether
+waves upon Mercury. We have seen that when aetherial light waves come
+into contact with any body, they exert a pressure upon that body (<a href='#ART_77'>Art. 77</a>), so that under the influence of the centrifugal force only, Mercury
+would be borne away from its central body, the sun, with a power and
+energy of motion entirely dependent upon the intensity of the<span class='pagenum'><a name='Page_243' id='Page_243'></a><a href='#TOC'>[243]</a></span>
+electro-magnetic Aether waves which give rise to the centrifugal force.
+</p>
+
+<p>
+Thus Mercury would be carried away from the sun, far far away into the
+depths of space, with ever-decreasing rapidity, the rapidity of its
+motion through space being entirely dependent upon the intensity and
+energy of the Aether waves; and, as that intensity varies inversely as
+the square of the distance from the central body, the sun, so the
+impelling and repelling energy of the Aetherial waves would vary
+inversely as the square of the distance from the central body.
+</p>
+
+<p>
+Thus the motion of Mercury or any other planet through space would not
+be uniform, but would gradually decrease, and such a result is perfectly
+in harmony with all experience and experiment in relation to moving
+bodies on this earth.
+</p>
+
+<p>
+This effect of the Aetherial electro-magnetic light waves upon a planet
+is in harmony with Newton's nineteenth query in <i>Optics,</i> and is indeed
+the physical illustration of that query in its corrected form which we
+have already referred to in <a href='#ART_46'>Art. 46</a>, where Newton says: &ldquo;Doth it
+(Aether) not grow denser and denser, etc.; every body endeavouring to go
+from the denser parts of the medium towards the rarer?&rdquo;
+</p>
+
+<p>
+That the Aether does grow denser and denser nearer to a body we have
+already seen in <a href='#ART_46'>Art. 46</a>, and now we learn that a body, when under the
+influence of the centrifugal force only, would pass from the denser
+parts of a medium to the rarer parts, as suggested by Newton. We will
+now suppose that Mercury has been repelled, by the pressure due to the
+aetherial waves generated by the sun, to the distance of Neptune, a
+distance of 2,780,000,000 miles; and that at this point the centrifugal
+force is cancelled, and in its place is put the centripetal force of
+Gravitation. What will be the effect upon Mercury then? At first sight
+the effect will be exceedingly slight, but slowly, yet surely, the
+attractive power of the sun would begin to make itself manifest, and we
+should find Mercury retracing its path along exactly the same straight
+line that it had taken in its outward journey.
+</p>
+
+<p>
+Not only so, but its motion would be accelerated just in the same
+proportion that it had decreased on its outward journey. On and on
+through the intervening space the planet would rush, and if there were
+no centrifugal force in existence, the planet would ultimately rush into
+the central body, the sun, and being swallowed up by it, would maintain
+for a time the heat thereof.
+</p>
+
+<p>
+Let us now view the case from the conjoint working of these forces, or
+motions, the centripetal and centrifugal, and we shall see, that under
+certain conditions it is possible to conceive physically of a planet
+being in a state of rest as stated in Newton's First Law of Motion, and<span class='pagenum'><a name='Page_244' id='Page_244'></a><a href='#TOC'>[244]</a></span>
+also remaining in that state of rest, until it is compelled by other
+forces or motions to change that state. Mercury is now situated at its
+mean distance of about 36,000,000 miles. At the same instant let both
+the centrifugal and the centripetal forces or motions be applied to it,
+and to the sun. What is the result of such application? Will the planet
+move nearer the sun, which we are supposing to be perfectly at rest, or
+will it be urged further away? The effect is nil! for the simple reason,
+that when we set in motion the centripetal force of Gravitation, at
+exactly the same time we set in motion an exactly opposite force which
+is the exact complement and counterpart of the other, so that they
+exactly counterbalance each other, and Mercury under the influence of
+both forces still retains its mean position of 36,000,000 miles; and,
+until we either set the sun rotating, or give it a motion of its own
+through space, Mercury would remain at its distance of 36,000,000 miles
+comparatively at rest. The same reasoning may be applied to all the
+other planets, in relation to their mean distances, with the result that
+they too would remain in a comparative state of rest, so long as they
+were only under the influence of the two forces or motions, viz. the
+centrifugal and centripetal.
+</p>
+
+<p>
+Each of these, being the exact complement and counterpart of the other,
+when applied together to any planet of any size or mass or density, at
+any distance, fails to affect the distance of that planet in its
+relation to the sun, but simply establishes it in that distance, subject
+to certain regulations dependent upon other motions of the sun, and the
+aetherial medium in which they exist. Thus we learn, that if, in the
+beginning, Mercury were formed at a distance of 36,000,000 miles, it
+would for ever remain at that distance; and the same is true of the
+other planets at their mean distances, no matter what their mass or
+density may be; and that, according to the first law of motion, the
+planet would remain in a state of rest until compelled by other forces
+or motions to change that state, when it would continue moving with
+uniform motion so long as the motive power applied was uniform.
+</p>
+
+<p>
+If, however, the motive power applied was not uniform, then the result
+would be an increase or decrease of the planet's motion, just in
+proportion to the increase or decrease of the motive power. This result
+is in perfect harmony with our statement in <a href='#ART_15'>Art. 15</a>, and is in
+accordance with observation and experience.
+</p>
+
+<p>
+<a name='ART_99' id='ART_99'></a><span class='smcap'>Art</span>. 99. <i>Second Law of Motion</i>.--According to Newton's Second Law of
+Motion, &ldquo;Change of motion is proportional to the impressed force, and
+takes place in the direction in which the force is impressed.&rdquo;
+</p>
+
+<p>
+From a consideration of this Law (<a href='#ART_15'>Art. 15</a>) we saw that the impressed<span class='pagenum'><a name='Page_245' id='Page_245'></a><a href='#TOC'>[245]</a></span>
+force was a compound quantity, being regulated by the mass of the moving
+body which exerted the impressed force, and that it was also
+proportionate to the velocity of the moving body; so that if either of
+these quantities are changed, the total impressed force would be changed
+also.
+</p>
+
+<p>
+We have now to show that our aetherial medium agrees with this second
+law of motion in so far as the second law of motion agrees with
+experience and experiments. To do this, we must review our conception of
+the universal Aether, and remember that Aether is matter, and being
+matter, it is atomic and gravitative, possessing density, elasticity,
+inertia, and kinetic energy, the same as any other moving matter.
+</p>
+
+<p>
+In this Aether medium we have, according to this conception, something
+that can both push and pull, or exert force upon any body with which it
+comes into contact. Further, the inertia and kinetic energy of the
+Aether at any part of space will be regulated by its mass in that
+particular part, and if its mass is denser in some parts than others,
+that part of the aetherial medium possessing the greatest mass will also
+possess the greatest capacity for impressing force upon any body that
+exists in the medium. Now we have learned from <a href='#ART_45'>Art. 45</a> that Aether being
+gravitative, it is denser nearer to the sun, getting gradually less and
+less dense, the further it recedes from the central body, except where
+it is bound or associated to some other planet or satellite, and there
+it gradually gets denser, for the same reason that it is denser nearer
+to the sun. As, therefore, the Aether gets gradually less dense as it
+recedes from the sun, the density of the Aether at the mean distance of
+Mercury, 35,900,000 miles, would not be so great as near the sun's
+surface; while the density of the aetherial medium at the distance of
+Venus, 67,000,000 miles, would be less than the density of the aetherial
+medium at the distance of Mercury. This principle may be applied right
+through the sun's aetherial electro-magnetic field, until we come to the
+mean distance of Neptune, which is 2,780,000,000 miles, and there the
+density of the Aether would be less than at any other part of the
+aetherial electro-magnetic field around the sun.
+</p>
+
+<p>
+So that the mass of the Aether at Mercury, which is equal to the number
+of aetherial atoms per unit volume, is greater than the mass at Venus.
+Thus the impressed force which the aetherial medium at the mean distance
+of Mercury can exert upon any body in its neighbourhood, is greater than
+the impressed force which the Aether can exert upon any body at the
+distance of Venus, because of its decreased mass at that distance. In
+the same way it can be proved that the impressed force which the
+electro-magnetic Aether exerts on any body at the distance of Venus, is<span class='pagenum'><a name='Page_246' id='Page_246'></a><a href='#TOC'>[246]</a></span>
+greater than the impressed force which the Aether exerts upon a body at
+the mean distance of the Earth. So that at the respective mean distances
+of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, the
+electro-magnetic Aether, if in motion, would exert less force at each of
+the mean distances of these planets exactly proportionate to the
+decreased mass and decreased velocity of the Aether.
+</p>
+
+<p>
+Now what is the motion which the Aether possesses, so far as the sun is
+concerned? because, upon the particular kind of motion which it
+possesses will depend the direction in which the impressed force will be
+exerted according to the second law of motion.
+</p>
+
+<p>
+In <a href='#ART_98'>Art. 98</a> we supposed the sun and planets to be stationary in the solar
+system, each planet being at its respective mean distance, from which it
+cannot move owing to the equality of the two forces. Now give to the
+central sun from whence the electro-magnetic Aether waves flow, a
+rotatory motion on its own axis, which it really possesses, as it
+rotates on its axis once in every twenty-six days nearly, and this will
+give to the Aether medium a circular or rotatory motion. This circular
+or rotatory motion the Aether has already been proved to possess (<a href='#ART_91'>Art. 91</a>, where we learned that all solar magnets were caused by
+electro-magnetic aetherial currents constantly circulating round them).
+So that the Aether will actually possess two motions: 1st, a radial
+motion due to the Aether waves generated by the sun, which are radiated
+out into space with the velocity of light; and 2nd, a circular or
+rotatory motion. This result is in perfect harmony with our hypothesis
+as to the cause of the electro-magnetism of the sun (<a href='#ART_91'>Art. 91</a>, where we
+saw that solar magnetism was due to electric currents circulating round
+the various planets), and we have proved that the Aether has an
+electro-magnetic basis; thus the rotatory Aether currents and the
+rotatory electro-magnetic currents are due to one and the same medium.
+</p>
+
+<p>
+Now what will be the effect of these circular or rotatory Aether
+currents on the bodies situated within their field? It must be
+remembered that we are no longer dealing with a frictionless medium, but
+with a medium which possesses inertia and kinetic energy the same as any
+other moving matter. Therefore, as soon as it is set in motion, it will
+impress its motions upon all planets that come under its control and
+influence, with the result that as the impressed force is ever directed
+in a circular form, the planet will be pushed along through space by the
+moving Aether, and the path it describes will be circular also.
+</p>
+
+<p>
+Thus the actual result of the rotatory electro-magnetic Aether currents
+will be, that all dependent and associated planets under their<span class='pagenum'><a name='Page_247' id='Page_247'></a><a href='#TOC'>[247]</a></span>
+influence will be carried by them around the central body which
+generates the Aether currents. So that they will literally and truly
+have an orbit, and the circle they describe will be, in its size and
+circumference, regulated by the mean distance of each planet, which mean
+distance will form the radius of the circular orbit.
+</p>
+
+<p>
+Further, as we shall see later, if the sun were always stationary, and
+had no orbital motion of its own, then the orbit of each planet would
+always be circular, each planet always occupying its mean distance from
+the sun, because at that mean distance the centripetal and centrifugal
+forces are equal.
+</p>
+
+<p>
+That the actual path of any planet is a circle has been proved by Sir W.
+R. Hamilton. Tait, in his <i>Natural Philosophy</i>, on this point writes
+(Art. 38): &ldquo;The Hodograph for the motion of a planet or comet is always
+a circle, whatever be the form and dimensions of the orbit.&rdquo; This path
+has been termed the Hodograph. So that we have in the circling
+electro-magnetic Aether currents a physical explanation for the
+Hodograph of any planet.
+</p>
+
+<p>
+In applying the rotatory Aether currents to the various planets, and in
+endeavouring to find out the quantity of the force impressed upon the
+various planets at their mean distances, by those currents, we have to
+take into consideration, as we have already seen, two facts, viz. the
+mass of the Aether at any point in space, and the velocity of the Aether
+at the same point. We will first take the effect of the difference in
+mass. We have seen that at the distance of Mercury from the sun the
+density of the Aether is greater than at the distance of Venus, and that
+the density at Mars is greater than the aetherial density at the Earth,
+the aetherial density decreasing the further the Aether recedes from the
+sun.
+</p>
+
+<p>
+What, therefore, is the effect of the decreased density of the Aether on
+each planet? Even supposing the velocity of the moving Aether is the
+same at the respective mean planetary distances, which it is not, the
+total impressed force at the respective mean planetary distances will
+gradually be decreased upon the various planets, proportionate to the
+decrease in the mass and density of the Aether.
+</p>
+
+<p>
+So that on Mercury, which is pushed along by a denser electro-magnetic
+Aether than Venus, the impressed force, according to Newton's Second Law
+of Motion, will be greater than the impressed force exerted by the
+moving electro-magnetic Aether on Venus; and, consequently, Mercury
+should have a greater velocity through space than Venus, due partly to
+the difference of the aetherial mass and density, by which the impressed
+force or motive power that acts upon Mercury is produced.<span class='pagenum'><a name='Page_248' id='Page_248'></a><a href='#TOC'>[248]</a></span>
+</p>
+
+<p>
+In the same
+way, Venus should have a greater velocity through space than Mars, and
+Mars a greater velocity than the Earth. The same principle, when applied
+to the outer planets, equally holds good; with the result, that the
+greater the mean distance, the less the orbital velocity of each planet,
+due partly to the decreased aetherial density at the increased distance
+from the sun. But this is only part of the cause. Not only is there a
+decrease in density of the Aether, as the distance from the sun is
+increased, but there is also a decrease in the velocity of the moving
+Aether, with the result that the Aether at the distance of Mercury,
+possesses a greater angular velocity than at the distance of Venus.
+</p>
+
+<p>
+It may be at once asked, How do we know that? Well, Philosophy alone can
+give us the key, and Philosophy tells us to base our theories and
+hypotheses on experience and experiment. Now what does experiment and
+experience teach us as to the effect of a body revolving in any medium
+upon that medium? If experience teaches us anything at all, it teaches
+us that the further away any medium is from the revolving body, the less
+is the angular velocity of that medium at that distance, while the
+nearer the medium is to the revolving body, the greater is the angular
+velocity.
+</p>
+
+<p>
+This applies in each and every case, whether the medium is either fluid
+or gaseous, and I will challenge the reader to perform any experiment on
+any solid body rotating in a fluid or gaseous medium, and prove by that
+experiment that the angular velocity of the outermost part of the fluid
+or gaseous medium is equal to the angular velocity of the medium
+directly associated with the body, or even at a short distance from it.
+</p>
+
+<p>
+But we have most conclusive evidence of the fact that a solid body does
+not communicate all its rotational surface motion to the medium directly
+in contact with that body in the case of the earth revolving on its
+axis, surrounded by an atmosphere. If the principle held good anywhere
+in relation to a revolving body, viz. that the whole of the rotational
+velocity is communicated to the medium surrounding the body, it should
+certainly hold good at the surface of the body where the two media, the
+solid and gaseous media, meet.
+</p>
+
+<p>
+If a solid body fails to impart all its rotational velocity to the
+medium there, then it will certainly fail to impart its full rotational
+velocity to the enveloping medium 100 miles away, and fail still more at
+a distance of 1000, and still more at a distance of 100,000,000, and so
+on proportionate to the distance.
+</p>
+
+<p>
+What, then, is the effect of the rotational velocity of the surface of
+the earth on the atmosphere near to it? We know that the velocity of the
+surface of the earth is greatest at the equator, as at that place the<span class='pagenum'><a name='Page_249' id='Page_249'></a><a href='#TOC'>[249]</a></span>
+circumference of the earth is about 25,000 miles, but the further we get
+away from the equator, and the nearer we get to the North and South
+poles, the velocity of the surface decreases, simply because the
+circumference of the earth decreases.
+</p>
+
+<p>
+Or, to reverse the statement, the velocity of the surface of the earth
+is least at the poles, but increases the nearer we get to the equator.
+It is also familiar knowledge that there are currents of cold air ever
+moving from the North and South poles to the equatorial regions near the
+surface of the earth. Thus the cold air currents, in passing from the
+North and South poles, are ever passing over surfaces which are
+increasing in velocity as they journey on their way to the equator. This
+of course occurs all round the earth, so that the earth is continually
+revolving in these currents, and if the rotational velocity of the
+surface of the earth were wholly imparted to the air directly over its
+surface, then the currents would be always flowing due North and South.
+</p>
+
+<p>
+If, however, the earth fails to impart all its rotational velocity to
+the atmosphere, or the atmosphere fails to pick up the whole of the
+rotational velocity at once, then the result will be that the atmosphere
+as it passes over the surfaces of greatest velocity will lag behind,
+because its rotational velocity will be less than the velocity of the
+earth's surface.
+</p>
+
+<p>
+Now this is exactly what does happen in regard to the atmosphere, with
+the result, that instead of getting winds blowing due north and south,
+we get what are known as Trade Winds, which blow north-east in the
+northern hemisphere and south-east in the southern hemisphere. Here then
+we have direct experimental proof on a large scale of the very principle
+I have stated, viz, that a medium surrounding any rotating body does not
+move through the whole of its extent with the same velocity as its does
+at the surface. Thus it can be seen that the velocity of the rotating
+Aether will be greatest at the surface of the sun, but its angular
+velocity will decrease the further the medium recedes from the sun.
+</p>
+
+<p>
+The same principle can easily be proved from an electrical standpoint;
+for if we consider the Aether currents as electric currents, no one
+would think of suggesting that the intensity of the currents was the
+same at a distance of several million miles away, as it is near the
+source of the currents, which in this case may be looked upon as the
+sun, because at its surface we have the greatest electric potential
+(<a href='#ART_80'>Art. 80</a>).
+</p>
+
+<p>
+So that we see from this reasoning, that not only is there a decreased
+mass of the Aether at the distance of Venus, compared with Mercury, but
+there is also a decreased velocity in the rotatory electro-magnetic
+Aether currents, with the result that the impressed force exerted upon<span class='pagenum'><a name='Page_250' id='Page_250'></a><a href='#TOC'>[250]</a></span>
+Venus is less than the impressed force exerted upon Mercury, and
+therefore Venus should move slower through space than Mercury, which is
+exactly what happens, as Mercury has an orbital velocity of 29 miles per
+second, while Venus has an orbital velocity of 22 miles per second.
+</p>
+
+<p>
+As the angular velocity decreases in proportion as the distance
+increases, it follows that at the respective mean distances not only of
+Venus, but also of Mars, Jupiter, Saturn, Uranus and Neptune, the
+capacity of the Aether to exert its impressed force upon the various
+planets will decrease as the distance increases, with the result that
+the farther a planet is from the sun, the less force will the Aether
+currents exert upon that planet, with the result that its orbital
+velocity should decrease as the distance increases, and this is
+perfectly in accordance with planetary phenomena.
+</p>
+
+<p>
+Here, then, we have at once a physical basis for Newton's Second Law of
+Motion, the results of which are entirely in harmony with observation
+and experiment, and whose conception fully satisfies all the Rules of
+Philosophy; as it is simple in conception, fully agrees with observation
+and experiment, and satisfactorily explains the Second Law of Motion
+sought to be explained.
+</p>
+
+<p>
+Thus we find that from the physical standpoint, as well as from the
+mathematical standpoint, &ldquo;Change of motion is proportional to the
+impressed force, and takes place in the direction in which the force is
+impressed,&rdquo; that is, in a circular direction.
+</p>
+
+<p>
+We have therefore arrived at exactly the same result that Newton arrived
+at, except that he had to introduce a third factor, viz. the
+Parallelogram of Forces, while we have produced the result by a simpler
+method, which, according to his own rules, is more philosophical, as all
+effects are produced by the simplest causes, as Newton himself stated in
+Rule 1. Thus it is the rotatory electro-magnetic Aether currents that
+urge the planets round the sun; and, as will be shown later, it is the
+same Aether currents in combination with the other motions that give
+rise to the physical cause of Kepler's Laws. It is the electro-magnetic
+Aether currents that produce the regular decrease in the velocity of the
+planets in their orbits, because of the regular decrease of the mass and
+velocity of the Aether currents themselves.
+</p>
+
+<p>
+We have now a physical cause as well as a mathematical explanation of
+the decrease of the velocity of a planet in its orbit, which physical
+cause is in perfect harmony with all philosophical rules. The following
+table shows the gradual decrease in the velocity of each planet as the<span class='pagenum'><a name='Page_251' id='Page_251'></a><a href='#TOC'>[251]</a></span>
+various planets recede from the sun--
+</p>
+
+<table summary='velocities'>
+
+<tr><th style='width: 10%;'></th><th style='width: 10%; text-align: center;'><span class='smcap'>mean<br />distance.</span></th><th style='width: 10%; text-align: center;'><span class='smcap'>period of<br />revolution.</span></th><th style='width: 10%; text-align: center;'><span class='smcap'>velocity in<br />orbit per hour.</span></th></tr>
+
+<tr><td style='text-align: left;'>Mercury</td><td style='text-align: right;'>35,900,000</td><td style='text-align: center;'>87.9 days</td><td style='text-align: right;'></td></tr>
+
+<tr><td style='text-align: left;'>Venus</td><td style='text-align: right;'>67,000,000</td><td style='text-align: center;'>224.7</td><td style='text-align: right;'>77.000</td></tr>
+
+<tr><td style='text-align: left;'>Earth</td><td style='text-align: right;'>92,700,000</td><td style='text-align: center;'>365.2</td><td style='text-align: right;'>66.500</td></tr>
+
+<tr><td style='text-align: left;'>Mars</td><td style='text-align: right;'>141,000,000</td><td style='text-align: center;'>686.9</td><td style='text-align: right;'>53.000</td></tr>
+
+<tr><td style='text-align: left;'>Jupiter</td><td style='text-align: right;'>482,000,000</td><td style='text-align: center;'>4,332.6</td><td style='text-align: right;'>28.744</td></tr>
+
+<tr><td style='text-align: left;'>Saturn</td><td style='text-align: right;'>884,000,000</td><td style='text-align: center;'>10,759.</td><td style='text-align: right;'>21.221</td></tr>
+
+<tr><td style='text-align: left;'>Uranus</td><td style='text-align: right;'>1,780,000,000</td><td style='text-align: center;'>30,687.</td><td style='text-align: right;'>14.963</td></tr>
+
+<tr><td style='text-align: left;'>Neptune</td><td style='text-align: right;'>2,780,000,000</td><td style='text-align: center;'>60,127.</td><td style='text-align: right;'>11.958</td></tr>
+
+</table>
+
+
+<p>
+<a name='ART_100' id='ART_100'></a><span class='smcap'>Art</span>. 100. <i>Aether and Third Law of Motion</i>.--We have seen (<a href='#ART_16'>Art. 16</a>) that
+action and reaction are equal and opposite, and that it is true of the
+centripetal force in its application to all matter throughout the
+universe. If, therefore, the centrifugal force is the exact opposite of
+the centripetal force, then the Third Law of Motion should equally hold
+good in relation to that force also.
+</p>
+
+<p>
+We have, therefore, to form a physical conception of the application of
+the third law of motion, as it relates to the centrifugal force. As we
+have already learned, this force is due to the universal
+electro-magnetic Aether, which being gravitative, surrounds all atoms
+and molecules that may exist throughout the whole universe. It can
+readily be seen, therefore, that if the Aether surrounds every atom and
+molecule, then each atom repels another atom or molecule when the two
+forces are in equilibrium with exactly the same intensity with which the
+atom and molecule attract each other.
+</p>
+
+<p>
+But the centrifugal force in each case is due to the pressure of the
+Aether, which presses always proportionately to the density of the
+Aether surrounding the atom or molecules, as suggested by Professor
+Challis.
+</p>
+
+<p>
+The mean density, however, of each atomic or molecular atmosphere is
+regulated solely by the mass of the atom or planet, therefore the
+pressure exerted by one atom on another is proportionate to the mass of
+each atom, and to that extent is strictly in accordance with the law
+which governs the proportion of the forces between the two atoms or
+molecules. If, therefore, we have two atoms, A and B, of different
+masses, then it is true that while A exerts a pressure on B, which
+pressure takes the form of a repulsion, at the same time B exerts a
+pressure on A which is equal and opposite in its character and
+intensity, and in each case the pressure is due to the aetherial medium
+which surrounds each atom or molecule.
+</p>
+
+<p>
+When the atoms are equal in mass, then the resultant motion produced on<span class='pagenum'><a name='Page_252' id='Page_252'></a><a href='#TOC'>[252]</a></span>
+each atom would be exactly equal, but when the masses vary, the
+resultant motion produced on each atom would vary also, though the
+momentum in each case would be exactly equal and opposite, as momentum
+is a compound term dependent partly upon the mass of the body concerned.
+</p>
+
+<p>
+In <a href='#ART_16'>Art. 16</a> we saw that when this third law was applied to planetary
+phenomena, not only did the sun attract all the planets, but all the
+planets attracted the sun with equal and opposite forces, and the
+planets also attracted each other with equal and opposite forces. In the
+same way it can be proved, that as the sun repels all the planets by the
+pressure exerted by the aetherial centrifugal force on those planets,
+the planets repel the sun with an exactly equal and opposite force at
+their mean distances. In Newton's conception, however, of the third law
+of motion, there was simply mathematical data to deal with, by which the
+law was shown to apply to the planetary and stellar world. In the case,
+however, of the centrifugal motion, we have a definite physical medium,
+which by its motions produces the pressure on the planets or suns that
+exist in space, which pressure forms the physical centrifugal force that
+forms the counterpart of Gravitation Attraction.
+</p>
+
+<p>
+Let us look at this phase of the case in detail, and by so doing help to
+establish and confirm the physical existence of the force or motion
+referred to. We have learned from Chapter <a href='#CHAPTER_IV'>IV</a>. that as Aether is
+gravitative, it surrounds all satellites and planets, suns and stars
+that exist in the universe.
+</p>
+
+<p>
+We have also learned from <a href='#ART_86'>Art. 86</a> that Aether has an electro-magnetic
+basis, as mathematically proved by Maxwell and experimentally proved by
+Hertz. Thus we came to the conclusion that each satellite and planet,
+sun and star, was an electrified body (<a href='#ART_81'>Art. 81</a>), or an electro-magnet
+(<a href='#ART_88'>Art. 88</a>), possessing its own electric or electro-magnetic field.
+</p>
+
+<p>
+We also learned that in every electro-magnetic field there was a
+pressure which was ever directed away from the body that generated the
+electro-magnetic waves. Now, as every satellite and planet, sun and
+star, is a generator of these waves according to our theory, it follows
+that every satellite and planet, sun and star, is the centre of a
+centrifugal force, which centrifugal force is regulated by the mass of
+the satellite, planet, sun or star which gives rise to the centrifugal
+force or motion.
+</p>
+
+<p>
+Now, in relation to all electro-magnetic action, it can be
+experimentally demonstrated, that action and reaction are equal and
+opposite, so that if we have two electrified or magnetized bodies, then
+the joint forces of attraction or repulsion between them are equal and
+opposite. This being so, when we apply the same law of action and<span class='pagenum'><a name='Page_253' id='Page_253'></a><a href='#TOC'>[253]</a></span>
+reaction to the planets' influence on each other, it follows that the
+same law must hold good in relation to them.
+</p>
+
+<p>
+So that if we compare the repulsive powers of two planets on each other
+in the solar system, say the Earth and Jupiter, then, according to the
+third law of motion, the repulsive action of Jupiter on the Earth is
+exactly equal and opposite to the repulsive action of the Earth on
+Jupiter. If we compare the Earth and the sun, the repulsive action of
+the sun on the Earth is exactly equal and opposite to the repulsive
+action of the Earth on the sun, that action or force being caused
+directly by the electro-magnetic Aether waves, which are generated by
+each electric, or electro-magnetic body.
+</p>
+
+<p>
+Thus, as the third law of motion is true of the centripetal force,
+whether in relation to the atomic world, or in relation to the solar
+system, or even to the universe at large, seeing that the centrifugal
+force is the exact counterpart in every way of the centripetal force,
+exactly fulfilling all the laws which govern it, it follows as a matter
+of absolute necessity that the third law is also applicable to its
+complement or counterpart also, or else it would cease to be the
+complement and counterpart of the centripetal force.
+</p>
+
+<p>
+<a name='ART_101' id='ART_101'></a><span class='smcap'>Art</span>. 101. <i>Why Planets revolve from West to East</i>.--In <a href='#ART_99'>Art. 99</a> we have
+seen that the revolution of the planets around the sun is produced and
+maintained by the electro-magnetic Aether currents, which are generated
+by the axial motion of that electro-magnetic body. There is, however,
+another effect produced, and another scientific fact which can be
+accounted for by the circulating motions of the Aether medium, viz. that
+the orbital direction of each and all the planets would not only be in
+the same direction, but they would also be in the same direction as the
+sun's rotation on its axis.
+</p>
+
+<p>
+So that, whichever way the sun turns upon its axis, that way, and that
+alone, should be the orbital direction of all the planets in which they
+are circled round the sun by the circulating electro-magnetic Aether
+currents. It is the sun's axial motion that partly gives to the Aether
+currents their circling motion, and it is the circling motion of the
+Aether currents that gives rise to the orbital motion of the planets,
+literally carrying them round the sun by their kinetic energy and power.
+</p>
+
+<p>
+Therefore, if this be true, whichever way the sun turns upon its axis,
+that will be the direction in which the Aether currents must circle
+round the sun, and in that direction the planets should travel in their
+orbits. As must readily be seen, it is the inevitable result of the
+established working of the electro-magnetic Aether currents. If the sun
+rotated on its axis from east to west, then the electro-magnetic Aether<span class='pagenum'><a name='Page_254' id='Page_254'></a><a href='#TOC'>[254]</a></span>
+currents would also travel in the same direction, from east to west, and
+the planets would then revolve round the sun from east to west.
+</p>
+
+<p>
+If the sun, however, rotates on its axis from west to east, then, if
+there are such electro-magnetic Aether currents in existence, as those
+we have already proved to exist, they, too, would travel from west to
+east, and as a natural result the planets, which are carried round the
+sun by the currents, would also possess the same orbital motion, that is
+from west to east.
+</p>
+
+<p>
+As is well known, the sun rotates on its axis from west to east,
+therefore the Aether currents also rotate from west to east, with the
+result that the orbital directions of all the planets should also be in
+the same direction, from west to east. Now, as is well known, all the
+planets without exception, Mercury, Venus, the Earth, Mars, Jupiter,
+Saturn, Uranus, and Neptune, all travel round the sun from west to east.
+</p>
+
+<p>
+Here, then, we have indisputable evidence of the existence and mode of
+working of the electro-magnetic aetherial currents, whose action alone
+can produce the phenomena with which we are so familiar, and for which
+there must be some physical cause. I am not aware that any reason or
+explanation either mathematical or otherwise has ever been given, or
+even suggested, as to the cause of the phenomena which we have just
+endeavoured to explain.
+</p>
+
+<p>
+Indeed, there can be no other physical explanation of the fact, that all
+the planets revolve round the sun in the same direction that the sun
+rotates on its axis, than the one here given, viz. that the cause is to
+be found, and alone found, in the circulating electro-magnetic Aether
+currents which are generated in the Aether by the electro-magnetic body,
+the sun. Again, in order to confirm the existence of these Aether
+currents that exist in space, not only those generated by the sun, but
+also by all the other electro-magnetic bodies, as all the planets (<a href='#ART_88'>Art. 88</a>), we will consider the working of the same upon the satellites of
+those planets which possess them.
+</p>
+
+<p>
+The Earth we know has one satellite, the moon, Mars has two satellites,
+Phobos and Deimos, Jupiter has five satellites, Saturn has eight
+satellites, while up to the present Uranus has been found to possess
+four, and Neptune one. There is, however, little doubt but that both
+Uranus and Neptune possess more than those already discovered, as it is
+inconceivable that Jupiter and Saturn, which are nearer to the sun,
+should possess a greater number of satellites by which the nights of the
+respective planets are illuminated, while the further planets, which
+need the increased lighting, because of the decreased intensity of the<span class='pagenum'><a name='Page_255' id='Page_255'></a><a href='#TOC'>[255]</a></span>
+aetherial light waves at the increased distance, possess apparently a
+less number of satellites, and therefore less illumination for their
+respective nights.
+</p>
+
+<p>
+But what have these satellites to teach us as to the existence of the
+electro-magnetic aetherial currents that circulate round the planets? We
+have to apply a similar course of reasoning to the planets, as we have
+done in the case of the sun. If the sun is an electro-magnetic body, by
+its axial rotation it generates rotating Aether currents, and those
+Aether currents partake of the same rotation as the revolving body, that
+is, from west to east. In a like manner each planet, being an
+electro-magnet, generates electro-magnetic aetherial currents which also
+possess the same rotation as the planetary body which gives rise to
+them.
+</p>
+
+<p>
+So that if the planets rotate on their axes from east to west, the
+Aether currents will also rotate from east to west, but if the rotation
+of each planet is from west to east, then the rotation of the Aether
+currents associated with each planet will also be from west to east,
+with the result that each satellite will be carried round its primary
+planet by the circulating Aether currents in exactly the same way as the
+planet rotates on its axis.
+</p>
+
+<p>
+Now if this is the case, then we have further evidence of the existence
+of the circulating electro-magnetic Aether currents, not only those
+associated with the sun, but those also associated with each of the
+planets, as explained in <a href='#ART_91'>Art. 91</a>. It might have been urged in the case
+of the planet's revolution round the sun being in the same direction as
+the sun's axial action, that such a fact was merely a coincidence, but
+such an objection loses its force if it is proved that the same
+principle or truth when applied to other bodies equally holds good. When
+we come to analyze the direction of the satellites round their primary
+planets, we find that each satellite has an orbital motion, or is
+carried round its central and controlling planet by that planet's Aether
+currents in exactly the same direction that the planet rotates on its
+axis, viz. from west to east. So that we have in the orbital direction
+of the satellites, as we have also in the orbital direction of the
+planets, conclusive evidence of the existence and mode of working of the
+Aether and of the electro-magnetic currents generated in that aetherial
+medium by the electro-magnetic bodies which rotate in it.
+</p>
+
+<p><span class='pagenum'><a name='Page_256' id='Page_256'></a><a href='#TOC'>[256]</a></span></p>
+<h2><a name='CHAPTER_XI' id='CHAPTER_XI'></a><a href='#CHAPTER_XI_TOC'>CHAPTER XI</a></h2>
+
+<h3>AETHER AND KEPLER'S LAWS</h3>
+
+<p>
+<a name='ART_102' id='ART_102'></a><span class='smcap'>Art</span>. 102. <i>Aether and Kepler's First Law</i>.--In <a href='#ART_26'>Art. 26</a> we learned that
+according to the First Law of Kepler, each planet revolves round the sun
+in an elliptic orbit, with the sun occupying one of the foci.
+</p>
+
+<p>
+We also saw that that elliptic orbit was produced according to Newton by
+the conjoint working of the centripetal and centrifugal forces in
+association with the three Laws of Motion, to which laws had to be added
+a corollary, which is termed the Parallelogram of Forces, before the
+First Law of Kepler could be fulfilled.
+</p>
+
+<p>
+In making any hypothesis as to the physical cause of Kepler's Laws, if
+it can be shown that the same aetherial medium that gives rise to the
+centrifugal force, also gives rise to the centripetal force, and that
+the same medium by its rotatory motions also fulfils the three laws of
+motion, and gives a satisfactory physical explanation of all Kepler's
+Laws; then, according to our three Rules of Philosophy, we shall have
+found a physical medium which, by its motions and pressures and
+tensions, can give rise to all the phenomena exhibited in the celestial
+mechanism. Such a physical explanation will be philosophically correct,
+in that it is simple in its conception, is entirely in harmony with
+observation and experiment, and satisfactorily accounts for, and that on
+a physical basis, all the phenomena associated with the whole of the
+celestial mechanism.
+</p>
+
+<p>
+We have therefore to apply the motions of the Aether medium to the solar
+system, and by so doing reveal the physical explanation of all Kepler's
+Laws, in the same way that Newton revealed their correctness from the
+mathematical standpoint. Let us review the conception of the solar
+system as given in <a href='#ART_99'>Art. 99</a>, so that we may be able to proceed from that
+physical conception of a stationary solar system to a moving system.
+</p>
+
+<p>
+Thus we see the sun in a stationary system occupying exactly the centre
+of that system. The solar energies are in full play, generating
+electro-magnetic Aether waves which are radiated forth into space with<span class='pagenum'><a name='Page_257' id='Page_257'></a><a href='#TOC'>[257]</a></span>
+the velocity of light. Then, as there is given to the sun a rotatory
+motion on its axis, that rotatory motion imparts to the gravitating
+aetherial medium a circulatory or rotatory motion which spreads out
+through space with ever-increasing intensity.
+</p>
+
+<p>
+By their radiating motion the Aether waves would repel all planets from
+their central body, the sun, if they were not counterbalanced by the
+centripetal force; and the two forces, the centrifugal and the
+centripetal forces, find their equilibrium at the mean distance of each
+planet, thus fixing and regulating permanently the distance and orbit of
+each planetary world.
+</p>
+
+<p>
+At the same time, the rotatory motion of the electro-magnetic Aether
+currents, according to the second law of motion, would act on the
+planets by their kinetic or moving energy, and so circle them round the
+sun, their controlling centre. As long as the sun was quite stationary,
+while still possessing a rotation on its axis, if such a thing were
+possible, so long would the conception of the ancients be fulfilled, and
+the rotation of all the planets would be strictly circular in form, and
+their orbits would be that of a circle only, as proved by Sir W. R.
+Hamilton (<a href='#ART_99'>Art. 99</a>).
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/271.jpg' width='400' height='320'
+alt='Fig: 24.'
+title='Fig: 24.' />
+</div>
+
+<p>
+But, as is well known, the sun itself possesses an orbital motion of its
+own, so that, while all the associated planetary system is revolving
+round it, the sun with all that system is being carried along through
+space in an orbit which is also elliptic in form, as we shall see later
+on.
+</p>
+
+<p>
+According to Herschel, the sun is moving towards the constellation of
+Hercules with a velocity of about 18,000 miles per hour, and the problem
+to be faced is, what is the effect of the sun's orbital velocity upon
+the circular motion of the planets? By solving that problem, we shall
+arrive at a physical conception for the first time of Kepler's Laws, and
+shall see that the first of Kepler's Laws is solved simply by giving an
+orbital velocity to any central body, the result of which will be that<span class='pagenum'><a name='Page_258' id='Page_258'></a><a href='#TOC'>[258]</a></span>
+the circular form of any planet's orbit will be changed from the
+circular into one of elliptic form.
+</p>
+
+<p>
+Let me ask the reader to perform a very simple experiment to confirm
+this fact. Take a piece of string and a lead pencil, and start to draw a
+circle on a piece of paper (Fig. 24). When, however, one quarter of the
+circle has been drawn, viz. <i>D F</i>, move the end of the piece of string
+representing the centre of the circle along the paper, as represented in
+the diagram, from <i>A</i> to <i>B</i>. The result will be that the pencil will
+now travel parallel with the moving centre for a time from <i>F</i> to <i>G</i>,
+and then, when the centre is brought to rest again, the other part of
+the half ellipse <i>G H</i> may be completed. In the same way, by reversing
+the motion, the other half of the ellipse may be completed. So that it
+is possible for an ellipse to be formed simply by moving the central
+point of a circle, and the motion of that central point will change the
+form of a circle into an ellipse. It is something like this that takes
+place in the planetary world, with this difference, that the central
+point which represents the sun does not return from one focus to
+another, but continues to journey on through space, with the result that
+the orbit of any planet is not strictly an ellipse, as we shall see
+later on. We have, then, the sun occupying the centre of the solar
+system, with all the planets revolving round it. We will take the sun
+and the Earth as examples. Let <i>S</i> in the diagram represent the sun, and
+<i>E</i> the Earth at its mean distance of 92,000,000 miles away (Fig. 25).
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/272.jpg' width='400' height='208'
+alt='Fig: 25.'
+title='Fig: 25.' />
+</div>
+
+<p>
+The Earth we know is moving with a velocity of about 64,800 miles per
+hour around the sun, or an average velocity of 18 miles per second, so
+that while the Earth is moving 64,800 miles through space to perform the
+half-circle, <i>E D C</i>, the sun is also travelling 18,000 miles towards
+the point <i>D</i>.
+</p>
+
+<p>
+What, therefore, is the effect of this onward movement of the sun
+towards the Earth as it tries to complete the half-circle <i>E D C</i>? We
+have seen that the centrifugal force due to the pressure of the
+electro-magnetic Aether waves is exactly equal to the centripetal force<span class='pagenum'><a name='Page_259' id='Page_259'></a><a href='#TOC'>[259]</a></span>
+exerted by the sun on any planet, and if that be so, it can be readily
+seen that as the sun journeys towards the point <i>D</i> of the Earth's
+orbit, it tends to approach nearer and nearer the Earth. Thus the
+intensity of the aetherial pressure owing to the decreased distance will
+be greatly increased, and the effect of the increased pressure of the
+Aether upon the planet will be to push it away from the sun, so that the
+two forces may be equalized, and its mean distance, which is definitely
+fixed, be maintained as far as possible.
+</p>
+
+<p>
+The result will be that, instead of the Earth describing the half-circle
+<i>E D C</i>, it actually describes the part of the ellipse <i>E F C</i>. Thus it
+can be seen that while the sun is travelling through space, it is at the
+same time giving rise to the electro-magnetic Aether waves, which, by
+their repelling power, repel the Earth from the sun in the direction
+that the sun is travelling, and hence the half-circle is elongated into
+that part of the elliptic orbit known as the perihelion, which is that
+part of the orbit where the distance of any planet from the sun is the
+least.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/273.jpg' width='400' height='283'
+alt='Fig: 26.'
+title='Fig: 26.' />
+</div>
+
+<p>
+The repelling power of the Aether waves is not, however, sufficient to
+overcome altogether the centripetal force in conjunction with the
+Earth's motion, with the result that when the Earth arrives at <i>F</i>, its
+distance is only 91 million miles, that being the least distance between
+the sun and the Earth. We shall see the result of this decreased
+distance when we deal with Kepler's Second Law.
+</p>
+
+<p>
+We will now proceed to notice the effect of the sun's orbital velocity
+upon that part of the Earth's orbit which includes the aphelion, or that
+part in which the Earth occupies a position of the greatest distance
+from the sun. Proceeding on the same method of reasoning, if the sun
+were stationary, with the Earth being circled round it by the
+electro-magnetic Aether currents, then the path described by the Earth
+would be that of a circle, being represented by the half-circle <i>C G E</i>
+(Fig. 26).
+</p>
+
+<p>
+But it has to be remembered that while the Earth is being circled round
+the sun by the rotatory electro-magnetic Aether currents, the sun is<span class='pagenum'><a name='Page_260' id='Page_260'></a><a href='#TOC'>[260]</a></span>
+still travelling on towards <i>S F</i> at the rate of 18,000 miles per hour,
+while the Earth is travelling in almost an opposite direction towards <i>C
+G</i>, so that by the time the Earth has got to <i>G</i>, which we will suppose
+is one quarter of its ellipse, the sun has travelled millions of miles
+in that time.
+</p>
+
+<p>
+Thus it can readily be seen, that by the time the Earth has got to its
+aphelion, it is at its furthest distance from the sun, simply because
+the sun has been travelling onwards through space all the time, while
+the Earth has been receding from it; and as the motion of the Earth has
+been in an opposite direction, the mean distance has been exceeded, and
+instead of the Earth being now at its mean distance from the sun, its
+distance is now 94,500,000 miles. At that part of its orbit, its orbital
+velocity is at a minimum, because the rotating Aether currents have
+there a decreased flow and a decreased mass and density, and therefore
+possess a decreased kinetic energy or motive power.
+</p>
+
+<p>
+Thus by the rotating Aether currents working in conjunction with the
+centrifugal and centripetal forces, can be accounted on a physical basis
+the first of Kepler's Laws in a manner which is strictly philosophical,
+as the explanation is simple in conception, does not violate experience
+or experiment, and satisfactorily accounts for, on a physical basis, the
+law which it is required to explain.
+</p>
+
+<p>
+If we consider the rotating Aether currents as purely currents of
+electricity, then exactly the same results follow. For, as we shall see
+later, Professor Lodge in his <i>Modern Views of Electricity</i> proves that
+electricity possesses both inertia and momentum, and if electricity
+possesses these properties, then it also possesses the requisite
+properties to enable the currents to propel or push any planet around
+its central body, or a satellite round its primary planet. Therefore the
+same course of reasoning that applies to the rotating Aether currents,
+equally applies to the currents of electricity that circulate round each
+satellite, planet, and sun and star, and by that circulation gives rise
+to the electro-magnetism associated with each body, while at the same
+time they supply the kinetic energy which enables any dependent or
+associated body to be propelled round their controlling centre.
+</p>
+
+<p>
+<a name='ART_103' id='ART_103'></a><span class='smcap'>Art</span>. 103. <i>Second Law of Kepler</i>.--According to Kepler's Second Law
+(<a href='#ART_27'>Art. 27</a>), we learn that the radius vector, which is the imaginary
+straight line joining any planet to the sun, describes, or sweeps over,
+equal areas in equal times. So that, while Kelper's First Law describes
+the path which a planet takes in revolving round the sun, the Second Law
+shows how the velocity of that planet varies in different parts of its
+orbit.
+</p>
+
+<p>
+While, however, there is a difference in the velocity of any planet at
+various points in the orbit, there is still a proportion existing<span class='pagenum'><a name='Page_261' id='Page_261'></a><a href='#TOC'>[261]</a></span>
+between its various velocities, in that equal areas are covered in equal
+times. We have now to apply the hypothesis of our rotatory Aether
+currents, in conjunction with the centripetal and centrifugal forces, in
+order to see whether the Second Law of Kepler can be explained on a
+physical basis, in the same way that Newton explained it from the
+mathematical standpoint.
+</p>
+
+<p>
+We have again to conceive the sun as the centre of two equal but exactly
+opposite forces, and also possessing a rotatory motion on its axis, with
+the electro-magnetic Aether currents ever circulating round it. If the
+sun were stationary, it will be manifest at once that Kepler's Second
+Law would be literally and strictly fulfilled, for in that case the
+orbit of all the planets would be perfect circles, and the motion of
+planets in their orbits would be perfectly uniform, and therefore equal
+areas would be covered by the radius vector in equal times. Thus any
+quarter of the orbit would be described in exactly a 1/4 of a year, 1/12
+in 1/12 of a year, 1/40 in 1/40 of a year, and so on, the time being
+exactly proportional to the proportion of the area covered by the radius
+vector.
+</p>
+
+<p>
+The area covered would always be uniform, because the radius vector
+would always be uniform in length. But, as we have seen in the previous
+article, the distance of a planet from the sun, that is, the length of
+the radius vector, is not uniform, as the Earth is nearer to the sun at
+perihelion, and further away at aphelion, its distance gradually
+changing as it passes from each of these points to the other.
+</p>
+
+<p>
+Now what is the effect of the decreased distance upon the circulating or
+rotatory Aether currents? We have already seen (<a href='#ART_99'>Art. 99</a>) that the closer
+these Aether currents are to the central body, the sun, the greater is
+their velocity and the greater their mass, so that the total impressed
+force which they exert over any planet is greater the nearer that planet
+is to the sun. This is proved by the fact that Mercury has a greater
+orbital velocity than Venus, Venus than the Earth, the Earth than Mars,
+and so on right through the whole of the planetary system. In view of
+these facts, let us again consider the effect of the sun not being
+stationary, but having an orbital velocity of its own through space.
+Thus let the sun be at <i>S</i> and the Earth be at point <i>D</i> of its orbit
+(Fig. 25).
+</p>
+
+<p>
+The circulating Aether currents are ever acting upon the Earth, carrying
+it round the sun with them, while at the same time the centripetal force
+is pulling it towards the sun with a certain intensity, but the
+centrifugal force is repelling the Earth with exactly the same
+intensity, and if the sun remained motionless the two forces would
+exactly balance each other, while the Earth would describe the
+half-circle <i>E D C</i>. But while the Earth is moving towards the point <i>D</i>
+with a velocity of 64,000 miles per hour, the sun is also moving at the<span class='pagenum'><a name='Page_262' id='Page_262'></a><a href='#TOC'>[262]</a></span>
+velocity of about 18,000 miles per hour towards that point.
+</p>
+
+<p>
+Thus the repelling power of the radiating electro-magnetic Aether waves
+has to overcome, not only its exact counterpart, the centripetal force,
+but also the onward motion of the sun as it rushes on its course through
+space. This the centrifugal force is unable to do, with the result that
+the distance is gradually lessened, and instead of the Earth describing
+the arc <i>E D</i>, it describes the arc <i>E F</i>, at which point its distance
+is at the minimum, or about 91 millions of miles.
+</p>
+
+<p>
+Or, to put the same fact in another way. When the Earth is at <i>E</i>, the
+centripetal force and the orbital velocity of the Earth and the sun are
+acting conjointly, with the result that they overcome the centrifugal
+force, and the distance is gradually decreased. This decreased distance
+means an increased aetherial density and an increased velocity of the
+aetherial currents, with the result, that as the distance is decreased,
+the orbital velocity of the Earth is gradually increased, so that by the
+time the Earth gets to <i>F</i>, at its perihelion, it has now acquired its
+greatest orbital velocity, and is carried round the sun by the
+electro-magnetic Aether currents at its maximum velocity.
+</p>
+
+<p>
+Now let us look at the Earth being circled round the sun by the
+electro-magnetic Aether currents as it goes on to perform the other half
+of the orbit. In this case we have the orbital motion of the sun and the
+centrifugal force working conjointly, with the result that together they
+overcome the centripetal force, and the Earth is repelled and carried
+beyond its mean distance. Let <i>S</i> represent the sun, the Earth being at
+point <i>C</i> of its orbit, after passing round its perihelion, and at this
+decreased distance it is carried along by the circulating and denser
+Aether with its maximum velocity (Fig. 26).
+</p>
+
+<p>
+Now while the Earth is going on to describe the half-circle <i>C G E</i>, the
+sun is still pursuing its journey at the rate of about 18,000 miles per
+hour, only this time in a direction away from the Earth. As, however,
+the Earth has not yet regained its mean distance of 92,000,000 miles,
+the centrifugal force is still greater than the centripetal force, so
+that the centrifugal force is urging the planet away from the sun with
+greater intensity than the centripetal force is attracting it, as the
+two forces are only in equilibrium at the mean distance of the Earth.
+</p>
+
+<p>
+Thus, as stated, the orbital motion of the sun and the centrifugal
+forces are now working conjointly together, with the result that the
+Earth is repelled gradually further and further from its central body,
+until it reaches its maximum distance of 94,500,000 miles. While,
+however, the distance is gradually being increased, it is passing into a
+part of the Aether possessing not only a decreased mass, but also a<span class='pagenum'><a name='Page_263' id='Page_263'></a><a href='#TOC'>[263]</a></span>
+decreased velocity, with the result that the motive power or kinetic
+energy of the aetherial currents at the increased distance is gradually
+lessened, and as a natural result the velocity of the Earth is also
+decreased; so that by the time the Earth has got to its furthest
+distance from the sun, its orbital velocity is slowest, because of the
+decreased momentum of the aetherial currents.
+</p>
+
+<p>
+Thus we can account for the difference of velocity of a planet in its
+orbit by the same electro-magnetic Aether currents working in
+conjunction with the sun's orbital motion, and that upon a strictly
+physical basis. This result is in perfect harmony with Kepler's Second
+Law, which states that equal areas are described by the radius vector in
+equal times. Newton proved that by the Law of Gravitation Attraction he
+could account for this second law, as well as all the others, and as we
+have not destroyed that law, but perfected it by giving it its exact
+complement and counterpart, the same mathematical reasoning that applies
+to the centripetal force must equally apply to the centrifugal force,
+and if it is true that the centripetal force works harmoniously with the
+second of Kepler's Laws, then it is equally true that the centrifugal
+force does also, as the two are inseparably and indisputably united
+together in the atomic Aether. We have, however, a physical basis for
+this centrifugal force, and we have an equal physical basis for the
+centripetal force, as we shall see later, and therefore, by the conjoint
+working of these two forces taken in conjunction with the orbital motion
+of the sun, we have now a physical conception for the first time of
+Kepler's Laws, as well as a mathematical conception, that physical
+conception being derived from the pressure and motions of the universal
+Aether.
+</p>
+
+<p>
+<a name='ART_104' id='ART_104'></a><span class='smcap'>Art</span>. 104. <i>Aether and Kepler's Third Law</i>.--In <a href='#ART_28'>Art. 28</a> we saw that
+according to the Third Law of Kepler, the square of the periodic time
+was proportionate to the cube of the mean distance of that planet from
+its controlling centre. Newton proved that this Third Law was
+mathematically correct, and that it could be mathematically accounted
+for by the existence and operation of the universal Law of Gravitation.
+As the centrifugal force is the exact opposite of that force in
+intensity, proportion and mode of operation, it follows that
+mathematically the centrifugal force also bears the same relation to the
+Third Law that the centripetal force does.
+</p>
+
+<p>
+We have, however, a physical basis for the centrifugal force, and it is
+with the physical conception of this Third Law rather than with its
+mathematical character that we are now dealing. Kepler by his Third Law
+showed that the chief regulating factor in the orbital velocity of a
+planet was its mean distance from the sun.
+</p>
+
+<p>
+The great regulator of the velocity of any planet in its orbit is<span class='pagenum'><a name='Page_264' id='Page_264'></a><a href='#TOC'>[264]</a></span>
+simply planetary distance, and planetary distance alone. If there were
+no other law which operated in the solar system than the centripetal
+force, or the attractive force due to gravity, then such factors as mass
+and density of a planet ought to play a most important part in the
+orbital velocity of a planet, as the centripetal force directly
+recognizes the influence of mass, that is, volume and density, but says
+nothing about mean distances. This fact unmistakably points to the
+existence, and demands the operation, of another force, which shall
+explain, and that on a physical as well as a mathematical basis, how it
+is that the mean distance of a planet from any centre regulates the
+orbital velocity of that planet.
+</p>
+
+<p>
+The only real and true conception of such a force is to be found in the
+radiating waves and circulating motions of the aetherial medium, which
+waves, like water waves, increase in their radial outflow and extent
+with a regular decreasing intensity, and at the same time decrease in
+their angular velocity as they recede from the sun. With such a regular
+decrease of kinetic energy, there must necessarily be imparted to the
+planets, as their mean distance is increased, a decreased velocity of
+motion, with the natural result, that the further a planet is from the
+sun, the less will be its orbital velocity, and that in a regular and
+uniform proportion as the distance is increased.
+</p>
+
+<p>
+Now let us view the matter for a moment in its application to the solar
+system, and by so doing show the simplicity of the explanation, and at
+the same time give added proof to the existence and operation of the
+circulating aetherial currents that exist in space. Let us again picture
+the solar fires burning in all their fierceness and intensity, every
+atom and particle of the sun being thrown thereby into the most intense
+state of activity, and by their energy of motion creating
+electro-magnetic Aether waves in their myriads, which speed away from
+the sun on every side.
+</p>
+
+<p>
+Under their influence, all subordinate worlds would be carried away into
+space, were it not for the complementary Law of Gravitation Attraction,
+that is, the centripetal force. But to every planet, by the operation of
+some governing and determining principle, a mean distance has been
+given, and at that mean distance the two forces find their equilibrium;
+and by their conjoint and co-equal working hold each planet at that mean
+distance with a power that cannot be broken. Each power or force may be
+modified under certain conditions, as shown in the two preceding
+articles; but, whether the planet be repelled further away, or attracted
+nearer to the sun, through the onward motion of the sun, the two forces
+ever seek to maintain their equilibrium, and to place the planet at its
+mean position assigned to it in the solar system.<span class='pagenum'><a name='Page_265' id='Page_265'></a><a href='#TOC'>[265]</a></span>
+</p>
+
+<p>
+The nearer that mean
+position is to the sun, the greater is the velocity of the aetherial
+currents which circulate round the sun; and the greater their mass,
+volume for volume, on account of the increasing density of the Aether,
+the nearer it is to the sun. The effect of this increased velocity, and
+the increased mass of the circulating Aether currents, is to impart to
+planets nearest to the sun the greatest orbital velocity; while, the
+greater the distance, the less will be the orbital velocity of the
+planet. That this is exactly in accordance with observation and
+experience may be proved by considering the respective mean distances
+and orbital velocities of the various planets.
+</p>
+
+<p>
+Mercury, with a mean distance of 35,900,000 miles, is circled round the
+sun at the enormous rate of about 108,000 miles per hour, accomplishing
+its entire journey in the short period of 88 days. Venus, whose mean
+distance is about 67,000,000 miles, is carried round the sun at the
+reduced rate of 78,000 miles per hour, completing her orbit in the
+increased time of 224 days. Our own Earth, at the still further
+increased mean distance of 92,000,000 miles, performs her journey at the
+reduced velocity of 64,000 miles per hour, accomplishing the journey
+round the sun in a period of 365 days.
+</p>
+
+<p>
+Thus, the further we get from the sun, the slower becomes the movement
+of a planet in its orbit, and the longer it takes to complete its
+revolution round its controlling centre. Mars, at the increased distance
+of 141,000,000 miles, possesses a reduced velocity of 54,000 miles per
+hour, and completes its orbit in the increased duration of 686 days. So
+the decrease of velocity goes on, as the planets increase their mean
+distance from the sun, as the following figures show--
+</p>
+
+<table summary='period_of_revolution'>
+
+<tr><th></th><th><span class='smcap'>mean distance.</span></th><th></th><th><span class='smcap'>period of<br />revolution.</span></th><th></th><th><span class='smcap'>orbital velocity<br />per hour.</span></th><th></th></tr>
+
+<tr><td style='text-align: left;'>Jupiter</td><td style='text-align: right;'>482</td><td style='text-align: center;'>millions</td><td style='text-align: right;'>4,332</td><td style='text-align: center;'>days</td><td style='text-align: right;'>28,000</td><td style='text-align: center;'>miles</td></tr>
+
+<tr><td style='text-align: left;'>Saturn</td><td style='text-align: right;'>884</td><td style='text-align: center;'>"</td><td style='text-align: right;'>10,759</td><td style='text-align: center;'>"</td><td style='text-align: right;'>21,600</td><td style='text-align: center;'>"</td></tr>
+
+<tr><td style='text-align: left;'>Uranus</td><td style='text-align: right;'>1,780</td><td style='text-align: center;'>"</td><td style='text-align: right;'>30,687</td><td style='text-align: center;'>"</td><td style='text-align: right;'>1,800</td><td style='text-align: center;'>"</td></tr>
+
+<tr><td style='text-align: left;'>Neptune</td><td style='text-align: right;'>2,780</td><td style='text-align: center;'>"</td><td style='text-align: right;'>60.127</td><td style='text-align: center;'>"</td><td style='text-align: right;'>900</td><td style='text-align: center;'>"</td></tr>
+
+</table>
+
+<p>
+The relation of this decrease of velocity to the mean distance is
+exactly determined by Kepler's Third Law, in which he states that the
+square of the periodic time is proportionate to the cube of the mean
+distance. That this is true has already been proved in <a href='#ART_28'>Art. 28</a>.
+</p>
+
+<p>
+In conclusion on this point, let me ask the reader to try to conceive
+any other physical explanation for this decrease of orbital velocity as
+the mean distance is increased, than the one given here, namely, the
+decrease in the velocity and mass of the radiating and circulating
+Aether currents, and if such attempt is made, I premise that its only<span class='pagenum'><a name='Page_266' id='Page_266'></a><a href='#TOC'>[266]</a></span>
+result will be utter failure. No other physical conception to account on
+a physical basis for all Kepler's Laws can be given or conceived, than
+that which finds its origin in the universal electro-magnetic Aether,
+which by its pressures, tensions and motions gives rise to all the
+phenomena incidental to, and associated with, planetary and stellar
+phenomena.
+</p>
+
+<p>
+Therefore, inasmuch as all the laws of motion, and all Kepler's Laws can
+be accounted for by a gravitating and rotatory Aether medium, those
+facts alone, apart from the explanation of other phenomena associated
+with light and heat, would stamp the circulating Aether medium as the
+physical cause of all the motions and phenomena associated with the
+whole of the celestial mechanism.
+</p>
+
+<p>
+<a name='ART_105' id='ART_105'></a><span class='smcap'>Art</span>. 105. <i>Orbital Motions of Satellites and Planets</i>.--According to
+Kepler's First Law, the Earth and all the other planets move round the
+sun in orbits which are in the shape of an ellipse. Not only, however,
+is the first law true of planetary motion, it is equally true of the
+motions of all satellites moving round their primary planets. I wish,
+however, to point out, and prove in an indisputable manner, that
+Kepler's First Law does not sufficiently explain and determine the exact
+orbit of any satellite as it revolves around its primary planet, or even
+of any planet as it revolves around the sun.
+</p>
+
+<p>
+Simply because, if any satellite or planet is to perform a perfect
+ellipse as it revolves around its central body, that central body must
+only move for a time and must then come to rest, or partly return in its
+journey in order for a perfect ellipse to be formed, as shown in a
+previous figure. Now we know from observation that such a thing as rest
+in space by any planet, or by the sun, is absolutely unknown in the
+celestial mechanism.
+</p>
+
+<p>
+From <a href='#ART_92'>Art. 92</a> we learned that the electro-magnetic Aether currents not
+only circulate round the sun, but they also circulate round each planet.
+Thus we found there were electro-magnetic Aether currents circulating
+round each planet, while those planets themselves were circled round the
+sun by the Aether currents generated by the sun; the planetary Aether
+currents in their turn propel the satellites round their primary
+planets. It can easily be seen, therefore, that such phenomena as rest
+and return of a planet in its journey are physical impossibilities, for
+either the circulating Aether currents would have to cease circulating,
+or would have to return upon themselves in some inconceivable manner.
+</p>
+
+<p>
+Thus there is ever going on this conjoint motion, so to speak, of the
+sun's aetherial currents which circle all the planets round that body,
+and the planetary aetherial currents which circle all the satellites<span class='pagenum'><a name='Page_267' id='Page_267'></a><a href='#TOC'>[267]</a></span>
+round their central body, and it is the effect of the conjoint working
+of these currents on the planets and satellites to which I wish to call
+the reader's attention.
+</p>
+
+<p>
+Let us in starting represent the earth's orbit by a perfect ellipse <i>A B
+C D</i>, with the sun occupying one of the foci <i>S</i> (Fig. 27). We will
+suppose that the earth is at point <i>A</i> of its orbit and is being circled
+round the sun with uniform velocity. As it is circled round the sun by
+the sun's aetherial currents, at the same time its satellite the moon is
+being circled round the earth by the electro-magnetic Aether currents
+which circulate round that planet. We will represent the orbit of the
+moon by part of a smaller circle <i>D E F</i>, and suppose the moon to be at
+point <i>D</i> of that orbit. The mean distance of the moon from the earth is
+about 240,000 miles, so that the diameter of the orbit is 480,000 miles,
+therefore the circumference of the orbit is 480,000 × 3.1416, which
+gives us about 1,500,000 miles.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/281.jpg' width='400' height='238'
+alt='Fig: 27.'
+title='Fig: 27.' />
+</div>
+
+<p>
+That distance is traversed in about 28 days, so that the moon's average
+velocity in its orbit, as it is circled or pushed round the earth, is
+about 2200 miles per hour. While, therefore, the moon is travelling 2200
+miles, the earth in its journey round the sun has travelled about 64,800
+miles in the same time. So that by the time the moon has travelled half
+its orbit, that is, from <i>D</i> to <i>F</i>, which would take about 14 days, the
+earth has also travelled in its orbit 64,800 × 24 × 14 = 21,772,800
+miles, with the result, that instead of the moon arriving at point <i>F</i>,
+which it would do if the earth were stationary, it really arrives at a
+point about 21,772,800 miles in front of that point.
+</p>
+
+<p>
+In a similar way, while the moon goes on to describe the other half of<span class='pagenum'><a name='Page_268' id='Page_268'></a><a href='#TOC'>[268]</a></span>
+the orbit, the earth still proceeds on its journey, so that at the end
+of 14 days it is again 21,772,800 miles further on, with the result,
+that the centripetal force (by which the moon is attracted to the earth)
+keeps it at the distance of 240,000 miles according to Kepler's Second
+Law as explained in <a href='#ART_103'>Art. 103</a>.
+</p>
+
+<p>
+The moon, therefore, completes its orbit about 21,772,800 miles further
+on than it would do if the earth were stationary. The effect of this
+continual progress of the earth on the moon's orbit as it describes its
+orbit round the sun is seen in the diagram. As the moon revolves round
+the earth thirteen times in one year, it performs thirteen revolutions
+round that planet; but it cannot be said that these orbits are perfect
+ellipses, as the earth is ever being circled round its central body, the
+sun. Even this diagram does not accurately represent the orbital motion
+of the moon through space, as it assumes that the earth returns to the
+same point in space from whence it started. This, however, is incorrect,
+as we have to remember that the sun has also an orbital velocity of
+18,000 miles per hour, so that while the earth has performed one
+revolution in its orbit, the sun has actually progressed through space
+to the extent of 18,000 × 24 × 365 = 157,680,000 miles.
+</p>
+
+<p>
+When we come to deal with the sun's motion through space, we shall see
+that this distance only represents a fraction of the sun's orbit, as it
+can be philosophically proved, that if the sun moves at all, it, too,
+obeys Kepler's Laws; and therefore, according to his First Law, it also
+describes and possesses an orbit of its own. So that by the time the
+earth has made its annual revolution round the sun, the whole system has
+been carried 157,680,000 miles through space, and therefore the earth
+does not complete a perfect ellipse, but its orbital motion round the
+sun will be represented by a similar kind of diagram to the one which
+represents the orbital motions of the moon, or any other satellite round
+its central body.
+</p>
+
+<p>
+<a name='ART_106' id='ART_106'></a><span class='smcap'>Art</span>. 106. <i>Eccentricity of Orbit of Moon</i>.--From astronomical
+observation we learn, that all the satellites and planets do not possess
+uniformity of motion, as they are carried round their controlling
+centres by the circulating aetherial currents, because the respective
+controlling centres themselves move through space. The result is, that
+the orbit of any satellite or planet is not always of the same size, but
+constantly varies, sometimes having a larger circumference than at other
+times, and sometimes a smaller circumference.
+</p>
+
+<p>
+This change in the size of the orbit of a satellite or planet is known
+as the eccentricity of the orbit, which eccentricity is constantly
+changing, being sometimes greater and sometimes less. We will look at
+this truth in its relation to the moon first, and then consider the<span class='pagenum'><a name='Page_269' id='Page_269'></a><a href='#TOC'>[269]</a></span>
+same principle in its relation to the earth and other planets later on.
+For the purpose of illustration, we will consider the earth as being
+circled round the sun by the electro-magnetic Aether currents in a closed
+orbit, <i>A B C D</i>, which forms a perfect ellipse, the sun occupying one
+of the foci <i>S</i> (Fig. 28), the earth occupying a position in the orbit
+represented by point <i>C</i>, with the moon being circled round the earth by
+that planet's aetherial currents. As we have already seen in <a href='#ART_103'>Art. 103</a>,
+according to Kepler's Second Law, at this point the earth is furthest
+from the sun, being now at a distance of 94-1/2 millions of miles, and
+therefore its orbital velocity will be slowest at that part of its
+orbit.
+</p>
+
+<p>
+If it were absolutely at rest in space, and simply revolving on its own
+axis, then the result would be that the moon would be circled round the
+earth in an orbit <i>M C F</i> which is perfectly circular in form; but, as
+the earth is being carried along slowly through space by the circulating
+Aether currents, this onward movement changes the circular orbit into an
+orbit of elliptic form.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/283.jpg' width='400' height='143'
+alt='Fig: 28.'
+title='Fig: 28.' />
+</div>
+
+<p>
+The eccentricity of the moon's orbit when the earth is at its aphelion,
+or furthest from the sun, is now at a minimum, for the simple reason
+that the earth is proceeding slowly through space, owing to the
+decreased kinetic energy of the aetherial currents at the increased
+distance.
+</p>
+
+<p>
+So that, at this point of the earth's orbit, the difference between the
+two axes of the moon's orbit will be the least, and its orbit at that
+point will be the nearest approach to that of a circle. But, as we have
+already seen, as soon as the earth leaves this part of its orbit, and
+begins to get nearer to the sun, it passes into a part of the aetherial
+medium possessing greater kinetic energy, with the result that its own
+velocity is accelerated. Now what is the effect of this increased
+acceleration of the earth on the eccentricity of the orbit of the moon?
+</p>
+
+<p>
+The earth's rotation on its axis remains unaltered during this
+increasing orbital velocity, consequently the aetherial currents
+generated by the earth will remain uniform, and the moon will still be
+circled round the earth in the same period of about 28 days. But while<span class='pagenum'><a name='Page_270' id='Page_270'></a><a href='#TOC'>[270]</a></span>
+the time of the moon's revolution remains unaltered, the orbit that she
+has to describe is now increased owing to the increased orbital velocity
+of its central body, with the result, that by the time the earth gets to
+that part of its orbit represented by point <i>D</i>, it is then two millions
+of miles nearer to the sun than at point <i>C</i>, and will be circled round
+the sun by the aetherial currents at a much greater rate. Therefore, the
+eccentricity of the moon's orbit is increased just in proportion to the
+increased velocity of the earth in its orbit round the sun. By the time
+the earth has arrived at point <i>A</i>, when it is only a distance of about
+91 millions of miles from the sun, it reaches the minimum distance, and
+is circled round at the decreased distance with its maximum velocity.
+</p>
+
+<p>
+At this point, therefore, the eccentricity of the orbit of the moon will
+be at its greatest, and, if one revolution could be represented by an
+ellipse <i>E G H</i>, then that ellipse would be more elongated, and the
+difference between the two axes of the moon's orbit would be greater
+than at any other point of the earth's orbit.
+</p>
+
+<p>
+Thus it can readily be seen that the eccentricity of the moon's orbit is
+primarily due to the different velocities of the central body, in this
+case the earth, as that body is carried round its central body, the sun.
+Where the earth's motion is slowest, there the eccentricity of the
+moon's orbit will be at a minimum; but where the earth's velocity is
+greatest, there the eccentricity of the moon's orbit will be at a
+maximum.
+</p>
+
+<p>
+Between this minimum and maximum velocity of the earth in its orbit
+there is the constant increase or decrease in the eccentricity of the
+orbit of the moon; the eccentricity increasing as the orbital velocity
+of the central body increases, and decreasing as the orbital velocity of
+the earth decreases. A further fact has, however, to be taken into
+consideration, which is that the primary body about which the moon
+revolves is itself subject to the same eccentricity of its orbit, and
+for similar reasons, as we shall see later on. So that when the
+eccentricity of the earth's orbit is at its greatest, then the moon's
+orbit will possess its greatest possible eccentricity, and as the
+eccentricity of the earth's orbit is dependent upon the orbital velocity
+of the sun, so the greatest possible eccentricity of the moon's orbit is
+indirectly connected and associated with the sun's motion through space,
+which motion will now be considered.
+</p>
+
+<p>
+<a name='ART_107' id='ART_107'></a><span class='smcap'>Art</span>. 107. <i>The Sun and Kepler's First Law</i>.--We have learned in the
+previous articles that Kepler's Laws not only apply to planetary motion,
+but are equally applicable to the motion of all satellites as they
+revolve round their respective planets.
+</p>
+
+<p>
+The question now confronts us, as to whether Kepler's Laws are equally<span class='pagenum'><a name='Page_271' id='Page_271'></a><a href='#TOC'>[271]</a></span>
+true in their application to the sun? Now the sun is one of the host of
+stars that move in the vast infinity of space, and if it can be proved
+that Kepler's Laws hold good in relation to one star, as they do in
+relation to all planets and satellites, then such a result will have a
+most important bearing upon the motions of other stars, and we shall be
+able to determine with some degree of exactness what are the motions and
+orbits by which all the stars in the universe are governed.
+</p>
+
+<p>
+Sir Wm. Herschel first attacked the question as to whether the sun, like
+all the other stars, was in motion, and if in motion, what was the shape
+of its orbit, and the laws which governed its orbital velocity.
+</p>
+
+<p>
+We know that the sun is the centre of the solar system, and the question
+to be considered is, whether that system is circled round a controlling
+centre while the sun is at rest in space, simply possessing its one
+axial rotation, or whether, like every planet and satellite, it is
+subject to two motions, an axial rotation and an orbital velocity
+through space. Further, if it possesses an orbital velocity through
+space, what is the cause of that orbital velocity?
+</p>
+
+<p>
+It was due to the genius of Sir Wm. Herschel to first solve this
+problem, and by careful research he was able to determine that the sun,
+with all its attendant planets, was indeed moving through space.
+</p>
+
+<p>
+Not only did he discover this fact, but he also found out the direction
+in which the whole of our solar system was moving, as well as the
+velocity with which the general movement was performed. Herschel proved
+that the onward march of the solar system was in the direction of the
+constellation of Hercules, and that the velocity of the march of this
+system exceeds five miles per second, or 500,000 miles per day.
+</p>
+
+<p>
+Thus we learn that the whole of our solar system, comprising the sun,
+with all its planets with their attendant satellites which circle round
+each planet, and the asteroids or minor planets, are bound together by
+the two forces, the centripetal and the centrifugal, while the system as
+a whole is urged on its way by some force or power through the realms of
+space.
+</p>
+
+<p>
+What that power is we shall try to find out as we consider the
+application of Kepler's Laws to this onward movement of the sun. If,
+then, the sun is moving through space with this enormous velocity, the
+question arises as to what is the shape of the path or orbit which it
+describes? Sir Wm. Herschel attacked this question from a mathematical
+standpoint, and came to a certain conclusion, as we shall see. We will,
+however, attack the problem solely from the philosophical standpoint, by
+applying to it the Rules of Philosophy given in our first chapter, and<span class='pagenum'><a name='Page_272' id='Page_272'></a><a href='#TOC'>[272]</a></span>
+we will then see whether our result is in harmony with the conclusions
+arrived at by Sir Wm. Herschel.
+</p>
+
+<p>
+Now what has experience and observation to tell us regarding the orbit
+which any body moving in space assumes? Take, for example, our moon as
+illustrating the movement of all satellites, and our earth as
+illustrating all planetary motion.
+</p>
+
+<p>
+What does observation teach us as to the orbits which these bodies
+describe? If it teaches us anything at all, it teaches us that every
+satellite and planet moves with varying velocity in a varying orbit
+around some central body. So far as our observation goes, then, in
+relation to planetary motion, or the motion of satellites, we learn that
+every body which moves in space fulfils Kepler's First Law, and
+describes an orbit round a central body, that body occupying one of the
+foci.
+</p>
+
+<p>
+Thus, wherever we get any body moving in space, if there be any truth in
+philosophy which is based on experiment and observation, that body ought
+also to move in similar elliptic orbits, and be subject to exactly
+similar conditions governing those orbits. But we have learned that the
+sun moves through space with a velocity of about five miles per second,
+therefore it follows, philosophically, that the sun must also move
+around some other central body, and the path of such movement is that of
+an elliptic orbit, with the central body around which it moves occupying
+one of the foci.
+</p>
+
+<p>
+In other words, the sun obeys the first of Kepler's Laws, the same as
+all the planets and satellites do. Suppose, for a moment, that it is
+denied that the sun moves in an elliptic orbit! What path would it
+pursue in place of that? Would the path be that of a straight line
+towards the constellation of Hercules? Such an assumption would be
+altogether unphilosophical, as it is contrary to all experience and
+observation, and is therefore untenable.
+</p>
+
+<p>
+Before such an assumption can be made, it must be proved that every
+planet and satellite moves in a straight line, and not till that has
+been done can it be assumed that the sun moves in a straight line, or
+indeed in any other path than that stated in the first of Kepler's Laws.
+</p>
+
+<p>
+This conclusion is in perfect harmony with the conclusion arrived at by
+Herschel, for in his work on <i>Astronomy</i>, in Arts. 292, 295 and 297, he
+points out that the sun's path is elliptic in form, and that Kepler also
+showed the sun fulfilled the first of his laws, and described an orbit
+which was in the shape of an ellipse. We have therefore philosophically
+arrived at the conclusion that the sun moves in an elliptic orbit, and
+to do so it must move round some central body, which is to the sun what
+the sun is to the planets, and what the planets are to the satellites.<span class='pagenum'><a name='Page_273' id='Page_273'></a><a href='#TOC'>[273]</a></span>
+</p>
+
+<p>
+It is impossible to conceive of the sun moving in an elliptic orbit,
+and yet not moving around some central body, as we should have a
+celestial phenomenon altogether opposed to all experience and
+observation. For we have already seen that the central body is just as
+important a factor to the elliptic orbit as the planet itself, because,
+without the central body there cannot possibly be any elliptic orbit.
+Where then in the universe is the central body around which the sun
+revolves? What is its distance away from the sun? What is its size?
+These are questions that philosophy alone cannot answer, as there is no
+law, so far as I can see, that regulates the size and distance of the
+central body in proportion to the size and distance of the planets or
+satellites.
+</p>
+
+<p>
+If there were, then it would be possible for philosophy to apply such a
+law or rule. That there is a central body around which the sun revolves
+is as true as the fact that there is a central body about which each
+planet revolves, or each satellite revolves, and it remains for the
+practical astronomer, or the mathematician, to endeavour to discover the
+exact part of the heavens in which it is situated, and ascertain its
+distance and possibly its size. What will be the effect of the existence
+of this central body of the sun upon the solar system? One effect will
+be to do away with that isolation that up to the present has apparently
+existed with regard to our solar system and stellar space.
+</p>
+
+<p>
+Instead of the solar system being a solitary system that moves through
+space subject to apparently no law, and moved by apparently no physical
+power, that system, through the influence and effect of the aetherial
+currents originated by that central body, will be linked to other parts
+of the universe, and will become a part of one harmonious whole, its
+physical connection being made manifest and plain in the self-same
+electro-magnetic Aether medium that forms the connecting medium between
+the satellites and planets, or the planets and the sun.
+</p>
+
+<p>
+Another result will be, that as the sun is a star, we shall be able to
+apply the self-same principles and laws of Kepler to the stellar world
+in exactly the same way that we have done to the solar system. Thus, by
+bringing all stellar phenomena under the influence of Kepler's Laws, we
+shall be able to philosophically give an unity to the universe, and
+show, within rational limits, how such unity may be physically
+conceived, which result will be an advance upon any physical conception
+of the universe hitherto manifested or revealed. Further, by accepting
+the first of Kepler's Laws in relation to the sun, and admitting the
+existence of a central body, we shall be able then to apply the second
+of Kepler's Laws, and by so doing shall be able to give a physical<span class='pagenum'><a name='Page_274' id='Page_274'></a><a href='#TOC'>[274]</a></span>
+explanation of two scientific facts which up to the present have never
+been physically explained, viz. the physical conception of the plane of
+the ecliptic, and a physical explanation of the eccentricity of the
+earth's orbit, which is but the result of the application of Kepler's
+Second Law to the sun's orbital motion around its central body.
+</p>
+
+<p>
+<a name='ART_108' id='ART_108'></a><span class='smcap'>Art</span>. 108. <i>The Sun and Kepler's Second Law</i>.--We will now proceed to
+apply the second of Kepler's Laws to the orbital motion of the sun, and,
+in so doing, shall find we are able to give at the same time a physical
+explanation of the eccentricity of the earth's orbit.
+</p>
+
+<p>
+In order to obtain a physical conception of the sun's orbital motion
+according to Kepler's First Law, it is essential that we should consider
+the effect of the existence of a central body around which the sun
+revolves; or, to put the matter into another form, we will ask the
+question as to what is the physical cause of the sun revolving round
+that central body?
+</p>
+
+<p>
+Let us look at the case for a moment. Here, according to astronomical
+observation, we find a certain phenomenon which takes the form of a huge
+body 865,000 miles in diameter moving through space with a velocity of
+nearly 500,000 miles per day. What then is the physical cause of the
+movement of this large sphere?
+</p>
+
+<p>
+Certainly there must be some physical cause, or else we have a violation
+of all experience, which indisputably teaches us that no body moves
+unless it is either pushed or pulled. We have, however, done away with a
+pulling power so far as the cause of the actual revolution of bodies
+around a central body is concerned, and in its place have substituted a
+medium that pushes or carries them round each central body. For over 200
+years the scientific world has accepted a pulling power, that is, an
+attractive power, solely as the cause of the movements of celestial
+bodies, with the result that the physical cause of all the motions of
+planets and satellites has been outstanding and undiscovered.
+</p>
+
+<p>
+It would, therefore, be unphilosophical to revert to the old conception
+of a gravitating attractive power as the sole cause of the sun's orbital
+motion through space. If we desire to know what is the cause of its
+revolution round that central body, then we must seek to find the same
+from the result of observation and experience in other directions.
+</p>
+
+<p>
+We have learned from <a href='#ART_102'>Art. 102</a> that the orbital motion of the moon is
+caused by the electro-magnetic Aether currents that circulate round its
+central body, the earth. By the same means every satellite is circled
+round its central body also. We have also learned from <a href='#ART_99'>Art. 99</a> that the
+earth is carried round the sun by the circulating and rotating<span class='pagenum'><a name='Page_275' id='Page_275'></a><a href='#TOC'>[275]</a></span>
+electro-magnetic Aether currents, and that these same currents also form
+the physical cause of the revolution of all the other planets round
+their central body, the sun.
+</p>
+
+<p>
+Thus we arrive at the fact that wherever there is a body moving in
+space, it is moving solely because it is pushed along, or carried round
+its controlling centre by the rotating Aether currents. But we have just
+learned that the sun is moving through space, and that it describes an
+elliptic orbit around some central body in accordance with Kepler's
+First Law. So that the only philosophical conclusion that we can
+possibly arrive at in relation to the orbital motion of the sun is, that
+such motion is caused by similar electro-magnetic Aether currents whose
+circulating motion is partly caused by the rotation of that central
+body.
+</p>
+
+<p>
+Thus we are led up to the philosophical conclusion, that it is the
+aetherial currents of the central body around which the sun revolves,
+that produce, and alone produce, the onward motion of the sun through
+space. Any other conclusion must be unphilosophical, and therefore
+untenable. We have, therefore, to conceive of the sun's central body
+generating and giving rise to electro-magnetic aetherial currents that
+extend through space to the limits at least of the solar system, and
+these aetherial currents, acting upon the sun's huge form by their
+kinetic energy, carry it with all its associated worlds through infinite
+space.
+</p>
+
+<p>
+There is nothing extravagant in this conception, when we remember that
+the solar system has been moving on and on through infinite space year
+after year, and yet it never seems to get appreciably nearer to the
+other stars, but I hope to show the reason of this by strictly
+philosophical reasoning later on. With this conception of the sun in its
+relation to its central body we are now in a position to consider the
+application of Kepler's Second Law upon the sun's orbital motion, and
+its resultant effect upon the orbit of our earth and all the other
+planets.
+</p>
+
+<p>
+From Kepler's Second Law we know that equal areas are described by the
+radius vector in equal times, and if the first law of Kepler is at all
+applicable to the sun, then it must follow that if the sun has an orbit,
+and moreover an elliptic orbit as stated by Kepler himself, then, as a
+natural result, the radius vector of the sun must move over equal areas
+in equal times.
+</p>
+
+<p>
+The physical explanation of Kepler's Second Law was given in <a href='#ART_103'>Art. 103</a>,
+and there is no need to traverse the same ground again. It is,
+therefore, true that the sun moves faster in certain parts of its orbit
+than in others, being urged through space at its greatest velocity when
+it is nearest its controlling centre, and slowest when farthest away
+from that controlling centre.<span class='pagenum'><a name='Page_276' id='Page_276'></a><a href='#TOC'>[276]</a></span>
+</p>
+
+<p>
+Herschel, in his work on <i>Astronomy</i>,
+states: &ldquo;The motion of the sun will be such that equal areas are thus
+swept over by the revolving radius vector in equal times in whatever
+part of the circumference of the ellipse the sun may be moving.&rdquo; He,
+however, suggested that the earth forms a focus of the sun's ellipse, a
+suggestion which is unphilosophical, it seems to me, as we might equally
+suggest that the earth revolves round the moon, which is contrary to all
+observation. Thus the sun is not carried uniformly through space by the
+aetherial currents of its central body, because it is nearer to that
+central body at certain times; its velocity being regulated by its
+distance from that body, the same being increased as the distance is
+decreased, and decreased as the distance increases.
+</p>
+
+<p>
+Now if this reasoning be correct, and if the sun really moves round a
+central body and is subject to Kepler's Second Law, then that increase
+and decrease of distance will be made manifest in the increase and
+decrease of the eccentricity of the earth's orbit.
+</p>
+
+<p>
+So that if the eccentricity of the earth's orbit should vary from
+century to century, then we have conclusive evidence that the sun obeys
+the first and second of Kepler's Laws, and therefore that it revolves
+around a controlling centre of its own. From observation we find that
+this is exactly what is happening, and that at the present time the
+eccentricity of the earth's orbit is gradually diminishing, and in about
+24,000 years the orbit will be very nearly a circle.
+</p>
+
+<p>
+Now, from what was stated in <a href='#ART_106'>Art. 106</a>, we know that the moon's orbit
+will be nearly a circular orbit when the earth is farthest from the sun,
+and that then its orbital velocity is at a minimum.
+</p>
+
+<p>
+In order for this result to be produced, the earth must reach that part
+of its orbit known as aphelion, where the distance from its controlling
+centre is greatest, so that the eccentricity of the moon's orbit is
+always an indication of the position of the earth in its relation to the
+sun. When the eccentricity of the moon's orbit is decreasing, the
+earth's distance from the sun is increasing, but when the eccentricity
+of the moon's orbit is increasing, then the earth's distance from the
+sun is decreasing.
+</p>
+
+<p>
+Now if we apply this analogy to the eccentricity of the earth's orbit,
+we shall be able to obtain some idea of the relation of the sun to its
+central body. We find then that the eccentricity of the earth's orbit is
+decreasing, therefore, arguing from analogy, we arrive at the conclusion
+that the sun's distance from its controlling centre is increasing, and
+that its orbital velocity is decreasing.
+</p>
+
+<p>
+If it be true that in 24,000 years the earth's orbit will be nearly<span class='pagenum'><a name='Page_277' id='Page_277'></a><a href='#TOC'>[277]</a></span>
+circular, then it follows that in 24,000 years the sun will be at that
+part of its orbit corresponding to the aphelion of the orbit of the
+earth, that is, its distance from its controlling centre will then be at
+a maximum. After that the eccentricity of the earth's orbit will begin
+to increase, and will continue to increase for about 40,000 years,
+according to some scientists, which implies that the sun will then have
+started from its aphelion point, so to speak, and will begin its return
+journey towards its central body, gradually getting nearer and nearer.
+As it gets nearer its orbital velocity will be proportionately
+increased, with the result that the eccentricity of the earth's orbit
+will increase also. From a consideration of the movement of the major
+axis of the earth's orbit, which is moving forward at the rate of 11°
+per year, we are told that a whole revolution will be made in 108,000
+years.
+</p>
+
+<p>
+We have here, then, an indication of the time that the sun takes to
+revolve round its central body, because the time of the whole revolution
+of the eccentricity of the orbit should correspond with one complete
+revolution of the sun around its central body. So that from a
+consideration of the eccentricity of the earth's orbit, we are not only
+able to demonstrate that the sun satisfactorily fulfils the first and
+second of Kepler's Laws, but, conversely, we are able to give a
+satisfactory physical explanation of the cause of the eccentricity of
+the earth's orbit, which explanation is again primarily to be found in
+the universal Aether medium.
+</p>
+
+<p>
+<a name='ART_109' id='ART_109'></a><span class='smcap'>Art</span>. 109. <i>Plane of the Ecliptic and Zodiacal Light</i>.--As already
+pointed out, another phenomenon which can be physically accounted for by
+the sun's orbital motion through space around its central body, is that
+celestial plane known as the Plane of the Ecliptic.
+</p>
+
+<p>
+What then is the Plane of the Ecliptic whose physical explanation we are
+to attempt? We know that the moon revolves round the earth as the earth
+revolves round the sun, while the sun is pursuing its way through space.
+It has been found also, that all these motions of these different bodies
+take place on one level, so to speak; that is to say, they do not go up
+or down in space, but straight on.
+</p>
+
+<p>
+So straight do they move, that their path has been likened to the level
+of the ocean, on which a ship may sail for thousands of miles, always
+keeping the same level and even course. On some such ocean as this in
+space all the planetary systems and solar systems seem to move, ever
+moving on and on with the same uniformity of level through infinite
+space. Further, this plane of the ecliptic is to the celestial sphere
+what the sea-level is to the earth. The height of a mountain on the
+earth is stated to be so much above the sea-level.<span class='pagenum'><a name='Page_278' id='Page_278'></a><a href='#TOC'>[278]</a></span>
+</p>
+
+<p>
+In a similar way
+astronomers say that a star is a certain height above the plane of the
+ecliptic. What then is the physical explanation of this scientific term?
+We will lead up to it by first considering the effect that rotation has
+upon a liquid body.
+</p>
+
+<p>
+It has been demonstrated that if a mass of oil is placed in a
+transparent liquid of the same density, so long as the oil is perfectly
+at rest, its shape will be that of a sphere which will float about in
+the liquid, but as soon as the oil is made to rotate by means of a piece
+of wire, then the spherical shape is changed into that of an oblate
+spheroid.
+</p>
+
+<p>
+Further, the faster it is made to rotate, the more it will bulge out, so
+that its equatorial diameter will greatly exceed its polar diameter. The
+same principle may be illustrated by making a hoop to revolve rapidly on
+its axis, when a similar effect of bulging out will be produced.
+</p>
+
+<p>
+Now let us apply this principle to the earth with its electro-magnetic
+Aether currents circulating round it, and ask what is the effect of the
+rotation first upon the earth, and then upon the rotating Aether
+currents?
+</p>
+
+<p>
+It is a matter of common knowledge that the effect of rotation upon the
+earth when it was in a fluid state was to make its equatorial parts
+bulge out as it rotated, with the result that as it solidified the
+equatorial diameter exceeded the polar diameter by 26 miles.
+</p>
+
+<p>
+If, therefore, the result of rotation upon the earth when in its fluid
+state was to make it spread out greater in the equatorial regions than
+in any other part of its surface, what must be the effect of a similar
+rotation upon the rotatory Aether currents? It can easily be seen that
+the rotation of these currents will be to make them spread out into
+space in a region which corresponds to the equatorial regions of the
+earth, so that the rotating Aether currents will be congregated more in
+the equatorial regions of the earth than in any other part of the
+earth's surface. The further also they extend into space the less depth
+they will have, gradually tapering off, as shown in the illustration,
+where <i>E</i> represents the earth and <i>B C</i> the Aether currents (Fig. 29).
+</p>
+
+<p>
+Any body, therefore, situated within the sphere of their influence would
+be carried round the earth by the currents, and the currents would be to
+them their governing and controlling level.
+</p>
+
+<p>
+So that the moon, which is held bound to the earth by the two opposite
+and equal forces, would always be carried around the earth by those
+electro-magnetic Aether currents, and outside of those currents it could
+not pass. But the earth is only 8000 miles in diameter, therefore if<span class='pagenum'><a name='Page_279' id='Page_279'></a><a href='#TOC'>[279]</a></span>
+the currents gradually tapered off as suggested, by the time the
+aetherial currents reached the distance of the moon, their depth would
+not exceed 2000 or 3000 miles.
+</p>
+
+<p>
+The diameter of the moon is, however, only 2160 miles, so that the
+rotating Aether currents would practically form an ocean in which the
+moon would swim, and one constant level on which it revolves in space.
+Wherever the earth was carried by the aetherial currents of the sun,
+there the aetherial currents of the earth would carry the moon, its mean
+distance by the conjoint working of the two co-equal forces having been
+permanently fixed.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/293.jpg' width='400' height='188'
+alt='Fig: 29.'
+title='Fig: 29.' />
+</div>
+
+<p>
+So that it can be readily seen, as regards the moon, that the earth's
+aetherial currents form the plane on which it revolves around the earth.
+Now in exactly the same way it can be proved that it is the sun's
+aetherial currents which form the plane or level on which all the
+planets revolve or are carried around their central body. We have only
+to enlarge our conception and the same result follows. Instead of
+dealing with a body 8000 miles in diameter, we are now dealing with a
+body 865,000 miles in diameter, and as this huge body is more or less in
+an incandescent state, the aetherial currents will therefore be
+proportionate in intensity and flow to its size and atomic activity.
+</p>
+
+<p>
+Instead, therefore, of the aetherial currents which circulate round the
+sun only extending a quarter of a million of miles, their energy and
+flow extend far away into space, even beyond the greatest distance of
+Neptune, a distance of 2,800,000,000 miles. The same truths apply here,
+however, as in the case of the earth and the moon. The aetherial
+currents which circulate round the sun congregate together, and possess
+their greatest depth nearest to the equator, while the further away they
+recede, the less and less depth they possess, with a decreased intensity
+and decreased kinetic energy. These Aether currents will be to all the<span class='pagenum'><a name='Page_280' id='Page_280'></a><a href='#TOC'>[280]</a></span>
+planets, therefore, what the earth's aetherial currents will be to the
+moon, being to them the ocean level on which they alone can move, and by
+which they are carried round their central body.
+</p>
+
+<p>
+Thus these currents will form for all the planets the level in infinite
+space upon which they float, and from which they cannot pass. Let us
+further consider the movements of these currents in space, and we shall
+find further confirmation of this fact by so doing. Astronomers tell us
+that it takes light about three and a half years to reach us from the
+nearest star. By calculation, therefore, we find that the nearest star
+to our system is about 205,000,000,000,000 miles away, that being about
+the distance that light travels in three and a half years.
+</p>
+
+<p>
+The diameter of the sun is about 865,000 miles, so that the distance of
+the nearest star is 240,000,000 times the diameter of the sun. We could
+therefore put 240,000,000 of our solar systems in the space that exists
+between us and the nearest star. How is it, then, that all the planets
+as they revolve round the sun do not float up and down in the space that
+extends between us and the nearest star?
+</p>
+
+<p>
+I can give no other answer, and can see no other possible physical
+explanation than the one already given, which is, that they are bound to
+the sun by the two co-equal forces, the centrifugal and centripetal
+forces, and while so bound are carried round the sun by the
+electro-magnetic aetherial currents which extend out into space. It has
+to be remembered that the aetherial electro-magnetic currents
+circulating round the earth are situated within the aetherial currents
+which circulate round the sun, therefore the plane of the moon's orbit
+will coincide more or less with the plane of the earth's orbit. We have
+now only to go one step further to get our complete conception of the
+plane of the ecliptic.
+</p>
+
+<p>
+In <a href='#ART_107'>Arts. 107</a> and <a href='#ART_108'>108</a> we learned that the sun was subject to Kepler's 1st
+and 2nd laws, and as a natural result we came to the conclusion that it,
+too, was circled round some central body. We have only to apply a
+similar course of reasoning to the sun and its central body as we have
+to the moon and the earth, and the earth and the sun, and then we arrive
+at our physical conception of the plane of the ecliptic, which is due to
+the aetherial currents that circle round the sun, while that body is
+carried round some other central body.
+</p>
+
+<p>
+Thus by the circulating Aether currents, originated and outflowing from
+their respective sources, each source being immutably fixed and bound to
+each other by the two equal and complementary forces, can be accounted
+for, the uniformity of position and plane of the various orbits of the
+various satellites, planets, and the sun, as they move in one great<span class='pagenum'><a name='Page_281' id='Page_281'></a><a href='#TOC'>[281]</a></span>
+plane, termed the Plane of the Ecliptic.
+</p>
+
+<p>
+It could not be otherwise than it is, and thus another celestial
+phenomenon can be accounted for on a real tangible basis by accepting
+the existence of those aetherial currents which form the physical basis
+of all the celestial mechanism.
+</p>
+
+<p>
+If further evidence were required of the existence of these rotating
+Aether currents round the sun, such evidence is found in that phenomenon
+of the solar system known as the Zodiacal Light, of which up to the
+present no physical explanation has been forthcoming. In the conception
+of the atomic and gravitating Aether which rotates round the sun, I
+venture to premise will be found the physical solution of this
+phenomenon also.
+</p>
+
+<p>
+I will refer the reader to an extract taken out of <i>Outlines of
+Astronomy</i>, by Herschel (Art. 894), so that we may see what his
+conception of the zodiacal light was, and we will see how far his
+explanation is in conformity with our hypothesis of an atomic,
+gravitating and rotatory Aether medium.
+</p>
+
+<p>
+He writes: &ldquo;We shall conclude this chapter by the mention of two
+phenomena, which to me indicate the existence of some slight degree of
+nebulosity about the sun itself, and even to place it in the list of
+nebulous stars. The first is that called the Zodiacal Light, which may
+be seen any very clear evening soon after sunset, about the months of
+March, April and May, as a cone or lenticularly-shaped light extending
+from the horizon obliquely upwards, and following generally the course
+of the ecliptic, or rather that of the sun's equator. The apparent
+angular distance of its vertex from the sun varies, according to
+circumstances, from 40° to 90°, and the breadth of its base
+perpendicular to its axis from 8° to 30°. It is extremely faint and
+ill-defined, at least in this climate, though better seen in tropical
+regions, but cannot be mistaken for any atmospheric meteor or aurora
+borealis. It is manifestly in the nature of a <i>lenticularly-formed
+envelope surrounding the sun</i>, and extending beyond the orbits of
+Mercury and Venus, and nearly, perhaps quite, attaining that of the
+earth, since its vertex has been seen fully 90° from the sun's place in
+a great circle. It may be conjectured to be no other than the <i>denser
+part</i> of that medium which we have some reason to believe resists the
+motions of comets; loaded perhaps with the actual materials of the tails
+of millions of those bodies of which they have been stripped in their
+successive perihelion passage. If its particles have inertia, they must
+necessarily stand with respect to the sun in the relation of separate
+and independent minute planets, each having its own orbit, plane of
+motion, and periodic time.&rdquo;
+</p>
+
+<p>
+Let me call the reader's special attention to one or two statements of<span class='pagenum'><a name='Page_282' id='Page_282'></a><a href='#TOC'>[282]</a></span>
+Herschel's given in this extract, in order to see how these statements
+harmonize with the view of the Aether submitted in this work. In the
+first place he states its shape is that of a lenticularly-formed
+envelope surrounding the sun, and extending beyond the orbits of Mercury
+and Venus, and probably to our earth. This harmonizes with the shape of
+the aetherial envelope as given in <a href='#ART_70'>Art. 70</a>. Then Herschel states it may
+be the denser part of that medium which we have reason to believe
+resists the motions of comets. That is exactly what it is, though
+Herschel failed to show why it should be the denser part of the Aether,
+as we have seen is the case, on account of its being gravitative. I will
+also prove later on, that Herschel was right with regard to the
+resistance of the motion of comets through it. Then he refers to its
+particles probably possessing inertia, as though he had anticipated the
+atomicity of the Aether, and assuming that atomicity, he was compelled
+to postulate inertia also as we have done in <a href='#ART_48'>Art. 48</a>.
+</p>
+
+<p>
+Lastly, he points out that each separate particle must have its own
+plane of motion, its own orbit, and its periodic time. Now this view
+fully coincides with that laid down in this article, where we have
+learned that the rotating Aether has its own plane of motion, that plane
+being the Plane of the Ecliptic, and as every particle or atom has its
+allotted place in the rotating Aether, then, as Herschel points out, the
+particle must have its own orbit, and plane of motion, and also its own
+periodic time. If, therefore, we had desired fuller confirmation of this
+atomic gravitating Aether, we could not have wished for more conclusive
+proof than that given by one of the greatest philosophical astronomers
+of the last century. We shall see later that Herschel also had a clearer
+view of cometary phenomena, and of the forces which played a part in
+those phenomena, than any of his contemporaries, when we deal with the
+origin and motions of all comets. Thus from Herschel we learn that the
+zodiacal light is caused by the atomic, gravitating, and rotatory Aether
+as that aetherial medium revolves round the sun, while at the same time
+every atom of the medium is itself in a state of rotation on its axis,
+as it performs its journey in its own orbit and in its own plane of
+motion.
+</p>
+
+<p>
+<a name='ART_110' id='ART_110'></a><span class='smcap'>Art</span>. 110. <i>Centripetal Force</i>.--We have now to consider what is the
+physical cause of that part of the compound Law of Gravitation known as
+the Centripetal Force. As we have already learned (<a href='#ART_10'>Art. 10</a>), this force
+is really none other than the Attractive Force of Gravitation, in that
+its mode of operation always acts towards the centre of the attracting
+body, and hence was called by Newton the Centripetal Force.<span class='pagenum'><a name='Page_283' id='Page_283'></a><a href='#TOC'>[283]</a></span>
+</p>
+
+<p>
+The
+centripetal force is, however, the exact counterpart and complement of
+the centrifugal force, in the same way that the latter is the exact
+counterpart of the former, as we have already learned that the
+centrifugal force operates along the same path, and that it is subject
+to the same law of proportion, being equal to the product of the masses
+of a body (<a href='#ART_85'>Art. 85</a>), and further, that its intensity is inversely as the
+square of the distance (<a href='#ART_66'>Arts. 66</a>, <a href='#ART_74'>74</a> and <a href='#ART_84'>84</a>).
+</p>
+
+<p>
+We have, however, discovered that the physical cause of the centrifugal
+force is due to the pressure of the electro-magnetic Aether (<a href='#ART_96'>Art. 96</a>).
+If, therefore, the physical cause of that law which is the complement
+and counterpart of Gravitation Attraction is to be found, and alone
+found, in the pressure and motions of the electro-magnetic Aether, then
+it is only logical and reasonable to infer that the physical cause of
+the Attraction of Gravitation is to be found in the same
+electro-magnetic Aether. That the Attraction of Gravitation is to be
+found in this medium is now an accepted hypothesis among scientists.
+Because, unless the physical cause of Gravitation Attraction is to be
+found in this electro-magnetic Aether, then, in order to account for
+that attraction, we should have to postulate the existence of another
+medium in space, in lieu of the Aether, which would be to the
+centripetal force what the Aether is to the centrifugal force. This
+would be distinctly unphilosophical, as it would be a violation of the
+first two rules of our philosophy, in that it would not be simple in its
+conception, and that such a hypothesis would imply the existence of two
+media which would occupy the same planetary and interstellar space at
+one and the same time, and this is a violation of all experience in its
+widest form.
+</p>
+
+<p>
+Therefore the physical cause of Gravitation must be sought for in the
+same medium which gives the physical cause of the companion force, and
+that medium is the electro-magnetic Aether. Professor Preston in his
+<i>Theory of Light</i> is of this opinion. In Art. 327 he writes: &ldquo;To account
+for the propagation of heat and light, that is, of radiant energy, we
+have postulated the existence of a medium filling all space. But the
+transference of the energy of radiant heat and light is not the only
+evidence we have in favour of the existence of an Aether. Electric,
+magnetic and electro-magnetic phenomena and Gravitation itself point in
+the same direction.&rdquo;
+</p>
+
+<p>
+Professor Lodge, in his <i>Modern Views of Electricity</i>, is even more
+explicit in his statement of the case. On page 338 he states:
+&ldquo;Gravitation is explainable by differences of pressure in the medium
+(<i>i. e.</i> the Aether) caused by some action between it and matter not
+yet understood.&rdquo; Further, Newton himself suggested that the physical
+cause of Gravitation Attraction was to be found in that aetherial<span class='pagenum'><a name='Page_284' id='Page_284'></a><a href='#TOC'>[284]</a></span>
+medium which pervaded all space.
+</p>
+
+<p>
+If, therefore, we attempt to explain the physical cause of Gravitation
+Attraction by the tensions of the universal Aether, we shall not only be
+dealing with the subject from a philosophical standpoint, but we shall
+solve the problem in that direction in which Professors Preston and
+Lodge and other scientists have suggested we are to seek for the
+solution. Professor Curry, in his <i>Theory of Electricity and Magnetism</i>,
+page 406, states: &ldquo;If we regard the luminiferous Aether, as defined by
+Von Helmholtz's equations, as the given medium or transmitter of
+so-called gravitating action, we are then able on the one hand to
+interpret its longitudinal oscillations as gravitational waves
+propagated through space with the given enormous velocity, and on the
+other hand, to form some conception of the mysterious force of
+Gravitation itself, for we can then conceive it as a medium stress
+arising from a certain type of Aether oscillations, its longitudinal
+ones, that pervade entire space.&rdquo;
+</p>
+
+<p>
+Now in order for us to lead up to the physical cause of the centripetal
+force, we must recall some of the facts already given with regard to
+planetary and solar space. Thus we have learned that the sun is an
+electro-magnet possessing its own magnetic field, with its lines of
+force (<a href='#ART_88'>Art. 88</a>). We have also learned that all the planets are
+electro-magnets, each possessing its own field with its lines of force
+(<a href='#ART_91'>Art. 91</a>).
+</p>
+
+<p>
+We have further seen that the cause of all this electro-magnetism is due
+to the fact that electric currents are continually circulating round
+each body, and by their conjoint action with the magnets there are
+produced the electro-magnetic fields that are associated with each body
+in the solar system. From this hypothesis we arrived at the conclusion,
+that wherever there was Aether, there we found electricity, because of
+the electro-magnetic basis which Aether possesses. This result is fully
+confirmed by Maxwell's electro-magnetic theory of light (<a href='#ART_78'>Art. 78</a>), which
+has been so fully experimentally demonstrated by Hertz. Indeed, in the
+minds of several scientists there is a growing conviction that Aether
+and Electricity are possibly one and the same substance.
+</p>
+
+<p>
+Professor Lodge, in the work already referred to, in relation to this
+hypothesis, writes in the preface to that book: &ldquo;Crudely, one may say
+that as heat is a form of energy, so electricity is a form of Aether, or
+a mode of aetherial manifestation.&rdquo; And again: &ldquo;A rough and crude
+statement adapted for popular use is that <i>Electricity and Aether are
+identical</i>. But that is not all that has to be said, for there are two
+opposite kinds of electricities, and there are not two Aethers. But
+there may be two aspects of one Aether, just as there are two sides to<span class='pagenum'><a name='Page_285' id='Page_285'></a><a href='#TOC'>[285]</a></span>
+a sheet of paper.&rdquo;
+</p>
+
+<p>
+As, therefore, we learn that Aether has an electro-magnetic basis, and
+that electricity is a mode of aetherial manifestation, we have therefore
+to consider one of the most fundamental laws of electricity, and note
+its application to solar and planetary space.
+</p>
+
+<p>
+It is one of the fundamental laws of electricity, that equal and
+opposite quantities of electricity are always generated at one and the
+same time. Faraday's well-known ice-pail experiment proved this. It is
+an absolute impossibility for one kind of electricity to be generated
+without an equal quantity of the opposite kind being produced, although
+it is not strictly correct to use the term generated or produced in
+relation to electricity, as electricity cannot really be produced by any
+process whatever.
+</p>
+
+<p>
+Another way of stating this law is, that the total induced charge on any
+body is always equal and opposite to the inducing charge. So that if we
+look upon the sun as an electrified body (<a href='#ART_80'>Art. 80</a>) surrounded by the
+aetherial envelopes or shells, then we can conceive of the inductive
+action of the sun upon any planet as taking place along the tubes of
+force in the Aether, which tubes are sections of the spherical envelopes
+that surround it. But this inductive action implies the existence of the
+very law already enunciated, viz. that equal and opposite quantities are
+always generated at one and the same time, and before that law can
+become operative in relation to the Aether, it must be postulated that
+the Aether possesses a dual character, that is, it possesses a positive
+and negative electrical basis.
+</p>
+
+<p>
+This view of the Aether has already been developed by Dr. Larmor in his
+Electron Basis of the Aether, as in that hypothesis he postulates both
+positive and negative electrons. In his <i>Aether and Matter</i> he writes,
+page 3: &ldquo;It assumes that the mass of each sub-atom is proportional to
+the absolute number of electrons, positive and negative, that it
+carries, and that the effective interatomic forces are entirely or
+mainly electric.&rdquo; Further, Professor Lodge on this point writes:<a name='FNanchor_39' id='FNanchor_39'></a><a href='#Footnote_39' class='fnanchor'>[39]</a>
+ &ldquo;We
+now proceed a step further and analyze the Aether into two constituents,
+two equal opposite constituents, each endowed with inertia and each
+connected to the Aether by elastic ties. The two constituents are called
+positive and negative electricity respectively, and of these two
+electricities we imagine the Aether to be composed.&rdquo; Again, later on, p.
+349 of the same work, he adds: &ldquo;Is Aether electricity then? I do not say
+so, but that they are connected there can be no doubt. What I have to
+suggest is, <i>that positive, and negative electricity together may make
+up the Aether.</i>&rdquo;<span class='pagenum'><a name='Page_286' id='Page_286'></a><a href='#TOC'>[286]</a></span>
+</p>
+
+<p>
+Now, accepting
+this as correct, and I will prove that it is correct later on, from
+experiments performed by Faraday, we can see how the inductive action of
+the sun may be transmitted through space, and how that inductive action
+will effect any body in its electrical field, such inductive action
+always taking place through the polarization of the atomic Aether, and
+taking the form of an attractive power which is exerted towards the
+centre of the attracting body.
+</p>
+
+<p>
+Further, this inductive action will be subject to the same laws of
+electricity as the centrifugal force is, which is the repulsive power
+due to the pressure of the Aether. Therefore the inductive action of the
+sun upon any body will, according to the laws of electricity, act
+inversely as the square of the distance (<a href='#ART_84'>Art. 84</a>), and will be directly
+as the product of the charges on the two attracting bodies, which we
+have seen according to <a href='#ART_85'>Art. 85</a> is equal to the product of their masses.
+Not only will this inductive action apply to the sun, but it will
+equally apply to all planets, satellites and stars that exist in the
+heavens, each of these bodies according to <a href='#ART_80'>Art. 80</a> being an electrified
+body possessing its electric field and lines of force radiating out into
+space.
+</p>
+
+<p>
+Thus we arrive at the conclusion, that each body in the solar system is
+not only the centre of a centrifugal force due to the pressure of the
+electro-magnetic Aether, but that it is also the centre of an attractive
+force due to the existence of the positive and negative elements of the
+Aether, and of their attractive power for each other.
+</p>
+
+<p>
+This attractive power is also subject to exactly the same laws that the
+centrifugal force is subject to in regard to intensity, proportion, and
+the direction which it takes. So that we have now two centripetal forces
+existing in space, which exactly correspond with each other, viz.
+Gravitation Attraction and the attraction due to Electrical Induction.
+The cause of one, however, is known, being due to the inductive
+influence of the various electrified bodies that exist in space, which
+inductive influence can be traced through the whole of the atomic Aether
+that exists between the two bodies, whereas the cause of the centripetal
+force or Gravitation Attraction is unknown. According to the Rules of
+Philosophy, therefore, it will be much simpler if we replace our
+Gravitation Attraction, whose cause is unknown, by the inductive power
+of the various bodies, the physical cause of which lies in the
+electro-magnetic Aether, or the dielectric as Faraday called it. In
+other words, we are compelled to come to the conclusion that the
+centripetal force, or Gravitation Attraction so called, is an electrical
+phenomenon, which finds its physical cause in the same universal Aether
+that the centrifugal force does.<span class='pagenum'><a name='Page_287' id='Page_287'></a><a href='#TOC'>[287]</a></span>
+</p>
+
+<p>
+Unless this view of the attraction of
+Gravitation is accepted, we should have two forces operating between all
+bodies, both operating at exactly the same time, in exactly the same
+direction, and with exactly the same intensity, and this phenomenon
+according to Newton would be unphilosophical. In <a href='#ART_4'>Art. 4</a> we learn that
+Newton in the first rule states that &ldquo;Nature is simple, and does not
+abound in superfluous causes of things.&rdquo; And again: &ldquo;In the nature of
+Philosophy nothing is done in vain; and by means of many things, it is
+done in vain when it can be done by fewer.&rdquo; Here then we have apparently
+two forces which act in the same molecular or planetary or interstellar
+space, at one and the same time. Therefore if this be true, Nature does
+abound in a superfluous cause, because we have two forces in existence
+where one will suffice, and one of them therefore exists in vain. So
+that it will be philosophical if we do away with one of the causes, and
+replace the two causes by only one. Now which shall be done away
+with--the electrical attraction which is due to a physical medium, the
+electro-magnetic Aether, or the Gravitation Attraction, that is caused
+by some virtue of a body of which we have no knowledge, which is
+transmitted through space in a way that we cannot understand, and acts
+upon distant bodies in a manner altogether outside our usual experience
+and observation? There can only be one answer. If either of the two
+forces has to be done away with, it must be the mysterious, intangible,
+unphilosophical attraction of Gravitation, which must be replaced by the
+philosophical and known attraction of electricity, which can be traced
+to a physical medium, the electro-magnetic Aether that joins atom to
+atom, molecule to molecule, satellite to planet, planet to sun, and sun
+to star, and so gives unity to the universe of worlds. From
+philosophical considerations, therefore, we are compelled to come to the
+conclusion that the attraction of gravity and electrical attraction are
+one and the same.
+</p>
+
+<p>
+Faraday arrived at this conclusion and performed certain experiments to
+confirm that conclusion, but he was unable to experimentally prove the
+truth. It does not follow, however, that because he failed to
+experimentally establish the connection, therefore the conclusion is
+wrong. In his <i>Experimental Researches</i> he writes, par. 2705, &ldquo;On the
+possible relation of gravity to electricity&rdquo;:--&ldquo;First of all, a body
+which was to be allowed to fall, was surrounded by a helix, and then its
+effect in falling sought for.&rdquo; This experiment Faraday states produced
+negative results (par. 2706). &ldquo;A solid cylinder of copper was introduced
+into the helix, and carefully fastened to it, and this compound
+arrangement was allowed to fall.&rdquo; &ldquo;The result of this experiment may be
+classified as doubtful. It gave very minute, but remarkable indications
+of a current in the galvanometer, and the probability of these being<span class='pagenum'><a name='Page_288' id='Page_288'></a><a href='#TOC'>[288]</a></span>
+related to gravity appeared the greater, when it was found, in raising
+the helix or core, similar indications of contrary currents appeared.&rdquo;
+In par. 2717 Faraday thus sums up: &ldquo;Here end my trials for the present.
+The results are negative. They do not shake my strong feeling of the
+existence of a relation between gravity and electricity, though they
+give no proof that such a relation exists.&rdquo; Here then we have expressed
+the strong conviction of the relation that undoubtedly exists between
+gravity and electricity by one of the greatest scientists that has ever
+lived, and I believe that it is a fact that he was engaged upon
+experiments to prove his conviction about the time of his death.
+</p>
+
+<p>
+We will now endeavour to trace the action of the Law of Gravitation in
+its compound working, in its application to the atomic Aether that fills
+all space, and by its gravitating property surrounds all bodies situated
+in that space. We are dealing no longer with a frictionless medium,
+which is incapable of accepting and transmitting motion of any kind or
+sort, but we are now dealing with a medium composed of atoms, which can
+give rise to pressures and tensions, or repulsions and attractions from
+any one part of space to another.
+</p>
+
+<p>
+If we can prove that an atomic Aether can give rise to these pressures
+and tensions from one body to another, and those pressures and tensions
+harmonize with, and satisfactorily account for, the phenomena sought to
+be explained, then we shall have succeeded in making our philosophy
+agree with our experience, and such a result as action at a distance
+will for ever disappear from the mental conception of all men, as it has
+long disappeared from the pages of philosophical and scientific works,
+though that disappearance was not accompanied with a satisfactory
+solution of the problem.
+</p>
+
+<p>
+Let us, therefore, consider these pressures and tensions, or so-called
+repulsions and attractions that exist in this electro-magnetic Aether
+from the atomic standpoint, and by so doing try to realize how it is
+that one body, as the sun, acts upon another body, as the earth, through
+the intervening medium, the Aether. We can either consider it from the
+material standpoint, that is, by considering the Aether as matter, pure
+and simple, or by viewing it from the electrical standpoint, which may
+be considered from Clerk Maxwell's physical conception of an electric
+field. We will briefly consider it from the latter standpoint. Our
+conception of an aetherial atom was that of a spherical vortex atom
+possessing polarity and rotation on an axis. We must, however, make the
+distinction between the two kinds of aetherial atoms that Clerk Maxwell
+first indicated in his paper on Physical Lines of Force, <i>Phil. Mag</i>.,
+1861, and that Dr. Larmor has worked out in his <i>Aether and Matter</i><span class='pagenum'><a name='Page_289' id='Page_289'></a><a href='#TOC'>[289]</a></span>
+from the electron standpoint, viz. that the Aether is composed of
+positive and negative electrons. Or we can accept Professor Lodge's
+theory, that Aether is made up of positive and negative electricity. We
+are compelled to accept the hypothesis of two kinds of aetherial or
+electrical atoms, whatever they may be called, in view of the teaching
+of electricity, that positive and negative electricity are always to be
+found in association, and in combination, wherever electricity exists.
+We have proved that electricity is to be found throughout the realm of
+space (<a href='#ART_78'>Art. 78</a>); therefore in all planetary and stellar regions
+electricity is present. Thus it exists in the so-called space between
+the sun and planets, and between the planets and satellites, forming
+around them all spherical shells, that become less and less dense as
+they recede from the central body. Now it is by the action of these
+positive and negative electrical atoms, that the attraction of one body
+is transmitted across space from the sun to the earth, or from the earth
+to the sun, or from the earth to Jupiter, or from Jupiter to any of the
+planets, the action always taking place along the line joining the
+centres of gravity of the bodies, <i>i. e.</i> the radius vector, and with a
+force equal to the quantities of electricity in association with those
+bodies (<a href='#ART_85'>Art. 85</a>), and with an intensity that always acts inversely as
+the square of the distance. Thus the inductive action of any sun, planet
+or satellite, or any other planet or satellite, can be mentally traced
+from atom to atom, across the intervening space, that is filled with the
+atomic Aether, between any two attracting bodies. So that, if the sun
+attracts the earth, it attracts it by and through the motions and
+properties of the electro-magnetic Aether that is made up of positive
+and negative electricity, and that attraction, being produced by a
+physical medium which is as real and tangible as air or water, is
+brought into harmony with our experience and observation, as no body
+pushes or pulls another body, be it what it may, unless both bodies are
+joined together by some medium which transmits the push or the pull.
+Professor Lodge, in his <i>Modern Views of Electricity</i>, has illustrated
+from an electrical standpoint how the pressure and tension in any
+electrical field may be transmitted from particle to particle, or atom
+to atom. He supposes that a positive atom of electricity rotates in one
+direction while a negative atom rotates in the opposite direction. In
+any electric field these atoms are so associated with each other, that
+when one atom revolves, it makes the other to revolve in the opposite
+direction, with the result, that the spin or rotation is transmitted
+through the medium at a speed dependent upon the density of the medium.
+</p>
+
+<p>
+For fuller details of the description I must refer the reader to the<span class='pagenum'><a name='Page_290' id='Page_290'></a><a href='#TOC'>[290]</a></span>
+work already referred to. What I wish to call the reader's attention to
+is, that the tension and pressure in this field is not transmitted
+across a vacuum, in some unknown way, but is transmitted solely by a
+physical medium. The action is direct, and is produced, and alone
+produced, continued, and perpetuated by a physical medium which is
+composed of atoms of negative and positive electricity. So that if one
+body <i>A</i> acts upon another body <i>B</i>, it acts upon <i>B</i> solely and
+entirely by the action of the atoms which form the magnetic lines of
+force, and the equipotential surfaces around the electrified body, and
+that action can be traced mentally step by step across the intervening
+space that may exist between the two bodies. It is in an exactly similar
+manner, that the Attraction of Gravitation, which we conceive to be the
+same as electrical attraction, is transmitted from body to body in the
+atomic, molecular, planetary or stellar world. In each and every case,
+the pressure and tensions, which are inseparably connected, are
+transmitted by the atoms of the electro-magnetic Aether, that is, by the
+positive and negative atoms of electricity of which, according to
+Professor Lodge and Dr. Larmor, the Aether is composed. So that, if the
+sun acts on the earth, by the centrifugal force, it acts on it solely
+through and by the pressures which are originated in the atomic Aether
+by the central body. If the sun attracts the earth, by the centripetal
+force, that action can also be traced to the tensions that are
+originated among the atoms of the electro-magnetic Aether. There is
+nothing mysterious about the phenomenon in either case, as by accepting
+this view of an atomic Aether with its dual character of positive and
+negative electricity, the action may be traced mentally from point to
+point across the so-called intervening space that exists between any two
+bodies. In each and every case, wherever the centripetal or centrifugal
+force acts, the action is direct, because it is caused by a physical
+medium, which physical medium is in direct contact with each body acted
+upon, and also fills the space between those bodies. With this view of
+the centripetal force of Gravitation, our Philosophy is made to agree
+definitely with our experience, which teaches us beyond contradiction,
+that no body moves, unless it is either pushed or pulled by a physical
+medium. Unless this view of the centripetal force is accepted, we shall
+have to stumble on in darkness as to the physical cause of the
+centripetal force, and mentally accept the unphilosophical proposition,
+that a body can act on another in a way that we cannot understand, and
+by means which lie outside our experience and observation, and this
+hypothesis, as Newton and Herschel pointed out, is distinctly an
+unphilosophical proposition.
+</p>
+
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_39' id='Footnote_39'></a><a href='#FNanchor_39'><span class='label'>[39]</span></a>
+<i>Modern Views of Electricity</i>, p. 221.
+</p></div>
+
+
+
+<p><span class='pagenum'><a name='Page_291' id='Page_291'></a><a href='#TOC'>[291]</a></span></p>
+<h2><a name='CHAPTER_XII' id='CHAPTER_XII'></a><a href='#CHAPTER_XII_TOC'>CHAPTER XII</a></h2>
+
+<h3>AETHER AND COMETS</h3>
+
+<p>
+<a name='ART_111' id='ART_111'></a><span class='smcap'>Art</span>. 111. <i>Comets. What are Comets?</i>--In addition to the planets and
+asteroids which revolve around the sun, there are also other bodies
+termed Comets, which revolve round the solar orb.
+</p>
+
+<p>
+Unlike the planets, however, they do not all keep to the plane of the
+ecliptic, but approach to, and recede from the sun at all angles to that
+plane, as well as in that plane itself. Comets are supposed to be huge
+masses of gaseous matter, in a more or less condensed condition. That
+they are not composed of absolutely solid matter is proved by the fact
+that it is possible to see the stars through the gaseous matter of which
+they are composed.
+</p>
+
+<p>
+How the gaseous matter of which these comets are formed is originated,
+or how it is formed in solar or stellar space, has, I believe, up to the
+present never been explained, and indeed, with the idea of a
+frictionless Aether, I fail to see how any physical explanation of the
+origin and development of a comet can be satisfactorily given. With the
+conception of the Aether, however, that is put forward in this work,
+viz. that Aether is matter in its most rarefied and attenuated form,
+which can be condensed into a gaseous condition, with such a conception
+of the universal aetherial medium, the origin and development of gaseous
+matter from this Aether becomes a physical possibility.
+</p>
+
+<p>
+Lord Kelvin, in the <i>Philosophical Magazine</i>, July 1902, on the
+&ldquo;Clustering of Gravitational Matter in any part of the Universe,&rdquo; has
+already suggested the possibility of the condensation of the Aether, but
+with the old idea of a frictionless Aether, that is, an Aether which
+does not possess mass, such a hypothesis is improbable. Because, if the
+Aether becomes condensed at all, it must be condensed into gaseous and
+solid matter, and all experiments and observation teach us that both
+these forms of matter possess mass and weight.
+</p>
+
+<p>
+Therefore, if the frictionless Aether, which possesses no mass and
+weight, is to be condensed into gaseous or solid matter, there must come
+a period in the process of condensation when it must pass out of the
+condition of possessing no mass and no weight, into the condition of<span class='pagenum'><a name='Page_292' id='Page_292'></a><a href='#TOC'>[292]</a></span>
+possessing mass and weight, which assumption is altogether opposed to
+those Rules of Philosophy based upon experiment and observation.
+</p>
+
+<p>
+Aether can only pass into a gaseous or solid condition, in which
+condition it will possess mass and weight, on the assumption that in the
+aetherial condition it possesses the same properties, only in a modified
+form, which it possesses after the process of condensation has taken
+place. In a similar way that air can pass out of its gaseous condition
+into a liquid condition, or any gas can pass out of its gaseous into a
+liquid condition, so Aether, on the conception as given in Chapter <a href='#CHAPTER_IV'>IV</a>.,
+can pass out of its aetherial and rarefied condition into that form of
+matter which is known as gaseous. We shall deal with this aspect of
+Aether more fully when we come to deal with the Nebular Hypothesis, as
+the same principle underlies that hypothesis as underlies the origin and
+development of comets.
+</p>
+
+<p>
+Thus, comets may be formed at any time in interstellar space out of the
+Aether that exists there, provided the conditions of its formation are
+to be found there. Then, as they are gradually formed, they would, like
+any other bodies, come more directly under the influence of any large
+bodies, as the sun, and be attracted by them.
+</p>
+
+<p>
+This conception of the origin and development of a comet will also
+account, and that on a logical and philosophical basis, for another fact
+which is associated with cometary phenomena. I refer to the fact of the
+expulsion of gaseous matter out of the head of a comet as it nears the
+sun, which expulsion will be dealt with in the article on &ldquo;Parts of a
+Comet.&rdquo;
+</p>
+
+<p>
+Another problem that might be solved by this conception of a comet lies
+in the question, as to whether comets shine by their own light?
+</p>
+
+<p>
+If comets are really formed of condensed Aether, as I believe them to
+be, then, as light is due to a periodic wave motion of the Aether, as
+soon as the Aether (of which the comets' tails, for example, were
+formed) was made to vibrate with that rapidity sufficient to produce
+light waves in the surrounding Aether, the tails would then shine by
+their own light, in exactly the same way that any other body emits light
+waves, as soon as its aetherial vibrations reach the rapidity necessary
+to produce the waves of light, which vibrations would lie between 2000
+to 8000 billions per second.
+</p>
+
+<p>
+The number of the comets that exist in the solar system cannot be
+ascertained with any degree of accuracy, but the total probably extends
+into millions. They are of all sizes, from those which possess diameters
+of several miles, to those extending over thousands of miles. They also
+possess orbits, with which we will now deal.<span class='pagenum'><a name='Page_293' id='Page_293'></a><a href='#TOC'>[293]</a></span>
+</p>
+
+<p>
+<a name='ART_112' id='ART_112'></a><span class='smcap'>Art</span>. 112.
+<i>Orbits of Comets</i>.--As has already been pointed out, comets perform their journey
+round the sun, not only in the plane of the ecliptic, but also at all
+angles relatively to that plane. In this respect they differ from the
+orbits of planets and satellites, which perform their journey in orbits
+situated wholly in the plane of the ecliptic (<a href='#ART_109'>Art. 109</a>).
+</p>
+
+<p>
+There is another important difference between the orbits of the comets
+and those of the planets. In the case of the latter the orbit is that of
+an ellipse, while in the case of the comet the orbit may be either that
+of a parabola or a hyperbola, which may be looked upon as elongated
+ellipses open at one end. There are, however, some comets whose orbits
+are perfectly elliptical, and whose return may be calculated with a fair
+amount of accuracy.
+</p>
+
+<p>
+These are known either as Short Period Comets, as represented by Faye's
+Comet, Encke's and De Vico's; or Long Period Comets, as represented by
+the comets of 1811, 1844, and 1858. In the case of all these, as their
+return to our solar system can be determined, it follows that they must
+revolve around the sun in some sort of a closed orbit, probably that of
+an exceedingly elongated ellipse.
+</p>
+
+<p>
+There are, however, other comets which appear once, or it may be several
+times only, and then disappear out of the solar system for ever. Now the
+question arises, as to whether the orbits of the comets which are so
+variable can be explained by the motions of the Aether which we have
+already ascribed to it? We have seen (<a href='#ART_109'>Art. 109</a>) how it is possible to
+account physically for the plane of the ecliptic from the motions of the
+Aether, and how it is that all the planets move within that plane, but
+here we have a phenomenon of a different kind, as observation distinctly
+teaches us that the comets do not move in, or keep within the plane of
+the ecliptic, but gravitate round the sun at all angles to that plane.
+</p>
+
+<p>
+In order for us, therefore, to be able to account, and that on a
+philosophical basis, for this fact, we must revert to our conception of
+the sun in its relation to the solar system. In <a href='#ART_88'>Art. 88</a> we learned that
+the sun was an electro-magnet possessing its electro-magnetic field, and
+generating electro-magnetic waves which were radiated forth from it on
+every side. From <a href='#ART_89'>Art. 89</a> we learn that an electro-magnetic body
+possesses lines of force, and that these lines of force take various
+directions as they are generated by the body, as proved by Faraday's
+illustrations. Further, a moving electro-magnet, as the sun for example,
+carries its lines of force with it, as proved by Maxwell.
+</p>
+
+<p>
+Now these lines of force extend not only east and west, but also north
+and south, as depicted in Fig. 29.<span class='pagenum'><a name='Page_294' id='Page_294'></a><a href='#TOC'>[294]</a></span>
+</p>
+
+<p>
+Hitherto we have only dealt with the
+lines of force proceeding from the sun equatorially, which lines form
+the plane of the ecliptic. We have, now, to take into consideration
+those lines which extend out into space, north and south of that plane.
+These are not so curved as the others, but are more inclined to be
+straight, or less curved, as they are really parts of large curves which
+extend much further outwards into space.
+</p>
+
+<p>
+The orbits of the Short or Long Period Comets can be explained by the
+fact that they perform their journey more or less in the plane of the
+ecliptic, though in some cases at a much greater angle than that of any
+of the planets. Provided, however, they remain within the influence of
+the electro-magnetic field of the sun, there is then a physical
+explanation as to their orbital motion round the sun, in a similar way
+to the orbital motion of the planets, though at greater angles to the
+plane of the ecliptic.
+</p>
+
+<p>
+For we have to remember, that wherever the electro-magnetic waves of the
+sun's electro-magnetic field extend, there we have also the rotation of
+that field round its central body, though with a continually decreasing
+intensity, as already pointed out. Wherever, therefore, we get rotatory
+Aether currents, due to the rotation of the electro-magnetic field,
+there we get the conditions which would enable any kind of gaseous or
+material body to be circulated round the sun. The case, however, of
+comets which do not return has to be viewed from a different standpoint.
+Here it seems to me we are dealing with masses of condensed Aether that
+come within the inductive influence of the electro-magnetic waves of the
+sun, as that body moves through space with its velocity of about 500,000
+miles per day. We have to conceive of this condensed Aether situated
+north and south of the plane of the ecliptic, and situated probably
+millions of miles away. As the sun moves onward in its journey through
+space, carrying its electro-magnetic field with it, then, by the
+inductive action of the sun, the comet would be attracted by that body,
+and so would be gradually drawn towards it.
+</p>
+
+<p>
+Under this inductive influence it would rush towards the sun, until,
+approaching very close to it, it would be repelled by the
+electro-magnetic waves or centrifugal force of that body, and be hurled
+again by their repulsive energy far far away into space to the north or
+south of the plane of the ecliptic. As it was moving away from the syn,
+north or south of the ecliptic, the sun would be moving onwards through
+space in the plane of the ecliptic, which would practically be at right
+angles to the motion of the comet, so that by the time the comet had
+receded far into the depths of space, the sun with its electro-magnetic
+field would have moved on also in a direction at right angles to the
+comet's motion.<span class='pagenum'><a name='Page_295' id='Page_295'></a><a href='#TOC'>[295]</a></span>
+</p>
+
+<p>
+The effect of the sun's orbital motion would be, that
+it would be unable to again exert sufficient inductive power upon the
+comet to bring it within its inductive influence once more. For example,
+suppose there is a mass of Aether condensing at point <i>A</i> in
+interstellar space situated some millions of miles north of the plane of
+the ecliptic, which is represented by the straight lines <i>B C</i>. The sun
+is moving in the direction towards the part of space represented by
+point <i>B</i>. We will suppose that when the sun is near point <i>C</i> the mass
+of Aether at point <i>A</i> is too far away to be appreciably influenced by
+the inductive action of the sun. But as the sun moves towards point <i>F</i>,
+then the condensed Aether, which practically forms the body of the
+comet, will come within its influence and be drawn towards the sun, at
+an angle to the plane of the ecliptic.
+</p>
+
+<div class='figcenter' style='width: 400px;'>
+<img src='images/309.jpg' width='400' height='210'
+alt='Fig: 30.'
+title='Fig: 30.' />
+</div>
+
+<p>
+By the time the body of the comet has reached the sun, it will have
+acquired a momentum which enables it to rush past the sun, and then it
+will be repelled by the electro-magnetic waves in the direction of <i>F
+G</i>, which is still at an angle to the plane of the ecliptic; but its
+motion, combined with the repulsive power of the electro-magnetic waves,
+is carrying it outside the sphere and influence of the sun's
+electro-magnetic field. At the same time the sun is proceeding onwards
+through space, leaving the comet far behind, so that by the time the
+comet has reached the confines of the solar system, it has either passed
+under the influence of another star, or has become further condensed to
+form a meteor, which begins to circle around the largest and nearest
+body. I do not assert that this hypothesis is strictly correct, but it
+seems to me that only on some such hypothesis can the appearance and
+apparent loss of irregular comets be explained.<span class='pagenum'><a name='Page_296' id='Page_296'></a><a href='#TOC'>[296]</a></span>
+</p>
+
+<p>
+<a name='ART_113' id='ART_113'></a><span class='smcap'>Art</span>. 113. <i>Short Period
+Comets and Long Period Comets</i>.--We have seen in the previous article,
+that some Comets revolve round the sun in closed orbits of exceeding
+great eccentricity, and the return of these may be calculated with
+certainty. There are about two dozen comets which revolve around the
+sun, and which return at intervals lying between three years and 76
+years.
+</p>
+
+<p>
+This class of comets may be divided into two kinds, which are known as
+Short Period Comets and Long Period Comets respectively. The following
+table gives a list of the chief of the Short Period Comets, together
+with some particulars relating to time of revolution, etc.:--
+</p>
+
+<table summary='velocities'>
+
+<tr><th colspan='1' style='text-align: left;'><span class='smcap'>comets.</span></th><th colspan='2'><span class='smcap'>period of<br />revolution.</span></th><th colspan='2'><span class='smcap'>perihelion<br />distance.</span></th><th colspan='2'><span class='smcap'>aphelion<br />distance</span></th></tr>
+
+<tr><td style='text-align: left;'>Encke's</td><td style='text-align: right;'>3-1/4</td><td style='text-align: center;'>years.</td><td style='text-align: right;'>32,000,000</td><td style='text-align: center;'>miles.</td><td style='text-align: right;'>387,000,000</td><td style='text-align: center;'>miles.</td></tr>
+
+<tr><td style='text-align: left;'>De Vico's</td><td style='text-align: right;'>5-1/2</td><td style='text-align: center;'>"</td><td style='text-align: right;'>110,000,000</td><td style='text-align: center;'>"</td><td style='text-align: right;'>475,000,000</td><td style='text-align: center;'>"</td></tr>
+
+<tr><td style='text-align: left;'>Biela's</td><td style='text-align: right;'>6-1/2</td><td style='text-align: center;'>"</td><td style='text-align: right;'>82,000,000</td><td style='text-align: center;'>"</td><td style='text-align: right;'>585,000,000</td><td style='text-align: center;'>"</td></tr>
+
+<tr><td style='text-align: left;'>D'Arrest's</td><td style='text-align: right;'>6-1/2</td><td style='text-align: center;'>"</td><td style='text-align: right;'></td><td style='text-align: center;'>"</td><td style='text-align: right;'></td><td style='text-align: center;'>"</td></tr>
+
+<tr><td style='text-align: left;'>Faye's</td><td style='text-align: right;'>7-1/2</td><td style='text-align: center;'>"</td><td style='text-align: right;'>192,000,000</td><td style='text-align: center;'>"</td><td style='text-align: right;'>603,000,000</td><td style='text-align: center;'>"</td></tr>
+
+<tr><td style='text-align: left;'>Halley's</td><td style='text-align: right;'>76-3/4</td><td style='text-align: center;'>"</td><td style='text-align: right;'>56,000,000</td><td style='text-align: center;'>"</td><td style='text-align: right;'>3,200,000,000</td><td style='text-align: center;'>"</td></tr>
+
+</table>
+
+
+<p>
+Encke's Comet was discovered by Professor Encke of Berlin, and named
+after him. It revolves in an ellipse of great eccentricity, as proved by
+the fact that when nearest to the sun, it is inside Mercury's orbit, but
+when furthest away from the sun, it passes beyond the orbit of Mars,
+reaching almost to the orbit of Jupiter. One of the most remarkable
+facts about this comet is, that it has done more to establish the
+existence of that resisting medium around the sun, whose existence we
+have demonstrated, than any other comet. Encke found on its periodical
+return that its mean distance was gradually getting less, and in order
+to account for this, he supposed that it was due to the existence of a
+resisting medium which enveloped the sun, and extended some distance
+into space.
+</p>
+
+<p>
+This conclusion has been supported in recent years by Von Asten, a
+German mathematician, who has supported the theory of a resisting
+medium. On this point Herschel writes in his <i>Outlines of Astronomy</i>,
+Art. 577: &ldquo;This is evidently the effect which would be produced by a
+resistance experienced by the comet from a very rare aetherial medium
+pervading the regions in which it moves; for such resistance, by
+diminishing its actual velocity, would diminish its centrifugal force.
+Accordingly, this is the solution proposed by Encke, and at present
+generally received.&rdquo;
+</p>
+
+<p>
+So that we have in Encke's Comet another proof of the existence of that
+aetherial medium, which is not frictionless, but has the power to oppose
+any body which moves through it, when that body moves in an opposite
+direction to its own motions.<span class='pagenum'><a name='Page_297' id='Page_297'></a><a href='#TOC'>[297]</a></span>
+</p>
+
+<p>
+Another Short Period Comet worthy of
+notice is that of Biela, named after M. Biela, its discoverer. This
+comet had a period of six and a half years, and reappeared at several
+successive intervals until about the year 1845, when it seems to have
+been broken or split up into two parts. In December 1845 the comet
+divided into two parts, which travelled parallel to each other for a
+long distance. During this separation, very singular changes were
+observed to be taking place in both the original comet and its offshoot.
+</p>
+
+<p>
+Both had a nucleus, and both had tails, which were parallel to each
+other. The comets continued to travel together until the 15th March
+1846, when the new comet began to fade away, until, on the 24th March,
+the old comet only was visible, while in April both had disappeared
+entirely. A similar phenomenon was again observed at its next passage in
+1852, but since then Biela's Comet has entirely disappeared. It is
+suggested by astronomers, that the comet has become condensed, and
+broken up, forming a shoal of meteors.
+</p>
+
+<p>
+Support is lent to this theory by the fact that in November 1872, when
+the earth was passing through space and had arrived at that part of its
+orbit which intercepted the orbit of Biela's Comet, instead of the comet
+being seen, the earth came into contact with a swarm of meteors, and
+this is accepted as evidence that Biela's Comet was condensed far away
+in the colder regions of interplanetary space into a more solid form of
+matter, known as meteors. One of the more famous of the short period
+class of comets is that known as Halley's Comet, which has a period of
+about 76 years. This comet has been seen in its return journey to the
+sun about 25 times. It was named after its discoverer, Edmund Halley. He
+was led to identify this comet with that of 1531 and 1607, and thus to
+conclude that it had a period of 75 or 76 years. He therefore predicted
+its reappearance in 1759. As the year approached, its arrival was
+eagerly looked for, to see if the prediction would be verified.
+</p>
+
+<p>
+It was thought, however, by a certain astronomer named Clairaut, that
+the larger planets, as Saturn and Jupiter, might interfere with its
+orbital motions, and after careful calculations a difference of 618 days
+was allowed, which brought its anticipated reappearance down to April
+1759. It actually reappeared in March of that year. Its next
+reappearance was fixed to take place about November 1835. The comet
+became visible on 5th August 1835, and continued to be seen till April
+1836, when it again disappeared.
+</p>
+
+<p>
+As the reappearance of the comet was calculated by the application of
+the Newtonian Law of Gravitation, such a result only gave added<span class='pagenum'><a name='Page_298' id='Page_298'></a><a href='#TOC'>[298]</a></span>
+confirmation to the application of that law to cometary bodies.
+</p>
+
+<p>
+Of the Long Period Comets there are several known. That of 1858 has a
+period, it is thought, of 2000 years. The 1811 comet has a period of
+3000 years, while that of 1844 has a period of over 10,000 years. All
+these comets move in orbits of such great size that their return is
+improbable. One of the characteristic features about Long Period Comets
+is their great brilliancy and size.
+</p>
+
+<p>
+The 1858 comet, known as Donati's Comet, was first seen by that
+astronomer at Florence in June. It was invisible, however, to the naked
+eye, as it only appeared through the telescope like a faint cloud of
+light, gradually getting brighter and brighter. Toward the end of August
+it began to show signs of developing a tail, and became visible to the
+eye on August 29th. During September and October it greatly increased in
+size and brilliancy, and was plainly visible in the western heavens.
+After October 10th it was only visible in the southern hemisphere,
+gradually decreasing in brightness. It was seen till March 1859, when it
+disappeared, and will probably not return till the year 3858, as its
+period of revolution is about 2000 years.
+</p>
+
+<p>
+Donati's Comet passed between the earth and many stars, which could be
+seen very distinctly through its tail. One of the stars was Arcturus,
+and, though some of the densest parts of the comet passed over it, yet
+the star could be seen all the time, thus conclusively proving that the
+head and tail of a comet are only composed of gaseous matter, probably
+condensed Aether, as suggested in <a href='#ART_111'>Art. 111</a>.
+</p>
+
+<p>
+<a name='ART_114' id='ART_114'></a><span class='smcap'>Art</span>. 114. <i>Parts of a Comet</i>.--A comet may be divided into three parts:
+1st, Nucleus; 2nd, Head or Coma; and 3rd, Tail.
+</p>
+
+<p>
+The nucleus is the central part of the head or coma, and is generally
+the brightest part of the whole comet. On the theory that a comet is due
+to the condensation of Aether, the nucleus would represent the first act
+in the process of condensation, as there would have to be some centre of
+condensation, and that centre would be represented by the nucleus.
+Further, the process of condensation would assume a spherical form, as
+the conception of our aetherial atom is that of a sphere or an oblate
+spheroid. As the process of condensation went on, the layers that would
+be produced would form a kind of envelope around the point of
+condensation, with the result that the nucleus would ultimately consist
+of a large mass of gaseous matter, made up of layer upon layer of
+condensed Aether around some central point, which formed the nucleus.
+</p>
+
+<p>
+This hypothesis agrees with observed phenomena, because, when we deal
+with the tails of comets, we shall see that the tail is simply formed<span class='pagenum'><a name='Page_299' id='Page_299'></a><a href='#TOC'>[299]</a></span>
+by the reverse process to that of condensation, as in the case of
+cometary tails the gaseous envelopes so formed will be thrown off
+(either through heat generated by friction, or by the increased heat as
+the comet nears the sun), which are then repelled away from the sun by
+the centrifugal force. Herschel,<a name='FNanchor_40' id='FNanchor_40'></a><a href='#Footnote_40' class='fnanchor'>[40]</a>
+ referring to the nucleus, states,
+paragraph 559: &ldquo;An atmosphere free to expand in all directions would
+envelop the nucleus spherically,&rdquo; while in his Reflection on Halley's
+Comet, he states, Art. 570, &ldquo;1st, That the matter of the nucleus of a
+comet is powerfully excited and dilated into a vaporous state by the
+action of the sun's rays, escaping in streams and jets at those points
+of its surface which oppose the least resistance. 2nd, That the process
+chiefly takes place in that portion of the nucleus which is turned
+towards the sun, the vapour escaping in that direction. 3rd, That when
+so emitted, it is prevented from proceeding in the direction originally
+impressed upon it, by some force directed <i>from</i> the sun, drifting it
+back and carrying it out to vast distances behind the nucleus forming
+the tail.&rdquo;
+</p>
+
+<p>
+When we come to deal with the question of the formation of the tail, we
+shall find that every reflection made by Herschel is satisfactorily
+fulfilled by the conception of a gravitating and condensing Aether.
+Before considering the tail, however, we will deal with the head or
+coma.
+</p>
+
+<p>
+The head or coma is that part of the comet which exists round the
+nucleus. It is less bright than the nucleus, and oftentimes appears as a
+shadowy mass of light. Herschel, in his 4th Reflection, states that &ldquo;a
+considerable part of the vapour actually produced remains in the
+neighbourhood of the nucleus forming the head or coma.&rdquo; So that the head
+of a comet is simply the vaporised part of the nucleus which is produced
+by the increased heat of the sun, in the same way that water would be
+vaporised by the addition of heat, the vapour in that case being thrown
+off in the form of steam.
+</p>
+
+<p>
+This formation of the head is but a continuation of the reversal of the
+process of condensation, which originally gave existence to the mass of
+matter termed the comet. The diameter of this head or coma often extends
+to thousands of miles. The head of the 1811 comet was 540,000 miles in
+diameter, while that of the 1843 was 112,000 miles. As the nucleus is
+formed of a series of envelopes, so the head also consists of a series
+of envelopes.
+</p>
+
+<p>
+The comet of 1858 constantly threw off these envelopes, which were first
+expelled <i>towards</i> the sun, and then repelled away <i>from</i> the sun,
+forming the tail. The matter forming the head and the nucleus is
+perfectly transparent, as stars have been seen<span class='pagenum'><a name='Page_300' id='Page_300'></a><a href='#TOC'>[300]</a></span>
+through the matter which forms
+those parts. Herschel,<a name='FNanchor_41' id='FNanchor_41'></a><a href='#Footnote_41' class='fnanchor'>[41]</a>
+ paragraph 558, states &ldquo;that whenever powerful
+telescopes have been turned on these bodies, they have not failed to
+dispel the illusion which attributes solidity to that more condensed
+part of the head which appears to the naked eye, though it is true that
+in some a very minute stellar point has been seen indicating the
+existence of a stellar body.&rdquo;
+</p>
+
+<p>
+<i>Tails</i>.--The tail of a comet is that part which flows from the head,
+and is afterwards repelled by the repulsive power of the sun into space.
+We shall deal with this repulsive power, whose existence we have already
+demonstrated, and the part which it plays in the formation of a comet's
+tail, in the next article. The tail of a comet is oftentimes considered
+to be the comet itself, rather than a part of the same, but as the tail
+is the most distinctive feature of a comet, and is the part most visible
+to the naked eye, there has arisen the popular but mistaken idea of
+identity between the tail and the comet itself.
+</p>
+
+<p>
+Tails are of all kinds. There are some which are short, while others are
+long. Then we have comets with single tails, or double, and in some
+cases even multiple tails. Occasionally comets appear which have no
+tails at all. The comet of 1744 had six tails, which spread out in the
+shape of a large fan.
+</p>
+
+<p>
+One of the most remarkable features of tails is their abnormal length,
+which oftentimes reaches into millions of miles. The comet of 1843 had a
+tail 112,000,000 miles long. Another feature about the tails of comets
+is that they are always directed <i>away</i> from the sun. Up to the present
+I believe no satisfactory explanation has been given of this fact, but
+with the conception of the rotating Aether as given in <a href='#ART_94'>Art. 94</a>, we shall
+for the first time be able to give a satisfactory physical explanation
+of that phenomenon. In addition to this, the formation of cometary tails
+of all shapes receives a physical explanation, when taken into account
+with the fact that the sun is an electro-magnet, possessing its
+electro-magnetic field, and its lines of force, as described in <a href='#ART_88'>Art. 88</a>.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_40' id='Footnote_40'></a><a href='#FNanchor_40'><span class='label'>[40]</span></a>
+<i>Outlines of Astronomy</i>.
+</p></div>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_41' id='Footnote_41'></a><a href='#FNanchor_41'><span class='label'>[41]</span></a>
+<i>Outlines of Astronomy</i>.
+</p></div>
+
+
+<p>
+<a name='ART_115' id='ART_115'></a><span class='smcap'>Art</span>. 115. <i>Centrifugal Force and Comets' Tails</i>.--In order to account
+for the existence of the tails of comets, various repulsive forces have
+been introduced from time to time into the solar system, so that the
+phenomena of cometary tails might be satisfactorily accounted for.
+</p>
+
+<p>
+It has been felt by every astronomer that some repulsive force, which
+had its origin in the sun, was absolutely necessary to explain the
+existence of the tails, and as no real force could be demonstrated to
+exist, recourse had to be made to repulsive<span class='pagenum'><a name='Page_301' id='Page_301'></a><a href='#TOC'>[301]</a></span>
+forces of a more or less
+hypothetical nature. The necessity of this repulsive force is nowhere
+more plainly indicated than by Sir J. Herschel in his <i>Lectures on
+Scientific Subjects</i>, where, dealing with the phenomena of comets'
+tails, he writes: &ldquo;They have furnished us with a proof, amounting to
+demonstration, of the existence of a repulsive force directed from the
+sun, as well as that great and general attractive force which keeps
+planets in their orbits.&rdquo;
+</p>
+
+<p>
+In the same work, referring to the comet of 1680, he writes: &ldquo;This comet
+was perhaps the most magnificent ever seen. It appeared from November
+1680 to March 1681. In its approach to the sun it was not very bright,
+but began to throw out its tail when about as far from the sun as the
+earth. It passed its perihelion on December 8th, and when nearest to the
+sun was only about 1/10 part of the sun's diameter from the surface. No
+wonder it gave evidence of violent excitement, coming from the cold
+region outside planetary space. Already, when arrived even in our
+temperate regions, it began to show signs of internal activity. The head
+had begun to develop and the tail to elongate, till the comet was for a
+time lost sight of. No human eye beheld the wondrous spectacle which it
+must have offered on December 8th. Only <i>four days</i> afterwards, however,
+it was seen again, and the tail, whose direction was reversed, and which
+observe could not possibly be the same tail, its tail had already
+lengthened out to the extent of about 90 millions of miles, so that it
+must have been shot out with immense force in a direction <i>from</i> the
+sun.&rdquo;
+</p>
+
+<p>
+The reader will have observed it took from November 10th to December
+8th, or 28 days, to fall to the sun for the same distance, and that with
+all the velocity it had on November 10th to start with. Herschel sums up
+the matter thus: &ldquo;Beyond a doubt, the widest and most interesting
+prospect of future discovery which their study (comets' tails) holds to
+us, is, that distinction between gravitating and levitating matter, that
+positive and unrefutable demonstration of the existence in nature of a
+repulsive force co-extensive with, but enormously more powerful than the
+attractive force we call gravity, which the phenomena of their tails
+afford.&rdquo;
+</p>
+
+<p>
+Thus the philosophic mind of Herschel saw in the existence of cometary
+tails, the irrefutable evidence of the existence of a repulsive force,
+not of a hypothetical character, but as real as the existence of gravity
+itself. Various attempts have been made to define that repulsive force
+which was thus demanded, and the same force has been ascribed by
+scientists to the repulsion due to heat, to light, and also to
+electricity.
+</p>
+
+<p>
+Several French scientists have suggested that the repulsive force was
+due to the heat of the sun. M. Roche was one of those who stated that<span class='pagenum'><a name='Page_302' id='Page_302'></a><a href='#TOC'>[302]</a></span>
+the phenomena of cometary tails was due to the repulsive power of heat,
+which found its origin in the heat of the sun. M. Faye, another French
+scientist, states that the repulsive force had its origin in the heat of
+the sun. By a series of experiments he demonstrated that there was a
+repulsive power in all heat waves, which gave his theory that
+experimental support that any theory must possess to make it permanent.
+</p>
+
+<p>
+Now in <a href='#ART_63'>Art. 63</a> it was shown that heat does possess a repulsive power,
+but that that power is rather due to the electro-magnetic Aether whose
+vibrations produce the heat waves, than to the repulsion of heat; so
+that, indirectly, the assumption of both these French scientists, that
+the repulsive power of heat gave rise to the tails of comets, is
+correct. Then again it has been suggested that the repulsive power is
+produced by the pressure of the light waves. Professor Lebedew suggested
+this after he had experimentally proved that light waves did possess a
+repulsive power (<i>Annalen der Physik</i>, November 1901). It can easily be
+seen, as pointed out in <a href='#ART_70'>Art. 70</a>, that, inasmuch as light is due to the
+vibrations of the Aether, they too possess this repulsive power, and
+therefore Professor Lebedew's suggestion as to the nature of the
+repulsive power is correct, as the real centrifugal force is really due
+to an aetherial pressure.
+</p>
+
+<p>
+Whether, therefore, we consider it from the standpoint of heat, or light
+or electricity, it ultimately resolves itself into the same aetherial
+medium which is at once the common source of all these forces. Again, it
+has been suggested that the repulsive power is electrical or
+electro-magnetic, and this view is receiving more support than either of
+the others from modern scientists.
+</p>
+
+<p>
+Herschel suggested that the repulsive power was electrical, while
+Bredichin has worked out a very careful theory as to the effect of
+electrical repulsion upon different elements that are found in the
+comets' tails, with a view to explain the different shapes of the tails.
+But whether the force is looked at from the standpoint of heat, light or
+electricity, it ultimately resolves itself into the motions of the
+Aether, which gives rise by its different vibrations and motions to all
+the three forms of energy referred to.
+</p>
+
+<p>
+When we also take into account the fact that Aether is gravitative, and
+therefore denser nearer to the sun than further away, and that it is
+also rotating round the central body the sun (<a href='#ART_91'>Art. 91</a>), then we have at
+once every condition necessary to explain all the various kinds of
+cometary tails, and also for the remarkable fact that the tail is always
+turned away from the sun, which is simply due to the effect of the
+rotating Aether with its outflowing electro-magnetic waves upon the
+gaseous matter of the comet. Thus from the phenomena of comets' tails,
+we have again arrived at the conclusion of the existence of that
+centrifugal force, whose origin and continuity are to be found in the<span class='pagenum'><a name='Page_303' id='Page_303'></a><a href='#TOC'>[303]</a></span>
+electro-magnetic Aether which surrounds the sun, and which by its
+electro-magnetic waves gives rise to pressure on all bodies upon which
+they fall.
+</p>
+
+
+<p>
+<a name='ART_116' id='ART_116'></a><span class='smcap'>Art</span>. 116. <i>Formation of Tails</i>.--With the conception of the formation of
+the comet advanced in <a href='#ART_111'>Art. 111</a>, viz. that it is nothing more or less
+than Aether in a state of condensation, and remembering the explanation
+given of the parts of the comet, as the nucleus, and head or coma, we
+are now in a position to give a philosophical account of the formation
+of the tails of comets, which will satisfactorily fulfil all the Rules
+of Philosophy. In addition to the facts already referred to in the
+previous articles of this chapter, we must also recall our conception of
+the Aether as given in Chapter <a href='#CHAPTER_IV'>IV</a>., remembering that it gets denser
+nearer the sun, and that it is not frictionless; therefore, when a body
+is urged through it, friction is produced, and heat is generated.
+</p>
+
+<p>
+We must also remember that the Aether is rotating round the sun as that
+body proceeds through space. We have, therefore, to picture the
+condensed mass of Aether situated out in the cold interstellar space,
+gradually coming under the influence of the sun, as that body rushes on
+its journey through space with a velocity of 500,000 miles per hour.
+</p>
+
+<p>
+Slowly, but surely, the mass of condensed Aether begins to respond to
+the attractive power of the sun, and to move through space towards the
+sun. So long as it is moving towards the sun, it is encountering and
+having to overcome the resistance of the Aether.
+</p>
+
+<p>
+At first this resistance is very feeble, owing to the decreased density
+of the Aether, but as it proceeds on its journey it is constantly
+passing into denser parts of the aetherial electro-magnetic field around
+the sun. The result is, that as the resistance is increased, so there is
+greater friction between the matter of the comet and the atomic Aether
+in space, and, in consequence, heat is generated.
+</p>
+
+<p>
+In addition to the generated heat, the comet is all the while passing
+into regions of greater intensity of heat. In both cases, the effect is
+only manifested on that side of the comet which is approaching the sun;
+for, if there be any friction at all, it will only be on that half of
+the comet which encounters the Aether, so to speak, while the same part
+will receive the added heat, as the distance between the comet and the
+sun is decreased. As can readily be seen therefore, this added heat acts
+only upon the half of the comet which is advancing, and which faces the
+sun, and as the effect of heat is always to vaporise, so the effect on
+the nucleus of the comet is to vaporise the condensed aetherial matter,
+and this vaporised aetherial matter is thrown off in layers which are<span class='pagenum'><a name='Page_304' id='Page_304'></a><a href='#TOC'>[304]</a></span>
+partly spherical in form, the layers always being expelled in the first
+instance <i>towards</i> the sun, on account of that centrifugal motion which
+has its birth in the nucleus of the comet.
+</p>
+
+<p>
+This explanation fully establishes and confirms the first and second
+Reflections of Herschel as given in <a href='#ART_114'>Art. 114</a>, and, moreover, is itself
+established by the very phenomena which comets present in their approach
+to the sun. As soon, however, as the vaporised matter is expelled from
+the nucleus towards the sun, it is met by the centrifugal motion of the
+electro-magnetic Aether which proceeds <i>from the sun</i>, and this pressure
+of the aetherial waves on the advancing comet acts as a repelling power,
+literally repelling the vaporised matter from the sun, and thus giving
+rise to the existence of its tail.
+</p>
+
+<p>
+This explanation fully confirms the third Reflection of Herschel
+referred to in <a href='#ART_114'>Art. 114</a>, and is itself also confirmed by actual
+observation. During all this time, however, the comet has been
+approaching the sun with a decreased velocity, for its velocity has been
+minimised by the resistance it has had to overcome in its approach to
+the sun. As soon, however, as it reaches the sun, it is whirled round
+that body by the rotating Aether medium, as the intensity of its
+rotation is greatest nearest the sun, with a velocity which often
+exceeds thousands of miles per hour.
+</p>
+
+<p>
+Having passed its perihelion, in view of the physical existence of our
+centrifugal motion, let us now ask ourselves what ought to happen to the
+comet? Previous to its perihelion, the comet's motion and the
+centrifugal motion due to the pressure of the Aether were in opposition,
+but after passing the perihelion, the comet's motion and the centrifugal
+motion will be acting conjointly, with the result that the motion of the
+comet would be accelerated. Now this is exactly what observation teaches
+us does happen in regard to comets, when they have passed their
+perihelion passage.
+</p>
+
+<p>
+As Herschel pointed out with reference to the comet of 1680 (<a href='#ART_114'>Art. 114</a>),
+it took 28 days to fall to the sun, but only took four days to cover the
+<i>same</i> distance, after it had passed the sun and rounded the perihelion.
+So that we have here, as Herschel stated, an irrefutable evidence of the
+existence of the repulsive power whose existence we have demonstrated.
+</p>
+
+<p>
+Again, there is another fact which has to be taken into consideration in
+regard to the tails of comets. Observation teaches us that their tails
+are invariably turned <i>from</i> the sun, though why they always are so
+turned away is an unsolved problem, apart from some real or hypothetical
+repulsive power. We have, however, to further remember that the
+electro-magnetic Aether around the sun is ever rotating with that body,<span class='pagenum'><a name='Page_305' id='Page_305'></a><a href='#TOC'>[305]</a></span>
+and carrying with it in its rotation all associated planets and meteors.
+</p>
+
+<p>
+This rotation of the Aether plays a most important part in the phenomena
+stated. Whether the comet is approaching the sun, or receding from the
+sun, it is still subject to the influence of this rotatory Aether
+medium. The result will be that the lighter particles of the vaporised
+matter will be acted upon more powerfully than the heavier parts, so
+that even when the comet is receding from the sun, after it has passed
+the perihelion, the lighter parts which go to form the tail will be more
+under the influence of the repelling Aether waves than the heavier
+parts, as the nucleus, as suggested by Bredichin.
+</p>
+
+<p>
+Thus the natural result will be that the tail will still be directed
+away from the sun even when it is receding from that body. Gradually,
+however, as the comet recedes, it passes out of the denser Aether, where
+the intensity of motion and vibration are greatest, to those slower
+parts of the sun's aetherial field where they are less intense.
+</p>
+
+<p>
+The effect of this is soon made manifest on the tail and head of the
+comet. The process which took place as it approached the sun is now
+exactly reversed, as it is now passing out of a denser into a more
+rarefied medium, where its motions and vibrations are less intense. The
+tail, therefore, appears to be drawn back to the head, while the head
+will itself gradually contract into the nucleus, as it recedes further
+and further into space. If the comet be situated within the plane, or
+nearly the plane of the ecliptic, then it is possible for it to return
+again, and go through the same process, unless it is captured on its
+outward journey by some of the large outer planets, as Jupiter. If,
+however, their planes do not coincide with the plane of the ecliptic,
+then it is very possible that they will not reappear again, but pass on
+to some other stellar system. Thus we can explain on a strictly
+philosophical basis one of the most interesting, and yet one of the most
+mysterious phenomena associated with our solar system, from the simple
+yet truly philosophical assumption that Aether is matter, in conjunction
+with all that that assumption logically involves.
+</p>
+
+<p><span class='pagenum'><a name='Page_306' id='Page_306'></a><a href='#TOC'>[306]</a></span></p>
+<h2><a name='CHAPTER_XIII' id='CHAPTER_XIII'></a><a href='#CHAPTER_XIII_TOC'>CHAPTER XIII</a></h2>
+
+<h3>AETHER AND STARS AND NEBULAE</h3>
+
+<p>
+<a name='ART_117' id='ART_117'></a><span class='smcap'>Art</span>. 117. <i>The Starry World</i>.--In addition to the planets and comets
+that are found in the heavens, there are other bodies, countless in
+their number, which we know as stars. Who has not looked up into the
+heavens on some clear night, and noticed how the vault of heaven was
+spangled over with points of light, each point representing a huge sun
+that exists in far-off space? For it must be remembered that every star
+is a sun, which, reasoning by analogy, is the centre of a stellar
+system, just in the same way that our sun is the centre of our solar
+system. Like our sun, all stars shine by their own light, and the
+quality of that brilliancy decides the magnitude of the star, the
+magnitude being indicative of the relative brilliancy of a star rather
+than its size. So that stars are divided into groups according to their
+magnitude, the magnitudes ranging from the first to the sixteenth, and
+even beyond. Those of the first magnitude are more brilliant than those
+of the second, those of the second more brilliant than those of the
+third, each magnitude decreasing in relative brilliancy as the number
+which indicates the magnitude increases. There are about sixteen
+different degrees of magnitude, in which are classified the millions of
+stars that exist in infinite space, but only stars up to the sixth
+magnitude are visible to the naked eye, the telescope revealing those
+which lie beyond. The total number of stars visible to the naked eye are
+about 6000, half of which are visible in each hemisphere.
+</p>
+
+<p>
+About 20 stars comprise the group of the first magnitude, which include
+all the brightest stars visible, as Sirius, Canopus, Alpha, Arcturus,
+Rigel, and Capella.
+</p>
+
+<p>
+Those of the second magnitude number about 65, and include the brighter
+stars to be found in the constellation known as the Great Bear. Stars of
+the third magnitude number about 200, of the fourth magnitude about 400,
+of the fifth magnitude 1100, and of the sixth magnitude about 3200.
+</p>
+
+<p>
+With the aid of the telescope about 13,000 stars of the seventh
+magnitude are revealed to us, and 40,000 of the eighth magnitude, while
+of the ninth magnitude over 140,000 are revealed by the telescope. As<span class='pagenum'><a name='Page_307' id='Page_307'></a><a href='#TOC'>[307]</a></span>
+the power of the telescope is increased, so the number revealed is
+increased also, until by the time we have reached stars of the
+fourteenth magnitude, at least 20,000,000 are revealed to us.
+</p>
+
+<p>
+If we look into the heavens on a clear moonlight night, we shall further
+see that here and there are groups of stars clustered together. These
+clusters are termed constellations, and are named after some object
+which the arrangement of the stars seemed to suggest. Thus every one is
+familiar with that constellation known as the Great Bear, or the
+&ldquo;Plough,&rdquo; so called because of its resemblance to a plough.
+</p>
+
+<p>
+The brightest stars of each constellation are named after the letters of
+the Greek alphabet, the brightest being called Alpha, the next in
+brilliancy Beta, and so on, right through the Greek alphabet. For
+example, the seven stars in the Great Bear are known as Alpha, Beta,
+Gamma, Delta, Epsilon, Zeta, and Eta.
+</p>
+
+<p>
+The constellations are grouped into two divisions, known as the Northern
+and Southern constellations respectively.
+</p>
+
+<p>
+The visible Northern constellations are 25 in number, and include the
+following well-known groups--
+</p>
+
+
+<table summary='constellations'>
+
+<tr><td></td><td style='text-align: left;'>Ursa Major</td><td style='text-align: left;'>The Great Bear</td><td></td></tr>
+
+<tr><td></td><td style='text-align: left;'>Ursa Minor</td><td style='text-align: left;'>The Little Bear</td><td></td></tr>
+
+<tr><td></td><td style='text-align: left;'>Draco</td><td style='text-align: left;'>The Dragon</td><td></td></tr>
+
+<tr><td></td><td style='text-align: left;'>Hercules</td><td style='text-align: left;'>Hercules</td><td></td></tr>
+
+<tr><td></td><td style='text-align: left;'>Cygnus</td><td style='text-align: left;'>The Swan</td><td></td></tr>
+
+<tr><td></td><td style='text-align: left;'>Lyra</td><td style='text-align: left;'>The Lyre</td><td></td></tr>
+
+</table>
+
+<p>
+The visible Southern constellations are 18 in number, and include such
+groups as--
+</p>
+
+<table summary='constellations'>
+<tr><td></td><td style='text-align: left;'>Cetus</td><td style='text-align: left;'>The Whale</td><td></td></tr>
+<tr><td></td><td style='text-align: left;'>Orion</td><td style='text-align: left;'>Orion</td><td></td></tr>
+<tr><td></td><td style='text-align: left;'>Canis Major</td><td style='text-align: left;'>The Great Dog</td><td></td></tr>
+<tr><td></td><td style='text-align: left;'>Canis Minor</td><td style='text-align: left;'>The Little Dog</td><td></td></tr>
+<tr><td></td><td style='text-align: left;'>Corona Australis</td><td style='text-align: left;'>The Southern Crown</td><td></td></tr>
+<tr><td></td><td style='text-align: left;'>Crux Australis</td><td style='text-align: left;'>The Southern Cross</td><td></td></tr>
+</table>
+
+<p>
+<i>Variable Stars</i>.--Not only are the stars of different magnitudes, but
+the brilliancy of some of them changes from time to time. This class of
+stars is known as variable stars, and has received the attention of
+modern astronomers for many years, in order that the cause of their
+variation might, if possible, be ascertained. The periods of variation
+differ in length, ranging from a number of days to 60 or 70 years.
+</p>
+
+<p>
+One of the most interesting of variable stars is that known as Omicron
+Ceti, whose period of change is about 331 days. Its brilliancy varies<span class='pagenum'><a name='Page_308' id='Page_308'></a><a href='#TOC'>[308]</a></span>
+from one of the second magnitude to one of the tenth.
+</p>
+
+<p>
+Beta Persei is another well-known variable star. This star shines as one
+of the second magnitude for 2 days and 13 hours, and then suddenly loses
+its light, and in less than 4 hours becomes a star of the fourth
+magnitude. Its brilliancy then increases again, and in a similar time it
+regains its former brilliancy.
+</p>
+
+<p>
+The conclusion that has been arrived at in regard to the cause of the
+variation of these stars is, that in each case the diminution of light
+is due to the existence of dark bodies, probably planets, which revolve
+round the central star.
+</p>
+
+<p>
+This hypothesis was confirmed by Professor Vogel about 1889 by means of
+spectroscopic results.
+</p>
+
+<p>
+Another interesting fact about stars is that they shine with various
+colours. The colours of stars are as various as the colours of the
+rainbow, and range through the whole spectrum, of red, orange, yellow,
+green, blue, indigo, violet, and white. What is more remarkable is the
+fact that the colours of the stars seem to change through great periods
+of time. If we turn to ancient records we learn that Sirius was red
+then, but is now green, while Capella was also red, but is now pale
+blue.
+</p>
+
+<p>
+<i>Double and Multiple Stars</i>.--Many stars when looked at through powerful
+telescopes are found to be double, triple, quadruple, and even multiple,
+although when looked at by the naked eye, they seem to be single in
+appearance.
+</p>
+
+<p>
+An example of a double star is to be found in the constellation of Lyra.
+A moderate telescope reveals this as a double star, while a still more
+powerful telescope reveals the strange fact that each apparently single
+star which forms the double is itself double, so that we have in this
+constellation a system of four stars, in which each pair revolves round
+a point situated between them.
+</p>
+
+<p>
+Several thousand double stars are known altogether, while the motions of
+several hundreds of them have been detected with powerful telescopes.
+Some of the double stars are as follows--Zeta Hercules, Eta Coronae
+Borealis, Gamma Coronae Borealis, Beta Cygni, Alpha Centauri.
+</p>
+
+<p>
+The colours of some of the double stars are very beautiful. Some are
+yellow and blue; others, yellow and purple, while others are orange and
+green. Some of the double stars are only optical doubles, that is to
+say, they apparently seem close together, while as a matter of fact they
+are immense distances from each other, the apparent doubleness being due
+to the fact that they are more or less in the same line of vision. Real
+double stars, where the component stars are situated close together,<span class='pagenum'><a name='Page_309' id='Page_309'></a><a href='#TOC'>[309]</a></span>
+are known as physical doubles, to distinguish them from the optical
+doubles.
+</p>
+
+<p>
+<i>Binary Stars</i>.--Another class of double stars are known as Binary
+Stars. This class of stars is composed of two stars which revolve around
+each other in regular orbits, and are among some of the most interesting
+objects in the heavens. About 1000 Binary stars are known altogether.
+Their motions, however, are very slow, and only in a comparatively few
+cases have the dimensions of their orbits been ascertained. Some of the
+Binary stars are Zeta Hercules, which has a period of about 36 years;
+Eta Coronae Borealis, which has a period of 43 years; while the
+brightest star, Sirius, is also a Binary star, with a period of about 50
+years.
+</p>
+
+<p>
+<i>The Milky Way</i>.--The Milky Way is the name given to that band of light
+which stretches across the sky at night-time, and forms a zone or belt
+that completely circles the celestial sphere.
+</p>
+
+<p>
+This belt of light has maintained from the earliest ages the same
+relative position among the stars, and, when resolved by powerful
+telescopes, is found to consist entirely of stars scattered by millions
+across the expanse of the heavens.
+</p>
+
+<p>
+The whole zone or belt is composed of nothing but stars, whose average
+magnitude, according to Herschel, is about the tenth.
+</p>
+
+<p>
+Stars of all magnitudes are, however, found in this zone.
+</p>
+
+<p>
+Of the brightest stars, about twelve are found in this region, while the
+majority of stars of the second, third, and fourth magnitudes are also
+found in or near it.
+</p>
+
+<p>
+The great majority of star clusters are also found along the course of
+the Milky Way, while many of the irresolvable nebulae seem to congregate
+near the poles of this starry region.
+</p>
+
+<p>
+The Milky Way is divided in one part of its course by a stream of stars,
+which seems to branch off as a separate stream, thus dividing it into
+two parts.
+</p>
+
+<p>
+All these facts seem to point to the conclusion that the stars of the
+universe, instead of being scattered about haphazard in the space, form
+a ring or layer, of which the thickness is very small compared with its
+length and breadth.
+</p>
+
+<p>
+Our own solar system, according to Herschel, occupies a place somewhere
+about the middle of the thickness of the zone, and near the point where
+it divides into two parts.
+</p>
+
+<p>
+Recent observations go to show that there is a tendency of the sun's
+apex to drift along the edge of the Milky Way, and this drift seems to
+point to a plane of motion of the sun, nearly coinciding with the plane
+of the Milky Way.
+</p>
+
+<p>
+<a name='ART_118' id='ART_118'></a><span class='smcap'>Art</span>. 118. <i>Stars and Kepler's Laws</i>.--We have learned in a previous<span class='pagenum'><a name='Page_310' id='Page_310'></a><a href='#TOC'>[310]</a></span>
+chapter that the sun is the centre of a system which comprises a
+retinue of planets, with their attendant satellites, together with a
+number of asteroids or minor planets, with the addition of meteors and
+comets to complete the system.
+</p>
+
+<p>
+Now if the sun is a star, then, according to our First and Second Rules
+of Philosophy, every star ought also to be the centre of a stellar
+system and the centre of two aetherial motions, that is, the Centrifugal
+and Centripetal forces, due to the pressures and tensions of the Aether
+medium. Further, every stellar system would be composed of exactly
+similar bodies to those which compose our solar system, as planets with
+their attendant satellites, together with meteors and comets; the whole
+of the stellar planets being bound to the central body by the
+combination of the two aetherial motions, and kept revolving round the
+central star by the rotating electro-magnetic Aether currents.
+</p>
+
+<p>
+Such a hypothesis is entirely philosophical, as it is simple in
+conception, and fully agrees with our experience in relation to the only
+star of which we have any complete knowledge.
+</p>
+
+<p>
+It is unthinkable to conceive of a star existing in so-called space, and
+constantly radiating out its light and heat for no purpose at all. All
+Nature teaches us that there is not a single thing in existence but what
+has a definite purpose, and a definite place to fill in the universe.
+Even the aetherial atoms, which form the foundation stones of the
+universe, have their own purpose to fulfil in the glorious scheme of the
+Universe conceived by the Eternal Infinite; and to suppose that a star
+has no purpose to fulfil, no task to perform, is to suppose something
+altogether opposed to the teaching of all Philosophy. Why even man, with
+his finite wisdom, would not be so foolish, so unwise, as to make a
+star, and set it in the firmament of heaven for no purpose at all! Are
+we therefore to suppose that the Divine Creator of all things possesses
+less wisdom than the creatures which He Himself hath made? Such an
+assumption would be a reflection not only on the wisdom of an All Wise
+Being, but would also be a reflection on our own ideas of philosophical
+reasoning.
+</p>
+
+<p>
+Therefore the conclusion that we are compelled to come to, in relation
+to the millions of stars that exist in interstellar space, is that every
+star is the centre of a stellar system, and the centre of two aetherial
+motions due to the pressures and tensions of the electro-magnetic
+Aether; while rotating round each star are the ever-circulating
+electro-magnetic Aether currents, which form the medium by which all the
+stellar planets with their attendant satellites are ever made to revolve
+around that central body which supplies them with their light and heat.
+Some such conclusion as this Sir John Herschel arrived at, for in his
+<i>Treatise of Astronomy</i>, Art. 592, he writes: &ldquo;Now for what purpose are
+we to suppose such magnificent bodies scattered through the abyss of<span class='pagenum'><a name='Page_311' id='Page_311'></a><a href='#TOC'>[311]</a></span>
+space? Surely not to illuminate our nights, which an additional moon of
+the 1/1000 part of our own moon would do much better. He must have
+studied astronomy to little purpose who can suppose man to be the only
+object of the Creator's care, or who does not see in the vast and
+wonderful apparatus around us, provisions for other races of animated
+beings. The stars, doubtless, are themselves suns, and may perhaps each
+in its sphere be the presiding centre around which other planets or
+bodies may be circulating.&rdquo;
+</p>
+
+<p>
+Further, with reference to the stability of each of these stellar
+systems, it is essential that the existence of a physical centrifugal
+force should be recognized, in order that the unity and harmony of the
+spheres should be maintained.
+</p>
+
+<p>
+Professor Challis points this out very conclusively in the <i>Phil. Mag</i>.
+of 1859, where, writing on this point, he states: &ldquo;It may also be
+remarked, that if the Law of Gravity be absolute, there is no security
+for the stability of a system of stars, whether the system be a Milky
+Way or a nebulous cluster. For, however small the mutual attraction
+between the constituent bodies may be, in the course of ages it must
+produce a general movement towards the centre or densest region. But the
+form of the Milky Way and of certain nebulae seems to present an utter
+contradiction to any such tendency.&rdquo; With the conception, however, of a
+physical centrifugal force or motion due to the pressure of a physical
+medium, the stability of even the Milky Way may be physically conceived
+and understood.
+</p>
+
+<p>
+Again, when we consider the sun as a star, we find that it has two
+motions of its own, one of rotation on an axis, and the other of
+translation in an orbit, such rotation being due to the fact that it is
+a magnet and has ever circulating round it electro-magnetic Aether
+currents (<a href='#ART_91'>Art. 91</a>). By inference, therefore, we arrive at the fact that
+every star is a magnet, as suggested by Professor Schuster, and
+possesses rotation on an axis, such rotation being due to exactly the
+same cause as produces the rotation of any other planetary or solar body
+(<a href='#ART_92'>Art. 92</a>). Not only has each star a rotation on its axis, but it must
+also possess translational motion in an orbit, and that orbital motion
+must be due to exactly a similar cause as that which produces the
+orbital motion of the sun. Are there any indications given by
+astronomical observations which lead us to the conclusion that stars do
+possess such orbital motions? The answer is unanimously in the
+affirmative; for, although all the stars and the constellations retain
+apparently the same relative position to each other, yet they are all in
+motion. The actual translational motion of the stars is termed proper
+motion, and has been calculated with more or less success in relation<span class='pagenum'><a name='Page_312' id='Page_312'></a><a href='#TOC'>[312]</a></span>
+to many of the stars nearest to us. There are other motions of the stars
+known as apparent motions, which are easily noted by any observer. These
+apparent motions are due to the rotation of the earth on its axis, and
+its orbital motion round the sun.
+</p>
+
+<p>
+Nothing is more certain, however, than that careful astronomical
+observations have revealed the fact that stars have actual orbital
+motions of their own through space. In many cases the orbital velocity
+has been approximately ascertained.
+</p>
+
+<p>
+Halley discovered proper motions of certain stars as far back as 1715,
+when he found out, by comparing different observations, that Sirius,
+Arcturus, and Aldebaran had moved during the period which had elapsed
+since the respective observations were taken.
+</p>
+
+<p>
+More recent observations tend to confirm the fact that stars have indeed
+proper motions, due to their actual translation through space. It has
+been ascertained, for example, that Arcturus is travelling at least 54
+miles per second.
+</p>
+
+<p>
+The proper motion of the stars, however, only gives us an indication of
+their relative motion through so-called space. It does not tell us
+whether the star is apparently receding from the earth, or approaching
+it.
+</p>
+
+<p>
+Dr. Vogel has ascertained by a special system of photography in relation
+to the spectra of stars, that Rigel has a velocity away from the earth
+of nearly 39 miles per sec., Aldebaran of 30 miles per sec., and Capella
+of 15 miles per sec., while the Pole star is apparently approaching the
+earth at a rate of nearly 16 miles per sec.
+</p>
+
+<p>
+Now if all the stars move through space with varying velocities, as
+spectroscopic and telescopic observations seem to suggest, the question
+naturally confronts us as to what is the particular kind of orbit which
+each star completes? Is the orbit that of an ellipse, or a circle, or a
+parabola?
+</p>
+
+<p>
+That it must have some kind of orbit is obvious from the proper motions
+exhibited by the several stars. We have already learned from <a href='#ART_107'>Arts. 107</a> and <a href='#ART_108'>108</a> that the sun possesses an orbit, which orbit fulfils the first
+and second of Kepler's Laws.
+</p>
+
+<p>
+If therefore the sun, as representing all stars, is subject to Kepler's
+Laws, then, according to our Second Rule of Philosophy by which we base
+our hypotheses on our experience, we are compelled to come to the
+conclusion that every star which possesses any motion at all through
+space must also be subject to Kepler's Laws, and therefore must each
+possess a controlling centre around which they severally revolve. Kepler
+himself was of the opinion that the stars were subject to the laws which
+go by his name, and this view of the subject was also accepted by Sir
+William Herschel.<span class='pagenum'><a name='Page_313' id='Page_313'></a><a href='#TOC'>[313]</a></span>
+</p>
+
+<p>
+Thus from philosophical considerations we affirm that
+each star, while it is itself the centre of a starry system, is also
+dependent upon and associated with some other body, to which it is held
+bound by the electro-magnetic Aether, and around which it is made to
+revolve by the circulating electro-magnetic currents associated with
+that central body. So that by philosophical reasoning we are led to view
+the whole of the innumerable stars that flood interstellar space, not as
+so many individual and isolated units, that have no relation to each
+other, but rather as parts of one great system, which in its entirety
+may form in its ultimate unity one harmonious whole, a universe.
+</p>
+
+<p>
+As we come to consider star clusters and nebulae, we shall see how this
+idea of unity seems to be manifested throughout all celestial phenomena.
+</p>
+
+<p>
+<a name='ART_119' id='ART_119'></a><span class='smcap'>Art</span>. 119. <i>Aether and Nebulae</i>.--In addition to the host of stars that
+flood the infinite space, there are other celestial bodies that meet the
+gaze of the astronomer as the telescope is turned upon the heavens.
+</p>
+
+<p>
+These bodies, which are glowing masses of gaseous matter, are termed
+Nebulae. The word Nebulae signifies a cloud, but they are not clouds in
+the same sense as we apply that term to masses of vapour that exist in
+our own atmosphere. Sir Wm. Herschel did more towards the discovery of
+nebulae than perhaps any other astronomer, either before his time or
+since. His labours in the direction were completed and enlarged by his
+son, Sir John Herschel, who surveyed the Southern heavens in a way that
+had never been accomplished before.
+</p>
+
+<p>
+The result of the combined labours of the two Herschels has placed
+information of the nebulae at our disposal which is invaluable. Several
+thousands of different nebulae are now known to us, and as the telescope
+is improved and its powers increased, fresh nebulae are being added to
+the number. Like stars, nebulae vary not only in size, but also in
+colour, shape, and even in the materials of which they are composed.
+They also vary in brightness, the light from some being much fainter
+than the light from others.
+</p>
+
+<p>
+It has been estimated by Huggins that the light received from a nebula
+will not exceed the light of a sperm candle looked at from a distance of
+a quarter of a mile. It is thought by some astronomers that the light
+received from a nebula is indicative of the stage of development to
+which it has arrived. Where the light is faint, the nebulae are in their
+first stages of formation, and where it is brighter it is indicative of
+a more advanced stage of development. Thus nebulae may consist of
+nebulous matter in various stages of condensation, but they are not yet
+in that condition which corresponds to the condition supposed to exist<span class='pagenum'><a name='Page_314' id='Page_314'></a><a href='#TOC'>[314]</a></span>
+in our sun.
+</p>
+
+<p>
+Nearly all the nebulae lie outside the Milky Way, so that it would seem
+as if in ages past all the nebulae that had ever existed in this starry
+zone had passed out of their nebulous condition and been further
+condensed into suns or stars, as they are called. Astronomical
+observations teach us that there are very few nebulae indeed to be seen
+in this starry highway, the part of the heavens which are richest in
+them lying far beyond the confines of this zone. For many years certain
+aggregations of luminous points in the heavens were supposed to be
+nebulae, but by the aid of more powerful telescopes they have now been
+resolved into clusters of stars. One of these clusters is the cluster in
+Hercules, while another is the great nebula of Orion. In the case of the
+former, situated in the constellation of Hercules, we find a great
+number of very small points of light grouped together in a more or less
+globular form. When looked at through a small telescope, this object
+looks like a nebula, but looked at through Lord Rosse's, or some other
+great telescope, it becomes at once resolved into an immense number of
+separate points of light, each one representing a star, there being
+between one and two thousand altogether in this constellation.
+</p>
+
+<p>
+Clusters of stars are usually globular in form, though some are
+irregular in outline. The latter are generally rich in stars, with a
+less condensation of stars towards the centre. Sir Wm. Herschel
+considered the irregular clusters as being in a less advanced stage of
+condensation, as he was of the opinion that all groups ultimately tended
+to clusters which were globular in form. Before dealing with the
+different kinds of true nebulae we will now consider the question as to
+&ldquo;What are Nebulae?&rdquo;
+</p>
+
+<p>
+<a name='ART_120' id='ART_120'></a><span class='smcap'>Art</span>. 120. <i>What are Nebulae?</i>--The question which presents itself to the
+mind of all astronomers when they have viewed the wondrous nebulae that
+exist in far-off space is, &ldquo;What are Nebulae?&rdquo; This question is so
+closely identified with the question as to &ldquo;What is Matter?&rdquo; that the
+solution of the one will give us the key to the solution of the other.
+It is now generally admitted, that nebulae are composed of a glowing
+mass of gaseous matter, that gaseous matter being partly composed of the
+gas Hydrogen. Dr. Huggins in 1864 first made the discovery of the
+existence of Hydrogen in certain nebulae by means of the spectroscope,
+which distinctly revealed certain lines that proved the existence of
+Hydrogen in the nebulae.
+</p>
+
+<p>
+In the spectra of some of the nebulae, that of 31 Andromeda, for
+example, there are no dark lines shown, but only a continuous band of
+bright light, which would seem to indicate that there was no glowing
+gaseous matter in that nebula at all. But accepting the fact that the<span class='pagenum'><a name='Page_315' id='Page_315'></a><a href='#TOC'>[315]</a></span>
+nebulae are composed of glowing gaseous matter, the problem confronts us
+as to where this gaseous matter comes from.
+</p>
+
+<p>
+If, as spectrum analysis seems to teach us, there are nebulae in various
+stages of formation, there must be a period in their history of
+development when they had an origin. What, then, is the origin of a
+nebula, and what the physical explanation of that origin? From optical
+phenomena we learn that all space is not empty, but filled with the
+Aether which is universal (<a href='#ART_42'>Art. 42</a>). What is the relation, then, of this
+glowing nebulous matter to this universal Aether? If it be suggested
+that there is no relation, then we are in the unphilosophical position
+of having to admit, either that the nebulous matter of which the nebulae
+are composed never had any origin, or that it had its origin in some
+unknown and still undiscovered medium which exists in space. But both of
+these hypotheses are unphilosophical, as the former is contrary to all
+experience, while the latter is opposed to that simplicity of conception
+by which we only postulate one medium, the Aether, to fill all space.
+</p>
+
+<p>
+Thus we are led to the conclusion, that the gaseous matter, be it
+hydrogen or nitrogen, must have some relation to the electro-magnetic
+Aether that is so universal in its extent. Already this relationship has
+been dealt with by one who has done more for the development of
+aetherial physics than any other scientist. Lord Kelvin, in his paper
+&ldquo;On the Clustering of Gravitational Matter in any part of the
+Universe,&rdquo;<a name='FNanchor_42' id='FNanchor_42'></a><a href='#Footnote_42' class='fnanchor'>[42]</a>
+ has solved this relationship, though in so doing he has
+had to depart somewhat from the idea of an incompressible Aether. In
+that paper he writes as follows: &ldquo;If we consider Aether to be matter, we
+postulate that it has rigidity enough for the vibrations of light, but
+we have no right to say that it is absolutely incompressible. We must
+admit that sufficiently great pressure could condense the Aether in a
+given space, allowing the Aether in the surrounding space to come in
+towards the ideal shrinking surface.&rdquo; In another part of the paper,
+dealing with the same question, he writes: &ldquo;In regions where the density
+was greater than in neighbouring regions, the density would become
+greater still; in places of less density, the density would become less,
+and large regions would quickly become void or nearly void of atoms.
+These large void regions would extend so as to completely surround
+regions of greater density.&rdquo; He then points out, that as soon as this
+density becomes something like the density of the atmosphere, then
+collisions would take place between the particles, and continues: &ldquo;Each
+collision would give rise to a train of waves in the Aether. These waves
+would<span class='pagenum'><a name='Page_316 ' id='Page_316 '></a><a href='#TOC'>[316 ]</a></span>
+carry away energy, spreading it out through the void Aether of infinite
+space. The loss of energy thus taken away from the atoms would reduce
+large condensing clusters to the conditions of a gas in equilibrium
+under the influence of its own gravity, rotating like our sun or moving
+at moderate speed as in spiral nebulae. Gravitational condensation would
+at first produce rise of temperature, followed later by cooling,
+ultimately freezing, giving solid bodies, collision between which would
+produce meteoric stones such as we see them.&rdquo;
+</p>
+
+<p>
+Here then we have a definitive relationship between Aether and nebulae
+given to us from one of the keenest intellects of the present time, but
+in order for that relationship to become strictly philosophical, the
+conception of the Aether as advanced in this work must be accepted. For
+with the present conception of a frictionless Aether, such a hypothesis
+is altogether untenable, because it supposes something that is contrary
+to all experience and observation.
+</p>
+
+<p>
+On the basis of a condensing frictionless Aether into any kind of solid
+body, be it nebula, meteor, sun or star, we have to suppose that it is
+possible for a medium (the Aether, which is outside the Law of
+Gravitation according to the present theory) to be condensed into a
+body, that is, a nebula or meteor which is subject to the Law of
+Gravitation; and the question arises, at what point in the history of
+its condensation does this frictionless Aether pass out of the condition
+of having no weight, to the condition when it has weight; or, in other
+words, from the condition when it is outside the Law of Gravitation, to
+the condition when it comes under the Law of Gravitation?
+</p>
+
+<p>
+No satisfactory solution can possibly be offered to such a problem.
+Therefore one of two results must follow, either that the Aether is not
+frictionless, but possesses weight; or, that the condensation of the
+Aether is not possible. With the theory of Aether presented in this
+work, the whole question receives a simple and philosophical solution.
+As Aether is matter, it is therefore atomic; and being atomic, it is
+subject to the Law of Gravitation; and therefore, possessing mass and
+weight, it can readily pass into other forms of matter, and with such a
+conception Lord Kelvin's hypothesis becomes not only possible but
+probable. So that it is exceedingly probable that nebulae are nothing
+more nor less than condensed Aether, the same as comets were suggested
+to be condensed Aether. It may be asserted that such a hypothesis lacks
+that experimental evidence which is so necessary for its establishment,
+but I hope to show in the last chapter that Faraday has given the world
+that very experimental evidence which will place this hypothesis upon a
+firm and solid foundation, and enable it to pass out of the region of<span class='pagenum'><a name='Page_317' id='Page_317'></a><a href='#TOC'>[317]</a></span>
+the hypothetical into the region of fact and experiment.
+</p>
+
+<p>
+According to our hypothesis, therefore, nebulae are simply condensations
+of the electro-magnetic Aether that exists in interstellar space, and
+the various spectra of the different nebulae indicate the stage of
+development to which the process has arrived. Where the spectra are
+bright, and continuous, and free from any dark lines, there we have
+simply the Aether in its very first stage of condensation; and where we
+have the dark lines appearing, such lines indicate a more advanced stage
+to which the process has arrived.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_42' id='Footnote_42'></a><a href='#FNanchor_42'><span class='label'>[42]</span></a>
+<i>Philosophical Magazine</i>, July 1902.
+</p></div>
+
+
+<p>
+<a name='ART_121' id='ART_121'></a><span class='smcap'>Art</span>. 121. <i>Nebular Hypothesis</i>.--The Nebular Hypothesis was first
+introduced by Kant in his work on the <i>History of the Earth and Theory
+of the Heavens</i>.
+</p>
+
+<p>
+In that work he attempted to explain the origin of the universe on
+purely mechanical lines. Laplace, a French mathematician, about the same
+time came to similar conclusions as Kant had done, and published his
+views in his work on <i>Exposition du Système du Monde</i>, and later on in
+his more famous work the <i>Mécanique Céleste</i>.
+</p>
+
+<p>
+A feature common to both these theories rested in the fact, that they
+supposed that all material bodies which exist in the universe once
+existed in a nebulous condition, and that they were formed out of this
+nebulous matter. Further, that this nebulous matter gradually condensed,
+and as it condensed, a rotational motion was imparted to them, which
+rotation quickened as the condensation was continued.
+</p>
+
+<p>
+Then, as the rotation was accelerated, portions were flung off by the
+centrifugal force, and these portions of nebulous matter gradually
+condensed, forming the various planets of the system. As these
+condensed, they, in their turn, parted with some of their nebulous
+matter through the repulsive energy of the centrifugal force, and these
+secondary parts gave origin to the various satellites that exist round
+the planets.
+</p>
+
+<p>
+Now, while the general principle involved in the nebular hypothesis is
+true, yet the conception according to Laplace is not verified by fact,
+as we learn that Uranus and Neptune are still in a state of
+self-luminosity, while their density is the smallest of all the planets.
+From this we should infer that the two outermost planets are the
+youngest planets of our solar system, but according to Laplace's theory,
+they ought to be the oldest, as they would have been flung off first by
+the parent body as it rotated; and therefore, being flung off first,
+should be in a more advanced stage of development than any of the inner
+planets. M. Faye has suggested a remedy for this defect in the theory.
+He supposes that the nebulous matter out of which the planets were<span class='pagenum'><a name='Page_318' id='Page_318'></a><a href='#TOC'>[318]</a></span>
+formed, was not flung off by the central body the sun, but that each
+planet was formed at different centres of condensation within the
+nebular mass that existed in space. This would, undoubtedly, meet the
+difficulty already referred to, and solves the problem as to how the
+various planets were formed at different distances in space.
+</p>
+
+<p>
+Further, such a solution is in perfect harmony with all the Rules of
+Philosophy. It is much more simple to conceive of Aether condensing at
+various points in what originally was the solar nebula, than it is to
+conceive of Aether condensing and shrinking towards one central point,
+and yet while condensing and shrinking, portions were flung off into
+space which would form the planet. A greater objection has to be met,
+when we come to deal with the origin of all the meteors and minor
+planets that exist in their numbers in the solar system. In relation to
+their origin, it is much easier to conceive of portions of the Aether
+condensing at different centres of condensation, than to suppose that
+each portion of aetherial matter that originally formed the meteor, or
+asteroid, was flung off as a separate portion from the central body.
+</p>
+
+<p>
+With the conception of an atomic and gravitating Aether, the Nebular
+Hypothesis, therefore, for the first time is placed upon a sound and
+philosophical basis, because the condensation of Aether, which is matter
+and possesses mass, admits of the origin of other matter from it which
+also possesses mass, together with other properties, as elasticity,
+density, compressibility and inertia.
+</p>
+
+<p>
+When there is added to the atomic Aether the conception of a rotatory
+aetherial atom, as was indicated in <a href='#ART_44'>Art. 44</a>, we have at once a source
+from whence the rotation of the whole mass may be derived. Thus, as the
+condensation continued, and the nucleus or central part of the body was
+gradually formed, the rotation would be accelerated, because of the
+inherent energy which would exist in the condensed part. Further, as the
+condensation continued, the body so formed would be more or less
+spherical in form, as the conception of our aetherial atom was
+spherical, and when we conceive of the primary point of condensation, we
+have to think of a large number of spherical atoms coming together; and,
+as all the motions of the Aether which give rise to light, heat,
+electricity and magnetism, and which now include gravitation, are
+spherical in their operations, so their effect upon any condensing
+Aether would take a spherical form. Thus such bodies as nebulae, comets,
+asteroids, satellites, planets and suns should possess bodies more or
+less of a spherical form, subject to certain qualifying conditions, as
+rotation and orbital velocity, and this is in harmony with observation
+and experience. For we shall find that even in the case of nebulae, we
+have globular, ring or annular nebulae, and elliptic nebulae, while in<span class='pagenum'><a name='Page_319' id='Page_319'></a><a href='#TOC'>[319]</a></span>
+the case of comets, the nuclei and coma are more or less spherical.
+Further, it is a familiar fact that the shape of all asteroids,
+satellites, planets, and even the sun is spherical or that of an oblate
+spheroid, which latter is simply due to its rotational velocity on its
+axis.
+</p>
+
+<p>
+Thus the principle involved in the nebular hypothesis receives its
+confirmation in the atomic and gravitating Aether, and with certain
+modifications of the different hypotheses advanced, is capable of
+uniting all those hypotheses that have ever been put forth in this
+direction into one perfect and harmonious whole.
+</p>
+
+<p>
+Again, the condensation of the Aether, composed as it is of its atoms,
+ever in a state of rotation, does away with the Primitive impulse which
+was objected to in <a href='#ART_9'>Art. 9</a>. For in that article it was shown that the
+conception of a primitive impulse as conceived by Newton was
+unphilosophical, in that its conception was not simple, and failed to
+satisfactorily account for observed phenomena. With the hypothesis,
+however, of a rotatory aetherial atom, we have at once those conditions
+which at any time, in the history of the universe, may give rise to
+those conditions by which a body may be set rotating not only on its
+axis, but also revolving around some central body, as the process of
+condensation is continued.
+</p>
+
+<p>
+So that in the primordial and universal electro-magnetic Aether that
+exists in all space, we get those conditions which will not only give
+rise to the phenomena of light, heat, magnetism and electricity, but
+also those properties, qualities and motions by which are produced,
+maintained and perpetuated, the various bodies that exist in the Aether,
+which is at once the physical source and cause of the bodies.
+</p>
+
+<p>
+<a name='ART_122' id='ART_122'></a><span class='smcap'>Art</span>. 122. <i>Kinds of Nebulae</i>.--Nebulae may be classified into the
+following groups--
+</p>
+
+<p style='margin-left: 5em;'>1. Irregular Nebulae.</p>
+<p style='margin-left: 5em;'>2. Ring and Elliptical Nebulae.</p>
+<p style='margin-left: 5em;'>3. Spiral or Whirlpool Nebulae.</p>
+<p style='margin-left: 5em;'>4. Planetary Nebulae.</p>
+
+
+<p>
+<i>Irregular Nebulae</i>.--Of this class the most conspicuous are those in
+the constellations of Orion and Andromeda. So clearly defined are they,
+that they are oftentimes seen by the naked eye on a clear night, and are
+often mistaken for comets.
+</p>
+
+<p>
+The great nebula in Orion is one of the most noticeable objects in the
+heavens. It is noted for its size and brilliancy, and also for the
+successful observation which it has been subjected to from time to time.
+This large nebula is situated in that part of Orion which is occupied by
+several stars known as the Sword Handle. These multiple stars are known<span class='pagenum'><a name='Page_320' id='Page_320'></a><a href='#TOC'>[320]</a></span>
+by the name of Theta. Around these multiple stars is to be seen the
+nebula, as though the multiple stars really were enveloped by the nebula
+extending for a great distance out into space. It is of a faint bluish
+colour, with the central parts possessing the greatest brilliancy. The
+suggestion arises in our mind as to whether the nebulae are in any ways
+indicative of the presence of the electro-magnetic aetherial field that
+each star undoubtedly possesses. We learned in <a href='#ART_88'>Art. 88</a> that the sun is
+an electro-magnet, and that it possesses its electro-magnetic field. We
+have also seen in <a href='#ART_109'>Art. 109</a> that the zodiacal light, which is to be
+observed in connection with our solar system, is really indicative of
+the presence of that electro-magnetic field, as it rotates round the
+central body. Now, if an observer were situated out in space, where the
+nebula of Orion is situated, and could look at our system with
+telescopes equally as powerful as those we possess, would not our sun
+present an equally nebulous light to them because of the presence of its
+electro-magnetic field?
+</p>
+
+<p>
+Conversely, if every star possesses an electro-magnetic aetherial field,
+as they undoubtedly do, then it seems only reasonable to infer that that
+electro-magnetic field possesses a nebulosity which corresponds with our
+zodiacal light. The fact that the spectra of the nebulae are continuous,
+revealing no dark lines, seems to indicate the purity of some of the
+nebulae, and that therefore they are free from all known elements.
+</p>
+
+<p>
+So that spectroscopic results seem to confirm this hypothesis, as the
+pure Aether that would surround every star, or multiples of stars, would
+certainly not reveal any dark lines by means of the spectroscope. Such a
+hypothesis, as to the real nature of a nebula, is entirely in harmony
+with the theory of the Aether presented in Chapter <a href='#CHAPTER_IV'>IV</a>., because being
+gravitative it will surround each star or multiples of stars, and
+therefore be denser nearest to those stars, and being atomic, there will
+be a certain amount of nebulosity manifested by the denser parts of the
+medium, as is the case in our own solar system.
+</p>
+
+<p>
+<i>Ring or Elliptical Nebulae</i>.--These forms of nebulae are so named from
+their ring-shaped appearance, sometimes being known as Annular Nebulae.
+The elliptical nebulae are usually classed with them, as they are
+supposed to be similar kinds of nebulae looked at edgeways. The best
+known of this class is that found in the constellation of Lyra, and
+known as 57M, which is the number of the star in Messier's catalogue of
+stars. It is small but well-defined, so that it looks more like a flat
+oval solid ring than a nebula.
+</p>
+
+<p>
+The central part is not entirely dark, but is filled up with a hazy
+light. Another annular nebula is that situated to the south-west of<span class='pagenum'><a name='Page_321' id='Page_321'></a><a href='#TOC'>[321]</a></span>
+Lambda Scorpii. Sir J. Herschel<a name='FNanchor_43' id='FNanchor_43'></a><a href='#Footnote_43' class='fnanchor'>[43]</a>
+ writes of it thus: &ldquo;It is a delicate
+but well-defined annulus. The field is crowded with stars, two of which
+are nebulae. A beautiful delicate ring of a faint ghost-like appearance,
+about 40" in diameter, in a field of about 150 stars, of 11 and 12
+magnitude and under.&rdquo;
+</p>
+
+<p>
+Of the elliptical nebulae the best known is the one in the constellation
+of Andromeda, which goes by the name of 31M. It is visible on a clear
+night, and can be seen by the naked eye as a hazy light. There are
+several other elliptical nebulae, lying to the north-west of this great
+nebula.
+</p>
+
+<p>
+<i>Planetary Nebulae</i>.--The planetary nebulae represent a number of minute
+objects visible in the heavens. They look like globes of a
+bluish-coloured gas and are sometimes mistaken for small stars. Sir J.
+Herschel writes about them as follows: &ldquo;Planetary nebulae are very
+extraordinary objects. They have, as their name implies, a resemblance
+to planets, presenting discs, round or slightly oval, some being quite
+sharply defined, terminating in others a little hazy or softened at the
+border. They are comparatively rare objects, not more than 25 having
+been observed, and of these nearly three-quarters are in the southern
+hemisphere. Their disc is circular or slightly elliptic, with sharp,
+clear, and well-defined outline, having exactly the appearance of a
+planet with the exception only of its colour, which is full blue,
+varying somewhat upon green. M. Arago has surmised that they may
+possibly be envelopes shining by reflected light from a solar body
+placed in their centre, invisible to us because of its excessive
+distance.&rdquo;
+</p>
+
+<p>
+The suggestion which arises to our mind in view of the atomic and
+gravitating Aether is, that the planetary nebulae are exactly what their
+names imply, that is, nebulous matter around planets. We have already
+learned that each satellite and planet possesses an electro-magnetic
+field, which field takes more or less the shape of a spherical form, so
+that if there are planets existing in the far-off systems in space, as
+we are compelled to believe that there are, then they too would possess
+an electro-magnetic field, which would be composed of spherical
+envelopes surrounding the several planets. These planets would shine by
+reflected light, as suggested by M. Arago.
+</p>
+
+<p>
+The possession by the planet of the nebulous matter, which we have
+already suggested is composed of the denser parts of the Aether around
+the planet, would give to the planet a nebulous appearance which would
+satisfactorily account for the term already given. They would indeed be
+what Sir John Herschel suggested they were, viz, planetary nebulae.<span class='pagenum'><a name='Page_322' id='Page_322'></a><a href='#TOC'>[322]</a></span>
+</p>
+
+<p>
+<i>Spiral Nebulae</i>.--The Spiral,
+or Whirlpool Nebulae, are remarkable objects, and were first discovered
+by Lord Rosse with his six-foot telescope. One of the best examples of
+the spiral nebulae is that known as 51M. Small telescopes show this as
+two clusters, one of them being surrounded by a ring, at a distance,
+which is divided into two parts. Lord Rosse, however, found it to be
+really a spiral nebula, the ring running into a series of spiral coils
+of nebulous matter, the outlying parts being connected with the main
+part by curved bands.
+</p>
+
+<p>
+Huggins has found that the spectrum of this nebula is not gaseous. Other
+examples of this class are 99M and 33M. What these spiral or whirlpool
+nebulae are, is unknown, but, on the hypothesis of a condensing and
+gravitating Aether which is in a state of rotation, the spiral nebulae
+can be easily pictured. For, as the condensation goes on, rotation will
+set in, and if we can picture such a phenomenon taking place in a plane
+which is at right angles to the line of vision, then we should have a
+full view of a nebula which would present a spiral form. Indeed, there
+is no phenomenon in connection with nebulae that cannot be physically
+explained by a condensing, gravitating and rotatory Aether; and as
+Aether is universal, the same properties will apply to it in distant
+space as they do in the solar system; and apart from a gravitating and
+rotatory electro-magnetic Aether, the phenomena of our own solar system
+cannot be physically conceived or explained.
+</p>
+
+<p>
+Therefore, if such an Aether can explain the phenomena associated with
+our own system, it ought also to explain, and that to the fullest
+extent, all phenomena incidental to and associated with the innumerable
+systems that flood the universe at large.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_43' id='Footnote_43'></a><a href='#FNanchor_43'><span class='label'>[43]</span></a>
+<i>Outlines of Astronomy</i>.
+</p></div>
+
+
+<p><span class='pagenum'><a name='Page_323' id='Page_323'></a><a href='#TOC'>[323]</a></span></p>
+<h2><a name='CHAPTER_XIV' id='CHAPTER_XIV'></a><a href='#CHAPTER_XIV_TOC'>CHAPTER XIV</a></h2>
+
+<h3>UNITY OF UNIVERSE</h3>
+
+<p>
+<a name='ART_123' id='ART_123'></a><span class='smcap'>Art</span>. 123. <i>The Universe</i>.--In the preceding chapters we have endeavoured
+to deal with some of the principal phenomena that help to give a
+mechanical conception to the entire Universe.
+</p>
+
+<p>
+It now remains for us to show, in this last chapter, how, underlying all
+the physical structure of the Universe, there is one fundamental and
+primordial medium, in which all the forms of matter and motion find
+their ultimate unity.
+</p>
+
+<p>
+The Universe literally means one ultimate whole, though that whole may
+be compounded of many parts, the very essence of the term embodying the
+idea of a complete unity which runs throughout its whole physical
+structure.
+</p>
+
+<p>
+Apart from some such hypothesis as will be suggested in this chapter,
+that ultimate unity is incapable of a physical or mechanical conception.
+In <a href='#ART_29'>Art. 29</a> we learned that the Universe was composed of two classes of
+things, matter and motion, while in <a href='#ART_30'>Art. 30</a> we learned that the sum
+total of matter according to the law of the conservation of matter ever
+remains the same; while further, in <a href='#ART_53'>Art. 53</a>, according to the law of the
+conservation of energy, the sum total of energy ever remains the same.
+We have also learned that the two are indissolubly united, so that
+wherever we found matter, whether that matter was in its atomic,
+molecular, planetary or stellar form, there, as its necessary complement
+and counterpart, was the ever-present and unceasing motion, in one or
+other of its many forms. Thus, throughout the entire Universe, we find
+the same two essentials ever working in unison and harmony.
+</p>
+
+<p>
+Nowhere in the realm of infinite space is there such a phenomenon as
+rest or absolute death. The ideal that seems to be the key of the
+Universe, is that continuity of motion which science teaches us is so
+inseparably connected with all matter. Grouped, however, here and there
+throughout the Universe are modifications of this aetherial matter,
+termed molecules, satellites, planets, suns, or stars, which
+modifications are, however, not so real and abiding as the
+electro-magnetic Aether from which they receive their physical origin.<span class='pagenum'><a name='Page_324' id='Page_324'></a><a href='#TOC'>[324]</a></span>
+</p>
+
+<p>
+The physical character of the universe is progressive. Even in its
+ultimate unity there is no such thing as stagnation or standing still;
+for, while in some parts of the Universe new stars and suns and planets,
+yea, even new systems are being evolved out of the primordial Aether, in
+other parts of the Universe old stars and suns, with all their attendant
+planets and satellites, are passing on towards that final end, when they
+themselves will be again resolved into the original form of matter from
+which they were first made. This assertion is in perfect harmony not
+only with science, but also with revelation. For even revelation teaches
+us that all the stars shall grow old as doth a garment, and as a vesture
+shall they be folded up (Heb. i. 11), and that (out of their ruins) a
+new heaven and a new earth shall be created and the former shall not be
+remembered (Isaiah lxv. 17).
+</p>
+
+<p>
+Thus amid all the modifications of that which is the real physical basis
+of all matter, we find indissolubly associated with each and all of the
+varied forms and modifications certain motions which are analogous to
+each other. In the aetherial atom itself, so infinitesimal in its
+proportions that even our imagination is almost strained in our attempt
+to conceive it, yet even here we have rotation and translation in an
+orbit, such rotation and translation being due to the motions of the
+electro-magnetic Aether. Then in the gaseous forms of matter into which
+these atoms may be condensed, we find the same two essentials, of matter
+and motion, of rotation and translation in an orbit, always working
+harmoniously together, through the motions of the selfsame Aether, which
+gives rise to the attraction and repulsions of the atoms.
+</p>
+
+<p>
+Then following the principle into the planetary world, and taking the
+planet Saturn with its ring of satellites as an example, we find again
+the same two factors ever working in unison and in harmony, with their
+incessant rotation and translation in an orbit, forming a complete and
+perfect unity in themselves, such unity being due to the pressures and
+tensions of the Aether combined with its rotatory character. Then going
+a step further, we find a number of planets, with or without satellites,
+all rotating around one central body, that rotation and translation
+again being due to the motions of the rotating electro-magnetic Aether,
+combined with its pressures and tensions.
+</p>
+
+<p>
+For millions of years, so far as we can tell, this solar system of ours
+has been moving through space as one complete unit.
+</p>
+
+<p>
+Then out in stellar space there are millions of such systems, each
+distinct and perfect in themselves, each of which is made up of exactly
+similar parts to our solar system, these innumerable systems being
+doubtless joined together by the same electro-magnetic Aether, forming<span class='pagenum'><a name='Page_325' id='Page_325'></a><a href='#TOC'>[325]</a></span>
+one larger and grander unity, known as a constellation. Then these
+constellations, increasing in their number, are again joined together,
+and form a still larger unity called a Galaxy; and galaxy being joined
+to galaxy, constellations to constellations, we get such an ocean of
+suns and stars like that known as the Milky Way, the ultimate whole
+revealing in all its beauty and harmony the unison of the two essentials
+of matter and motion. It may even be that all the oceans of suns and
+stars, that exist in far-off space, are joined together by one common
+bond, the universal electro-magnetic Aether by its two complementary
+motions, the centripetal and the centrifugal, the whole forming one
+ultimate unity which we call the Universe, having for its centre one
+common point or central orb, which indeed forms the centre of gravity of
+the entire Universe.
+</p>
+
+<p>
+Thus the key to the physical conception of the Universe is to be found,
+and alone found, in that beauty of order, and harmony of motion, which
+are so inseparably associated with the varied forms of matter,
+graduating through a series of units or atoms, each with its dual nature
+complete in itself, through a series of minor entities termed elements,
+which in their aggregations form meteorites, satellites, planets, suns
+and stars, and systems of stars and oceans of suns and stars, until all
+are united into one ultimate unity where all are blended into one
+complete and perfect whole; the whole of the universal fabric being held
+together in its mechanical order and beauty by the electro-magnetic
+Aether. Then in the very centre of the Universe there dwells that
+Supreme Being whom we call God, who is at once the one real fountain and
+source of all the light and life of the Universe itself. For it is His
+universal Spirit that moulds and fashions the plastic matter into the
+many forms which it assumes, and uses the various modes of motion, as
+heat, light, electricity and magnetism, as instruments to build up and
+erect in all their beauty and harmony the innumerable systems that flood
+immensity and space.
+</p>
+
+<p>
+For if there be a centre of gravity to an atomic system, and a centre of
+gravity to a planetary system, and a centre of gravity to a solar
+system, then there is also a centre of gravity to a group of systems,
+even to a constellation, or a galaxy; otherwise our philosophy relative
+to the centres of gravity of masses fails in its application to wider
+phenomena of an exactly similar kind.
+</p>
+
+<p>
+Thus, if there is a centre of gravity to a galaxy, even to the Milky Way
+itself, then, going one step further, with a faith that laughs at
+scientific data and leaps beyond the narrow bounds of pure reasoning, we
+affirm that there must even be a centre of gravity to the entire
+Universe. Now let me ask the reader, What can be more fitting, more
+appropriate, more reasonable than to infer that the centre of gravity<span class='pagenum'><a name='Page_326' id='Page_326'></a><a href='#TOC'>[326]</a></span>
+of the Universe is to be found in that celestial orb or orbs where the
+throne of God exists and endures, and where ultimately there will be
+congregated together in perfect felicity the spirits of just men made
+perfect, not only from our insignificant planet, but all the spirits of
+all beings from all the planets which in their almost infinite number
+are circled round their central suns by the electro-magnetic Aether? It
+is there, in these bright orbs, with their vision and powers
+spiritualized, quickened and intensified, that all perfected spirits
+shall look out into space, with increasing wonder, upon the birth and
+decay of worlds, the evolution and devolution of planets and systems and
+constellations, and shall watch the continuation and working out of that
+grand and glorious plan, which alone finds its perfection and its
+ultimate fulfilment in the wisdom, and power, and glory of the Eternal
+Spirit of the Living God.
+</p>
+
+<p>
+To see if this conception of the Universe is borne out by scientific
+data, we will now address ourselves more particularly to those
+fundamental truths which underlie the unity of the Universe.
+</p>
+
+<p>
+<a name='ART_124' id='ART_124'></a><span class='smcap'>Art</span>. 124. <i>The Unity of the Universe</i>.--The Unity of the Universe is a
+dream which has passed before the imagination of many philosophers in
+by-gone times, and has been a fruitful source of speculation to
+old-world, as well as more modern philosophers. The researches of such
+living scientists as Sir William Crookes, Professor J. J. Thomson and
+others, have, however, made this dream come within the range of
+practical research and direct experiment. Professor J. J. Thomson
+believes that it is possible to break off from an atom, a part which is
+only 1/1000 part of the whole, and these infinitesimal parts he has
+called corpuscles, which he considers are the carriers of the electric
+current.
+</p>
+
+<p>
+If, therefore, it can be philosophically proved that the hypothesis of
+an atomic, gravitating, and condensing Aether can satisfactorily account
+for the physical existence of all atoms, and therefore of all matter,
+the dream of old-world philosophers will be helped on its way to a
+successful realization.
+</p>
+
+<p>
+We have already suggested, that nebulae are formed out of the
+condensation of the electro-magnetic Aether that fills the Universe; and
+as that nebula, according to the Nebular Hypothesis, ultimately resolves
+itself into a sun, or planet, or satellite, as the case may be, it
+follows that the condensation of this electro-magnetic Aether forms the
+basis of all the various elements, as Hydrogen, Nitrogen, Oxygen and the
+other seventy elements of which those bodies are composed. Thus the
+conclusion that we are compelled to come to in regard to the ultimate
+nature of matter, in its primordial condition, is, that all matter which
+exists in its varied forms throughout the entire Universe finds its<span class='pagenum'><a name='Page_327' id='Page_327'></a><a href='#TOC'>[327]</a></span>
+physical origin and source in the universal electro-magnetic Aether,
+which is itself atomic, and possesses all the essential properties of
+matter.
+</p>
+
+<p>
+With the conception of the Aether as advanced in this work, this
+hypothesis is perfectly philosophical and logical. For the conception is
+simple, in that it supposes one form of matter to spring out of another
+form, that is, from an aetherial form to gaseous, in a similar manner to
+that in which a gaseous form changes into a liquid form, that is, by
+condensation, or a closer drawing together of the aetherial elastic
+envelopes that surround each atom; each particular gas, as Hydrogen,
+Nitrogen, or Oxygen, representing different quantities of aetherial
+condensations, as will be seen in the next article.
+</p>
+
+<p>
+The aetherial constitution of matter has received recognition from the
+hands of such scientists as Lord Kelvin and Dr. Larmor. The latter, in
+his <i>Aether and Matter</i>, writes on the subject as follows (page 7):
+&ldquo;Matter must be constituted of isolated portions, each of which is of
+necessity a permanent nucleus or singularity in and belonging to the
+Aether, of some such type as is represented for example by a minute
+vortex ring in a perfect fluid, or a centre of permanent strain in a
+rotational elastic medium.&rdquo; And again on the same page he adds: &ldquo;It is
+incumbent on us to recognize an aetherial substratum of matter, in so
+far as this proves conducive to simplicity and logical consistency in
+our scheme of physical relations, and helpful towards the discovery of
+hitherto unnoticed ones.&rdquo;
+</p>
+
+<p>
+Dr. Larmor, as has already been pointed out in <a href='#ART_44'>Art. 44</a>, speaks of his
+aetherial atoms as electrons, which are of two kinds, negative and
+positive, and of these he states (page 97): &ldquo;Each electron has an
+effective mass of aetherial origin, which forms part, and may be the
+whole of the mass of the matter to which it is attached.&rdquo;
+</p>
+
+<p>
+Here, then, we have definite statements as to the hypothesis of all
+matter having a definite aetherial origin. If, therefore, it can be
+proved experimentally that matter does possess this aetherial basis,
+then the hypothesis will pass out of the region of speculation into the
+region of fact and science.
+</p>
+
+<p>
+The question, therefore, suggests itself to our mind, as to whether
+among all the experiments that have ever been performed by any
+scientist, there are any which will conclusively confirm and establish
+the hypothesis as to the aetherial origin of all matter. In my opinion
+there are such experiments, which have been given to the world by such
+eminent scientists as Faraday and Sir Humphry Davy. Before, however, the
+value of their experiments can be rightly understood and valued, we
+shall have to ask ourselves another question, and that is, &ldquo;What is the<span class='pagenum'><a name='Page_328' id='Page_328'></a><a href='#TOC'>[328]</a></span>
+relation of Aether to electricity?&rdquo; Upon the correct answer to this
+question depends the application of Faraday's experiments to the
+hypothesis of the aetherial constitution of all matter, and therefore of
+the great underlying principle of the unity of the Universe.
+</p>
+
+<p>
+Is there any relation therefore between Aether and electricity? If so,
+what is that relation, and to what extent does it hold good? Professor
+Lodge, in his preface to <i>Modern Views of Electricity</i>, asks a similar
+question. &ldquo;Electricity,&rdquo; he states, &ldquo;has been thought to be a form of
+energy, it has been shown to be a form of Aether. There remains the
+question, What is Aether?&rdquo;
+</p>
+
+<p>
+While again he writes: &ldquo;A rough and crude statement adopted for popular
+use is that electricity and Aether are identical. But that is not all
+that has to be said, for there are two opposite kinds of electricities,
+and there are not two Aethers. But there may be two aspects of one
+Aether, just as there are two sides to a sheet of paper.&rdquo;
+</p>
+
+<p>
+That there is a definite relation between Aether and electricity is as
+certain as there is a definite relation between electricity and light.
+In order to find out how far the relationship and identity between
+Aether and electricity extend we will review our conception of the
+Aether as given in Chapter <a href='#CHAPTER_IV'>IV</a>. According to the conception advanced in
+that chapter, on the hypothesis that Aether was matter, we
+philosophically came to the conclusion that Aether was atomic, and
+therefore gravitative. Because it was gravitative, it possessed density,
+and varying degrees of density; and having mass, it possesses the
+property of inertia the same as any other matter; and was also elastic.
+</p>
+
+<p>
+We have now to add to these properties that of compressibility, which
+property we have ascribed to it from philosophical considerations when
+dealing with comets, and nebulae, and the origin of planets and
+satellites. Now, if there is any identity between Aether and
+electricity, then it follows that that identity will be more or less
+manifested, as we find electricity possessing more or less of the
+properties which have been ascribed to the electro-magnetic Aether. For,
+if we find two apparently different substances, or entities, possessing
+exactly the same properties, and occupying the same space at one and the
+same time, then the only logical conclusion that we can come to is, that
+these two apparently different substances are not two substances, but
+one.
+</p>
+
+<p>
+We have already proved that they both occupy exactly the same space,
+that is, they occupy the planetary and interstellar regions of space,
+and fill indeed the entire Universe. The electro-magnetic theory of
+Light (<a href='#ART_78'>Art. 78</a>) indisputably proves this. We will therefore find out if<span class='pagenum'><a name='Page_329' id='Page_329'></a><a href='#TOC'>[329]</a></span>
+electricity possesses the properties which have already been ascribed to
+the Aether. The first property, and indeed the fundamental property, of
+Aether is that it is atomic, and upon the atomicity of the medium
+depends the whole of the theory as worked out in relation to heat,
+light, electricity and so-called gravitational phenomena. Is there
+anything about electricity that can suggest the hypothesis that
+electricity is atomic? The answer is unquestionably in the affirmative.
+Many of the greatest scientists of the past and present century have
+believed and worked at the hypothesis of the atomic character of
+electricity, and none more so than Dr. Larmor in his <i>Aether and Matter</i>
+and Professor J. J. Thomson.
+</p>
+
+<p>
+Now what is Dr. Larmor's opinion as to the atomicity of electricity?
+These are some of his statements quoted in the work. In the very first
+words of his preface he writes:<a name='FNanchor_44' id='FNanchor_44'></a><a href='#Footnote_44' class='fnanchor'>[44]</a>
+ &ldquo;The following essay was originally
+undertaken mainly as a contribution towards the development of the
+standpoint which considers electricity, as well as the matter, to be
+constituted on an atomic basis.&rdquo; He continues: &ldquo;Since Faraday's work on
+Electrolysis, the notion of the atomic constitution of electrification
+in its electro-chemical aspect has never been entirely absent.&rdquo; While
+later on he adds: &ldquo;Thus, for example, the present view of the atomic
+character of electricity, which is at length coming within the scope of
+direct experiment, has been in evidence with gradually increasing
+precision ever since theoretical formulations were attempted on the
+subject.&rdquo;
+</p>
+
+<p>
+We are, however, possibly indebted to Professor J. J. Thomson for the
+most direct experimental evidence as to the atomic nature of
+electricity, for, as is well known to scientists, he has discovered what
+he termed corpuscles, in association with electricity, which he makes
+the carriers of the charges involved in electrical phenomena.
+</p>
+
+<p>
+Here, then, we have one proof of the identity that exists between Aether
+and electricity, in that while they both fill the same space, they are
+both equally atomic; Dr. Larmor's ultimate atom, as we have already
+seen, being known as positive and negative electrons. Aether, we also
+learned, was gravitative (<a href='#ART_45'>Art. 45</a>), but we have since learned that
+gravitation is itself an electrical phenomenon, in that both the
+centripetal and centrifugal forces are due to the repulsions and
+attractions or pressure and tension of this electro-magnetic Aether.
+</p>
+
+<p>
+So that when we affirm that Aether is gravitative, we do but affirm it
+is subject to the laws of electricity, which govern all electrical
+phenomena, and therefore we might just as truly affirm<span class='pagenum'><a name='Page_330' id='Page_330'></a><a href='#TOC'>[330]</a></span>
+that electricity is gravitative,
+because such an affirmation is simply another way of saying that
+electricity gives rise to the attractions and repulsions incidental to,
+and associated with, all electrical phenomena. Here, again, we have
+further evidence of the identity that exists between Aether and
+electricity.
+</p>
+
+<p>
+Then we learned that Aether possessed density, and also different
+degrees of density, and the question arises as to whether there is
+anything corresponding to this property in electricity. As a matter of
+fact, this very property of density is itself recognized and known to
+all scientists by the term Electric Density, the electric density being
+always proportionate to the charge of electricity on a given area.
+</p>
+
+<p>
+We learned also in <a href='#ART_79'>Art. 79</a> that aetherial density and electrical density
+were identical in relation to solar and planetary space; so that,
+wherever there was the denser Aether, there was also the denser
+electricity, the density of the one increasing or decreasing exactly in
+the same ratio as the other increased or decreased. From aetherial and
+electrical density, therefore, we have another proof of the close
+identity that exists between Aether and electricity.
+</p>
+
+<p>
+Again, we learned (<a href='#ART_48'>Art. 48</a>) that Aether possessed inertia. Here at
+least, it may be thought, we shall find the first point of difference
+between the two entities. Surely such an intangible, aetherial
+manifestation as electricity cannot possess inertia. Let us see what
+Professor Lodge has to say on the subject. In the chapter on electrical
+inertia he writes (p. 89, par. 365 of <i>Modern Views of Electricity</i>): &ldquo;A
+current does not start instantaneously: it takes a certain time, often
+very short, to rise to its full strength; and when started it tends to
+persist, so that if its circuit be suddenly broken, it refuses to stop
+quite suddenly, and bursts through the introduced insulating partition
+with violence and heat. It is this ram or impetus of the electric
+current which causes the spark seen on breaking a circuit; and the more
+sudden the breakage, the more violent is the spark apt to be. We shall
+understand them better directly; meanwhile they appear to be direct
+consequences of the inertia of electricity; and certainly if electricity
+were a fluid possessing inertia it would behave to a superficial
+observer just in this way.&rdquo;
+</p>
+
+<p>
+From these statements we learn then that electricity does possess
+inertia, although there are other phenomena of electricity that would
+destroy the hypothesis. But undoubtedly an electric current possesses
+momentum, and it is philosophically impossible to associate momentum
+with any body that does not possess inertia, as one of the factors of
+momentum implies mass, even though it be a mass of an infinitesimal
+form, and mass is the very essence of the property of inertia (<a href='#ART_40'>Art. 40</a>).<span class='pagenum'><a name='Page_331' id='Page_331'></a><a href='#TOC'>[331]</a></span>
+</p>
+
+<p>
+Dr. Larmor, in the work already referred to, dealing with the subject
+of electric inertia, explains that it is concentrated at the nucleus of
+the electron (p. 230), while on p. 202 he states: &ldquo;Each electron as it
+is moved by the aetherial displacement belonging to the radiation,
+resists with its own definite inertia.&rdquo;
+</p>
+
+<p>
+Apart from this evidence, the philosophical evidence already adduced in
+Chapter <a href='#CHAPTER_X'>X</a>. is altogether in favour of the fact that electricity
+possesses inertia. So that we may say that, though the evidence as to
+the identity of electrical and aetherial inertia is not fully complete,
+the balance of opinion lies in favour of the identity rather than
+otherwise. See <i>Appendix A</i>.
+</p>
+
+<p>
+It can further be demonstrated that electricity possesses elasticity the
+same as the Aether does. The charge and discharge of a Leyden jar are
+conclusive evidence of the elasticity associated with electrical
+phenomena, while further proof is to be found in the fact that Dr.
+Larmor attributes elasticity to his electrons, such elasticity being of
+a rotational type.
+</p>
+
+<p>
+The identity, therefore, that exists between Aether is now almost
+complete. We have now only to prove that both are compressible, and the
+identity is fully established. This will be done by reference to certain
+of Faraday's experiments before the conclusion of this article. As we
+have established, logically, the identity that exists between Aether and
+electricity, the question arises now as to whether they are not one and
+the same medium. If they are not one and the same medium, then we are in
+the distinctly unphilosophical position of having to admit that all
+interplanetary and interstellar space are filled at one and the same
+time by two different media, and such an assumption is directly opposed
+to all observation and experience.
+</p>
+
+<p>
+Therefore, to be strictly philosophical, one of these media must be done
+away with, and we may either assert that interplanetary and interstellar
+space is filled with electricity, or else it is filled with Aether, as
+it is much simpler to conceive of space being filled with one medium,
+than it is to suppose it to be filled with two media, which are
+absolutely identical in all their characteristic properties and
+functions. Both can give rise to exactly the same kind of phenomena,
+whether they are the phenomena of heat, light, electricity, or
+magnetism, and even gravitation itself. So that, if Science wishes to be
+distinctly philosophical in her statements in future, it will be
+necessary, it seems to me, to do away either with the Aether, or with
+the electricity, and as the latter is the better known entity, I am of
+the opinion that Science will retain the electric conception of space
+and matter, and do away with the aetherial, as being altogether
+unnecessary. See <i>Appendix B</i>.
+</p>
+
+<p>
+Thus are we led to the conclusion that electricity is itself a form of<span class='pagenum'><a name='Page_332' id='Page_332'></a><a href='#TOC'>[332]</a></span>
+matter, as indeed it must be if it is atomic, as suggested by Dr. Larmor
+and Professor Thomson.
+</p>
+
+<p>
+Professor Lodge, on p. 9 of the work already referred to, states:
+&ldquo;Electricity in this respect behaves just like a substance;&rdquo; and again,
+p. 313, he writes: &ldquo;We cannot assert that it is a form of matter,
+neither can we deny it; on the other hand, we certainly cannot assert
+that it is a form of energy, and I should be disposed to deny it. It may
+be that electricity is an <i>entity per se, just as matter is an entity
+per se</i>.&rdquo;
+</p>
+
+<p>
+Whether electricity be a form of matter or not, as I believe it
+undoubtedly is, we have arrived at the fact, in view of the identity
+between Aether and electricity, that, wherever the one is present, the
+other is present also. So that if it can be demonstrated by direct
+experiment that matter can be changed into its equivalent quantities of
+electricities, or that equivalent quantities of electricities could
+produce their equivalent forms of matter, then the electrical basis of
+matter, and consequently the aetherial basis of matter, are proved
+beyond contradiction, and we are thus led one step nearer to the
+ultimate unity of the Universe, which unity is to be found in the
+universal electro-magnetic Aether, which is identical with universal
+electricity. For if Aether be the basis of all modes of motion, as heat,
+light, and gravitation, and it is identical with electricity, it follows
+that electricity is equally the basis of all the varied phenomena, and
+if to that we add the constitution of matter itself, then we are within
+sight of the medium in which the ultimate unity of the Universe is to be
+found.
+</p>
+
+<p>
+This view of the subject has already been dealt with by a German
+scientist, Professor Vogt, in his book on <i>The Nature of Electricity and
+Magnetism</i>, a book, however, which is not translated into English. In
+that work I believe he shows the possibility of all matter having its
+origin in electricity; and if that be so, then that theory is really
+identical with an aetherial basis of matter, seeing that Aether and
+electricity philosophically seem to be one and the same medium. Let us
+therefore turn to Faraday's experiments, and see what they teach us on
+the subject of the electrical basis of matter, and therefore the
+aetherial basis at the same time.
+</p>
+
+<p>
+In paragraph 852 of his <i>Experimental Researches</i> Faraday writes: &ldquo;The
+theory of definite electro-chemical action appears to me to touch upon
+the absolute quantity of electricity, or electrical power, belonging to
+different bodies. Although we know nothing of what an atom is, yet we
+cannot resist forming some idea of a small particle which represents it
+to our mind, and though we cannot say what electricity is, so as to be
+able to say whether it is a particular <i>matter or matters</i>, or mere
+motion of ordinary matter, yet there is immensity of facts which<span class='pagenum'><a name='Page_333' id='Page_333'></a><a href='#TOC'>[333]</a></span>
+justify us in believing that the atoms of matter are in some way endowed
+or associated with electrical powers to which they owe their most
+striking qualities, and amongst them their chemical affinity. As soon as
+we perceive, through the teaching of Dalton, that chemical powers are
+(however varied the circumstances in which they are exerted) definite
+for each body, we learn to estimate the relative degree of Force which
+resides in such bodies; and when upon that knowledge comes the fact that
+electricity, which we appear to be capable of loosening from its
+habitation for a while, or conveying from place to place, whilst it
+retains its chemical Force, can be measured out, and being so measured,
+is found to be as definite in its action as any of those portions which,
+remaining associated with the particles of matter, give them their
+chemical relation, we seem to have found a link which connects the
+proportion of that belonging to the particles in their natural state.&rdquo;
+</p>
+
+<p>
+Then in paragraph 855 he writes as follows: &ldquo;It seems a probable and
+almost a natural consequence, that the quantity which passes is the
+equivalent of, and therefore equal to, that of the particles separated,
+<i>i. e</i>. that if the electrical power which holds the elements of a grain
+of water in combination (or which makes a grain of oxygen and hydrogen,
+in the right proportions, unite into water when they are made to
+combine) could be thrown into the condition of a current, it would
+exactly equal the current required for the separation of that grain of
+water into its elements again.&rdquo;
+</p>
+
+<p>
+Further, in Art. 857, he states, &ldquo;I can have no doubt that, assuming
+hydrogen as 1, and dismissing small fractions for the simplicity of
+expression, the equivalent number or atomic weight of oxygen is 8, of
+chlorine 36, of bromine 78.4, of lead 103.5, of tin 59, etc.,
+notwithstanding that a very high authority doubles several of these
+numbers.&rdquo; Then, writing upon the definite relationship of
+electro-chemical equivalents, he states, Art. 835: &ldquo;Electro-chemical
+equivalents are always consistent; <i>i. e</i>. the same number which
+represents the equivalent of a substance <i>A,</i> when it is separating from
+a substance <i>B</i>, will also represent <i>A</i> when separating from a third
+substance <i>C</i>. Thus 8 is the electro-chemical equivalent of oxygen,
+whether separating from hydrogen or tin or lead; and 103.5 is the
+electro-chemical equivalent of lead, whether separating from oxygen or
+chlorine or iodine.&rdquo;
+</p>
+
+<p>
+So that from Faraday's experiments we learn definitely that the
+electro-chemical equivalents coincide with and agree with the ordinary
+chemical equivalents according to Dalton's theory. From these
+experimental results of Faraday's we therefore learn that Faraday was of
+the opinion that each atom had a definite and certain quantity of<span class='pagenum'><a name='Page_334' id='Page_334'></a><a href='#TOC'>[334]</a></span>
+electricity associated with it; and if this be true, then, in view of
+the identity of Aether with electricity, it follows that each atom must
+have definite and certain quantities of Aether associated with each
+atom. So that through Faraday's experimental researches we are again led
+to the hypothesis enunciated by Lord Kelvin in his paper &ldquo;On the
+Clustering of Gravitational Matter in any part of the Universe,&rdquo; viz.
+that all matter has an aetherial, that is, an electrical basis, and that
+it is by the condensation of this electricity, and combinations of the
+condensational particles, that all the various elements are formed which
+compose the infinite variety of forms that constitute the entire
+Universe. Here, then, it seems to me, we have the evidence which gives
+to the aetherial Nebular Hypothesis (<a href='#ART_121'>Art. 121</a>) that experimental
+evidence which places that hypothesis upon a firm and philosophical
+foundation, and conclusively proves that it is possible for Aether out
+in the colder regions of interstellar space to be condensed into masses
+of gaseous matter, which form nebulae, and other masses in the cold
+regions of interplanetary space to condense and form comets and meteors.
+</p>
+
+<div class='footnote' style='margin-left: 5em;'><p><a name='Footnote_44' id='Footnote_44'></a><a href='#FNanchor_44'><span class='label'>[44]</span></a>
+<i>Aether and Matter</i>.
+</p></div>
+
+
+<p>
+<a name='ART_125' id='ART_125'></a><span class='smcap'>Art</span>. 125. <i>Physical Constitution of Matter</i>.--In <a href='#ART_31'>Art. 31</a> we learned that
+all matter was made up of minute parts called atoms. When these atoms
+enter into combination with each other, they form the smallest particles
+of elementary substances as well as compound bodies, these particles or
+bodies being termed molecules.
+</p>
+
+<p>
+A molecule, therefore, may consist of any number of atoms of the same
+element, or may be formed of the union of the atoms of two different
+elements. In the preceding article we have learned that the atom of
+hydrogen or carbon, however, is divisible, at least theoretically if not
+experimentally, as we came to the conclusion that all atoms are composed
+of infinitesimal aetherial atoms, which are synonymous with atoms of
+electricity.
+</p>
+
+<p>
+Whether we shall ever be able to experimentally prove the existence of
+such an atom remains to be seen, though Dr. Larmor states that the
+atomicity of electricity is coming within the scope of direct
+experiment; while the researches of Professors Crookes and J. J. Thomson
+have undoubtedly given direct evidence of the existence of corpuscles,
+which are part of the atoms of the various elements.
+</p>
+
+<p>
+When we try to conceive, however, of the manner in which the various
+elements can be formed from one primary medium, that is, the Aether or
+electricity, we find it difficult to arrive at a simple physical
+conception of the process involved.
+</p>
+
+<p>
+We are indebted to Professor J. J. Thomson for what is practically the
+only simple physical conception of the method in which various elements
+may be formed from that medium, which gives unity to the whole of the<span class='pagenum'><a name='Page_335' id='Page_335'></a><a href='#TOC'>[335]</a></span>
+universe. In the Adams Prize Essay of 1883 Professor Thomson indicated a
+theory based on the vortex atom (<a href='#ART_43'>Art. 43</a>) which satisfactorily accounted
+for the various laws which governed gaseous matter, and also showed how
+the varied chemical combinations might be physically conceived as being
+produced from one primary medium.
+</p>
+
+<p>
+In this theory we have to conceive of the vortex atom as possessing a
+hollow core, while in our conception of an aetherial atom (<a href='#ART_43'>Art. 43</a>) we
+conceived it as being more of a spherical or globular form than
+ring-shaped. We have, then, to consider the atom of any element as being
+composed of a vortex ring of various thickness, the thickness of the
+ring being an indication of its atomic weight.
+</p>
+
+<p>
+Each vortex ring must also be conceived as itself being composed of a
+number of aetherial atoms, or atoms of electricity, the number of such
+atoms being proportionate to the respective atomic weights of the
+various elements. Dr. Larmor suggests that a vortex ring may have this
+constitution in his work on <i>Aether and Matter</i>.
+</p>
+
+<p>
+According to Professor J. J. Thomson, then, any vortex ring, which we
+have supposed to be constituted of aetherial atoms, or atoms of
+electricity, may unite with any other vortex ring, thus producing a
+vortex ring of double density, which would possess double the
+electricity of the unit vortex ring. If we united three vortex rings,
+then the result would be an atom of threefold the density and strength
+of the unit vortex ring.
+</p>
+
+<p>
+We might conceive of four or any number of these rings uniting together
+to form a separate element, and then each element would simply be a
+multiple of the unit vortex ring, and so possess regular multiples of
+the atoms of electricity, each multiple representing a distinct element.
+</p>
+
+<p>
+We will now let Professor Thomson speak for himself on the matter, and
+will describe the theory in his own words, always keeping in mind the
+hypothesis that the unit vortex ring is itself composed of a definite
+number of atoms of electricity or electrons, as proved by Faraday. See
+<i>Appendix C</i>.
+</p>
+
+<p>
+In the work already referred to, Professor Thomson states: &ldquo;We may
+suppose that the union or pairing in this way of two vortex rings of
+different kinds is what takes place, when two elements of which these
+vortex rings are atoms combine chemically; while, if the vortex rings
+are of the same kind, this process is what occurs when atoms combine to
+form molecules. Now let us suppose that the atoms of different chemical
+elements are made up of vortex rings, all of the same strength, but that
+some of these elements consist of only one ring, others of two rings
+linked together, others of three loops, and so on. Then if any of these<span class='pagenum'><a name='Page_336' id='Page_336'></a><a href='#TOC'>[336]</a></span>
+rings combine to form a permanent combination, the strength of all the
+primaries in the system so formed by the combination must be equal.&rdquo;
+</p>
+
+<p>
+&ldquo;Thus an atom of one element may combine with another atom of the same
+kind, to form a molecule of that substance consisting of two atoms.
+Again, three of these atoms may combine, and form a system consisting of
+three primary elements, but the chance of their doing so is small
+compared with the chance of two pairing; so that the number of systems
+of this kind will be small compared with the number of the systems
+consisting only of two atoms. We might have systems of four atoms, but
+the number would be small compared with the number of systems that
+consist of three atoms.&rdquo;
+</p>
+
+<p>
+&ldquo;Now, suppose that an atom of one element is to combine with an atom of
+another. Suppose, to fix our ideas, that the atom consisting of two
+vortex rings linked together, is to combine with an atom consisting of
+one vortex ring; then, since, for the stability of connection, the
+strength of all the primaries which form the components of the compound
+must be equal, the atom consisting of two links must unite with
+molecules containing two atoms of the one with one link. Thus the
+compound formed will be the simplest combination, consisting of one of
+the atoms which consist of two vortex rings linked together with two of
+the atoms consisting of only one vortex ring. Similarly, if an atom
+consisting of three vortex rings linked together were to combine
+directly with atoms consisting of only one vortex ring, the compound
+formed would consist of the three linked atoms with three of the others,
+and so on for all the combinations of atoms formed by any number of
+vortex rings linked together. This suggests that the elements, called by
+the chemists monads, dyads, triads and so on, consist of one, two, etc.
+vortex rings linked together, for then we should know that a dyad could
+not combine with less than two atoms of a monad to form a stable
+compound, or a triad with less than three, and so on, which is just the
+definition of the terms monad, dyad, triad.&rdquo;
+</p>
+
+<p>
+&ldquo;On looking at chemical combination from this point, we expect to find
+that such compounds as Hydrochloric acid, where one atom of Hydrogen has
+only to meet one atom of Chlorine; or water, where one atom of Oxygen
+has only to meet two atoms or a molecule of Hydrogen, would be much more
+easily and quickly formed than a compound such as ammonia gas, to form
+which an atom of Nitrogen has to find itself close to three atoms of
+Hydrogen at once.&rdquo;
+</p>
+
+<p>
+&ldquo;It is the case, I believe, in direct combination, that simple compounds
+are formed more quickly than compound ones. We might call the ratio of
+the number of links in the atom of any element, to the number in the<span class='pagenum'><a name='Page_337' id='Page_337'></a><a href='#TOC'>[337]</a></span>
+atom of Hydrogen, the Valency of the element. Thus the compounds H-CL,
+H-I, H-F, show that the atoms of Chlorine, Iodine, Fluorine have the
+same number of links as the atom of Hydrogen, so that the valency of
+each of these elements is unity. From the compound H<sub>2</sub>O we infer that
+the atom of Oxygen consists of twice as many links as the atom of
+Hydrogen. The compound H<sub>2</sub>S indicates that the atoms of Sulphur have
+twice as many links as the atom of Hydrogen.&rdquo;
+</p>
+
+<p>
+&ldquo;The molecules CO<sub>2</sub> and Marsh Gas have each three primaries
+represented by C-O-O and C-H-H respectively. According to the view we
+have taken, atomicity corresponds to complexity of atomic arrangement,
+and the elements of high atomicity consist of more vortex rings than
+those whose atomicity is low.&rdquo;
+</p>
+
+<p>
+&ldquo;Thus high atomicity corresponds to complicated atomic arrangement, and
+we should expect to find the spectra of bodies of low atomicity much
+simpler than those of high. This seems to be the case, for we find that
+the spectra of Sodium, Potassium, Lithium, Hydrogen, Chlorine, which are
+all monad elements, consist of comparatively few lines.&rdquo;
+</p>
+
+<p>
+Here then, on the vortex theory of matter, especially when that vortex
+theory is given an electric basis, as is the case in Dr. Larmor's
+electron theory, we have a thinkable and logical explanation of the
+physical and chemical properties of matter, by which all elements and
+compounds may be formed from the primordial aetherial or electric atom.
+As all Nature is composed of about seventy elements, and it has been
+conclusively demonstrated that an atom of Hydrogen is the same all over
+the universe, no matter whether it exists on this planet, or in some
+distant star or nebula, we arrive at the conclusion that all the other
+elements are exactly the same in their properties and qualities wherever
+they are found. If, therefore, we couple Faraday's experiments and
+results as to the electro-chemical equivalents of all atoms, with this
+theory of Professor J. J. Thomson's, then we are again compelled to come
+to the conclusion that the unity of the universe in all its
+universality, and infinite variety of forms and modes of matter, is to
+be found, and alone found, in the universal Aether, which is co-existent
+and coextensive with electricity.
+</p>
+
+<p>
+<a name='ART_126' id='ART_126'></a><span class='smcap'>Art</span>. 126. <i>Quod Erat Faciendum</i>.--Before concluding this work let us
+briefly review the whole of the theory submitted herein to the reader.
+</p>
+
+<p>
+That which was to be done consisted primarily in ascertaining the
+physical cause of Gravitation, by which would be accounted for on a
+philosophical basis all the phenomena incidental to and associated with
+the Law of Gravitation. Such phenomena included the physical cause of<span class='pagenum'><a name='Page_338' id='Page_338'></a><a href='#TOC'>[338]</a></span>
+the Centripetal and Centrifugal Forces, the physical cause of Kepler's
+Laws, together with a physical conception of the application of Newton's
+Laws of Motion to all solar and stellar bodies. In addition to this,
+there were other outstanding problems in physics that it was premised
+would receive either a partial or an entire physical explanation. It was
+premised, for example, that the problem of the relative motion of Aether
+and matter would be solved, that the cause of the permanent magnetism of
+the earth would be revealed, and the great problem of the constitution
+of matter attacked, together with the unity of the universe which arose
+from that conception.
+</p>
+
+<p>
+In order, however, for any theory to be philosophical in its initial
+stages, the rules of some of the greatest philosophers which govern the
+making of any hypotheses were briefly outlined, and were found to
+resolve themselves into three divisions.
+</p>
+
+<p>
+The first rule dealt with the general simplicity of Nature's mode of
+working, and therefore the general simplicity which must govern our
+hypotheses in perfecting any theory as to the cause of all phenomena,
+gravitational or otherwise.
+</p>
+
+<p>
+The second rule showed that the only sound basis from whence we could
+derive all our data upon which to speculate and reason, lay in our
+experience of all natural phenomena. Whatever else we might do, or not
+do, it was absolutely necessary, if we wished to be perfectly
+philosophical in our conclusions, that we should not traverse the direct
+results of observations and experiments.
+</p>
+
+<p>
+The third rule laid down was the obvious axiom, that the theory so
+perfected by logical reasoning must satisfactorily account for and
+explain all the phenomena sought to be explained.
+</p>
+
+<p>
+Now I wish to submit the whole theory as propounded in this work in its
+completion and in its entirety to the reader, and to ask him if the
+Rules of Philosophy have not been adhered to throughout the whole work?
+Can any theory be more simple than the one submitted in this work, by
+which we have endeavoured to account for all, and even more, than was
+premised in the opening chapters?
+</p>
+
+<p>
+The very simplicity of the fundamental hypothesis that Aether is matter,
+in all its properties and qualities, has been the chief obstacle to the
+retardation of its earlier discovery.
+</p>
+
+<p>
+Any proposition more simple, more easy of comprehension, is, to my mind,
+difficult of conception. Why, children in our homes and schools may be
+taught the truth, and grasp it in its concrete form, and that is the
+highest test of the simplicity of any hypothesis.
+</p>
+
+<p>
+Thus the first Rule of Philosophy is satisfied and fulfilled in the
+initial hypothesis, and I venture to affirm that the same simplicity has
+characterized the development of the theory throughout its entire<span class='pagenum'><a name='Page_339' id='Page_339'></a><a href='#TOC'>[339]</a></span>
+progress. Step by step, simple facts and simple truths which are known
+to any ordinary student have been shown to have a wider and more
+universal application than even the writer dreamed of, when he started
+out on his voyage of discovery in philosophical research.
+</p>
+
+<p>
+When we consider the second Rule of Philosophy in its application to our
+theory, we find that experience, as revealed by observation and
+experiment, is fulfilled to the minutest detail. The simple hypothesis
+that Aether is matter, fulfils to the very fullest extent all
+requirements demanded by the experience of all the scientists and
+experimentalists that the world has ever known. To assert that Aether is
+not matter is to assert a proposition contrary to all the accumulated
+experience of the past generations. Therefore, if Aether is matter, then
+its fundamental qualities must be those which belong to and are
+associated with all matter, those qualities being atomicity, gravity,
+density, elasticity, inertia, and compressibility.
+</p>
+
+<p>
+The objector to this statement is himself violating the chief rule of
+all philosophy, in that he is going contrary to the tenor and teaching
+of his own experience. Then, following out the second rule step by step
+we arrive at the one grand central truth, that electricity is also a
+form of matter, and that all the forces of the entire universe are but
+different modes of motion, different vibrations of the universal
+electro-magnetic Aether; while all the varied bodies that exist are
+themselves but different manifestations in a gaseous, liquid, or solid
+form of the same electro-magnetic substance.
+</p>
+
+<p>
+Thus, step by step, we have tried to build up a theory of the physical
+cause of all phenomena, which will satisfactorily account for those
+phenomena, and even for the structure of the universe itself, from the
+mechanical standpoint, and by so doing have fulfilled the third Rule of
+our Philosophy as enunciated by Newton and others.
+</p>
+
+<p>
+So that by the conception that Aether is matter, in its primordial
+state, we have more than fulfilled all that was premised should be done.
+</p>
+
+<p>
+Thus the long-sought-for and long-expected cause of Gravitation,
+together with the cause of the two complementary forces, is found in the
+simple statement that Aether is matter, with all that is logically
+included therein. Kepler's Laws and Newton's Laws of Motion also receive
+a physical explanation in the same universal electro-magnetic Aether.
+</p>
+
+<p>
+In addition to the solution of these problems, the transverse vibrations
+of light has received for the first time a physical conception, and a
+physical explanation, even admitting that that explanation may not be
+perfect in detail.<span class='pagenum'><a name='Page_340' id='Page_340'></a><a href='#TOC'>[340]</a></span>
+</p>
+
+<p>
+The origin of the permanent magnetism of the earth
+has also received a physical explanation through the motions of this
+same electro-magnetic Aether, while certain theories in relation to
+electricity given to the world by Ampère, Weber, Faraday, and Clerk
+Maxwell have found their consummation in this atomic electro-magnetic
+medium.
+</p>
+
+<p>
+Further, astronomical hypotheses in relation to comets and nebulae are
+not untouched by the theory of a compressible and condensing atomic
+Aether. Indeed, there is not a phase of natural phenomena which is not
+affected in some way or other by the philosophical result arrived at
+that Aether is matter in its original state. Therefore, we claim,
+however imperfectly it may have been done, that not only have the Rules
+of Philosophy been fulfilled, but that the theory so advanced has
+accomplished more than even we in our wildest imagination hoped and
+dreamed for it.
+</p>
+
+<p>
+Look at the problem of the Aether how we may, the advantages of the
+theory of an atomic electro-magnetic Aether far surpass and outweigh the
+advantages of a frictionless medium, which in some unknown way possesses
+mass and inertia, although the conception of such properties themselves
+disproves the existence of such a frictionless medium.
+</p>
+
+<p>
+After all, how much of this theory is there which is entirely new or
+absolutely original? Age after age, men have had exactly similar dreams,
+and seen similar visions. In the old Grecian days similar views were
+expressed by their philosophers; and, even in the philosophy of less
+civilized countries, many of the suggested hypotheses found their place
+in a more or less perfect form.
+</p>
+
+<p>
+Analyze the whole theory from its initial stages to the last chapter,
+and we shall find, with the exception of one or two features, that every
+hypothesis first had its origin in the mind of some of the greatest
+thinkers and philosophers that the world has ever known.
+</p>
+
+<p>
+Take several hypotheses as examples. The hypothesis that Aether is
+atomic was suggested by such men as Newton, Huyghens, Descartes,
+Challis, Clerk Maxwell, and others.
+</p>
+
+<p>
+That Aether is gravitative has been suggested by Young, Grove, Faraday,
+and Lord Kelvin. Huyghens, Fresnel, and Young postulated different
+degrees of density for the Aether, while Stokes and McCullagh have
+affirmed and proved different degrees of elasticity of the medium.
+</p>
+
+<p>
+The inertia of the medium has received experimental evidence from
+Tyndall, Maxwell, Faraday, Lodge, and others, and its compressibility
+has received the adherence of men like Faraday, Maxwell, and Lord
+Kelvin.<span class='pagenum'><a name='Page_341' id='Page_341'></a><a href='#TOC'>[341]</a></span>
+</p>
+
+<p>
+Then, when we come to deal with the causes of the forces
+involved in gravitational phenomena, we find that exactly similar
+hypotheses in regard to the Centrifugal Force have been postulated by
+Herschel, Bredichin, M. Faye, and Lebedew; while Faraday, Gauss and
+others have suggested the close relationship that exists between
+electrical and gravitational phenomena.
+</p>
+
+<p>
+The physical explanation of Kepler's Laws was suggested by Kepler
+himself, while Huyghens, Bernoulli, Descartes, and many of their
+contemporaries believed in the existence of some kind of vortices.
+</p>
+
+<p>
+The unity of the universe has been a dream of philosophers for
+generations past, and that dream is now crystallized in the definite
+conception of an atomic universal electro-magnetic medium, while the
+electrical basis of matter receives the support of such men as Crookes,
+J. J. Thomson, Larmor and Vogt.
+</p>
+
+<p>
+Thus we learn that all the dreams and thoughts, all the hypotheses and
+postulates of old-world as well as present-day philosophers find their
+consummation and ultimate realization in one universal, atomic,
+electro-magnetic medium.
+</p>
+
+<p>
+If this fact does not stamp the theory with that authority which is
+undeniably associated with the names of some of the scientists quoted,
+then all the greatest men in the scientific world have lived and toiled,
+thought and dreamed in vain, while the priceless gems of their
+imagination and research are treated as worthless and valueless.
+</p>
+
+<p>
+Again, what shall we say of the discoveries of to-day?
+</p>
+
+<p>
+What is the key to the greatest scientific discovery of modern times,
+viz. wireless or aetherial telegraphy, which is girdling the earth with
+its mysterious communications? Is not the key to that discovery to be
+found in this universal electro-magnetic medium?
+</p>
+
+<p>
+Whence come the X-rays, Rontgen rays, and other light rays with their
+adaptability to human suffering, if they come not from this same
+electro-magnetic medium? their adaptability to human suffering being
+dependent upon the intimate and close relationship that exists between
+the physical body and the electro-magnetic medium.
+</p>
+
+<p>
+Where is the key to the principle underlying the gramophone, the
+phonograph and the telephone, if it be not in this self-same atomic and
+easily impressible medium?
+</p>
+
+<p>
+Nay! let us go further, and ask ourselves where is the key to be found
+for the many marvellous effects of so-called spirit phenomena? Who can
+read F. W. Myer's <i>Human Personality and its Survival of Bodily Death</i>,
+and not feel that we are standing on the threshold of the unseen world?<span class='pagenum'><a name='Page_342' id='Page_342'></a><a href='#TOC'>[342]</a></span>
+</p>
+
+<p>
+Already men are asking themselves the meaning of the strange sensations
+which they receive from unseen sources; already men's spirits are
+vibrating in unison with vibrations that come from the unseen world; and
+to-day we see spiritual phenomena as through a glass darkly, and the
+question arises, what is the medium of all this communication, of all
+these vibrations?
+</p>
+
+<p>
+Is there no medium at all which forms the medium of communication? To
+assert that would be to assert something opposed to all experience and
+therefore would be unphilosophical.
+</p>
+
+<p>
+May not then the theory of an atomic universal electro-magnetic medium
+help us on in our groping and searching after light in this direction?
+Who will uplift the veil? Already we peer almost into the spirit world.
+A little more light, a little more truth, and then there will burst
+forth upon the hearts and minds of men the grandest and most glorious
+truth that Nature can reveal of her Creator, and then men shall come to
+know and understand the place that God holds in the Universe, such truth
+being advanced on its way by an atomic, universal electro-magnetic
+Aether which is as truly matter as our own bodies.
+</p>
+
+<p>
+<a name='ART_127' id='ART_127'></a><span class='smcap'>Art</span>. 127. <i>God and the Universe</i>.--To the superficial reader it may
+appear at first sight, that the theory of the Aether suggested in this
+work leaves no place in the Universe for the operations and existence of
+an Infinite and living Spirit, a God. It may be objected, that if all
+matter and all modes of motion find their physical origin in one common
+and primordial medium, the electro-magnetic Aether, where is the
+necessity for the existence of an Eternal and Infinite Spirit?
+</p>
+
+<p>
+At first sight there appears some force in the objection, but it loses
+its point when we come to view the Universe from the standpoint of
+spirit phenomena. The purpose of the writer in this work has been to
+deal with natural phenomena only, purely from the philosophical and
+scientific standpoint. Spirit phenomena (which is equally as real and
+obvious as natural phenomena) have no part or place in a work which
+deals with scientific facts and data, but demand and will receive in a
+future work equal consideration and philosophic treatment. A man must
+indeed be lacking in vision who cannot see behind all things the
+evidence of a richer and fuller truth than that which merely lies on the
+surface, or who fails to read and learn the greatest truth that circles
+the Universe in its ultimate unity, which indisputably points to the
+existence of an Eternal and ever-living Spirit, a God. I affirm that
+there is no scientific truth, even including the law of the conservation
+of matter and motion, which has been enunciated in this work, but what
+is reconcilable with the existence of an Eternal and Infinite Spirit;<span class='pagenum'><a name='Page_343' id='Page_343'></a><a href='#TOC'>[343]</a></span>
+and although such a statement may seem a paradox, yet I am convinced
+that before many more years have passed, the reconciliation of natural
+with spiritual phenomena will be an accomplished fact. The fool to-day
+may say in his heart, there is no God, but ere long not only religion,
+but Science herself, shall expose his lack of wisdom and his folly.
+</p>
+
+<p>
+For all things derive their existence primarily, with all the energies
+and powers they possess, from God. Look where we will, or at what we
+will, from the smallest atom or molecule up to the most stupendous
+world, or myriads of worlds that roll and sparkle in the blue infinity,
+in each and all we see the indisputable evidence of the existence of a
+mysterious spirit, or power, that controls and governs them. A spirit or
+power that we cannot see, but which is so indisputably evidenced that
+its existence cannot be denied. For example, we see forms of many kinds,
+some of which are simple entities of themselves, while others are
+complex and made up of many parts, but while each part is inseparably
+connected with the other, yet each part is itself distinct from the
+others in nature and substance. The whole combined forms a complete
+mechanism or organism, and, like all mechanisms of human make, not only
+needs a controlling and governing power, but also evidences a maker.
+Even the laws of Nature and modes of motion, whether it be heat, light,
+electricity, or magnetism, are, however, unable of themselves to control
+the mechanism, and therefore prove themselves to be but the servants of
+an infinite Intelligence, a <span class='smcap'>God</span>.
+</p>
+
+<p>
+Thus, behind and beyond all we see, in every living form, there is the
+evidence of a hidden spirit, which is the governing and controlling and
+sustaining power, and without which the organism ceases to be an
+organism. A spirit which animates the mechanism, and uses its activities
+and powers as it wills for its own purposes and ends. This spirit or
+power we call its life, which gives to the form its existence, together
+with all that it possesses, as its powers, activities, energies and
+productions, for all are but the effects of the hidden life. If this
+mysterious something, termed its life, becomes in any way separated from
+the mechanism or organism, then as a distinct and separate organism it
+ceases to be; and though the mechanism may still exist for a time, yet
+all its powers are gone, while the organism, robbed of its very life,
+begins slowly to decay.
+</p>
+
+<p>
+We cannot see this power; we cannot find it We may search for it, rend
+and tear part from part, only to find that it baffles all our skill, and
+laughs at our endeavours to discover the secret of its existence. We
+know that it is there, just as truly as we know that in these forms of
+ours, these living stoves, these perfect mechanisms called our bodies,<span class='pagenum'><a name='Page_344' id='Page_344'></a><a href='#TOC'>[344]</a></span>
+there exists and dwells a spirit, a living, conscious, self-acting and
+controlling power. A spirit which we know is not the mechanism itself,
+and which by experience and observation we know to be distinct from the
+organism. It is this mysterious spirit which controls and governs all
+our acts, that rules and reigns as king of our bodies, and makes the
+physical mechanism, with all its wondrous parts, obey and do its
+bidding. That this is so, that the spirit is distinct from the body, and
+is the controlling and governing principle within us, is evident in a
+thousand ways. If, however, that spirit departs from the mechanism of
+our bodies, then the controlling and governing influence is gone; and
+the mechanism, robbed of its life, ceases to work, ceases to fulfil its
+functions, and ceases to exist in that particular form.
+</p>
+
+<p>
+Just as it is with ourselves, so it is with the Universe. For look where
+we will, from the smallest atom to the great aggregation of atoms, as
+our earth, or even to the more stupendous orbs of heaven, the working of
+a secret and mysterious power or spirit meets our gaze. A spirit or
+power that is not the form or the mechanism, but is separate and
+distinct from the mechanism, while at the same time it is inseparably
+connected with each and all. For everything that we see, from an atom to
+the Universe itself, is a perfect mechanism, or complexity of
+mechanisms. The entire Universe is one vast, intricate, and elaborate
+piece of mechanism, beginning with the simple aetherial atom, ranging
+through all the atomic systems, graduating by successive steps through
+compound substances, which, in their aggregations, form meteors,
+satellites, planets, suns, and stars; until the ultimate whole is
+reached, where everything is blended into one vast whole; a perfect,
+infinite, complex mechanism, a Universe.
+</p>
+
+<p>
+Now if philosophy teaches anything at all regarding mechanisms of human
+invention, it indisputably teaches that every machine or mechanism that
+has ever been made, implies the existence of a maker, and that the maker
+possessed intelligent attributes, as reason, judgment, perception, and
+imagination. For example, stand before some elaborate machine of human
+invention, as a lace machine, and watch the working of that machine in
+all its details. It is composed of many parts, each of which is perfect
+in itself. Each part may be distinct in nature and purpose, yet each and
+all are inseparably and unitedly connected with each other, and all work
+harmoniously together for the accomplishment of a definite and specific
+end, that is, the production of a lace curtain of exquisite design and
+pattern. As we watch the machine and its workings, we see therein the
+evidence of the existence of a spirit or power that gave it its birth.<span class='pagenum'><a name='Page_345' id='Page_345'></a><a href='#TOC'>[345]</a></span>
+A spirit or mind that made and formed the machine, that constituted,
+arranged, and gave it its governing and controlling power; fitted and
+ordered every part, gave to each part its allotted task, and moulded all
+to the harmonious fulfilment of the definite end and purpose he had in
+view.
+</p>
+
+<p>
+Thus in the machine we see evidence of contrivance and design, of method
+and arrangement, of conception, perception and judgment, which are all
+the effects and outflowings of intelligence which belong, and alone
+belong, to mind; and therefore we say, &ldquo;The machine was made, and there
+was and must have been a maker.&rdquo; So universally is this fact accepted,
+that any one who seriously challenged the statement, or dared to deny
+it, would be at once pitied as insane or laughed at as a fool. Thus all
+experience proves, and philosophy testifies, that wherever we get a
+machine or mechanism of any kind or sort, there must have been a living,
+conscious being or person, who is distinct from and outside of the
+machine. He made it, and therefore must have existed before it, in order
+to make it. Wherever, therefore, we find a mechanism that bears the
+marks of intelligence and design, of judgment, perception and
+conception, it is only logical and philosophical to infer, that such a
+mechanism equally evidences the existence of an intelligent being. The
+more intricate and elaborate the mechanism, the greater the ingenuity
+displayed, the more complex and perfect the design, the more harmonious
+the working, the greater will be the wisdom, the more profound the
+judgment, the keener the perception, the more perfect the understanding,
+and the vaster, nobler, and more sublime the order of Being who
+originated and made it. This being so, according to philosophical
+reasoning, let us glance at the Universe in all its fulness and oneness,
+and we shall see the indisputable evidence of the existence of an
+Infinite Being, who made, controls and governs the infinite Universe.
+</p>
+
+<p>
+In the atomic world we get an illustration of the perfect mechanism that
+underlies all atomic systems. Our conception of an aetherial atom was
+based upon the analogy of our own planet, and there is every reason to
+believe that the little world in which all atoms live and move and have
+their being, is analogous to a planetary or solar system, in which we
+find the two essentials of matter and motion ever associated together,
+to form a larger and more complete mechanism. For atoms are not simply
+mere points; they possess real dimensions, with a determinate and fixed
+form, differing in their relative weights, and in the amount of motion
+or force with which each is endowed. The very fact that they possess
+atomic weights which are unalterable throughout the long periods of time
+that mark the history of the Universe, and that they combine in<span class='pagenum'><a name='Page_346' id='Page_346'></a><a href='#TOC'>[346]</a></span>
+definite and fixed proportions, indisputably evidence the fact that
+they but do the bidding of an Eternal and Infinite Spirit, a God. Thus
+each molecule, or atomic system forms a perfect mechanism in itself,
+with its own centre of gravity, and subject to the same laws of
+repulsion and attraction, or pressures and tensions--due to the
+vibrations and motions of the universal electro-magnetic Aether.
+</p>
+
+<p>
+In each of the planetary systems we get an illustration of the same
+perfect mechanism, which is indicative of all systems whether large or
+small; each system being characterised by the same beauty of order and
+harmony of motion which are equally characteristic of atomic systems.
+</p>
+
+<p>
+Our own solar system, composed as it is of many parts, of thousands of
+meteors and comets, of numbers of satellites and planets, all revolving
+around one common centre, also forms a complete and perfect mechanism in
+itself. For millions and millions of years this perfect mechanism has
+been harmoniously working together in all its parts, as it moves in all
+its unity through the realms of infinite space. Yet through all the
+unknown ages of the past, such a phenomenon as disorder in the working
+of any part of the system is inconceivable and unknown. Out in stellar
+space there are, however, innumerable systems, similar to our own solar
+system, each distinct and perfect in itself; each being made up of
+similar parts, as meteors, comets, satellites, planets, and central sun.
+These systems are, however, united together into one vast aggregation of
+worlds, having one common controlling centre of their own, and by their
+unity form a constellation, a larger and grander mechanism. Throughout
+the whole constellation there is the same order, and harmonious working
+of part with part, that characterise the solar system. Then these
+constellations increasing in their aggregations form a still larger
+complexity of systems, called a Galaxy; and galaxy being added to
+galaxy, constellation to constellation, there is formed by such union,
+an ocean of suns and stars like our own Milky Way, the ultimate whole
+being characterised by the same mechanical order and harmonious working
+that characterise the solar system. It may even be, that there are
+numbers of these oceans of suns and stars existing in infinite space,
+all bound together by one common bond, the universal electro-magnetic
+Aether, and forming one vast ultimate whole, a Universe; with all its
+oceans of suns moving around one central Orb or mass of Orbs called the
+Throne of <span class='smcap'>God</span>.
+</p>
+
+<p>
+Thus the whole Universe is a mechanism, complete and perfect in every
+detail, and forming a system, so great, so grand, so sublime, so
+magnificent that it puts all mechanisms of human origin to shame and
+scorn. Now, if a mechanism of human invention evidences the existence<span class='pagenum'><a name='Page_347' id='Page_347'></a><a href='#TOC'>[347]</a></span>
+of intelligence and mind, and proves itself to be the production of a
+living, sentient, conscious, and intelligent being, how much more,
+incomparably more, does the Universe with its infinite complexity
+evidence a Maker also; and that Maker must be as infinitely greater in
+wisdom, knowledge, perception and judgment as the Universe is infinitely
+greater in mechanical perfection than any mechanism of human origin.
+</p>
+
+<p>
+The Universe is God's teaching in symbol and in type. It is His great
+picture-book, where in living form He has portrayed Himself, and all
+that belongs to Him--His nature, character, wisdom; His greatness,
+glory, and His power. The Universe is a temple, where He sits enshrined
+in the things His own hands have made, and where those who have eyes to
+see, and hearts to learn and understand, may adore and worship Him.
+</p>
+
+<p>
+Thus is it true that &ldquo;the heavens declare the glory of God,&rdquo; <i>i. e.</i> the
+character of God, His infinite wisdom, His infinite knowledge, His
+profound judgment, and His eternal righteousness; while the firmament
+showeth His handiwork. &ldquo;Day unto day uttereth speech, and night unto
+night showeth (His) knowledge.&rdquo;
+</p>
+
+<p>
+&ldquo;The Lord by wisdom hath founded the earth, by understanding hath He
+established the heavens.&rdquo;
+</p>
+
+<p>
+&ldquo;He hath made the earth by His power. He hath established the world by
+His wisdom, and hath stretched out the heavens by His discretion.&rdquo;
+</p>
+
+<p>
+&ldquo;Thou, Lord, in the beginning hast laid the foundations of the earth,
+and the heavens are the work of Thy hands; they shall perish, but Thou
+remainest; and they all shall wax old, as doth a garment; and as a
+vesture shalt Thou fold them up, and they shall be changed; but Thou art
+the same, and Thy years shall not fail.&rdquo;
+</p>
+
+<p>
+To prove the validity of these statements from a scientific and
+philosophic standpoint, and to show the harmony that exists between the
+natural and the Divine revelation as given in the Word of God, will form
+the subject of a future work.
+</p>
+
+
+<p><span class='pagenum'><a name='Page_349' id='Page_349'></a><a href='#TOC'>[349]</a></span></p>
+<h2>APPENDIX A</h2>
+
+<p>
+According to Sir Oliver Lodge the fact that electricity possesses mass
+or inertia has now passed out of the hypothetical stage into the realm
+of fact and experiment. In his Romanes Lecture recently published, he
+states, page 4: &ldquo;My first thesis is that an electric charge possesses
+the most fundamental and characteristic property of matter, viz. mass or
+inertia; so that if any one were to speak of a milligramme or an ounce
+or a ton of electricity, though he would certainly be speaking
+inconveniently, he might not necessarily be speaking erroneously.&rdquo;
+</p>
+
+<p>
+Now in view of the identity that exists between Aether and electricity,
+as proved by Hertz' experiments, the only logical conclusion that can be
+arrived at is, that Aether must also possess mass and inertia. So that
+the most recent experiments in relation to electricity confirm the
+theory of the Aether presented in this work, viz. that it also possesses
+mass and inertia, otherwise we should have a massless medium being
+composed of electrons which possess mass, and that would be a violation
+of all experience, and therefore an unphilosophical statement.
+</p>
+
+
+
+<h2>APPENDIX B</h2>
+
+<p>
+The hypothesis of electricity being the fundamental basis of all matter
+made in the last chapter on the &ldquo;Unity of the Universe,&rdquo; receives
+confirmation from Sir Oliver Lodge in his <i>Modern Views of Matter</i>,
+where he writes, page 13: &ldquo;The fundamental ingredient of which, in this
+view, the whole of matter is made up, is nothing more or less than
+electricity, in the form of an aggregate of an equal number of positive
+and negative electric charges. This, when established, will be a
+unification of matter such as has through all the ages been sought; it
+goes further than had been hoped, for the substratum is not an unknown
+and hypothetical protile, but the familiar electric charge.&rdquo;
+</p>
+
+<p><span class='pagenum'><a name='Page_350' id='Page_350'></a><a href='#TOC'>[350]</a></span></p>
+<h2>APPENDIX C</h2>
+
+<p>
+The hypothesis that all elements have definite quantities of electricity
+in them, or a definite number of electrons, as suggested on page 335,
+receives added weight by the testimony of Sir Oliver Lodge in the work
+already referred to. Writing on the subject, he says: &ldquo;It is a
+fascinating guess that the electrons constitute the fundamental
+substratum of which all matter is composed. That a grouping of say 700
+electrons, 350 positive and 350 negative, interleaved or interlocked in
+a state of violent motion so as to produce a stable configuration under
+the influence of their centrifugal inertia and their electric forces,
+constitutes an atom of hydrogen. That sixteen times as many, in another
+stable grouping, constitute an atom of oxygen. That some 16,000 of them
+go to form an atom of sodium; about 100,000 an atom of barium; and
+160,000 an atom of radium.&rdquo;
+</p>
+
+<p>
+From these extracts, taken from <i>Modern Views of Matter,</i> the author
+claims that the theory of the Aether presented to the reader in <i>Aether
+and Gravitation</i> receives added confirmation and support.
+</p>
+
+<hr style='width: 65%;' />
+
+<h2>ERRATA</h2>
+
+<p>
+The author regrets that Professor J. J. Thomson's name has been
+incorrectly spelled in several places.
+</p>
+
+
+
+
+<p><span class='pagenum'><a name='Page_351' id='Page_351'></a><a href='#TOC'>[351]</a></span></p>
+<h2>INDEX</h2>
+
+<p>
+Aberration of light, <a href='#Page_69'>69</a>, <a href='#Page_149'>149</a>, <a href='#Page_218'>218</a><br />
+<br />
+Absorption, <a href='#Page_104'>104</a>-6<br />
+<br />
+Acceleration, <a href='#Page_239'>239</a><br />
+<br />
+Actinic rays, <a href='#Page_141'>141</a><br />
+<br />
+Action at a distance, <a href='#Page_96'>96</a>, <a href='#Page_174'>174</a>, <a href='#Page_176'>176</a><br />
+<span style='margin-left: 2em;'>and re-action, <a href='#Page_20'>20</a>, <a href='#Page_251'>251</a></span><br />
+<br />
+Adams' discovery of Neptune, <a href='#Page_25'>25</a><br />
+<br />
+Aether is matter, <a href='#Page_54'>54</a>-8<br />
+<span style='margin-left: 2em;'>is atomic, <a href='#Page_59'>59</a>-<a href='#Page_67'>67</a></span><br />
+<span style='margin-left: 2em;'>is gravitative, <a href='#Page_64'>64</a>-9</span><br />
+<span style='margin-left: 2em;'>density of, <a href='#Page_69'>69</a>, <a href='#Page_71'>71</a>, <a href='#Page_136'>136</a>, <a href='#Page_243'>243</a></span><br />
+<span style='margin-left: 2em;'>elasticity of, <a href='#Page_74'>74</a>-7</span><br />
+<span style='margin-left: 2em;'>inertia of, <a href='#Page_76'>76</a>, <a href='#Page_330'>330</a></span><br />
+<span style='margin-left: 2em;'>its motions, <a href='#Page_80'>80</a></span><br />
+<span style='margin-left: 2em;'>compressibility of, <a href='#Page_291'>291</a>, <a href='#Page_315'>315</a></span><br />
+<span style='margin-left: 2em;'>waves, <a href='#Page_79'>79</a>-<a href='#Page_80'>80</a></span><br />
+<br />
+Aetherial basis of matter, <a href='#Page_326'>326</a><br />
+<br />
+Affinity, chemical, <a href='#Page_43'>43</a><br />
+<br />
+Aldebaran, <a href='#Page_312'>312</a><br />
+<br />
+Aluminium, <a href='#Page_79'>79</a><br />
+<br />
+Ampère, <a href='#Page_192'>192</a><br />
+<br />
+Ampère's theory of magnetism, <a href='#Page_193'>193</a><br />
+<br />
+Andromeda, <a href='#Page_314'>314</a><br />
+<br />
+Annual magnetic variation, <a href='#Page_208'>208</a><br />
+<br />
+Annular nebulae, <a href='#Page_320'>320</a><br />
+<br />
+Aphelion of earth, <a href='#Page_36'>36</a><br />
+<br />
+Arago, M., <a href='#Page_321'>321</a><br />
+<br />
+Arcturus, <a href='#Page_312'>312</a><br />
+<br />
+Areas, Kepler's law of, <a href='#Page_36'>36</a><br />
+<br />
+Asten, Von, <a href='#Page_234'>234</a>, <a href='#Page_296'>296</a><br />
+<br />
+Asteroids, <a href='#Page_31'>31</a><br />
+<br />
+Atmosphere, <a href='#Page_68'>68</a>, <a href='#Page_73'>73</a>, <a href='#Page_102'>102</a>, <a href='#Page_225'>225</a><br />
+<br />
+Atom, vortex, <a href='#Page_45'>45</a>, <a href='#Page_46'>46</a>, <a href='#Page_61'>61</a><br />
+<span style='margin-left: 2em;'>what it is, <a href='#Page_43'>43</a></span><br />
+<span style='margin-left: 2em;'>electron, <a href='#Page_63'>63</a></span><br />
+<span style='margin-left: 2em;'>Boscovitch, <a href='#Page_61'>61</a></span><br />
+<span style='margin-left: 2em;'>hard, <a href='#Page_61'>61</a></span><br />
+<span style='margin-left: 2em;'>size of, <a href='#Page_43'>43</a></span><br />
+<br />
+Attraction, electrical, <a href='#Page_2'>2</a>, <a href='#Page_286'>286</a><br />
+<span style='margin-left: 2em;'>of gravitation, <a href='#Page_13'>13</a>, <a href='#Page_24'>24</a>, <a href='#Page_31'>31</a></span><br />
+<span style='margin-left: 2em;'>magnetic, <a href='#Page_195'>195</a></span><br />
+<br />
+<br />
+Balance, Torsion, <a href='#Page_187'>187</a><br />
+<br />
+Bernoulli, <a href='#Page_221'>221</a>, <a href='#Page_341'>341</a><br />
+<br />
+Beta Persei, <a href='#Page_308'>308</a><br />
+<br />
+Biela's comet, <a href='#Page_296'>296</a>-7<br />
+<br />
+Binary compound, <a href='#Page_143'>143</a><br />
+<span style='margin-left: 2em;'>stars, <a href='#Page_25'>25</a>, <a href='#Page_309'>309</a></span><br />
+<br />
+Biot, <a href='#Page_138'>138</a><br />
+<br />
+Boscovitch atoms, <a href='#Page_44'>44</a>, <a href='#Page_138'>138</a><br />
+<br />
+Boyle and Marriotte's law, <a href='#Page_76'>76</a>, <a href='#Page_103'>103</a><br />
+<br />
+Bradley's discovery of aberration, <a href='#Page_149'>149</a><br />
+<br />
+Bredichin on comets' tails, <a href='#Page_302'>302</a><br />
+<br />
+Brilliancy of stars, <a href='#Page_307'>307</a>, <a href='#Page_309'>309</a><br />
+<br />
+British Association Report, <a href='#Page_57'>57</a>, <a href='#Page_59'>59</a><br />
+<br />
+<br />
+Calcium, <a href='#Page_79'>79</a><br />
+<br />
+Canis major, <a href='#Page_307'>307</a><br />
+<span style='margin-left: 2em;'>minor, <a href='#Page_307'>307</a></span><br />
+<br />
+Capella, <a href='#Page_312'>312</a><br />
+<br />
+Carbon, <a href='#Page_48'>48</a><br />
+<br />
+Carboniferous period, <a href='#Page_115'>115</a><br />
+<br />
+Carnot on heat, <a href='#Page_116'>116</a>-18<br />
+<br />
+Cassini, <a href='#Page_307'>307</a><br />
+<br />
+Cause and effect, <a href='#Page_14'>14</a><br />
+<span style='margin-left: 2em;'>of gravitation, <a href='#Page_1'>1</a>, <a href='#Page_282'>282</a>-9</span><br />
+<br />
+Cavendish experiment, <a href='#Page_24'>24</a><br />
+<br />
+Centauri, <a href='#Page_79'>79</a><br />
+<br />
+Centre of gravity, <a href='#Page_325'>325</a><br />
+<br />
+Centrifugal force, <a href='#Page_9'>9,</a> <a href='#Page_13'>13</a>, <a href='#Page_15'>15,</a> <a href='#Page_30'>30,</a> <a href='#Page_236'>236</a>-8<br />
+<br />
+Centripetal force, <a href='#Page_9'>9,</a> <a href='#Page_12'>12,</a> <a href='#Page_282'>282</a><br />
+<br />
+Cetus, <a href='#Page_307'>307</a><br />
+<br />
+Chalk, <a href='#Page_6'>6</a><br />
+<br />
+Challis, Prof., <a href='#Page_74'>74</a>, <a href='#Page_96'>96</a>, <a href='#Page_100'>100</a>, <a href='#Page_107'>107</a>, <a href='#Page_151'>151</a>, <a href='#Page_155'>155</a>, <a href='#Page_214'>214</a>, <a href='#Page_227'>227</a>, <a href='#Page_311'>311</a><br />
+<br />
+Chemistry, <a href='#Page_47'>47</a>, <a href='#Page_336'>336</a><br />
+<br />
+Coal, <a href='#Page_86'>86</a>, <a href='#Page_88'>88</a><br />
+<br />
+Clairaut, <a href='#Page_297'>297</a><br />
+<br />
+Clusters of stars, <a href='#Page_314'>314</a><br />
+<br />
+Cohesion, <a href='#Page_48'>48</a><br />
+<br />
+Colour, <a href='#Page_138'>138</a><br />
+<br />
+Colours of stars, <a href='#Page_308'>308</a><br />
+<span style='margin-left: 2em;'>seven primary, <a href='#Page_139'>139</a></span><br />
+<br />
+Comets, <a href='#Page_291'>291</a><br />
+<span style='margin-left: 2em;'>attracted by planets, <a href='#Page_298'>298</a></span><br />
+<span style='margin-left: 2em;'>condensation of, <a href='#Page_292'>292</a></span><br />
+<br />
+Comets and meteors, <a href='#Page_297'>297</a><br />
+<span style='margin-left: 2em;'>short period, <a href='#Page_293'>293</a>-4</span><br />
+<span style='margin-left: 2em;'>long period, <a href='#Page_293'>293</a>-4</span><br />
+<span style='margin-left: 2em;'>tails of, <a href='#Page_298'>298</a>-9</span><br />
+<span style='margin-left: 2em;'>orbits of, <a href='#Page_293'>293</a></span><br />
+<span style='margin-left: 2em;'>nucleus of, <a href='#Page_298'>298</a>-9</span><br />
+<span style='margin-left: 2em;'>coma, <a href='#Page_298'>298</a>-9</span><br />
+<br />
+Compressibility of aether, <a href='#Page_291'>291</a>, <a href='#Page_315'>315</a><br />
+<br />
+Condensation of gases, <a href='#Page_47'>47</a><br />
+<br />
+Conservation of matter, <a href='#Page_42'>42</a><br />
+<span style='margin-left: 2em;'>of energy, <a href='#Page_84'>84</a></span><br />
+<span style='margin-left: 2em;'>of motion, <a href='#Page_92'>92</a></span><br />
+<br />
+Constellations, <a href='#Page_307'>307</a><br />
+<br />
+Corollary, <a href='#Page_15'>15</a><br />
+<br />
+Corona Borealis, <a href='#Page_309'>309</a><br />
+<br />
+Corpuscles, <a href='#Page_42'>42</a>, <a href='#Page_64'>64</a>, <a href='#Page_136'>136</a><br />
+<br />
+Corpuscular theory of light, <a href='#Page_122'>122</a><br />
+<br />
+Correlation of forces, <a href='#Page_83'>83</a><br />
+<br />
+Coulomb Torsion balance, <a href='#Page_185'>185</a>, <a href='#Page_187'>187</a><br />
+<br />
+Crookes, Sir William, <a href='#Page_42'>42</a>, <a href='#Page_136'>136</a>, <a href='#Page_326'>326</a>, <a href='#Page_341'>341</a><br />
+<br />
+Current, electric, <a href='#Page_163'>163</a><br />
+<span style='margin-left: 2em;'>magnetic, <a href='#Page_192'>192</a></span><br />
+<br />
+Currents, <a href='#Page_90'>90</a><br />
+<br />
+Curry, Prof., <a href='#Page_284'>284</a><br />
+<br />
+Cycle of operations, <a href='#Page_114'>114</a>, <a href='#Page_116'>116</a><br />
+<br />
+Cygnus, <a href='#Page_307'>307</a><br />
+<br />
+<br />
+Dalton's atomic theory, <a href='#Page_42'>42</a><br />
+<br />
+Davy, 99, <a href='#Page_107'>107</a><br />
+<br />
+Day and night, <a href='#Page_4'>4</a><br />
+<br />
+D'Arrest's comet, <a href='#Page_296'>296</a><br />
+<br />
+Deimos, <a href='#Page_38'>38</a><br />
+<br />
+Democritus, <a href='#Page_44'>44</a><br />
+<br />
+Density of matter, <a href='#Page_51'>51</a><br />
+<span style='margin-left: 2em;'>of aether, <a href='#Page_69'>69</a></span><br />
+<span style='margin-left: 2em;'>electric, <a href='#Page_170'>170</a></span><br />
+<span style='margin-left: 2em;'>of earth, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>of sun, <a href='#Page_27'>27</a></span><br />
+<span style='margin-left: 2em;'>of planets, <a href='#Page_242'>242</a></span><br />
+<br />
+Descartes, <a href='#Page_221'>221</a>-2, <a href='#Page_341'>341</a><br />
+<br />
+Dewar, Prof., <a href='#Page_47'>47</a><br />
+<br />
+Diameter of earth, <a href='#Page_29'>29</a><br />
+<span style='margin-left: 2em;'>polar, <a href='#Page_29'>29</a></span><br />
+<span style='margin-left: 2em;'>equatorial, <a href='#Page_29'>29</a></span><br />
+<span style='margin-left: 2em;'>of sun, <a href='#Page_280'>280</a></span><br />
+<span style='margin-left: 2em;'>of planets, <a href='#Page_29'>29</a></span><br />
+<br />
+Dielectric, <a href='#Page_168'>168</a>, <a href='#Page_175'>175</a><br />
+<br />
+Diffusion, <a href='#Page_49'>49</a><br />
+<br />
+Dip, magnetic, <a href='#Page_199'>199</a><br />
+<br />
+Distances of stars, <a href='#Page_280'>280</a><br />
+<br />
+Diurnal variations, magnetic, <a href='#Page_209'>209</a><br />
+<br />
+Dog star (Sirius), <a href='#Page_306'>306</a><br />
+<br />
+Donati's comet, <a href='#Page_298'>298</a><br />
+<br />
+Double stars, <a href='#Page_308'>308</a><br />
+<br />
+Draco, <a href='#Page_307'>307</a><br />
+<br />
+Dynamical equivalent of heat, <a href='#Page_114'>114</a><br />
+<span style='margin-left: 2em;'>value of light, <a href='#Page_150'>150</a></span><br />
+<br />
+Dynamics, laws of thermo-, <a href='#Page_114'>114</a>-18<br />
+<br />
+Dynamo, <a href='#Page_87'>87</a>, <a href='#Page_90'>90</a><br />
+<br />
+<br />
+Ear, <a href='#Page_120'>120</a><br />
+<br />
+Earth, mass of, <a href='#Page_235'>235</a>, <a href='#Page_242'>242</a><br />
+<span style='margin-left: 2em;'>a magnet, <a href='#Page_196'>196</a>-8</span><br />
+<span style='margin-left: 2em;'>size of, <a href='#Page_29'>29</a></span><br />
+<span style='margin-left: 2em;'>rotation of, <a href='#Page_219'>219</a></span><br />
+<span style='margin-left: 2em;'>orbit of, <a href='#Page_276'>276</a></span><br />
+<span style='margin-left: 2em;'>periodic time of, <a href='#Page_251'>251</a></span><br />
+<span style='margin-left: 2em;'>gravity of, <a href='#Page_29'>29</a></span><br />
+<span style='margin-left: 2em;'>shape of, <a href='#Page_29'>29</a></span><br />
+<span style='margin-left: 2em;'>distance from sun, <a href='#Page_242'>242</a>, <a href='#Page_251'>251</a></span><br />
+<span style='margin-left: 2em;'>velocity in orbit, <a href='#Page_251'>251</a></span><br />
+<br />
+Eccentricity of orbits, <a href='#Page_268'>268</a>, <a href='#Page_276'>276</a><br />
+<br />
+Eclipse, <a href='#Page_145'>145</a>, <a href='#Page_148'>148</a><br />
+<br />
+Ecliptic, plane of, <a href='#Page_277'>277</a>-9<br />
+<br />
+Elasticity, <a href='#Page_46'>46</a><br />
+<span style='margin-left: 2em;'>of matter, <a href='#Page_51'>51</a></span><br />
+<span style='margin-left: 2em;'>of aether, <a href='#Page_74'>74</a></span><br />
+<br />
+Electric current, <a href='#Page_154'>154</a><br />
+<span style='margin-left: 2em;'>potential, <a href='#Page_170'>170</a></span><br />
+<span style='margin-left: 2em;'>induction, <a href='#Page_175'>175</a></span><br />
+<span style='margin-left: 2em;'>radiation, <a href='#Page_182'>182</a></span><br />
+<span style='margin-left: 2em;'>density, <a href='#Page_170'>170</a></span><br />
+<span style='margin-left: 2em;'>energy, <a href='#Page_179'>179</a></span><br />
+<span style='margin-left: 2em;'>field, <a href='#Page_166'>166</a>, <a href='#Page_179'>179</a></span><br />
+<span style='margin-left: 2em;'>lines of force, <a href='#Page_173'>173</a></span><br />
+<br />
+Electricity, <a href='#Page_64'>64</a>, <a href='#Page_162'>162</a><br />
+<span style='margin-left: 2em;'>two kinds of, <a href='#Page_175'>175</a></span><br />
+<span style='margin-left: 2em;'>positive, <a href='#Page_175'>175</a></span><br />
+<span style='margin-left: 2em;'>negative, <a href='#Page_175'>175</a></span><br />
+<span style='margin-left: 2em;'>laws of, <a href='#Page_184'>184</a></span><br />
+<span style='margin-left: 2em;'>theories of, <a href='#Page_162'>162</a></span><br />
+<br />
+Electrons, <a href='#Page_136'>136</a>, <a href='#Page_163'>163</a><br />
+<br />
+Electro-static, <a href='#Page_158'>158</a>, <a href='#Page_164'>164</a><br />
+<span style='margin-left: 2em;'>kinetic, <a href='#Page_158'>158</a>, <a href='#Page_164'>164</a></span><br />
+<span style='margin-left: 2em;'>kinetic energy, <a href='#Page_217'>217</a></span><br />
+<span style='margin-left: 2em;'>magnetism, <a href='#Page_192'>192</a>-5</span><br />
+<span style='margin-left: 2em;'>magnets, <a href='#Page_199'>199</a></span><br />
+<span style='margin-left: 2em;'>magnetic theory of light, <a href='#Page_229'>229</a></span><br />
+<span style='margin-left: 2em;'>chemical equivalents, <a href='#Page_189'>189</a>, <a href='#Page_333'>333</a></span><br />
+<br />
+Elements of matter, <a href='#Page_47'>47</a><br />
+<br />
+Ellipse, <a href='#Page_34'>34</a><br />
+<span style='margin-left: 2em;'>Kepler's discovery of, <a href='#Page_34'>34</a></span><br />
+<br />
+Elliptical nebulae, <a href='#Page_320'>320</a><br />
+<br />
+Emission theory of light, <a href='#Page_122'>122</a><br />
+<br />
+Encke's comet, <a href='#Page_293'>293</a>, <a href='#Page_296'>296</a><br />
+<span style='margin-left: 2em;'>resisting medium, <a href='#Page_228'>228</a></span><br />
+<br />
+Energy, <a href='#Page_83'>83</a>, <a href='#Page_84'>84</a><br />
+<span style='margin-left: 2em;'>what it is, <a href='#Page_83'>83</a></span><br />
+<span style='margin-left: 2em;'>conservation of, <a href='#Page_84'>84</a></span><br />
+<span style='margin-left: 2em;'>transformation of, <a href='#Page_86'>86</a></span><br />
+<span style='margin-left: 2em;'>potential, <a href='#Page_87'>87</a></span><br />
+<span style='margin-left: 2em;'>kinetic, <a href='#Page_89'>89</a>, <a href='#Page_164'>164</a></span><br />
+<span style='margin-left: 2em;'>radiant, <a href='#Page_109'>109</a></span><br />
+<span style='margin-left: 2em;'>electrical, <a href='#Page_179'>179</a></span><br />
+<span style='margin-left: 2em;'>and motion, <a href='#Page_91'>91</a></span><br />
+<br />
+Engine, Carnot's heat, <a href='#Page_116'>116</a><br />
+<br />
+Envelopes of comets, <a href='#Page_298'>298</a><br />
+<br />
+Epicureans, <a href='#Page_44'>44</a><br />
+<br />
+Equal areas, <a href='#Page_36'>36</a><br />
+<span style='margin-left: 2em;'>times, <a href='#Page_36'>36</a></span><br />
+<br />
+Equator, N. and S. Poles, <a href='#Page_29'>29</a><br />
+<span style='margin-left: 2em;'>magnetic, <a href='#Page_202'>202</a></span><br />
+<span style='margin-left: 2em;'>terrestrial, <a href='#Page_29'>29</a></span><br />
+<br />
+Equipotential surfaces, <a href='#Page_171'>171</a><br />
+<br />
+Equivalents, electro-chemical, <a href='#Page_189'>189</a>, <a href='#Page_333'>333</a><br />
+<br />
+Euler, <a href='#Page_123'>123</a><br />
+<br />
+Exchanges, theory of, <a href='#Page_105'>105</a><br />
+<br />
+Experience, <a href='#Page_4'>4</a><br />
+<br />
+Experiments of Rumford, <a href='#Page_98'>98</a><br />
+<span style='margin-left: 2em;'>of Michelson and Morley, <a href='#Page_67'>67</a>, <a href='#Page_227'>227</a></span><br />
+<span style='margin-left: 2em;'>of Lebedew, <a href='#Page_302'>302</a></span><br />
+<span style='margin-left: 2em;'>of Nichols and Hull, <a href='#Page_153'>153</a></span><br />
+<span style='margin-left: 2em;'>of Hertz, <a href='#Page_165'>165</a></span><br />
+<span style='margin-left: 2em;'>of Faraday, <a href='#Page_65'>65</a>, <a href='#Page_285'>285</a></span><br />
+<span style='margin-left: 2em;'>of M. Faye, <a href='#Page_302'>302</a></span><br />
+<span style='margin-left: 2em;'>of Joule, <a href='#Page_114'>114</a></span><br />
+<br />
+<br />
+Falling stone, <a href='#Page_21'>21</a>, <a href='#Page_29'>29</a><br />
+<br />
+Faraday, <a href='#Page_45'>45</a>, <a href='#Page_175'>175</a>, <a href='#Page_220'>220</a><br />
+<span style='margin-left: 2em;'>on matter, <a href='#Page_56'>56</a></span><br />
+<span style='margin-left: 2em;'>on Lines of Force, <a href='#Page_168'>168</a>, <a href='#Page_200'>200</a>, <a href='#Page_203'>203</a>-5</span><br />
+<span style='margin-left: 2em;'>on magnetic space, <a href='#Page_208'>208</a></span><br />
+<span style='margin-left: 2em;'>on gravitation, <a href='#Page_287'>287</a></span><br />
+<span style='margin-left: 2em;'>on electricity, <a href='#Page_332'>332</a></span><br />
+<span style='margin-left: 2em;'>on induction, <a href='#Page_176'>176</a></span><br />
+<br />
+Faye, M., <a href='#Page_111'>111</a>, <a href='#Page_302'>302</a>, <a href='#Page_319'>319</a><br />
+<br />
+Faye's comet, <a href='#Page_293'>293</a>, <a href='#Page_296'>296</a><br />
+<br />
+Field, electric, <a href='#Page_179'>179</a><br />
+<span style='margin-left: 2em;'>magnetic, <a href='#Page_199'>199</a></span><br />
+<br />
+Fizeau, <a href='#Page_149'>149</a>, <a href='#Page_224'>224</a><br />
+<br />
+Fluids, <a href='#Page_48'>48</a><br />
+<br />
+Food, <a href='#Page_89'>89</a><br />
+<br />
+Forbes, <a href='#Page_121'>121</a><br />
+<br />
+Force, <a href='#Page_16'>16</a>, <a href='#Page_19'>19</a>, <a href='#Page_90'>90</a><br />
+<span style='margin-left: 2em;'>centrifugal, <a href='#Page_9'>9</a>, <a href='#Page_13'>13</a>, <a href='#Page_236'>236</a></span><br />
+<span style='margin-left: 2em;'>centripetal, <a href='#Page_9'>9</a>, <a href='#Page_12'>12</a>, <a href='#Page_282'>282</a></span><br />
+<span style='margin-left: 2em;'>lines of, <a href='#Page_200'>200</a></span><br />
+<br />
+Forces, direction of the, <a href='#Page_26'>26</a><br />
+<span style='margin-left: 2em;'>proportion of the, <a href='#Page_26'>26</a></span><br />
+<br />
+Foucault, <a href='#Page_149'>149</a><br />
+<br />
+Franklin, <a href='#Page_106'>106</a><br />
+<br />
+Fresnel, <a href='#Page_75'>75</a>, <a href='#Page_131'>131</a><br />
+<br />
+Frictionless medium, <a href='#Page_17'>17</a>, <a href='#Page_131'>131</a>, <a href='#Page_136'>136</a>, <a href='#Page_224'>224</a><br />
+<br />
+Fundamental medium, <a href='#Page_54'>54</a><br />
+<br />
+<br />
+Galaxy, <a href='#Page_325'>325</a>, <a href='#Page_346'>346</a><br />
+<br />
+Gaseous nebulae, <a href='#Page_313'>313</a><br />
+<br />
+Gases, condensation of, <a href='#Page_47'>47</a><br />
+<span style='margin-left: 2em;'>liquefaction of, <a href='#Page_47'>47</a></span><br />
+<span style='margin-left: 2em;'>kinetic theory of, <a href='#Page_49'>49</a></span><br />
+<br />
+Glazebrook, Prof., on aether and gravitation, <a href='#Page_22'>22</a><br />
+<br />
+Globular clusters of stars, <a href='#Page_314'>314</a><br />
+<br />
+Gravitation, law of, <a href='#Page_61'>61</a>, <a href='#Page_65'>65</a><br />
+<span style='margin-left: 2em;'>universal, <a href='#Page_24'>24</a></span><br />
+<span style='margin-left: 2em;'>intensity of, <a href='#Page_27'>27</a></span><br />
+<span style='margin-left: 2em;'>law of proportion, <a href='#Page_26'>26</a></span><br />
+<span style='margin-left: 2em;'>cause of, <a href='#Page_1'>1</a>, <a href='#Page_282'>282</a></span><br />
+<span style='margin-left: 2em;'>and binary stars, <a href='#Page_25'>25</a></span><br />
+<br />
+Gravity, centre of, <a href='#Page_325'>325</a><br />
+<br />
+Great Bear, <a href='#Page_307'>307</a><br />
+<br />
+Grove, <a href='#Page_83'>83</a><br />
+<br />
+<br />
+Halley's comet, <a href='#Page_296'>296</a>-7<br />
+<br />
+Hamilton, Sir W. R., <a href='#Page_247'>247</a><br />
+<br />
+Head of comets, <a href='#Page_298'>298</a><br />
+<br />
+Heat is motion, <a href='#Page_98'>98</a><br />
+<span style='margin-left: 2em;'>a mode of motion, <a href='#Page_107'>107</a></span><br />
+<span style='margin-left: 2em;'>radiant, <a href='#Page_109'>109</a></span><br />
+<span style='margin-left: 2em;'>dynamical equivalent of, <a href='#Page_116'>116</a></span><br />
+<span style='margin-left: 2em;'>effects of, <a href='#Page_107'>107</a></span><br />
+<span style='margin-left: 2em;'>nature of, <a href='#Page_98'>98</a></span><br />
+<span style='margin-left: 2em;'>radiation of, <a href='#Page_109'>109</a></span><br />
+<span style='margin-left: 2em;'>transformation of, <a href='#Page_87'>87</a></span><br />
+<br />
+Heat engine, Carnot's, <a href='#Page_116'>116</a><br />
+<span style='margin-left: 2em;'>of sun, <a href='#Page_109'>109</a></span><br />
+<span style='margin-left: 2em;'>and matter, <a href='#Page_100'>100</a></span><br />
+<span style='margin-left: 2em;'>and work, <a href='#Page_114'>114</a></span><br />
+<span style='margin-left: 2em;'>refraction of, <a href='#Page_121'>121</a></span><br />
+<br />
+Helmholtz, Von, <a href='#Page_45'>45</a>, <a href='#Page_86'>86</a><br />
+<br />
+Hercules, <a href='#Page_257'>257</a>, <a href='#Page_271'>271</a>, <a href='#Page_307'>307</a><br />
+<br />
+Herschel, Sir J., <a href='#Page_3'>3</a>, <a href='#Page_4'>4</a>, <a href='#Page_7'>7</a>, <a href='#Page_226'>226</a>, <a href='#Page_228'>228</a>, <a href='#Page_281'>281</a>, <a href='#Page_299'>299</a>, <a href='#Page_301'>301</a>, <a href='#Page_310'>310</a>, <a href='#Page_321'>321</a><br />
+<span style='margin-left: 2em;'>Sir W., <a href='#Page_109'>109</a>, <a href='#Page_271'>271</a>-2, <a href='#Page_313'>313</a></span><br />
+<br />
+Hertz, <a href='#Page_138'>138</a>, <a href='#Page_159'>159</a>, <a href='#Page_182'>182</a><br />
+<br />
+Hicks, Prof., <a href='#Page_13'>13</a><br />
+<br />
+Hodograph of planets, <a href='#Page_247'>247</a><br />
+<br />
+Hot springs, <a href='#Page_90'>90</a><br />
+<br />
+Huggins, <a href='#Page_313'>313</a>-14<br />
+<br />
+Huyghens, <a href='#Page_54'>54</a>, <a href='#Page_123'>123</a>, <a href='#Page_125'>125</a>, <a href='#Page_128'>128</a><br />
+<br />
+Hydrogen, <a href='#Page_40'>40</a>, <a href='#Page_42'>42</a>, <a href='#Page_44'>44</a>, <a href='#Page_60'>60</a>, <a href='#Page_93'>93</a>, <a href='#Page_314'>314</a>, <a href='#Page_333'>333</a><br />
+<br />
+Hypotheses, <a href='#Page_3'>3</a>, <a href='#Page_338'>338</a><br />
+<br />
+<br />
+Ice, <a href='#Page_42'>42</a><br />
+<br />
+Identity of heat and light, <a href='#Page_119'>119</a><br />
+<span style='margin-left: 2em;'>light and electricity, <a href='#Page_156'>156</a>, <a href='#Page_160'>160</a>, <a href='#Page_165'>165</a></span><br />
+<span style='margin-left: 2em;'>aether and electricity, <a href='#Page_331'>331</a></span><br />
+<br />
+Imponderable, <a href='#Page_71'>71</a><br />
+<br />
+Impressed force, <a href='#Page_20'>20</a><br />
+<br />
+Impressible aether, <a href='#Page_78'>78</a><br />
+<br />
+Induction, electric, <a href='#Page_174'>174</a>-5<br />
+<span style='margin-left: 2em;'>magnetic, <a href='#Page_199'>199</a></span><br />
+<span style='margin-left: 2em;'>Faraday's theory of, <a href='#Page_175'>175</a></span><br />
+<br />
+Inertia of matter, <a href='#Page_52'>52</a><br />
+<span style='margin-left: 2em;'>of aether, <a href='#Page_330'>330</a></span><br />
+<br />
+Intensity of light, <a href='#Page_28'>28</a>, <a href='#Page_146'>146</a><br />
+<span style='margin-left: 2em;'>of heat, <a href='#Page_28'>28</a>, <a href='#Page_113'>113</a></span><br />
+<span style='margin-left: 2em;'>of electricity, <a href='#Page_184'>184</a></span><br />
+<span style='margin-left: 2em;'>of gravity, <a href='#Page_28'>28</a></span><br />
+<br />
+Iron, <a href='#Page_42'>42</a><br />
+<span style='margin-left: 2em;'>expansion by heat, <a href='#Page_101'>101</a></span><br />
+<span style='margin-left: 2em;'>contraction by cold, <a href='#Page_102'>102</a></span><br />
+<br />
+<br />
+Joule, 85, <a href='#Page_114'>114</a><br />
+<br />
+Jupiter, 26, <a href='#Page_68'>68</a><br />
+<span style='margin-left: 2em;'>mass of, <a href='#Page_235'>235</a></span><br />
+<span style='margin-left: 2em;'>satellites of, <a href='#Page_149'>149</a>, <a href='#Page_178'>178</a></span><br />
+<span style='margin-left: 2em;'>rotation of, <a href='#Page_219'>219</a></span><br />
+<span style='margin-left: 2em;'>orbital velocity of, <a href='#Page_251'>251</a>, <a href='#Page_265'>265</a></span><br />
+<span style='margin-left: 2em;'>size of, <a href='#Page_235'>235</a></span><br />
+<span style='margin-left: 2em;'>distance from sun, <a href='#Page_242'>242</a>, <a href='#Page_251'>251</a></span><br />
+<span style='margin-left: 2em;'>density of, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>and comets, <a href='#Page_305'>305</a></span><br />
+<br />
+<br />
+Kant, <a href='#Page_317'>317</a><br />
+<br />
+Kelvin, Lord, <a href='#Page_43'>43</a>, <a href='#Page_71'>71</a>, <a href='#Page_77'>77</a>, <a href='#Page_80'>80</a>, <a href='#Page_95'>95</a>, <a href='#Page_216'>216</a>, <a href='#Page_227'>227</a><br />
+<span style='margin-left: 2em;'>on aether, <a href='#Page_56'>56</a>-7</span><br />
+<span style='margin-left: 2em;'>on vortex atom, <a href='#Page_63'>63</a></span><br />
+<span style='margin-left: 2em;'>on compressible aether, <a href='#Page_291'>291</a>, <a href='#Page_315'>315</a></span><br />
+<span style='margin-left: 2em;'>on light, <a href='#Page_151'>151</a></span><br />
+<br />
+Kepler's laws, <a href='#Page_32'>32</a><br />
+<span style='margin-left: 2em;'>first, <a href='#Page_33'>33</a>, <a href='#Page_256'>256</a>-9</span><br />
+<span style='margin-left: 2em;'>second, <a href='#Page_36'>36</a>, <a href='#Page_260'>260</a>-2</span><br />
+<span style='margin-left: 2em;'>third, <a href='#Page_37'>37</a>, <a href='#Page_263'>263</a>-5</span><br />
+<span style='margin-left: 2em;'>on vortex motion, <a href='#Page_221'>221</a>-2</span><br />
+<br />
+Kinetic energy, <a href='#Page_89'>89</a><br />
+<span style='margin-left: 2em;'>electro, <a href='#Page_217'>217</a></span><br />
+<br />
+Kirchhoff, <a href='#Page_43'>43</a><br />
+<br />
+<br />
+Laplace, <a href='#Page_317'>317</a><br />
+<span style='margin-left: 2em;'>nebular hypothesis, <a href='#Page_317'>317</a></span><br />
+<br />
+Larmor, Dr., <a href='#Page_22'>22</a>, <a href='#Page_44'>44</a>, <a href='#Page_56'>56</a>, <a href='#Page_63'>63</a>, <a href='#Page_93'>93</a>, <a href='#Page_163'>163</a><br />
+<span style='margin-left: 2em;'>on electrons, <a href='#Page_284'>284</a></span><br />
+<span style='margin-left: 2em;'>on aetherial physics, <a href='#Page_22'>22</a>, <a href='#Page_327'>327</a>-9</span><br />
+<br />
+Lavoisier, <a href='#Page_42'>42</a><br />
+<br />
+Law of gravitation, <a href='#Page_24'>24</a><br />
+<span style='margin-left: 2em;'>of inverse squares, <a href='#Page_27'>27</a></span><br />
+<br />
+Laws of electricity, <a href='#Page_184'>184</a><br />
+<span style='margin-left: 2em;'>of light, <a href='#Page_145'>145</a></span><br />
+<span style='margin-left: 2em;'>of heat, <a href='#Page_113'>113</a></span><br />
+<span style='margin-left: 2em;'>of motion, <a href='#Page_9'>9</a>, <a href='#Page_15'>15</a>, <a href='#Page_233'>233</a></span><br />
+<br />
+Lead, <a href='#Page_88'>88</a>, <a href='#Page_333'>333</a><br />
+<br />
+Lebedew, <a href='#Page_32'>32</a>, <a href='#Page_76'>76</a>, <a href='#Page_153'>153</a><br />
+<br />
+Le Verrier, <a href='#Page_25'>25</a><br />
+<span style='margin-left: 2em;'>discovery of Neptune, <a href='#Page_25'>25</a></span><br />
+<br />
+Leyden jar, <a href='#Page_157'>157</a><br />
+<br />
+Liebnitz, <a href='#Page_223'>223</a><br />
+<br />
+Light, <a href='#Page_75'>75</a><br />
+<span style='margin-left: 2em;'>a mode of motion, <a href='#Page_122'>122</a></span><br />
+<span style='margin-left: 2em;'>corpuscular theory of, <a href='#Page_123'>123</a></span><br />
+<span style='margin-left: 2em;'>undulatory theory of, <a href='#Page_123'>123</a>, <a href='#Page_136'>136</a></span><br />
+<span style='margin-left: 2em;'>electro-magnetic theory of, <a href='#Page_156'>156</a></span><br />
+<span style='margin-left: 2em;'>path of a ray of, <a href='#Page_144'>144</a></span><br />
+<span style='margin-left: 2em;'>intensity of, <a href='#Page_145'>145</a></span><br />
+<span style='margin-left: 2em;'>reflection of, <a href='#Page_136'>136</a></span><br />
+<span style='margin-left: 2em;'>refraction of, <a href='#Page_135'>135</a></span><br />
+<span style='margin-left: 2em;'>aberration of, <a href='#Page_149'>149</a></span><br />
+<span style='margin-left: 2em;'>composition of, <a href='#Page_139'>139</a></span><br />
+<span style='margin-left: 2em;'>velocity of, <a href='#Page_148'>148</a></span><br />
+<span style='margin-left: 2em;'>zodiacal, <a href='#Page_277'>277</a></span><br />
+<span style='margin-left: 2em;'>transverse vibration of, <a href='#Page_130'>130</a></span><br />
+<br />
+Lines of force, electric, <a href='#Page_173'>173</a><br />
+<span style='margin-left: 2em;'>magnetic, <a href='#Page_201'>201</a>-3</span><br />
+<br />
+Liquefaction of gases, <a href='#Page_47'>47</a><br />
+<br />
+Liquid air, <a href='#Page_47'>47</a><br />
+<br />
+Liquids, <a href='#Page_48'>48</a><br />
+<br />
+Little Bear, <a href='#Page_307'>307</a><br />
+<span style='margin-left: 2em;'>Dog, <a href='#Page_307'>307</a></span><br />
+<br />
+Lockyer, <a href='#Page_109'>109</a><br />
+<br />
+Lodge, Dr., <a href='#Page_219'>219</a><br />
+<span style='margin-left: 2em;'>on aether density, <a href='#Page_69'>69</a></span><br />
+<span style='margin-left: 2em;'>on aether, <a href='#Page_284'>284</a>, <a href='#Page_289'>289</a>, <a href='#Page_328'>328</a>, <a href='#Page_332'>332</a></span><br />
+<span style='margin-left: 2em;'>on electric inertia, <a href='#Page_330'>330</a></span><br />
+<span style='margin-left: 2em;'>on electricity, <a href='#Page_64'>64</a>, <a href='#Page_69'>69</a>, <a href='#Page_284'>284</a>, <a href='#Page_285'>285</a></span><br />
+<span style='margin-left: 2em;'>on force, <a href='#Page_17'>17</a></span><br />
+<span style='margin-left: 2em;'>on gravitation, <a href='#Page_283'>283</a></span><br />
+<br />
+Lorentz on light, <a href='#Page_154'>154</a><br />
+<br />
+Lyra, <a href='#Page_307'>307</a><br />
+<br />
+<br />
+MacLaurin, <a href='#Page_2'>2</a>, <a href='#Page_10'>10</a>, <a href='#Page_17'>17</a><br />
+<br />
+Magnesium, <a href='#Page_79'>79</a><br />
+<br />
+Magnet, <a href='#Page_21'>21</a><br />
+<br />
+Magnets, bar, <a href='#Page_199'>199</a><br />
+<span style='margin-left: 2em;'>moving, <a href='#Page_211'>211</a></span><br />
+<br />
+Magnetic axis, <a href='#Page_202'>202</a><br />
+<span style='margin-left: 2em;'>field, <a href='#Page_199'>199</a></span><br />
+<span style='margin-left: 2em;'>lines of force, <a href='#Page_200'>200</a></span><br />
+<span style='margin-left: 2em;'>shells, <a href='#Page_205'>205</a></span><br />
+<span style='margin-left: 2em;'>equator, <a href='#Page_202'>202</a></span><br />
+<span style='margin-left: 2em;'>induction, <a href='#Page_199'>199</a></span><br />
+<span style='margin-left: 2em;'>variation, <a href='#Page_208'>208</a></span><br />
+<span style='margin-left: 2em;'>molecules of, <a href='#Page_193'>193</a></span><br />
+<span style='margin-left: 2em;'>polarity, <a href='#Page_194'>194</a></span><br />
+<br />
+Magnetism of earth, <a href='#Page_207'>207</a>-12<br />
+<span style='margin-left: 2em;'>of planets, <a href='#Page_211'>211</a></span><br />
+<span style='margin-left: 2em;'>cause of solar, <a href='#Page_211'>211</a></span><br />
+<span style='margin-left: 2em;'>Ampère's theory of, <a href='#Page_193'>193</a></span><br />
+<br />
+Mars, <a href='#Page_68'>68</a>, <a href='#Page_79'>79</a><br />
+<span style='margin-left: 2em;'>a magnet, <a href='#Page_196'>196</a></span><br />
+<span style='margin-left: 2em;'>rotation of, <a href='#Page_219'>219</a></span><br />
+<span style='margin-left: 2em;'>size of, <a href='#Page_236'>236</a></span><br />
+<span style='margin-left: 2em;'>orbital velocity of, <a href='#Page_251'>251</a></span><br />
+<span style='margin-left: 2em;'>satellites of, <a href='#Page_178'>178</a></span><br />
+<span style='margin-left: 2em;'>orbit of, <a href='#Page_33'>33</a></span><br />
+<br />
+Mass, <a href='#Page_27'>27</a>, <a href='#Page_53'>53</a>, <a href='#Page_187'>187</a><br />
+<span style='margin-left: 2em;'>of earth, <a href='#Page_235'>235</a>, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>of planets, <a href='#Page_235'>235</a>, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>of sun, <a href='#Page_190'>190</a></span><br />
+<br />
+Matter, elements of, <a href='#Page_40'>40</a><br />
+<span style='margin-left: 2em;'>properties of, <a href='#Page_42'>42</a>, <a href='#Page_50'>50</a></span><br />
+<span style='margin-left: 2em;'>and motion, <a href='#Page_41'>41</a>, <a href='#Page_322'>322</a></span><br />
+<span style='margin-left: 2em;'>conservation of, <a href='#Page_42'>42</a></span><br />
+<span style='margin-left: 2em;'>divisibility of, <a href='#Page_44'>44</a></span><br />
+<span style='margin-left: 2em;'>four states of, <a href='#Page_48'>48</a></span><br />
+<span style='margin-left: 2em;'>aetherial basis of, <a href='#Page_48'>48</a>, <a href='#Page_333'>333</a></span><br />
+<span style='margin-left: 2em;'>physical constitution of, <a href='#Page_334'>334</a></span><br />
+<br />
+Maxwell, J. C., <a href='#Page_43'>43</a>, <a href='#Page_73'>73</a>, <a href='#Page_85'>85</a>, <a href='#Page_151'>151</a>, <a href='#Page_211'>211</a><br />
+<span style='margin-left: 2em;'>on physical lines of force, <a href='#Page_168'>168</a>, <a href='#Page_203'>203</a>-5, <a href='#Page_288'>288</a></span><br />
+<span style='margin-left: 2em;'>on aether, <a href='#Page_59'>59</a>, <a href='#Page_206'>206</a></span><br />
+<span style='margin-left: 2em;'>on magnetism, <a href='#Page_205'>205</a></span><br />
+<span style='margin-left: 2em;'>on electro-kinetic energy, <a href='#Page_180'>180</a>, <a href='#Page_217'>217</a></span><br />
+<span style='margin-left: 2em;'>on aether, <a href='#Page_58'>58</a></span><br />
+<br />
+Mayer, <a href='#Page_84'>84</a>, <a href='#Page_86'>86</a>, <a href='#Page_114'>114</a>, <a href='#Page_118'>118</a><br />
+<br />
+McCullagh, <a href='#Page_75'>75</a><br />
+<br />
+Mechanical energy, <a href='#Page_87'>87</a><br />
+<br />
+Medium, Descartes on a, <a href='#Page_221'>221</a><br />
+<span style='margin-left: 2em;'>Kepler on a, <a href='#Page_222'>222</a></span><br />
+<br />
+Mercury, <a href='#Page_68'>68</a>, <a href='#Page_79'>79</a><br />
+<span style='margin-left: 2em;'>a magnet, <a href='#Page_196'>196</a></span><br />
+<span style='margin-left: 2em;'>rotation of, <a href='#Page_219'>219</a></span><br />
+<span style='margin-left: 2em;'>eccentricity of orbit, <a href='#Page_33'>33</a></span><br />
+<span style='margin-left: 2em;'>mass of, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>orbital velocity of, <a href='#Page_251'>251</a></span><br />
+<br />
+Meteorites, <a href='#Page_95'>95</a>, <a href='#Page_118'>118</a><br />
+<br />
+Meteors, <a href='#Page_31'>31</a>, <a href='#Page_85'>85</a>, <a href='#Page_118'>118</a><br />
+<br />
+Michelson and Morley, <a href='#Page_7'>7</a>, <a href='#Page_67'>67</a><br />
+<br />
+Milky way, <a href='#Page_79'>79</a>, <a href='#Page_309'>309</a>, <a href='#Page_314'>314</a><br />
+<br />
+Molecules, <a href='#Page_44'>44</a><br />
+<br />
+Momentum, <a href='#Page_20'>20</a><br />
+<br />
+Moon, <a href='#Page_61'>61</a><br />
+<br />
+Motion of stars, <a href='#Page_310'>310</a><br />
+<span style='margin-left: 2em;'>planetary, <a href='#Page_253'>253</a></span><br />
+<span style='margin-left: 2em;'>of sun, <a href='#Page_274'>274</a></span><br />
+<span style='margin-left: 2em;'>of aether, <a href='#Page_80'>80</a></span><br />
+<span style='margin-left: 2em;'>and work, <a href='#Page_95'>95</a></span><br />
+<span style='margin-left: 2em;'>modes of, <a href='#Page_92'>92</a>, <a href='#Page_122'>122</a>, <a href='#Page_163'>163</a></span><br />
+<span style='margin-left: 2em;'>first law of, <a href='#Page_15'>15</a>, <a href='#Page_16'>16</a>, <a href='#Page_239'>239</a></span><br />
+<span style='margin-left: 2em;'>second law of, <a href='#Page_19'>19</a>, <a href='#Page_244'>244</a></span><br />
+<span style='margin-left: 2em;'>third law of, <a href='#Page_20'>20</a>, <a href='#Page_251'>251</a></span><br />
+<br />
+Multiple stars, <a href='#Page_308'>308</a><br />
+<br />
+<br />
+Natural philosophy, <a href='#Page_4'>4</a><br />
+<br />
+Nebulae and aether, <a href='#Page_313'>313</a><br />
+<span style='margin-left: 2em;'>structure of, <a href='#Page_314'>314</a></span><br />
+<span style='margin-left: 2em;'>spiral, <a href='#Page_322'>322</a></span><br />
+<span style='margin-left: 2em;'>annular, <a href='#Page_320'>320</a></span><br />
+<span style='margin-left: 2em;'>elliptical, <a href='#Page_320'>320</a></span><br />
+<span style='margin-left: 2em;'>planetary, <a href='#Page_321'>321</a></span><br />
+<span style='margin-left: 2em;'>spectrum of, <a href='#Page_314'>314</a></span><br />
+<span style='margin-left: 2em;'>irregular, <a href='#Page_319'>319</a></span><br />
+<br />
+Nebular hypothesis, <a href='#Page_317'>317</a><br />
+<br />
+Nebulous stars, <a href='#Page_311'>311</a><br />
+<br />
+Neptune, <a href='#Page_68'>68</a><br />
+<span style='margin-left: 2em;'>discovery of, <a href='#Page_25'>25</a></span><br />
+<span style='margin-left: 2em;'>mass of, <a href='#Page_235'>235</a></span><br />
+<span style='margin-left: 2em;'>orbital velocity of, <a href='#Page_251'>251</a>, <a href='#Page_265'>265</a></span><br />
+<span style='margin-left: 2em;'>distance from sun, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>a magnet, <a href='#Page_196'>196</a></span><br />
+<br />
+Newton's coloured rings, <a href='#Page_107'>107</a><br />
+<span style='margin-left: 2em;'><i>Optics</i>, <a href='#Page_72'>72</a>, <a href='#Page_98'>98</a>, <a href='#Page_122'>122</a></span><br />
+<span style='margin-left: 2em;'>letter to Bentley, <a href='#Page_2'>2</a>, <a href='#Page_96'>96</a></span><br />
+<span style='margin-left: 2em;'>Rules of Philosophy, <a href='#Page_3'>3</a></span><br />
+<span style='margin-left: 2em;'><i>Principia</i>, <a href='#Page_3'>3</a>, <a href='#Page_7'>7</a>, <a href='#Page_38'>38</a></span><br />
+<span style='margin-left: 2em;'>emission theory, <a href='#Page_123'>123</a></span><br />
+<span style='margin-left: 2em;'>law of gravitation, <a href='#Page_24'>24</a></span><br />
+<span style='margin-left: 2em;'>atoms, <a href='#Page_44'>44</a></span><br />
+<span style='margin-left: 2em;'>on aether, <a href='#Page_98'>98</a></span><br />
+<br />
+Nichols and Hull, <a href='#Page_32'>32</a>, <a href='#Page_153'>153</a><br />
+<br />
+<br />
+Ocean, <a href='#Page_81'>81</a>, <a href='#Page_90'>90</a><br />
+<br />
+Operations, cycle of, <a href='#Page_114'>114</a><br />
+<br />
+<i>Optics</i>, Newton's, <a href='#Page_2'>2</a>, <a href='#Page_122'>122</a><br />
+<br />
+Orbital motions of planets, <a href='#Page_266'>266</a><br />
+<br />
+Orbit of earth, <a href='#Page_33'>33</a><br />
+<span style='margin-left: 2em;'>of Venus, <a href='#Page_33'>33</a></span><br />
+<br />
+Orbits of satellites, <a href='#Page_34'>34</a><br />
+<span style='margin-left: 2em;'>of planets, <a href='#Page_33'>33</a>-4, <a href='#Page_266'>266</a></span><br />
+<span style='margin-left: 2em;'>moon, <a href='#Page_267'>267</a></span><br />
+<span style='margin-left: 2em;'>stars, <a href='#Page_310'>310</a></span><br />
+<span style='margin-left: 2em;'>sun, <a href='#Page_270'>270</a></span><br />
+<br />
+Origin of sun's heat, <a href='#Page_95'>95</a><br />
+<br />
+Orion, <a href='#Page_79'>79</a>, <a href='#Page_307'>307</a>, <a href='#Page_314'>314</a>, <a href='#Page_319'>319</a><br />
+<br />
+Oxygen, <a href='#Page_40'>40</a>, <a href='#Page_44'>44</a>, <a href='#Page_60'>60</a>, <a href='#Page_93'>93</a><br />
+<br />
+<br />
+Parallelogram of forces, <a href='#Page_15'>15</a><br />
+<br />
+Pendulum, <a href='#Page_88'>88</a><br />
+<br />
+Periodic times, <a href='#Page_37'>37</a><br />
+<br />
+Perpetual motion, <a href='#Page_93'>93</a>, <a href='#Page_220'>220</a><br />
+<br />
+<i>Phil. Mag</i>., <a href='#Page_58'>58</a>, <a href='#Page_67'>67</a>, <a href='#Page_71'>71</a>, <a href='#Page_73'>73</a>, <a href='#Page_74'>74</a>, <a href='#Page_80'>80</a><br />
+<br />
+<i>Phil. Trans</i>., <a href='#Page_58'>58</a>, <a href='#Page_62'>62</a>, <a href='#Page_64'>64</a>, <a href='#Page_75'>75</a><br />
+<br />
+Philosophy, Rules of, <a href='#Page_3'>3</a><br />
+<br />
+Phobos, <a href='#Page_38'>38</a><br />
+<br />
+Physical lines of force, <a href='#Page_203'>203</a>-6<br />
+<br />
+Pitch of Sound, <a href='#Page_105'>105</a>, <a href='#Page_120'>120</a>, <a href='#Page_139'>139</a><br />
+<br />
+Plane of ecliptic, <a href='#Page_277'>277</a>-9<br />
+<br />
+Planetoids, <a href='#Page_31'>31</a><br />
+<br />
+Planets, minor, <a href='#Page_31'>31</a><br />
+<span style='margin-left: 2em;'>origin of, <a href='#Page_240'>240</a></span><br />
+<span style='margin-left: 2em;'>orbits of, <a href='#Page_33'>33</a>, <a href='#Page_266'>266</a></span><br />
+<span style='margin-left: 2em;'>electrified bodies, <a href='#Page_177'>177</a></span><br />
+<span style='margin-left: 2em;'>masses of, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>relative distances of, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>orbital velocities of, <a href='#Page_251'>251</a></span><br />
+<span style='margin-left: 2em;'>periodic times of, <a href='#Page_251'>251</a></span><br />
+<br />
+Platinum, <a href='#Page_48'>48</a><br />
+<br />
+Pleiades, <a href='#Page_79'>79</a><br />
+<br />
+Polarization, <a href='#Page_176'>176</a><br />
+<br />
+Potential energy, <a href='#Page_87'>87</a><br />
+<br />
+Potential, electric, <a href='#Page_170'>170</a><br />
+<span style='margin-left: 2em;'>magnetic, <a href='#Page_194'>194</a></span><br />
+<br />
+Pouillet, M., <a href='#Page_109'>109</a><br />
+<br />
+Poynting, <a href='#Page_91'>91</a><br />
+<br />
+Pressure, aetherial, <a href='#Page_181'>181</a><br />
+<br />
+Preston, Prof., <a href='#Page_283'>283</a><br />
+<br />
+Prevost, theory of exchanges, <a href='#Page_105'>105</a><br />
+<br />
+Primitive impulse, <a href='#Page_9'>9</a>, <a href='#Page_10'>10</a>, <a href='#Page_12'>12</a>, <a href='#Page_319'>319</a><br />
+<br />
+<i>Principia</i>, Newton's, <a href='#Page_3'>3</a>, <a href='#Page_7'>7</a>, <a href='#Page_38'>38</a>-9, <a href='#Page_122'>122</a><br />
+<br />
+Properties of matter, <a href='#Page_42'>42</a><br />
+<br />
+<br />
+Quantity of sun's heat, <a href='#Page_109'>109</a><br />
+<br />
+Query, <a href='#Page_18'>18</a>-<a href='#Page_19'>19</a><br />
+<span style='margin-left: 2em;'><i>Optics</i>, <a href='#Page_72'>72</a>, <a href='#Page_122'>122</a></span><br />
+<br />
+<br />
+Radiant heat, <a href='#Page_109'>109</a><br />
+<span style='margin-left: 2em;'>energy, <a href='#Page_115'>115</a></span><br />
+<br />
+Radiation, <a href='#Page_104'>104</a><br />
+<br />
+Radius Vector, <a href='#Page_26'>26</a><br />
+<br />
+Rankine, <a href='#Page_103'>103</a><br />
+<br />
+Rays, actinic, <a href='#Page_141'>141</a><br />
+<span style='margin-left: 2em;'>dark heat, <a href='#Page_140'>140</a></span><br />
+<span style='margin-left: 2em;'>infra-red, <a href='#Page_141'>141</a></span><br />
+<span style='margin-left: 2em;'>ultra-violet, <a href='#Page_140'>140</a></span><br />
+<span style='margin-left: 2em;'>Rontgen, <a href='#Page_341'>341</a></span><br />
+<span style='margin-left: 2em;'>X, <a href='#Page_341'>341</a></span><br />
+<br />
+Rectilinear propagation of light, <a href='#Page_144'>144</a><br />
+<span style='margin-left: 2em;'>of heat, <a href='#Page_111'>111</a></span><br />
+<br />
+Reflection, <a href='#Page_160'>160</a><br />
+<br />
+Refraction, <a href='#Page_160'>160</a><br />
+<br />
+Relative motion of aether and matter, <a href='#Page_224'>224</a>-6<br />
+<br />
+Resistance to motion, <a href='#Page_17'>17</a><br />
+<br />
+Resisting medium, <a href='#Page_228'>228</a><br />
+<br />
+Reversible cycle, <a href='#Page_116'>116</a>, <a href='#Page_118'>118</a><br />
+<br />
+Rings, vortex, <a href='#Page_45'>45</a><br />
+<br />
+Rival theories, <a href='#Page_8'>8</a><br />
+<br />
+Rivers, <a href='#Page_89'>89</a>-<a href='#Page_90'>90</a><br />
+<br />
+Roemer, and velocity of light, <a href='#Page_148'>148</a><br />
+<br />
+Rotation of earth, <a href='#Page_219'>219</a><br />
+<span style='margin-left: 2em;'>of planets, <a href='#Page_219'>219</a></span><br />
+<span style='margin-left: 2em;'>of sun, <a href='#Page_246'>246</a></span><br />
+<br />
+Rotatory motion, <a href='#Page_93'>93</a><br />
+<br />
+Rucker, Prof., <a href='#Page_59'>59</a><br />
+<br />
+Rules of Philosophy, <a href='#Page_3'>3</a><br />
+<span style='margin-left: 2em;'>first, <a href='#Page_3'>3</a></span><br />
+<span style='margin-left: 2em;'>second, <a href='#Page_4'>4</a></span><br />
+<span style='margin-left: 2em;'>third, <a href='#Page_3'>3</a>, <a href='#Page_7'>7</a></span><br />
+<br />
+Rumford, <a href='#Page_98'>98</a><br />
+<br />
+Running water, <a href='#Page_95'>95</a><br />
+<br />
+<br />
+Satellites of Mars, <a href='#Page_38'>38</a>, <a href='#Page_178'>178</a><br />
+<span style='margin-left: 2em;'>Jupiter, <a href='#Page_149'>149</a>, <a href='#Page_178'>178</a></span><br />
+<span style='margin-left: 2em;'>Uranus, <a href='#Page_254'>254</a></span><br />
+<span style='margin-left: 2em;'>Neptune, <a href='#Page_254'>254</a></span><br />
+<br />
+Saturn, <a href='#Page_26'>26</a>-7, <a href='#Page_68'>68</a><br />
+<span style='margin-left: 2em;'>mass of, <a href='#Page_235'>235</a>, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>orbital velocity of, <a href='#Page_251'>251</a>, <a href='#Page_265'>265</a></span><br />
+<span style='margin-left: 2em;'>rotation of, <a href='#Page_219'>219</a></span><br />
+<span style='margin-left: 2em;'>density of, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>a magnet, <a href='#Page_196'>196</a></span><br />
+<span style='margin-left: 2em;'>satellites of, <a href='#Page_178'>178</a></span><br />
+<br />
+Schuster, Prof., <a href='#Page_8'>8</a>, <a href='#Page_218'>218</a>, <a href='#Page_311'>311</a><br />
+<br />
+Sirius, <a href='#Page_306'>306</a>, <a href='#Page_308'>308</a>-9<br />
+<br />
+Sodium, <a href='#Page_43'>43</a><br />
+<br />
+Solar system, motion of, <a href='#Page_257'>257</a>, <a href='#Page_271'>271</a><br />
+<span style='margin-left: 2em;'>spectrum, <a href='#Page_79'>79</a>, <a href='#Page_139'>139</a></span><br />
+<span style='margin-left: 2em;'>magnetism, <a href='#Page_211'>211</a></span><br />
+<br />
+Sound, <a href='#Page_75'>75</a><br />
+<span style='margin-left: 2em;'>waves, <a href='#Page_104'>104</a>, <a href='#Page_120'>120</a></span><br />
+<br />
+Space, interstellar, <a href='#Page_310'>310</a>, <a href='#Page_313'>313</a><br />
+<br />
+Spectroscope, <a href='#Page_47'>47</a>, <a href='#Page_79'>79</a><br />
+<br />
+Spectrum analysis, <a href='#Page_50'>50</a>, <a href='#Page_139'>139</a><br />
+<br />
+Spiral nebulae, <a href='#Page_322'>322</a><br />
+<br />
+Stars, fixed, <a href='#Page_58'>58</a><br />
+<span style='margin-left: 2em;'>number of, <a href='#Page_11'>11</a>, <a href='#Page_306'>306</a></span><br />
+<span style='margin-left: 2em;'>binary, <a href='#Page_309'>309</a></span><br />
+<span style='margin-left: 2em;'>distances of, <a href='#Page_280'>280</a></span><br />
+<span style='margin-left: 2em;'>magnitude of, <a href='#Page_306'>306</a>, <a href='#Page_309'>309</a></span><br />
+<span style='margin-left: 2em;'>colour of, <a href='#Page_79'>79</a>, <a href='#Page_308'>308</a></span><br />
+<span style='margin-left: 2em;'>motion of, <a href='#Page_310'>310</a>-11</span><br />
+<span style='margin-left: 2em;'>nebulous, <a href='#Page_320'>320</a></span><br />
+<span style='margin-left: 2em;'>proper motions of, <a href='#Page_312'>312</a></span><br />
+<span style='margin-left: 2em;'>variable, <a href='#Page_307'>307</a></span><br />
+<span style='margin-left: 2em;'>double, <a href='#Page_308'>308</a></span><br />
+<span style='margin-left: 2em;'>clusters of, <a href='#Page_314'>314</a></span><br />
+<span style='margin-left: 2em;'>orbits of, <a href='#Page_310'>310</a></span><br />
+<span style='margin-left: 2em;'>are magnets, <a href='#Page_307'>307</a></span><br />
+<br />
+Stokes, Sir G., <a href='#Page_69'>69</a>, <a href='#Page_152'>152</a>, <a href='#Page_218'>218</a><br />
+<br />
+String, <a href='#Page_21'>21</a><br />
+<br />
+Sun, diameter of, <a href='#Page_280'>280</a><br />
+<span style='margin-left: 2em;'>constitution of, <a href='#Page_79'>79</a></span><br />
+<span style='margin-left: 2em;'>a magnet, <a href='#Page_164'>164</a>, <a href='#Page_198'>198</a>-9</span><br />
+<span style='margin-left: 2em;'>mass of, <a href='#Page_190'>190</a></span><br />
+<span style='margin-left: 2em;'>heat of, <a href='#Page_109'>109</a></span><br />
+<span style='margin-left: 2em;'>motions of, <a href='#Page_270'>270</a></span><br />
+<span style='margin-left: 2em;'>orbital velocity of, <a href='#Page_35'>35</a></span><br />
+<span style='margin-left: 2em;'>rotation of, <a href='#Page_246'>246</a></span><br />
+<span style='margin-left: 2em;'>centre of two forces, <a href='#Page_186'>186</a></span><br />
+<br />
+<br />
+Tails of comets, <a href='#Page_300'>300</a>, <a href='#Page_304'>304</a><br />
+<span style='margin-left: 2em;'>straight, <a href='#Page_300'>300</a></span><br />
+<span style='margin-left: 2em;'>curved, <a href='#Page_301'>301</a></span><br />
+<span style='margin-left: 2em;'>multiple, <a href='#Page_300'>300</a></span><br />
+<br />
+Tait, Prof., <a href='#Page_18'>18</a>, <a href='#Page_40'>40</a>-1, <a href='#Page_88'>88</a>, <a href='#Page_247'>247</a><br />
+<br />
+Telescope, <a href='#Page_79'>79</a><br />
+<br />
+Temperature, <a href='#Page_104'>104</a>-5<br />
+<br />
+Terrestrial magnetism, <a href='#Page_207'>207</a>-12<br />
+<span style='margin-left: 2em;'>gravity, <a href='#Page_29'>29</a></span><br />
+<br />
+Theory, atomic, <a href='#Page_44'>44</a><br />
+<span style='margin-left: 2em;'>rules for making, <a href='#Page_3'>3</a></span><br />
+<span style='margin-left: 2em;'>undulatory, <a href='#Page_123'>123</a></span><br />
+<span style='margin-left: 2em;'>of exchanges, <a href='#Page_105'>105</a></span><br />
+<br />
+Thermodynamics, first law of, <a href='#Page_87'>87</a>, <a href='#Page_114'>114</a><br />
+<span style='margin-left: 2em;'>second law of, <a href='#Page_116'>116</a></span><br />
+<br />
+Thomson, J. J., Prof., <a href='#Page_43'>43</a>, <a href='#Page_326'>326</a>, <a href='#Page_335'>335</a><br />
+<br />
+Tidal water-power, <a href='#Page_88'>88</a><br />
+<br />
+Tides, <a href='#Page_89'>89</a>, <a href='#Page_96'>96</a><br />
+<br />
+Torsion balance, <a href='#Page_185'>185</a><br />
+<br />
+Trade winds, <a href='#Page_96'>96</a>, <a href='#Page_249'>249</a><br />
+<br />
+Transformation of energy, <a href='#Page_86'>86</a><br />
+<span style='margin-left: 2em;'>of motion, <a href='#Page_93'>93</a></span><br />
+<br />
+Transverse vibration of light, <a href='#Page_130'>130</a><br />
+<br />
+Tuning-fork, <a href='#Page_104'>104</a><br />
+<br />
+Tympanum, <a href='#Page_120'>120</a><br />
+<br />
+Tyndall on radiation, <a href='#Page_104'>104</a>, <a href='#Page_106'>106</a><br />
+<span style='margin-left: 2em;'>on light, <a href='#Page_71'>71</a></span><br />
+<span style='margin-left: 2em;'>on Lines of Force, <a href='#Page_174'>174</a></span><br />
+<span style='margin-left: 2em;'>on aether, <a href='#Page_77'>77</a></span><br />
+<span style='margin-left: 2em;'>on atoms, <a href='#Page_106'>106</a></span><br />
+<span style='margin-left: 2em;'>on aether waves, <a href='#Page_112'>112</a></span><br />
+<br />
+<br />
+Ultra-violet rays, <a href='#Page_140'>140</a><br />
+<span style='margin-left: 2em;'>red rays, <a href='#Page_140'>140</a></span><br />
+<br />
+Unity of universe, <a href='#Page_322'>322</a>-9<br />
+<br />
+Universal gravitation, <a href='#Page_24'>24</a><br />
+<span style='margin-left: 2em;'>aether, <a href='#Page_58'>58</a></span><br />
+<br />
+Universe, <a href='#Page_313'>313</a>, <a href='#Page_322'>322</a>, <a href='#Page_347'>347</a><br />
+<br />
+Uranus, <a href='#Page_68'>68</a><br />
+<span style='margin-left: 2em;'>mass of, <a href='#Page_235'>235</a></span><br />
+<span style='margin-left: 2em;'>density of, <a href='#Page_242'>242</a></span><br />
+<span style='margin-left: 2em;'>orbital velocity of, <a href='#Page_265'>265</a></span><br />
+<span style='margin-left: 2em;'>a magnet, <a href='#Page_196'>196</a></span><br />
+<br />
+Ursa Major, <a href='#Page_307'>307</a><br />
+<span style='margin-left: 2em;'>Minor, <a href='#Page_307'>307</a></span><br />
+<br />
+<br />
+Vapour, <a href='#Page_49'>49</a><br />
+<br />
+Variation, magnetic, <a href='#Page_209'>209</a>-11<br />
+<br />
+Velocity of light, <a href='#Page_148'>148</a><br />
+<span style='margin-left: 2em;'>of electric waves, <a href='#Page_182'>182</a></span><br />
+<span style='margin-left: 2em;'>of heat waves, <a href='#Page_148'>148</a></span><br />
+<span style='margin-left: 2em;'>of falling bodies, <a href='#Page_21'>21</a></span><br />
+<span style='margin-left: 2em;'>of wave motion, <a href='#Page_76'>76</a></span><br />
+<br />
+Velocity, angular, <a href='#Page_250'>250</a><br />
+<br />
+Venus, <a href='#Page_33'>33</a>, <a href='#Page_68'>68</a>, <a href='#Page_79'>79</a><br />
+<span style='margin-left: 2em;'>a magnet, <a href='#Page_197'>197</a></span><br />
+<span style='margin-left: 2em;'>mass of, <a href='#Page_235'>235</a></span><br />
+<span style='margin-left: 2em;'>rotation of, <a href='#Page_219'>219</a></span><br />
+<span style='margin-left: 2em;'>orbital velocity of, <a href='#Page_251'>251</a></span><br />
+<span style='margin-left: 2em;'>periodic time of, <a href='#Page_251'>251</a></span><br />
+<br />
+Vibration, atomic, <a href='#Page_75'>75</a><br />
+<br />
+Vibrations, transverse, <a href='#Page_130'>130</a><br />
+<span style='margin-left: 2em;'>longitudinal, <a href='#Page_130'>130</a></span><br />
+<span style='margin-left: 2em;'>of sound, <a href='#Page_123'>123</a></span><br />
+<br />
+Vibratory motion, <a href='#Page_91'>91</a><br />
+<br />
+Vogel, Prof., <a href='#Page_308'>308</a>, <a href='#Page_312'>312</a><br />
+<br />
+Vogt, Prof., <a href='#Page_332'>332</a><br />
+<br />
+Volume of sun, <a href='#Page_27'>27</a><br />
+<br />
+Von Asten, <a href='#Page_234'>234</a>, <a href='#Page_296'>296</a><br />
+<br />
+Vortex theory, <a href='#Page_92'>92</a>, <a href='#Page_337'>337</a><br />
+<span style='margin-left: 2em;'>motion, <a href='#Page_221'>221</a>-4</span><br />
+<span style='margin-left: 2em;'>atom, <a href='#Page_93'>93</a>, <a href='#Page_126'>126</a>, <a href='#Page_337'>337</a></span><br />
+<span style='margin-left: 2em;'>rings, <a href='#Page_125'>125</a>, <a href='#Page_337'>337</a></span><br />
+<br />
+Vortices, molecular, <a href='#Page_103'>103</a><br />
+<br />
+<br />
+Water waves, <a href='#Page_124'>124</a><br />
+<span style='margin-left: 2em;'>currents, power of, <a href='#Page_95'>95</a></span><br />
+<span style='margin-left: 2em;'>composition of, <a href='#Page_141'>141</a></span><br />
+<span style='margin-left: 2em;'>power, <a href='#Page_88'>88</a></span><br />
+<br />
+Wave front, <a href='#Page_128'>128</a><br />
+<span style='margin-left: 2em;'>motion, <a href='#Page_124'>124</a>, <a href='#Page_160'>160</a></span><br />
+<br />
+Wave lengths, <a href='#Page_120'>120</a><br />
+<span style='margin-left: 2em;'>envelope, <a href='#Page_112'>112</a></span><br />
+<br />
+Waves, chemical, <a href='#Page_141'>141</a><br />
+<span style='margin-left: 2em;'>sound, <a href='#Page_104'>104</a>, <a href='#Page_120'>120</a>, <a href='#Page_124'>124</a></span><br />
+<span style='margin-left: 2em;'>light, <a href='#Page_126'>126</a></span><br />
+<span style='margin-left: 2em;'>heat, <a href='#Page_141'>141</a></span><br />
+<span style='margin-left: 2em;'>electric, <a href='#Page_159'>159</a></span><br />
+<span style='margin-left: 2em;'>spherical, <a href='#Page_112'>112</a></span><br />
+<span style='margin-left: 2em;'>electro-magnetic, <a href='#Page_165'>165</a></span><br />
+<br />
+Weight, <a href='#Page_29'>29</a>, <a href='#Page_69'>69</a>, <a href='#Page_84'>84</a><br />
+<span style='margin-left: 2em;'>variation of, <a href='#Page_29'>29</a></span><br />
+<span style='margin-left: 2em;'>pound, <a href='#Page_30'>30</a></span><br />
+<br />
+Whewell, <a href='#Page_3'>3</a>, <a href='#Page_221'>221</a><br />
+<br />
+Winds, <a href='#Page_81'>81</a>, <a href='#Page_90'>90</a><br />
+<span style='margin-left: 2em;'>energy of, <a href='#Page_90'>90</a></span><br />
+<span style='margin-left: 2em;'>trade, <a href='#Page_225'>225</a></span><br />
+<br />
+Work, <a href='#Page_96'>96</a><br />
+<span style='margin-left: 2em;'>and energy, <a href='#Page_84'>84</a></span><br />
+<span style='margin-left: 2em;'>from heat, <a href='#Page_116'>116</a></span><br />
+<br />
+<br />
+Young, Thomas, <a href='#Page_54'>54</a>, <a href='#Page_64'>64</a>, <a href='#Page_67'>67</a>, <a href='#Page_123'>123</a><br />
+<span style='margin-left: 2em;'>on aether, <a href='#Page_58'>58</a></span><br />
+<span style='margin-left: 2em;'>fourth hypothesis, <a href='#Page_70'>70</a></span><br />
+<span style='margin-left: 2em;'>Prof., of America, on electric space, <a href='#Page_166'>166</a></span><br />
+<br />
+<br />
+Zinc, <a href='#Page_88'>88</a><br />
+<br />
+Zodiacal light, <a href='#Page_277'>277</a>-9<br />
+</p>
+
+
+<p><i>Richard Clay &amp; Sous, Limited, London &amp; Bungay</i>.</p>
+
+
+
+<hr style='width: 65%;' />
+
+<h2>Some New Publications</h2>
+
+<h2>OF</h2>
+
+<h1>Messrs. Chapman &amp; Hall, Ltd.</h1>
+
+<h2>1903-4</h2>
+
+<hr style='width: 15%;' />
+
+<h3>MR. H. G. WELLS'S NEW WORK.</h3>
+
+<p><b>MANKIND IN THE MAKING</b>.By H. G. <span class='smcap'>Wells</span>, author of &ldquo;Anticipations,&rdquo; etc.
+Crown 8vo, <i>7s. 6d.</i><br /></p>
+
+<p>
+In this new and important work Mr. Wells attempts to deal with social
+and political questions in a new way and from a new starting-point,
+viewing the whole social and political world as aspects of one universal
+evolving scheme, and placing all social and political activities in a
+defined relation to that; and it is to this general method and trend
+that the attention of the reader is especially directed.
+</p>
+
+<h3>DR. ALFRED RUSSEL WALLACE'S NEW BOOK.</h3>
+
+<p><b>MAN'S PLACE IN THE UNIVERSE</b>. A study of the results of scientific
+research in relation to the unity or plurality of worlds. By <span class='smcap'>Alfred
+Russel Wallace</span>, LL.D., D.C.I., F.R.S., author of &ldquo;Natural Selection,&rdquo;
+&ldquo;Darwinism,&rdquo; etc., etc. With Diagrams. Demy 8vo, <i>12s. 6d. net</i>.<br /></p>
+
+<p>
+This volume is an amplification and extension of the much-discussed
+article contributed by Dr. Wallace to the <i>Fortnightly Review</i> for March
+1903, and presents the whole subject in a more complete and systematic
+manner, besides containing many new and forcible arguments which a more
+careful consideration of the whole problem has suggested.
+</p>
+
+<p>
+In the course of the work the various astronomical and other criticisms
+of the article are considered and replied to.
+</p>
+
+<h3>A NEW THEORY OF GRAVITATION.</h3>
+
+<p><b>AETHER AND GRAVITATION</b>. By W. G. <span class='smcap'>Hooper</span>, F.S.S. With Diagrams. Demy 8vo,
+<i>12s. 6d. net</i>.<br /></p>
+
+<p>
+This work seeks to offer an acceptable solution of the greatest
+scientific problem that has puzzled scientists for the past 200 years.
+Ever since the discovery of universal gravitation by Sir Isaac Newton,
+the question has arisen, over and over again, as to what is the physical
+cause of the attraction of gravitation. Is it due, as Newton himself
+suggested, to the properties and qualities of the universal aether, or
+is it due to some still unknown and undiscovered medium?
+</p>
+
+<p>
+By the theory propounded in this work, the author has for the first time
+brought aetherial physics into harmony with all observation and
+experiments; so that the inertia, the density, and the elasticity of the
+aether are brought into harmony with all experience by philosophical
+reasoning based on Newton's Rules of Philosophy.
+</p>
+
+<h3>LIFE AND TOPOGRAPHY OF DICKENS.</h3>
+
+<p><b>THE REAL DICKENS LAND</b>. With an outline of Charles Dickens's life. By<span class='smcap'> H.
+Snowden Ward</span> and <span class='smcap'>Catharine Ward</span>, authors of &ldquo;Shakespeare's Town and
+Times.&rdquo; With a Steel Plate Portrait of Dickens, Three Photogravures, and
+nearly 300 full-page and other Illustrations. Crown 4to, <i>10s. 6d. net</i>.<br /></p>
+
+<p>
+Charles Dickens's understanding of the human character is apparent to
+every good reader of his works; but his intimate knowledge of the
+&ldquo;character&rdquo; of places, and of the important effect of place upon the
+human being, is not so apparent, because the reader has not the
+necessary knowledge of the places upon which to base an estimate.
+</p>
+
+<p>
+In &ldquo;The Real Dickens Land&rdquo; the authors have attempted to supply this
+necessary knowledge, not only by literary identification, but by
+presenting one of the fullest collections of photographic views thus
+identified ever got together.
+</p>
+
+<p class='center'>LONDON: CHAPMAN &amp; HALL, <span class='smcap'>Ltd</span>.</p>
+
+<hr style='width: 65%;' />
+
+<h3>CARLYLE'S LIFE AND TOPOGRAPHY.</h3>
+
+
+<p><b>THE CARLYLE COUNTRY.</b> With a study of Carlyle's life. By J. M. <span class='smcap'>Sloan</span>.
+With a Foreword by <span class='smcap'>Sir James Crichton-Brown</span>, M.D., LL.D., F.R.S. With a
+Photogravure of the Whistler Portrait of Carlyle, Two other
+Photogravures, and about 100 Portraits, full-page and other
+Illustrations. Crown 4to, <i>10s. 6d. net</i>.<br /></p>
+
+<p>
+This new Carlyle Book deals with the Carlyles in all their multiform
+relations to the Carlyle Country, and casts much valuable light upon the
+complex problems raised by Carlyle's earlier and later life.
+</p>
+
+<p>
+It forms a most useful and instructive Guide to the Carlyle Country, and
+will appeal to old Carlylean Readers by its careful grouping of
+biographical events around the places with which they are inextricably
+identified.
+</p>
+
+<p>
+A valuable Carlyle Chronology is appended, together with an Index and
+Map.
+</p>
+
+
+<h3>HISTORY OF CHINA.</h3>
+
+<p>CHINA, PAST AND PRESENT. By E. H. <span class='smcap'>Parker</span>, Professor of Chinese at the
+Owens College, Manchester; formerly H.B.M. Consul at Kiungchow; Author
+of &ldquo;China,&rdquo; &ldquo;John Chinaman,&rdquo; etc., etc. With a Map of China. Demy 8vo,
+<i>10s. 6d. net</i>.<br /></p>
+
+<p>
+Mr. Parker is one of the great authorities on all that concerns China
+and the Chinese, and has been writing upon every phase of the subject
+for many years past. In this work he deals with the whole history of the
+nation from the earliest times to the present day. His volume is divided
+into nine books: I. Historical and Statistical; II. The &ldquo;Boxer&rdquo; Wars;
+III. Religious; IV. The Imperial Power; V. The Foreigner in China; VI.
+Mandarin or Official; VII. Celestial Peculiarities; VIII. Political; IX.
+The Seamy Side.
+</p>
+
+<p>
+Each of these books is divided into chapters dealing comprehensively
+with the whole subject.
+</p>
+
+<h3>NEW WORK ON PAGAN IDOLATRY.</h3>
+
+<p><b>THE WORSHIP OF THE DEAD.</b> The Origin, Nature, and History of Pagan
+Idolatry. By <span class='smcap'>Colonel J. Garnier</span>, R.E. With Four full-page Illustrations
+and numerous Pictures in the text. Demy 8vo, <i>16s. net</i>.<br /></p>
+
+<p>
+The intimate relation of the ancient Paganism to the early history of
+mankind and its influence on the fate and fortunes of the human race
+gives no little interest and importance to any inquiry into its origin
+and nature, and the facts collected and compared in the present work
+will be found, not only to throw a remarkable light on the early history
+of Egypt and Babylonia but to have an especial bearing on important
+questions of the present day.
+</p>
+
+<h3>EVERYDAY LIFE IN CHINA.</h3>
+
+<p><b>LIFE AND SPORT IN CHINA</b>. By <span class='smcap'>Oliver G. Ready</span>, B.A. With Thirteen
+Illustrations and a Map. Demy 8vo, <i>10s. 6d. net</i>.<br /></p>
+
+<p>
+In this work the author, who has resided in various parts of the country
+for upwards of twelve years, has endeavoured to place before readers an
+account of things and events as he saw them, and to convey to their
+minds an idea of how Europeans live there, of their amusements, of their
+work, and of those things which are matters of daily interest to them,
+so that the work may serve as a kind of preface to that enthralling
+volume, the current history of China, as it is daily revealed in the
+Press, in Magazines, and in learned works.
+</p>
+
+
+<h3>IZAAK WALTON.</h3>
+
+<p><b>IZAAK WALTON AND HIS FRIENDS.</b> By <span class='smcap'>Stapleton Martin</span>, M.A., Christ's
+College, Cambridge, Barrister-at-Law. With Portraits and Illustrations.
+Demy 8vo, <i>10s. 6d. net</i>.<br /></p>
+
+<p>
+Mr. Stapleton Martin has written this book with the primary object of
+bringing out the spiritual side of Walton's character. He traces
+carefully the inner workings of Walton's mind, and aims at setting forth
+the man as he was best known to the circle of intimates with whom he
+shared his confidences.
+</p>
+
+<p>
+The better to indicate this aspect, the volume also contains brief
+biographical sketches of Walton's: poet and ecclesiastic friends,
+together with a fine collection of portraits and illustrations of places
+connected with Walton's life. There is also a selection from the
+poetical works of Walton, Cotton, Donne, Herbert, Wotton, Duport.
+</p>
+
+<p class='center'>LONDON: CHAPMAN &amp; HALL, <span class='smcap'>Ltd</span>.</p>
+
+<p>&nbsp;</p>
+<hr />
+<p>&nbsp;</p>
+
+
+<h4>Transcribers note:</h4>
+
+<p>ART. 41 is missing from the book.</p>
+
+<p>In several instances changed S, W, E into italics
+to be consistent with the rest of the book.</p>
+
+<p>Page 194: Fixed typo for demonstated</p>
+
+<p>Changed Figure captions to be consistent and of the form "Fig: number."</p>
+
+<p>Page 249/250 A table that spun across the page boundary
+has been merged into page 249</p>
+
+<p>Left unknown/misspelt word protile in appendix b</p>
+
+<p>Page 148/ ... and the Index, The surname of Ole Christensen Rømer is
+spelt multiple times Roemer and once as Römer in the index. Changed
+Römer to the English spelling "Roemer."</p>
+
+<p>&nbsp;</p>
+<p>&nbsp;</p>
+<hr class="full" />
+<p>***END OF THE PROJECT GUTENBERG EBOOK AETHER AND GRAVITATION***</p>
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@@ -0,0 +1,17818 @@
+The Project Gutenberg eBook, Aether and Gravitation, by William George
+Hooper
+
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+
+
+
+Title: Aether and Gravitation
+
+
+Author: William George Hooper
+
+
+
+Release Date: February 22, 2008  [eBook #24667]
+
+Language: English
+
+Character set encoding: ISO-646-US (US-ASCII)
+
+
+***START OF THE PROJECT GUTENBERG EBOOK AETHER AND GRAVITATION***
+
+
+E-text prepared by Barbara Tozier, Ronnie Sahlberg, Bill Tozier, and the
+Project Gutenberg Online Distributed Proofreading Team
+(https://www.pgdp.net)
+
+
+
+Note: Project Gutenberg also has an HTML version of this
+      file which includes the original illustrations.
+      See 24667-h.htm or 24667-h.zip:
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+
+
+Transcriber's note:
+
+      Numbers preceded by a carat character are superscripts
+      (example: 3^2 = 9).
+
+      Numbers preceded by an underscore are subscripts
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+
+      Text enclosed by underscores is italicized.
+
+      A detailed transcriber's note is at the end of the text.
+
+
+
+
+
+AETHER AND GRAVITATION
+
+by
+
+WILLIAM GEORGE HOOPER, F.S.S.
+
+
+
+
+
+
+
+[Illustration]
+
+
+London
+Chapman and Hall, Ltd.
+1903
+
+
+
+
+INTRODUCTORY NOTES
+
+
+The author in this work endeavours to solve the greatest scientific
+problem that has puzzled scientists for the past two hundred years. The
+question has arisen over and over again, since the discovery of
+universal gravitation by Sir Isaac Newton, as to what is the physical
+cause of the attraction of gravitation.
+
+"Action at a distance" has long ceased to be recognized as a possible
+phenomenon, although up to the present, the medium and method of
+gravitational attraction have not yet been discovered.
+
+It is, however, generally accepted by scientists, that the only possible
+medium which can give rise to the phenomena incidental to, and
+associated with the Law of Gravitation, must be the universal aether,
+which forms the common medium of all phenomena associated with light,
+heat, electricity and magnetism.
+
+It is impossible, however, to reconcile gravitational phenomena with the
+present conception of the universal aether medium, and a new theory is
+therefore demanded, before the long-sought-for explanation will be
+forthcoming.
+
+Professor Glazebrook definitely states the necessity for a new theory in
+his work on J. C. Maxwell, page 221, where he writes: "We are waiting
+for some one to give us a theory of the aether, which shall include the
+facts of electricity and magnetism, luminous radiation, and it may be
+gravitation."
+
+A new theory of the aether is also demanded in view of the recent
+experimental results of Professor Lebedew, and Nichols and Hull of
+America. It is logically impossible to reconcile a frictionless aether,
+with their results relative to the pressure of light waves.
+
+In the following pages of this work the author has endeavoured to
+perfect a theory, which will bring aetherial physics more into harmony
+with modern observation and experiments; and by so doing, believes that
+he has found the key that will unlock the problem not only of the cause
+of universal gravitation, but also other problems of physical science.
+The author has taken Newton's Rules of Philosophy as his guide in the
+making of the new theory, as he believes that if any man knew anything
+of the rules of Philosophy, that man was Sir Isaac Newton. The first
+chapter therefore deals with the generally recognized rules which govern
+philosophical reasoning, the same being three in number; the fundamental
+rule being, that in making any hypothesis, the results of experience as
+obtained by observation and experiments must not be violated.
+
+In applying the rules to the present theory of the aether, he found that
+the theory as at present recognized violated two of the most important
+rules of Philosophy, because, while aether is supposed to be matter, yet
+it failed to fulfil the primary property of all matter, that is, it is
+not subject to the Law of Gravitation. If aether is matter, then, to be
+strictly logical and philosophical, it must possess the properties of
+matter as revealed by observation and experiment.
+
+Those properties are given in Chapter III., where it is shown that they
+are atomicity, heaviness or weight, elasticity, density, inertia, and
+compressibility. To be strictly logical and philosophical, the author
+was compelled to postulate similar properties for the aether, or else
+his hypotheses would contravert the results of all experience.
+
+The application of these properties to the aether will be found in
+Chapter IV., where the author has postulated atomicity, heaviness or
+weight, density, elasticity, inertia, and compressibility for the
+aether, and so brought the theory of the aether into perfect harmony
+with all observation and experiments relative to ordinary matter. It
+will be shown that Clerk Maxwell also definitely affirms the atomicity
+of the aether, while Tyndall and Huyghens also use the term "_particles
+of aether_" over and over again.
+
+Moreover, in view of the most recent researches in electricity made by
+Sir William Crookes and Professor J. J. Thomson, we are compelled to
+accept an atomic basis for electricity, and as Dr. Lodge, in his _Modern
+Views of Electricity_, states that "Aether is made up of positive and
+negative electricity," then, unless we postulate atomicity for the
+aether, we have to suppose that it is possible for a non-atomic body
+(aether) to be made up of atoms or corpuscles, which conclusion is
+absurd, and therefore must be rejected as illogical and unphilosophical.
+
+After postulating atomicity for the aether, we are then able to apply
+the Newtonian Law of Gravitation to it, which distinctly affirms that
+"every particle of matter attracts every other particle," and so we
+arrive at Thomas Young's fourth hypothesis given in the Philosophical
+Transactions of 1802, where he asserts that "All material bodies have an
+attraction for the aetherial medium, by means of which it is
+accumulated within their substance, and for a small distance around them
+in a state of greater density." He adds the significant remark that this
+hypothesis is opposed to that of Newton's. With an atomic and
+gravitative aether it is shown in Chapter IV. how the elasticity,
+density, and inertia of the medium are brought into harmony with all
+observation and experiments.
+
+In the succeeding chapters the new theory is applied to the phenomena of
+heat, light, electricity, and magnetism, and the principles enunciated
+therein are then applied to solar and stellar phenomena.
+
+One of the greatest stumbling-blocks to the discovery of the physical
+cause of gravitation, apart from the unphilosophical theory of the
+aether medium, lies in the fact that apparently the Law of Gravitation
+only recognizes a force of one kind. Dr. Lodge refers to this phase of
+the subject on page 39 of his _Modern Views of Matter_ just published.
+It is here where scientists have failed to solve the problem of
+universal gravitation, as there are _two_ forces at work in the solar
+system and not one; that is, if we are to accept the results of
+up-to-date experiments in relation to radiant light and heat as
+performed by Professor Lebedew, and Nichols and Hull of America. Their
+experiments conclusively prove that light waves exert a pressure upon
+all bodies on which they fall, and by no reasoning can this pressure be
+resolved into an attractive force.
+
+Herschel in his _Lectures on Scientific Subjects_ definitely refers to
+the existence of a repulsive force in the solar system, and asserts that
+it offers the most interesting prospect of any future discovery.
+
+The author has therefore attacked the problem of the cause of
+gravitation, by trying to solve the problem of the cause of the
+_repulsive_ force which has been experimentally demonstrated to exist by
+Professor Lebedew and others.
+
+In his efforts to ascertain the physical cause of the Centrifugal Force,
+he has been assisted by an unknown and original essay written by an
+unknown writer over twenty years ago. That unknown writer was the
+author's father, who wrote an essay on the _Complementary Law of
+Gravitation_, and if it had not been for that essay, the present work
+would never have been attempted.
+
+The main object of the author in Chapters VI., VII., and VIII., is to
+prove beyond the possibility of contradiction, from the phenomena of
+heat, light, and electricity, the existence of _two_ forces in the solar
+system; and by so doing, to bring our philosophy of the aether medium,
+and all gravitational phenomena, into harmony with all observation and
+experiments, which at present is not the case. In seeking to do this he
+found that the new theory of the aether harmonized with views given, by
+Faraday and Clerk Maxwell in relation to electric and magnetic
+phenomena, and by the new theory Maxwell's hypothesis of "Physical Lines
+of Force" receives a definite and physical basis. In Chapter X. the
+author endeavours to show what the Electro-Kinetic energy is, which term
+is used by Clerk Maxwell, the term being brought for the first time into
+harmony with our experience. The Electro-Magnetic Theory of Light also
+receives fresh light from the new theory of an atomic and gravitating
+aether.
+
+In the succeeding chapters the theory is applied to Newton's Laws of
+Motion and Kepler's Laws, and is found to harmonize with all the results
+given by these laws. Such a result is a distinct advance on the
+application of a frictionless aether to solar and stellar phenomena, as
+it is impossible for Kepler's Laws to be reconciled in any way with our
+present theory of the aether.
+
+In the concluding chapter on the unity of the universe, certain views
+are suggested as to the ultimate constitution of all matter, upon an
+aetherial basis, which hypothesis practically resolves itself into an
+electric basis for all matter. It is suggested that aether and
+electricity are one and the same medium, both being a form of matter,
+and both possessing exactly the same properties, viz. atomicity, weight,
+density, elasticity, inertia, and compressibility. This view of matter
+harmonizes with the most "Modern Views of Matter" as suggested by Sir
+Oliver Lodge in his Romanes Lecture 1903.
+
+The author has accepted Newton's way of spelling "_aether_" as given in
+his work on _Optics_, and has given "_aetherial_" the same suffix as
+"material," in order to differentiate the word from "ethereal," which is
+too metaphysical a term for a material medium.
+
+    _Nottingham_,
+        _Sept._ 1903.
+
+
+
+
+CONTENTS
+
+
+                             CHAPTER I
+
+                     PHILOSOPHY OF GRAVITATION
+
+                                                                  PAGE
+ART.   1. GRAVITATION                                                1
+ "     2. CAUSE OF GRAVITATION                                       1
+ "     3. NEWTON'S RULES OF PHILOSOPHY                               3
+ "     4. FIRST RULE OF PHILOSOPHY                                   3
+ "     5. SECOND RULE OF PHILOSOPHY                                  4
+ "     6. THIRD RULE OF PHILOSOPHY                                   7
+ "     7. APPLICATION OF RULES TO GRAVITATION                        9
+ "     8. ANALYSIS OF LAW OF GRAVITATION                             9
+ "     9. PRIMITIVE IMPULSE                                         10
+ "    10. CENTRIPETAL FORCE                                         12
+ "    11. CENTRIFUGAL FORCE                                         13
+ "    12. NEWTON'S LAWS OF MOTION                                   15
+ "    13. FORCE                                                     16
+ "    14. FIRST LAW OF MOTION                                       16
+ "    15. SECOND LAW OF MOTION                                      19
+ "    16. THIRD LAW OF MOTION                                       20
+ "    17. SUMMARY OF CHAPTER                                        22
+
+
+                             CHAPTER II
+
+                PHILOSOPHY OF GRAVITATION--(_continued_)
+
+ART.  18. GRAVITATION ATTRACTION                                    24
+ "    19. UNIVERSALITY OF GRAVITATION                               24
+ "    20. DIRECTION OF THE FORCES                                   26
+ "    21. PROPORTION OF THE FORCES                                  26
+ "    22. LAW OF INVERSE SQUARES                                    27
+ "    23. TERRESTRIAL GRAVITY                                       29
+ "    24. CENTRIFUGAL FORCE                                         30
+ "    25. KEPLER'S LAWS                                             32
+ "    26. FIRST LAW OF KEPLER                                       33
+ "    27. SECOND LAW OF KEPLER                                      36
+ "    28. THIRD LAW OF KEPLER                                       37
+
+
+                             CHAPTER III
+
+                                MATTER
+
+ART.  29. WHAT IS MATTER?                                           40
+ "    30. CONSERVATION OF MATTER                                    42
+ "    31. MATTER IS ATOMIC                                          42
+ "    32. WHAT IS AN ATOM?                                          43
+ "    33. THE ATOMIC THEORY                                         44
+ "    34. KINDS OF ATOMS                                            44
+ "    35. ELEMENTS OF MATTER                                        47
+ "    36. THREE KINDS OF MATTER                                     47
+ "    37. MATTER IS GRAVITATIVE                                     50
+ "    38. MATTER POSSESSES DENSITY                                  51
+ "    39. MATTER POSSESSES ELASTICITY                               51
+ "    40. MATTER POSSESSES INERTIA                                  52
+
+
+                             CHAPTER IV
+
+                               AETHER
+
+ART.  42. AETHER IS MATTER                                          54
+ "    43. AETHER IS UNIVERSAL                                       58
+ "    44. AETHER IS ATOMIC                                          59
+ "    45. AETHER IS GRAVITATIVE                                     64
+ "    46. AETHER POSSESSES DENSITY                                  71
+ "    47. AETHER POSSESSES ELASTICITY                               74
+ "    48. AETHER POSSESSES INERTIA                                  76
+ "    49. AETHER IS IMPRESSIBLE                                     78
+ "    50. AETHER AND ITS MOTIONS                                    80
+
+
+                             CHAPTER V
+
+                              ENERGY
+
+ART.  51. ENERGY                                                    83
+ "    52. CONSERVATION OF ENERGY                                    84
+ "    53. TRANSFORMATION OF ENERGY                                  86
+ "    54. POTENTIAL ENERGY                                          87
+ "    55. KINETIC ENERGY                                            89
+ "    56. ENERGY AND MOTION                                         91
+ "    57. CONSERVATION OF MOTION                                    92
+ "    58. TRANSFORMATION OF MOTION                                  93
+ "    59. MOTION AND WORK                                           95
+
+
+                             CHAPTER VI
+
+                       HEAT, A MODE OF MOTION
+
+ART.  60. HEAT, A MODE OF MOTION                                    98
+ "    61. HEAT AND MATTER                                          100
+ "    62. RADIATION AND ABSORPTION                                 104
+ "    63. HEAT IS A REPULSIVE MOTION                               107
+ "    64. RADIANT HEAT                                             109
+ "    65. DIRECTION OF A RAY OF HEAT                               111
+ "    66. LAW OF INVERSE SQUARES                                   112
+ "    67. FIRST LAW OF THERMODYNAMICS                              114
+ "    68. SECOND LAW OF THERMODYNAMICS                             116
+ "    69. IDENTITY OF HEAT AND LIGHT                               119
+
+
+                            CHAPTER VII
+
+                      LIGHT, A MODE OF MOTION
+
+ART.  70. LIGHT, A MODE OF MOTION                                  122
+ "    71. TRANSVERSE VIBRATION OF LIGHT                            130
+ "    72. REFLECTION AND REFRACTION                                135
+ "    73. THE SOLAR SPECTRUM                                       139
+ "    74. DIRECTION OF A RAY OF LIGHT                              144
+ "    75. INTENSITY OF LIGHT                                       145
+ "    76. VELOCITY OF LIGHT                                        148
+ "    77. DYNAMICAL VALUE OF LIGHT                                 150
+ "    78. ELECTRO-MAGNETIC THEORY OF LIGHT                         155
+
+
+                            CHAPTER VIII
+
+                       AETHER AND ELECTRICITY
+
+ART.  79. ELECTRICITY, A MODE OF MOTION                            162
+ "    80. ELECTRIC FIELD                                           166
+ "    81. ELECTRIC INDUCTION                                       174
+ "    82. ELECTRIC ENERGY                                          179
+ "    83. ELECTRIC RADIATION                                       182
+ "    84. LAW OF INVERSE SQUARES                                   184
+ "    85. SECOND LAW OF ELECTRICITY                                186
+
+
+                             CHAPTER IX
+
+                        AETHER AND MAGNETISM
+
+ART.  86. ELECTRO-MAGNETISM                                        192
+ "    87. THE EARTH A MAGNET                                       195
+ "    88. THE SUN AN ELECTRO-MAGNET                                199
+ "    89. FARADAY'S LINES OF FORCE                                 203
+ "    90. TERRESTRIAL MAGNETISM                                    206
+ "    91. SOLAR MAGNETS                                            211
+ "    92. CAUSE OF ROTATION OF THE EARTH ON ITS AXIS               219
+ "    93. VORTEX MOTION                                            221
+ "    94. RELATIVE MOTION OF AETHER AND MATTER                     224
+ "    95. VIBRATIONS IN THE ELECTRO-MAGNETIC THEORY OF LIGHT       228
+
+
+                             CHAPTER X
+
+                  AETHER AND NEWTON'S LAWS OF MOTION
+
+ART.  96. AETHER AND CENTRIFUGAL FORCE                             232
+ "    97. AETHER AND CENTRIPETAL FORCE                             236
+ "    98. AETHER AND NEWTON'S FIRST LAW OF MOTION                  239
+ "    99. AETHER AND NEWTON'S SECOND LAW OF MOTION                 244
+ "   100. AETHER AND NEWTON'S THIRD LAW OF MOTION                  251
+ "   101. WHY PLANETS REVOLVE FROM WEST TO EAST                    253
+
+
+                             CHAPTER XI
+
+                      AETHER AND KEPLER'S LAWS
+
+ART. 102. AETHER AND KEPLER'S FIRST LAW                            256
+ "   103. AETHER AND KEPLER'S SECOND LAW                           260
+ "   104. AETHER AND KEPLER'S THIRD LAW                            263
+ "   105. ORBITAL MOTION OF PLANETS                                266
+ "   106. ECCENTRICITY OF THE MOON'S ORBIT                         268
+ "   107. THE SUN AND KEPLER'S FIRST LAW                           270
+ "   108. THE SUN AND KEPLER'S SECOND LAW                          274
+ "   109. AETHER AND THE PLANE OF THE ECLIPTIC                     277
+ "   110. AETHER AND THE CENTRIPETAL FORCE                         282
+
+
+                             CHAPTER XII
+
+                          AETHER AND COMETS
+
+ART. 111. WHAT IS A COMET?                                         291
+ "   112. ORBITS OF COMETS                                         293
+ "   113. KINDS OF COMETS                                          296
+ "   114. PARTS OF A COMET                                         298
+ "   115. CENTRIFUGAL FORCE AND COMETS                             300
+ "   116. FORMATION OF TAILS                                       303
+
+
+                            CHAPTER XIII
+
+                       AETHER AND STARRY WORLD
+
+ART. 117. STARRY WORLD                                             306
+ "   118. STARS AND KEPLER'S LAWS                                  309
+ "   119. AETHER AND NEBULAE                                       313
+ "   120. WHAT IS A NEBULA?                                        314
+ "   121. AETHER AND NEBULAR HYPOTHESIS                            317
+ "   122. KINDS OF NEBULAE                                         319
+
+
+                             CHAPTER XIV
+
+                       AETHER AND THE UNIVERSE
+
+ART. 123. THE UNIVERSE                                             323
+ "   124. UNITY OF THE UNIVERSE                                    326
+ "   125. CONSTITUTION OF MATTER                                   334
+ "   126. QUOD ERAT FACIENDUM                                      337
+ "   127. GOD AND THE UNIVERS                                      342
+
+APPENDIX                                                           349
+INDEX                                                              351
+
+
+
+
+                        AETHER AND GRAVITATION
+
+
+
+
+                               CHAPTER I
+
+                       PHILOSOPHY OF GRAVITATION
+
+
+ART. 1. _Gravitation._--In the realm of Science, there exists a Force or
+Law that pervades and influences all Nature, and from the power of
+which, nothing, not even an atom, is free.
+
+It holds together the component parts of each and every individual
+world, and in the world's revolving prevents both its inhabitants and
+its vegetation from being whirled off its surface into space. It exists
+in each and every central sun, and circles round each sun its associated
+system of planets. It rolls each satellite around its primary planet,
+and regulates the comet's mysterious flight into the depths of space,
+while the pendulation of even the remotest star is accomplished by this
+same force. Our own rocking world obeys the same mysterious power, that
+seems to grasp the entire material creation as with the grasp of the
+Infinite.
+
+It exists in, and influences every atom, whose combinations compose and
+constitute the entire material creation, or each and every orb that
+bespangle the blue infinity.
+
+As is readily seen, it weaves as it were around each and all, a
+mysterious network or chain, that binds star to star, and world to
+world, blending all into one entire, vast and complete unity. It decides
+all their orbits and distances, regulates and controls all their
+motions, from the most simple even to the more complex and intricate,
+ultimately producing that wondrous and beauteous order, unity and
+harmony that everywhere pervade and blend all the universe into one
+grand and harmonious whole.
+
+That Law I need hardly say is the Law of Gravitation.
+
+
+ART. 2. _Cause of Gravitation._--Now the question arises, and indeed has
+arisen a thousand times since the discovery of this law by Sir Isaac
+Newton over two hundred years ago, as to what is the physical cause, the
+true explanation of this universal attraction.
+
+MacLaurin in his work on the philosophical discoveries of Sir Isaac
+Newton says: "In all cases when bodies seem to act upon each other at a
+distance, and tend towards one another without any apparent cause
+impelling them, this force has been commonly called Attraction, and this
+term is frequently used by Sir Isaac Newton. But he gives repeated
+caution that he pretends not by the use of this term to define the
+nature of the power, or the manner in which it acts. Nor does he ever
+affirm or insinuate that a body can act upon another body at a distance,
+but by the intervention of other bodies."
+
+The results of modern discovery show that action at a distance, without
+the intervention of any medium, as for example the sun attracting the
+earth, is not the universal condition which governs all so-called
+forces.
+
+It is now recognized that light and heat are both forms of energy, and
+therefore forces, using the term in the same sense that it is applied to
+Gravitation.
+
+Both light and heat are transmitted through space with finite velocity
+through the intervention of a medium, the universal Aether. It is
+therefore only reasonable to suppose, that if one or more particular
+kinds of energy, or forces, require a medium for their transmission, why
+not another force, as for example Gravitation?
+
+Gravitation is an universal force which operates throughout the length
+and breadth of the entire universe, and if there be a medium which is to
+Gravitation, what the Aether is to light and heat, the question at once
+confronts us, as to what are the characteristics, properties, and
+qualities of that universal medium, which is to form the physical basis
+of this universal attraction?
+
+Newton himself suggested that Gravitation was due to an aetherial subtle
+medium, which filled all space.
+
+In his well-known letter to Bentley, Newton writes as follows: "That
+Gravity should be innate, inherent, and essential to matter, so that one
+body can act upon another body at a distance through a vacuum, without
+the mediation of anything else, by and through which their action and
+force may be conveyed from one to another, is to me so great an
+absurdity, that I believe no man who has any philosophical nature or
+competent faculty of thinking can ever fall into it."
+
+We also know from his Queries in his book on _Optics_, that he sought
+for the explanation of Gravitation in the properties of a subtle,
+aetherial medium diffused over the universe.
+
+MacLaurin on this point says: "It appears from his letters to Boyle,
+that this was his opinion early, and if he did not publish his opinion
+sooner, it proceeded from hence only, that he found he was not able from
+experiment and observation to give a satisfactory account of this
+medium, and the manner of its operations in producing the chief
+phenomena of Nature."
+
+Therefore, if we accept Newton's suggestion, and endeavour to trace the
+physical cause of Gravitation in the qualities, properties, and motions
+of this subtle aetherial medium to which he refers, we shall be simply
+working on the lines laid down by Sir Isaac Newton himself.
+
+I wish therefore to premise, that the future pages of this work will
+deal with the hypothesis of this aetherial medium, by which will be
+accounted for, and that on a satisfactory and physical basis, the
+universal Law of Gravitation.
+
+
+ART. 3. _Rules of Philosophy._--In order that we may rightly understand
+the making of any hypothesis, I purpose giving some rules laid down by
+such philosophers as Newton and Herschel, so that we may be guided by
+right principles in the development of this new hypothesis as to the
+cause of Gravitation.
+
+The rules that govern the making of any hypotheses, so far as I can
+discern, may be summed up under the three following heads--
+
+    (1) Simplicity of conception.
+
+    (2) Agreement with experience, observation, and experiment.
+
+    (3) Satisfactorily accounting for, and explaining all phenomena
+        sought to be explained.
+
+
+ART. 4. _1st Rule. Simplicity of Conception._--From this rule we learn
+that the hypothesis must be simple in conception, and simple in its
+fundamental principles, and further, that the same characteristic of
+simplicity must mark each step of its development.
+
+This rule of simplicity is distinctly laid down by Sir Isaac Newton in
+his _Principia_, Book 3, under the heading "Regulae Philosophandi."
+
+In that work he writes: "Natura simplex est, et rerum causis superfluis
+non luxuriat."--"Nature is simple, and does not abound in superfluous
+causes of things."
+
+He further states that: "Not more of the natural causes of things ought
+to be admitted, than those which are true and suffice to explain
+phenomena. In the nature of Philosophy nothing is done in vain, and by
+means of many things, it is done in vain when it can be done by fewer.
+For Nature is simple, and does not abound in superfluous causes."
+
+While again in Rule 3, he adds: "Natura simplex est et sibi semper
+consona."--"Nature is simple, and always agrees with itself."
+
+Whewell also considers simplicity as a fundamental principle of all true
+hypotheses. On this point he writes: "All the hypotheses should tend to
+simplicity and harmony. The new suppositions resolve themselves into the
+old ones, or at least only require some easy modification of the
+hypothesis first assumed. In false theories the contrary is the case."
+
+Thus, it is the very essence of philosophy to build upon a foundation of
+simplicity, combined with the results of experience, observation, and
+experiment. For example, if we desired to form a hypothesis as to the
+cause of day and night, two hypotheses might be assigned as to the
+cause.
+
+First, that the earth revolves on its axis once a day, and so presents
+each part successively to the light and heat of the sun; and second,
+that the sun revolves round the earth once every 24 hours. But such an
+assumption as the latter would involve the revolution of the sun through
+an immense orbit at an enormous velocity, in order for the journey to be
+accomplished in the time. So that it is much simpler to conceive of the
+earth revolving on its axis once every 24 hours, than it is for the sun
+to perform this journey in the same period. Hence the rule of simplicity
+is in favour of day and night being caused by the revolving of the earth
+on its axis. The same rule might be illustrated in many ways; but,
+however illustrated, the principle, according to Newton, always holds
+good that all effects are produced by the simplest causes, and if there
+are apparently two causes to the same phenomenon, then the simpler cause
+is the true and correct one. So that in the making and development of
+any hypotheses of the physical cause of Gravitation, this rule of
+simplicity must always be recognized; and, in conjunction with the other
+rules, we must seek to make our hypotheses, so as to be able to account
+and explain all phenomena sought to be explained.
+
+
+ART. 5. _2nd Rule. Experience._--Newton fully recognized the necessity
+of experience in Philosophy. He saw the absolute necessity of appealing
+to experience, observation, and experiment, both as a basis for
+philosophical reasoning, and further, for the data which were necessary
+to verify particular applications of the hypotheses suggested.
+
+In his Rules of Philosophy, referring to experience as a guide, he says:
+"Hoc est fundamentum philosophiae."--"This is the basis of philosophy."
+
+Herschel, writing on the same subject in his _Natural Philosophy_,
+writes thus with regard to experience: "We have pointed out that the
+great, and indeed the only ultimate source of our knowledge of nature,
+and its laws, is experience. By which I mean, not the experience of one
+man only, or of one generation, but the accumulated experience of all
+mankind in all ages registered in books or recorded in tradition. But
+experience may be acquired in two ways, either first by noticing facts
+as they occur without any attempt to influence the frequency of their
+occurrence, or to vary the circumstances under which they occur. This is
+observation. Second, by putting in action causes and agents over which
+we have no control, and purposely varying their combination, and then
+noticing what effects take place. This is experiment. To these two
+sources we must look as the fountains of all natural science."
+
+Herschel further writes: "Experience once recognized as the fountain of
+all our knowledge of nature, it follows, that in our study of nature and
+its laws, we ought at once to make up our minds to dismiss, as idle
+prejudices, or at least suspend as premature, all preconceived notion of
+what might, or ought to be the order of nature in any proposed case, and
+content ourselves as a plain matter of fact with what is. _To experience
+we refer as the only ground for all physical enquiry._ But before
+experience itself can be used to advantage, there is one preliminary
+step to make which depends wholly upon ourselves."
+
+"It is the _absolute dismissal_ and clearing the mind _of all
+prejudices_ from whatever source arising, and the determination to stand
+or fall by the result of direct appeal to facts in the first instance,
+and to strict logical deduction from them afterwards."
+
+From extracts like these, from such men as Newton and Herschel, it can
+at once be seen that experience, and experience alone, should be the
+chief fountain from whence we draw all our data to form the bases of any
+hypothesis or theory. If the hypothesis formed is contradicted by the
+result of any present or future observation or experiment, then such
+hypothesis will either become untenable, or must be so modified as to
+take in the new fact furnished by that observation and experiment.
+
+It is a _sine qua non_ of all true philosophy, that philosophy should
+always agree with experience. To the extent that our Philosophy of
+Nature fails to agree with our experience, or with the results of
+observation and experiment, then to that extent it ceases to be
+philosophy. It may be a hypothesis or even a theory, but certainly it is
+not true Philosophy.
+
+Now, in the elaboration and development of the theory as to the physical
+cause of Gravitation, I can premise that nothing will be postulated or
+supposed, unless such supposition can be directly verified by our own
+observation and experiments.
+
+Any theory or hypotheses that are contradicted by our own experience in
+its widest form, will find no place in the development of this work.
+Further, any present accepted theory in relation to any natural
+phenomena, which is controverted by experiment, or observation, will be
+rejected as untenable in the scheme of Natural Philosophy to be
+submitted to the reader.
+
+Whatever else the theory suggested may, or may not be, one thing it
+certainly shall be, and that is, that it shall be strictly based upon
+the Philosophical Rules as given by some of the greatest philosophers
+the world has ever seen. I do not premise that the hypotheses advanced
+will be strictly correct in every detail.
+
+That would be to assume that my experience of all natural phenomena was
+perfect. To the extent that our experience is limited, to that extent
+our hypotheses will be limited and faulty. It would need an Infinite
+mind to form a perfect theory of the philosophy of the universe, because
+only an Infinite mind possesses infinite experience. A finite mind can,
+however, form true philosophical conceptions of natural phenomena, if
+that mind will only follow the guidance of his own experience, and be
+willing to accept the teaching that always arises from the results of
+that experience. In order to do this, however, it must be observed, as
+Herschel points out, that all old prejudices must be put away, and the
+question or problem to be considered must be viewed with an open mind.
+Let me illustrate what I mean. Suppose, for example, that for two
+hundred years, chalk had always been thought to be a mineral, and then,
+owing to the development of the microscope, and to the increased
+magnifying powers of the lenses, it was conclusively demonstrated that
+chalk is made up of the shells and remains of certain organisms that
+lived in the sea ages ago. Would it be philosophical to throw over the
+results of the microscopical research, and, simply because for two
+hundred years chalk had been thought to be a mineral, to argue, and
+still retain the idea that chalk was a mineral?
+
+Such a result would be entirely opposed to all the teaching and
+principles of philosophy. In a similar way, suppose in the development
+of the physical cause of Gravitation, a certain conception of the
+universal Aether has to be put forth in order to account for
+Gravitation, and that that conception is opposed to some of the theories
+which have been held relative to the Aether medium for the past two
+hundred years; but that the conception so advanced is supported by the
+experiments and observation of some of the ablest scientists of the
+present century, would it be philosophical to reject the newer
+conception which harmonized with all experiment and observation, and
+still retain the old conception of the aetherial medium; or, to accept
+the newer conception of that medium, and to reject some of the ideas
+included in the old conception? From a purely philosophic standpoint,
+there can only be one reply, which would be in favour of the newer
+conception, by which our philosophy would be brought into harmony with
+our experience.
+
+This I premise will be done in this work, and the result will be, that
+for the first time, our philosophy of the aetherial medium will agree
+with our experience; and, as the natural result, several outstanding
+problems will be explained on a physical basis, which at the present
+time cannot be satisfactorily explained except from the mathematical
+standpoint.
+
+
+ART. 6. _3rd Rule. Satisfactory explanation of the Phenomena sought to
+be Explained._--The third rule which governs the making of any
+hypothesis is, that the hypothesis formed in accordance with the first
+and second rules shall satisfactorily account for all the phenomena
+sought to be explained.
+
+Newton writes on this point as follows: "No more causes of natural
+things are to be admitted, than such as are true, and sufficient to
+explain the phenomena." While again in his fourth rule he states: "In
+experimental philosophy, propositions collected by induction from
+phenomena are to be regarded as accurately true, or very nearly true,
+notwithstanding any contrary hypothesis, till other phenomena occur by
+which they are made more accurate, or are rendered subject to
+exceptions." _Principia_, Book 3. Herschel in his _Natural Philosophy_
+points out, that one of the chief requirements of any assumed hypothesis
+is, that it shall be sufficient to account for the phenomena to be
+explained, and that it shall be suggested by analogy.
+
+Now the object of this work is to give a physical explanation of the
+cause and working of Gravitation, and to show how, by the properties,
+qualities and motions of the universal Aether, Universal Gravitation may
+be accounted for on a physical basis. So that every phenomenon,
+associated with, or included in the Law of Gravitation, should receive a
+satisfactory physical explanation by the proposed theory.
+
+Thus the physical cause of the centripetal and centrifugal forces should
+receive for the first time a physical explanation.
+
+Newton's Laws of Motion, in so far as they conform to his own Rules of
+Philosophy, should also receive a physical explanation.
+
+Kepler's Laws, which govern the motion of planets in their orbits,
+should also receive a similar physical explanation. Indeed, all
+phenomena which the Law of Gravitation explains from a mathematical
+standpoint, ought to receive a physical explanation by the proposed new
+conception of the Aether medium.
+
+In addition to the outstanding physical cause of Gravitation, there are
+other physical problems that yet remain to be solved; as, for example,
+there is the question as to what is the relative motion of Aether to
+moving matter. Does the Aether move with matter through space as
+suggested by Michelson's and Morley's experiment of America, or does it
+flow freely through all matter, as it is usually thought to do? I
+premise I will give a satisfactory solution of this problem in due
+course.
+
+Again, in relation to the Phenomena of Light, there is still outstanding
+the problem of the physical explanation as to the transverse vibration
+of light. This problem will also be dealt with from the standpoint of
+our new conception of the Aether. Whether it will be as satisfactorily
+solved, as the physical cause of Gravitation, remains to be seen.
+
+Further, there is also the important question yet unsolved, as to what
+Matter is. Lord Kelvin and Dr. Larmor have recently given to the world
+certain conceptions as to the origin of Matter, and I shall endeavour to
+show that such conceptions receive confirmation and support by the
+proposed new conception of the Aether.
+
+Another problem that will be attacked and solved, will be the cause of
+the Permanent Magnetism of the earth, with an answer to some of the
+questions propounded by Professor Schuster at the British Association of
+1892 relative to the magnetism of solar bodies.
+
+There is certainly some physical explanation as to the cause of the
+earth being a magnet, yet up to the present no satisfactory physical
+theory has been given. I premise that the new conception of the Aether,
+to be submitted in the after pages, will satisfactorily account, and
+that on a philosophical basis, for this phenomenon.
+
+Lastly, one of the most interesting discoveries of the present day will
+receive an added confirmation and explanation in the conception of the
+Aether medium to be advanced. I refer to the system of Wireless
+Telegraphy that has been so successfully developed by Signor Marconi,
+and I premise that new light will be thrown on that discovery by the
+suggested theory of the Aether.
+
+Now, if all these problems can be partially or wholly solved by the same
+theory that is advanced to explain the physical cause of Gravitation, it
+needs no further comment to show that that theory is considerably
+strengthened and more firmly established.
+
+For it is a rule in Philosophy, that the more problems any suggested
+theory can solve, the greater are the claims of that theory for
+acceptance by scientists generally. For, if two rival theories can solve
+three and ten physical problems respectively, then, in giving a decision
+as to which is the better theory, the balance of opinion would be
+overwhelming in favour of that theory which could solve the ten
+problems. So that, if in addition to the satisfactory explanation of the
+physical cause of Gravitation, some, if not all of the other problems
+can be solved, as I premise they can, by the same conception of the
+Universal Aether, then it follows our third rule of Philosophy will be
+more than fulfilled, and the theory so advanced will be placed upon such
+a strong foundation, that it can only be overthrown by proving that it
+contradicts the results of some undiscovered phenomena.
+
+
+ART. 7. _Application of Rules to Gravitation._--Let us therefore apply
+Newton's own Rules of Philosophy to the Law of Gravitation, and
+endeavour to find out if the law, as at present understood, fully
+satisfies his own Rules of Philosophy. No one can reasonably object to
+subjecting the Law of Gravitation to the test of those principles which
+he lays down as the fundamental Rules of Philosophy.
+
+If it comes through the ordeal with complete success, that is, if it is
+essentially simple in its conception and development, and if all its
+details are fully in accord with experience, as revealed by observation
+and experiment, then there will be no need to alter any of its
+hypotheses or axioms. If, on the other hand, it violates any of the
+rules as laid down by Newton, then, to that extent, an alteration will
+be necessary, in order that the Law of Gravitation may be brought into
+conformity with his own rules, and our Philosophy made to agree with our
+experience and observation.
+
+
+ART. 8. _Analysis of Law of Gravitation._--In order to accomplish this,
+let us ask ourselves, "What are the component parts of this Law of
+Gravitation?" The Law is not a simple law, but a compound one. It is
+compounded primarily of three parts.
+
+    1st. A Primitive Impulse.
+
+    2nd. A Centripetal Force.
+
+    3rd. A Centrifugal Force.
+
+To these must be added the three Laws of Motion; although they are not
+directly part of the Law of Gravitation, yet they are essential to its
+effectiveness and completion. Without any one of these, the Law of
+Gravitation would fail to account for all the phenomena that it does
+account for.
+
+If there were no Primitive Impulse, then the planets and meteors, sun
+and stars would for ever remain at rest, and the Laws of Motion would
+remain inoperative. If there were no Centripetal Force, then the
+Centrifugal Force would hurl the planets and comets, asteroids or minor
+planets away into the depths of space, never to return to their central
+sun.
+
+If there were no Centrifugal Force, then the Centripetal Force would
+draw all bodies, _i. e._ all planets, etc., to their central sun, and,
+instead of the planets continually revolving round the sun, there would
+be but one immense solitary mass in the centre of the solar system.
+
+If there were no Laws of Motion, with their necessary corollary the
+Parallelogram of Forces, the Primitive Impulse would cease to act, and
+the Law of Gravitation would again fail in its attempt to account for
+those phenomena it does account for.
+
+Thus, as it may easily be seen, Gravitation is a compound Law, depending
+upon at least four hypotheses, and therefore is not essentially a simple
+Force, or Law.
+
+If, therefore, in giving a physical explanation of the cause of
+Gravitation, we can reduce all these four elements of the Law into one
+single physical cause, _i. e._ the Universal Aether, and show how they
+may all be explained and accounted for by the properties, qualities and
+motions of that physical medium, then such a result will be strictly in
+harmony with the first Rule of Philosophy, as laid down by Newton and
+others.
+
+We will, therefore, proceed to consider some of these parts of the Law
+of Gravitation in detail.
+
+
+ART. 9. _Primitive Impulse._--This may be explained as follows. At the
+creating and launching of each world, Newton supposed that there was
+given to each world an impulse or tendency to fly off from the
+controlling centre into space. On this matter MacLaurin writes as
+follows: "If we had engines of sufficient force, bodies might be
+projected from them, so as not only to be carried a vast distance away
+without falling to the earth, but so as to move round the whole earth
+without touching it; and, after returning to the first place, commence a
+new revolution with the same force they first received from the engine;
+and after the second revolution, a third, and thus revolve as a moon or
+satellite round the earth for ever. If this can be effected near the
+earth's surface, it may be done higher in the air, or even as high as
+the moon. By increasing the force or power, a body proportionately
+larger may be thus projected, and by a power sufficiently great, a heavy
+body, not inferior to the moon, might be put in motion, which might
+revolve for ever round the earth. Thus Sir Isaac Newton saw that the
+curvilineal motion of the moon in her orbit, and of a projectile at the
+surface of the earth, were phenomena of the same kind, and might be
+explained from the same principle extended from the earth so as to reach
+the moon, and that the moon was only a greater projectile that received
+its motion in the beginning of things from the Almighty Author of the
+Universe."
+
+Now what I desire to know is, "What is the nature, the mode of
+operation, and, above all, the physical cause of this Primitive
+Impulse?" Is it in its nature and mode of operation a simple Force, or
+Cause? Does it fulfil the condition of Newton's First Rule of
+Philosophy? Permit me to suggest several lines of thought which may be
+made the basis of its analysis.
+
+Astronomers tell us that there are in existence millions of stars, and
+suns, flooding immensity and space with their light and heat.
+
+Now the question I wish to ask regarding Primitive Impulse in relation
+to all these stars is this: "Was the Primitive Impulse imparted to each
+sun, and star, and planet, separately and distinctly?" If so, then there
+must have been just as many Primitive Impulses as there are stars and
+suns and planets, and there would be according to a certain astronomer's
+estimate at least 800,000,000 Primitive Impulses, which assumption is
+altogether opposed to, and violates the First Rule of Philosophy.
+
+If, on the other hand, it is affirmed that they all received their
+motion at one and the same time, then I ask: "What was the physical
+cause and method adopted to communicate the impulse to each one at the
+same time?" If the reply is given, that it was by Universal Gravitation,
+I have two objections to make to such a reply: first, that Gravitation
+is altogether inoperative without the Primitive Impulse, otherwise why
+was it conceived? and secondly, what is the physical cause of
+Gravitation?
+
+Again, scientists inform us that there is every reason for believing,
+that stars and suns are still being formed in the universe, and that
+there are certain distinctive phenomena which go to prove that
+statement. Now, if that be true, and I believe it to be true, I wish to
+ask if the Primitive Impulse as suggested by Newton, is applicable to
+the stars and suns already in process of formation in the various
+nebulae? and, if so, at what point in the star's history or development
+is that Impulse applied?
+
+Personally, I cannot conceive of the Great Creator of all things being
+so lacking in inventive genius, if I may reverently use that term, as to
+necessitate a separate Impulse being given to every separate star, or
+sun, as each one is created or formed during the progress and
+development of the universe of worlds.
+
+I would much rather believe that which I hold to be the correct
+explanation, viz. that He has given to a certain fundamental and
+primordial medium, certain qualities and properties, by, and through
+which are originated and perpetuated, all the motions of the heavenly
+bodies already existent in the universe, or that are ever likely to be
+existent throughout all time.
+
+The question of separate Primitive Impulses for separate bodies becomes
+more and more incongruous and inadmissible, as we consider it in its
+application to such small bodies as meteors and planetoids. Is it not
+contrary to our fundamental principles of Philosophy, that a separate
+Impulse should be necessary for all small bodies that exist in their
+myriads throughout the solar system, not to speak of the universe of
+which that system forms a part? Such a conception as Primitive Impulse,
+to each separate world, is altogether opposed to one's idea of that
+simplicity and beauty which govern the universe at large, and violates
+the first rule of our philosophical reasoning, and for this reason must
+be rejected from the System of Philosophy to be propounded in this work.
+
+
+ART. 10. _Centripetal Force._--Let us now look at the Centripetal Force,
+and ask ourselves what is meant by such a force, and what is its mode of
+action and working. Centripetal Force, strictly, may be defined as that
+force which is always exerted towards the centre of the attracting body.
+
+Taking the earth as an example, Newton points out, that though the
+gravity of bodies arises from their gravitation towards several parts of
+the earth; yet, because this power acts always towards the centre of
+gravity of the earth, it is therefore called the Centripetal Force.
+
+This force, then, is that part of the Law of Gravitation which
+corresponds to the Attraction of Gravitation, and is always exerted in
+that straight line from the body attracted, to the centre of the
+attracting body, which joins the centres of gravity of the two bodies
+concerned.
+
+The combination and effect of the various forces included in the Law of
+Gravitation are illustrated by the familiar illustration of the ball
+whirled round the hand by a piece of string, or the bucket filled with
+water, whirled round in the same way. Let us take the former. A piece of
+string with a ball attached to one of the ends is held firmly by the
+hand. An impulse or motion is imparted to the ball by the hand, that
+motion being continued by the movement from the hand. The first impulse
+given to the ball by the hand represents the Primitive Impulse. The
+tension on the string which holds the ball to its controlling centre
+represents the Centripetal Force, while the opposite force on the
+string, which takes up the Primitive Impulse and continues it, is
+represented by the Centrifugal Force.
+
+The conception of the Centripetal Force is therefore simple, and
+entirely in accordance with our experience as gathered from observation
+and experiments. Both in the spheres of electricity, and magnetism, we
+find a similar force acting, which tends towards the centre of the
+attracting body, and therefore the Centripetal Force satisfies the first
+two Rules of our Philosophy.
+
+Further, it adequately accounts for certain distinctive phenomena which
+occur through the Law of Gravitation, as, for example, the falling of
+bodies to the earth, and therefore is entirely in harmony with all the
+requirements of those principles enunciated by Newton for the successful
+explanation of any phenomena. I need hardly point out, therefore, this
+being so, any physical cause suggested as the explanation of Gravitation
+must deal with the Centripetal Force, and be able to give a physical
+explanation of the mode and manner in which the Centripetal Force
+operates.
+
+The Attraction of Gravitation or the Centripetal Force, however, being,
+as its name implies, simply a drawing or pulling power to a centre, that
+is, a force that is ever and ever only drawing matter to matter, or body
+to body, it could not of, and by itself, accomplish those necessary
+stellar and planetary motions by which are produced that universal
+order, unity and harmony which characterize the universe. It is
+essentially in its operations and influences, a one-sided force, ever
+tending and influencing towards self, and therefore by itself would only
+be a detriment and an evil; and, unless it were accompanied by some
+companion or complementary and counter force, with which it acts in
+union and concert, and which exactly counteracts its pulling power and
+influence, it would soon draw star to star, and world to world, crashing
+and heaping them together in ruinous and dire confusion. So that,
+instead of the infinitude of worlds which now exist, which flash and
+sparkle in the heavens, and in their intricate, elaborate, and mazy
+motions move through the vast infinity like stately armies on the march,
+there would only be one agglomeration of matter, a silent and solitary
+mass existing in the vast abyss of space.
+
+Therefore, as soon as Sir Isaac Newton had discovered and demonstrated
+the existence of the power of Attraction, as represented by the
+Centripetal Force, and its association with the universe at large, there
+was seen at once the necessity of another Force, of an opposite
+character, which would form the companion and complementary force to
+Attraction; a repulsive, repellent force, one tending or repelling from
+a centre, so as to counterbalance the influence of the Centripetal Force
+which ever tends towards the centre.
+
+To fill up the blank, there was conceived to exist what is called a
+Centrifugal Force, that is, literally, a Force acting, and ever acting
+from a centre, and with that Force we will now deal.
+
+
+ART. 11. _Centrifugal Force._--In applying our Rules of Philosophy to
+this Force, if by Centrifugal Force is simply meant that Force which is
+the exact opposite of the Centripetal Force, that is, a Force which acts
+from a centre, instead of to a centre, then such a Force is strictly in
+harmony with, and satisfies all the conditions of the two first Rules of
+Philosophy.
+
+Not only is such a conception simple, but it is also in accordance with
+experience and observation. Professor Hicks in his address to the
+British Association in 1895 said: "What is called Centrifugal Force is
+an apparent bodily Force directed outwards from the centre of curvature
+of the body's path, and having an intensity equal to the distance from
+the centre multiplied by the square of the absolute angular velocity."
+
+In the sphere of magnetism and electricity, the operation of two equal
+and opposite forces prevails. The attractive force of electricity, which
+is exerted to the centre, is always accompanied by the generation and
+development of a repulsive force, it being one of the fundamental rules
+of electricity that equal and opposite quantities of electricity are
+always generated at one and the same time. So that if the Centrifugal
+Force is viewed as being simply the exact opposite of the Centripetal
+Force, it fully satisfies the test when the first two rules laid down by
+Newton are applied to it.
+
+If, on the other hand, Centrifugal Force implies and embodies the idea
+of continuance of the Primitive Impulse, as I believe it is supposed to
+do, then to that extent it is not conformable to the principles of our
+Philosophy, as embodied in the rules given by Newton.
+
+Simply because, while it supposes a source or origin of its activity at
+the first, it goes on to suppose a continuance of that activity, without
+recognizing a continuing source or cause. It only recognizes and
+supposes the one original impulse given at the beginning, to account for
+the cause of the continually existing, and exerted power of the
+Centrifugal Force. I do not for a moment suggest, that the Divine
+Creator of all things, and the Ordainer and Upholder of all powers,
+forces and laws could not, had He chosen to give such a force, have
+given it and for ever operating. With that aspect of the question I have
+nothing to do, and of it nothing to say. I am dealing, and only wish to
+deal, with scientific facts, and scientific teaching from the purely
+philosophical standpoint.
+
+Such an idea of a continuing effect, without a continuing cause, is
+altogether opposed to experience and observation, and is a violation of
+the second Rule of Philosophy.
+
+Look where we will, or at what we will, and not only effects and causes
+are seen on every side, and in every thing, linked together inseparably,
+but wherever, and in whatever phenomena there is found a continuance of
+effect or effects, there is always and without exception found also a
+continuing source or cause.
+
+Wherever Nature, therefore, gives us a continuous effect of any kind or
+sort, she always gives us a continuing cause, that can be both proved
+and demonstrated to exist. Nowhere in Nature, amid all her powers,
+principles and laws, is there to be found an effect without a cause, and
+in all continuing effects, a continuing and perpetuating cause also, and
+that effect exists just as long as the cause exists.
+
+If the effect is perpetual, then the source and cause is perpetual also,
+both in its existence and energy. Hence if the Centrifugal Force
+embodies the idea of continuance of the Primitive Impulse, without
+showing how that Primitive Impulse is continued, then such an idea is an
+anomaly in the universe, is altogether opposed to the teaching of Nature
+and science, and violates the most fundamental principles of our
+Philosophy.
+
+The philosophic explanation, therefore, of the Centrifugal Force, is
+that Force which flows from a centre, and _which is the exact opposite
+and counterpart of the Centripetal Force_. Further, as the Centripetal
+Force is an attractive Force ever attracting to a centre, so the
+Centrifugal Force, being its exact opposite, is a repulsive Force, which
+fulfils all the laws and conditions which govern the Centripetal Force,
+as it is in every phase and aspect the exact opposite, being indeed its
+complement and counterpart.
+
+Any physical explanation of the Law of Gravitation, therefore, must also
+give a satisfactory physical explanation of this Force, and show its
+mode of operation and working. This I premise I will do without the
+faintest shadow of doubt or failure; that is, if we are to accept the
+evidence of some of the most delicate experiments of modern times
+relative to aetherial physics.
+
+
+ART. 12. _Laws of Motion._--One of the most important factors in the
+successful application of the Attraction of Gravitation to the universe
+at large, are the Laws of Motion enunciated by Sir Isaac Newton. These
+are three in number, and are as follows--
+
+1st. Every body continues in its state of rest, or of uniform motion in
+a straight line, except in so far as it may be compelled by impressed
+Forces to change that state.
+
+2nd. Change of motion is proportionate to the impressed Force, and takes
+place in the direction of the straight line in which the Force acts.
+
+3rd. To every action there is always an equal and contrary reaction.
+
+_Corollary._--To these must be added the first Corollary of the three
+laws which is commonly known as the Parallelogram of Forces, which is as
+follows: "That when a body is acted upon by two Forces at the same time,
+it will describe a diagonal, by the motion resulting from their
+composition, in the same time that it would describe the sides of the
+parallelogram."
+
+Now let us apply Newton's Rules of Philosophy to these laws, and see if
+they fulfil the conditions laid down therein.
+
+In the first place, there being three laws necessary to cover all the
+motions involved, there is not that simplicity of conception which is a
+primary factor in the making of any hypothesis. Then it will be observed
+that even after postulating the three laws, Newton was unable to account
+for the elliptic orbits of the planets, until he had added a Corollary
+known as the Parallelogram of Forces.
+
+
+ART. 13. _Force._--The question has arisen also, as to the meaning of
+the term Force which Newton uses. What is a Force, its cause and mode of
+operation? The idea of Force is conveyed to us by our "muscular sense,"
+which gives us the idea of pressure, as for example when we push or pull
+a body along the ground.
+
+We must not, however, limit our idea of Force to that narrow circle. It
+has now been fully established that Sound and Heat, Light, Magnetism,
+and Electricity are Forces, and therefore capable of doing work, as will
+be shown later on. Newton's use of the term Force is therefore somewhat
+vague; he does not definitely say what the Force is which causes the
+change of position, of the body, or of the rate of motion of that body.
+That it is something to do with Gravitation is obvious, but its exact
+nature or character is not revealed.
+
+Since Newton's time we have made an advance in the definition of Force,
+and have come to consider Force as a kind of energy; the application of
+Force being the application of energy. Such terms as Mechanical Force,
+Chemical Force, Vital Force, are therefore out of date, and in their
+place the more definite ideas of energy are substituted. Instead,
+therefore, of getting such terms as Transformation of Forces, we now get
+Transformations of Energy. In the chapter on Energy, I hope to show that
+even that is not a satisfactory solution of the definition of a Force.
+If we are to make our Philosophy agree with our experience, then Force
+is due to motion, and motion alone.
+
+So that Centrifugal Force will imply a motion from the centre;
+Centripetal Force a motion whose effect is ever towards the centre of
+gravity of any body.
+
+
+ART. 14. _First Law of Motion._--This may naturally be divided into two
+parts for the purpose of applying the Rules of Philosophy.
+
+(I) Every body continues in a state of rest, except in so far as it is
+compelled by impressed Forces to change that state. To what extent is
+this statement conformable to our experience and observation? If I place
+a body, as for example a weight, on a table, will it remain in that
+state until it is moved by some other Force? I think that it will so
+remain, and to that extent the law conforms to experiment.
+
+Wider observation, and all experience, also prove the conformity of this
+part of the First Law of Motion to the second Rule of Philosophy, as all
+experience testifies to the fact that a body remains at rest, until some
+other power or force moves it from the position of rest. The application
+of this position of rest to any of the planets is, however, very
+difficult to conceive. MacLaurin, in relation to this fact, states:
+"This perseverance of a body in a state of rest can only take place in
+absolute space, and can then only be intelligible by admitting it." In
+dealing with the physical cause of Gravitation, I hope to be able to
+show that it can not only be admitted as a mathematical proposition, but
+that it can be made intelligible from the physical standpoint.
+
+The second part of the First Law of Motion may be stated as follows:
+"Every body continues in a state of uniform motion in a straight line,
+except in so far as it is compelled by impressed forces to change that
+state."
+
+Now what is the testimony of observation and experiment in regard to
+this part of the First Law of Motion? Let us test the question by the
+results of our experience. If a ball is sent rolling along the ground,
+its motion is gradually reduced until it comes to rest. If the ground is
+very rough indeed, as for example a ploughed field, then its speed will
+be very soon reduced, and the ball quickly comes to a standstill. If,
+however, the ground is smooth and level, like a well-kept cricket-field,
+then the motion of the ball will be reduced more slowly, and it will
+travel further before being brought to rest; while, if the ball is
+thrown along a very smooth surface of ice, it will travel a much longer
+distance before it is finally brought to rest.
+
+Thus we learn, that the more we can get rid of all resistances to the
+motion of any body, the greater distance will the body travel, and the
+less diminution there is in the uniform motion of the body. So that, if
+it were possible to obtain a medium which offered no resistance at all
+to a moving body, then it would be a legitimate inference to infer that
+a body in such a medium, when once set in motion, would move with
+uniform motion for ever. Under such conditions, therefore, this part of
+Newton's First Law of Motion is physically conceivable. The crux of the
+whole matter, therefore, lies in the problem as to whether there is, or
+there is not, in existence, such a thing as a frictionless medium. We
+will therefore consider the problem of the existence of a frictionless
+medium from the philosophical standpoint.
+
+Professor Lodge, in _Modern Views of Electricity_, p. 331, writes: "Now,
+if there is one thing with which the human race has been more conversant
+than another, and concerning which more experience has been
+unconsciously accumulated than about almost anything else that can be
+mentioned, it is the action of one body upon another; the exertion of
+Force by one body on another, the transfer of motion and energy from one
+body to another, any kind of effect, no matter what, which can be
+produced in one body by means of another, whether the bodies be animate
+or inanimate."
+
+"Now I wish to appeal to this mass of experience, and to ask, Is not the
+direct action of one body on another across empty space, and with no
+means of communication whatever, is not this absolutely unthinkable? We
+must not answer the question offhand, but must give it due
+consideration, and we shall find, I think, that wherever one body acts
+on another body by obvious contact, we are satisfied and have a feeling
+that the phenomena is simple and intelligible, and that, whenever one
+body apparently acts on another body at a distance, we are irresistibly
+impelled to look for the connecting medium."
+
+Again, on p. 333 of the same work, he adds: "Remember then, that
+whenever we see a thing being moved, we must look for the rope. It may
+be visible, or it may be invisible, but unless there is either a push or
+a pull, there can be no action."
+
+Now, in relation to celestial phenomena, we are confronted with the fact
+of bodies acting on one another, and yet apparently they do not act upon
+one another by or through a medium, and to that extent according to the
+above extracts, such phenomena are opposed to universal experience.
+Again, we find planets and satellites moving through space with more or
+less uniform speed, and yet apparently there is no physical medium that
+acts upon them with either a push or a pull, as the present conception
+of the Aether is that of a frictionless medium, so that experience in
+its widest form seems altogether opposed to the existence of a
+frictionless medium.
+
+Again, Tait in his _Natural Philosophy_ says: "The greater masses,
+planets and comets moving in a less resisting medium, show less
+indications of resistance. Indeed it cannot be said that observations
+upon any one of these bodies, with the exception of Encke's Comet, has
+demonstrated resistance. The greater masses, planets and comets moving
+in a less resisting medium, show less indications. No motion in Nature
+can take place without meeting resistance due to some if not all of
+these influences. _The analogies of Nature and the ascertained facts of
+physical science forbid us to doubt that every one of them, every star,
+and every body of every kind has its relative motion impeded by the air,
+gas, vapour, medium, or whatever we choose to call the substance
+occupying the space around it_, just as the motion of a rifle-bullet is
+impeded by the resistance of the air."
+
+What is the testimony of our own personal observation and experiments to
+such an impossible entity as a frictionless medium? Can any of the
+readers tell me of any medium, be it solid, liquid, or gaseous, that
+they have ever heard of, or read of, or experimented with, that
+possesses the quality of being frictionless? The answer is unanimously
+in the negative. But a frictionless medium was absolutely imperative to
+the success of the Newtonian aspect of the Law of Gravitation. If the
+Aether had not been frictionless, then the First Law of Motion would
+have been violated, and a body, as for example a planet set in motion,
+would not then have moved with uniform motion, but would have been
+brought to a standstill by the resistance of the Aether. Accepting
+therefore experience as a guide, as we are bound to do if we wish to be
+strictly philosophical, as Newton pointed out, then we are compelled to
+come to the conclusion that there is no such thing in the entire
+universe as a frictionless medium. Such a hypothesis is contrary to all
+laws and rules of Philosophy, and to continue to advocate its claims is
+to remain where we are in relation to the cause of Gravitation, and in
+complete ignorance of the beauty and harmony of the wonderful physical
+mechanism that underlies the whole of the universe. Of course, if
+experience and observation are no guide to Philosophy, then we will let
+imagination run riot, and postulate the most extravagant explanations
+for the varied phenomena of the heavens. With experience of no account,
+we will affirm that the moon is made of green cheese, that the earth is
+flat, that the sun revolves round the moon, and a host of other absurd
+hypotheses that require no correction by experience and observation. But
+there, a truce to such absurd imaginations. Experience is a guide to
+Philosophy, its claims are recognized by the greatest Philosopher the
+world has ever known, and therefore as either experience or a
+frictionless medium has to go, we will part with the frictionless
+medium, and endeavour to make a hypothesis of the Aether that is in
+greater harmony with our Rules of Philosophy.
+
+
+ART. 15. _Second Law of Motion._--The application of Newton's Rules of
+Philosophy to the Second Law of Motion is attended with greater success
+than was the case with his First Law. "Change of motion," he states, "is
+proportionate to the impressed Force, and takes place in the direction
+of the straight line in which the Force acts."
+
+Newton adds this explanation to his Second Law: "If a Force generates
+any motion, a double Force will generate double motion, and a triple
+Force triple motion, whether they are applied simultaneously or
+gradually and successively. And this motion, if the body were already
+moving, is either added to the previous motion, if it is in the same
+direction, or subtracted from it if directly opposed to it, or is
+compounded with the previous motion if the two are inclined at an
+angle."
+
+According to that, a force which presses or pushes with a four-pound
+pressure per square inch, if doubled, would press with a force of eight
+pounds per square inch, which fact agrees with experience. If the force
+is applied gradually, then the change of motion would be gradual; if
+applied suddenly, then the resultant motion would be sudden and violent.
+
+The impressed force, therefore, always produces a definite and
+corresponding effect on any moving body, however that force may be
+originated, and however it may be applied. The effect so produced is
+always a change of motion, or, in present scientific terms, a change of
+momentum in the moving body. If the impressed force is halved, by an
+alteration in the mass of the body which exerts the impressed force,
+then the resultant momentum produced is halved also. If the impressed
+force is doubled, through any alteration in the velocity of the body
+which exerts the force, then the momentum produced in the moving body
+will be doubled also. So that the impressed force is equal to the change
+of momentum in the moving body upon which it is impressed.
+
+When similar forces are impressed upon exactly similar bodies, the
+velocities produced are exactly the same; but, if similar forces act on
+dissimilar bodies, then the velocities produced in the different bodies
+are not the same; yet the total motion produced on all bodies, according
+to the Second Law of Motion, must always be proportionate to the
+impressed force. So that when we compare the effect of similar forces on
+different bodies, we find that there are two factors involved, viz., the
+mass and velocity of the moving body. The product of these two
+quantities is termed the momentum of the body.
+
+When we apply the Second Law of Motion to the theory of aetherial
+dynamics, as suggested in this work, we shall seek to show that Newton's
+Second Law of Motion holds good in its application to the new theory.
+With the present conception of a frictionless Aether, however, it is
+philosophically impossible for the Aether to exert force on any body
+that may exist in it. Because, to the extent that it is frictionless, to
+that extent it ceases to possess mass. If it does possess mass, then it
+cannot be frictionless. Such an assumption violates all the Rules of
+Philosophy.
+
+Yet the Aether is supposed, in some unknown manner, to possess inertia,
+which property is also dependent on mass. If the Aether really possesses
+inertia, then it must possess mass, and possessing mass it ceases to be
+a frictionless medium. So that if it possesses mass, then it can exert
+force the same as any other body, and Newton's Second Law of Motion is
+applicable to it.
+
+
+ART. 16. _Third Law of Motion._--Newton's Third Law of Motion reads as
+follows--
+
+"Action and re-action are equal and opposite, or, to every action there
+is always an equal and contrary re-action." This law is also conformable
+to experience; for, by experiment, it has been proved to hold good for
+electric and magnetic action. As MacLaurin points out, the Third Law of
+Motion may be extended to all sorts of powers that take place in Nature,
+and belongs to attraction and repulsion of all kinds, and must not be
+considered as being arbitrarily introduced by Newton.
+
+The mutual action between any two bodies has, therefore, a double
+action. Thus a piece of stretched string must be conceived as pulling at
+both ends; the pull at the one end being exactly equal and opposite to
+the pull on the other end.
+
+A magnet will attract a piece of iron with a certain force, but it is
+equally true that the iron attracts the magnet with an exactly equal and
+opposite force. We might even extend the application of this Third Law
+to a falling stone in its relation to the earth. Thus, if a stone is
+dropped from a high altitude to the surface of the earth, although the
+motion seems to be all in one direction, yet if the Third Law holds
+good, then the earth is attracted by the stone in exactly an equal, but
+opposite direction, to that in which the earth attracts the stone.
+
+As, however, the mass of the earth is very great compared with that of
+the stone, it follows that the velocity of the stone compared with the
+velocity of the earth, must be very much greater, in order that the
+forces shall be equal.
+
+The application of this Third Rule of Motion to planetary and celestial
+phenomena is therefore philosophical, in that its conception agrees with
+experience and observation.
+
+Thus, while it is true that the sun attracts each of the planets in his
+system, it is equally true that the planets, in their turn, attract the
+sun with an exactly equal and opposite force. But the velocity of motion
+induced by the earth's attractive power upon the sun, would be less than
+the velocity of motion induced by the sun's attractive power upon the
+earth, although the two forces would be equal and opposite, simply
+because force, being a compound quantity, is dependent upon the mass of
+a body as well as upon its velocity.
+
+Not only, however, is it true that the sun and all the planets jointly
+attract each other, but it is equally true that the planets attract each
+other also, with an exactly equal and opposite effect. Indeed, as
+Gravitation is universal, it has to be conceived that there are no two
+bodies existing, but what the Third Law of Motion equally applies to
+those two bodies; so that equality of action and re-action is as
+universal as the Law of Gravitation itself.
+
+In coming to a conclusion with reference to Philosophy and the Laws of
+Motion, I wish to say that I am strongly of the opinion that the day has
+come, or will soon come, when they will pass away and give place to a
+more direct and simple method of working of the great Law of
+Gravitation. I look upon the Laws of Motion as part of the scaffolding
+which has been used to build up the Law of Gravitation. That Law has now
+been erected, and stands firm and secure in its position in the
+universe. Whatever changes may take place in its scaffolding, the Law
+itself will stand out with greater beauty and clearness, if we could but
+see the perfected structure, apart from the props and helps which have
+assisted in its successful erection and completion. As Dr. Larmor said,
+in his address to the British Association, 1900: "There has even
+appeared a disposition to consider that the Newtonian principles, which
+have formed the basis of physical phenomena for nearly two centuries,
+must be replaced in these deeper subjects by a method of more direct
+description of the cause of the phenomena. The question has arisen, as
+to how far the new methods of aetherial physics are to be considered as
+an independent departure; or how far they form the natural development
+of existing dynamical science."
+
+I hope, therefore, to be able in this work to do something towards
+clearing the completed Law from some of the outside props, which have
+long hidden the simplicity, beauty and harmony of the physical working
+of Gravitation from the eyes of those who feign would see its wonderful
+mechanism.
+
+In the elaboration and development, therefore, of the physical cause of
+Gravitation, it will be necessary to conceive a medium, whose properties
+and motions shall be able to account for all the movements of the
+planets, comets, suns and stars that the Laws of Motion now account for.
+Instead, however, of there being several Laws purely and simply
+mathematical in their application, there will be one physical medium,
+which will by its properties and motions account for--and that in a
+satisfactory manner--all the motions of the heavenly bodies. That such a
+medium is required in the scientific world is proved by the statement
+made by Professor Glazebrook, in his work on J. C. Maxwell, page 221,
+where he says: "We are still waiting for some one to give us a theory of
+the Aether, which shall include the facts of electricity and magnetism,
+luminous radiation, and it may be Gravitation."
+
+
+ART. 17. _Summary of the Chapter._--In summing up the contents of this
+chapter, we find therefrom, that there is a Universal Law in existence
+that is known as the Law of Gravitation. The physical cause of this Law,
+however, is unknown; Newton suggesting that it was due to the properties
+of an aetherial medium that pervaded the universe.
+
+To form a right conception of this medium, and to develop the hypotheses
+of the same on strictly philosophical lines, it is essential for us to
+know the rules which govern the making of any hypothesis.
+
+Those rules, according to Newton, and other philosophers, are chiefly
+three in number, and form the very essence of any philosophical
+reasoning. Any departure from those rules will entail partial or entire
+failure in the success of the undertaking.
+
+The application of Newton's rules to parts of the great Law of
+Gravitation show that some of those parts are not fully in harmony with
+the rules which Newton laid down in his _Principia_.
+
+Any physical theory that may be hereafter suggested as the physical
+basis for the Law of Gravitation, must itself not only account for the
+various forces already referred to, but must itself fulfil the Rules of
+Philosophy laid down by Newton. That is to say, the conception of the
+physical medium must be simple in character, its properties and motions
+must agree with all our experience, as given by observation, and
+experiments; and the properties and motions postulated for it must
+satisfactorily account for, and explain all the phenomena that are
+presented to us by the Universal Law of Gravitation.
+
+If all this be done, then from the standpoint of strict philosophical
+reasoning, the physical medium so suggested, and the theory so made,
+will be incapable of being overthrown or disproved.
+
+
+
+
+                              CHAPTER II
+
+                       PHILOSOPHY OF GRAVITATION
+
+
+ART. 18. _Gravitation Attraction._--The Law of Gravitation being a
+compound law, and not a simple law (Art. 8), it is necessary that the
+principles which govern universal attraction should now be considered.
+
+The law which governs Gravitation Attraction may be defined as follows:
+Every particle of matter in the universe attracts every other particle
+with a force whose direction is that of a line joining the centre of
+their masses, whose magnitude is directly as the product of their
+masses, and inversely as the square of the distance between them.
+
+This may be divided into four parts.
+
+    (1) The Universality of Gravitation.
+    (2) The Direction of the Forces involved.
+    (3) The Proportion of these Forces.
+    (4) The Law of Inverse Squares.
+
+The theory of the Aether, therefore, which will be perfected in this
+work, must not only satisfactorily account for the Attraction of
+Gravitation on a strictly philosophical basis, but the laws, governing
+the pressures or tensions of that physical medium, must harmonize with
+each of the parts of the complex Law of Gravitation into which it has
+been resolved.
+
+
+ART. 19. _Universality of the Attractive Force._--The principle upon
+which Universal Attraction rests is found in the words: "Every particle
+of matter in the universe attracts every other particle." It must,
+however, be admitted that this statement has never actually been proved.
+The smallest body that Newton used to prove his Law of Attraction was
+our satellite the moon.
+
+Cavendish, however, in 1798, by a series of experiments, conclusively
+demonstrated that the force of Gravitation existed in small bodies. He
+took two small leaden balls of a certain weight, and fixed them at the
+ends of a rod about six feet long, the rod being suspended by a piece of
+wire in the air. Large leaden balls were then brought near the small
+ones, and great care was taken to see if there were any twist in the
+wire by which they were suspended. It was found that the wire had become
+twisted on the approach of the large leaden balls, and thus he was able
+to prove that every particle of the attracted and attracting body are
+mutually concerned in the Attraction of Gravitation. There is abundant
+evidence of the application of this force in relation to our earth, as
+we shall see later on.
+
+The universality of the Attraction of Gravitation is a fact that has
+been proved in a thousand ways, and a thousand times. All stars and
+suns, and all planets, satellites and comets and nebulae are subject to
+this universal law. Astronomy teaches us that its power extends across
+the vast abysses of space, and that stars situated at distances that
+cannot possibly be measured, are subject to this world-wide law. Some of
+the greatest discoveries in astronomical science were due to the
+operations of this wonderful law, the gravitating influences of certain
+planets indicating their existence, although their discovery had not yet
+been made.
+
+The discovery of Neptune through the mathematical calculations of Le
+Verrier and Mr. Adams in 1846 was the crowning proof of the Law of
+Gravitation. Mr. Adams in England had noticed that the planet Uranus was
+being pulled out of the course by some unknown power, and so set to work
+to calculate the position of the body which thus influenced the motion
+of Uranus in its orbit. He located the position of the supposed
+influencing body strictly by mathematical calculations, and then took
+his results to the Astronomer Royal. Delay, however, occurred in the
+search for the supposed new planet, and nothing was done further in the
+matter for many months. Meanwhile Le Verrier in France, unknown to Mr.
+Adams, had been making similar calculations with reference to the
+perturbations of Uranus, and had arrived at similar results.
+
+These results were sent to the Berlin astronomers, and the heavens were
+searched for the supposed new planet. After a time, the planet was
+discovered in that part of the heavens indicated by Le Verrier, and for
+a time his name stood out as the sole discoverer. Gradually, however,
+the claims of Adams were admitted and recognized, and to-day his claims
+to participate in the honour of the wonderful achievement are generally
+admitted. Thus the discovery of Neptune gave to the Law of Gravitation a
+stability and proof that perhaps it had never received before.
+
+Further evidence of the existence of the universality of the attractive
+force, is to be found in a certain system of stars known as binary
+stars, which revolve around each other, while they gravitate around a
+common centre. Recent researches in astronomy only seek more and more to
+confirm the universality and effectiveness of this grand law, that seems
+to hold the entire universe in its sway.
+
+Any medium, therefore, which is postulated as the physical cause of
+Gravitation, must itself be as universal as Gravitation, in order for it
+to be able to fulfil this condition of universality. We shall find, as
+we proceed, that the only possible medium which can fulfil this
+condition, is the universal Aether, whose qualities and properties are
+already partly known and partly understood.
+
+
+ART. 20. _Direction of the Forces._--The attraction of Gravitation is
+always directed along the straight line which joins the centres of
+masses of the attracting and attracted bodies. Thus, if the earth and
+moon are taken as examples, an imaginary straight line drawn from the
+centre of the earth's mass to the centre of the mass of the moon would
+be the direction in which the gravitative force would be exerted. Now a
+line which joins the central body to its satellite we shall see when we
+come to deal with Kepler's Laws is known as the Radius Vector. Thus the
+path of the attraction between the two bodies is along the Radius
+Vector. It is a singular coincidence that the path of a ray of light
+from the sun also coincides with the Radius Vector, as it is one of the
+laws of light that the path of a ray always follows a straight line.
+
+It must not, however, be assumed, that while the attractive power is
+being exerted along any one straight line joining the centres of two
+bodies, therefore the attractive power is not operative in relation to
+any other part of the space, around the body. If our earth, for example,
+had four moons instead of one, and they were each in different positions
+in relation to the earth, then the law as to the direction of the forces
+would still hold good. We have examples of this in the case of Jupiter
+with his five moons, and Saturn with his eight moons. So that the
+attractive force of Gravitation is again like light, it operates on all
+sides equally at one and the same time. A lamp in the middle of a room
+sends its light waves on every side at one and the same time, so that
+while each ray has for its path a straight line, yet those rays are
+emitted equally on every side. In like manner, though the direction of
+the forces between two attracting bodies is that of a straight line, yet
+the law of universal attraction is equally exerted on every side of the
+planet at one and the same time.
+
+In the theory of the Aether, therefore, to be developed in this work, it
+will have to be demonstrated that the direction of the forces, which are
+originated and transmitted by that physical medium, must philosophically
+fulfil the conditions which govern the direction of the forces, as
+observed in gravitational phenomena.
+
+
+ART. 21. _Proportion of the Forces._--Newton proved that the attraction
+is proportional to the product of the masses of the bodies concerned.
+
+Hence it is that the sun, which is the centre of the solar system, is
+capable of attracting the most remote planets, because the mass of the
+sun is greater than the mass of all the planets put together. Or take
+another illustration. Suppose that the sun and the earth are at equal
+distances from Saturn. Now the sun's mass is about 300,000 times that of
+our earth. Therefore if the earth draws Saturn through a certain
+distance in one second, the sun would draw Saturn through a distance
+which is 300,000 greater than the earth in the same period.
+
+The governing principle, therefore, which decides the proportion of the
+attractive forces between two bodies is mass, and not simply density or
+volume. The mass of a body is a property which remains the same, as long
+as the inertia of the body remains constant. Mass is really a measure of
+the inertia of a body, or that property of a body by which it continues
+in its state of motion or of rest.
+
+Mass is therefore a compound quantity, being equal to volume multiplied
+by density, so that if the volume of any body is halved, the density is
+doubled. Thus, the proportion of the attractive force between any two
+bodies ever remains the same, so long as the masses of the two bodies
+remain the same. Through all the changes of volume and density of any
+body, its attractive force remains constant, as long as the mass remains
+constant; for the simple reason, that as the volume of a body is
+increased, the density is proportionately decreased; or, as the volume
+is decreased, the density is increased.
+
+For example, the volume of the sun as compared with the volume of the
+earth, is about 1,300,000 times greater, but the proportion of the
+attractive forces between the two bodies, is about 324,000 to 1. This
+difference is accounted for by the fact, that the density of the sun is
+about one quarter the mean density of the earth, hence their masses are
+in the proportion of 324,000 to 1. Thus the proportion of the attractive
+forces between any two bodies is dependent upon their masses, and not
+simply upon their volume or density.
+
+
+ART. 22. _Law of Inverse Squares._--The Law of Inverse Squares which is
+applicable to Gravitation is equally true of Sound, Light, Heat and
+Electricity, the Law being that Gravitation acts inversely as the square
+of distance. That is to say, if the distance of any body from the sun,
+for example, be doubled, then the force of Gravitation is diminished to
+one quarter of the intensity which would be exerted on the body in the
+first position.
+
+Thus the further a body is from its controlling centre, the weaker the
+Attraction of Gravitation upon it becomes. Taking therefore Mercury and
+the earth as examples, we find that their mean distances are
+respectively 35,000,000 miles and 92,000,000, which is a proportion of
+about 1 to 2-1/2. So that the intensity of the sun's attraction on the
+earth is about four-twenty-fifths of what it is on Mercury, that being
+the inverse square of the relative distances of the two bodies.
+
+Now the intensity of Light and Heat received by the earth is regulated
+by the same law of inverse squares, so that the earth would receive
+about four-twenty-fifths the intensity of light and heat which Mercury
+receives when they are both at their mean distances.
+
+This law of inverse squares is applicable to every body which acts as a
+gravitating source throughout the whole of the universe, whether that
+body be small or large, and whether it be in the form of meteor,
+satellite, planet, sun or star.
+
+Each satellite, planet or sun exerts an attractive influence upon every
+body that exists, that attractive influence being regulated by the
+masses of the respective bodies, and decreasing inversely as the square
+of the distance from the body viewed as the centre of attraction. So
+that, the further the attracted body is from the attracting body, the
+less is the intensity of the mutual attracting forces, though that
+intensity does not vary simply as the distance, but rather as the square
+of the distance, and that in its inverse ratio. Thus if we take two
+masses of any kind or sort, and place them at various distances as
+represented by the numbers 1, 2, 3, 4, 5, 6, the intensity of the
+attracting forces between the same masses at the relative distances will
+be represented by the numbers 1, 1/4, 1/9, 1/16, 1/25, 1/36, which are
+the inverse squares of the respective numbers representing their
+distances. As we shall see, the same law holds good in relation to heat,
+light and electricity, and indeed to all forms of energy which radiate
+out from a centre equally in all directions.
+
+There is no need to apply Newton's Rules of Philosophy to this
+Attraction of Gravitation, as it has been demonstrated to exist, times
+without number. Moreover its laws are exactly the same as those
+governing the phenomena of sound, light, heat, and electricity, so that
+apart from being proved by actual experiments in relation to the gravity
+of the earth, we have a wider experience of the application of the same
+ruling principles of the law in other departments of science.
+
+The Law of Universal Attraction, which is strictly the Centripetal Force
+of the compound Law of Gravitation, fully satisfies the three governing
+rules of Newton's Philosophy. Not only is it simple in its conception,
+but it is borne out by experience, and adequately accounts for the
+distinctive phenomena which it seeks to explain. By it, astronomical
+observations can be taken with a precision and certainty that defy error
+or failure. The motion of a planet in its orbit can be so perfectly
+calculated, that its position in space in relation to other planets can
+be foretold years in advance. The theory of the Aether, therefore, which
+is to be perfected in this work, must philosophically show that the
+pressures or tensions of that medium, which are postulated as the cause
+of Gravitation Attraction, must themselves fulfil the laws of inverse
+squares, which govern light, heat, electricity and the Attraction of
+Gravitation. I premise that this will be done in the theory of the
+Aether to be submitted to the reader in the after pages of this work.
+
+
+ART. 23. _Terrestrial Gravity._--Before passing from this phase of the
+subject, I should like briefly to look at the question of the Attraction
+of Gravitation from the standpoint of our own earth, as by so doing we
+shall notice some facts regarding the same, hitherto unnoticed, in the
+preceding articles.
+
+Terrestrial Gravity is but a phase of Universal Gravitation. One of the
+most familiar facts and phenomena of everyday life is, that when a body,
+such as a stone or stick or bullet, is thrown or projected into the air,
+it always falls to the earth again. This is due to the attraction of the
+earth and the stone for each other. It has been proved experimentally
+that if a stone and a weight are let fall from a height of 16 feet, they
+would reach the earth in one second of time. Again, a feather, or cork,
+or even a piece of iron would take exactly the same time falling through
+the same space, provided that the feather or cork could be screened from
+the resistance of the air.
+
+The distance, however, through which a body falls in one second varies
+at different parts of the earth's surface, being least at the equator,
+and greatest at the North and South Poles. This is accounted for by the
+fact that the polar diameter is only 7899 miles, while the equatorial
+diameter is 7925 miles, thus the distance from the centre of the earth
+to either pole is about 3950 miles, or 13 miles less than the equatorial
+radius of the earth. Now the force of gravity decreases upwards from the
+earth's surface inversely as the square of the distance from the earth's
+centre of gravity, but decreases downwards simply as the distance from
+the centre decreases. Thus if a ball were taken down 2000 miles, that is
+half the distance to the centre, it would only weigh half-a-pound, while
+if it were taken to the centre of the earth, it would have no weight at
+all; while a pound weight at the equator would not weigh one pound at
+the poles, because it would be nearer the centre of the earth by 13
+miles.
+
+Thus a pound weight is not always a pound weight. It varies as we carry
+it to different parts of the earth's surface, depending upon its
+relation to the centre of the earth for its exact weight. The point
+which I wish to make perfectly clear, as it will be necessary for future
+reference, is, that there is no such thing as weight apart from the
+gravity of the earth; or, if we apply the principle to the solar system,
+there is no gravitating force in that system apart from the gravitating
+force of the central body, the sun, or the planets and other bodies
+which form the solar system.
+
+Let us look at this matter from another standpoint, in order to prove
+this truth and make the same perfectly clear. If a pound weight were put
+in a spring-balance, then at the surface of the earth it would weigh one
+pound. Now, we will suppose that we have taken the weight to a height of
+4000 miles above the surface of the earth, that is exactly double the
+distance from the centre of the earth, the radius of the earth being
+approximately 4000 miles. According to the law of inverse squares, the
+force of Gravitation decreases inversely as the square of the distance.
+The distance having been doubled, the proportion of the forces at the
+two places, _i. e._ the earth's surface and 4000 miles above it, are as
+1 to 1/4.
+
+Thus at a distance of 4000 miles the weight which weighed one pound at
+the earth's surface, now only weighs a quarter of a pound. At a distance
+of 8000 miles, the distance would be trebled, therefore the force of
+Gravitation is one-ninth, and the weight would weigh one-ninth of a
+pound. If we could take the pound weight to the moon, the attractive
+force of the earth would be reduced to 1-3600, as the moon is 240,000
+miles distant, that is sixty times the earth's radius. The square of 60
+is 3600, and if we invert that we get 1-3600, so that the weight which
+weighs a pound at the earth's surface, would only weigh 1-3600 part of a
+pound at the distance of the moon. This again proves, that apart from
+the Attraction of Gravitation, there is no such thing as weight, and
+that the weight so called of any body, such as a planet or satellite,
+increases or decreases as its distance increases or decreases from its
+central attracting body.
+
+
+ART. 24. _Centrifugal Force._--I have already shown in Art. 10 that
+the Centripetal Force and Universal Attraction are one and the same; as
+the Centripetal Force always acts towards the centre, and must therefore
+be in its operation and influence a gravitating or attractive power.
+
+I have also pointed out in the same article, the necessity of another
+force, which is to be the complement, and the counter part of
+Gravitation Attraction. That complement and counter force was conceived
+by Newton, and called by him the Centrifugal Force. The very nature of
+the Centripetal Force demands and necessitates a force which in its mode
+of operation is exactly the opposite of the Centripetal Force. Unless
+there were such a force, a repellent and repulsive force, then instead
+of there being that harmonious working of the universe that now exists,
+there must inevitably be a gradual drawing together of all planets and
+satellites, of all stars and suns, into one vast, solitary, and ruinous
+body.
+
+There are also other phenomena which demand a Centrifugal Force in the
+universe. It is a well-known fact, that there exist between the orbits
+of Jupiter and Mars, what are called planetoids, about 500 in number,
+which are supposed to be the remnants of a broken or shattered world. As
+may be expected from such an accumulation, they present the most
+extraordinary diversities and eccentricities in the orbits that can
+possibly be conceived. They are of all shapes and sizes, and besides
+their orbits round the sun, have orbits among themselves. They are so
+clustered together that their orbits intersect each other at numerous
+points, and when in conjunction are said to suffer great perturbations,
+being pulled great distances this way and that by each other's
+attractive influence. It is further stated that their orbits so
+intersect each other, that if they were imagined to be material rings,
+they would be inseparable, and the whole could be suspended by taking
+any one of them up at random. Here, then, is presented to us a kind or
+order of celestial phenomena for whose well-being and effectual working
+the Centripetal Force or the Attraction of Gravitation cannot possibly
+account. In their case another force is demanded which shall be the
+exact complement and counterpart of the Centripetal Force. There needs
+therefore a force, not an imagined one, simply conceived to fill a want,
+but a real Force, as real and as plainly to be understood as the
+Centripetal Force. A force existing in each world just like the
+Attraction of Gravitation, only the reverse of Gravitation, a repellent,
+repulsive Force, acting in the reverse mode, and way, to universal
+attraction. This Force must be governed by the same rules and laws that
+govern the Centripetal Force, if it is to work in harmony with the same.
+It must be universal in its character, having a proportion of forces
+equal to the product of the masses of the two bodies which are
+concerned, and its path must coincide with the path of gravitational
+attraction, that is, in the straight line which joins the centres of
+gravity of the two bodies. Further, and what is perhaps the most
+important of all, it must act as a repelling or repulsive force which
+shall be in the same proportion in regard to distance, as the law
+governing Centripetal Force, that is, inversely as the square of the
+distance.
+
+Again, and briefly, there are also in existence small bodies called
+meteors, which are said to exist by myriads, which float in space, and
+circle round the sun. They are of all shapes and sizes, from one ounce
+to a ton or even tons, thousands of them coming into contact with our
+earth's atmosphere every year, especially in August and November. All of
+these small bodies have orbits among themselves, and gravitate round one
+another, as they revolve round the sun. Now if the orbits of the
+planetoids be such an entangled mass, what must be the orbits of these
+meteors? What an indescribable, unimaginable mass of labyrinthian
+motions must exist among these myriads of little bodies! How they must
+intersect, cross and intermingle each other's orbits! What attraction
+and counter-attraction they must exert upon each other! Let me ask any
+man to sit down and try to imagine how the present recognized
+Centripetal and Centrifugal Forces can account for the effectual working
+of these meteors. As illustrating the necessity of a real and physical
+Centrifugal Force which is to be the exact counterpart of the
+Centripetal Force, I would call the attention of the reader to
+Herschel's view of this matter. In dealing with the phenomena of comets'
+tails he writes:[1] "Beyond a doubt, the widest and most interesting
+prospect of future discovery, which this study holds out to us, is, that
+distinction between gravitating and levitating matter, that positive and
+irrefutable demonstration in nature of a repulsive force, co-extensive
+with, but enormously more powerful than the attractive force we call
+gravity which the phenomena of their tails afford." I premise that this
+prophecy of Herschel's will be fully demonstrated and proved in the
+succeeding pages of this work. For, in the theory of the Aether that is
+to be afterwards perfected, it will be philosophically proved that the
+physical medium so conceived will satisfactorily account for a force or
+motion from the centre of all bodies; which motions fulfil all the
+conditions required by that Centrifugal Force, which is the complement
+and counterpart of the Attraction of Gravitation. At the present time,
+with the conception of a frictionless Aether, it is impossible to
+harmonize the existence of such a force or motion with our theory of the
+Aether. Yet Professor Lebedew of Moscow, and Nichols and Hull of
+America, have incontrovertibly demonstrated by actual experiments the
+existence of such a force. Therefore it follows, that if our present
+theory of the Aether fails to agree with experimental evidence, such a
+theory must be reconstructed in order that our philosophy may be made to
+agree with our experiments and our experience.
+
+[Footnote 1: _Lectures on Scientific Subjects._]
+
+
+ART. 25. _Kepler's Laws._--A long time before Newton had discovered the
+Law of Gravitation, Kepler had found out that the motions of the planets
+were governed by certain laws, and these came to be known as Kepler's
+Laws.
+
+These laws which were given to the world by Kepler, simply represented
+facts or phenomena which had been discovered by observation, as Kepler
+was unable to account for them, or to give any mathematical basis for
+the same.
+
+On the discovery, however, of Universal Gravitation, Newton saw at once
+that these laws were simply the outcome of the application of the Law of
+Gravitation to the planets, and that they could be accounted for on a
+mathematical basis by the Law of Gravitation, as they seemed to flow
+naturally from that law.
+
+Kepler's Laws are three in number and may be thus stated--
+
+_1st Law._ Each planet revolves round the sun in an elliptic orbit, with
+the sun occupying one of the Foci.
+
+_2nd Law._ In the revolution of a planet round the sun, the Radius Vector
+describes equal areas in equal times.
+
+_3rd Law._ The squares of the periodic times of planets are proportional
+to the cubes of their mean distances.
+
+Now the question arises, whether it is possible to form a theory of the
+Aether which shall satisfactorily and philosophically account for all
+the phenomena associated with Kepler's Laws in their relation to the
+motions of planets, satellites, or other solar bodies? On the present
+conception of the Aether such a result is an absolute impossibility.
+With the theory of the Aether, however, to be submitted to the reader in
+this work, the result is possible and attainable. If, therefore, such a
+result is philosophically proved, as I submit will be done, then we
+shall have greater evidence still that the theory so propounded is a
+more perfect theory than the one at present recognized by scientists
+generally.
+
+
+ART. 26. _Kepler's First Law._--Each planet revolves round the sun in an
+elliptic orbit, the sun occupying one of the Foci.
+
+The ancients thought that the paths of the planets around the sun were
+circular in form, because they held that circular motion was perfect. A
+system of circular orbits for the paths of the planets round the sun
+would be very simple in its conception, and would be full of beauty and
+harmony. But exact calculations reveal to us that the path of a planet
+is not exactly that of a circle, as the distance of a planet from the
+sun in various parts of its orbit is sometimes greater, and sometimes
+less, than its mean distance.
+
+The planet Venus has the nearest approach to a circular orbit, as there
+are only 500,000 miles between the mean, and greatest and least
+distances, but both Mercury and Mars show great differences between
+their greatest and least distances from the sun.
+
+If, therefore, the orbits of a planet are not exactly circular, what is
+their exact shape? Kepler solved this problem, and proved that the exact
+path of a planet round its central body the sun was that of an ellipse,
+or an elongated circle. Thus he gave to the world the first of his
+famous laws which stated that each planet revolves round the sun in an
+orbit which has an elliptic form, the sun occupying one of the Foci.
+
+Not only is the orbit of a planet round the sun elliptic in form, but
+the path of the moon round the earth, or the path of any satellite, as
+for example a satellite of Mars or Jupiter or Saturn, is also that of an
+ellipse, the planet round which it revolves occupying one of the Foci.
+
+It has also been found that certain comets have orbits which cannot be
+distinguished from that of an elongated ellipse, the sun occupying one
+of the Foci.
+
+Now let us apply the Law of Gravitation to Kepler's First Law, and note
+carefully its application.
+
+[Illustration: Fig: 1.]
+
+Let _A_, _B_, _C_, _D_ be an ellipse representing the orbit of the earth,
+and let _S_ represent the sun situated at one of the Foci.
+
+We will suppose that the earth is projected into space at the point _A_,
+then according to the First Law of Motion, it would proceed in a
+straight line in the direction of _A_ _E_, if there were no other force
+acting upon the earth. But it is acted upon by the attraction of the
+sun, that is the Centripetal Force which is exerted along the straight
+line _S_ _A_ (Art. 20), which continues to act upon it according to the
+principle already explained in Arts. 21 and 22.
+
+Now, according to the Second Law of Motion and the Parallelogram of
+Forces, instead of the earth going off at a tangent in the direction of
+_A_ _E_, it will take a mean path in the direction of _A_ _B_, its path
+being curved instead of being a straight line.
+
+If the sun were stationary in space, then the mean distance, that is,
+the length of the imaginary straight line joining the sun _S_ _A_ to the
+earth, would remain unaltered. The Radius Vector _S_ _A_, or the
+straight line referred to, would then be perpendicular to the tangent,
+and the velocity of the earth round the sun would be uniform, its path
+being that of a circle.
+
+The Radius Vector _S_ _A_, however, is not always perpendicular to the
+tangent _F_ _E_, and therefore the velocity of the earth is not always
+uniform in its motion in its orbit, as sometimes it travels at a lesser
+or greater speed than its average speed, which is about 18 miles per
+second.
+
+It has to be remembered that the sun itself is in motion, having a
+velocity through space of about 4-1/2 miles per second, so that, while
+the earth is travelling from _A_ to _B_ the sun is also travelling in
+the direction of _S_ _B_. Thus the orbital velocity of the earth, and the
+orbital velocity of the sun, together with the Centripetal Force or
+universal Gravitation Attraction, are all acting in the same direction
+when the earth is travelling from _A_ to _B_, that is, in the direction
+of the orbit situated at _B_. This point of the orbit is known as the
+perihelion, and at that point the velocity of the earth is at its
+greatest, because the earth is then nearest the sun.
+
+According to Newton, the planet when at _B_ would still have a tendency
+to fly off into space owing to its Centrifugal Force, but it is held in
+check by the Centripetal Force, so that instead of it flying off into
+space, it is whirled round and starts off on its journey away from the
+sun in the direction of _B_, _C_. The sun, however, is still continuing
+its journey in the direction of _S_, _H_, so that not only is the
+increased orbital velocity of the earth, which it obtained at its
+perihelion, urging the earth away from the sun, but the sun itself in
+its advance through space is leaving the earth behind it. The combined
+effect of the two motions, the advancing motion of the sun, and the
+receding motion of the earth, due to its increased orbital velocity,
+drives the earth towards the aphelion, where its distance from the sun
+is greatest, and its orbital velocity is the least.
+
+By the time the planet has arrived at point _C_, its motion through
+space has gradually decreased, and the Centripetal Force begins to
+re-assert itself, with the result that the earth is slowly made to
+proceed towards the point _D_ of the ellipse, at which point its motion
+is the slowest in orbital velocity, only travelling about 16 miles per
+second, while the distance of the earth from the sun is the greatest and
+has increased from 91,000,000 miles at the perihelion to 94,500,000.
+This point of the orbit is known as its aphelion.
+
+After rounding this point, the orbital velocity of the earth begins to
+increase again, owing to the diminishing distance of the earth from the
+sun, which according to the law of inverse squares (Art. 22) gives an
+added intensity to the Centripetal Force.
+
+Thus by the combination of the Laws of Motion and the Law of Gravitation
+discovered by Newton, he was able to satisfactorily account for and
+explain on a mathematical basis, the reason why the earth and all the
+other planets move round the sun in elliptic orbits, according to
+Kepler's First Law.
+
+In the development of the physical cause of gravitation, therefore, the
+same physical medium, which accounts for that law, must also give a
+satisfactory explanation of the first of Kepler's Laws.
+
+
+ART. 27. _Kepler's Second Law._--This law states that the Radius Vector
+describes equal areas in equal times. The Radius Vector is the imaginary
+straight line joining the centres of the sun and the earth or planet.
+While the First Law shows us the kind of path which a planet takes in
+revolving round the sun, the Second Law describes how the velocity of
+the planet varies in different parts of its orbit.
+
+If the earth's orbit were a circle, it can be readily seen that equal
+areas would be traversed in equal times, as the distance from the sun
+would always be the same, so that the Radius Vector being of uniform
+length, the rate of motion would be uniform, and consequently equal
+areas would be traversed in equal times. Take as an illustration the
+earth, which describes its revolution round the sun in 365-1/4 days. Now
+if the orbit of the earth were circular, then equal parts of the earth's
+orbit would be traversed by the Radius Vector in equal times. So that
+with a perfectly circular orbit, one half of the orbit would be
+traversed by the Radius Vector in half a year, one quarter in one
+quarter of a year, one-eighth in one-eighth of a year, and so on; the
+area covered by the Radius Vector being always exactly proportionate to
+the time.
+
+From Kepler's First Law, however, we know that the planet's distance
+does vary from the sun, and therefore the Radius Vector is sometimes
+longer and sometimes shorter than when the earth is at its mean
+distance; the Radius Vector being shortest at the perihelion of the
+orbit, and longest at the aphelion. We learn from Kepler's Second Law
+that when the Radius Vector is shortest, that is, when the planet is
+nearest the sun, it acquires its greatest orbital velocity; and when the
+Radius Vector is longest, that is, when the planet is farthest from the
+sun, the orbital velocity of a planet is the slowest.
+
+Let _A_, _B_, _D_, _C_ represent the elliptic orbit of a planet, with
+_S_ sun at one of the Foci, and let the triangles _A_, _S_, _B_ and _D_,
+_S_, _C_ be triangles of equal area. Then, according to Kepler's Second
+Law, the time taken for the Radius Vector to traverse the area _A_, _S_,
+_B_ is equal to the time that the Radius Vector takes to traverse the
+area _D_, _S_, _C_. So that the planet would take an equal time in going
+from _A_ to _B_ of its orbit, as it would take in going from _D_ to _C_.
+Thus the nearer the planet is to the sun, the greater is its orbital
+velocity, and the farther it is away from the sun the slower is its
+velocity, the velocity being regulated by the distance. The manner in
+which the difference of velocity is accounted for by the Law of
+Gravitation has already been explained in the preceding article. Thus
+Newton proved that Kepler's Second Law was capable of being
+mathematically explained, and accounted for, by the universal Law of
+Gravitation.
+
+[Illustration: Fig: 2.]
+
+If, therefore, a physical cause can be given for Newton's Law of
+Gravitation, then such physical cause must also be able to account for,
+and that on a strictly philosophical basis, the second of Kepler's Laws
+as well as the first.
+
+
+ART. 28. _Kepler's Third Law._--The Third Law of Kepler gives the
+relation between the periodic time of a planet, and its distance from
+the sun. The periodic time of any planet is the time which it takes to
+go once round the sun. Thus the periodic time of the earth is 365-1/4
+days. The periodic time of Venus is 224.7 days, while that of Mars is
+686.9 days.
+
+Kepler had found out that different planets had different periodic
+times; he also found out that the greater the mean distance of the
+planet, the greater was the time which the planet took to perform its
+journey round the sun, and so he set to work to find out the
+relationship of the periodic time to the planet's mean distance.
+
+After many trials and many failures he arrived at the right conclusion,
+and at last discovered the true law which is known as Kepler's Third
+Law, which states that for each and every planet, the squares of their
+periodic times are proportional to the cubes of their mean distances.
+
+For purposes of illustration let us take the earth and the planet Venus
+and compare these two. The periodic time of the earth is 365 days,
+omitting the quarter day. The periodic time of Venus is 224 days
+approximately. Now, according to Kepler's Third Law, the square of 365
+is to the square of 224, as the cube of the earth's mean distance is to
+the cube of Venus's mean distance, which are 92.7 millions of miles and
+67 millions of miles respectively. The problem may be thus stated--
+
+As 365^2: 224^2:: 92.7^3: 67^3:
+
+This worked out gives--
+
+133,225: 50,176: 796,597.982: cube of Venus's mean distance.
+
+So that by Kepler's Third Law, if we have the periodic time of any two
+planets, and the mean distance of either, we can find out the mean
+distance of the other by simple proportion.
+
+In making astronomical calculations, the distances of the planets are
+generally obtained by means of Kepler's Third Law, as the periodic time
+of the planet is a calculation that may be made by astronomers with
+great certainty, and when once the periodic times are found, and the
+mean distance of a planet, as our earth for example, is known, the mean
+distances of all the other planets in the solar system may soon be
+obtained.
+
+In like manner this Third Law of Kepler's is equally applicable to the
+satellites of any planet. For example, when the periodic time of both of
+Mars' satellites, Phobos and Deimos, are known, being about 8 hours and
+30 hours respectively, and the distance of either is known, as Phobos
+with a mean distance of 5800 miles, then the mean distance of Deimos can
+easily be calculated by this law, and is found to be 14,500 miles.
+
+As discovered by Kepler, the Third Law was simply the result of
+observation. He was unable to give any mathematical basis for its
+existence. The Laws as they were given to the world by Kepler were
+simply three great truths which had been discovered by observation. It
+rested with Newton to show how these laws could be accounted for on a
+mathematical basis, and to show how they all sprang from one and the
+same source, namely the universal Law of Gravitation. In his
+_Principia_, he proved that all Kepler's Laws were fully expounded and
+explained by his great discovery of Universal Gravitation.
+
+Now what Newton has done for Kepler's Laws from the mathematical
+standpoint, we propose to do from the physical standpoint. In the
+development of the physical agency or cause of Gravitation, therefore,
+among the phenomena and laws, which have to be satisfactorily accounted
+for on a physical basis, are these three Laws of Kepler's just referred
+to.
+
+So that in addition to the satisfactory explanation of a physical cause
+for the Laws of Motion, and the Centripetal and Centrifugal Forces, the
+hypothesis of a physical cause of Gravitation must fully and
+satisfactorily account for the Laws of Kepler, whose mathematical
+explanation was given by Newton.
+
+Further, and what is as equally important, the explanation so given must
+be strictly in harmony with the Rules of Philosophy as laid down in Art.
+3. That is, the explanation must be simple in character, must not be
+contrary to experience or observation, and must satisfactorily account
+for the laws which the hypothesis of the physical cause of Gravitation
+seeks to explain. This I premise we will do as we pass from stage to
+stage in the development of the theory.
+
+I can safely premise that it will be simple in character and conception,
+that it will be entirely in harmony with all experience and observation,
+and that the physical cause so advanced will give as physical a basis to
+Kepler's Laws as Newton's mathematical calculations gave them a
+mathematical basis.
+
+In summing up, I need hardly point out, that if all that I have premised
+in this and the preceding chapter is accomplished in the after chapters
+of this book, then for the first time since the discovery of Universal
+Gravitation by Sir Isaac Newton, his great discovery will have received
+the long-expected and long-desired physical explanation, that
+explanation and cause being founded on his own Rules of Philosophy given
+in his immortal _Principia_, and for the first time our Philosophy will
+be brought strictly into harmony with our universal experience.
+
+
+
+
+                              CHAPTER III
+
+                                MATTER
+
+
+ART. 29. _What is Matter?_--The law of Universal Attraction states that
+"Every particle of matter attracts every other particle," etc., and the
+question at once arises as to what is meant by the term Matter, what are
+its properties and its constitution? Tait, in his _Natural Philosophy_,
+gives the following as the definition: "Matter is that which can be
+perceived by the senses, or is that which can be acted upon by, or can
+exert force."
+
+It has already been pointed out in Art. 13 that force is due to motion,
+and that wherever we get motion of any kind or sort, there we get
+energy, or what used to be termed force. The consideration of this phase
+of the question will be more fully dealt with in the chapter on Energy
+and Motion. Suffice to say, that all experience teaches us that force is
+the outcome of motion.
+
+Accepting this definition therefore of force, Tait's definition of
+matter will read thus, if brought up to date: "Matter is that which can
+be perceived by the senses, or is that which can be acted upon by
+motion, or which can exert motion."
+
+The common idea that matter can only be that which can be seen or
+actually felt, is not large enough for a definition of Matter. There are
+numbers of things in Nature which cannot either be seen or felt, yet
+which are included in the term Matter. Let us take one or two examples.
+Every one admits that nitrogen and oxygen are matter, yet I venture to
+say that no one has actually seen or felt either of these gases. Both of
+these gases are colourless and invisible, and are both tasteless. You
+may open your mouth and inspire both gases, and yet if they are pure,
+you cannot taste either of them. They are only matter, in the sense that
+they appeal to our sense of force through the motion which they may
+acquire.
+
+Or again, take air, which is a mechanical mixture of several gases. Can
+you see air? If it be free from vapour and smoke, air is invisible, and
+on a clear day you may look for miles across the sea, or from the top of
+a mountain, and yet not have your sight impeded in any way by the
+atmosphere. Neither can it be felt by the sense of touch. Open and shut
+your hand, and see if you can feel the air while you do so. In similar
+ways it may be demonstrated that the air is tasteless. So that it is not
+necessary for us to see, or feel, or taste, or even smell that which we
+term Matter, in order for it to be included in that term. So long as
+that which we term Matter is able to accept motion in any manner from
+any body that is either moving, or in a state of vibration, and not only
+accepts, but also transmits the vibratory, or the kinetic motion so
+called of the moving body, then that which accepts the motion is
+legitimately termed Matter.
+
+It becomes perfectly clear, therefore, why air, aether, oxygen, and
+hydrogen are termed Matter. Because they can be all acted upon by
+motion, and after being so acted upon, they can exert motion upon some
+other body. Heat is a form of motion, and when heat acts upon the air,
+the latter is set in motion, and we have what are commonly known as
+winds. It is unnecessary for me to prove that the motion of winds can be
+transmitted to other matter, as we have numerous examples from our
+observation and experience, in the case of windmills driven by the
+motive power of the winds, and also balloons urged along by the same
+cause; apart from the devastating effect produced in towns and country
+by a hurricane or storm.
+
+The point which I wish to emphasize is, that Matter, strictly defined,
+is that which can be acted upon by motion, such as heat or electricity,
+both being forms of motion, and which can exert the motion so derived
+upon some other body.
+
+Wherever, therefore, in the universe we find any body, whether it be
+solid, liquid or gaseous, or any medium which can be acted upon by
+motion, and after being so acted upon, can exert motion, that body or
+medium may legitimately be included in the term Matter, although it may
+be absolutely invisible to the eyes, or insensible to the sense of
+touch, or taste, or smell. In the same work,[2] Tait states that in the
+physical universe there are but two classes of things, "Matter and
+Energy," and then goes on to give examples of both. He adds that a
+stone, piece of brass, water, air, _aether_, are particles of matter,
+while springs, water-power, wind, waves, heat and electric currents are
+examples of energy associated with Matter.
+
+Now I may add here, that within these two statements is to be found the
+germ of the physical cause of Gravitation, together with the
+satisfactory explanation of all phenomena that the universe reveals to
+us, either by observation or by experiments. I purpose therefore, before
+giving any detailed accounts of that medium which is to form the
+physical basis for the cause of Gravitation, to look at the term Matter
+in all its aspects, in order that we may get a right conception of the
+universe, and of the part that Matter plays in the same.
+
+[Footnote 2: Tait, _Natural Philosophy_.]
+
+
+ART. 30. _Conservation of Matter._--The Theory of the Indestructibility
+of Matter was first introduced by Lavoisier in 1789. This theory may be
+thus summed up; that Matter which fills the universe is unchangeable in
+quantity, so that the total quantity ever remains the same. Changes may
+take place in regard to the state of the Matter, but the sum-total of
+Matter throughout all the changes remains unaltered. Thus when we burn
+coal, it is changed into carbonic acid by combination with the oxygen of
+the atmosphere; when sugar is put into water, it simply passes from the
+solid to the liquid condition. If a piece of iron or steel is allowed to
+rust, the surface of the iron has entered into combination with the
+oxygen and water of the atmosphere, and formed a new substance. So that
+a body may change from solid to liquid, as for example from ice to
+water, or from liquid to a gaseous condition, as from water to steam,
+and probably from a gaseous condition to an aetherial condition as we
+shall see later on, but the sum-total of Matter throughout all these
+changes ever remains the same. Thus, throughout all the physical and
+chemical changes that Matter may undergo in the universe, there is no
+actual loss in weight or quantity. Throughout the whole realm of Nature
+we do not find a single instance of the production of absolutely new
+Matter. We may, and can produce new combinations of the forms of Matter.
+The substance so formed by chemical combination may be different from
+anything that has ever been seen or produced before, but the elements of
+which it is formed must have existed in some other form before its
+production.
+
+This principle is the great underlying principle of all chemical
+investigation and research, and may be proved at any time by means of
+the scales or balance in the laboratory. Lavoisier first made the
+experiment with the scales and proved this truth by actual
+demonstration.
+
+
+ART. 31. _Matter is Atomic._--The hypothesis that Matter is made up of
+infinitely small particles which are termed atoms, was first proposed by
+the Grecian philosophers. This hypothesis has gradually taken definite
+shape, but it remained for Dalton to first put the hypothesis into a
+connected form, and that form is now known as Dalton's Atomic Theory.
+
+According to this theory, an atom of hydrogen was the lightest atom
+known, but comparatively recent researches by Sir W. Crookes have shown
+that there are possibly in existence minute particles which are even
+lighter than an atom of hydrogen. Thus Sir W. Crookes has suggested that
+there are certain particles associated with an atom of hydrogen which
+are 700 times less in weight than the atom itself.
+
+Professor J. J. Thompson has further suggested that if we could divide
+an atom into a thousand parts, and could take one of those parts, we
+should find that this corpuscle, as he has termed it, would be the
+carrier of the charges in an electric current, so that it will be seen
+that we are moving into the direction of the continuity of Matter. Let
+us now look at the question as to what is meant by an atom more fully.
+
+
+ART. 32. _What is an Atom?_--Clerk Maxwell's definition of an atom is,
+"a body that cannot be cut in two." An atom is the smallest part of a
+simple substance which can enter into combination with another element,
+and is incapable of being further subdivided.
+
+An atom of hydrogen is the smallest part of that particular gas which
+can enter into combination with any other element, as oxygen, to form a
+chemical compound as water, which is composed of two atoms of hydrogen
+and one of oxygen.
+
+Further, an atom of any kind or sort, retains its identity and remains
+the same throughout all chemical combinations or physical changes which
+it may undergo. By spectroscopic analysis, it has been ascertained, for
+example, that hydrogen exists in the sun and stars, and the conclusion
+is arrived at in connection therewith, that an atom of hydrogen in any
+sun or star is the same as an atom of hydrogen in our atmosphere, or in
+any of the compounds, as water, in which it is found. Thus it has come
+to be received as an accepted fact, that every atom of any substance, as
+oxygen, nitrogen, and hydrogen, whether they exist in the earth or sun,
+in meteorites or the farthest stars or nebulae, wherever they are found,
+possesses the same identity and the same physical properties.
+
+Atoms attract one another, and this atomic attraction is known as
+affinity. There is not the least possible doubt that affinity is a form
+of universal attraction, except that the affinity of atoms is selective.
+This affinity of atoms for each other gives rise to the combination of
+atoms known as molecules and chemical compounds.
+
+_Size of Atoms._--It has been computed by Lord Kelvin and others, that
+an atom may be as small as 1/50,000,000 of an inch in diameter, so that
+if 50,000,000 of them were put side by side, they would just measure one
+inch in length. Atoms are not all of the same size or weight. An atom of
+oxygen weighs 16 times as much as an atom of hydrogen. It has been
+proved by Kirchhoff and Bunsen, that the 3/1,000,000 part of a
+milligramme of sodium chloride is sufficient to give a yellow colour to
+a gas-jet. Faraday prepared some sheets of gold, so thin that he
+estimated they only measured the 1/100 part of the length of a
+light-wave. We have to remember that each sheet of gold must have
+contained molecules of gold composed of atoms. What must have been the
+size of the atoms therefore of which the sheet was composed?
+
+
+ART. 33. _The Atomic Theory._--The Atomic Theory was revived by Dalton
+in 1804, in order to account for the fact that elements unite in certain
+definite proportions. From that time to the present, the theory has
+grown and developed until at the present time it is looked upon as a
+well-established theory. It is, however, simply a theory, and from the
+very nature of the hypothesis is incapable of proof. No one has ever
+seen an atom of hydrogen or oxygen, or an atom of any solid, liquid, or
+gaseous matter. The Atomic Theory suggests, therefore, that there is a
+limit to the divisibility of matter. All chemical experiments lend
+support to the theory, and by it we are able to give an intelligible and
+easy method of expression to what would otherwise be difficult phenomena
+to explain.
+
+Ancient philosophers were divided on the question of the infinite
+divisibility of matter. The Epicureans were of the opinion that matter
+was incapable of infinite division, and that even if we were able to
+make the smallest possible division, it would be impossible for us to
+reach the smallest particle termed "Atom."
+
+
+ART. 34. _Kinds of Atoms._--Various forms of atoms have been conceived
+by philosophers from time to time, ranging from the Hard Atom, and the
+simple point-centres of Boscovitch, until we come to the more modern
+Vortex Atom of Lord Kelvin, or the Strain Atom of Dr. Larmor, which will
+be looked at separately. Democritus conceived a hard atom as long ago as
+500 B.C., while the notion of a hard atom is not absent from the works
+of Newton himself. We find that Newton suggested that the particles of
+air might be hard spherical bodies, at a distance from one another of
+about nine times their diameter.
+
+The hard atom, however, seems to be refuted by spectroscopic analysis,
+which reveals to us in a manner that has never been revealed before,
+something of the sizes and vibrations of atoms.
+
+From the phenomenon of heat, which is simply matter in motion, we feel
+compelled to accept the fact that an atom is not a hard particle, but
+that it is something which is more closely allied to the Vortex Atom, or
+the Strain Atom of Dr. Larmor.
+
+_Boscovitch Atom._--According to Boscovitch's theory, each atom is
+simply an indivisible point in space capable of motion, and possessing a
+certain mass whereby a certain amount of energy is required to produce a
+certain change of motion. In addition to this, any two atoms could
+attract or repel each other with a force depending upon their distance
+apart. The Law which regulates these forces for all distances greater
+than 1/1000 of an inch is an attraction varying inversely as the square
+of the distance, and a repulsion for less distances.
+
+We have, therefore, to suppose that in place of the hard atom, there is
+merely a geometrical point which can exert attractive or repulsive
+forces to, or from, the central point. So far as external particles are
+concerned, they would behave just the same as a hard atom would do. This
+conception was largely entertained in recent times by Faraday. It is
+more a mathematical explanation than a physical one, but has been found
+convenient in explaining what takes place in the interior of bodies in
+their three states, namely: solid, liquid, and gaseous.
+
+_Lord Kelvin's Vortex Atom._--Another hypothesis which has been
+suggested for the constitution of an atom, is that known as the Vortex
+Atom, which received its birth at the hands of Lord Kelvin. The
+underlying principle of this Vortex Atom is, that matter may be entirely
+due to the rotating parts of a fundamental medium, the Aether, which
+fills all space.
+
+The properties of vortex motion were first mathematically calculated by
+Helmholtz, but it was left to Sir Wm. Thompson, now Lord Kelvin, to give
+a physical idea of the Vortex Atom.
+
+Before entering further into the question of the Vortex Atom, it may be
+as well to explain how vortex smoke rings may be made.
+
+[Illustration: Fig: 3.]
+
+All that is required is a wooden box, about one cubic foot in size, with
+a round hole perforated in one of the sides, and the opposite side
+covered with a piece of linen in place of the wooden side. The bottom of
+the box should then be covered with some strong solution of ammonia, and
+some hydrochloric acid poured into a saucer and put into the box. The
+combination of these two will cause thick clouds to form in the box, and
+if the linen is sharply tapped by the hand, a ring of this cloud will be
+forced through the hole on the opposite side of the box. The ring so
+formed will be circular in shape, and will go sailing through the room
+in which it is made.
+
+When the hole is circular, the rings will be found circular also, but if
+the hole is square, then the rings will be irregular in shape. One
+remarkable characteristic about these rings is, that when two of the rings
+are travelling in the same straight line, the one behind will overtake the
+front one, and while so doing, the diameter of the front one is enlarged,
+while that of the one behind contracts. The front one will also travel
+slower, while the one behind travels faster until it has caught up the
+former, and then the latter, having contracted sufficiently, will pass
+through the diameter of the former as illustrated in the figure. This
+alternation of contraction and expansion is continued as long as the two
+rings move in the same plane and until they are destroyed. When, however,
+the two rings are moving in opposite directions, and meeting each other in
+the same straight line, they will repel one another, instead of attracting
+each other.
+
+Their rate of progress is gradually reduced as they approach together,
+and they begin to expand and enlarge, but they never touch each other.
+Another peculiar feature about the rings consists in the fact, that the
+central core of air in the ring remains the same all the time the ring
+is in motion through the room, so that it has the same core of air at
+the end of its journey as it had when it left the box.
+
+As Lord Kelvin pointed out, if there were no friction of the air, the
+ring once created would rotate for ever. If, therefore, there were such
+a thing as a perfect fluid, and there were vortex rings in it, nothing
+could destroy these rings when once they were created, and this is one
+of the most striking suggestions with reference to the Vortex Atom
+theory of matter. It remains to be seen whether in the universe we have
+such a medium as a perfect fluid.
+
+Sir Wm. Thompson has applied the Vortex Atom theory of matter to the
+Aether, but from mathematical calculation he was unable to arrive at a
+satisfactory conclusion as to the Aether being composed of vortex atoms.
+
+Another remarkable property belonging to these rings, lies in the fact
+that they cannot be cut in two. It will be found that when the knife is
+brought near to them, they seem to recoil from the knife. In that sense,
+it is literally an atom, a thing which cannot be cut in two.
+
+The Vortex Atom has many recommendations in its favour. Many of the most
+important properties of matter are possessed by it, as for example
+indestructibility, elasticity, inertia, compressibility, and its
+incapability to be cut in two. Further, it may be linked with another
+ring, and so give the basis to the combining properties of atomic
+weights.
+
+The Vortex Atom theory is simple in character, as it does not postulate
+any extravagant hypothesis, but makes use of the Aether as the common
+basis for all matter, simply stating that this property of rotation may
+be the basis of all that we call matter. We shall further consider the
+relation of the Vortex Atom to matter, when we deal with the
+constitution of matter and the unity of the universe.
+
+
+ART. 35. _Elements of Matter._--As is well known, modern chemistry has
+succeeded in reducing all the complex forms of matter in Nature into a
+number of simple substances, which are called elements. Of these
+elements about seventy are at present known, some of which, however, are
+very rare. An element therefore is a simple substance which cannot be
+decomposed by any known force or process, as heat or electricity, into
+other elements.
+
+There are, however, only about fourteen of these elements that enter
+largely into the constitution of the earth, the most common being oxygen
+and silicon. By the use of the spectroscope, it has been proved that
+many of these elements, as for example oxygen, hydrogen, sodium and
+calcium, exist in the sun and stars, as well as in the most distant
+nebulae. Most of the elementary bodies are to be found in a gaseous form
+as hydrogen, oxygen, fluorine and chlorine, though it has been found
+possible to liquefy even these gases. Thus we see that matter may be
+roughly divided into three states, viz. solid, liquid, or gaseous.
+
+The condition in which the substance is found depends upon its
+temperature and pressure. An example of matter in its three stages is
+best shown in the case of water, where in the solid condition we have it
+as ice, in the liquid condition as water, and in the gaseous condition
+as steam.
+
+By recent researches it has been found possible to liquefy gases at a
+very low temperature and increased pressure, with the result that now
+nearly all known gases as hydrogen, oxygen, and carbonic acid are to be
+obtained in liquid form. By still more recent experiments made by
+Professor Dewar, it has even become possible to liquefy the air we
+breathe, with the result that at a temperature of about 270 degrees
+below freezing-point and at an increased pressure, the otherwise
+invisible and gaseous air may be changed into a liquid, and poured out
+from one vessel into another in the same way that water can be poured
+out. A vessel, however, at the ordinary temperature into which such
+liquid air is poured, would be so hot compared with the coldness of the
+liquid air, that as soon as the exceedingly cold liquid air came into
+contact with the vessel, the comparatively hot vessel would make the
+liquid air to boil.
+
+
+ART. 36. _Three Divisions of Matter._--Matter has been divided into
+three divisions, viz. solid, liquid, and gaseous. These divisions are
+each known by characteristic qualities, which separate the one division
+from another. At the same time, it is possible for matter to pass from
+one division into another, as for example in the case of water, which
+may exist in solid, liquid, and gaseous form. In view of the recent
+researches of Sir. Wm. Crookes and Professor J. J. Thompson, it is very
+probable that before long we shall have to add a fourth division to
+matter, which we should have to call ultra-gaseous form, or it may
+possibly be the aetherial form. If it should prove to be true that
+Aether is matter, and possesses the essential qualities of matter as
+suggested by Lord Kelvin, then certainly we shall have reached the
+boundary of another great division of matter, and our conception of the
+divisions of matter will have to be enlarged to take in that form, so
+that matter would then be divided into four great divisions, viz. solid,
+liquid, gaseous, and aetherial.
+
+We will now consider the three groups as at present recognized.
+
+_Solid._--Examples of solid bodies are common and familiar, and are
+typified by such things as iron, silver, copper, and lead. The chief
+characteristic of this condition of matter is that its condition or
+state is fixed, and cannot be altered without the expenditure of heat or
+electricity or some other form of energy.
+
+All solid elementary substances, with the exception of carbon, can be
+melted or reduced to a molten condition, although some of them require a
+very high temperature to effect this reduction, as, for example,
+platinum. When a still higher temperature is applied, the metals may be
+vaporized, or reduced from a molten state to that of a vaporous
+condition. In the case of solids, the atoms have not a free path in
+which to move. It must not be thought, however, that the atoms of a
+solid are motionless, as there is nothing absolutely motionless in the
+universe. In the case of the solid, the molecules which compose it,
+preserve their relative position and are linked together in relation to
+each other by the force of Cohesion.
+
+_Liquid._--When matter is in a liquid condition, as, for example, water
+and oil, the condition of its molecules are not so fixed and stable as
+they are in the solid state. The molecules can move freely about one
+another, and their freedom is increased compared with their condition
+when in the solid state.
+
+As already indicated, the reduction of a solid body to a liquid or
+molten state may be effected by heat. When heat is applied to a solid
+body, several results follow, each of which is the outcome of the other.
+
+1. There is an increase of temperature which is due to the increased
+energy of the molecules, through the added heat.
+
+2. There is an enlargement of the volume or size of the body, and if the
+addition of heat be continued, the molecular forces which hold the
+molecules together are broken down, and then the molecules, loosened
+from those forces which in the solid state have bound them together,
+begin to move about with greater freedom, and thus give rise to the
+molten condition of metals, or liquid condition of water. Thus, it is
+the heat which has set the atoms which compose the molecules in motion.
+The atoms of the solid have absorbed the heat, and the heat which has
+thus been absorbed has imparted vibratory energy to the atoms, which
+they did not possess before. Now when a substance is in the liquid
+state, the atoms of that substance have not only a vibratory motion, but
+have also a translatory motion, so that they can move in and out among
+one another. This is proved by the phenomenon of diffusion, where we
+have the case of two different-coloured liquids, for example,
+intermingling with each other, which is conclusive evidence of the
+translatory motion of the atoms in liquids.
+
+_Gaseous._--The third state in which matter is found is the gaseous
+state. In this condition, the particles of matter which form the gas
+have the greatest possible freedom of movement, and are able to move
+about with inconceivable velocity. There is abundant evidence to prove
+that gases consist of particles of matter which are perfectly free, and
+are able to fly about in all directions. The simplest proof is obtained
+by mixing two gases together, as, for example, when any gaseous
+substance is allowed to mix with the air of a room, when we find that
+the particular gas soon mixes itself thoroughly with all the air in the
+room. This process of mixing is known as Diffusion, and the lighter a
+gas is, the more quickly does it diffuse itself. The rate of movement of
+the various particles is varied, by reason of the encounters which each
+particle undergoes from time to time. Through experiments made by Joule,
+he arrived at the conclusion that particles of hydrogen attained a
+velocity of 6055 feet per second at 0 deg. C., which is a velocity much
+greater than that of a cannon-ball. In spite of the enormous velocity
+with which a particle of hydrogen would move, there are such a large
+number of particles in a single cubic inch of space, that no one
+particle has an absolutely free path from the one side of the enclosed
+space to the other. To this constant movement of the individual
+particles is due the elasticity or pressure of gases. The outward
+pressure which they exert on any body which encloses the gas is caused
+by the total effect of the impact of the particles, and is proportional
+to the sum of their masses multiplied into the square of their
+velocities. If we halve the enclosed space, then we should double the
+number of impacts in a given time, so that the number of impacts is
+inversely as the volume of the gas. This is equivalent to the statement,
+that the pressure of a gas varies inversely as its volume, which is
+Boyle and Marriotte's Law.
+
+
+ART. 37. _Matter is Gravitative._--If there is one property which is
+essentially characteristic to all matter, it is that all matter is
+gravitative. To this rule there is no exception, as the universal Law of
+Attraction states that "every particle of matter attracts every other
+particle." Thus, wherever in the whole universe there is a particle of
+matter of any kind or sort, whether such matter be solid, liquid, or
+gaseous, there the force of attraction will be exerted with a force
+proportionate to the mass of the particle, and inversely as the square
+of the distance between the attracted particles.
+
+Gravitation, then, is a property which is essentially inherent in
+matter, and any substance which is termed matter, or fulfils the
+conditions that govern matter, must be gravitative, whatever other
+property it may, or may not, possess. Unless this be so, we should have
+a violation of the universal Law of Gravitation, which would cease at
+once to be a universal law, for instead of reading "every particle of
+matter attracts every other particle," we should have to say that "some
+particles of matter attract some other particles," which would be a
+violation of that universal law which, through the genius of Newton, has
+given to the universe an unity from the philosophical standpoint that it
+did not possess before.
+
+Some matter may, or may not be elastic; it may, or may not be solid, or
+liquid, or gaseous; but there is this fact regarding matter which is
+absolutely undeniable, and that is, "All matter is gravitative."
+
+That this is true of each and all kinds of matter has been proved by
+direct experiment times without number, and the constant application of
+the law to all forms of matter is a fact observable from the phenomena
+incidental to every-day life. Astronomical observation teaches us also,
+that all stars, suns, planets, satellites, and comets are subject to
+this great Law of Gravitation, as indeed they must be if they are
+composed of matter. That they are all composed of exactly similar
+elements of which the earth is composed, has been proved again and again
+by spectroscopic analysis, which teaches that hydrogen, iron, and
+calcium, etc., are to be found in distant stars and nebulae, as they are
+equally to be found in the composition of the earth. Thus throughout the
+wide universe so far as observation and experiment can teach us, we
+learn that without any exception, everything that is termed matter is
+subject to this universal Law of Gravitation.
+
+
+ART. 38. _Matter possesses Density._--Density is that property of matter
+which decides the weight of a body per unit of volume.
+
+The density of any substance may be shown in several ways. It may
+denote, first of all, the number of molecules in a given body. Let us
+take as an illustration, the case of air being forced into a vessel of a
+given size, say one cubic foot capacity. We will suppose that in such a
+vessel there are 1,000,000 molecules. If we pump in a quantity of air
+equal to the amount it contained at first, then it is obvious that we
+have doubled the number of molecules in the same vessel, and therefore
+we say we have doubled the density. Not only so, but the weight of the
+air in the vessel will have been doubled. Looked at from this
+standpoint, density means the number of molecules in unit volume such as
+a cubic inch, or cubic centimetre.
+
+Again, as has already been shown in Art. 35, the different elements have
+different atomic weights. Thus an atom of carbon weighs twelve times as
+much as an atom of hydrogen, that is to say, there are twelve times as
+much matter by weight in an atom of carbon as there is in an atom of
+hydrogen, so that it would take twelve times as many hydrogen atoms to
+weigh a pound as compared with the number of atoms of carbon. This is
+only another way of stating that carbon has twelve times the density of
+hydrogen. If we compare lead and silver with hydrogen in the same way,
+we find that the density is 206 times and 107 times greater than that of
+hydrogen.
+
+Thus, it may be seen, that all matter possesses density, and that that
+density depends partly upon its atomic constitution. If the molecule of
+matter is composed of atoms whose atomic weights are very large compared
+with that of hydrogen, as iron, silver, lead and gold, then the
+molecules will have a much greater density, than a molecule formed of
+oxygen and hydrogen, _i. e._ water. This property of the density of
+matter plays a most important part in the transmission of any kind of
+wave-motion.
+
+
+ART. 39. _Matter possesses Elasticity._--Matter possesses elasticity.
+Elasticity is that property of matter which enables all bodies to resume
+their original shape, when the pressure which has caused the alteration
+of shape has been removed.
+
+For example, suppose an ivory ball be dropped upon a marble table, or
+any other hard surface. It will then rebound, and rise almost to the
+same height from which it was dropped. If the surface upon which it fell
+was first covered with blacklead, a circular spot of lead will be found
+on the ivory ball. From this fact, we arrive at the conclusion that when
+the ball came into contact with the table, at the moment of contact it
+was flattened, and then owing to its elasticity it rebounded into the
+air again.
+
+Now the measure of the elasticity of a body is proportionate to the
+velocity of the wave-motion which it can transmit. A good illustration
+of the transmission of wave-motion may be shown with a number of ivory
+bagatelle or billiard balls. If eight or more of these be put in a row,
+all touching each other, and a single ball be placed about an inch or so
+away from the others in a straight line with them, then when the single
+ball is struck with a cue against the other eight, the motion of the
+single ball is transmitted by each one of the eight successively with
+such rapidity, that the end ball would be set in motion in a quicker
+time than a single ball would take to reach the end ball, if it had been
+free to move along without encountering any opposition.
+
+It is a fact capable of demonstration, that the smaller the particle of
+matter, the greater will be its vibratory motion. Thus the particles of
+air are very, very small, and consequently air is found to be very
+elastic, and allows sound to be transmitted through it with
+comparatively great velocity, some sounds travelling at the rate of over
+1000 feet per second.
+
+A most important factor in determining the propagation of any
+wave-motion, through a gas or solid, is the relationship of the
+elasticity of the gas or solid to its density. Suffice to say, that the
+velocity of any wave-motion is determined by the relation of the
+elasticity to the density. For example, sound, which is a wave-motion of
+the air, can not only be transmitted through gaseous bodies as air, but
+also through liquids and solids. Sound travels faster through solids
+than through liquids, and faster through liquids than through gases. In
+liquids, the relation of the elasticity to density is greater than in
+air, and in solids the relation is greater still. Therefore sound
+travels much faster in liquids than in gases, and faster in solids than
+in liquids.
+
+This is the reason why a train can be heard coming if the ear is put to
+the railway-line, when no indication of its approach is given to the ear
+by the atmosphere. Some examples of the velocities of sound through
+different substances are as follows--
+
+    Gases O. C.             Liquids.                         Solids.
+       FEET                   FEET                            FEET
+
+Air    1090 per sec. Water   4708 per sec. (8 deg. C.).  Gold   5717 per sec.
+Oxygen 1040  "   "   Alcohol 4218  "   "   (20 deg. C.). Silver 8553  "   "
+
+
+ART. 40. _Matter possesses Inertia._--Inertia is that property of
+matter, by which matter cannot of itself alter, or change its state of
+motion, or of rest.
+
+Newton's first law of motion states that a body at rest remains at rest
+until some force or motion acts upon it. If a stone be dropped from a
+balloon, the stone does not fall because of any property which it
+possesses, but because the force of gravity acts upon it. If it were
+possible to eliminate this force of gravity, then if there were no other
+force which could act upon the stone, it would remain suspended in
+space.
+
+The inertia of a body is equal to the mass of that body, or the amount
+of matter in the body as measured by gravity, so that if a body is
+halved, its inertia will be halved also, and if doubled, its inertia
+will be doubled also. As the inertia of matter opposes all kinds of
+motion, the amount of force required to overcome the inertia of a body
+is proportionate to its mass. So that if the mass of a body is doubled,
+then twice the force would be required to move it, while if the body
+were halved, half the force would suffice to do it.
+
+Inertia is possessed quite as much by a moving body as a body at rest.
+The definition given points this out, as it states that matter cannot of
+itself change its state of motion. If a body therefore is in motion, it
+requires a certain amount of resistance to bring the body to a state of
+rest, or the loss of an equal amount of energy, by friction or
+otherwise, equal to the quantity which it absorbed in order for it to be
+set in motion.
+
+We get numerous examples of this property of the inertia of bodies in
+our daily experience. Many of the accidents that befall people in
+various ways are due to this property of the inertia of matter. A
+cyclist is riding a machine down-hill, and loses control over his
+machine, with the result that he runs into a wall, and is killed. Now
+what has happened? The cyclist has participated in the motion of the
+machine, with the result that when the machine has been suddenly
+stopped, the body has been thrown forward owing to the momentum it had
+acquired.
+
+We are constantly being affected by the property of inertia of matter,
+in tram and train and bus. Whenever any of these are suddenly stopped,
+or suddenly started, we are thrown either backward or forward, owing to
+the body either not having acquired the motion of the train, or, having
+acquired it, is unable to lose its motion as quickly as the train, and
+is therefore thrown forward.
+
+
+
+
+                               CHAPTER IV
+
+                             AETHER IS MATTER
+
+
+ART. 42. _Aether is Matter._--The hypothesis of an Aether which fills
+all space was made in order that scientists might be able to account for
+certain phenomena of Light, which otherwise were difficult to account
+for. Its existence is demanded not only for the phenomena of Light, and
+Heat, but, in view of the comparatively recent researches of Hertz on
+"Electric Waves," of Electricity also.
+
+The Aetherial Medium is generally assumed to be that fundamental medium,
+by means of which possibly all the properties of matter, and all the
+phenomena of motion of the universe are to be explained. Light and Heat
+have been proved to be due to the periodic wave-motion of this universal
+Aether, while from the investigations and researches of such men as
+Clerk Maxwell, Poynting, Thompson and Hertz, it has been proved that
+electro-magnetic phenomena are due to this same medium.
+
+Several different forms of Aether have been postulated by various
+philosophers from time to time, but the only Aether that has survived,
+is that which was first conceived by Huyghens to explain the phenomena
+of Light, though it was Thomas Young who finally succeeded in placing
+the conception of the Aether on a sound basis. Each discovery of science
+has only strengthened the hypothesis and existence of the Aether, the
+latest discovery, that of wireless telegraphy so successfully developed
+by Signor Marconi, being attributed to the electro-magnetic properties
+of this self-same Aether.
+
+It has already been pointed out that Newton endeavoured to account for
+Gravitation by the pressure of the Aether. If, therefore, Gravitation be
+really due to this universal medium it becomes necessary to ask
+ourselves, What are the properties and characteristic qualities of this
+wonderful medium? What then is Aether, and what its properties?
+
+It has already been pointed out in Art. 29 that Aether is matter. Such
+an assumption is strictly in accordance with the Rules of Philosophy,
+quoted in Chap. I.
+
+Not only is this hypothesis a simple one, but it is also in accord with
+all our experience and observation.
+
+It is a simple supposition, because, unless Aether is assumed to be
+matter, then, instead of the universe being composed of two classes of
+things, matter and motion, we have to add a third class, which we call
+Aether. It can be readily seen, that by the introduction of a third
+class into the composition of the universe, such an addition, instead of
+simplifying the constitution of the universe, adds greater complexity to
+the same.
+
+By accepting the hypothesis that Aether is matter, we do away with the
+third class of essentials in the universe, and so reduce the number to
+two classes. If we could go one step further, and prove that instead of
+there being two classes of things in the universe, there was only one
+group, and show that all material things, and all phenomena could come
+under the head of either matter, or motion, then we should have reduced
+the universe to the simplest conception possible. As, however, it is not
+possible, at least in our present state of knowledge, for us to come to
+this fundamental and simple hypothesis of unity for the entire universe,
+we must accept the next simpler solution, and affirm that the universe
+is composed of two classes of things, viz. matter and motion, and this
+as I have already shown is a simpler classification than by putting
+Aether into a class by itself, and therefore is in accord with our first
+Rule of Philosophy.
+
+Again, it is entirely in accord with our second Rule of Philosophy, as
+it in no way violates the results of experiment, experience, or
+observation. Look where we will, or at what we will, whatever we see,
+touch, taste, or smell is termed matter. The burning sun, the glowing
+star, the flying meteor, the glowing comet, the earth, our own island
+home, the towering rock, the wide ocean, the running river, the green
+trees of the forest, the tiny insect, the lordly elephant, all animals,
+plants, and our own physical body, all are composed of matter, either in
+solid, liquid or gaseous form. Therefore when we affirm that Aether is
+matter, the affirmation is strictly in accordance with the elementary
+principles of Philosophy, and in no way violates their rules or laws. To
+affirm that Aether is not matter, is to affirm something contrary to all
+experience, unless it be affirmed that Aether is motion, for which
+assumption the evidence is not nearly so strong or conclusive as that it
+is matter. Therefore the objector to this assumption is himself
+unphilosophical, in that he postulates or supposes that the Aether is a
+medium, with qualities which lie altogether outside the range of our
+experience and observation.
+
+There is a growing conviction in the minds of scientific men, that
+Aether belongs to that group of things which we describe by the term
+matter. Lord Kelvin in giving an address to the British Association,
+1901, on "Clustering of Gravitational Matter in any part of the
+Universe," said: "We are all convinced with our President (Professor
+Rucker) that _Aether is Matter_. Aether we relegate to a distinct
+species of matter which has inertia, rigidity, elasticity,
+compressibility, but not heaviness."
+
+Dr. Larmor in _Aether and Matter_ writes: "Matter must be constituted of
+isolated portions, each of which is of necessity a permanent nucleus
+belonging to the Aether, of some such type as is represented for example
+by a minute vortex ring in a perfect fluid."
+
+Faraday in relation to this subject writes (_Exp. Res._, vol. ii.): "The
+view now stated of the composition of matter would seem to involve the
+conclusion that matter fills all space, or at least all space to which
+Gravitation extends, _including the sun and its system_, for Gravitation
+is a property of matter dependable on a certain Force, and it is this
+Force which constitutes matter." As the Aether fills all space,
+including the solar system, therefore, according to Faraday, "Aether
+must also be Matter."
+
+By the hypothesis that Aether is matter, with all the properties that
+such a hypothesis logically gives to Aether, I venture to premise that
+the third Rule of Philosophy will be fulfilled, and that there is no
+phenomenon of the astronomical world, and no part of the universal Law
+of Gravitation which such a hypothesis will fail to account for on a
+satisfactory physical basis. For the first time a physical explanation
+will be given to Newton's Laws of Motion, at least to those laws which
+are strictly in accordance with the first and second Rules of
+Philosophy. For the first time a physical conception will be given to
+all Kepler's Laws, and what the mathematical Laws of Gravitation have
+done to Kepler's Laws, in giving them a mathematical basis, the simple
+hypothesis that Aether is matter, with all that is logically involved
+therein, will do for the same laws from the physical standpoint. For the
+first time a physical conception will be given to the Centrifugal and
+Centripetal Forces, which are the complement and the counterpart of each
+other, that physical conception being the outcome of the same hypothesis
+that Aether is matter.
+
+In addition to this, light is thrown upon such problems as are referred
+to by Lord Kelvin (_Phil. Mag._, July 1902) in his paper on "Clouds on
+the Undulatory Theory of Light," and further light is given to some
+theories of Electricity advanced by such men as Faraday, Clerk Maxwell,
+and Professor Thompson. I venture to think, therefore, that the
+hypothesis advanced, and the conception put forward that Aether is
+matter, is philosophically correct, and is warranted by the results that
+arise out of such a hypothesis.
+
+It may be thought by some that the hypothesis that I have advanced is
+already conceded, and that the fact that Aether is matter is already
+admitted by scientists and advanced thinkers generally. But such an idea
+is only partly correct. It is already admitted by some of our most
+advanced scientists that Aether is matter, but that admission is only
+carried partially to its logical conclusion.
+
+Lord Kelvin in an address to the British Association, 1901, gave
+utterance to the following remarks on the relation of Aether to Matter:
+"We are convinced with our President (Professor Rucker) that Aether is
+Matter, but we are forced to say that the properties of Matter are not
+to be looked for in Aether, as generally known to us by action resulting
+from force between atoms of Matter and atoms of Aether. _Here I am_
+ILLOGICAL _when I say between Matter and Aether_, as if Aether were not
+Matter. Aether we relegate to a distinct species of Matter which has
+inertia, rigidity, elasticity, compressibility, but NOT HEAVINESS."
+
+From a quotation of this kind, which is from the lips of one of the
+keenest intellects of the present time, I think I am justified when I
+make the statement, that it is not conceded that Aether is matter, with
+all that that concession logically involves. Because, as Lord Kelvin
+points out, though it is admitted that Aether is matter, yet that
+admission is only a qualified admission, and not one which carries with
+it all the properties that essentially belong to matter, or an admission
+which includes the fact that Aether is gravitative, that is, subject to
+Gravitation. To be strictly logical and philosophical, in the statement
+that Aether is matter, it must be conceded not only that Aether is
+subject to such properties as elasticity, inertia, and compressibility,
+but that it is also gravitative or possesses weight. For either Aether
+is matter, or it is not matter.
+
+It cannot be both at one and the same time. Such a conception is
+altogether opposed to that simplicity which is the chief characteristic
+of Nature as pointed out by Newton.
+
+If therefore Aether be matter, then, to be strictly logical and
+philosophical, it must be conceded that Aether is gravitative, as well
+as having the other properties of matter, as elasticity and inertia,
+etc. Unless this is conceded, then we have the anomaly in Nature of
+matter, which is not matter, because it violates the very principles
+which above all others decide what is matter, viz., "That every particle
+of matter attracts every other particle," etc., that is, that it is
+gravitative. Thus by supposing that the Aether is matter, and yet not
+being gravitative, all the Rules of Philosophy are violated, as such a
+hypothesis is opposed to both the first and second Rules of Philosophy,
+and is contrary to all observation and experience. If Aether therefore
+be matter, as is conceded by the most advanced thinkers of the time,
+then it follows that the only logical and philosophical conclusion that
+can be arrived at is, that it is also subject to those properties which
+are the chief characteristics of all matter. These properties may be
+classified as follows: atomicity, gravitation, density, elasticity,
+inertia, and compressibility.
+
+
+ART. 43. _Aether is Universal._--Young in his first Hypothesis on the
+Aether medium states that, "A Luminiferous Aether pervades the Universe
+rare and elastic in a high degree" (_Phil. Tran._, 1802).
+
+As Young points out, this invisible and elastic Aether fills all space
+and floods the universe at large. In it suns blaze, stars shine, worlds
+and planets roll, meteors flash, and comets rush in their mysterious
+flight. In it all material and physical things exist, for it is to them
+not only the primary medium of their existence, but, just as the
+infinite and ever-active energy of the Divine is to the universe in its
+entirety and fulness, the exciting and stimulating spirit of its
+energies and powers, so this aetherial ocean is to the material and
+physical universe, the exciting and stimulating medium of all its
+activities, energies, and powers; and without which, though all material
+and physical things were endowed with the varied capacities of their
+kind or life, yet they could neither exert nor exercise them, nor even
+exhibit the simple activity of motion. Hence everywhere, where material
+and physical things are, there, as the medium of their existence and
+energy, the Aether is; and where the Aether is not, no material or
+physical thing is, or can be. That the Aether is universal is proved by
+the phenomena of light. Light-waves have a velocity of about 186,000
+miles per second. Now the distance of the sun from the earth is about
+92,000,000 of miles, so that light takes about eight minutes and a half
+to travel from the sun to the earth.
+
+A ray of light from the nearest fixed star takes about three and a half
+years to reach the earth, while there are some stars so far away that
+astronomers tell us, that though light travels with so great a velocity,
+yet it would take several thousand years to reach the earth. This fact
+implies that throughout boundless space there is to be found this
+aetherial medium. Thus interplanetary and interstellar space is not
+empty, but is filled with this ever-present, all-pervading Aether; and
+not only so, but every particle of matter in the universe is surrounded
+by this universal Aether, which forms the exciting and stimulating
+medium of all the activities, energies, and motions of all Matter. Thus
+the Aether is both universal and infinite in its extent.
+
+Clerk Maxwell, in his paper on "Action at a Distance" (_Collected
+Works_, by Niven), with reference to the universality of the Aether,
+writes: "The vast interplanetary and interstellar regions will no longer
+be regarded as waste places in the universe, which the Creator has not
+seen fit to fill with the symbols of the manifold order of His Kingdom.
+We shall find them to be full of this wonderful medium, so full, that no
+human power can remove it from the smallest portion of space, or
+produce the slightest flaw in its infinite continuity. It extends
+unbroken from star to star, and when a molecule of hydrogen vibrates in
+the Dog Star, the medium receives the impulses of those vibrations, and
+transmits them to distant worlds. But the medium has other functions
+besides bearing light from world to world, and giving evidence of the
+absolute unity of the material system of the universe. Its minute parts
+may have rotatory as well as vibratory motions, and the axes of rotation
+form those lines of magnetic force which extend in unbroken continuity
+into regions which no eye has seen, and which, by their action on our
+magnets, are telling us in language not yet interpreted what is going on
+in the hidden world from century to century." Now I premise, that in the
+theory of the Aether to be submitted in this work, the physical
+interpretation of this statement of Maxwell's will receive its literal
+fulfilment.
+
+
+ART. 44. _Aether is Atomic._--If there is one fundamental truth which is
+applicable to all matter, it is, that all matter is atomic.
+
+Professor Rucker, in his Presidential Address to the British Association
+of 1901, in dealing with this question, said: "The believer in the
+atomic theory asserts that matter exists in a particular state, that it
+consists of parts which are separate and distinct from one another, and
+as such are capable of independent movement. It is certain that matter
+consists of discrete parts in a state of motion, which can penetrate
+into spaces between the corresponding parts of surrounding bodies. Every
+great advance in chemical knowledge during the last ninety years finds
+its interpretation in Dalton's Atomic Theory."
+
+From such an authority as this, and from the facts which he gave in his
+dealing with the question, we are bound to admit that all matter is
+atomic. That being granted, when the statement is made, therefore, that
+Aether is matter, the only logical conclusion that can be arrived at,
+with reference to the question of the atomicity of the Aether, is, that
+Aether is also atomic. Unless this be conceded, we have the first and
+second rules of our Philosophy violated, as an atomless Aether is
+opposed to that simplicity of conception, which is an essential
+requirement of all hypotheses, and is moreover contrary to that
+presumptive evidence gathered from observation and experiment, which
+teaches us that all matter is atomic. If it be argued, that it is
+impossible to decide upon a question as to the atomicity of the Aether,
+my reply is that the same argument may reasonably be applied to all
+matter. But, as Professor Rucker stated, all the evidence on matter
+points out and supports the theory of its atomicity, and, therefore, the
+only logical and philosophical conclusion is, that Aether is atomic
+also. Again, it may be suggested that we cannot see or touch an atom of
+Aether, and that it is not only invisible, but apparently incapable of
+being made sensible to our senses. In reply to that, as I have already
+shown in Art. 31, that objection can be equally used against an atom of
+hydrogen, or an atom of oxygen. Does any one doubt the existence of the
+hydrogen atom or the atom of oxygen, because it is invisible to the
+sense of sight, or cannot be revealed to the limited sense of touch?
+Certainly not! By the same reasoning, it is just as illogical to deny
+the existence of an atom of Aether because it cannot be seen or felt, as
+it is to deny the existence of an atom of hydrogen or oxygen. An atom of
+Aether reveals itself to the senses in the same way that an atom of
+hydrogen or oxygen does, that is, by the force or energy which it
+exerts. Its vibrations can be manifested to the body in the form of
+heat, while the undulatory motion which the aetherial atoms transmit in
+the form of light, reveal the presence of the aetherial atom to the
+sense of sight. The question at once arises as to what constitutes an
+aetherial atom, what are its properties and motions?
+
+Now, in order for us to enter successfully into this speculative region,
+it is essential that we should, as far as possible, conform to the Rules
+of Philosophy, and endeavour to gain some conception of an aetherial
+atom from the results of experience and observation. In doing this, we
+are at once confronted with the difficulty, that no one has ever seen an
+atom, or analyzed the properties of one. Actual experiment has revealed
+nothing absolutely certain as to the ultimate character of an atom, and
+if this be true of the atoms of matter, then it must also be true of an
+aetherial atom. It would seem at first, therefore, that we have no
+results of experiment, or observation, by which we may be guided in
+formulating a right conception as to the constitution of an aetherial
+atom, and therefore we are thrown simply into the regions of speculation
+as to its constitution and properties.
+
+But I venture to suggest, that there is a method which is strictly
+philosophical in its application, by which we may possibly arrive at a
+clear conception of an aetherial atom. All great discoveries of science
+have been the outcome of applying the principle, that what is true of
+the visible and seen, is true of the invisible and unseen; that what is
+true of the known, is true of the unknown; that the principles and laws
+which govern the small also govern the large and the great. It was thus
+that Newton discovered his great Law of Gravitation, as he was able from
+the falling of an apple, to rise to the application of the same
+principle to our satellite the moon, and this led him on to the
+discovery of the Law of Gravitation.
+
+If, therefore, in Philosophy, the laws governing the small things are
+also applicable to the great things, then the converse equally holds
+good, that the laws governing great things are the reflex of the laws
+which govern the small things. For example, the laws which govern the
+light and heat of the sun are the same which govern the light and heat
+of a candle or a glow-worm; and the laws which govern a planet or world
+are the same as those which govern an atom. Thus a planet or world,
+which is simply an agglomeration of atoms, may reveal to us in its
+motions and laws, what are the motions and laws which govern the atomic
+world.
+
+In looking at the properties and motions of a planet, therefore, as our
+earth for example, we find that a planet is a sphere, or more correctly
+an oblate spheroid; that the earth or planet is a magnet possessing
+polarity, having a north and south pole; that it has rotation on an
+axis, in addition to translation in an orbit, and that it is subject to
+the universal Law of Gravitation.
+
+If, therefore, it holds good in Philosophy, that the small things are
+the index to the greater, and that the laws governing the small things
+also govern the greater, then the converse holds good, that what is true
+of the large is true of the small, and that the laws governing the great
+also govern the small.
+
+So that gathering up those chief properties of the earth to which I have
+already referred, and applying them to an aetherial atom, or any other
+atom if necessary, we arrive at the conclusion that an atom must be
+spherical in shape, must possess rotation, and must have an orbit, must
+possess polarity, and also be subject to the universal Law of
+Gravitation.
+
+Here, then, we have given to us certain data by which we are enabled to
+form our conception of an atom, aetherial or otherwise. The question
+arises, whether, among the forms of atoms which have been devised by
+scientists, any of the atoms so conceived fulfil all, or nearly all of
+these requirements. We have Boscovitch's Atom, the Hard Atom of
+Lucretius, and the more recent conception of the Vortex Atom of Lord
+Kelvin. Of all the hypotheses in regard to the ultimate nature and
+constitution of an atom, the Vortex Theory probably is the one which
+offers to the mind the simplest conception of an aetherial atom.
+
+The Vortex Ring Atom, however, which has been so fully developed by Lord
+Kelvin, hardly fulfils all the requirements of an aetherial atom. In the
+first place it is not spherical in shape, and I hold that to be one of
+the fundamental bases of the aetherial atom. Then, in the next place it
+does not, so far as I can read, possess polarity; that is, it does not
+possess a north and south pole, through being a magnet in the same way
+as the earth is a magnet. We must therefore look for a modification of
+the vortex ring to discover the constitution of our aetherial atom, and
+I venture to think that such a modification is to be found in Professor
+Hill's conception of a Spherical Vortex Atom (_Phil. Trans._, 1894).
+
+In the conception there put forward, and mathematically worked out,
+Professor Hill showed that his spherical vortex atom possessed similar
+properties and characteristics to the vortex rings of Lord Kelvin. So
+that the spherical vortex atom would possess rotation on an axis, and it
+would be a magnet, as I shall prove later on, because it rotates in an
+electro-magnetic medium. It would possess elasticity, compressibility,
+inertia, and, further, would possess a certain amount of mass. That mass
+might be infinitely small, but nevertheless it would possess mass of an
+infinitesimal order.
+
+Further, if we are to be strictly correct, in our analogy between the
+earth and the aetherial atom, its polar diameter must be shorter than
+its equatorial diameter, as that is one of the facts observable
+regarding the shape of our earth, so that the shape of the aetherial
+atom will not be strictly spherical, but its actual shape would be that
+of an oblate spheroid, being flatter at the poles, and bulging out in
+the equatorial regions.
+
+This exact analogy between the earth and an aetherial atom may not at
+present seem of very great importance, but its importance will be seen
+later on, when we come to deal with the phenomena of heat, light, and
+electricity.
+
+Here, then, is our conception of an aetherial atom in the rough, based
+not upon any imaginative hypothesis, but rather upon that strict
+conformity to observation and experience, which is the very groundwork
+of all true Philosophy.
+
+For, after all, what is the earth but an atom on a large scale? In
+comparison with illimitable space, with its infinite distances, that can
+alone be measured by the velocity of light, our own earth is but a speck
+of dust, a very atom that helps to make up the universe, and, as such,
+should teach us the shape and properties of other atoms of which the
+same universe is composed.
+
+We have therefore to conceive of the all-space-pervading Aether as being
+composed of infinitesimal portions of Aether, which are nearly spherical
+in shape, and ever in a state of rotation; this state of rotation
+differentiating the atom of Aether from the free Aether, if such an
+entity exists. So that an atom of Aether would simply be an
+infinitesimal portion of the Aether in a state of rotation.
+
+If, by any means, we could stop the rotation, we should at once destroy
+the atom, in the same way that the smoke vortex ring would cease to be a
+ring, if its rotation were stopped. The cessation of the rotation I,
+however, believe to be impossible. So that even in the ultimate atom of
+that universal medium the Aether, we have an illustration of the
+combination of those two forms which are inseparably connected
+throughout the whole universe, viz. matter and motion, and it is the
+combination of these two that gives to the aetherial atom its form, and
+its very existence, without which it has no life, and ceases to exist.
+
+It may be necessary in the development of this work as we proceed, to
+slightly modify our conception of the aetherial atom, but that
+modification will rather be of a constructive character, than a
+destructive one. There may also be certain objections to meet and
+explain away when we deal with the phenomena of light, heat, and
+electricity, and Gravitation, and the part which the aetherial atom
+plays in those phenomena, but these objections I hope to meet and answer
+as they arise.
+
+The atomicity of the Aether has already been suggested by such
+scientists as Clerk Maxwell, Lord Kelvin, Dr. Larmor, and Professors
+Lodge and J. J. Thompson. Clerk Maxwell, in an article on "Action at a
+Distance,"[3] referring to the atomicity of the Aether, writes: "Its
+minute parts may have rotatory as well as vibratory motions, and the
+axes of rotation may form those lines of magnetic force which extend in
+unbroken continuity into regions which no eye has seen." I premise that
+I will conclusively prove that this statement finds its literal
+fulfilment in the theory of the Aether that will be developed in this
+work.
+
+Lord Kelvin, in several articles on "Vortex Motion" in the Philosophical
+Magazines of recent years, has mathematically dealt with the Aether from
+the atomic standpoint, and has endeavoured to prove that the Aether
+medium is composed of vortex rings, but he was unable to come to any
+satisfactory conclusion. With the theory that Aether is matter, and
+therefore possesses mass, his conception is now brought within the range
+of physical explanation, as well as mathematical calculation.
+
+Dr. Larmor, in his _Aether and Matter_, has successfully applied the
+principle of the atomicity to the Aether, on what is termed the
+"Electron" basis. He states that an electron is nothing more or less
+than "a point singularity in the electro-dynamic and optical Aether." So
+that our aetherial atom is practically synonymous with Dr. Larmor's
+electron. Again, Dr. Larmor, in the same work, states that "the
+atomicity of electricity is coming within the scope of direct
+experiment."[4] But Professor Lodge, in his _Modern Views of
+Electricity_, states that "the Aether is composed of positive and
+negative electricity, the combination of these two forming the Aether
+medium."[5] Now, if the Aether is composed of positive and negative
+electricity, and the atomicity of electricity is coming within the scope
+of direct experiment, it follows as a matter of necessity that the
+atomicity of Aether and the atomicity of electricity are one and the
+same, and therefore the atomicity of Aether is coming within the scope
+of direct experiment. Professor J. J. Thompson, who has also attacked
+the problem of the atomicity of electricity, speaks of "corpuscles"
+which are the actual carriers of the positive and negative electricity,
+in the atoms of the various elements. These corpuscles therefore
+indicate the fact that electricity has an atomic basis.
+
+Now if there is any such identity between Aether and electricity, as
+there undoubtedly is, and electricity has an atomic basis, then the
+atomicity of the Aether follows as a matter of course, otherwise we
+shall have a medium composed of atoms which is itself not atomic, which
+conclusion is absurd and therefore unphilosophical. So that the most
+recent researches into electricity confirm and establish the atomicity
+of the Aether.
+
+[Footnote 3: _Collected Works_, by Niven.]
+
+[Footnote 4: Preface to _Aether and Matter_.]
+
+[Footnote 5: Page 348.]
+
+
+ART. 45. _Aether is Gravitative._--Young, in the _Philosophical Trans._
+of 1802, in regard to this question, states in his Fourth Hypothesis:
+"All material bodies have an attraction for the aetherial medium, by
+means of which it is accumulated within their substance, and for a small
+distance around them, in a state of greater density, but not greater
+elasticity." He adds that "this fourth hypothesis is opposed to that of
+Newton's."
+
+Scientific research has justified the conception of his first three
+hypotheses with respect to the universality, elasticity and vibrations
+of the aetherial medium, but up to the present I am not aware that
+science has accepted his fourth hypothesis.
+
+I propose to show how, from a strictly philosophical and logical
+standpoint, his fourth hypothesis is just as true as his first three
+hypotheses, and that it henceforth passes out of the realm of the
+hypothetical into the realms of fact and science, not only by
+philosophical reasoning, but by actual experiment made by some of the
+most advanced scientists of the present time.
+
+Let us consider the question first from the standpoint of the Rules of
+Philosophy. Our first Rule of Philosophy states, that any hypothesis
+must be simple in connection. Now I put it to any intelligent man, and
+ask him which is the simpler conception of Aether? To affirm that Aether
+is matter, and therefore subject to the properties of matter, as
+elasticity, density, inertia and Gravitation, or to affirm that Aether
+is matter, but while it is subject to some of the properties of matter,
+as elasticity, density and inertia, it is not subject to the very
+property which of all properties is the most fundamental, viz.
+Gravitation. There can, in my opinion, only be one answer to the
+question, so that, when we affirm that Aether is matter, we are
+compelled to affirm, in order to conform to the first Rule of
+Philosophy, that it is gravitative also. Faraday was also of the opinion
+that Aether was subject to the Law of Gravity, for, writing in
+_Experimental Researches_, he states: "The view now stated of the
+constitution of matter, would seem to involve the conclusion, that
+matter fills all space, or at least all space to which Gravitation
+extends, INCLUDING THE SUN AND ITS SYSTEM. For Gravitation is a property
+of matter, dependable on a certain force, and it is this force which
+constitutes matter."
+
+Let us also test the question by our second Rule of Philosophy, and we
+shall find greater evidence still for the statement that Aether is
+gravitative. What do experience and observation teach us with reference
+to matter? As we have already seen (Art. 37), if there is one truth that
+they teach us regarding matter, it is that it is gravitative.
+
+There is not the slightest evidence throughout the universe, as far as
+our observation can lead us to form an opinion, that there is any kind
+of matter which is not subject to the Law of Gravitation. Therefore to
+assume that Aether is matter, and yet not to assume that it is also
+subject to Gravitation, is to assume that which is directly opposed to
+the most fundamental principle of all philosophical teaching and
+scientific research. If Aether be matter, therefore, and yet is not
+gravitative, we shall have an anomaly in an otherwise universal law, as
+we shall have some kind of matter which fails to come within the scope
+of the universal Law of Gravitation.
+
+To be consistent, therefore, we must either cease to call Aether matter,
+or else admit that Aether, like all other matter, is gravitative. It is
+absolutely impossible to be strictly logical and admit that Aether is
+matter, and not to admit that it is subject to the most universal law
+that governs matter, as the Law of Gravitation distinctly states that
+"every particle or atom of matter attracts every other particle." This
+universal law in view of a gravitationless Aether would have to be
+amended to "Some particles of matter attract some other particles." Thus
+the universal Law of Gravitation ceases at once to be a universal law,
+and such a result is opposed to all experience and experiment. Again,
+let us apply our third Rule of Philosophy to this supposed
+gravitationless Aether, and see what the result is.
+
+Our third rule states, that any hypothesis put forward must satisfactorily
+account for the phenomena sought to be explained and accounted for. The
+Aether was conceived in order to explain the phenomena of light, and one
+of the properties it was conceived to possess was elasticity, yet that
+very conception was devoid of the most fundamental property of matter,
+without which there is no elasticity, that is, that it was not atomic.
+
+I have already shown in Art. 44, that Aether is atomic, and therefore
+there is given to the Aether a structure which is capable of exhibiting
+elasticity, inertia, density, and even Gravitation, while at the same
+time, the conception is fully in harmony with philosophical reasoning
+and Newton's Rules of Philosophy.
+
+Let us consider the question whether Aether is, or is not gravitative,
+from another aspect. For several hundred years, the physical cause of
+Gravitation has been outstanding, while the world has held the
+conception that Aether is a gravitationless and frictionless medium. The
+earth has been rolling on in her orbit year in, year out, together with
+all the other planets in their annual march round the sun, and yet
+through all that time no one has been able to suggest, or give any
+satisfactory or adequate physical explanation, as to what moves the
+earth along.
+
+I am fully aware that Newton suggested and proved, that it was because
+of the Law of Gravitation. But I look upon that as a mathematical
+explanation and not as a physical one.
+
+Now I venture to predict this, that on the assumption of a
+gravitationless medium, the physical explanation so longed for will
+always be outstanding, as a gravitationless Aether is synonymous with a
+frictionless medium, and so long as we admit that there is a
+frictionless medium, so long will the physical cause of Gravitation, and
+therefore the physical cause of all the movements of the planets and
+comets, be outstanding and unexplained.
+
+If, however, instead of being illogical in our reasoning, we become
+logical, and affirm that Aether is matter, and because all matter is
+gravitative, therefore Aether is gravitative; and if, instead of being
+unphilosophical, we become philosophical, and affirm that because a
+gravitationless Aether violates both the first and second Rules of
+Philosophy, such a conception must be put away, and in its place a more
+philosophical conception must be forthcoming, which is that Aether is
+gravitative; then, upon such a logical and philosophical basis, I
+venture to premise that the great problem which is still outstanding of
+the cause of Gravitation, will remain outstanding no longer, and the
+physical cause of all the movements of all celestial bodies will be put
+upon a physical basis, in addition to a mathematical one.
+
+If such a result can be arrived at by the logical and philosophical
+conception of a gravitative Aether, then the three Rules of Philosophy
+are fully satisfied, and the assumption of a gravitative Aether is
+warranted on a strictly philosophical basis.
+
+So that Thomas Young is strictly correct from a philosophical standpoint
+in his fourth hypothesis, when he states: "That all material bodies have
+an attraction for the aetherial medium, by means of which it is
+accumulated within their substance and for a small distance around them
+in a state of greater density but not greater elasticity." He is not,
+however, correct when he states that though there is a greater density
+near the body, there is not a greater elasticity, as such an assumption
+is opposed to experiment and observation in relation to perfect gases,
+as I shall show when dealing with the elasticity of the Aether.
+
+Again, in view of the fact that the Aether is atomic, it can now be
+easily understood how it may be subject to Gravitation. The very essence
+of Gravitation is that atoms, or particles, attract each other. If there
+were no particles, or atoms, it is obvious that there would be no
+attraction, and therefore no Gravitation. Wherever, therefore, there are
+to be found atoms of any kind or sort, whether they be atoms of
+hydrogen, oxygen, silver or aetherial atoms, there the Law of
+Gravitation holds good, and attraction between these atoms is to be
+found. In other words, any substance which is atomic, is also
+gravitative. Now Aether is atomic as has been shown, and therefore from
+that standpoint it is also gravitative. It may, however, be objected
+that the assumption of gravitative properties for the Aether is after
+all but a speculation, and that Young's fourth hypothesis was only a
+hypothesis, and that the gravitating properties of the aetherial medium
+have never come within the scope of direct experiment, without which no
+hypothesis can be fully accepted.
+
+If such an argument be advanced against a gravitating Aether, then I
+must differ from those scientists who advance such an objection. My
+contention is that the gravitating properties of the Aether have already
+been made the subject of some of the most refined and delicate
+experiments that have been made during the past few years.
+
+I refer to the experiments of Michelson and Morley of America.
+
+For an outline and explanation of such experiments I must refer the
+reader to the _Phil. Mag._ of December 1887.
+
+Now what is the result of these experiments?
+
+I believe it is almost unanimously conceded by all scientists, that
+their experiments prove that the Aether is carried along by the earth.
+Let us carefully look at this conclusion and see what it implies in
+relation to the question at issue.
+
+If the Aether is carried along by the earth, it necessarily follows that
+there is some governing law or principle which holds it to the earth,
+while the earth moves through space with its velocity of 68,000 miles per
+hour.
+
+Now what is that governing principle or law, which is capable of holding
+such an aetherial atmosphere to its central body? If we wish to be
+strictly philosophical, it is necessary, according to our second Rule of
+Philosophy, that we should not go outside experience and the analogy of
+Nature.
+
+Where is there a similar analogy in Nature to that of the Aether being
+carried along through space by the earth? I know of only one analogy
+which can be used, and that is the analogy of the atmosphere, which is
+also carried along by the earth through space, as it rushes on in its
+orbit round the sun.
+
+That being so, the question arises, what principle or law holds the
+atmosphere to the earth? for, whatever be the law which governs the
+atmosphere, to be consistent with the second Rule of Philosophy, we must
+infer that the same law also holds the Aether in its place. There is
+only one answer to the latter question, and that is the Law of
+Gravitation. If it were not for that law, and the fact that the
+atmosphere is subject to that law, the atmosphere would simply be swept
+off from its central body, the earth, as the latter rushed through space
+with its comparatively enormous velocity.
+
+The only legitimate and philosophical conclusion that we can arrive at,
+therefore, is that the Aether must be carried along with its central
+body, the earth, through being acted upon by the self-same Law of
+Gravitation, and for it to be so acted upon it must obviously be
+gravitative. It would be unphilosophical to suggest that it was held in
+its place by any other force, as that would be introducing a new force
+or law into Nature, contrary to our experience in relation to an exactly
+similar phenomenon of Nature.
+
+We have therefore, it seems to me, direct proof by actual experiment
+that Young's fourth hypothesis was correct, and that not only in
+relation to the atomic world, but also in relation to the planetary
+world, and the stellar world, all bodies exert an attractive influence
+upon the surrounding Aether, by means of which the Aether is accumulated
+near the surfaces of all bodies in a state of greater density, and
+therefore of greater elasticity.
+
+Let us apply this truth to the solar system, and see what we get. If it
+is true that the earth exerts an attractive influence upon the
+surrounding Aether by means of which it is held in its place relatively
+to the earth, then it is equally true that Mercury, Venus, Mars,
+Jupiter, Saturn, Uranus and Neptune also exert gravitating or attractive
+influences upon the surrounding Aether, in the same way that they do
+upon their own atmospheres. So that in their cases also, the surrounding
+Aether is carried along by them through space. Professor Stokes has
+suggested that this is so, in order to account for the aberration of
+light, as we shall see later on.
+
+Not only so, but the sun also would have an attractive power over the
+Aether by means of which its aetherial atmosphere would be carried
+through space, as it moved along in its progress at an estimated rate of
+17,000 or 18,000 miles per hour.
+
+I would like to point out here, that this explanation of the effect of
+the planets' attractive power over the surrounding Aether is only a
+partial one, as there are other effects directly involved in the fact
+that the Aether is subject to the gravitating influence of all
+satellites and planets.
+
+This is not the place, however, to go fuller into the matter, the
+consideration of the subject being taken up in a later chapter.
+
+Thus I have tried to show a gravitating Aether is strictly in accord
+with the three Rules of Philosophy, for it is simple in conception, is
+not contrary to experience, and by it I premise that it is possible to
+explain the physical cause of Gravitation, with all that is involved in
+that law.
+
+Once more, if Aether is gravitative, then every atom and particle in the
+universe, as well as every planet, and sun, and star, exert an
+attractive power over the Aether, so that every atom is enveloped in an
+atmosphere of Aether, in the same way that every planet, and sun, and
+star is enveloped by the aetherial atmosphere.
+
+The Aether, however, while it may flow through the spaces that exist
+between the molecules of bodies, yet is held bound to those molecules in
+the same way, and by exactly the same force, that holds the atmosphere
+to a planet or world.
+
+Further, if the atoms possess different masses or weights, as they do,
+then each atom would possess an aetherial atmosphere proportionate to
+its mass, with the result that an atom of carbon, with its atomic weight
+of 12, ought to possess a denser aetherial atmosphere than an atom of
+hydrogen, and so on right through the atomic scale. I need hardly point
+out that this conception of the Aether in relation to atoms, and
+molecules of bodies, will solve certain problems relating to the density
+of Aether in connection with matter, which problem up to the present
+cannot be solved by the present conception of a frictionless medium.
+
+That problem may be stated as follows: Does the presence of matter
+affect the Aether in any way, so as to load or make it denser? Professor
+Lodge, in _Modern Views of Electricity_, in relation to the density of
+the Aether, writes: "The neighbourhood of gross matter seems to render
+Aether more dense. It is difficult to suppose that it can really
+condense an incompressible fluid, but it may load it, or otherwise
+modify it, so as to produce the effect of increased density."
+
+In view of the fact that Aether is gravitative, the reply is to be found
+in the Law of Gravitation, "Every particle of matter attracts every
+other particle of matter, etc.," and as Aether is matter, it will be
+attracted by the other matter irrespective of whether that matter be in
+the atomic, molecular, or planetary or stellar form. We shall see that
+this is so when we come to deal with the density of the Aether.
+
+It may be objected in relation to this aspect of Aether, that Young also
+asserted that the Aether flows as freely through matter, as the air
+flows through the trees of the forest, and that such a statement
+therefore contradicts his fourth proposition regarding the gravitating
+properties of Aether. A little reflection will, however, put a different
+construction on this objection.
+
+Let us consider the analogy from the standpoint of experience, and see
+what that analogy teaches us. From experience we learn that the air is
+gravitative, but we also learn that it is possible to be moved from
+place to place as winds, and that as such it can move freely between the
+trees of the forest, causing their boughs and leaves to tremble and bend
+beneath its energy and power.
+
+I have yet to learn, however, that while it moves between the trees as
+separate and distinct objects, such a movement militates or destroys its
+gravitating properties.
+
+Does the air cease to be any less gravitative, or subject to the Law of
+Gravity, when it is subject to certain movements, which give rise to
+certain currents as winds? Such an assumption is altogether opposed to
+philosophical reasoning.
+
+Whether the air is stationary or in motion, it is ever subject to the
+great Law of Gravitation, and accepting that as an analogy, the apparent
+contradiction between the oft-quoted simile of Young and his fourth
+hypothesis is at once removed, and from analogy we learn that it is
+quite possible for Aether to move between bodies because of certain
+currents which may be originated by heat, light or electricity, yet at
+the same time the existence of such currents does not violate its
+gravitating tendency.
+
+Young's fourth hypothesis is therefore in perfect harmony with his
+oft-quoted simile, that the Aether flows through the interstices of
+bodies as the wind flows through a group of trees, but like the
+air-currents it does not so flow unless the currents are generated by
+some form of energy, as heat or light, electricity or magnetism.
+
+From these considerations therefore we are compelled to come to the
+conclusion that Aether, like all other matter, is subject to the same
+universal Law of Gravitation. If further evidence of the gravitating
+tendency of the Aether were required, I would refer the reader to Lord
+Kelvin's utterance on this subject.
+
+Lord Kelvin, _Phil. Mag._, November 1899, in relation to the Aether
+writes: "We are accustomed to call Aether imponderable. How do we know
+that it is imponderable? If we had never dealt with air except by our
+senses, air would be imponderable to us, but we know by experiment that
+a vacuum glass tube shows an increased weight when air is allowed to
+flow into it. We have not the slightest reason to believe that Aether is
+imponderable. It is just as likely to be attracted by the sun as air is.
+At all events the _onus of proof rests with those who assert it is
+imponderable_. I think we shall have to modify our ideas of what
+Gravitation is, if we have a mass spreading through space with mutual
+attraction between its parts, without being attracted by other bodies."
+
+We have already seen in the previous article that Faraday was of opinion
+that the Law of Gravitation extended throughout the whole of the solar
+system, and as Aether fills the solar system, then obviously Aether must
+also be subject to the Law of Gravitation.
+
+
+ART. 46. _Aether possesses Density._--That matter possesses density has
+already been shown in Art. 38, and on the hypothesis that Aether is
+matter, Aether must possess density also. This property has already been
+postulated for the Aether, in order to account for certain phenomena in
+connection with the reflection and refraction of light. Young assumed
+different densities for the Aether near bodies owing to its being
+attracted by those bodies (Art. 45). Reflection and refraction of light
+are produced by a change of density of the Aether. It is now generally
+accepted that the optical difference of bodies depends mainly on the
+different densities of Aether in association with those bodies.
+Professor Tyndall, in his _Lectures on Light_, writes on the density of
+the Aether as follows: "The density of the Aether is greater in liquids
+and solids than in gases, and greater in gases than in vacuo. A
+compressing force seems to be exerted on the Aether by the molecules of
+these bodies."
+
+Apart, however, from the atomicity and gravitative properties of the
+Aether, it is difficult to understand how there can be density of the
+medium, and still more difficult to give a satisfactory explanation of
+different degrees of density for the same medium, which some scientists
+assume it to have.
+
+If, however, all that is logically included in the statement that Aether
+is matter, and therefore is atomic and gravitative, is conceded, then,
+from the analogy of our own atmosphere in relation to the earth, the
+density of the Aether, and different degrees of density also, is at once
+put upon a logical and philosophical basis, as it is brought into
+harmony with all experience and observation, and is simple in its
+conception.
+
+On the other hand, an Aether which is not atomic or gravitative cannot
+possess different degrees of density, except by assuming the existence
+of some unknown law of which we have no knowledge, which conception is
+altogether opposed to the fundamental principles of simplicity,
+observation, and experiment as laid down not only by Newton but by every
+true philosopher.
+
+Therefore, that Aether can possess different degrees of density, is only
+the logical outcome of the statement that Aether is matter, seeing that
+such a statement without the shadow of a doubt must at least imply that
+it is gravitative.
+
+I need hardly point out, that it is much more philosophical to be able
+to account for the density of the Aether in a reasonable and
+philosophical manner, than simply to postulate for the Aether certain
+properties and qualities, because certain phenomena demand the existence
+of such properties.
+
+The Aether has been such a hypothetical medium, that it has been easy to
+postulate for it certain properties, if certain phenomena have demanded
+the existence of those properties.
+
+Thus if the Aether were required to be elastic, then elasticity was
+postulated for it; if more elastic, then greater elasticity was added.
+If density were demanded, then density was postulated, and if less or
+more density, less or more density was given to it.
+
+That method of speculation may be satisfactory up to a certain point,
+but no one will admit that such a method is wholly philosophical. It
+will be a far better method to adopt, if, in dealing with the universal
+Aether, we can make it conform to certain recognized laws and
+principles, and from the application of those well-known laws, be able
+to infer the exact constitution of this space-filling Aether medium.
+
+Now the question arises, if Aether is gravitative, what effect has the
+Gravitation of any body, be it an atom, or a meteor or planet, sun or
+star, upon the Aether in which it moves, and which surrounds it?
+
+That we may have some light thrown upon the matter, I would like now to
+take the reader to Newton's _Optics_, in order that he may give us his
+opinion as to this property of density of the Aether. In his nineteenth
+query Newton (_Optics_) asks this question--
+
+"Is not this medium much rarer within the dense bodies of the sun,
+stars, planets and comets than in the empty spaces between them, and in
+passing from them to great distances, doth it not grow denser and denser
+perpetually, and thereby cause the gravity of those great bodies towards
+one another, and of their part towards the bodies, every body
+endeavouring to go from the denser parts of the medium towards the
+rarer?"
+
+Here then we have given to us an indication of what is the possible
+state of things in relation to the gravitation of the Aether, and all
+bodies in solar and stellar space. The only mistake that Newton made,
+was in inverting the right order of comparatively dense and rarer parts
+of the aetherial medium, by putting the rarer parts of the medium near
+to the bodies, and supposing the denser parts to be farther away in
+space.
+
+As a matter of fact, the correct view is exactly the opposite, that is,
+if we are to form our conception by following out those philosophical
+rules that Newton laid down. For either the rules are right, or his
+supposition is right. They cannot both be right, as his supposition is
+contrary to the second Rule of Philosophy, as all experience and
+observation from the analogy of Nature teach us that a medium enveloping
+any body, as planet, star or sun, is densest nearest to the body,
+becoming rarer the further that medium gets away from the central body.
+Let us take for our illustration the best example, that experience and
+observation afford, that of the atmosphere surrounding the earth. The
+analogy is so perfect, that one is almost tempted to believe that the
+atmosphere and the Aether are in some way intimately associated with
+each other. Some years ago Lord Kelvin was of the opinion that the
+Aether was but an extension of the atmosphere, though I am not certain
+whether he holds that view at the present time. Clerk Maxwell, writing
+in the _Phil. Mag._ in May 1861, writes: "I have deduced from this
+result the relation between statical or dynamical electricity, and have
+shown that the elasticity of the magnetic medium in air is the same as
+that of the luminiferous medium, _if these two coexistent, coextensive,
+and equally elastic media are not rather one medium_."
+
+Now for the comparison. Both the atmosphere and Aether are matter. Both
+are atomic, both are gravitative, both possess elasticity, and both
+possess density. The atmosphere also possesses different degrees of
+density, so does the Aether. In the case of the atmosphere, however,
+experience and experiment teach us that the atmosphere is denser nearer
+the earth than farther away.
+
+When we ascend mountains, it is a matter of common knowledge that the
+higher we ascend, that is the further we get from the earth, the rarer
+the atmosphere becomes. When we ascend in balloons, we find that the air
+becomes so rare and so light, that the blood will flow from the nose, on
+account of the reduced pressure exerted on it, the pressure inside the
+body being greater than that outside. Now in accordance with our second
+Rule of Philosophy, if experience is to be any guide at all, then it
+most conclusively teaches us that the Aether being subject to the same
+laws as the atmosphere, the same results inevitably follow. Therefore
+the Aether nearest the earth is denser than any layer immediately above
+it, and that layer denser than the one above it, and so on for great
+distances, with the result that the only conclusion we can come to in
+regard to the density and rarity of Aether in relation to all
+gravitating bodies is, that the densest part of the Aether is nearest to
+them, and the rarest, the farthest away from them. So that while
+Newton's suggestion in his nineteenth query is correct in principle, it
+is incorrect in application to space.
+
+I would like to point out here, that what is true of the earth in
+relation to the density of the surrounding Aether, must also be true,
+according to our second Rule of Philosophy, of every other planet, or
+sun, or star. So that every planet, satellite, every sun or star has its
+atmosphere, if I may so term it, of Aether, which obeys and follows the
+same laws as the earth's atmosphere does.
+
+This is a most important fact, and has a most important bearing upon the
+physical cause of Gravitation as applied to each planet, and sun and
+star, as I shall afterwards show.
+
+I wish now to bring the reader into contact with a Theory of Gravitation
+that was given to the world by Professor Challis of Cambridge, 1872. In
+the _Philosophical Magazine_ of June of that year he writes: "I assume
+that all the active forces of Nature are different modes of pressure
+under different circumstances of a universal elastic Aether, which
+presses always proportionately to its density."
+
+Now what I wish to point out is, that while Prof. Challis admits the
+density of the Aether, and also varying degrees of density, as he states
+that the Aether presses proportionately to the density, he does not show
+how that varying density is accounted for. If there is this varying
+density, then there must be some underlying principle which governs the
+variation in density, and I know of only one principle or law which can
+regulate that variation in density, and that is that Aether is
+gravitative, and being gravitative it not only possesses density, but
+also variations in density.
+
+Thus by admitting that Aether is gravitative, because it is matter, we
+have at once a satisfactory explanation for the density of the Aether
+and also for different degrees of density both in the atomic world, and
+in the planetary and stellar world.
+
+
+ART. 47. _Aether is Elastic._--In Art. 39, matter was shown to be
+elastic, and on the assumption that Aether is matter, the elasticity of
+the Aether, which has been postulated for it by various scientists, can
+be logically and philosophically accounted for.
+
+In view of the transmission of light through space with a definite and
+finite velocity, we are compelled to regard Aether as possessing
+elasticity, similar to that of an elastic solid body.
+
+If we take the analogy of sound, we find that sound is transmitted and
+propagated through matter, by waves of alternate condensation and
+rarefaction, and that transmission is regulated by the relation of the
+density of the medium to its elasticity. Light has been proved to be due
+to the undulatory wave-motions of the Aether, and in order to account
+for the transmission of the wave-motion, it is essential that the Aether
+should possess the property of elasticity.
+
+As Young points out in his First Hypothesis,[6] the Aether possesses
+this property of elasticity, but with the advance of scientific
+knowledge and research, the elasticity of the Aether may be said to have
+passed out of the hypothetical stage, into the state of actual fact and
+experiment. Both McCullagh and Fresnel have assumed this property of
+elasticity for the aetherial medium in order to account for certain
+phenomena of light.
+
+Apart, however, from the atomicity of the Aether, it is exceedingly
+difficult to understand how such a property can belong to it. Atoms are
+exceedingly small particles, possessing the property of elasticity, or
+the power to recover their original shape after distortion or change of
+shape. If the Aether therefore be atomic, as is pointed out in Art. 44,
+it can at once be readily understood how the Aether as a whole can
+possess the property of elasticity. The atoms of the Aether must be
+inconceivably small, as the light-waves travel with the enormous
+velocity of 186,000 miles per second.
+
+What must therefore be the atomic vibration which such a statement
+implies? If, on the other hand, the Aether is assumed to be continuous
+and non-atomic, it must be seen how exceedingly difficult it is to
+account for the elasticity of the Aether, as it seems absolutely
+impossible for a medium which is continuous, and non-atomic, to be able
+to transmit the waves of light with a finite velocity.
+
+Apart, therefore, from atomicity of some kind or other, elasticity of
+the Aether is an assumption philosophically incorrect, as it is contrary
+to that simplicity of conception laid down by Newton, and is also
+contrary to all experience, and thus violates the second Rule of
+Philosophy.
+
+Aether therefore must be said to be perfectly elastic; so perfectly
+elastic, that it is susceptible to the least touch of any natural thing,
+so that even an atom, so small that it cannot be seen with the most
+powerful microscope, yet so elastic is this Aether medium, that the
+least motion or vibration of one of these atoms, though the motion did
+not exceed the 20- or 40-millionth part of an inch, yet even this would
+create in the aetherial ocean, Aether-waves, just as a body moving in
+water creates water-waves, which, radiating from the place of their
+birth, beget and create others, the process continuing until they reach
+the margin of the water in which they were generated. It is precisely
+so with these Aether-waves, when once generated and set in motion. They
+create others, the process being continued and perpetuated; and, unless
+arrested in their course, may continue until they reach the very limits
+and confines of material immensity and space.
+
+It is, perhaps, only necessary to say, regarding the perfection of the
+elasticity of the Aether medium, that though it takes from 40,000 to
+69,000 waves to complete the space of one inch in extent, yet it is done
+with such miraculous rapidity, as to speed the distance of 186,000 miles
+in the short space of a second of time; or, taking the number of
+Aether-waves to complete an inch as 50,000, its elasticity is such that
+it makes 50,000 x 186,000 x 12 x 5280 vibrations in one second of time.
+
+We have already seen in Art. 39, that according to Boyle and Marriotte's
+Law, the velocity of a wave-motion, as sound in the air, is determined
+by the relation of the elasticity of the medium to its density. If the
+temperature of the atmosphere remains the same, then the _elasticity_
+varies in the same proportion as its density.
+
+According to Art. 45, Aether is gravitative, and that fact produces
+different degrees of density in the aetherial atmosphere of an atom or
+planet or meteor, sun or star; that part of the Aether being densest
+nearest the central body, and rarer the further we go away from that
+body.
+
+Now the question at once arises, what is the effect of the increased
+density of the Aether near the body upon the elasticity of the Aether?
+
+From the analogy of sound in air, we arrive at the conclusion that Boyle
+and Marriotte's Law equally applies to the Aether, as it does to the
+atmosphere of any planet. That is, if the temperature of any stratum or
+layer of the Aether remains the same, then the elasticity of the
+aetherial medium in that layer is proportionate to its density, so that
+while the gravitating property of the Aether makes it denser nearest the
+central body, the fact that the elasticity is proportionate to the
+density, does not affect the transmission of any wave-motion.
+
+[Footnote 6: _Phil. Trans._, 1802.]
+
+
+ART. 48. _Aether possesses Inertia._--From Art. 40 we have seen that all
+matter possesses inertia, inertia being that property of matter by which
+it cannot of itself change its state of motion or of rest.
+
+If Aether be matter, therefore, then it must also possess inertia. This
+property of inertia is already postulated for Aether by scientists, and to
+that extent is conformable to the Rules of Philosophy. Professor Tyndall,
+with reference to the inertia of the Aether, writes: "The motion of
+Aether communicated to material substances throws them into motion. It
+must be therefore itself a substance. Aether is a substance endowed with
+inertia, and capable, in accordance with the established laws of motion,
+of imparting its motion to other substances."[7]
+
+Again, Lord Kelvin in his Address to the British Association, 1901, on
+the "Clustering of Gravitational Matter in any part of the Universe,"
+states: "Aether we relegate to a distinct species of matter which has
+inertia, etc." Aether, therefore, according to Tyndall, "is a substance
+or medium endowed with inertia, and capable, in accordance with Newton's
+Laws of Motion, of imparting its motion to other substances."
+
+If, however, the Aether is frictionless, as has generally been supposed,
+then it cannot possess inertia, because to the extent that a body
+possesses inertia, to that extent it is opposed to being frictionless.
+
+Inertia is really the equivalent of mass, or the amount of matter
+measured by gravity, and if Aether possesses mass in any sense at all,
+as it must do if it is matter, then, possessing mass or weight, it must
+offer resistance to any body moving through it, and to that extent
+cannot be frictionless. To suppose that the Aether is frictionless, and
+yet possesses inertia, is to suppose something altogether opposed to all
+the Rules of Philosophy and therefore of experience.
+
+I have already shown that a frictionless medium is opposed to all
+philosophy and experience, and is an anomaly in the universe.
+
+On the strictly philosophical assumption that Aether is matter, and
+therefore atomic and gravitative, the whole question of the inertia of
+the Aether is reduced to one of common experience. It is, at least to my
+mind, difficult to conceive of mass without weight or without atomicity,
+and yet that is the unphilosophical position of the present state of
+science in relation to the Aether. In other words, while the Aether is
+supposed to possess inertia, which is dependent upon mass, as measured
+by gravity, yet it is supposed not to be gravitative, that is, that the
+mass of the Aether has no weight at all, and therefore is not mass,
+which assumption contradicts itself. From Arts. 44 and 45, however, we
+have seen, to be strictly philosophical, that Aether must be atomic and
+also gravitative. It can now be easily understood how it can possess
+inertia like any other matter, and is therefore capable of receiving
+motion from other matter, and also of imparting that motion to other
+matter.
+
+So that, wherever there is motion of any kind in the Aether, either in
+the form of vibratory motion as heat, or undulatory motion as light, or
+rotatory motion as electricity, those motions will affect adjoining
+matter in the same way that the motion of any other moving matter
+affects any body with which it comes into contact.
+
+From the fact that Aether possesses inertia, and is also gravitative, we
+have now to alter our conception of this universal space-filling medium,
+and in place of a frictionless medium, which is incapable of imparting
+motion to any body, we have now to remember henceforth that the Aether
+is matter, which possesses inertia, and therefore has the capacity not
+only of offering resistance to any body moving through it, as a comet or
+meteor, but also of imparting the motion which it may receive in any
+manner to any other matter, as a planet, satellite, or sun, that may be
+floating in it.
+
+With this philosophical view of the Aether, which is entirely in harmony
+with our first and second Rules of Philosophy, we shall be able to give
+a physical explanation of the Law of Gravitation, as we have now a
+physical medium existing in all atomic, solar, and stellar space, which
+can both accept motion, and transmit that motion to other bodies. In
+other words, we have a medium which can both push and pull.
+
+[Footnote 7: _Lectures on Light._]
+
+
+ART. 49. _Aether is Impressible._--Another characteristic property of
+this Aether medium is, that it is as perfectly impressible as it is
+elastic. So perfectly impressible, that it receives, retains, and
+perpetuates for thousands of years, and for distances to human mind
+incalculable, every impression given to it of light, form, colour, tint,
+and shade; and that, too, with a perfect fidelity that nothing mars,
+even to the least and most infinitesimal detail.
+
+Therefore, irrespective of distance, wherever there is matter to arrest
+and reflect the impressions received, there those impressions of light
+(and all that in the luminosity is involved and contained) become
+visible and revealed, and wherever there is power of vision to receive
+and concentrate these Aether- or light-waves, there, not only luminosity
+or light, but all that constitutes and is involved in that luminosity,
+becomes at once visible and seen.
+
+It is by this means we see the colour, tints, shades, and forms of suns
+and planets; of stars, constellations, etc., with all the varied forms,
+configurations, and movements of the celestial phenomena. Each and every
+one, small or great, glittering or blazing, sun or planet, are ever
+creating or generating Aether-waves, and impressing them with all the
+details and particulars of their nature and existence; and these
+Aether-waves ever bear upon their mystic wings the impressions received,
+carrying the information given with lightning speed to the very confines
+and limits of infinite space or the material universe; beyond which
+exists nothing but the ever-living and active energy of the Divine, the
+only unlimited, unbounded, and absolute infinitive.
+
+It is by the interception and concentration of these waves by our
+perceptive powers, aided with the giant powers of the telescope, that we
+obtain the information given, or become cognizant of the nature and
+existence of the varied lights, colours, tints, and shades of the
+celestial bodies.
+
+The vision, assisted by the giant power of the telescope, collects and
+concentrates these Aether-waves into a perfect image of those things
+that gave them birth, and by this means reveals to us the knowledge of
+things afar, their existence, nature, characteristics, properties, and
+powers.
+
+Thus it is we see the solar orb, with its huge fires all aglow, obtain a
+knowledge of its character and powers, see its huge spots, its quivering
+fringe of flame, and high-leaping prominences, or watch its slowly
+revolving form.
+
+Thus we see the planets that around it sweep and roll; swift-footed
+Mercury with his wondrous speed, and dazzling Venus with her silver
+sheen; Mars the god of war with his ruddy glow, and mighty Jupiter with
+his orange hue, and the yellow Saturn with her mysterious rings, the
+blue Uranus, and the more distant Neptune, with all the satellites that
+to it belong.
+
+Then far far away the brilliant Sirius--the Dog Star, Cygnet, Centauri,
+the Great Bear, and a thousand others.
+
+The Pleiades and the twenty millions of suns that form our own galaxy
+and the Milky Way, with all their varied colours, tints, and hues of
+white, golden, orange, ruby, red and blue, green and grey, silver,
+purple and yellow, buff and fawn, emerald and green, lilac and coppery.
+Thus we see the distant Orion, so far away that swift-footed Light, with
+its speed of more than eleven million miles per minute, has to travel
+for more than thirty thousand years before it spans the gulf that
+intervenes between it and us, and brings to us the news of its existence
+there.
+
+Then the spectroscope with its revealing power literally tears asunder
+wave from wave, and reveals the mystic message which each doth bear, of
+the distant things from which they come, of each and every sort and
+kind.
+
+Thus we know, that in the solar fires there ever burn such things as
+hydrogen, oxygen and nitrogen, and also, in a vaporous state, aluminium,
+sodium, iron, magnesium, cobalt, calcium, chromium, copper, manganese,
+zinc, and others.
+
+Thus light-waves are speeding everywhere, and from all material things.
+They come from our own sun, and rush in, and flood the earth's aerial
+veil, the atmosphere; and "Each little atom of matter, like a mirror,
+reflects and re-reflects them as if in sport, buffeting each luminous
+ray from one to another, increasing and amplifying it by an infinity of
+repercussions" (Herschel), and then in their entirety and whole, like a
+huge multi-mirror, so blend and mingle them that they come to earth's
+surface in that soft radiance we call Light, and bathe it as in a sea
+of mellowed glory.
+
+
+ART. 50. _Aether: its Motions._--The question of the exact motions of
+the Aether is a question which has involved the attention of scientific
+men for many years, and which is at the present time receiving the
+attention of some of our most advanced scientists, not only in this
+country but in other countries also.
+
+Whether the Aether in space is at rest, or is moving along with all the
+bodies that float in it, so to speak, is a question of the greatest
+importance to scientists and philosophers generally, as the particular
+character of the motions of the Aether, which are either suggested or
+ascribed to it from the analogies of Nature, are sure to have a most
+important bearing not only on the motions of all the planets and
+satellites, but also upon such questions as the aberration of light, and
+such difficulties as presented by Lord Kelvin in his paper on "Clouds on
+the Undulatory Theory of Light" (_Phil. Mag._, July 1902).
+
+I need hardly point out that the hypothesis that Aether is gravitative,
+is bound to play a most important part in the consideration and
+development of this phase of the study of the universal aetherial
+medium. It is not my intention, however, at this stage of the work to go
+fully into the development of this aspect of the subject.
+
+The application of this principle will be considered at the right time,
+and in the right place. It is, however, generally assumed, that the
+Aether is at rest in space, and that the earth, the planets, and the sun
+and all stars, move through it with varying velocity, although, as Lord
+Kelvin points out, such an assumption is covered with a cloud which up
+to the present is "as dense as ever." Of course, if the Aether be at
+rest, and the planets and other heavenly bodies move through it with
+varying velocity, then the only assumption regarding the Aether is, that
+it is frictionless, but, as I have shown in Art. 45, this is opposed to
+all philosophical reasoning, and therefore to experience and
+observation.
+
+We have, therefore, to postulate for the Aether such motions as shall
+fulfil all the Rules of Philosophy, that is, shall be simple in
+conception, shall be in harmony with our experience and observation, and
+which shall satisfactorily account for the phenomena sought to be
+explained, that is, the universal Law of Gravitation; for it is by the
+properties, combined with the motions of the Aether, that the physical
+cause of Gravitation is alone to be explained.
+
+Let us revert to the question of a stationary Aether for a moment or
+two, and let us ask ourselves, where is the evidence for such an
+assumption? Has the sun ever ceased to shine, or to send its light-waves
+with their enormous velocity speeding through the solar system? So far
+as experience and observation go, I have never read of any record of
+such a fact, or that light-waves have ceased to proceed from the sun and
+fill the solar system with Aether-waves.
+
+Not only is this true of the sun, but it is equally true of every planet
+and satellite, every meteor or comet, every star and sun that exist or
+dwell in this aetherial medium; for, as has already been shown (Art.
+49), every body emits Aether-waves, and these waves spread out in all
+directions in a spherical form.
+
+The truth is, that the universal Aether is in eternal motion, and that
+motion forms the physical life of the universe. If it were possible to
+destroy the motion, then the whole fabric of the universe would fall to
+pieces, and the beauty, order, and harmony of the celestial mechanism
+would be replaced by disorder, confusion, and ultimate ruin. Take any
+analogy of Nature, and see what such an analogy teaches us. Look at any
+planet, sun, or star. Do we find any one of these stationary or at rest?
+Why from the smallest meteorite or satellite, to the largest star that
+shines in the firmament of heaven, there is nothing but motion; each
+satellite, planet, sun, and star moving on and on, ever and ever through
+the countless ages of time until its course is run and its existence
+ended. But rest, never! Such a thing as rest is unknown in the entire
+universe, whether it be in the atomic systems of matter, or the systems
+of stars and suns that form the universe of worlds.
+
+Take another illustration--that of the ocean! Is that ever at rest, with
+its unceasing wave and tidal motion? Has the reader ever stood on the
+shore and seen the ocean when it has been absolutely still, or when the
+tide has ceased to flow? Such a possibility is almost absurd to
+contemplate. The same argument applies to the air with its regular flow
+of winds. Now in regard to the aetherial and universal medium, there are
+just as regular motions as the flowing of the tide round the earth, or
+the revolving of a satellite round a planet, or a planet round the sun.
+
+And what is as important, all the motions can be as satisfactorily
+explained and accounted for from the physical standpoint, as the flow of
+the tide, or the revolution of a planet.
+
+Year in and year out, the motions of the Aether remain the same, governed
+by the same laws and producing the same effects. Age after age, the Aether
+has been moving, producing by its various motions the continuity of that
+beauty, order, and harmony that govern the universe as a whole.
+
+I have already indicated in Art. 45 the effect of Gravitation on the
+Aether surrounding each satellite, or planet, or star, or sun. As each
+satellite, or planet, or star moves through the universal Aether, it
+takes with it its surrounding Aether as indicated in Art. 45, in the
+same way that each planet or sun takes with it its own associated
+atmosphere, which is held in contact with it by the self-same force of
+Gravitation.
+
+In addition to this motion of the aetherial atmosphere through space,
+there are other motions of this same gravitating Aether that have to be
+taken into consideration, before a complete and adequate conception of
+all the motions of the Aether can be arrived at.
+
+I do not intend, however, at this stage to go fully into such motions,
+but rather wish to lead up to them from a consideration of hypotheses
+put forward by such men as Rankine, Challis, Maxwell, Lord Kelvin,
+McCullagh, and Helmholtz, and from a consideration of such hypotheses in
+the realm of heat, light, and electricity to be able to form a
+scientific conception of the proper motions of the Aether, as well as a
+philosophical one.
+
+
+
+
+                               CHAPTER V
+
+                                 ENERGY
+
+
+ART. 51. _Energy._--In the days of Newton, and for a long time afterwards,
+all energy went by the name of "Force." Thus Newton in his Laws of
+Motion refers to the action of forces on stationary or moving bodies,
+and shows how the motion of any body is effected by the impressed force.
+(Art 13.)
+
+As science advanced, and scientific research was carried into the fields
+of heat, light, and electricity, we find that the various forces began
+to be particularized, with the result that such terms as electrical
+force, magnetic force, chemical force, etc., became common and familiar
+terms. As gradually it became known that one particular kind of force
+was the outcome of another kind, there was given to the world such terms
+as the Correlation of Forces (Grove), in which he proved that whenever
+one kind of force appeared as heat or light, it was at the expense of
+another kind of force, as electricity.
+
+Of later years, however, another term has crept into Philosophy, and
+instead of the term Force, which is very indistinct and indefinite in
+character, there appeared the term Energy, although Force and Energy are
+not exactly synonymous terms. Thus electricity, heat, and light are
+forms of energy, and are convertible into one another, in the same way
+that the forces were convertible. Thus we get transformations of energy
+in the same way that we had transformations of force, and conservation
+of energy in the same way that we had conservation of force.
+
+Even the term Energy, however, is being replaced in the present times by
+something more definite and simple, and instead of the term Energy, we
+shall find, in the development of this phase of natural phenomena, that
+that term is being replaced by the simple idea of motion, or modes of
+motion, and that all forms of energy, as light, heat, magnetism, and
+electricity, and even Gravitation itself, are due to motion of some kind
+or other. We will, however, lead up to this truth by looking briefly at
+the term Energy, and see what it implies and embodies.
+
+Energy, therefore, is that property which a body possesses, by which it
+is capable of doing work. Thus our ideas of work give us our conception
+of energy. For example, when a weight is lifted, work is done, and a
+certain amount of energy is expended in the process. Further, the amount
+of work done is proportionate to the weight lifted, and the height to
+which the body is raised. Work is done against resistance, so that
+whenever resistance is overcome, then work is the result. For example,
+suppose one pound is lifted one foot high, in opposition to the force of
+gravity, then work is done, and this amount of work is known as a
+foot-pound.
+
+If a body weighs ten pounds, and is lifted ten feet, the work done is
+equal to ten pounds multiplied by ten feet (10 x 10 equals 100), so that
+one hundred times the amount of work has been done in comparison with
+the lifting of the one pound one foot high.
+
+As all weight is essentially a gravitational measure, depending upon the
+intensity of gravity at the place, then, whenever a body is raised or
+lifted, the work so done is done against the gravity of the earth.
+
+Work is also done, as Newton points out in the first and second laws,
+whenever we apply force to any body, either stationary or already in
+motion. The results of all observation and experiments prove, that
+whenever we have two bodies upon which work is being done, the amount of
+work is determined by the amount of energy transferred from one body to
+the other, and that the actual amount of energy gained by one is equal
+to the amount of energy lost by the other.
+
+Energy is always found in association with matter, so that matter has
+sometimes been termed the Vehicle of Energy. Wherever, therefore, we
+find energy of any kind or sort, there we find matter also, as the two
+are inseparably connected together. Thus, wherever we have heat, we have
+matter in a particular state of motion, generally understood as
+vibratory motion Wherever we have light, which is also a form of energy,
+we also have matter in motion, that is the Aether, in a state of
+periodic wave-motion; and wherever we have electricity, we have again
+matter possibly in a state of rotatory motion, as we shall see later on.
+Energy, therefore, is the power which a body possesses to do work.
+
+
+ART. 52. _Conservation of Energy._--The principle of the Conservation of
+Energy was first enunciated by Mayer in 1842. The principle may be
+defined as follows: The total amount of all the energy, as light, heat,
+electricity and magnetism, Gravitation, etc., in Nature is unchangeable;
+so that, according to this law, the universe possesses a store of energy
+which is unchangeable in quantity throughout all time. The energy may
+pass from one form to another, yet the total amount ever remains the
+same. It is almost unnecessary to say, that this is a principle which,
+like the conservation of matter, is incapable of absolute proof, but its
+assumption has greatly helped scientific thought and speculation from
+time to time. Clerk Maxwell says (_Theory of Heat_) on this point: "The
+total energy of any body is a quantity which can neither be increased
+nor decreased by any mutual action of the bodies, though it may be
+transformed into those forms of which energy is susceptible."
+
+The conservation of energy is inseparably connected with the
+conservation of matter (Art. 30). They cannot be divided, because, if
+energy is only to be found in association with matter, then if the law
+of the conservation of matter falls to the ground, the principle of the
+conservation of energy falls with it. Energy, therefore, like matter,
+cannot be destroyed or created by any process known to man. As there is
+no process known, either in the chemical or in the physical world, by
+which new matter may be created by man, so, in relation to energy of any
+kind or sort, there is no process known by which man can create or even
+destroy the smallest form of energy that exists. If energy appears in
+any body or in any particular form, it is solely because of the loss of
+energy in some other body, or in some other form.
+
+All changes of energy, therefore, are simply changes due to the
+difference in form in which the energy is manifested. At one time it
+will be manifested in the form of light, then of heat, then in
+mechanical motion, and so on. Joule gave us some good illustrations of
+this principle of the conservation of energy. He showed us how
+electricity could be changed into heat, and the heat into work. When
+light, which is a form of energy, is absorbed by any opaque body, it is
+found that the body which has absorbed it has become hotter. The energy
+of light has not been destroyed, but as its energy cannot pass through
+the opaque body, it has been employed in agitating the particles and
+atoms of that body, which becomes hotter in consequence.
+
+Thus from the principle of the conservation of energy, which is in
+operation not only in our planetary world, but throughout the whole of
+the solar and stellar space, and indeed throughout the whole universe,
+we arrive at the conclusion that the total quantity of energy throughout
+the universe is unchangeable. In the evolution and development of
+worlds, and in the destruction of those worlds after long periods of
+time, throughout all the varied manifestations of heat, light,
+electricity, and magnetism, associated with the development and
+destruction of each globe, the sum-total of the energy of the universe
+remains the same. Meteors may rush into the atmosphere of planets, and
+be dissolved into Aether through the friction, comets may be dissolved
+into their component gases as they near the sun, water may be changed
+into vapour by the heat of the summer sun, vegetation may be produced
+from apparently dead matter, and then that vegetation may itself decay
+and return to the dust by which it had been built up, but throughout all
+these processes of birth and death, of evolution and devolution, the
+sum-total of active living energy which is associated with all the
+phenomena, remains unalterable and unchangeable. Such is the teaching of
+the great principle of the Conservation of Energy as enunciated by Mayer
+and Helmholtz.
+
+
+ART. 53. _Transformation of Energy._--One of the chief characteristics
+of energy is, that we can transform it, and it is chiefly of use to us
+because of its capability to be transformed, but in all its
+transformations, the total quantity of energy remains the same. The
+transformation of energy renders it necessary to the existence of all
+life, and to all physical change in the universe. Mayer showed us that
+all energy in the solar system primarily derives its existence from the
+sun, and that all plant life and physical life owe their continued
+existence to the energy which is poured out from the sun upon the
+planetary worlds. So that energy is always flowing from the sun into the
+surrounding space in the form of light, heat, and electricity, the
+medium of its passage being the universal Aether.
+
+This principle of transformation teaches us, that heat may be converted
+into electricity; that light may be converted into heat, or electricity
+may be converted into either heat or light or both. This principle of
+transformation naturally follows from the principle of the conservation
+of energy; because, if energy cannot be destroyed in any way, but is
+made to disappear by any process, it must reappear in some other form,
+and therefore has been transformed from its original state. So that,
+whenever one kind of energy disappears, then it is absolutely necessary,
+according to the principle of conservation of energy, that some other
+kind shall be produced. There cannot be any real loss or destruction.
+
+That leads us to the next point regarding this principle of
+transformation, which is that all transformations of energy take place
+in fixed proportions. When a certain quantity of coal is burned, a
+certain quantity of heat, or thermal energy as it is sometimes called,
+is produced, and the quantity of heat so produced is definitely
+proportionate to the quantity of coal consumed.
+
+If a certain quantity of coal were burned in a perfect steam-engine,
+that is one in which there would be no loss of heat, then also a
+definite amount of mechanical work would be done, which would be
+strictly proportionate to the heat generated by the consumption of the
+coal. So that when coal is put into an engine, the potential energy of
+the coal is transformed into kinetic energy of the steam, and that is
+again transformed into actual mechanical energy of the engine itself, by
+which work is done in driving or pushing or pulling the train along, and
+the amount of work done is proportionate to the coal consumed.
+Illustrations of transformation are common, and may be seen by any
+person living in a large town. Thus at any electrical station or
+electric tram terminus, these transformations of various forms of energy
+are very familiar sights. We have first the transformation of the coal
+in the furnace into heat. This heat converts water into steam, whose
+motion is communicated by proper machinery into a dynamo, the product of
+which is electricity. That electricity is then conveyed along wires, and
+work is done by it, by moving trams along the connected tram system, or
+it may be converted into heat in the carbon filament in the car itself,
+which, if heated enough, will then produce the electric light. So that
+starting from the coal, we have several transformations therefrom into
+the forms of heat, light, motion, and finally mechanical energy, which
+results in Work. The question arises as to what is the law of
+equivalence in regard to the transformation of energy. That is, if we
+have a certain amount of energy of a given sort, how much of any other
+sort can be produced by it? The answer is partly to be found in a
+statement made by Joule in 1843, which practically embodies what is
+known as the first law of Thermo-dynamics, and is as follows: "When
+equal quantities of mechanical effects are produced by any means
+whatever, from purely thermal sources, or lost in purely thermal
+effects, then equal quantities of heat are put out of existence or are
+generated, and for every unit of heat measured by raising a pound of
+water one degree F. in temperature, you have to expend 772 foot-pounds
+of work." From this law we learn that heat may be used to do work, but
+that a certain amount of heat is always used up in the process. It can
+also be demonstrated that electric currents can do work, but to generate
+the currents a certain amount of work must be done.
+
+This equivalence and transformation prevail in all forms of energy,
+whether it be mechanical energy, thermal or heat energy, or electrical
+energy.
+
+
+ART. 54. _Potential Energy._--Energy has been divided into two classes,
+which are termed respectively Potential Energy and Kinetic Energy. We
+will look at the former first.
+
+_Potential Energy_ may be briefly defined as energy of position.
+
+Thus if we lift a body from the ground, the energy which has been
+imparted to it is energy of position, or potential energy. A glacier
+high up the mountain possesses potential energy, because of its
+position. By the mere fact that it is situated high up the mountain, it
+has a capacity for doing work by its descent, and if that descent be
+very sudden, the work done will be destructive work, as it may sweep
+away all houses and villages in its sudden descent. Thus, by the mere
+fact of its elevation, it possesses a power of doing work, which it has
+lost when it has descended. Again, work done in winding up the spring of
+a clock is stored up in the form of potential energy, and gradually runs
+out in the form of motion or kinetic energy.
+
+Potential energy is really the complementary principle of kinetic
+energy. That is to say, the amount of potential energy lost by any body,
+is equal to the amount of kinetic energy gained by the other body, to
+which the energy has been transferred. In the case of a body falling, as
+the potential energy diminishes, the kinetic energy increases, but the
+total amount of the two combined always remains the same. This is well
+illustrated in the case of a swinging pendulum. When a pendulum is at
+the highest point of its swing, its velocity or kinetic energy is zero,
+but at that point its potential energy is greatest. As it descends, the
+potential energy decreases, but the kinetic energy increases. When the
+pendulum is at the lowest point its energy is wholly kinetic, the
+potential energy being zero at that point, while it has sufficient
+kinetic energy to raise it to the highest level again. Throughout the
+cycle of these operations, the sum-total of the two energies always
+remains the same.
+
+Professor Tait points out, in his _Recent Advances in Physical Science_,
+that the available sources of all potential energy may be divided into
+four classes--
+
+    1st. Fuel.
+    2nd. Food of Animals.
+    3rd. Water-power.
+    4th. Tidal Water-power.
+
+All these are different forms of potential energy. Under the head of
+fuel he includes not only wood, coal, but also all forms of matter that
+may be used or burnt up by heat, or dissolved by chemical agencies. Thus
+zinc and lead, which are used in batteries, are merely forms of fuel.
+That potential energy resides in such things as wood and coal is a
+matter of common experience. All our coal-fields are stores of energy,
+which received their energy when in plant form, ages ago, from the sun,
+and this energy is now being used to drive our machinery, to warm our
+houses, and to give light to our homes and our cities. It has been
+calculated that a pound of coal would give out 14,000 heat units, which
+is equal to 11,000,000 foot-pounds of work, which is also equal to the
+amount of work a horse can do in five hours. Again, all food, whether it
+be the food of animals, as vegetables and plants, or of man, as bread,
+meat, etc., are all forms of potential energy, or energy which is stored
+up in matter. All forms of food have a certain amount of energy in them,
+which is used up in the body in building up waste tissue and imparting
+energy to the physical frame.
+
+Again, all forms of water-power, whether it be in the form of the
+flowing river or the tidal motion of the sea, possess a large amount of
+potential energy which may be used up to do mechanical work. They also
+possess kinetic energy, or energy of motion. We find illustrations of
+the possession of potential energy by rivers and tides, in the fact that
+by their fall from a higher to a lower level they may be made to do
+mechanical work, as in the case of the turning of the water-wheel by the
+fall of the water, which motion is communicated to machinery, and
+various forms of work are the result. In Switzerland and America
+advantage is being taken of the energy of falling water to generate
+electricity, by means of which villages and towns are being supplied
+with electric light at a very small cost.
+
+
+ART. 55. _Kinetic Energy._--Kinetic energy may be defined as energy of
+motion, and is the energy which a body possesses in consequence of its
+motion. A body in motion thus possesses kinetic energy, which it must
+impart to some other body before it can be brought to a state of rest.
+The body may be simply an atom, as a vortex atom, but if it be in
+motion, as all atoms are, then it must possess kinetic energy, which may
+be transferred to another atom by collision, or by some other method. As
+has already been pointed out in previous articles, kinetic and potential
+energy are complementary to one another, the sum-total of the two
+combined always remaining the same in any cycle of work, according to
+the principle of the conservation of energy. We get a good example of
+this oscillation from kinetic to potential, and _vice versa_, in the
+planetary system. When the earth is farthest from the sun, its velocity,
+and consequently its kinetic energy, is at its lowest point; but there
+the potential energy is at its greatest. As the earth turns round in its
+orbit, however, and begins to approach the sun again, its potential
+energy decreases, while its kinetic energy increases with its increased
+velocity. So that by the time it has reached the nearest part of its
+orbit to the sun, its velocity, and consequently its kinetic energy, is
+at a maximum, while the potential energy is at a minimum. Then as the
+earth passes round its perihelion, the kinetic energy is used up in
+assisting the earth to overcome the attraction of the sun. Thus there is
+this oscillation from kinetic to potential, and from potential to
+kinetic, year in and year out, as the earth performs its cycle round its
+central body the sun.
+
+Professor Tait, in the work referred to in the previous Article, gives
+examples of kinetic forms of energy under the following heads--
+
+    1st. Winds.
+    2nd. Currents of Water.
+    3rd. Hot Springs and Volcanoes.
+
+It can be readily seen that winds are a form of energy, as we have
+innumerable instances of the power and energy which they exert.
+Advantage is taken of that kinetic energy by means of windmills, in
+which the energy of the wind is imparted to the revolving sails, and
+thence to the machinery, various forms of mechanical work being the
+result, as, for example, the grinding of corn, or the pumping of water.
+The pressure or energy of winds has even been calculated, the following
+figures being examples--
+
+VELOCITY IN MILES PER HOUR.   FORCE IN LBS. PER SQ. FOOT
+
+           1 mile.               .005 lb. per sq. foot.
+           5  "                  .123  "   "     "
+          10  "                  .496  "   "     "
+          15  "                 1.11   "   "     "
+          20  "                 1.98   "   "     "
+          30  "                 4.5    "   "     "
+          40  "                 7.9    "   "     "
+          50  "                12.5    "   "     "
+
+In the case of currents of water, whether they are in the form of river
+currents or ocean currents, as has already been pointed out in the
+previous article, the question of potential energy, or energy of
+position, is associated with their kinetic energy. Water is taken at a
+certain elevation, and then allowed to fall to a lower level, and in its
+fall from the high level to the lower level, its kinetic energy is used
+to drive mill-wheels, and thus work is done, the kinetic energy of the
+water being transformed into the motion of the machinery. This machinery
+may be used to work a dynamo, and thus electric light may be generated,
+or it may drive an electric motor which may perform all sorts of
+mechanical work. The great underlying principle of either kinetic or
+potential energy rests in the fact, that wherever we have energy of any
+kind or sort, whether it be associated with water, wind, or Aether,
+there we have the capacity to do work, the amount of work depending upon
+the amount of energy that exists in the matter which is the vehicle of
+energy.
+
+In Art. 50 it has been indicated that the Aether possesses several kinds
+of motions. From the sphere of light and heat, we learn that the Aether
+possesses certain motions which are always exerted in a direction from
+the central body, which gives rise to the light- and heat-waves. That
+being so, it conclusively follows that the Aether possesses kinetic
+energy, and therefore, possessing this energy, it also possesses the
+power to do work. It must be remembered we are no longer dealing with a
+frictionless medium, but with a gravitating medium, possessing mass and
+inertia, and, that being so, wherever we have the Aether in motion,
+there we have kinetic energy or the power to do work; and that work will
+correspond to the particular kind of motion which is exerted on any body
+by the aetherial motions, and will be equally subject to Newton's Laws
+of Motion.
+
+
+ART. 56. _Energy and Motion._--An advance, however, as to the meaning of
+the term Energy has been made within recent years, which brings it more
+into harmony with that simplicity of conception, and accordance with
+experience which are the very foundation of all philosophy. Instead of
+the term Energy, there is now being used another term to denote the
+forces which form the life of the universe, and that term is the word
+"Motion."
+
+Professor Poynting says: "All energy is energy of motion" (_British
+Association Report_, 1899).
+
+Thus motion is the fundamental principle of all phenomena. If we analyze
+all forms of energy with which we are familiar, we shall soon find that
+they are only changes of one form of motion into another. Thus we shall
+see that heat is a mode of motion, as has been proved by Tyndall, that
+light is another mode of motion, and that electricity is also a mode of
+motion. I need hardly point out that this advance in our conception of
+energy is strictly in accord with the Rules of Philosophy. First, it is
+simple in conception. When we say that a body possesses energy, whether
+that energy be potential energy or kinetic energy, it does not convey to
+the mind some definite concrete fact, as does the statement that a body
+possesses motion. Every one, whether familiar with scientific teaching
+or not, understands and is familiar with the word Motion, as it is a
+common phenomenon of everyday life and experience. As Energy was simpler
+in conception than Newton's term Force, so Motion is simpler in
+conception than the rather vague and indefinite term Energy; therefore
+when we say that all energy is energy of motion of some kind or sort, we
+state that which is philosophically correct.
+
+It is also in accord with the second Rule of Philosophy, in that it is
+strictly in harmony with experience and observation. Look where we will,
+or at what we will, there we find motion of some kind or other, whether
+it be among the innumerable stars, or in our own solar system, or any
+phenomena on the earth, or even among the world of atoms in their minute
+and atomic systems. Such a thing as absolute rest, or stagnation, is
+unknown in the universe. Wherever there is matter, there we find motion
+of some kind or other. It may be vibratory motion as heat, or wave
+motion as light, or rotatory motion as electricity, but motion of some
+sort is inseparably connected with all matter. So that when we say that
+all energy of the universe is the energy of motion, and motion only, we
+state that which according to the second Rule of Philosophy is
+absolutely correct.
+
+Further, I wish to premise that by the use of the term modes of motion,
+in lieu of energy, the third Rule of Philosophy will be fulfilled. For
+if all phenomena of the universe, whether it be heat, light,
+electricity, be due to different modes of motion, then Gravitation
+should be explained from the physical standpoint by some kind of
+aetherial motion also. This I can safely premise will be done, and in
+the later chapters of this work, Gravitation will be shown to be due to
+the motions of the aetherial medium which floods all space. By so doing,
+all the Rules of Philosophy will be fully satisfied, and Gravitation
+will then be brought into line with all the other forms of motion, as
+heat, light, electricity, and magnetism, which are in themselves modes
+of motion, as will be shown in subsequent articles.
+
+
+ART. 57. _Conservation of Motion._--If it be true that all energy is the
+energy of motion, then the principle of the conservation of energy ought
+also to apply to all the modes of motion, and in its place we should
+then have the principle of the conservation of the various forms of
+motion. This defined would be, that the total amount of all motion in
+the universe, as heat and light, electricity, magnetism, and Gravitation
+also, if that be due to the motion of the Aether, is unalterable and
+unchangeable.
+
+There may be changes from one form of motion to another, from heat to
+light, and light back to heat; heat into electricity, and electricity
+into light or heat; from Gravitation into heat or into light, or even
+into electricity; but the sum-total of the whole remains the same.
+
+Again, as the principle of the conservation of energy is inseparably
+connected with the conservation of matter, so the principle of the
+conservation of all the modes of motion is also inseparably connected
+with the conservation of matter. They cannot be divided, so that
+wherever we get matter of any kind or sort, there we get motion of some
+kind, either in the form of heat, light, or electricity, or those
+aetherial motions which produce those phenomena associated with
+Gravitation.
+
+As matter cannot be destroyed by any known process to man, so motion
+cannot be destroyed either. On the vortex atom theory of matter, this
+principle of the conservation of any mode of motion is perfectly
+intelligible, especially if added to that theory we have Dr. Larmor's
+electron theory as the basis of the vortex atom. An atom in its ultimate
+state is nothing more or less than Aether in rotation, and as Aether is
+matter, we see that on the assumption of this atomic basis, we have even
+in the atomic world an illustration of this conservation of matter and
+motion, as in such an atom we have nothing but matter (_i. e._ Aether)
+and motion. Carrying the idea upwards in the atomic scale, if atoms of
+hydrogen or oxygen are multiples of these vortex atoms, then again we
+have nothing in all the elements, or combination of the elements, but
+matter and motion. Again, as all planets and satellites, suns and stars,
+are but agglomerations of elements, we have still the same two classes
+of things, matter and motion, and so from the most infinitesimal atom in
+existence, up to the most ponderous star that exists in the universe, we
+have running through them all the principle of the conservation of
+motion, which is to matter the source of all its activities, energies,
+and powers. Motion, therefore, might almost be said to be eternal. We
+have heard from time to time of the term perpetual motion. Philosophers
+have from time to time endeavoured to discover some application of this
+perpetual motion, but all efforts in this direction up to the present
+have proved futile. In one sense there is no such thing as perpetual
+motion. In another sense, that is from the standpoint of the
+conservation of all modes of motion, as motion cannot be destroyed, it
+must therefore be perpetual.
+
+It is an absolute impossibility to obtain motion except from some
+antecedent energy, which is itself a form of motion. It would require
+the distinctive fiat of an Almighty Creator to produce motion from
+nothing, and I question whether such a result is obtainable, as I hold
+that if the Creator, at any time in the history of the universe, set any
+substance in motion, the source from which that motion was derived, was
+His own Divine Energy, and in that sense the physical motion was not
+produced from nothing. Such an assumption is altogether opposed to all
+philosophical reasoning and experience. I hope to deal with the question
+either in the last chapter of this book, or in another work.
+
+
+ART. 58. _Transformation of Motion._--Again, if energy be the energy of
+motion, and the principle of the transformations of energy holds good,
+then it is equally true that all modes of motion are also transformable.
+Thus heat is a mode of motion, being due to the vibration of the atoms
+which go to make up any body. Light is also a mode of motion, being due,
+as far as solar light is concerned, to the periodic wave motion of the
+Aether. While electricity, as we shall see later on, is also due to some
+form of rotatory motion. It has already been shown (Art. 54) that light
+can be converted into heat, so that the periodic wave motion of light
+can be transformed into the vibratory motion of heat.
+
+Heat can also be converted into electricity, and if electricity be
+rotatory motion, then the vibratory motion of heat can be transformed
+into the rotatory motion of electricity. Again, as electricity can be
+converted into light, the rotatory motion of electricity can thus be
+transformed into the periodic wave motion of light. Thus through all the
+forms of motion with which we are familiar, we find this principle of
+transformation holds good, so that each form of motion may be directly
+or indirectly transformed into any one of the other kinds. Whenever,
+therefore, one kind of motion disappears, it is absolutely necessary,
+according to the principle of the conservation of motion, that some
+other kind shall be produced. There cannot be any real loss or
+destruction of the motion. It may be transformed, but not lost. By the
+use of proper apparatus, therefore, any form of motion with which we are
+familiar may be converted into another form, and in the process not the
+least quantity of any form of motion is lost. Heat may be changed into
+light, and light into heat; electricity into light, and light into
+electricity; heat into electricity, and electricity into heat. Indeed,
+starting from any one form, any of the other modes of motion may be
+produced, either directly or indirectly, and mechanical effects or work
+may be produced by each and all. Then, again, the order can be reversed,
+as by doing work which is simply applied motion, any of the other modes
+of motion can be produced. Thus heat can be produced by friction, and if
+the friction which is the outcome of muscular energy be continued long
+enough, a light will be the result, in the form of fire. When certain
+forms of work are done, as the turning of the handle of an electrical
+machine, frictional electricity will be produced. So that not only are
+all the modes of motion convertible into work, but work itself can be
+transformed into the modes of motion known as heat, light, electricity,
+and magnetism.
+
+Now, if Gravitation be due to motion of the Aether, and if it is true
+that all modes of motion are convertible, then the application of this
+principle should also hold good in relation to Gravitation. It has been
+demonstrated by Joule and others that Gravitation can be converted into
+heat, light, and electricity. It can be converted first into heat. Joule
+made a number of experiments to ascertain what quantity of heat is
+produced by falling bodies, that is bodies under the influence of
+Gravitation. From experiments he has calculated that if one lb. of water
+falls through a space of 772 feet, it would raise the temperature of
+the water one degree Fahrenheit--that is, the water after its fall will
+be one degree hotter than when it started to fall. Here, then, we have
+the exact equivalence of a certain amount of gravitational motion
+expressed in terms of heat. So that, whenever motion of a falling body
+produced by gravity is arrested, heat is generated, and as heat is a
+mode of motion, it follows that the motion of Gravitation has been
+converted into the motion of heat. Again, the motion of gravity may be
+converted into that of light. This may be demonstrated as follows: Lord
+Kelvin has suggested that the light and heat of the sun are maintained
+by the falling into the sun of meteorites. Now the cause of the falling
+of these meteorites into the sun is the Attraction of Gravitation, and
+therefore if the falling of these meteorites produces light and heat, it
+necessarily follows that the motion of Gravitation, whatever that may be
+due to, is converted into the motion known as light and heat. Thus it
+can be seen that Gravitation, looked at from the standpoint of a mode of
+motion, is itself conformable to the principle of the transformation of
+motion, and this is an indirect argument in favour of the fact that
+Gravitation is itself due to certain motions of the universal Aether.
+
+
+ART. 59. _Motion and Work._--In Art. 52 we have seen that energy is the
+power which a body possesses to do work, the amount of work which a body
+can perform being regulated by the amount of energy which such a body
+possesses. In Art. 57 we have further seen that all energy is the energy
+of motion, and that wherever we have energy of any kind or sort, whether
+it be in the form of light, heat, or electricity, there we have motion
+of some kind or other. That being so, we arrive at the conclusion, that
+wherever in the universe we have motion of any kind or sort, whether it
+be the motion of Aether, or wind, or water, there we have the power of
+doing work, and the work so done will be proportionate to the motion
+which the medium possesses. The amount of work that air in motion can do
+has been measured, as we have already seen (Art. 55) that air which
+moves at the rate of 30 miles per hour exerts a force of 4-1/2 lb. per
+square foot.
+
+The amount of work that water in motion can do has also been measured.
+The carrying and erosive powers of a river depend on the rapidity of its
+currents. It has been calculated that a velocity of three inches per
+second will transport fine clay; eight inches per second coarse sand;
+while three feet per second will transport stones as large as eggs.
+
+If, therefore, air moving at the rate of 30 miles an hour can exert a
+force of 4-1/2 lb. per square foot, what must be the force or pressure
+of aetherial motion, as light-waves for example, which move with a
+velocity of 186,000 miles per second? The amount of work which such an
+aetherial motion can perform has actually been measured by Professor
+Lebedew of Moscow, and will be dealt with in the chapter on "Light, a
+Mode of Motion," when the application of the work done on a body, as a
+planet for example, will also be considered. Work, therefore, can always
+be done by motion against resistance. This is a fundamental principle in
+the sphere of dynamics, which is incontrovertible, as all experience,
+observation, and experiment teach us, that wherever we get motion of any
+kind or sort, there we have the capacity or power to do work. The work
+done may be either in the form of pushing a body along, or pulling a
+body towards a centre. All experience and observation teach us that no
+body moves (whether it be an atom, or moon, or planet, or sun, or star),
+unless some other body or medium, which is in direct contact with the
+moving body, exercises some pressure or pull upon the moving body. The
+action is purely and simply a mechanical one. So that if this be true,
+then the earth and the planets, the sun and stars, comets and meteors,
+are moved through space solely because they are being pushed by some
+medium, or pulled to the centre by the motions of the same medium. If
+this can be proved to be true, then, as can be readily seen, our
+philosophy will then be made to agree with our experience, and the
+second Rule of Philosophy fully satisfied. As has already been pointed
+out, there is no such thing as action at a distance, therefore the Law
+of Gravitation demands a medium for its operation, production, and
+continuity. Newton distinctly points this out in his Letters to Bentley,
+where he says: "That one body should act upon another through empty
+space without the mediation of anything else, by and through which their
+action and pressure may be conveyed from one to another, is to me so
+great an absurdity that I believe no man who has in philosophical
+matters a faculty for thinking can ever fall into it." It has already
+been pointed out (Art. 42), that the only medium which is universal is
+the Aether medium, and we have therefore to look to the motions and
+properties of that medium for the solution of the problem as to the
+physical cause of Gravitation. That such a medium has motions which are
+as regular as the tides of the sea, or the trade winds of the
+atmosphere, will be proved later on, when it will be found that
+Gravitation, with all that that law implies, is due, as Newton and
+Challis suggested, to the pressure, properties, and motions of the
+aetherial medium, which is as universal as Gravitation itself. This
+being so, it is essential that we should set ourselves to find out from
+the analogies of Nature, what are those properties and motions of the
+Aether which give rise to the universal Law of Gravitation. This I
+propose doing by a consideration of three different modes of
+motion--viz. Heat, a mode of motion; Light, a mode of motion; and
+Electricity, a mode of motion. I venture to premise, from a careful
+consideration of these three truths, that we shall be able logically and
+philosophically to arrive at the simple, yet grand truth which reveals
+the physical source of all motion of the universe.
+
+
+
+
+                              CHAPTER VI
+
+                            HEAT IS MOTION
+
+
+ART. 60. _Heat is Motion._--On the phenomena of Heat, Newton in his
+eighteenth query in _Optics_ asks the questions: "Is not the heat of a
+warm room conveyed through the vacuum by the vibrations of a much
+subtler medium than air, and is not the medium the same as that medium
+by which light is reflected and refracted, or by whose vibrations light
+communicates heat to bodies? And do not the vibrations of this medium in
+hot bodies, contribute to the intenseness and duration of their heat?
+And do not hot bodies communicate their heat to contiguous cold ones by
+the vibrations of this medium propagated from them into the cold ones?
+And is not this medium exceedingly more rare and subtle than air, and
+exceedingly more elastic and active?" Thus it can be seen that Newton
+was of the opinion that heat consists in a minute vibratory motion of
+the particles of bodies, and that such motion was communicated through
+what he calls a vacuum by the vibrations of an elastic medium, the
+Aether, which was also concerned in the phenomena of light.
+
+One of the first experimental investigations into the real nature of
+Heat was made in 1798 by Count Rumford.
+
+While he was engaged in boring brass cannon in the arsenal at Munich, he
+was struck with the degree of heat which the brass gun acquired, and
+with the still more intense heat which the metallic chips, which were
+thrown off, possessed. Of the phenomena he says: "The more I meditated
+on these phenomena, the more they appeared to me to be curious and
+interesting. A thorough investigation seemed even to bid fair to give us
+a farther insight into the hidden nature of Heat." Rumford therefore set
+himself to find out by actual experiments what the nature of Heat was.
+For this purpose he constructed a cylinder, and mounted it so that it
+could be made to rotate by horse-power. At the beginning of the
+experiment the thermometer stood at 60 deg. Fahrenheit, and after
+half-an-hour, when the cylinder had made 900 revolutions, the
+temperature was found to be 130 deg. Fahrenheit, so that there had been
+an increase in the temperature of the cylinder of 70 deg. Fahrenheit.
+The experiment was again repeated in another form with similar results.
+Rumford in dealing with the results of his experiments said: "It appears
+to me to be extremely difficult, if not quite impossible, to form any
+distinct idea of anything capable of being excited and communicated, in
+the manner the Heat was excited and communicated, in these experiments,
+except it be Motion."
+
+Only a year later, Davy gave to the world some results of experiments
+which he had performed, by which he had arrived at a similar conclusion
+to that of Rumford, viz. that "Heat is motion of some kind." His
+experiment consisted of rubbing two pieces of ice together, and by so
+doing showed the ice could be melted. He then caused two pieces of metal
+to be rubbed together, keeping them surrounded by ice, and still he
+found that the two pieces of metal when rubbed together, produced heat,
+and melted the ice. He therefore rightly concluded that heat was
+produced by friction, and of the experiment adds: "A motion or vibration
+of the corpuscles of bodies must necessarily be generated by friction.
+Therefore we may reasonably conclude that this motion or vibration is
+Heat. Heat then may be defined as a peculiar motion, probably a
+vibration of the corpuscles of bodies tending to separate them. It may
+with propriety be called a repulsive motion. Now bodies exist in
+different states, and those states depend upon the action of the
+attractive and of the repulsive powers on their corpuscles, or in other
+words, on their different quantities of repulsion and attraction." It
+was not, however, till 1812 that Davy confidently stated that "The
+immediate cause of the phenomena of Heat is motion, and the laws of its
+communication are precisely the same as the laws of the communication of
+motion."
+
+The question therefore confronts us, if heat be motion, what is the
+particular character of that motion? Is it a vibratory motion as Davy
+suggested, or is it similar to the undulatory wave motion of light? I
+need hardly point out, that we have evidence in favour of the hypothesis
+that light is due to some form of periodic wave motion in the Aether,
+the hypothesis being that known as the undulatory theory. We have also
+similar evidence in favour of the hypothesis, that heat is also due to
+some form of motion of the same aetherial medium. Indeed, it can be
+shown that heat possesses all the properties of light, and is subject to
+the same laws, with the exception that it cannot affect the sense of
+sight.
+
+Heat, then, is due to some motion in the universal aetherial medium,
+that not only fills all space, but also forms an atmosphere around every
+atom or particle of matter that exists in the universe, and that motion
+is generally known as a vibratory or backward and forward motion.
+
+Heat, then, may be said to be due to the vibrations of the Aether that
+surrounds all atoms and molecules, and of which those very atoms are
+composed, that is if we accept the aetherial constitution of all matter.
+So that, whenever a body, whether it be an atom or a molecule, or a
+planet or sun or star, is heated in any way whatever, such bodies excite
+waves in the surrounding Aether, and these waves travel through the
+Aether towards us from the heated body with the velocity of light. When
+these waves fall upon any other body, they become more or less absorbed
+by the body on which they fall, and cause corresponding vibratory
+motions in the same, which give rise to the phenomenon of heat in that
+particular body.
+
+It has to be remembered that nothing definite is actually known as to
+the character of this vibratory motion. It is called a vibratory motion
+because it possesses a periodic vibratory movement, but as to its exact
+character, that has not yet been discovered. I hope, however, to
+indicate what the motion is that produces heat before the completion of
+this work.
+
+
+ART. 61. _Heat and Matter._--If it be true that heat is due to the
+vibrations of the aetherial medium, the question now arises, as to how a
+body may become heated, and by so doing be transformed into the three
+stages in which matter is found. We have already seen (Art. 36), that
+matter may be found in three forms, viz. solid, liquid, and gaseous, and
+that all these different forms of matter are composed of minute parts
+called atoms. In the case of the solid, the atoms are held closely
+together by some strong attractive power, termed cohesion; in the case
+of the liquid, the atoms have a greater freedom; while in the gaseous
+form they have a greater freedom of movement than when in either the
+liquid or the solid state. According to Young's Fourth Hypothesis (Art.
+45), we find that all matter, and therefore all atoms have an attraction
+for the Aether, by means of which it is accumulated within their
+substance, and for a small distance around them in a state of greater
+density, and therefore of greater elasticity. In other words, as Aether
+is gravitative, every atom possesses an atmosphere of Aether in the same
+way that the earth has its atmosphere of air; and further, the aetherial
+atmosphere of each atom is densest nearest to the atom, gradually
+getting rarer and rarer the further the atmosphere recedes from the
+nucleus or centre, the elasticity or pressure being always proportionate
+to the density. Professor Challis, in his Dynamical Theory of Light and
+Heat, states that all the forces in Nature are different modes of
+pressure under different circumstances of the universal Aether, and as
+heat is a Force, and therefore a mode of motion, that also must be due
+to some form of pressure due to the vibrations of the Aether.
+
+Professor Challis[8] on this point says: "According to this theory, the
+atoms of any substance are kept in position of equilibrium by attractions
+and repulsions resulting from the dynamical action of the vibrations of
+the Aether which have their origin at the atoms. Each atom is the centre
+of vibration propagated equally from it in all directions, and that part
+of the velocity of the vibration which is accompanied by change of density
+(of the Aether) gives rise to a repulsive action on the surrounding
+atoms. This action is the repulsion of heat, which keeps the individual
+atoms asunder."
+
+With all these facts before us, we are now in a position to account for
+the changes of matter which take place when heat is applied to either
+a solid or a liquid body. We have already seen (Art. 36) that it is by
+the application of heat that matter in its solid form is changed into a
+liquid, and from a liquid into a vaporous or gaseous form. It is now for
+us to endeavour to form a mental picture as to how this is done.
+
+For example, let us take an iron ball, and apply heat to it, either by
+putting it in a furnace or suspending it in some way over an intense
+heat. As the heat, which is vibratory motion of the Aether, begins to be
+absorbed by the iron ball, it sets the atoms which compose the ball in
+motion, urging them to separate, and thus cause the iron ball to expand
+and increase in volume. As greater heat is absorbed, so greater motion
+among the atoms is the result. So that the motion of heat is tending
+all the time to expand the body, while they are held together by the
+attraction of cohesion, whatever that may be. As the heat is further
+increased, the iron ball begins to assume a liquid or molten form, its
+atoms beginning to move about with greater freedom, though held together
+by a decreased attractive power. In this condition we now say that it is
+in the molten state. Now during all this time, what has the Aether been
+doing, or what part has it played in the expansion and changing of the
+solid to a liquid? We have to remember, from Art. 60, that wherever
+there is motion of any kind or sort, there we have a capacity to do
+work, and that the aetherial motion which we term heat is no exception
+to this rule. We are now no longer dealing with a frictionless medium,
+but with a medium which possesses weight, because it is gravitative, and
+consequently possesses inertia also. So that whenever the Aether is set
+in motion by flame or heat, its motion would be transmitted by waves of
+some kind to the iron ball. These periodic waves, acting upon the mass
+of the ball, attack the molecules of the ball and begin to set them in
+motion. It is supposed that they are already in motion, as nothing is
+absolutely cold, and the motion of the aetherial waves imparts a greater
+motion still to the molecules, with the result that the agitation
+becomes greater and greater, until at length the agitation becomes so
+great, that the molecules break away from the power of attraction that
+holds them together, and so begin to move about with greater freedom and
+with greater rapidity. It is this state which we call molten. Now if
+Aether be frictionless, as has hitherto been supposed, and if heat be
+due to the vibratory motions of Aether, the problem confronts us, as to
+how the motion of a frictionless medium can do work in expanding a body,
+and urging the molecules of a body further and further apart. If the
+Aether be frictionless, then the waves of Aether known as aetherial heat
+waves ought to pass between the atoms as water passes through a sieve,
+or wind passes through a forest. Yet it is assumed that the vibratory
+motions of a hot body are caused by vibrations of the periodic waves of
+the Aether, which act upon the molecules of the body; and, in order for
+such an assumption to be consistent with the results, the only possible
+conception that can be accepted of the Aether, is that it is
+gravitative, and consequently possesses mass and inertia, and therefore
+has a capacity not only to accept motion, but also to transmit motion to
+another body, and impart the motion which it has accepted to a colder
+body.
+
+By imparting such motion, it increases the motion of the cold body, and
+gradually changes its state from a solid to a liquid condition. Here,
+then, from the realm of heat we have another argument in favour of the
+fact that Aether is gravitative, and therefore possesses mass and
+inertia.
+
+In the experiment of reducing the iron ball from a liquid state, so to
+speak, to a vaporous condition, we have practically a continuation of
+the same process, only that greater heat or greater aetherial motion is
+required, and whereas in the previous experiment the molecules of the
+ball were acted upon, in this case the atoms are more directly acted
+upon by the Aether waves. In all these processes it suggests itself to
+me that the aetherial atmosphere must take its share in the expansion
+and transformation of the liquid form into a gaseous form, or the solid
+into a liquid form. Taking the analogy of our atmosphere in its relation
+to the earth, we know that when heat is absorbed by it, it expands, the
+result being that a greater pressure is exerted by the expanding
+atmosphere, than would be exerted if it remained at the same temperature
+all the time. If, therefore, each atom has an aetherial atmosphere,
+which is capable of expansion, then the effect of the absorbed aetherial
+motion of the heat waves on each atomic atmosphere must be to expand it,
+and thus there will be a pressure _away from_ the atom, because of the
+increased elasticity acquired by the heated aetherial atmosphere. So
+that the expansion of the liquid is due to the increased elasticity of
+the aetherial atomic atmosphere, which has been expanded by heat, and
+which exerts an increased pressure on neighbouring atoms, thus seeking
+to push them farther away from each other. There are other motions of
+the atoms themselves in addition to this to be considered, but I am now
+seeking to show only the effect of the aetherial atmosphere of each atom
+upon the neighbouring atoms. This would give each atom a larger sphere
+of freedom in which to move, and that state would then be called a
+gaseous and not a liquid one. This assumption of the part which the
+aetherial atmosphere plays in the expansion of a body is therefore in
+agreement with Professor Challis' theory of heat already referred to, in
+which he states that heat gives rise to aetherial vibrations which act
+repulsively on the neighbouring atoms. In further confirmation of the
+existence of these aetherial atmospheres that exist around atoms, I
+would like to draw the attention of the reader to a theory of heat given
+to the world by Rankine, _Phil. Mag._, 1851. His theory is known as the
+"Hypothesis of Molecular Vortices."
+
+He assumed that "each atom of matter consists of a nucleus or central
+point, enveloped by an elastic atmosphere, which is retained in its
+position by attractive forces, and that the elasticity due to heat
+arises from the centrifugal force of those atmospheres revolving or
+oscillating about their nuclei or centres."
+
+Now in this assumption we find that he admits that each atom has an
+atmosphere, such atmosphere evidently being an aetherial one, and in
+that case the hypothesis would agree with the statement in Art. 46, that
+every atom possesses an aetherial atmosphere. He further points out that
+the atmosphere is retained in its position by attractive forces. This is
+also in harmony with the hypothesis given in Art. 45, which proves that
+Aether is gravitative, and therefore the atmosphere of the atom would be
+held in its position by the attractive force of Gravitation, as
+suggested by Young in his Fourth Hypothesis.
+
+Further, he goes on to show that the elasticity of the atomic atmosphere
+is proportionate to its density, which is also in conformity with the
+statement made in Art. 47, and is also in accordance with Boyle's Law.
+Then he goes on to prove that the quantity of heat in a body is measured
+by the molecular revolutions of the vortices.
+
+He does not clearly define the exact character of those molecular
+vortices, but I take it to mean that each atmosphere is in a state of
+revolution around its atomic centre, in the same way that the atmosphere
+of a planet is in a state of revolution around its central body.
+
+Such an assumption is entirely in harmony with experience, as there is
+an analogy for its assumption from the planetary system; and if an atom
+is a world in miniature, as I believe it to be, then the atmosphere of
+the atom ought to revolve around its central nucleus in the same way
+that the atmosphere of a planet revolves around its nucleus or central
+body.
+
+He then deals with temperature, and with the pressure of gases caused by
+heat, showing the relation of elasticity and pressure to temperature in
+a table of results given in the _Phil. Mag._ for 1851. I must refer the
+reader to the paper itself for fuller details. Thus from one of the
+greatest thinkers of modern times we have further testimony to the
+hypothesis that Aether is matter and is therefore gravitative, and
+because of its gravitating tendency, it forms around every atom and
+molecule elastic envelopes or atmospheres, whose pressure is always
+proportionate to their density.
+
+[Footnote:8 _Phil Mag._, 1859.]
+
+
+ART. 62. _Radiation and Absorption._--We have already seen (Art. 31)
+that all matter is made up of atoms and molecules, each of which is
+surrounded by its atmosphere of Aether. By means of the Aether, motion
+in the form of light and heat may be transmitted from one atom and
+molecule to another. The transmission of heat from one body to another
+is termed Radiation, while the acceptance of heat is termed Absorption.
+Tyndall defines Radiation as "the communication of molecular motion from
+the heated body to the Aether in which it is immersed,"[9] and
+Absorption, therefore, would be the acceptance of motion by the body
+from the Aether. So that in Radiation, the atom, molecule, or body parts
+with motion to the Aether, while in Absorption it gains motion from the
+Aether.
+
+Now in order for us to understand this theory of Radiation and
+Absorption, it will be well for us if we look at a similar effect in the
+sphere of music and sound. Let us suppose that we have two tuning-forks
+of the same pitch, placed on a table at a distance of a foot from each
+other. If we set one of the forks vibrating, the waves which it radiates
+through the air will fall upon the other one, and will also set it in
+vibration, because they are of the same period or size as those waves
+which it would itself give off when sounded. Thus while one is losing
+its motion, the other is gaining it, or while one is radiating motion,
+the other is absorbing motion. This can readily be proved by stopping
+the vibration of the first fork, when it will be found that the second
+fork is now giving out a similar note to the first, although it was
+silent at the commencement. Thus we have here an example of radiation
+and absorption of sound, the success of the experiment depending upon
+the fact that both forks shall have the same pitch. Again, it must be
+noted, that if we have two tuning-forks both of which are of the same
+pitch, and both vibrating at the same time, then, while one is radiating
+sound and consequently losing motion to the other, yet at the same time
+it is absorbing motion from the other. Because, if fork A can transfer
+motion to fork B, the latter can equally transfer its motion to fork A,
+and when both are vibrating together, each is the recipient of part of
+the other's motion, while at the same time giving off motion in the form
+of sound waves itself. So that the power of a fork to radiate sound
+waves equals its power to absorb sound waves. If now we apply this
+simile to the atomic and molecular world, we shall be able to form a
+mental picture as to what takes place in radiation and absorption.
+
+All atoms and molecules are ever in a state of ceaseless motion, ever
+moving, never still. All are creating Aether waves which move away with
+the velocity of light. If, in the transmission of the waves by the
+Aether, they fall upon another atom which can emit a wave of similar
+length, in the same way that two tuning-forks emitted sound waves of the
+same length, then the atom upon which the waves strike will be set in
+vibration, as the second tuning-fork was set in vibration by the first.
+We shall look again at the principle of wave motion in the next chapter.
+Further, from the simile of the two forks, which absorb sound at the
+same time that they radiate sound, we learn that an atom or body
+radiates heat waves at the same time that it is absorbing heat waves.
+Suppose that we have two bodies at equal temperatures, it must not be
+thought that the radiation or absorption has ceased, for, according to
+the simile used, they both still continue to vibrate and emit the
+aetherial heat waves; but where we get equality of temperatures, there
+we get equality of radiation and absorption. Before this equality of
+temperatures, however, is reached, the hotter body will radiate more
+heat waves than it absorbs, while the colder body will absorb more heat
+waves than it emits. All bodies, whatever their temperature, are
+incessantly radiating heat waves. This may be proved experimentally with
+proper apparatus, as for example with an instrument known as the
+thermopile. When, however, the total heat waves radiated out by a body
+are less than it absorbs, the body gets gradually colder, and the
+temperature decreases. So long as this is continued, so long will the
+body continue to get colder and colder, until it arrives at the same
+temperature as the surrounding bodies, at which point the total heat
+waves radiated out will equal the total heat waves absorbed, and at that
+point the temperature of the body will remain constant.
+
+This aspect of temperature was first introduced by Prevost of Geneva in
+1792, in an article in which he tried to explain the radiation from a
+cold body. According to his reasoning, a body is not simply regarded as
+radiating heat when its temperature is falling, or absorbing heat when
+it is rising.
+
+What he tried to make clear was, that both radiation and absorption were
+going on at one and the same time; the radiation depending upon the body
+itself, but the absorption depending upon the nature of the body. While
+radiation and absorption are thus reciprocal, which implies that a good
+radiator is a good absorber, and a bad radiator is a bad absorber, it
+does not follow that all bodies radiate and absorb alike.
+
+The capacity of bodies to radiate and to absorb differ considerably. Dr.
+Franklin made several simple experiments to prove the relative powers of
+radiation and absorption with several pieces of cloth. These were put
+out on the snow, and exposed to the heat of the sun. He found that the
+pieces which were dark in colour sank deepest into the snow, while those
+which were lightest in colour sank the least. From this he inferred that
+the darkest pieces were the best absorbers, and therefore the best
+radiators, while the light-coloured cloths were the worst absorbers, and
+therefore the worst radiators.
+
+Radiation, therefore, may be said to be the propagation of a wave motion
+through the Aether; and, as all motion is a source of power or energy,
+we have in the radiation of heat from one body to another by the
+aetherial waves, the transmission of a motive power capable of doing
+work, either internal work as increasing the temperature of the molecule
+or body, or external work as separating the atoms, or driving them
+further apart. It can readily be seen that if the Aether were
+frictionless, as has generally been supposed, the Aether could not have
+any motive power at all, and therefore could not transmit heat from one
+body to another. Professor Tyndall[10] on this point says, referring to
+the cooling of a red-hot ball: "The atoms of the ball oscillate in a
+resisting medium, which accepts their motion and transmits it on all
+sides with inconceivable velocity." Now in the previous quotation given
+in this article from the same authority, he states that the atoms are
+immersed in the Aether. So that evidently in his opinion the Aether and
+the resisting medium are one and the same. So that our assumption of the
+gravitative property of the Aether is perfectly in accord with Professor
+Tyndall's conception of the Aether, in so far as it concerns the
+propagation of heat waves; and, as will be shown later on, heat and
+light waves are due to the same physical agent--that is, the Aether;
+therefore, wherever we get heat and light, there, according to Professor
+Tyndall's statement, we must have a resisting medium, and as Aether
+fills all space, the resisting medium must fill all space. This is
+perfectly in accord with our assumption that the Aether is gravitative
+and possesses inertia--that is, the capacity to receive and to impart
+motion, and being gravitative it possesses mass or weight, which is the
+very quality necessary for the existence of a resisting medium.
+
+[Footnote 9: _Heat, a Mode of Motion._]
+
+[Footnote 10: _Heat, a Mode of Motion._]
+
+
+ART. 63. _Heat is a Repulsive Motion._--Whatever be the particular
+character of the vibratory motion of the Aether termed heat, there is
+one fact regarding the same that is very patent and obvious to all; and
+that is, that the vibratory motion of heat is essentially a repulsive
+motion, or a motion from a centre and not one to a centre.
+
+Professor Davy points this out (Art. 60) where he says of heat, "It may
+with propriety be called a repulsive motion," while Professor Challis
+(Art. 61) states that "Each atom is the centre of vibrations propagated
+from it equally in all directions, which give rise to a repulsive action
+on the surrounding atoms. This action (he adds) is the repulsion of heat
+which keeps the individual atoms asunder."
+
+There have been many experiments undertaken which go to prove that a
+repulsive action between atoms and molecules is produced by heat. It has
+been demonstrated that certain coloured rings, known as Newton's rings,
+change their shape and position when the glasses between which they
+appear are heated, thus indicating the presence of a repulsive power due
+to the increased heat. If we consider the change of state that heat
+induces in matter, as, for example, from solid to a liquid, or liquid to
+a gaseous form, we are compelled to admit that heat possesses an
+expanding and therefore a repulsive motion. It is almost an universal
+law that heat expands and cold contracts, and the greater the heat
+absorbed, the greater the expansion. In the case of a solid being
+converted into a liquid, a much greater heat or repulsive motion is
+required to separate the particles, on account of the power of cohesion
+being greater in the solid than in the liquid. As Professor Tyndall[11]
+states when dealing with the stability of matter from the molecular
+standpoint: "Every atom is held apart from its neighbour by a force of
+repulsion. Why then do not the mutually repellent members of the group
+part company? The reason of this stability is that _two_ forces, the one
+attractive and the other repulsive, are in operation between every two
+atoms, and the position of every atom is determined by the equilibration
+of these two forces. The points at which attraction and repulsion are
+equal to each other is the atom's position of equilibrium. When the
+atoms approach too near each other, repulsion predominates and drives
+them apart; when they recede to too great a distance, attraction
+predominates and draws them together." If, therefore, there are TWO
+forces at work in the atomic world, viz. attraction and repulsion, then
+the question arises, Can that repulsive power be increased in any way,
+and if so, by what means? Such repulsive motion, as experiment and
+experience teach us, can be increased, and such increase may be derived
+from the absorption of heat which gives rise to increased atomic motion,
+and so to increased aetherial motion away from the atom, by which the
+repulsive action of one atom upon another is increased. Thus an atom's
+repulsive power may be increased by heat; the greater the heat absorbed,
+the greater the repulsive power that any atom or body exerts upon a
+neighbouring atom or body. We can therefore understand how it is, that a
+body when changed from a solid to a liquid condition occupies a larger
+space in the latter condition than in the former; or why a body when
+changed from a liquid to a gaseous condition occupies a still larger
+volume in the latter than in its previous condition. The expansion in
+both cases is essentially the result of the increased repulsive motion
+that has been imparted to its atoms or molecules by the increased heat,
+and this increased repulsive power has overcome the attractive power of
+the atoms or molecules, with the result that they have been driven
+further and further apart, until, in the gaseous state, the atoms may
+be very far apart indeed. Wherever, therefore, we have heat of any kind,
+there we have a repulsive motion, such motion being proportionate to the
+heat radiated, that is, the aetherial waves propagated by the body. If,
+therefore, in the atomic world we find a repulsive motion, which is due
+to the vibratory motions of the Aether generated by heat, the question
+now confronts us, as to whether in the solar system, and indeed all
+through the universe, there is not the same repulsive motion from a
+central body due to the wave motions of the Aether termed Heat.
+
+May we not find in the repulsive power of heat in the atomic world, an
+indication of that very power for which we are seeking in the solar
+system--that is, a Centrifugal Force or motion which is the exact
+opposite of the Centripetal Force or attractive power of Gravitation?
+For if heat be a repulsive motion at all, then to be strictly logical it
+must be equally repulsive in relation to large masses, the sun and the
+planets for example, as it is in the atomic world, otherwise we have a
+phenomenon in Nature which contradicts itself, which assumption would be
+contrary to the simplicity which is to govern our philosophy, and also
+contradictory to experience, which is the primary factor of
+philosophical reasoning. Now what are the facts with reference to the
+sun, which is the central body of our solar system, and the source of
+all light and heat in that system? We will look at this aspect of the
+question under the heading of Radiant Heat.
+
+[Footnote 11: _Heat, a Mode of Motion._]
+
+
+ART. 64. _Radiant Heat._--The source of all light and heat, not only of
+our earth, but also of all the other planets, is to be found in the sun.
+We have therefore to deal, not with an atom which is generating heat
+waves on every side, but with a globe about 860,000 miles in diameter,
+and with a circumference of over 2,700,000 miles. This huge orb consists
+of a central body, molten or partly solid, with a temperature so hot
+that it is almost impossible to conceive its intensity. The quantity of
+heat emitted by the sun has been ascertained by Sir John Herschel from
+experiments made at the Cape of Good Hope, and by M. Pouillet in Paris.
+
+Sir John Herschel found that the heating power of the sun when it was
+directly overhead was capable of melting .00754 of an inch of ice per
+minute. According to M. Pouillet the quantity was .00703 of an inch,
+which is equal to about half-an-inch per hour. From these results it has
+been calculated that if the direct heat of the sun were received upon a
+block of ice one mile square, 26,000 tons would be melted per hour by
+the heat which would be absorbed. Again, as Herschel[12] puts it:
+"Supposing a cylinder of ice, 45 miles in diameter, to be continually
+darted into the sun with the velocity of light, the heat given off
+constantly from the sun by radiation would be wholly expended in
+liquefaction on the one hand, while on the other, the actual temperature
+at the sun's surface would undergo no diminution." Sir John Herschel
+further says: "All the heat we enjoy comes from the sun. Imagine the
+heat we should have to endure if the sun were to approach us, or we the
+sun, to a point the one hundred and sixtieth part of the present
+distance. It would not be merely as if 160 suns were shining on us all
+at once, but 160 times 160 suns according to the rule of inverse
+squares--that is, 25,600. Imagine a globe emitting heat 25,600 times
+fiercer than that of an equatorial sunshine at noonday, with the sun
+vertical. In such a heat there is no solid substance we know of which
+would not run like water, boil, or be converted into smoke or vapour."
+
+Lockyer points out that the heat radiated from every square yard of the
+sun's surface is equal to the amount of heat produced by the burning of
+six tons of coal on that area in one hour. Now the surface of the sun
+may be estimated at 2,284,000,000,000 square miles, and there are
+3,097,600 square yards in each square mile; what therefore must be the
+number of tons of coal which must be burnt per hour to represent the
+amount of heat radiated from the sun into space? The approximate result
+may be calculated by multiplication, but the figures arrived at fail to
+give any adequate conception of the actual result.
+
+From these facts it may be seen that the sun has a temperature far
+exceeding any temperature that can be produced on the earth by
+artificial means. All known elements would be transformed into a
+vaporous condition if brought close to the sun's surface. It may readily
+be seen, therefore, that the sun is constantly sending forth an
+incessant flood of radiant heat in all directions, and on every side
+into space. Now if heat be motion, and be primarily due to the vibratory
+motion of Aether, what must be the volume and the intensity of the
+aetherial waves, known as heat waves, generated by the sun? When we
+remember its ponderous mass, with its volume more than 1,200,000 times
+that of our earth, its huge girth of more than 2-1/2 millions of miles,
+and this always aglow with fire the most extensive known--fires so
+intense that they cover its huge form with a quivering fringe of
+flames which leap into space a distance of 80,000 miles, or even
+100,000 miles, or over one-third of the distance of the moon from the
+earth,--remembering all these facts, what must be the volume and
+intensity of the aetherial heat waves which they generate and send upon
+their course into space on all sides! What a very storm of energy and
+power must there be in this aetherial atmosphere which exists around the
+sun's huge form, and with what volume of power must the aetherial heat
+waves speed away from so great a generating source! Some idea as to
+their velocity of motion may be gained by the fact, that these aetherial
+heat waves traverse the distance of 92,000,000 miles between the sun and
+our earth in the short space of 8-1/2 minutes. With such a velocity of
+motion as that, and with the fact before us that all motion is a source
+of energy or power, what must be the energy possessed by these heat
+waves! There must, therefore, be a power in these aetherial heat waves
+which is strictly proportionate to their intensity and flow. So that,
+whenever they come into contact with any body, as a planet, as they flow
+outwards from the sun, they must exert a power upon such a planet which
+is directed _away_ from the sun, and therefore act upon that planet by
+the energy of their motion away from the sun, the source of the
+aetherial heat waves. Therefore, not only in the atomic world is heat a
+repulsive motion, but equally in the solar world, which is but an atomic
+world on a large scale, the same principle prevails, and the effect of
+radiant heat is essentially a repulsive, that is, a centrifugal motion,
+as it is always directed from the central body, the sun.
+
+Further, it can be shown that the repulsive power of heat in the solar
+system has already received the attention of scientists, especially in
+France. This will be seen more fully when we come to deal with the
+phenomena of comets' tails. One remarkable feature about comets' tails
+is, that they are always directed away from the sun, and various
+hypotheses have been advanced to account for that fact. Among them is
+the hypothesis of M. Faye, in which he assumes that there is a repulsive
+force which has its origin in the heat of the sun. This repulsive force
+is not propagated instantaneously, but the velocity of propagation is
+the same as that of a ray of light. By means of this repulsive power due
+to the heat of the sun, M. Faye explains how it is that the tails of
+comets are always turned away from the sun. Here, then, we have an
+indication of the existence of this repulsive force of heat which we are
+considering--a repulsive power which finds its source in the aetherial
+waves, which give rise to the phenomena of Heat, and to which we must
+look for the ultimate source of that repulsive power or Centrifugal
+Force which is to form the complementary power to the attractive force
+of Gravitation.
+
+[Footnote 12: _Lectures on Scientific Subjects._]
+
+
+ART. 65. _Direction of Ray of Heat._--The question as to the path which
+a ray of heat takes may best be attacked by finding out what is the path
+which a ray of light takes in its progress through the Aether. When we
+come to deal with light, we shall find that it has been experimentally
+proved that the path of a ray of light is that of a straight line
+through space; so that if we have any body emitting light, the rays of
+light will proceed from that body in straight lines, with decreasing
+intensity, according to the law of inverse squares, the same as
+Gravitation.
+
+It can readily be shown, that wherever there is light there is heat. For
+example, the radiant heat from the sun proceeds through space along with
+the light from the sun, and when one set of waves, the light waves for
+instance, are intercepted, the heat waves are also intercepted. Or, to
+take another illustration, when the sun is eclipsed, we feel the sun's
+heat as long as any portion of the sun is visible, but as soon as the
+sun is totally eclipsed, then the light waves disappear, and with it the
+heat waves. From this we can readily see, that not only do the heat and
+light waves from the sun proceed in the same straight line, but that
+they also travel at the same rate through space, at the rate of 186,000
+miles per second. Then again the common lens, which is so familiar to
+every one, will prove the same fact by concentrating the rays of light
+to a focus, and by so doing will produce sufficient heat to burn a piece
+of paper, or even set fire to wood. If, therefore, the path of a ray of
+light be that of a straight line, proceeding from the luminous or
+lighted body, and the path of a ray of heat coincides with the path of a
+ray of light, the path of the ray of heat must also be in the direction
+of a straight line from the heated or luminous body, which, as we shall
+see in a subsequent article, also decreases in intensity according to
+the law of inverse squares the same as Gravitation Attraction.
+
+Professor Tyndall, on the direction of a ray of heat,[13] states his
+opinion on the matter as follows: "A wave of Aether starting from a
+radiant point in all directions in a uniform medium constitutes a
+spherical shell, which expands with the velocity of light or of radiant
+heat. A ray of light or a ray of heat is a line perpendicular to the
+wave, and in the case here supposed, the rays would be the radii of the
+spherical shell." From this it can be seen that a ray of light or heat
+corresponds to what is known as the radius vector of a circle (Art. 20),
+and therefore a ray of light and heat takes exactly the same path
+through space (if we consider the sun as the source of the light and
+heat) as the path of the attractive power of Gravitation. Collecting,
+therefore, our results from the preceding articles of this chapter, we
+learn that heat is due to vibrating wave motion of the Aether, and that
+that motion is a motion which is always directed from the central body
+which is the source of the heat; and further, that this motion amounts
+to a repulsive motion acting in an opposite direction to the attractive
+power of gravity or to the centripetal force of Gravitation. What is
+more remarkable still, the path of a ray of heat corresponds with, and
+takes up exactly the same direction through space, whether it be atomic
+space, solar space, or interstellar space, as the attractive force of
+Gravitation.
+
+Looking at the subject from the standpoint of the solar system, with the
+sun as the central body, we see that while we have the sun, which acts
+as the controlling centre of the particular system of planets, holding
+all the planets in their orbits by its attractive power, yet at the same
+time it is also the source of all light and heat. Now heat being due to
+the wave motion of the aetherial medium, such motion being always
+exerted from the central body, we arrive at the only legitimate
+conclusion that can be arrived at, viz. that the sun is also the source
+of a repulsive motion, which motion coincides with the path that the
+attractive power of Gravitation takes, that is, along the radius vector
+of the circle, as shown in Art. 20.
+
+
+ART. 66. _Law of Inverse Squares applied to Heat._--The law of inverse
+squares which governs not only the Law of Gravitation Attraction (Art.
+22), but also electricity and light, is equally applicable to the
+phenomena of heat, so that we say the intensity of heat varies inversely
+as the square of the distance. Thus, if we double the distance of any
+body from the source of heat, the amount of heat which such a body
+receives at the increased distance is one-quarter of the heat compared
+with its original position. If the distance were trebled, then the
+intensity of the heat would be reduced to one-ninth; while if the
+distance were four times as great, the intensity of the heat would only
+be one-sixteenth of what it would receive in its first position. This
+may be proved from experiments as given by Tyndall in his _Heat, a Mode
+of Motion_.
+
+Let us apply the law of inverse squares in relation to heat to the solar
+system, and see what the result gives. In our solar system, we have the
+sun as the central body, the source of all light and heat, with the
+eight planets, Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus,
+Neptune, describing orbits around the central body, and at the same time
+receiving from it the light and heat which the sun is ever pouring
+forth into space. The mean distance of Mercury from the sun is about
+36,000,000 miles, while that of the Earth is about 92,000,000 miles, so
+that reckoning the distance of Mercury as unity, the distance of the
+Earth is a little more than 2-1/2 times that of Mercury from the sun.
+Now the square of 2-1/2 is 25/4, and that inverted gives us 4/25, so
+that according to the law of inverse squares, the intensity of heat at
+the Earth's distance from the sun is 4/25 of what the intensity of heat
+is at the mean distance of Mercury. Again, the mean distance of Mars is
+141,000,000 miles, while the mean distance of Saturn is 884,000,000
+miles, and taking Mars' distance from the sun as unity, the distance of
+Saturn would be represented by 6-1/4. Now the square of 6-1/4 is
+(25/4)^{2} which gives 625/16 and the inverse of that is 16/625, so that
+the intensity of heat at the distance of Saturn's mean distance from the
+sun, in comparison with the intensity of heat at Mars' mean distance,
+would be about 16/625; or in other words, the heat received by Saturn
+would be only 16/625 of the intensity of heat received by the planet
+Mars. In Art. 63 we have seen that heat is a repulsive motion, being a
+wave motion of the Aether which is propagated from the heated and
+central body, which in this case is the sun. Therefore, according to the
+law of inverse squares from the standpoint of heat, we find in the solar
+system a repulsive motion, due to the wave motion of the Aether, which
+is always exerted away from the sun in the same path that the
+centripetal force takes, and which like that force diminishes in
+intensity inversely as the square of the distance. So that, wherever the
+centripetal force, or the attractive force of Gravitation, is diminished
+on account of the increased distance from the sun, the repulsive motion
+due to heat is also diminished in exactly the same proportion and along
+exactly the same path. If at any point in the solar system the
+attractive force is doubled, then according to our repulsive theory of
+heat, and the law of inverse squares, the repulsive motion is also
+doubled. If the attractive force is halved, then the repulsive motion is
+halved also, the repulsive motion being always and at all places exactly
+proportional to the increase or decrease of the attraction of
+Gravitation.
+
+[Footnote 13: _Heat, a Mode of Motion._]
+
+
+ART. 67. _First Law of Thermodynamics._--The Law of Thermodynamics is
+based on two fundamental truths which have reference to the conversion
+of Heat into Work, and Work into Heat. In Art. 54 we have already seen
+that energy in the form of heat, light, electricity and magnetism is
+capable of being converted into other forms of energy, while in Art. 59
+we have seen that Joule gave us the exact relation in foot-pounds
+between heat and work. He showed that when 1 lb. of water fell through
+772 feet its temperature was raised one degree Fahr. Thus the principle
+underlying the first law of thermodynamics states, that whenever work is
+spent in producing heat, the amount of work done is proportionate to the
+quantity of heat generated; and conversely, whenever heat is employed to
+do work, a certain amount of heat is used up, which is the equivalent of
+the work done. This principle is also in accord with the conservation of
+Energy and Motion (Arts. 52 and 57), which assert that whenever energy
+or motion disappears in one form, it is manifested in some other form.
+Thus, from the first law of thermodynamics, we learn that wherever we
+have heat we have the power to do work, and the amount of work so done
+is proportionate to the heat used up. Heat, then, has a capacity to
+perform work, and that power is known as the mechanical equivalent of
+heat. Both Mayer of Germany, and Dr. Joule of Manchester, have worked
+out this problem, and have given us the mechanical value of heat. By
+experiments Mayer found out that a quantity of heat sufficient to raise
+1 lb. of water one degree Fahr. in temperature was able to raise a
+weight 771.4 lb. one foot high. Dr. Joule of Manchester, after making a
+number of experiments which lasted over many years, came to the
+conclusion that the mechanical equivalent of a unit heat was 772
+foot-pounds, a unit of heat being the quantity of heat which would raise
+1 lb. of water one degree Fahr. So that if a 1-lb. weight fell from a
+height of 772 feet, an amount of heat is generated which would raise 1
+lb. of water one degree Fahr.; and conversely, to lift 1 lb. 772 feet
+high, one degree Fahr. of heat would be consumed.
+
+Now if this law of thermodynamics is true, it must not only be true in
+relation to terrestrial heat, or heat produced by artificial means on
+our earth, but it must equally hold good in relation to the solar
+system; and not only the solar system, but equally true throughout all
+the systems of worlds that flood the universe. So that wherever we get
+heat in the universe, in the solar system for example, there, according
+to our first law of thermodynamics, we should have the capacity to do
+work of some kind or other. That work may take either the form of
+expanding a body, as the atmosphere of a planet for example, or it may
+take a mechanical form, that is, actually moving a body by the increased
+pressure due to aetherial heat waves generated by the sun. We have
+already seen in Art. 64, on Radiant Heat, what a store of heat the sun
+has. For thousands and millions of years the sun has been pouring forth
+its heat rays into space, and yet its temperature does not seem to be
+diminished. The great Carboniferous or coal period of past geological
+times is an indication of the heat and light of the sun, which it must
+have radiated out millions of years ago; and year by year, these
+aetherial heat waves are still being poured forth by the sun on every
+side into space, so that no matter where a planet may be in its orbit,
+there it may be the recipient of these aetherial heat waves which break
+upon its surface. Now if there be this quantity of heat existing in the
+sun, and heat according to the first law of thermodynamics has a
+mechanical value, which is that it can push or lift a body through
+space, the question arises, as to what is the mechanical value of this
+heat of the sun? Are we to suppose that if one unit of heat can lift 1
+lb. 772 feet, the millions and millions of units of heat which are
+constantly being poured out of the sun into space are doing no work at
+all? Such an assumption is not only contrary to that simplicity which
+governs our Philosophy, but is entirely opposed to experience, which is
+the very foundation of all philosophical reasoning. If, therefore,
+experience is to be any guide at all, we are compelled to come to the
+conclusion that the heat poured forth into space does do work on the
+bodies, as comets, meteors, planets, upon which the aetherial heat waves
+fall. The problem is, what is the character of the work done? I have
+already indicated part of the work, viz. in the expansion of the
+atmosphere of the planets. Then there is also the reception of the heat
+by the animal and vegetable life of the planet, but these do not account
+for all the motive power of the aetherial waves, which break upon the
+planet or its atmospheres.
+
+The true solution of the first law of thermodynamics, in its relation to
+the solar system, seems to me to be found in the fact already stated in
+Art. 63, viz. that heat is a repulsive motion, and the law of
+thermodynamics confirms that statement, and shows that the work done on
+a planet by the aetherial heat waves is that of pushing it, or urging it
+by their very energy and motion away from their controlling centre, the
+sun. This would practically amount to a repulsive force which had its
+home in the sun, and this conception would bring our Philosophy into
+harmony with our experience, which teaches us that wherever there is
+heat there is the capacity of doing work, the amount of work being
+proportionate to the heat generated and consumed.
+
+
+ART. 68. _Second Law of Thermodynamics._--This law was enunciated by
+Sadi Carnot in 1824, when he wrote an essay on the Motive Power of Heat.
+Previous to the time of Carnot no definite relation seems to have been
+suggested between work and heat; Carnot, however, discovered what were
+those general laws which govern the relation between heat and work. In
+arriving at his conclusion, he based his results on the truth of the
+principle of the conservation of energy already referred to (Art. 52).
+
+Carnot started his reasoning on the assumption that heat was matter, and
+therefore indestructible. The two great truths in relation to heat and
+work, enunciated by Carnot, are known as, first, a Cycle of operations;
+and, secondly, what he termed a Reversible Cycle. In order to be able to
+reason upon the work done by a heat-engine, say a steam-engine for
+example, Carnot stated we must imagine a cycle of operations, by which,
+at the end of such operations, the steam or water is brought back to
+exactly the same state in which it was at its start. He calls this a
+cycle of operations, and of it he says, that only at the conclusion of
+the cycle are we entitled to reason upon the relation between the work
+done and the heat spent in doing it. His other idea of the reversible
+cycle implies that an engine is reversible when, instead of using heat
+and getting work from it, the engine may be driven through the cycle of
+operations the reverse way, that is, by taking in work, it can pump back
+heat to the boiler again. Carnot showed that if you can obtain such a
+reversible engine, it is a perfect engine. All perfect engines, that is
+all reversible engines, will do exactly the same amount of work with the
+same amount of heat, the amount of work being strictly proportionate to
+the amount of heat consumed. I need hardly point out that the reversible
+engine, or the perfect engine of Carnot, is only the ideal one, as there
+is no engine in which all the heat is converted into work, as a great
+deal of the heat is radiated away and not converted into work at all.
+Again, working from the standpoint that heat is matter, Carnot reasoned
+that in the heat-engine the work is performed, not by the actual
+consumption of heat, but by its transportation from a hot body to a cold
+one. Thus, by the fall of heat from a higher to a lower temperature,
+work could be done in the same way that work could be done by allowing
+water to fall from a higher to a lower level. The quantity of water
+which reaches the lower level is exactly the same as that which leaves
+the higher level, as none of the water is destroyed in the fall. He
+argued, therefore, that the work produced by a heat-engine was produced
+in a similar manner, the quantity of heat which reaches the condenser
+being supposed to be equal to that which left the source. Thus the work
+was done by the heat flowing from a hot body to a cold one, and, in
+doing this work, it lost its momentum like falling water, and was
+brought to rest. One of the most important points noted by Carnot is
+the necessity that, in all engines which derive work from heat, there
+must be two bodies at different temperatures, that is, a source and a
+condenser, which correspond to a hot and cold body, so that there may be
+the passage of heat from the hot to the cold body. In order to get work
+out of heat it is absolutely necessary to have a hotter and a colder
+body. From this reasoning we learn, therefore, that work is obtained
+from heat by using up the heat of the hotter body, part of which is
+converted into actual work, while part is absorbed by the colder body.
+So that wherever we have two bodies at different temperatures, according
+to the second law of thermodynamics, there we have the power of doing
+work by the transmission of heat, from the body of higher to the one of
+lower temperature.
+
+That Carnot ultimately came to believe in the dynamical theory of heat,
+is proved by the following passage taken from his notes on the Motive
+Power of Heat: "It would be ridiculous to suppose that it is an emission
+of matter, while the light which accompanies it could only be a
+movement. Could a motion produce matter? No! undoubtedly, it can only
+produce a motion. Heat is then the result of motion. It is plain then
+that it could be produced by the consumption of motive power, and that
+it could produce this power. Heat is then simply motive power, or rather
+motion which has changed its form. It is a movement among the particles
+of bodies. Wherever there is a destruction of motive power, there is at
+the same time production of heat in quantity exactly proportional to the
+quantity of motive power destroyed. Reciprocally, whenever there is
+destruction of heat there is production of motive power."
+
+Let us apply this principle to the solar system, and endeavour to find
+out whether in that system we have, in relation to the heat thereof,
+either a cycle of operations or a reversible cycle. We have again to
+consider the sun as the source of all light and heat in the solar
+system, radiating forth on every side, year by year, the countless units
+of heat which go to form the continuance of all planetary life and
+existence. One of the problems that has confronted scientific men for
+many years is this, Where does the sun get its supply of heat from? When
+we remember the incessant loss of heat which the sun suffers through its
+radiation of heat into space, we are compelled to ask, How is that
+supply maintained, and how has it been kept up through the countless
+ages of the past? Several suggestions have been made, and several
+theories advanced to account for the fact. Mayer, of Germany, suggested
+that the heat is partly maintained by the falling into the sun of
+meteors, which, like comets, pursue a path through the heavens, and are
+subject to the attractive influence of the sun. In the combustion of
+these meteorites, or meteors, he contended there were the means by which
+the light and heat of the sun might be maintained. Whatever theory,
+however, may be suggested as to the maintenance and the source of the
+continuity of the sun's heat, I do not think it has been suggested by
+any scientist that the heat emitted and radiated by the sun is ever
+returned in any way back to the sun from infinite space, whether by
+reflection or by any other method. So far as I can learn, there are no
+facts in connection with the solar system which would lead us to make
+that assumption. On the contrary, experience and experiment teach us
+that radiation implies loss of heat, and that the body, which so
+radiates, ultimately becomes cold, unless its internal heat is kept up
+by some means or other. So that the terms introduced by Carnot in the
+second law of thermodynamics, viz. that of a Cycle of Operations and of
+a Reversible Cycle, do not apply to the solar system, and the solar
+system, viewed from the standpoint of a machine, with the sun as the
+source of the heat, does not represent a perfect engine, that is, all
+the heat is not used up in doing work, some of it being radiated out
+into space. Wherever, however, the heat, that is the aetherial heat
+waves generated by the sun, comes into contact with a planet, as
+Mercury, Venus, or Jupiter, then, in accordance with Carnot's reasoning,
+work is done. Carnot points out that, in order for work to be done, we
+must have a source and a condenser, that is, two bodies at different
+temperatures, a hot body and a cold one. Now these conditions of work
+are satisfactorily fulfilled in the solar system, and as a result work
+is performed. We have the sun with its huge fires, and its intensity of
+heat, representing the source or the hot body, while every planet and
+every meteor and comet, that come under its influence, represent the
+cold body, and between the two work is always going on. That work is
+represented by the repulsive power of heat, which I have already
+indicated, so that, viewed from Carnot's standpoint with relation to the
+motive power of heat, we find that there are in the solar system those
+conditions which govern work, and by which, from a mechanical
+standpoint, work is performed; further, that work takes the form of a
+repulsive power on every planet or other body upon which the aetherial
+heat waves fall. Therefore, from the second law of thermodynamics we
+have another proof of this repulsive power of heat already indicated and
+referred to in Art. 63.
+
+
+ART. 69. _Identity of Heat and Light._--We have seen from the preceding
+articles of this chapter, that heat is due to a periodic wave motion of
+the Aether, and in the succeeding chapter we shall also see that light
+is due to some kind of periodic wave motion in the Aether. So that not
+only heat, but light also, it would appear, is due to certain periodic
+wave motions that are set up in the Aether by the vibrations of hot or
+luminous bodies. The question therefore arises, how many wave motions
+are there in the Aether? Are there different wave motions which in one
+case produce light, and in the other case produce heat, or are light and
+heat both produced by the same set of aetherial waves? The identity of
+light waves with heat waves is manifested by the fact that wherever we
+get light we get heat, as can be proved in many ways. One of the
+simplest proofs is found in the common lens or burning-glass, by which
+the light waves are brought to a focus, and as a result, heat is
+manifested. Although there is this close identity between light and heat
+waves, yet there must be some distinction between the heat and light
+waves, because while light waves affect the eye, heat waves do not.
+There is actually a difference between the two kinds of waves, and that
+difference is one of period or length. It must not, however, be thought
+that there are really two classes or sets of waves in the Aether, one of
+which could be called light waves, and the other heat waves, but rather
+the same wave may be manifested in two different forms because of its
+different wave lengths. In one case the waves may affect the eye, and we
+have the sensation of sight, but in the other case they affect the body,
+and we experience the sensation of warmth. An analogy from the waves of
+sound may make these facts much clearer. We know that sound travels
+about 1100 feet per second. If, therefore, we have a bell which vibrates
+about 1100 times per second, we should have a wave one foot long. If it
+vibrated 100 times per second the waves would be 11 feet long, while if
+it vibrated only 11 times per second, the waves would be 100 feet long.
+Now the impression made upon the ear depends upon the number of
+vibrations the bell makes per second, and from the rate of vibration we
+get the idea of pitch. If the vibrations are very rapid, then we get a
+note of high pitch, and if the vibrations are slow, then we get a note
+of low pitch. A note of high pitch, therefore, will correspond to waves
+of short length, while a low note will correspond to waves of a greater
+length; so that the greater the rapidity with which a sounding bell
+vibrates, the shorter will be the length of the sound waves which it
+generates, and _vice versa_. The range of the ear however for sound
+waves is limited, so that if the vibrations be too rapid or too slow,
+the ear may not be able to respond to the vibrations, and so no distinct
+impression of the sound will be conveyed to the brain. It need hardly be
+pointed out, that both the very short and long waves are of exactly the
+same character as those of a medium length, which the ear can detect,
+the only difference being one of rapidity. We do not therefore suggest
+that in the case of sound, where the vibrations lie outside the compass
+of the ear, those which lie outside are not sound waves, or that they
+are different from those which lie within the compass of the ear, and
+which the ear can detect. Whether the sound waves are long or short,
+whether they can be detected by the ear or not, we still say that all
+are sound waves, and that all are due to the vibrations of the sounding
+body, which vibrations are transmitted through the air, in waves, that
+fall upon the tympanum or drum of the ear, and set that vibrating, which
+vibrations are transmitted to the auditory nerve and so give rise to the
+sensation of hearing. In a similar manner, every atom and every particle
+of matter, every planet, every sun and star, is constantly in a state of
+vibration, sending off aetherial waves on every side. Nothing in Nature
+is absolutely cold, nothing is absolutely still. Therefore all matter,
+whether in the atomic form, or in the planetary or solar world, is
+constantly generating aetherial waves, which travel from their source or
+origin with the velocity of light. If these aetherial waves so generated
+fall within certain limits, then they affect the eye, and we get the
+sensation of sight. To do this they must vibrate 5000 billion times per
+second, and if they fail to do this, they fail to give rise to the
+sensation of sight. If the aetherial waves fall below this limit, then
+they affect the body, and give rise to the sensation of heat. For it
+must be remembered, that as the ear has a certain compass for sound
+waves, which may vary in different individuals, so the eye has also a
+certain compass for aetherial waves, with the result that some waves may
+be too slow or too rapid to affect the eye, and consequently fail to
+give rise to the sensation of sight. When that is so, the sensation of
+warmth helps us to detect these longer waves, so that the longer waves
+would warm us and make their presence felt in that manner. We shall see
+in the next chapter that there are both shorter and longer waves, which
+may be detected in other ways. From these facts it can be readily seen,
+that we have a common origin for both light and heat, and that they are
+both due to periodic waves in the Aether, and therefore all the laws
+that govern heat should also govern the phenomena of light. Further, if
+heat possesses a dynamical value, and if there be such a truth as the
+motive power of heat, then there ought equally to be a motive power of
+light; and further, if heat possesses a repulsive motion, then because
+of the identity of light and heat, light should equally possess this
+repulsive power, because it is due to similar periodic wave motions in
+the Aether. With regard to the same laws governing both light and heat,
+we shall see that this fact also holds good. We have already seen (Art.
+66) that the intensity of heat is inversely as the square of the
+distance, and we shall also see in the succeeding chapter that the same
+law holds good in relation to light. We have seen (Art. 65) that the
+path of a ray of heat is that of a straight line; we shall see in the
+succeeding chapter that the path of a ray of light is that of a straight
+line also.
+
+Indeed, there is no law applicable to heat which is not applicable to
+light. The law of reflection and refraction of heat equally holds good
+in relation to light; and further, Professor Forbes has shown that heat
+can be polarized in a similar manner to the polarization of light. This
+last fact is considered the most conclusive argument as to the identity
+of light and heat, and proves that the only difference between the two
+is simply the difference corresponding to the difference between a high
+note and a low note in sound. That being so, I hope to be able to show
+that as heat possesses a dynamical value, so light equally possesses a
+dynamical value, and that as heat is a repulsive motion, then light must
+equally possess a similar repulsive motion, that motion always being
+directed from the central body, being caused by the same agency, viz.
+the waves of the Aether, the common source of both light and heat. I
+purpose to address myself to this subject in the following chapter,
+which I have termed Light, a Mode of Motion.
+
+
+
+
+                              CHAPTER VII
+
+                        LIGHT, A MODE OF MOTION
+
+
+ART. 70. _Light, a Mode of Motion._--No subject has in the past received
+greater attention from philosophers and scientists than that involved in
+the question as to "What is Light?" Indeed, it may truthfully be said,
+that even to-day its exact character is not positively known. That it is
+due like heat to some periodic wave motion in the Aether is known, but
+the exact character of that wave motion has yet to be determined. As in
+the case of heat, so in the case of light, there have been two theories
+which have contended with each other for supremacy in endeavouring to
+answer the question as to "What is Light?" Those two theories are known
+as the Emission or Corpuscular Theory, and the Undulatory or Wave
+Theory. The corpuscular theory was introduced and developed by Newton in
+his work on _Optics_, which ranks second only to the _Principia_ as a
+work revealing masterly research and scientific genius. Newton supposed
+that a luminous or lighted body actually emitted minute particles, which
+were shot out from the body with the velocity of light, that is, at the
+rate of 186,000 miles per second. These minute particles he termed
+corpuscles. In the work just referred to regarding this matter, he asks
+the question, "Are not rays of light very small bodies emitted from
+shining substances?" These small particles or corpuscles were supposed
+by him to actually strike the retina of the eye, and so produce the
+sensation of Sight, in the same way that odorous particles entering the
+nostril, come into contact with the olfactory nerves and produce the
+sensation of Smell. In order, however, to account for certain phenomena
+of light, he was compelled to postulate an aetherial medium to fill all
+space, in which his luminous corpuscles travelled, and which would
+excite waves in that medium. In his eighteenth query on this point he
+asks: "Is not the heat of a warm room conveyed through the vacuum by the
+vibration of a much subtler medium than air, and is not this medium the
+same with that medium by which light is reflected or refracted, and by
+whose vibrations light communicates Heat to bodies, and is put into fits
+of easy reflection and easy transmission?" The corpuscular theory,
+however, received its death-blow when, in competition with the wave
+theory of light, as developed by Young, it was found that the latter
+theory satisfactorily accounted for certain phenomena as the refraction
+of light, which the corpuscular theory did not adequately account for.
+Even while Newton was developing his theory, Huyghens, a contemporary of
+Newton, was developing another theory which is now known as the
+undulatory or wave theory. Huyghens drew his conclusions from the
+analogy of sound. He knew that sounds were propagated by waves through
+the air, and from the region of the known, endeavoured to carry the
+principle into the region of the unknown, a strictly philosophical
+method, and one in accordance with the second Rule of Philosophy. He
+supposed that light, therefore, like sound, might be due to wave motion,
+but if it were wave motion, there must have been a medium to propagate
+the waves. In order to account for this wave motion, he supposed all
+space to be filled with a luminiferous Aether, which would be to his
+light waves what air is to sound waves. In this conception he was
+supported by Euler the mathematician, and in 1690 he was able to give a
+satisfactory explanation of the reflection and refraction of light, on
+the hypothesis that light was due to wave motion in the Aether. It was
+not, however, till the advent of Thomas Young, that the undulatory or
+wave theory reached its perfection, and finally overthrew its competitor
+the corpuscular theory. Young made himself thoroughly acquainted with
+wave motion of all kinds, and applied his knowledge and experience to
+the phenomena of light, and from the analogies so obtained, he gradually
+built up the undulatory theory, and gave to it a foundation from which
+it has not yet been moved. Young made use of the same aetherial medium
+in order to propagate the wave motion of light in the same way that
+Huyghens did. From that conception, the Aether has been gradually
+perfected, until we have the conception which has been presented to the
+reader in Chapter IV., in which I have endeavoured to show that this
+aetherial medium is matter, but infinitely more rarefied and infinitely
+more elastic, but notwithstanding its extreme rarefaction and
+elasticity, it possesses inertia, because it is gravitative. It is this
+Aether, then, that is concerned in the propagation of light, and is the
+universal medium which is to light what air is to sound. Young,
+therefore, having applied himself to the wave motion of sound, from such
+researches was able to explain the physical cause of colour, and that
+phenomenon termed interference.
+
+We will therefore look at wave motion, in order to understand the wave
+theory of light.
+
+Now in all wave motion, whether it be water waves or sound waves, that
+which is propagated or conveyed from place to place is energy, or
+motion. If a stone is thrown into water, a series of concentric circles
+of waves are generated, which spread out with increasing size, but
+decreasing power or motion, regularly on all sides. The water, however,
+does not move away from the generating source. There is a motion of the
+water, but it is simply a wave motion, so that the propagation of a wave
+is the propagation of motion, rather than the transference of the actual
+water which constitutes the wave. In the case of sound waves, we have
+again an illustration of the same principle. For example, suppose we
+strike a bell, and so set the particles of that bell in a state of
+vibration. These vibrations give the air in contact with the bell a
+forward movement, and then, owing to the elasticity and inertia of the
+air, a backward movement is set up, with the result that a series of
+waves are set in motion from the bell on every side, which gradually
+diminish in intensity the farther they recede from the generating body.
+According to the wave theory, therefore, we have to picture all heated
+and luminous bodies in a state of vibration, and the atoms of such
+luminous bodies imparting the vibrations to the atoms of the Aether, in
+the same way that the atoms of a bell impart their vibrations to the
+atoms of the air in contact with it. These vibrations are then
+propagated through the Aether in waves, which, entering the eye, impinge
+or strike upon the retina at the back of the eye, and being transmitted
+to the brain give rise to the sensation of sight. It must not be
+forgotten that the waves of Aether, as pointed out in Art. 64 in
+relation to heat, really form spherical shells which radiate out in all
+directions from the central body which gives rise to them. Thus it can
+be seen, that all points in the spherical wave which are at equal
+distances from the vibratory or luminous body, must possess the same
+intensity, and possess equal lighting powers. Light, therefore, like
+heat, is due to a periodic wave motion set up in the Aether by the
+vibrating atomic motion of heated or luminous bodies. It must be also
+noticed, that if we could see the air through which the sound waves are
+passing, we should see that each atom or particle of the atmosphere was
+vibrating to and fro in the direction of propagation. If, however, we
+could see an atom of Aether in vibration, accepting the principle that
+Aether is atomic, we should see that each aetherial atom is not
+vibrating in the direction of propagation, but across the line in which
+the wave is travelling. Thus the vibration of the air is said to be
+longitudinal, but the vibrations of the Aether are transversal. An
+illustration of the transverse motion of a light wave may be obtained by
+taking a rope and imparting to it a series of undulations by shaking it
+up and down, when it will be observed that the wave motion of the rope
+is transverse to the straight line in which it is propagated. The
+physical explanation of the transverse vibration of light will be dealt
+with in a subsequent article.
+
+Now the question suggests itself to our mind, as to what effect the
+atomicity of the Aether has upon the undulatory theory of light. Does it
+establish it upon a firmer basis, or does it in any way destroy its
+truth as a theory? I venture to think that the atomicity of the Aether
+in no sense destroys any part of the undulatory theory of light, but
+rather tends to confirm and establish it upon a logical and
+philosophical basis.
+
+For instance, as has been pointed out in Art. 47, in order for the
+undulatory theory to have any existence at all, it is essential that the
+Aether should possess the property of elasticity. But how the Aether
+possessed the property of elasticity while at the same time it was
+frictionless, and therefore possessed no mass, has been a problem that
+has taxed the ingenuity and resources of scientists for a century past,
+and up to the present is a problem which still remains unsolved. Now,
+however, with our atomic Aether, it is just as easy to conceive Aether
+transmitting a wave as it is for air to transmit sound waves, or water
+to transmit water waves.
+
+Tyndall, in his _Lectures on Light_, seems to have appreciated the
+difficulty, and to avoid confusion, again and again refers to a
+_particle_ of Aether. While Huyghens himself in speculating upon the
+elasticity of the Aether in his _Traite de la Lumiere_, 1678, makes a
+suggestion as to its origin, which practically amounts to the fact that
+the aetherial atom which gives rise to this elasticity is the core or
+centre of a vortex ring. Thus it can be seen that the elasticity of the
+Aether, so essential to the undulatory theory, is a problem that cannot
+be solved apart from recognizing the hypothesis of an atomic Aether.
+
+Then, again, in the undulatory theory of light, the density of the
+Aether around molecules of bodies has to be taken into consideration to
+account for such phenomena as the refraction and reflection of light,
+but, as we have seen in Art. 46, such a property as density is
+inconceivable in connection with a medium which is neither atomic and
+possesses no mass. On the assumption, however, of an atomic and
+gravitative Aether, the difficulty is at once solved, and the density of
+the Aether, and different degrees of density are at once placed upon a
+logical and philosophical basis. So that in relation to the elasticity
+and density of the Aether upon which the transmission and reflection of
+wave motion depend, an atomic and gravitative Aether establishes and
+confirms the undulatory theory.
+
+There is also another aspect of the subject that is worthy of notice. I
+refer to the effect of an atomic and gravitative Aether upon Newton's
+corpuscular theory of light. Newton's corpuscular theory failed in not
+being able to account for the relative velocity of light in rare and
+denser media, and if by an atomic Aether in conjunction with the
+undulatory theory, the phenomenon can be accounted for, as I believe it
+can, then our aetherial vortex atoms are analogous to Newton's
+corpuscles. This distinction will, however, have to be made, viz. that
+Newton supposed his luminous corpuscles to be emitted by the luminous
+body, whereas in the conception of our aetherial atoms, we conceive them
+to be stationary relatively in space, and only subject to those
+vibrations and oscillations that give rise to the aetherial waves
+recognized in the undulatory theory.
+
+It would indeed be a consummation to be desired, if, by an atomic
+Aether, it can be proved that Newton's Corpuscular Theory was made to
+harmonize with the Undulatory Theory, and that it can be I am profoundly
+convinced. Professor Preston is also of this view, for in his _Theory of
+Light_, writing on this subject, he says, page 19: "In conclusion, we
+may state that we believe an ingenious exponent of the emission theory,
+by suitably framing his fundamental postulates, might fairly meet all
+the objections that have been raised against it."
+
+We will now apply the hypothesis of an atomic and gravitating Aether to
+Huyghens' principle of wave propagation, and see if this atomicity in
+any way destroys that principle, or whether it simplifies and confirms
+it.
+
+Let us briefly review our conception of the Aether before making the
+application. In the first place, because Aether is gravitative, we
+learned from Art. 45 that it surrounds all bodies in the universe, from
+the smallest atom to the largest sun or star in the firmament of heaven.
+Our sun, then, which is to our system the source of all its light, will
+be surrounded by what are practically spherical aetherial envelopes or
+shells which decrease in density as they recede from the sun (Art. 46).
+These aetherial shells are, according to our conception, made up of
+minute aetherial spherical vortex atoms possessing polarity and rotation
+(Art. 43), and these atoms will be closer together the nearer they are
+to the central body, because of the increased density of the Aether due
+to the attractive influence of the sun. Thus, when a wave motion is set
+up in the Aether around the sun by the intense atomic activity of that
+incandescent body, each atom of that aetherial spherical shell or
+envelope participates in the motion or impulse received, at one and the
+same time, so that the wave is transmitted from envelope to envelope, by
+the elasticity of the aetherial atoms which compose the envelope or
+shell. Thus the light wave is always spherical in form, or nearly so, as
+the rotational and orbital motion of the sun affect the exact shape of
+the aetherial envelope as we shall learn more fully later on.
+
+Further, the wave front always takes the form of a sphere, as the waves
+are radiated out from the luminous body in all directions, and we shall
+learn, in the next article, that the vibrations are always in the wave
+front, that is, take place on the surface of each of these envelopes,
+and these vibrations are also transverse to the propagation of the wave.
+As these aetherial envelopes extend right into space, the wave is
+transmitted from envelope to envelope by means of the aetherial atoms
+with the velocity of 186,000 miles per second, but as each succeeding
+envelope possesses a larger surface than the preceding one, the
+intensity of the light is proportionally decreased. The surface of such
+envelope is always proportionate to the square of the radius, the other
+quantities remaining equal. So that the intensity of the light waves,
+which are coincident with the surface of each spherical envelope, will
+always vary inversely as the square of the distance from the luminous
+body, which agrees with the law of inverse squares that governs light
+and heat.
+
+[Illustration: Fig: 4.]
+
+We have considered the wave motion as a whole, that is, we have viewed
+it from the standpoint of the whole of the aetherial elastic envelope.
+Now we will look at the subject from the atomic standpoint, and see if
+it is in accordance with Huyghens' principle of wave propagation.
+
+We will suppose that an undulatory movement is started by a luminous
+body at point _A_ situated in the Aether, and surrounded by that medium.
+_A_ may represent a part of any luminous body, as the sun or star, while
+_B_ _C_ and _B'_ _C'_ represent a segment of the aetherial envelopes
+already referred to, which exist around the sun. We will further suppose
+that the small dots surrounding the luminous body represent the
+aetherial atoms forming the envelope, which transmit the impulse or
+energy received from the atomic vibrations of the luminous body. As each
+aetherial atom is moved or pushed forwards, each atom directly in
+contact with it accepts and transmits the impulse. But each of these
+atoms stands in relation to those in front of them, as they did in
+relation to the first row of atoms, so to speak, and therefore exert a
+corresponding impulse on the front row.
+
+But the third row stands in relation to the fourth row as the second row
+did to the third, and so on to infinity. Thus each atom being surrounded
+by other atoms may be looked on as the centre of a new wave system, so
+that every particle of the wave system is itself a centre of a new wave
+system which is transmitted in all directions. As these innumerable and
+minute wave systems co-operate with one another, they form a principal
+wave system which is coincident with the surface of the spherical
+envelope, part of which is represented by _B_ _C_. Then if we conceive of
+all the aetherial atoms in part of the principal wave system _B_ _C_, as
+themselves becoming the centre of wave propagation, by their wave
+systems the principal wave will be transmitted further on into space to
+another aetherial envelope _B'_ _C'_, which represents part of another
+principal wave, which again is coincident with the surface of one of the
+spherical aetherial envelopes. So that by the action of the aetherial
+atoms which exist on all sides of the luminous body, the aetherial wave
+can be transmitted from atom to atom in more or less spherical form.
+
+Now let us compare this explanation of the transmission of light by an
+atomic Aether with the celebrated Huyghens' principle which is thus
+enunciated. "When an undulatory movement propagates itself through an
+elastic medium, every _particle_ imitates the movement of the particle
+first excited. But every particle stands in relation to the adjoining
+ones in exactly the same relation that the first particle did to its
+neighbours, and consequently must exert upon those surrounding it,
+exactly the same influence as the first did. Every vibratory particle is
+therefore to be regarded as if it were the originally excited particle
+of the wave system; and as the innumerable and simultaneous elementary
+wave systems co-operate with one another at each instant, we obtain
+exactly that principal wave system by which the elastic medium appears
+at any moment to be moved." Now here, in this statement, we have the
+definite term _particles_ used several times by Huyghens. But in the
+generally accepted theory of the Aether, such a term is unknown and
+unrecognized, with the obvious result that the definite and simple
+statement of Huyghens loses all its simplicity and meaning. Replace,
+however, the non-atomic Aether as at present recognized, by an atomic
+and gravitating Aether, and then Huyghens' exposition or principle
+stands out in all its simplicity and clearness, and finds in an atomic
+Aether its literal fulfilment and complete verification.
+
+In conclusion on this point, viz. that light is a mode of aetherial
+motion, let us endeavour to form a mental picture of our atomic and
+aetherial world. We have to remember that every particle and atom of
+matter in existence are ever vibrating, and by their vibrations are ever
+creating and generating Aether waves in the aetherial medium. These
+waves, begetting others, the process is continued until they are either
+intercepted and brought to rest by other matter, or else speed away
+until they reach the boundary of space.
+
+Now it is scarcely necessary for me to say, that if one atom can create
+and generate these Aether waves, a thousand atoms can create them in
+greater abundance still, and millions of atoms in even still greater
+abundance, and so on in proportion to the quantity or bulk of the matter
+vibrating. Further, as it is with quantity, so will it be with
+intensity, or activity of vibration. The more intensely an atom
+vibrates, the more intense would be the movement of the generated Aether
+waves, and the intensity would be in exact proportion to the intensity
+of the motion of the atoms vibrating. In regard to the power of atomic
+motions or vibrations, those are the greatest and most intense in energy
+or motion, which are produced by combustion or burning. The chemical
+activity by which the burning is brought about arouses and excites the
+atoms of matter subject thereto, into an intensity of motion, thousands,
+it may be millions of times greater than can be produced by any other
+known means. Therefore it can be readily seen, that the Aether waves
+generated by this means will be greater and more abundant, both in their
+volume and intensity, than the Aether waves produced merely by a cold
+body. For example, take a candle at night-time when the light has
+disappeared; look at it and feel it. Though its atoms are all in motion,
+generating Aether waves which are impressed with its own particular form
+and colour, yet it can scarcely be seen even at a short distance; but
+light it, and what a change takes place! We can both see it, and are
+enabled by its light to see other things also. By the power of
+combustion, its atoms have been excited into greater energy or motion,
+generating and speeding Aether waves on every side, and these Aether
+waves being reflected and re-reflected by the atoms of the air, and the
+walls of the house, give light to all that are in the house. I must now
+ask the reader to refer to Art. 64 on Radiant Heat, in order that we may
+recall facts regarding the heat of the sun. Remembering the intensity
+of the heat of the sun as calculated by Herschel and others, and
+remembering that the sun is 1,200,000 times larger in volume than our
+earth, the question naturally suggests itself to our mind, what must be
+the volume and intensity of the light waves as they flow from the sun
+into space? What a storm of fury and of motion must there be within the
+aetherial atmosphere around the sun, and with what volume and power must
+these light waves speed away from so mighty a source! Some idea may be
+gained from the fact that they speed away to the distant Neptune, a
+distance of nearly three thousand millions of miles, and impart to that
+planet the energy of light and heat which to the planet forms the
+physical source of all its life and activities. Thus from the sun, the
+centre of the solar system, there are ever being poured forth into space
+these aetherial light waves. The solar fires are ever glowing, and their
+flames ever burning, robing the solar disc with its quivering fringe, or
+madly leaping on every side to a distance of one hundred thousand miles,
+and by their madness lashing the aetherial atmosphere into fury,
+creating aetherial waves, myriads upon myriads, and sending them with
+lightning speed across the intervening space. As swift-footed messengers
+they come, the bearers of life and beauty to distant planets. They come
+to this our island home in space, these aetherial light waves, like rich
+argosies freighted with the treasures of light, of life, of beauty, and
+of glory, and the transmission of this life and beauty is effected by
+the incessant wave motion generated in the Aether by the central body of
+our solar system, the sun. Let us therefore endeavour to form a mental
+picture of this aetherial wave motion with its transverse vibrations.
+
+
+ART. 71. _Transverse Vibration of Light._--In the previous article we
+saw that the vibration of light was transverse to the line of
+propagation. If we could see the particles of air which are vibrating
+when sound waves are produced, we should find that each particle or atom
+is vibrating backwards and forwards in the direction of propagation.
+
+In the case of an aetherial atom, however, which, according to our own
+theory, participates in the vibration, we have to try to conceive of
+each atom as vibrating across the line of propagation. So that if _A_
+_B_ represents a ray of light proceeding from a luminous body, as the
+sun (Fig. 5), then the vibration must be across the line, as up and down
+and across that line as shown in the figure, each phase of the vibration
+being at right angles to the line of propagation--that is, to _A_ _B_.
+How can we form a physical conception of this phenomenon? There must be
+some physical explanation to it, for if it be an effect there must be a
+cause for its existence and production. Up to the present, however, no
+physical explanation has been forthcoming, so that for over 200 years a
+frictionless medium has failed to account for, or to explain, the
+transverse vibration of light as suggested by Fresnel.
+
+If, therefore, by the hypothesis of an atomic and gravitative Aether, we
+succeed in accomplishing a result that a frictionless Aether has failed
+to accomplish, then the explanation will be a most important factor in
+proving the atomicity and consequent gravitative property of the Aether.
+
+Let us therefore revert to our hypothesis of the Aether as given in Art.
+45. From that we learn, because Aether is atomic, it is also
+gravitative, and therefore forms around every atom and molecule, every
+satellite, planet, sun and star, an aetherial atmosphere--such aetherial
+atmosphere being doubtless proportionate to the mass of the atom or
+molecule or planet as the case may be, in accordance with the Law of
+Gravitation. We shall consider this view of the subject later on.
+
+[Illustration: Fig: 5.]
+
+Thus we learn that every particle of matter, and every body in the
+universe has its aetherial atmosphere so to speak, to which it is held
+bound by the universal Law of Gravitation. In the case of a satellite
+or planet or sun or star, that atmosphere will be more or less spherical
+in shape, decreasing in density as it recedes from the attracting body.
+As we saw in the previous chapter, Tyndall stated that the waves of
+light really formed spherical shells which surrounded the luminous body.
+In the conception of an atomic and gravitating Aether we can form a
+physical conception of these aetherial shells, which can be pictured as
+elastic envelopes, or rather series of envelopes surrounding each
+particle of matter, and also surrounding each satellite, planet, sun,
+and star; each envelope getting gradually less and less dense as the
+distance from the central body is increased.
+
+Now we learn from experiments that the vibration is always in the wave
+front, but the wave front is coincident with the surface of each
+aetherial spherical shell, therefore the vibration must be in, and
+coincide with, the surfaces of the spherical shells that are formed
+around every body in the universe.
+
+We are now, however, dealing specially with one body which is the source
+of light, viz. the sun, and have therefore to picture the sun as being
+surrounded by these aetherial elastic envelopes, which gradually get
+less and less dense as they recede from it. What, therefore, will be the
+effect of the heat of that body as it is poured forth into space? We
+have already learned (Art. 63) of the untold quantity of heat that is
+continually being poured forth into space from the sun with its diameter
+of 856,000 miles, and its circumference of over 2-1/2 million miles.
+What intense activity it must generate in the Aether near its surface!
+and what must be the direct effect of that heat upon the aetherial
+elastic envelopes or shells which surround it?
+
+Perhaps the answer can be best illustrated by a simple experiment. Let
+us take an ordinary toy balloon, with its elastic envelope, and fill it
+moderately full with air, and observe what the effect on it is when we
+put it near the fire. Gradually, as heat is imparted to the air in the
+balloon, the air which is also elastic expands, with the result that the
+envelope of the balloon is extended, and its size enlarged. Now withdraw
+it from the fire and note what happens.
+
+As the air inside gets cold again, the elastic envelope of the balloon
+gradually shrinks, until it has been reduced to its former size. What
+has been taking place during this experiment with regard to the elastic
+envelope and the atoms thereof? May we not say that there has been a
+vibration or oscillation, among the particles which go to make up the
+elastic envelope, that forms the surface of the balloon? Certainly there
+has been some form of motion, and that motion took first the form of an
+expansion, and then contraction of the individual particles; and we have
+only to conceive of this process being repeated quickly and
+continuously, to form a mental picture of what takes place in any
+aetherial elastic envelope or shell that surrounds the sun.
+
+The illustration is not, however, perfect, because we have made the
+source of heat to be outside instead of inside the elastic envelope, as
+is the case with the sun and its aetherial atmosphere or envelope. We
+will therefore slightly modify the experiment, and take two balloons,
+_A_, _B_, one smaller than the other, and put the smaller one _A_ into
+the interior of the larger one, inflating the smaller one, so that it
+can be situated in the middle of the larger one, the latter having twice
+the diameter of the smaller one, as in the diagram (Fig. 6). To the neck
+of the smaller balloon _A_ we will attach an india-rubber tube which
+ends in a closed bulb _C_. We have now the two balloons inflated. Let us
+press the bulb _C_ and notice what happens. The effect will be exactly
+the same as it was when we brought the balloon in contact with the heat
+of the fire in the first experiment--that is, the elastic envelope will
+be again expanded. As soon as we take the pressure from the bulb _C_ the
+envelope, being elastic, seeks to recover its original position, with
+the result that it springs back to its original size. If we pressed the
+bulb _C_ 20 times per minute, we should get 20 vibrations of the
+particles of the envelopes per minute, and if we pressed it 1000 times
+per minute, we should get 1000 vibrations among the particles of the
+elastic envelope, so that the number of vibrations would correspond to
+the number of times we pressed the bulb. Now how did this vibration
+reach the elastic envelope of the balloon _B_ from the balloon _A_?
+
+[Illustration: Fig: 6.]
+
+The reply is, by means of the particles, or atoms of air that exist
+between the two surfaces of the balloons, and that transmission would
+take the form of a wave propagated from particle to particle, so that we
+might put dots on the right side of _A_ to represent the atoms of air
+which transmit the wave from _A_ to _B_.
+
+But the vibration which takes place in the surface of the envelope of
+the outer balloon is _across_ this line of propagation, because as the
+wave proceeds from _A_ to _B_, the elastic envelope expands and
+stretches always _across_ the line of propagation--that is, it stretches
+up and down, left and right, as it is expanded outwards, so that the
+vibration or oscillation of the particles always takes place in the
+surface of the elastic envelope across the line of propagation. Let us
+therefore apply the result of this simple experiment to our solar system
+and the Aether, and see if it can be made to explain the transverse
+vibration of light. Let _A_ represent the sun (Fig. 7) and _B_ an
+aetherial elastic envelope surrounding the sun. In this case we dispense
+with the bulb _C_, as the sun possesses within itself the power to
+generate heat, and so to produce the required expansion of the elastic
+aetherial envelopes _B_, _G_, _H_, etc.
+
+[Illustration: Fig: 7.]
+
+Instead, however, of having air particles between _A_ and _B_, we will
+put in their place our aetherial atoms which we have conceived according
+to Art. 44. These surround the sun, represented by _A_, forming elastic
+spherical shells or envelopes. As the sun radiates its heat into space,
+it urges the aetherial atoms against each other, with the result that
+they transmit the energy from atom to atom, or particle to particle,
+till they come to the elastic aetherial envelopes of _H_, _G_, _B_.
+
+The effect on _B_, or on any other aetherial envelope, is to expand it
+outwardly, and thus set the atoms of which it is composed into
+vibration. The wave, which is now an aetherial wave travelling with a
+velocity of 186,000 miles per second, may be represented by the line _D_
+_E_. But while it is travelling from _D_ to _E_ the same energy is being
+radiated out in all directions, so that a wave reaches the whole surface
+of the elastic envelope _B_ at the same time, with the result that the
+whole of the shell or envelope is set in vibration as it expands
+outwardly.
+
+Thus the vibration is always in the wave front, and the wave front is
+always coincident with the surface of one of these envelopes, and as
+these aetherial envelopes are themselves formed by aetherial atoms, the
+wave is spread outwardly from any central point in a spherical form as
+proved by experiment. Not only, therefore, is the vibration in the wave
+front, but it is always transverse to the line of propagation, for the
+simple reason that the surface of the spherical shell or envelope is
+always at right angles to the radius vector or straight line which joins
+any centre to the surface of a spherical envelope.
+
+As soon as the aetherial atom which forms the spherical aetherial
+envelope has reached the limit of its expansion, it seeks to recover its
+former position because of its elasticity, with the result that the
+whole envelope contracts again, and arrives at its original position in
+space ready to accept motion again and transmit it onwards in the same
+manner as before.
+
+Thus, by the acceptance of an atomic and gravitating Aether, we may form
+a physical conception of one of the greatest problems in optical
+phenomena, viz. the transverse vibration of light which always takes
+place in the wave front, and across the line of propagation. Whether
+this explanation is exactly correct in detail, or not, I am convinced
+that the true physical explanation of the problem is to be found in an
+atomic and gravitating Aether, as hitherto a frictionless Aether has
+failed even to suggest to any scientist how such a transverse vibration
+can take place.
+
+
+ART. 72. _Reflection and Refraction._--A ray or wave of light is said to
+be reflected when it meets with an obstacle which opposes its free
+passage and turns it back. We have illustrations of this law of
+reflection in the case of water waves striking against a breakwater, or
+a sound wave striking against the wall of a room. In either case the
+wave is turned back, and reflection is the result. A ray or a wave of
+light is said to be refracted when, in passing from one medium into
+another, it is turned from the straight path in which it was going
+before it entered the refracting medium. An illustration of the
+refraction of light is to be found in the case of the glass lens, so
+often used to converge the light waves into one focus. We have up to the
+present dealt with only two theories of light, the Corpuscular theory
+and the Undulatory or Wave theory. We have seen how both harmonize with
+Huyghens' principle, and the question arises as to whether both can be
+made to harmonize with the phenomena of reflection and refraction.
+
+In the Corpuscular theory we have luminous particles emitted by luminous
+bodies. These particles we have learned are practically synonymous with
+our aetherial atoms.
+
+In the Wave theory it is impossible to conceive of a wave without
+conceiving of particles which transmit the wave; even Huyghens refers to
+particles of Aether, and so does Tyndall in his _Notes on Light_.
+
+In the Electro-magnetic theory of light we have again to think of atoms,
+which are termed electrons by Dr. Larmor and Sir William Crookes; while
+Professor J. J. Thompson calls them corpuscles.
+
+So that in all three theories we have the same fundamental idea of
+atoms, either expressed or imagined, underlying all the three theories.
+Now what is the property of the Aether on which all reflection and
+refraction is based? Is it not the property of density? Fresnel assumes
+that reflection and refraction of light are dependent upon different
+degrees of density of the Aether associated with any body, and has given
+a mathematical formula, which decides the index of refraction, such
+formula being entirely dependent upon the relative density of the Aether
+in association with the refracting medium.
+
+But with a frictionless medium, it is an absolute impossibility to
+conceive of different degrees of density of the Aether in association
+with matter.
+
+If the Aether does possess different degrees of density which decide the
+refractive index of the substance, then of a certainty there must be
+some law to govern and decide the density, and that law can only be the
+Law of Gravitation.
+
+As Young points out in his Fourth Hypothesis, every particle of matter
+has an attraction for the Aether by which it is accumulated around it
+with greater density. Now on the basis of our conception of a
+gravitative Aether, every atom and molecule, and indeed every body in
+the universe, possess aetherial atmospheres, which possess varying
+degrees of density, the denser layers being nearest to the nucleus of
+the atom or molecule as the case may be, the elasticity of each layer or
+envelope being always proportionate to its density.
+
+When we apply the corpuscular theory to the reflection of light we find
+that it satisfactorily accounts for the phenomenon.
+
+According to Newton's corpuscular theory, each luminous particle travels
+in a straight line through a homogeneous medium. When, however, it comes
+almost into contact with a reflecting surface, which in our case we
+conceive to be a layer of one of the aetherial elastic envelopes
+surrounding the atoms or molecules of the reflecting body, then,
+according to Newton, the light particle is repelled, or reflected by the
+medium; the angle of reflection or repulsion being always equal to the
+angle of incidence. So that the emission theory harmonizes with the wave
+theory in regard to reflection.
+
+When, however, we come to deal with the refraction of light, the
+corpuscular theory apparently breaks down, and it was in relation to
+this phase of the phenomena of light that the undulatory theory
+overthrew the corpuscular theory.
+
+According to the corpuscular theory, when a luminous particle or
+corpuscle is nearing the surface of a denser medium, as glass or water,
+it was attracted by the denser medium, with the result that the velocity
+of the particle in the denser medium was greater than its velocity in
+air. But direct experiments prove exactly the opposite, as it is found
+that when light passes from a rare into a denser medium, the velocity of
+light in the denser or more refracting medium is less than it was in the
+air. Here then was a test to decide the respective merits of the two
+theories. As the undulatory theory was able to give a satisfactory
+explanation of the phenomenon, the corpuscular theory was rejected, and
+the undulatory theory was accepted. Now the question suggests itself, as
+to whether it is possible to reconcile the two theories in relation to
+the refraction of light by our conception of an atomic and gravitative
+Aether. I believe it is possible. Let us look at the case for a moment.
+We have, according to our theory of the Aether, to conceive of all atoms
+and molecules, of all planets and suns and stars, being surrounded by
+aetherial elastic atmospheres, or envelopes, which, like the atmosphere
+in association with the earth, are always the densest nearest the
+nucleus of the atom, getting gradually less and less dense the further
+they recede from the central point. Further, according to our theory,
+with regard to the elasticity or pressure of these elastic envelopes,
+they exert a pressure proportionate to their density. So that the nearer
+the aetherial atmosphere or envelope is to the central point or nucleus
+of the atom, the greater will be the elasticity or pressure.
+
+Now what I wish to call the reader's special attention to is, that the
+pressure in each and every case of the aetherial elastic envelopes which
+surround the central nucleus, is always directed _away from_ the central
+point, and here it seems to me is the solution of the difficulty which
+Newton failed to solve. For when a luminous corpuscle enters any medium,
+assuming it to do so, it would have to overcome the pressure due to the
+increased elasticity of the denser aetherial envelopes, and as the two
+motions, viz. that of the incident ray, and the pressure due to the
+elasticity of the elastic envelope, would be in opposition to each
+other, the result would be that the luminous corpuscle, if it entered
+the medium at all, would be retarded and not accelerated as suggested by
+Newton, and such a result is perfectly in harmony with experiment. So
+that by our theory of an atomic and gravitating Aether, it seems to me
+that it now becomes possible to reconcile the two theories.
+
+There is another difficulty that the emission theory had to contend
+with, and that was, how was it possible for the same surface of any
+substance to reflect and refract a corpuscle at one and the same time?
+Newton overcame this difficulty by suggesting, from the results of his
+observations on certain coloured rings, that each particle had what he
+called certain phases or fits, of easy reflection or refraction, so that
+at certain times they would be refracted, and at other times they would
+be reflected.
+
+Boscovitch has suggested that the fits were due to the fact that each
+luminous corpuscle possessed polarity; which, by rotating, alternately
+offered their different sides to the refractive and reflecting surfaces,
+so that sometimes they would be reflected or repelled, and at other
+times attracted or refracted.
+
+A similar hypothesis has also been suggested by Biot. Now if such a
+hypothesis will satisfactorily account for the fact that the same medium
+will reflect or refract the luminous corpuscles, as the case may be,
+then in our aetherial atom we have the very conditions which would
+satisfy both Boscovitch and Biot's hypothesis. For one of the properties
+that we suggested regarding our aetherial atom was, that it possessed
+rotation like our own earth, and that it also possessed polarity.
+
+The harmonizing of the two theories, therefore, seems to rest upon the
+atomicity or non-atomicity of the Aether.
+
+It is absolutely certain that the electro-magnetic theory of light
+demands the recognition of some form of atomicity for the Aether. For if
+light be really an electro-magnetic phenomena, as has been proved by
+Maxwell and experimentally demonstrated by Hertz, then, in view of the
+fact that the atomicity of electricity is coming within the scope of
+direct experiment as asserted by Dr. Larmor, unless we accept atomicity
+of the Aether in some way, we shall be in the unphilosophical position
+of having the Aether of space not being composed of atoms, while the
+electricity associated with that Aether in some unknown way is composed
+of atoms. In other words, we shall have a non-atomic body composed of
+atoms, which conclusion is absurd. Therefore, from the electro-magnetic
+theory of light, we are again compelled to postulate atoms of some kind
+for the Aether.
+
+If there are electrical atoms in association with the Aether, then they
+must be of two kinds, positive and negative, as it is impossible to find
+positive electricity disassociated from negative. Therefore, from the
+electro-magnetic theory of light we get further evidence of the polarity
+of the aetherial atom, by which Newton's fits of easy reflection or
+refraction may be physically conceived.
+
+I am convinced, that with the hypothesis of an atomic and gravitative
+Aether as suggested by Young in his Fourth Hypothesis, all three
+theories of light in relation to the phenomena of reflection and
+refraction can be harmonized. I wish only to point out the direction in
+which to look for the solution, and must leave it to scientists to work
+out the problem.
+
+
+ART. 73. _The Solar Spectrum._--When a ray or beam of solar light is
+passed through a prism, it is broken up or decomposed into its
+constituent parts. This is called dispersion, and conclusively proves
+that the light from the sun is not a simple, but a compound colour. We
+have illustrations of this decomposition of pure white light in the
+rainbow, where the colours of the sunlight are revealed against the sky
+with clearness and precision. A simple experiment to prove that the
+solar light is a compound one may be made by boring a small hole in a
+shutter, and then allowing the sunlight that passes through the hole to
+fall upon a prism, such as the pendant of a candelabrum. When this is
+done, then on the opposite wall of the room will be seen, not one
+colour, but seven colours, ranged in the following order: Red, Orange,
+Yellow, Green, Blue, Indigo, Violet. This is termed the Visible
+Spectrum.
+
+It may be asked, What is the cause of the various colours in the
+spectrum? We have already seen that light is due to a wave motion of the
+Aether, and it can be demonstrated that the various colours of light are
+due to different wave lengths. Colour is to light what pitch is to
+sound. As has been shown in Art. 62, the pitch of a note depends upon
+the number of air waves which strike upon the tympanum of the ear in a
+given time. The more rapid the vibration, the higher the note. The more
+rapidly a sounding body vibrates, the shorter will be the length of each
+wave. If a violinist wants to produce a note of higher pitch, he presses
+his finger on the string, thereby shortening it, and by so doing
+increases the rapidity of vibration, and raises the pitch of the note.
+Now the colours of the spectrum are to the eye what the notes are to the
+ear. The aetherial waves which produce the red colour are slower in
+their vibrations, and are longer than those which produce the orange
+colour. Those which produce the orange colour are of slower vibrations,
+and longer than those which produce the yellow colour, and so on through
+all the other colours; until we get to the violet and to the
+ultra-violet, or invisible violet rays, which are the most rapid in
+their vibrations, and consequently their wave lengths are the shortest
+of the whole group. It has been ascertained that it takes about 39,000
+waves of red light to measure an inch if placed end to end. Now light
+has a velocity of 186,000 miles per second. If this is reduced to
+inches, we find that there are 11,784,960,000 in that distance. Let us
+therefore multiply this number by 39,000, and we shall then find how
+many waves of red light must enter the eye to produce the sensation of
+red colour. That number is 459,613,440,000,000, so that all these waves
+enter the eye in one second of time, and must strike the retina of the
+eye in order to produce the sensation of redness. In the same way, the
+number of waves that must strike the retina of the eye to produce the
+sensation of violet can be determined. It takes about 57,500 waves of
+violet to measure an inch, so that a violet wave is only 1/57000 part of
+an inch in length. All the other colours of the spectrum which lie
+between the violet and the red waves gradually get longer and longer in
+their wave lengths, and slower and slower in their vibrations, until at
+the red end of the spectrum and beyond it we have the longest waves,
+which are from 1/39000 part of an inch in length to 1/10000 part of an
+inch.
+
+The seven colours seen in the spectrum are called the Visible Spectrum.
+There are, however, rays of light beyond both ends of the spectrum which
+do not affect the optic nerves of the eye, and therefore are invisible
+to sight. The rays in the spectrum which lie beyond the red are termed
+ultra-red rays, while those beyond the violet are called ultra-violet
+rays. It can be proved the former are rich in heating power, while the
+latter possess great chemical power. By means of an instrument known as
+the thermo-electric pile, or thermopile, the various heating power of
+the whole spectrum, visible and invisible, can be determined.
+
+Let us look for a moment at these invisible or dark rays. Strictly
+speaking, all light is invisible, as we cannot see light itself, we can
+only see it by reflection. We have seen that light is due to a wave
+motion in the Aether, but we cannot see that wave motion, neither can we
+see the Aether itself, so that it is not strictly correct to call a ray
+visible or invisible. We have, however, accepted the terms in relation
+to the rays of the spectrum, to distinguish between the invisible or
+obscure rays of the spectrum and the visible rays. It was Sir W.
+Herschel who first discovered the existence of these invisible waves. He
+passed a thermometer through the various colours of the solar spectrum,
+and then noted the temperature of each colour. He did not, however, stop
+at the limit of the visible spectrum, but experimented with his
+thermometer beyond its limits, and then found that beyond the red rays
+there were other rays, the ultra-red rays, which possessed greater
+heating power than any other rays of the spectrum. Thus his experiments
+proved, that side by side with the luminous or light waves, there were
+other rays, which, though they possessed greater heating power, yet were
+not able to excite the optic nerve, and so produce the sensation of
+sight.
+
+From these facts we learn that the solar spectrum may be divided into
+three parts--
+
+1. The red or ultra-red end of the spectrum which possesses the greatest
+heating power.
+
+2. The central part, yellow and green, which is the greatest in luminous
+power or light waves.
+
+3. The violet or ultra-violet end, which possesses great chemical or
+actinic power as it is sometimes termed.
+
+We have already seen (Art. 69) that the same aetherial waves which give
+rise to heat, also give rise to light, and that the only physical
+difference between heat and light is, that the waves which cause the
+phenomena of heat are of slower period, and of greater length, than
+those which cause the phenomena of light. From the solar spectrum we
+learn that there are a third class of Aether waves, which are of more
+rapid vibration, and therefore shorter in length than either the
+aetherial heat waves or the aetherial light waves. As already stated,
+these are called chemical or actinic waves, because they possess a
+greater chemical power than either the heat or the light waves that form
+the central part of the spectrum.
+
+Now this question suggests itself to us in relation to these chemical
+waves. What are these so-called chemical waves that are produced in the
+aetherial medium by the activity and heat of the sun? It must be
+remembered that the aetherial waves which give rise to both light and
+heat, and also these chemical waves, are first set in motion by the sun,
+at least as far as our solar system is concerned. We are perfectly
+conversant with the phenomena and characteristics of both heat and
+light. We are able to exactly determine what their particular effect
+will be on matter, and to describe that effect in a perfectly
+straightforward manner. The same, however, cannot be said of these
+so-called chemical waves that lie chiefly in the violet and ultra-violet
+end of the solar spectrum. What, then, is a chemical wave, its
+particular nature, and its exact properties? That we know it can
+decompose certain compounds, as Carbonic Acid Gas, CO_2, and so give
+rise to chemical decomposition, has been proved by Professor Tyndall and
+others, but I have never yet seen any record of any attempt to find out
+what these chemical waves are. There may have been such attempts made to
+discover their origin and character, but I have not seen any such
+record. I purpose, therefore, to offer an explanation as to the
+character and origin of these chemical or actinic waves, which I hope to
+prove by philosophical reasoning. We have already seen (Arts. 54 and 59)
+that both heat and light are convertible, or can be transformed into
+electricity, so that the same aetherial wave motion which can produce
+light can also produce heat, and that in its turn can produce
+electricity. Thus we learn that there is a very close identity between
+light, heat, and electricity; indeed it can be demonstrated that the
+same aetherial wave motion which produces electricity can produce the
+other two.
+
+Lorentz,[14] in an article on "The Identity of Light Vibrations with
+Electric Currents," states that "the vibrations of light are themselves
+electric currents." Now if this is true, and I believe it to be true, as
+I hope to prove later on from Clerk Maxwell's works, then it necessarily
+follows, that wherever we get aetherial light waves, we must at the
+same time also get aetherial electric waves. If that be so, then in the
+solar spectrum we ought to have revealed to us, not only indications of
+the presence of the heat and light vibrations, but equally so the
+presence of electric waves. This, I believe, is actually the case, and
+the electric waves are the so-called chemical waves in the violet and
+ultra-violet end of the spectrum. I think that we shall find sufficient
+arguments and analogy to support this hypothesis, as we look further
+into the matter. One of the greatest scientists of the past century,
+Clerk Maxwell, has given to the world the genesis of what he termed the
+Electro-Magnetic Theory of Light, in which he proved that light was
+nothing more nor less than an electro-magnetic phenomenon. He pointed out
+that the same Aether which was concerned in the propagation of light and
+heat through space, must therefore be equally concerned in the
+propagation of electric displacements in the free Aether; as he states,
+it would be philosophically wrong to assume that there was one aetherial
+medium for light, and another for electric phenomena. If, therefore,
+there is such a theory as the Electro-Magnetic Theory of Light, and
+there undoubtedly is, as has been proved by the researches of Hertz on
+electric waves, then it follows, either that light waves are themselves
+electric currents, as suggested by Lorentz, or that the light waves are
+directly associated with electric waves in the same way that they are
+associated with heat waves. So that the only difference between them
+would be one of period of vibration and of length, the electric waves of
+the Aether being of greater rapidity and therefore of shorter length
+than either the light or heat waves. The only conclusion, therefore,
+that it seems possible to come to regarding these chemical waves is,
+that they are the electric waves of the spectrum. Thus, in the solar
+spectrum, there are three classes of waves indicated by the various
+colours, and beyond the limits of these colours, viz. (1) Thermal or
+Heat waves in the red or ultra-red end of the spectrum; (2) Luminous or
+Light waves at the middle of the spectrum; and (3) Electric or Chemical
+waves in the violet or ultra-violet end of the spectrum. Now in looking
+at this hypothesis from the standpoint of our Rules of Philosophy, I
+venture to assert that all the three rules are satisfactorily fulfilled,
+and that being so, the hypothesis advanced is philosophically correct.
+In the first place, such a conception that the chemical waves or violet
+waves are really electric waves is simple in its hypothesis, and so
+fulfils our first Rule of Philosophy. It is simple, because it puts in
+the place of unknown chemical waves, a certain kind of aetherial waves
+with whose action we are definitely familiar, and whose origin and
+effect can be satisfactorily accounted for, as proved by Hertz. Chemical
+waves are not simple in conception, because we do not know exactly what
+they are, or how they are originated. Besides, as Newton points out,
+there is nothing superfluous in Nature. If one cause can effect the
+desired end, as electric waves, then another cause as chemical waves is
+superfluous and unnecessary. Further, in our hypothesis of the electric
+character of these chemical waves, we have a solution which
+satisfactorily fulfils the second Rule of our Philosophy. Experience and
+experiment teach us, that there are electric waves constantly being
+generated in a thousand ways. Indeed, it is an absolute impossibility to
+perform the simplest act of ordinary life, as brushing a hat, or wiping
+the boots on a mat, cutting an orange, or any other act of simple
+everyday life, but that these aetherial electric waves are generated.
+But as for these so-called chemical waves, experience has little to say
+about them, and experiment still less. If we decompose water, dividing
+it up into two gases, Oxygen and Hydrogen, we do it by passing a current
+of electricity through the water. If we want to decompose or split up a
+binary compound, as HCl, into its two elements, Hydrogen and Chlorine,
+then we can do it by electricity--that is, by the decomposing action of
+these electric waves. In all these experiments and results we know
+definitely what we are doing, and what the effect will be. There is no
+vagueness about the terms used. When we speak of chemical action we look
+to a definite source for that action, and we do not say that such action
+is produced by chemical waves, but rather by electricity. So that all
+experience teaches us, and all experiments made by such men as Faraday,
+Davy, Maxwell, and Hertz confirm the statement, that these aetherial
+electric currents can accomplish all that the so-called chemical waves
+accomplish, and that being so, the third Rule of our Philosophy is also
+fulfilled, as we have in the aetherial electric waves a satisfactory
+explanation for the fact which we seek to explain, viz. the character
+and origin of the chemical waves that exist in the violet end of the
+spectrum. Thus, we learn, that not only is the sun the source of all
+heat and light, in that it gives rise to the vibrations of the Aether
+which are propagated through it in waves, but that it is also the source
+of all electric waves in the solar system, in that electric currents are
+primarily due to the wave motion set up in the Aether, those electric
+waves also traversing space with the velocity of light.
+
+[Footnote 14: _Phil. Mag._, 1867.]
+
+
+ART. 74. _Direction of Ray of Light._--In Art. 65 it was shown that the
+direction of a ray of heat was that of a straight line from the heated
+or luminous body from which the Aether waves proceeded. We have also
+seen in Art. 69 that the aetherial waves which give rise to the
+phenomena of heat are identical with those that give rise to light, so
+the direction of a ray of light must also be that of a straight line
+proceeding from the luminous body. A ray of light is a line
+perpendicular to the Aether waves which are propagated through space in
+concentric spheres from the luminous body, which, by its atomic
+vibrations, gives rise to the light waves. It must, however, be
+remembered that rays have no physical existence, for it is the waves
+that are propagated, and not the ray, which simply indicates the
+direction that the light takes, this truth being known as the
+rectilineal propagation of light. That light proceeds in straight lines
+may be proved in several ways. For example, we cannot see round corners,
+which would be possible if light took a curved path instead of a
+straight one. A better proof, however, may be obtained by making a small
+hole in the window-shutter, and allowing the sunlight to pass into the
+darkened room. The beam of light which passes into the room will then be
+seen to take a straight course, its presence being revealed by the
+particles of dust that float about the room.
+
+Another conclusive proof that light proceeds in straight lines is to be
+found in the fact, that all images formed on any screen by the rays of
+light after passing through a small hole are inverted. For example,
+suppose we have a window-shutter with a small hole in it, while in the
+garden fronting the window there stands a tree. Now if the rays of light
+which pass from the tree through the hole in the window-shutter are
+allowed to fall upon a screen in the darkened room, it will be found
+that the image is inverted.
+
+This is accounted for by the fact, that the rays cross each other at the
+hole, and proceeding in straight lines, form an inverted picture on the
+screen. It can further be proved, that the path of a ray of light
+through space as it proceeds from the sun is also that of a straight
+line. Whenever there is a solar eclipse we have light so long as we can
+see the smallest part of the sun's surface. The instant, however, that
+we have a total eclipse, at that instant the whole of the light of the
+sun is shut off, and for a brief space there is darkness, until the
+planet which is causing the eclipse has passed on in its orbit and the
+sun's surface reappears again. Now if light did not proceed in straight
+lines, such an event as a total eclipse would be impossible; because, if
+the light proceeded in curved lines instead of straight ones from the
+sun, then even when the planet which causes the eclipse got directly
+between the earth and the sun, the rays of light being curved instead
+of straight would bend round the eclipsing planet, and so would not all
+be intercepted, and thus such an event as a total eclipse would be an
+impossibility. From this we learn, therefore, that the path of a ray of
+light as it proceeds from the sun through space is that of a straight
+line, and that the path corresponds to the radius vector of a circle,
+which is also the path that the centripetal force takes.
+
+Viewing the matter from the standpoint of the solar system, we find the
+sun, which is the centre of that system, exerting an attractive force
+along the radius vector of all the orbits of the planets, with a force
+which decreases in intensity inversely as the square of the distance. At
+the same time, being the source of all light, it is constantly
+propagating into space aetherial light waves with a velocity almost
+inconceivable; which also decrease in exactly the same ratio as the
+attractive power of the sun decreases. If, therefore, it can be shown
+that there is such a truth as the dynamical value of light, in the same
+way that it has been shown that there is a dynamical value of heat, then
+it follows, that not only is the sun the centre of an attractive power
+which proceeds in straight lines, but it is equally the centre of a
+power whose influence and motion are exerted along exactly the same path
+as the centripetal force, but in an opposite direction, that is, away
+from the sun. I hope to be able to show that the aetherial light waves
+do possess such a dynamical value, and if that is accomplished, then not
+only from the realm of heat, but also from the realm of light, we shall
+have conclusive evidence of a power or motion whose influence is
+directed away from the sun, which, therefore, would correspond to a
+centrifugal force--that is, a force or motion directed from a central
+body as the sun.
+
+
+ART. 75. _Intensity of Light._--The intensity of light diminishes with
+the distance from the luminous body, according to the same law that
+governs sound, and heat, and electricity. We have already seen (Art. 67)
+that the intensity of heat diminishes inversely as the square of the
+distance, so that if the same law holds good for light that holds good
+for heat, then, according to the law of the inverse squares, if we
+double the distance from the luminous body, the intensity of light is
+only 1/4 of what it was in its first position. If the distance be
+trebled, then the intensity will be decreased 1/9. This can easily be
+proved by the following experiment: Suppose we have a lighted lamp, and
+at a distance of 1, 2 and 3 feet respectively, we have three square
+surfaces. It can then be demonstrated that the light which falls on the
+square 1 foot away, if allowed to fall upon the square 2 feet away,
+would cover four times the area of the first square; and if allowed to
+fall on the square 3 feet away, it would cover nine times the area.
+Therefore the intensity of the light on the square 2 feet away, covering
+four times the area, would only be 1/4 of what it is on the square 1
+foot away, while the intensity of light on the square 3 feet away, which
+covers nine times the area, would only be 1/9 of the intensity received
+by the first square.
+
+If the difference in the distances therefore be represented by the
+figures 1, 2, and 3 feet respectively, the intensity would be
+represented by the figures 1, 1/4, 1/9. The decrease in the intensity of
+light is really a decrease in motion. The intensity of a note in sound
+depends upon the vibration of the particles of air, while the intensity
+of light also depends upon the vibrations of the aetherial atom.
+
+If, therefore, we get a decrease in the vibration of the aetherial atom,
+the further we get from the luminous body, it can be readily seen that
+the intensity of light really implies a decrease of motion.
+
+Now let us apply the law of inverse squares in relation to light to the
+solar system. We have the sun with its huge form all aglow with fires,
+as the source of all light to the planetary worlds that revolve around
+it. Year in and year out, for many ages past, the sun has been pouring
+out its light into space on every side, lighting up the planets or other
+bodies that revolve round it on that side only which is presented to the
+sun. Thus Mercury, at its distance of about 36,000,000 miles, obtains a
+light from the sun which is of far greater intensity than the light
+which Venus receives, while Venus receives a light of greater intensity
+than the light which the Earth receives, and the Earth receives light of
+greater intensity than any of the planets outside its orbit in the solar
+system, as Mars, Jupiter, Saturn, Uranus, or Neptune. This decrease in
+the intensity of light is according to the inverse square of the
+distance from the central body, the sun. So that if we have one planet
+at twice the distance from the sun, as compared with another planet, the
+intensity of light at that distance will be only 1/4 of the intensity
+received by the nearer planet. This decrease of the intensity of light,
+however, may be compensated for by a difference in the constituents of
+the planets' atmosphere, by means of which it may be possible that the
+outermost planets enjoy climatic conditions similar to our own.
+
+Now we have proved, in the previous chapter, that heat is a repulsive
+motion, and as the same aetherial waves give rise to the phenomena of
+light, then it ought to follow that light has equally a repulsive power
+on the planets with which it comes into contact. If that can be proved,
+and I submit that it can, then from the phenomena of light, we learn
+that there is a force, or rather a motion, ever proceeding from the sun
+in straight lines, as shown in the previous Art., which decreases in
+power or intensity inversely as the square of the distance. So that not
+only is the sun the centre of an attractive Force, the Centripetal
+force, or the attractive Force of Gravity, which proceeds in straight
+lines through space, decreasing in intensity inversely as the square of
+the distance, but at the same time it is also the centre of a motion,
+that is, the aetherial wave motion of light, which takes exactly the
+same path as Gravitation Attraction, and which is subject to exactly the
+same laws. Unlike Gravitation Attraction, however, its power and motion
+is ever directed away from the central body, the sun; and if such motion
+exerts any power on any planet with which it comes into contact, that
+power or motion can only be a repulsive motion in the same way that heat
+is a repulsive motion. Assuming, therefore, that light, through the
+medium of the aetherial waves, does exert this repulsive motion, then,
+according to the law of inverse squares, it can be seen that if a
+planet's distance be doubled, the repelling power of the aetherial light
+waves would be decreased 1/4, while at the same time the attractive
+power of the centripetal force would be decreased 1/4 also. If, on the
+other hand, the planet's distance from the sun be reduced to 1/2 of its
+former distance, then the repelling power of the aetherial light waves
+would be increased four times, but contemporaneously with the increase
+there would be an increase in the attractive power of gravity, which
+would exactly counterbalance the increased repelling power of the light
+waves. So that in assuming that there is this repelling power in the
+light waves, there are thus two forces in existence in the solar system
+(which is a type of all other systems), or rather two motions, as all
+forces resolve themselves into motions of some kind, one motion ever
+tending from the central body, that is, the motion of the aetherial
+light waves, and the other tending to the central body, that is, the
+force of gravity, which we shall see later on is also a motion of the
+Aether, whose influence is ever towards the central body, be it a sun,
+star, or planet. These two motions, therefore, are subject to the same
+law, viz. that their power or intensity is not only directed in straight
+lines from the central body, but their intensity is regulated exactly by
+the same law of inverse squares. If the repelling motion be doubled,
+then the attractive motion or power would be doubled also; if the
+repelling motion be quadrupled or halved, then the attractive force of
+gravity would be quadrupled or halved in the same way, the two forces
+being exactly increased or decreased in the same ratio according to the
+law of inverse squares.
+
+
+ART. 76. _Velocity of Light._--The transmission of light is not
+instantaneous, as it requires time for its propagation through space,
+from the luminous body which gives rise to all light, as the sun for
+example, until it reaches the body which it lights up. The velocity of
+the light waves, however, is so great, that it is almost impossible to
+give any comparative idea of their rate of transmission. The velocity of
+the light waves was first established by Roemer, a Danish astronomer, in
+1675. He ascertained the velocity of light by observations made on the
+satellites of Jupiter. His methods of reasoning can easily be understood
+by reference to the following diagram.
+
+[Illustration: Fig: 8.]
+
+Let _S_ represent the sun, and _A_ and _B_ the orbit of the earth round
+the sun; _C_ _E_ _D_ part of Jupiter's orbit round the sun; while _D_
+_E_ _F_ represents the orbit of Jupiter's satellite. When the earth,
+Jupiter, and the satellite are in a straight line with each other, the
+satellite suffers an eclipse through passing into the shadow thrown by
+Jupiter. Now Roemer found that there was a difference in the time of the
+eclipse when the earth was at _B_, that is, when it was nearest to
+Jupiter, and when it was at _A_, which is that part of the earth's orbit
+furthest away from Jupiter. That difference was accounted for by the
+fact, that when the earth was at _A_ the light had to travel further
+from Jupiter than when the earth was nearest to Jupiter, that is at
+point _B_. Thus, when the earth was nearest to Jupiter, the light had a
+shorter journey to travel than when it was furthest from Jupiter. The
+difference, he found, was about 16 minutes, and he reasoned that this
+difference was caused by the light having to cross the earth's orbit
+from _B_ to _A_, in its longer journey, than when it only had to reach
+the earth at _B_. The mean distance of the earth from the sun, that is,
+the radius of the earth's orbit, is about 92-1/2 million miles, so that
+the diameter of the earth's orbit is about 185,000,000 miles, and if it
+takes about 16 minutes for light to traverse this distance, we find that
+light has a velocity, according to Roemer, of 192,500 miles per second.
+The result, however, arrived at by Roemer was not generally accepted at
+that time, and it was not till 1728 that Bradley discovered what is
+known as the Aberration of Light, and from that discovery proved that
+light was not transmitted instantaneously through space, but that it was
+transmitted with finite velocity; and that that velocity corresponded
+fairly well with the velocity given by Roemer. Bradley, in his
+astronomical observations, noticed that some of the fixed stars, so
+called, did not appear to be really fixed, but that they described small
+circles in the heavens each year. This fact greatly perplexed him, until
+at last he hit upon the true solution by taking into account the motion
+of the earth in its orbit, together with the fact that light had a
+finite velocity. This result showed that the light from the stars
+travelled with the same velocity as that which travelled from Jupiter's
+satellites. The Aberration of Light, as his discovery was termed, may be
+illustrated in the following way--Suppose that you are standing still,
+and that it is raining, the rain descending vertically on the umbrella
+that you hold up to cover you. As soon as you begin to walk, the
+rain-drops will apparently begin to slant, and if the walk is changed
+into a run, the greater apparently will be the slanting direction that
+the rain-drops take. In the same way, the rays of light from a star
+would fall vertically upon the earth if it were motionless, but as the
+earth is moving through space with varying velocity, it gives to the
+rays of light a slanting direction. By calculating the speed of the
+earth, and ascertaining the exact slanting direction of the rays, the
+velocity of light may be ascertained. This Bradley did, and showed that
+it coincided almost with the result arrived at by Roemer. Various other
+means have been adapted to test the results arrived at by these two
+astronomers. Fizeau, in 1849, was able to measure the velocity of light
+by using, not planetary or stellar distances, but by simply using
+distances in the city of Paris; while Foucault, in 1860, devised a
+method of measuring the velocity of light in air or any other medium.
+The results arrived at by these men leave no doubt as to the exact speed
+of light, which may now be reckoned to have a velocity of 186,000 miles,
+or 300,000,000 metres per second. Notwithstanding this great speed at
+which light travels, the nearest stars are so far off that their light
+takes about 3-1/2 years to reach the earth, while scientists tell us
+that some of the most distant stars are so remote, that their light
+takes thousands of years to reach our earth, travelling at the rate of
+186,000 miles per second. From considerations like these we get a dim
+conception of the almost illimitable extent of the universe. Now let us
+try to understand what this rate of motion really means. We have to
+remember that light is caused by wave motions in the Aether, so that we
+have here a wave motion which is travelling through the Aether at the
+enormous rate already quoted. Light takes about 8-1/2 minutes to travel
+from the sun to the earth, a distance of 92,000,000 miles. Our fastest
+trains do not travel 80 miles an hour, and if a train left the sun and
+continued its journey through space at that rate, it would take over 130
+years before it reached our earth, while the light would perform the
+journey in 8-1/2 minutes. We have some idea of the velocity of a train
+travelling at 80 miles an hour; what, however, must be the velocity of a
+wave motion which travels 22,500 times as fast? In Art. 56 we have seen
+that all energy is the energy of motion, and therefore wherever we get
+motion of any kind or sort, there we must have energy accompanying it,
+or the power to do work. We have here, then, a source of energy in the
+aetherial waves known as light waves, with their enormous velocity which
+is almost inconceivable and illimitable. What must be the energy which
+exists in space due to the wave motion of the Aether? We have to
+remember on this point that we are no longer dealing with a frictionless
+medium, but that we are dealing with matter, only in a far more rarefied
+and far more elastic form than ordinary matter, but nevertheless matter
+just as air is considered matter, and, being matter, its very motion
+imparts to the light waves a power and a force which make them capable
+of doing work. The kind of work done will be considered later on, when
+we deal with the dynamical value of light. That we do not feel the power
+and energy of the light waves is due to the well-known fact that their
+power is broken by the activity of the atmospheric particles, each of
+which, in their myriads, is ever moving with great velocity, and
+therefore bombard the light waves, as they endeavour to strike the
+earth. Thus the aetherial light waves are broken up and shattered, and
+fall to the earth not with their full energy or power, but in a blended
+form, or with that reflected energy which we call light. If they were to
+come unbroken and unchecked upon us, and on the earth, in the same way
+that they apparently do upon our satellite the moon, we doubtless should
+experience very different effects of their energy and power due to their
+enormous velocity.
+
+
+ART. 77. _Dynamical Value of Light._--We have already learned (Art. 68)
+that heat possesses a dynamical value, such value being measured by
+Joule, and its equivalent in foot-pounds being exactly ascertained. We
+have further seen (Art. 69, on the identity of light and heat), that the
+same aetherial waves which produce heat are also concerned in the
+production of light. If, therefore, the aetherial waves which give rise
+to heat possess a dynamical action and equivalent, it follows that light
+must also possess a dynamical action and equivalent, and such action
+should be capable of being expressed in terms of foot-pounds. Clerk
+Maxwell has recorded the exact dynamical equivalent of light. On this
+matter he writes:[15] "If in strong sunlight the energy of light which
+falls upon a square foot is 83.4 foot-pounds per second, the mean energy
+of one cubic foot of sunlight is about .0,000,000,882 of a foot-pound,
+and the mean pressure on a square foot is .0,000,000,882 of a pound
+weight." We have here then the exact dynamical equivalent, according to
+Maxwell, of a cubic foot of sunlight near the earth's surface, and of
+the pressure exerted by light on a body with which it comes into
+contact.
+
+Again, Lord Kelvin[16] has measured the exact dynamical equivalent of a
+cubic mile of sunlight, both near the surface of the sun and then near
+the surface of the earth, and in a note adds that the relation of the
+two values is as 46,000 to 1. So that if the dynamical value of a cubic
+mile of sunlight near the earth's surface be represented by unity, then
+the value of a cubic mile of sunlight near the sun's surface would be
+46,000 times greater, while he further adds that it would take 4140
+horse-power every minute, as the amount of work required to generate the
+energy existing in a cubic kilometre of light near the sun, a kilometre
+being equal to about 1093 yards.
+
+Professor Challis[17] stated in 1872 that "Light is to be ranked with
+the physical forces, and its dynamical action is equally to be ascribed
+to the pressure of the Aether." Now I want to put this question to the
+reader: If light possesses this dynamical action, that is, if it
+possesses a motive or driving power, what must be the exact effect of
+the dynamical action of the light waves from the sun upon all the
+planets and meteors that revolve round it? We know that the sun is
+324,000 times the mass of our earth, and that it has a diameter of about
+856,000 miles and a circumference of over two million and a half miles.
+What, therefore, must be the energy of the aetherial light waves that it
+speeds on their way through space on every side? Stokes,[18] in regard
+to the mechanical energy of Light, states that "the amount of energy
+poured forth into space corresponds in round numbers to 12,000
+horse-power per square foot," and that every square foot of the sun's
+surface supplies energy at the above rate. The number of feet in the
+sun's surface can be approximately determined. Roughly, there are
+2,284,000,000 square miles of surface on the sun's huge form, and there
+are 27,878,400 square feet in a mile. By multiplying these two numbers
+we can ascertain the exact number of square feet on the surface of the
+sun. If, therefore, every square foot possesses a mechanical value equal
+to 12,000 horse-power, what must be the mechanical equivalent of the
+sun's radiation of light that it pours forth into space?
+
+I want to call the attention of the reader to another fact, and that is,
+that light always proceeds in straight lines from the sun (Art. 76), and
+therefore if there be any mechanical action in light at all, that action
+must be one which is always directed from the sun in straight lines. Now
+experience universally teaches us, that if a body is pushed, and pushed
+with such a force as has been indicated, then that body not only moves,
+but moves in the direction that the supposed horses would push. I have
+already shown (Art. 76) that the path of light is that of a straight
+line corresponding to the path of the attractive force of gravity;
+therefore these horses must ever push in a direction _from_ the sun
+along the same path that the sun's attractive power takes. In other
+words, the mechanical action of these supposed horses will be a
+repulsive one, that repulsion being due to the dynamical action of the
+light waves upon the body that they come into contact with. If this is
+correct, then not only is heat a repulsive motion, as stated in Art. 63,
+but light is equally the possessor of a repulsive motion, because its
+action is ever directed from the sun. We might continue to follow the
+supposed horses as they continued their course through space, and we
+should find that their energy decreased inversely as the square of the
+distance, partly because the further they proceeded into space the
+larger the area would be they would have to cover, and therefore their
+energy would be decreased proportionately.
+
+Professor Stokes, in the same work[19] already referred to, in
+continuation of the same idea, states: "At the distance of the earth the
+energy received would correspond to about one horse-power for every
+square of 5 feet, on that side of the earth's surface facing the sun,
+supposing the rays to fall perpendicularly." That being so, we can
+exactly calculate in horse-power the energy received from light on that
+side of the earth facing the sun, at its distance of 92,000,000 miles.
+The area of the earth's surface is, roughly, 200,000,000 x 5280 square
+feet, and if the energy received is equal to one horse-power for every 5
+square feet, then the amount of energy received by the earth on that
+side facing the sun would be equal to 200,000,000 x 5280 x 1/2 x 1/5
+horse-power. This power, it must be remembered, is ever directed _away
+from_ the sun, and upon that side of the planet that faces the solar
+orb. So that we have virtually a repulsive force ever directed against
+the earth, estimated by Professor Stokes to be equal to the estimated
+horse-power.
+
+This assumption of the repulsive power of light brings the phenomena of
+light into harmony with that of heat, because we have already seen (Art.
+63) that heat is essentially a repulsive motion, as indicated by Davy,
+Rumford and others; and, as heat and light both have a common origin,
+then light should possess a repulsive power also.
+
+As further proof of this statement, let me again quote from Clerk
+Maxwell. In the quotation already given in this Art. we have seen that
+the pressure of sunlight on a square foot is equal to 83.4 lb. He adds
+the following words to those already quoted: "A flat body exposed to
+sunlight would experience this pressure on its illuminated side only,
+and would therefore be repelled from the side on which the light falls."
+
+Now if more conclusive proof of the correctness of the argument I am
+advancing were required, I do not think it could be given from any
+greater authority than that just quoted. Coming from the pen of one of
+the most brilliant scientists that the past century has known, I venture
+to think the opinion will be received with that due weight which it
+demands.
+
+This statement of Clerk Maxwell's has received, however, definite and
+experimental proof from Professor Lebedew of Moscow University, and by
+Nichols and Hull of America. The former has given, in the _Annalen der
+Physik_ for November 1901, the results of his experiments in relation to
+the pressure of light. The following are the results: He proved, 1st,
+that the incident beam of light exerts pressure both upon an absorbing
+and a reflecting body; 2nd, that the pressure of light is proportionate
+to the amount of incident energy, and is independent of the colour of
+light; 3rd, that the pressure of light corresponds with the forces of
+radiation as calculated by Maxwell.
+
+About the same time, Nichols and Hull of America were engaged upon
+experiments relating to the pressure of light waves, and their results
+were published in the November _Physical Review_, 1901. Thus, from two
+separate and independent sources, Maxwell's equations as to the pressure
+which light waves exert upon any body on which they fall received
+definite experimental confirmation.
+
+The repulsive power of the light waves receives further confirmation from
+that theory known as the electro-magnetic theory, which supposes light to
+be nothing more or less than an electro-magnetic phenomenon; that is to
+say, it is directly or indirectly due to the action of electric currents.
+
+As already indicated, Lorentz was of the opinion that the light waves
+were themselves electric currents, and whether this is the actual fact
+or not, certainly it is true that the electro-magnetic theory of light
+is no mere fable or myth, but that it ranks as one of the most advanced
+and correct hypotheses in regard to light that has ever been given to
+the world. According to that theory, which we shall look at
+subsequently, we find that the aetherial medium is not only the medium
+for the light waves, but that it is also the medium which conveys and
+carries the electric currents through space, and even through all
+matter. Further, from that theory we shall have good reasons for
+assuming that the aetherial light waves are either themselves electric
+currents, or closely identified with them, in the same way that the
+light waves are identified with heat waves. If these facts should be
+found to hold good relative to the identity of aetherial light waves and
+the aetherial electric waves, then it can very readily be seen that such
+a hypothesis gives added weight to the repulsive power of light. One of
+the very commonest facts regarding electricity and its currents is, that
+wherever we get electricity, we not only get attraction, but there is
+always associated with that attractive force a repulsive force, which is
+equal in amount to the attractive force. So that if, wherever we get
+electric currents, we find associated with those currents a repulsive
+force, then, in view of the electro-magnetic theory of light, it should
+also follow that on that hypothesis we ought also to find a repulsive
+power in light. From the dynamical aspect of light on the bases of facts
+given to the world by such men as Professor Stokes, Clerk Maxwell, Lord
+Kelvin, and Professor Lebedew, we are compelled, therefore, to come to
+the conclusion that light does possess such a repulsive force, such
+force being due to the dynamical action of the aetherial light waves.
+
+Thus we learn from the dynamical action of light, that not only is the
+sun the centre of an attractive force, but that it is equally the centre
+of a repellent or repulsive power or motion; which repulsive power
+always follows the path of the radius vector, and diminishes with an
+intensity which is inversely as the square of the distance. What we have
+to ask ourselves therefore is, whether the repulsive power of light is
+the Centrifugal Force that we are trying to discover? In Art. 24 we
+found out what were the necessary characteristics of the Centrifugal
+Force, which is to form the companion law to the attractive law of
+gravity, or the Centripetal Force. We there saw that this centrifugal
+law must be universal in character; that it must coincide with the path
+of the centripetal force; that it must also be subject to the same law
+of intensity, viz. the law of inverse squares; and further, that the
+force must be proportional to the product of the two masses concerned.
+We find in the repulsive power of light three at any rate of these
+conditions fulfilled. Light is universal because Aether is universal.
+It is always subject to the law of inverse squares, and what is more,
+its repelling power coincides exactly with the path which the
+centripetal force takes, that is, the radius vector. We have not,
+however, discovered that light fulfils the remaining necessary
+condition, which is, that the repelling powers of light emitted by any
+two bodies are equal to the product of their masses. So that until this
+is done, it cannot be said that the aetherial light waves form the
+centrifugal force or motion from a central body that we are seeking for.
+But while that may be true, yet if light be not the centrifugal motion,
+it certainly indicates in what direction we are to look for that force,
+and that is to the Aether, whose periodic waves give rise to the
+phenomena of light. For, after all, light is due to aetherial wave
+motion, and, therefore, while light from certain standpoints may be
+conceived to be the cause of other phenomena, yet primarily the real
+cause of all phenomena which are due to light are due to the aetherial
+waves which themselves give rise to the phenomena of light. Thus light
+acts as a guide-post to us, pointing out the direction we should take in
+order to find out the real centrifugal force or motion, and as plainly
+as it possibly can, it indicates to us that the true solution of our
+centrifugal motion that we are seeking for is to be found, and alone
+found, in that universal aetherial medium which, by its vibrations and
+wave motions, gives rise to that which we term Light. In conclusion of
+this point, it may be pointed out that Professor Challis[20] also took
+this view of light, as he distinctly states that "Light is to be ranked
+with the physical forces, and its dynamical action is equally to be
+ascribed to the pressure of the Aether," and then proceeded to show how
+repulsion could be exerted on atoms by the periodic wave motion of the
+Aether.
+
+[Footnote 15: _Magnetism and Electricity._]
+
+[Footnote 16: _Phil. Mag._, 1902.]
+
+[Footnote 17: _Ibid._, 1872.]
+
+[Footnote 18: _Burnet Lectures._]
+
+[Footnote 19: _Burnet Lectures._]
+
+[Footnote 20: _Phil. Mag._, 1872.]
+
+
+ART. 78. _The Electro-Magnetic Theory of Light._--We have seen (Art.
+71) that light is due to a periodic wave motion of the Aether, and we
+have previously seen that heat is also due to a periodic wave motion of
+the Aether. Thus in the phenomena of light and heat, Aether is the
+medium in which the energy of light is stored, and by which it is
+transmitted in its passage from a luminous body, as the sun, until it
+comes into contact with a planet or satellite from which it is
+reflected, thus giving rise to light and heat. When, however, we come to
+deal with electro-magnetic phenomena, which are the results and effects
+produced by electricity and magnetism, we find certain phenomena similar
+to those that we find in relation to light and heat. Thus, when light is
+emitted by a luminous body, a certain amount of energy is given out by
+that body, and if such light is absorbed by another body, the latter
+becomes heated, a clear proof that it has received energy or motion from
+some outside source. From the time it left the luminous body till it
+reached the lighted or absorbing body, it must have existed as energy,
+that is, motion in the Aether. As we have already seen, Newton thought
+that the transference of energy was accomplished by the actual
+transference of certain small corpuscles or atoms given out by the
+luminous body, which conveyed the energy of the one body to the other.
+According to the wave theory of light, however, we find that the
+transference of energy is accomplished by a wave motion in the Aether,
+which is periodic both in time and space, by which wave motion the
+energy is transferred from the luminous to the illuminated body. Now
+every one is familiar with the effects of magnetism and electricity in
+some form or other, and such familiarity teaches that various kinds of
+work may be done by electricity. If an electric current be generated and
+allowed to flow through any circuit, as the ramifications, for example,
+of an electric-tram system, it can readily be seen that by the action of
+the current large masses or bodies as trams may be moved. To generate
+the current requires the expenditure of energy, and for the tram to be
+moved requires the transmission of that energy from the generating
+station till it reaches the body to be moved. By what means is such
+energy transmitted? because if it disappears at one place and reappears
+at another, it must have passed through a medium during the interval. It
+has been demonstrated that the medium which conveys the current from
+place to place is the Aether, so that as light is transmitted through
+space by the Aether, in a similar manner electric currents are
+transmitted through space also by the same medium. The discoverer of
+this great truth was Clerk Maxwell, and it was from the consideration of
+electro-magnetic phenomena that he was able to lay the foundation of
+that theory known as the Electro-Magnetic Theory of Light. In paragraph
+781 of his greatest work[21] he says: "In several parts of this treatise
+an attempt has been made to explain electro-magnetic phenomena by means
+of mechanical action from one body to another by means of a medium
+occupying space between them. The undulatory theory of light also
+assumes the existence of a medium. We have now to show that the
+properties of the electro-magnetic medium are identical with those of
+the luminiferous medium." He then points out that, "to fill all space
+with a new medium, whenever any new phenomenon is to be explained, is by
+no means philosophical"; and further adds, that "If it should be found
+that the velocity of propagation of electro-magnetic disturbances is the
+same as the velocity of light, and this not only in air, but in other
+transparent media, we shall have strong reasons for believing that light
+is an electro-magnetic phenomena." In the wave theory of light we have
+seen (Art. 70), that two properties are necessary to any medium before
+it is capable of transmitting wave motion of any kind. Those two
+properties are elasticity and inertia. Water possesses these properties,
+and so can transmit ocean waves; air also possesses these properties,
+and so can transmit sound waves; and Aether, being matter, also
+possesses these properties (Arts. 47 and 48), and is therefore capable
+of transmitting light waves. The elasticity is essential in order for
+the medium to store up energy, and also to enable it to resume its
+original shape after deformation, while the inertia is necessary in
+order that the medium may transmit the impulse, and oscillate to and fro
+until the impulse received has been passed on. This elasticity and
+inertia may be well illustrated by the bending of a lath or cane. If we
+pull one end down, holding the other end quite still, we shall see that
+the lath oscillates to and fro until gradually it comes to rest. The
+elasticity of the lath allows it to be pulled out of its original
+position, and also enables it to rebound, while its inertia causes it to
+swing back again past its original position. Both combined together
+cause it to swing backwards and forwards till its energy is used up. If
+such a series of springs could be set in motion at equal intervals of
+space and time, we should then have a good illustration of a wave
+motion.
+
+What analogy, may be asked, is there in electro-magnetic phenomena to
+correspond to this elasticity and inertia of the Aether, so essential to
+the propagation of light? Let us look at the familiar illustration of
+charging a Leyden jar. In charging a Leyden jar with electricity a
+certain amount of energy is spent, work is done, and the result is found
+in the electrified state of the jar. That which has actually been
+accomplished is the storing up of energy in the Aether around the jar.
+This storing up of energy is analogous to pulling aside the lath, and is
+the making use of the elasticity of the Aether, in order to produce a
+tendency to recoil. When the jar is discharged, which is analogous to
+letting go the lath, the Aether seeks to recover its former condition by
+discharging the energy it received. In these operations the elasticity
+of the Aether is called into play. After the jar is discharged, however,
+the recoil of the Aether produces a current, and the inertia of the
+current causes it to overshoot its original position, and for an instant
+the charge of the jar is reversed. The current now flows backwards in
+the same way that the lath returned back, and charges the jar as at
+first. This discharging and recharging continue backward and forward, so
+to speak, until all the energy which was originally given to the jar has
+been expended, and it resumes its normal condition. In this experiment
+the elasticity and inertia of the Aether have both been called into
+play, so that we see in this electrical experiment a similar
+illustration of the elasticity and inertia of the Aether, as manifested
+in the undulatory or wave theory of light. The question now arises, what
+are the corresponding properties as given by Maxwell in his
+electro-magnetic theory? In Art. 782 he writes: "In the theory of
+electricity and magnetism adopted in this treatise two forms of energy
+are recognized--the electro-static and the electro-kinetic--and these
+are supposed to have their seat, not merely in the electrified or
+magnetized bodies, but in every part of the surrounding space where
+electric or magnetic force is observed to act. Hence our theory agrees
+with the undulatory theory in assuming the existence of a medium which
+is capable of becoming a receptacle of two forms of energy." Faraday, in
+his _Experimental Researches_, paragraph 3075, in referring to the
+character of magnetic phenomena external to the magnet, writes: "I am
+more inclined to the notion that in the transmission of force there is
+such an action external to the magnet, than that the effects are merely
+attraction and repulsion at a distance. Such a function may be a
+function of the Aether if it should have other uses than simply the
+conveyance of radiations" (light and heat). From this extract we learn
+that Faraday was also of the opinion that the Aether around a magnet or
+any electrified body was directly concerned in the propagation of the
+electric and magnetic forces, these forces according to Maxwell being of
+two kinds. From the illustration of the charging and discharging of the
+Leyden jar, we learn that aetherial electrical waves can be produced by
+electric means, and from the alternate charging and recharging of the
+jar we learn that these aetherial waves travel to and from the jar with
+a periodic wave motion. Here, therefore, we have an aetherial wave
+motion which is produced wholly by electricity, and yet which answers
+our definition of a wave motion of light, in that it is periodic both
+in time and space, and in that aetherial wave motion Maxwell states that
+two forms of energy are called into play, which he calls Electro-Static
+and Electro-Kinetic. These correspond respectively to the elasticity and
+inertia in the older theory of the wave motion of light. It was upon
+this basis that Maxwell built up his electro-magnetic theory. Even this
+theory does not tell us what is the exact character or nature of the
+periodic wave motion of the Aether. All it tells us is, that the
+electro-magnetic wave motion of the Aether is the same in nature and
+character as the wave motion which produces light and heat. Thus it
+shows that light and electricity have a common origin, and proves that
+light is nothing more or less than an electro-magnetic phenomenon.
+Maxwell gave a number of proofs in support of his theory. He showed that
+the velocity of the electro-magnetic waves was almost identical with the
+velocity of light waves, his results being as follows--
+
+  VELOCITY OF ELECTRO-MAGNETIC            VELOCITY OF LIGHT IN
+             WAVES.                         METRES PER SEC.
+
+  Weber      310,740,000 metres per sec.   Fizeau    314,000,000
+  Maxwell    288,000,000   "       "       Foucault  298,360,000
+  Thompson   282,000,000   "       "
+
+
+From these figures it can readily be seen that the velocity of an
+aetherial wave, generated by electric means, is approximately the same
+as an aetherial wave generated by a luminous body. Thus one of the most
+important results of Maxwell's theory was to show that electro-magnetic
+disturbances produced in the Aether by an electrified or magnetic body
+might be propagated through space with a velocity equal to that of
+light.
+
+It was left, however, for Professor Hertz to place the electro-magnetic
+theory of light upon a sure and certain foundation. The results are to
+be found in his work on _Electric Waves_, translated by Professor Jones,
+1893.
+
+In his paper on "The Velocity of Propagation of Electro-dynamic Action,"
+he gave definite and experimental proof of the hitherto theoretical fact
+that the velocity of the electric waves in air was exactly the same as
+that of light, whereas he found that in wires the ratio was not the
+same, being 4 to 7. This was afterwards found out to be an error by some
+experiments made at Geneva, when it was discovered that the propagation
+in wires was the same as in the air. Among his experiments Hertz
+succeeded in producing very short electric waves of 30 centimetres in
+length, that is, about one and one-fifth of an inch. According to
+Maxwell's theory, such a wave ought to behave exactly as a beam of
+ordinary light does. Hertz proved that this was the case, and published
+his proofs in his paper on "Electric Radiation." In that paper he showed
+how such electric radiation was propagated in straight lines, like
+light, and that it could also be refracted and reflected. Thus he gave
+to Maxwell's electro-magnetic theory experimental demonstration, and
+placed it on a solid and immovable foundation. In summing up the results
+of this theory, we learn, therefore, that Hertz has conclusively proved
+that electric and magnetic effects are propagated through the Aether
+which fills all space with the same velocity that light is propagated.
+Further, he has conclusively proved the identity between light and
+electricity, and shown that electric and light radiations are
+essentially one and the same, and that they are both propagated by
+periodic wave motions of the Aether. Further, he has proved that the
+velocity of the propagation of light is the same as that of the
+electro-magnetic waves, and that these waves obey all the laws that
+govern light and heat. We have here, therefore, experimental proof of
+the identity between electricity and light, and in Art. 69 we have also
+proved the identity of light and heat, so that we have now experimental
+proof that light, heat and electricity are all due to the periodic wave
+motions and vibrations of the universal Aether, which not only fills all
+space, but which surrounds every atom and every particle of matter
+throughout the whole universe. Having established, therefore, the
+identity of heat, light and electricity, and having proved that they are
+all due to the periodic wave motions or vibrations of the universal
+Aether, it must follow as a matter of necessity that wherever in
+interplanetary or interstellar space we find light or heat waves we must
+also find electricity. We have already seen that aetherial light waves
+flood all space, both interplanetary and interstellar space, so that in
+view of the identity of the aetherial light waves and aetherial electric
+waves, it follows that the aetherial electric waves flood all space in
+the same way, and at the same time. Wherever, therefore, we find the
+light waves, there we find the electric waves also; and it will be
+impossible to find the one without the other. Thus, throughout all
+space, and indeed throughout the universe, light waves will not be found
+apart from electric waves. They are as incapable of being dissociated as
+are light and heat waves. Now we have already seen (Art. 64), so far as
+the solar system is concerned, that the sun is the generator of all
+light and heat, and that these light waves speed from the sun on every
+side with a velocity of 186,000 miles per second. From the identity of
+light and electric waves, therefore, given to us by the electro-magnetic
+theory of light, it must follow that the sun is equally the source and
+generator of the electric waves. Not only so, but as the light waves
+flood all solar space, these electric waves, being identical with the
+light waves, must flood the solar system also. Thus we learn from
+Maxwell's theory as developed by Hertz, that not only is the sun the
+generator of light and heat waves which are poured forth into space
+continually with a velocity almost inconceivable, but at the same time
+the sun is pouring forth into space electric waves which travel outwards
+in spherical shells in the same way as light waves do, and with a
+similar intensity, as we shall see in the next chapter. Now let me ask
+the reader to ponder over the fact given to us by this electro-magnetic
+theory in its relation to the solar system, and endeavour to find out
+what such an application teaches us. Let it be remembered that we are
+looking for a Centrifugal force or motion, that is, a motion from a
+centre, which is to be the exact counterpart of the Centripetal force,
+_i. e._ motion to a centre; and further, that the Centrifugal motion
+must be a repulsive motion acting in the opposite way to the attractive
+power of the Centripetal force, that is, the attractive power of
+gravity. We have seen (Art. 77) that light possesses a repulsive power.
+We have now only to prove that electricity or the aetherial electric
+waves have a repulsive motion, which will be the easiest of all to
+prove, and then we shall have proved beyond the possibility of
+contradiction, the existence of that repulsive force referred to by
+Herschel in Art. 24, which is to form the complementary and counterpart
+of the attractive power of gravity. If it can be proved that electricity
+does possess such a power, that is, a repulsive power, ever acting from
+a centre, then in view of the identity of light, heat and electricity,
+the correctness of the views we have advanced as to the repulsive power
+of light and heat will be proved beyond the shadow of a doubt, otherwise
+Maxwell's electro-magnetic theory of light is a fable and a myth, and
+Hertz' experiments were never performed. Further, if all
+electro-magnetic phenomena are due to the same aetherial medium which
+gives rise by its wave motions to light, heat and electricity, then we
+shall have discovered a medium which throughout the universe can by its
+wave motions transmit and propagate both repulsions and attractions,
+that is, the aetherial medium which is to be the physical cause of
+Universal Gravitation. In order to further develop and establish this
+point we will now consider the subject of Electricity as a Mode of
+Motion.
+
+[Footnote 21: _Mag. and Elec._]
+
+
+
+
+                              CHAPTER VIII
+
+                         AETHER AND ELECTRICITY
+
+
+ART. 79. _Electricity, a Mode of Motion._--The question as to What is
+Electricity? is one of the greatest problems of modern times. In view of
+the electro-magnetic theory of light, however, science is able to give a
+better definition as to what electricity is, than it was able to do
+previous to the introduction of the theory by Maxwell, and its practical
+establishment by Hertz.
+
+If that theory teaches us anything at all with regard to the nature of
+electricity, it teaches us that electricity is due to certain motions of
+the universal Aether, that not only fills all so-called Space, but
+surrounds all particles and atoms of all Matter.
+
+The question has been asked by various scientists, "Is Aether
+Electricity, or, in other words, are Aether and Electricity one and the
+same?" Let us look at the question from the standpoint of the analogy
+from the phenomena of light and heat. As we have already seen (Art. 61),
+heat is due to a particular kind of motion of the universal Aether,
+generally known as vibratory motion, which motion is communicated to the
+Aether by a luminous or heated body.
+
+So that we learn that heat at any rate has an aetherial basis, as it is
+a particular kind of aetherial motion. From Art. 70 we learn also that
+light is due to an undulatory or wave motion in the Aether; the waves,
+however, in this case being shorter, and of more rapid vibration than
+those waves which give rise to heat.
+
+Thus light and heat both have an aetherial basis, being due to
+vibrations of that medium. From these analogies, therefore, we come to
+the conclusion that electricity and magnetism have an aetherial basis,
+and are also due to certain kinds of motion in the Aether.
+
+That motion may be rotatory motion or vibratory motion, as the case may
+be, but whatever definition we give of electricity, we cannot as yet say
+definitely that Aether is electricity.
+
+We may assume, and indeed prove, that Aether has an electrical and
+magnetic basis, in the same way that it has a thermal or heat basis, or
+a luminiferous or light basis; but while we admit such a hypothesis, we
+cannot admit as yet that Aether and electricity are one and the same
+thing. It is not within the province of this work, however, to prove
+what electricity is, or show the relation of Aether to all the various
+forms of electricity with which we are conversant, but I think I may
+venture to make this statement, that all forms of electricity, whether
+it is electro-static, that is electricity at rest, or current
+electricity, or electro-magnetism, are due to certain forms of motion
+of the universal Aether, in the same way that light and heat are also
+particular forms of motion of the same medium. I need hardly point out
+that it is an absolute impossibility for me to deal with such a subject
+as Electricity in all its details and various aspects in one chapter; so
+that I shall have to assume that the reader is familiar with some of the
+elementary truths of the subject.
+
+At the same time, I will endeavour to make clear most of the technical
+terms used as we proceed. From the Electro-Magnetic theory of light,
+therefore, we learn that Aether has an electrical or electro-magnetic
+basis, so that, wherever we get Aether, there we have the bases and
+conditions which will produce all the phenomena with which we are
+conversant in the sphere of electricity. Given the required motions in
+the Aether necessary to produce any particular form of electricity, then
+that form is produced as soon as the motions of the Aether are generated
+by any charged or electrified body. Produce a circular current in any
+way in the Aether, and you will have a circular current of electricity;
+produce radiations from a radiating body, and you will get electric
+radiations which speed away with the velocity of light.
+
+This phase of the Aether is entirely in harmony with Dr. Larmor's
+Hypothesis of Electrons, which has already been referred to in Art. 44.
+Dr. Larmor in his work indicates that electricity has an atomic basis,
+and further states that "the atomicity of electricity is coming within
+the scope of direct experiment."[22]
+
+Now, if electricity, as I have indicated, be due to certain motions in
+the Aether, then it can easily be seen that postulating atomicity for
+electricity will be the same as postulating atomicity for the Aether.
+Dr. Larmor[23] definitely and clearly states, "that each electron has an
+effective mass of aetherial origin, which forms part, and may be the
+whole, of the mass of matter to which it is attached;" and again points
+out (p. 64) that "an electron is nothing more than a point singularity
+or pole in the electro-dynamic and optical Aether." Thus we see that Dr.
+Larmor's hypothesis as to the atomicity of electricity is a further
+proof of the atomicity of Aether, and is also in harmony with the
+electro-magnetic theory of light.
+
+Now in dealing with electricity as a mode of motion, it will be
+necessary to show that electricity is also a form of energy in the same
+way that heat and light are forms of energy.
+
+If it can be demonstrated that electricity is a form of energy, then it
+can easily be demonstrated that work can be done by it, and that that
+work may take a mechanical form in the same way that the energy of heat
+and light may produce mechanical results. Clerk Maxwell has given us, in
+his greatest work, his conception of the two kinds of energy due to
+electricity and magnetism. On the subject he writes: "In the theory of
+Electricity and Magnetism accepted in this treatise, two forms of energy
+are recognized, the Electro-Static and Electro-Kinetic (paragraphs 630
+and 636), and these are supposed to have their seat not merely in
+electrified or magnetized bodies, but in every part of surrounding
+space, wherever electric or magnetic force is observed to act. Hence our
+theory agrees with the undulatory theory of light in assuming the
+existence of a medium which is capable of becoming susceptible to two
+forms of energy."[24] The question has arisen many times as to what is
+meant by the terms Electro-Static and Electro-Kinetic energy used by
+Maxwell, and various hypotheses have been advanced to explain the same.
+
+Electro-static energy is said to be that phase of electricity in which
+we deal with stresses set up in the Aether by an electrified body at
+rest, whether that body be small or large. It further deals with the
+process of induction, that is, the action of an electrified body upon
+another body, such action taking place through the medium between the
+two bodies. Electro-kinetic energy is the energy due to electricity in
+motion. On this point Maxwell says: "A conducting circuit in which the
+current has been set up has the power of doing work in virtue of the
+current, for it is really and truly energy. It appears, therefore, that
+a system containing an electric current is a seat of energy of some
+kind; and, since we can form no conception of electric current except as
+a kinetic phenomenon, its energy must be kinetic energy, that is to say,
+the energy which a moving body has in virtue of its motion." (Arts. 551
+and 552.)
+
+It is not our purpose to deal with the electro-kinetic form of energy
+referred to by Maxwell in this chapter. We shall deal with that form of
+energy due to electricity in the succeeding chapter. We will consider
+first the effect of the electro-static energy in relation to
+electrified bodies, but I wish it to be distinctly understood, that in
+all the different kinds of electric phenomena manifested, the Aether
+plays the chief part, and without it, none of the phenomena observed
+could be produced; because, what Aether is to light and heat, so it is
+to electricity, being that medium which by its motions propagates and
+gives rise to all electrical phenomena.
+
+This being so, we have now to apply some of the facts taught us by
+electricity, and especially by the electro-magnetic theory of light, to
+our solar system, with the hope that we shall find further evidence of a
+Centrifugal Force which is physical in character, and whose action can
+be traced throughout the whole realm of space. Let us, in starting to
+apply some of the truths already learned, recall some of the facts
+concerning light, its production and its propagation. We recall the fact
+that light is produced by the action of the sun upon the Aether, giving
+rise to waves which speed away from the generating source with a
+velocity of 186,000 miles per second. We further remember that Hertz has
+definitely proved that these light waves are identical with
+electro-magnetic waves, as they ought to be if the Aether possesses an
+electrical basis, as Dr. Larmor and Professor Lodge suggest.
+
+In order that there may be no mistake on this point, let me quote from
+one of Hertz' papers, where, in his conclusion, he says: "The
+experiments described appear to me, at any rate, eminently adapted to
+remove any doubt of the identity of light, radiant heat, and
+electro-magnetic wave motion." Now, what I want to point out regarding
+this fact is this. If the sun gives rise to the aetherial light waves,
+and these light waves are identical with electro-magnetic waves as
+proved by Hertz, then the sun must either be an electrified body or else
+a magnet.
+
+It must be one or the other, because, if it were not, we should then
+have an anomaly in Nature of a body emitting electro-magnetic waves
+which is itself neither electrified nor a magnet. Therefore, according
+to our second Rule of Philosophy, such a body would be incapable of
+giving rise to these waves, as such a result would be contrary to
+universal experience and experiment.
+
+We know that the earth is a magnet, but up to the present it has never
+been proved that the sun is a magnet, although, as I shall show later
+on, Lord Kelvin and others have suggested such a possibility. If we
+assume that the sun is a magnet, our grounds for assumption would not be
+so strong at this point, and our reasons so philosophical, as they are
+if we assume that the sun is an electrified body.
+
+We have philosophical reasoning to prove that the sun is an electrified
+body in the fact that it emits or gives rise to electro-magnetic waves
+in the Aether, and no other hypothesis can be made other than that the
+sun is an electrified body, in order to prove the connection between the
+two.
+
+Thus we affirm that the sun is an electrified body, which like any
+other electrified body is capable of generating electric waves, and
+speeding them through the Aether with similar velocity to that of light.
+Not only so, but, like any other electrified body, it must have its
+electric field and possess the ability to electrify any other body by
+induction, that may happen to be in its electric field, as we shall see
+later on.
+
+Further, being an electrified body, the electric density will be
+greatest near the sun's surface, and this fact fully accords with our
+statement in Art. 45, that Aether is gravitative. As pointed out in that
+Art., if Aether be gravitative, it must be densest nearest to the
+attracting body; and, as Aether has an electric basis, then with the
+denser Aether there must be an increased electric density, which can
+only happen provided the sun is an electrified body.
+
+Sir G. Stokes was also of this opinion, for in his Burnet Lectures on
+Light he writes (p. 212): "There is nothing, therefore, unreasonable
+in supposing that the sun may be a permanently charged body."
+
+So that all the reasoning that has led to this result seems to harmonize
+and confirm each several hypothesis which has been advanced. There can
+be little doubt, therefore, that the sun is an electrified body, and it
+is for us now to carry out this fact to its logical and philosophical
+conclusion, by applying all the truths which circle round it to the
+solar system, when we shall find greater confirmation of the statement
+just advanced than any we have yet adduced.
+
+According to Professor Young of America, the sun is not only an
+electrified body, but is also the abode of living and sentient beings.
+This astronomer has suggested that the sun is the centre of electric
+force, and that converging streams of Electricity are ever flowing to it
+as a centre; but on meeting with the atmosphere they give rise to
+brilliant discharges, which thus gives the appearance of a solid
+incandescent body.
+
+Now, whether this hypothesis is correct or not, it is absolutely
+certain that the sun is an electrified body, as it gives rise to
+electro-magnetic waves in the Aether, as philosophically proved by
+direct experiments.
+
+[Footnote 22: _Aether and Matter_, p. 8.]
+
+[Footnote 23: _Ibid._, p. 64.]
+
+[Footnote 24: _Magnetism and Electricity_, by C. Maxwell, Art. 782.]
+
+
+ART. 80. _Aether and Electric Fields._--Before proceeding to apply some
+of the facts of Electricity to the solar system, let us find out what is
+meant by an Electric Field. An electric field is to an electrified body,
+what a thermal or heat field is to a heated body, or a luminous or
+lighted field is to a luminous body. If a lamp, for example, be lighted,
+its light waves spread out on every side, and extend for a considerable
+distance unless impeded by such obstacles as the wall of a room.
+
+The extent to which the light waves reach and flow might well be called
+the lighted or luminous field, and in that field the effect of the
+aetherial light waves would be manifested and seen.
+
+Now, in a similar manner, when any body is electrified, the electric
+waves spread out on every side of the electrified body, and the extent
+to which the waves spread out form what is known as an electric field.
+
+So that an electric field may be defined as any region or space in which
+electric energy is manifested by means of the aetherial electric waves,
+and across which induction may take place.
+
+[Illustration: Fig: 9.]
+
+Thus, for example, let _E_ be an electrified body (Fig. 9), then it will
+generate electric waves which will speed from the body with a velocity
+equal to that of light. If the body be a sphere, then the waves will be
+spherical in shape, and will proceed from the generating source in the
+shape of concentric spheres as indicated in the figure. Before
+proceeding any further, it is necessary that we should look at the
+electric field from the physical aspect, with a view to discover
+something of what takes place therein. As has already been indicated,
+all electric phenomena are due to motions of the universal Aether.
+
+It was left for Faraday to give us a true conception of an electric
+field, and for Maxwell to perfect that conception and give us a physical
+aspect of the same. Faraday conceived that stretching out from a magnet
+or electrified body through space, that is, through the Aether, were
+what he called "Lines of Force," and that these lines of force indicated
+not only the direction of the magnetic and electric forces, but also
+their intensity or power.
+
+Where the lines of force were closest together, there the electric or
+magnetic energy was the greatest and most intense; and where they were
+the farthest apart, there the field was weakest in energy. An
+illustration of the magnetic lines of force may be obtained by placing a
+piece of paper over a magnet, and then strewing iron filings over the
+same, when it will be seen that the iron filings will arrange themselves
+in certain curved lines, which Faraday called Magnetic Lines of Force.
+In this way Faraday mapped out the lines of force, relative not only to
+single magnets, but also to magnets with poles placed in various
+positions relatively to poles of other magnets.
+
+Now as there are lines of force which reveal the intensity and direction
+of the magnetic energy, so there are lines of force radiating out from
+electrified bodies which reveal the intensity and power of the electric
+field. The electric lines of force are radial, and are shown in the
+figure (Fig. 9) by the straight lines _D_ _F_, _D_ _H_, _D_ _K_.
+
+If an electrified pith ball, for example, be hung up in a room, then the
+lines of force, which extend from the ball, indicate the stress in the
+Aether surrounding the pith ball, so that if a hair be placed across
+these lines of force, any movement of the pith ball will be indicated by
+the motion of the hair.
+
+It was Clerk Maxwell, however, who gave to the world a true physical
+conception of Faraday's Lines of Force, in his paper on "Physical Lines
+of Force."[25]
+
+In the opening words of that paper he writes as follows: "We cannot help
+thinking that in every place where we find these lines of force, some
+physical state or action must exist in sufficient energy to produce the
+actual phenomena." Maxwell then went on to show what these physical
+actions were, which took place in the dielectric--that is, the medium
+surrounding the electrified body which we now know to be the Aether.
+
+This electric field, he pointed out, was "in a state of stress, which
+consisted of pressures or tensions different in different directions at
+the same part of the medium. The relation of these forces were
+threefold, and consisted in the most general type of stress of three
+pressures or tensions in directions at right angles to each other."
+
+Thus, in Maxwell's opinion, the existence of a medium, which by its
+physical character was able to exert energy on material bodies, was one
+of the fundamental hypotheses of his theory as to the physical character
+of Faraday's Lines of Force.
+
+This physical medium was to be capable of certain motions, and both
+electric and magnetic forces were produced by its motions and its
+stresses. Maxwell's conception, however, of the physical lines of force
+was more or less hypothetical, and up to the present, as far as I can
+learn, has not received that authority from science that such a
+hypothesis requires to make it an accepted theory in science.
+
+But what I venture to point out is, that with the view of the aetherial
+medium that is submitted in this work, Maxwell's hypothesis remains a
+hypothesis no longer, and that the hypothetical character of his theory
+ceases to exist. For, by our conception of an atomic and gravitative
+Aether, we are able to see that his physical lines of force are indeed
+physical, and that his brilliant hypothesis now receives a true physical
+foundation which otherwise it would not receive from a frictionless
+Aether.
+
+There is nothing, I venture to predict, in Maxwell's hypothesis which
+cannot be accounted for on a truly physical basis, by the conception of
+the Aether as given in this work. So that when Faraday saw in his mind's
+eye lines of force traversing space, he saw by his imagination that
+which was actually the real state of affairs, and when Maxwell enlarged
+the conception by giving to those lines of force a definite atomic and
+cellular structure, he, too, but anticipated the real nature and
+character of the Aether as given in Chapter IV., which theory is the
+direct outcome of Newton's philosophical rules, and the result of
+discarding everything that is not in accordance with experience and
+observation. Thus the lines of force which exist and surround a magnetic
+or electrified body are as real as ocean currents, or the waves of the
+sea, in that they are the manifestations of the motions of the universal
+Aether, which is as truly matter as air or water.
+
+Let us look at the analogy which exists between the lines of force and
+the gravitative Aether, and we shall see that a gravitative Aether fully
+agrees with the conception of an electric Aether as revealed to us by
+the lines of force in an electric field.
+
+As is well known, the lines of force are closer together in that part of
+the electric field where the intensity of the field is greatest; and the
+intensity of a field being greatest at the surface of an electrified
+body, the lines of force are therefore closer together nearest to the
+surface of such a body than further away.
+
+Now according to Art. 45 Aether is gravitative, therefore the Aether
+nearest the surface of a body is densest, and the aetherial atoms are
+therefore more pressed upon than the layer immediately above it. Such a
+result is exactly what should happen provided that Aether has an
+electric basis, and that Aether is gravitative. For, in Art. 45, we have
+seen that because Aether is gravitative, therefore it must possess
+various degrees of density, being densest nearest the surface of an
+attracting body.
+
+In electricity we find a similar phenomenon which corresponds to
+aetherial density, which is known as Electric Density, by which term is
+meant the amount or quantity of electricity spread over a certain area
+or surface. If we double the quantity of electricity on that given
+surface, then we double the density, and we say that the electric
+density is doubled, while if we halve the quantity of electricity, then
+we say the electric density is halved, and so on.
+
+But this is exactly what happens in the case of aetherial density, as
+proved in Art. 46. We have only to picture the number of aetherial atoms
+being doubled on a given area, and at once the physical conception of
+electric density is furnished, if we remember that Aether has an
+electric basis as suggested by Maxwell and proved by Hertz. Thus we see
+at once why it is the lines of force should be closer together nearer
+the electrified body than farther away.
+
+_Electric Potential._--There is another aspect of the electric field
+that I wish to call the reader's attention to, and that is the Electric
+Potential of such a field.
+
+Electric potential is to electricity what temperature is to heat, or
+pressure is to any medium of different densities. We have already seen,
+according to the laws of thermodynamics, that heat will flow from a
+higher temperature to a lower one, with the result that work is done. In
+the case also of water at two different levels, work can also be done by
+the water flowing from a higher to a lower level.
+
+A similar thing happens in electricity; where we have two conductors or
+two parts of an electrical fluid at different potentials, electricity
+will flow from the place of higher potential, until the potentials are
+equalized, in the same way that the temperature of two bodies at
+different temperatures would be equalized by the flow of heat.
+
+So that electric potential agrees with our conception of a gravitative
+Aether in that, being gravitative, it is denser in those parts nearest
+to the attracting body than farther away, and as the elasticity or
+pressure is proportionate to the density (Art. 47), therefore we learn
+that the electric potential of the Aether, and the thermal condition of
+the Aether, if I may use such a term, both agree and coincide with the
+density and elasticity of the Aether.
+
+Any equipotential surface which represents a particular aetherial
+density, would also correspond with a particular elasticity or pressure
+of the Aether, while it would further correspond with a particular
+temperature, if such a term is applicable to the Aether.
+
+_Equipotential Surfaces._--The fact that in an electric field there are
+different points at different potentials, leads us to the truth that in
+an electric field there are also equipotential surfaces; that is to say,
+there are surfaces where the electric density or the aetherial density
+are equal at all points on such a surface. If, for example, _E_ be an
+electrified body (Fig. 9), and _A_ _A'_, _B_ _B'_, represent equipotential
+surfaces around the body, then all the points on _A_ _A'_ would be of
+equal potential--that is, of equal energy, or pressure.
+
+We have to remember that _A_ _A'_, _B_ _B'_, are sections of a sphere, so
+that when the body as _E_ is a sphere, then the equipotential surfaces
+are spheres also. This agrees with Art. 77, in which we saw that the
+pressure around any body due to aetherial density also possessed
+equipotential surfaces.
+
+It could equally be shown that there were equipotential surfaces so far
+as the phenomena of heat and light are concerned, as these also are
+subject to the same laws. Having now very briefly considered the meaning
+of the Electric Field, Electric Potential, Electric Density, and
+Equipotential Surfaces, we are now in a position to apply these facts to
+our solar system, at least as far as the sun is concerned.
+
+In the foregoing Art. we arrived at the conclusion that the sun was an
+electrified body, therefore, in accordance with all experiment and
+observation, it, too, must have an electric field. Not only must it have
+an electric field; but that field must possess different potentials,
+possessing a higher potential the nearer the field gets to the sun, and
+a lower potential the farther away the field is.
+
+Further, around the sun there must also exist not imaginary but real
+physical lines of force which indicate the electric and magnetic forces,
+and which are made real by the atomic character of the Aether that
+surrounds it; and those lines of force would be closer together the
+nearer they got to the sun on account of the electric density of the
+electric Aether, which coincides with the density of the Aether from the
+gravitative standpoint. There would also be aetherial equipotential
+spheres, or rather oblate spheroids around the sun, as the sun is not
+strictly a sphere, its polar diameter being less than its equatorial
+diameter.
+
+[Illustration: Fig: 10.]
+
+Let us therefore endeavour to picture the sun under these conditions as
+the centre of our solar system. Let _S_ be the sun (Fig. 10), and the
+lines _A_ _A'_, _B_ _B'_, _C_ _C'_, etc. represent Equipotential
+Surfaces, Fig. 11 being a vertical section and Fig. 10 being an
+equatorial section. In Fig. 11 the sections of the equipotential
+surfaces would be vertical, while in Fig. 10 the sections of the
+equipotential surfaces would be horizontal, while the electric lines
+of force would be radial, as all electric radiations take place in
+straight lines, as we shall see was proved by Hertz, later on. We
+will suppose that the sun is stationary, as the question of the
+movement of the sun, both axially and through space, will be
+considered in a subsequent article.
+
+[Illustration: Fig: 11.]
+
+Then the question arises, How far does the sun's electric field extend?
+That is rather a difficult question to answer, but the correct answer
+would be, "As far as the sun's light extends, so far does the sun's
+electric field extend." From the electro-magnetic theory of light we
+know that wherever there are light waves, there are electro-magnetic
+waves, though at the present moment we are only dealing with the
+electric aspect of those waves.
+
+We know that the aetherial light waves reach at least as far as Neptune,
+a distance of 2,750,000,000 miles, therefore we know that the sun's
+electric field must also extend to that distance. How much further in
+space it extends we cannot tell, because the data on which to form a
+basis is inadequate.
+
+[Illustration: Fig: 12.]
+
+Thus we learn that the sun's electric field extends east and west for
+that enormous distance, but we cannot say that it extends the same
+distance north and south. Now why is that? The first reason I should
+give is the well-known experiment of a revolving body, by which we learn
+that when a body is revolving, as the sun for example, the atmosphere
+around it would seek to extend itself east and west, owing to the
+Centrifugal Force so called. But a better reason than that will be found
+from an analogy of a magnetized body. Faraday has shown in his drawings
+illustrating lines of force, that if a spherical body is magnetized, the
+magnetic lines of force extend in circles east and west, but go out into
+space in almost straight lines north, and south as the preceding figure
+shows.
+
+Therefore, accepting Faraday's experiment as the basis for our
+conception of the magnetic lines of force in the sun's electric field,
+we come to the conclusion that the electric field around the sun extends
+east and west, while the lines of force, north and south, are more or
+less radial into space as depicted in the figure.
+
+Throughout the whole of the field, the electric potential, at different
+distances from the sun, would differ in accordance with all experiment
+and observation. The greatest electric potential would therefore be
+nearest the sun's surface, and would be greatest in the equatorial
+regions of the sun, in accordance with a well-known rule which
+determines electric density and electric potential on conductors.
+
+As we proceed from the sun's surface east and west into space, we should
+pass equipotential surfaces of different potentials. Thus the pressure
+on every point of equipotential surfaces would be regulated by the
+electric density of the Aether, which would coincide with the actual
+aetherial density at that point; and as the aetherial density is the
+measure of its elasticity or pressure, so the electric potential would
+correspond with the elasticity or pressure at the same point.
+
+Thus it is possible to map out the electric field east and west by
+ever-increasing and widening circles which would be at lower potential
+the further they receded from the sun. So that by carrying out the
+electro-magnetic theory of light to its logical conclusion, we are able
+to bring the whole of the solar system into line with electric
+phenomena; and, as we proceed, we shall see that all other facts
+relating to electricity, and magnetism also, are equally as applicable
+thereto, otherwise this theory of light must fall to the ground.
+
+That this conception of the universal Aether in its application to solar
+space is not extravagant may be proved from the writings of Prof.
+Tyndall and Clerk Maxwell. Tyndall, writing on the subject of Faraday's
+Lines of Force, says:[26] "The aspect of these curves so fascinated
+Faraday that the greater part of his intellectual life was devoted to
+pondering over them. He invested the space through which they run with a
+kind of materiality, and the probability is that the progress of
+science, by connecting the phenomena of magnetism with the luminiferous
+Aether, will prove these 'Lines of Force,' as Faraday loved to call
+them, to represent a condition of this mysterious substratum of all
+radiant action."
+
+While Clerk Maxwell,[27] writing on "Action at a Distance," says: "These
+Lines of Force _must not be regarded as mere mathematical abstractions_.
+They are the _directions in which the medium is exerting tension like
+that of a rope_, or rather like that of our own muscles." I therefore
+premise, that both these statements will find a literal fulfilment in
+the conception of the Aether advanced and perfected in this work.
+
+[Footnote 25: _Phil. Mag._, 1861.]
+
+[Footnote 26: Tyndall on _Light_.]
+
+[Footnote 27: _Collected Papers_, by Niven.]
+
+
+ART. 81. _Aether and Induction._--We have seen in the preceding Arts.
+that the sun is an electrified body, possessing an electric field, which
+field possesses different intensities at different distances from its
+surfaces.
+
+If such be the case, the question at once confronts us, as to what is
+the effect of such an electrified body with its electric field upon all
+the planets which revolve around it; for, if its electric field extends
+as far as Neptune, then all the planets and meteors, that revolve
+around the sun, must revolve in the sun's electric field.
+
+Such a question can best be answered from the consideration of
+experiments and theories advanced first by Faraday, who gave to the
+world his theory of Induction, which we shall now consider.
+
+Let _A_ be an electrified body (Fig. 13), and _C_ be a body not
+electrified, but situated within the electric field of _A_. Then it can
+be experimentally proved, that _C_ will also become an electrified body
+by induction. As is well known, there are two kinds of electricity,
+Positive and Negative. We will suppose _A_ to be charged with positive
+electricity. Then it can be proved that _C_ will also be charged with
+negative electricity on the half nearest to _A_, while the other half
+will be charged with positive electricity.
+
+[Illustration: Fig: 13.]
+
+Now how has this result been brought about? According to Faraday's
+theory the particles of air, the dielectric, between _A_ and _C_ play a
+most important part in the process. As a matter of fact, each atom or
+particle of air is polarized, as the process of separating the two kinds
+of electricity is termed, so that every atom has one half of it covered
+with positive electricity, and the other half with negative electricity.
+
+For example, let _A_ and _C_ be the same brass balls with the particles
+of air between them, _A_ being the positively charged ball and _C_ the
+unelectrified ball, the shaded parts representing positive electricity
+and the unshaded parts negative electricity.
+
+Then _A_ will act inductively on the unelectrified ball _C_ through the
+medium of the particles of air _d_, _e_, _f_, _g_, _h_. The electrified
+ball _A_ will act first on the layer of particles next to it, attracting
+their negative electricity and repelling the positive according to the
+well-known law that "Unlike electricities attract, like electricities
+repel each other."
+
+The positive electricity in the first layer then acts in the particles
+of the next layer in the same way, and thus the inductive action is
+transmitted through the particles, from layer to layer, until we come to
+the last layer of particles next to the ball _C_.
+
+As the half of each atom or particle nearest to _C_ is positively
+electrified, then the half of the ball _C_ nearest to the layer becomes
+negatively electrified, while the half further away is positively
+electrified. Thus we say that _C_ has become electrified by induction
+through the polarization of the particles of air which lie between the
+two bodies. Faraday on this point says: "Thus induction appears to be
+essentially an action of contiguous particles, through the
+intermediations of which the Electric Force, originating at a certain
+place, is propagated or sustained at a distance, appearing there as a
+Force of the same kind exactly equal in amount, but opposite in its
+direction and tendencies."[28]
+
+While again he states:[29] "Induction appears to consist in a certain
+polarized state of particles into which they are thrown by the
+electrified body sustaining the action, the particles assuming positive
+and negative parts which are symmetrically the lines of Inductive
+Force." Thus in the case of any electrified body, acting on an
+unelectrified body at a distance, it has to be definitely understood
+that _the action at a distance_ is alone communicated and propagated by
+the dielectric or medium which exists between the two bodies. Though in
+the case of Gravitation it has been mathematically assumed, that action
+at a distance is possible, yet experimentally and physically such an
+assumption is philosophically incorrect, as all experience and
+experiment go to prove that there is no such thing as action at a
+distance manifested, except such action is propagated through the
+intervening medium, as stated and proved by Faraday.
+
+In order to bring Gravitation, therefore, into line with our experience,
+it will have to be demonstrated that it, too, is the result of the
+action of the intervening medium, that is, the Aether, which is a result
+we are being led up to.
+
+We have already seen that the sun is an electrified body, possessing an
+electric field, and as all electrified bodies can act on other bodies in
+their field inductively, then a similar result should happen in the
+solar system, that happens in any electrical experiment on induction,
+with the result that all the planets should become electrified bodies by
+induction, such action taking place, as Faraday points out, through the
+medium which divides the sun and the planets, that is, the Aether.
+
+Of course with a frictionless and non-atomic Aether such a result would
+be an impossibility, but with our conception of an atomic and
+gravitative Aether the result is now attainable. We have therefore to
+think of the sun, the centre of the solar system, being an electrified
+body, and for illustration we will suppose it to be a positively charged
+body.
+
+All around the sun is the atomic Aether, which is polarized in the same
+way that the particles of air were polarized; that is, the two kinds of
+electricities in the aetherial atom are separated, the negative being on
+that side nearest to the sun, and the positive on the side further away.
+In this way the whole aetherial medium would be polarized, and any body
+in the field would be electrified by induction, with the result that the
+side nearest the sun would be negatively charged, and the opposite side
+positively charged.
+
+Thus let _S_ (Figs. 10 and 11) be the sun, and the circles represent
+equipotential surfaces, then one half of every surface would be
+negatively electrified and the other half positively electrified, that
+is, assuming the sun to be a positively electrified body.
+
+If _M_ represents Mercury, _V_ represents Venus, and _E_ represents the
+Earth (Fig. 10), then it can readily be seen that all these would be
+negatively electrified on the side facing the sun; and, as they rotate
+on their axes, each part of the planet would be positively and
+negatively electrified once each day.
+
+We are assuming that the medium is at rest, but according to our
+conception in Art. 44, all the aetherial atoms are in rotation on their
+axes, in the same way that the earth rotates on its axis, so that each
+of these aetherial atoms would present different parts of its surface to
+the sun as it rotates on its axis; but, as that does not affect the
+principle of induction, such a fact need not now be fully considered.
+
+Let us now ask, What is the result of all the planets becoming
+electrified bodies in the same way that the sun is an electrified body?
+Arguing from experience, we come to the conclusion that each planet must
+also possess its electric field, which also must have its lines of
+force, its different potentials at different distances, and its
+equipotential surfaces. So that Mercury, Venus, the Earth, Mars,
+Jupiter, Saturn, Uranus, and Neptune all have their electric fields,
+with their own lines of force, and with their equipotential surfaces.
+
+If we carry the analogy further still, then it can also be proved that
+the Earth, and those planets which have moons or satellites, also act
+inductively on their satellites, with the result that they too become
+electrified bodies, with their own smaller electric fields and lines of
+force. This may seem at first sight a little confusing, but the
+confusion will gradually disappear if we will look at it carefully for a
+moment or two. Let us endeavour to picture the solar system from this
+new standpoint, and map out the equipotential surfaces, which this idea
+suggests. Let _S_ represent the sun (Fig. 14), the initials of all the
+planets and satellites representing the various planets; then we get the
+following plan of the solar system with the various equipotential
+surfaces shown by the circular lines.
+
+We are now supposed to be looking down on all the solar system from
+above it, so to speak, so that we should be looking at what we call the
+North Poles of the sun and planets.
+
+[Illustration: Fig: 14.]
+
+Thus we see that the equipotential surfaces around the sun are huge
+circles which stretch out as far as Neptune or even beyond, but within
+those circles we find each of the planets revolving round the sun, each
+with its own equipotential spheres, which are circles also, while around
+the various planets are the satellites, from the moon of our Earth, to
+the two satellites of Mars, five of Jupiter, eight of Saturn, each with
+its own lines of force and electric fields.
+
+Of course we must not forget that all these revolve round the sun, and
+the question may suggest itself to the reader's mind, if such a result
+is possible. I shall prove later on, that according to Maxwell such an
+event is possible, but at present we will consider them stationary.
+
+Now let us see how such a conception compares with our hypothesis of a
+gravitative Aether. If Aether be gravitative, then the sun must have an
+attraction for the Aether, and its aetherial field would stretch out
+into space as far as Neptune at least.
+
+So that it can readily be seen that the aetherial field of the sun's
+attractive power coincides with the electric field which the sun
+possesses as an electrified body. Again, if Aether be gravitative, then
+all the planets must also have an aetherial field, which will be
+co-extensive with their electric field also. The same principle applies
+to each of the satellites, with the result that they too will possess an
+aetherial field which will be equal in extent and limit to their
+electric field.
+
+As the satellites revolve around their primary planet taking their
+electric fields with them, so the planets with their associated
+satellites revolve around the sun taking their electric and aetherial
+fields with them. Thus we get a glimpse, though at this point very
+shadowy and indistinct, of those motions of the universal Aether, which
+help to constitute the harmony, beauty, and order of the universe. We
+have seen, therefore, that as the sun is an electrified body, so all the
+planets and satellites are electrified bodies also, each possessing its
+own field, with all that such a field implies.
+
+We shall find that such a conception is borne out by experience and
+observation, when we come to deal with the Earth as a magnet; because we
+shall afterwards learn that the Earth is an electro-magnet, possessing
+its magnetic field, which is co-existent and equipollent with its
+electric field.
+
+[Footnote 28: _Exp. Res._, 1297, 1298.]
+
+[Footnote 29: Par. 1298.]
+
+
+ART. 82. _Energy of the Field._--We have seen in Art. 79 that every
+electrified body has an electric field. We have further learned, in
+carrying the electro-magnetic theory of light to its logical conclusion,
+that all the planets and satellites together with the sun must be
+electrified bodies, each possessing its electric field.
+
+We have now to determine the effect of such a truth from its dynamical
+aspect upon the bodies within the field, that is to say, we have to
+consider the energy of such electric fields, and endeavour to find out
+the effect of such energy upon other bodies within that field.
+Maxwell,[30] in his introduction to a paper on "The Dynamical Theory of
+the Electro-magnet Field," writes on the matter thus: "It appears
+therefore that certain phenomena in electricity and magnetism lead to
+the same conclusion as those of optics, namely, that there is an
+aetherial medium pervading all bodies and modified only in degree by
+their presence; that the parts of this medium are capable of being set
+in motion by electric currents and magnets; that this motion is
+communicated from one part of the medium to another by forces arising
+from the connection of these parts; that under the action of these
+forces, there is a certain yielding depending upon the elasticity of
+these connections; and that therefore energy in two different forms may
+exist in the medium, the one form being the actual energy of motion of
+its parts, and the other being the potential energy stored up in the
+connections in virtue of their elasticity."
+
+The two forms of energy he gives us in his work on _Magnetism and
+Electricity_, where, in the quotation already given in Art. 79, he
+states them to be electro-static and electro-kinetic energy, while in
+paragraph 792 of the same work he adds: "The intrinsic energy of the
+medium is half electro-static and half electro-kinetic, that is, half is
+due to electricity and half is due to magnetism."
+
+We are, however, only dealing at this point with the electro-static
+energy in the electric field, as we shall deal with the electro-kinetic
+energy in the following chapter.
+
+We have, therefore, to conceive of an electrified body generating
+electric or electro-magnetic waves, which speed away from the generating
+source on every side with the velocity of light. Now we have already
+seen that the aetherial waves which give rise to heat and light possess
+a repulsive power, that is, they exert a pressure on the body with which
+they come into contact.
+
+If, therefore, in the electric field there is this energy manifested as
+proved by Maxwell, and that energy takes partly the form of a pressure
+as stated by Maxwell, then we have in the electro-static energy of the
+electric field, another indication of that centrifugal force for which
+we are looking, and whose existence was so satisfactorily demonstrated
+to Herschel by the phenomena of comets' tails.
+
+That there is this pressure in an electric field was conclusively proved
+by Maxwell, and experimentally demonstrated by Professor Lebedew (Art.
+77). Maxwell distinctly states on this point, "that the combined effect
+of the electro-static and electro-kinetic stresses is a pressure equal
+to 2 P. in the direction of the propagation of the waves," that is, away
+from the electrified or charged body.
+
+He continues: "Thus, if in strong sunlight the energy of light which
+falls on one square foot is 83.4 foot-pounds per second, the mean energy
+in one cubic foot of sunlight is about .0,000,000,882 of a foot-pound,
+and the mean pressure on a square foot is .0,000,000,882 of a pound
+weight. A flat body exposed to sunlight would experience this pressure
+on its illuminated side only, and would therefore be _repelled_ from the
+side on which the light falls."[31]
+
+This pressure only gives the result due to the pressure of one cubic
+foot of sunlight. What must be the pressure, therefore, due to the whole
+of the sunlight received by the flat body from the sun? The total
+pressure, whatever it may be, would be equal to 2 P. according to
+Maxwell, and half of that is due to electricity, and half due to
+magnetism. Now such a result is entirely in harmony with the conception
+of the Aether as given in this work. For, if Aether possess an electric
+basis as suggested by Maxwell, and it is also gravitative as suggested
+in Art. 45, then it must follow, as pointed out in a previous Art., that
+throughout the field there is a varying difference in the potential of
+the field; the potential being regulated by the electric density, that
+density being equivalent to the aetherial density. Further, as the
+elasticity of the medium which regulates the pressure is proportional to
+the density, so the pressure must decrease, as the elasticity
+decreases--that is, as the electric potential decreases, or the electric
+density is diminished. Therefore, if the sun be an electrified body,
+ever generating electro-magnetic waves which speed away from it on every
+side, then, whenever any of these waves come into contact with a planet
+or comet, that planet or comet would be repelled from the sun by the
+pressure of these electro-magnetic waves to which the sun gives rise in
+its electric or electro-magnetic field.
+
+Thus we again come to the conclusion that the sun is not only the centre
+of a centripetal force due to Gravitation, and subject to certain laws,
+whose physical cause is unknown, but it is equally the centre and source
+of a centrifugal force, in that it is an electrified body, and gives
+rise to electric waves which produce a pressure on any body upon which
+they fall, in the sun's electric or aetherial field. It has only to be
+demonstrated, therefore, that this centrifugal force satisfactorily
+fulfils all the laws required as laid down in Art. 24, that is, that its
+course is along the same path as the Centripetal Force of Gravitation,
+that it is subject to the same law of intensity, which is inversely as
+the square of the distance; and further (what is the most important at
+this stage), that the combined effect of the pressure of two bodies is
+equal to the product of their masses, then we shall have discovered that
+which we set out to discover, viz. a complementary force to the
+attractive force of Gravitation.
+
+Unlike the centripetal force, however, the centrifugal force will be
+purely a physical one, due to a purely physical medium, the Aether,
+whose properties and motions can be accounted for on a physical, and not
+on a hypothetical basis.
+
+Further, as the planets are also electrified bodies (Art. 81), they too
+will possess an electric field, and will generate electric waves, which
+will also exert a centrifugal force upon all bodies upon which the waves
+fall. So that, like the sun, the planets are not only the centre of a
+centripetal force, which ever acts towards their centre; but they are
+also the centre of a centrifugal force, due to the aetherial electric
+waves to which they give rise in the Aether.
+
+The application of the same principle may be extended to every satellite
+that exists in the solar system, and indeed to every particle and atom
+of matter that exist throughout the universe, for wherever we find the
+Aether, there we find this centrifugal force, which is due to the
+electric aetherial waves generated by the atom or particle of matter, or
+by any combination of atoms, as a meteor, satellite, planet, sun or
+star.
+
+[Footnote 30: _Collected Papers_, by Niven.]
+
+[Footnote 31: _Magnetism and Electricity_, Arts. 791 and 793.]
+
+
+ART. 83. _Electric Radiation._--We learn, therefore, that the sun,
+together with every planet and satellite in the solar system, is the
+centre of a centrifugal force, which is due to the radiation of electric
+waves by an electrified body. We have now to prove that this force
+fulfils all the laws required, in order for it to become the
+complementary law to the Centripetal Force of Gravitation. We will first
+show that this centrifugal force which proceeds from the electrified
+body is radiated out into space in straight lines with the velocity of
+light and radiant heat.
+
+As we have already seen, it was due to the genius of Hertz to show the
+identity between electric radiation and radiant light and heat. In his
+paper on Electric Radiation he says:[32] "I have succeeded in producing
+distinct rays of electric force, and in carrying out with them the
+elementary experiments which are commonly performed with light and
+radiant heat." We have seen in Arts. 65 and 76 that radiant heat and
+light are propagated in straight lines, so that, according to Maxwell's
+electro-magnetic theory, a ray of electric radiation should also be
+propagated in straight lines.
+
+This Hertz proved, and gave his results in his paper "On the Action of a
+Rectilinear Oscillation upon a Neighbouring Circuit," in which he fully
+demonstrated that when electric action takes place between two charged
+bodies, the electric force is radiated out into space in straight lines
+in the same way that light and radiant heat are radiated. In his paper
+on "The Finite Velocity of Electro-magnetic Actions," he showed that the
+velocity of the electro-magnetic waves was the same as that of light. In
+the summary of this paper (paragraph 3) he states: "There are many
+reasons for believing that the transverse waves of light are
+electro-magnetic waves; a firm foundation for this hypothesis is
+furnished by showing the actual existence in free space of
+electro-magnetic transverse waves which are propagated with a velocity
+akin to light."
+
+Again, in his paper on "Electric Radiation," he not only showed how the
+radiation was propagated in straight lines, like light, but also proved
+that while it was reflected by metals, the electric beam was able to
+pass through doors and stone walls, and adds, "that it was with
+astonishment that one saw the electric beam appear inside a closed room
+after its passage through the door."
+
+Thus Hertz has shown that both electric and magnetic effects are
+propagated through the Aether with finite velocity, and that that
+velocity is exactly the same as the velocity of light. He further proved
+that this propagation takes place in straight lines, in the same way
+that radiant heat and light are propagated. This being so, it is
+necessary for us to apply these truths to the solar system, with a view
+to find out what such a result teaches us.
+
+We have seen in a preceding article, that the sun is an electrified
+body; therefore it, too, must generate these electro-magnetic waves, and
+radiate them into space on every side with the velocity of light. Let us
+try to picture the scene. Let _S_ represent the sun, and the circle
+round it represent the equipotential spheres which exist round the sun.
+(See Figs. 10 and 11.) As the intensity of the electric force is greater
+nearer the sun than further away, these equipotential surfaces will be
+closer nearer the sun than further away.
+
+Then let the straight lines which radiate out from the sun represent the
+path of an electric ray. It can be easily seen that these electric rays
+cut the equipotential surfaces at right angles, as they pass from the
+centre of the sun outwards into space. Now these lines not only
+represent the path which the electric ray takes in its journey through
+space, but exactly coincide with the electric lines of force as
+conceived by Faraday. This great thinker and experimentalist not only
+conceived lines of magnetic forces existing in the dielectric or medium
+between two electrified bodies, which in this case is the Aether, but
+also conceived lines of electric force which started at a conductor, or
+an electrified body, and radiated out into space.
+
+Thus a line of electric force has a definite direction, and always
+starts from an electrified body. If it were possible to move a planet
+along one of these lines of force, its path would be that of a straight
+line. If on the other hand a planet moved at right angles to one of
+these lines of force, that is, along the surface of an equipotential
+sphere, then no work would be done against the electric force, as on
+such a sphere the electric force would be of the same intensity.
+
+So that from Hertz' experiments it can be demonstrated, that if there be
+any electric force existent in the Aether, due to the action of the sun
+upon the Aether, then such a force is directed along the path of a
+straight line into space with the velocity of light, which, as already
+pointed out, is the path taken by a ray of radiant heat and light, and
+coincides with the path taken by the centripetal force.
+
+It has been demonstrated that such electric force is accompanied by a
+repulsive force, or more correctly a pressure, so that here we have
+further evidence of the existence of a centrifugal force which finds its
+generating source in the sun, which is also the centre of the attractive
+force of Gravitation in the solar system.
+
+The application of Hertz' experiments may be made not only to the sun,
+but also to every planet and satellite that exists in space with the
+same result; and, further, may be extended to every particle and atom
+that exists throughout the universe. For, according to Art. 43, we have
+learned that Aether is universal, and we have seen that it is
+gravitative, and have learned from the electro-magnetic theory of light
+that it has an electro-magnetic basis. Therefore, to be thoroughly
+consistent, we must not stop in the application of this principle at any
+point in the whole universe.
+
+Either the whole principle is of universal application, or it ceases to
+be a universal law. Therefore, if there is this centrifugal force
+operating along a straight line from the centre of an electrified body,
+such centrifugal force must be in its application universal, in order to
+be complete, and in order to satisfactorily form the counterpart of the
+centripetal force which is also universal, and operates along the
+straight line joining the centres of gravity of any two bodies.
+
+[Footnote 32: Hertz on _Electric Waves_.]
+
+
+ART. 84. _Law of Inverse Squares._--We have learned therefore from the
+preceding Arts., that the solar system may be looked upon as an electric
+field, with the sun as the electrified body occupying the centre. We
+have also seen that there is a centrifugal force in all electric fields,
+which is due partly to electric waves, and partly to the magnetic waves
+of the Aether.
+
+It will be interesting to find out, what law governs the intensity of
+this force in any part of the field, or at a given distance from the
+central body. We have seen (Art. 66) that the law governing the
+intensity of heat at any distance from the sun, is the law of inverse
+squares. Further, from Art. 75 we have also learned that light is
+subject to the same law of inverse squares, as indeed it should be, if
+it be due to one and the same medium, the Aether.
+
+If, therefore, electricity is also due to certain motions of the
+aetherial medium originated by the action of an electrified body as the
+sun, in the same way that light and heat waves are originated, then it
+ought to follow that the repulsive power of electricity is also subject
+to the same law of inverse squares. As a matter of fact, that is exactly
+the state of affairs, so that we find the intensity of the repulsive power
+in the Aether from any central body, due to the electric waves, or the
+pressure due to the wave motions of the electric Aether, in relation to
+that body, is governed and controlled by the same law that governs light
+and heat.
+
+It may be suggested that such a coincidence is not a very strong
+argument, as all forces emanating from a central body are subject to the
+same law of inverse squares. In reply to that, I should like to point
+out, that even that objection only strengthens the conception of the
+Aether that we are endeavouring to complete. Our contention is, that all
+physical forces, whether they be light, heat, electricity, magnetism or
+Gravitation, are all due to the motions of the aetherial medium; which
+motions may be generated by a heated or luminous or electrified body,
+and are radiated from such a body in waves of concentric spherical form,
+and are all subject to the laws of inverse squares.
+
+So that the fact of the intensity of the centrifugal force due to the
+repulsive power of electricity falling into line with the law governing
+light and heat is, to my mind at any rate, only a clearer proof of the
+one common origin of all the physical forces. The law of inverse squares
+in relation to electricity may be thus stated. The Centrifugal or
+Repulsive Force between two charged electrified bodies acts inversely as
+the square of the distance between them.
+
+This law was proved by Coulomb by means of an instrument known as
+Coulomb's Torsion Balance, and I must refer the reader to any work on
+electricity for a full establishment of this law. Suffice to say, that
+it has been experimentally demonstrated that the law holds good in
+relation to the phenomena of electricity; and, wherever we get the two
+kinds of electricity present in any medium or conductor, owing to the
+polarization of its particles, there we have this law operating in
+relation to the intensity of the repulsions of the two bodies directly
+concerned.
+
+We have already learned that the sun is an electrified body, and from
+that hypothesis we have arrived at the conclusion that the earth and all
+the other planets are electrified bodies. This being so, it naturally
+follows that the intensity of the centrifugal force between any two of
+these bodies, as the sun and the earth for example, or the sun and
+Jupiter, is subject to the law of inverse squares; and that the
+repulsion of the sun and the earth for each other is always regulated by
+their distance, being inversely as the squares of the distance between
+them.
+
+Thus, if the distance between the sun and any planet is reduced to
+one-half, which is an exaggerated view, the intensity of the centrifugal
+force is increased four times; if the distance be doubled the force is
+reduced to four times its former intensity, and so on.
+
+Whatever the distance may be between the sun and any of the planets, if
+that distance be increased or decreased, then the intensity of the
+centrifugal force due to electric waves is increased or decreased in
+accordance with the law of inverse squares. This agrees with the
+centripetal law of Gravitation, as the Attraction of Gravitation is also
+subject to the same law of inverse squares, and, as we have seen (Art.
+83), its path coincides with the path of centrifugal force, as it
+pursues the path represented by the straight lines joining the two
+bodies.
+
+So that, whenever, and wherever, at any point in space in relation to
+the central body, the sun, the intensity of the attractive force is
+increased according to the law of inverse squares by the distance from
+the central body being diminished, at exactly the same time and in
+exactly the same manner, the repulsive force due to aetherial electric
+waves is also increased. If the attractive force is doubled, then the
+repulsive force is doubled. If the attractive force is halved, the
+repulsive force is halved. If the attractive force is lessened
+gradually, then the repulsive force is lessened gradually; and if
+quickly, by the quicker motion of the planet through space, then the
+repulsive motion is also increased with a quicker motion.
+
+Further, like the repulsive power of light and heat, the repulsive power
+of electricity takes exactly the same path as the attractive power of
+Gravitation.
+
+Thus we learn that the sun is the centre of two forces: first, a
+centrifugal force due to the pressure of the aetherial medium which is
+ever directed away from the sun, and which may either be produced by
+electric or thermal or light waves; and second, it is the centre of a
+centripetal force known as the Law of Gravity, whatever that may be due
+to. Further, the centrifugal force is also subject to the same law of
+intensity as the centripetal force, and moreover takes exactly the same
+path which the centripetal force takes.
+
+So that we have only to prove that they both agree in another
+particular, viz. that their power is regulated by the product of their
+masses, and then we shall have discovered a real physical force, which
+is the exact complement and counterpart of the centripetal force due to
+gravity.
+
+
+ART. 85. _Second Law of Electricity. (Product of Masses.)_--We have now
+to prove that the centrifugal force exerted by any electrified body
+operates upon another electrified body in the same proportion and with
+exactly the same force which governs the centripetal force. From Art. 21
+we learn that the centripetal force which is exerted by one body upon
+another is equal to the product of their masses. In order, therefore,
+for any centrifugal force to be the exact counterpart of that force, it
+too must be subject to the same law of proportion, that is, the
+repulsive force between any two bodies must be equal to the product of
+their masses.
+
+We have shown that there is a repulsive force exerted by the Aether from
+the phenomena of heat, light, and electricity, and that that repulsive
+force or energy fulfils every condition required by a centrifugal force
+or motion, with the exception of the part referring to the fact that
+such a force must be proportionate to the product of their masses. What
+we were unable to accomplish, however, from the phenomena of heat or
+light we are now able to accomplish from the phenomena of electricity.
+
+For in the phenomena of electricity we find a law which runs thus: "The
+force of repulsion" (which is the part of electricity we are now dealing
+with) "between two electrified bodies is equal to the quantities of
+electricity with which the body is charged." This law was established
+and proved by Coulomb by means of a delicate instrument known as the
+Torsion Balance, with which he also established the law of inverse
+squares.
+
+It will be seen at a glance that there is a slight difference between
+stating the law of proportion with reference to the centripetal force,
+and the centrifugal force or motion. In the former we state the
+proportion is equal to the product of the masses, while in the latter we
+say that the proportion is equal to the product of the quantities of
+electricity.
+
+In the one case we deal with the mass of the body, whether it be atom,
+molecule, planet or star; in the other case we deal with quantities of
+electricity. At first sight it may seem that there is little, if any,
+connection between the two laws, but a careful reflection of the
+hypotheses laid down with regard to the aetherial medium will show that
+there is not only a close connection between these two laws of
+proportion, but also that the law governing the repulsive power of the
+aetherial electric waves is the direct outcome of the law of proportion
+governing the centripetal force. Let us restate our case in regard to
+the aetherial medium.
+
+We have learned that the Aether is gravitative, and that it also has an
+electro-magnetic basis is proved from Maxwell's electro-magnetic theory
+of light. Let me ask the reader this question therefore. If the Aether
+be gravitative, what must be the rule governing the extent and density
+of the aetherial atmosphere surrounding any planet or sun or other body?
+If the Law of Gravity teaches us anything at all, it distinctly teaches
+us that the gravitating power of any body is regulated by the mass of
+the body, as the law states that the attraction is proportionate to the
+product of the masses. It states nothing about volume or condition of a
+body.
+
+The exact size or state of a body has no direct result bearing on
+gravitation attraction; the underlying principle being that the
+attractive force is dependent on the mass, and only on the mass of a
+body. So that if the volume of any body, whether atom, planet, satellite
+or sun, be doubled, its attractive power remains the same, simply
+because the mass of the whole body remains the same. Mass, we are told
+by mathematicians, is equal to the volume multiplied by the density, and
+whenever we increase the volume of a body we decrease the density, the
+total mass of the body remaining the same.
+
+If the volume be doubled, then the density of the body would be halved,
+and _vice versa_, but through all the changes of volume and density that
+may arise from the addition of heat or diminution of heat, the total
+mass of a body always remains the same. Looked at from the atomic
+standpoint, taking hydrogen as unity, an atom of oxygen would always
+weigh sixteen times an atom of hydrogen, and this principle applies
+throughout the whole realm of the atomic world. Further, the same
+principle or law, that the mass is equal to the volume multiplied by the
+density, is true of the planetary or even the stellar world. Thus the
+great regulating principle of the attractive force of gravity is mass,
+and not volume, or density, or any other condition.
+
+Now as Aether is subject to the attractive force of gravity, the extent
+of the aetherial field, and the density of the Aether near the surface
+of any body, must be subject to the same law regarding mass. That is,
+the aetherial atmosphere of any atom, or molecule, or satellite, or
+planet, or star is dependent upon the mass of the atom, the molecule, or
+the planet, or the star as the case may be.
+
+Thus an atom of oxygen would have a larger or denser aetherial
+atmosphere than an atom of hydrogen, exactly proportionate to their
+respective masses. A planet whose mass was represented by 1,000,000 tons
+would have twice the quantity of Aether around it, compared to a planet
+weighing only 500,000 tons, and so on, the aetherial atmosphere always
+being proportionate to the mass of the planet, or the satellite, or the
+sun, or the star. The fact which we learn from these considerations is
+that the quantity of Aether, which is attracted by any body, is always
+proportionate to the mass of the body attracting it.
+
+But we have learned from Art. 78 that Aether has an electro-magnetic
+basis, and that the density of the Aether is co-equal with electric
+density, so that the quantity of Aether which is attracted and held
+bound by any body is really equal to the quantity of electricity that
+such a body is covered with, or is charged with. If the quantity of
+Aether around any body is doubled because its mass is doubled, then the
+quantity of electricity is also doubled, but as long as the mass remains
+unaltered, the quantity of electricity held bound by that mass remains
+unaltered also. The area of the mass may be doubled, and in that case
+the density of the electricity would be halved, but as long as the mass
+remained the same, the quantity of electricity would remain the same
+also. So that we learn from this reasoning that the mass of a body, and
+quantities of electricity on that mass, are always proportionate to each
+other, because of the fact that Aether is gravitative, and also has an
+electro-magnetic basis.
+
+If we wanted further evidence of the hypothesis that has just been
+advanced, such evidence is to be found in the hypothesis suggested by
+Faraday as to the electro-chemical equivalents of all elements.
+According to this hypothesis every element has its exact
+electro-chemical equivalent, or definite quantities of electricity are
+to be found in association with each and every particular atom of each
+element. Writing on the subject in his _Exp. Res._, par. 852, he says:
+"The theory of definite electro-chemical action appears to me to touch
+upon the absolute quantity of electricity or electrical power belonging
+to different bodies. Although we know nothing of what an atom is, yet we
+cannot resist forming some idea of a small particle which represents it
+to our mind, and though we cannot say what electricity is, so as to be
+able to say whether it is a particular matter or matters, or mere motion
+of ordinary matter, yet there is immensity of facts which justify us in
+believing that the atoms of matter are in some way endowed or associated
+with electrical powers to which they owe their most striking qualities,
+and amongst them their chemical affinity." Further, in Art. 857, he
+states: "I can have no doubt that, assuming hydrogen as 1, and
+dismissing small fractions for the simplicity of expression, the
+equivalent number or atomic weight of oxygen is 8, of chlorine 36, of
+bromine 78.4, and of lead 103.5, etc., notwithstanding that a high
+authority doubles several of these numbers."
+
+Then, writing upon the definite relationship of these equivalents in
+compounds, he states (Art. 835): "Electro-chemical equivalents are
+always consistent, that is, the same number which represents the
+equivalent of a substance _A_ when it is separating from a substance _B_
+will also represent _A_ when separating from a third substance _C_. Thus
+8 is the electro-chemical equivalent of oxygen, whether separating from
+hydrogen, tin, or lead; and 103.5 is the electro-chemical equivalent of
+lead, whether separating from oxygen, or chlorine, or iodine."
+
+Here, then, from the pen of one of the greatest thinkers and
+experimentalists of modern times we have confirmatory evidence that the
+mass of any body is practically synonymous with the quantity of
+electricity associated with that body. For if the principle is true in
+its application to atoms, it is true in its application to molecules;
+and if it is true in relation to molecules, it is equally true in
+relation to small bodies composed of molecules. And if it holds good in
+relation to small bodies, the principle is equally true in its
+application to larger bodies, as the earth, and therefore is of
+universal application and proves the statement already made, that the
+masses of bodies and quantities of electricity in association with that
+mass are always proportionate to each other.
+
+We are now in a position to compare the proportion of the centripetal
+and centrifugal forces. The attractive power of the former, between two
+bodies, is equal to the product of their masses; the repulsive power of
+the latter is equal to the product of the quantities of electricity
+bound to them, and that, as we have seen, is regulated by the respective
+mass of each body. Let us apply this fact to the solar system and see
+how it works.
+
+Taking the mass of the earth as unity, we find that the mass of the sun
+is 324,000 greater, so that the attractive power of the two bodies would
+be represented by the product of the two numbers; but because the sun is
+that number of times greater, its aetherial and, therefore, its electric
+field would be so many times greater, with the result that the
+proportion of the repulsive forces between the two bodies would be
+exactly the same as the attractive forces between the two bodies, that
+is, if the mean distance remains the same.
+
+In the same way, it can be shown that the attractive forces between the
+earth and Jupiter exactly equal the repulsive forces between the two
+planets at their mean distance, or the attractive forces between any two
+planets or satellites are exactly counterbalanced by the repulsive power
+of the centrifugal force at their mean distances.
+
+Thus the centrifugal force of every body is the exact opposite of its
+centripetal force at their mean distance, because the laws governing the
+centrifugal force are the exact counterpart of the laws governing the
+centripetal force. A comparison of the two will prove this. From Arts.
+20, 21, and 22 we have seen that the centripetal force is exerted along
+the straight lines joining the attracting bodies, that the intensity of
+the attracting body is inversely as the square of the distance, while
+the total force is proportionate to the product of their masses.
+
+From the phenomena of light, heat, and electricity, we learn that the
+centrifugal force due to aetherial pressure is exerted along straight
+lines, that the intensity is inversely as the square of the distance,
+while the total force between two bodies is equal to the product of the
+quantities of electricity, which are regulated by the product of their
+masses.
+
+Thus, if every planet and satellite could be conceived to be motionless
+in space, and these two forces could be set in operation without
+producing rotation or translation in space, which is impossible, then
+every planet and satellite would occupy, by the joint exercise of these
+two forces, the same position in relation to the sun represented by
+their mean distances, as long as the solar system existed as a separate
+system in the realm of aetherial space. We have therefore discovered by
+strict philosophical reasoning, based on Newton's Rules of Philosophy, a
+real tangible centrifugal force existing throughout the universe;
+because it is entirely due to the pressure of an universal Aether, whose
+operation is ever directed from a central body, which force was
+indicated by Herschel, and its existence to his mind was demonstrated by
+the repulsion exhibited in connection with the tails of comets.
+
+We have now to go a step further, and show that the same pressure also
+includes the magnetic phenomena, as indicated by Clerk Maxwell, and that
+magnetic phenomena are also due to the aetherial medium, and then we
+shall have linked together in one common medium the majority of the
+forms of energy, as light, heat, electricity and magnetism, with which
+we are familiar.
+
+If it be demonstrated that these two forces, the centrifugal force and
+the centripetal force, can conjointly account for all the motions of the
+celestial bodies, then we shall have conclusive evidence that one of the
+forces is physical and due to the pressure of a physical medium. After
+that it will be comparatively easy to show that the centripetal force is
+also due to the same aetherial medium, and then we shall have
+accomplished that which we set out to accomplish, viz. the establishment
+of a physical cause for universal Gravitation, which physical cause is
+alone to be found in the pressures, tensions and motions of an universal
+Aether.
+
+
+
+
+                               CHAPTER IX
+
+                          AETHER AND MAGNETISM
+
+
+ART. 86. _Electro-magnetism._--We have now to look at the relation of
+magnetism to electricity, or, in other words, to prove the identity that
+exists between magnetism and electricity. In Art. 78 we have proved the
+identity between electricity and light, so that if we can now prove the
+identity between electricity and magnetism, then, wherever we get
+aetherial light waves, we must also get aetherial electro-magnetic
+waves.
+
+As the light waves due to the vibrations of the Aether are practically
+universal in extent, then it must follow, if the identity of the light
+waves with electro-magnetic waves is established, that the universality
+of electro-magnetic waves is established also, with the natural result,
+that, wherever we get these electro-magnetic waves, there we shall have
+the conditions by which all electro-magnetic phenomena are produced.
+
+Now it can be demonstrated by actual experiment that wherever we get a
+circular current of electricity, there we have magnetic phenomena
+manifested. The two are inseparably connected, and it is impossible to
+obtain the one without the other. For example, suppose we have a wire
+conveying a current of electricity and make it into a coil as in Figure
+15, what is the result? The result is, that the coil of wire has
+actually been converted into a magnet.
+
+It will attract iron filings that are brought near it, and also
+magnetize an iron bar placed in the centre of the coils, and convert
+that into a magnet. Indeed, there is nothing which can be done by an
+ordinary bar magnet which cannot be done by a coiled wire conveying an
+electric current.
+
+From this and similar experiments it can be demonstrated that wherever
+we get a circular current of electricity, there, associated with that
+current, are all the phenomena incidental to and associated with the
+ordinary bar magnet. This leads us to the truth discovered by Ampere,
+that magnetism is nothing more or less than electricity in rotation, or
+that it is due to a whirl of electricity circulating round the molecule
+of any body. From certain experiments which he made in relation to the
+mutual action of two circuits on each other, with currents flowing
+through them, he came to the conclusion that the magnetism of the
+molecule of each magnet is due to electric currents circulating round
+it.
+
+The question arises as to what effect our new theory of the Aether has
+upon Ampere's theory: does it confirm it, or does it destroy it? We have
+learned that every atom has its aetherial atmosphere, so to speak, which
+is bound to the atom by the Law of Gravitation (Art. 45). We have also
+learned that Aether has an electrical basis, as proved by Maxwell and
+Hertz, so that we learn that every atom has really an aetherial electric
+atmosphere in association with it. We have only to conceive of this
+atmosphere being set in rotation either by the rotation of the atom or
+molecule itself, or by outside agencies, and we have at once a physical
+interpretation of Ampere's theory of magnetism in the rotation of electric
+currents around the atom, such currents being due to the circulating or
+rotating motion of the Aether which surrounds the atom or molecule.
+
+[Illustration: Fig: 15.]
+
+Thus we learn from experiment, and from Ampere's theory also, that
+magnetism is directly associated with circulating currents of
+electricity, and that wherever we get currents of electricity
+circulating round any atom or body, there we get all the phenomena
+associated with magnetism. That is to say, we shall have such phenomena
+as magnetic fields, magnetic lines of force, magnetic induction, and the
+production of permanent magnets by electricity.
+
+Further, with reference to the identity of electricity and magnetism,
+Faraday has conclusively proved their relation to each other; and I
+would strongly advise any reader who desires further light on the
+subject to carefully read paragraphs 3265-3269 in his _Experimental
+Researches_, where he will find experiments which place the identity of
+electricity and magnetism beyond the possibility of doubt. In paragraph
+3265 he writes: "The well-known relation of the electric and magnetic
+forces may be thus stated. Let two rings in planes at right angles to
+each other represent them. If a current of electricity be sent round the
+ring _E_ in the direction marked, then lines of magnetic force will be
+produced. As these rings represent the lines of electro-dynamic force
+and of magnetic force respectively, they will serve for a standard of
+comparison."
+
+"I have elsewhere called the electric current or the line of
+electro-dynamic force an axis of power having contrary forces exactly
+equal in amount in contrary directions (517). The line of magnetic force
+may be described in precisely the same terms, and these two axes of power
+considered as right lines are perpendicular to each other," etc.
+
+[Illustration: Fig: 16.]
+
+Again in 3267 he adds: "Like electric currents or lines of force, or
+axes of power when placed side by side attract each other. This is well
+known and well illustrated when wires carrying such currents are placed
+parallel to each other. But like magnetic axes of power or lines of
+force repel each other. The parallel case to that of electric currents
+is given by placing two magnetic needles side by side with like poles in
+the same direction."
+
+Then in 3268 he shows that these effects are not merely contrasts, but
+they are contrasts which coincide when the two axes of power at right
+angles to each other are considered. Then in 3269 he adds: "The mutual
+relation of the magnetic lines of force and the electric axis of power
+has been known since the time of Oersted and Ampere," and further states
+he is of the opinion that "the magnetic lines have a physical existence
+the same as the electric lines," and having that opinion, asks whether
+"the lines have a dynamic condition analogous to the electric axis to
+which they are so closely and inevitably associated, or whether they
+consist in a state of tension of the Aether round the electric axis, and
+may therefore be considered as static in their nature." Thus Faraday
+proved the intimate and close relationship that existed between the
+electric current and the circles which represent the magnetic force in
+association with that current; and, what is more noticeable, he asks
+whether such magnetic results are due to a state of tension in the
+Aether around the axis of the electric current, evidently being of the
+opinion that the Aether played an important part in the phenomena of
+magnetism, as well as in electricity, as other parts of his writings
+abundantly show.
+
+If, therefore, there is this close identity between electricity and
+magnetism, then in view of the fact that all electricity is due to the
+motions of the universal Aether, it must follow that all magnetism is
+also due to motions of the same aetherial medium, which is as universal
+as it is invisible.
+
+What these motions are has already been indicated by previous statements
+in this article, being comprised of circular or rotatory motions of the
+aetherial electric medium about any body, whether that body be an atom,
+planet, or sun or star. Such a conclusion as this is perfectly in
+harmony with Maxwell's electro-magnetic theory of light, as the
+conclusion that he arrived at in that theory was, that the light waves
+were identical in nature and character with electro-magnetic waves
+produced by an electro-magnetic source.
+
+Up to the present we have only dealt with the electric character of
+those waves, and have therefore now to deal with the magnetic character
+of the same. So that throughout the whole realm of space, and indeed
+wherever there is Aether, there we have the conditions which give rise
+to magnetic phenomena, such as those already indicated.
+
+It matters not whether it be in the atomic systems whose combinations
+comprise all material forms of life with which we are familiar, or
+whether it is in the systems of planets that revolve around their
+central sun, or whether it be in the constellations that fill the
+universe, wherever we find the Aether, there we find the conditions in
+that Aether which will produce all the results ordinarily produced by
+magnetism, or with which magnetism is associated, and it is to the
+application of these phenomena to our solar system that we will now turn
+our attention.
+
+
+ART. 87. _The Earth a Magnet._--If there is any fact in relation to a
+planet that holds good, it is that the earth, with which planet we are
+more intimately associated than any other, is a magnet.
+
+This truth was clearly explained by Dr. Gilbert about the year 1600 in
+his work on "De Magnete." Not only has the earth geographical North and
+South poles, but it has also magnetic North and South poles, and indeed
+has all the phenomena incidental to a magnet, such as magnetic dip and
+magnetic lines of force, as we shall see later on.
+
+We know, however, that the earth is simply one of a system of planets,
+which revolves with all the others of that system round its central body
+the sun; and the question arises, whether the earth is the only one out
+of all the planets that is actually a magnet. Suppose it is affirmed
+that the earth is the only planet which is a magnet. On what basis would
+such a statement be made? The only ground for making such a statement
+that I can see is, that we have never lived on Mars or Jupiter or
+Saturn, or any of the other planets, and therefore been unable to
+experiment on them, which reason is totally insufficient and inadequate
+for such a conclusion.
+
+If philosophy simply dealt with the results attained by such limited
+reasoning, then the progress of science would be retarded, and would be
+limited and confined to actual experience obtained on our own planet and
+in relation only to that planet. But philosophy is not satisfied with
+such a narrow and limited outlook, but drawing its conclusions from
+actual experience on our own planet, in accordance with the rules of
+philosophy, it seeks to apply such experience gained to the explanation
+of phenomena of other planets which also revolve round the sun.
+
+By such reasoning we learn that all the other planets have North and
+South geographical poles like our earth, although we have never actually
+trodden on those planets, or discovered the poles. We also learn that
+Mars possesses climatic conditions probably similar to our own earth, as
+there are certain changes on the surface around the poles, which by
+analogy we assume to be caused by increase and decrease of snow during
+the Arctic winter and summer of Mars respectively.
+
+The analogy between our earth and the other planets is very full and
+complete, as the following results show. Our earth has an atmosphere, so
+have all the rest of the planets. The earth revolves on its axis from
+West to East, so do all the rest. The earth possesses two geographical
+poles, so do all the other planets. The earth revolves round the sun in
+an orbit of elliptic form, so do the other planets. The earth fulfils
+all the laws of motion as given by Newton, and all the other planets do
+the same. The earth fulfils all Kepler's laws, and this is also true of
+all the others. Indeed, the only difference apparently that exists at
+present between the earth and all the other planets is, that our earth
+is a magnet, while at present it is not conceded that all the others are
+magnets.
+
+Now such a conclusion I venture to say is altogether opposed to every
+rule of philosophy. For if experience be any guide in philosophy, then
+according to experience and observations made in respect to the only
+planet that we can actually experiment on, it most conclusively follows,
+that not only the earth, but every planet, and indeed every satellite
+that revolves round its primary planet, is a magnet; otherwise the rule
+of philosophy which permits us to formulate hypotheses based on
+experience is entirely violated, and ceases at once to be an universal
+rule.
+
+So that either the earth is not a magnet, or else, being a magnet by our
+second Rule of Philosophy, all the other planets are magnets also. This
+conclusion has already been arrived at by Lord Kelvin, who in writing in
+his _Popular Lectures_[33] on the subject says: "If it is true that
+terrestrial magnetism is a necessary consequence of the magnetism and
+the rotation of the earth, other bodies comparable in these qualities
+with the earth, and comparable also with the earth in respect to
+materials and temperature, such as Venus and Mars, must be magnets,
+comparable in strength with the earth; and they must have poles similar
+to the earth, North and South poles on the North and South sides of the
+equator. It seems probable also that the sun, because of its great mass
+and its rotation in the same direction as the earth's rotation, is a
+magnet, with polarities on the North and South sides of the equator,
+similar to terrestrial North and South magnetic poles." Further, such a
+conclusion is entirely in harmony with the view of the solar system
+revealed in Art. 81, where we saw that each planet was an electrified
+body having its own electric field, with its lines of force, being
+capable of giving rise to all the phenomena associated with electricity.
+So that if we combine that view of the subject with the view that we are
+now coming to, we arrive at the conclusion that each planet and
+satellite, and indeed all bodies that move or revolve in space, are
+electro-magnets giving rise to magnetic waves in the Aether, which
+assumption is fully consistent with the electro-magnetic theory of light.
+
+We must now go one step further and apply a similar line of reasoning to
+the sun, when we shall arrive at exactly the same result that Lord
+Kelvin arrived at, according to the previous extract. All planets
+possess an atmosphere, the sun also possesses an atmosphere. All planets
+revolve on their axes from West to East, so does the sun. All planets
+possess a North and South pole the same as the sun.
+
+The equatorial diameter of every planet is greater than its polar
+diameter, and the same truth applies to the sun. It is hotter at the
+equatorial regions of every planet, and this truth also applies to the
+sun. Now, if the sun agrees with all the planets in these respects, then
+we may philosophically conclude that it agrees with them in another
+respect, viz. that the sun is also a magnet possessing its own magnetic
+field, which is co-equal and co-extensive with its aetherial electrical
+field. We have already seen that the sun is an electrified body,
+possessing its electric field, with its electric lines of force.
+Therefore the sun is also a magnet, or, to speak more correctly, it is
+an electro-magnet, and as such gives rise to electro-magnetic waves.
+
+The conclusion to which we have come, that the sun is an electro-magnet,
+can be arrived at from an altogether different method of reasoning, and
+as that different method of reasoning will tend to confirm the statement
+made, I will just indicate it, and then leave it for fuller development
+in another article.
+
+It is a matter of common knowledge to all students, that the magnetism
+of the earth varies in several important particulars from time to time.
+The magnetic poles of the earth do not always occupy the same place in
+relation to the geographical poles, so that the magnetic force varies as
+regards intensity or magnitude. The reasons of the variations have never
+been satisfactorily accounted for, though various hypotheses have been
+suggested as a solution from time to time.
+
+There is, I believe, only one satisfactory solution to the problem, and
+that is, that the sun is an electro-magnet, and this conclusion may be
+arrived at by strictly adhering to Newton's rules of Philosophy. For we
+have learned that any hypothesis put forward to account for any
+phenomena, must be simple in character, must agree with experience and
+observation, and, lastly, must satisfactorily account for the phenomena
+sought to be explained.
+
+Here then are the variations in time of the magnetic force of the earth,
+the variations in intensity, and in the inclination of the magnetic
+axis, together with other variations. What solution shall we offer to
+such a problem? The only philosophical solution that can be suggested
+lies in the statement that the sun is an electro-magnet. Such statement
+is simple in conception, does not violate our experience or observation,
+as we find a similar revolving body, the earth, which is a magnet; and
+further, such a statement I premise will satisfactorily account for the
+whole of the variations and changes in relation to the magnetic forces
+of the earth. We shall see that this is so when we consider more fully
+the sun as an electro-magnet. Therefore, apart altogether from any
+previous analogies, we can philosophically arrive at the conclusion that
+the sun is an electro-magnet, as well as all the planets.
+
+That being so, it will possess its magnetic field, its magnetic lines of
+force, and be capable of bringing into operation in the solar system all
+the phenomena or effects associated with any ordinary magnet that we may
+experiment with on the earth.
+
+[Footnote 33: _Popular Lectures_, Vol. II.]
+
+
+ART. 88. _The Sun an Electro-magnet._--If the sun is an electro-magnet,
+as stated in the previous article, then it is necessary for us to apply
+the phenomena of magnetism to it in order to ascertain what effect such
+application will have on the solar system as a whole.
+
+[Illustration: Fig: 17.]
+
+The first thing that we will look at is the magnetic field which is
+always associated with every magnet. The magnetic field may be defined
+as that region or space around every magnet in which the magnetic force
+acts or is in operation. An illustration of a magnetic field may easily
+be obtained by taking a bar magnet and bringing near to it a magnetized
+needle, when it will be found that the needle will set itself in various
+positions relative to the magnet, on account of the lines of force which
+exist in the field. Thus let _A_ _B_ (Fig. 17) be a bar magnet with its
+North pole at point _A_ and South pole at point _B_. If a number of
+freely suspended needles be hung above it, as shown in the figure, they
+assume the positions indicated there. It will be seen that at the North
+and South poles the needles hang vertical, while midway between the two
+poles there is no dip of the needle, as it is parallel to the bar
+magnet; while between the place of no dip and the place of vertical dip,
+which is directly over each pole, the dip gradually changes, becoming
+more and more vertical as it gets nearer to the pole. If the bar magnet
+be a strong one, then its magnetic field will be manifested at a great
+distance; and any magnetized needle brought into the field will be,
+affected by the same, and will tend to set itself along the lines of
+force.
+
+As already stated in Art. 80, it was Faraday who originated the term
+"Lines of Force," and gave to the world some idea of the motions of the
+aetherial medium, which plays so important a part in electro-magnetic
+phenomena. A visible manifestation of these lines of force which gather
+round every magnet may be made by strewing iron filings over a piece of
+glass, underneath which are several bar magnets, when it will be found
+that the iron filings will set themselves in well-defined lines or
+curves, which Faraday termed "Lines of Force."
+
+[Illustration: Fig: 18.]
+
+As the bar magnets are placed in different positions, North pole to
+North pole, or North to South, and so on, the iron filings will change
+the figures assumed, indicating in, each case the effect of the lines of
+force of each magnet upon one another. The iron filings strewed over the
+magnet are magnetized by induction, with the result that the North pole
+of one filing attracts the South pole of the next one to it, and this is
+continued along the whole of one line of force, as revealed by the united
+iron filings. Faraday believed in the real physical existence of these
+lines of force, and that belief has been perfected by Clerk Maxwell in two
+papers which he wrote on "Physical Lines of Force," which will be
+considered in another article. We will simply deal with them at present
+as indications of the existence of the magnetic forces in the medium
+surrounding any magnet.
+
+Let us apply these facts to the solar system and see what the
+application yields. We have the sun revolving in the Aether medium
+represented by the circle _S_ in Fig. 19. Then we have the lines of
+force extending in curved lines _E._ and _W._, but in almost straight
+lines North and South. We will suppose the axis of the sun to be
+vertical for the sake of simplicity. It may be asked, how far will these
+lines of force stretch out into space? The reply is that they stretch
+and extend throughout the whole solar system, and far away into the
+depths of space, though with ever-decreasing intensity according to the
+law of inverse squares. Wherever the aetherial light waves are
+manifested, there the electro-magnetic waves, with all that they imply,
+are manifested also. We know that the light waves are existent at least
+as far as Neptune, a distance of 2800 millions of miles, therefore at
+least to that extent the electro-magnetic waves are manifested; and
+wherever the electro-magnetic waves to which the sun has given birth are
+manifested, there we have the existence of the electro-magnetic field,
+which is co-existent and co-extensive with the electric field of the
+sun. Further, wherever we get the magnetic field, there we get the lines
+of force which are as real as air or ocean currents, and are caused, as
+Maxwell indicated (Art. 44), by the motions of the atomic Aether.
+Wherever these lines of force are closest together, there the intensity
+of the magnetic force is at its greatest.
+
+[Illustration: Fig: 19.]
+
+By actual experiment, it can be demonstrated that the lines of force are
+closest together nearest to the magnet, and therefore applying that fact
+to the solar magnetic field, the lines of force should be closest
+together nearest to the surface of the sun, which is exactly what we
+have already learned. For if Aether be gravitative, then it will be
+densest nearest to the sun than further away, and the vortex atoms which
+represent our aetherial atoms will be pressed more closely together near
+to the surface than further away.
+
+We have learned that Aether has an electro-magnetic basis, and it is
+that very fact which gives rise to the existence of these lines of
+force. So that the magnetic phenomena as indicated in the lines of force
+conceived by Faraday harmonize with the fact that the sun is an
+electro-magnet; and that Aether, which has an electro-magnetic basis, is
+also gravitative, with the result that the lines of force are closest
+together nearest the surface of the sun, where the magnetic force is
+greatest in its intensity and power.
+
+Now let us apply the principle of the experiment to the solar system by
+bringing a magnet into a magnetic field, and let us see what the result
+is. We have learned from the experiment, that if a magnet is moved along
+any one of the lines of force the dip of the magnet changes, gradually
+changing from a horizontal to a perpendicular position in accordance
+with its relation to the two poles of the magnet. From the previous
+article we have come to the conclusion that not only is the earth a
+magnet, but that all the other planets are magnets also, so that if any
+of these are brought into the magnetic field of the sun, then the
+magnetic axis of the planet, which corresponds to the needle in our
+experiment, must assume a certain dip in relation to the sun, setting
+itself along those lines of force which are in the immediate
+neighbourhood of the planet.
+
+Let us place the earth, for example, at a distance of 90 millions of
+miles from the sun in the magnetic equator, or that line which exactly
+divides the magnetic field into two equal halves. According to our
+experiment, the magnetic axis will now be exactly parallel with the axis
+of the sun, that is, exactly vertical, pointing North and South, as seen
+in position 1 in Fig. 19. But suppose that the earth is to the North of
+the magnetic equator of the field, what happens then? The result will be
+that the magnetic axis of the earth will dip towards the magnetic North
+pole of the sun (position 2, Fig. 19), while if the earth be to the
+South of the magnetic equator, its axis will dip in the opposite
+direction (position 3), the magnetic axis setting itself in each case
+along the lines of force which exist in the Aether in that region or
+space. Thus it can be seen at a glance, that if the earth changes its
+position at any time in its orbit in relation to the magnetic equator,
+such a change will effect the total dip of the magnetic axis. In other
+words, the magnetic poles which indicate the position of the magnetic
+axis will not occupy the same position in relation to the geographical
+North and South poles, sometimes appearing to the East and sometimes to
+the West, and at other times being coincident with the same as it moves
+to the North or South of the magnetic equator of the sun's
+electro-magnetic field.
+
+We have to remember, also, that the earth is constantly varying its
+distance in relation to the sun, being at a distance of ninety and a
+half millions of miles at its perihelion, or that part of its orbit
+nearest to the sun; while it is ninety-four and a half millions of miles
+at its aphelion, or that part of its orbit furthest away from the sun.
+This implies that as it proceeds from that point in space furthest away
+from the sun, and approaches a point nearer to the sun, it will pass
+into places of greater magnetic intensity, with the result that the
+intensity of the electro-magnetic waves is increased; and the magnetism
+of the earth is accordingly affected by that fact.
+
+When we come to deal with the earth as a magnet more directly, we shall
+see that all the variations of terrestrial magnetism may be
+satisfactorily explained by the fact that the sun is, as we have
+indicated in this article, an electro-magnet, possessing its magnetic
+field with its lines of force, and therefore able to give rise to all
+the phenomena incidental to and associated with any ordinary magnet.
+
+
+ART. 89. _Aether and Faraday's Lines of Force._--We have now to face the
+question of the physical character of the Lines of Force conceived by
+Faraday. We have seen in Fig. 18 illustration of these lines of force,
+which are manifested by the iron filings in the neighbourhood of a
+magnet, and the question suggests itself to the mind, as to what is the
+relation of the Aether to those lines of force? Does the Aether play any
+part in their existence, and if so what?
+
+Faraday was of the opinion that the Aether did play some part in the
+existence of the lines, and that they were no mere hypothetical lines,
+but were caused by the actual physical state or condition of the
+aetherial medium, which existed around every magnet and every
+electrified body. On this point he says, Art. 3263:[34] "To acknowledge
+the action in curved lines seems to me to imply at once that the lines
+have a physical existence. It may be the vibration of the hypothetical
+Aether, or a state of tension of that Aether equivalent to either a
+dynamic or static condition."
+
+Par. 3277: "I conceive that when a magnet is in free space, there is
+such a medium, magnetically speaking, around it. That a vacuum has its
+own magnetic relations of attractions and repulsions is manifest from
+former experimental results (2787). What that surrounding magnetic
+medium deprived of all material substance may be, I cannot tell, perhaps
+the Aether."
+
+It was, however, left for Clerk Maxwell to develop the idea as to their
+physical character, and this he did in his paper on "Physical Lines of
+Force," _Phil. Mag._, 1861. He had previously written a paper on
+"Faraday's Lines of Force," delivered to the Cambridge Phil. Society in
+1855 and 1856, but his more matured conception of Faraday's Lines of
+Force was given in the later article.
+
+What Maxwell did was to conceive a physical theory of electricity and
+magnetism, by which electrified and magnetized bodies could act upon
+each other by means of the stress or strain of some medium, which
+existed in the space surrounding these bodies. Now Faraday looked upon
+electro-static and magnetic induction as always taking place along
+curved lines. These lines may be conceived as atoms or molecules
+starting from the poles of a magnet, and acting on all bodies in the
+electro-magnetic field. These atoms or molecules, joined together in a
+definite manner, tend to shorten in the direction of their length, that
+is to say, there is a tension along the lines of force while at the same
+time they swell out laterally or sideways. Thus there is a tension along
+the lines of force, and a pressure at right angles to them owing to
+their bulging out sideways. Maxwell used as an illustration of the
+tension and pressure, the contraction and thickening of a muscle. As the
+fibres of the muscle contract, and the arm or leg is drawn up, the
+muscle swells in its centre outwardly, and so thickens. Thus there would
+be a tension along the muscle, and a pressure at right angles to it,
+which would cause any body placed on it to move away from it, owing to
+the pressure of the contracted muscle.
+
+In the conception of an aetherial atom (Art. 44) drawn purely from
+observation of the shape of the earth, we came to the conclusion that
+the aetherial atom was a spherical vortex atom, or, to be more correct,
+that it was an oblate spheroid with its polar diameter, so to speak,
+shorter than its equatorial diameter, and further, that the aetherial
+atom possessed polarity.
+
+Now if we can conceive of these aetherial vortex atoms being joined
+together, North pole to South pole, and revolving round their axes, we
+shall then have an exact image of Maxwell's physical conception of
+Faraday's Lines of Force.
+
+We know that when any liquid body is caused to rotate rapidly about its
+axis, it will expand laterally and contract longitudinally in the
+direction of the axis; and it was on this analogy that Maxwell worked
+out his physical conception of the lines of force. Maxwell's fundamental
+idea was, that in a magnetic field there is a rotation of the molecule
+ever going on about the lines of force. For example, let _A_ _B_ be a
+magnet, and _A_ _C_ _B_ be a line of force composed of spherical vortex
+atoms joined end to end, that is, each North pole (assuming the vortex
+atoms to be magnets) being directly associated with the South pole of
+the one next to it, and _vice-versa_ (Fig. 20).
+
+Thus it can be readily seen that there will be a tension along the line
+of force, while there will be a pressure at right angles to it owing to
+the lateral expansion, partly due to the rotation of the vortex atom,
+and partly due to the attraction of the vortices for each other in the
+direction of the line of force.
+
+Maxwell in his paper says: "It appears therefore that the stress in the
+axis of the line of magnetic force is a tension like that of a rope."
+Further, he adds: "Let us now suppose that the phenomena of magnetism
+depend upon the existence of the tension in the direction of the lines
+of force, combined with a hydrostatic pressure, or in other words, a
+pressure greater in the equatorial than in the axial direction. The next
+question is, What mechanical explanation can we give of these
+inequalities of pressure in a fluid or mobile medium? The explanation
+which most readily occurs to the mind is, that the excess of pressure in
+the equatorial direction arises from the centrifugal force of the
+vortices or eddies in the medium, having their axes in the direction
+parallel to the lines of force." He adds: "A medium of this kind filled
+with molecular vortices, having their axes parallel, differs from an
+ordinary medium in having different pressures in different directions."
+
+[Illustration: Fig: 20.]
+
+He then goes on to develop the idea in relation to different intensities
+of the magnetic field. I must, however, refer the reader to the paper
+itself for fuller details. In his greatest work,[35] writing on this
+subject, he says: "I think we have good evidence for the opinion that
+some phenomenon of rotation is going on in the magnetic field, that this
+rotation is performed by a great number of very small portions of
+matter, each rotating on its own axis, being parallel to the direction
+of the magnetic force, and that the rotations of these different
+vortices are made to depend on one another by means of some kind of
+mechanism."
+
+From the foregoing extracts taken from Maxwell's writings, we learn that
+the constitution of the Aether, as given in Art. 44, exactly coincides
+with, and satisfactorily fulfils the conditions that he lays down with
+reference to his physical conception of the lines of force around a
+magnet or electrified body.
+
+So that the theory of Maxwell is not merely hypothetical, as is
+suggested by scientists, but exactly describes the conditions and state
+of the atomic Aether medium which surrounds all magnets. We have,
+however, seen that the sun is a magnet, and therefore it possesses
+around it on every side, the same as any other magnet, these aetherial
+lines of force composed of infinitesimal vortices, or mere whirling
+points which correspond to an aetherial atom.
+
+These aetherial lines of force stretch out into space on every side of
+the sun, and in fact form concentric magnetic shells around the sun;
+which magnetic shells coincide with the equipotential surfaces of the
+Aether viewed merely from the point of elasticity and density of the
+medium. We learn by experiment, that these lines are closest together
+nearest to the magnet, which fact agrees with the statement that Aether
+is gravitative, and therefore the Aether would be densest nearest the
+sun. That is, the atoms would be pressed closer together, so that the
+lines of force of which these atoms are composed ought also to be closer
+together at the surface of the magnet, which we find by experiment is
+the case. As the sun is an electro-magnet, therefore, it possesses these
+magnetic lines of force on all sides, forming a series of magnetic
+shells. We have now arrived by the aid of Maxwell's theory to a physical
+conception of the Aether from a magnetic standpoint, which fully agrees
+with our physical conception of the Aether which was arrived at by
+purely philosophical reasoning, based on Newton's Rules of Philosophy.
+
+Thus we are able to combine into one whole by our conception that Aether
+is matter, and therefore atomic and gravitative, not only Faraday's
+Lines of Force, but also Maxwell's physical conception of the same,
+apart from the solutions given to the other problems of science by the
+self-same conception, which solutions will be dealt with in their proper
+order.
+
+As further evidence of Maxwell's belief in the physical existence of
+Faraday's Lines of Force, let me again quote from his paper on "Action
+at a Distance,"[36] already referred to in Art. 43. He writes: "Its
+minute parts may have rotatory as well as vibratory motions, and the
+axes of rotation form those lines of Magnetic Force which extend in
+unbroken continuity into regions which no eye has seen.... These lines
+must _not be regarded as mere mathematical abstractions_. They are the
+directions in which the medium is exerting tension like that of a rope,
+or rather like that of our own muscles."
+
+[Footnote 34: _Exp. Res._]
+
+[Footnote 35: _Magnetism and Electricity._]
+
+[Footnote 36: _Collected Works_, by Niven.]
+
+
+ART. 90. _Terrestrial Magnetism._--We have already seen that the earth
+is a magnet, and like any other magnet will therefore possess its
+magnetic field with its magnetic lines of force. The earth's magnetic
+field is co-existent and co-equal with its electric field (Art. 80), and
+that is co-existent with the earth's aetherial atmosphere which is held
+bound to the planet by the force of gravity.
+
+How far the earth's magnetic field reaches, is impossible to say, but we
+know that it extends at least as far as 260,000 miles, the distance of
+the moon; as we find that this satellite of the earth is affected very
+considerably by the electro-magnetic attractive power of the earth. Any
+body which is placed in the earth's magnetic field is affected by the
+lines of force which exist in the magnetic field; for wherever the field
+exists, there the lines of force exist also.
+
+These lines of force, which are associated with the earth, extend
+therefore into space, and any body such as the moon would become a
+magnet, if not already one by the process known as magnetic induction,
+which physical process is well illustrated in the action of a magnet
+upon iron filings strewed over it as in the illustration (Art. 88).
+
+An experiment which well illustrates the inductive power of the earth's
+magnetism, may be made by placing a poker in one of these lines of
+force, whose direction can be found at any part of the earth's surface
+by means of proper instruments. When the poker is so placed, it will be
+seen that it has actually become magnetized by the magnetism of the
+earth, and it is itself able to attract iron filings or small needles.
+These lines of force of the earth are closer together nearest to the
+earth's surface than further away in space, and congregate around the
+North and South magnetic poles, where they are greatest in number in a
+given area, and there the magnetic intensity is the greatest.
+
+Faraday, writing on the terrestrial lines of force, says: "The lines of
+force issue from the earth in the northern and southern parts with
+different but corresponding degrees of inclination, and incline to, and
+coalesce with each other over the equatorial parts. There seems reason
+to believe that the lines of magnetic force which proceed from the earth
+return to it, but in their circuitous course they may extend through
+space to a distance of many diameters of the earth, to tens of thousands
+of miles."[37]
+
+From this extract it will be seen that Faraday was of the opinion that
+the lines of force extended beyond the atmosphere of the earth into the
+Aether, which statement is confirmed by other parts of his writings;
+though he was not able to give any physical explanation of how these
+lines extended beyond the atmosphere on account of the doubtful
+constitution and character of the Aether, although in another part of
+his work he definitively refers to the magnetic character of space.
+
+In writing on the magnetic character of space he says:[38] "From such
+experiments, and also from general observations and knowledge, it seems
+manifest that the lines of magnetic force can traverse pure space, just
+as gravitating force does, and as static electric forces do (1616), and
+therefore space has a magnetic character of its own, and one that we shall
+probably find hereafter to be of the utmost importance in natural
+phenomena." With the view of the Aether presented in this work, viz. that
+Aether is matter, though in an infinitely more rarefied and elastic form,
+we can now see the physical cause of the lines of force with which by his
+imagination he filled all space.
+
+Again, from the conception of the Aether presented to the reader in Art.
+45, we learn that around any body in space there are existing aetherial
+concentric spheres or shells which are equipotential surfaces, or
+surfaces of equal pressure, and that these surfaces coincide with the
+electric equipotential surfaces, as shown in Art. 80.
+
+Not only so, but they coincide with the magnetic shells which the lines
+of force actually form around a circular and globular magnet, as the
+earth. For it must not be forgotten that these lines of force exist
+equally on all sides of the earth, and therefore really form a spherical
+shell, or to speak more correctly an aetherial electro-magnetic shell,
+which is an oblate spheroid in shape, partaking of the shape of the
+earth or other planet which the lines of force surround.
+
+If these shells were divided into two equal halves, the line so dividing
+them would be called the magnetic equator, and on that line any magnet
+would set itself in a horizontal position, so that all round the earth
+on the magnetic equator would correspond to a line of no dip. At the
+magnetic poles, a magnet would set itself vertically, or at an angle of
+90 deg., and between these two parts, the place of no dip, and that of
+90 deg., the dip gradually changes as illustrated in the figure. Again,
+in relation to the magnetism of the earth we find that there are certain
+variations in the magnetic force, which not only influence the dip at
+any place, but also the intensity at that place. The variations in
+Magnetic Force are chiefly three--
+
+    1st. Diurnal Variations.
+    2nd. Annual Variations.
+    3rd. Secular Variations.
+
+Let us look at these three variations from the standpoint of the
+magnetic lines of force which exist around the earth, and around every
+planet. In relation to the variations of the magnetic forces upon the
+surface of the earth, Faraday points out that these variations are
+caused by the action of the sun's rays upon the terrestrial lines of
+force. He uses the following figure to illustrate his meaning. Let _H_
+be the sun, _E_ the earth--
+
+[Illustration: Fig: 21.]
+
+He writes as follows: "If the magnetic and astronomical poles of our
+earth be supposed to be coincident, then North and South poles will also
+represent the North and South magnetic poles, and the different curves
+cutting the earth will sufficiently represent a course of magnetic lines
+as they occur at, or about, the surface of the earth. _H_ represents the
+sun, and _a_ the place immediately underneath it, which is also
+coincident with the magnetic equator. Point _a_ will be a line of no
+dip, while at point _b_ there will be dip. This dip will be increased by
+the action of the sun's rays, because the atmosphere under the influence
+of the sun's rays has expanded the air, and has thus acquired a power to
+affect the lines of magnetic force."
+
+"All the lines passing through the heated and expanded air will, because
+of its being a worse magnetic conductor, tend to open out, and the mass
+of heated air will as a whole assume the condition of diamagnetic
+polarity (2923). The case may be more simply stated for the facility of
+recollection by saying, that the effect of the sun is to raise the
+magnetic circles over the equatorial and neighbouring parts from their
+normal position, in doing which the North and South dip are
+simultaneously affected and increased."
+
+Thus it can readily be seen that every day as the earth turns round on
+its axis, and presents each side of the globe successively to the rays
+of the sun, there should be a gradual change in the intensity of the
+terrestrial magnetism. In Art. 2925, Faraday points out that the maximum
+of dip would be when the sun was at its zenith or directly overhead.
+With reference to the Annual Variation, Faraday points out (2882) that
+if the axis of the earth were perpendicular to the plane of its orbit,
+the intensity and direction of the magnetic forces might be considered
+constant, but (2883) as the axis of the earth's rotation is inclined
+23 deg. to the plane of the ecliptic, the two hemispheres will become
+alternately warmer and colder than each other, and then a variation in
+the magnetic condition may arise. The consideration of this annual
+variation is further considered by Faraday in the subsequent paragraphs
+to those already quoted, and I must refer the reader to them for fuller
+details; I wish simply to indicate the possible explanation of the
+terrestrial magnetism, in so far as that explanation is in conformity
+with the aspect of the Aether submitted in Chapter IV.
+
+With regard to secular variations Faraday points out (2880) that the
+temperature of the air at the equatorial parts of the earth is greater
+than in latitudes north and south, and as an elevation of temperature
+diminishes the conducting power of magnetism, so the proportion of force
+passing through those parts ought to be less, and that passing through
+the cooler parts, greater, than if the temperature were at the same
+degree over the whole surface of the globe.
+
+Now with our definite conception of the aetherial lines of force
+traversing space, and existing on all sides of the earth, these
+suggestions of Faraday's obtain an increased value in relation to the
+varying intensity of terrestrial magnetism, and will account for the
+variations in a satisfactory manner from the aetherial standpoint, if
+taken in conjunction with the electro-magnetic character of the Aether.
+Of course, what applies to the earth equally applies to all the other
+planets, as they also are magnets according to Art. 87, so that they
+will also possess their magnetic fields, with their own lines of force,
+and their variations in intensity and magnetic dip.
+
+Hitherto we have only considered the problem of the earth and all the
+other planets, as magnets, from the stationary standpoint, and the
+problem faces us as to what effect the movement of the earth and all
+other planets through the Aether will have upon their magnetic fields,
+and their lines of force. Now from Clerk Maxwell's mathematical
+calculations, we learn that the movement of any magnetic body through
+space will practically have no effect upon the relation of the field,
+and the lines of force to the moving magnet; that is to say, the
+magnetic field and the lines of force move with the earth and the
+planets through space, as they journey round the sun with their varying
+velocity. Maxwell has conclusively proved that the mathematical
+equations for moving bodies in relation to their magnetic lines of
+force, and induction, are exactly the same as the equations for
+stationary bodies, and if this be true, then it follows that the
+physical conditions for both stationary and moving bodies are the same.
+
+On this point Maxwell writes: "By its motions this (moving) matter
+carries with it its lines of force, and electricity and magnetism may be
+regarded as free ends of these lines. Hence when both causes act
+together there can be no relative motion of true magnetism with
+reference to surrounding matter," etc.
+
+"Under these circumstances electricity and magnetism move with the
+matter in which they are present as if they were indestructible and
+adhered firmly to the parts thereof." So that from Maxwell's equations
+and statements we learn that the magnetic lines of force around every
+planet, and every satellite in space, move with the planets in their
+orbits round the sun. But as these magnetic lines of force are composed
+of aetherial atoms, as already indicated, it follows that the Aether
+which is associated with each planet and held bound to it by the
+so-called force of gravity moves with the planet also.
+
+This result is entirely consistent with our experience and observation,
+as we shall see later on. We find that the atmosphere, which is also
+gravitative, moves with the earth, and therefore from experience we are
+compelled to arrive at the conclusion that the Aether which is also
+gravitative moves with each planet, and this result is confirmed by
+mathematical calculations given by Clerk Maxwell, and is in perfect
+harmony with the same.
+
+Here then is the key to one of the problems that has been the subject of
+investigation and research for many years past, and one which is at the
+present time occupying the attention of some of our most advanced
+scientists, viz. the relation of the Aether to moving matter.
+
+That problem was solved by Maxwell from an electric and magnetic
+standpoint, and his result was that the Aether, which we now know to be
+the source of all electricity and magnetism, moves with the moving
+matter. What is more, this result has been confirmed by actual
+experiment made by Michelson and Morley in America, which experiment
+conclusively proves that Maxwell's result is physically correct, and
+that the Aether does move through space with its associated planet, and
+therefore its magnetic field and its lines of force move with it because
+of the electro-magnetic character of the Aether.
+
+[Footnote 37: Art. 2850, _Exp. Res._]
+
+[Footnote 38: Art. 2757, _Exp. Res._]
+
+
+ART. 91. _Solar Magnets._--We have now to attack the problem as to the
+cause of all the satellites and planets, together with the sun, being
+electro-magnets. What is the continuing and ever-acting cause which
+makes all planetary bodies, including the sun, their centre, to be
+permanent magnets? According to the Rules of Philosophy there are two
+causes which would be simple in conception, which are suggested by
+experiment and observation, and both causes would satisfactorily account
+for all the planets being magnets.
+
+The first cause suggested to our minds is, that in view of the fact that
+the sun is an electro-magnet, and therefore possesses a magnetic field
+with its aetherial line of force, all the planets may become magnets by
+the process of magnetic induction, which process has already been
+illustrated by the action of the iron filings placed over the magnet.
+Such a hypothesis would fulfil all the Rules of Philosophy, as it would
+be simple in conception, would not violate experience, and would
+satisfactorily account for the fact sought to be explained.
+
+But such a hypothesis would be based upon the assumption that the sun
+was an electro-magnet, and then we should have to find out the cause of
+that fact also. Hence the hypothesis that the planets are magnets,
+because they are situated in the magnetic field of the sun, is not a
+satisfactory solution of the whole problem, as it fails to account for
+the fact that the sun is also an electro-magnet. We must therefore seek
+for another solution of the problem, which, while fulfilling all the
+Rules of Philosophy as laid down in Art. 3, will also account for the
+sun being an electro-magnet, as well as every planet, satellite, meteor,
+or any other body that exists in space. If we can ascertain such a cause
+by philosophical reasoning, then we may say we have satisfactorily
+solved the problem as to the cause of all planetary and stellar bodies
+being electro-magnets.
+
+If, at the same time, we can solve other outstanding problems by the
+solution thus offered, then such solution is more likely to be correct
+than if it simply solved the problem of solar magnetism. The only other
+solution that can possibly present itself to our minds, as to the cause
+of all magnetism in any planet, sun, or star, is the explanation which
+has already been given in Art. 86 on electro-magnetism.
+
+In that article we learned that magnetism was really due to the circular
+motion of an electric current; and that, whenever and wherever we had an
+electric current moving or revolving with a circular motion, there we
+should always have those conditions which would give rise to an
+electro-magnet. As long as the current continued to flow in its circular
+course, so long would there be those conditions which would give rise to
+permanent magnetism.
+
+Now in the solar system we find that there are these magnets, which have
+been in existence for millions of years. We also learn from the
+electro-magnetic theory of light that Aether has an electro-magnetic
+basis, which gives rise to electro-magnetic waves when disturbed, or set
+in motion by any heated or luminous body. It can readily be seen,
+therefore, that we have only to set this electro-magnetic Aether in
+circular motion around any planet or sun, and we have at once a circular
+current of electricity flowing round that planet or sun, which would
+give rise to those conditions by which any body within its influence may
+be formed into a magnet.
+
+Our hypothesis, therefore, to explain the reason why all the planets and
+the sun are magnets, is that the electro-magnetic Aether moves round the
+sun or planet or satellite as the case may be, thus giving rise to
+currents of electricity around the planet or sun, and so forming those
+conditions in the Aether by which the permanency of any planetary or
+stellar magnetism may be maintained and perpetuated.
+
+In other words, to put it plainly and tersely, each aetherial atmosphere
+revolves round the planet, subject to certain limitations, in the same
+way that the aerial atmosphere turns round with the earth, as that
+planet revolves on its axis. At first sight, such an assumption may seem
+impossible, but a little careful consideration will show not only the
+possibility of such a cause, but will establish it, as the only
+reasonable and philosophical explanation for the phenomena we are
+seeking to explain, viz. the electro-magnetism of all celestial bodies.
+
+There is nothing extravagant in this assumption, as we already have a
+similar illustration in the case of the atmosphere which goes round with
+the earth as it revolves on its axis. We have only to extend the same
+principle a little further, viz. to the aetherial atmosphere, and we at
+once get the true physical conception of the hypothesis suggested to
+explain the magnetism of all celestial bodies. We have already learned
+that Maxwell has proved that the equations for moving magnetic bodies
+are the same as those for stationary bodies, from which we came to the
+conclusion that the electric and magnetic field of any planet goes with
+that planet as it revolves on its axis in its journey round the sun.
+
+I would like to ask the reader to try to conceive of any electric or
+magnetic field traversing space in association with any planet or sun
+which is revolving on its axis, while that electric or magnetic field
+does not revolve either partially or wholly with the revolving body. The
+field can only be stationary relatively to the planet or sun, as it
+revolves with the planet or sun on its axis.
+
+There may be, as there doubtless are, conditions governing that
+revolution, as is the case with the atmosphere moving and revolving with
+the planet, but it is an absolute impossibility for Maxwell's equations
+relating to moving magnetic bodies to be carried to their logical
+conclusion, without affirming some such hypothesis as we have affirmed
+in relation to the cause of all solar magnetism.
+
+Let me at once point out, this solution has already been offered by one
+whose name has been referred to several times. I refer to Professor
+Challis. Let us see what he has to say as to the cause of the earth's
+magnetism. In dealing with this subject, and writing in the _Phil.
+Mag._, 1872, par. 42, he states: "With respect to all magnetism which
+has a cosmical origin, the view I now take is that it is due to
+gyrations of the Aether, produced by the impulses which it receives from
+the motions of the constituent atoms of the bodies of the solar system.
+The gyrations may either be immediately generated by the rotations of
+the bodies about their axes, or directly result from disturbances of the
+Aether caused by their motions of translation. This impressed motion
+will be converted into circulatory or gyratory motion. Such circulatory
+motion will necessarily partake of the motion of translation of the
+bodies which generate them, so as to have always the same geometrical
+relation to these bodies provided their motion be uniform."
+
+In paragraph 46 he continues: "From what has been already argued (42),
+the motions impressed on the Aether by the earth in consequence of its
+rotatory or orbital motions result in circulating motions which would be
+steady motions, having always the same geometrical relation to the
+position of the earth's centre."
+
+Again, Ampere and Faraday were also of the opinion that the magnetism of
+the earth was due to the circulation of electric currents round it, for
+in par. 446, _Exp. Res._, Faraday states: "Assuming with Ampere that the
+magnetism of the earth is due to electric currents circulating round it,
+parallel to the equator."
+
+I think it will be seen from these extracts that the hypothesis
+suggested for all planetary and stellar magnetic bodies is thus
+confirmed by Professor Challis, and by Faraday and Ampere. Professor
+Challis in these passages clearly and definitely points out that there
+are circulatory motions in the Aether, which motions are produced by the
+rotation of the earth or other body on its axis, and that these circular
+motions of the aetherial medium always maintain the same geometrical
+shape relative to the earth's centre. So that we have only to combine
+with his hypothesis the electro-magnetic basis of the Aether, and we at
+once get the circulating currents of electricity constantly flowing
+round the heavenly bodies, which produce and give rise to the permanent
+magnetism of those bodies.
+
+If we desired still further confirmation as to the circulating motions of
+the Aether caused by a rotating body, we find it in the writings of
+Herschel, who in relation to this matter asks:[39] "What is the law of
+density of the resisting medium which surrounds the sun? Is it at rest or
+in motion? If the latter, in what direction does it move? Circularly round
+the sun, or traversing space? If circularly, in what plane? Supposing the
+neighbourhood of the sun to be filled with material fluid, it is not
+conceivable that the circulation of the planets in it for ages should not
+have impressed upon it some degree of rotation in their own direction, and
+this may preserve them from the extreme effects of accumulated
+resistance!" Words like these from one of the most searching intellects of
+the last century are well worthy of our consideration, and the suggested
+effect on the Aether caused by the continued rotation of the earth gives
+us the key not only to the problem of celestial magnetism, but also to the
+other outstanding scientific problems.
+
+For example, there is the problem of the relation of moving matter to
+the Aether around it which still remains unsolved. The physical cause of
+the rotation of the earth, and all other celestial bodies upon their
+axes, with unceasing regularity, still remains to be discovered. The
+physical explanation as to the reason why the earth moves round the sun
+in its orbit according to Kepler's Laws, has yet to be determined, and,
+lastly, there is the relation of the magnetic vibration to the electric
+vibration in connection with the electro-magnetic theory of light still
+to be solved.
+
+Now, presuming that all these can be solved by the philosophical
+hypothesis, that the electro-magnetic Aether circulates round each
+planet and sun and star, that revolves in space, then we are justified
+in our conclusion that such is the true cause of all electro-magnetism
+that exists in connection with planetary and stellar bodies. I venture
+to premise that all these problems can be solved by the simple solution
+here given, and will prove that this solution adequately accounts for
+all the other phenomena referred to.
+
+Before proceeding to do this, we will endeavour to prove this hypothesis
+by an altogether different method of reasoning, in order to confirm the
+statements made in this article. Let us therefore endeavour to form a
+complete view of the physical state of the solar system, and for the
+sake of simplicity we will suppose it to be at rest in space. We shall
+deal with the effect of its motion upon its own planetary system, when
+we explain Kepler's Laws.
+
+We have, therefore, the Sun in the centre (see Fig. 14) of the system,
+with Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus, and
+Neptune revolving round the sun at their respective distances, which are
+subject to variations owing to certain causes which can be
+satisfactorily explained. But circulating round the sun, in the same
+direction as the rotation of the sun on its axis, we have the
+electro-magnetic Aether, with its wide-spreading flow and extensive
+electro-magnetic field. In like manner, we have each planet with its
+aetherial electro-magnetic field, which also circulates round each
+planet in the same direction as the planet revolves, that is, from west
+to east, and in the same direction as the sun's electro-magnetic field
+revolves.
+
+Thus we have to picture the whole of the solar system in a state of
+regular and harmonious rotation, while each planet adds to the harmony
+of the rotation by itself rotating in its own aetherial electro-magnetic
+field, while all rotate in the same direction, viz. from west to east.
+
+Of course there are several objections that can be raised to such a
+hypothesis, and those objections will be briefly dealt with in a
+subsequent article, but I venture to think that this hypothesis is the
+true philosophical explanation of a problem which has formed one of the
+greatest outstanding difficulties in regard to the Aether medium for
+many years, that problem being the relative motion of the Aether and
+Matter. Lord Kelvin, in an article in the _Phil. Mag._ for July 1901,
+entitled "Clouds over the Dynamical Theory of Light," refers to this
+very difficulty, and states there are two clouds over the present
+undulatory theory of light, one of which has reference to the difficulty
+of conceiving a body like the earth or any planet rushing through the
+Aether without subjecting the Aether to enormous laceration, and
+concludes by saying that "we must still regard this cloud as very
+dense." Here, then, is the key to the solution of the problem.
+
+The earth does not rush through the Aether, but the Aether being
+gravitative, it is associated with and bound to each planet, and
+accompanies that planet in its journey though space, rotating with it in
+the same way that the atmosphere does, as we shall prove later on.
+
+This conception is fully in accord with our hypothesis as to the
+physical explanation of the cause of the electro-magnetic character of
+all the heavenly bodies, and indeed is the only physical solution that
+can adequately account for all the varied phenomena hitherto unexplained
+in connection with the celestial mechanism.
+
+From the foregoing statements, we are now in a position to consider the
+term Electro-Kinetic Energy, as used by Clerk Maxwell. What does he mean
+by Electro-Kinetic Energy? Let us see what he has to say about the term
+himself.
+
+In par. 636 of his _Magnetism and Electricity_ he writes: "According to
+our hypothesis we assume kinetic energy to exist wherever there is
+magnetic force, that is, in general, in every part of the field. This
+energy exists, therefore, in some kind of motion of the matter in every
+portion of space;" while again, in par. 569, he states: "The electric
+current cannot be conceived except as a kinetic phenomenon." Even
+Faraday speaks of the electric current as "something progressive, and
+not a mere arrangement" (_Exp. Res._ 283).
+
+Then again in par. 552 he writes: "It appears, therefore, that a system
+containing an electric current is a seat of energy of some kind, and,
+since we can form no conception of an electric current except as a
+kinetic phenomenon, its energy must be kinetic energy, that is to say,
+the energy which a moving body has in virtue of its motion."
+
+Here, therefore, according to Clerk Maxwell, the kinetic energy of an
+electro-magnetic field is nothing more or less than the energy which a
+moving body possesses in virtue of its motion. Any other explanation of
+kinetic energy would be opposed to all the Rules of Philosophy; for
+experience in its widest form incontrovertibly proves that all kinetic
+energy is associated, and alone associated, with a moving body;
+therefore in all electro-magnetic fields there is this kinetic energy
+ever being manifested. We have, however, learned that the solar system
+forms a huge electro-magnetic field, traversed by lines of force, as
+Maxwell and Faraday suggested. Therefore, in the solar system, there
+must be this kinetic energy due to the motion of a moving body, which is
+the electro-magnetic Aether.
+
+We have, however, just arrived at the conclusion that in the solar
+system there is ever going on a circulatory or rotatory movement of the
+electro-magnetic Aether forming currents around each electro-magnet. On
+the hypothesis of an atomic and gravitating Aether we have, therefore, a
+medium or body continually circulating, which medium possesses inertia
+and momentum, and it is philosophically possible for such a rotating
+medium to possess kinetic energy. So that our explanation of this term,
+as used by Clerk Maxwell, is, that this kinetic energy is indeed due to
+the momentum of the moving Aether. Such a hypothesis is strictly
+philosophical, and literally fulfils the statements made by Clerk
+Maxwell himself in the paragraphs already referred to.
+
+A remarkable feature about this hypothesis lies in the fact, that it is
+the very hypothesis that Von Helmholtz suggested as the explanation of
+the term. He came to the conclusion that the kinetic energy was due to
+the momentum of the moving Aether. But with a frictionless Aether such a
+hypothesis, although correct, was philosophically untenable. In view of
+the theory of the Aether presented in this work, however, both Clerk
+Maxwell's and Von Helmholtz's statements find their literal and perfect
+fulfilment. So that in an atomic Aether, which is gravitative because
+atomic, and rotatory because it is gravitative, combined with its
+electro-magnetic basis as proved by Hertz, we find for the first time a
+correct philosophical explanation of one of the most puzzling terms used
+by Maxwell in his greatest work on _Magnetism and Electricity_. This
+solution alone ought to stamp the theory of an atomic and gravitating
+electro-magnetic Aether with that authority that is always associated
+with the names of two such great thinkers and experimentalists as those
+just mentioned.
+
+The fact that the Aether is held bound to a planet has already been
+suggested by Sir G. Stokes to account for the aberration of light
+already referred to. In the _Phil. Mag._, July 1845, he writes: "I shall
+suppose that the earth and the planets carry a portion of Aether along
+with them, so that the Aether close to the surface is at rest relatively
+to the earth, while its velocity alters as we recede from its surface,
+till at no great distance it is at rest in space." Sir G. Stokes does
+not, however, say how the Aether is held bound to the earth, and apart
+from an Aether which is gravitative, no satisfactory explanation can be
+given. Further, it is noticeable, that he suggests that the other
+planets also carry part of the Aether associated with them along with
+each planet as it pursues its journey. It would be distinctly
+unphilosophical to assume that the earth was the only planet that
+carried its aetherial field with it. So that by following Sir G. Stokes'
+suggestion, we practically arrive at the same conclusion in relation to
+the motions of the Aether that we have already arrived at from magnetic
+phenomena.
+
+With this view of the case we are now in a position to answer a question
+asked by Professor Schuster at the British Association in 1892. He
+asked, "Is not every large rotating mass a magnet?" and added, "If it
+is, the sun must be a powerful magnet. The comets' tails, which eclipse
+observations show stretching out from the sun in all directions,
+probably consist of electric discharges." Now, in relation to this
+question, the answer is that every rotating body in the Aether is
+undoubtedly an electro-magnet. Thus, not only is the sun an
+electro-magnet, but every planet and satellite, and every meteor that
+rotates in the electro-magnetic Aether, is converted into a magnet,
+partly by that rotation, and partly by the currents induced in the
+Aether by that rotation. We shall also find when we come to deal with
+the phenomena of comets' tails, that Professor Schuster is also right as
+to their cause, and that they are due to electro-magnetic repulsions
+originated in the Aether by the sun, which is an electro-magnet.
+
+[Footnote 39: _Outlines of Astronomy_, Herschel.]
+
+
+ART. 92. _Cause of Rotation of the Earth on its Axis._--If there is one
+fact true in relation to the earth as a planet, it is that the earth
+rotates on its axis every 24 hours. Day in and day out, for centuries
+past, this revolution has taken place as the earth journeys in its
+annual path round the sun.
+
+Not only does the earth rotate on its axis, but every other planet
+rotates on its axis in varying times, as the following table shows--
+
+                  HRS.  MIN.  SEC.
+
+    Mercury        24     5     0
+    Venus          23    24     0
+    The Earth      23    56     4
+    Mars           24    37    23
+    Jupiter         9    55     0
+    Sarturn        10    14    23
+    Uranus          ?
+    Neptune         ?
+
+Further, the sun also rotates on its axis in a period of 26 days. Here,
+then, are certain phenomena in connection with the solar system, for
+which up to the present no explanation as to the physical cause of
+rotation has ever been offered. Surely there is some physical cause, to
+account for such a rotation, and if there be a physical cause, then the
+problem to be solved is--find the physical cause to account for the
+continuous and ever-recurring rotation of all the planets and the sun on
+their axes, which shall be so effective and continual that, year in and
+year out, the rotation of all the planets may be continued as observed.
+In solving this problem we have to revert to our reason why the earth is
+a magnet. In Art. 91 we learned that the earth and all the other
+planets, and indeed all stellar bodies, were electro-magnets, because
+the electro-magnetic Aether was constantly circulating round them.
+
+If, by accepting this explanation, we can at the same time solve the
+problem of the rotation of the planets, and the sun, on their axes, then
+we shall have further evidence that our hypothesis is the correct one.
+Now let me ask, What is the effect of an electric current continually
+circulating round any magnet in the same way that the electro-magnetic
+Aether continually circulates round the earth, which is a magnet?
+
+To find out what the effect is, we must resort to experiment. Professor
+Lodge, in his _Modern Views of Electricity_, shows us the effect of any
+circulating current of electricity revolving round a magnet. In his
+chapter on Electro-Magnetism he writes as follows: "How does a current
+act on a magnetic pole? Two currents attract or repel each other, two
+poles attract or repel each other, but a current and a pole exert a
+mutual force which is neither attraction nor repulsion. It is a rotatory
+force. They tend neither to approach nor to recede, they tend to revolve
+round each other." "A singular action this and at first sight unique"
+(p. 135). "The two things will revolve round each other for ever. This
+affords and has afforded a fine field for the perpetual motionist, and
+if only the current would maintain itself without a sustaining power,
+perpetual motion in fact would be attained."
+
+Faraday has shown by experiment the action of a current on the magnet,
+and _vice versa_. Faraday, in his description of an electro-magnetic
+apparatus for the exhibition of rotatory motion, shows how the rotation
+of a current round a magnet, and a magnet round a current, may be
+experimentally proved. With the apparatus used he shows that the current
+of electricity may be made to revolve round the pole of the magnet in
+the direction dependent on the pole used, and further, illustrates how
+the magnet may be made to revolve round the current. (Plate 4, Fig. 5,
+_Exp. Res._)
+
+Thus we learn that wherever we have a current constantly circulating
+round a magnet, there we have the conditions by which, according to
+Professor Lodge, perpetual motion may be obtained, that is to say, the
+two will revolve round each other as long as the current is maintained.
+Here then we find in space those very conditions by which perpetual
+motion may be obtained.
+
+We find the electro-magnetic Aether constantly circulating round the
+planetary magnets, with the result that not only will the current
+continue to revolve around the planet, but the planet will continue to
+revolve upon its axis as it revolves round the current. In fact we get
+in space an example of perpetual motion. We know that the rotation of
+the earth on its axis has been in existence for several thousand years,
+and therefore we have a right to assume that it revolved on its axis
+through the untold ages of past geological times as revealed by the
+strata, and rocks of pre-historic ages. Thus the motion must have
+continued, so far as the earth is concerned, at least 100,000,000 years,
+accepting that period as the age of the earth, but no physical reason so
+far as I know has ever been assigned for such continued rotation.
+
+If, therefore, it be true that the joint action of a current and a
+magnet is a rotatory one, then, seeing that in all planetary and stellar
+space we have both these conditions of matter, that is, the
+electro-magnetic aetherial current, constantly circulating round an
+electro-magnet, we have, in space, the conditions by which perpetual
+rotation may be maintained. We have therefore presented to us in that
+joint action, the true cause of the continued rotation of the earth on
+its axis, and therefore of all the planets on their axes, together with
+the sun on its axis; and, if we carry the principle into the stellar
+world, we can philosophically come to the conclusion that the same
+conditions prevail there that prevail in the solar system, with the
+result that we have now a physical cause which fully satisfies all Rules
+of Philosophy to account for certain phenomena which up to the present
+have never yet been accounted for from the physical standpoint. Thus in
+solving the problem of the earth's rotation on its axis, we find greater
+confirmation in the view presented in a previous article as to the
+circulating motion of the electro-magnetic Aether around any and every
+body in space. We shall deal again with the relation of a current and a
+magnet, when we come to the physical explanation of Kepler's Laws.
+
+
+ART. 93. _Vortex Motion._--From Art. 91 we have seen that the
+electro-magnetic Aether possesses a circulating or rotatory motion
+around each central body, and because of this rotatory motion, the body
+is at once converted into a magnet. We have also seen that Professor
+Challis believed in the circulatory or rotatory motion of the Aether, as
+also did Ampere.
+
+Thus we are led back by scientific experiment and philosophical
+reasoning to the conception of vortex motion with which the world was
+familiar in the days of Kepler, Descartes, Huyghens and Bernoulli. There
+is this difference, however, that whereas the vortex motion of those
+philosophers was to displace and do away with Gravitation, the
+circulatory or rotatory Aether suggested by electro-magnetic phenomena
+is to supplement, confirm and establish more firmly than ever the true
+powers and laws of Gravitation Attraction.
+
+Before passing, it will be as well to briefly glance at the conception
+of vortex motion as suggested by Kepler and Descartes and others.
+Whewell on this matter in his _Inductive Sciences_ states that "Kepler
+assumed that a certain force or virtue resided in the sun by which all
+bodies within his influence were carried round him. He illustrated the
+nature of the force in various ways, comparing it to light, and to the
+magnetic power which it resembles in the circumstances of operating at a
+distance, and also of exercising a feebler influence as the distance
+increases." "Another image to which he referred suggested a much more
+conceivable kind of mechanical action by which the celestial motions
+might be produced, viz. a current of fluid matter circulating round the
+sun, and carrying the planets with it like a boat in a stream." Whewell
+adds: "A Vortex fluid constantly whirling round the sun, kept in this
+whirling motion by the sun itself, and carrying the planets round the
+sun by its revolution, as a whirlpool carries straws, could be readily
+understood, and though it appears to have been held by Kepler that this
+current and Vortex were immaterial, he ascribes to it the power of
+overcoming the inertia of bodies, and of putting them and keeping them
+in motion."
+
+Now, as we have seen, the electro-magnetic Aether is not immaterial but
+material, as it is matter possessing mass and inertia, the same as any
+other matter, as Tyndall and Lord Kelvin stated (Chap. IV.). Thus the
+objection to Kepler's immaterial vortices is met and overcome by our
+conception of the Aether (Chap. IV.). Descartes, as Whewell points out,
+asserted, "that a vacuum in any part of the universe is impossible. The
+whole universe must be filled with matter, which must be divided into
+equal angular parts. This matter being in motion, the parts are
+necessarily grounded into a spherical form, and the corners thus rubbed
+off, forming a second or subtle matter. There is besides a third kind of
+matter, of parts more coarse and less fitted for motion. The first part
+makes the luminous bodies as sun and stars, the second part is the
+transparent substance of the skies, and the third part is the material
+of opaque bodies as the earth, planets and comets. We may suppose that
+the motion of these parts takes the form of revolving circular currents
+or vortices. By this means the first matter will be collected to the
+centre of each vortex, while the second or subtle matter surrounds it,
+and by its centrifugal effect constitutes light. The planets are carried
+round the sun by the motion of the vortex, each planet being at such
+distance from the sun as to be in a part of the vortex suitable to its
+solidity and mobility. The satellites are in like manner carried round
+their ordinary planets by subordinate vortices."
+
+It would almost seem from this quotation that we had adopted purely and
+simply Descartes' and Kepler's ideas _in toto_, whereas the truth is
+that the hypothesis of a rotating electro-magnetic Aether has been
+arrived at by following Newton's own Rules of Philosophy, and by
+discarding everything not in harmony with experience and experiment.
+
+Further, Descartes was unable to give, or explain the ellipticity of the
+orbits of planets, and had to assume that there were elliptic vortices.
+When we come to deal with Kepler's Laws, and their physical
+interpretation, the correct solution of this problem will be given from
+a purely experimental and philosophical standpoint, and in a way and
+manner never suggested by Descartes or any other believer in the theory
+of vortices as then known and understood. Indeed there is no objection
+to the theory of vortices, which cannot be satisfactorily explained by a
+rotating electro-magnetic Aether, as we shall see when we deal with
+Newton's Laws of Motion and Kepler's Laws.
+
+Both Liebnitz and Huyghens were believers in the theory of vortices, and
+the fact that Huyghens' undulatory theory of light stands to-day as an
+accepted theory, is conclusive evidence that he was a philosopher of the
+highest order, and his adhesion to the theory of vortices proves that he
+was convinced that there was some truth in it.
+
+It is a result greatly to be desired, therefore, if it can be
+demonstrated, that in the Aether there is this rotatory motion
+continually going on around every planet, satellite, sun or star;
+because it will then join together, in perfect harmony, two great
+theories in relation to celestial phenomena, that contended with each
+other for supremacy for very many years.
+
+It will prove that, after all, men like Kepler, Descartes, Huyghens, and
+Bernoulli had caught glimpses of the great truth which was partly
+revealed by celestial phenomena, and that it was only for lack of data
+that they were unable to successfully compete with Newton's mathematical
+genius, by which he was able to bring his Law of Gravitation safely
+through the conflict with the simpler conception of aetherial vortex
+motion. Of course certain objections will have to be met and answered
+before this aspect of aetherial dynamics can be expected to supplant the
+more cumbrous and somewhat intricate mathematical laws of motion, but I
+shall prove later on, that all these objections can be answered from a
+satisfactory standpoint.
+
+So that if a modified form of aetherial vortex motion can be
+successfully demonstrated to exist in the electro-magnetic Aether, then
+we shall see the conflict that waged about two hundred years ago,
+brought to a satisfactory issue, in the union of the two greatest
+philosophic theories for the explanation of celestial phenomena that the
+world has ever seen.
+
+From that union, therefore, there will then emerge a truer, simpler, and
+yet grander conception of the motions of the universe, which, when
+perfected by abler minds, will be as perfect a theory as human
+intelligence and philosophy can make it. So that, what an atomic and
+gravitative Aether has done for Newton's corpuscular theory of light, in
+showing that it can be united and combined with the undulatory theory,
+and by such combination, for the first time, such phenomena as the
+transverse action of light can be probably demonstrated and explained,
+together with other phenomena relating to reflection and refraction of
+light, the enlarged conception of a rotating electro-magnetic Aether will
+do for the two great theories that vied with each other for supremacy
+for so many years. Thus it will be shown that the philosophers like
+Kepler, Descartes, and Huyghens, the former of whom has stamped his name
+on the three laws that bear his name to-day, and the latter who gave us
+the inception of the very theory that overthrew Newton's theory of
+light, had after all a more or less true philosophic conception of the
+physical mechanism of the solar system and of the universe at large.
+
+
+ART. 94. _Relative Motion of Aether and Matter._--There is hardly any
+subject of greater importance which is engaging the attention of
+scientists at the present time, than the question as to what is the
+relative motion of Matter to the Aether in which it moves.
+
+I venture to premise the successful solution of the problem will be
+accompanied with the greatest advance to science that has been known for
+a long time. The problem to be solved may be stated thus: "Does the
+Aether surrounding a planet or sun or any body in space move with that
+body, or does it allow the body to pass through it?"
+
+Up to the present, opinions on the subject have been varied and
+conflicting. Some scientists hold that the planetary and other bodies in
+space pass through the Aether without disturbing it, while others hold
+that part of the Aether is carried along by the moving planet. Fresnel
+assumed that the surrounding Aether was carried along by the earth, so
+that all relative phenomena would be the same as if the earth were at
+rest. Fizeau, from experiments which he conducted on running water, also
+came to the same conclusion.
+
+With the old idea of a frictionless medium, some of the present accepted
+theories are altogether untenable, because, if Aether is frictionless,
+how can it be carried along with the moving body, unless it is held
+bound to that body? and how can it be held bound to that body if it is
+frictionless?
+
+The whole view of the Aether is, however, changed by the conception of
+the Aether put forward in Chapter IV. Aether is Matter, and being matter
+it is also gravitative, and therefore is just as much subject to the Law
+of Gravitation as any other kind of matter, as Young stated in his
+Fourth Hypothesis (Art. 45).
+
+We will therefore attack the problem of the relative motion of the earth
+and the Aether around it from this new standpoint. In order to be
+strictly philosophical, we must base our hypothesis and conception on
+experience and observation. Where in the whole of planetary phenomena do
+we find similar conditions which exist between the Aether and the earth?
+Such conditions are alone to be found between the atmosphere and the
+earth. The analogy between the atmosphere and the earth, and the Aether
+and the earth is very striking, as the following comparisons will prove.
+
+The atmosphere (when pure) is invisible, so is the Aether. The
+atmosphere is atomic, the Aether is also atomic. Both are subject to the
+same laws of elasticity and density, and both are gravitative, according
+to our conception of the Aether. Now what is the effect of any large
+revolving body on a liquid or gaseous medium surrounding that revolving
+body?
+
+If experience is any guide, we learn that the motion of the revolving
+body is either partially or entirely transmitted to the liquid or
+gaseous medium surrounding such a body. So far as our experience teaches
+us anything, it teaches us that to that rule there is no exception, and
+no experiment can be devised of any body revolving in water or a gaseous
+medium as air, without that body imparting its rotation to the water or
+the air. The atmosphere in relation to the earth is no exception to this
+rule. We know that the earth has an equatorial circumference of about
+24,000 miles, and that it revolves on its axis once every day, so that
+at the equator the surface of the earth is whirling round in space at
+the rate of 1000 miles per hour.
+
+Try to conceive what the result would be if the atmosphere were
+stationary at the earth's surface in the equatorial regions. It would
+mean that any body on its surface would be whirled round at that rate,
+while the atmosphere, being stationary, would exert a power equal to a
+wind travelling at the rate of 1000 miles per hour.
+
+Under the influence of such a hurricane, nothing could exist on the
+surface of the earth at the equator, if the earth revolved on its axis
+and the atmosphere did not participate in that motion. But the
+atmosphere is gravitative, and being gravitative, it is not only held
+bound to the earth as it revolves on its axis in its onward rush through
+space, but accepts the revolving motion of the earth, with the result
+that as the earth revolves on its axis, the atmosphere revolves also.
+
+Thus a balloon at the equator if allowed to rise several hundred feet
+above the surface could remain comparatively stationary if held by a
+rope to overcome its tendency to rise, whereas such an event would be
+impossible if the atmosphere failed to receive only half of the motion
+of the earth's surface, as it would still have a power equal to that of
+a wind blowing at the rate of 500 miles an hour. If, however, we come
+further north, or go further south, then we find that the surface of the
+earth does not have the same velocity as at the equator, with the result
+that the atmosphere has not the same velocity either; consequently it
+would travel slower in the temperate regions than in the equatorial
+regions, and slower still at the poles than in the temperate regions.
+
+We know by experiment what the effect of increased velocity has upon any
+whirling body; it tends to enlarge the body at those parts where the
+velocity is the greatest, the consequence being that the bulging out of
+the atmosphere would be greatest at the equator. We find a similar
+result in the shape of the earth, where the equatorial diameter is
+greater than the polar diameter, because of the centrifugal force being
+greatest in the equatorial regions.
+
+We have, therefore, to apply these facts to the aetherial medium which
+surrounds all planetary and stellar bodies in the same way as the
+atmosphere does; and which, being also gravitative, is equally subject
+to the same laws of motion. We have seen, therefore, that not only does
+the earth revolve on its axis, but that the atmosphere revolves on its
+axis also, and that the velocity of its revolution is greatest in the
+equatorial regions, the atmosphere spreading or bulging out in those
+parts more than in any other part of the earth's surface.
+
+Let us suppose that the atmosphere extends 200 miles above the earth,
+and that there we come to the pure Aether of universal space. In view of
+the fact that Aether is Matter, and therefore gravitative, it is
+reasonable and logical to conclude that exactly the same result follows
+in relation to the atmosphere and the Aether at that height, as follows
+in relation to the earth and the atmosphere 200 miles beneath.
+
+Unless this view is accepted, we should then have our second Rule of
+Philosophy violated, as we should have matter revolving in more rarefied
+matter, and failing to impress upon that rarefied condition of matter
+the motion either partially or wholly which it itself possesses; and
+such a result being contradictory to all experience cannot be admitted
+from a philosophical standpoint.
+
+Therefore, the only solution is, that the rotating atmosphere imparts
+some of its motion to the aetherial atmosphere, which in its turn
+rotates, and that that rotation is governed by exactly the same
+conditions as govern the relation that exists between the earth and the
+atmosphere. Therefore the Aether in space associated with each planet or
+satellite or sun or star, rotates with the rotating body, and that
+rotation imparts to the Aether a greater bulging out in the equatorial
+regions of the aetherial atmosphere than in any other part thereof. It
+is interesting in relation to this point to note Herschel's view of the
+effect of the rotation of any body upon the Aether. In his _Outlines of
+Astronomy_, in a note, p. 358, he states: "Supposing the neighbourhood
+of the sun to be filled with a material fluid; it is not conceivable
+that the circulation of planets in it for ages should not have impressed
+upon it some degree of rotation in their own direction, and this may
+preserve them from the effects of accumulated resistance."
+
+In this way we arrive at the conception of the motions of the Aether
+suggested by Prof. Challis from the magnetic character of the earth,
+which he thought were due to aetherial currents circulating around it,
+and we learn that such physical conception of the Aether fully agrees
+with the explanation of celestial bodies being electro-magnets; because,
+we have only to add to our rotating Aether that which it has been proved
+to possess, viz. an electro-magnetic basis, and we have at once the
+currents of electricity circulating round the earth and other planetary
+or solar bodies, by which is obtained the true explanation of the
+permanent magnetism of all celestial bodies.
+
+Now to some minds unconversant with scientific research and knowledge,
+such a supposition may seem to be incredible, but that incredibility may
+disappear, when I say that the fact that the Aether is bound to the
+earth, and goes along through space with it, has actually been proved by
+some of the most delicate and successful experiments that have been made
+in recent times: experiments of which Lord Kelvin has stated that he can
+find no error or flaw in them. I refer to the scientific experiments of
+Michelson and Morley of America. For full particulars of these
+experiments I must refer the reader to the _American Journal of
+Science_, 1886, vol. 31, or to the _Phil. Mag._, vol. 44.
+
+The conclusion which is arrived at from their experiments is, that the
+Aether is carried along with the earth as it rushes on its journey
+through space. Of course such a result is altogether opposed to the
+ordinary conception of a frictionless medium, and indeed to any
+conception of the Aether except to that submitted in this work, which is
+also in harmony with Young's Fourth Hypothesis (Art. 45).
+
+So that Michelson's and Morley's experiment is a direct experimental
+demonstration of the fact that Aether is gravitative, and because it is
+gravitative, it is carried along with the earth, as that planet journeys
+through space. It further conclusively proves that not only is the
+Aether carried along with the earth, but that the Aether circulates
+round the earth in the same way that the atmosphere circulates round the
+earth.
+
+This result naturally follows from the experiment, because, if it were
+carried along by the earth and yet did not rotate with the atmosphere,
+then we should have a result opposed to all experience and experiment,
+as these teach us that when a body revolves in a medium which is held
+bound to that body by Gravitation, the medium so held bound participates
+in the rotation of the revolving body.
+
+So that in Michelson's and Morley's experiment we have experimental
+evidence of the fact, already stated, that the Aether circulates round the
+earth, and therefore, in view of the electro-magnetic character of the
+Aether, this circulation results in the production of magnetism in all the
+planets, and other bodies around which it circulates.
+
+Thus not only does the Aether circulate round the earth, but it also
+circulates around every other planet, and not only round every other
+planet, but equally so around every sun and star, as stated in Art. 91.
+
+These results are perfectly consistent with philosophical reasoning, and
+any other result would be inconsistent with the analogies presented to
+us by the phenomena of the Aether in relation to our earth as
+ascertained by experiments made by the scientists referred to. Thus for
+the first time the experiment is brought into harmony with our
+Philosophy, which up to the present has not been the case, a result
+which at once stamps the experiment with that validity of truth and fact
+which will ultimately win for it universal acceptance and favour.
+
+We are now in a position to answer some queries regarding the motions of
+the Aether asked by Herschel in his work on _Astronomy_, p. 345. These I
+give with the answers opposite.
+
+
+              QUERIES.             |          ANSWERS.
+                                   |
+  1. What is the law of density    |  The Law of Gravitation
+     of the resisting medium which |  (Art. 45).
+     surrounds the sun?            |
+                                   |
+  2. Is it at rest or in motion?   |  In motion.
+                                   |
+  3. If the latter, in what        |  Rotates round the sun.
+     direction does it move?       |
+                                   |
+  4. Circularly round the sun      |  Both, as it circulates round
+     or traversing space?          |  the sun while that body
+                                   |  traverses space.
+                                   |
+  5. If circularly, in what        |  The plane of the ecliptic.
+     plane?                        |
+
+
+ART. 95. _Physical Explanation of the Vibration in the Electro-Magnetic
+Theory of Light._--In Art. 78 we learned that light was an
+electro-magnetic disturbance in the Aether which was propagated through
+the Aether, with a finite velocity; and from this we gathered that light
+waves were nothing more or less than electro-magnetic waves, which were
+radiated from the sun, out into the Aether on every side.
+
+We were unable, however, at that time to give a definite physical
+conception of the aetherial vibrations, or of the relation of the
+various types of vibration to each other. Since, however, the
+development of the Aether from the electric and magnetic standpoint,
+which has led us up to the fact that the Aether possesses a circulating
+motion round the sun (Art. 91), the solution of the problem appears
+probable. I am of the opinion that the physical conception of the
+various vibrations to each other is now within the region of
+possibility, and in this article I wish to endeavour to give what seems
+to me to be a correct and philosophical explanation of this part of the
+electro-magnetic theory of light, the physical conception of which up to
+the present has not been generally understood.
+
+The explanation may, or may not, be fully complete, but even if it be
+not perfectly correct, I am convinced that it will ultimately lead to a
+satisfactory physical explanation of this part of Maxwell's Theory of
+Light. In forming a conception as to the physical character of the
+vibrations in the electro-magnetic theory, we have to remember that
+there are three distinct vibrations, or motions, concerned in this
+theory.
+
+[Illustration: Fig: 22.]
+
+    1st. There is the direction of propagation.
+
+    2nd. There is the direction of the electric vibration which is
+         at right angles to the direction of propagation.
+
+    3rd. There is the direction of the magnetic vibration or
+         motion which is at right angles to both of the other two.
+
+Now we have seen that the direction of propagation of any aetherial
+light ray, is that of a straight line from the sun corresponding to the
+radius vector (Art. 76). We have also seen that the front of a light
+wave is really that of a spherical shell (Art. 71).
+
+We have also learned that the electric and the magnetic vibrations are
+in the wave front, so that these two vibrations, which are at right
+angles to each other, are to be found on the surface, so to speak, of
+each aetherial spherical shell, that surrounds the sun with
+ever-decreasing density, and ever-decreasing elasticity.
+
+Let us try to picture the actual fact by an illustration. Let _S_ be the
+sun, with concentric spherical aetherial shells surrounding it (Fig.
+22). Then _S_ _A_ and _S_ _C_ will be rays of light being radiated out
+from the sun, and the magnetic and electric vibrations have to be both
+at right angles to the line of propagation and in the wave front; the
+wave front being represented by the circular lines showing the section
+of the concentric shells running north and south.
+
+Now how can we picture these two motions at right angles to each other,
+and yet both at right angles to the line of propagation? First, let us
+take three straight lines and see how this may be done (Fig. 23).
+
+Let _A_ _B_, _A_ _S_ be two straight lines at right angles to each
+other, and _A_ _C_ another straight line at right angles to both. This
+can only be done by making _A_ _C_ perpendicular to the plane of the
+paper, and can be illustrated by supposing that it represents a pencil
+or pen placed upright on the paper, the point of the pencil being at
+point _A_. If this be done, then not only will _A_ _B_ and _A_ _C_ be at
+right angles to each other, but both will be at right angles to _A_ _S_,
+which corresponds to the line of propagation.
+
+[Illustration: Fig: 23.]
+
+Now refer to Fig. 22, and we shall see that the line _A_ _B_ and the
+boundary of the shell will practically correspond. So that any section
+of a spherical wave front will always be at right angles to the ray of
+light. But we have learned from Art. 89 that these sections of the
+aetherial spherical shell are really identical with Faraday's Lines of
+Force, with the result that along any line which stretches from the
+North pole of the sun to the South pole, there will ever be an electric
+vibration, which is put into motion by the elasticity of the aetherial
+vortex atoms. So that on every side of the sun there is ever going on
+this electric vibration, along the lines of force which correspond to a
+section of the aetherial shell, the surface of which really constitutes
+the wave front.
+
+Therefore it can readily be seen, that, as these lines are at right
+angles to the propagation of the ray of light, the electric vibration is
+at right angles to the lines of propagation, and is thus in accordance
+with the result demanded by Maxwell's theory.
+
+We have now to give a physical conception of the magnetic vibration or
+motion of the Aether, and this has to be at right angles to both the
+electric vibration and the line of propagation.
+
+In Art. 91 we have learned that the Aether possesses a rotatory motion, by
+which it rotates round the central body of the solar system, the sun. So
+that if we take any point, for example, in the path of the ray as _S_{1},
+_S_{2}, _S_{3}, and _S_{4}, situated upon some definite equipotential
+surface or lines of force, and if we will imagine those lines to rotate
+round the sun, as the sun rotates on its axis, then in time the points
+will have described half the circle, and will come to the position on the
+right of the sun indicated by the same Nos. _S_{1}, _S_{2}, _S_{3},
+_S_{4}. Thus there has been an aetherial motion at right angles to the
+electric motion, as the Aether circulates round the sun, because this
+motion may be represented as taking place from west to east of the sun,
+while the electric vibration takes place from north to south, or
+transverse to the line of propagation.
+
+We have, however, learned that the Aether has an electro-magnetic basis,
+and therefore the rotation of the Aether gives rise to electro-magnetic
+currents; hence the motion west to east is really the motion of
+electro-magnetic currents which circulate round the sun. As these are at
+right angles to the line of propagation, and we have seen that they are
+at right angles to the electric vibration, it follows that all three are
+at right angles to each other, which is in accordance with the
+requirements as laid down by Maxwell.
+
+We have considered these vibrations, first, from the view of the solar
+system as a whole in its relation to the universal Aether; but the same
+principle holds good if considered from the aetherial atomic standpoint.
+For if we take a line of force, composed as it is of aetherial vortex
+atoms, and suppose them to be rotating, we know that by that rotation
+there will be a tension due to that rotation, and Maxwell has shown this
+tension is due to magnetism, as in his standard work he says: "This
+magnetic force is the effect of the Centrifugal Force of the Vortices."
+
+So that by postulating a rotatory movement for the Aether around the
+sun, as we have done in Art. 92, we have not only solved the problem of
+all planetary and solar magnetism, but we have also solved the problem
+of the relative motion of the Aether and the earth, and also given for
+the first time (though it may be in an incomplete form) a physical
+explanation of that part of the electro-magnetic theory of light, which
+has hitherto been unexplained from the purely physical standpoint.
+
+Such results, therefore, supported as they are by the direct experiment
+of Michelson and Morley of America, justify us in concluding that the
+conception of a rotating Aether is not only philosophically correct, but
+is in actual accord with experimental investigation and research, as
+indeed it ought to be.
+
+
+
+
+                               CHAPTER X
+
+                  AETHER AND NEWTON'S LAWS OF MOTION
+
+
+ART. 96. _Centrifugal Force._--Before proceeding to apply some of the
+principles and laws which govern the electro-magnetic aetherial medium
+to solar and stellar phenomena, it will be as well just to review the
+conception of our new aetherial Centrifugal Force, so that we may form a
+right view of it in its completeness and entirety.
+
+In Art. 11 we premised that there was in existence another force, which
+was the exact opposite of the centripetal force, and that this force was
+the complementary and counterpart of the centripetal force or
+Gravitation Attraction; and further, that this force was due to the
+motion of the universal Aether which filled all space.
+
+In Art. 13 we saw that all force resolved itself into energy of some
+kind, the same being due either to potential energy, _i. e._ energy of
+position, or to kinetic energy, which is the energy belonging to matter
+actually in motion. From Art. 56 we learned that all energy was energy
+of motion, so that all force resolves itself into motion of some kind.
+
+Thus our term Centrifugal Force really implies, and demands, a motion of
+the Aether which is ever directed away from the centre of gravity of any
+body, whether that body be an atom or molecule, satellite or planet, sun
+or star. From the phenomena of heat we have seen that there exists a
+repulsive motion, due to the aetherial medium, which is ever exerted
+from the central body of any atomic, planetary or stellar system, that
+repulsive motion being due to the pressure of the universal Aether,
+which not only surrounds all atoms, but also surrounds all other bodies
+in the universe.
+
+From the phenomena of light we have also seen that the Aether possesses
+a repulsive or centrifugal motion, which is also due to the pressure of
+the same Aether as mathematically proved by Maxwell, and experimentally
+proved by Prof. Lebedew, and Nichols and Hull of America. Further, from
+the phenomena of electricity, we have also seen that there exists this
+centrifugal motion, due to the pressure of the same aetherial medium,
+which pressure is ever directed away from the electrified body, as the
+sun or planets.
+
+So that from these three phases of the universal Aether, that is, from
+its thermal or heat manifestation, its luminiferous or light
+manifestation, and its electro-magnetic manifestation, we get
+irrefutable evidence of the existence of a centrifugal motion, which
+motion is ever directed away from the central body; and the result of
+that motion takes the form of a pressure upon any body with which the
+motion comes into contact.
+
+Again, it was premised, that such a centrifugal force or motion must
+fulfil all the laws which governed the centripetal force or motion.
+
+First, it had to be universal (Art. 19). Second, it had to follow
+exactly the same path as the centripetal force or motion, which was that
+of a straight line joining the centre of gravity of two bodies, as for
+example the earth and the sun (Art. 20). Third, the centrifugal force or
+motion must be equal to the product of the masses, in the same way that
+the centripetal force was governed by such a law (Art. 21). Fourth, its
+intensity was to be governed by the law of inverse squares, the same as
+the centripetal force or Gravitation Attraction was governed (Art. 22).
+
+Now all these conditions are satisfactorily fulfilled, and have been
+shown to be satisfactorily fulfilled, from the phenomena of heat, light,
+and electricity in their relation to the universal Aether. For in Art.
+43 we saw that the Aether was universal, and therefore if the
+centrifugal motion is produced and originated by the Aether, then such
+motions must be as universal as that medium, which under qualifying
+conditions gives rise to these motions.
+
+From Arts. 65 and 76 we have learned that the path of this centrifugal
+motion is that of a straight line, and follows exactly the same path
+that the centripetal force of gravity takes. In Art. 85 we learned that
+the centrifugal force between any two bodies was equal to the product of
+their masses, which is exactly the same as the centripetal force that
+exists between any two bodies; and, lastly, from the phenomena of heat,
+light, and electricity we learned that the intensity of this centrifugal
+motion due to aetherial pressure was inversely as the square of the
+distance, which is the law governing the intensity of its counterpart,
+the centripetal force. Thus we have learned that there is in existence
+throughout universal space, a physical force or motion due to a physical
+medium, the universal Aether, which force or motion is the exact
+opposite of the centripetal force or Gravitation Attraction, which may
+be stated as follows--
+
+Every particle in the universe repels every other particle with a force
+whose direction is in the line joining the centres of gravity of the two
+bodies, and whose magnitude is directly as the product of their masses,
+and inversely as the square of the distance between them, at their mean
+distances.
+
+We shall see that it is by the conjoint working of these two forces, the
+Centripetal and Centrifugal, in combination with other motions of the
+Aether, that the harmonious working of the whole celestial mechanism is
+maintained and perpetuated. In confirmation of the existence of the
+centrifugal force, I should like to draw the attention of the reader to
+certain phenomena relative to the solar system, which phenomena violate
+the centripetal force as at present recognized, and can alone be
+accounted for by the existence of another force or motion existing in
+space, such as the centrifugal motion already proved and demonstrated.
+
+We know that the law governing the centripetal force, or Gravitation
+Attraction, is regulated by the product of the masses of the two
+attracting bodies. So that if there were three bodies in space whose
+masses are respectively represented by 2, 3 and 100, the proportion of
+the attractive force of gravitation between the largest and the other
+two, would be 200 (100 x 2) and 300 (100 x 3) respectively. So that if
+the centripetal force, or the Attraction of Gravitation, is the only
+governing force in the universe, then it naturally follows that the two
+bodies, between which the attractive force is greater, will be closer
+together than the two bodies between which the attractive force is less.
+
+Thus the two bodies, whose product of their masses is represented by
+300, will, according to the Law of Gravitation, be closer together than
+the two bodies, the product of whose masses is represented by only 200.
+Unless this is so, we should have a violation of the Law of Gravitation,
+and it would at once cease to be a law.
+
+Let us therefore apply the centripetal force, or Gravitation Attraction,
+to the solar system, and see how it works out. The law strictly defined
+is given in Art. 18, from which we learn that the attractive force
+between two bodies is as the product of their masses. Now what are the
+masses of some of the bodies in the solar system?
+
+We find that the sun, with its diameter of 865,000 miles, is about
+324,000 times greater in mass than our earth, so that it would take
+about 324,000 bodies of the size and density of our earth to equal a
+body of the size and density of the sun. It has been calculated,
+however, by Von Asten, from observations made on comets by the planet
+Mercury, that the mass of Mercury is about 1/24 of the mass of the
+Earth. Therefore the mass of the sun must exceed the mass of Mercury
+324,000 x 24 = 7,776,000; the exact relation according to Von Asten is
+7,636,440. Again, the planet Jupiter, with its diameter of 85,000 miles
+and its density of 1.38, is only 1/1048 part of the mass of the sun, so
+that it would take about 1048 Jupiters to equal the mass of the sun,
+therefore Jupiter must weigh about 7400 times the mass of Mercury.
+
+If the mass of Mercury, therefore, be represented by 1, the mass of the
+Earth would be represented by 24, the mass of Jupiter by 7400, and the
+mass of the sun by 7,636,400. So that the attractive forces between the
+planets as regards their masses only will be represented numerically as
+follows--
+
+    Sun and Mercury    7,636,400 x 1      =       7,636,400.
+
+    Sun and Earth      7,636,400 x 24     =     190,008,000.
+
+    Sun and Jupiter    7,636,400 x 7,400  =  56,435,360,000.
+
+Thus we see that the attractive force between the sun and the earth
+exceeds 24 times the attractive force between the sun and Mercury, while
+the attractive force of gravity between the sun and Jupiter is 7400
+times greater than the attractive force between the sun and Mercury,
+relative to their masses.
+
+Therefore, according to the Law of Gravity, as regards the masses of
+bodies, Jupiter and the sun should be nearer together than Mercury and
+the sun, because their attractive powers are greater, and the earth and
+the sun should be nearer together than Mercury and the sun, because
+their joint attractive powers are also greater. In the same way it can
+be proved that all the other planets whose masses are greater than
+Mercury ought, according to the Law of Gravity in regard to masses only,
+to be nearer to the sun than what Mercury is, simply because the total
+attractive forces between any two are greater than the attractive force
+between Mercury and the sun.
+
+The respective masses of the planets compared with the sun, taking the
+mass of the sun as unity, are as follows--
+
+    Jupiter  1/1,048  of mass of sun.
+
+    Saturn   1/3,529     "  "
+
+    Neptune  1/18,520    "  "
+
+    Uranus   1/22,020    "  "
+
+    Earth    1/324,439   "  "
+
+    Venus    1/397,000   "  "
+
+    Mars    1/2,994,790  "  "
+
+    Mercury 1/7,636,440  "  "
+
+Therefore, if the total attractive force of gravity is equal to the
+product of the masses of any two bodies, then the planets ought to be in
+the following order in relation to their distance from the sun: Jupiter,
+first, followed by Saturn, Neptune, Uranus, Earth, Venus, Mars and
+Mercury; that being the order in which the attractive power of gravity
+is regulated by their respective masses.
+
+Yet the very opposite is nearly the case, as we find that some of the
+further planets, as Jupiter, Saturn, Uranus and Neptune, possess greater
+masses than any of the nearer planets; so that here we have a distinct
+violation of the Law of Gravitation Attraction, which states that the
+attraction between any two bodies is directly as the product of their
+masses, because we find certain bodies with greater attracting powers
+further away from the sun, than other planets possessing less attracting
+powers, because of their smaller masses. I cannot recall having ever
+read of any explanation which has been given for such an anomaly, and
+indeed this apparent violation admits of no other explanation than the
+conception of the dual character of the so-called Law of Universal
+Gravitation, which includes a repelling or repulsive force or motion,
+such motion being due to the pressure of the universal Aether.
+
+Thus in the light of the centrifugal motion, combined with the fact that
+Aether is gravitative, by which each body possesses an aetherial
+atmosphere and electrical equivalent proportionate to its mass, it can
+be demonstrated within a reasonable limit how it is that such planets as
+Jupiter, Saturn, Uranus, Neptune, possessing aetherial atmospheres and
+electrical equivalents proportionate to their masses, revolve in orbits
+round the sun at much greater distances than Mercury, Venus, the Earth,
+or Mars. This explanation will follow as we consider the Centrifugal
+Force and the Centripetal Force in their relation to Newton's Laws of
+Motion.
+
+
+ART. 97. _Centripetal Force._--We have now to apply the Centripetal
+Force, together with the new Aetherial Centrifugal Force, to the solar
+system, and show that by their conjoint working taken in conjunction
+with the motions of the Aether, all celestial phenomena may be
+satisfactorily explained on a physical basis, in a similar way that
+Newton proved the same result from the mathematical standpoint.
+
+We saw in Art. 10 that the centripetal force was really none other than
+the Attraction of Gravitation, in that it always acted to a centre, and
+in no other way, and therefore by the centripetal force for the present
+we must understand is meant the attractive power of Gravitation.
+
+Afterwards, when it has been demonstrated that the centripetal force and
+the new aetherial centrifugal force can account for all celestial
+phenomena, then we shall be in a position to show what the physical
+cause of the centripetal force is.
+
+Let us again refer to the centripetal force, so that we may see exactly
+what its governing conditions are. In Art. 18 we learned that this force
+might be thus expressed: "Every particle of matter in the universe
+attracts every other particle with a force whose direction is that of a
+line joining their centres of gravity, and whose magnitude is directly
+as the product of their masses, and inversely as the square of the
+distance between them." Now we have seen from the previous Art. that the
+centrifugal force due to the pressure of the Aether medium is the exact
+counterpart of this, in every way, so that if we combine the two, we get
+the complete statement of the universal law which governs all matter,
+and which we may define as follows--
+
+"Every particle in the universe attracts and repels every other
+particle in the universe with a force whose direction is that of a line
+joining their centres of gravity, and whose magnitude is directly as the
+product of their masses, and inversely as the square of the distance
+between them." This complete law, however, only holds good when the two
+forces are in equilibrium.
+
+With this conception of the universal law which governs all matter, the
+harmony and stability of the universe becomes possible from the physical
+standpoint. Apart from this conjoint working of the two forces or
+motions, a physical explanation of Universal Gravitation is impossible,
+as with one force operating only throughout the universe, ultimate
+stability is inconceivable, and the harmony of the spheres might at any
+time be suddenly destroyed.
+
+With this conception of the universal law which governs all matter, the
+great Law of Gravitation is brought into harmony with all experience and
+observation. Look where we will, or at what we will, there we find
+forces possessing a dual character, as we have already seen proved.
+Professor Tyndall, as we have already learned (Art. 63), definitely
+states that the stability of atomic systems is preserved by the
+existence and operation of _two forces, one attractive and the other
+repulsive_, and what is true of the atomic world is equally true of
+solar or stellar worlds. Thus for the first time in this respect, our
+philosophy agrees with our experience, and the true relation of the
+centrifugal force or motion to the centripetal force is made manifest.
+So that, wherever in the solar system the centripetal force or
+Gravitation Attraction operates, there, with exactly equal intensity and
+power, the aetherial centrifugal force operates, at the respective mean
+distances of the planets and satellites, where the two forces are in
+equilibrium.
+
+If it were possible to conceive of a stationary solar system, then, by
+the conjoint working of the two forces, it would be equally possible to
+conceive of perfect stability and harmony existing between the
+respective planets and satellites of that system while stationary.
+
+Such a conception is altogether impossible in the present state of
+Philosophy, as the stability of the system, with the old view of the
+Centrifugal Force, is entirely dependent upon the motions of the
+respective bodies in that system; and if such orbital motions could be
+stayed, then the only physical conception possible would be, that every
+planet and satellite, planetoid and meteor within the attractive force
+of the central body, the sun, would be slowly but surely drawn to a
+fiery death, as they would all ultimately be attracted and swallowed up
+by the sun.
+
+Thus we learn, that while the sun is the centre of a centripetal force,
+which ever operates far and wide throughout space, it is equally the
+centre of a repulsive or centrifugal force or motion which also operates
+co-extensively and co-equally with the former.
+
+Not only so, but every planet and satellite, nay every particle and
+every atom, while it is the centre of a centripetal force, is also the
+centre of a repulsive force, as pointed out by Professor Tyndall, which
+force is due in each and every case to the pressure of the aetherial
+atmosphere which surrounds the atom or molecule, satellite or planet.
+Thus the physical conception of heat in its effect on molecules having a
+repulsive force (Art. 63) is confirmed, and that that force is due to
+the pressure of the Aether is also confirmed by subsequent
+investigations into the phenomena of light and electricity, by which we
+have arrived at our physical conception of the Universal Centrifugal
+Force.
+
+So that we have now a physical conception of the experiment performed by
+Nichols and Hull of America, and by Professor Lebedew of Russia, in
+which they conclusively demonstrated the existence of the pressure of
+aetherial light waves, which proves beyond the possibility of doubt the
+existence of this physical centrifugal force. Every atom and molecule,
+therefore, is the centre of two forces, which co-exist together, and
+every meteor and satellite and every planet is also the centre of the
+same two forces, and this we shall find in its application to planetary
+phenomena will have a most important bearing on the physical conception
+of those phenomena. Thus it is the Aether medium, by its energy of
+motions, that constitutes the companion and complementary force to
+Gravitation Attraction, and which, as we shall see later, is the medium
+which forms the physical basis of that attraction also. It is, then, by
+the combined and harmonious working of these two co-equal, co-existent,
+and co-extensive forces that worlds roll and rush, sweep and swing, move
+and rotate about their respective centres; and, by these two forces
+working in perfect harmony, that that order and stability are produced,
+which everywhere pervade the universe of worlds, and form them in their
+entirety into one grand, ultimate, and harmonious system.
+
+To develop and prove this fact, by explaining their manner and mode of
+working, we shall now proceed to consider Newton's Laws of Motion, and
+their relation to the aetherial medium, and by so doing shall be able to
+show the unmistakable reality and complete efficiency of this physical
+conception of the Aether medium, which forms the physical basis of all
+universal motion and phenomena.
+
+
+ART. 98. _Newton's First Law of Motion._--We will now apply the
+centrifugal and centripetal forces to Newton's Laws of Motion, and
+endeavour to form a physical conception of the same from the aetherial
+standpoint. Before doing so, we must recall some of the statements made
+in Art. 14 with reference to the First Law of Motion.
+
+It will be remembered that we divided the First Law of Motion into two
+parts: 1st, "Every body continues in a state of rest except in so far as
+it is compelled by impressed forces, _i. e._ impulses or motions, to
+change that state." This we saw agreed with our experience, and
+therefore was philosophically correct, and must hold good in its
+application to the centrifugal and centripetal forces of the Aether in
+their effect upon any body in space.
+
+Let us proceed to apply the First Law of Motion to the planetary world.
+We have seen in the previous Art. so far as the distances of the planets
+are concerned in their relation to the sun, that the Law of Gravity is
+violated, and that planetary distance is not regulated by the law
+governing the centripetal force of Gravitation, otherwise the planets
+possessing the largest masses would be nearer to the sun than those
+possessing smaller masses.
+
+The question arises, as to whether there is any law which governs
+planetary distance, by which the distance of any planet was regulated at
+the birth or creation of the solar system. It has been assumed by some
+scientists that planetary density is the regulating factor which
+determines the relative distance of the respective planets from their
+central body, the sun, but such an assumption is not consistent with
+scientific data. For we find that Venus, with a density of 4.81 compared
+with water, occupies a nearer position than the Earth with a density of
+5.66, whereas the reverse should be the case if the density of a planet
+were the deciding factor in regulating a planet's distance.
+
+Again, we find Saturn, which possesses a density of .75, occupying a
+nearer position to the sun than Uranus, which possesses a density of
+1.28; so that here again, if density were the regulating factor which
+decided planetary distance, such a law is violated. According to the
+various densities of the planets, the respective positions of the
+planets in relation to the sun would be as follows: The nearest planet
+would be Mercury, which possesses a density of 6.85. This would be
+followed by the Earth, with a density of 5.66. Then Venus would come
+next, with a density of 4.81, followed by Mars, with a density of 4.01.
+After these we should have Jupiter, whose density is 1.38, with Uranus,
+whose density is 1.28, followed by Neptune possessing a density of 1.15,
+and Saturn would take Neptune's place, as it possesses the least density
+of all, its density being only .75. So that it is manifest, that density
+cannot be the governing condition, as has been proved in the previous
+article.
+
+Now, if all the planets ever formed part of the sun, and they were
+hurled off into space by the centrifugal motion of the Aether, then
+there certainly would be some law which governs the relative distance of
+the various planets; but as far as we can see, there is no such law, as
+a law which is violated ceases to be a law, so that the law of masses or
+densities of a planet, governing their distances, has no place in the
+solar system.
+
+This leads up to the question as to whether the planets ever did form
+part of the sun, as is generally supposed; and, in view of the fact that
+there is no law by which planetary distances are regulated, we are
+compelled to come to the conclusion that each planet and satellite once
+existed in an aetherial condition in space, and that it was by the
+condensation of that Aether, that each planet was formed; and that, at
+its birth, each planet occupied the relative distance from the sun which
+it occupies to-day.
+
+At first sight this may appear startling, but I would ask the reader how
+he can account otherwise for the great irregularity which exists in the
+distances of the planets in their relation to the sun, as every known
+law which governs masses and density seems to be altogether set at
+defiance.
+
+I hope to prove later on, that all matter has an aetherial origin, and
+if that be correct, then the origin of a planet briefly outlined can be
+accepted without violating the results of experience or experiment, and
+to that extent will be philosophically correct.
+
+Dr. Larmor speaks of the aetherial constitution of matter, and refers to
+the views of Faraday and Davy in support of such a theory, while Lord
+Kelvin has referred to the same principle in an article on the
+"Condensation of Gravitational Matter in any part of the Universe"
+(_Phil. Mag._, July 1902). So that if it be possible for Aether to be
+condensed, and so form the nucleus of a planet or satellite, then,
+seeing that the Aether is universal, any planet or satellite or meteor
+may be formed in any part of the solar system; and the process has only
+to be continued, until we have planets of various sizes at various
+distances from the central body, the sun.
+
+Here, therefore, at any rate, is a physical hypothesis which will
+satisfactorily account for all the different distances of the various
+planets. Apart from some such hypothesis, I fail to see how we can
+account for the irregularity that exists between planetary distances,
+when viewed from the standpoint of their masses and their densities.
+
+Further, such a conception is entirely in harmony with the view of the
+dual character of the motions or powers of the aetherial medium, that
+would co-exist with the evolution and development of the planet. For, as
+the planet was evolved and developed from the aetherial medium which
+surrounded it on every side, two motions would be developed and grow
+with it--the centrifugal force or motion, and the centripetal motion of
+the Aether, or the attractive force known as Gravity. Thus, through all
+the growth and development of a planet, these two powers, the
+centripetal force and the centrifugal force, would be co-equal and
+co-existent.
+
+The same truth applies to the sun or any other body in the universe; so
+that, if a planet, as the Earth, was formed in the beginning at its mean
+distance of 92,700,000 miles, then the joint centripetal motions
+produced by the Earth and sun in the Aether, would always equal the
+joint centrifugal motions produced by the same two bodies, simply
+because the two laws are the exact opposite of each other both in regard
+to intensity, distance, and magnitude.
+
+Thus the Earth would always occupy its relative position in relation to
+the sun that it occupies to-day, as long as the two aetherial forces or
+motions, the centripetal and the centrifugal, exist. With this brief
+outline of a planet's history, we are now in a position to form a
+physical picture of the solar system when it first existed in the
+beginning.
+
+We find the sun then occupying its centre. At various distances, we find
+the various planets situated without any regard to their relative masses
+or densities, as the following table shows. (The mass of sun is taken as
+unity.)
+
+                MEAN DISTANCE.    MASS.      DENSITY.
+
+    Mercury       35,900,000   1/7,636,440     6.85
+
+    Venus         67,000,000    1/397,000      4.81
+
+    Earth         92,700,000    1/324,439      5.66
+
+    Mars         141,000,000   1/2,994,790     4.01
+
+    Jupiter      482,000,000     1/1,048       1.38
+
+    Saturn       884,000,000     1/3,529        .75
+
+    Uranus     1,780,000,000     1/22,020      1.28
+
+    Neptune    2,780,000,000     1/18,520      1.15
+
+Now, in order for any of these planets to fulfil Newton's First Law of
+Motion, the sun, which occupies the centre of the solar system, must be
+assumed to have no rotatory or orbital motion of its own; because, so
+long as it has a rotatory motion on its axis, or an orbital motion of
+its own through space, so long will even the first part of Newton's
+First Law of Motion be inapplicable to the solar system.
+
+But if the sun can be assumed to possess at some point in its history no
+orbital motion, or rotatory motion on its axis, then the physical
+interpretation of the first law of motion can be physically conceived,
+and a planet at rest will remain at rest relatively to its central body,
+the sun, for ever.
+
+Let us take the sun and Mercury as an example of the effect of the two
+motions operating in the aetherial medium. We will consider first the
+effect of the centrifugal motion. The sun, with its huge form, occupies
+the centre of the solar system, while Mercury has its mean distance
+about 36,000,000 miles away.
+
+The solar fires are intensely burning, and every atom and every particle
+composing them are excited thereby into the most intense activity, and
+by their energy of motion create myriads upon myriads of waves in the
+surrounding Aether, which flow away on every side with the velocity of
+light.
+
+With such velocity are they generated, that they speed across the
+distance of 36,000,000 miles which exist between Mercury and the sun in
+the short time of about three minutes, and if it were not for the
+aetherial and aerial atmosphere of the planet, would fall upon the
+surface of Mercury with an intensity of heat that would scorch up all
+vegetable life, if any existed thereon.
+
+Now let us for a moment ignore the existence of the centripetal force,
+and then in that light view the influence of the electro-magnetic Aether
+waves upon Mercury. We have seen that when aetherial light waves come
+into contact with any body, they exert a pressure upon that body (Art.
+77), so that under the influence of the centrifugal force only, Mercury
+would be borne away from its central body, the sun, with a power and
+energy of motion entirely dependent upon the intensity of the
+electro-magnetic Aether waves which give rise to the centrifugal force.
+
+Thus Mercury would be carried away from the sun, far far away into the
+depths of space, with ever-decreasing rapidity, the rapidity of its
+motion through space being entirely dependent upon the intensity and
+energy of the Aether waves; and, as that intensity varies inversely as
+the square of the distance from the central body, the sun, so the
+impelling and repelling energy of the Aetherial waves would vary
+inversely as the square of the distance from the central body.
+
+Thus the motion of Mercury or any other planet through space would not
+be uniform, but would gradually decrease, and such a result is perfectly
+in harmony with all experience and experiment in relation to moving
+bodies on this earth.
+
+This effect of the Aetherial electro-magnetic light waves upon a planet
+is in harmony with Newton's nineteenth query in _Optics_, and is indeed
+the physical illustration of that query in its corrected form which we
+have already referred to in Art. 46, where Newton says: "Doth it
+(Aether) not grow denser and denser, etc.; every body endeavouring to go
+from the denser parts of the medium towards the rarer?"
+
+That the Aether does grow denser and denser nearer to a body we have
+already seen in Art. 46, and now we learn that a body, when under the
+influence of the centrifugal force only, would pass from the denser
+parts of a medium to the rarer parts, as suggested by Newton. We will
+now suppose that Mercury has been repelled, by the pressure due to the
+aetherial waves generated by the sun, to the distance of Neptune, a
+distance of 2,780,000,000 miles; and that at this point the centrifugal
+force is cancelled, and in its place is put the centripetal force of
+Gravitation. What will be the effect upon Mercury then? At first sight
+the effect will be exceedingly slight, but slowly, yet surely, the
+attractive power of the sun would begin to make itself manifest, and we
+should find Mercury retracing its path along exactly the same straight
+line that it had taken in its outward journey.
+
+Not only so, but its motion would be accelerated just in the same
+proportion that it had decreased on its outward journey. On and on
+through the intervening space the planet would rush, and if there were
+no centrifugal force in existence, the planet would ultimately rush into
+the central body, the sun, and being swallowed up by it, would maintain
+for a time the heat thereof.
+
+Let us now view the case from the conjoint working of these forces, or
+motions, the centripetal and centrifugal, and we shall see, that under
+certain conditions it is possible to conceive physically of a planet
+being in a state of rest as stated in Newton's First Law of Motion, and
+also remaining in that state of rest, until it is compelled by other
+forces or motions to change that state. Mercury is now situated at its
+mean distance of about 36,000,000 miles. At the same instant let both
+the centrifugal and the centripetal forces or motions be applied to it,
+and to the sun. What is the result of such application? Will the planet
+move nearer the sun, which we are supposing to be perfectly at rest, or
+will it be urged further away? The effect is nil! for the simple reason,
+that when we set in motion the centripetal force of Gravitation, at
+exactly the same time we set in motion an exactly opposite force which
+is the exact complement and counterpart of the other, so that they
+exactly counterbalance each other, and Mercury under the influence of
+both forces still retains its mean position of 36,000,000 miles; and,
+until we either set the sun rotating, or give it a motion of its own
+through space, Mercury would remain at its distance of 36,000,000 miles
+comparatively at rest. The same reasoning may be applied to all the
+other planets, in relation to their mean distances, with the result that
+they too would remain in a comparative state of rest, so long as they
+were only under the influence of the two forces or motions, viz. the
+centrifugal and centripetal.
+
+Each of these, being the exact complement and counterpart of the other,
+when applied together to any planet of any size or mass or density, at
+any distance, fails to affect the distance of that planet in its
+relation to the sun, but simply establishes it in that distance, subject
+to certain regulations dependent upon other motions of the sun, and the
+aetherial medium in which they exist. Thus we learn, that if, in the
+beginning, Mercury were formed at a distance of 36,000,000 miles, it
+would for ever remain at that distance; and the same is true of the
+other planets at their mean distances, no matter what their mass or
+density may be; and that, according to the first law of motion, the
+planet would remain in a state of rest until compelled by other forces
+or motions to change that state, when it would continue moving with
+uniform motion so long as the motive power applied was uniform.
+
+If, however, the motive power applied was not uniform, then the result
+would be an increase or decrease of the planet's motion, just in
+proportion to the increase or decrease of the motive power. This result
+is in perfect harmony with our statement in Art. 15, and is in
+accordance with observation and experience.
+
+
+ART. 99. _Second Law of Motion._--According to Newton's Second Law of
+Motion, "Change of motion is proportional to the impressed force, and
+takes place in the direction in which the force is impressed."
+
+From a consideration of this Law (Art. 15) we saw that the impressed
+force was a compound quantity, being regulated by the mass of the moving
+body which exerted the impressed force, and that it was also
+proportionate to the velocity of the moving body; so that if either of
+these quantities are changed, the total impressed force would be changed
+also.
+
+We have now to show that our aetherial medium agrees with this second
+law of motion in so far as the second law of motion agrees with
+experience and experiments. To do this, we must review our conception of
+the universal Aether, and remember that Aether is matter, and being
+matter, it is atomic and gravitative, possessing density, elasticity,
+inertia, and kinetic energy, the same as any other moving matter.
+
+In this Aether medium we have, according to this conception, something
+that can both push and pull, or exert force upon any body with which it
+comes into contact. Further, the inertia and kinetic energy of the
+Aether at any part of space will be regulated by its mass in that
+particular part, and if its mass is denser in some parts than others,
+that part of the aetherial medium possessing the greatest mass will also
+possess the greatest capacity for impressing force upon any body that
+exists in the medium. Now we have learned from Art. 45 that Aether being
+gravitative, it is denser nearer to the sun, getting gradually less and
+less dense, the further it recedes from the central body, except where
+it is bound or associated to some other planet or satellite, and there
+it gradually gets denser, for the same reason that it is denser nearer
+to the sun. As, therefore, the Aether gets gradually less dense as it
+recedes from the sun, the density of the Aether at the mean distance of
+Mercury, 35,900,000 miles, would not be so great as near the sun's
+surface; while the density of the aetherial medium at the distance of
+Venus, 67,000,000 miles, would be less than the density of the aetherial
+medium at the distance of Mercury. This principle may be applied right
+through the sun's aetherial electro-magnetic field, until we come to the
+mean distance of Neptune, which is 2,780,000,000 miles, and there the
+density of the Aether would be less than at any other part of the
+aetherial electro-magnetic field around the sun.
+
+So that the mass of the Aether at Mercury, which is equal to the number
+of aetherial atoms per unit volume, is greater than the mass at Venus.
+Thus the impressed force which the aetherial medium at the mean distance
+of Mercury can exert upon any body in its neighbourhood, is greater than
+the impressed force which the Aether can exert upon any body at the
+distance of Venus, because of its decreased mass at that distance. In
+the same way it can be proved that the impressed force which the
+electro-magnetic Aether exerts on any body at the distance of Venus, is
+greater than the impressed force which the Aether exerts upon a body at
+the mean distance of the Earth. So that at the respective mean distances
+of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, the
+electro-magnetic Aether, if in motion, would exert less force at each
+of the mean distances of these planets exactly proportionate to the
+decreased mass and decreased velocity of the Aether.
+
+Now what is the motion which the Aether possesses, so far as the sun is
+concerned? because, upon the particular kind of motion which it
+possesses will depend the direction in which the impressed force will be
+exerted according to the second law of motion.
+
+In Art. 98 we supposed the sun and planets to be stationary in the solar
+system, each planet being at its respective mean distance, from which it
+cannot move owing to the equality of the two forces. Now give to the
+central sun from whence the electro-magnetic Aether waves flow, a
+rotatory motion on its own axis, which it really possesses, as it
+rotates on its axis once in every twenty-six days nearly, and this will
+give to the Aether medium a circular or rotatory motion. This circular
+or rotatory motion the Aether has already been proved to possess (Art.
+91, where we learned that all solar magnets were caused by
+electro-magnetic aetherial currents constantly circulating round them).
+So that the Aether will actually possess two motions: 1st, a radial
+motion due to the Aether waves generated by the sun, which are radiated
+out into space with the velocity of light; and 2nd, a circular or
+rotatory motion. This result is in perfect harmony with our hypothesis
+as to the cause of the electro-magnetism of the sun (Art. 91, where we
+saw that solar magnetism was due to electric currents circulating round
+the various planets), and we have proved that the Aether has an
+electro-magnetic basis; thus the rotatory Aether currents and the
+rotatory electro-magnetic currents are due to one and the same medium.
+
+Now what will be the effect of these circular or rotatory Aether
+currents on the bodies situated within their field? It must be
+remembered that we are no longer dealing with a frictionless medium, but
+with a medium which possesses inertia and kinetic energy the same as any
+other moving matter. Therefore, as soon as it is set in motion, it will
+impress its motions upon all planets that come under its control and
+influence, with the result that as the impressed force is ever directed
+in a circular form, the planet will be pushed along through space by the
+moving Aether, and the path it describes will be circular also.
+
+Thus the actual result of the rotatory electro-magnetic Aether currents
+will be, that all dependent and associated planets under their influence
+will be carried by them around the central body which generates the
+Aether currents. So that they will literally and truly have an orbit,
+and the circle they describe will be, in its size and circumference,
+regulated by the mean distance of each planet, which mean distance will
+form the radius of the circular orbit.
+
+Further, as we shall see later, if the sun were always stationary, and
+had no orbital motion of its own, then the orbit of each planet would
+always be circular, each planet always occupying its mean distance from
+the sun, because at that mean distance the centripetal and centrifugal
+forces are equal.
+
+That the actual path of any planet is a circle has been proved by Sir W.
+R. Hamilton. Tait, in his _Natural Philosophy_, on this point writes
+(Art. 38): "The Hodograph for the motion of a planet or comet is always
+a circle, whatever be the form and dimensions of the orbit." This path
+has been termed the Hodograph. So that we have in the circling
+electro-magnetic Aether currents a physical explanation for the
+Hodograph of any planet.
+
+In applying the rotatory Aether currents to the various planets, and in
+endeavouring to find out the quantity of the force impressed upon the
+various planets at their mean distances, by those currents, we have to
+take into consideration, as we have already seen, two facts, viz. the
+mass of the Aether at any point in space, and the velocity of the Aether
+at the same point. We will first take the effect of the difference in
+mass. We have seen that at the distance of Mercury from the sun the
+density of the Aether is greater than at the distance of Venus, and that
+the density at Mars is greater than the aetherial density at the Earth,
+the aetherial density decreasing the further the Aether recedes from the
+sun.
+
+What, therefore, is the effect of the decreased density of the Aether on
+each planet? Even supposing the velocity of the moving Aether is the
+same at the respective mean planetary distances, which it is not, the
+total impressed force at the respective mean planetary distances will
+gradually be decreased upon the various planets, proportionate to the
+decrease in the mass and density of the Aether.
+
+So that on Mercury, which is pushed along by a denser electro-magnetic
+Aether than Venus, the impressed force, according to Newton's Second Law
+of Motion, will be greater than the impressed force exerted by the
+moving electro-magnetic Aether on Venus; and, consequently, Mercury
+should have a greater velocity through space than Venus, due partly to
+the difference of the aetherial mass and density, by which the impressed
+force or motive power that acts upon Mercury is produced.
+
+In the same way, Venus should have a greater velocity through space than
+Mars, and Mars a greater velocity than the Earth. The same principle, when
+applied to the outer planets, equally holds good; with the result, that
+the greater the mean distance, the less the orbital velocity of each
+planet, due partly to the decreased aetherial density at the increased
+distance from the sun. But this is only part of the cause. Not only is
+there a decrease in density of the Aether, as the distance from the sun
+is increased, but there is also a decrease in the velocity of the moving
+Aether, with the result that the Aether at the distance of Mercury,
+possesses a greater angular velocity than at the distance of Venus.
+
+It may be at once asked, How do we know that? Well, Philosophy alone can
+give us the key, and Philosophy tells us to base our theories and
+hypotheses on experience and experiment. Now what does experiment and
+experience teach us as to the effect of a body revolving in any medium
+upon that medium? If experience teaches us anything at all, it teaches
+us that the further away any medium is from the revolving body, the less
+is the angular velocity of that medium at that distance, while the
+nearer the medium is to the revolving body, the greater is the angular
+velocity.
+
+This applies in each and every case, whether the medium is either fluid
+or gaseous, and I will challenge the reader to perform any experiment on
+any solid body rotating in a fluid or gaseous medium, and prove by that
+experiment that the angular velocity of the outermost part of the fluid
+or gaseous medium is equal to the angular velocity of the medium
+directly associated with the body, or even at a short distance from it.
+
+But we have most conclusive evidence of the fact that a solid body does
+not communicate all its rotational surface motion to the medium directly
+in contact with that body in the case of the earth revolving on its
+axis, surrounded by an atmosphere. If the principle held good anywhere
+in relation to a revolving body, viz. that the whole of the rotational
+velocity is communicated to the medium surrounding the body, it should
+certainly hold good at the surface of the body where the two media, the
+solid and gaseous media, meet.
+
+If a solid body fails to impart all its rotational velocity to the
+medium there, then it will certainly fail to impart its full rotational
+velocity to the enveloping medium 100 miles away, and fail still more at
+a distance of 1000, and still more at a distance of 100,000,000, and so
+on proportionate to the distance.
+
+What, then, is the effect of the rotational velocity of the surface of
+the earth on the atmosphere near to it? We know that the velocity of the
+surface of the earth is greatest at the equator, as at that place the
+circumference of the earth is about 25,000 miles, but the further we get
+away from the equator, and the nearer we get to the North and South
+poles, the velocity of the surface decreases, simply because the
+circumference of the earth decreases.
+
+Or, to reverse the statement, the velocity of the surface of the earth
+is least at the poles, but increases the nearer we get to the equator.
+It is also familiar knowledge that there are currents of cold air ever
+moving from the North and South poles to the equatorial regions near the
+surface of the earth. Thus the cold air currents, in passing from the
+North and South poles, are ever passing over surfaces which are
+increasing in velocity as they journey on their way to the equator. This
+of course occurs all round the earth, so that the earth is continually
+revolving in these currents, and if the rotational velocity of the
+surface of the earth were wholly imparted to the air directly over its
+surface, then the currents would be always flowing due North and South.
+
+If, however, the earth fails to impart all its rotational velocity to
+the atmosphere, or the atmosphere fails to pick up the whole of the
+rotational velocity at once, then the result will be that the atmosphere
+as it passes over the surfaces of greatest velocity will lag behind,
+because its rotational velocity will be less than the velocity of the
+earth's surface.
+
+Now this is exactly what does happen in regard to the atmosphere, with
+the result, that instead of getting winds blowing due north and south,
+we get what are known as Trade Winds, which blow north-east in the
+northern hemisphere and south-east in the southern hemisphere. Here then
+we have direct experimental proof on a large scale of the very principle
+I have stated, viz, that a medium surrounding any rotating body does not
+move through the whole of its extent with the same velocity as its does
+at the surface. Thus it can be seen that the velocity of the rotating
+Aether will be greatest at the surface of the sun, but its angular
+velocity will decrease the further the medium recedes from the sun.
+
+The same principle can easily be proved from an electrical standpoint;
+for if we consider the Aether currents as electric currents, no one
+would think of suggesting that the intensity of the currents was the
+same at a distance of several million miles away, as it is near the
+source of the currents, which in this case may be looked upon as the
+sun, because at its surface we have the greatest electric potential
+(Art. 80).
+
+So that we see from this reasoning, that not only is there a decreased
+mass of the Aether at the distance of Venus, compared with Mercury, but
+there is also a decreased velocity in the rotatory electro-magnetic
+Aether currents, with the result that the impressed force exerted upon
+Venus is less than the impressed force exerted upon Mercury, and
+therefore Venus should move slower through space than Mercury, which is
+exactly what happens, as Mercury has an orbital velocity of 29 miles per
+second, while Venus has an orbital velocity of 22 miles per second.
+
+As the angular velocity decreases in proportion as the distance
+increases, it follows that at the respective mean distances not only of
+Venus, but also of Mars, Jupiter, Saturn, Uranus and Neptune, the
+capacity of the Aether to exert its impressed force upon the various
+planets will decrease as the distance increases, with the result that
+the farther a planet is from the sun, the less force will the Aether
+currents exert upon that planet, with the result that its orbital
+velocity should decrease as the distance increases, and this is
+perfectly in accordance with planetary phenomena.
+
+Here, then, we have at once a physical basis for Newton's Second Law of
+Motion, the results of which are entirely in harmony with observation
+and experiment, and whose conception fully satisfies all the Rules of
+Philosophy; as it is simple in conception, fully agrees with observation
+and experiment, and satisfactorily explains the Second Law of Motion
+sought to be explained.
+
+Thus we find that from the physical standpoint, as well as from the
+mathematical standpoint, "Change of motion is proportional to the
+impressed force, and takes place in the direction in which the force is
+impressed," that is, in a circular direction.
+
+We have therefore arrived at exactly the same result that Newton arrived
+at, except that he had to introduce a third factor, viz. the
+Parallelogram of Forces, while we have produced the result by a simpler
+method, which, according to his own rules, is more philosophical, as all
+effects are produced by the simplest causes, as Newton himself stated in
+Rule 1. Thus it is the rotatory electro-magnetic Aether currents that
+urge the planets round the sun; and, as will be shown later, it is the
+same Aether currents in combination with the other motions that give
+rise to the physical cause of Kepler's Laws. It is the electro-magnetic
+Aether currents that produce the regular decrease in the velocity of the
+planets in their orbits, because of the regular decrease of the mass and
+velocity of the Aether currents themselves.
+
+We have now a physical cause as well as a mathematical explanation of
+the decrease of the velocity of a planet in its orbit, which physical
+cause is in perfect harmony with all philosophical rules. The following
+table shows the gradual decrease in the velocity of each planet as the
+various planets recede from the sun--
+
+                   MEAN            PERIOD OF     VELOCITY IN
+                 DISTANCE.        REVOLUTION.    ORBIT PER HOUR.
+
+    Mercury      35,900,000         87.9 days
+
+    Venus        67,000,000        224.7             77.000
+
+    Earth        92,700,000        365.2             66.500
+
+    Mars        141,000,000        686.9             53.000
+
+    Jupiter     482,000,000      4,332.6             28.744
+
+    Saturn      884,000,000     10,759.              21.221
+
+    Uranus    1,780,000,000     30,687.              14.963
+
+    Neptune   2,780,000,000     60,127.              11.958
+
+
+ART. 100. _Aether and Third Law of Motion._--We have seen (Art. 16) that
+action and reaction are equal and opposite, and that it is true of the
+centripetal force in its application to all matter throughout the
+universe. If, therefore, the centrifugal force is the exact opposite of
+the centripetal force, then the Third Law of Motion should equally hold
+good in relation to that force also.
+
+We have, therefore, to form a physical conception of the application of
+the third law of motion, as it relates to the centrifugal force. As we
+have already learned, this force is due to the universal
+electro-magnetic Aether, which being gravitative, surrounds all atoms
+and molecules that may exist throughout the whole universe. It can
+readily be seen, therefore, that if the Aether surrounds every atom and
+molecule, then each atom repels another atom or molecule when the two
+forces are in equilibrium with exactly the same intensity with which the
+atom and molecule attract each other.
+
+But the centrifugal force in each case is due to the pressure of the
+Aether, which presses always proportionately to the density of the
+Aether surrounding the atom or molecules, as suggested by Professor
+Challis.
+
+The mean density, however, of each atomic or molecular atmosphere is
+regulated solely by the mass of the atom or planet, therefore the
+pressure exerted by one atom on another is proportionate to the mass of
+each atom, and to that extent is strictly in accordance with the law
+which governs the proportion of the forces between the two atoms or
+molecules. If, therefore, we have two atoms, A and B, of different
+masses, then it is true that while A exerts a pressure on B, which
+pressure takes the form of a repulsion, at the same time B exerts a
+pressure on A which is equal and opposite in its character and
+intensity, and in each case the pressure is due to the aetherial medium
+which surrounds each atom or molecule.
+
+When the atoms are equal in mass, then the resultant motion produced on
+each atom would be exactly equal, but when the masses vary, the
+resultant motion produced on each atom would vary also, though the
+momentum in each case would be exactly equal and opposite, as momentum
+is a compound term dependent partly upon the mass of the body concerned.
+
+In Art. 16 we saw that when this third law was applied to planetary
+phenomena, not only did the sun attract all the planets, but all the
+planets attracted the sun with equal and opposite forces, and the
+planets also attracted each other with equal and opposite forces. In the
+same way it can be proved, that as the sun repels all the planets by the
+pressure exerted by the aetherial centrifugal force on those planets,
+the planets repel the sun with an exactly equal and opposite force at
+their mean distances. In Newton's conception, however, of the third law
+of motion, there was simply mathematical data to deal with, by which the
+law was shown to apply to the planetary and stellar world. In the case,
+however, of the centrifugal motion, we have a definite physical medium,
+which by its motions produces the pressure on the planets or suns that
+exist in space, which pressure forms the physical centrifugal force that
+forms the counterpart of Gravitation Attraction.
+
+Let us look at this phase of the case in detail, and by so doing help to
+establish and confirm the physical existence of the force or motion
+referred to. We have learned from Chapter IV. that as Aether is
+gravitative, it surrounds all satellites and planets, suns and stars
+that exist in the universe.
+
+We have also learned from Art. 86 that Aether has an electro-magnetic
+basis, as mathematically proved by Maxwell and experimentally proved by
+Hertz. Thus we came to the conclusion that each satellite and planet,
+sun and star, was an electrified body (Art. 81), or an electro-magnet
+(Art. 88), possessing its own electric or electro-magnetic field.
+
+We also learned that in every electro-magnetic field there was a
+pressure which was ever directed away from the body that generated the
+electro-magnetic waves. Now, as every satellite and planet, sun and
+star, is a generator of these waves according to our theory, it follows
+that every satellite and planet, sun and star, is the centre of a
+centrifugal force, which centrifugal force is regulated by the mass of
+the satellite, planet, sun or star which gives rise to the centrifugal
+force or motion.
+
+Now, in relation to all electro-magnetic action, it can be
+experimentally demonstrated, that action and reaction are equal and
+opposite, so that if we have two electrified or magnetized bodies, then
+the joint forces of attraction or repulsion between them are equal and
+opposite. This being so, when we apply the same law of action and
+reaction to the planets' influence on each other, it follows that the
+same law must hold good in relation to them.
+
+So that if we compare the repulsive powers of two planets on each other
+in the solar system, say the Earth and Jupiter, then, according to the
+third law of motion, the repulsive action of Jupiter on the Earth is
+exactly equal and opposite to the repulsive action of the Earth on
+Jupiter. If we compare the Earth and the sun, the repulsive action of
+the sun on the Earth is exactly equal and opposite to the repulsive
+action of the Earth on the sun, that action or force being caused
+directly by the electro-magnetic Aether waves, which are generated by
+each electric, or electro-magnetic body.
+
+Thus, as the third law of motion is true of the centripetal force,
+whether in relation to the atomic world, or in relation to the solar
+system, or even to the universe at large, seeing that the centrifugal
+force is the exact counterpart in every way of the centripetal force,
+exactly fulfilling all the laws which govern it, it follows as a matter
+of absolute necessity that the third law is also applicable to its
+complement or counterpart also, or else it would cease to be the
+complement and counterpart of the centripetal force.
+
+
+ART. 101. _Why Planets revolve from West to East._--In Art. 99 we have
+seen that the revolution of the planets around the sun is produced and
+maintained by the electro-magnetic Aether currents, which are generated
+by the axial motion of that electro-magnetic body. There is, however,
+another effect produced, and another scientific fact which can be
+accounted for by the circulating motions of the Aether medium, viz. that
+the orbital direction of each and all the planets would not only be in
+the same direction, but they would also be in the same direction as the
+sun's rotation on its axis.
+
+So that, whichever way the sun turns upon its axis, that way, and that
+alone, should be the orbital direction of all the planets in which they
+are circled round the sun by the circulating electro-magnetic Aether
+currents. It is the sun's axial motion that partly gives to the Aether
+currents their circling motion, and it is the circling motion of the
+Aether currents that gives rise to the orbital motion of the planets,
+literally carrying them round the sun by their kinetic energy and power.
+
+Therefore, if this be true, whichever way the sun turns upon its axis,
+that will be the direction in which the Aether currents must circle
+round the sun, and in that direction the planets should travel in their
+orbits. As must readily be seen, it is the inevitable result of the
+established working of the electro-magnetic Aether currents. If the sun
+rotated on its axis from east to west, then the electro-magnetic Aether
+currents would also travel in the same direction, from east to west, and
+the planets would then revolve round the sun from east to west.
+
+If the sun, however, rotates on its axis from west to east, then, if
+there are such electro-magnetic Aether currents in existence, as those
+we have already proved to exist, they, too, would travel from west to
+east, and as a natural result the planets, which are carried round the
+sun by the currents, would also possess the same orbital motion, that is
+from west to east.
+
+As is well known, the sun rotates on its axis from west to east,
+therefore the Aether currents also rotate from west to east, with the
+result that the orbital directions of all the planets should also be in
+the same direction, from west to east. Now, as is well known, all the
+planets without exception, Mercury, Venus, the Earth, Mars, Jupiter,
+Saturn, Uranus, and Neptune, all travel round the sun from west to east.
+
+Here, then, we have indisputable evidence of the existence and mode of
+working of the electro-magnetic aetherial currents, whose action alone
+can produce the phenomena with which we are so familiar, and for which
+there must be some physical cause. I am not aware that any reason or
+explanation either mathematical or otherwise has ever been given, or
+even suggested, as to the cause of the phenomena which we have just
+endeavoured to explain.
+
+Indeed, there can be no other physical explanation of the fact, that all
+the planets revolve round the sun in the same direction that the sun
+rotates on its axis, than the one here given, viz. that the cause is to
+be found, and alone found, in the circulating electro-magnetic Aether
+currents which are generated in the Aether by the electro-magnetic body,
+the sun. Again, in order to confirm the existence of these Aether
+currents that exist in space, not only those generated by the sun, but
+also by all the other electro-magnetic bodies, as all the planets (Art.
+88), we will consider the working of the same upon the satellites of
+those planets which possess them.
+
+The Earth we know has one satellite, the moon, Mars has two satellites,
+Phobos and Deimos, Jupiter has five satellites, Saturn has eight
+satellites, while up to the present Uranus has been found to possess
+four, and Neptune one. There is, however, little doubt but that both
+Uranus and Neptune possess more than those already discovered, as it is
+inconceivable that Jupiter and Saturn, which are nearer to the sun,
+should possess a greater number of satellites by which the nights of the
+respective planets are illuminated, while the further planets, which
+need the increased lighting, because of the decreased intensity of the
+aetherial light waves at the increased distance, possess apparently a
+less number of satellites, and therefore less illumination for their
+respective nights.
+
+But what have these satellites to teach us as to the existence of the
+electro-magnetic aetherial currents that circulate round the planets? We
+have to apply a similar course of reasoning to the planets, as we have
+done in the case of the sun. If the sun is an electro-magnetic body, by
+its axial rotation it generates rotating Aether currents, and those
+Aether currents partake of the same rotation as the revolving body, that
+is, from west to east. In a like manner each planet, being an
+electro-magnet, generates electro-magnetic aetherial currents which also
+possess the same rotation as the planetary body which gives rise to
+them.
+
+So that if the planets rotate on their axes from east to west, the
+Aether currents will also rotate from east to west, but if the rotation
+of each planet is from west to east, then the rotation of the Aether
+currents associated with each planet will also be from west to east,
+with the result that each satellite will be carried round its primary
+planet by the circulating Aether currents in exactly the same way as the
+planet rotates on its axis.
+
+Now if this is the case, then we have further evidence of the existence
+of the circulating electro-magnetic Aether currents, not only those
+associated with the sun, but those also associated with each of the
+planets, as explained in Art. 91. It might have been urged in the case
+of the planet's revolution round the sun being in the same direction as
+the sun's axial action, that such a fact was merely a coincidence, but
+such an objection loses its force if it is proved that the same
+principle or truth when applied to other bodies equally holds good. When
+we come to analyze the direction of the satellites round their primary
+planets, we find that each satellite has an orbital motion, or is
+carried round its central and controlling planet by that planet's Aether
+currents in exactly the same direction that the planet rotates on its
+axis, viz. from west to east. So that we have in the orbital direction
+of the satellites, as we have also in the orbital direction of the
+planets, conclusive evidence of the existence and mode of working of the
+Aether and of the electro-magnetic currents generated in that aetherial
+medium by the electro-magnetic bodies which rotate in it.
+
+
+
+
+                               CHAPTER XI
+
+                        AETHER AND KEPLER'S LAWS
+
+
+ART. 102. _Aether and Kepler's First Law._--In Art. 26 we learned that
+according to the First Law of Kepler, each planet revolves round the sun
+in an elliptic orbit, with the sun occupying one of the foci.
+
+We also saw that that elliptic orbit was produced according to Newton by
+the conjoint working of the centripetal and centrifugal forces in
+association with the three Laws of Motion, to which laws had to be added
+a corollary, which is termed the Parallelogram of Forces, before the
+First Law of Kepler could be fulfilled.
+
+In making any hypothesis as to the physical cause of Kepler's Laws, if
+it can be shown that the same aetherial medium that gives rise to the
+centrifugal force, also gives rise to the centripetal force, and that
+the same medium by its rotatory motions also fulfils the three laws of
+motion, and gives a satisfactory physical explanation of all Kepler's
+Laws; then, according to our three Rules of Philosophy, we shall have
+found a physical medium which, by its motions and pressures and
+tensions, can give rise to all the phenomena exhibited in the celestial
+mechanism. Such a physical explanation will be philosophically correct,
+in that it is simple in its conception, is entirely in harmony with
+observation and experiment, and satisfactorily accounts for, and that on
+a physical basis, all the phenomena associated with the whole of the
+celestial mechanism.
+
+We have therefore to apply the motions of the Aether medium to the solar
+system, and by so doing reveal the physical explanation of all Kepler's
+Laws, in the same way that Newton revealed their correctness from the
+mathematical standpoint. Let us review the conception of the solar
+system as given in Art. 99, so that we may be able to proceed from that
+physical conception of a stationary solar system to a moving system.
+
+Thus we see the sun in a stationary system occupying exactly the centre
+of that system. The solar energies are in full play, generating
+electro-magnetic Aether waves which are radiated forth into space with
+the velocity of light. Then, as there is given to the sun a rotatory
+motion on its axis, that rotatory motion imparts to the gravitating
+aetherial medium a circulatory or rotatory motion which spreads out
+through space with ever-increasing intensity.
+
+By their radiating motion the Aether waves would repel all planets from
+their central body, the sun, if they were not counterbalanced by the
+centripetal force; and the two forces, the centrifugal and the
+centripetal forces, find their equilibrium at the mean distance of each
+planet, thus fixing and regulating permanently the distance and orbit of
+each planetary world.
+
+At the same time, the rotatory motion of the electro-magnetic Aether
+currents, according to the second law of motion, would act on the
+planets by their kinetic or moving energy, and so circle them round the
+sun, their controlling centre. As long as the sun was quite stationary,
+while still possessing a rotation on its axis, if such a thing were
+possible, so long would the conception of the ancients be fulfilled, and
+the rotation of all the planets would be strictly circular in form, and
+their orbits would be that of a circle only, as proved by Sir W. R.
+Hamilton (Art. 99).
+
+[Illustration: Fig: 24.]
+
+But, as is well known, the sun itself possesses an orbital motion of its
+own, so that, while all the associated planetary system is revolving
+round it, the sun with all that system is being carried along through
+space in an orbit which is also elliptic in form, as we shall see later
+on.
+
+According to Herschel, the sun is moving towards the constellation of
+Hercules with a velocity of about 18,000 miles per hour, and the problem
+to be faced is, what is the effect of the sun's orbital velocity upon
+the circular motion of the planets? By solving that problem, we shall
+arrive at a physical conception for the first time of Kepler's Laws, and
+shall see that the first of Kepler's Laws is solved simply by giving an
+orbital velocity to any central body, the result of which will be that
+the circular form of any planet's orbit will be changed from the
+circular into one of elliptic form.
+
+Let me ask the reader to perform a very simple experiment to confirm
+this fact. Take a piece of string and a lead pencil, and start to draw a
+circle on a piece of paper (Fig. 24). When, however, one quarter of the
+circle has been drawn, viz. _D_ _F_, move the end of the piece of string
+representing the centre of the circle along the paper, as represented in
+the diagram, from _A_ to _B_. The result will be that the pencil will
+now travel parallel with the moving centre for a time from _F_ to _G_,
+and then, when the centre is brought to rest again, the other part of
+the half ellipse _G_ _H_ may be completed. In the same way, by reversing
+the motion, the other half of the ellipse may be completed. So that it
+is possible for an ellipse to be formed simply by moving the central
+point of a circle, and the motion of that central point will change the
+form of a circle into an ellipse. It is something like this that takes
+place in the planetary world, with this difference, that the central
+point which represents the sun does not return from one focus to
+another, but continues to journey on through space, with the result that
+the orbit of any planet is not strictly an ellipse, as we shall see
+later on. We have, then, the sun occupying the centre of the solar
+system, with all the planets revolving round it. We will take the sun
+and the Earth as examples. Let _S_ in the diagram represent the sun, and
+_E_ the Earth at its mean distance of 92,000,000 miles away (Fig. 25).
+
+[Illustration: Fig: 25.]
+
+The Earth we know is moving with a velocity of about 64,800 miles per
+hour around the sun, or an average velocity of 18 miles per second, so
+that while the Earth is moving 64,800 miles through space to perform the
+half-circle, _E_ _D_ _C_, the sun is also travelling 18,000 miles
+towards the point _D_.
+
+What, therefore, is the effect of this onward movement of the sun
+towards the Earth as it tries to complete the half-circle _E_ _D_ _C_?
+We have seen that the centrifugal force due to the pressure of the
+electro-magnetic Aether waves is exactly equal to the centripetal force
+exerted by the sun on any planet, and if that be so, it can be readily
+seen that as the sun journeys towards the point _D_ of the Earth's
+orbit, it tends to approach nearer and nearer the Earth. Thus the
+intensity of the aetherial pressure owing to the decreased distance will
+be greatly increased, and the effect of the increased pressure of the
+Aether upon the planet will be to push it away from the sun, so that the
+two forces may be equalized, and its mean distance, which is definitely
+fixed, be maintained as far as possible.
+
+The result will be that, instead of the Earth describing the half-circle
+_E_ _D_ _C_, it actually describes the part of the ellipse _E_ _F_ _C_.
+Thus it can be seen that while the sun is travelling through space, it is
+at the same time giving rise to the electro-magnetic Aether waves, which,
+by their repelling power, repel the Earth from the sun in the direction
+that the sun is travelling, and hence the half-circle is elongated into
+that part of the elliptic orbit known as the perihelion, which is that
+part of the orbit where the distance of any planet from the sun is the
+least.
+
+[Illustration: Fig: 26.]
+
+The repelling power of the Aether waves is not, however, sufficient to
+overcome altogether the centripetal force in conjunction with the
+Earth's motion, with the result that when the Earth arrives at _F_, its
+distance is only 91 million miles, that being the least distance between
+the sun and the Earth. We shall see the result of this decreased
+distance when we deal with Kepler's Second Law.
+
+We will now proceed to notice the effect of the sun's orbital velocity
+upon that part of the Earth's orbit which includes the aphelion, or that
+part in which the Earth occupies a position of the greatest distance
+from the sun. Proceeding on the same method of reasoning, if the sun
+were stationary, with the Earth being circled round it by the
+electro-magnetic Aether currents, then the path described by the Earth
+would be that of a circle, being represented by the half-circle _C_ _G_
+_E_ (Fig. 26).
+
+But it has to be remembered that while the Earth is being circled round
+the sun by the rotatory electro-magnetic Aether currents, the sun is
+still travelling on towards _S_ _F_ at the rate of 18,000 miles per
+hour, while the Earth is travelling in almost an opposite direction
+towards _C_ _G_, so that by the time the Earth has got to _G_, which we
+will suppose is one quarter of its ellipse, the sun has travelled
+millions of miles in that time.
+
+Thus it can readily be seen, that by the time the Earth has got to its
+aphelion, it is at its furthest distance from the sun, simply because
+the sun has been travelling onwards through space all the time, while
+the Earth has been receding from it; and as the motion of the Earth has
+been in an opposite direction, the mean distance has been exceeded, and
+instead of the Earth being now at its mean distance from the sun, its
+distance is now 94,500,000 miles. At that part of its orbit, its orbital
+velocity is at a minimum, because the rotating Aether currents have
+there a decreased flow and a decreased mass and density, and therefore
+possess a decreased kinetic energy or motive power.
+
+Thus by the rotating Aether currents working in conjunction with the
+centrifugal and centripetal forces, can be accounted on a physical basis
+the first of Kepler's Laws in a manner which is strictly philosophical,
+as the explanation is simple in conception, does not violate experience
+or experiment, and satisfactorily accounts for, on a physical basis, the
+law which it is required to explain.
+
+If we consider the rotating Aether currents as purely currents of
+electricity, then exactly the same results follow. For, as we shall see
+later, Professor Lodge in his _Modern Views of Electricity_ proves that
+electricity possesses both inertia and momentum, and if electricity
+possesses these properties, then it also possesses the requisite
+properties to enable the currents to propel or push any planet around
+its central body, or a satellite round its primary planet. Therefore the
+same course of reasoning that applies to the rotating Aether currents,
+equally applies to the currents of electricity that circulate round each
+satellite, planet, and sun and star, and by that circulation gives rise
+to the electro-magnetism associated with each body, while at the same
+time they supply the kinetic energy which enables any dependent or
+associated body to be propelled round their controlling centre.
+
+
+ART. 103. _Second Law of Kepler._--According to Kepler's Second Law
+(Art. 27), we learn that the radius vector, which is the imaginary
+straight line joining any planet to the sun, describes, or sweeps over,
+equal areas in equal times. So that, while Kelper's First Law describes
+the path which a planet takes in revolving round the sun, the Second Law
+shows how the velocity of that planet varies in different parts of its
+orbit.
+
+While, however, there is a difference in the velocity of any planet at
+various points in the orbit, there is still a proportion existing
+between its various velocities, in that equal areas are covered in equal
+times. We have now to apply the hypothesis of our rotatory Aether
+currents, in conjunction with the centripetal and centrifugal forces, in
+order to see whether the Second Law of Kepler can be explained on a
+physical basis, in the same way that Newton explained it from the
+mathematical standpoint.
+
+We have again to conceive the sun as the centre of two equal but exactly
+opposite forces, and also possessing a rotatory motion on its axis, with
+the electro-magnetic Aether currents ever circulating round it. If the
+sun were stationary, it will be manifest at once that Kepler's Second
+Law would be literally and strictly fulfilled, for in that case the
+orbit of all the planets would be perfect circles, and the motion of
+planets in their orbits would be perfectly uniform, and therefore equal
+areas would be covered by the radius vector in equal times. Thus any
+quarter of the orbit would be described in exactly a 1/4 of a year, 1/12
+in 1/12 of a year, 1/40 in 1/40 of a year, and so on, the time being
+exactly proportional to the proportion of the area covered by the radius
+vector.
+
+The area covered would always be uniform, because the radius vector
+would always be uniform in length. But, as we have seen in the previous
+article, the distance of a planet from the sun, that is, the length of
+the radius vector, is not uniform, as the Earth is nearer to the sun at
+perihelion, and further away at aphelion, its distance gradually
+changing as it passes from each of these points to the other.
+
+Now what is the effect of the decreased distance upon the circulating or
+rotatory Aether currents? We have already seen (Art. 99) that the closer
+these Aether currents are to the central body, the sun, the greater is
+their velocity and the greater their mass, so that the total impressed
+force which they exert over any planet is greater the nearer that planet
+is to the sun. This is proved by the fact that Mercury has a greater
+orbital velocity than Venus, Venus than the Earth, the Earth than Mars,
+and so on right through the whole of the planetary system. In view of
+these facts, let us again consider the effect of the sun not being
+stationary, but having an orbital velocity of its own through space.
+Thus let the sun be at _S_ and the Earth be at point _D_ of its orbit
+(Fig. 25).
+
+The circulating Aether currents are ever acting upon the Earth, carrying
+it round the sun with them, while at the same time the centripetal force
+is pulling it towards the sun with a certain intensity, but the
+centrifugal force is repelling the Earth with exactly the same
+intensity, and if the sun remained motionless the two forces would
+exactly balance each other, while the Earth would describe the
+half-circle _E_ _D_ _C_. But while the Earth is moving towards the
+point _D_ with a velocity of 64,000 miles per hour, the sun is also
+moving at the velocity of about 18,000 miles per hour towards that
+point.
+
+Thus the repelling power of the radiating electro-magnetic Aether waves
+has to overcome, not only its exact counterpart, the centripetal force,
+but also the onward motion of the sun as it rushes on its course through
+space. This the centrifugal force is unable to do, with the result that
+the distance is gradually lessened, and instead of the Earth describing
+the arc _E_ _D_, it describes the arc _E_ _F_, at which point its
+distance is at the minimum, or about 91 millions of miles.
+
+Or, to put the same fact in another way. When the Earth is at _E_, the
+centripetal force and the orbital velocity of the Earth and the sun are
+acting conjointly, with the result that they overcome the centrifugal
+force, and the distance is gradually decreased. This decreased distance
+means an increased aetherial density and an increased velocity of the
+aetherial currents, with the result, that as the distance is decreased,
+the orbital velocity of the Earth is gradually increased, so that by the
+time the Earth gets to _F_, at its perihelion, it has now acquired its
+greatest orbital velocity, and is carried round the sun by the
+electro-magnetic Aether currents at its maximum velocity.
+
+Now let us look at the Earth being circled round the sun by the
+electro-magnetic Aether currents as it goes on to perform the other half
+of the orbit. In this case we have the orbital motion of the sun and the
+centrifugal force working conjointly, with the result that together they
+overcome the centripetal force, and the Earth is repelled and carried
+beyond its mean distance. Let _S_ represent the sun, the Earth being at
+point _C_ of its orbit, after passing round its perihelion, and at this
+decreased distance it is carried along by the circulating and denser
+Aether with its maximum velocity (Fig. 26).
+
+Now while the Earth is going on to describe the half-circle _C_ _G_ _E_,
+the sun is still pursuing its journey at the rate of about 18,000 miles
+per hour, only this time in a direction away from the Earth. As, however,
+the Earth has not yet regained its mean distance of 92,000,000 miles,
+the centrifugal force is still greater than the centripetal force, so
+that the centrifugal force is urging the planet away from the sun with
+greater intensity than the centripetal force is attracting it, as the
+two forces are only in equilibrium at the mean distance of the Earth.
+
+Thus, as stated, the orbital motion of the sun and the centrifugal
+forces are now working conjointly together, with the result that the
+Earth is repelled gradually further and further from its central body,
+until it reaches its maximum distance of 94,500,000 miles. While,
+however, the distance is gradually being increased, it is passing into a
+part of the Aether possessing not only a decreased mass, but also a
+decreased velocity, with the result that the motive power or kinetic
+energy of the aetherial currents at the increased distance is gradually
+lessened, and as a natural result the velocity of the Earth is also
+decreased; so that by the time the Earth has got to its furthest
+distance from the sun, its orbital velocity is slowest, because of the
+decreased momentum of the aetherial currents.
+
+Thus we can account for the difference of velocity of a planet in its
+orbit by the same electro-magnetic Aether currents working in
+conjunction with the sun's orbital motion, and that upon a strictly
+physical basis. This result is in perfect harmony with Kepler's Second
+Law, which states that equal areas are described by the radius vector in
+equal times. Newton proved that by the Law of Gravitation Attraction he
+could account for this second law, as well as all the others, and as we
+have not destroyed that law, but perfected it by giving it its exact
+complement and counterpart, the same mathematical reasoning that applies
+to the centripetal force must equally apply to the centrifugal force,
+and if it is true that the centripetal force works harmoniously with the
+second of Kepler's Laws, then it is equally true that the centrifugal
+force does also, as the two are inseparably and indisputably united
+together in the atomic Aether. We have, however, a physical basis for
+this centrifugal force, and we have an equal physical basis for the
+centripetal force, as we shall see later, and therefore, by the conjoint
+working of these two forces taken in conjunction with the orbital motion
+of the sun, we have now a physical conception for the first time of
+Kepler's Laws, as well as a mathematical conception, that physical
+conception being derived from the pressure and motions of the universal
+Aether.
+
+
+ART. 104. _Aether and Kepler's Third Law._--In Art. 28 we saw that
+according to the Third Law of Kepler, the square of the periodic time
+was proportionate to the cube of the mean distance of that planet from
+its controlling centre. Newton proved that this Third Law was
+mathematically correct, and that it could be mathematically accounted
+for by the existence and operation of the universal Law of Gravitation.
+As the centrifugal force is the exact opposite of that force in
+intensity, proportion and mode of operation, it follows that
+mathematically the centrifugal force also bears the same relation to the
+Third Law that the centripetal force does.
+
+We have, however, a physical basis for the centrifugal force, and it is
+with the physical conception of this Third Law rather than with its
+mathematical character that we are now dealing. Kepler by his Third Law
+showed that the chief regulating factor in the orbital velocity of a
+planet was its mean distance from the sun.
+
+The great regulator of the velocity of any planet in its orbit is
+simply planetary distance, and planetary distance alone. If there were
+no other law which operated in the solar system than the centripetal
+force, or the attractive force due to gravity, then such factors as mass
+and density of a planet ought to play a most important part in the
+orbital velocity of a planet, as the centripetal force directly
+recognizes the influence of mass, that is, volume and density, but says
+nothing about mean distances. This fact unmistakably points to the
+existence, and demands the operation, of another force, which shall
+explain, and that on a physical as well as a mathematical basis, how it
+is that the mean distance of a planet from any centre regulates the
+orbital velocity of that planet.
+
+The only real and true conception of such a force is to be found in the
+radiating waves and circulating motions of the aetherial medium, which
+waves, like water waves, increase in their radial outflow and extent
+with a regular decreasing intensity, and at the same time decrease in
+their angular velocity as they recede from the sun. With such a regular
+decrease of kinetic energy, there must necessarily be imparted to the
+planets, as their mean distance is increased, a decreased velocity of
+motion, with the natural result, that the further a planet is from the
+sun, the less will be its orbital velocity, and that in a regular and
+uniform proportion as the distance is increased.
+
+Now let us view the matter for a moment in its application to the solar
+system, and by so doing show the simplicity of the explanation, and at
+the same time give added proof to the existence and operation of the
+circulating aetherial currents that exist in space. Let us again picture
+the solar fires burning in all their fierceness and intensity, every
+atom and particle of the sun being thrown thereby into the most intense
+state of activity, and by their energy of motion creating
+electro-magnetic Aether waves in their myriads, which speed away from
+the sun on every side.
+
+Under their influence, all subordinate worlds would be carried away into
+space, were it not for the complementary Law of Gravitation Attraction,
+that is, the centripetal force. But to every planet, by the operation of
+some governing and determining principle, a mean distance has been
+given, and at that mean distance the two forces find their equilibrium;
+and by their conjoint and co-equal working hold each planet at that mean
+distance with a power that cannot be broken. Each power or force may be
+modified under certain conditions, as shown in the two preceding
+articles; but, whether the planet be repelled further away, or attracted
+nearer to the sun, through the onward motion of the sun, the two forces
+ever seek to maintain their equilibrium, and to place the planet at its
+mean position assigned to it in the solar system.
+
+The nearer that mean position is to the sun, the greater is the velocity
+of the aetherial currents which circulate round the sun; and the greater
+their mass, volume for volume, on account of the increasing density of the
+Aether, the nearer it is to the sun. The effect of this increased
+velocity, and the increased mass of the circulating Aether currents, is to
+impart to planets nearest to the sun the greatest orbital velocity; while,
+the greater the distance, the less will be the orbital velocity of the
+planet. That this is exactly in accordance with observation and
+experience may be proved by considering the respective mean distances
+and orbital velocities of the various planets.
+
+Mercury, with a mean distance of 35,900,000 miles, is circled round the
+sun at the enormous rate of about 108,000 miles per hour, accomplishing
+its entire journey in the short period of 88 days. Venus, whose mean
+distance is about 67,000,000 miles, is carried round the sun at the
+reduced rate of 78,000 miles per hour, completing her orbit in the
+increased time of 224 days. Our own Earth, at the still further
+increased mean distance of 92,000,000 miles, performs her journey at the
+reduced velocity of 64,000 miles per hour, accomplishing the journey
+round the sun in a period of 365 days.
+
+Thus, the further we get from the sun, the slower becomes the movement
+of a planet in its orbit, and the longer it takes to complete its
+revolution round its controlling centre. Mars, at the increased distance
+of 141,000,000 miles, possesses a reduced velocity of 54,000 miles per
+hour, and completes its orbit in the increased duration of 686 days. So
+the decrease of velocity goes on, as the planets increase their mean
+distance from the sun, as the following figures show--
+
+                 MEAN DISTANCE.   PERIOD OF   ORBITAL VELOCITY
+                                  REVOLUTION.     PER HOUR.
+
+    Jupiter       482 millions    4,332 days    28,000 miles
+    Saturn        884    "       10,759  "      21,600   "
+    Uranus      1,780    "       30,687  "       1,800   "
+    Neptune     2,780    "       60.127  "         900   "
+
+The relation of this decrease of velocity to the mean distance is
+exactly determined by Kepler's Third Law, in which he states that the
+square of the periodic time is proportionate to the cube of the mean
+distance. That this is true has already been proved in Art. 28.
+
+In conclusion on this point, let me ask the reader to try to conceive
+any other physical explanation for this decrease of orbital velocity as
+the mean distance is increased, than the one given here, namely, the
+decrease in the velocity and mass of the radiating and circulating
+Aether currents, and if such attempt is made, I premise that its only
+result will be utter failure. No other physical conception to account on
+a physical basis for all Kepler's Laws can be given or conceived, than
+that which finds its origin in the universal electro-magnetic Aether,
+which by its pressures, tensions and motions gives rise to all the
+phenomena incidental to, and associated with, planetary and stellar
+phenomena.
+
+Therefore, inasmuch as all the laws of motion, and all Kepler's Laws can
+be accounted for by a gravitating and rotatory Aether medium, those
+facts alone, apart from the explanation of other phenomena associated
+with light and heat, would stamp the circulating Aether medium as the
+physical cause of all the motions and phenomena associated with the
+whole of the celestial mechanism.
+
+
+ART. 105. _Orbital Motions of Satellites and Planets._--According to
+Kepler's First Law, the Earth and all the other planets move round the
+sun in orbits which are in the shape of an ellipse. Not only, however,
+is the first law true of planetary motion, it is equally true of the
+motions of all satellites moving round their primary planets. I wish,
+however, to point out, and prove in an indisputable manner, that
+Kepler's First Law does not sufficiently explain and determine the exact
+orbit of any satellite as it revolves around its primary planet, or even
+of any planet as it revolves around the sun.
+
+Simply because, if any satellite or planet is to perform a perfect
+ellipse as it revolves around its central body, that central body must
+only move for a time and must then come to rest, or partly return in its
+journey in order for a perfect ellipse to be formed, as shown in a
+previous figure. Now we know from observation that such a thing as rest
+in space by any planet, or by the sun, is absolutely unknown in the
+celestial mechanism.
+
+From Art. 92 we learned that the electro-magnetic Aether currents not
+only circulate round the sun, but they also circulate round each planet.
+Thus we found there were electro-magnetic Aether currents circulating
+round each planet, while those planets themselves were circled round the
+sun by the Aether currents generated by the sun; the planetary Aether
+currents in their turn propel the satellites round their primary
+planets. It can easily be seen, therefore, that such phenomena as rest
+and return of a planet in its journey are physical impossibilities, for
+either the circulating Aether currents would have to cease circulating,
+or would have to return upon themselves in some inconceivable manner.
+
+Thus there is ever going on this conjoint motion, so to speak, of the
+sun's aetherial currents which circle all the planets round that body,
+and the planetary aetherial currents which circle all the satellites
+round their central body, and it is the effect of the conjoint working
+of these currents on the planets and satellites to which I wish to call
+the reader's attention.
+
+Let us in starting represent the earth's orbit by a perfect ellipse _A_
+_B_ _C_ _D_, with the sun occupying one of the foci _S_ (Fig. 27). We
+will suppose that the earth is at point _A_ of its orbit and is being
+circled round the sun with uniform velocity. As it is circled round the
+sun by the sun's aetherial currents, at the same time its satellite the
+moon is being circled round the earth by the electro-magnetic Aether
+currents which circulate round that planet. We will represent the orbit of
+the moon by part of a smaller circle _D_ _E_ _F_, and suppose the moon to
+be at point _D_ of that orbit. The mean distance of the moon from the
+earth is about 240,000 miles, so that the diameter of the orbit is 480,000
+miles, therefore the circumference of the orbit is 480,000 x 3.1416, which
+gives us about 1,500,000 miles.
+
+[Illustration: Fig: 27.]
+
+That distance is traversed in about 28 days, so that the moon's average
+velocity in its orbit, as it is circled or pushed round the earth, is
+about 2200 miles per hour. While, therefore, the moon is travelling 2200
+miles, the earth in its journey round the sun has travelled about 64,800
+miles in the same time. So that by the time the moon has travelled half
+its orbit, that is, from _D_ to _F_, which would take about 14 days, the
+earth has also travelled in its orbit 64,800 x 24 x 14 = 21,772,800
+miles, with the result, that instead of the moon arriving at point _F_,
+which it would do if the earth were stationary, it really arrives at a
+point about 21,772,800 miles in front of that point.
+
+In a similar way, while the moon goes on to describe the other half of
+the orbit, the earth still proceeds on its journey, so that at the end
+of 14 days it is again 21,772,800 miles further on, with the result,
+that the centripetal force (by which the moon is attracted to the earth)
+keeps it at the distance of 240,000 miles according to Kepler's Second
+Law as explained in Art. 103.
+
+The moon, therefore, completes its orbit about 21,772,800 miles further
+on than it would do if the earth were stationary. The effect of this
+continual progress of the earth on the moon's orbit as it describes its
+orbit round the sun is seen in the diagram. As the moon revolves round
+the earth thirteen times in one year, it performs thirteen revolutions
+round that planet; but it cannot be said that these orbits are perfect
+ellipses, as the earth is ever being circled round its central body, the
+sun. Even this diagram does not accurately represent the orbital motion
+of the moon through space, as it assumes that the earth returns to the
+same point in space from whence it started. This, however, is incorrect,
+as we have to remember that the sun has also an orbital velocity of
+18,000 miles per hour, so that while the earth has performed one
+revolution in its orbit, the sun has actually progressed through space
+to the extent of 18,000 x 24 x 365 = 157,680,000 miles.
+
+When we come to deal with the sun's motion through space, we shall see
+that this distance only represents a fraction of the sun's orbit, as it
+can be philosophically proved, that if the sun moves at all, it, too,
+obeys Kepler's Laws; and therefore, according to his First Law, it also
+describes and possesses an orbit of its own. So that by the time the
+earth has made its annual revolution round the sun, the whole system has
+been carried 157,680,000 miles through space, and therefore the earth
+does not complete a perfect ellipse, but its orbital motion round the
+sun will be represented by a similar kind of diagram to the one which
+represents the orbital motions of the moon, or any other satellite round
+its central body.
+
+
+ART. 106. _Eccentricity of Orbit of Moon._--From astronomical
+observation we learn, that all the satellites and planets do not possess
+uniformity of motion, as they are carried round their controlling
+centres by the circulating aetherial currents, because the respective
+controlling centres themselves move through space. The result is, that
+the orbit of any satellite or planet is not always of the same size, but
+constantly varies, sometimes having a larger circumference than at other
+times, and sometimes a smaller circumference.
+
+This change in the size of the orbit of a satellite or planet is known
+as the eccentricity of the orbit, which eccentricity is constantly
+changing, being sometimes greater and sometimes less. We will look at
+this truth in its relation to the moon first, and then consider the same
+principle in its relation to the earth and other planets later on. For
+the purpose of illustration, we will consider the earth as being circled
+round the sun by the electro-magnetic Aether currents in a closed orbit,
+_A_ _B_ _C_ _D_, which forms a perfect ellipse, the sun occupying one of
+the foci _S_ (Fig. 28), the earth occupying a position in the orbit
+represented by point _C_, with the moon being circled round the earth by
+that planet's aetherial currents. As we have already seen in Art. 103,
+according to Kepler's Second Law, at this point the earth is furthest
+from the sun, being now at a distance of 94-1/2 millions of miles, and
+therefore its orbital velocity will be slowest at that part of its
+orbit.
+
+If it were absolutely at rest in space, and simply revolving on its own
+axis, then the result would be that the moon would be circled round the
+earth in an orbit _M_ _C_ _F_ which is perfectly circular in form; but, as
+the earth is being carried along slowly through space by the circulating
+Aether currents, this onward movement changes the circular orbit into an
+orbit of elliptic form.
+
+[Illustration: Fig: 28.]
+
+The eccentricity of the moon's orbit when the earth is at its aphelion,
+or furthest from the sun, is now at a minimum, for the simple reason
+that the earth is proceeding slowly through space, owing to the
+decreased kinetic energy of the aetherial currents at the increased
+distance.
+
+So that, at this point of the earth's orbit, the difference between the
+two axes of the moon's orbit will be the least, and its orbit at that
+point will be the nearest approach to that of a circle. But, as we have
+already seen, as soon as the earth leaves this part of its orbit, and
+begins to get nearer to the sun, it passes into a part of the aetherial
+medium possessing greater kinetic energy, with the result that its own
+velocity is accelerated. Now what is the effect of this increased
+acceleration of the earth on the eccentricity of the orbit of the moon?
+
+The earth's rotation on its axis remains unaltered during this
+increasing orbital velocity, consequently the aetherial currents
+generated by the earth will remain uniform, and the moon will still be
+circled round the earth in the same period of about 28 days. But while
+the time of the moon's revolution remains unaltered, the orbit that she
+has to describe is now increased owing to the increased orbital
+velocity of its central body, with the result, that by the time the
+earth gets to that part of its orbit represented by point _D_, it is
+then two millions of miles nearer to the sun than at point _C_, and will
+be circled round the sun by the aetherial currents at a much greater
+rate. Therefore, the eccentricity of the moon's orbit is increased just
+in proportion to the increased velocity of the earth in its orbit round
+the sun. By the time the earth has arrived at point _A_, when it is only
+a distance of about 91 millions of miles from the sun, it reaches the
+minimum distance, and is circled round at the decreased distance with
+its maximum velocity.
+
+At this point, therefore, the eccentricity of the orbit of the moon will
+be at its greatest, and, if one revolution could be represented by an
+ellipse _E_ _G_ _H_, then that ellipse would be more elongated, and the
+difference between the two axes of the moon's orbit would be greater
+than at any other point of the earth's orbit.
+
+Thus it can readily be seen that the eccentricity of the moon's orbit is
+primarily due to the different velocities of the central body, in this
+case the earth, as that body is carried round its central body, the sun.
+Where the earth's motion is slowest, there the eccentricity of the
+moon's orbit will be at a minimum; but where the earth's velocity is
+greatest, there the eccentricity of the moon's orbit will be at a
+maximum.
+
+Between this minimum and maximum velocity of the earth in its orbit
+there is the constant increase or decrease in the eccentricity of the
+orbit of the moon; the eccentricity increasing as the orbital velocity
+of the central body increases, and decreasing as the orbital velocity of
+the earth decreases. A further fact has, however, to be taken into
+consideration, which is that the primary body about which the moon
+revolves is itself subject to the same eccentricity of its orbit, and
+for similar reasons, as we shall see later on. So that when the
+eccentricity of the earth's orbit is at its greatest, then the moon's
+orbit will possess its greatest possible eccentricity, and as the
+eccentricity of the earth's orbit is dependent upon the orbital velocity
+of the sun, so the greatest possible eccentricity of the moon's orbit is
+indirectly connected and associated with the sun's motion through space,
+which motion will now be considered.
+
+
+ART. 107. _The Sun and Kepler's First Law._--We have learned in the
+previous articles that Kepler's Laws not only apply to planetary motion,
+but are equally applicable to the motion of all satellites as they
+revolve round their respective planets.
+
+The question now confronts us, as to whether Kepler's Laws are equally
+true in their application to the sun? Now the sun is one of the host of
+stars that move in the vast infinity of space, and if it can be proved
+that Kepler's Laws hold good in relation to one star, as they do in
+relation to all planets and satellites, then such a result will have a
+most important bearing upon the motions of other stars, and we shall be
+able to determine with some degree of exactness what are the motions and
+orbits by which all the stars in the universe are governed.
+
+Sir Wm. Herschel first attacked the question as to whether the sun, like
+all the other stars, was in motion, and if in motion, what was the shape
+of its orbit, and the laws which governed its orbital velocity.
+
+We know that the sun is the centre of the solar system, and the question
+to be considered is, whether that system is circled round a controlling
+centre while the sun is at rest in space, simply possessing its one
+axial rotation, or whether, like every planet and satellite, it is
+subject to two motions, an axial rotation and an orbital velocity
+through space. Further, if it possesses an orbital velocity through
+space, what is the cause of that orbital velocity?
+
+It was due to the genius of Sir Wm. Herschel to first solve this
+problem, and by careful research he was able to determine that the sun,
+with all its attendant planets, was indeed moving through space.
+
+Not only did he discover this fact, but he also found out the direction
+in which the whole of our solar system was moving, as well as the
+velocity with which the general movement was performed. Herschel proved
+that the onward march of the solar system was in the direction of the
+constellation of Hercules, and that the velocity of the march of this
+system exceeds five miles per second, or 500,000 miles per day.
+
+Thus we learn that the whole of our solar system, comprising the sun,
+with all its planets with their attendant satellites which circle round
+each planet, and the asteroids or minor planets, are bound together by
+the two forces, the centripetal and the centrifugal, while the system as
+a whole is urged on its way by some force or power through the realms of
+space.
+
+What that power is we shall try to find out as we consider the
+application of Kepler's Laws to this onward movement of the sun. If,
+then, the sun is moving through space with this enormous velocity, the
+question arises as to what is the shape of the path or orbit which it
+describes? Sir Wm. Herschel attacked this question from a mathematical
+standpoint, and came to a certain conclusion, as we shall see. We will,
+however, attack the problem solely from the philosophical standpoint, by
+applying to it the Rules of Philosophy given in our first chapter, and
+we will then see whether our result is in harmony with the conclusions
+arrived at by Sir Wm. Herschel.
+
+Now what has experience and observation to tell us regarding the orbit
+which any body moving in space assumes? Take, for example, our moon as
+illustrating the movement of all satellites, and our earth as
+illustrating all planetary motion.
+
+What does observation teach us as to the orbits which these bodies
+describe? If it teaches us anything at all, it teaches us that every
+satellite and planet moves with varying velocity in a varying orbit
+around some central body. So far as our observation goes, then, in
+relation to planetary motion, or the motion of satellites, we learn that
+every body which moves in space fulfils Kepler's First Law, and
+describes an orbit round a central body, that body occupying one of the
+foci.
+
+Thus, wherever we get any body moving in space, if there be any truth in
+philosophy which is based on experiment and observation, that body ought
+also to move in similar elliptic orbits, and be subject to exactly
+similar conditions governing those orbits. But we have learned that the
+sun moves through space with a velocity of about five miles per second,
+therefore it follows, philosophically, that the sun must also move
+around some other central body, and the path of such movement is that of
+an elliptic orbit, with the central body around which it moves occupying
+one of the foci.
+
+In other words, the sun obeys the first of Kepler's Laws, the same as
+all the planets and satellites do. Suppose, for a moment, that it is
+denied that the sun moves in an elliptic orbit! What path would it
+pursue in place of that? Would the path be that of a straight line
+towards the constellation of Hercules? Such an assumption would be
+altogether unphilosophical, as it is contrary to all experience and
+observation, and is therefore untenable.
+
+Before such an assumption can be made, it must be proved that every
+planet and satellite moves in a straight line, and not till that has
+been done can it be assumed that the sun moves in a straight line, or
+indeed in any other path than that stated in the first of Kepler's Laws.
+
+This conclusion is in perfect harmony with the conclusion arrived at by
+Herschel, for in his work on _Astronomy_, in Arts. 292, 295 and 297, he
+points out that the sun's path is elliptic in form, and that Kepler also
+showed the sun fulfilled the first of his laws, and described an orbit
+which was in the shape of an ellipse. We have therefore philosophically
+arrived at the conclusion that the sun moves in an elliptic orbit, and
+to do so it must move round some central body, which is to the sun what
+the sun is to the planets, and what the planets are to the satellites.
+
+It is impossible to conceive of the sun moving in an elliptic orbit,
+and yet not moving around some central body, as we should have a
+celestial phenomenon altogether opposed to all experience and
+observation. For we have already seen that the central body is just as
+important a factor to the elliptic orbit as the planet itself, because,
+without the central body there cannot possibly be any elliptic orbit.
+Where then in the universe is the central body around which the sun
+revolves? What is its distance away from the sun? What is its size?
+These are questions that philosophy alone cannot answer, as there is no
+law, so far as I can see, that regulates the size and distance of the
+central body in proportion to the size and distance of the planets or
+satellites.
+
+If there were, then it would be possible for philosophy to apply such a
+law or rule. That there is a central body around which the sun revolves
+is as true as the fact that there is a central body about which each
+planet revolves, or each satellite revolves, and it remains for the
+practical astronomer, or the mathematician, to endeavour to discover the
+exact part of the heavens in which it is situated, and ascertain its
+distance and possibly its size. What will be the effect of the existence
+of this central body of the sun upon the solar system? One effect will
+be to do away with that isolation that up to the present has apparently
+existed with regard to our solar system and stellar space.
+
+Instead of the solar system being a solitary system that moves through
+space subject to apparently no law, and moved by apparently no physical
+power, that system, through the influence and effect of the aetherial
+currents originated by that central body, will be linked to other parts
+of the universe, and will become a part of one harmonious whole, its
+physical connection being made manifest and plain in the self-same
+electro-magnetic Aether medium that forms the connecting medium between
+the satellites and planets, or the planets and the sun.
+
+Another result will be, that as the sun is a star, we shall be able to
+apply the self-same principles and laws of Kepler to the stellar world
+in exactly the same way that we have done to the solar system. Thus, by
+bringing all stellar phenomena under the influence of Kepler's Laws, we
+shall be able to philosophically give an unity to the universe, and
+show, within rational limits, how such unity may be physically
+conceived, which result will be an advance upon any physical conception
+of the universe hitherto manifested or revealed. Further, by accepting
+the first of Kepler's Laws in relation to the sun, and admitting the
+existence of a central body, we shall be able then to apply the second
+of Kepler's Laws, and by so doing shall be able to give a physical
+explanation of two scientific facts which up to the present have never
+been physically explained, viz. the physical conception of the plane of
+the ecliptic, and a physical explanation of the eccentricity of the
+earth's orbit, which is but the result of the application of Kepler's
+Second Law to the sun's orbital motion around its central body.
+
+
+ART. 108. _The Sun and Kepler's Second Law._--We will now proceed to
+apply the second of Kepler's Laws to the orbital motion of the sun, and,
+in so doing, shall find we are able to give at the same time a physical
+explanation of the eccentricity of the earth's orbit.
+
+In order to obtain a physical conception of the sun's orbital motion
+according to Kepler's First Law, it is essential that we should consider
+the effect of the existence of a central body around which the sun
+revolves; or, to put the matter into another form, we will ask the
+question as to what is the physical cause of the sun revolving round
+that central body?
+
+Let us look at the case for a moment. Here, according to astronomical
+observation, we find a certain phenomenon which takes the form of a huge
+body 865,000 miles in diameter moving through space with a velocity of
+nearly 500,000 miles per day. What then is the physical cause of the
+movement of this large sphere?
+
+Certainly there must be some physical cause, or else we have a violation
+of all experience, which indisputably teaches us that no body moves
+unless it is either pushed or pulled. We have, however, done away with a
+pulling power so far as the cause of the actual revolution of bodies
+around a central body is concerned, and in its place have substituted a
+medium that pushes or carries them round each central body. For over 200
+years the scientific world has accepted a pulling power, that is, an
+attractive power, solely as the cause of the movements of celestial
+bodies, with the result that the physical cause of all the motions of
+planets and satellites has been outstanding and undiscovered.
+
+It would, therefore, be unphilosophical to revert to the old conception
+of a gravitating attractive power as the sole cause of the sun's orbital
+motion through space. If we desire to know what is the cause of its
+revolution round that central body, then we must seek to find the same
+from the result of observation and experience in other directions.
+
+We have learned from Art. 102 that the orbital motion of the moon is
+caused by the electro-magnetic Aether currents that circulate round its
+central body, the earth. By the same means every satellite is circled
+round its central body also. We have also learned from Art. 99 that the
+earth is carried round the sun by the circulating and rotating
+electro-magnetic Aether currents, and that these same currents also form
+the physical cause of the revolution of all the other planets round
+their central body, the sun.
+
+Thus we arrive at the fact that wherever there is a body moving in
+space, it is moving solely because it is pushed along, or carried round
+its controlling centre by the rotating Aether currents. But we have just
+learned that the sun is moving through space, and that it describes an
+elliptic orbit around some central body in accordance with Kepler's
+First Law. So that the only philosophical conclusion that we can
+possibly arrive at in relation to the orbital motion of the sun is, that
+such motion is caused by similar electro-magnetic Aether currents whose
+circulating motion is partly caused by the rotation of that central
+body.
+
+Thus we are led up to the philosophical conclusion, that it is the
+aetherial currents of the central body around which the sun revolves,
+that produce, and alone produce, the onward motion of the sun through
+space. Any other conclusion must be unphilosophical, and therefore
+untenable. We have, therefore, to conceive of the sun's central body
+generating and giving rise to electro-magnetic aetherial currents that
+extend through space to the limits at least of the solar system, and
+these aetherial currents, acting upon the sun's huge form by their
+kinetic energy, carry it with all its associated worlds through infinite
+space.
+
+There is nothing extravagant in this conception, when we remember that
+the solar system has been moving on and on through infinite space year
+after year, and yet it never seems to get appreciably nearer to the
+other stars, but I hope to show the reason of this by strictly
+philosophical reasoning later on. With this conception of the sun in its
+relation to its central body we are now in a position to consider the
+application of Kepler's Second Law upon the sun's orbital motion, and
+its resultant effect upon the orbit of our earth and all the other
+planets.
+
+From Kepler's Second Law we know that equal areas are described by the
+radius vector in equal times, and if the first law of Kepler is at all
+applicable to the sun, then it must follow that if the sun has an orbit,
+and moreover an elliptic orbit as stated by Kepler himself, then, as a
+natural result, the radius vector of the sun must move over equal areas
+in equal times.
+
+The physical explanation of Kepler's Second Law was given in Art. 103,
+and there is no need to traverse the same ground again. It is,
+therefore, true that the sun moves faster in certain parts of its orbit
+than in others, being urged through space at its greatest velocity when
+it is nearest its controlling centre, and slowest when farthest away
+from that controlling centre.
+
+Herschel, in his work on _Astronomy_, states: "The motion of the sun will
+be such that equal areas are thus swept over by the revolving radius
+vector in equal times in whatever part of the circumference of the ellipse
+the sun may be moving." He, however, suggested that the earth forms a
+focus of the sun's ellipse, a suggestion which is unphilosophical, it
+seems to me, as we might equally suggest that the earth revolves round the
+moon, which is contrary to all observation. Thus the sun is not carried
+uniformly through space by the aetherial currents of its central body,
+because it is nearer to that central body at certain times; its velocity
+being regulated by its distance from that body, the same being increased
+as the distance is decreased, and decreased as the distance increases.
+
+Now if this reasoning be correct, and if the sun really moves round a
+central body and is subject to Kepler's Second Law, then that increase
+and decrease of distance will be made manifest in the increase and
+decrease of the eccentricity of the earth's orbit.
+
+So that if the eccentricity of the earth's orbit should vary from
+century to century, then we have conclusive evidence that the sun obeys
+the first and second of Kepler's Laws, and therefore that it revolves
+around a controlling centre of its own. From observation we find that
+this is exactly what is happening, and that at the present time the
+eccentricity of the earth's orbit is gradually diminishing, and in about
+24,000 years the orbit will be very nearly a circle.
+
+Now, from what was stated in Art. 106, we know that the moon's orbit
+will be nearly a circular orbit when the earth is farthest from the sun,
+and that then its orbital velocity is at a minimum.
+
+In order for this result to be produced, the earth must reach that part
+of its orbit known as aphelion, where the distance from its controlling
+centre is greatest, so that the eccentricity of the moon's orbit is
+always an indication of the position of the earth in its relation to the
+sun. When the eccentricity of the moon's orbit is decreasing, the
+earth's distance from the sun is increasing, but when the eccentricity
+of the moon's orbit is increasing, then the earth's distance from the
+sun is decreasing.
+
+Now if we apply this analogy to the eccentricity of the earth's orbit,
+we shall be able to obtain some idea of the relation of the sun to its
+central body. We find then that the eccentricity of the earth's orbit is
+decreasing, therefore, arguing from analogy, we arrive at the conclusion
+that the sun's distance from its controlling centre is increasing, and
+that its orbital velocity is decreasing.
+
+If it be true that in 24,000 years the earth's orbit will be nearly
+circular, then it follows that in 24,000 years the sun will be at that
+part of its orbit corresponding to the aphelion of the orbit of the
+earth, that is, its distance from its controlling centre will then be at
+a maximum. After that the eccentricity of the earth's orbit will begin
+to increase, and will continue to increase for about 40,000 years,
+according to some scientists, which implies that the sun will then have
+started from its aphelion point, so to speak, and will begin its return
+journey towards its central body, gradually getting nearer and nearer.
+As it gets nearer its orbital velocity will be proportionately
+increased, with the result that the eccentricity of the earth's orbit
+will increase also. From a consideration of the movement of the major
+axis of the earth's orbit, which is moving forward at the rate of
+11 deg. per year, we are told that a whole revolution will be made in
+108,000 years.
+
+We have here, then, an indication of the time that the sun takes to
+revolve round its central body, because the time of the whole revolution
+of the eccentricity of the orbit should correspond with one complete
+revolution of the sun around its central body. So that from a
+consideration of the eccentricity of the earth's orbit, we are not only
+able to demonstrate that the sun satisfactorily fulfils the first and
+second of Kepler's Laws, but, conversely, we are able to give a
+satisfactory physical explanation of the cause of the eccentricity of
+the earth's orbit, which explanation is again primarily to be found in
+the universal Aether medium.
+
+
+ART. 109. _Plane of the Ecliptic and Zodiacal Light._--As already
+pointed out, another phenomenon which can be physically accounted for by
+the sun's orbital motion through space around its central body, is that
+celestial plane known as the Plane of the Ecliptic.
+
+What then is the Plane of the Ecliptic whose physical explanation we are
+to attempt? We know that the moon revolves round the earth as the earth
+revolves round the sun, while the sun is pursuing its way through space.
+It has been found also, that all these motions of these different bodies
+take place on one level, so to speak; that is to say, they do not go up
+or down in space, but straight on.
+
+So straight do they move, that their path has been likened to the level
+of the ocean, on which a ship may sail for thousands of miles, always
+keeping the same level and even course. On some such ocean as this in
+space all the planetary systems and solar systems seem to move, ever
+moving on and on with the same uniformity of level through infinite
+space. Further, this plane of the ecliptic is to the celestial sphere
+what the sea-level is to the earth. The height of a mountain on the
+earth is stated to be so much above the sea-level.
+
+In a similar way astronomers say that a star is a certain height above
+the plane of the ecliptic. What then is the physical explanation of this
+scientific term? We will lead up to it by first considering the effect
+that rotation has upon a liquid body.
+
+It has been demonstrated that if a mass of oil is placed in a
+transparent liquid of the same density, so long as the oil is perfectly
+at rest, its shape will be that of a sphere which will float about in
+the liquid, but as soon as the oil is made to rotate by means of a piece
+of wire, then the spherical shape is changed into that of an oblate
+spheroid.
+
+Further, the faster it is made to rotate, the more it will bulge out, so
+that its equatorial diameter will greatly exceed its polar diameter. The
+same principle may be illustrated by making a hoop to revolve rapidly on
+its axis, when a similar effect of bulging out will be produced.
+
+Now let us apply this principle to the earth with its electro-magnetic
+Aether currents circulating round it, and ask what is the effect of the
+rotation first upon the earth, and then upon the rotating Aether
+currents?
+
+It is a matter of common knowledge that the effect of rotation upon the
+earth when it was in a fluid state was to make its equatorial parts
+bulge out as it rotated, with the result that as it solidified the
+equatorial diameter exceeded the polar diameter by 26 miles.
+
+If, therefore, the result of rotation upon the earth when in its fluid
+state was to make it spread out greater in the equatorial regions than
+in any other part of its surface, what must be the effect of a similar
+rotation upon the rotatory Aether currents? It can easily be seen that
+the rotation of these currents will be to make them spread out into
+space in a region which corresponds to the equatorial regions of the
+earth, so that the rotating Aether currents will be congregated more in
+the equatorial regions of the earth than in any other part of the
+earth's surface. The further also they extend into space the less depth
+they will have, gradually tapering off, as shown in the illustration,
+where _E_ represents the earth and _B_ _C_ the Aether currents (Fig. 29).
+
+Any body, therefore, situated within the sphere of their influence would
+be carried round the earth by the currents, and the currents would be to
+them their governing and controlling level.
+
+So that the moon, which is held bound to the earth by the two opposite
+and equal forces, would always be carried around the earth by those
+electro-magnetic Aether currents, and outside of those currents it could
+not pass. But the earth is only 8000 miles in diameter, therefore if the
+currents gradually tapered off as suggested, by the time the aetherial
+currents reached the distance of the moon, their depth would not exceed
+2000 or 3000 miles.
+
+The diameter of the moon is, however, only 2160 miles, so that the
+rotating Aether currents would practically form an ocean in which the
+moon would swim, and one constant level on which it revolves in space.
+Wherever the earth was carried by the aetherial currents of the sun,
+there the aetherial currents of the earth would carry the moon, its mean
+distance by the conjoint working of the two co-equal forces having been
+permanently fixed.
+
+[Illustration: Fig: 29.]
+
+So that it can be readily seen, as regards the moon, that the earth's
+aetherial currents form the plane on which it revolves around the earth.
+Now in exactly the same way it can be proved that it is the sun's
+aetherial currents which form the plane or level on which all the
+planets revolve or are carried around their central body. We have only
+to enlarge our conception and the same result follows. Instead of
+dealing with a body 8000 miles in diameter, we are now dealing with a
+body 865,000 miles in diameter, and as this huge body is more or less in
+an incandescent state, the aetherial currents will therefore be
+proportionate in intensity and flow to its size and atomic activity.
+
+Instead, therefore, of the aetherial currents which circulate round the
+sun only extending a quarter of a million of miles, their energy and
+flow extend far away into space, even beyond the greatest distance of
+Neptune, a distance of 2,800,000,000 miles. The same truths apply here,
+however, as in the case of the earth and the moon. The aetherial
+currents which circulate round the sun congregate together, and possess
+their greatest depth nearest to the equator, while the further away they
+recede, the less and less depth they possess, with a decreased intensity
+and decreased kinetic energy. These Aether currents will be to all the
+planets, therefore, what the earth's aetherial currents will be to the
+moon, being to them the ocean level on which they alone can move, and by
+which they are carried round their central body.
+
+Thus these currents will form for all the planets the level in infinite
+space upon which they float, and from which they cannot pass. Let us
+further consider the movements of these currents in space, and we shall
+find further confirmation of this fact by so doing. Astronomers tell us
+that it takes light about three and a half years to reach us from the
+nearest star. By calculation, therefore, we find that the nearest star
+to our system is about 205,000,000,000,000 miles away, that being about
+the distance that light travels in three and a half years.
+
+The diameter of the sun is about 865,000 miles, so that the distance of
+the nearest star is 240,000,000 times the diameter of the sun. We could
+therefore put 240,000,000 of our solar systems in the space that exists
+between us and the nearest star. How is it, then, that all the planets
+as they revolve round the sun do not float up and down in the space that
+extends between us and the nearest star?
+
+I can give no other answer, and can see no other possible physical
+explanation than the one already given, which is, that they are bound to
+the sun by the two co-equal forces, the centrifugal and centripetal
+forces, and while so bound are carried round the sun by the
+electro-magnetic aetherial currents which extend out into space. It has
+to be remembered that the aetherial electro-magnetic currents
+circulating round the earth are situated within the aetherial currents
+which circulate round the sun, therefore the plane of the moon's orbit
+will coincide more or less with the plane of the earth's orbit. We have
+now only to go one step further to get our complete conception of the
+plane of the ecliptic.
+
+In Arts. 107 and 108 we learned that the sun was subject to Kepler's 1st
+and 2nd laws, and as a natural result we came to the conclusion that it,
+too, was circled round some central body. We have only to apply a
+similar course of reasoning to the sun and its central body as we have
+to the moon and the earth, and the earth and the sun, and then we arrive
+at our physical conception of the plane of the ecliptic, which is due to
+the aetherial currents that circle round the sun, while that body is
+carried round some other central body.
+
+Thus by the circulating Aether currents, originated and outflowing from
+their respective sources, each source being immutably fixed and bound to
+each other by the two equal and complementary forces, can be accounted
+for, the uniformity of position and plane of the various orbits of the
+various satellites, planets, and the sun, as they move in one great
+plane, termed the Plane of the Ecliptic.
+
+It could not be otherwise than it is, and thus another celestial
+phenomenon can be accounted for on a real tangible basis by accepting
+the existence of those aetherial currents which form the physical basis
+of all the celestial mechanism.
+
+If further evidence were required of the existence of these rotating
+Aether currents round the sun, such evidence is found in that phenomenon
+of the solar system known as the Zodiacal Light, of which up to the
+present no physical explanation has been forthcoming. In the conception
+of the atomic and gravitating Aether which rotates round the sun, I
+venture to premise will be found the physical solution of this
+phenomenon also.
+
+I will refer the reader to an extract taken out of _Outlines of
+Astronomy_, by Herschel (Art. 894), so that we may see what his
+conception of the zodiacal light was, and we will see how far his
+explanation is in conformity with our hypothesis of an atomic,
+gravitating and rotatory Aether medium.
+
+He writes: "We shall conclude this chapter by the mention of two
+phenomena, which to me indicate the existence of some slight degree of
+nebulosity about the sun itself, and even to place it in the list of
+nebulous stars. The first is that called the Zodiacal Light, which may
+be seen any very clear evening soon after sunset, about the months of
+March, April and May, as a cone or lenticularly-shaped light extending
+from the horizon obliquely upwards, and following generally the course
+of the ecliptic, or rather that of the sun's equator. The apparent
+angular distance of its vertex from the sun varies, according to
+circumstances, from 40 deg. to 90 deg., and the breadth of its base
+perpendicular to its axis from 8 deg. to 30 deg. It is extremely faint
+and ill-defined, at least in this climate, though better seen in
+tropical regions, but cannot be mistaken for any atmospheric
+meteor or aurora borealis. It is manifestly in the nature of a
+_lenticularly-formed envelope surrounding the sun_, and extending
+beyond the orbits of Mercury and Venus, and nearly, perhaps quite,
+attaining that of the earth, since its vertex has been seen fully 90
+deg. from the sun's place in a great circle. It may be conjectured to
+be no other than the _denser part_ of that medium which we have some
+reason to believe resists the motions of comets; loaded perhaps with
+the actual materials of the tails of millions of those bodies of which
+they have been stripped in their successive perihelion passage. If its
+particles have inertia, they must necessarily stand with respect to
+the sun in the relation of separate and independent minute planets,
+each having its own orbit, plane of motion, and periodic time."
+
+Let me call the reader's special attention to one or two statements of
+Herschel's given in this extract, in order to see how these statements
+harmonize with the view of the Aether submitted in this work. In the
+first place he states its shape is that of a lenticularly-formed
+envelope surrounding the sun, and extending beyond the orbits of Mercury
+and Venus, and probably to our earth. This harmonizes with the shape of
+the aetherial envelope as given in Art. 70. Then Herschel states it may
+be the denser part of that medium which we have reason to believe
+resists the motions of comets. That is exactly what it is, though
+Herschel failed to show why it should be the denser part of the Aether,
+as we have seen is the case, on account of its being gravitative. I will
+also prove later on, that Herschel was right with regard to the
+resistance of the motion of comets through it. Then he refers to its
+particles probably possessing inertia, as though he had anticipated the
+atomicity of the Aether, and assuming that atomicity, he was compelled
+to postulate inertia also as we have done in Art. 48.
+
+Lastly, he points out that each separate particle must have its own
+plane of motion, its own orbit, and its periodic time. Now this view
+fully coincides with that laid down in this article, where we have
+learned that the rotating Aether has its own plane of motion, that plane
+being the Plane of the Ecliptic, and as every particle or atom has its
+allotted place in the rotating Aether, then, as Herschel points out, the
+particle must have its own orbit, and plane of motion, and also its own
+periodic time. If, therefore, we had desired fuller confirmation of this
+atomic gravitating Aether, we could not have wished for more conclusive
+proof than that given by one of the greatest philosophical astronomers
+of the last century. We shall see later that Herschel also had a clearer
+view of cometary phenomena, and of the forces which played a part in
+those phenomena, than any of his contemporaries, when we deal with the
+origin and motions of all comets. Thus from Herschel we learn that the
+zodiacal light is caused by the atomic, gravitating, and rotatory Aether
+as that aetherial medium revolves round the sun, while at the same time
+every atom of the medium is itself in a state of rotation on its axis,
+as it performs its journey in its own orbit and in its own plane of
+motion.
+
+
+ART. 110. _Centripetal Force._--We have now to consider what is the
+physical cause of that part of the compound Law of Gravitation known as
+the Centripetal Force. As we have already learned (Art. 10), this force
+is really none other than the Attractive Force of Gravitation, in that
+its mode of operation always acts towards the centre of the attracting
+body, and hence was called by Newton the Centripetal Force.
+
+The centripetal force is, however, the exact counterpart and complement
+of the centrifugal force, in the same way that the latter is the exact
+counterpart of the former, as we have already learned that the
+centrifugal force operates along the same path, and that it is subject
+to the same law of proportion, being equal to the product of the masses
+of a body (Art. 85), and further, that its intensity is inversely as the
+square of the distance (Arts. 66, 74 and 84).
+
+We have, however, discovered that the physical cause of the centrifugal
+force is due to the pressure of the electro-magnetic Aether (Art. 96).
+If, therefore, the physical cause of that law which is the complement
+and counterpart of Gravitation Attraction is to be found, and alone
+found, in the pressure and motions of the electro-magnetic Aether, then
+it is only logical and reasonable to infer that the physical cause of
+the Attraction of Gravitation is to be found in the same
+electro-magnetic Aether. That the Attraction of Gravitation is to be
+found in this medium is now an accepted hypothesis among scientists.
+Because, unless the physical cause of Gravitation Attraction is to be
+found in this electro-magnetic Aether, then, in order to account for
+that attraction, we should have to postulate the existence of another
+medium in space, in lieu of the Aether, which would be to the
+centripetal force what the Aether is to the centrifugal force. This
+would be distinctly unphilosophical, as it would be a violation of the
+first two rules of our philosophy, in that it would not be simple in its
+conception, and that such a hypothesis would imply the existence of two
+media which would occupy the same planetary and interstellar space at
+one and the same time, and this is a violation of all experience in its
+widest form.
+
+Therefore the physical cause of Gravitation must be sought for in the
+same medium which gives the physical cause of the companion force, and
+that medium is the electro-magnetic Aether. Professor Preston in his
+_Theory of Light_ is of this opinion. In Art. 327 he writes: "To account
+for the propagation of heat and light, that is, of radiant energy, we
+have postulated the existence of a medium filling all space. But the
+transference of the energy of radiant heat and light is not the only
+evidence we have in favour of the existence of an Aether. Electric,
+magnetic and electro-magnetic phenomena and Gravitation itself point in
+the same direction."
+
+Professor Lodge, in his _Modern Views of Electricity_, is even more
+explicit in his statement of the case. On page 338 he states:
+"Gravitation is explainable by differences of pressure in the medium
+(_i. e._ the Aether) caused by some action between it and matter not
+yet understood." Further, Newton himself suggested that the physical
+cause of Gravitation Attraction was to be found in that aetherial medium
+which pervaded all space.
+
+If, therefore, we attempt to explain the physical cause of Gravitation
+Attraction by the tensions of the universal Aether, we shall not only be
+dealing with the subject from a philosophical standpoint, but we shall
+solve the problem in that direction in which Professors Preston and
+Lodge and other scientists have suggested we are to seek for the
+solution. Professor Curry, in his _Theory of Electricity and Magnetism_,
+page 406, states: "If we regard the luminiferous Aether, as defined by
+Von Helmholtz's equations, as the given medium or transmitter of
+so-called gravitating action, we are then able on the one hand to
+interpret its longitudinal oscillations as gravitational waves
+propagated through space with the given enormous velocity, and on the
+other hand, to form some conception of the mysterious force of
+Gravitation itself, for we can then conceive it as a medium stress
+arising from a certain type of Aether oscillations, its longitudinal
+ones, that pervade entire space."
+
+Now in order for us to lead up to the physical cause of the centripetal
+force, we must recall some of the facts already given with regard to
+planetary and solar space. Thus we have learned that the sun is an
+electro-magnet possessing its own magnetic field, with its lines of
+force (Art. 88). We have also learned that all the planets are
+electro-magnets, each possessing its own field with its lines of force
+(Art. 91).
+
+We have further seen that the cause of all this electro-magnetism is due
+to the fact that electric currents are continually circulating round
+each body, and by their conjoint action with the magnets there are
+produced the electro-magnetic fields that are associated with each body
+in the solar system. From this hypothesis we arrived at the conclusion,
+that wherever there was Aether, there we found electricity, because of
+the electro-magnetic basis which Aether possesses. This result is fully
+confirmed by Maxwell's electro-magnetic theory of light (Art. 78), which
+has been so fully experimentally demonstrated by Hertz. Indeed, in the
+minds of several scientists there is a growing conviction that Aether
+and Electricity are possibly one and the same substance.
+
+Professor Lodge, in the work already referred to, in relation to this
+hypothesis, writes in the preface to that book: "Crudely, one may say
+that as heat is a form of energy, so electricity is a form of Aether, or
+a mode of aetherial manifestation." And again: "A rough and crude
+statement adapted for popular use is that _Electricity and Aether are
+identical_. But that is not all that has to be said, for there are two
+opposite kinds of electricities, and there are not two Aethers. But
+there may be two aspects of one Aether, just as there are two sides to a
+sheet of paper."
+
+As, therefore, we learn that Aether has an electro-magnetic basis, and
+that electricity is a mode of aetherial manifestation, we have therefore
+to consider one of the most fundamental laws of electricity, and note
+its application to solar and planetary space.
+
+It is one of the fundamental laws of electricity, that equal and
+opposite quantities of electricity are always generated at one and the
+same time. Faraday's well-known ice-pail experiment proved this. It is
+an absolute impossibility for one kind of electricity to be generated
+without an equal quantity of the opposite kind being produced, although
+it is not strictly correct to use the term generated or produced in
+relation to electricity, as electricity cannot really be produced by any
+process whatever.
+
+Another way of stating this law is, that the total induced charge on any
+body is always equal and opposite to the inducing charge. So that if we
+look upon the sun as an electrified body (Art. 80) surrounded by the
+aetherial envelopes or shells, then we can conceive of the inductive
+action of the sun upon any planet as taking place along the tubes of
+force in the Aether, which tubes are sections of the spherical envelopes
+that surround it. But this inductive action implies the existence of the
+very law already enunciated, viz. that equal and opposite quantities are
+always generated at one and the same time, and before that law can
+become operative in relation to the Aether, it must be postulated that
+the Aether possesses a dual character, that is, it possesses a positive
+and negative electrical basis.
+
+This view of the Aether has already been developed by Dr. Larmor in his
+Electron Basis of the Aether, as in that hypothesis he postulates both
+positive and negative electrons. In his _Aether and Matter_ he writes,
+page 3: "It assumes that the mass of each sub-atom is proportional to
+the absolute number of electrons, positive and negative, that it
+carries, and that the effective interatomic forces are entirely or
+mainly electric." Further, Professor Lodge on this point writes:[40] "We
+now proceed a step further and analyze the Aether into two constituents,
+two equal opposite constituents, each endowed with inertia and each
+connected to the Aether by elastic ties. The two constituents are called
+positive and negative electricity respectively, and of these two
+electricities we imagine the Aether to be composed." Again, later on, p.
+349 of the same work, he adds: "Is Aether electricity then? I do not say
+so, but that they are connected there can be no doubt. What I have to
+suggest is, _that positive, and negative electricity together may make
+up the Aether_."
+
+Now, accepting this as correct, and I will prove that it is correct later
+on, from experiments performed by Faraday, we can see how the inductive
+action of the sun may be transmitted through space, and how that inductive
+action will effect any body in its electrical field, such inductive action
+always taking place through the polarization of the atomic Aether, and
+taking the form of an attractive power which is exerted towards the
+centre of the attracting body.
+
+Further, this inductive action will be subject to the same laws of
+electricity as the centrifugal force is, which is the repulsive power
+due to the pressure of the Aether. Therefore the inductive action of the
+sun upon any body will, according to the laws of electricity, act
+inversely as the square of the distance (Art. 84), and will be directly
+as the product of the charges on the two attracting bodies, which we
+have seen according to Art. 85 is equal to the product of their masses.
+Not only will this inductive action apply to the sun, but it will
+equally apply to all planets, satellites and stars that exist in the
+heavens, each of these bodies according to Art. 80 being an electrified
+body possessing its electric field and lines of force radiating out into
+space.
+
+Thus we arrive at the conclusion, that each body in the solar system is
+not only the centre of a centrifugal force due to the pressure of the
+electro-magnetic Aether, but that it is also the centre of an attractive
+force due to the existence of the positive and negative elements of the
+Aether, and of their attractive power for each other.
+
+This attractive power is also subject to exactly the same laws that the
+centrifugal force is subject to in regard to intensity, proportion, and
+the direction which it takes. So that we have now two centripetal forces
+existing in space, which exactly correspond with each other, viz.
+Gravitation Attraction and the attraction due to Electrical Induction.
+The cause of one, however, is known, being due to the inductive
+influence of the various electrified bodies that exist in space, which
+inductive influence can be traced through the whole of the atomic Aether
+that exists between the two bodies, whereas the cause of the centripetal
+force or Gravitation Attraction is unknown. According to the Rules of
+Philosophy, therefore, it will be much simpler if we replace our
+Gravitation Attraction, whose cause is unknown, by the inductive power
+of the various bodies, the physical cause of which lies in the
+electro-magnetic Aether, or the dielectric as Faraday called it. In
+other words, we are compelled to come to the conclusion that the
+centripetal force, or Gravitation Attraction so called, is an electrical
+phenomenon, which finds its physical cause in the same universal Aether
+that the centrifugal force does.
+
+Unless this view of the attraction of Gravitation is accepted, we should
+have two forces operating between all bodies, both operating at exactly
+the same time, in exactly the same direction, and with exactly the same
+intensity, and this phenomenon according to Newton would be
+unphilosophical. In Art. 4 we learn that Newton in the first rule states
+that "Nature is simple, and does not abound in superfluous causes of
+things." And again: "In the nature of Philosophy nothing is done in vain;
+and by means of many things, it is done in vain when it can be done by
+fewer." Here then we have apparently two forces which act in the same
+molecular or planetary or interstellar space, at one and the same time.
+Therefore if this be true, Nature does abound in a superfluous cause,
+because we have two forces in existence where one will suffice, and one
+of them therefore exists in vain. So that it will be philosophical if we
+do away with one of the causes, and replace the two causes by only one.
+Now which shall be done away with--the electrical attraction which is due
+to a physical medium, the electro-magnetic Aether, or the Gravitation
+Attraction, that is caused by some virtue of a body of which we have no
+knowledge, which is transmitted through space in a way that we cannot
+understand, and acts upon distant bodies in a manner altogether outside
+our usual experience and observation? There can only be one answer. If
+either of the two forces has to be done away with, it must be the
+mysterious, intangible, unphilosophical attraction of Gravitation, which
+must be replaced by the philosophical and known attraction of electricity,
+which can be traced to a physical medium, the electro-magnetic Aether that
+joins atom to atom, molecule to molecule, satellite to planet, planet to
+sun, and sun to star, and so gives unity to the universe of worlds. From
+philosophical considerations, therefore, we are compelled to come to the
+conclusion that the attraction of gravity and electrical attraction are
+one and the same.
+
+Faraday arrived at this conclusion and performed certain experiments to
+confirm that conclusion, but he was unable to experimentally prove the
+truth. It does not follow, however, that because he failed to
+experimentally establish the connection, therefore the conclusion is
+wrong. In his _Experimental Researches_ he writes, par. 2705, "On the
+possible relation of gravity to electricity":--"First of all, a body
+which was to be allowed to fall, was surrounded by a helix, and then its
+effect in falling sought for." This experiment Faraday states produced
+negative results (par. 2706). "A solid cylinder of copper was introduced
+into the helix, and carefully fastened to it, and this compound
+arrangement was allowed to fall." "The result of this experiment may be
+classified as doubtful. It gave very minute, but remarkable indications
+of a current in the galvanometer, and the probability of these being
+related to gravity appeared the greater, when it was found, in raising
+the helix or core, similar indications of contrary currents appeared."
+In par. 2717 Faraday thus sums up: "Here end my trials for the present.
+The results are negative. They do not shake my strong feeling of the
+existence of a relation between gravity and electricity, though they
+give no proof that such a relation exists." Here then we have expressed
+the strong conviction of the relation that undoubtedly exists between
+gravity and electricity by one of the greatest scientists that has ever
+lived, and I believe that it is a fact that he was engaged upon
+experiments to prove his conviction about the time of his death.
+
+We will now endeavour to trace the action of the Law of Gravitation in
+its compound working, in its application to the atomic Aether that fills
+all space, and by its gravitating property surrounds all bodies situated
+in that space. We are dealing no longer with a frictionless medium,
+which is incapable of accepting and transmitting motion of any kind or
+sort, but we are now dealing with a medium composed of atoms, which can
+give rise to pressures and tensions, or repulsions and attractions from
+any one part of space to another.
+
+If we can prove that an atomic Aether can give rise to these pressures
+and tensions from one body to another, and those pressures and tensions
+harmonize with, and satisfactorily account for, the phenomena sought to
+be explained, then we shall have succeeded in making our philosophy
+agree with our experience, and such a result as action at a distance
+will for ever disappear from the mental conception of all men, as it has
+long disappeared from the pages of philosophical and scientific works,
+though that disappearance was not accompanied with a satisfactory
+solution of the problem.
+
+Let us, therefore, consider these pressures and tensions, or so-called
+repulsions and attractions that exist in this electro-magnetic Aether
+from the atomic standpoint, and by so doing try to realize how it is
+that one body, as the sun, acts upon another body, as the earth, through
+the intervening medium, the Aether. We can either consider it from the
+material standpoint, that is, by considering the Aether as matter, pure
+and simple, or by viewing it from the electrical standpoint, which may
+be considered from Clerk Maxwell's physical conception of an electric
+field. We will briefly consider it from the latter standpoint. Our
+conception of an aetherial atom was that of a spherical vortex atom
+possessing polarity and rotation on an axis. We must, however, make the
+distinction between the two kinds of aetherial atoms that Clerk Maxwell
+first indicated in his paper on Physical Lines of Force, _Phil. Mag._,
+1861, and that Dr. Larmor has worked out in his _Aether and Matter_ from
+the electron standpoint, viz. that the Aether is composed of positive
+and negative electrons. Or we can accept Professor Lodge's theory, that
+Aether is made up of positive and negative electricity. We are compelled
+to accept the hypothesis of two kinds of aetherial or electrical atoms,
+whatever they may be called, in view of the teaching of electricity,
+that positive and negative electricity are always to be found in
+association, and in combination, wherever electricity exists. We have
+proved that electricity is to be found throughout the realm of space
+(Art. 78); therefore in all planetary and stellar regions electricity is
+present. Thus it exists in the so-called space between the sun and
+planets, and between the planets and satellites, forming around them all
+spherical shells, that become less and less dense as they recede from
+the central body. Now it is by the action of these positive and negative
+electrical atoms, that the attraction of one body is transmitted across
+space from the sun to the earth, or from the earth to the sun, or from
+the earth to Jupiter, or from Jupiter to any of the planets, the action
+always taking place along the line joining the centres of gravity of the
+bodies, _i. e._ the radius vector, and with a force equal to the
+quantities of electricity in association with those bodies (Art. 85),
+and with an intensity that always acts inversely as the square of the
+distance. Thus the inductive action of any sun, planet or satellite, or
+any other planet or satellite, can be mentally traced from atom to
+atom, across the intervening space, that is filled with the atomic
+Aether, between any two attracting bodies. So that, if the sun attracts
+the earth, it attracts it by and through the motions and properties of
+the electro-magnetic Aether that is made up of positive and negative
+electricity, and that attraction, being produced by a physical medium
+which is as real and tangible as air or water, is brought into harmony
+with our experience and observation, as no body pushes or pulls another
+body, be it what it may, unless both bodies are joined together by some
+medium which transmits the push or the pull. Professor Lodge, in his
+_Modern Views of Electricity_, has illustrated from an electrical
+standpoint how the pressure and tension in any electrical field may be
+transmitted from particle to particle, or atom to atom. He supposes that
+a positive atom of electricity rotates in one direction while a negative
+atom rotates in the opposite direction. In any electric field these
+atoms are so associated with each other, that when one atom revolves, it
+makes the other to revolve in the opposite direction, with the result,
+that the spin or rotation is transmitted through the medium at a speed
+dependent upon the density of the medium.
+
+For fuller details of the description I must refer the reader to the
+work already referred to. What I wish to call the reader's attention to
+is, that the tension and pressure in this field is not transmitted
+across a vacuum, in some unknown way, but is transmitted solely by a
+physical medium. The action is direct, and is produced, and alone
+produced, continued, and perpetuated by a physical medium which is
+composed of atoms of negative and positive electricity. So that if one
+body _A_ acts upon another body _B_, it acts upon _B_ solely and
+entirely by the action of the atoms which form the magnetic lines of
+force, and the equipotential surfaces around the electrified body, and
+that action can be traced mentally step by step across the intervening
+space that may exist between the two bodies. It is in an exactly similar
+manner, that the Attraction of Gravitation, which we conceive to be the
+same as electrical attraction, is transmitted from body to body in the
+atomic, molecular, planetary or stellar world. In each and every case,
+the pressure and tensions, which are inseparably connected, are
+transmitted by the atoms of the electro-magnetic Aether, that is, by the
+positive and negative atoms of electricity of which, according to
+Professor Lodge and Dr. Larmor, the Aether is composed. So that, if the
+sun acts on the earth, by the centrifugal force, it acts on it solely
+through and by the pressures which are originated in the atomic Aether
+by the central body. If the sun attracts the earth, by the centripetal
+force, that action can also be traced to the tensions that are
+originated among the atoms of the electro-magnetic Aether. There is
+nothing mysterious about the phenomenon in either case, as by accepting
+this view of an atomic Aether with its dual character of positive and
+negative electricity, the action may be traced mentally from point to
+point across the so-called intervening space that exists between any two
+bodies. In each and every case, wherever the centripetal or centrifugal
+force acts, the action is direct, because it is caused by a physical
+medium, which physical medium is in direct contact with each body acted
+upon, and also fills the space between those bodies. With this view of
+the centripetal force of Gravitation, our Philosophy is made to agree
+definitely with our experience, which teaches us beyond contradiction,
+that no body moves, unless it is either pushed or pulled by a physical
+medium. Unless this view of the centripetal force is accepted, we shall
+have to stumble on in darkness as to the physical cause of the
+centripetal force, and mentally accept the unphilosophical proposition,
+that a body can act on another in a way that we cannot understand, and
+by means which lie outside our experience and observation, and this
+hypothesis, as Newton and Herschel pointed out, is distinctly an
+unphilosophical proposition.
+
+[Footnote 40: _Modern Views of Electricity_, p. 221.]
+
+
+
+
+                              CHAPTER XII
+
+                           AETHER AND COMETS
+
+
+ART. 111. _Comets. What are Comets?_--In addition to the planets and
+asteroids which revolve around the sun, there are also other bodies
+termed Comets, which revolve round the solar orb.
+
+Unlike the planets, however, they do not all keep to the plane of the
+ecliptic, but approach to, and recede from the sun at all angles to that
+plane, as well as in that plane itself. Comets are supposed to be huge
+masses of gaseous matter, in a more or less condensed condition. That
+they are not composed of absolutely solid matter is proved by the fact
+that it is possible to see the stars through the gaseous matter of which
+they are composed.
+
+How the gaseous matter of which these comets are formed is originated,
+or how it is formed in solar or stellar space, has, I believe, up to the
+present never been explained, and indeed, with the idea of a
+frictionless Aether, I fail to see how any physical explanation of the
+origin and development of a comet can be satisfactorily given. With the
+conception of the Aether, however, that is put forward in this work,
+viz. that Aether is matter in its most rarefied and attenuated form,
+which can be condensed into a gaseous condition, with such a conception
+of the universal aetherial medium, the origin and development of gaseous
+matter from this Aether becomes a physical possibility.
+
+Lord Kelvin, in the _Philosophical Magazine_, July 1902, on the
+"Clustering of Gravitational Matter in any part of the Universe," has
+already suggested the possibility of the condensation of the Aether, but
+with the old idea of a frictionless Aether, that is, an Aether which
+does not possess mass, such a hypothesis is improbable. Because, if the
+Aether becomes condensed at all, it must be condensed into gaseous and
+solid matter, and all experiments and observation teach us that both
+these forms of matter possess mass and weight.
+
+Therefore, if the frictionless Aether, which possesses no mass and
+weight, is to be condensed into gaseous or solid matter, there must come
+a period in the process of condensation when it must pass out of the
+condition of possessing no mass and no weight, into the condition of
+possessing mass and weight, which assumption is altogether opposed to
+those Rules of Philosophy based upon experiment and observation.
+
+Aether can only pass into a gaseous or solid condition, in which
+condition it will possess mass and weight, on the assumption that in the
+aetherial condition it possesses the same properties, only in a modified
+form, which it possesses after the process of condensation has taken
+place. In a similar way that air can pass out of its gaseous condition
+into a liquid condition, or any gas can pass out of its gaseous into a
+liquid condition, so Aether, on the conception as given in Chapter IV.,
+can pass out of its aetherial and rarefied condition into that form of
+matter which is known as gaseous. We shall deal with this aspect of
+Aether more fully when we come to deal with the Nebular Hypothesis, as
+the same principle underlies that hypothesis as underlies the origin and
+development of comets.
+
+Thus, comets may be formed at any time in interstellar space out of the
+Aether that exists there, provided the conditions of its formation are
+to be found there. Then, as they are gradually formed, they would, like
+any other bodies, come more directly under the influence of any large
+bodies, as the sun, and be attracted by them.
+
+This conception of the origin and development of a comet will also
+account, and that on a logical and philosophical basis, for another fact
+which is associated with cometary phenomena. I refer to the fact of the
+expulsion of gaseous matter out of the head of a comet as it nears the
+sun, which expulsion will be dealt with in the article on "Parts of a
+Comet."
+
+Another problem that might be solved by this conception of a comet lies
+in the question, as to whether comets shine by their own light?
+
+If comets are really formed of condensed Aether, as I believe them to
+be, then, as light is due to a periodic wave motion of the Aether, as
+soon as the Aether (of which the comets' tails, for example, were
+formed) was made to vibrate with that rapidity sufficient to produce
+light waves in the surrounding Aether, the tails would then shine by
+their own light, in exactly the same way that any other body emits light
+waves, as soon as its aetherial vibrations reach the rapidity necessary
+to produce the waves of light, which vibrations would lie between 2000
+to 8000 billions per second.
+
+The number of the comets that exist in the solar system cannot be
+ascertained with any degree of accuracy, but the total probably extends
+into millions. They are of all sizes, from those which possess diameters
+of several miles, to those extending over thousands of miles. They also
+possess orbits, with which we will now deal.
+
+
+ART. 112. _Orbits of Comets._--As has already been pointed out, comets
+perform their journey round the sun, not only in the plane of the
+ecliptic, but also at all angles relatively to that plane. In this
+respect they differ from the orbits of planets and satellites, which
+perform their journey in orbits situated wholly in the plane of the
+ecliptic (Art. 109).
+
+There is another important difference between the orbits of the comets
+and those of the planets. In the case of the latter the orbit is that of
+an ellipse, while in the case of the comet the orbit may be either that
+of a parabola or a hyperbola, which may be looked upon as elongated
+ellipses open at one end. There are, however, some comets whose orbits
+are perfectly elliptical, and whose return may be calculated with a fair
+amount of accuracy.
+
+These are known either as Short Period Comets, as represented by Faye's
+Comet, Encke's and De Vico's; or Long Period Comets, as represented by
+the comets of 1811, 1844, and 1858. In the case of all these, as their
+return to our solar system can be determined, it follows that they must
+revolve around the sun in some sort of a closed orbit, probably that of
+an exceedingly elongated ellipse.
+
+There are, however, other comets which appear once, or it may be several
+times only, and then disappear out of the solar system for ever. Now the
+question arises, as to whether the orbits of the comets which are so
+variable can be explained by the motions of the Aether which we have
+already ascribed to it? We have seen (Art. 109) how it is possible to
+account physically for the plane of the ecliptic from the motions of the
+Aether, and how it is that all the planets move within that plane, but
+here we have a phenomenon of a different kind, as observation distinctly
+teaches us that the comets do not move in, or keep within the plane of
+the ecliptic, but gravitate round the sun at all angles to that plane.
+
+In order for us, therefore, to be able to account, and that on a
+philosophical basis, for this fact, we must revert to our conception of
+the sun in its relation to the solar system. In Art. 88 we learned that
+the sun was an electro-magnet possessing its electro-magnetic field, and
+generating electro-magnetic waves which were radiated forth from it on
+every side. From Art. 89 we learn that an electro-magnetic body
+possesses lines of force, and that these lines of force take various
+directions as they are generated by the body, as proved by Faraday's
+illustrations. Further, a moving electro-magnet, as the sun for example,
+carries its lines of force with it, as proved by Maxwell.
+
+Now these lines of force extend not only east and west, but also north
+and south, as depicted in Fig. 29.
+
+Hitherto we have only dealt with the lines of force proceeding from the
+sun equatorially, which lines form the plane of the ecliptic. We have,
+now, to take into consideration those lines which extend out into space,
+north and south of that plane. These are not so curved as the others, but
+are more inclined to be straight, or less curved, as they are really
+parts of large curves which extend much further outwards into space.
+
+The orbits of the Short or Long Period Comets can be explained by the
+fact that they perform their journey more or less in the plane of the
+ecliptic, though in some cases at a much greater angle than that of any
+of the planets. Provided, however, they remain within the influence of
+the electro-magnetic field of the sun, there is then a physical
+explanation as to their orbital motion round the sun, in a similar way
+to the orbital motion of the planets, though at greater angles to the
+plane of the ecliptic.
+
+For we have to remember, that wherever the electro-magnetic waves of the
+sun's electro-magnetic field extend, there we have also the rotation of
+that field round its central body, though with a continually decreasing
+intensity, as already pointed out. Wherever, therefore, we get rotatory
+Aether currents, due to the rotation of the electro-magnetic field,
+there we get the conditions which would enable any kind of gaseous or
+material body to be circulated round the sun. The case, however, of
+comets which do not return has to be viewed from a different standpoint.
+Here it seems to me we are dealing with masses of condensed Aether that
+come within the inductive influence of the electro-magnetic waves of the
+sun, as that body moves through space with its velocity of about 500,000
+miles per day. We have to conceive of this condensed Aether situated
+north and south of the plane of the ecliptic, and situated probably
+millions of miles away. As the sun moves onward in its journey through
+space, carrying its electro-magnetic field with it, then, by the
+inductive action of the sun, the comet would be attracted by that body,
+and so would be gradually drawn towards it.
+
+Under this inductive influence it would rush towards the sun, until,
+approaching very close to it, it would be repelled by the
+electro-magnetic waves or centrifugal force of that body, and be hurled
+again by their repulsive energy far far away into space to the north or
+south of the plane of the ecliptic. As it was moving away from the syn,
+north or south of the ecliptic, the sun would be moving onwards through
+space in the plane of the ecliptic, which would practically be at right
+angles to the motion of the comet, so that by the time the comet had
+receded far into the depths of space, the sun with its electro-magnetic
+field would have moved on also in a direction at right angles to the
+comet's motion.
+
+The effect of the sun's orbital motion would be, that it would be unable
+to again exert sufficient inductive power upon the comet to bring it
+within its inductive influence once more. For example, suppose there is
+a mass of Aether condensing at point _A_ in interstellar space situated
+some millions of miles north of the plane of the ecliptic, which is
+represented by the straight lines _B_ _C_. The sun is moving in the
+direction towards the part of space represented by point _B_. We will
+suppose that when the sun is near point _C_ the mass of Aether at point
+_A_ is too far away to be appreciably influenced by the inductive action
+of the sun. But as the sun moves towards point _F_, then the condensed
+Aether, which practically forms the body of the comet, will come within
+its influence and be drawn towards the sun, at an angle to the plane of
+the ecliptic.
+
+[Illustration: Fig: 30.]
+
+By the time the body of the comet has reached the sun, it will have
+acquired a momentum which enables it to rush past the sun, and then it
+will be repelled by the electro-magnetic waves in the direction of _F_
+_G_, which is still at an angle to the plane of the ecliptic; but its
+motion, combined with the repulsive power of the electro-magnetic waves,
+is carrying it outside the sphere and influence of the sun's
+electro-magnetic field. At the same time the sun is proceeding onwards
+through space, leaving the comet far behind, so that by the time the
+comet has reached the confines of the solar system, it has either passed
+under the influence of another star, or has become further condensed to
+form a meteor, which begins to circle around the largest and nearest
+body. I do not assert that this hypothesis is strictly correct, but it
+seems to me that only on some such hypothesis can the appearance and
+apparent loss of irregular comets be explained.
+
+
+ART. 113. _Short Period Comets and Long Period Comets._--We have seen in
+the previous article, that some Comets revolve round the sun in closed
+orbits of exceeding great eccentricity, and the return of these may be
+calculated with certainty. There are about two dozen comets which revolve
+around the sun, and which return at intervals lying between three years
+and 76 years.
+
+This class of comets may be divided into two kinds, which are known as
+Short Period Comets and Long Period Comets respectively. The following
+table gives a list of the chief of the Short Period Comets, together
+with some particulars relating to time of revolution, etc.:--
+
+    COMETS.          PERIOD OF         PERIHELION         APHELION
+                    REVOLUTION.         DISTANCE.         DISTANCE.
+
+    Encke's    ...  3-1/4 years.    32,000,000 miles.   387,000,000 miles.
+    De Vico's  ...  5-1/2   "      110,000,000   "      475,000,000   "
+    Biela's    ...  6-1/2   "       82,000,000   "      585,000,000   "
+    D'Arrest's ...  6-1/2   "
+    Faye's     ...  7-1/2   "      192,000,000   "      603,000,000   "
+    Halley's   ... 76-3/4   "       56,000,000   "    3,200,000,000   "
+
+Encke's Comet was discovered by Professor Encke of Berlin, and named
+after him. It revolves in an ellipse of great eccentricity, as proved by
+the fact that when nearest to the sun, it is inside Mercury's orbit, but
+when furthest away from the sun, it passes beyond the orbit of Mars,
+reaching almost to the orbit of Jupiter. One of the most remarkable
+facts about this comet is, that it has done more to establish the
+existence of that resisting medium around the sun, whose existence we
+have demonstrated, than any other comet. Encke found on its periodical
+return that its mean distance was gradually getting less, and in order
+to account for this, he supposed that it was due to the existence of a
+resisting medium which enveloped the sun, and extended some distance
+into space.
+
+This conclusion has been supported in recent years by Von Asten, a
+German mathematician, who has supported the theory of a resisting
+medium. On this point Herschel writes in his _Outlines of Astronomy_,
+Art. 577: "This is evidently the effect which would be produced by a
+resistance experienced by the comet from a very rare aetherial medium
+pervading the regions in which it moves; for such resistance, by
+diminishing its actual velocity, would diminish its centrifugal force.
+Accordingly, this is the solution proposed by Encke, and at present
+generally received."
+
+So that we have in Encke's Comet another proof of the existence of that
+aetherial medium, which is not frictionless, but has the power to oppose
+any body which moves through it, when that body moves in an opposite
+direction to its own motions.
+
+Another Short Period Comet worthy of notice is that of Biela, named
+after M. Biela, its discoverer. This comet had a period of six and a half
+years, and reappeared at several successive intervals until about the
+year 1845, when it seems to have been broken or split up into two parts.
+In December 1845 the comet divided into two parts, which travelled
+parallel to each other for a long distance. During this separation, very
+singular changes were observed to be taking place in both the original
+comet and its offshoot.
+
+Both had a nucleus, and both had tails, which were parallel to each
+other. The comets continued to travel together until the 15th March
+1846, when the new comet began to fade away, until, on the 24th March,
+the old comet only was visible, while in April both had disappeared
+entirely. A similar phenomenon was again observed at its next passage in
+1852, but since then Biela's Comet has entirely disappeared. It is
+suggested by astronomers, that the comet has become condensed, and
+broken up, forming a shoal of meteors.
+
+Support is lent to this theory by the fact that in November 1872, when
+the earth was passing through space and had arrived at that part of its
+orbit which intercepted the orbit of Biela's Comet, instead of the comet
+being seen, the earth came into contact with a swarm of meteors, and
+this is accepted as evidence that Biela's Comet was condensed far away
+in the colder regions of interplanetary space into a more solid form of
+matter, known as meteors. One of the more famous of the short period
+class of comets is that known as Halley's Comet, which has a period of
+about 76 years. This comet has been seen in its return journey to the
+sun about 25 times. It was named after its discoverer, Edmund Halley. He
+was led to identify this comet with that of 1531 and 1607, and thus to
+conclude that it had a period of 75 or 76 years. He therefore predicted
+its reappearance in 1759. As the year approached, its arrival was
+eagerly looked for, to see if the prediction would be verified.
+
+It was thought, however, by a certain astronomer named Clairaut, that
+the larger planets, as Saturn and Jupiter, might interfere with its
+orbital motions, and after careful calculations a difference of 618 days
+was allowed, which brought its anticipated reappearance down to April
+1759. It actually reappeared in March of that year. Its next
+reappearance was fixed to take place about November 1835. The comet
+became visible on 5th August 1835, and continued to be seen till April
+1836, when it again disappeared.
+
+As the reappearance of the comet was calculated by the application of
+the Newtonian Law of Gravitation, such a result only gave added
+confirmation to the application of that law to cometary bodies.
+
+Of the Long Period Comets there are several known. That of 1858 has a
+period, it is thought, of 2000 years. The 1811 comet has a period of
+3000 years, while that of 1844 has a period of over 10,000 years. All
+these comets move in orbits of such great size that their return is
+improbable. One of the characteristic features about Long Period Comets
+is their great brilliancy and size.
+
+The 1858 comet, known as Donati's Comet, was first seen by that
+astronomer at Florence in June. It was invisible, however, to the naked
+eye, as it only appeared through the telescope like a faint cloud of
+light, gradually getting brighter and brighter. Toward the end of August
+it began to show signs of developing a tail, and became visible to the
+eye on August 29th. During September and October it greatly increased in
+size and brilliancy, and was plainly visible in the western heavens.
+After October 10th it was only visible in the southern hemisphere,
+gradually decreasing in brightness. It was seen till March 1859, when it
+disappeared, and will probably not return till the year 3858, as its
+period of revolution is about 2000 years.
+
+Donati's Comet passed between the earth and many stars, which could be
+seen very distinctly through its tail. One of the stars was Arcturus,
+and, though some of the densest parts of the comet passed over it, yet
+the star could be seen all the time, thus conclusively proving that the
+head and tail of a comet are only composed of gaseous matter, probably
+condensed Aether, as suggested in Art. 111.
+
+
+ART. 114. _Parts of a Comet._--A comet may be divided into three parts:
+1st, Nucleus; 2nd, Head or Coma; and 3rd, Tail.
+
+The nucleus is the central part of the head or coma, and is generally
+the brightest part of the whole comet. On the theory that a comet is due
+to the condensation of Aether, the nucleus would represent the first act
+in the process of condensation, as there would have to be some centre of
+condensation, and that centre would be represented by the nucleus.
+Further, the process of condensation would assume a spherical form, as
+the conception of our aetherial atom is that of a sphere or an oblate
+spheroid. As the process of condensation went on, the layers that would
+be produced would form a kind of envelope around the point of
+condensation, with the result that the nucleus would ultimately consist
+of a large mass of gaseous matter, made up of layer upon layer of
+condensed Aether around some central point, which formed the nucleus.
+
+This hypothesis agrees with observed phenomena, because, when we deal
+with the tails of comets, we shall see that the tail is simply formed by
+the reverse process to that of condensation, as in the case of cometary
+tails the gaseous envelopes so formed will be thrown off (either through
+heat generated by friction, or by the increased heat as the comet nears
+the sun), which are then repelled away from the sun by the centrifugal
+force. Herschel,[41] referring to the nucleus, states, paragraph 559:
+"An atmosphere free to expand in all directions would envelop the
+nucleus spherically," while in his Reflection on Halley's Comet, he
+states, Art. 570, "1st, That the matter of the nucleus of a comet is
+powerfully excited and dilated into a vaporous state by the action of
+the sun's rays, escaping in streams and jets at those points of its
+surface which oppose the least resistance. 2nd, That the process chiefly
+takes place in that portion of the nucleus which is turned towards the
+sun, the vapour escaping in that direction. 3rd, That when so emitted,
+it is prevented from proceeding in the direction originally impressed
+upon it, by some force directed _from_ the sun, drifting it back and
+carrying it out to vast distances behind the nucleus forming the tail."
+
+When we come to deal with the question of the formation of the tail, we
+shall find that every reflection made by Herschel is satisfactorily
+fulfilled by the conception of a gravitating and condensing Aether.
+Before considering the tail, however, we will deal with the head or
+coma.
+
+The head or coma is that part of the comet which exists round the
+nucleus. It is less bright than the nucleus, and oftentimes appears as a
+shadowy mass of light. Herschel, in his 4th Reflection, states that "a
+considerable part of the vapour actually produced remains in the
+neighbourhood of the nucleus forming the head or coma." So that the head
+of a comet is simply the vaporised part of the nucleus which is produced
+by the increased heat of the sun, in the same way that water would be
+vaporised by the addition of heat, the vapour in that case being thrown
+off in the form of steam.
+
+This formation of the head is but a continuation of the reversal of the
+process of condensation, which originally gave existence to the mass of
+matter termed the comet. The diameter of this head or coma often extends
+to thousands of miles. The head of the 1811 comet was 540,000 miles in
+diameter, while that of the 1843 was 112,000 miles. As the nucleus is
+formed of a series of envelopes, so the head also consists of a series
+of envelopes.
+
+The comet of 1858 constantly threw off these envelopes, which were first
+expelled _towards_ the sun, and then repelled away _from_ the sun,
+forming the tail. The matter forming the head and the nucleus is
+perfectly transparent, as stars have been seen through the matter which
+forms those parts. Herschel,[42] paragraph 558, states "that whenever
+powerful telescopes have been turned on these bodies, they have not
+failed to dispel the illusion which attributes solidity to that more
+condensed part of the head which appears to the naked eye, though it is
+true that in some a very minute stellar point has been seen indicating
+the existence of a stellar body."
+
+_Tails._--The tail of a comet is that part which flows from the head,
+and is afterwards repelled by the repulsive power of the sun into space.
+We shall deal with this repulsive power, whose existence we have already
+demonstrated, and the part which it plays in the formation of a comet's
+tail, in the next article. The tail of a comet is oftentimes considered
+to be the comet itself, rather than a part of the same, but as the tail
+is the most distinctive feature of a comet, and is the part most visible
+to the naked eye, there has arisen the popular but mistaken idea of
+identity between the tail and the comet itself.
+
+Tails are of all kinds. There are some which are short, while others are
+long. Then we have comets with single tails, or double, and in some
+cases even multiple tails. Occasionally comets appear which have no
+tails at all. The comet of 1744 had six tails, which spread out in the
+shape of a large fan.
+
+One of the most remarkable features of tails is their abnormal length,
+which oftentimes reaches into millions of miles. The comet of 1843 had a
+tail 112,000,000 miles long. Another feature about the tails of comets
+is that they are always directed _away_ from the sun. Up to the present
+I believe no satisfactory explanation has been given of this fact, but
+with the conception of the rotating Aether as given in Art. 94, we shall
+for the first time be able to give a satisfactory physical explanation
+of that phenomenon. In addition to this, the formation of cometary tails
+of all shapes receives a physical explanation, when taken into account
+with the fact that the sun is an electro-magnet, possessing its
+electro-magnetic field, and its lines of force, as described in Art. 88.
+
+[Footnote 41: _Outlines of Astronomy._]
+
+[Footnote 42: _Outlines of Astronomy._]
+
+
+ART. 115. _Centrifugal Force and Comets' Tails._--In order to account
+for the existence of the tails of comets, various repulsive forces have
+been introduced from time to time into the solar system, so that the
+phenomena of cometary tails might be satisfactorily accounted for.
+
+It has been felt by every astronomer that some repulsive force, which
+had its origin in the sun, was absolutely necessary to explain the
+existence of the tails, and as no real force could be demonstrated to
+exist, recourse had to be made to repulsive forces of a more or less
+hypothetical nature. The necessity of this repulsive force is nowhere
+more plainly indicated than by Sir J. Herschel in his _Lectures on
+Scientific Subjects_, where, dealing with the phenomena of comets'
+tails, he writes: "They have furnished us with a proof, amounting to
+demonstration, of the existence of a repulsive force directed from the
+sun, as well as that great and general attractive force which keeps
+planets in their orbits."
+
+In the same work, referring to the comet of 1680, he writes: "This comet
+was perhaps the most magnificent ever seen. It appeared from November
+1680 to March 1681. In its approach to the sun it was not very bright,
+but began to throw out its tail when about as far from the sun as the
+earth. It passed its perihelion on December 8th, and when nearest to the
+sun was only about 1/10 part of the sun's diameter from the surface. No
+wonder it gave evidence of violent excitement, coming from the cold
+region outside planetary space. Already, when arrived even in our
+temperate regions, it began to show signs of internal activity. The head
+had begun to develop and the tail to elongate, till the comet was for a
+time lost sight of. No human eye beheld the wondrous spectacle which it
+must have offered on December 8th. Only _four days_ afterwards, however,
+it was seen again, and the tail, whose direction was reversed, and which
+observe could not possibly be the same tail, its tail had already
+lengthened out to the extent of about 90 millions of miles, so that it
+must have been shot out with immense force in a direction _from_ the
+sun."
+
+The reader will have observed it took from November 10th to December
+8th, or 28 days, to fall to the sun for the same distance, and that with
+all the velocity it had on November 10th to start with. Herschel sums up
+the matter thus: "Beyond a doubt, the widest and most interesting
+prospect of future discovery which their study (comets' tails) holds to
+us, is, that distinction between gravitating and levitating matter, that
+positive and unrefutable demonstration of the existence in nature of a
+repulsive force co-extensive with, but enormously more powerful than the
+attractive force we call gravity, which the phenomena of their tails
+afford."
+
+Thus the philosophic mind of Herschel saw in the existence of cometary
+tails, the irrefutable evidence of the existence of a repulsive force,
+not of a hypothetical character, but as real as the existence of gravity
+itself. Various attempts have been made to define that repulsive force
+which was thus demanded, and the same force has been ascribed by
+scientists to the repulsion due to heat, to light, and also to
+electricity.
+
+Several French scientists have suggested that the repulsive force was
+due to the heat of the sun. M. Roche was one of those who stated that
+the phenomena of cometary tails was due to the repulsive power of heat,
+which found its origin in the heat of the sun. M. Faye, another French
+scientist, states that the repulsive force had its origin in the heat of
+the sun. By a series of experiments he demonstrated that there was a
+repulsive power in all heat waves, which gave his theory that
+experimental support that any theory must possess to make it permanent.
+
+Now in Art. 63 it was shown that heat does possess a repulsive power,
+but that that power is rather due to the electro-magnetic Aether whose
+vibrations produce the heat waves, than to the repulsion of heat; so
+that, indirectly, the assumption of both these French scientists, that
+the repulsive power of heat gave rise to the tails of comets, is
+correct. Then again it has been suggested that the repulsive power is
+produced by the pressure of the light waves. Professor Lebedew suggested
+this after he had experimentally proved that light waves did possess a
+repulsive power (_Annalen der Physik_, November 1901). It can easily be
+seen, as pointed out in Art. 70, that, inasmuch as light is due to the
+vibrations of the Aether, they too possess this repulsive power, and
+therefore Professor Lebedew's suggestion as to the nature of the
+repulsive power is correct, as the real centrifugal force is really due
+to an aetherial pressure.
+
+Whether, therefore, we consider it from the standpoint of heat, or light
+or electricity, it ultimately resolves itself into the same aetherial
+medium which is at once the common source of all these forces. Again, it
+has been suggested that the repulsive power is electrical or
+electro-magnetic, and this view is receiving more support than either of
+the others from modern scientists.
+
+Herschel suggested that the repulsive power was electrical, while
+Bredichin has worked out a very careful theory as to the effect of
+electrical repulsion upon different elements that are found in the
+comets' tails, with a view to explain the different shapes of the tails.
+But whether the force is looked at from the standpoint of heat, light or
+electricity, it ultimately resolves itself into the motions of the
+Aether, which gives rise by its different vibrations and motions to all
+the three forms of energy referred to.
+
+When we also take into account the fact that Aether is gravitative, and
+therefore denser nearer to the sun than further away, and that it is
+also rotating round the central body the sun (Art. 91), then we have at
+once every condition necessary to explain all the various kinds of
+cometary tails, and also for the remarkable fact that the tail is always
+turned away from the sun, which is simply due to the effect of the
+rotating Aether with its outflowing electro-magnetic waves upon the
+gaseous matter of the comet. Thus from the phenomena of comets' tails,
+we have again arrived at the conclusion of the existence of that
+centrifugal force, whose origin and continuity are to be found in the
+electro-magnetic Aether which surrounds the sun, and which by its
+electro-magnetic waves gives rise to pressure on all bodies upon which
+they fall.
+
+
+ART. 116. _Formation of Tails._--With the conception of the formation of
+the comet advanced in Art. 111, viz. that it is nothing more or less
+than Aether in a state of condensation, and remembering the explanation
+given of the parts of the comet, as the nucleus, and head or coma, we
+are now in a position to give a philosophical account of the formation
+of the tails of comets, which will satisfactorily fulfil all the Rules
+of Philosophy. In addition to the facts already referred to in the
+previous articles of this chapter, we must also recall our conception of
+the Aether as given in Chapter IV., remembering that it gets denser
+nearer the sun, and that it is not frictionless; therefore, when a body
+is urged through it, friction is produced, and heat is generated.
+
+We must also remember that the Aether is rotating round the sun as that
+body proceeds through space. We have, therefore, to picture the
+condensed mass of Aether situated out in the cold interstellar space,
+gradually coming under the influence of the sun, as that body rushes on
+its journey through space with a velocity of 500,000 miles per hour.
+
+Slowly, but surely, the mass of condensed Aether begins to respond to
+the attractive power of the sun, and to move through space towards the
+sun. So long as it is moving towards the sun, it is encountering and
+having to overcome the resistance of the Aether.
+
+At first this resistance is very feeble, owing to the decreased density
+of the Aether, but as it proceeds on its journey it is constantly
+passing into denser parts of the aetherial electro-magnetic field around
+the sun. The result is, that as the resistance is increased, so there is
+greater friction between the matter of the comet and the atomic Aether
+in space, and, in consequence, heat is generated.
+
+In addition to the generated heat, the comet is all the while passing
+into regions of greater intensity of heat. In both cases, the effect is
+only manifested on that side of the comet which is approaching the sun;
+for, if there be any friction at all, it will only be on that half of
+the comet which encounters the Aether, so to speak, while the same part
+will receive the added heat, as the distance between the comet and the
+sun is decreased. As can readily be seen therefore, this added heat acts
+only upon the half of the comet which is advancing, and which faces the
+sun, and as the effect of heat is always to vaporise, so the effect on
+the nucleus of the comet is to vaporise the condensed aetherial matter,
+and this vaporised aetherial matter is thrown off in layers which are
+partly spherical in form, the layers always being expelled in the first
+instance _towards_ the sun, on account of that centrifugal motion which
+has its birth in the nucleus of the comet.
+
+This explanation fully establishes and confirms the first and second
+Reflections of Herschel as given in Art. 114, and, moreover, is itself
+established by the very phenomena which comets present in their approach
+to the sun. As soon, however, as the vaporised matter is expelled from
+the nucleus towards the sun, it is met by the centrifugal motion of the
+electro-magnetic Aether which proceeds _from the sun_, and this pressure
+of the aetherial waves on the advancing comet acts as a repelling power,
+literally repelling the vaporised matter from the sun, and thus giving
+rise to the existence of its tail.
+
+This explanation fully confirms the third Reflection of Herschel
+referred to in Art. 114, and is itself also confirmed by actual
+observation. During all this time, however, the comet has been
+approaching the sun with a decreased velocity, for its velocity has been
+minimised by the resistance it has had to overcome in its approach to
+the sun. As soon, however, as it reaches the sun, it is whirled round
+that body by the rotating Aether medium, as the intensity of its
+rotation is greatest nearest the sun, with a velocity which often
+exceeds thousands of miles per hour.
+
+Having passed its perihelion, in view of the physical existence of our
+centrifugal motion, let us now ask ourselves what ought to happen to the
+comet? Previous to its perihelion, the comet's motion and the
+centrifugal motion due to the pressure of the Aether were in opposition,
+but after passing the perihelion, the comet's motion and the centrifugal
+motion will be acting conjointly, with the result that the motion of the
+comet would be accelerated. Now this is exactly what observation teaches
+us does happen in regard to comets, when they have passed their
+perihelion passage.
+
+As Herschel pointed out with reference to the comet of 1680 (Art. 114),
+it took 28 days to fall to the sun, but only took four days to cover the
+_same_ distance, after it had passed the sun and rounded the perihelion.
+So that we have here, as Herschel stated, an irrefutable evidence of the
+existence of the repulsive power whose existence we have demonstrated.
+
+Again, there is another fact which has to be taken into consideration in
+regard to the tails of comets. Observation teaches us that their tails
+are invariably turned _from_ the sun, though why they always are so
+turned away is an unsolved problem, apart from some real or hypothetical
+repulsive power. We have, however, to further remember that the
+electro-magnetic Aether around the sun is ever rotating with that body,
+and carrying with it in its rotation all associated planets and meteors.
+
+This rotation of the Aether plays a most important part in the phenomena
+stated. Whether the comet is approaching the sun, or receding from the
+sun, it is still subject to the influence of this rotatory Aether
+medium. The result will be that the lighter particles of the vaporised
+matter will be acted upon more powerfully than the heavier parts, so
+that even when the comet is receding from the sun, after it has passed
+the perihelion, the lighter parts which go to form the tail will be more
+under the influence of the repelling Aether waves than the heavier
+parts, as the nucleus, as suggested by Bredichin.
+
+Thus the natural result will be that the tail will still be directed
+away from the sun even when it is receding from that body. Gradually,
+however, as the comet recedes, it passes out of the denser Aether, where
+the intensity of motion and vibration are greatest, to those slower
+parts of the sun's aetherial field where they are less intense.
+
+The effect of this is soon made manifest on the tail and head of the
+comet. The process which took place as it approached the sun is now
+exactly reversed, as it is now passing out of a denser into a more
+rarefied medium, where its motions and vibrations are less intense. The
+tail, therefore, appears to be drawn back to the head, while the head
+will itself gradually contract into the nucleus, as it recedes further
+and further into space. If the comet be situated within the plane, or
+nearly the plane of the ecliptic, then it is possible for it to return
+again, and go through the same process, unless it is captured on its
+outward journey by some of the large outer planets, as Jupiter. If,
+however, their planes do not coincide with the plane of the ecliptic,
+then it is very possible that they will not reappear again, but pass on
+to some other stellar system. Thus we can explain on a strictly
+philosophical basis one of the most interesting, and yet one of the most
+mysterious phenomena associated with our solar system, from the simple
+yet truly philosophical assumption that Aether is matter, in conjunction
+with all that that assumption logically involves.
+
+
+
+
+                              CHAPTER XIII
+
+                      AETHER AND STARS AND NEBULAE
+
+
+ART. 117. _The Starry World._--In addition to the planets and comets
+that are found in the heavens, there are other bodies, countless in
+their number, which we know as stars. Who has not looked up into the
+heavens on some clear night, and noticed how the vault of heaven was
+spangled over with points of light, each point representing a huge sun
+that exists in far-off space? For it must be remembered that every star
+is a sun, which, reasoning by analogy, is the centre of a stellar
+system, just in the same way that our sun is the centre of our solar
+system. Like our sun, all stars shine by their own light, and the
+quality of that brilliancy decides the magnitude of the star, the
+magnitude being indicative of the relative brilliancy of a star rather
+than its size. So that stars are divided into groups according to their
+magnitude, the magnitudes ranging from the first to the sixteenth, and
+even beyond. Those of the first magnitude are more brilliant than those
+of the second, those of the second more brilliant than those of the
+third, each magnitude decreasing in relative brilliancy as the number
+which indicates the magnitude increases. There are about sixteen
+different degrees of magnitude, in which are classified the millions of
+stars that exist in infinite space, but only stars up to the sixth
+magnitude are visible to the naked eye, the telescope revealing those
+which lie beyond. The total number of stars visible to the naked eye are
+about 6000, half of which are visible in each hemisphere.
+
+About 20 stars comprise the group of the first magnitude, which include
+all the brightest stars visible, as Sirius, Canopus, Alpha, Arcturus,
+Rigel, and Capella.
+
+Those of the second magnitude number about 65, and include the brighter
+stars to be found in the constellation known as the Great Bear. Stars of
+the third magnitude number about 200, of the fourth magnitude about 400,
+of the fifth magnitude 1100, and of the sixth magnitude about 3200.
+
+With the aid of the telescope about 13,000 stars of the seventh
+magnitude are revealed to us, and 40,000 of the eighth magnitude, while
+of the ninth magnitude over 140,000 are revealed by the telescope. As
+the power of the telescope is increased, so the number revealed is
+increased also, until by the time we have reached stars of the
+fourteenth magnitude, at least 20,000,000 are revealed to us.
+
+If we look into the heavens on a clear moonlight night, we shall further
+see that here and there are groups of stars clustered together. These
+clusters are termed constellations, and are named after some object
+which the arrangement of the stars seemed to suggest. Thus every one is
+familiar with that constellation known as the Great Bear, or the
+"Plough," so called because of its resemblance to a plough.
+
+The brightest stars of each constellation are named after the letters of
+the Greek alphabet, the brightest being called Alpha, the next in
+brilliancy Beta, and so on, right through the Greek alphabet. For
+example, the seven stars in the Great Bear are known as Alpha, Beta,
+Gamma, Delta, Epsilon, Zeta, and Eta.
+
+The constellations are grouped into two divisions, known as the Northern
+and Southern constellations respectively.
+
+The visible Northern constellations are 25 in number, and include the
+following well-known groups--
+
+    Ursa Major          The Great Bear.
+    Ursa Minor          The Little Bear.
+    Draco               The Dragon.
+    Hercules            Hercules.
+    Cygnus              The Swan.
+    Lyra                The Lyre.
+
+The visible Southern constellations are 18 in number, and include such
+groups as--
+
+    Cetus               The Whale.
+    Orion               Orion.
+    Canis Major         The Great Dog.
+    Canis Minor         The Little Dog.
+    Corona Australis    The Southern Crown.
+    Crux Australis      The Southern Cross.
+
+_Variable Stars._--Not only are the stars of different magnitudes, but
+the brilliancy of some of them changes from time to time. This class of
+stars is known as variable stars, and has received the attention of
+modern astronomers for many years, in order that the cause of their
+variation might, if possible, be ascertained. The periods of variation
+differ in length, ranging from a number of days to 60 or 70 years.
+
+One of the most interesting of variable stars is that known as Omicron
+Ceti, whose period of change is about 331 days. Its brilliancy varies
+from one of the second magnitude to one of the tenth.
+
+Beta Persei is another well-known variable star. This star shines as one
+of the second magnitude for 2 days and 13 hours, and then suddenly loses
+its light, and in less than 4 hours becomes a star of the fourth
+magnitude. Its brilliancy then increases again, and in a similar time it
+regains its former brilliancy.
+
+The conclusion that has been arrived at in regard to the cause of the
+variation of these stars is, that in each case the diminution of light
+is due to the existence of dark bodies, probably planets, which revolve
+round the central star.
+
+This hypothesis was confirmed by Professor Vogel about 1889 by means of
+spectroscopic results.
+
+Another interesting fact about stars is that they shine with various
+colours. The colours of stars are as various as the colours of the
+rainbow, and range through the whole spectrum, of red, orange, yellow,
+green, blue, indigo, violet, and white. What is more remarkable is the
+fact that the colours of the stars seem to change through great periods
+of time. If we turn to ancient records we learn that Sirius was red
+then, but is now green, while Capella was also red, but is now pale
+blue.
+
+_Double and Multiple Stars._--Many stars when looked at through powerful
+telescopes are found to be double, triple, quadruple, and even multiple,
+although when looked at by the naked eye, they seem to be single in
+appearance.
+
+An example of a double star is to be found in the constellation of Lyra.
+A moderate telescope reveals this as a double star, while a still more
+powerful telescope reveals the strange fact that each apparently single
+star which forms the double is itself double, so that we have in this
+constellation a system of four stars, in which each pair revolves round
+a point situated between them.
+
+Several thousand double stars are known altogether, while the motions of
+several hundreds of them have been detected with powerful telescopes.
+Some of the double stars are as follows--Zeta Hercules, Eta Coronae
+Borealis, Gamma Coronae Borealis, Beta Cygni, Alpha Centauri.
+
+The colours of some of the double stars are very beautiful. Some are
+yellow and blue; others, yellow and purple, while others are orange and
+green. Some of the double stars are only optical doubles, that is to
+say, they apparently seem close together, while as a matter of fact they
+are immense distances from each other, the apparent doubleness being due
+to the fact that they are more or less in the same line of vision. Real
+double stars, where the component stars are situated close together, are
+known as physical doubles, to distinguish them from the optical doubles.
+
+_Binary Stars._--Another class of double stars are known as Binary
+Stars. This class of stars is composed of two stars which revolve around
+each other in regular orbits, and are among some of the most interesting
+objects in the heavens. About 1000 Binary stars are known altogether.
+Their motions, however, are very slow, and only in a comparatively few
+cases have the dimensions of their orbits been ascertained. Some of the
+Binary stars are Zeta Hercules, which has a period of about 36 years;
+Eta Coronae Borealis, which has a period of 43 years; while the
+brightest star, Sirius, is also a Binary star, with a period of about 50
+years.
+
+_The Milky Way._--The Milky Way is the name given to that band of light
+which stretches across the sky at night-time, and forms a zone or belt
+that completely circles the celestial sphere.
+
+This belt of light has maintained from the earliest ages the same
+relative position among the stars, and, when resolved by powerful
+telescopes, is found to consist entirely of stars scattered by millions
+across the expanse of the heavens.
+
+The whole zone or belt is composed of nothing but stars, whose average
+magnitude, according to Herschel, is about the tenth.
+
+Stars of all magnitudes are, however, found in this zone.
+
+Of the brightest stars, about twelve are found in this region, while the
+majority of stars of the second, third, and fourth magnitudes are also
+found in or near it.
+
+The great majority of star clusters are also found along the course of
+the Milky Way, while many of the irresolvable nebulae seem to congregate
+near the poles of this starry region.
+
+The Milky Way is divided in one part of its course by a stream of stars,
+which seems to branch off as a separate stream, thus dividing it into
+two parts.
+
+All these facts seem to point to the conclusion that the stars of the
+universe, instead of being scattered about haphazard in the space, form
+a ring or layer, of which the thickness is very small compared with its
+length and breadth.
+
+Our own solar system, according to Herschel, occupies a place somewhere
+about the middle of the thickness of the zone, and near the point where
+it divides into two parts.
+
+Recent observations go to show that there is a tendency of the sun's
+apex to drift along the edge of the Milky Way, and this drift seems to
+point to a plane of motion of the sun, nearly coinciding with the plane
+of the Milky Way.
+
+
+ART. 118. _Stars and Kepler's Laws._--We have learned in a previous
+chapter that the sun is the centre of a system which comprises a retinue
+of planets, with their attendant satellites, together with a number of
+asteroids or minor planets, with the addition of meteors and comets to
+complete the system.
+
+Now if the sun is a star, then, according to our First and Second Rules
+of Philosophy, every star ought also to be the centre of a stellar
+system and the centre of two aetherial motions, that is, the Centrifugal
+and Centripetal forces, due to the pressures and tensions of the Aether
+medium. Further, every stellar system would be composed of exactly
+similar bodies to those which compose our solar system, as planets with
+their attendant satellites, together with meteors and comets; the whole
+of the stellar planets being bound to the central body by the
+combination of the two aetherial motions, and kept revolving round the
+central star by the rotating electro-magnetic Aether currents.
+
+Such a hypothesis is entirely philosophical, as it is simple in
+conception, and fully agrees with our experience in relation to the only
+star of which we have any complete knowledge.
+
+It is unthinkable to conceive of a star existing in so-called space, and
+constantly radiating out its light and heat for no purpose at all. All
+Nature teaches us that there is not a single thing in existence but what
+has a definite purpose, and a definite place to fill in the universe.
+Even the aetherial atoms, which form the foundation stones of the
+universe, have their own purpose to fulfil in the glorious scheme of the
+Universe conceived by the Eternal Infinite; and to suppose that a star
+has no purpose to fulfil, no task to perform, is to suppose something
+altogether opposed to the teaching of all Philosophy. Why even man, with
+his finite wisdom, would not be so foolish, so unwise, as to make a
+star, and set it in the firmament of heaven for no purpose at all! Are
+we therefore to suppose that the Divine Creator of all things possesses
+less wisdom than the creatures which He Himself hath made? Such an
+assumption would be a reflection not only on the wisdom of an All Wise
+Being, but would also be a reflection on our own ideas of philosophical
+reasoning.
+
+Therefore the conclusion that we are compelled to come to, in relation
+to the millions of stars that exist in interstellar space, is that every
+star is the centre of a stellar system, and the centre of two aetherial
+motions due to the pressures and tensions of the electro-magnetic
+Aether; while rotating round each star are the ever-circulating
+electro-magnetic Aether currents, which form the medium by which all the
+stellar planets with their attendant satellites are ever made to revolve
+around that central body which supplies them with their light and heat.
+Some such conclusion as this Sir John Herschel arrived at, for in his
+_Treatise of Astronomy_, Art. 592, he writes: "Now for what purpose are
+we to suppose such magnificent bodies scattered through the abyss of
+space? Surely not to illuminate our nights, which an additional moon of
+the 1/1000 part of our own moon would do much better. He must have
+studied astronomy to little purpose who can suppose man to be the only
+object of the Creator's care, or who does not see in the vast and
+wonderful apparatus around us, provisions for other races of animated
+beings. The stars, doubtless, are themselves suns, and may perhaps each
+in its sphere be the presiding centre around which other planets or
+bodies may be circulating."
+
+Further, with reference to the stability of each of these stellar
+systems, it is essential that the existence of a physical centrifugal
+force should be recognized, in order that the unity and harmony of the
+spheres should be maintained.
+
+Professor Challis points this out very conclusively in the _Phil. Mag._
+of 1859, where, writing on this point, he states: "It may also be
+remarked, that if the Law of Gravity be absolute, there is no security
+for the stability of a system of stars, whether the system be a Milky
+Way or a nebulous cluster. For, however small the mutual attraction
+between the constituent bodies may be, in the course of ages it must
+produce a general movement towards the centre or densest region. But the
+form of the Milky Way and of certain nebulae seems to present an utter
+contradiction to any such tendency." With the conception, however, of a
+physical centrifugal force or motion due to the pressure of a physical
+medium, the stability of even the Milky Way may be physically conceived
+and understood.
+
+Again, when we consider the sun as a star, we find that it has two
+motions of its own, one of rotation on an axis, and the other of
+translation in an orbit, such rotation being due to the fact that it is
+a magnet and has ever circulating round it electro-magnetic Aether
+currents (Art. 91). By inference, therefore, we arrive at the fact that
+every star is a magnet, as suggested by Professor Schuster, and
+possesses rotation on an axis, such rotation being due to exactly the
+same cause as produces the rotation of any other planetary or solar body
+(Art. 92). Not only has each star a rotation on its axis, but it must
+also possess translational motion in an orbit, and that orbital motion
+must be due to exactly a similar cause as that which produces the
+orbital motion of the sun. Are there any indications given by
+astronomical observations which lead us to the conclusion that stars do
+possess such orbital motions? The answer is unanimously in the
+affirmative; for, although all the stars and the constellations retain
+apparently the same relative position to each other, yet they are all in
+motion. The actual translational motion of the stars is termed proper
+motion, and has been calculated with more or less success in relation to
+many of the stars nearest to us. There are other motions of the stars
+known as apparent motions, which are easily noted by any observer. These
+apparent motions are due to the rotation of the earth on its axis, and
+its orbital motion round the sun.
+
+Nothing is more certain, however, than that careful astronomical
+observations have revealed the fact that stars have actual orbital
+motions of their own through space. In many cases the orbital velocity
+has been approximately ascertained.
+
+Halley discovered proper motions of certain stars as far back as 1715,
+when he found out, by comparing different observations, that Sirius,
+Arcturus, and Aldebaran had moved during the period which had elapsed
+since the respective observations were taken.
+
+More recent observations tend to confirm the fact that stars have indeed
+proper motions, due to their actual translation through space. It has
+been ascertained, for example, that Arcturus is travelling at least 54
+miles per second.
+
+The proper motion of the stars, however, only gives us an indication of
+their relative motion through so-called space. It does not tell us
+whether the star is apparently receding from the earth, or approaching
+it.
+
+Dr. Vogel has ascertained by a special system of photography in relation
+to the spectra of stars, that Rigel has a velocity away from the earth
+of nearly 39 miles per sec., Aldebaran of 30 miles per sec., and Capella
+of 15 miles per sec., while the Pole star is apparently approaching the
+earth at a rate of nearly 16 miles per sec.
+
+Now if all the stars move through space with varying velocities, as
+spectroscopic and telescopic observations seem to suggest, the question
+naturally confronts us as to what is the particular kind of orbit which
+each star completes? Is the orbit that of an ellipse, or a circle, or a
+parabola?
+
+That it must have some kind of orbit is obvious from the proper motions
+exhibited by the several stars. We have already learned from Arts. 107
+and 108 that the sun possesses an orbit, which orbit fulfils the first
+and second of Kepler's Laws.
+
+If therefore the sun, as representing all stars, is subject to Kepler's
+Laws, then, according to our Second Rule of Philosophy by which we base
+our hypotheses on our experience, we are compelled to come to the
+conclusion that every star which possesses any motion at all through
+space must also be subject to Kepler's Laws, and therefore must each
+possess a controlling centre around which they severally revolve. Kepler
+himself was of the opinion that the stars were subject to the laws which
+go by his name, and this view of the subject was also accepted by Sir
+William Herschel.
+
+Thus from philosophical considerations we affirm that each star, while it
+is itself the centre of a starry system, is also dependent upon and
+associated with some other body, to which it is held bound by the
+electro-magnetic Aether, and around which it is made to revolve by the
+circulating electro-magnetic currents associated with that central body.
+So that by philosophical reasoning we are led to view the whole of the
+innumerable stars that flood interstellar space, not as so many individual
+and isolated units, that have no relation to each other, but rather as
+parts of one great system, which in its entirety may form in its ultimate
+unity one harmonious whole, a universe.
+
+As we come to consider star clusters and nebulae, we shall see how this
+idea of unity seems to be manifested throughout all celestial phenomena.
+
+
+ART. 119. _Aether and Nebulae._--In addition to the host of stars that
+flood the infinite space, there are other celestial bodies that meet the
+gaze of the astronomer as the telescope is turned upon the heavens.
+
+These bodies, which are glowing masses of gaseous matter, are termed
+Nebulae. The word Nebulae signifies a cloud, but they are not clouds in
+the same sense as we apply that term to masses of vapour that exist in
+our own atmosphere. Sir Wm. Herschel did more towards the discovery of
+nebulae than perhaps any other astronomer, either before his time or
+since. His labours in the direction were completed and enlarged by his
+son, Sir John Herschel, who surveyed the Southern heavens in a way that
+had never been accomplished before.
+
+The result of the combined labours of the two Herschels has placed
+information of the nebulae at our disposal which is invaluable. Several
+thousands of different nebulae are now known to us, and as the telescope
+is improved and its powers increased, fresh nebulae are being added to
+the number. Like stars, nebulae vary not only in size, but also in
+colour, shape, and even in the materials of which they are composed.
+They also vary in brightness, the light from some being much fainter
+than the light from others.
+
+It has been estimated by Huggins that the light received from a nebula
+will not exceed the light of a sperm candle looked at from a distance of
+a quarter of a mile. It is thought by some astronomers that the light
+received from a nebula is indicative of the stage of development to
+which it has arrived. Where the light is faint, the nebulae are in their
+first stages of formation, and where it is brighter it is indicative of
+a more advanced stage of development. Thus nebulae may consist of
+nebulous matter in various stages of condensation, but they are not yet
+in that condition which corresponds to the condition supposed to exist
+in our sun.
+
+Nearly all the nebulae lie outside the Milky Way, so that it would seem
+as if in ages past all the nebulae that had ever existed in this starry
+zone had passed out of their nebulous condition and been further
+condensed into suns or stars, as they are called. Astronomical
+observations teach us that there are very few nebulae indeed to be seen
+in this starry highway, the part of the heavens which are richest in
+them lying far beyond the confines of this zone. For many years certain
+aggregations of luminous points in the heavens were supposed to be
+nebulae, but by the aid of more powerful telescopes they have now been
+resolved into clusters of stars. One of these clusters is the cluster in
+Hercules, while another is the great nebula of Orion. In the case of the
+former, situated in the constellation of Hercules, we find a great
+number of very small points of light grouped together in a more or less
+globular form. When looked at through a small telescope, this object
+looks like a nebula, but looked at through Lord Rosse's, or some other
+great telescope, it becomes at once resolved into an immense number of
+separate points of light, each one representing a star, there being
+between one and two thousand altogether in this constellation.
+
+Clusters of stars are usually globular in form, though some are
+irregular in outline. The latter are generally rich in stars, with a
+less condensation of stars towards the centre. Sir Wm. Herschel
+considered the irregular clusters as being in a less advanced stage of
+condensation, as he was of the opinion that all groups ultimately tended
+to clusters which were globular in form. Before dealing with the
+different kinds of true nebulae we will now consider the question as to
+"What are Nebulae?"
+
+
+ART. 120. _What are Nebulae?_--The question which presents itself to the
+mind of all astronomers when they have viewed the wondrous nebulae that
+exist in far-off space is, "What are Nebulae?" This question is so
+closely identified with the question as to "What is Matter?" that the
+solution of the one will give us the key to the solution of the other.
+It is now generally admitted, that nebulae are composed of a glowing
+mass of gaseous matter, that gaseous matter being partly composed of the
+gas Hydrogen. Dr. Huggins in 1864 first made the discovery of the
+existence of Hydrogen in certain nebulae by means of the spectroscope,
+which distinctly revealed certain lines that proved the existence of
+Hydrogen in the nebulae.
+
+In the spectra of some of the nebulae, that of 31 Andromeda, for
+example, there are no dark lines shown, but only a continuous band of
+bright light, which would seem to indicate that there was no glowing
+gaseous matter in that nebula at all. But accepting the fact that the
+nebulae are composed of glowing gaseous matter, the problem confronts us
+as to where this gaseous matter comes from.
+
+If, as spectrum analysis seems to teach us, there are nebulae in various
+stages of formation, there must be a period in their history of
+development when they had an origin. What, then, is the origin of a
+nebula, and what the physical explanation of that origin? From optical
+phenomena we learn that all space is not empty, but filled with the
+Aether which is universal (Art. 42). What is the relation, then, of this
+glowing nebulous matter to this universal Aether? If it be suggested
+that there is no relation, then we are in the unphilosophical position
+of having to admit, either that the nebulous matter of which the nebulae
+are composed never had any origin, or that it had its origin in some
+unknown and still undiscovered medium which exists in space. But both of
+these hypotheses are unphilosophical, as the former is contrary to all
+experience, while the latter is opposed to that simplicity of conception
+by which we only postulate one medium, the Aether, to fill all space.
+
+Thus we are led to the conclusion, that the gaseous matter, be it
+hydrogen or nitrogen, must have some relation to the electro-magnetic
+Aether that is so universal in its extent. Already this relationship has
+been dealt with by one who has done more for the development of
+aetherial physics than any other scientist. Lord Kelvin, in his paper
+"On the Clustering of Gravitational Matter in any part of the
+Universe,"[43] has solved this relationship, though in so doing he has
+had to depart somewhat from the idea of an incompressible Aether. In
+that paper he writes as follows: "If we consider Aether to be matter, we
+postulate that it has rigidity enough for the vibrations of light, but
+we have no right to say that it is absolutely incompressible. We must
+admit that sufficiently great pressure could condense the Aether in a
+given space, allowing the Aether in the surrounding space to come in
+towards the ideal shrinking surface." In another part of the paper,
+dealing with the same question, he writes: "In regions where the density
+was greater than in neighbouring regions, the density would become
+greater still; in places of less density, the density would become less,
+and large regions would quickly become void or nearly void of atoms.
+These large void regions would extend so as to completely surround
+regions of greater density." He then points out, that as soon as this
+density becomes something like the density of the atmosphere, then
+collisions would take place between the particles, and continues: "Each
+collision would give rise to a train of waves in the Aether. These waves
+would carry away energy, spreading it out through the void Aether of
+infinite space. The loss of energy thus taken away from the atoms would
+reduce large condensing clusters to the conditions of a gas in
+equilibrium under the influence of its own gravity, rotating like our
+sun or moving at moderate speed as in spiral nebulae. Gravitational
+condensation would at first produce rise of temperature, followed later
+by cooling, ultimately freezing, giving solid bodies, collision between
+which would produce meteoric stones such as we see them."
+
+Here then we have a definitive relationship between Aether and nebulae
+given to us from one of the keenest intellects of the present time, but
+in order for that relationship to become strictly philosophical, the
+conception of the Aether as advanced in this work must be accepted. For
+with the present conception of a frictionless Aether, such a hypothesis
+is altogether untenable, because it supposes something that is contrary
+to all experience and observation.
+
+On the basis of a condensing frictionless Aether into any kind of solid
+body, be it nebula, meteor, sun or star, we have to suppose that it is
+possible for a medium (the Aether, which is outside the Law of
+Gravitation according to the present theory) to be condensed into a
+body, that is, a nebula or meteor which is subject to the Law of
+Gravitation; and the question arises, at what point in the history of
+its condensation does this frictionless Aether pass out of the condition
+of having no weight, to the condition when it has weight; or, in other
+words, from the condition when it is outside the Law of Gravitation, to
+the condition when it comes under the Law of Gravitation?
+
+No satisfactory solution can possibly be offered to such a problem.
+Therefore one of two results must follow, either that the Aether is not
+frictionless, but possesses weight; or, that the condensation of the
+Aether is not possible. With the theory of Aether presented in this
+work, the whole question receives a simple and philosophical solution.
+As Aether is matter, it is therefore atomic; and being atomic, it is
+subject to the Law of Gravitation; and therefore, possessing mass and
+weight, it can readily pass into other forms of matter, and with such a
+conception Lord Kelvin's hypothesis becomes not only possible but
+probable. So that it is exceedingly probable that nebulae are nothing
+more nor less than condensed Aether, the same as comets were suggested
+to be condensed Aether. It may be asserted that such a hypothesis lacks
+that experimental evidence which is so necessary for its establishment,
+but I hope to show in the last chapter that Faraday has given the world
+that very experimental evidence which will place this hypothesis upon a
+firm and solid foundation, and enable it to pass out of the region of
+the hypothetical into the region of fact and experiment.
+
+According to our hypothesis, therefore, nebulae are simply condensations
+of the electro-magnetic Aether that exists in interstellar space, and
+the various spectra of the different nebulae indicate the stage of
+development to which the process has arrived. Where the spectra are
+bright, and continuous, and free from any dark lines, there we have
+simply the Aether in its very first stage of condensation; and where we
+have the dark lines appearing, such lines indicate a more advanced stage
+to which the process has arrived.
+
+[Footnote 43: _Philosophical Magazine_, July 1902.]
+
+
+ART. 121. _Nebular Hypothesis._--The Nebular Hypothesis was first
+introduced by Kant in his work on the _History of the Earth and Theory
+of the Heavens_.
+
+In that work he attempted to explain the origin of the universe on
+purely mechanical lines. Laplace, a French mathematician, about the same
+time came to similar conclusions as Kant had done, and published his
+views in his work on _Exposition du Systeme du Monde_, and later on in
+his more famous work the _Mecanique Celeste_.
+
+A feature common to both these theories rested in the fact, that they
+supposed that all material bodies which exist in the universe once
+existed in a nebulous condition, and that they were formed out of this
+nebulous matter. Further, that this nebulous matter gradually condensed,
+and as it condensed, a rotational motion was imparted to them, which
+rotation quickened as the condensation was continued.
+
+Then, as the rotation was accelerated, portions were flung off by the
+centrifugal force, and these portions of nebulous matter gradually
+condensed, forming the various planets of the system. As these
+condensed, they, in their turn, parted with some of their nebulous
+matter through the repulsive energy of the centrifugal force, and these
+secondary parts gave origin to the various satellites that exist round
+the planets.
+
+Now, while the general principle involved in the nebular hypothesis is
+true, yet the conception according to Laplace is not verified by fact,
+as we learn that Uranus and Neptune are still in a state of
+self-luminosity, while their density is the smallest of all the planets.
+From this we should infer that the two outermost planets are the
+youngest planets of our solar system, but according to Laplace's theory,
+they ought to be the oldest, as they would have been flung off first by
+the parent body as it rotated; and therefore, being flung off first,
+should be in a more advanced stage of development than any of the inner
+planets. M. Faye has suggested a remedy for this defect in the theory.
+He supposes that the nebulous matter out of which the planets were
+formed, was not flung off by the central body the sun, but that each
+planet was formed at different centres of condensation within the
+nebular mass that existed in space. This would, undoubtedly, meet the
+difficulty already referred to, and solves the problem as to how the
+various planets were formed at different distances in space.
+
+Further, such a solution is in perfect harmony with all the Rules of
+Philosophy. It is much more simple to conceive of Aether condensing at
+various points in what originally was the solar nebula, than it is to
+conceive of Aether condensing and shrinking towards one central point,
+and yet while condensing and shrinking, portions were flung off into
+space which would form the planet. A greater objection has to be met,
+when we come to deal with the origin of all the meteors and minor
+planets that exist in their numbers in the solar system. In relation to
+their origin, it is much easier to conceive of portions of the Aether
+condensing at different centres of condensation, than to suppose that
+each portion of aetherial matter that originally formed the meteor, or
+asteroid, was flung off as a separate portion from the central body.
+
+With the conception of an atomic and gravitating Aether, the Nebular
+Hypothesis, therefore, for the first time is placed upon a sound and
+philosophical basis, because the condensation of Aether, which is matter
+and possesses mass, admits of the origin of other matter from it which
+also possesses mass, together with other properties, as elasticity,
+density, compressibility and inertia.
+
+When there is added to the atomic Aether the conception of a rotatory
+aetherial atom, as was indicated in Art. 44, we have at once a source
+from whence the rotation of the whole mass may be derived. Thus, as the
+condensation continued, and the nucleus or central part of the body was
+gradually formed, the rotation would be accelerated, because of the
+inherent energy which would exist in the condensed part. Further, as the
+condensation continued, the body so formed would be more or less
+spherical in form, as the conception of our aetherial atom was
+spherical, and when we conceive of the primary point of condensation, we
+have to think of a large number of spherical atoms coming together; and,
+as all the motions of the Aether which give rise to light, heat,
+electricity and magnetism, and which now include gravitation, are
+spherical in their operations, so their effect upon any condensing
+Aether would take a spherical form. Thus such bodies as nebulae, comets,
+asteroids, satellites, planets and suns should possess bodies more or
+less of a spherical form, subject to certain qualifying conditions, as
+rotation and orbital velocity, and this is in harmony with observation
+and experience. For we shall find that even in the case of nebulae, we
+have globular, ring or annular nebulae, and elliptic nebulae, while in
+the case of comets, the nuclei and coma are more or less spherical.
+Further, it is a familiar fact that the shape of all asteroids,
+satellites, planets, and even the sun is spherical or that of an oblate
+spheroid, which latter is simply due to its rotational velocity on its
+axis.
+
+Thus the principle involved in the nebular hypothesis receives its
+confirmation in the atomic and gravitating Aether, and with certain
+modifications of the different hypotheses advanced, is capable of
+uniting all those hypotheses that have ever been put forth in this
+direction into one perfect and harmonious whole.
+
+Again, the condensation of the Aether, composed as it is of its atoms,
+ever in a state of rotation, does away with the Primitive impulse which
+was objected to in Art. 9. For in that article it was shown that the
+conception of a primitive impulse as conceived by Newton was
+unphilosophical, in that its conception was not simple, and failed to
+satisfactorily account for observed phenomena. With the hypothesis,
+however, of a rotatory aetherial atom, we have at once those conditions
+which at any time, in the history of the universe, may give rise to
+those conditions by which a body may be set rotating not only on its
+axis, but also revolving around some central body, as the process of
+condensation is continued.
+
+So that in the primordial and universal electro-magnetic Aether that
+exists in all space, we get those conditions which will not only give
+rise to the phenomena of light, heat, magnetism and electricity, but
+also those properties, qualities and motions by which are produced,
+maintained and perpetuated, the various bodies that exist in the Aether,
+which is at once the physical source and cause of the bodies.
+
+
+ART. 122. _Kinds of Nebulae._--Nebulae may be classified into the
+following groups--
+
+    1. Irregular Nebulae.
+    2. Ring and Elliptical Nebulae.
+    3. Spiral or Whirlpool Nebulae.
+    4. Planetary Nebulae.
+
+_Irregular Nebulae._--Of this class the most conspicuous are those in
+the constellations of Orion and Andromeda. So clearly defined are they,
+that they are oftentimes seen by the naked eye on a clear night, and are
+often mistaken for comets.
+
+The great nebula in Orion is one of the most noticeable objects in the
+heavens. It is noted for its size and brilliancy, and also for the
+successful observation which it has been subjected to from time to time.
+This large nebula is situated in that part of Orion which is occupied by
+several stars known as the Sword Handle. These multiple stars are known
+by the name of Theta. Around these multiple stars is to be seen the
+nebula, as though the multiple stars really were enveloped by the nebula
+extending for a great distance out into space. It is of a faint bluish
+colour, with the central parts possessing the greatest brilliancy. The
+suggestion arises in our mind as to whether the nebulae are in any ways
+indicative of the presence of the electro-magnetic aetherial field that
+each star undoubtedly possesses. We learned in Art. 88 that the sun is
+an electro-magnet, and that it possesses its electro-magnetic field. We
+have also seen in Art. 109 that the zodiacal light, which is to be
+observed in connection with our solar system, is really indicative of
+the presence of that electro-magnetic field, as it rotates round the
+central body. Now, if an observer were situated out in space, where the
+nebula of Orion is situated, and could look at our system with
+telescopes equally as powerful as those we possess, would not our sun
+present an equally nebulous light to them because of the presence of its
+electro-magnetic field?
+
+Conversely, if every star possesses an electro-magnetic aetherial field,
+as they undoubtedly do, then it seems only reasonable to infer that that
+electro-magnetic field possesses a nebulosity which corresponds with our
+zodiacal light. The fact that the spectra of the nebulae are continuous,
+revealing no dark lines, seems to indicate the purity of some of the
+nebulae, and that therefore they are free from all known elements.
+
+So that spectroscopic results seem to confirm this hypothesis, as the
+pure Aether that would surround every star, or multiples of stars, would
+certainly not reveal any dark lines by means of the spectroscope. Such a
+hypothesis, as to the real nature of a nebula, is entirely in harmony
+with the theory of the Aether presented in Chapter IV., because being
+gravitative it will surround each star or multiples of stars, and
+therefore be denser nearest to those stars, and being atomic, there will
+be a certain amount of nebulosity manifested by the denser parts of the
+medium, as is the case in our own solar system.
+
+_Ring or Elliptical Nebulae._--These forms of nebulae are so named from
+their ring-shaped appearance, sometimes being known as Annular Nebulae.
+The elliptical nebulae are usually classed with them, as they are
+supposed to be similar kinds of nebulae looked at edgeways. The best
+known of this class is that found in the constellation of Lyra, and
+known as 57M, which is the number of the star in Messier's catalogue of
+stars. It is small but well-defined, so that it looks more like a flat
+oval solid ring than a nebula.
+
+The central part is not entirely dark, but is filled up with a hazy
+light. Another annular nebula is that situated to the south-west of
+Lambda Scorpii. Sir J. Herschel[44] writes of it thus: "It is a delicate
+but well-defined annulus. The field is crowded with stars, two of which
+are nebulae. A beautiful delicate ring of a faint ghost-like appearance,
+about 40" in diameter, in a field of about 150 stars, of 11 and 12
+magnitude and under."
+
+Of the elliptical nebulae the best known is the one in the constellation
+of Andromeda, which goes by the name of 31M. It is visible on a clear
+night, and can be seen by the naked eye as a hazy light. There are
+several other elliptical nebulae, lying to the north-west of this great
+nebula.
+
+_Planetary Nebulae._--The planetary nebulae represent a number of minute
+objects visible in the heavens. They look like globes of a
+bluish-coloured gas and are sometimes mistaken for small stars. Sir J.
+Herschel writes about them as follows: "Planetary nebulae are very
+extraordinary objects. They have, as their name implies, a resemblance
+to planets, presenting discs, round or slightly oval, some being quite
+sharply defined, terminating in others a little hazy or softened at the
+border. They are comparatively rare objects, not more than 25 having
+been observed, and of these nearly three-quarters are in the southern
+hemisphere. Their disc is circular or slightly elliptic, with sharp,
+clear, and well-defined outline, having exactly the appearance of a
+planet with the exception only of its colour, which is full blue,
+varying somewhat upon green. M. Arago has surmised that they may
+possibly be envelopes shining by reflected light from a solar body
+placed in their centre, invisible to us because of its excessive
+distance."
+
+The suggestion which arises to our mind in view of the atomic and
+gravitating Aether is, that the planetary nebulae are exactly what their
+names imply, that is, nebulous matter around planets. We have already
+learned that each satellite and planet possesses an electro-magnetic
+field, which field takes more or less the shape of a spherical form, so
+that if there are planets existing in the far-off systems in space, as
+we are compelled to believe that there are, then they too would possess
+an electro-magnetic field, which would be composed of spherical
+envelopes surrounding the several planets. These planets would shine by
+reflected light, as suggested by M. Arago.
+
+The possession by the planet of the nebulous matter, which we have
+already suggested is composed of the denser parts of the Aether around
+the planet, would give to the planet a nebulous appearance which would
+satisfactorily account for the term already given. They would indeed be
+what Sir John Herschel suggested they were, viz, planetary nebulae.
+
+_Spiral Nebulae._--The Spiral, or Whirlpool Nebulae, are remarkable
+objects, and were first discovered by Lord Rosse with his six-foot
+telescope. One of the best examples of the spiral nebulae is that known
+as 51M. Small telescopes show this as two clusters, one of them being
+surrounded by a ring, at a distance, which is divided into two parts.
+Lord Rosse, however, found it to be really a spiral nebula, the ring
+running into a series of spiral coils of nebulous matter, the outlying
+parts being connected with the main part by curved bands.
+
+Huggins has found that the spectrum of this nebula is not gaseous. Other
+examples of this class are 99M and 33M. What these spiral or whirlpool
+nebulae are, is unknown, but, on the hypothesis of a condensing and
+gravitating Aether which is in a state of rotation, the spiral nebulae
+can be easily pictured. For, as the condensation goes on, rotation will
+set in, and if we can picture such a phenomenon taking place in a plane
+which is at right angles to the line of vision, then we should have a
+full view of a nebula which would present a spiral form. Indeed, there
+is no phenomenon in connection with nebulae that cannot be physically
+explained by a condensing, gravitating and rotatory Aether; and as
+Aether is universal, the same properties will apply to it in distant
+space as they do in the solar system; and apart from a gravitating and
+rotatory electro-magnetic Aether, the phenomena of our own solar system
+cannot be physically conceived or explained.
+
+Therefore, if such an Aether can explain the phenomena associated with
+our own system, it ought also to explain, and that to the fullest
+extent, all phenomena incidental to and associated with the innumerable
+systems that flood the universe at large.
+
+[Footnote 44: _Outlines of Astronomy._]
+
+
+
+
+                              CHAPTER XIV
+
+                           UNITY OF UNIVERSE
+
+
+ART. 123. _The Universe._--In the preceding chapters we have endeavoured
+to deal with some of the principal phenomena that help to give a
+mechanical conception to the entire Universe.
+
+It now remains for us to show, in this last chapter, how, underlying all
+the physical structure of the Universe, there is one fundamental and
+primordial medium, in which all the forms of matter and motion find
+their ultimate unity.
+
+The Universe literally means one ultimate whole, though that whole may
+be compounded of many parts, the very essence of the term embodying the
+idea of a complete unity which runs throughout its whole physical
+structure.
+
+Apart from some such hypothesis as will be suggested in this chapter,
+that ultimate unity is incapable of a physical or mechanical conception.
+In Art. 29 we learned that the Universe was composed of two classes of
+things, matter and motion, while in Art. 30 we learned that the sum
+total of matter according to the law of the conservation of matter ever
+remains the same; while further, in Art. 53, according to the law of the
+conservation of energy, the sum total of energy ever remains the same.
+We have also learned that the two are indissolubly united, so that
+wherever we found matter, whether that matter was in its atomic,
+molecular, planetary or stellar form, there, as its necessary complement
+and counterpart, was the ever-present and unceasing motion, in one or
+other of its many forms. Thus, throughout the entire Universe, we find
+the same two essentials ever working in unison and harmony.
+
+Nowhere in the realm of infinite space is there such a phenomenon as
+rest or absolute death. The ideal that seems to be the key of the
+Universe, is that continuity of motion which science teaches us is so
+inseparably connected with all matter. Grouped, however, here and there
+throughout the Universe are modifications of this aetherial matter,
+termed molecules, satellites, planets, suns, or stars, which
+modifications are, however, not so real and abiding as the
+electro-magnetic Aether from which they receive their physical origin.
+
+The physical character of the universe is progressive. Even in its
+ultimate unity there is no such thing as stagnation or standing still;
+for, while in some parts of the Universe new stars and suns and planets,
+yea, even new systems are being evolved out of the primordial Aether, in
+other parts of the Universe old stars and suns, with all their attendant
+planets and satellites, are passing on towards that final end, when they
+themselves will be again resolved into the original form of matter from
+which they were first made. This assertion is in perfect harmony not
+only with science, but also with revelation. For even revelation teaches
+us that all the stars shall grow old as doth a garment, and as a vesture
+shall they be folded up (Heb. i. 11), and that (out of their ruins) a
+new heaven and a new earth shall be created and the former shall not be
+remembered (Isaiah lxv. 17).
+
+Thus amid all the modifications of that which is the real physical basis
+of all matter, we find indissolubly associated with each and all of the
+varied forms and modifications certain motions which are analogous to
+each other. In the aetherial atom itself, so infinitesimal in its
+proportions that even our imagination is almost strained in our attempt
+to conceive it, yet even here we have rotation and translation in an
+orbit, such rotation and translation being due to the motions of the
+electro-magnetic Aether. Then in the gaseous forms of matter into which
+these atoms may be condensed, we find the same two essentials, of matter
+and motion, of rotation and translation in an orbit, always working
+harmoniously together, through the motions of the selfsame Aether, which
+gives rise to the attraction and repulsions of the atoms.
+
+Then following the principle into the planetary world, and taking the
+planet Saturn with its ring of satellites as an example, we find again
+the same two factors ever working in unison and in harmony, with their
+incessant rotation and translation in an orbit, forming a complete and
+perfect unity in themselves, such unity being due to the pressures and
+tensions of the Aether combined with its rotatory character. Then going
+a step further, we find a number of planets, with or without satellites,
+all rotating around one central body, that rotation and translation
+again being due to the motions of the rotating electro-magnetic Aether,
+combined with its pressures and tensions.
+
+For millions of years, so far as we can tell, this solar system of ours
+has been moving through space as one complete unit.
+
+Then out in stellar space there are millions of such systems, each
+distinct and perfect in themselves, each of which is made up of exactly
+similar parts to our solar system, these innumerable systems being
+doubtless joined together by the same electro-magnetic Aether, forming
+one larger and grander unity, known as a constellation. Then these
+constellations, increasing in their number, are again joined together,
+and form a still larger unity called a Galaxy; and galaxy being joined
+to galaxy, constellations to constellations, we get such an ocean of
+suns and stars like that known as the Milky Way, the ultimate whole
+revealing in all its beauty and harmony the unison of the two
+essentials of matter and motion. It may even be that all the oceans of
+suns and stars, that exist in far-off space, are joined together by one
+common bond, the universal electro-magnetic Aether by its two
+complementary motions, the centripetal and the centrifugal, the whole
+forming one ultimate unity which we call the Universe, having for its
+centre one common point or central orb, which indeed forms the centre of
+gravity of the entire Universe.
+
+Thus the key to the physical conception of the Universe is to be found,
+and alone found, in that beauty of order, and harmony of motion, which
+are so inseparably associated with the varied forms of matter,
+graduating through a series of units or atoms, each with its dual nature
+complete in itself, through a series of minor entities termed elements,
+which in their aggregations form meteorites, satellites, planets, suns
+and stars, and systems of stars and oceans of suns and stars, until all
+are united into one ultimate unity where all are blended into one
+complete and perfect whole; the whole of the universal fabric being held
+together in its mechanical order and beauty by the electro-magnetic
+Aether. Then in the very centre of the Universe there dwells that
+Supreme Being whom we call God, who is at once the one real fountain and
+source of all the light and life of the Universe itself. For it is His
+universal Spirit that moulds and fashions the plastic matter into the
+many forms which it assumes, and uses the various modes of motion, as
+heat, light, electricity and magnetism, as instruments to build up and
+erect in all their beauty and harmony the innumerable systems that flood
+immensity and space.
+
+For if there be a centre of gravity to an atomic system, and a centre of
+gravity to a planetary system, and a centre of gravity to a solar
+system, then there is also a centre of gravity to a group of systems,
+even to a constellation, or a galaxy; otherwise our philosophy relative
+to the centres of gravity of masses fails in its application to wider
+phenomena of an exactly similar kind.
+
+Thus, if there is a centre of gravity to a galaxy, even to the Milky Way
+itself, then, going one step further, with a faith that laughs at
+scientific data and leaps beyond the narrow bounds of pure reasoning, we
+affirm that there must even be a centre of gravity to the entire
+Universe. Now let me ask the reader, What can be more fitting, more
+appropriate, more reasonable than to infer that the centre of gravity of
+the Universe is to be found in that celestial orb or orbs where the
+throne of God exists and endures, and where ultimately there will be
+congregated together in perfect felicity the spirits of just men made
+perfect, not only from our insignificant planet, but all the spirits of
+all beings from all the planets which in their almost infinite number
+are circled round their central suns by the electro-magnetic Aether? It
+is there, in these bright orbs, with their vision and powers
+spiritualized, quickened and intensified, that all perfected spirits
+shall look out into space, with increasing wonder, upon the birth and
+decay of worlds, the evolution and devolution of planets and systems and
+constellations, and shall watch the continuation and working out of that
+grand and glorious plan, which alone finds its perfection and its
+ultimate fulfilment in the wisdom, and power, and glory of the Eternal
+Spirit of the Living God.
+
+To see if this conception of the Universe is borne out by scientific
+data, we will now address ourselves more particularly to those
+fundamental truths which underlie the unity of the Universe.
+
+
+ART. 124. _The Unity of the Universe._--The Unity of the Universe is a
+dream which has passed before the imagination of many philosophers in
+by-gone times, and has been a fruitful source of speculation to
+old-world, as well as more modern philosophers. The researches of such
+living scientists as Sir William Crookes, Professor J. J. Thomson and
+others, have, however, made this dream come within the range of
+practical research and direct experiment. Professor J. J. Thomson
+believes that it is possible to break off from an atom, a part which is
+only 1/1000 part of the whole, and these infinitesimal parts he has
+called corpuscles, which he considers are the carriers of the electric
+current.
+
+If, therefore, it can be philosophically proved that the hypothesis of
+an atomic, gravitating, and condensing Aether can satisfactorily account
+for the physical existence of all atoms, and therefore of all matter,
+the dream of old-world philosophers will be helped on its way to a
+successful realization.
+
+We have already suggested, that nebulae are formed out of the
+condensation of the electro-magnetic Aether that fills the Universe; and
+as that nebula, according to the Nebular Hypothesis, ultimately resolves
+itself into a sun, or planet, or satellite, as the case may be, it
+follows that the condensation of this electro-magnetic Aether forms the
+basis of all the various elements, as Hydrogen, Nitrogen, Oxygen and the
+other seventy elements of which those bodies are composed. Thus the
+conclusion that we are compelled to come to in regard to the ultimate
+nature of matter, in its primordial condition, is, that all matter which
+exists in its varied forms throughout the entire Universe finds its
+physical origin and source in the universal electro-magnetic Aether,
+which is itself atomic, and possesses all the essential properties of
+matter.
+
+With the conception of the Aether as advanced in this work, this
+hypothesis is perfectly philosophical and logical. For the conception is
+simple, in that it supposes one form of matter to spring out of another
+form, that is, from an aetherial form to gaseous, in a similar manner to
+that in which a gaseous form changes into a liquid form, that is, by
+condensation, or a closer drawing together of the aetherial elastic
+envelopes that surround each atom; each particular gas, as Hydrogen,
+Nitrogen, or Oxygen, representing different quantities of aetherial
+condensations, as will be seen in the next article.
+
+The aetherial constitution of matter has received recognition from the
+hands of such scientists as Lord Kelvin and Dr. Larmor. The latter, in
+his _Aether and Matter_, writes on the subject as follows (page 7):
+"Matter must be constituted of isolated portions, each of which is of
+necessity a permanent nucleus or singularity in and belonging to the
+Aether, of some such type as is represented for example by a minute
+vortex ring in a perfect fluid, or a centre of permanent strain in a
+rotational elastic medium." And again on the same page he adds: "It is
+incumbent on us to recognize an aetherial substratum of matter, in so
+far as this proves conducive to simplicity and logical consistency in
+our scheme of physical relations, and helpful towards the discovery of
+hitherto unnoticed ones."
+
+Dr. Larmor, as has already been pointed out in Art. 44, speaks of his
+aetherial atoms as electrons, which are of two kinds, negative and
+positive, and of these he states (page 97): "Each electron has an
+effective mass of aetherial origin, which forms part, and may be the
+whole of the mass of the matter to which it is attached."
+
+Here, then, we have definite statements as to the hypothesis of all
+matter having a definite aetherial origin. If, therefore, it can be
+proved experimentally that matter does possess this aetherial basis,
+then the hypothesis will pass out of the region of speculation into the
+region of fact and science.
+
+The question, therefore, suggests itself to our mind, as to whether
+among all the experiments that have ever been performed by any
+scientist, there are any which will conclusively confirm and establish
+the hypothesis as to the aetherial origin of all matter. In my opinion
+there are such experiments, which have been given to the world by such
+eminent scientists as Faraday and Sir Humphry Davy. Before, however, the
+value of their experiments can be rightly understood and valued, we
+shall have to ask ourselves another question, and that is, "What is the
+relation of Aether to electricity?" Upon the correct answer to this
+question depends the application of Faraday's experiments to the
+hypothesis of the aetherial constitution of all matter, and therefore of
+the great underlying principle of the unity of the Universe.
+
+Is there any relation therefore between Aether and electricity? If so,
+what is that relation, and to what extent does it hold good? Professor
+Lodge, in his preface to _Modern Views of Electricity_, asks a similar
+question. "Electricity," he states, "has been thought to be a form of
+energy, it has been shown to be a form of Aether. There remains the
+question, What is Aether?"
+
+While again he writes: "A rough and crude statement adopted for popular
+use is that electricity and Aether are identical. But that is not all
+that has to be said, for there are two opposite kinds of electricities,
+and there are not two Aethers. But there may be two aspects of one
+Aether, just as there are two sides to a sheet of paper."
+
+That there is a definite relation between Aether and electricity is as
+certain as there is a definite relation between electricity and light.
+In order to find out how far the relationship and identity between
+Aether and electricity extend we will review our conception of the
+Aether as given in Chapter IV. According to the conception advanced in
+that chapter, on the hypothesis that Aether was matter, we
+philosophically came to the conclusion that Aether was atomic, and
+therefore gravitative. Because it was gravitative, it possessed density,
+and varying degrees of density; and having mass, it possesses the
+property of inertia the same as any other matter; and was also elastic.
+
+We have now to add to these properties that of compressibility, which
+property we have ascribed to it from philosophical considerations when
+dealing with comets, and nebulae, and the origin of planets and
+satellites. Now, if there is any identity between Aether and
+electricity, then it follows that that identity will be more or less
+manifested, as we find electricity possessing more or less of the
+properties which have been ascribed to the electro-magnetic Aether. For,
+if we find two apparently different substances, or entities, possessing
+exactly the same properties, and occupying the same space at one and the
+same time, then the only logical conclusion that we can come to is, that
+these two apparently different substances are not two substances, but
+one.
+
+We have already proved that they both occupy exactly the same space,
+that is, they occupy the planetary and interstellar regions of space,
+and fill indeed the entire Universe. The electro-magnetic theory of
+Light (Art. 78) indisputably proves this. We will therefore find out if
+electricity possesses the properties which have already been ascribed to
+the Aether. The first property, and indeed the fundamental property, of
+Aether is that it is atomic, and upon the atomicity of the medium
+depends the whole of the theory as worked out in relation to heat,
+light, electricity and so-called gravitational phenomena. Is there
+anything about electricity that can suggest the hypothesis that
+electricity is atomic? The answer is unquestionably in the affirmative.
+Many of the greatest scientists of the past and present century have
+believed and worked at the hypothesis of the atomic character of
+electricity, and none more so than Dr. Larmor in his _Aether and Matter_
+and Professor J. J. Thomson.
+
+Now what is Dr. Larmor's opinion as to the atomicity of electricity?
+These are some of his statements quoted in the work. In the very first
+words of his preface he writes:[45] "The following essay was originally
+undertaken mainly as a contribution towards the development of the
+standpoint which considers electricity, as well as the matter, to be
+constituted on an atomic basis." He continues: "Since Faraday's work on
+Electrolysis, the notion of the atomic constitution of electrification
+in its electro-chemical aspect has never been entirely absent." While
+later on he adds: "Thus, for example, the present view of the atomic
+character of electricity, which is at length coming within the scope of
+direct experiment, has been in evidence with gradually increasing
+precision ever since theoretical formulations were attempted on the
+subject."
+
+We are, however, possibly indebted to Professor J. J. Thomson for the
+most direct experimental evidence as to the atomic nature of
+electricity, for, as is well known to scientists, he has discovered what
+he termed corpuscles, in association with electricity, which he makes
+the carriers of the charges involved in electrical phenomena.
+
+Here, then, we have one proof of the identity that exists between Aether
+and electricity, in that while they both fill the same space, they are
+both equally atomic; Dr. Larmor's ultimate atom, as we have already
+seen, being known as positive and negative electrons. Aether, we also
+learned, was gravitative (Art. 45), but we have since learned that
+gravitation is itself an electrical phenomenon, in that both the
+centripetal and centrifugal forces are due to the repulsions and
+attractions or pressure and tension of this electro-magnetic Aether.
+
+So that when we affirm that Aether is gravitative, we do but affirm it
+is subject to the laws of electricity, which govern all electrical
+phenomena, and therefore we might just as truly affirm that electricity
+is gravitative, because such an affirmation is simply another way of
+saying that electricity gives rise to the attractions and repulsions
+incidental to, and associated with, all electrical phenomena. Here,
+again, we have further evidence of the identity that exists between
+Aether and electricity.
+
+Then we learned that Aether possessed density, and also different
+degrees of density, and the question arises as to whether there is
+anything corresponding to this property in electricity. As a matter of
+fact, this very property of density is itself recognized and known to
+all scientists by the term Electric Density, the electric density being
+always proportionate to the charge of electricity on a given area.
+
+We learned also in Art. 79 that aetherial density and electrical density
+were identical in relation to solar and planetary space; so that,
+wherever there was the denser Aether, there was also the denser
+electricity, the density of the one increasing or decreasing exactly in
+the same ratio as the other increased or decreased. From aetherial and
+electrical density, therefore, we have another proof of the close
+identity that exists between Aether and electricity.
+
+Again, we learned (Art. 48) that Aether possessed inertia. Here at
+least, it may be thought, we shall find the first point of difference
+between the two entities. Surely such an intangible, aetherial
+manifestation as electricity cannot possess inertia. Let us see what
+Professor Lodge has to say on the subject. In the chapter on electrical
+inertia he writes (p. 89, par. 365 of _Modern Views of Electricity_): "A
+current does not start instantaneously: it takes a certain time, often
+very short, to rise to its full strength; and when started it tends to
+persist, so that if its circuit be suddenly broken, it refuses to stop
+quite suddenly, and bursts through the introduced insulating partition
+with violence and heat. It is this ram or impetus of the electric
+current which causes the spark seen on breaking a circuit; and the more
+sudden the breakage, the more violent is the spark apt to be. We shall
+understand them better directly; meanwhile they appear to be direct
+consequences of the inertia of electricity; and certainly if electricity
+were a fluid possessing inertia it would behave to a superficial
+observer just in this way."
+
+From these statements we learn then that electricity does possess
+inertia, although there are other phenomena of electricity that would
+destroy the hypothesis. But undoubtedly an electric current possesses
+momentum, and it is philosophically impossible to associate momentum
+with any body that does not possess inertia, as one of the factors of
+momentum implies mass, even though it be a mass of an infinitesimal
+form, and mass is the very essence of the property of inertia (Art. 40).
+
+Dr. Larmor, in the work already referred to, dealing with the subject
+of electric inertia, explains that it is concentrated at the nucleus of
+the electron (p. 230), while on p. 202 he states: "Each electron as it
+is moved by the aetherial displacement belonging to the radiation,
+resists with its own definite inertia."
+
+Apart from this evidence, the philosophical evidence already adduced in
+Chapter X. is altogether in favour of the fact that electricity
+possesses inertia. So that we may say that, though the evidence as to
+the identity of electrical and aetherial inertia is not fully complete,
+the balance of opinion lies in favour of the identity rather than
+otherwise. See _Appendix A_.
+
+It can further be demonstrated that electricity possesses elasticity the
+same as the Aether does. The charge and discharge of a Leyden jar are
+conclusive evidence of the elasticity associated with electrical
+phenomena, while further proof is to be found in the fact that Dr.
+Larmor attributes elasticity to his electrons, such elasticity being of
+a rotational type.
+
+The identity, therefore, that exists between Aether is now almost
+complete. We have now only to prove that both are compressible, and the
+identity is fully established. This will be done by reference to certain
+of Faraday's experiments before the conclusion of this article. As we
+have established, logically, the identity that exists between Aether and
+electricity, the question arises now as to whether they are not one and
+the same medium. If they are not one and the same medium, then we are in
+the distinctly unphilosophical position of having to admit that all
+interplanetary and interstellar space are filled at one and the same
+time by two different media, and such an assumption is directly opposed
+to all observation and experience.
+
+Therefore, to be strictly philosophical, one of these media must be done
+away with, and we may either assert that interplanetary and interstellar
+space is filled with electricity, or else it is filled with Aether, as
+it is much simpler to conceive of space being filled with one medium,
+than it is to suppose it to be filled with two media, which are
+absolutely identical in all their characteristic properties and
+functions. Both can give rise to exactly the same kind of phenomena,
+whether they are the phenomena of heat, light, electricity, or
+magnetism, and even gravitation itself. So that, if Science wishes to be
+distinctly philosophical in her statements in future, it will be
+necessary, it seems to me, to do away either with the Aether, or with
+the electricity, and as the latter is the better known entity, I am of
+the opinion that Science will retain the electric conception of space
+and matter, and do away with the aetherial, as being altogether
+unnecessary. See _Appendix B_.
+
+Thus are we led to the conclusion that electricity is itself a form of
+matter, as indeed it must be if it is atomic, as suggested by Dr. Larmor
+and Professor Thomson.
+
+Professor Lodge, on p. 9 of the work already referred to, states:
+"Electricity in this respect behaves just like a substance;" and again,
+p. 313, he writes: "We cannot assert that it is a form of matter,
+neither can we deny it; on the other hand, we certainly cannot assert
+that it is a form of energy, and I should be disposed to deny it. It may
+be that electricity is an _entity per se, just as matter is an entity
+per se_."
+
+Whether electricity be a form of matter or not, as I believe it
+undoubtedly is, we have arrived at the fact, in view of the identity
+between Aether and electricity, that, wherever the one is present, the
+other is present also. So that if it can be demonstrated by direct
+experiment that matter can be changed into its equivalent quantities of
+electricities, or that equivalent quantities of electricities could
+produce their equivalent forms of matter, then the electrical basis of
+matter, and consequently the aetherial basis of matter, are proved
+beyond contradiction, and we are thus led one step nearer to the
+ultimate unity of the Universe, which unity is to be found in the
+universal electro-magnetic Aether, which is identical with universal
+electricity. For if Aether be the basis of all modes of motion, as heat,
+light, and gravitation, and it is identical with electricity, it follows
+that electricity is equally the basis of all the varied phenomena, and
+if to that we add the constitution of matter itself, then we are within
+sight of the medium in which the ultimate unity of the Universe is to be
+found.
+
+This view of the subject has already been dealt with by a German
+scientist, Professor Vogt, in his book on _The Nature of Electricity and
+Magnetism_, a book, however, which is not translated into English. In
+that work I believe he shows the possibility of all matter having its
+origin in electricity; and if that be so, then that theory is really
+identical with an aetherial basis of matter, seeing that Aether and
+electricity philosophically seem to be one and the same medium. Let us
+therefore turn to Faraday's experiments, and see what they teach us on
+the subject of the electrical basis of matter, and therefore the
+aetherial basis at the same time.
+
+In paragraph 852 of his _Experimental Researches_ Faraday writes: "The
+theory of definite electro-chemical action appears to me to touch upon
+the absolute quantity of electricity, or electrical power, belonging to
+different bodies. Although we know nothing of what an atom is, yet we
+cannot resist forming some idea of a small particle which represents it
+to our mind, and though we cannot say what electricity is, so as to be
+able to say whether it is a particular _matter or matters_, or mere
+motion of ordinary matter, yet there is immensity of facts which justify
+us in believing that the atoms of matter are in some way endowed or
+associated with electrical powers to which they owe their most striking
+qualities, and amongst them their chemical affinity. As soon as we
+perceive, through the teaching of Dalton, that chemical powers are
+(however varied the circumstances in which they are exerted) definite
+for each body, we learn to estimate the relative degree of Force which
+resides in such bodies; and when upon that knowledge comes the fact that
+electricity, which we appear to be capable of loosening from its
+habitation for a while, or conveying from place to place, whilst it
+retains its chemical Force, can be measured out, and being so measured,
+is found to be as definite in its action as any of those portions which,
+remaining associated with the particles of matter, give them their
+chemical relation, we seem to have found a link which connects the
+proportion of that belonging to the particles in their natural state."
+
+Then in paragraph 855 he writes as follows: "It seems a probable and
+almost a natural consequence, that the quantity which passes is the
+equivalent of, and therefore equal to, that of the particles separated,
+_i. e._ that if the electrical power which holds the elements of a grain
+of water in combination (or which makes a grain of oxygen and hydrogen,
+in the right proportions, unite into water when they are made to
+combine) could be thrown into the condition of a current, it would
+exactly equal the current required for the separation of that grain of
+water into its elements again."
+
+Further, in Art. 857, he states, "I can have no doubt that, assuming
+hydrogen as 1, and dismissing small fractions for the simplicity of
+expression, the equivalent number or atomic weight of oxygen is 8, of
+chlorine 36, of bromine 78.4, of lead 103.5, of tin 59, etc.,
+notwithstanding that a very high authority doubles several of these
+numbers." Then, writing upon the definite relationship of
+electro-chemical equivalents, he states, Art. 835: "Electro-chemical
+equivalents are always consistent; _i. e._ the same number which
+represents the equivalent of a substance _A_, when it is separating from
+a substance _B_, will also represent _A_ when separating from a third
+substance _C_. Thus 8 is the electro-chemical equivalent of oxygen,
+whether separating from hydrogen or tin or lead; and 103.5 is the
+electro-chemical equivalent of lead, whether separating from oxygen or
+chlorine or iodine."
+
+So that from Faraday's experiments we learn definitely that the
+electro-chemical equivalents coincide with and agree with the ordinary
+chemical equivalents according to Dalton's theory. From these
+experimental results of Faraday's we therefore learn that Faraday was of
+the opinion that each atom had a definite and certain quantity of
+electricity associated with it; and if this be true, then, in view of
+the identity of Aether with electricity, it follows that each atom must
+have definite and certain quantities of Aether associated with each
+atom. So that through Faraday's experimental researches we are again led
+to the hypothesis enunciated by Lord Kelvin in his paper "On the
+Clustering of Gravitational Matter in any part of the Universe," viz.
+that all matter has an aetherial, that is, an electrical basis, and that
+it is by the condensation of this electricity, and combinations of the
+condensational particles, that all the various elements are formed which
+compose the infinite variety of forms that constitute the entire
+Universe. Here, then, it seems to me, we have the evidence which gives
+to the aetherial Nebular Hypothesis (Art. 121) that experimental
+evidence which places that hypothesis upon a firm and philosophical
+foundation, and conclusively proves that it is possible for Aether out
+in the colder regions of interstellar space to be condensed into masses
+of gaseous matter, which form nebulae, and other masses in the cold
+regions of interplanetary space to condense and form comets and meteors.
+
+[Footnote 45: _Aether and Matter._]
+
+
+ART. 125. _Physical Constitution of Matter._--In Art. 31 we learned that
+all matter was made up of minute parts called atoms. When these atoms
+enter into combination with each other, they form the smallest particles
+of elementary substances as well as compound bodies, these particles or
+bodies being termed molecules.
+
+A molecule, therefore, may consist of any number of atoms of the same
+element, or may be formed of the union of the atoms of two different
+elements. In the preceding article we have learned that the atom of
+hydrogen or carbon, however, is divisible, at least theoretically if not
+experimentally, as we came to the conclusion that all atoms are composed
+of infinitesimal aetherial atoms, which are synonymous with atoms of
+electricity.
+
+Whether we shall ever be able to experimentally prove the existence of
+such an atom remains to be seen, though Dr. Larmor states that the
+atomicity of electricity is coming within the scope of direct
+experiment; while the researches of Professors Crookes and J. J. Thomson
+have undoubtedly given direct evidence of the existence of corpuscles,
+which are part of the atoms of the various elements.
+
+When we try to conceive, however, of the manner in which the various
+elements can be formed from one primary medium, that is, the Aether or
+electricity, we find it difficult to arrive at a simple physical
+conception of the process involved.
+
+We are indebted to Professor J. J. Thomson for what is practically the
+only simple physical conception of the method in which various elements
+may be formed from that medium, which gives unity to the whole of the
+universe. In the Adams Prize Essay of 1883 Professor Thomson indicated a
+theory based on the vortex atom (Art. 43) which satisfactorily accounted
+for the various laws which governed gaseous matter, and also showed how
+the varied chemical combinations might be physically conceived as being
+produced from one primary medium.
+
+In this theory we have to conceive of the vortex atom as possessing a
+hollow core, while in our conception of an aetherial atom (Art. 43) we
+conceived it as being more of a spherical or globular form than
+ring-shaped. We have, then, to consider the atom of any element as being
+composed of a vortex ring of various thickness, the thickness of the
+ring being an indication of its atomic weight.
+
+Each vortex ring must also be conceived as itself being composed of a
+number of aetherial atoms, or atoms of electricity, the number of such
+atoms being proportionate to the respective atomic weights of the
+various elements. Dr. Larmor suggests that a vortex ring may have this
+constitution in his work on _Aether and Matter_.
+
+According to Professor J. J. Thomson, then, any vortex ring, which we
+have supposed to be constituted of aetherial atoms, or atoms of
+electricity, may unite with any other vortex ring, thus producing a
+vortex ring of double density, which would possess double the
+electricity of the unit vortex ring. If we united three vortex rings,
+then the result would be an atom of threefold the density and strength
+of the unit vortex ring.
+
+We might conceive of four or any number of these rings uniting together
+to form a separate element, and then each element would simply be a
+multiple of the unit vortex ring, and so possess regular multiples of
+the atoms of electricity, each multiple representing a distinct element.
+
+We will now let Professor Thomson speak for himself on the matter, and
+will describe the theory in his own words, always keeping in mind the
+hypothesis that the unit vortex ring is itself composed of a definite
+number of atoms of electricity or electrons, as proved by Faraday. See
+_Appendix C_.
+
+In the work already referred to, Professor Thomson states: "We may
+suppose that the union or pairing in this way of two vortex rings of
+different kinds is what takes place, when two elements of which these
+vortex rings are atoms combine chemically; while, if the vortex rings
+are of the same kind, this process is what occurs when atoms combine to
+form molecules. Now let us suppose that the atoms of different chemical
+elements are made up of vortex rings, all of the same strength, but that
+some of these elements consist of only one ring, others of two rings
+linked together, others of three loops, and so on. Then if any of these
+rings combine to form a permanent combination, the strength of all the
+primaries in the system so formed by the combination must be equal."
+
+"Thus an atom of one element may combine with another atom of the same
+kind, to form a molecule of that substance consisting of two atoms.
+Again, three of these atoms may combine, and form a system consisting of
+three primary elements, but the chance of their doing so is small
+compared with the chance of two pairing; so that the number of systems
+of this kind will be small compared with the number of the systems
+consisting only of two atoms. We might have systems of four atoms, but
+the number would be small compared with the number of systems that
+consist of three atoms."
+
+"Now, suppose that an atom of one element is to combine with an atom of
+another. Suppose, to fix our ideas, that the atom consisting of two
+vortex rings linked together, is to combine with an atom consisting of
+one vortex ring; then, since, for the stability of connection, the
+strength of all the primaries which form the components of the compound
+must be equal, the atom consisting of two links must unite with
+molecules containing two atoms of the one with one link. Thus the
+compound formed will be the simplest combination, consisting of one of
+the atoms which consist of two vortex rings linked together with two of
+the atoms consisting of only one vortex ring. Similarly, if an atom
+consisting of three vortex rings linked together were to combine
+directly with atoms consisting of only one vortex ring, the compound
+formed would consist of the three linked atoms with three of the others,
+and so on for all the combinations of atoms formed by any number of
+vortex rings linked together. This suggests that the elements, called by
+the chemists monads, dyads, triads and so on, consist of one, two, etc.
+vortex rings linked together, for then we should know that a dyad could
+not combine with less than two atoms of a monad to form a stable
+compound, or a triad with less than three, and so on, which is just the
+definition of the terms monad, dyad, triad."
+
+"On looking at chemical combination from this point, we expect to find
+that such compounds as Hydrochloric acid, where one atom of Hydrogen has
+only to meet one atom of Chlorine; or water, where one atom of Oxygen
+has only to meet two atoms or a molecule of Hydrogen, would be much more
+easily and quickly formed than a compound such as ammonia gas, to form
+which an atom of Nitrogen has to find itself close to three atoms of
+Hydrogen at once."
+
+"It is the case, I believe, in direct combination, that simple compounds
+are formed more quickly than compound ones. We might call the ratio of
+the number of links in the atom of any element, to the number in the
+atom of Hydrogen, the Valency of the element. Thus the compounds H-CL,
+H-I, H-F, show that the atoms of Chlorine, Iodine, Fluorine have the
+same number of links as the atom of Hydrogen, so that the valency of
+each of these elements is unity. From the compound H_{2}O we infer that
+the atom of Oxygen consists of twice as many links as the atom of
+Hydrogen. The compound H_{2}S indicates that the atoms of Sulphur have
+twice as many links as the atom of Hydrogen."
+
+"The molecules CO_{2} and Marsh Gas have each three primaries
+represented by C-O-O and C-H-H respectively. According to the view we
+have taken, atomicity corresponds to complexity of atomic arrangement,
+and the elements of high atomicity consist of more vortex rings than
+those whose atomicity is low."
+
+"Thus high atomicity corresponds to complicated atomic arrangement, and
+we should expect to find the spectra of bodies of low atomicity much
+simpler than those of high. This seems to be the case, for we find that
+the spectra of Sodium, Potassium, Lithium, Hydrogen, Chlorine, which are
+all monad elements, consist of comparatively few lines."
+
+Here then, on the vortex theory of matter, especially when that vortex
+theory is given an electric basis, as is the case in Dr. Larmor's
+electron theory, we have a thinkable and logical explanation of the
+physical and chemical properties of matter, by which all elements and
+compounds may be formed from the primordial aetherial or electric atom.
+As all Nature is composed of about seventy elements, and it has been
+conclusively demonstrated that an atom of Hydrogen is the same all over
+the universe, no matter whether it exists on this planet, or in some
+distant star or nebula, we arrive at the conclusion that all the other
+elements are exactly the same in their properties and qualities wherever
+they are found. If, therefore, we couple Faraday's experiments and
+results as to the electro-chemical equivalents of all atoms, with this
+theory of Professor J. J. Thomson's, then we are again compelled to come
+to the conclusion that the unity of the universe in all its
+universality, and infinite variety of forms and modes of matter, is to
+be found, and alone found, in the universal Aether, which is co-existent
+and coextensive with electricity.
+
+
+ART. 126. _Quod Erat Faciendum._--Before concluding this work let us
+briefly review the whole of the theory submitted herein to the reader.
+
+That which was to be done consisted primarily in ascertaining the
+physical cause of Gravitation, by which would be accounted for on a
+philosophical basis all the phenomena incidental to and associated with
+the Law of Gravitation. Such phenomena included the physical cause of
+the Centripetal and Centrifugal Forces, the physical cause of Kepler's
+Laws, together with a physical conception of the application of Newton's
+Laws of Motion to all solar and stellar bodies. In addition to this,
+there were other outstanding problems in physics that it was premised
+would receive either a partial or an entire physical explanation. It was
+premised, for example, that the problem of the relative motion of Aether
+and matter would be solved, that the cause of the permanent magnetism of
+the earth would be revealed, and the great problem of the constitution
+of matter attacked, together with the unity of the universe which arose
+from that conception.
+
+In order, however, for any theory to be philosophical in its initial
+stages, the rules of some of the greatest philosophers which govern the
+making of any hypotheses were briefly outlined, and were found to
+resolve themselves into three divisions.
+
+The first rule dealt with the general simplicity of Nature's mode of
+working, and therefore the general simplicity which must govern our
+hypotheses in perfecting any theory as to the cause of all phenomena,
+gravitational or otherwise.
+
+The second rule showed that the only sound basis from whence we could
+derive all our data upon which to speculate and reason, lay in our
+experience of all natural phenomena. Whatever else we might do, or not
+do, it was absolutely necessary, if we wished to be perfectly
+philosophical in our conclusions, that we should not traverse the direct
+results of observations and experiments.
+
+The third rule laid down was the obvious axiom, that the theory so
+perfected by logical reasoning must satisfactorily account for and
+explain all the phenomena sought to be explained.
+
+Now I wish to submit the whole theory as propounded in this work in its
+completion and in its entirety to the reader, and to ask him if the
+Rules of Philosophy have not been adhered to throughout the whole work?
+Can any theory be more simple than the one submitted in this work, by
+which we have endeavoured to account for all, and even more, than was
+premised in the opening chapters?
+
+The very simplicity of the fundamental hypothesis that Aether is matter,
+in all its properties and qualities, has been the chief obstacle to the
+retardation of its earlier discovery.
+
+Any proposition more simple, more easy of comprehension, is, to my mind,
+difficult of conception. Why, children in our homes and schools may be
+taught the truth, and grasp it in its concrete form, and that is the
+highest test of the simplicity of any hypothesis.
+
+Thus the first Rule of Philosophy is satisfied and fulfilled in the
+initial hypothesis, and I venture to affirm that the same simplicity has
+characterized the development of the theory throughout its entire
+progress. Step by step, simple facts and simple truths which are known
+to any ordinary student have been shown to have a wider and more
+universal application than even the writer dreamed of, when he started
+out on his voyage of discovery in philosophical research.
+
+When we consider the second Rule of Philosophy in its application to our
+theory, we find that experience, as revealed by observation and
+experiment, is fulfilled to the minutest detail. The simple hypothesis
+that Aether is matter, fulfils to the very fullest extent all
+requirements demanded by the experience of all the scientists and
+experimentalists that the world has ever known. To assert that Aether is
+not matter is to assert a proposition contrary to all the accumulated
+experience of the past generations. Therefore, if Aether is matter, then
+its fundamental qualities must be those which belong to and are
+associated with all matter, those qualities being atomicity, gravity,
+density, elasticity, inertia, and compressibility.
+
+The objector to this statement is himself violating the chief rule of
+all philosophy, in that he is going contrary to the tenor and teaching
+of his own experience. Then, following out the second rule step by step
+we arrive at the one grand central truth, that electricity is also a
+form of matter, and that all the forces of the entire universe are but
+different modes of motion, different vibrations of the universal
+electro-magnetic Aether; while all the varied bodies that exist are
+themselves but different manifestations in a gaseous, liquid, or solid
+form of the same electro-magnetic substance.
+
+Thus, step by step, we have tried to build up a theory of the physical
+cause of all phenomena, which will satisfactorily account for those
+phenomena, and even for the structure of the universe itself, from the
+mechanical standpoint, and by so doing have fulfilled the third Rule of
+our Philosophy as enunciated by Newton and others.
+
+So that by the conception that Aether is matter, in its primordial
+state, we have more than fulfilled all that was premised should be done.
+
+Thus the long-sought-for and long-expected cause of Gravitation,
+together with the cause of the two complementary forces, is found in the
+simple statement that Aether is matter, with all that is logically
+included therein. Kepler's Laws and Newton's Laws of Motion also receive
+a physical explanation in the same universal electro-magnetic Aether.
+
+In addition to the solution of these problems, the transverse vibrations
+of light has received for the first time a physical conception, and a
+physical explanation, even admitting that that explanation may not be
+perfect in detail.
+
+The origin of the permanent magnetism of the earth has also received a
+physical explanation through the motions of this same electro-magnetic
+Aether, while certain theories in relation to electricity given to the
+world by Ampere, Weber, Faraday, and Clerk Maxwell have found their
+consummation in this atomic electro-magnetic medium.
+
+Further, astronomical hypotheses in relation to comets and nebulae are
+not untouched by the theory of a compressible and condensing atomic
+Aether. Indeed, there is not a phase of natural phenomena which is not
+affected in some way or other by the philosophical result arrived at
+that Aether is matter in its original state. Therefore, we claim,
+however imperfectly it may have been done, that not only have the Rules
+of Philosophy been fulfilled, but that the theory so advanced has
+accomplished more than even we in our wildest imagination hoped and
+dreamed for it.
+
+Look at the problem of the Aether how we may, the advantages of the
+theory of an atomic electro-magnetic Aether far surpass and outweigh the
+advantages of a frictionless medium, which in some unknown way possesses
+mass and inertia, although the conception of such properties themselves
+disproves the existence of such a frictionless medium.
+
+After all, how much of this theory is there which is entirely new or
+absolutely original? Age after age, men have had exactly similar dreams,
+and seen similar visions. In the old Grecian days similar views were
+expressed by their philosophers; and, even in the philosophy of less
+civilized countries, many of the suggested hypotheses found their place
+in a more or less perfect form.
+
+Analyze the whole theory from its initial stages to the last chapter,
+and we shall find, with the exception of one or two features, that every
+hypothesis first had its origin in the mind of some of the greatest
+thinkers and philosophers that the world has ever known.
+
+Take several hypotheses as examples. The hypothesis that Aether is
+atomic was suggested by such men as Newton, Huyghens, Descartes,
+Challis, Clerk Maxwell, and others.
+
+That Aether is gravitative has been suggested by Young, Grove, Faraday,
+and Lord Kelvin. Huyghens, Fresnel, and Young postulated different
+degrees of density for the Aether, while Stokes and McCullagh have
+affirmed and proved different degrees of elasticity of the medium.
+
+The inertia of the medium has received experimental evidence from
+Tyndall, Maxwell, Faraday, Lodge, and others, and its compressibility
+has received the adherence of men like Faraday, Maxwell, and Lord
+Kelvin.
+
+Then, when we come to deal with the causes of the forces involved in
+gravitational phenomena, we find that exactly similar hypotheses in
+regard to the Centrifugal Force have been postulated by Herschel,
+Bredichin, M. Faye, and Lebedew; while Faraday, Gauss and others have
+suggested the close relationship that exists between electrical and
+gravitational phenomena.
+
+The physical explanation of Kepler's Laws was suggested by Kepler
+himself, while Huyghens, Bernoulli, Descartes, and many of their
+contemporaries believed in the existence of some kind of vortices.
+
+The unity of the universe has been a dream of philosophers for
+generations past, and that dream is now crystallized in the definite
+conception of an atomic universal electro-magnetic medium, while the
+electrical basis of matter receives the support of such men as Crookes,
+J. J. Thomson, Larmor and Vogt.
+
+Thus we learn that all the dreams and thoughts, all the hypotheses and
+postulates of old-world as well as present-day philosophers find their
+consummation and ultimate realization in one universal, atomic,
+electro-magnetic medium.
+
+If this fact does not stamp the theory with that authority which is
+undeniably associated with the names of some of the scientists quoted,
+then all the greatest men in the scientific world have lived and toiled,
+thought and dreamed in vain, while the priceless gems of their
+imagination and research are treated as worthless and valueless.
+
+Again, what shall we say of the discoveries of to-day?
+
+What is the key to the greatest scientific discovery of modern times,
+viz. wireless or aetherial telegraphy, which is girdling the earth with
+its mysterious communications? Is not the key to that discovery to be
+found in this universal electro-magnetic medium?
+
+Whence come the X-rays, Rontgen rays, and other light rays with their
+adaptability to human suffering, if they come not from this same
+electro-magnetic medium? their adaptability to human suffering being
+dependent upon the intimate and close relationship that exists between
+the physical body and the electro-magnetic medium.
+
+Where is the key to the principle underlying the gramophone, the
+phonograph and the telephone, if it be not in this self-same atomic and
+easily impressible medium?
+
+Nay! let us go further, and ask ourselves where is the key to be found
+for the many marvellous effects of so-called spirit phenomena? Who can
+read F. W. Myer's _Human Personality and its Survival of Bodily Death_,
+and not feel that we are standing on the threshold of the unseen world?
+
+Already men are asking themselves the meaning of the strange sensations
+which they receive from unseen sources; already men's spirits are
+vibrating in unison with vibrations that come from the unseen world; and
+to-day we see spiritual phenomena as through a glass darkly, and the
+question arises, what is the medium of all this communication, of all
+these vibrations?
+
+Is there no medium at all which forms the medium of communication? To
+assert that would be to assert something opposed to all experience and
+therefore would be unphilosophical.
+
+May not then the theory of an atomic universal electro-magnetic medium
+help us on in our groping and searching after light in this direction?
+Who will uplift the veil? Already we peer almost into the spirit world.
+A little more light, a little more truth, and then there will burst
+forth upon the hearts and minds of men the grandest and most glorious
+truth that Nature can reveal of her Creator, and then men shall come to
+know and understand the place that God holds in the Universe, such truth
+being advanced on its way by an atomic, universal electro-magnetic
+Aether which is as truly matter as our own bodies.
+
+
+ART. 127. _God and the Universe._--To the superficial reader it may
+appear at first sight, that the theory of the Aether suggested in this
+work leaves no place in the Universe for the operations and existence of
+an Infinite and living Spirit, a God. It may be objected, that if all
+matter and all modes of motion find their physical origin in one common
+and primordial medium, the electro-magnetic Aether, where is the
+necessity for the existence of an Eternal and Infinite Spirit?
+
+At first sight there appears some force in the objection, but it loses
+its point when we come to view the Universe from the standpoint of
+spirit phenomena. The purpose of the writer in this work has been to
+deal with natural phenomena only, purely from the philosophical and
+scientific standpoint. Spirit phenomena (which is equally as real and
+obvious as natural phenomena) have no part or place in a work which
+deals with scientific facts and data, but demand and will receive in a
+future work equal consideration and philosophic treatment. A man must
+indeed be lacking in vision who cannot see behind all things the
+evidence of a richer and fuller truth than that which merely lies on the
+surface, or who fails to read and learn the greatest truth that circles
+the Universe in its ultimate unity, which indisputably points to the
+existence of an Eternal and ever-living Spirit, a God. I affirm that
+there is no scientific truth, even including the law of the conservation
+of matter and motion, which has been enunciated in this work, but what
+is reconcilable with the existence of an Eternal and Infinite Spirit;
+and although such a statement may seem a paradox, yet I am convinced
+that before many more years have passed, the reconciliation of natural
+with spiritual phenomena will be an accomplished fact. The fool to-day
+may say in his heart, there is no God, but ere long not only religion,
+but Science herself, shall expose his lack of wisdom and his folly.
+
+For all things derive their existence primarily, with all the energies
+and powers they possess, from God. Look where we will, or at what we
+will, from the smallest atom or molecule up to the most stupendous
+world, or myriads of worlds that roll and sparkle in the blue infinity,
+in each and all we see the indisputable evidence of the existence of a
+mysterious spirit, or power, that controls and governs them. A spirit or
+power that we cannot see, but which is so indisputably evidenced that
+its existence cannot be denied. For example, we see forms of many kinds,
+some of which are simple entities of themselves, while others are
+complex and made up of many parts, but while each part is inseparably
+connected with the other, yet each part is itself distinct from the
+others in nature and substance. The whole combined forms a complete
+mechanism or organism, and, like all mechanisms of human make, not only
+needs a controlling and governing power, but also evidences a maker.
+Even the laws of Nature and modes of motion, whether it be heat, light,
+electricity, or magnetism, are, however, unable of themselves to control
+the mechanism, and therefore prove themselves to be but the servants of
+an infinite Intelligence, a GOD.
+
+Thus, behind and beyond all we see, in every living form, there is the
+evidence of a hidden spirit, which is the governing and controlling and
+sustaining power, and without which the organism ceases to be an
+organism. A spirit which animates the mechanism, and uses its activities
+and powers as it wills for its own purposes and ends. This spirit or
+power we call its life, which gives to the form its existence, together
+with all that it possesses, as its powers, activities, energies and
+productions, for all are but the effects of the hidden life. If this
+mysterious something, termed its life, becomes in any way separated from
+the mechanism or organism, then as a distinct and separate organism it
+ceases to be; and though the mechanism may still exist for a time, yet
+all its powers are gone, while the organism, robbed of its very life,
+begins slowly to decay.
+
+We cannot see this power; we cannot find it We may search for it, rend
+and tear part from part, only to find that it baffles all our skill, and
+laughs at our endeavours to discover the secret of its existence. We
+know that it is there, just as truly as we know that in these forms of
+ours, these living stoves, these perfect mechanisms called our bodies,
+there exists and dwells a spirit, a living, conscious, self-acting and
+controlling power. A spirit which we know is not the mechanism itself,
+and which by experience and observation we know to be distinct from the
+organism. It is this mysterious spirit which controls and governs all
+our acts, that rules and reigns as king of our bodies, and makes the
+physical mechanism, with all its wondrous parts, obey and do its
+bidding. That this is so, that the spirit is distinct from the body, and
+is the controlling and governing principle within us, is evident in a
+thousand ways. If, however, that spirit departs from the mechanism of
+our bodies, then the controlling and governing influence is gone; and
+the mechanism, robbed of its life, ceases to work, ceases to fulfil its
+functions, and ceases to exist in that particular form.
+
+Just as it is with ourselves, so it is with the Universe. For look where
+we will, from the smallest atom to the great aggregation of atoms, as
+our earth, or even to the more stupendous orbs of heaven, the working of
+a secret and mysterious power or spirit meets our gaze. A spirit or
+power that is not the form or the mechanism, but is separate and
+distinct from the mechanism, while at the same time it is inseparably
+connected with each and all. For everything that we see, from an atom to
+the Universe itself, is a perfect mechanism, or complexity of
+mechanisms. The entire Universe is one vast, intricate, and elaborate
+piece of mechanism, beginning with the simple aetherial atom, ranging
+through all the atomic systems, graduating by successive steps through
+compound substances, which, in their aggregations, form meteors,
+satellites, planets, suns, and stars; until the ultimate whole is
+reached, where everything is blended into one vast whole; a perfect,
+infinite, complex mechanism, a Universe.
+
+Now if philosophy teaches anything at all regarding mechanisms of human
+invention, it indisputably teaches that every machine or mechanism that
+has ever been made, implies the existence of a maker, and that the maker
+possessed intelligent attributes, as reason, judgment, perception, and
+imagination. For example, stand before some elaborate machine of human
+invention, as a lace machine, and watch the working of that machine in
+all its details. It is composed of many parts, each of which is perfect
+in itself. Each part may be distinct in nature and purpose, yet each and
+all are inseparably and unitedly connected with each other, and all work
+harmoniously together for the accomplishment of a definite and specific
+end, that is, the production of a lace curtain of exquisite design and
+pattern. As we watch the machine and its workings, we see therein the
+evidence of the existence of a spirit or power that gave it its birth. A
+spirit or mind that made and formed the machine, that constituted,
+arranged, and gave it its governing and controlling power; fitted and
+ordered every part, gave to each part its allotted task, and moulded all
+to the harmonious fulfilment of the definite end and purpose he had in
+view.
+
+Thus in the machine we see evidence of contrivance and design, of method
+and arrangement, of conception, perception and judgment, which are all
+the effects and outflowings of intelligence which belong, and alone
+belong, to mind; and therefore we say, "The machine was made, and there
+was and must have been a maker." So universally is this fact accepted,
+that any one who seriously challenged the statement, or dared to deny
+it, would be at once pitied as insane or laughed at as a fool. Thus all
+experience proves, and philosophy testifies, that wherever we get a
+machine or mechanism of any kind or sort, there must have been a living,
+conscious being or person, who is distinct from and outside of the
+machine. He made it, and therefore must have existed before it, in order
+to make it. Wherever, therefore, we find a mechanism that bears the
+marks of intelligence and design, of judgment, perception and
+conception, it is only logical and philosophical to infer, that such a
+mechanism equally evidences the existence of an intelligent being. The
+more intricate and elaborate the mechanism, the greater the ingenuity
+displayed, the more complex and perfect the design, the more harmonious
+the working, the greater will be the wisdom, the more profound the
+judgment, the keener the perception, the more perfect the understanding,
+and the vaster, nobler, and more sublime the order of Being who
+originated and made it. This being so, according to philosophical
+reasoning, let us glance at the Universe in all its fulness and oneness,
+and we shall see the indisputable evidence of the existence of an
+Infinite Being, who made, controls and governs the infinite Universe.
+
+In the atomic world we get an illustration of the perfect mechanism that
+underlies all atomic systems. Our conception of an aetherial atom was
+based upon the analogy of our own planet, and there is every reason to
+believe that the little world in which all atoms live and move and have
+their being, is analogous to a planetary or solar system, in which we
+find the two essentials of matter and motion ever associated together,
+to form a larger and more complete mechanism. For atoms are not simply
+mere points; they possess real dimensions, with a determinate and fixed
+form, differing in their relative weights, and in the amount of motion
+or force with which each is endowed. The very fact that they possess
+atomic weights which are unalterable throughout the long periods of time
+that mark the history of the Universe, and that they combine in definite
+and fixed proportions, indisputably evidence the fact that they but do
+the bidding of an Eternal and Infinite Spirit, a God. Thus each
+molecule, or atomic system forms a perfect mechanism in itself, with its
+own centre of gravity, and subject to the same laws of repulsion and
+attraction, or pressures and tensions--due to the vibrations and motions
+of the universal electro-magnetic Aether.
+
+In each of the planetary systems we get an illustration of the same
+perfect mechanism, which is indicative of all systems whether large or
+small; each system being characterised by the same beauty of order and
+harmony of motion which are equally characteristic of atomic systems.
+
+Our own solar system, composed as it is of many parts, of thousands of
+meteors and comets, of numbers of satellites and planets, all revolving
+around one common centre, also forms a complete and perfect mechanism in
+itself. For millions and millions of years this perfect mechanism has
+been harmoniously working together in all its parts, as it moves in all
+its unity through the realms of infinite space. Yet through all the
+unknown ages of the past, such a phenomenon as disorder in the working
+of any part of the system is inconceivable and unknown. Out in stellar
+space there are, however, innumerable systems, similar to our own solar
+system, each distinct and perfect in itself; each being made up of
+similar parts, as meteors, comets, satellites, planets, and central sun.
+These systems are, however, united together into one vast aggregation of
+worlds, having one common controlling centre of their own, and by their
+unity form a constellation, a larger and grander mechanism. Throughout
+the whole constellation there is the same order, and harmonious working
+of part with part, that characterise the solar system. Then these
+constellations increasing in their aggregations form a still larger
+complexity of systems, called a Galaxy; and galaxy being added to
+galaxy, constellation to constellation, there is formed by such union,
+an ocean of suns and stars like our own Milky Way, the ultimate whole
+being characterised by the same mechanical order and harmonious working
+that characterise the solar system. It may even be, that there are
+numbers of these oceans of suns and stars existing in infinite space,
+all bound together by one common bond, the universal electro-magnetic
+Aether, and forming one vast ultimate whole, a Universe; with all its
+oceans of suns moving around one central Orb or mass of Orbs called the
+Throne of GOD.
+
+Thus the whole Universe is a mechanism, complete and perfect in every
+detail, and forming a system, so great, so grand, so sublime, so
+magnificent that it puts all mechanisms of human origin to shame and
+scorn. Now, if a mechanism of human invention evidences the existence of
+intelligence and mind, and proves itself to be the production of a
+living, sentient, conscious, and intelligent being, how much more,
+incomparably more, does the Universe with its infinite complexity
+evidence a Maker also; and that Maker must be as infinitely greater in
+wisdom, knowledge, perception and judgment as the Universe is infinitely
+greater in mechanical perfection than any mechanism of human origin.
+
+The Universe is God's teaching in symbol and in type. It is His great
+picture-book, where in living form He has portrayed Himself, and all
+that belongs to Him--His nature, character, wisdom; His greatness,
+glory, and His power. The Universe is a temple, where He sits enshrined
+in the things His own hands have made, and where those who have eyes to
+see, and hearts to learn and understand, may adore and worship Him.
+
+Thus is it true that "the heavens declare the glory of God," _i. e._ the
+character of God, His infinite wisdom, His infinite knowledge, His
+profound judgment, and His eternal righteousness; while the firmament
+showeth His handiwork. "Day unto day uttereth speech, and night unto
+night showeth (His) knowledge."
+
+"The Lord by wisdom hath founded the earth, by understanding hath He
+established the heavens."
+
+"He hath made the earth by His power. He hath established the world by
+His wisdom, and hath stretched out the heavens by His discretion."
+
+"Thou, Lord, in the beginning hast laid the foundations of the earth,
+and the heavens are the work of Thy hands; they shall perish, but Thou
+remainest; and they all shall wax old, as doth a garment; and as a
+vesture shalt Thou fold them up, and they shall be changed; but Thou art
+the same, and Thy years shall not fail."
+
+To prove the validity of these statements from a scientific and
+philosophic standpoint, and to show the harmony that exists between the
+natural and the Divine revelation as given in the Word of God, will form
+the subject of a future work.
+
+
+
+
+                              APPENDIX A
+
+
+According to Sir Oliver Lodge the fact that electricity possesses mass
+or inertia has now passed out of the hypothetical stage into the realm
+of fact and experiment. In his Romanes Lecture recently published, he
+states, page 4: "My first thesis is that an electric charge possesses
+the most fundamental and characteristic property of matter, viz. mass or
+inertia; so that if any one were to speak of a milligramme or an ounce
+or a ton of electricity, though he would certainly be speaking
+inconveniently, he might not necessarily be speaking erroneously."
+
+Now in view of the identity that exists between Aether and electricity,
+as proved by Hertz' experiments, the only logical conclusion that can be
+arrived at is, that Aether must also possess mass and inertia. So that
+the most recent experiments in relation to electricity confirm the
+theory of the Aether presented in this work, viz. that it also possesses
+mass and inertia, otherwise we should have a massless medium being
+composed of electrons which possess mass, and that would be a violation
+of all experience, and therefore an unphilosophical statement.
+
+
+
+
+                              APPENDIX B
+
+
+The hypothesis of electricity being the fundamental basis of all matter
+made in the last chapter on the "Unity of the Universe," receives
+confirmation from Sir Oliver Lodge in his _Modern Views of Matter_,
+where he writes, page 13: "The fundamental ingredient of which, in this
+view, the whole of matter is made up, is nothing more or less than
+electricity, in the form of an aggregate of an equal number of positive
+and negative electric charges. This, when established, will be a
+unification of matter such as has through all the ages been sought; it
+goes further than had been hoped, for the substratum is not an unknown
+and hypothetical protile, but the familiar electric charge."
+
+
+
+
+                              APPENDIX C
+
+
+The hypothesis that all elements have definite quantities of electricity
+in them, or a definite number of electrons, as suggested on page 335,
+receives added weight by the testimony of Sir Oliver Lodge in the work
+already referred to. Writing on the subject, he says: "It is a
+fascinating guess that the electrons constitute the fundamental
+substratum of which all matter is composed. That a grouping of say 700
+electrons, 350 positive and 350 negative, interleaved or interlocked in
+a state of violent motion so as to produce a stable configuration under
+the influence of their centrifugal inertia and their electric forces,
+constitutes an atom of hydrogen. That sixteen times as many, in another
+stable grouping, constitute an atom of oxygen. That some 16,000 of them
+go to form an atom of sodium; about 100,000 an atom of barium; and
+160,000 an atom of radium."
+
+From these extracts, taken from _Modern Views of Matter_, the author
+claims that the theory of the Aether presented to the reader in _Aether
+and Gravitation_ receives added confirmation and support.
+
+
+                        *    *    *    *    *
+
+
+
+
+                                ERRATA
+
+
+The author regrets that Professor J. J. Thomson's name has been
+incorrectly spelled in several places.
+
+
+
+
+                                INDEX
+
+
+Aberration of light, 69, 149, 218
+
+Absorption, 104-6
+
+Acceleration, 239
+
+Actinic rays, 141
+
+Action at a distance, 96, 174, 176
+  and re-action, 20, 251
+
+Adams' discovery of Neptune, 25
+
+Aether is matter, 54-8
+  is atomic, 59-67
+  is gravitative, 64-9
+  density of, 69, 71, 136, 243
+  elasticity of, 74-7
+  inertia of, 76, 330
+  its motions, 80
+  compressibility of, 291, 315
+  waves, 79-80
+
+Aetherial basis of matter, 326
+
+Affinity, chemical, 43
+
+Aldebaran, 312
+
+Aluminium, 79
+
+Ampere, 192
+
+Ampere's theory of magnetism, 193
+
+Andromeda, 314
+
+Annual magnetic variation, 208
+
+Annular nebulae, 320
+
+Aphelion of earth, 36
+
+Arago, M., 321
+
+Arcturus, 312
+
+Areas, Kepler's law of, 36
+
+Asten, Von, 234, 296
+
+Asteroids, 31
+
+Atmosphere, 68, 73, 102, 225
+
+Atom, vortex, 45, 46, 61
+  what it is, 43
+  electron, 63
+  Boscovitch, 61
+  hard, 61
+  size of, 43
+
+Attraction, electrical, 2, 286
+  of gravitation, 13, 24, 31
+  magnetic, 195
+
+
+Balance, Torsion, 187
+
+Bernoulli, 221, 341
+
+Beta Persei, 308
+
+Biela's comet, 296-7
+
+Binary compound, 143
+  stars, 25, 309
+
+Biot, 138
+
+Boscovitch atoms, 44, 138
+
+Boyle and Marriotte's law, 76, 103
+
+Bradley's discovery of aberration, 149
+
+Bredichin on comets' tails, 302
+
+Brilliancy of stars, 307, 309
+
+British Association Report, 57, 59
+
+
+Calcium, 79
+
+Canis major, 307
+  minor, 307
+
+Capella, 312
+
+Carbon, 48
+
+Carboniferous period, 115
+
+Carnot on heat, 116-18
+
+Cassini, 307
+
+Cause and effect, 14
+  of gravitation, 1, 282-9
+
+Cavendish experiment, 24
+
+Centauri, 79
+
+Centre of gravity, 325
+
+Centrifugal force, 9, 13, 15, 30, 236-8
+
+Centripetal force, 9, 12, 282
+
+Cetus, 307
+
+Chalk, 6
+
+Challis, Prof., 74, 96, 100, 107, 151, 155,
+214, 227, 311
+
+Chemistry, 47, 336
+
+Coal, 86, 88
+
+Clairaut, 297
+
+Clusters of stars, 314
+
+Cohesion, 48
+
+Colour, 138
+
+Colours of stars, 308
+  seven primary, 139
+
+Comets, 291
+  attracted by planets, 298
+  condensation of, 292
+
+Comets and meteors, 297
+  short period, 293-4
+  long period, 293-4
+  tails of, 298-9
+  orbits of, 293
+  nucleus of, 298-9
+  coma, 298-9
+
+Compressibility of aether, 291, 315
+
+Condensation of gases, 47
+
+Conservation of matter, 42
+  of energy, 84
+  of motion, 92
+
+Constellations, 307
+
+Corollary, 15
+
+Corona Borealis, 309
+
+Corpuscles, 42, 64, 136
+
+Corpuscular theory of light, 122
+
+Correlation of forces, 83
+
+Coulomb Torsion balance, 185, 187
+
+Crookes, Sir William, 42, 136, 326, 341
+
+Current, electric, 163
+  magnetic, 192
+
+Currents, 90
+
+Curry, Prof., 284
+
+Cycle of operations, 114, 116
+
+Cygnus, 307
+
+
+Dalton's atomic theory, 42
+
+Davy, 99, 107
+
+Day and night, 4
+
+D'Arrest's comet, 296
+
+Deimos, 38
+
+Democritus, 44
+
+Density of matter, 51
+  of aether, 69
+  electric, 170
+  of earth, 242
+  of sun, 27
+  of planets, 242
+
+Descartes, 221-2, 341
+
+Dewar, Prof., 47
+
+Diameter of earth, 29
+  polar, 29
+  equatorial, 29
+  of sun, 280
+  of planets, 29
+
+Dielectric, 168, 175
+
+Diffusion, 49
+
+Dip, magnetic, 199
+
+Distances of stars, 280
+
+Diurnal variations, magnetic, 209
+
+Dog star (Sirius), 306
+
+Donati's comet, 298
+
+Double stars, 308
+
+Draco, 307
+
+Dynamical equivalent of heat, 114
+  value of light, 150
+
+Dynamics, laws of thermo-, 114-18
+
+Dynamo, 87, 90
+
+
+Ear, 120
+
+Earth, mass of, 235, 242
+  a magnet, 196-8
+  size of, 29
+  rotation of, 219
+  orbit of, 276
+  periodic time of, 251
+  gravity of, 29
+  shape of, 29
+  distance from sun, 242, 251
+  velocity in orbit, 251
+
+Eccentricity of orbits, 268, 276
+
+Eclipse, 145, 148
+
+Ecliptic, plane of, 277-9
+
+Elasticity, 46
+  of matter, 51
+  of aether, 74
+
+Electric current, 154
+  potential, 170
+  induction, 175
+  radiation, 182
+  density, 170
+  energy, 179
+  field, 166, 179
+  lines of force, 173
+
+Electricity, 64, 162
+  two kinds of, 175
+  positive, 175
+  negative, 175
+  laws of, 184
+  theories of, 162
+
+Electrons, 136, 163
+
+Electro-static, 158, 164
+  kinetic, 158, 164
+  kinetic energy, 217
+  magnetism, 192-5
+  magnets, 199
+  magnetic theory of light, 229
+  chemical equivalents, 189, 333
+
+Elements of matter, 47
+
+Ellipse, 34
+  Kepler's discovery of, 34
+
+Elliptical nebulae, 320
+
+Emission theory of light, 122
+
+Encke's comet, 293, 296
+  resisting medium, 228
+
+Energy, 83, 84
+  what it is, 83
+  conservation of, 84
+  transformation of, 86
+  potential, 87
+  kinetic, 89, 164
+  radiant, 109
+  electrical, 179
+  and motion, 91
+
+Engine, Carnot's heat, 116
+
+Envelopes of comets, 298
+
+Epicureans, 44
+
+Equal areas, 36
+  times, 36
+
+Equator, N. and S. Poles, 29
+  magnetic, 202
+  terrestrial, 29
+
+Equipotential surfaces, 171
+
+Equivalents, electro-chemical, 189, 333
+
+Euler, 123
+
+Exchanges, theory of, 105
+
+Experience, 4
+
+Experiments of Rumford, 98
+  of Michelson and Morley, 67, 227
+  of Lebedew, 302
+  of Nichols and Hull, 153
+  of Hertz, 165
+  of Faraday, 65, 285
+  of M. Faye, 302
+  of Joule, 114
+
+
+Falling stone, 21, 29
+
+Faraday, 45, 175, 220
+  on matter, 56
+  on Lines of Force, 168, 200, 203-5
+  on magnetic space, 208
+  on gravitation, 287
+  on electricity, 332
+  on induction, 176
+
+Faye, M., 111, 302, 319
+
+Faye's comet, 293, 296
+
+Field, electric, 179
+  magnetic, 199
+
+Fizeau, 149, 224
+
+Fluids, 48
+
+Food, 89
+
+Forbes, 121
+
+Force, 16, 19, 90
+  centrifugal, 9, 13, 236
+  centripetal, 9, 12, 282
+  lines of, 200
+
+Forces, direction of the, 26
+  proportion of the, 26
+
+Foucault, 149
+
+Franklin, 106
+
+Fresnel, 75, 131
+
+Frictionless medium, 17, 131, 136, 224
+
+Fundamental medium, 54
+
+
+Galaxy, 325, 346
+
+Gaseous nebulae, 313
+
+Gases, condensation of, 47
+  liquefaction of, 47
+  kinetic theory of, 49
+
+Glazebrook, Prof., on aether and gravitation, 22
+
+Globular clusters of stars, 314
+
+Gravitation, law of, 61, 65
+  universal, 24
+  intensity of, 27
+  law of proportion, 26
+  cause of, 1, 282
+  and binary stars, 25
+
+Gravity, centre of, 325
+
+Great Bear, 307
+
+Grove, 83
+
+
+Halley's comet, 296-7
+
+Hamilton, Sir W. R., 247
+
+Head of comets, 298
+
+Heat is motion, 98
+  a mode of motion, 107
+  radiant, 109
+  dynamical equivalent of, 116
+  effects of, 107
+  nature of, 98
+  radiation of, 109
+  transformation of, 87
+
+Heat engine, Carnot's, 116
+  of sun, 109
+  and matter, 100
+  and work, 114
+  refraction of, 121
+
+Helmholtz, Von, 45, 86
+
+Hercules, 257, 271, 307
+
+Herschel, Sir J., 3, 4, 7, 226, 228, 281, 299, 301, 310, 321
+  Sir W., 109, 271-2, 313
+
+Hertz, 138, 159, 182
+
+Hicks, Prof., 13
+
+Hodograph of planets, 247
+
+Hot springs, 90
+
+Huggins, 313-14
+
+Huyghens, 54, 123, 125, 128
+
+Hydrogen, 40, 42, 44, 60, 93, 314, 333
+
+Hypotheses, 3, 338
+
+
+Ice, 42
+
+Identity of heat and light, 119
+  light and electricity, 156, 160, 165
+  aether and electricity, 331
+
+Imponderable, 71
+
+Impressed force, 20
+
+Impressible aether, 78
+
+Induction, electric, 174-5
+  magnetic, 199
+  Faraday's theory of, 175
+
+Inertia of matter, 52
+  of aether, 330
+
+Intensity of light, 28, 146
+  of heat, 28, 113
+  of electricity, 184
+  of gravity, 28
+
+Iron, 42
+  expansion by heat, 101
+  contraction by cold, 102
+
+
+Joule, 85, 114
+
+Jupiter, 26, 68
+  mass of, 235
+  satellites of, 149, 178
+  rotation of, 219
+  orbital velocity of, 251, 265
+  size of, 235
+  distance from sun, 242, 251
+  density of, 242
+  and comets, 305
+
+
+Kant, 317
+
+Kelvin, Lord, 43, 71, 77, 80, 95, 216, 227
+  on aether, 56-7
+  on vortex atom, 63
+  on compressible aether, 291, 315
+  on light, 151
+
+Kepler's laws, 32
+  first, 33, 256-9
+  second, 36, 260-2
+  third, 37, 263-5
+  on vortex motion, 221-2
+
+Kinetic energy, 89
+  electro, 217
+
+Kirchhoff, 43
+
+
+Laplace, 317
+  nebular hypothesis, 317
+
+Larmor, Dr., 22, 44, 56, 63, 93, 163
+  on electrons, 284
+  on aetherial physics, 22, 327-9
+
+Lavoisier, 42
+
+Law of gravitation, 24
+  of inverse squares, 27
+
+Laws of electricity, 184
+  of light, 145
+  of heat, 113
+  of motion, 9, 15, 233
+
+Lead, 88, 333
+
+Lebedew, 32, 76, 153
+
+Le Verrier, 25
+  discovery of Neptune, 25
+
+Leyden jar, 157
+
+Liebnitz, 223
+
+Light, 75
+  a mode of motion, 122
+  corpuscular theory of, 123
+  undulatory theory of, 123, 136
+  electro-magnetic theory of, 156
+  path of a ray of, 144
+  intensity of, 145
+  reflection of, 136
+  refraction of, 135
+  aberration of, 149
+  composition of, 139
+  velocity of, 148
+  zodiacal, 277
+  transverse vibration of, 130
+
+Lines of force, electric, 173
+  magnetic, 201-3
+
+Liquefaction of gases, 47
+
+Liquid air, 47
+
+Liquids, 48
+
+Little Bear, 307
+  Dog, 307
+
+Lockyer, 109
+
+Lodge, Dr., 219
+  on aether density, 69
+  on aether, 284, 289, 328, 332
+  on electric inertia, 330
+  on electricity, 64, 69, 284, 285
+  on force, 17
+  on gravitation, 283
+
+Lorentz on light, 154
+
+Lyra, 307
+
+
+MacLaurin, 2, 10, 17
+
+Magnesium, 79
+
+Magnet, 21
+
+Magnets, bar, 199
+  moving, 211
+
+Magnetic axis, 202
+  field, 199
+  lines of force, 200
+  shells, 205
+  equator, 202
+  induction, 199
+  variation, 208
+  molecules of, 193
+  polarity, 194
+
+Magnetism of earth, 207-12
+  of planets, 211
+  cause of solar, 211
+  Ampere's theory of, 193
+
+Mars, 68, 79
+  a magnet, 196
+  rotation of, 219
+  size of, 236
+  orbital velocity of, 251
+  satellites of, 178
+  orbit of, 33
+
+Mass, 27, 53, 187
+  of earth, 235, 242
+  of planets, 235, 242
+  of sun, 190
+
+Matter, elements of, 40
+  properties of, 42, 50
+  and motion, 41, 322
+  conservation of, 42
+  divisibility of, 44
+  four states of, 48
+  aetherial basis of, 48, 333
+  physical constitution of, 334
+
+Maxwell, J. C., 43, 73, 85, 151, 211
+  on physical lines of force, 168, 203-5, 288
+  on aether, 59, 206
+  on magnetism, 205
+  on electro-kinetic energy, 180, 217
+  on aether, 58
+
+Mayer, 84, 86, 114, 118
+
+McCullagh, 75
+
+Mechanical energy, 87
+
+Medium, Descartes on a, 221
+  Kepler on a, 222
+
+Mercury, 68, 79
+  a magnet, 196
+  rotation of, 219
+  eccentricity of orbit, 33
+  mass of, 242
+  orbital velocity of, 251
+
+Meteorites, 95, 118
+
+Meteors, 31, 85, 118
+
+Michelson and Morley, 7, 67
+
+Milky way, 79, 309, 314
+
+Molecules, 44
+
+Momentum, 20
+
+Moon, 61
+
+Motion of stars, 310
+  planetary, 253
+  of sun, 274
+  of aether, 80
+  and work, 95
+  modes of, 92, 122, 163
+  first law of, 15, 16, 239
+  second law of, 19, 244
+  third law of, 20, 251
+
+Multiple stars, 308
+
+
+Natural philosophy, 4
+
+Nebulae and aether, 313
+  structure of, 314
+  spiral, 322
+  annular, 320
+  elliptical, 320
+  planetary, 321
+  spectrum of, 314
+  irregular, 319
+
+Nebular hypothesis, 317
+
+Nebulous stars, 311
+
+Neptune, 68
+  discovery of, 25
+  mass of, 235
+  orbital velocity of, 251, 265
+  distance from sun, 242
+  a magnet, 196
+
+Newton's coloured rings, 107
+  _Optics_,72, 98, 122
+  letter to Bentley, 2, 96
+  Rules of Philosophy, 3
+  _Principia_, 3, 7, 38
+  emission theory, 123
+  law of gravitation, 24
+  atoms, 44
+  on aether, 98
+
+Nichols and Hull, 32, 153
+
+
+Ocean, 81, 90
+
+Operations, cycle of, 114
+
+_Optics_, Newton's, 2, 122
+
+Orbital motions of planets, 266
+
+Orbit of earth, 33
+  of Venus, 33
+
+Orbits of satellites, 34
+  of planets, 33-4, 266
+  moon, 267
+  stars, 310
+  sun, 270
+
+Origin of sun's heat, 95
+
+Orion, 79, 307, 314, 319
+
+Oxygen, 40, 44, 60, 93
+
+
+Parallelogram of forces, 15
+
+Pendulum, 88
+
+Periodic times, 37
+
+Perpetual motion, 93, 220
+
+_Phil. Mag._, 58, 67, 71, 73, 74, 80
+
+_Phil. Trans._, 58, 62, 64, 75
+
+Philosophy, Rules of, 3
+
+Phobos, 38
+
+Physical lines of force, 203-6
+
+Pitch of Sound, 105, 120, 139
+
+Plane of ecliptic, 277-9
+
+Planetoids, 31
+
+Planets, minor, 31
+  origin of, 240
+  orbits of, 33, 266
+  electrified bodies, 177
+  masses of, 242
+  relative distances of, 242
+  orbital velocities of, 251
+  periodic times of, 251
+
+Platinum, 48
+
+Pleiades, 79
+
+Polarization, 176
+
+Potential energy, 87
+
+Potential, electric, 170
+  magnetic, 194
+
+Pouillet, M., 109
+
+Poynting, 91
+
+Pressure, aetherial, 181
+
+Preston, Prof., 283
+
+Prevost, theory of exchanges, 105
+
+Primitive impulse, 9, 10, 12, 319
+
+_Principia_, Newton's, 3, 7, 38-9, 122
+
+Properties of matter, 42
+
+
+Quantity of sun's heat, 109
+
+Query, 18-19
+  _Optics_, 72, 122
+
+
+Radiant heat, 109
+  energy, 115
+
+Radiation, 104
+
+Radius Vector, 26
+
+Rankine, 103
+
+Rays, actinic, 141
+  dark heat, 140
+  infra-red, 141
+  ultra-violet, 140
+  Rontgen, 341
+  X, 341
+
+Rectilinear propagation of light, 144
+  of heat, 111
+
+Reflection, 160
+
+Refraction, 160
+
+Relative motion of aether and matter, 224-6
+
+Resistance to motion, 17
+
+Resisting medium, 228
+
+Reversible cycle, 116, 118
+
+Rings, vortex, 45
+
+Rival theories, 8
+
+Rivers, 89-90
+
+Roemer, and velocity of light, 148
+
+Rotation of earth, 219
+  of planets, 219
+  of sun, 246
+
+Rotatory motion, 93
+
+Rucker, Prof., 59
+
+Rules of Philosophy, 3
+  first, 3
+  second, 4
+  third, 3, 7
+
+Rumford, 98
+
+Running water, 95
+
+
+Satellites of Mars, 38, 178
+  Jupiter, 149, 178
+  Uranus, 254
+  Neptune, 254
+
+Saturn, 26-7, 68
+  mass of, 235, 242
+  orbital velocity of, 251, 265
+  rotation of, 219
+  density of, 242
+  a magnet, 196
+  satellites of, 178
+
+Schuster, Prof., 8, 218, 311
+
+Sirius, 306, 308-9
+
+Sodium, 43
+
+Solar system, motion of, 257, 271
+  spectrum, 79, 139
+  magnetism, 211
+
+Sound, 75
+  waves, 104, 120
+
+Space, interstellar, 310, 313
+
+Spectroscope, 47, 79
+
+Spectrum analysis, 50, 139
+
+Spiral nebulae, 322
+
+Stars, fixed, 58
+  number of, 11, 306
+  binary, 309
+  distances of, 280
+  magnitude of, 306, 309
+  colour of, 79, 308
+  motion of, 310-11
+  nebulous, 320
+  proper motions of, 312
+  variable, 307
+  double, 308
+  clusters of, 314
+  orbits of, 310
+  are magnets, 307
+
+Stokes, Sir G., 69, 152, 218
+
+String, 21
+
+Sun, diameter of, 280
+  constitution of, 79
+  a magnet, 164, 198-9
+  mass of, 190
+  heat of, 109
+  motions of, 270
+  orbital velocity of, 35
+  rotation of, 246
+  centre of two forces, 186
+
+
+Tails of comets, 300, 304
+  straight, 300
+  curved, 301
+  multiple, 300
+
+Tait, Prof., 18, 40-1, 88, 247
+
+Telescope, 79
+
+Temperature, 104-5
+
+Terrestrial magnetism, 207-12
+  gravity, 29
+
+Theory, atomic, 44
+  rules for making, 3
+  undulatory, 123
+  of exchanges, 105
+
+Thermodynamics, first law of, 87, 114
+  second law of, 116
+
+Thomson, J. J., Prof., 43, 326, 335
+
+Tidal water-power, 88
+
+Tides, 89, 96
+
+Torsion balance, 185
+
+Trade winds, 96, 249
+
+Transformation of energy, 86
+  of motion, 93
+
+Transverse vibration of light, 130
+
+Tuning-fork, 104
+
+Tympanum, 120
+
+Tyndall on radiation, 104, 106
+  on light, 71
+  on Lines of Force, 174
+  on aether, 77
+  on atoms, 106
+  on aether waves, 112
+
+
+Ultra-violet rays, 140
+  red rays, 140
+
+Unity of universe, 322-9
+
+Universal gravitation, 24
+  aether, 58
+
+Universe, 313, 322, 347
+
+Uranus, 68
+  mass of, 235
+  density of, 242
+  orbital velocity of, 265
+  a magnet, 196
+
+Ursa Major, 307
+  Minor, 307
+
+
+Vapour, 49
+
+Variation, magnetic, 209-11
+
+Velocity of light, 148
+  of electric waves, 182
+  of heat waves, 148
+  of falling bodies, 21
+  of wave motion, 76
+
+Velocity, angular, 250
+
+Venus, 33, 68, 79
+  a magnet, 197
+  mass of, 235
+  rotation of, 219
+  orbital velocity of, 251
+  periodic time of, 251
+
+Vibration, atomic, 75
+
+Vibrations, transverse, 130
+  longitudinal, 130
+  of sound, 123
+
+Vibratory motion, 91
+
+Vogel, Prof., 308, 312
+
+Vogt, Prof., 332
+
+Volume of sun, 27
+
+Von Asten, 234, 296
+
+Vortex theory, 92, 337
+  motion, 221-4
+  atom, 93, 126, 337
+  rings, 125, 337
+
+Vortices, molecular, 103
+
+
+Water waves, 124
+  currents, power of, 95
+  composition of, 141
+  power, 88
+
+Wave front, 128
+  motion, 124, 160
+
+Wave lengths, 120
+  envelope, 112
+
+Waves, chemical, 141
+  sound, 104, 120, 124
+  light, 126
+  heat, 141
+  electric, 159
+  spherical, 112
+  electro-magnetic, 165
+
+Weight, 29, 69, 84
+  variation of, 29
+  pound, 30
+
+Whewell, 3, 221
+
+Winds, 81, 90
+  energy of, 90
+  trade, 225
+
+Work, 96
+  and energy, 84
+  from heat, 116
+
+
+Young, Thomas, 54, 64, 67, 123
+  on aether, 58
+  fourth hypothesis, 70
+  Prof., of America, on electric space, 166
+
+
+Zinc, 88
+
+Zodiacal light, 277-9
+
+
+              _Richard Clay & Sous, Limited, London & Bungay._
+
+
+
+
+                        Some New Publications
+
+                                 OF
+
+                     Messrs. Chapman & Hall, Ltd.
+
+                               1903-4
+
+                              * * * * *
+
+                      MR. H. G. WELLS'S NEW WORK.
+
+MANKIND IN THE MAKING. By H. G. WELLS, author of "Anticipations," etc.
+Crown 8vo, _7s. 6d._
+
+In this new and important work Mr. Wells attempts to deal with social
+and political questions in a new way and from a new starting-point,
+viewing the whole social and political world as aspects of one universal
+evolving scheme, and placing all social and political activities in a
+defined relation to that; and it is to this general method and trend
+that the attention of the reader is especially directed.
+
+
+                   DR. ALFRED RUSSEL WALLACE'S NEW BOOK.
+
+MAN'S PLACE IN THE UNIVERSE. A study of the results of scientific
+research in relation to the unity or plurality of worlds. By ALFRED
+RUSSEL WALLACE, LL.D., D.C.I., F.R.S., author of "Natural Selection,"
+"Darwinism," etc., etc. With Diagrams. Demy 8vo, _12s. 6d. net_.
+
+This volume is an amplification and extension of the much-discussed
+article contributed by Dr. Wallace to the _Fortnightly Review_ for March
+1903, and presents the whole subject in a more complete and systematic
+manner, besides containing many new and forcible arguments which a more
+careful consideration of the whole problem has suggested.
+
+In the course of the work the various astronomical and other criticisms
+of the article are considered and replied to.
+
+
+                       A NEW THEORY OF GRAVITATION.
+
+AETHER AND GRAVITATION. By W. G. HOOPER, F.S.S. With Diagrams. Demy 8vo,
+_12s. 6d. net_.
+
+This work seeks to offer an acceptable solution of the greatest
+scientific problem that has puzzled scientists for the past 200 years.
+Ever since the discovery of universal gravitation by Sir Isaac Newton,
+the question has arisen, over and over again, as to what is the physical
+cause of the attraction of gravitation. Is it due, as Newton himself
+suggested, to the properties and qualities of the universal aether, or
+is it due to some still unknown and undiscovered medium?
+
+By the theory propounded in this work, the author has for the first time
+brought aetherial physics into harmony with all observation and
+experiments; so that the inertia, the density, and the elasticity of the
+aether are brought into harmony with all experience by philosophical
+reasoning based on Newton's Rules of Philosophy.
+
+
+                    LIFE AND TOPOGRAPHY OF DICKENS.
+
+THE REAL DICKENS LAND. With an outline of Charles Dickens's life. By H.
+SNOWDEN WARD and CATHARINE WARD, authors of "Shakespeare's Town and
+Times." With a Steel Plate Portrait of Dickens, Three Photogravures, and
+nearly 300 full-page and other Illustrations. Crown 4to, _10s. 6d. net_.
+
+Charles Dickens's understanding of the human character is apparent to
+every good reader of his works; but his intimate knowledge of the
+"character" of places, and of the important effect of place upon the
+human being, is not so apparent, because the reader has not the
+necessary knowledge of the places upon which to base an estimate.
+
+In "The Real Dickens Land" the authors have attempted to supply this
+necessary knowledge, not only by literary identification, but by
+presenting one of the fullest collections of photographic views thus
+identified ever got together.
+
+
+                     LONDON: CHAPMAN & HALL, LTD.
+
+
+
+
+                     CARLYLE'S LIFE AND TOPOGRAPHY.
+
+THE CARLYLE COUNTRY. With a study of Carlyle's life. By J. M. SLOAN.
+With a Foreword by SIR JAMES CRICHTON-BROWN, M.D., LL.D., F.R.S. With a
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+Photogravures, and about 100 Portraits, full-page and other
+Illustrations. Crown 4to, _10s. 6d. net_.
+
+This new Carlyle Book deals with the Carlyles in all their multiform
+relations to the Carlyle Country, and casts much valuable light upon the
+complex problems raised by Carlyle's earlier and later life.
+
+It forms a most useful and instructive Guide to the Carlyle Country, and
+will appeal to old Carlylean Readers by its careful grouping of
+biographical events around the places with which they are inextricably
+identified.
+
+A valuable Carlyle Chronology is appended, together with an Index and
+Map.
+
+
+                            HISTORY OF CHINA.
+
+CHINA, PAST AND PRESENT. By E. H. PARKER, Professor of Chinese at the
+Owens College, Manchester; formerly H.B.M. Consul at Kiungchow; Author
+of "China," "John Chinaman," etc., etc. With a Map of China. Demy 8vo,
+_10s. 6d. net_.
+
+Mr. Parker is one of the great authorities on all that concerns China
+and the Chinese, and has been writing upon every phase of the subject
+for many years past. In this work he deals with the whole history of the
+nation from the earliest times to the present day. His volume is divided
+into nine books: I. Historical and Statistical; II. The "Boxer" Wars;
+III. Religious; IV. The Imperial Power; V. The Foreigner in China; VI.
+Mandarin or Official; VII. Celestial Peculiarities; VIII. Political; IX.
+The Seamy Side.
+
+Each of these books is divided into chapters dealing comprehensively
+with the whole subject.
+
+
+                       NEW WORK ON PAGAN IDOLATRY.
+
+THE WORSHIP OF THE DEAD. The Origin, Nature, and History of Pagan
+Idolatry. By COLONEL J. GARNIER, R.E. With Four full-page Illustrations
+and numerous Pictures in the text. Demy 8vo, _16s. net_.
+
+The intimate relation of the ancient Paganism to the early history of
+mankind and its influence on the fate and fortunes of the human race
+gives no little interest and importance to any inquiry into its origin
+and nature, and the facts collected and compared in the present work
+will be found, not only to throw a remarkable light on the early history
+of Egypt and Babylonia but to have an especial bearing on important
+questions of the present day.
+
+
+                       EVERYDAY LIFE IN CHINA.
+
+LIFE AND SPORT IN CHINA. By OLIVER G. READY, B.A. With Thirteen
+Illustrations and a Map. Demy 8vo, _10s. 6d. net_.
+
+In this work the author, who has resided in various parts of the country
+for upwards of twelve years, has endeavoured to place before readers an
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+minds an idea of how Europeans live there, of their amusements, of their
+work, and of those things which are matters of daily interest to them,
+so that the work may serve as a kind of preface to that enthralling
+volume, the current history of China, as it is daily revealed in the
+Press, in Magazines, and in learned works.
+
+
+                            IZAAK WALTON.
+
+IZAAK WALTON AND HIS FRIENDS. By STAPLETON MARTIN, M.A., Christ's
+College, Cambridge, Barrister-at-Law. With Portraits and Illustrations.
+Demy 8vo, _10s. 6d. net_.
+
+Mr. Stapleton Martin has written this book with the primary object of
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+
+The better to indicate this aspect, the volume also contains brief
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+
+
+                    LONDON: CHAPMAN & HALL, LTD.
+
+
+
+                        *    *    *    *    *
+
+
+
+Transcriber's note:
+
+   ART. 41 is missing from the book.
+
+   In several instances changed S, W, E into italics to be
+   consistent with the rest of the book.
+
+   Page 194: Fixed typographical error for demonstated
+
+   Changed Figure captions so that all are of the form
+   "Fig: number."
+
+   Left unknown/misspelled word protile in appendix b
+
+   Page 148: ... and the Index, The surname of Ole Christensen
+   Romer [with o-slash] is spelled multiple times Roemer and
+   once as Roemer [with o-umlaut] in the index. These have been
+   changed to the English spelling "Roemer."
+
+
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