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diff --git a/.gitattributes b/.gitattributes new file mode 100644 index 0000000..6833f05 --- /dev/null +++ b/.gitattributes @@ -0,0 +1,3 @@ +* text=auto +*.txt text +*.md text diff --git a/18791-0.txt b/18791-0.txt new file mode 100644 index 0000000..1deb34e --- /dev/null +++ b/18791-0.txt @@ -0,0 +1,8041 @@ +Project Gutenberg's Outlines of a Mechanical Theory of Storms, by T. Bassnett + +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: Outlines of a Mechanical Theory of Storms + Containing the True Law of Lunar Influence + +Author: T. Bassnett + +Release Date: July 8, 2006 [EBook #18791] + +Language: English + +Character set encoding: UTF-8 + +*** START OF THIS PROJECT GUTENBERG EBOOK THEORY OF STORMS *** + + + + +Produced by Curtis Weyant, Laura Wisewell and the Online +Distributed Proofreading Team at http://www.pgdp.net + + + + + + +------------------------------------------------------------------+ + | | + | Transcriber's Note | + | | + | Special characters: This UTF-8 text file uses the following | + | special characters: | + | α δ ε η ι λ μ ν ο π ρ ς σ τ φ Ἡ ϛ | + | ☾ ♃ ♄ ♅ ♆ ♈ ⊿ ′ ″ ⅓ œ | + | If these do not display, you may prefer to use the HTML version | + | which provides mouse-hovers for the more unusual characters, or | + | the ISO-8859-1 text which transliterates them. | + | | + | Printer errors: Obvious typographical errors in the original | + | have been corrected in this version, and full details of the | + | corrections can be found in the HTML version of this ebook. | + | However, the inconsistent spelling of Ottawa/Ottowa, and the | + | inconsistent use of comma or full-stop as thousands separators | + | has been left as in the original. The value given for the | + | eccentricity of Uranus may also be a printer error. | + | | + +------------------------------------------------------------------+ + + + OUTLINES + + OF + + A MECHANICAL THEORY OF STORMS, + + CONTAINING + + THE TRUE LAW OF LUNAR INFLUENCE, + + WITH + + PRACTICAL INSTRUCTIONS TO THE NAVIGATOR, TO ENABLE + HIM APPROXIMATELY TO CALCULATE THE COMING + CHANGES OF THE WIND AND WEATHER, + FOR ANY GIVEN DAY, AND FOR + ANY PART OF THE OCEAN. + + + BY T. BASSNETT. + + Ἡ δε μεσοτης εν πασιν ασφαλεϛερα + + NEW YORK: + D. APPLETON & COMPANY, + 346 & 348 BROADWAY, + AND 16 LITTLE BRITAIN, LONDON. + 1854. + + + + Entered, according to Act of Congress, in the year 1853, by + T. BASSNETT, + In the Clerk's Office of the Southern District of New York. + + + + +CONTENTS. + + +SECTION FIRST. + +Present State of the Science of Meteorology--Primordial Condition of the + Solar System--Theory of Gravitation the great key of Nature--Bessell's + doubts of its perfect adequacy--the Newtonian Vacuum: its + difficulties--Nature of the element called Ether--The Medium of Space + and the Electric Fluid--Ponderosity of Matter--Dynamical law of + Equilibrium--Specific heat and its relation to space--A Plenum not + opposed to Gravitation--The medium of space in motion--Formation of + Vortices--A new principle developed--Elements of the problem--Hutton's + theory of the production of rain--Indications of change and the + cause--Action of the Ethereal Current--Physical process of Atmospheric + Derangement--Redfield's theory of Storms: its difficulties--All storms + are of brief duration and limited extent. 13 + + +SECTION SECOND. + +Mechanical action of the Moon--The Moon's mass--Axis of the Terral + Vortex affected by the Moon: its inclination and position: its + displacement--An example of the principle--Corrections + necessary--Milwaukie storm--New York storm--Ottawa storm--Liverpool + storm--Names and recurring order of the storm-producing agents--Record + of the weather--Second New York storm. 58 + + +SECTION THIRD. + +Lunar influence rejected by the learned--Their conclusions not + valid--Modifying causes in accordance with these principles--Years and + seasons vary in character--Superficial temperature of different + Planets--No storms on the planet Mars--Rotation the cause of Ocean and + Atmospheric Currents--Pressure of the atmosphere and its regular and + irregular variations--Terrestrial Magnetism--Internal Constitution of + the Globe--Magnetic variations--Cause of these variations--Magnetic + storms--Aurora Borealis: its altitude--Earthquakes; their possible + connection with Storms. 101 + + +SECTION FOURTH. + +The solar spots--Law of periodicity compared with the theory--Existence + of another planet beyond Neptune probable--Masses of the Sun and + Planet yet uncertain--The Law of Gravitation not above + suspicion--Proofs of this--The full of the Moon--Density of the + Ethereal Medium: its law in the Solar Vortex--Bode's law of the + planetary distances--Law of planetary density--Law connecting the + present and former diameters of the planets--Disturbing action of the + Ether--Kepler's third law not rigidly exact--Inconsistencies of + Astronomers--Nature of light and heat--Distinction between light and + heat. 147 + + +SECTION FIFTH. + +Comets--Their small inclinations--Their motions chiefly direct--Comet of + 1770 and 1844--Cause of acceleration in the case of Encke--Anomalous + motions of the comet of 1843--Change of diameter at different + distances of a comet from the sun--Cause of this change--Nature of the + nebulosity--Formation of the tail--Compound nature of a comet's + light--motion and direction of a comet's tail--Phenomena presented by + the great comet of Halley--Mass of a comet--The Zodial light--Nebulous + stars--Shooting stars--Periodic showers--Periodicity doubtful--Cause + of the apparent periodicity--Cause for being more numerous in Autumn + than in Spring. 187 + + +SECTION SIXTH. + +State of the polar ice since 1845--Sir John Franklin's track--Probable + existence of islands north of Behring's Straits--Possibility of + subsisting in the Arctic islands--News from the + Investigator--Necessity of searching in a higher latitude than the + Investigator visited--Franklin's misfortunes due to Scientific + Errors--Relative levels of the Atlantic and Pacific Oceans--The Arctic + seas more accessible in a few years--Conclusion. 233 + + + + +PREFACE. + + +On presenting to the public a work of this novel character, +overstepping, as it does, the barriers erected by modern systems to the +further progress of knowledge, a few words of explanation may not be +inappropriate. Early imbued with a desire to understand the _causes_ of +natural phenomena, the author devoured with avidity the interpretations +contained in the elementary works of orthodox science, until reason and +observation rendered him dissatisfied with the repast. To him it +appeared that there was an evident tendency in scholastic instruction, +to make the knowledge of nature inaccessible to the many, that the world +might be made more dependent on the few; while many of the _established +principles_, on which the learned rested, seemed to be at variance with +the simplicity and consistency of truth. Thus situated, he ventured to +think for himself, and looking back on the history of the past, and +finding so many cases in which the philosophy of to-day was supplanted +by a different system on the morrow, he was led to suspect the +possibility of future revolutions, and was thus determined to be no +longer embarrassed by previous systems, nor deterred by opinions +however learned, which conflicted with a rational recognition of the +mechanical nature of all physical phenomena. + +The science of meteorology, to which the following pages are devoted, +is, and always has been, a confessedly complex subject; and on this +account, any suggestions and facts which observation gleans,--no matter +how humble the source may be, should not be denied a hearing by those +professedly engaged in the pursuit of truth. Step by step, the author +became more and more confirmed in his doubts of the soundness of many +modern theories; and in 1838 he had attained a position which enabled +him to allege in the public prints of the day, that there did exist +certain erroneous dogmas in the schools, which stood in the way of a +fuller development of the causes of many meteorological phenomena. This +annunciation was made in general terms, and no notice was taken of it. +Subsequently, he forwarded to the British Association of Science, then +convened at Birmingham, a communication of similar tenor; and at a later +date still, a more particular statement of the advantages of his +discoveries to the navigator and agriculturist, was sent to the British +admiralty. The first of these communications was treated with silent +contempt; the last elicited some unimportant reply. In 1844 a memorial +was presented to Congress, accompanied with a certified copy of +_predictions_ of the weather, written several weeks before the event, +and attested in due form by two impartial witnesses; but neither did +this result in any inquiry as to its truth. During the time since +elapsed, he has been engaged in pursuits which prevented him from +pressing the subject elsewhere, until the spring of 1853, he brought +his theory under the notice of the Smithsonian Institution. This led to +a correspondence between himself and the gentlemanly Secretary of the +Institution, whose doubts of the truth of his allegations were expressed +with kindness, and whose courtesy was in strange contrast with the +conduct of others. In the communications which he forwarded to that +Institution, he gave a detailed statement of the difficulties he had met +with, and expressed the hope that an Institution, created for the +purpose of increasing and diffusing knowledge, would feel justified in +lending the influence of its name to facilitate the completion of a +theory which was yet undeniably imperfect. In view of this, a test was +proposed.[1] "Give us, for example, a prediction of the weather for one +month in each season of the year 1854, for the City of Washington." This +test the author refused, for the reason that he did not consider it +necessary to wait so long; but he informed the Secretary of the +Institution, that he would prepare an outline of his theory, which would +enable him to decide upon the merits of the discoveries claimed. This +outline is contained in the following pages. During the summer of 1853 +he called upon Professor Henry, then at Chicago, with his manuscript; +but a sudden indisposition prevented that gentleman from having it read. +He, however, strongly recommended its publication from such impressions +he then received.[2] This the author had resolved on, from a sense of +duty to the world at large, although the promise was rather of +prospective loss than of present benefit. The peculiar form under which +the theory appears, is, therefore, a result of the circumstances above +stated, and of the author's present inability to enter into the minute +details of a subject, which embraces in its range the whole visible +creation. + +In extending the theory to other phenomena, he has only fearlessly +followed out the same principles which have conducted him to a knowledge +of a disturbing cause, to which atmospheric storms owe their origin, and +in doing so he has conferred with no one. For whatever of merit or of +blame may therefore justly attach to these views, he alone is +responsible. If he has charged the scientific with inconsistency, or +with sometimes forgetting that the truth of their unnecessarily abstruse +investigations depends on the truth of the data, he at least is +conscientious; for he is too well aware that to provoke an unfavorable +verdict by contending against such fearful odds, is not the surest way +to either wealth or fame, or even to an acknowledgment of at least _the +mite_, which he cannot but feel that he has contributed to the treasury +of knowledge. That the scientific organisations of the day do tend to +curb the aberrations of a fanciful philosophy, cannot be denied; but at +the same time there is engendered such a slavish subordination as checks +the originality of thought, and destroys that perfect freedom from the +trammels of system, so necessary to success in the pursuit of truth. Of +such an influence the author explicitly asserts his entire independence. + +In thus introducing his theory, the reader is forewarned that he will +not find it dressed in the fascinating garb of the popular literature of +the day, whose chief characteristic is to promise much when possessing +little. It is, however, a plant of the author's own raising, unpropped, +unpruned, with none of the delicate tendrils or graceful festoons of the +trellissed vine; yet he flatters himself that its roots are watered by +the springs of truth, and hopes that he who is in quest of _that_, will +not find, amidst its many clusters, any fruit to set his teeth on +edge. + + +FOOTNOTES: + +[1] Extract from a letter from Professor Henry. + +[2] This gentleman kindly offered to contribute from his own private +means, to forward the publication, but he could do nothing officially +without submitting the manuscript to three different censors. He who +claims a new discovery, will seldom be satisfied to have it judged by +men who are engaged in the same investigations, however pure and +honorable they may be. Is this Institution adopting the best plan of +aiding truth, in its struggles against error? Should any man sit as +judge in his own trial? If there had been a powerful Institution to +stand between Galileo and the scientific of his day, his doctrines would +not have been condemned, and the world would have been fifty years more +in advance. + + + + +MECHANICAL THEORY OF STORMS. + + + +SECTION FIRST. + + +PRESENT STATE OF METEOROLOGY. + +The present state of the science of which we are about to treat, cannot +be better defined than in the words of the celebrated Humboldt, who has +devoted a long life to the investigation of this department of Physics. +He says: "The processes of the absorption of light, the liberation of +heat, and the variations in the elastic and electric tension, and in the +hygrometric condition of the vast aërial ocean, are all so intimately +connected together, that each individual meteorological process is +modified by the action of all the others. The complicated nature of +these disturbing causes, increases the difficulty of giving a full +explanation of these involved meteorological phenomena; and likewise +limits, or _wholly precludes_ the possibility of that predetermination +of atmospheric changes, which would be so important for horticulture, +agriculture, and navigation, no less than for the comfort and enjoyment +of life. Those who place the value of meteorology in this problematic +species of prediction, rather than in the knowledge of the phenomena +themselves, are firmly convinced that this branch of science, on account +of which so many expeditions to distant mountainous regions have been +undertaken, has not made any very considerable progress for centuries +past. The confidence which they refuse to the physicist they yield to +changes of the moon, and to certain days marked in the calender by the +superstition of a by-gone age." + +The charge thus skilfully repelled, contains, however, much truth; there +has been no adequate return of the vast amount of labor and expense thus +far devoted to this branch of knowledge. And it is not wonderful that +the popular mind should expect a result which is so much in accordance +with the wants of mankind. Who is there whose happiness, and health, and +comfort, _and_ safety, and prosperity, may not be more or less affected +by reducing to law, the apparently irregular fluctuations of the +weather, and the predetermination of the storm? To do this would be the +crowning triumph of the age; and the present theory has pioneered the +way for its speedy accomplishment. + + +ORIGINAL CONDITION OF THE EARTH. + +That the present order of things had a beginning, is taught by every +analogy around us, and as we have the glaring fact forced upon us, that +our globe has experienced a far higher temperature on its surface than +obtains at present, and moreover, as it is demonstrated beyond a cavil, +that the interior is now of far higher temperature than is due to solar +radiation, we are justified in concluding, not only that the condition +of the interior of our globe is that of fusion, but that its original +temperature was far higher than at present; so that the inference is +allowable that there has been a time when the whole globe was _perhaps_ +in this state. But why should we stop here? There are three states of +matter, the solid, the fluid, and the gaseous; and with this passing +glance at the question, we will jump at once to the theory of La +Place,--that not only our own globe, but the whole solar system, has +been once in the nebulous state. + +In justice to himself, the author ought to remark, that he had reasoned +his way up to this starting point, before even the name of La Place had +reached his ears. He makes the remark in order to disclaim any desire to +appropriate that which belongs to another; as he may innocently speak of +things hereafter, the idea of which has occurred to others. It is not +his intention here to say a word _pro_ or _con_ on the nebular +hypothesis; it is sufficient to allude to the facts, that the direction +of rotation and of revolution is the same for all the planets and +satellites of our system; and that the planes on which these motions are +performed, are nearly coincident. That this concordance is due to one +common cause, no one acquainted with the theory of probabilities will +pretend to deny. + + +GREAT OBJECT OF LA PLACE. + +The science of Astronomy occupies a pre-eminent rank in the physical +circle, not only on account of that dignity conferred upon it in the +most remote antiquity, or as being the grand starting point--the +earliest born of science--from whence we must contemplate the visible +creation, if we would reduce its numerous details into one harmonious +whole; but also on account of its practical fruits, of the value of +which modern commerce is an instance. Accordingly we will glance at its +past history. In the earliest ages there was no doubt a rational view +entertained of the movements of the planets in space. From the Chaldeans +to the Arabs, a belief prevailed, that space was filled with a pure +ethereal fluid, whose existence probably did not rest on any more solid +foundation than analogy or tradition. One hundred years after Copernicus +had given to the world the true arrangements of our planetary system, +Descartes advanced his theory of vortices in the ethereal medium, in +which the planets were borne in orbits around the sun, and the +satellites around their primaries. This idea retained its ground with +various additions, until the Geometry of Newton reconciled the laws of +Kepler with the existence of a power pertaining to matter, varying +inversely as the squares of the distances, to which power he showed the +weight of terrestrial bodies was owing, and also the revolution of +the moon about the earth. Since Newton's day, those deviations from the +strict wording of Kepler's laws, have been referred to the same law, +and the avowed object of the author of the "Mechanique Celeste," was to +bring all the great phenomena of nature within the grasp of analysis, by +referring them to one single principle, and one simple law. And in his +Introduction to the Theory of the Moon, he remarks: "Hence it +incontestibly follows, that the law of gravitation is the sole cause of +the lunar inequalities." + + +BESSEL'S OPINION. + +However beautiful the conception, it must be admitted that in its _à +priori_ aspect, it was not in accordance with human experience and +analogy to anticipate a successful issue. In nature law re-acts upon +law, and change induces change, through an almost endless chain of +consequences; and it might be asked, why a simple law of matter should +thus be exempt from the common lot? Why, in a word, there should be no +intrinsic difference in matter, by which the gravitation of similar or +dissimilar substances should be affected? But experiment has detected no +such differences; a globe of lead and a globe of wood, of equal weight, +attract contiguous bodies with equal force. It is evident, therefore, +that if there be such differences, human means are not yet refined +enough to detect them. Was the issue successful then? Generally +speaking, we may say yes. But where there is a discrepancy between +theory and observation, however small that may be, it shows there is +still something wanting; and a high authority (Professor Bessel) says in +relation to this: "But I think that the certainty that the theory based +upon this law, _perfectly_ explains all the observations, is not +correctly inferred." We will not here enumerate the cases to which +suspicion might be directed, neither will we more than just allude to +the fact, that the Theory of Newton requires a vacuum, in order that the +planetary motions may be mathematically exact, and permanent in their +stability. + + +A VACUUM REQUIRED BY MODERN SYSTEMS. + +Whatever may be the practical belief of the learned, their fundamental +principles forbid the avowal of a plenum, although the undulatory theory +of light renders a plenum necessary, and is so far virtually recognized +by them, and a correction for resistance is applied to the Comet of +Encke. Yet there has been no attempt made to reconcile these opposing +principles, other than by supposing that the celestial regions are +filled with an extremely rare and elastic fluid. That no definite view +has been agreed on, is not denied, and Sir John Herschel speculates on +the reality of a resisting medium, by suggesting questions that will +ultimately have to be considered, as: "What is the law of density of the +resisting medium which _surrounds_ the sun? Is it in rest or in motion? +If the latter, in what direction does it move?" In these queries he +still clings to the idea of Encke, that the resistance is confined to +the neighborhood of the sun and planets, like a ponderable fluid. But +the most profound analyst the world has ever boasted, speaks less +cautiously, (Poisson Rech.) "It is difficult to attribute, as is usually +done, the incandescence of aërolites to friction against the molecules +of the atmosphere, at an elevation above the earth where the density of +the air is almost null. May we not suppose that the electric fluid, in a +neutral condition, forms a kind of atmosphere, extending far beyond the +mass of our atmosphere, yet _subject to terrestrial attraction_, yet +_physically imponderable_, and, consequently, following our globe in its +motion?" The incandescence of aërolites must, therefore, be owing to +friction against the molecules of the electric fluid which forms an +atmosphere around the globe. According to this view, some force keeps it +there, yet it is not ponderable. As it is of limited extent, this is not +the medium whose undulations brings to light the existence of the stars; +neither is Encke's, nor Herschel's, nor any other resisting medium. +Where shall we find the present established principles of science? If we +grant the Newtonians a plenum, they still cling to attraction of _all +matter_ in some shape. If we confine them to a vacuum, they will +virtually deny it. Is not this solemn trifling? How much more noble +would it be to exhibit a little more tolerance, seeing that they +themselves know not what to believe? We do not offer these remarks as +argument, but merely as indications of that course of reasoning by which +we conclude that the upholders of the present systems of science are not +entitled to any other ground than the pure Newtonian basis of an +interplanetary vacuum. + + +DIFFICULTIES OF THIS VIEW. + +This, then, is the state of the case: Matter attracts matter directly as +the mass, and inversely as the squares of the distances. This law is +derived from the planetary motions; space is, consequently, a void; and, +therefore, the power which gives mechanical momentum to matter, is +transferred from one end of creation to the other, without any physical +medium to convey the impulse. At the present day the doctrines of +Descartes are considered absurd; yet here is an absurdity of a far +deeper dye, without we resort to the miraculous, which at once +obliterates the connection between cause and effect, which it is the +peculiar province of physical science to develop. Let us take another +view. The present doctrine of light teaches that light is an undulation +of an elastic medium necessarily filling all space; and this branch of +science probably rests on higher and surer grounds than any other. Every +test applied to it by the refinements of modern skill, strengthens its +claims. Here then the Newtonian vacuum is no longer a void. If we get +over this difficulty, by attributing to this medium a degree of tenuity +almost spiritual, we shall run upon Scylla while endeavoring to shun +Charybdis. Light and heat come bound together from the sun, by the same +path, and with the same velocity. Heat is therefore due also to an +excitement of this attenuated medium. Yet this heat puts our atmosphere +in motion, impels onward the waves of the sea, wafts our ships to +distant climes, grinds our corn, and in various ways does the work of +man. If we expose a mass of metal to the sun's rays for a single hour +the temperature will be raised. To do the same by an artificial fire, +would consume fuel, and this fuel would generate the strength or force +of a horse. Estimate, therefore, the amount of force received from the +sun in a single day for the whole globe, and we shall find that nothing +but a material medium will suffice to convey this force. + +Let us appeal to analogy. The undulations of our atmosphere produce +sound; that is, convey to the ear a part of a mechanical force imparted +to a solid body--a bell for instance. Let us suppose this force to equal +one pound. On account of the elasticity of the bell, the whole of the +force is not instantaneously imparted to the surrounding air; but the +denser the air the sooner it loses its motion. In a dense fluid like +water, the motion is imparted quickly, and the sound is not a ring but a +click. If we diminish the density of the air, the loss of motion is +retarded; so that we might conceive it possible, provided the bell could +be suspended in a _perfect vacuum_, without a mechanical tie, and there +was no friction to overcome from the rigidity of its particles, that the +bell would vibrate forever, although its sound could never reach the +ear. We see, therefore, that the mechanical effect in a given time, is +owing to the density of the medium. But can we resort to such an +analogy? Every discovery in the science confirms more and more the +analogy between the motions of air and the medium of space; the angle of +reflexion and incidence follows the same law in both; the law of +radiation and interference; and if experiments were instituted, there +can be but little doubt that sound has also got its spectrum. + + +ETHER IMPONDERABLE. + +The medium of space, therefore, is capable of conveying a mechanical +force from one body to another; it therefore possesses inertia. Does it +also possess gravity? If we forsake not the principles of science, it is +but right that we expect science shall abide by her own principles. +Condensation in every elastic medium is as the compressing power, +according to all experiments. In the case of our atmosphere under the +law of gravitation, the density of air, (supposing it to be infinitely +expansible,) at a height only of ten semidiameters of the earth above +its surface, would have only a density equal to the density of one cubic +inch of such air we breathe, if that cubic inch was to be expanded so as +to fill a globular space whose centre should be the earth, and whose +surface should take inside the whole visible creation. Such a medium +could convey no mechanical force from the sun, and therefore the medium +of space cannot be ponderable. Simple as the argument is, it is +unassailable. + + +ELECTRIC FLUID THE MEDIUM OF SPACE. + +Let us take yet another view. All experiments prove that the phenomenon +we call electricity, is owing to a disturbance of the equilibrium or +natural condition of a highly elastic fluid. In certain conditions of +the atmosphere, this fluid is accumulated in the region of the clouds, +and by its tension is enabled to force a passage through opposing +obstacles, in order to restore the equilibrium. By experiment it is +found that dry dense air opposes the greatest obstacle to its escape. As +the air is rarefied, this obstacle diminishes; until in a vacuum the +transmission may be considered instantaneous. There ought to be, +therefore, a greater escape of electricity from the clouds upwards than +downwards; and, if space be void, or only filled with an extremely +attenuated matter, the electricity of the earth, considered as an +elastic fluid without ponderosity, (and no law of condensation from the +law of gravity in harmony with its other attributes, will allow us to +consider it otherwise,) _would long since have left the earth_. The same +objection applies in the case of the galvanic and magnetic fluids. If we +entertain the idea that electricity is a mere disturbance of natural +condition, wherein two fluids are united, and that an excess of one is +necessarily attended by deficiency in the other, we depart from the +first rule of philosophy, which teaches us to admit no greater number of +causes than are sufficient to explain the phenomenon. For we fearlessly +assert that not a single fact exists in electrical science, which can be +explained better on Dufoy's theory than on Franklin's; and the former +objections would still apply. + + +NEWTONIAN GRAVITY. + +But what is gravity? According to Newton: "Hæc est qualitas omnium in +quibus experimenta instituere licet, et propterea per Reg. 3 de +universes affirmanda est." _Vide_ Prin. Lib. Ter. Cor. 2. Prop. vi. + +Now the other primary qualities of matter are unaffected by +circumstances. The inertia of a particle of matter is the same at +Jupiter as on the earth, so also is its extension; but not so with +gravity. It depends on other matter, and on its distance from it; and +may be less or greater at different times, and in different places. It +is, therefore, not philosophical to say that all matter is necessarily +ponderous, inasmuch as it is a virtue not residing in itself alone, but +needs the existence of other matter to call it into action. If an atom +were isolated in space it would have no weight. If influenced by other +matter, there must be some physical medium to convey the influence, or +gravity is not in accordance with the laws of force and motion. Which +horn of the dilemma shall we take? Let us first admit that there is a +principle of gravitation, affecting all planetary or atomic matter, and +that there exists a highly elastic medium, pervading all space, +conveying to us the light of the most distant stars, and that this +medium is not affected by gravity. In this summary way, therefore, we +have arrived at the pivot on which this theory turns. + +The prominent feature of the theory, therefore, is the necessity it will +show for the existence of an all-pervading medium, and that it possesses +inertia without ponderosity. That electricity is nothing more than the +effects of the condensation and rarefaction of this medium by force. +That it also pervades all atomic matter, whose motions necessarily move +the medium; and, consequently, that there can be no motion without some +degree of electricity. That no change can take place in bodies either by +chemical decomposition, by increase or decrease of temperature, by +friction or contact, without in some measure exciting electricity or +motion of the ether. That galvanism and magnetism are but ethereal +currents without condensation, induced by peculiar superficial and +internal molecular arrangement of the particles of certain substances. +That light and heat are effects of the vibrations of atoms, propagated +through this universal medium from body to body. That the atomic motion +of heat can be produced by the motion of translation or momentum of +bodies in the gross, that is, by friction, by compression, &c.; and can +be reconverted into momentum at our pleasure. Hence the latent heat or +specific atomic motion of combustibles, originally derived from the sun, +is transferred to atoms, which are capable of being inclosed in +cylinders, so as to make use of their force of expansion, which is thus +converted into momentum available for all the wants of man. + + +GRAVITY MECHANICAL. + +When we come to a full examination of this theory, we shall further +reason that this _ether_ so far from being of that quasi spiritual +nature which astronomers would have us believe, is a fearfully energetic +fluid, possessing considerable inertia and elasticity; that its law of +condensation is that of all other fluids, that is, as the compressing +force directly; and that its effects are simply a product of matter and +motion. We will next endeavor to prove that the gravity of planetary +matter could not exist without this ethereal medium, by showing that it +is an effect produced by the interference of _opposing waves_, whereby a +body is prevented from radiating into space its own atomic motion, from +the side opposite which another body is placed, as much as on the +opposite side, and consequently it is propelled by its own motion +towards the other body. And this effect following the simple law of +inertia and radiation, is directly as the mass, and inversely as the +squares of the distances. + + +GREAT PRINCIPLE OF DYNAMICS. + +One great principle to be kept in view in this investigation, is that +which teaches that the product of matter, angular velocity, and distance +from the centre of motion, must ever be a constant quality in every +balanced system. Yet this principle does not seem to be observed in the +case of the planets. We will, however, endeavor to show that it is +rigidly observed. And we will extend the principle further, and contend +that all the phenomena of nature are consequences of the constant +tendency of matter to conform to this principle of equilibrium, when +suffering temporary derangement from the operation of other laws. That +throughout the system of nature, equal spaces possess equal force. That +what we call temperature, is nothing more than the motion of equilibrium +or atomic momentum of space; or, in other words, that if all space were +fluid, and in a state of equilibrium, the product of each atom of equal +volume, by its motion would be a constant quality. From this it would +seem to follow, that the specific heat of bodies should be inversely as +their atomic weights; and this does, no doubt, _approximately_ obtain as +was proved by Dulong and Petit, for metallic substances, more recently +by Regnault, and has since been extended by Garnier to other substances. +But it is to the gaseous state that we must look for confirmation of the +principle that equal spaces possess equal power; and in doing so, it +will be necessary to bear in mind, that the ether also is affected by +temperature. + + +SPECIFIC HEAT. + +It has been contended by some that the medium which conveys the +impression of light through transparent, bodies, is necessarily more +dense within the body than without; but according to this theory the +converse is true. A ray of light is a mechanical impulse, propagated +through an elastic medium, and, like a wave in water, tends to the side +of least resistance. Within a refracting body the ether is rarefied, not +only by the proximity of the atoms of the body (or its density), but +also by the motions of those atoms; so that if two _simple_ gases of +different specific gravity be made equal in density by compression, +their refraction will be approximately as their specific heats. In the +case of solids and liquids, or even compound gases, there is a continual +absorption of motion to produce the cohesion of composition and +aggregation. And the specific heats of compound gases will be found +greater than those of simple gases, in proportion to the loss of volume +by combination, _ceteris paribus_. If impenetrability be a law of +matter, the more a portion of atomic matter is condensed, the less ether +will be found in the same space. The same is also true when the natural +density or specific gravity of a gas is greater than that of another. +And the lighter the gas, the more will this circumstance vitiate the +experiments to determine its specific heat. There is, therefore, this +great source of fallacy in such experiments, viz.: that the ether +permeates all fluids and solids, and that _its specific heat probably +far exceeds that of all other matter_. This is a fundamental position of +the theory, in support of which we will introduce a fact announced by +M. V. Regnault, which was published in the Comptes Rendus of the French +Academy for April, 1853. He says: "In the course of my researches I have +encountered, indeed, at every step, anomalies which appeared to me +inexplicable, in accordance with the theories formally recognized. For +the sake of illustration I will quote one instance: 1st, a mass of gas, +under a pressure of ten atmospheres, is contained in a space which is +suddenly doubled; the pressure falls to five atmospheres. 2d. Two +reservoirs of equal capacity are placed in a calorimeter; the one is +filled with a gas, under a pressure of ten atmospheres; the second is +perfectly empty. In these two experiments, the initial and final +conditions of the gas are the same; but this identity of condition is +accompanied by calorific results which are very different; for while in +the former experiment there is a reduction of temperature, in the second +the calorimeter does not indicate the slightest alteration of +temperature." This experiment tends to confirm the theory. In the first +experiment, the sudden doubling of the space causes the ether also to +expand, inasmuch as the sides of the vessel prevent the instantaneous +passage of the external ether. In the second, both vessels are full, one +of ether, and the other of air mixed with ether; so that there is no +actual expansion of the space, and consequently no derangement of the +quantity of motion in that space. + + +LAW OF SPECIFIC HEAT. + +From this view it is evident that the specific heat of elastic fluids +can only be considered as approximately determined. If equal spaces +possess equal momenta, and the ethereal or _tomic_ matter be inversely +as the weight of the atomic matter in the same space, it follows that +the product of the specific gravities and specific heats of the simple +gases should be constant; or that the specific heats should be inversely +as the specific gravities,--taking pound for pound in determining those +specific heats. If we test the matter by the data now afforded, it is +best to obey the injunction, "_In medio tutissimus ibis_." In the +following table, the first column are the values obtained by Regnault; +in the second, the former values; and in the third, the mean of the two. + + Gases. Reg. specific heats. Former specific heats. Mean. + Atmospheric air, .237 .267 .252 + Oxygen, .218 .236 .227 + Nitrogen, .244 .275 .260 + Hydrogen, 3.405 3.294 3.350 + +The specific gravities of these gases, according to the best tables in +our possession, are: + + Specific gravities. Mean. Products. + Atmospheric air, 1.0000 × .252 = .252 + Oxygen, 1.1111 × .227 = .252 + Nitrogen, 0.9722 × .260 = .252 + Hydrogen, 0.0745 × 3.350 = .249 + +As might be expected, there is a greater discrepancy in the case of +hydrogen. + +If we test the principle by the vapor of water, we must consider that it +is composed of two volumes of hydrogen and one volume of oxygen, and +that one volume disappears; or that one-third of the whole atomic +motion is consumed by the interference of the vibrations of the ether, +necessary to unite the atoms, and form an atom of water. We must +therefore form this product from its specific gravity and two-thirds of +its specific heat. On no one subject in chemistry has there been so much +labor expended, as in determining the specific heat of watery vapor. In +relation to this, Regnault observes: "It is important to remark that an +immense number of experiments have been made, to find the specific heat +of steam, and that it is about one-half of what it was thought to be." +He gives its value .475; but this is vitiated still, by the +non-recognition of the specific heat of the ether. Former experiments +give .847. Perhaps Regnault's numbers are entitled to the most weight. +Instead of taking the mean, therefore, we will give double weight to his +results; so that we get .600 for the specific heat of vapor, and as its +specific gravity is .625, the product .400 × .625 is .250, the same as +for hydrogen. Little importance, however, should be attached to such +coincidences, owing to the uncertainty of the numbers. If our position +be correct, the specific heat of hydrogen should be 10 times greater +than of oxygen. The atomic weights are as 1 to 8, while their volumes +are as 2 to 1; therefore, for equal spaces, the matter is as 1 to 16. +Calling the specific heat 10 to 1, and taking the amount due to half the +space, the product becomes as 8 to 16; but in the rarer gas there is +_8 times_ as much ethereal momentum or matter, which, added to the +atomic matter, renders the spaces equal.[3] Regnault's results give a +ratio of specific heats = 1 to 3.405/.215 = 1 to 15.6. + + +THE GOLDEN MEAN. + +The history of science proves how few have practically respected the +adage of the ancients, which we have chosen for our motto; words which +ought to be written in letters of gold in every language under the sun. +Descartes, by considering the mechanical impulse of the ether sufficient +to explain the planetary motions, failed to detect the force of gravity +in the heavens. Newton, on the other hand, feeling that his law was +sufficient to explain them, and requiring a vacuum for its mathematical +accuracy, rejected the notion of an ethereal medium. His successors, +following too closely in his footsteps, and forgetting the golden law, +have forced themselves into a position by no means enviable. The +short-period comet has driven them to a resisting medium, which, while +according to Encke's hypothesis of increasing density around the sun, it +explains the anomalies of one periodical comet, requires a different +law of density for another, and a negative resistance for a third. + + +OUTLINES OF THE PROBLEM. + +From the position we now occupy, we can see the outlines of the problem +before us, viz.: To reconcile the existence of an ethereal medium with +the law of gravitation, and to show the harmony between them. We shall +thus occupy the middle ground, and endeavor to be just to the genius of +Descartes, without detracting from the glory of Newton, by demonstrating +the reality of the Cartesian vortices, and by showing that the ether is +not affected by gravitation, but on the other hand is _least dense_ in +the centre of our system. But what (it may be asked) has this to do with +the theory of storms? Much every way. And we may so far anticipate our +subject as to _assert_ that every phenomenon in meteorology where force +is concerned, is dependent on the motions of the great sea of electric +fluid which surrounds us, in connection with its great specific, +caloric. If we are chargeable with overweening pretensions, let it be +attributed to the fact that for the last fifteen years we have treated +the weather as an astronomical phenomenon, calculated by simple formulæ, +and that the evidence of its truth has been almost daily presented to +us, so as to render it by this time one of the most familiar and +palpable of all the great fundamental laws of nature. True, we have +neither had means nor leisure to render the theory as perfect as we +might have done, the reason of which we have already communicated. + + +MOTIONS OF THE STARS. + +In investigating the question now before us, we shall first take the +case of an ethereal vortex without any reference to the ponderable +bodies which it contains, considering the ether to possess only inertia. +If there be a vortex around the sun, it is of finite extent; for if the +ether be co-extensive with space, and the stars likewise suns with +surrounding vortices, the solar vortex cannot be infinite. That there is +an activity in the heavens which the mere law of attraction is +incompetent to account for, is an admitted fact. The proper motions of +the fixed stars have occupied the attention of the greatest names in +astronomy, and motions have been detected, which according to the theory +of gravity, requires the admission of invisible masses of matter in +their neighborhood, compared with which the stars themselves are +insignificant. But this is not the only difficulty. No law of +arrangement in the stars can exist that will save the Stellar system +from ultimate destruction. The case assumed by Sir John Herschel, of a +cluster, wherein the periods shall be equal, cannot be made to fulfil +the conditions of being very numerous, without infringing the other +condition--the non-intersection of their orbits; while the outside stars +would have to obey another law of gravitation, and consequently would be +still more liable to derangement from their ever-changing distances +from each other, and from those next outside; in brief, the stability of +those stars composing the cluster would necessarily depend on the +existence of outside stars, and plenty of them. But those outside stars +would follow the common law of gravity, and must ultimately bring ruin +on the whole. We know such clusters do exist in the heavens, and that +the law of gravity alone must bring destruction upon them. This is a +case wherein modern science has been instrumental in drawing a veil over +the fair proportions of nature. That such collections of stars are not +designed thus to derange the order of nature, proves _à priori_, that +some other conservative principle must exist; that the medium of space +must contain many vortices--eddies, as it were, in the great ethereal +ocean, whose currents are sweeping along the whole body of stars. We +shall consider, (as a faint shadowing of the glorious empire of +Omnipotence,) that the whole infinite extent of space is full of motion +and power to its farthest verge; and it may be an allowable stretch of +the imagination to conceive that the whole comprises one infinite +cylindrical vortex, whose axis is the only thing in the universe in a +state of absolute unchangeableness. + + +VORTICOSE MOTION. + +Let us for a moment admit the idea of an infinite ocean of fluid matter, +having inertia without gravity, and rotating around an infinite axis, in +this case there is nothing to counteract the effect of the centrifugal +force. The elasticity of the medium would only oppose resistance in a +vortex of finite diameter. Where it is infinite, each cylindrical layer +is urged outward by its own motion, and impelled also by those behind. +The result would be that all the fluid would at last have left the axis, +around which would exist an absolute and eternal void; into which +neither sound, nor light, nor aught material, could enter. The case of +a finite vortex is very different. However great the velocity of +rotation, and the tendency of the central parts to recede from the axis, +there would be an inward current down either pole, and meeting at the +equatorial plane to be thence deflected in radii. But this radiation +would be general from every part of the axis, and would be kept up as +long as the rotation continued, if the polar currents can supply the +drain of the radial stream, that is, if the axis of the vortex is not +too long for the velocity of rotation and the elasticity of the ether, +there will be no derangement of the density, only a tendency. And in +this case the periodic times of the parts of the vortex will be directly +as the distances from the axis, and the absolute velocities will be +equal. + + +FORMATION OF VORTICES. + +There is reason to suspect that Newton looked at this question with a +jaundiced eye. To do it justice, we must consider the planetary matter +in a vortex, as the exponent of its motion, and not as originating or +directing it. If planetary matter becomes involved in any vortex, it +introduces the law of gravitation, which counteracts the expulsive force +of the radial stream, and is thus enabled to retain its position in the +centre. A predominating mass in the centre will, by its influence, +retain other masses of matter at a distance from the centre, even when +exposed to the full power of the radial stream. If the power of the +central mass is harmoniously adjusted to the rotation of the vortex, +(and the co-existence of the phenomena is itself the proof that such an +adjustment does obtain,) the two principles will not clash or interfere +with each other. Or in other words, that whatever might have been the +initial condition of the solar vortex, the ultimate condition was +necessarily one of equilibrium, or the system of the planets would not +now exist. With this view of its constitution, we must consider that the +periodic times of the planets approximately correspond to the times of +the contiguous parts of the vortex. Consequently, in the solar vortex, +the density of the ether is directly as the square roots of the +distances from the axis. This is not the place fully to enter into a +discussion of the question, or to show that the position of each planet +in the system is due to the outstanding, uncompensated, portion of the +expulsive force of the radial stream, modified by the density of the +ether within the planets, and also by their own densities, diameters, +inclinations of axis, and periods of rotation. That Jupiter could not +remain in the orbit of Mercury, nor Mercury in that of Jupiter, by +merely exchanging periods and distances, but that each planet can only +be in equilibrio in its own orbit. That any change in the eccentricities +of the planetary orbits will neither increase nor diminish the action of +the radial stream of the vortex, and consequently will not interfere +with the law of gravitation. In relation to the numerous questions that +will spring up from such a position, it is sufficient here to say, that +it is believed all objections can be satisfactorily answered; while, by +this light, a long range of phenomena that have hitherto baffled the +sagacity of the wise, come out plainly, and discover their parentage. + +In cometary astronomy we shall find much to substantiate these views. +The anomalies in their motions, the discrepancies in their periods, +calculated from different sets of observations, their nebulosities and +appendages, will all receive a satisfactory solution; and these lawless +wanderers of the deep be placed in a more interesting light. + + +TEST OF A THEORY. + +It has been remarked that the best evidence of the truth of a theory, is +its ability to refer to some general principle, the greatest number of +relevant phenomena, that, like the component masses of the chiselled +arch, they may mutually bind and strengthen each other. This we claim +to be the characteristic of this theory. At the outset it was not +intended to allude to more than was actually necessary to give an +outline of the theory, and to introduce the main question, yet +untouched. We have exhibited the stones of which the arch is composed; +but they may be pasteboard,--for the reader has not handled them. We +will now produce the keystone, and put it in its place. This he shall +handle and weigh. He will find it hard,--a block of granite, cut from +the quarry of observed facts, and far too heavy to be held in its place +by a mere pasteboard structure. + + +ENUNCIATION OF THE THEORY. + +Quitting, therefore, the region of the planets, we will come down to the +surface of our own globe, to seek for some more palpable evidence of the +truth of the following propositions: + +1st. That space is filled with an elastic fluid, possessing inertia +without weight. + +2d. That the parts of this fluid in the solar system circulate, after +the manner of a vortex, with a direct motion. + +3d. That there are also secondary vortices, in which the planets are +placed. + +4th. That the earth is also placed in a vortex of the ethereal medium. + +5th. That the satellites are passively carried around their primaries, +with the ethereal current, and have no rotation relative to the ether, +and therefore they always present the same face to their primaries, and +have no vortex. + +The consideration of these propositions involves many others, many +difficulties, many apparent anomalies and contradictions, which should +bespeak for such a theory,--the offspring of observation, without the +aid afforded by the knowledge of others, and of toil without leisure,--a +large share of indulgence. With this we will close these preliminary +remarks, and present our theory of the physical cause which disturbs +the equilibrium of our atmosphere, and which appears the principal agent +in the production of storms, in the following words: + +The dynamical axis of the terral vortex passes through the centre of +gravity of the earth and moon, and is continually circulating over the +earth's surface in both hemispheres, in a spiral,--its latitude and +longitude, at any particular time, being dependent,-- + +1st. On the relative mass of the moon. + +2d. On the inclination of the axis of the vortex to the earth's axis. + +3d. On the longitude of the ascending node of the vortex on the lunar +orbit. + +4th. On the longitude of the ascending node of the lunar orbit on the +ecliptic. + +5th. On the eccentricity of the lunar orbit at the time. + +6th. On the longitude of the perigee of the lunar orbit at the time. + +7th. On the moon's true anomaly at the time. + + +MASS OF THE MOON. + +Those elements which represent the moon's distance and motion are +accurately known, and may be taken from the Nautical Almanac, being all +embodied in the moon's parallax or semi-diameter, and in the declination +and right ascension; but for the most important element,--the moon's +mass, we in vain look to astronomy. In fact, it may be averred that the +importance attached to astronomical authority, concerning the mass of +the moon, has caused more trouble than any other question of the whole +theory, until we trusted implicitly to the theory itself to determine +it. The determination of three unknown elements, viz.: the moon's mass, +the inclination of the axis of the vortex, and the right ascension of +that axis, is a more difficult problem than at first sight appears, +owing to the nature of the phenomena, which affords the only clue for +its solution. There are six principal vortices ever in operation on the +surface of the earth, and their disturbing influence extends from 200 to +400 miles. To find the precise centre, by one observer confined to one +place, is difficult; and to separate them, so as to be fully assured +that you have the right one, is perhaps still more so. Happily this +tedious labor is accomplished, and we are able with confidence to give +the following important elements, as very close approximations to the +truth: + + Mass of the moon 1/72.3 + Obliquity of the axis of the vortex 15° to 32° variable. + Right ascension of ditto 250° to 290° variable. + +It must be borne in mind that we are now discussing the main or central +vortex of the earth; but before applying them to the calculation, we +will explain the _modus operandi_, waiving for the present the +consideration of the law of density in the Terral vortex. It is evident +at first sight that if the periodic times of the parts of the vortex +contiguous to the moon, are equal to the moon's period approximately, +that the velocity of the ether is greater at the surface of the earth +than the velocity of that surface. Now, we have before argued that the +ether possesses inertia, it therefore would under such circumstances +exert some mechanical action. Consequently, the aërial envelope of our +globe, or its superior stratum, is impelled eastward by _convection_[4] +of the more rapidly rotating ether. And from the extreme tenuity of its +upper layers, is probably forced into immense waves, which will observe +to a certain degree, a general parallelism north and south. + + +ATMOSPHERIC CURRENTS. + +It is a well-known fact, that the prevailing current of the atmosphere +in high latitudes is from the westward. The cause of this is ascribed by +Professor Dove to the transfer of the equatorial portions to a higher +latitude, by which the excess of its rotative velocity is made apparent, +by outstripping the slower moving surface in its progress eastward. No +doubt some effect is due to this, but still a difficulty remains. Let us +follow this current. The polar current reaches the surface on the +borders of the trades with less rotative velocity than the surface, and +is, therefore, met by the surface as a current partaking of both +motions. In the northern hemisphere it is north-east deflected to east +as it approaches the southern trades. By the same reasoning, coming from +the north before it readies the surface, it ought to be also a +north-east wind above the lower westerly currents. Now it is an observed +fact, that while in the latitude of New York, for instance, the lower +westerly winds are to the easterly, as 3 or 4 to 1, in the highest +regions of observed clouds, the ratio is much increased; and according +to our own observations in this place,[5] we have never seen the highest +cirrus clouds moving westward. How then is this continual interchange +kept up? Assuredly we cannot have a current from the poles without a +contrary current to the poles. If we go into the arctic circle, we again +find the westerly and northerly winds predominating. If the current from +the equator follows the surface, the westerly winds ought to be +south-west. If it be above the surface wind, then the surface wind is +the polar current, and ought to be north-east. Whereas, from the +testimony of all who have visited these regions, the prevailing winds +are north-west. How can this be? + +Again, it is proved that the upper current near the equator is also from +the westward--as near due west as possible. Take the latitude of St +Vincent. The difference between the cosine of 13° and radius applied +to the circumference, is about 600 miles, which would give 25 miles per +hour to the eastward, in lat. 13°. But to do this, it is necessary to +transfer it suddenly from the equator; for by a slow motion the easterly +tendency would be lost. Give it 24 hours from the equator to lat. 13°, +without any loss of easterly tendency, and it comes to that latitude +with a velocity of 38 miles per hour to the northward, and only 25 to +the eastward; we have, therefore, a wind from south-west by south. Yet +it is known that in the tropics the highest visible clouds move from the +westward. But as no such case could occur as a transfer in twenty-four +hours without loss, and if we diminish the time, the wind is still more +southerly. Meteorologists usually cite the falling of ashes at Jamaica +during the eruption of Coseguina, in Guatamala, in February 1835, as +coming from south-west, whereas the true direction was about west +south-west, and the trade wind below was about north. But do we deny +that there is an interchange between the frigid and torrid zones? By no +means; but we would show that the great controlling power is external to +our atmosphere, and that the relative velocities of the earth and the +atmosphere is not alone adequate to account for it. By this view the +polar current is a north-west wind (which is impossible by Professor +Dove's theory), or is carried eastward by electric convection. + + +HUTTON'S THEORY. + +Whether we adopt the views of Fourier or Poullet, as to the temperature +of the planetary spaces, it is certain that it is at least equal to, or +less than, the lowest temperature of our globe. It is also a well-known +fact, that the capacity of air to hold vapor in solution, increases in a +higher ratio than the temperature, so that the intermingling of +saturated portions of air, at different temperatures, must _necessarily_ +be attended by precipitation of moisture. This idea was advanced by +Doctor Hutton, and considered competent to account for the prominent +meteorological phenomena, until Professor Espy broached a questionable +principle, (and which is rendered still more so by the late +investigations of Regnault,) in opposition to Hutton's theory. That the +theory is deficient, no one can gainsay. That Espy has rendered the +question clearer, is equally hazardous to assert. Hutton failed in +showing a cause for such intermingling on a sufficient scale; while +Espy, it may be suspected, has misinterpreted facts, and incautiously +rejected the only element possessing the power of raising the storm. + + +GREAT SPECIFIC HEAT OF THE ETHER. + +Whatever may be the degree of condensation or rarefaction in the terral +vortex, there must necessarily be a current down the pole or axis, +thence to be deflected along the equatorial plane of the vortex, and +this drain will be as perpetual as the rarefaction of the centre, +(caused by the centrifugal force of rotation,) which calls it forth. It +will now be perceived that the fluid of the vortex, which we shall still +term ether, is neither more nor less than the electric fluid,--the +mighty energising principle of space,--the source of motion,--the cause +of magnetism, galvanism, light, heat, gravity, of the aurora, the +lightning, the zodiacal light, of the tails and nebulosities of comets, +of the great currents of our atmosphere, of the samiel, the hurricane, +and the earthquake. It will be perceived that we treat it as any other +fluid, in relation to its law of motion and condensation. But we have no +right to base our calculations on its resistance, by the analogies +presented by ponderable or atomic matter. Atomic fluids,--even pure air, +may be considered viscid and tenacious when compared to an infinitely +divisible fluid, between whose particles (if we may use the term) no +_attraction_ of any kind exists. No ponderable matter can come in close +contact without feeling the influence of the gravitating force which, at +insensible distances,--such as the breadth of a wave of ether, is +increased in power, and becomes a cohering and combining force. We +contend that this fluid is the only fluid of space; when condensed it is +positive, and seeks to escape; when rarefied it is negative, and +receives from the contiguous space a restoration of its power. That it +can give and receive, from planetary matter, what we call motion; and +consequently can affect the temperature of such matter, and be in turn +affected by it. And finally that, for its degree of inertia, it exceeds +in elasticity and specific heat all other matter. + + +PROCESS OF DERANGEMENT. + +This premised, we see that as the axis of the vortex traverses the +surface of the earth, there is a tendency to derange the electric state +of the parts travelled over, by bringing the atmosphere and surface of +the earth under the rarefied centre of the vortex. For it is not the +ether of the atmosphere alone that is affected. It is called forth from +the earth itself, and partakes of the temperature of the +crust,--carrying up into the upper regions the vapor-loaded atmosphere +of the surface. The weather now feels close and warm; even in winter +there is a balmy change in the feelings. The atmosphere then fills with +haze, even to the highest regions of the clouds; the clouds themselves +are ill defined; generally the wind comes in at E. S-E., or S., getting +very fresh by the time it chops round to W. In from six to twelve hours +from the time of the meridian passage, in this latitude, the Big Cumuli +have formed, and commenced their march eastward. In summer time there is +always thunder and lightning, when the passage is attended or followed +by a storm. In winter, generally, but not always. In summer, the +diameter of the storm is contracted; in winter, dilated; in consequence +of this, summer is the best season to trace the vortices of the earth +through their revolutions. Let us now attend a little to the results. +The ether of the surface atmosphere partakes of the temperature of that +atmosphere, so also the ether of the earth's crust partakes of the +temperature of the crust; and its escape is rapid, compared with the +ascent of the air. When it arrives at the colder layers of air above, +its temperature sinks, and, on account of the greater specific caloric, +it imparts a much higher temperature to those layers than is due to +their position; an elevation consequently takes place,--begetting a +drain from below, until the upper regions are loaded with a warm and +vapory atmosphere. If the action of the sun conspires at the same time +to increase the effect, the storm will be more violent. In twelve hours +after the meridian passage of the vortex, the storm is brought under the +parts of the ethereal atmosphere of the earth most remote from the axis; +a reaction now takes place; the cold ether of space rushes in, and, on +account of its great specific caloric, it abstracts from the warm +atmosphere more than pertains to the difference of temperature, and +there is a great condensation. Rain and hail may form in fearful +quantities; and when the equilibrium is restored, the temperature will +have fallen many degrees. + +As it is important that we should have a clear view of the character of +the ether, we will revert to the principle we have advocated, viz.: that +in equal spaces there are equal momenta. What the ether wants in +inertia, is made up by its motion or specific heat, considering in this +case inertia to stand for weight when compared with ponderable matter; +so that to raise an equivalent amount of inertia of ether to the same +temperature as atmospheric air, will require as much more motion or +specific heat as its matter is less. And this we conceive to be a law of +space in relation to all free or gaseous matter. To apply it to solids +would require a knowledge of the amount of force constituting the +cohesion of the solid. + + +INFLUENCE OF DIMINISHED PRESSURE. + +But there is another principle which modifies these effects. We have +already adverted to the action of the tangential current of the vortex +forcing the outer layers of the atmosphere into waves. These waves will +be interfered with by the different vortices, sometimes being increased +and sometimes diminished by them.[6] If these waves are supposed very +wide, (which would be the case in the attenuated outside layers of the +atmosphere,) the action of the vortex will be greater in its passage +over a place, which at the time corresponded to the depression point of +the wave, that is, to the line of low barometer; because here there +would be less resistance to overcome in the passage of the ether from +the surface of the earth into space; so that we may conceive each vortex +making a line of storms each day around the earth, separated by less +disturbed intervals. After the formation of the storm, it of course has +nothing to do with the vortex that produced it; it travels in the +general direction of the local atmosphere of the place--in intratropical +latitudes westward, in extratropical latitudes eastward. If, therefore, +the disturbance forms at the place of observation, there will probably +be no storm; but further eastward its action would be more apparent or +violent. It is impossible, of course, to lay down any general +description which shall meet every case. It is a knowledge that can only +be acquired by observation, and then is not readily or easily +communicated. There are many contingencies to be allowed for, and many +modifying causes to keep sight of, to enter into which would only be +tedious; we shall, therefore, confine ourselves to the prominent +phenomena. + + +ACTION OF THE POLAR CURRENT. + +We have seen how the passage of the axis of the vortex may derange the +electric tension of the parts passed over; but there is another mode of +action not yet adverted to. + +[Illustration: Fig. 1] + +When the moon is at her perigee, the axis of the vortex passes through +the centre of gravity of the earth and moon at C, and cuts off the +segment RR. At the apogee, on account of her greater distance, and of +her consequent power to _push_ the earth out from the axis of the vortex +XX, the segment R′R′ is only cut off by the axis; and the angle which +the axis makes with the surface will vary with the arcs AR and A′R′; for +these arcs will measure the inclination from the nature of the circle. +In passing from the perigee to the apogee the axis will pass over the +latitudes intermediate between R and R′ in both hemispheres, neither +reaching to the equator E, nor to the pole P. Let us now suppose a +meridian of the earth, represented by the line NRS, N being north, and S +south, and the surface of the atmosphere by N′S′; XX still representing +the axis of the vortex, ordinarily inclined 34° or 35° to the surface. +Let us also conceive the rotation of the earth to cease, (the action of +the vortex remaining the same,) thus leaving the axis over a particular +longitude. If the ether possesses inertia, there will be an actual +scooping out of the upper portions, driving them southward to a certain +distance, where the atmosphere will be piled up above the ordinary +level. There will, therefore, be a strong contrary current at the +surface of the earth to restore the equilibrium, and if the action be +violent, the surface wind will be increased; so that if it be considered +tangential to the surface at S, its own momentum will tend to make it +leave the surface and mount up to T; and in this way increase the action +due to the ether. Now, although the axis is never stationary, but +travels round the earth in less than twenty-five hours, yet there is a +tendency to this mode of action; and it is even sometimes palpable to +the observer when the axis has passed immediately to the northward; for +the pinnate shafts and branching plumes of the cirri often reach far to +the south of the southern boundary of the storm. These shafts are always +longer when radiating from the northward than when proceeding from the +southward. The cause is understood by the above figure. At such a time, +after dark, the auroral shafts will also be seen over the storm to the +northward, but will be invisible to those beneath. There is this to be +observed, however, that the visibility of the ethereal current (or the +aurora) is more frequent when the passage of the vortex is not attended +with any great commotion, its free passage being perhaps obstructed by +too dry an atmosphere; hence it becomes more visible. But it may be +asserted that a great aurora is never seen except when a vortex is near, +and to the northward, and within a few hours of its passage over the +meridian. We have, however, seen partial auroras to the south when none +existed north, and also cases when the radiation was from west, but they +are never as bright as in the north. They are all due, however, to the +same cause; and we have frequently followed a vortex for three days to +the northward, (that is, seen the effects of its meridian passage,) at +700 miles distance, by the aurora, and even by the lightning, which +proves plainly that the _exterior layers_ of our atmosphere can reflect +a flash of lightning, assisted by the horizontal refraction, otherwise +the curvature of the earth would sink it ten miles below the horizon. + +[Illustration: Fig. 2] + + +LIMITS OF THE VORTEX. + +The action of the polar current of the ether, therefore, tends to cause +a depression of the barometer, and an elevation to the _northward_ and +southward, and there is a general set of the wind below to the point of +greatest depression. The action of the tangential current works the +outer surface of the atmosphere into great ridges and hollows, whose +distances apart as well as actual dimensions, are continually changing +under the influences of causes not yet alluded to, and it is in the +hollows where the action of the polar current will be principally +expended. Luckily for the earth, the axis of the vortex is never long in +passing over any particular place. In this latitude, whose natural +cosine is three-fourths, the velocity _westward_ is over 700 miles per +hour; but at its extreme limits north, the motion is much slower, and is +repeated for two or three days in nearly the same latitude, for then it +begins to return to the south; thus oscillating in about one sidereal +period of the moon. At its southern limit, the vortex varies but slowly +in latitude for the same time, but the velocity is much greater. The +extreme latitudes vary at different times with the eccentricity of the +lunar orbit, with the place or longitude of the perigee, and with the +longitude of the moon's ascending node, but in no case can the _central +vortex_ reach within 5° of the equator, or higher than about 75° of +latitude north or south. Hence there are no storms strictly speaking +beyond 88°[7] of latitude; although a storm may be raging close by, at +the turning point south, and draw in a very strong gale from the +northward with a clear sky above. So also, although rains and short +squalls may be frequent in the vapor-loaded atmosphere of the equator, +yet the hurricane does not reach there, owing to the adjustment of the +mass and distance of the moon, and the inclination of the axes of the +vortices to the axis of the earth. If the temperature of the upper limit +or highest latitude of the vortex, was equal to the temperature which +obtains at its lowest limit, and the daily extremes of the solar +influence as great, the hurricanes would be as violent at the one as the +other, and even more so on account of the smaller velocity. But the +deficiency of temperature and moisture, (which last is all-important,) +prevents the full development of the effect. And even in the tropics, +the progress of the sun, by its power in directing the great annual +currents of the atmosphere, only conspires in the summer and autumn +months, to bring an atmosphere in the track of the vortices, possessing +the full degree of moisture and deficiency of electric tension, to +produce the derangement necessary to call forth the hurricane in its +greatest activity. + + +ROUTINE OF A STORM. + +The novelty and originality of this theory will perhaps justify us in +dwelling a little longer on what observation has detected. The vortex +(and we are now speaking only of the central vortex) does not derange +every place alike, but _skips_ over large tracts of longitude in its +progress westward. We speak here of the immovable axis of the vortex as +in motion; in reality it is the rotation of the earth which brings every +meridian under its influence in some latitude once every twenty-four +hours. The centre of greatest derangement forms the nucleus, towards +which the surface currents, under certain restrictions, flow. The +strongest current will, however, usually be from the south, on account +of the inclination of the axis of the vortex to the surface of the +earth.[8] These currents continuing onwards by their vires inertiæ, +according to the first law of motion, assist somewhat in conveying the +warm surface wind, loaded with moisture, into the region of cloud; and +the diminution of temperature causes the condensation of large masses of +vapor, according to Hutton's views; and the partial vacuum thus +produced, causes a still greater intermingling. But we have already +shown that this is not the sole cause, nor is it ever more than +partially accomplished. The ether of the lower atmosphere, and of the +crust of the earth, is disturbed, and rushes towards the rarefied axis +from the surface, and with the temperature of the surface, thus +conveying the surface atmosphere, in a measure, along with it. In the +upper regions, this ether (or electric fluid) cools down, or parts with +some of its heat, to the air of those regions, and, by its great +specific caloric, necessarily and unduly increases the temperature of +the air. This, by its expansion and ascension will cause a further +influx from below, until the upper atmosphere becomes loaded with vapor. +In twelve hours, at least, a reaction must take place, as that part of +the earth's surface is carried six or seven thousand miles from the +axis, where the ether is more dense. This in turn descends to the +surface, carrying with it the temperature of space, at least 60° below +zero; a great condensation must follow; local derangements of the +electric equilibrium in the centre of large clouds, when the +condensation is active, must now take place, while partially +nonconducting masses intervene, to prevent an instantaneous restoration +of the equilibrium, until the derangement is sufficient to cause the +necessary tension, when all obstacles are rent asunder, and the ether +issues forth, clothed in the power and sublimity of the lightning. It is +a fearfully-energetic fluid, and, when sufficiently disturbed, competent +to produce the most violent tornado, or the most destructive earthquake. +That these two phenomena have simultaneously occurred, seems well +authenticated; but the earthquake, of course, must be referred generally +to derangements of the electric equilibrium of the earth's interior, of +which at present we know but little. + +The day or morning previous to the passage of the vortex, is frequently +very fine, calm, mild, and sleepy weather,--commonly called a weather +breeder. After the storm has fully matured, there is an approach of the +clouds to the surface, a reduction of the temperature above, and the +human body feels the change far more than is due to the fall of +temperature. This is owing to the cold ether requiring so much heat to +raise its temperature to that of surrounding bodies, or, in other words, +is due to its great specific caloric. In summer, this falling of the +upper layers in front of the storm is so apparent, that every part is +seen to expand under the eye by perspective,--swelling, and curling, and +writhing, like the surface of water or oil when just commenced boiling. +The wind now partakes of the motion of the external ether, and moves +with the storm eastward (in this latitude), or from N-E. to S-E., until +the action ceases. + + +CONDITIONS NECESSARY TO PRODUCE A STORM. + +The vortex, in its passage round the earth, may only meet with a few +localities favorable for producing a very violent storm; but these +nuclei will generally be connected by bands of cloudy atmosphere; so +that could we view them from the moon, the earth would be belted like +the planet Jupiter. There is reason to suspect, also, that there are +variations in the energy of the ethereal motions, independent of the +conditions of the earth and its atmosphere, which affects even the +radial stream of the sun. For the zodiacal light, which is caused by +this radial stream, is at times much more vivid than at others. Also in +the case of the aurora, on our own globe. On this point there is much to +say, but here is not the place. The conditions favorable for the +production of a storm at the _central_ passage of a vortex, are a +previous exemption from excitement _ceteris paribus_, a high temperature +and dew point, a depression of the barometer, and local accumulation of +electric tension, positive or negative; and these are influenced by the +storms in other places controlling the aërial currents, and thus +determining the atmosphere of the place. + + +LATERAL VORTICES. + +We have already alluded to the lateral vortices of the terral system. We +must now resort to a diagram. + +In the following figure, the arrows represent the ethereal current of +the terral vortex; the linear circle, the earth; C the centre of gravity +of the earth and moon, and, consequently, the central vortex or axis of +the vortex of the earth, I represents the position of the inner vortex, +and O that of the outer vortex. These two last are eddies, caused by the +obstacle presented by the earth in being _pushed_ out from the centre by +the moon, and are called lateral vortices. There are, therefore, two +lateral vortices, and one central, in both hemispheres, and by this +simple arrangement is the earth watered, and the atmospheric circulation +produced. + +[Illustration: Fig. 3] + + +ILLUSTRATION OF THEIR ACTION. + +If we place a globe in a vessel of water, so that the vertex shall only +just be covered, and place the globe eccentrically in the vessel so that +the centre of the vessel may not be too far from the outside of the +globe, and then impart an equable but slow motion to the water, in the +manner of a vortex; by viewing the reflected light of the sky from the +surface of the water above the globe, we shall be able to trace a +succession of dimples, originating at I and O, and passing off with the +current, and dying away. The direction of the fluid in these little +eddies, will be the same as the direction of the current in the main +vortex. If we displace the globe, so as to remove it far from the centre +of the vessel, and impart the same motion, the vortex I will be found at +E, and the direction of the current will be contrary to the direction +of the fluid in the vessel. In the case of the earth and moon, the +displacement can never change the position of the inner vortex much. It +will always be to the right hand of the central vortex in north +latitudes, and in consequence of the ether striking our globe in such a +position, the current that is deflected from its true path, by the +protuberance of the earth forcing it inside, is prevented by the +circular current of the parts nearer the axis of the vortex, from +passing off; so that a vortex is formed, and is more violent, _ceteris +paribus_, than the vortex at O. + + +ORDER OF OCCURRENCE. + +Whether this mode of action has been correctly inferred, matters little; +the lateral vortices follow the law of such a position. The inner vortex +always precedes the central from five to eight days, when ascending in +this latitude, and comes to the meridian after the moon. The outer +vortex, on the contrary, follows the central in its monthly round, and +comes to the meridian before the moon. It will be readily understood +that if the axes of these lateral vortices be produced through the +earth, they will pass through similar vortices in the opposite +hemisphere; but as the greatest latitude of the one, corresponds to the +least latitude of the other, the same calculation will not answer for +both. The same remark applies to the central vortex also. + +Thus there are six passages each month over latitude 41°; but as there +are intervals of 3° to 6° between two consecutive passages of the same +vortex, it may happen that an observer in the middle latitude, would +perhaps see nothing of their effects without looking for them. Generally +speaking, they are not only seen, but felt. The time of the passage of +the outer vortex ascending, corresponds so nearly (in 38° of latitude) +at certain times, with the passage of the central vortex descending, +that the two may be considered one if attention is not directed to it. +The orbits of these lateral vortices depend, like that of the central +vortex, on the orbit of the moon for eccentricity, but the longitudes of +the perigee will not correspond with the longitude of the moon's +perigee. This follows from the theory. As the elements of these orbits +are only approximately determined, we shall confine our calculations to +the orbit of the central vortex. + + +REDFIELD'S THEORY OF STORMS. + +It will now appear plainly to the reader, that this theory of storms +differs in every particular from the rival theories of Redfield and +Espy, both as to the cause and the _modus agendi_. It would appear at +first sight, as if the discovery of these vortices would at once remedy +the great defect in the theory of Redfield, viz.: that no adequate cause +is assigned for the commencement and continuation of the vorticose +motion, in the great circular whirlwinds which compose a storm. The +facts, however, are adverse to such an application. According to +Mr. Redfield, the rotation of a circular storm in the northern +hemisphere is from right to left, and the reverse in the southern. The +author's attention has, of course, been considerably directed to this +point; but in every case he has been unfortunate in finding in the +clouds a rotation from left to right. Some cases are mentioned in the +appended record of the weather. He has also noticed many of those small +whirlwinds on arid plains, in Egypt, in Mexico, and in California, +which, in the great majority of cases, were also from left to right. His +opportunities, however, have not extended to the southern hemisphere. +This theory has not, however, been formed on theoretic views, but by +looking nature in the face for years, and following her indications. +Accordingly, we find that the changes of the wind in a storm forbid the +adoption of the circular hypothesis. + + +WHIRLWINDS VERY LIMITED IN DIAMETER. + +The theory, as extended by Col. Reid, rests on a simple rotation around +a progressing centre, and is found sometimes supported by evidence of +the most violent action at the centre, and sometimes by showing that the +central portion is often in a state of calm. We do not attempt to +reconcile these views; but would merely observe, that an atmospheric +vortex must be subject to the same dynamical laws as all other vortices; +and inasmuch as the medium cannot differ greatly in density, from the +centre to the circumference, the periodic times of the parts of the +vortex, must be directly as their distances from the axis, and +consequently the absolute velocities must be equal. If Mr. Redfield +resorts to a spirally inward current, it would be a centripetal instead +of a centrifugal current, and therefore could not cause the barometer to +fall, which was the best feature of the theory in its primitive form. +The absolute velocity of the wind is the important element which most +concerns us. In the case of a tornado of a few yards in diameter, there +is no doubt a circular motion, caused by the meeting of opposing +currents; but this may be considered a circle of a very small diameter. +The cause is due to a rapid escape of electric or ethereal matter, from +the crust of the earth, called forth by the progressing, disturbed space +above; this involves the air, and an ascending column in rotation begets +the rush on all sides to that column in straight lines: consequently, +the velocities will be inversely as the distances from the axis, and the +force of the current as the squares of the velocities. On the circular +theory, no increase of velocity would be conferred by the approach of +the centre, and consequently no increase of power. + + +OBJECTION TO CIRCULAR STORMS. + +Another objection to the circular theory of storms, is the uniformity of +phase. If that theory be true, we see no reason why a person should not +be sometimes on the northern side of the gale. By referring to a +diagram, we perceive that on the northern side the changes of the wind +pursue a contrary direction to what they do on the south, yet in nine +cases out of ten, each vessel meeting a hurricane will find the same +changes of wind as are due to the southern side of the storm. It is +true, that if a vessel be to the northward of a great hurricane, there +will almost certainly be a north-east gale drawn in, and this might be +set down as the outer limits of a circular storm. But when the storm +really begins, the wind comes round south-east, south, south-west, +ending at north-west, and frequently is succeeded, on the following day, +(if in middle latitude,) by a moderate breeze from the northward. Now, +if the north-east gale spoken of above, was the outer limits of an +atmospheric vortex, a vessel sailing west ought not to meet the +hurricane, as a north-east wind is indicative of being already on the +west side, or behind the storm. + +Again, the characters of the winds, and appearances at the different +changes, are opposed to the circular theory. At a distance of fifty +miles from the centre of a storm, the wind which passes over a ship as a +southerly wind, will have made a rotation and a half, with the hurricane +velocity, before the same wind can again pass the ship as a northerly +wind, (supposing the progress eastward, and the ship lying to,) that is, +the same wind which in another place was a south wind two hours before, +and after only going one degree north, becomes a northerly +wind,--changed in character and temperature, as every seaman is well +aware. In a storm, if the circular theory be true, the character and +temperature should be the same, no matter from what point the wind is +blowing. This should be a conclusive argument. + +Mr. Espy has also changed his ground on the storms of the United States; +he does not now contend that the winds blow inwards to a centre, but to +a line either directly or obliquely. Thus we see that while Mr. Redfield +concedes to Mr. Espy a spirally inward current, the latter also gives up +a direct current to the centre, to Mr. Redfield. This shows at least an +approximation to the truth. + +It is not necessary for the support of this theory, that we should +derive any materials from the ruins of others; we shall therefore not +avail ourselves of certain discrepant results, which can be found in +many of the storms cited by Colonel Reid. With respect to Mr. Espy's +_cause_ of storms, the experiments of Regnault may be considered as +decisive of the question:--1st, because the specific heat of vapor is so +much less than Espy assumed it to be; and 2d, because the expansion of +air in a free space does not suffer any change of volume by ascending, +except what is due to diminished pressure, and the natural temperature +of that elevation. + + +INDICATIONS OF A STORM. + +In accordance with our theory, the direction and force of the wind in a +storm are due to ascending columns of air, supplied from the upper +portion of the atmospheric stratum beneath the clouds. The commotion +begins at the highest limits of the cirri, and even at greater +elevations. Hence, the hazy appearance of the sky is a legitimate +precursor of the coming gale. As a general thing, the wind will blow (at +the surface) towards the centre of greatest commotion, but it is too +dependent on the ever-varying position and power of temporary nuclei of +disturbance, to be long steady, except when the disturbance is so remote +that its different centres of induction are, as it were, merged into one +common focus. When a vortex is descending, or passing from north to +south, and withal very energetic at the time, the southerly wind (which +may always be considered the principal wind of the storm in this +hemisphere) may blow steadily towards the vortex for three or even four +days. When a vortex is ascending, the induced northerly current will be +comparatively moderate, and be frequently checked by the southerly wind +overblowing the storm, and arriving the day before the vortex which +produced it. + +The important point for the navigator, is to know the time of meridian +passage of the vortex, and its latitude at the time of the passage, and +then be guided by the indications of the weather and the state of +barometer. If it commences storming the day before the passage, he may +expect it much worse soon after the passage; and again, if the weather +looks bad when no vortex is near, he may have a steady gale setting +towards a storm, but no storm until the arrival of a vortex. Again, if +the barometer is low the day before the vortex passes, there may be high +barometer to the west, and the passage be attended by no great +commotion, as it requires time for the storm to mature, and consequently +its greatest violence will be to the east. If at the ship the barometer +is high, the vortex may still produce a storm on a line of low barometer +to the west, and this line may reach the ship at the time of the +passage. In tropical climates the trouble must be looked for to the +eastward; as a storm, once excited, will travel westward with that +stratum of atmosphere in which the great mass of vapor is lodged, and in +which, of course, the greatest derangement of electric tension is +produced. + +It will now be seen that we do not admit, with Col. Reid, that a storm +continues in existence for a week together. Suppose a hurricane to +originate in the Antilles at the southern limits of a vortex, the +hurricane would die away, according to our theory, if the vortex did not +come round again and take up the same nucleus of disturbance. On the +third day the vortex is found still further north, and the apparent path +of the hurricane becomes more curved. In latitude 30° the vortex passes +over 3° or 5° of latitude in a day; and here being the latitude where +the lower atmospheric current changes its course, the storm passes due +north, and afterwards north-east. Now, each day of the series there is a +distinct hurricane, (caused by an increase of energy in a particular +vortex, as we have before hinted,) each one overlapping on the remains +of the preceding; but in each the same changes of the wind are gone +through, and the same general features preserved, as if it were truly a +progressive whirlwind, except that each vessel has the violent part of +it, as if she was in the southern half of the whirl. The apparent +regularity of the Atlantic storms in direction, as exhibited by Col. +Reid, are owing in a great degree to the course of the Gulf Stream, in +which a vortex, in its successive passages in different latitudes, finds +more favorable conditions for the development of its power, than in +other parts of the same ocean; thus showing the importance of regarding +the established character of storms in each locality, as determined by +observation. In this connection, also, we may remark, that the meridians +of greatest magnetic intensity are, _ceteris paribus_, also the +meridians of greatest atmospheric commotion. The discovery of this fact +is due to Capt. Sabine. The cause is explained by the theory. + +As it is the author's intention to embody the practical application of +this theory to navigation, with the necessary rules and tables, in a +separate work, sufficient has been said to familiarize the reader with +the general idea of a cause external to the earth, as the active motor +in all atmospheric phenomena. We will therefore only allude in a general +way to the principal distinguishing feature of the theory. We say, then, +that the wind in a storm is not in rotation, and it is a dangerous +doctrine to teach the navigator. We also assert as distinctly, that the +wind _in_ a storm does not blow from all sides towards the centre, which +is just as dangerous to believe. If it were wise to pin our faith to any +Procrustean formula, we might endorse the following propositions: That +at the beginning of a storm the wind is from the equator towards the +poles in every part of the storm; that, at a later date, another current +(really a polar current deflected by convection) sets in at right angles +to the first one; and that at the end of the storm there is only _one_ +wind blowing at right angles to the direction at the beginning. Outside +the storm, considered as a hundred, or two or three hundred miles in +diameter, there is, under certain limitations, a surface wind setting +towards the general focus of motion and condensation, and this surface +wind will be strongest from the westward, on account of the motion of +the whole atmosphere in which these other motions are performed being to +the eastward.[9] The whole phenomenon is electrical or magnetic, or +electro-magnetic or ethereal, whichever name pleases best. The vortex, +by its action, causes a current of induction below, from the equator, as +may be understood by inspecting Fig. 2, which in the northern hemisphere +brings in a southerly current by convection: the regular circular +current, however, finally penetrates below, as soon as the process of +induction has ceased; and thus the polar current of the atmosphere at +last overcomes the equatorial current in a furious squall, which ceases +by degrees, and the equilibrium is restored. + +Every locality will have its peculiar features; in each, the prevailing +wind will be at right angles to the magnetic meridian, and the progress +of the storm will tend to follow the magnetic parallel, which is one +reason why the Atlantic and Indian Ocean storms have been mistaken for +progressive whirlwinds. When these views are developed in full, the +mariner can pretty certainly decide his position in the storm, the +direction of its progress, and its probable duration. + + +FOOTNOTES: + +[3] The specific heat of the ether being a constant factor, it may be +divided out. + +[4] A term adopted by Prof. Faraday to denote the mode in which bodies +are carried along by an electrical current. + +[5] Ottawa, Ill. + +[6] The principal cause of these waves is, no doubt, due to the +vortices, and the eastern progress of the waves due to the rotating +ether; but, at present, it will not be necessary to separate these +effects. + +[7] The inner vortex may reach as high as 83° when the moon's orbit is +favorably situated. + +[8] The curvature of the earth is more than 10 miles in a distance of +300 miles. + +[9] In middle latitudes. + + + + +SECTION SECOND. + + +MECHANICAL ACTION OF THE MOON. + +We will now proceed to give the method of determining the latitude of +the axis of the vortex, at the time of its passage over any given +meridian, and at any given time. And afterwards we will give a brief +abstract from the record of the weather, for one sidereal period of the +moon, in order to compare the theory with observation. + +[Illustration: Fig. 4] + +In the above figure, the circle PER represents the earth, E the equator, +PP′ the poles, T the centre of the earth, C the mechanical centre of the +terral vortex, M the moon, XX′ the axis of the vortex, and A the point +where the radius vector of the moon pierces the surface of the earth. If +we consider the axis of the vortex to be the axis of equilibrium in the +system, it is evident that TC will be to CM, as the mass of the moon to +the mass of the earth. Now, if we take these masses respectively as 1 to +72.3, and the moon's mean distance at 238,650 miles, the mean value of +TC is equal to this number, divided by the sum of these masses,--_i.e._ +the mean radius vector of the little orbit, described by the earth's +centre around the centre of gravity of the earth and moon, is equal +238650/(72.3+1) = 3,256 miles; and at any other distance of the moon, is +equal to that distance, divided by the same sum. Therefore, by taking CT +in the inverse ratio of the mean semi-diameter of the moon to the true +semi-diameter, we shall have the value of CT at that time. But TA is to +TC as radius to the cosine of the arc AR, and RR′ are the points on the +earth's surface pierced by the axis of the vortex, supposing this axis +coincident with the pole of the lunar orbit. If this were so, the +calculation would be very short and simple; and it will, perhaps, +facilitate the investigation, by considering, for the present, that the +two axes do coincide. + +In order, also, to simplify the question, we will consider the earth a +perfect sphere, having a diameter of 7,900 miles, equal to the actual +polar diameter, and therefore TA is equal to 3,950 miles. + +In the spherical triangle given on next page, we have given the point A, +being the position of the moon in right ascension and declination in the +heavens, and considered as terrestrial latitude and longitude. + +Therefore, PA is equal to the complement of the moon's declination, P +being the pole of the earth, and L being the pole of the lunar orbit; PL +is equal to the obliquity of the lunar orbit, with respect to the earth, +and is therefore given by finding the true inclination of the lunar +orbit at the time, equal EL, (E being the pole of the ecliptic,) also +the true longitude of the ascending node, and the obliquity of the +ecliptic PE. Now, as we are supposing the axis of the vortex parallel +to the pole of the lunar orbit, and to pierce the earth's surface at R, +ARL will evidently all be in the same plane; and, as in the case of A +and L, this plane passes through the earth's centre, ARL must all lie in +the same great circle. Having, therefore, the right ascension of A, and +the right ascension of L, we have the angle P. This gives us two sides, +and the included angle, to find the side LA. But we have before found +the arc AR; we therefore know LR. But in finding LA, we found both the +angles L and A, and therefore can find PR, which is equal to the +complement of the latitude sought. + +[Illustration: Fig. 5] + +We have thus indicated briefly the simple process by which we could find +the latitude of the axis of the central vortex, supposing it to be +always coincident with the pole of the lunar orbit. The true problem is +more complicated, and the principal modifications, indicated by the +theory, are abundantly confirmed by observation. The determination of +the inclination of the axis of the vortex, its position in space at a +given time, and the law of its motion, was a work of cheerless labor for +a long time. He that has been tantalized by hope for years, and ever on +the eve of realization, has found the vision vanish, can understand the +feeling which proceeds from frequent disappointment in not finding that, +whose existence is almost demonstrated; and more especially when the +approximation differs but slightly from the actual phenomena. + +The chief difficulty at the outset of these investigations, arose from +the conflicting authority of astronomers in relation to the mass of the +moon. We are too apt to confound the precision of the laws of nature, +with the perfection of human theories. Man observes the phenomena of the +heavens, and derives his means of predicting what will be, from what has +been. Hence the motions of the heavenly bodies are known to within a +trifling amount of the truth; but it does not follow that the true +explanation is always given by theory. If this were so, the mass of the +moon (for instance) ought to be the same, whether deduced from the +principle of gravitation or from some other source. This is not so. +Newton found it 1/40 of that of the earth. La Place, from a profound +theoretical discussion of the tides, gave it as 1/58.6, while from other +sources he found a necessity of diminishing it still more, to 1/68, and +finally as low as 1/75. Bailly, Herschel, and others, from the nutation +of the earth's axis, only found 1/80, and the Baron Lindenau deduced the +mass from the same phenomenon 1/88. In a very recent work by Mr. Hind, +he uses this last value in certain computations, and remarks, that we +shall not be very far wrong in considering it as 1/80 of the mass of the +earth. This shows the uncertainty of the matter in 1852. If astronomy is +so perfect as to determine the parallax of a fixed star, which is almost +always less than one second, why is it that the mass of the moon is not +more nearly approximated? Every two weeks the sun's longitude is +affected by the position of the moon, alternately increasing and +diminishing it, by a quantity depending solely upon the relative mass of +the earth and moon, and is a gross quantity compared to the parallax of +a star. So, also, the horizontal parallax--the most palpable of all +methods--taken by different observers at Berlin, and the Cape of Good +Hope, (a very respectable base line, one would suppose,) makes the mass +of the moon greater than its value derived from nutation; the first +giving about 1/70, the last about 1/74.2. Does not this declare that it +is unsafe to depend too absolutely on the strict wording of the +Newtonian law of gravitation. Happily our theory furnishes us with the +correct value of the moon's mass, written legibly on the surface of the +earth; and it comes out nearly what these two phenomena always gave it, +viz.: 1/72.3 of that of the earth. In another place we shall inquire +into the cause of the discrepancy as given by the nutation of the earth. + + +MOTION OF THE AXIS OF THE VORTEX. + +If the axis of the terral vortex does not coincide with the axis of the +lunar orbit, we must derive this position from observation, which can +only be done by long and careful attention. This difficulty is increased +by the uncertainty about the mass of the moon, already alluded to, and +by the fact that there are three vortices in each hemisphere which pass +over _twice_ in each month, and it is not _always_ possible to decide by +observation, whether a vortex is ascending or descending, or even to +discriminate between them, so as to be assured that this is the central +descending, and that the outer vortex ascending. A better acquaintance, +however, with the phenomenon, at last dissipates this uncertainty, and +the vortices are then found to pursue their course with that regularity +which varies only according to law. The position of the vortex (the +central vortex is the one under consideration) then depends on the +inclination of its axis to the axis of the earth, and the right +ascension of that axis at the given time. For we shall see that an +assumed immobility of the axis of the vortex, would be in direct +collision with the principles of the theory. + +Let the following figure represent a globe of wood of uniform density +throughout. Let this globe be rotated round the axis. It is evident that +no change of position of the axis would be produced by the rotation. If +we add two equal masses of lead at m and m′, on opposite sides of the +axis, the globe is still in equilibrium, as far as gravity is concerned, +and if perfectly spherical and homogeneous it might be suspended from +its centre in any position, or assume indifferently any position in a +vessel of water. If, however, the globe is now put into a state of rapid +rotation round the axis, and then allowed to float freely in the water, +we perceive that it is no longer in a state of equilibrium. The mass m +being more dense than its antagonist particle at n, and having equal +velocity, its momentum is greater, and it now tends continually to pull +the pole from its perpendicular, without affecting the position of the +centre. The same effect is produced by m′, and consequently the axis +describes the surface of a double cone, whose vertices are at the centre +of the globe. If these masses of lead had been placed at opposite sides +of the axis on the _equator_ of the globe, no such motion would be +produced; for we are supposing the globe formed of a hard and unyielding +material. In the case of the ethereal vortex of the earth, we must +remember there are two different kinds of matter,--one ponderable, the +other not ponderable; yet both subject to the same dynamical laws. If we +consider the axis of the terral vortex to coincide with the axis of the +lunar orbit, the moon and earth are placed in the equatorial plane of +the vortex, and consequently there can be no derangement of the +equilibrium of the vortex by its own rotation. But even in this case, +seeing that the moon's orbit is inclined to the ecliptic, the +gravitating power of the sun is exerted on the moon, and of necessity +she must quit the equatorial plane of the vortex; for the sun can exert +no influence on the _matter_ of the vortex by his attracting power. The +moment, however, the moon has left the equatorial plane of the vortex, +the principle of momentum comes into play, and a conical motion of the +axis of the vortex is produced, by its seeking to follow the moon in her +monthly revolution. This case is, however, very different to the +illustration we gave. The vortex is a fluid, through which the moon +freely wends her way, passing through the equatorial plane of the vortex +twice in each revolution. These points constitute the moon's nodes on +the plane of the vortex, and, from the principles laid down, the force +of the moon to disturb the equilibrium of the axis of the vortex, +vanishes at these points, and attains a maximum 90° from them. And the +effect produced, in passing from her ascending to her descending node, +is equal and contrary to the effect produced in passing from her +descending to her ascending node,--reckoning these points on the plane +of the vortex. + +[Illustration: Fig. 6] + + +INCLINATION OF THE AXIS. + +By whatever means the two planes first became permanently inclined, we +see that it is a necessary consequence of the admission of these +principles, not only that the axis of the vortex should be drawn aside +by the momentum of the earth and moon, ever striving, as it were, to +maintain a dynamical balance in the system, in accordance with the +simple laws of motion, and ever disturbed by the action of gravitation +exerted on the grosser matter of the system; but also, that this axis +should follow, the axis of the lunar orbit, at the same mean +inclination, during the complete revolution of the node. The mean +inclination of the two axes, determined by observation, is 2° 45′, and +the monthly equation, at a maximum, is about 15′, being a plus +correction in the northern hemisphere, where the moon is between her +descending and ascending node, reckoned on the plane of the vortex, and +a minus correction, when between her ascending and descending node. And +the mean longitude of the node will be the same as the true longitude of +the moon's orbit node,--the maximum correction for the true longitude +being only about 5° ±. + +[Illustration: Fig. 7] + +In the following figure, P is the pole of the earth; E the pole of the +ecliptic; L the pole of the lunar orbit; V the mean position of the pole +of the vortex at the time; the angle ♈EL the true longitude of the pole +of the lunar orbit, equal to the _true_ longitude of the ascending node +± 90°. VL is therefore the mean inclination ± 2° 45′; and the little +circle, the orbit described by the pole of the vortex _twice_ in each +sidereal revolution of the moon. The distance of the pole of the vortex +from the mean position V, may be approximately estimated, by multiplying +the maximum value 15′ by the sine of twice the moon's distance from the +node of the vortex, or from its mean position, viz.: the true longitude +of the ascending node of the moon on the ecliptic. From this we may +calculate the true place of the node, the true obliquity, and the true +inclination to the lunar orbit. Having indicated the necessity for this +correction, and its numerical coefficient, we shall no longer embarrass +the computation by such minutiæ, but consider the mean inclination as +the true inclination, and the mean place of the node as the true place +of the node, and coincident with the ascending node of the moon's orbit +on the ecliptic. + + +POSITION OF THE AXIS OF THE VORTEX. + +It is now necessary to prove that the axis of the vortex will still pass +through the centre of gravity of the earth and moon. + +[Illustration: Fig. 8] + +Let XX now represent the axis of the lunar orbit, and C the centre of +gravity of the earth and moon, X′X′ the axis of the vortex, and KCR the +inclination of this axis. Then from + + similarity Ct : Tt :: Cm : Mm + but Tt : Mm :: Moon's mass : Earth's mass. + That is Tt : Mm :: TC : MC. + +Therefore the system is still balanced; and in no other point but the +point C, can the intersection of the axes be made without destroying +this balance. + +It will be observed by inspecting the figure, that the arc R′K′ is +greater than the arc RK. That the first increases the arc AR, and the +second diminishes that arc. The arc R′K′ is a plus correction therefore, +and the smaller arc RK a minus correction. If the moon is between her +descending and ascending node, (taking now the node on the ecliptic,) +the correction is negative, and we take the smaller arc. If the moon is +between her ascending and descending node, the correction is positive, +and we take the larger arc. If the moon is 90° from the node, the +correction is a maximum. If the moon is at the node, the correction is +null. In all other positions it is as the sine of the moon's distance +from the nodes. We must now find the maximum value of these arcs of +correction corresponding to the mean inclination of 2° 45′. + +To do this we may reduce TC to Tt in the ratio of radius to cosine of +the inclination, and taking TS for radius. + +[Illustration: Fig. 9] + +{TC × Cos &c. (inclination 2° 45′)}/R is equal the cosine of the arc SK′ +and SK′ + AS = AK′ and AK′ + AR′ = R′K′. But from the nature of the +circle, arc RK + arc R′K′ = angle RCK + angle R′CK′, or equal to double +the inclination; and therefore, by subtracting either arc from double +the inclination, we may get the other arc. + +The maximum value of these arcs can, however, be found by a simple +proportion, by saying; as the arc AR, plus the inclination, is to the +inclination, so is the inclination to the difference between them; and +therefore, the inclination, plus half the difference, is equal the +greater arc, and the inclination, minus half the difference, is equal +the lesser; the greater being positive, and the lesser negative. + +Having found the arc AR, and knowing the moon's distance from either +node, we must reduce these values of the arcs RK and R′K′ just found, in +the ratio of radius to the sine of that distance, and apply it to the +arc AR or A′R′, and we shall get the first correction equal to the +arc AK or AK′. + + Call the arc AR = a + " inclination = n + " distance from the node = d + " arc AK = k + +and supposing the value of AK be wanted for the northern hemisphere when +the moon is between her descending and ascending node, we have + + n² + ------- + a + n + (n - ------- ) sin d. + 2 + k = a - ---------------------- + R + +If the moon is between her ascending and descending node, then + + n² + ------- + a + n + (n - ------- ) sin d. + 2 + k = a + ---------------------- + R + +The computation will be shorter, however, if we merely reduce the +inclination to the sine of the distance from the node for the first +correction of the arc AR, if we neglect the semi-monthly motion of the +axis; for this last correction diminishes the plus corrections, and the +first one increases it. If, therefore, one is neglected, it is better to +neglect the other also; especially as it might be deemed affectation to +notice trifling inequalities in the present state of the elements of the +question. + +There is one inequality, however, which it will not do to neglect. This +arises from the displacement of the axis of the vortex. + + +DISPLACEMENT OF THE AXIS. + +We have represented the axis of the terral vortex as continually passing +through the centre of gravity of the earth and moon. Now, by following +out the principles of the theory, we shall see that this cannot be the +case, except when the moon is in quadrature with the sun. To explain +this: + +[Illustration: Fig. 10] + +Let the curve passing through C represent a portion of the orbit of the +earth, and S the sun. From the principles laid down, the density of the +ethereal medium increases outward as the square roots of the distances +from the sun. Now, if we consider the circle whose centre is C to +represent the whole terral vortex, it must be that the medium composing +it varies also in density at different distances from the sun, and at +the same time is rotating round the centre. That half of the vortex +which is exterior to the orbit of the earth, being most dense, has +consequently most inertia, and if we conceive the centre of gravity of +the earth and moon to be in the orbit (as it must be) at C, there will +not be dynamical balance in the terral system, if the centre of the +vortex is also found at C. To preserve the equilibrium the centre of the +vortex will necessarily come nearer the sun, and thus be found between T +and C, T representing the earth, and ☾ the moon, and C the centre of +gravity of the two bodies. If the moon is in opposition, the centre of +the vortex will fall between the centre of gravity and the centre of the +earth, and have the apparent effect of diminishing the mass of the moon. +If, on the other hand, the moon is in conjunction, the centre of the +vortex will fall between the centre of gravity and the moon, and have +the apparent effect of increasing the mass of the moon. If the moon is +in quadrature, the effect will be null. The coefficient of this +inequality is 90′, and depends on the sun's distance from the moon. When +the moon is more than 90° from the sun, this correction is positive, and +when less than 90° from the sun, it is negative. If we call this second +correction C, and the moon's distance from her quadratures Q, we have +the value of C = ±(90′ × sin Q)/R. + +[Illustration: Fig. 11] + +This correction, however, does not affect the inclination of the axis of +the vortex, as will be understood by the subjoined figure. If the moon +is in opposition, the axis of the vortex will not pass through C, but +through C′, and QQ′ will be parallel to KK′. If the moon is in +conjunction, the axis will be still parallel to KK′, as represented by +the dotted line qq′. The correction, therefore, for displacement, is +equal to the arc KQ or Kq, and the correct position of the vortex on the +surface of the earth at a given time will be at the points Q or q and Q′ +or q′, considering the earth as a sphere. + +[Illustration: Fig. 12] + +In the spherical triangle APV, P is the pole of the earth, V the pole of +the vortex, A the point of the earth's surface pierced by the radius +vector of the moon, AQ is the corrected arc, and PV is the obliquity of +the vortex. Now, as the axis of the vortex is parallel to the pole V, +and the earth's centre, and the line MA also passes through the earth's +centre, consequently AQV will all lie in the same great circle, and as +PV is known, and PA is equal to the complement of the moon's declination +at the time, and the right, ascensions of A and V give the angle P, we +have two sides and the included angle to find the rest, PQ being the +complement of the latitude sought. + +We will now give an example of the application of these principles. + +_Example._[10] Required the latitude of the central vortex at the time +of its meridian passage in longitude 88° 50′ west, July 2d, 1853. + +CENTRAL VORTEX ASCENDING. + + Greenwich time of passage 2d. 3h. 1m. + Mean longitude of moon's node 78° 29′ + True " " 79 32 + Mean inclination of lunar orbit 5 9 + True " " 5 13 + Obliquity of ecliptic 23 27 32″ + Mean inclination of vortex 2 45 0 + +Then in the spherical triangle PEV, + + PE is equal 23° 27′ 32″ + EV " 7 58 0 + E " 100 28 0 + P " 18 5 7 + PV " 26 2 32 + +Calling P the polar angle and PV the obliquity of vortex. + +[Illustration: Fig. 13] + +To find the arc AR. + +By combining the two proportions already given, we have by logarithms: + + M.R.V. minor = 3256 Log. 3.512683 + M.S.D. of moon = 940″ " 2.973128 + P.S.D. of earth = 3950 A. C. 6.403403 + Radius 10.000000 + T.S.D. of moon 885″.5 A. C. 7.052811 + Log. Cosine arc AR = 28° 57′ 3″ 9.942025 + --------- + +As the only variable quantity in the above formula is the "True" +semi-diameter of the moon at the time, we may add the Constant logarithm +2.889214 to the arithmetical complement of the logarithm of the true +semi-diameter, and we have in two lines the log. cosine of the arc AR. + +We must now find the arc RK equal at a maximum to 2° 45′. The true +longitude of the moon's node being 79° 32′, and the moon's longitude, +per Nautical Almanac, being 58° 30′, the distance from the node is 21° +2′, therefore, the correction is + + -2° 45′ × sin 21° 2′ + -arc RK = --------------------- = -59′ 13″ + R + +To find the correction for displacement. + + True longitude of sun at date 100° 30′ + " of moon " 58 30 + Moon's distance from quadrature 48 0 + +As the moon is less than 90° from the sun this correction is also +negative, or + + -90′ × sin 48° + Arc Kq = --------------- = -1° 6′ 46″. + R + + Arc AR = 28° 57′ 3″ + RK = - 0° 39′ 13″ + Kq = - 1° 6′ 46″ + Sum = 26° 51′ 4″ = corrected arc AQ. + +We have now the necessary elements in the Nautical Almanac, which we +must reduce for the instant of the vortex passing the meridian in +Greenwich time. + + July 2d. + Meridian passage, local time, at 9h. 5m. A.M. + " in Greenwich time 2d. 3h. 1m. + Right ascension same time 56° 42′ 45″ + Declination north " 18 00 1 + Obliquity of the vortex " 26 2 32 + Polar angle " 18 5 7 + Arc AQ " 26 51 4 + +[Illustration: Fig. 14] + + PA = 17° 59′ 59″ } P = 128° 37′ 38″ + PV = 26 2 32 } + VA = 89 3 0 V = 47 59 44 + VQ = 62 11 56 A = 20 3 42 + PQ = 47 14 22 Q = 26 22 55 + Latitude of Q on the sphere = 42° 45′ 38″ + + +CORRECTION FOR PROTUBERANCE. + +We have hitherto considered the earth a perfect sphere with a diameter +of 7,900 miles. It is convenient to regard it thus, and afterwards make +the correction for protuberance. We will now indicate the process for +obtaining this correction by the aid of the following diagram. + +[Illustration: Fig. 15] + +Let B bisect the chord ZZ′. Then, by geometry, the angle FQY is equal to +the angle BTF, and the protuberance FY is equal the sine of that angle, +making QF radius. This angle, made by the axis of the vortex and the +surface of the sphere, is commonly between 30° and 40°, according as the +moon is near her apogee or perigee; and the correction will be greatest +when the angle is least, as at the apogee. At the equator, the whole +protuberance of the earth is about 13 miles. Multiply this by the cosine +of the angle and divide by the sine, and we shall get the value of the +arc QY for the equator. For the smallest angle, when the correction is a +maximum, this correction will be about 20′ of latitude at the equator; +for other latitudes it is diminished as the squares of the cosines of +the latitude. Then add this amount to the latitude EQ, equal the +latitude EY. This, however, is only correct when the axis of the vortex +is in the same plane as the axis of the earth; it is, therefore, subject +to a minus correction, which can be found by saying, as radius to cosine +of obliquity so is the correction to a fourth--the difference of these +corrections is the maximum minus correction, and needs reducing in the +ratio of radius to the cosine of the angle of the moon's distance from +the node; but as it can only amount to about 2′ at a maximum under the +most favorable circumstances, it is not necessary to notice it. The +correction previously noticed is on the supposition that the earth is +like a sphere having TF for radius; as it is a spheroid, we must correct +again. From the evolute, draw the line SF, and parallel to it, draw TW; +then EW is the latitude of the point F on the surface of the spheroid. +This second correction is also a plus correction, subject to the same +error as the first on account of the obliquity, its maximum value for an +angle of 30° is about 6′, and is greatest in latitude 45°; for other +latitudes, it is equal {6′ × sin(double the lat.)}/R. + +The three principal corrections for protuberance may be _estimated_ from +the following table, calculated for every 15° of latitude for an angle +of 30°, or when the correction is greatest. + + Latitude. 1st Corr. 2d Corr. 3d Corr. + 0 + 20′ + 0 - 2 + 15 + 19 + 3 - 1.5 + 30 + 15 + 5 - 1.5 + 45 + 10 + 6 - 1. + 60 + 5 + 5 - 1 + 70 + 1 + 3 - 0.5 + +We can now apply this correction to the latitude of the vortex just +found: + + Latitude on the sphere 42° 45′ 38″ n. + Correction for protuberance + 14 22 + ---------- + Correct latitude 43 00 00 + + +MILWAUKIE STORM, JULY 2. + +As this example was calculated about ten days before the actual date, we +have appended an extract from the Milwaukie papers, which is in the same +longitude as Ottawa, in which place the calculation was made. It is +needless to remark that the latitude of Milwaukie corresponds to the +calculated latitude of the centre of the vortex. It is not intended, +however, to convey the idea that the central line is always the most +subject to the greatest violence--a storm may have several centres or +nuclei of disturbance, which are frequently waning and reviving as the +storm progresses. Generally speaking, however, the greatest action is +developed along the line previously passed over by the axis of the +vortex. + + "SUMMIT, Waukesha Co., Wis., July 4, 1853. + + "Our town, on Saturday, the 2d, was visited by a terrible storm, + which will long be remembered by those who witnessed its effects and + suffered from its fury. It arose in the south-west, and came + scowling in blackness, sufficient to indicate its anger, for the + space of eighty or a hundred rods in _width_, covering our usually + quiet village; and for nearly half an hour's duration, the rain fell + in torrents, the heavens blazed with the lightning's flashes, trees + fell and were uprooted by the fury of the blast, fragments of gates + and of buildings, shingles, roof-boards, rafters, circled through + the air, the playthings of the wind--and buildings themselves were + moved entire from their foundations, and deposited at different + distances from their original positions. A barn, fifty-five feet + square on the ground, owned by Mr. B. R. Hinckley, is moved from its + position some ten feet to the eastward; and a house, some fifteen by + eighteen feet on the ground, owned by the same person, fronting the + east, was driven by the wind to the opposite side of the street, and + now fronts nearly west; and what is most strange, is that the grass, + in the route the house must have passed over, stands straight as + usual, and gives no evidence that the building was pushed along on + the ground. A lady running from a house unroofed by the storm, took + an aërial flight over two fences, and finally caught against a tree, + which arrested her passage for a moment only, when, giving way, she + renewed her journey for a few rods, and was set down unhurt in + Mr. O. Reed's wheat field, where, clinging to the growing grain, she + remained till the gale went by."[11] + +The weather at this place is briefly recorded in the accompanying +abstract from the journal, as well as in an extract from a note to +Professor Henry, of the Smithsonian Institution, from a friend of the +authors, who has long occupied a high official station in Illinois. But +such coincidences are of no value in deciding on the merits of such a +theory, it must be tried before the tribunal of the world, and applied +to phenomena in other countries with success, before its merits can be +fully appreciated. The accompanying record, therefore, is only given to +show how these vortices render themselves apparent, and what ought to be +observed, and also to exhibit the order of their recurrence and their +positions at a given time. + +_Extract of a note addressed to the Secretary of the Smithsonian +Institution, by Hon. John Dean Caton, on this subject._ + + "As a striking instance of the remarkable coincidences confirmatory + of these calculations, I will state, that on Friday, the first of + July last, this gentleman[12] stated that on the next day a storm + would pass north of us, being central a little south of Milwaukie, + and that he thought, from the state of the atmosphere, the storm + would be severe, and that its greatest violence would be felt on the + afternoon or night of the next day. At this time the weather was + fine, without any indications of a storm, so far as I could judge. + At noon on the following day he pointed out the indications of a + storm at the north and north-west, consisting of a dark, hazy belt + in that direction, extending up a few degrees above the horizon, + although so indistinct as to have escaped my observation. At five + o'clock a violent storm visited us, which lasted half an hour, + although a clear sky was visible at the south the whole time. On + Monday morning I learned, from the telegraph office at Chicago, that + early on Saturday afternoon communication with Milwaukie had been + interrupted by atmospheric electricity, and that the line had been + broken by a storm." + + +NEW YORK STORM. + +After this was written, the author discovered that the vortex was +equally violent the day before at New York, July 1st, 1853. An account +of this storm follows. The calculation has not been made, but it is easy +to perceive that the latitude of the vortex, on July 1st, must be very +nearly that of New York--being in latitude 43° next day and ascending. + +"At a meeting of the American Association, convened at Cleveland, +Professor Loomis presented a long notice of the terrible hail storm in +New York on the 1st of July. He traced its course, and minutely examined +all the phenomena relating to it, from a mile and a half south-east of +Paterson, N.J., to the east side of Long Island, where it appeared +nearly to have spent its force. It passed over the village of Aqueenac, +striking the Island of New York in the vicinity of the Crystal Palace. +It was not much more than half a mile wide. The size of the hail-stones +was almost incredibly large, many of them being as large as a hen's egg, +and the Professor saw several which he thought as large as his fist. +Some of them weighed nearly half a pound. The principal facts in +relation to this storm were published at the time, and need not be +repeated. The discussions arising among the members as to the origin and +the size of these hail-stones, and the phenomena of the storm, were +exceedingly interesting. They were participated in by Professors Heustus +and Hosford, of Cambridge University, Professor Loomis, and Professors +Bache and Redfield. The latter two gentlemen differ somewhat, we should +suppose radically, in their meteorological theories, and had some very +sharp but very pleasant "shooting" between them."[13] + + +CENTRAL VORTEX DESCENDING. + +We will now make the calculation for the central vortex _descending_, +for longitude 88° 50′ west, August 7, 1853,--putting down the necessary +elements for the time of the meridian passage in order: + + Meridian passage in local time at 2h. 25m. P.M. + " " in Greenwich time 7d. 8h. 18m. + Mass of the moon 1/12.3 M. R. V. minor 3,256 miles. + Obliquity of the vortex, same time 26° 5′ 0″ + Polar angle of " " 17 41 47 + True longitude of moon's node " 78 42 0 + " inclination of orbit " 5 5 0 + " longitude of the sun " 135 20 0 + Moon's longitude " 169 44 0 + " distance from node " 91 2 0 + " distance from quadrature " 55 36 0 + " true semi-diameter " 943 + " right ascension " 172 30 0 + " declination north " 8 42 20 + Constant logarithm 2.889214 + Arith. comp. of log. of 943 7.025488 + Log. cos. arc. AR 9.914702 = 34° 44′ 48″ + 1st. correction, + 2 45 0 + 2d. correction, - 1 14 15 + -------------- + Corrected arc AQ = 36 15 33 + PA = 81° 17′ 40″ + PV = 26 5 0 + P = 115 11 47 + V = 63 34 26 + A = 23 28 24 + AV = 92 48 39 + Q = 31 32 18 + Complement of lat. = PQ = 48° 49′ 41″ + The latitude is therefore for + the earth, as a sphere 41 10 18 + Correction for protuberance + 0 16 0 + ------------ + True latitude of centre 41 26 18 north. + ------------ + Latitude of Ottowa 41 20 0 " + ------------ + Vortex passed 6 18 north of Ottowa. + +[Illustration: Fig. 16] + +As this was nearly a central passage, and as the influence was less +extensive than usual, on account of great atmospheric pressure with a +low dew point, the central disturbance could the more readily be +located, and was certainly to the north, and but a few miles. The +following is from the record of the weather: + +_August_ 6th. Very fine and clear all day; wind from S.-W.; a light +breeze; 8 P.M. frequent flashes of lightning in the northern sky; +10 P.M. a _low bank of dense clouds in north_, fringed with cirri, +visible during the flash of the lightning; 12 P.M. same continues. + +7th. Very line and clear morning; wind S.-W. moderate; noon, clouds +accumulating in the northern half of the sky; wind fresher S.-W.; 3 P.M. +a clap of thunder overhead, and black cumuli in west, north, and east; +4 P.M. much thunder, and scattered showers; six miles west rained very +heavily; 6 P.M. the heavy clouds passing over to the south; 10 P.M. +clear again in north. + +_August_ 8th. Clear all day; wind the same (S.-W.); a hazy bank visible +all along on _southern horizon_. + +This was not a storm, in the ordinary acceptation of the term; but the +same cause, under other circumstances, would have produced one; and let +it be borne in mind, that although the moon is the chief disturbing +cause, and the passages of the vortices are the periods of greatest +commotion in both settled and unsettled weather, still the sun is +powerful in predisposing the circumstances, whether favorable or +unfavorable; and as there is no periodic connection between the passage +of a vortex and the concurrence of the great atmospheric waves, it will, +of course, happen only occasionally that all the circumstances will +conspire to make a storm. There are also other modifying causes, to +which we have not yet alluded, which influence the storms at different +seasons of the year,--exaggerating their activity in some latitudes, and +diminishing it in other latitudes. In this latitude, the months of May, +June, and July are marked by more energetic action than August, +September, and October. The activity of one vortex also, in one place, +seems to modify the activity of another vortex in another place. But the +great question to decide is: Do these vortices really exist? Do they +follow each other in the _order_ indicated by the theory? Do they pass +from south to north, and from north to south, at the _times_ indicated +by the theory? Do they obey, in their monthly revolutions, a +mathematical law connecting them with the motions of the moon? We answer +emphatically, Yes! And the non-discovery of these facts, is one of the +most humiliating features of the present age. + + +OTTOWA STORM, DECEMBER 22, 1852. + +To show that the same calculations are applicable for other times, we +will make the calculation for the _centre ascending_, for the 22d +December, 1852, taking the following elements: + + Moon's mer. passage, Dec. 22d 15h. 16m. G. time. + " right ascension, same time 51° 57′ + " declination north 15 42 + " true S. Diameter 886.6″ + " distance from node 37 + " " " quadrature 52 + -------- + Which gives the arc AR 29 5 + 1st correction -1 51 + 2d +1 11 + -------- + Corrected arc AQ 28 25 + -------- + +And the latitude at the time of the meridian passage = 42° north, or +about forty miles north of Ottawa. + +Abstract from the record:-- + +[14]_Dec._ 21st, 1852. Wind N.-E., fine +weather. + +_Dec._ 22d. Thick, hazy morning, wind east, much lighter in S.-E. than +in N.-W.; 8 A.M., a clear arch in S.-E. getting more to south; noon, +very black in W. N.-W.; above, a broken layer of cir. cumulus, the sun +visible sometimes through the waves; wind round to S.-E., and fresher; +getting thicker all day; 10 P.M., wind south, strong; thunder, +lightning, and heavy rain all night, with strong squalls from south. + +_Dec._ 23d. Wind S.-W., moderate, drizzly day; 10 P.M., wind west, and +getting clearer. + +The next day the vortex passed the latitude of Montreal (the moon being +on the meridian about 10 P.M.) + + +MAGNETIC STORM, DECEMBER 23, 1852. + +In the July number of Vol. XVI. of Silliman's Journal, we find certain +notices of the weather in 1852, by Charles Smallwood, of St. Martins, +nine miles east of Montreal. He mentions "two remarkable electrical +storms (which) occurred on the 23d and 31st of December, (in which) +sparks 5/40 of an inch were constantly passing from the conductor to the +discharger for several hours each day." At 10 P.M. (23d) the vortex +passed over Montreal, and again descending on the 31st North, and was +visible at Ottowa on the morning of the 1st of January, with southerly +wind setting towards it. On the 29th of December, Mr. Smallwood records +"a low auroral arch, sky clear." On the 20th, the vortex was 5° to the +northward of Montreal, and the aurora was consequently low--the +brightest auroras being when the vortex is immediately north without +storm, or one day to the northward, although we have seen it _very low_ +when the vortex was three days to the north, and no other vortex near. + + +LIVERPOOL STORM. + +On the night of the 24th of December, the same central vortex ascending +passed between Cape Clear and Liverpool. + +On the 25th, at midnight, the vortex passed to the north of Liverpool: +its northerly progress being very slow, being confined for three days +between the parallel of Liverpool and its extreme northern limit in +latitude about 57°. The accompanying account of the weather will show +the result of a long-continued disturbance near the same latitude: + +The Baltic, three days out from Liverpool, encountered the vortex on the +night of the 23d. On the morning of the 25th, very early, the gale +commenced at Liverpool, and did much damage. On the 26th, the vortex +attained its northern limit; but we have not been able to procure any +account of its effects to the northward of Liverpool, although there can +be but little doubt that it was violent on the coast of Scotland on the +26th; for the next day (27th) the vortex having made the turn, was near +the latitude of Liverpool, and caused a _tremendous_ storm, thus showing +a continued state of activity for several days, or a peculiarly +favorable local atmosphere in those parts. It is very probable, also, +that there was a conjunction of the central and inner vortex on the +27th. The inner vortex precedes the central in passing latitude 41°; but +as the mean radius of its orbit is less than that of the central, it +attains to a higher latitude, and has, consequently, to cross the path +of the central, in order again to precede it descending in latitude 41°. +As a very trifling change in the elements of the problem will cause +great changes in the positions of the vortices on the surface of the +earth, it cannot now be asserted that such a conjunction did positively +occur at that time; but, it maybe suspected, that a double disturbance +would produce a greater commotion, or, in other words, a more violent, +storm. + +It is on this account, combined with other auxiliary causes, that the +vicinity of Cape Horn is so proverbially stormy, as well as for the low +standard of the barometer in that latitude, it is the stationary point +of the vortices in ordinary positions of the nodes and perigee of the +moon. We have already alluded to the fact, that none of the vortices +scarcely ever pass much beyond latitude 80°, and then only under +favorable circumstances, so that we ought to infer, that gales in high +latitudes should set from the poles towards the storms in lower +latitudes. This is, no doubt, the fact, but, nevertheless, a hard +southerly blow _may possibly_ occur in high northern latitudes, if a +storm should be raging very violently in a lower latitude on the +opposite side of the pole, the distance across the circle of 80° being +only about 1,400 miles. As the different vortices have a different limit +in latitude every year, the determination of this turning point is +obviously of great practical utility, as the fact may yet be connected +with other phenomena, so as to give us the probable character of the +polar ice at any assigned time. On this point we have more to say. + + +PASSAGES OF ALL THE VORTICES. + +Our remarks have hitherto been confined to the central vortex. We shall +now show from the record, that the other vortices are as effective in +deranging the equilibrium of our atmosphere. In the following table we +have given the passages of the different vortices, which will serve as +their true positions within moderate limits, to calculate from, for all +future time. + + +PASSAGES OF THE CENTRAL AND LATERAL VORTICES, OBSERVED IN JUNE AND JULY, +1853, IN LATITUDE 41° 20′ NORTH. + +I signifying Inner; O, outer; C, central; A, ascending; D, descending. + + ____________________________________________________________________ + | | | | | | | + | Order.|Vortex.| Date. | Meridian |Passage.| Calculated latitude | + | | | | Passage. | | and Remarks. | + |_______|_______|_________|__________|________|______________________| + | | | | | | | + | 1st | I. A. | June 22 | 7 A.M. | south | Centre. About 40°. | + | | | 23 | 8 A.M. | north | Warsaw. Storm. | + | 2d | O. D. | 27 | 0 noon | north | | + | | | 28 | 1 A.M. | south | See record. | + | 3d | C. A. | July 1 | 9 A.M. | south | | + | | | 2 | 10 A.M. | north | Lat. 43°. Storm. | + | 4th | I. D. | 7 | 5 P.M. | north | | + | | | 8 | 6 P.M. | south | Lat. New York. Storm.| + | 5th | C. D. | 12 | 5 P.M. | north | Aurora. | + | | | 13 | 6 P.M. | south | Stormy, very. | + | 6th | O. A. | 14 | 10 A.M. | south | | + | | | 15 | 11 A.M. | north | See Record. | + |_______|_______|_________|__________|________|______________________| + +The intervals between the ascending and descending passages of the +different vortices, are + + Between I. A. and I. D. from 11 to 14 days. + " O. A. " O. D. " 10 " 12 " + " C. A. " C. D. " 9 " 11 " + +and the effect is greatest when the vortex comes to the meridian before +the sun, and least when after the sun; in which case the full effect is +not developed, sometimes until the following day. + +A brief abstract from a journal of the weather for one sidereal period +of the moon, in 1853. + +_June_ 21st. Fine clear morning (S. fresh)[15]: noon very warm 88°; +4 P.M. plumous _cirri in south_; ends clear. + +22d. Hazy morning (S. very fresh) arch of cirrus in west; 2 P.M., black +in W.-N.-W.; 3 P.M., overcast and rainy; 4 P.M., a heavy gust from +south; 4.30 P.M., blowing furiously (S. by W.); 5 P.M., tremendous +squall, uprooting trees and scattering chimneys; 6 P.M., more moderate +(W.) + +23d. Clearing up (N.-W.); 8 A.M., quite clear; 11 A.M., bands of mottled +cirri pointing N.-E. and S.-W.; ends cold (W. N.-W.); the cirri seem to +rotate from left to right, or with the sun. + +24th. Fine clear cool day, begins and ends (N.-W.) + +25th. Clear morning (N.-W, light); 2 P.M. (E.) calm; tufts of tangled +cirri in north intermixed with radiating streaks, all passing eastward; +ends clear. + +26th. Hazy morning (S.-E) cloudy; noon, a heavy windy looking bank in +north (S. fresh), with dense cirrus fringe above on its upper edge; +clear in S. + +27th. Clear, warm, (W.); bank in north; noon bank covered all the +northern sky, and fresh breeze; 10 P.M., a few flashes to the northward. + +28th. Uniform dense cirro-stratus, (S. fresh); noon showers all round; +2 P.M., a heavy squall of wind, with thunder and rain (S.-W. to N.-W.); +8 P.M., a line of heavy cumuli in south; 8.30 P.M., a very bright and +high cumulus in S.-W., protruding through a layer of dark stratus; +8.50 P.M., the cloud bearing E. by S., with three rays of electric +light.[16] + +[Illustration: Fig. 17] + +_June_ 29th. A stationary stratus over all, (S.-W. light); clear at +night, but distant lightning in S. + +30th. Stratus clouds (N.-E. almost calm); 8 A.M., raining gently; +3 P.M., stratus passing off to S; 8 P.M., clear, pleasant. + +_July_ 1st. Fine and clear; 8 A.M., cirrus in sheets, curls, wisps, and +gauzy wreathes, with patches beneath of darker shade, all nearly +motionless; close and warm (N.-E.); a long, low bank of haze in S., with +one large cumulus in S.-W., but very distant. + +_July_ 2d. At 5 A.M., overcast generally with hazy clouds and fog of +prismatic shades, chiefly greenish-yellow; 7 A.M., (S.-S.-E. +freshening,) thick in W; 8 A.M., (S. fresh) much cirrus, thick and +gloomy; 9 A.M., a clap of thunder, and clouds hurrying to N.; a reddish +haze all around; at noon the margin of a line of yellowish-red cumuli +just visible above a gloomy-looking bank of haze in N.-N.-W., (S. very +fresh;) warm, 86°; more cumuli in N.-W.--the whole line of cumuli N. are +separated from the clouds south by a clear space. These clouds are borne +rapidly past the zenith, but never get into the clear space--they seem +to melt or to be turned off N.-E. The cumuli in N. and N.-W., slowly +spreading E. and S.; 3 P.M., the bank hidden by small cumuli; 4 P.M., +very thick in north, magnificent cumuli visible sometimes through the +breaks, and beyond them a dark, watery back-ground, (S. strong); +4.30 P.M., wind round to N.-W. in a severe squall; 5 P.M., heavy rain, +with thunder, &c.--all this time there is a bright sky in the south +visible through the rain 15° high; 7 P.M., clearing, (S.-W. mod.) + +_July_ 3d. Very fine and clear, (N.-W.); noon, a line of large cumuli in +N., and dark lines of stratus below, the cumuli moving eastward; 6 P.M., +their altitude 2° 40′. Velocity 1° per minute; 9 P.M., much lightning in +the bank north.[17] + +_July_ 4th. 6 A.M., a line of small cumulo-stratus, extending east and +west, with a clear horizon north and south 10° high. This band[18] seems +to have been thrown off by the central yesterday, as it moves slowly +south, preserving its parallelism, although the clouds composing it move +eastward. Fine and cool all day--(N.-W. mod.)--Lightning in N. + +_July_ 5th. Cloudy (N. almost calm), thick in E., clear in W.; same all +day. + +6th. Fine and clear (E. light); small cumuli at noon; clear night. + +7th. Warm (S. E. light); cirrus bank N. W.; noon (S.) thickening in N.; +6 P.M., hazy but fine; 8 P.M., lightning in N.; 10 P.M., the lightning +shows a heavy line of cumuli along the northern horizon; calm and very +dark and incessant lightning in N. + +8th. Last night after midnight commencing raining, slowly and steadily, +but leaving a line of lighter sky south; much lightning all night, but +little thunder. + +8th. 6 A.M. Very low scud (500 feet high) driving south, still calm +below, (N. light); 10 A.M., clearing a little; a bank north with cirrus +spreading south; same all day; 9 P.M., wind freshening (N. stormy); +heavy cumuli visible in S.; 10.30 P.M., quite clear, but a dense watery +haze obscuring the stars; 12 P.M., again overcast: much lightning in S. +and N.-W. + +9th. Last night (2 A.M. of 9th) squall from N.-W. very black; 4 A.M., +still raining and blowing hard, the sky a perfect blaze, but very few +flashes reach the ground; 7 A.M., raining hard; 8 A.M. (N.-W. strong); a +constant roll of thunder; noon (N.-E.); 2 P.M. (N.); 4 P.M. clearing; +8 P.M., a line of heavy cumuli in S., but clear in N-W., N., and +N.-E.[19] + + +NEW YORK STORM, JULY 8, 1853. + +"At 5 o'clock Friday afternoon, a terrible storm of rain, hail, and +lightning, rose suddenly from the north-west, and passed over the upper +part of the city and neighborhood. It was quite moderate in the lower +part of the town, and probably scarcely felt on Staten Island. The whole +affair lasted not more than a quarter of an hour, yet the results were +most disastrous, as will be seen by the following accounts from our +reporters: + +"Happening to be in the neighborhood of the Palace about 5 o'clock +Friday evening, we sought shelter under its ample roof from an impending +thunder storm, of very threatening appearance, rapidly approaching from +the west. We had scarcely passed the northern entrance, and reached the +gallery by the nearest flight of steps, when the torrent--it was not +rain, but an avalanche of water--struck the building; the gutters were +filled on the windward side in a moment, and poured over an almost +unbroken sheet of water, which was driven through the Venetian blind +ventilators, into and half way across the north-west gallery, and also +through the upper ventilators, falling upon the main floor of the north +transept. Workmen hastened to close the blinds, but that did not prevent +the deluge. The tinning of the dome being unfinished, the water, of +course, came down in showers all over the centre. Many workmen were +engaged on the dome when the shower struck it; several of them, in their +haste to escape such dangerous proximity to the terrific lightning, came +down single ropes, hand over hand. Large number of workmen were engaged +all over the exterior, and such a scampering will rarely be witnessed +but once in a lifetime. It was found impossible to close a north window, +used for ingress and egress of workmen upon the rod, and the water came +in, in almost solid columns. For a time the water was nearly two inches +deep on the gallery floor, and poured down the stairs in miniature +cascades. + +"A great number of boxes, bales, and packages of goods lay upon the main +floor, among which the water poured down from the edge of the gallery +floor in destructive quantities; Fortunately but few goods were opened, +and were upon the tables, or the damage would have been irreparable. As +it is, we fear some of the goods are injured. In the height of the +storm, the centre portion of the fanlight over the western entrance +burst in, and several single lights were broken, by staging or +otherwise. + +"About ten minutes after the storm burst, the most terrific hailstorm we +ever saw began to rattle, like discharges of musketry, upon the tin roof +and glass sides. Some of the masses of ice were as large as hen's eggs. +There were probably a thousand excited workmen in the building, and a +good many exhibitors and visitors, among whom there were some twenty +ladies, some of whom appeared a good deal alarmed at the awful din. A +portion of the frame-work of the addition next to 42d street, went down +with a terrible crash, and a part of the brick wall of the engine-house +on the opposite side of the street, was blown over, crushing two or +three shanties, fortunately without any other injury than driving the +occupants out into the storm. But an awful scene occurred on the north +side of 43d street, directly opposite the Latting Tower. Here two large +unfinished frame buildings were blown, or rather, we should judge from +appearances, were crushed down into a mass of ruins, such as may be +imagined by supposing a great weight had fallen, with a circular, +grinding motion, upon the first fine fabrics. One of them was partly +sided, and had the rafters up, but no roof; the other was sided and +rooted with tin, and was being plastered. We were told it was three +stories high, 50 by 98 feet. + +"We reached the ruins among the first, after the burst of the storm +subsided a little. The scene was such as we pray God we may never +witness again. A small portion of the roof and upper part of the front +of the building stood or rather partly hung over the side-walk. The +chamber and lower floor of the front rooms lay flat together. The sides +were standing. In the rear all were down. In this building, besides the +workmen, there were numerous laborers who had taken shelter under its +roof when the storm drove them hurriedly from their work. How so many +persons escaped death is truly wonderful. It can only be accounted for +by supposing that they had a moment's warning, and rushed into the +street. The first alarm was from the tearing off a portion of the tin +roof, which was carried high over another building, and fell in the +street. A horse and cart barely escaped being buried under this. It +seems the frame of the other building came down with a deafening crash +at the same time, confusing instead of warning those in danger. At any +rate, before they could escape, they were buried in a mass of timber, +and three of them instantly killed, and four or five dangerously +wounded; and others slightly bruised and badly frightened. Several would +have perished but for timely assistance to extricate them. In this they +were greatly assisted by Jacob Steinant, boss carpenter of the Tower, +who with his men rushed to the rescue, notwithstanding the pouring down +torrents. + +"In Williamsburgh, the storm lasted about fifteen minutes, doing an +incalculable amount of damage to dwellings, foliage, &c. Hailstones came +down in sizes from that of a hickory-nut to a large apple, some with +such force as to drive them through the cloth awnings. + +"The storm passed over Brooklyn lightly, in comparison with the effects +across the Williamsburgh line. On Flushing avenue, beyond the Naval +Hospital, a number of trees were uprooted, and the window-panes of the +houses shattered. On the corner of Fulton and Portland avenues, three +buildings were unroofed, and the walls of the houses were sprung to the +foundation. + +"On Spencer street, a new frame building was levelled with the ground. +Along Myrtle, Classon, and other streets and avenues of East Brooklyn, +many of the shade trees were uprooted, and the windows smashed. In Jay +street, two trees were struck by lightning, but no other damage ensued. + +"Several schooners at the foot of Jay street were forced from their +moorings, but were soon after secured. A small frame house in Spencer +street, just put under roof, was prostrated to the ground. + +"We understand that a large barn filled with hay, situated on the road +between Bushwick and Flushing, was struck by lightning and destroyed +with its contents, embracing several head of live stock."[20] + +_July_ 10th, 3 A.M. Overcast and much lightning in south (N. mod.); +7 A.M., clear except in south; 6 P.M. (E.); 10 P.M., lightning south; +11 P.M., auroral rays long but faint, converging to a point between +Epsilon Virginis and Denebola, in west; low down in west thick with +haze; on the north the rays converged to a point still lower; lightning +still visible in south. This is an aurora in the west. + +11th. Fine clear morning (N.-E.); same all day; no lightning visible +to-night, but a bank of clouds low down in south, 2° high, and streaks +of dark stratus below the upper margin. + +12th. Fine and clear (N.-E.); noon, a well defined arch in S.-W., rising +slowly; the bank yellowish, with prismatic shades of greenish yellow on +its borders. This is the O. A. At 6 P.M., the bank spreading to the +northward. At 9 P.M., thick bank of haze in north, with bright auroral +margin; one heavy pyramid of light passed through Cassiopæa, travelling +_westward_ 1½° per minute. This moves to the other side of the pole, +but not more inclined towards it than is due to prospective, if the +shaft is very long; 11.10 P.M., saw a mass of light more diffuse due +east, reaching to _Markab_, then on the prime vertical. It appears +evident this is seen in profile, as it inclines downwards at an angle of +10° or 12° from the perpendicular. It does not seem very distant. +12 P.M., the aurora still bright, but the brightest part is now west of +the pole, before it was east. + +13th, 6 A.M. Clear, east and north; bank of cirrus in N.-W., _i.e._, +from N.-N.-E. to W. by S.; irregular branches of cirrus clouds, reaching +almost to south-eastern horizon; wind changed (S.-E. fresh); 8 A.M., the +sky a perfect picture; heavy regular shafts of dense cirrus radiating +all around, and diverging from a thick nucleus in north-west, the spaces +between being of clear blue sky. The shafts are rotating from north to +south, the nucleus advancing eastward. + +Appearance of the central vortex descending at 8 A.M., July 13th, 1853: + +In Fig. 18, the circle represents the whole sky from the zenith to the +horizon, yet it can convey but a very faint idea of the regularity and +vividness of this display. The reflected image of the sky was received +from a vessel of turbid water, which will be found better than a mirror, +when the wind will permit. + +[Illustration: Fig. 18] + +At noon (same day) getting thicker (S.-E. very fresh); 6 P.M., moon on +meridian, a prismatic gloom in south, and very thick stratus of all +shades; 9 P.M., very gloomy; wind stronger (S.-E.): 10 P.M., very black +in south, and overcast generally. + +14th. Last night about 12 P.M. commenced raining; 3 A.M., rained +steadily; 7 A.M., same weather; 8.20 A.M., a line of low storm-cloud, or +seud, showing very sharp and white on the dark back ground all along the +southern sky. This line continues until noon about 10° at the highest, +showing the northern boundary of the storm to the southward; 8 P.M., +same bank visible, although in rapid motion eastward; same time clear +overhead, with cirrus fringe pointing north from the bank; much +lightning in south (W. fresh); so ends. + +15th. Last night a black squall from N.-W. passed south without rain; at +3 A.M. clear above, but very black in south (calm below all the time); +9 A.M., the bank in south again throwing off rays of cirri in a +well-defined arch, whose vortex is south: these pass east, but continue +to form and preserve their linear direction to the north; no lightning +in south to-night. + +16th. Clear all day, without a stain, and calm. + +17th. Fine and clear (N.-E. light); 6 P.M., calm. + +18th. Fair and cloudy (N.-E. light); 6 P.M., calm. + +19th. Fine and clear (N. fresh); I. V. visible in S.-W. + +20th. 8 A.M., bank in N.-W. with beautiful cirrus radiations; 10 A.M., +getting thick with dense plates of cream-colored cirrus visible through +the breaks; gloomy looking all day (N.-E. light).[21] + +Appearance of the Inner Vortex at 8 A.M., July 20th, 1853, including the +whole sky. (See Fig. 19.) + +[Illustration: Fig. 19] + +This was a different passage of the Inner Vortex ascending as compared +with the same 28 days before. At that date (June 22) it did great damage +in the central parts of Illinois. Still this last passage was very +palpable--the clouds were very irregularly assorted--plates of cirrus +above and beneath cumulus--various kinds of cirrus clouds, and that +peculiar prismatic haze which is a common sign of the passage of a +vortex. The appearance depicted above is a very common, although a very +evanescent appearance. When the sky appears of a clear blue through the +cirri, there will be generally fresh gales without any great electrical +derangement; but if the clear spaces are hazy, gradually thickening +towards the nucleus, a storm may be expected. Any one who wishes to +understand the indications of the clouds, must watch them closely for +many years, before he can place much reliance upon them. But we shall +again advert to this point. + +We have now passed through one sidereal period of the moon. We might +continue the record, but it would be tedious. The passages of these +vortices vary in violence at different times, as we might expect; but +they never cease to circulate, and never will as long as the moon +remains a satellite to the earth; and if we take the passage of any of +these vortices, and add thereto the time of one sidereal period of the +moon, we get approximately the time of the next passage. When the +elements of the lunar orbit tend to accelerate the passages, they may +come in 26 days; and when to retard, in 28 days; and these are about the +limits of the theory. + +Having begun and ended this record of the weather with the passage of +the Inner vortex ascending, it may not be amiss to notice one more, (the +August passage,) as it offers a peculiarity not often so distinctly +marked. We have alluded to the greater force of the storms when the +passage of the vortex corresponds to the passage of the line of low +barometer or the depression point of a great atmospheric wave, which is +also due to the action of the ether. In consequence of these waves +passing from west to east, the storm will only be violent when formed a +little to the westward. If the storm forms to the eastward, we neither +see it nor feel it, as it requires time to develop its strength, and +always in this latitude travels eastward; so that storms may generally +be said to come from the west, although the exciting cause travels from +east to west. In the case now alluded to, the weather indicated a high +barometer, and the storm formed immediately to the eastward, even +showing a distinct circular outline. We subjoin a description. + +_August_ 15th. Clear morning (N.-E.), a bank of cumuli in south: noon +quite cloudy in S. and clear in north. (N.-E.) + +16th. Clear morning (N.-E.); 3 P.M., getting very black in E. and S.-E., +very _clear_ to the _westward_; 4 P.M., much thunder and lightning in +east, and evidently raining hard; 5 P.M., a violent squall from _east_ +for 10 minutes; tore up several trees; 6 P.M., the storm passing +eastward, clear in west all this time; 6.30 P.M., the storm forming a +regular arch, the vertex being in _S.-E._; the arch of hazy cirrus and +heavy cumulus much lower in S.-E., wind still moderate from east; +10 P.M., clear all around, but lightning in S.-E. and E. + +17th. Fine clear morning (W.); noon, scattered cumuli in north; 6 P.M., +a beautifully regular arch of dense cumuli and cirrus margin in _N.-E._, +with a constant glimmer of lightning; 7 P.M., very clear to the west, +and north-west, and south; along the northern horizon a line of high +peaked cumuli terminating in N.-N.-W.; a continued roll of distant +thunder in the circular bank in N.-E., and not a moment's cessation to +the lightning; the electric excitement advancing westward along the +lines of cumuli; the cirrus haze also rising and passing towards S.-W.; +8 P.M., the sky alive with lightning, the cirrus now reaches the zenith; +no streaks of lightning coming to the earth; they seem to radiate from +the heaviest mass of cumuli, and spread slowly (sufficiently so to +follow them) in innumerable fibres over the cloudy cirrus portion of the +sky; every flash seems to originate in the same cloud; 8.30 P.M., one +branching flash covered the whole north-eastern half of the sky, no +leafless tree of the forest could show so many branches; 9.30 P.M., all +passed to S.-W. without rain, leaving behind a large cumulus, as if it +lagged behind. From this cumulus a straight line of lightning shot up +10° above the cloud into a perfectly clear sky, and terminated abruptly +without branching. + +We have been thus particular in giving these details, as this was a +clear case confirming the principles advanced, that the vortices do not +form a continuous line of disturbance, in their daily passage around the +earth. It shows also that the barometer, in connection with these +principles, will be a far more useful instrument than it has yet proved +itself, for practical service as an indicator of the weather. + + +FOOTNOTES: + +[10] For convenience to those wishing to verify the calculation of these +triangles, we have put down each side and angle as found. Also, as an +aid to the navigator. + +[11] Daily Wisconsin, July 7. + +[12] The author. + +[13] Chicago Democrat. + +[14] This was also calculated before the event. + +[15] The letters in a parenthesis signify the direction of the wind. + +[16] Giving this cloud the average velocity of thirty miles per hour, +its altitude was determined by the sextant at twelve miles, and we think +under-estimated. While measuring, the author's attention was drawn to +the fact, that although it appeared equally dense above and below, yet +its middle part was the brightest, and as there was only a faint glimmer +of twilight in the N.-W., he concluded that the cloud was self-luminous; +for when the smallest stars were visible, it glowed about as bright as +the milky-way in Sagittarius. Occasionally the whole cloud was lit up +internally by the lightning, and about this time it sent off three rays: +one horizontally, westward, which was the faintest; one about N.-W., +towards Jupiter, and the brightest of the three; and another towards the +north. These were not cirrus streaks, but veritable streams of electric +matter, and had a very decided rotation from left to right, and +continued visible about twenty minutes, as represented above. + +[17] This day the central vortex passed in about latitude 47° N.--the +southern margin cannot be nearer than 250 miles, throwing off the 40′ +for the horizontal refraction, would give eight miles of altitude above +a tangential plane. Then another seven miles, for curvature, will give +an altitude of fifteen miles for the cumuli. The height of these +thunder-clouds has been much under-estimated. They seem to rise in +unbroken folds to a height of ten and twelve miles frequently; from the +data afforded by the theory, we believe they will be found much higher +sometimes--even as much as sixteen miles. + +[18] These parallel bands, and bands lying east and west, are frequent +in fine weather between two vortices. Sailors consider them a sign of +settled weather. After dark there was frequently seen along the northern +horizon flashes of lightning in a perfectly clear sky. But they were +both faint and low, not reaching more than 4° or 5° above the horizon. +After sunset there were very distinct rays proceeding from the sun, but +they were shorter than on the evening of the 3d. These are caused by the +tops of the great cumuli of the storm, when sunk below the horizon, +intercepting the sun's rays, which still shine on the upper atmosphere. +The gradation was very marked, and accorded with the different distances +of the central vortex on the 3d and 4th--although, on the 4th, the +nearest distance must have been over four hundred miles to the southern +boundary of the storm. + +[19] It is worthy of notice here, that New York, which only differs by +about 40 miles of latitude and 800 in longitude, had the storm earlier, +near the time of the passage, as appears by the appended account of it. +This proves, that a storm affects a particular latitude simultaneously, +or approximately so. If this had to travel eastward to reach New York, +it would have been the 10th instead of the 8th. The principal trouble +was, however, in the early part of the evening of the 8th, to the south +of Ottawa, where the strong wind was drawn in from the northward. If a +vortex passes from north to south, leaving the observer between the +passages, there must, nearly always, be a winding up squall from the +north to clear away the vapory atmosphere. + +[20] From the _New York Tribune_, July 9, 1853. + +[21] These pages are now in the compositors' hands, (Nov. 21st,) and up +to the last moment the Author has observed carefully in New York the +passages of these vortices. October 24th, in the inner vortex descending +produced a violent storm on the coast, and much damage ensued. November +7th, the same vortex ascending was also severe. And on November 13th, +early, the passage of the central vortex ascending, caused a flood in +Connecticut of a very disastrous nature. Would it not pay the insurance +offices to patronize such investigations in view of such palpable facts +as these? + + + + +SECTION THIRD. + + +OBJECTIONS TO LUNAR INFLUENCE. + +We have now presented a theory of the weather, which accounts for many +prominent phenomena, a few of which we shall enumerate. It is an +observed fact, that in all great storms electrical action is more or +less violent, and that without this element it seems impossible to +explain the velocity of the wind in the tornado, its limited track, and +the formation of large masses of ice or hail in the upper regions of the +atmosphere. It is also an observed fact, that the barometer is in +continued motion, which can only be legitimately referred to a change in +the weight of the atmospheric column. This we have explained as due to +atmospheric waves, caused by the greater velocity of rotation of the +external ether, as well as to the action of the three great vortices. +These causes, however, only partially produce the effect--the greater +portion of the daily oscillations is produced by the action of the great +radial stream of the solar vortex, as we shall presently explain. It is +an observed fact, that, although the storm is frequently violent, +according to the depression of the barometer, it is not always so. +According to the theory, the storm will be violent, _ceteris paribus_, +on a line of low barometer, but may still be violent, when the contrary +obtains. Another fact is the disturbance of the magnetic needle during a +storm. Storms are also preceded generally by a rise in the thermometer, +and succeeded by a fall; also by a fall in the barometer, and succeded +by a rise. It is also well known, that hurricanes are unknown at the +equator, and probably at the poles also. At all events, they are rare in +lat. 80°, and, according to Capt. Scoresby, storms are there frequently +raging to the south, while above, there is clear sky and fine weather, +with a stiff breeze from the northward. The greater violence of storms +in those regions where the magnetic intensity is greater in the same +latitude, the probable connection of peculiarities in the electric state +of the atmosphere with earthquakes, and the indications of the latter +afforded by the magnet; the preponderance of westerly winds at a great +elevation in every latitude on the globe visited by man; and the +frequent superposition of warm layers of air above cold ones at those +elevations, are all facts worthy of note. And the connection of cirrus +clouds with storms, as well as with the aurora, indicates that the +producing cause is external to the atmosphere, and gradually penetrates +below. The theory fully explains this, and is confirmed by the fantastic +wreathings and rapid formation of these clouds in straight lines of a +hundred miles and upwards. But time would fail us in pointing out a +tithe of the phenomena, traceable to the same cause, which keeps our +atmosphere in a perpetual state of change, and we shall only advert to +one more peculiarity of the theory. It places meteorology on a +mathematical basis, and explains why it is that a storm may be raging at +one place, while in another, not very remote, the weather may be fine, +and yet be dependent on the position of the moon. + +That the moon has exerted an influence on the weather has been the +popular creed from time immemorial; but, ignorant of the mode in which +this influence was exerted, men have often been found who have fostered +the popular belief for their own vanity or advantage; and, on the other +hand, philosophers have assailed it more by ridicule than by argument, +as a relic of a barbarian age. Not so with all; for we believe we are +not wrong in stating, that the celebrated Olbers compared the moon's +positions with the weather for fifty years, before he gave his verdict +against it. He found the average amount of rain at the perigee about +equal to the amount at the apogee, as much at the full as at the change, +and no difference at the quadratures. But this fact does not throw a +feather in the scale by which this theory is weighed. Popular opinions, +of remote origin, have almost always some foundation in fact, and it is +not much more wise to reject them, than to receive them. The Baron Von +Humboldt--a man possessing that rare ingredient of learning, a practical +common sense--observes: "That arrogant spirit of incredulity which +rejects facts, without attempting to investigate them, is, in some +cases, more injurious than an unquestioning credulity."[22] If a popular +belief or prejudice be absurd, its traditional preservation for a +thousand years or more may very well account for the absurdity. + +The present system of astronomy still retains the motley garniture of +the celestial sphere, as handed down from the most remote antiquity; and +granting that ages of ignorance and superstition have involved the +history of the different constellations in a chaos of contradictory +traditions, there is no doubt at the foundation some seeds of truth +which may even yet emerge from the rubbish of fable, and bear fruit most +precious. That the zodial[23] signs are significant records of something +worthy of being preserved, is prejudice to deny; and we must be allowed +to regard the Gorgons and Hydras of the skies as interesting problems +yet unsolved, as well as to consider that the belief in lunar influence +is a fragment of a true system of natural philosophy which has become +more and more debased in postdiluvian times. Amongst those who have not +summarily ignored the influence of the moon, is Toaldo, a Spanish +physicist, who endeavored to show the connection between the recurrence +of warm and cold seasons, and the semi-revolution of the lunar nodes and +apogee, and proposed six of those periods, or about fifty-four years, as +the cycle in which the changes of the weather would run through their +course. According to the present theory, it is not likely such a cycle +will ever be discovered. There are too many secular, as well as periodic +influences combining, to produce the effect; and the times are too +incommensurable. Lately, Mr. Glaisher has presented a paper to the Royal +Society, giving about fourteen years from observation. Others have +lately attempted to connect the changes of the seasons with the solar +spots, as well as with the variations of the magnetism of the earth, but +without any marked result. + +It may, however, be urged, that if the sidereal period of the moon be +approximately a cycle of change, it would have been detected long ago. +One reason why this has been so long concealed, is the high latitude of +the observers. Spain, Italy, and Turkey, are better situated than other +European countries; but the scientific nations lie further north; and +from these the law has gone forth to regulate more southern lands. In +the United States, particularly in the great plains of the west, the +weather can be better compared; not only on account of the latitude +being more favorable, but also on account of the greater magnetic +intensity of the western hemisphere. + +It must also be remembered that there are in latitude 40°, five or six +distinct passages of the disturbing cause in one sidereal period of the +moon. If two of these periods are drawn closer together by the change of +the elements, the interval between two others must necessarily be +increased. Besides, the effect produced is not always the same, for +reasons already adverted to. One vortex may be more violent one month, +or for a few days in one month, while another may be more active the +next. It may also happen that for several successive passages, the +passage shall be central in one latitude, while two or three degrees +north or south, another place shall be passed by. In different months +and in different years, as well as in different seasons of the year, the +energy of the ether may be augmented or diminished. But it may be said, +that, supposing the theory true, if its indications are so uncertain, it +is of little value. By no means. It is true there are many things to be +inquired into; but it is a great thing in this science to be able to +take the first step in the right direction,--to find even the _key_ of +the portal. It is a great stride to be able to say, a storm may happen +at such a time, but cannot happen at another; that a storm, when raging, +will go in this direction, rather than in that; that it will be central +here, and less violent yonder; and when we consider its bearing on +astronomical and other science, it is difficult to exaggerate its value +to the world at large. + +Again, it may be said that rain, and cloudy days, and fresh breezes, and +even strong winds, sometimes occur, when the vortices do not pass +centrally. This is true; yet only indicating that where the vortices are +central, an unusual disturbance is taking place. But there is another +cause, which was purposely omitted in considering the prominent features +of the theory, in order not to encumber the question with secondary +influences. By referring to Fig. 3, section 1, we see that the lateral +vortices of the globe are continually passing off to the southward, in +the northern hemisphere, in a succession of dimples, and continually +reforming. We will now represent this mode of action in profile, as it +actually occurs in the illustration we have used. + +The vortex passing off from O, (Fig. 20,) although it does not actually +reach the surface of the atmosphere, affects the equilibrium of the +ether, and, for a short distance from the parent vortex, may cause an +ascensional movement of the air. If to this is conjoined a northerly +wind from the vortex, a band of clouds will be produced, and perhaps +rain; but violent storms never occur in the intervals, except as a +steady gale, caused by the violence of a distant storm. Thus, it will +frequently be noticed that these vortices are flanked by bands of +clouds, which pass southward, although the individual clouds may be +moving eastward. Hence, instead of disproving the theory, they offer +strong evidence of its truth; and could we view the earth from the moon +with a telescope, we should no doubt see her beautifully belted. + +[Illustration: Fig. 20] + +But it may be again asked, why should not the weather be the same +generally, in the same latitude, if this theory be true? If the earth +were a globe of level land, or altogether of water, no doubt it would be +similar; but it must be remembered, that both land and water are very +unequally distributed: that the land is of varying extent and +elevation--here a vast plain, far removed from the ocean, and there a +mountain chain, interposing a barrier to the free course of the +atmospheric currents; sometimes penetrating in full width into the +frigid zone, and again dwindling to a few miles under the equator. One +very important distinction is also to be remarked, in the superficial +area of the different zones, reckoning from the equator, and taking the +hemisphere as 100 parts: + + Frigid zone 8 parts. + Temperate " 52 " + Torrid " 40 " + +For as the time of rotation in every latitude is the same, the area to +be disturbed in the same time, is less in high latitudes, and there a +greater similarity will obtain, _ceteris paribus_. In lower latitudes, +where both land and water stretch away for thousands of miles, it is not +wonderful that great differences should exist in the electrical and +hygrometric state of the air. + +The summer of many countries is always dry--California for instance. In +winter, in the same country, the rains are apparently incessant. This of +course depends on the power of the sun, in diverting the great annual +currents of the atmosphere. As long as the dry north-west trade sets +down the coast of California, the circumstances are not favorable for +giving full development to the action of the vortices. When the trade +wind ceases, and the prevailing winds come from the south, loaded with +vapor, the vortices produce storms of any magnitude; but (and we speak +from two years' observation) the passages of the vortices are as +distinctly marked there in winter time, as they are in the eastern +States; and in summer time, also, they are very perceptible. The same +remark applies to Mediterranean countries, particularly to Syria and +Asia Minor; although the author's opportunity for observing lasted only +from April to December, during one season. If we are told it never rains +on the coast of Peru, or in Upper Egypt, it does not seriously militate +against the theory. The cause is local, and the Samiel and the sand +storm of the desert, is but another phase of the question, explicable on +the same general principles. From the preceding remarks it will be seen, +that in order to foretell the character of particular days, a previous +knowledge of the weather at that particular place, and for some +considerable time, is requisite; and hence the difficulty of laying down +general rules, until the theory is more fully understood. + + +MODIFYING CAUSES. + +We now come to the causes which are auxiliary and interfering. It is +natural that we should regard the sun as the first and most influential +of these causes, as being the source of that variation in the +temperature of the globe, which alternately clothes the colder regions +in snow and verdure. The heat of the sun undoubtedly causes the ether of +the lower atmosphere to ascend, not by diminution of its specific +gravity; for it has no ponderosity; but precisely by increase of +tension, due to increase of motion. This aids the ascensional movement +of the air, and therefore, when a vortex is in conjunction with the sun, +its action is increased--the greatest effect being produced when the +vortex comes to the meridian a little before the sun. This has a +tendency to make the period of action to appear dependent on the phases +of the moon, which being the most palpable of all the moon's variations, +has been naturally regarded by mankind as the true _cause_ of the +changes of the weather. Thus Virgil in his Georgics, speaking of the +moon's influence and its signs: + + "Sin ortu in quarto (Namque is certissimus auctor) + Pura, nec obtusis per cœlum cornibus ibit; + Totus et ille dies, et qui nascentur ab illo, + Exactum ad mensem, pluviâ ventisque carebunt." + +Hence, also, in the present day we hear sailors speak of the full and +change, or the quartering of the moon, in connection with a gale at sea; +thus showing, at least, their faith in the influence of the phenomenon. +Yet it is actually the case, at certain times, that in about latitude +40° and 41°, the storms appear about a week apart. + +There is some reason, also, to suspect, that there is a difference of +temperature on opposite sides of the sun. As the synodical rotation is +nearly identical with the siderent period of the moon, this would +require about forty-four years to run its course, so as to bring the +phenomena to exact coincidence again. Since these observations were +made, it is understood that Sig. Secchi has determined that the +equatorial regions of the sun are hotter than his polar regions. It may +be owing to this fact, that we have inferred a necessity for a change, +whose period is a multiple of the sun's synodical rotation, but it is +worthy of examination by those who possess the necessary conveniences. + +Another period which must influence the character of different years, +depends on the conjunction of the perigee of the lunar orbit with the +node. Taking the mean direct motion of the moon's perigee, and the mean +retrograde motion of the node, we find that it takes six years and one +day nearly from conjunction to conjunction. Now, from the principles +laid down, it follows, that when the perigee of the orbit is due north, +and the ascending node in Aries, that the vortices of the earth will +attain their greatest north latitude; and when these conditions are +reversed, the vortices will reach their highest limit in the lowest +latitude. This will materially affect the temperature of the polar +regions. In the following table, we have calculated the times of the +conjunctions of the apogee and pole of the orbit, taking the mean +motions. It may be convenient to refer to by-and-bye, remembering that +when the conjunction takes place due south, the vortices reach the +highest, but when due north, the vortices in the northern hemisphere +have their lowest upper limit: + + CONJUNCTION OF APOGEE AND POLE OF ORBIT.[24] + + Year. Month and Day. Longitude. + 1804, April 18th, 220° + 1810, " 17th, 104 + 1816, " 16th, 348° + 1822, " 15th, 232 + 1828, " 14th, 116 + 1834, " 12th, 360 + 1840, " 11th, 244 + 1846, " 10th, 128 + 1852, " 9th, 12 + 1858, " 8th, 255 + 1864, " 7th, 139 + 1870, " 6th, 23 + 1876, " 5th, 267 + +By this we see that the vortices have never attained their highest limit +during the present century, but that in 1858 their range will be in a +tolerable high latitude, and still higher in 1876--neglecting the +eccentricity of the orbit. + +A very potent influence is also due to the heliocentric longitude of the +sun, in determining the character of any given year. Let us explain: + +The moon's inertia forces the earth from the mechanical centre of the +terral system, but is never able to force her clear from the central +axis. With the sun it is different. He possesses many satellites +(planets). Jupiter alone, from his great mass and distance, is able to +displace the whole body of the sun. If other planets conspire at the +same side, the centre of the sun may be displaced a million of miles +from the mechanical centre of the solar system. Considering this centre, +therefore, as the centre of an imaginary sun, from which heliocentric +longitudes are reckoned, the longitude of the real sun will vary with +the positions of the great planets of the system. Now, although this +_systematic_ longitude will not be exactly similar to the heliocentric +longitude reckoned from the sun's centre, yet, for the purposes +intended, it will correspond sufficiently, and we shall speak of the +longitude of the sun as if we reckoned heliocentric longitudes from the +mechanical centre of the system. When we come to consider the solar +spots, we shall enter into this more fully. In the following diagram we +shall be able to perceive a cause for variation of seasons in a given +year, as well as for the general character of that year. + +[Illustration: Fig. 21] + +Let S represent the centre of the sun, and the circle a vertical section +of the sun, cutting; through the centre,--SJ being in the equatorial +plane of the vortex, of which ZZ′ represents the axis. As the ether +descends the poles or axis at Z, it is met by the current down the +opposite pole, and is thence deflected in radii along the equatorial +plane to J. But on the side S, the ether is opposed by the body of the +sun; its direction is consequently changed, and cross currents are +produced, assuming it as a principle, that the ethereal fluid is +permeable by other currents of similar matter, and that it tends always +to move in right lines. This granted, it is evident that, in passing the +sun, the quick moving ether forms a conical shell, (the sun being at the +apex,) so that the strongest current of ether is in this conical shell, +or at the surface of this conical space. As the plane of the ecliptic is +not much inclined to the sun's equator, and this last probably not much +inclined to the plane of the vortex, should the earth have the same +_heliocentric_ longitude at the time, (or nearly the same,) she would +be in an eddy, as respects the radial stream, and be protected from its +full force by the body of the sun. + +Now, the ether comes down the axis with the temperature of space, and +may possibly derive a _little_ additional temperature in passing over +the body of the sun; so that in this position the earth is protected +from the chilling influence of the radial stream, by being protected by +the body of the sun. And although, from the immense velocity of the +ether, it cannot derive much additional temperature, there may still be +an appreciable difference, due to this cause. + +It is the chilling influence of the ethereal stream which originated the +idea among philosophers, of _frigorific impressions, darted from a clear +sky_. In some years the sun will be nearly in the centre of the system; +in other years the axis of the vortex will not come near the sun. And as +the sun's longitude may vary through the entire circle, it may happen +that the earth's longitude shall coincide in winter or summer, or spring +or autumn. When, however, the earth emerges from the protection of the +sun, and enters the conical shell, considered as a space of considerable +depth, she will again be exposed to the full force of the radial stream, +rendered more active by the previous deflection, and by the numerous +cross currents pervading it; so that a mild and calm winter may be +succeeded by a cold and stormy spring. The present season, (1853) the +earth's longitude coincided with the sun's longitude in about 135°, and +consequently was in the conical space spoken of, during February and +March; but the radius vector of the sun's centre, being then less +than 300,000 miles, the protection was not as complete as it is +sometimes. Still, the general fineness of these months was remarkable; +yet in April and May, when the earth became again exposed to the action +of the solar stream, the effect was to retard the spring, and disappoint +the prognostications of the weather-wise. In applying these principles, +we must consider the effect in those latitudes which are more readily +affected,--that is, in the temperate zone, midway between the two +extreme zones of heat and cold. + +In 1837 and 1838, the longitude of the sun's centre corresponded with +the earth's, in August and September, when there was neither rain nor +electrical excitement; and consequently those seasons were sickly over +the whole country. Now, there is another cause which renders the months +of August, September, and October, deficient in electrical energy, and +consequently more prone to be sickly. If, therefore, the two causes +unite their influence, the autumnal months will be more sickly at those +times. This last cause, however, only affects the _northern latitudes_ +in autumn, and consequently, _ceteris paribus_, the autumnal months +should not be so proverbially sickly in the southern hemisphere. This +is, however, only suggestive. + +Again, in 1843, the winter was very mild in January and February; but in +March it turned cold and stormy, and continued through April. In this +year the longitude of the sun was nearly the same as in 1853,--the two +longitudes of the earth and sun corresponding about the last of January; +but in March, the earth forsook the comparative calm produced by the +sun's position, and hence the greater cold.[25] + +Thus it appears at every step we take, that the different members of the +solar system do indeed belong to the same family, whose least motions +have their influence on the rest. Who could have anticipated that the +position of Jupiter in his orbit had anything to do with the health of +this remote planet, or with the mildness of its seasons? In this we have +a clue to the origin of that astrological jargon about planetary aspects +being propitious or malign. Philosophers are even yet too prone to wrap +themselves in their mantle of academic lore, and despise the knowledge +of the ancients, while there is reason to believe that the world once +possessed a true insight into the structure of the solar system. As war +became the occupation of mankind, under the despotic rule of ambition, +so truth retired, and ignorance seizing upon her treasures, has so +mutilated and defaced them, that their original beauty no longer +appears. Let us hope that the dawn of a better day is approaching. + +There is yet another cause (just alluded to) which modifies the action +of the vortices. + +We have shown that, if the periodic times of the planets are +approximately equal to the periodic times of the contiguous parts of the +solar vortex, the density of the ether is directly as the square roots +of the distances from the centre. As the earth is at her perihelion +about the first of January, the density of the surrounding ether is then +less than in other parts of the orbit; consequently, if we suppose that +there is a continual tendency to equilibrium, the ether of space must +press inwards, during the time between the perihelion and aphelion, +(_i.e._ from January to July,) lowering the temperature and increasing +the electrical action of those months. As the distance from the sun is +most rapidly augmenting about the first of April, and the effective +power of the sun's radiation is most rapidly increasing in May; by +combining the two we shall find, that about the first of May we shall +have considerable electrical action, and cold weather. This explains +also, in part, the prevalent tradition of certain days in May being very +cold.[26] When the earth leaves the aphelion, a reaction takes place, +being most rapid in September. There is then an _escape_ of ether from +the earth, which keeps up the temperature, and causes these months to be +sickly, from the negative electrical state of the atmosphere. In the +southern hemisphere, the effects in the same season will be reversed, +which may partly account for the greater degree of cold in that +hemisphere, and for accelerating the approach of both summer and winter, +while in the north they were both retarded. + +We must now advert to another cause, which of all others is probably the +most important, at least to the other members of the solar system. + +In every part of the solar vortex the ether is continually pressing +outwards. We are not now speaking of the radial stream, but of the +slower spiral motion of the ether around the axis of the vortex, whose +centrifugal force is bearing the whole body of the ether outwards, thus +rarefying the central parts, and thus giving rise to the polar influx, +from which arises the radial stream. This may be made more intelligible, +by reflecting that the polar current is comparatively dense ether, and +that the length of the axis of the vortex prevents this influx current +coming in sufficient quantities to restore an equilibrium in the density +of the medium. Yet, what does come down the poles, is distributed +rapidly along the equatorial plane, leaving the space still rarefied. +Now we perceive, that in order for the radial stream to continue in +action, requires the whole medium of the vortex to be also moving +outward; it is therefore continually condensed as it proceeds. This +condensation necessarily converts much of the specific heat of the ether +into sensible heat; so that the _temperature_ of the medium is +continually increasing, as the distance from the sun increases. + +When we contemplate the solar system as the emanation of one Great Mind, +we naturally seek for evidence of the wisdom of a supreme intelligence +in _all_ the arrangements of that system. But, however humbly and +reverently we may speak of these arrangements, we can scarcely avoid the +wish, that the planetary distances had been differently arranged, if +Newton's doctrine be true, that space is a vacuum, and that the heat of +a planet, is inversely as the squares of the distances from the sun. +For, to speak of the temperature of space, except as dependent on this +law, is one of those many incomprehensible inconsistencies with which +philosophers are chargeable. If the Newtonian philosophy is literally +true, space has _no temperature_, and the surface heat of the planet +Neptune is nearly 1,000 times less than on our own globe. Again, on +Mercury it is seven times greater, which heat would scorch and consume +every organic substance on the earth, and speedily envelope the boiling +ocean in a shroud of impermeable vapor. Granting even that space may not +be a vacuum, and yet the law of gravitation be true, we may still be +allowed to consider both Saturn and Uranus and Neptune, as inhospitable +abodes for intelligent creatures; and, seeing the immensity of room in +the system, there is no reason why these planets might not have been +permitted to revolve nearer the great source of light and life and +cheering emanations. To suggest the resources of Omnipotence is no +argument. He has surrounded us with analogies which are seen, by which +we may attain a knowledge of those which are not seen; and we have every +reason to suppose that the great Author of nature is not indifferent to +the aspects under which his works reveal him unto his creatures. Yet +there is (on the above hypothesis) an apparent want of harmony in the +planetary distances; and if frail mortality may be permitted to speak +out, an explanation is needed to obviate this seeming anomaly in the +economy of the world. The more we learn of the physical arrangements of +the universe, the more do they correspond with our experience of the +nice adaptation of the means to the end which obtains in our own globe, +and we can only judge of other planets by the analogies around us. Here, +there, are extremes of temperature it is true: it is necessary there +should be, and we can see and understand the necessity in all such +cases, and how they conduce to the general average of good. But, +astronomers can give no reason why it is necessary that some planets of +our system should be placed so remote that the sun is frittered down to +a star, whose heatless light is but a mockery to those frigid realms. + +Now, according to this theory, the temperature of Neptune may be far +more uniform and conducive to life than that of our own globe. The +chilling influence of the solar stream at that planet being nearly null, +and the temperature of the surrounding space far greater. So also +Mercury, instead of being the burning planet of the schools, may suffer +the most from cold. + +The planet Mars is generally considered, of all the members of the +system, most nearly to resemble our own world. The telescope not only +reveals seas and continents, but the snowy circles round his poles, +which appear to increase and diminish, as his winter is beginning or +ending. This planet's ecliptic is similar to our own in inclination or +obliquity, his distance, also, is far greater, and his winter longer; +yet, for all this, his snow zones are less than on our own globe. This +anomalous fact has, we believe, never been noticed before; but it is +explicable on the theory, and therefore confirms it. Mars has no +satellite, and therefore his centre will be coincident with the centre +of the marsial vortex. There will be no _lateral vortices_ to derange +his atmosphere, and if the axis of his vortex coincides also with the +axis of the planet, the central vortex will be continually over the +poles, _and there will be no storms on the planet Mars_. A capital fact +connected with this, is the want of belts, as in Jupiter and Saturn; for +these planets have satellites, and if _they_ are not massive enough, the +belts may be produced by an obliquity in the axis of the Jovial and +Saturnial vortices. If Mars had an aurora like the earth, it is fair to +presume the telescope would ere this have shown it. He is, therefore, in +equilibrium. In applying this reasoning to the earth, we perceive that a +certain influence is due to the difference of temperature of the +ethereal medium surrounding the earth, at perihelion and aphelion, being +least at the former, and greatest at the latter. + +As a modifying and interfering cause in the action of the vortices, we +must mention the great natural currents of the atmosphere, due to the +earth's rotation. + +It is considered that the sun is the principal cause of these great +currents. By elevating the surface atmosphere of the equator, a lateral +current is induced from the north and south; but on account of the +enlarging circles of latitude, their direction tends more from the +north-east and south-east. These currents are usually called the trades. +Without disputing the correctness of this, it may be doubted whether the +whole effect is due to the sun. As this principle affects the ocean +likewise, it is necessary to look into it; and in order to simplify the +question, we will first suppose our globe covered entirely by the ocean, +without any protuberant land. + +Let us assign a uniform depth of ten miles to this ocean. In the Fig. +following, the two circles will represent the surface and bottom of the +ocean respectively. The axis of rotation is thus represented by the line +PP′. Let us consider two particles of water at m and n, as feeling the +influence of this rotation; they will, of course, be both urged towards +the equator by the axifugal force. Now, every particle in the ocean +being also urged by the same force, it might be supposed that after a +protuberant mass of water had accumulated at the equator EE′, the whole +ocean would be in equilibrium. This would not follow. The particle at m +is urged by a greater force than n; consequently the particle at n is +overborne by the pressure at m. Considering both in the same direction, +yet the particle at n must give way, and move in the opposite direction. +Just as the heaviest scale of the balance bears up the lightest, +although both gravitate towards the same point. This is so self-evident +that it would seem unnecessary to dwell upon it, had not the scientific +world decided that the rotation of the earth can cause no currents +either in the atmosphere or in the ocean. + +[Illustration: Fig. 22] + +The axifugal forces of the two particles m and n are directly as the +lines Mm and Nn, and if the gravitating forces were also as the radii Tm +and Tn, no motion would be produced. Admitting even the Newtonian law to +be rigidly exact, the earth cannot be considered a homogeneous globe, +but, on the contrary, the density of the central parts must be nearly +thirty times greater than the density of the surface of the ocean. The +ratio of the gravitating forces of these two particles is, therefore, +less than the ratio of their respective radii, and the axifugal tendency +of the particle at n is more than proportionally restrained by the +central gravitation; and hence m will move towards the equator, and n +towards the poles, as represented in the Fig. + +It is on account of the overwhelming momentum of the surface waters of +the South Pacific over the North, that the Pacific, at Panama, stands +six or seven feet higher than the Atlantic. We shall again allude to +this interesting fact. + +According to newspaper reports of a lecture, delivered in New York, by +Lieut. Maury, U. S. N., this gentleman endeavors to explain the currents +of the ocean, by referring them to evaporation in the tropics. The vapor +leaves the salt of the water behind, and thus, by continual +accumulation, the specific gravity of the tropical waters is greater +than that of the superficial waters nearer the poles; the lighter +water, therefore, passes towards the equator, and the heavier water +below, towards the poles. If this be a correct statement of that +gentleman's theory, fidelity to our standards compels us to question the +soundness of the conclusion. The mere fact of the surface water of the +ocean being lighter than that of the bottom, cannot on any known +principles of science cause any movement of the surface waters towards +the equator. When such an acute and practical physicist is driven, by +the palpability of the fact that the polar waters are continually +tending towards the equator, to seek the cause in the tropical +evaporation, it shows that the dogma, which teaches that rotation can +produce no motion, is unsound. + +Sir John Herschel, in speaking of the solar spots, says: "We may also +observe that the tranquillity of the sun's polar, as compared with his +equatorial regions (if his spots be really atmospheric), cannot be +accounted for by its rotation on its axis only, but must arise from some +cause external to the sun, as we see the belts of Jupiter and Saturn and +our trade winds arise from a cause external to these planets combining +itself with their rotations, which _alone_ (and he lays an emphasis on +the word) can produce no motions when once the form of equilibrium is +attained." + +With respect to the origin of the solar spots, we have no disposition to +question the conclusion; but, as regards the _principle_ laid down, that +rotation can produce no motions when once the form of equilibrium is +attained, we must unequivocally dispute it. If our atmosphere were of +uniform density, the rotation of the earth would cause no current such +as we have described; with our atmosphere as it is, the result will be +different. The momenta of two portions of matter are the products of +their inertiæ by their motions, and, in the present case, we must take +the inertiæ of equal spaces. A cubic inch of air at the surface, and at +three miles above the surface, is as 2 to 1; but their centrifugal +velocity varies only as the radii of the respective spheres, or as 1320 +to 1321. In the polar regions, therefore, the momentum of the surface +air preponderates, and, in this case, the _surface_ current is towards +the equator, and the upper current towards the poles. When, however, the +centrifugal velocity is considerably increased in a lower latitude, and +the curvature of the surface becomes more and more inclined to the +direction of that resolved part of the centrifugal force, which is +always _from_ the axis, the surface layers will evince a tendency to +leave the surface, and an intermingling will then take place in the +space between latitude 70° and 50°, or in latitude 60°. As this layer is +continually urged on in the same direction by the surface layer of +latitudes above 60°, the upper layer now becomes a current setting +_towards_ the equator, and, consequently, the back current occupies the +surface. Now, considering that the rarefying action of the sun is +elevating the air under the equator, there must necessarily be an upper +current from the equator to the poles; so that if we conceive the two +currents to meet about latitude 30°, there will be a second +intermingling, and the current from the poles will again occupy the +surface. Thus, we regard a part of the effect of the trades to the +rotation of the earth, which is the chief impelling power at the poles, +as the sun is at the equator; and the latitudes 60° and 30° will be +marked by some especial phenomena of temperature, and other +meteorological features which do actually obtain. These would be much +more marked if the irregular configuration of land and sea, the +existence of mountain chains, and the different heating power of +different latitudes, owing to the unequal distribution of the land, did +not interfere; and the currents of the air (disregarding the deflection +east and west) might then be represented by a treble link or loop, whose +nodes would vary but little from latitudes 30° and 60°. As it is, it +has, no doubt, its influence, although unimportant, when compared with +the disturbing action of the ethereal vortices. + +There is another phenomenon due to the action of the radial stream, +which has given much trouble to the physicist, and which has yet never +been explained. This is the horary oscillations of the atmospheric +pressure which, in some countries are so regular that the time of day +may be ascertained by the height of the barometer. According to +Humboldt, the regularity of the ebb and flow in the torrid regions of +America, is undisturbed by storms or earthquake. It is supposed that the +maxima occur at 9 A.M. and 10½ P.M., and the minima at 4 A.M. and +4¼ P.M. From the morning minimum to the morning maximum is, +therefore, five hours; from the evening minimum to the evening maximum +is 6¼ hours; from the evening maximum to the morning minimum is 5½ +hours, and from the morning maximum to the evening minimum is 7¼ +hours. Again, these oscillations are greatest at the equator, and +diminish with the increase of latitude. + +[Illustration: Fig. 23] + +If we suppose the earth's axis perpendicular to the plane of the vortex, +and P the pole in the above figure, and SP the line joining the centre +of the earth and sun, M and m will represent the points in the earth's +equator where it is midday and midnight respectively. The solar stream +penetrates the terral vortex; and strikes the earth's atmosphere along +the lines parallel to SP. The direct effect would be to pile up the +atmosphere at N and n; and therefore, were the earth at rest, the +maximum would be at 6 A.M. and 6 P.M., and the minimum at midday and +midnight; but the earth rotating from N towards M, carries along the +accumulated atmosphere, being more sluggish in its motions than the +producing cause, which cause is still exercised to force it back to N. +From this cause the maximum is now found at K. For a like reason the +minimum at M would be found at L, but on account of the motion of the +earth being now in the same direction as the solar stream, the minimum +is found still more in advance at k; so that, according to the theory, +the interval between the morning maximum and the evening maximum, should +be greater than the interval between the evening maximum and the morning +maximum; and so it is, the first being 13½ hours and the last 10½ +hours. The morning minimum should also be less marked than the evening +minimum, and this also is a fact. The effect also should be greater in +the tropics than in high latitudes, which again also obtains; being 1.32 +French lines at the equator, and only 0.18 at latitude 70°. Had the +earth no obliquity, the effect would be as the squares of the cosines of +the latitude; but the ratio is diminished by the inclination of the +axis. But there are other variations of the barometer of longer period, +apparently depending on the phases of the moon, but which cannot be +reconciled to the attracting power of the moon as an atmospheric tide; +and Arago concluded that they were due to some _special cause_, of which +the nature and mode of action are unknown. Perhaps this theory will +obviate the difficulty, as although the central vortex comes to the +meridian at the same time as the moon, its effect will be different on +the inferior meridian to what it is on the superior one; whereas the +moon's attraction should be the same on both. That the passage of a +vortex over or near a particular place should affect the barometer, is +too obvious to need explanation, and therefore we may say that the +theory will explain all those varieties both small and great, which have +caused so much speculation for the last fifty years. + + +TERRESTRIAL MAGNETISM. + +In applying the theory to the magnetism of the earth, we must bear in +mind that the earth is probably magnetic by induction, and not in virtue +of its own specific action. The rotation of the surrounding ether, and +the consequent production of a radial stream, calls the ether into +motion within the earth's interior, as well as on the surface; but it +does not follow that the ether shall also enter the earth at its poles +and escape at its equator, for the obliquity of the vortex would +interfere with this result. It is sufficient that this does occur in the +terral vortex immediately surrounding the earth. From late experiments +it is pretty well established that the axial direction of the needle, +(and of other bodies also,) is due to peculiar internal arrangement in +laminæ or layers, the existence of which is favorable to the passage of +the magnetic current. + +According to the experiments[27] of Dr. Tyndal, it is found that the +magnetism of a body is strongest along the line of greatest density. As, +therefore, the laminæ of bodies may be considered planes of pressure, +when these planes are suspended horizontally, the directive force is +greatest, and the longest diameter of the body sets axial. On the other +hand, when the body was suspended so that the laminæ were vertical, the +longest diameter set equatorial. Now, we know that the crust of the +earth is composed of laminæ, just as the piece of shale in Doctor +Tyndal's experiments, and that these layers are disposed horizontally. +And whatever force originally arranged the land and water on our globe, +it is evident that the continents are longest from north to south, and +therefore correspond to the natural direction of the magnetic force. + +In consequence of the intrinsic difficulties of this question, and the +mystery yet attaching to it, we may be permitted to enter a little more +minutely into it, and jointly consider other questions of interest, that +will enable us to refer the principal phenomena of terrestrial magnetism +to our theory. + +We have before adverted to the discrepancies in the earth's compression, +as determined by the pendulum, and also to the uncertainty of the moon's +mass, as deduced from the nutation of the earth's axis. It is also +suspected that the southern hemisphere is more compressed than the +northern; and other phenomena also point out the inadequacy of the law +of gravitation, to account for the figure of the earth. + +From the invariability of the axis of rotation, we must conclude that +whatever form is the true form, it is one of equilibrium. In casting our +eyes over the map of the world, we perceive that the surface is very +unequally divided into land and sea; and that the land is very unequally +arranged, both north and south, and east and west. If we compare the +northern and southern hemisphere, we find the land to the water about 3 +to 1. If we take the Pacific portion, and consider the north end of New +Zealand as a centre, we can describe a great circle taking in one half +the globe, which shall not include one-tenth of the whole land. Yet the +average height of the remaining nine-tenths, above the level of the sea, +is nearly 1,000 feet. Call this nine-tenths nearly equal to one-fourth +of the whole surface, and the protuberant land in the hemisphere, +opposite the South Pacific, amounts to 1/30,000 part of the whole mass +of the earth, or about 1/700 of the mass of the moon. Again, the mean +density of the earth is about 5½--water being unity,--and the mean +density of the surface land is only about half this: but three-fourths +of the whole surface is water. Hence, we see that the materials of the +interior of the earth must be either metallic or very compressible. To +assign a metallic nucleus to the earth, is repugnant to analogy; and it +is not rendered even probable by facts, as we find volcanic emissions to +contain no heavier elements than the sedimentary layers. Besides, there +are indications of a gradual increase of density downwards, such as +would arise from the compressibility of the layers. Seeing, therefore, +the equilibrium of the whole mass, and the consequent hydrostatic +balance of the land in the sea,--seeing also the small compressibility +of the solid portions, and the great compressibility of the fluid, the +inference is legitimate that the whole is hydrostatically balanced, and +that our globe is a globe of water, with an intermediate shell of land, +specifically lighter than the fluid in which it is suspended. Where this +shell is of great thickness, it penetrates to greater depths, and +attains to greater elevations above the surface of the aqueous globe; +where it is less thick, it is found below the surface, and forms the +bottom of the upper ocean. Recent soundings give much greater depths to +some parts of the ocean, than the most elevated land upon the globe. +Captain Denham, of H. B. M. ship Herald, lately sounded in 37° south and +37° west, and found bottom at 7,706 fathoms, or about nine English +miles. + +As the interior portions of our globe are totally unknown, and the +compressibility of water is well established, it is just as sane to +consider water the most abundant element of nature, as solid land. The +great question to ask is, whether there may not be other phenomena +incompatible with this supposition? It is plain that the permanency of +terrestrial latitudes and longitudes would be unaffected by the +conditions we have supposed. Would the precession of the equinoxes be +also unaffected? Mr. Hopkins has entered into such an investigation, and +concludes: "Upon the whole, then, we may venture to assert that the +minimum thickness of the crust of the globe, which can be deemed +consistent with the observed amount of precession, cannot be less than +one-fourth or one-fifth of the radius of the earth." These +investigations were made on the hypothesis of the interior fluidity +being caused by the fusion of the central portions of a solid globe; but +it is evident that the analytical result would be the same if these +central parts were water, inclosed by an irregularly-spherical shell of +land. Nor would the result be affected, if we considered certain +portions of the interior of this solid shell to be in a state of fusion, +as no doubt is the case. + +May not the uncertainty of the mass of the moon, be owing to the fact +that this shell is not so rigidly compacted but that it may yield a +little to external force, and thus also account for the tides in the +Pacific groups, rather obeying the centrifugal force due to the orbit +velocity of the earth, than the attraction of the moon? + +Since the days of Hipparchus the sidereal day has not diminished by the +hundredth part of a second; and, consequently, seeing that the +contraction of the mass must be limited by the time of rotation, it is +inferred that the earth has not lost 1/508th of one degree of heat since +that time. This conclusion, sound as it is, is scarcely credible, when +we reflect on the constant radiation into a space 60° below zero. Admit +that the globe is a globe of water, whose average temperature is the +temperature it receives from the sun, and the difficulty vanishes at +once. Its diameter will be invariable, and the only effect of the +cooling of the solid parts will be to immerse them deeper in the water, +to change the _relative_ level of the sea without changing its volume. +This is no puerile argument when rightly considered; but there is +another phenomenon which, if fairly weighed, will also conduct us to the +same views. + +It is now a fact uncontroverted, that the sea does actually change its +level, or rather, that the elevation of continents is not only apparent +but real. The whole coast of Sweden and Finland is rising at the present +day at the rate of four feet in a century, while on the south a contrary +effect is produced. Various hypotheses have been formed concerning this +interesting fact. Yet from the indications of geology, it must have been +an universal phenomenon in the early ages of the world, in order to +account for the emersion of sedimentary deposits from the fluid which +deposited them. May not internal fires be yet spreading, and the +continents expanding instead of contracting? And may there not be an +inequality in this process, so as necessarily to immerse in one +direction nearly as much as to elevate in another? One fact is certain, +the elements are scattering the materials of the land along its Oceanic +coasts, which of itself must produce a very minute effect in disturbing +the hydrostatic balance; but a more efficient agent is the earthquake +and volcano. + +The upheaving of tracts of land by earthquakes, as on the coast of Chili +would thus be satisfactorily explained, by attributing a certain +resistance due to cohesion or friction preventing a _gradual_ change of +level, but producing it suddenly by the jar of the earthquakes. May we +not inquire also, whether the facility with which the earth seems moved +by this destructive agent, does not point to the same solution as the +irregularity of the figure of the earth? + +This is a subject on which it is allowable to speculate, especially if +any light can be thereby thrown on the still more mysterious source of +terrestrial magnetism. It is for such a purpose that we have permitted +ourselves to digress from that subject. In this connection we also may +acknowledge our indebtedness to the sacred volume for the first germ of +this theory of the weather. + +Believing in the authenticity of the Mosaic history of the deluge, the +author found it difficult to refer that event to other than natural +causes, called into action by the operation of other causes, and all +simultaneous with the going forth of the fiat of Omnipotence. Thus +reasoning, he was led to regard the deluge as a physical phenomenon +inviting solution, and as a promising exponent to the climatology of +the early world. He looked upon the bow of promise, as the autograph of +the Creator, the signature to a solemn bond, upon which the eye of man +had never before rested. But if there was no rainbow before the deluge, +there was no rain; and following up this clue, he was not only enabled +to solve the problem, but also led to the true cause, which produces the +principal commotions in our atmosphere. + +Science boasts of being the handmaid of religion; yet there are names of +note in her ranks who have labored rather to invest this phenomenon with +the mantle of fable, and to force it into collision with the records +graven on the rocky pages of geognosy. But the world is ever prone to be +captivated by the brilliancy of misapplied talents, instead of weighing +merit by its zeal in reconciling the teachings of those things which are +seen, with those which are revealed. + +If our globe be constituted as we suppose, the land might experience +repeated submersions, without involving the necessity of any great +departure from established laws. And we might refer to the historical +record of one of these, with all the minute particulars as positive +data, imposing on us the necessity of admitting that the solid parts of +the globe are hydrostatically balanced in the sea. But, modern science +is not always correctly defined when called the pursuit of truth, nor +human learning the means of discovering it. + +If we could divest ourselves of this prejudice, we should have a ready +solution of the difficulty presented by the earth having two north +magnetic poles, and probably two also in the south. For, by regarding +the old and new continents as two distinct masses of land whose bases +are separated by 6,000 miles of water, we recognize two great magnets, +dependent, however, for their magnetism, on the rotation of the terral +vortex. + +This is no place to enter into a lengthy discussion of such a difficult +subject as magnetism, but we may be allowed to enter a protest against +the current theory of electro-magnetism, viz.: that a force is generated +by a galvanic current at right angles to the producing cause, which is +contrary to the fundamental principles of mechanics. We may conceive +that a current is induced from or to the surrounding space by the +rarefaction or condensation attending the transmission of such a current +along a wire, and that rotation should follow, just as a bent pipe full +of small holes at the lower end, and immersed in water as a syphon, will +generate a vorticose motion in the water; but mere juxtaposition, +without participation and communication with the general current, is +irrational, and, therefore, not true. + +We have always regarded a magnetic needle as a part of the great natural +magnet, the earth; that its north pole actually points to the north, and +its south pole to the south; and, being free to move, it is affected by +the circular motion of the surrounding ether, and by every motion by +which the ether is directed. If there was any attraction between the +earth and the needle, opposite poles would be presented, but it is not +so--the force is merely directive. + + +MAGNETIC VARIATIONS. + +Let us now see whether we cannot assign an adequate cause for the +secular and periodic variations in the inclination and declination of +the needle. These have been generally referred to changes of +temperature, as in fact, also, the magnetism of the earth is sometimes +ascribed to galvanic or electric currents, called forth by a daily +change of temperature. Our theory gives a totally different explanation +of these variations. + +In the northern hemisphere, the north point of the needle moves from +east to west in the morning from about 8½ A.M. to 1½ P.M., and +returns to its mean position about 10 P.M. It then passes over to the +east, and again returns to its mean position about 8 or 9 A.M. The +analogy of this motion, with the horary changes in the barometer, +indicate a common origin. Humboldt, in the instructions he drew up for +the Antarctic Expedition under Sir James Ross, says: "The phenomena +of periodical variations depend manifestly on the action of _solar +heat_, operating probably through the medium of thermo electric currents +induced on the earth's surface. Beyond this rude guess, however, +_nothing is yet known of their physical cause_. It is even still a +matter of speculation whether the solar influence be a principal or only +a subordinate cause." That the sun may exert a modifying influence on +the phenomenon is not unlikely, but that he cannot be the principal +cause, is evident from the following considerations. These horary +variations of the magnetic needle are as great at the bottom of deep +mines far removed from solar influence, as on the surface. They are as +great, _ceteris paribus_ on a small island in the midst of the ocean, as +in the interior of continents, where the heating power of the surface is +vastly greater. They are extremely regular, so that between the tropics, +according to the sagacious Humboldt, "the time of the day may be known +by the direction of the needle, as well as by the height of the +barometer." + +But what is the cause of these variations? This question is the most +difficult of all physical problems, and we shall only aim at indicating +the causes which are yet perhaps too intricately involved to afford a +positive numerical determination. Admitting the existence of two +principal solid masses whose general direction is from south to north, +and that these masses are more susceptible of permeation by the ethereal +fluid than the waters in which they are suspended, we have a general +solution of the position of the magnetic poles, and of the isogonic, +isoclinic, and isodynamic lines. Considering, too, that the southern +poles of these masses are the points of ingress, and the northern poles +the points of egress, it is easily understood that the ethereal medium +having the temperature of space, will cause the southern hemisphere to +be colder than the northern, and also that the magnetic poles will be +the poles of maximum cold, and the centres respected by the isothermal +and isogeothermal lines. + +The general direction of the magnetism of the earth may be considered as +the controlling influence, therefore, in determining the position of the +magnetic needle; but there are other causes which, to some extent, will +modify the result. That half of the globe turned away from the sun will +partake of the density of the ether at that distance, which is greater +than on the side next the sun; the magnetic intensity ought, therefore, +to be greater in the night than in the day. The poles of the great +terrestrial magnets, or even the position of a magnetic needle on the +surface, are continually placed by the earth's rotation in a different +relation to the axes of the terral vortex, and the tangential current, +which is continually circulating around the globe, has its inclination +to a given meridian in a perpetual state of change. If we conceive that +there is a tendency to force the needle at right angles to this current, +we shall have an influence which varies during the day, during the year, +and during the time occupied by a complete revolution of the node. The +principal effect, however, of the horary variation of the needle is due +to the radial stream of the sun, which not only penetrates the +atmosphere, but also the solid crust of the earth. Its principal +influence is, however, an indirect influence, as we shall endeavor to +explain. + +No fact in the science of electro-magnetism is, perhaps, better +established than the disposition of an ethereal current to place itself +at right angles to the magnetic meridian, and conversely, when the +current is not free to move, to place the needle at right angles to the +current. Now, the terrestrial magnet or magnets, may be considered to be +surrounded by a body of ether in rotation, which, in the earth, on its +surface, and for some distance from the surface, is made to conform to +the general rule, that is, to circulate at right angles to the magnetic +meridian. Outside this again, the ether more and more conforms to the +position of the axis of the vortex, and this position varying, it must +exert _some_ influence on the surface currents, and, therefore, change +in some degree the position of the magnetic meridian. The radial stream +comes from the sun in parallel lines, and strikes the globe and its +superficial ethereal envelope just as we have shown its action on the +atmosphere; but in this last case the magnetic equator is not a great +circle, neither can we suppose its effects to be an accumulation of a +fluid which is imponderable at points 90° from the plane passing through +the centre of the earth and sun, and coincident with the plane of the +central meridian, and a depressing effect on that meridian. Its precise +influence must be, from the nature of the cause, to deflect the circular +current towards the poles, in places less than 90° from the meridian, +and a contrary effect must be produced in places greater than 90° from +the meridian. Let us assume, for argument's sake, that the magnetic +poles of the earth correspond to the poles of rotation, the parallels of +latitude will, therefore, represent the ethereal currents circulating +around the globe. Now, at sunrise, the radial stream of the solar vortex +is tangential to the surface, and, therefore, can produce no change in +these currents. As the sun ascends say about 8 or 9 A.M., the radial +stream striking only the surface of the earth perpendicularly in that +place where the sun is vertical (which we will suppose at the equator), +streams off on every side, as the meridians do from the pole, and the +circles of latitude (that is the ethereal currents) being parallel to +the equator, they are met by the radial stream obliquely, and deflected +towards either pole. By this deflection they are no longer at right +angles to the meridians. But, from the principle of reaction above +noticed, the magnetic meridians will place themselves at right angles to +the current, or, in other words, the magnetic pole will change its +position on the surface of the earth with respect to that particular +place. But, in other parts of the world, the meridians are in opposite +phases at the same instant of absolute time; therefore, the magnetic +poles are not points, but wide areas enclosing the magnetic poles of all +the countries under the sun. As this conforms to observation, it is +worthy our especial attention, and may be understood by the subjoined +figure, in which the oblique curves represent the course of the +tangential current in the different positions of the sun, the parallel +lines representing the solar radial stream. + +[Illustration: Fig. 24] + +As the sun gains altitude the action of the radial stream is at a +greater and greater angle to the circular currents, and attains its +maximum at noon, still acting, however, after noon; but seeing that the +circular current possesses a force of re-action, that is, that the +magnetism of the earth is ever striving to bring these currents to their +natural direction, an hour or two after noon, the currents tend again to +the equator, and the maximum deflection is passed, and finally ceases a +few hours after sunset. Now let us attend to what is going on on the +opposite side of the world. The radial stream passing over the polar +regions, now produces a contrary effect; the ethereal atmosphere of the +great magnet is accumulated on the farthest side from the sun, by the +action of the radial stream passing over the polar region, the parallel +currents are now bent towards the equator, being at a maximum in places +where it is an hour or two past midnight. Before they were concave to +the equator, and now they are convex; the magnetic meridian is therefore +deflected the contrary way to what it was in the day time, by the same +principle of reaction. After the maximum, say at 4 A.M., the deflection +gradually ceases, and the magnetic meridian returns to its mean position +at 8 or 9 A.M. These times, however, of maximum and minimum, must vary +with the time of the year, or with the declination of the sun, with the +position of the moon in her orbit, with the perigee of the orbit, and +with the place of the ascending node; there are also minor influences +which have an effect, which present instrumental means cannot render +appreciable. + +What says observation? The needle declines from its mean position in the +whole northern hemisphere to the westward, from about 8.30 A.M., until +1.30 P.M.; it then gradually returns to its mean position by 10 A.M. +After 10 P.M., it passes over to the eastward, and attains its maximum +deflection about three or four hours after midnight, and is found again +at its mean position about 9 A.M. Now, this is precisely the direction +of the deviation of the magnetic meridian, the needle therefore only +follows the meridian, or still continues to point to the temporary +magnetic pole. And although we have assumed, for the sake of simplicity, +that the mean magnetic pole corresponds to the pole of rotation; in +truth there are two magnetic poles, neither of which correspond; yet +still the general effect will be the same, although the numerical +verification will be rendered more difficult. + +In the southern hemisphere the effect is the reverse, (this southern +hemisphere, however, must be considered separated from the northern by +the magnetic equator, and not by the geographical one,) the needle +declines to the eastward in the morning, and goes through the same +changes, substituting east for west, and west for east. Does observation +decide this to be to be a fact also? Most decidedly it does; and this +alone may be considered a positive demonstration, that the theory which +explains it is true. The contrary deflection of the needle in the +northern and southern hemisphere may be formally proclaimed as utterly +beyond the reach of the common theory of magnetism to explain. This +difficulty arises from considering the needle as the disturbed body +instead of the earth; and also from the fact that the effect of solar +heat must be common to needles in both hemispheres, and act upon similar +poles, and consequently the deflection must be in the same direction. + +But a still more capital feature is presented by the discovery of +Colonel Sabine, that the deflection is in contrary directions at the +Cape of Good Hope, at the epoch of the two equinoxes. This arises from +the great angle made by the magnetic meridian at this place, with the +terrestrial meridian--the variation being by Barlow's tables, 30° to the +westward. The sun varies in declination 47° throughout the year. At the +southern solstice, therefore the radial stream strikes the circular +current on the southern side, and deflects it towards the equator, +rendering the declination to the westward in the morning; but at the +northern solstice the radial stream strikes the current on its northern +side, and the deflection is eastward in the morning. And the vicinity of +the Cape of Good Hope is, perhaps, the only part of the world where this +anomaly will obtain; as it is necessary not only that the declination +shall be considerable, but also that the latitude shall not be very +great. + +Observation also determines that the amount of the horary variation +increases with the latitude. Near the equator, according to Humboldt, it +scarcely amounts to three or four minutes, whilst it is from thirteen to +fourteen minutes in the middle of Europe. The theory explains this also; +for as the circles recede from the equator, the angles made by their +planes with the direction of the radial stream increases, and hence the +force of deflection is greater, and the effect is proportioned to the +cause. We have also a satisfactory explanation of the fact that there +has not yet been discovered a line of _no variation of horary +declination_ as we might reasonably anticipate from the fact that the +declinations are in _contrary directions_ in the northern and southern +hemisphere. This is owing to the ever-varying declination of the sun. +There would be such a line, no doubt, if the axis of the earth were +perpendicular to the plane of the orbit, and the magnetic pole coincided +with the pole of rotation: for then the equator would be such a line. + + +MAGNETIC STORMS. + +But there are also irregular fluctuations in the direction of the +magnetic needle. These depend on the moon, and are caused by the passage +of the vortices over or near to the place of observation. The action of +these vortices is proved to be of variable force, whether arising from +atmospheric conditions, or due to an increased activity of the ethereal +medium throughout the whole system, is at present immaterial. They do +vary, and sometimes the passage of a vortex will deflect the needle a +whole degree. At other times, there are magnetic storms extending over a +great part of the earth's surface; but there is reason to suppose, that +the extent of these storms has been over estimated. Thus, on the 25th of +September, 1841, a magnetic storm was observed in Toronto, and at the +same time there was one felt at the Cape of Good Hope. There is no great +mystery in this. If we suppose the axis of the central vortex, for +instance, to have passed Toronto in latitude 43° 33′ north, in ordinary +positions of the moon, in her orbit, the southern portion of the axis +would be in 33° or 34° south latitude, and consequently would have +passed near the Cape of Good Hope on the same night. Now, we certainly +could not expect the northern portion of the vortex to be intensely +active, without the southern portion being in the same state of +activity. That this is the true explanation is proved by magnetic storms +in the same hemisphere being comparatively limited in extent; as, +according to Gauss and Weber, magnetic storms which were simultaneously +felt from Sicily to Upsala, did not extend from Upsala to Alten. Still +it would not be wonderful if they were felt over a vast area of +thousands of miles as a consequence of _great_ disturbance in the +elasticity of the ether in the terral vortex; as the solid earth must be +permeable to all its motions, and thus be explicable on the general +principles we have advanced. + +But besides these variations which we have mentioned, there are changes +steadily going on, by which the isodynamic, isogonic and isoclinic lines +are permanently displaced on the surface of our planet. These must be +attributed to changes of temperature in the interior of the globe, and +to the direction in the progress of subterranean fires, which it may +also be expected will change the isogeothermal lines. But there are +changes, which although of long period, are yet periodic, one of which +is obviously due to the revolution of the lunar nodes in eighteen and a +half years, and the revolution of the apogee in nine years. The first is +continually changing the obliquity of the axis of the vortex, and they +both tend to limit the vortices in their extreme latitudes; but the +planet Jupiter has an indirect influence, which is probably equal, if +not greater, than the action of the moon, in changing the magnetic +declination. + +From the investigations of Lamont, it would appear, that the period of +the variations of magnetic declination is about 10⅓ years, while, +more recently, R. Wolfe has suggested the connection between this +variation and the solar spots, and assigns a period of 11.11 years, and +remarks, that it "corresponds more exactly with the variations in +magnetic declination than the period of 10⅓ years established by +Lamont. The magnetic variations accompany the solar spots, not only in +their regular changes, but even in their minor irregularities: this +latter fact is itself sufficient to prove definitely the important +relations between them."[28] + +As the planet Jupiter exerts the greatest influence on the sun, in +forcing the centre from the mechanical centre of the system, the +longitude of the sun will in a great measure depend on the position of +this planet; and, in consequence, the sun will generally revolve around +this centre in a period nearly equal to the period of Jupiter. The +sidereal period of Jupiter is about twelve years, but the action of the +other planets tend to shorten this period (at least, that has been the +effect for the last twenty or thirty years), and bring it nearly to the +period assigned by M. Wolfe to the variations in the magnetic +declinations. As this has its influence on the radial stream, and the +radial stream on the declination, we see at once the connection between +them. When we come to a consideration of the solar spots, we shall +exhibit this influence more fully. + + +AURORA BOREALIS. + +Let us now examine another phenomenon. The Aurora Borealis has been +generally considered to be in some way connected with the magnetism of +the earth, and with the position of the magnetic pole. It is certain +that the appearance of this meteor does affect the needle in a way not +to be mistaken, and (although not invariably) the vertex of the luminous +arch will usually conform to the magnetic meridian. Yet (and this is +worthy of attention), the observations made in the North Polar +Expeditions[29] "appear to prove, that in the immediate vicinity of the +magnetic pole the development of light is not in the least degree more +intense or frequent than at some distance from it." In fact, as the +American magnetic pole is, as stated, in latitude 73°, the central +vortex will seldom reach so high, and, consequently, the aurora ought +at such times to be more frequent in a lower latitude. In a late work by +M. de la Rive, this gentleman expresses the opinion, that the cause of +the aurora is not due to a radiation of polar magnetism, but to a purely +electrical action.[30] His explanation, however, is not so satisfactory +as his opinion. Now, we have examined numerous cases of auroral +displays, and never yet found one which could not be legitimately +referred to the action of ethereal vortices. Generally, the aurora will +not be visible, when the upper surface of the atmosphere of that +latitude in which the vortex is known to be (reckoning in the direction +of the magnetic meridian) is below the horizon, which shows that the +brightest portion is in the atmosphere. In latitude 41° even, it may +show itself when the vortex is three days north, more frequently when +one or two days north; but when the vortex passes centrally, or south, +it rarely is seen, and this is the only difficulty in explaining it by +the theory. But, when we reflect that the ether shoots out in straight +lines, and at an angle corresponding to the magnetic dip, we are at no +loss to perceive the reason of this. If each minute line composing the +light were seen endwise, it would be invisible; if there were millions +such in the same position, they could add nothing to the general effect; +but, when viewed sideways, the case would be different, there would be a +continued reduplication of ray upon ray, until in the range of some +hundreds of miles an effect might be produced amounting to any degree of +intensity on record. Now, this is the case when the aurora is +immediately overhead, it will be invisible to those below, but may be +seen by persons a hundred miles south; so, also, when it is to the +south, it is too oblique to the line of vision to be seen, especially as +all the rays to the northward of the observer can contribute nothing to +increase the effect. That it is of the nature of rays very much +diffused, can hardly be doubted; and, therefore, if only of a few miles +in depth, its impressions are too faint to be sensible. By referring to +the record of the weather in the second section of this work, an auroral +display will be found on July 12th, the central vortex having passed a +little to the northward the same evening, and the next day passing south +_descending_. On that occasion the author saw an inclined column, in +profile, due east, and between himself and a line of bluffs and timber, +about eight miles distant; And, he has not any doubt that the mass of +rays began where he stood. As in a shower, every drop, passing through a +conical surface, whose axis passes through the sun and through the eye, +contributes to form the apparently distant rainbow. + +The altitude of this meteor has been much exaggerated, especially of +those rings or luminous arches, which are often detached completely from +the luminous bank. On the 24th of May, a bright aurora was visible at +Ottawa, but the author's attention was engrossed by the most brilliant +arch of light he had ever seen. It was all the time south of the zenith, +and had no visible connection with the aurora north. At 9 hours, 59 +minutes, 30 seconds mean solar time, Arcturus was in the exact centre of +the band, at which time it was very bright, and full 7° wide. At the +same time, Prof. G.W. Wheeler observed the aurora in Perryville, in the +State of Missouri, only 1° of longitude to the westward, but did not see +the arch.[31] The difference of latitude between the two places being 3° +30′, and the weather, as he states, clear and still, there is only one +reason why he did not see the arch: it must have been too _low_, and had +become merged in the bank of light. At the time mentioned, the altitude +of Arcturus was 68° 30′, and, as Prof. Wheeler assigns only 10° as the +altitude of the bank, the maximum elevation of the arch, on the +supposition of its composing a part of the bank, was 43 miles. At +Perryville, the bank and streamers had disappeared at 10 o'clock. At +Ottawa, the arch or bow disappeared at 10 h. 5 m., differing only the +fraction of a minute from the time at Perryville; but, the bank was +still visible, but low and faint, the greatest altitude having been over +30°. To show the rapid fluctuations in width and position of this bow, +we will add a few of the minutes taken at the time with great care, in +hopes some other observer had been equally precise. When first seen, +there were three luminous patches, or elongated clouds of light; one in +Leo, one in Bootes, and another in Ophinchus, all in line. This was +about 9h. 15m. The times following are correct to 30 seconds: + + 9h. 42m. 30s. Bow complete; south edge 2° north of Arcturus. + + 9 45 30 Northern edge diffuse south; edge bright, and well + defined; 10° wide in zenith; north edge on Alphacca. + + 9 47 30 South edge 5° north of Arcturus; north edge close to + Cor. Caroli. + + 9 53 30 Eastern half composed of four detached bands + _shingling_ over each other. + + 58 30 Arcturus on south; bow narrower. + + 9 59 30 Arcturus in the middle of the band; very bright and + regular in outline, and widest at the zenith. + + 10 0 30 Arcturus on northern edge; north side better defined + than the southern. + + 10 2 0 Arcturus 1° north; very bright. + + 10 2 30 Gamma and Delta Leonis, northern edge. + + 10 3 Regulus on southern age; getting faint. + + 10 5 Fast fading away. + + 10 5 30 Scarcely visible; bank in north faint. + +This aurora was due to the _inner vortex ascending_, whose period was at +this time 28 days. + +There are several circumstances to be observed in this case. The bow +brightened and faded simultaneously with the aurora, and respected the +vertex of the auroral bank, being apparently concentric with it. The +bow, therefore, depends on the same cause, but differs from the aurora +in being limited to the _surface_ of the atmosphere in which the vortex +has produced a wave to the southward of its central path, as may be +understood by inspecting Fig. 2, Sec. 1,--the figure representing the +polar current of the central vortex. On the 29th of May, 1840,[32] the +author saw a similar phenomenon, at the same time of night, and passing +over the same stars southward until it reached within 5° of Jupiter and +Saturn, to which it was parallel. This atmospheric wave offers a greater +resistance to the passage of the ether: hence the light. On this account +it is, also, that when the passage of a vortex is attended by an auroral +display there will be no thunder-storm. There may be an increase of +wind; but the atmosphere at such times is too dry to make a violent +storm, and there is a silent restoration of the equilibrium, by the +ether passing through the dry atmosphere, without meeting any +condensable vapor, and becoming luminous on account of the greater +resistance of the air when unmixed with vapor. We thus see also the +connection between the aurora and the linear cirri, and we have a +triumphant explanation of the fact, that when the observer is north of +the northern limit of the vortices, he sees the aurora to the south and +not to the north; for, to see it to the northward, he would have to see +it in the same latitude as it appears in the south, and, consequently, +have to see across twice the complement of the latitude. We thus see, +also, why the temperature falls after an aurora; for, the passage of +electricity in any shape, must have this effect on account of the great +specific caloric of this fluid. We see, also, why the aurora should be +more frequent where the magnetic intensity is greatest and be +consequently invisible at the equator, and why the magnetic needle is so +sensibly affected at the time of its occurrence. We may, perhaps, here +be allowed to allude to another phenomenon connected with terrestrial +magnetism and electricity. + + +EARTHQUAKES. + +The awful and destructive concussions which sometimes are produced at +great depths beneath the surface of the soil, would seem to indicate +that no force but that of electricity is adequate to account for the +almost instantaneous desolation of wide tracts of the earth's surface. +But we do not mean to say that the action of the terral vortices, +combined with the internal conditions of our planet, is the only cause; +although it is far from improbable that the same activity of the ether, +which generates through these vortices, the full fury of the hurricane +in the tropics, may be simultaneously accompanied by a _subterranean_ +storm. And physicists are too rash to reject the evidence on which the +connection of the phenomena rests. + +In the extract given by Colonel Reid, in his "Law of Storms," from Sir +George Rodney's official report of the great hurricane of 1780, it is +stated, that, "Nothing but an earthquake could have occasioned the +_foundations_ of the strongest buildings to be rent; and I am convinced +that the violence of the wind must have prevented the inhabitants from +feeling the earthquake which certainly attended the storm."[33] Again, +in the Savannah-la-Mar hurricane, which occurred the same year and +month, the Annual Register, published at Jamaica, states, that at the +same time, "a smart shock of an earthquake was felt." The general +serenity of equatorial regions is due to the fact that they are beyond +the limit of the vortices, as in Peru, where neither rain nor lightning +nor storm is ever seen. Thunder and rain, without storms, however, are +common in other tropical countries, also out of the reach of the +vortices. But even in those parts, (as the Antilles,) lying in the track +of these vortices, the weather is not as _frequently_ disturbed as in +higher latitudes. The storms of the Antilles, when they do occur, +however, are fearful beyond any conception, showing the presence of some +cause, auxiliary to the ordinary disturbing action of the vortices, +which, when simultaneously occurring, adds tremendously to their force. + +That earthquakes are preceded _sometimes_ by a peculiar haziness and +oppressiveness, similar to that which sometimes precedes a storm, is a +current opinion in volcanic countries. And Humboldt, who doubts the +connection, has to confess that sudden changes of weather have +_succeeded_ violent earthquakes, and that "during the great earthquake +of Cumana, he found the inclination of the needle was diminished 48′." +He also mentions the simultaneous occurrence of shocks, from +earthquakes, and a clap of thunder, and the agitation of the +electrometer during the earthquake, which lasted from the 2d of April to +the 17th of May, 1808; but concluding that "these indications presented +by clouds, by modifications of atmospheric electricity, or by calms, +cannot be regarded as _generally_ or _necessarily_ connected with +earthquakes, since in Peru, Canada, and Italy, earthquakes are observed, +along with the purest and clearest skies, and with the freshest land and +sea breezes. But if no meteorological phenomena indicates the coming +earthquake, either on the morning of the shock or a few days previously, +the influence of certain periods of the year, (the vernal and autumnal +equinoxes,) the commencement of the rainy season in the tropics, after +long drought, cannot be overlooked, even though the genetic connection +of meteorological processes, with those going on in the interior of our +globe, is still enveloped in obscurity."[34] + +It is at the equinoxes that the earth changes her distances from the sun +most rapidly, and whether she is passing from her perihelion or from +her aphelion, the density of the ether externally is changing in the +subduplicate ratio of these distances and consequently at these times +there will be the greatest disturbance of the electric equilibrium. How +far our views of the internal structure of our globe, (considered along +a diameter as a solid crust, then a fused mass separated from the lower +ocean by another solid crust, and separated from a similar arrangement +on the opposite side by an interposed mass of water, perhaps also +possessing a solid nucleus,) may affect this question, is difficult to +say; but that the agent is electric, appears highly probable; and very +recently it has been discovered, by M. Ratio Menton, that a piece of +iron, suspended by attraction to a magnet, will fall on the approach of +an earthquake; thus indicating that the power of the magnet is +temporarily weakened by the action of some disturbing force. + + +FOOTNOTES: + +[22] Hum. Cosmos, art Aerolites. + +[23] We shall in all cases use this abbreviation for the extremely +awkward word zodiacal. + +[24] It is here assumed, that all the vortices are at their apogee at +the same time, and, consequently, they lie in different longitudes, but +the central being between, its position is taken for the average +position of the three. + +[25] It is far from improbable that the effect produced in one zone of +climate, may be reversed in another, from the nature of the cause. + +[26] That the 11th, 12th, and 13th of May should recede 2° in +temperature as determined by Mædler from observations of 86 years, at a +time when the power of the sun so rapidly augments, is strongly +confirmatory of the theory. See _Cosmos_, p. 121. + +[27] Plucker first discovered that a plate of tourmaline suspended with +its axis vertical, set axial. + +[28] Silliman's Journal for March and April, 1853. + +[29] Humboldt, _Cosmos_ p. 193, London ed. + +[30] See Silliman's Journal for September, 1853. + +[31] See Silliman's Journal for September, 1853. + +[32] This was the central vortex ascending. + +[33] Reid's Law of Storms, p. 350. + +[34] Humboldt, _Cosmos_, p. 203. + + + + +SECTION FOURTH. + + +THE SOLAR SPOTS. + +We have yet many phenomena to investigate by the aid of the theory, and +we will develop them in that order which will best exhibit their mutual +dependence. The solar spots have long troubled astronomers, and to this +day no satisfactory solution of the question has been proposed; but we +shall not examine theories. It is sufficient that we can explain them on +the same general principles that we have applied to terrestrial +phenomena. There can be but little doubt about the existence of a solar +atmosphere, and, reasoning from analogy, the constituent elements of the +sun must partake of the nature of other planetary matter. That there are +bodies in our system possessing the same elements as our earth, is +proved by the composition of meteoric masses, which, whether they are +independent bodies of the system, or fragments of an exploded planet, or +projected from lunar volcanoes, is of little consequence; they show that +the same elements are distributed to other bodies of the system, +although not necessarily in the same proportions. The gaseous matter of +the sun's atmosphere may, therefore, be safely considered as vapors +condensable by cold, and the formation of vortices over the surface of +this atmosphere, brings down the ether, and causes it to intermingle +with this atmosphere. But, from the immensely rapid motion of the polar +current of the solar vortex, this ether may be considered to enter the +atmosphere of the sun with the temperature of space. + +Sir John Herschel, in commenting on the theory of Mr. Redfield before +the British Association, convened at Newcastle in 1838,[35] suggested an +analogy to terrestrial hurricanes, from a suspected rotation and +progressive motion in these spots. From their rapid formation, change of +shape, and diameter, this view is allowable, and, taken in conjunction +with the action of the ethereal currents, will account for all the +phenomena. The nucleus of the spot is dense, like the nucleus of a storm +on the earth, and surrounded by a penumbon precisely as our storms are +fringed with lighter clouds, permitting the light of the sun to +penetrate. And, it has been observed, that these spots seem to follow +one another in lines on the same parallel of solar latitude (or nearly +the same), exactly as we have determined the action of the vortices on +the surface of the earth from observation. These spots are never found +in very high latitudes--not much above 30° from the solar equator. If we +consider this equator to be but slightly inclined to the plane of the +vortex, this latitude would be the general position of the lateral solar +vortices, and, in fact, be confined principally to a belt on each side +of the equator, between 15° and 30° of solar latitude, rather than at +the equator itself. This, it is needless to say, is actually the case. +But, a more capital feature still has been more recently brought to +light by observation, although previously familiar to the author, who, +in endeavoring to verify the theory, seriously injured his sight, by +observing with inadequate instrumental means. This is the periodicity of +the spots. + +We have already observed, that there is reason to suppose that the +action of the inner vortex of the earth is probably greater than that of +the outer vortex, on account of the conflicting currents by which it is +caused. And the full development of this vortex requires, that the +central vortex or mechanical axis of the system shall be nearly +tangential to the surface. In this position, the action of the central +vortex is itself at a maximum; and, when the planets of the system are +so arranged as to produce this result, we may expect the greatest number +of spots. If the axis or central vortex approaches to coincidence with +the axis of the sun, the lateral vortices disappear, and the central +vortex being then perpendicular to the surface, is rendered ineffective. +Under these circumstances, there will be no spots on the sun's disc. +When, on the other hand, all the planets conspire at the same side to +force the sun out from the mechanical centre of the system, the surface +is too distant to be acted on by the central vortex, and the lateral +vortices are also thrown clear of the sun's surface, on account of the +greater velocity of the parts of the vortex, in sweeping past the body +of the sun. In this case, there will be but few spots. The case in which +the axis of the vortex coincides with the axis of the sun, is much more +transient than the first position, and hence, although the interval +between the maxima will be tolerably uniform, there will be an +irregularity between a particular maximum, and the preceding and +subsequent minimum. + +The following table exhibits the solar spots, as determined by Schwabe, +of Dessau: + + Year of observation. Groups of spots observed. Number of days. + 1826 118 277 + 1827 161 273 + 1828 225 282 + 1829 199 244 + 1830 190 217 + 1831 149 239 + 1832 84 270 + 1833 33 267 + 1834 51 273 + 1835 173 244 + 1836 272 200 + 1837 333 168 + 1838 282 202 + 1839 162 205 + 1840 152 263 + 1841 102 283 + 1842 68 307 + 1843 34 324 + +Previous to the publication of this table, the author had inferred the +necessity of admitting the existence of another planet in the solar +system, from the phenomenon of which we are speaking. He found a +sufficient correspondence between the minima of spots to confirm the +explanation given by the theory, and this was still more confirmed by +the more exact determination of Schwabe; yet there was a little +discrepancy in the synchronous values of the ordinates, when the theory +was graphically compared with the table. Previous to the discovery of +Neptune, the theory corresponded much better than afterwards, and as no +doubt could be entertained that the anomalous movements of Uranus were +caused by an exterior planet, he adopted the notion that there were two +planets exterior to Uranus, whose positions at the time were such, that +their mechanical affects on the system were about equal and contrary. +Consequently, when Neptune became known, the existence of another planet +seemed a conclusion necessary to adopt. Accordingly, he calculated the +heliocentric longitudes and true anomalies, and the values of radius +vector, for all the planets during the present century, but not having +any planetary tables, he contented himself with computing for the +nearest degree of true anomaly, and the nearest thousand miles of +distance. Then by a composition and resolution of all the forces, he +deduced the radius vector of the sun, and the longitude of his centre, +for each past year of the century. It was in view of a little +outstanding discrepancy in the times of the minima, as determined by +theory and observation, that he was induced to consider as almost +certain the existence of a theoretical planet, whose longitude, in 1828, +was about 90°, and whose period is from the theory about double that of +Neptune. And for convenience of computation and reference, he has been +in the habit of symbolizing it by a volcano. The following table of the +radii vectores of the sun, and the longitude of his centre, for the +years designated in Schwabe's table, is calculated from the following +data for each planet: + + Long. of + Planets. Masses. Mean distances. Eccentricities. Perihelion. + ♃ 1/1648 494.800.000 0.0481 11° + ♄ 1/3310 907.162.000 0.0561 89 + ♅ 1/23000 1824.290.000 0.0166 167 + ♆ 1/20000 2854.000.000 0.0088 0 + ⊿ 1/28000 4464.000.000 + + No. of spots in + Dates. Rad. vector. Sun's long. Ordinates. Schwabe's table. + Jan. 1, 1826 528,000 320° + 84 118 + " 1827 480,000 339 + 36 161 + " 1828 432,000 352 - 12 Max. 225 Max. + " 1829 397,000 38 - 47 199 + " 1830 858,000 71 - 86 190 + " 1831 324,000 104 - 120 149 + " 1832 311,000 144 - 133 84 + " 1833 300,000 183 - 144 Min. 33 Min. + " 1834 307,000 220 - 137 51 + " 1835 338,000 263 - 106 173 + " 1836 380,000 302 - 55 272 + " 1837 419,000 337 + 25 Max. 333 Max. + " 1838 488,000 3 + 44 282 + " 1839 651,000 29 + 107 162 + " 1840 632,000 51 + 188 152 + " 1841 680,000 80 + 236 102 + " 1842 730,000 105 + 286 68 + " 1843 160,000 128 + 322 34 Min. + " 1844 188,000 152 + 339 Min. 52 + " 1845 772,000 174 + 328 114 + " 1846 728,000 196 + 284 157 + " 1847 660,000 218 + 216 + " 1848 563,000 240 + 119 Observed. Max. + " 1849 447,000 261 + 3 Max. + " 1850 309,000 283 - 135 + " 1851 170,000 323 - 274 + " 1852 53,000 41 - 391 Min. + " 1853 167,000 133 - 277 + " 1854 315,000 160 - 129 + " 1855 475,000 183 + 31 Max. + " 1856 611,000 203 + 167 + " 1857 720,000 225 + 276 + +It is necessary to observe here, that the values of the numbers in +Schwabe's table are the numbers for the whole year, and, therefore, the +1st of July would have been a better date for the comparison; but, as +the table was calculated before the author was cognizant of the fact, +and being somewhat tedious to calculate, he has left it as it was, viz., +for January 1st of each year. Hence, the minimum for 1843 appears as +pertaining to 1844. The number of spots ought to be inversely as the +ordinates approximately--these last being derived from the Radii +Vectores minus, the semi-diameter of the sun = 444,000 miles. + +In passing judgment on this relation, it must also be borne in mind, +that the recognized masses of the planets cannot be the true masses, if +the theory be true. Both sun and planets are under-estimated, yet, as +they are, probably, all to a certain degree proportionally undervalued, +it will not vitiate the above calculation much. + +The spots being considered as solar storms, they ought also to vary in +number at different times of the year, according to the longitude of the +earth and sun, and from their transient character, and the slow rotation +of the sun, they ought, _ceteris paribus_, to be more numerous when the +producing vortex is over a visible portion of the sun's surface. + +The difficulty of reconciling the solar spots, and their periodicity to +any known principle of physics, ought to produce a more tolerant spirit +amongst the scientific for speculations even which may afford the +slightest promise of a solution, although emanating from the humblest +inquirer after truth. The hypothesis of an undiscovered planet, exterior +to Neptune, is of a nature to startle the cautions timidity of many; +but, if the general theory be true, this hypothesis becomes extremely +probable. We may not have located it exactly. There may be even two such +planets, whose joint effect shall be equivalent to one in the position +we have assigned. There may even be a comet of great mass, capable of +producing an effect on the position of the sun's centre (although it +follows from the theory that comets have very little mass). Yet, in view +of all these suppositions, there can be but little doubt that the solar +spots are caused by the solar vortices, and these last made effective on +the sun by the positions of the great planets, and, therefore, we have +indicated a new method of determining the existence and position of all +the planets exterior to Neptune. On the supposition that there is only +one more in the system, from its deduced distance and mass, it will +appear only as a star of the eleventh magnitude, and, consequently, will +only be recognizable by its motion, which, at the greatest, will only be +ten or eleven seconds per day. + + +MASSES OF THE SUN AND PLANETS. + +We have alluded to the fact of the radial stream of the sun necessarily +diminishing the sun's power, and, consequently, diminishing his apparent +mass. The radial stream of all the planets will do the same, so that +each planet whose mass is derived from the periodic times of the +satellites, will also appear too small. But, there is also a great +probability that some modification must be made in the wording of the +Newtonian law. The experiments of Newton on the pendulum, with every +variety of substance, was sufficient justification to entitle him to +infer, that inertia was as the weight of matter universally. But, there +was one condition which could not be observed in experimenting on these +substances, viz., the difference of temperature existing between the +interior and surface of a planet. + +We have already expressed the idea, that the cause of gravity has no +such mysterious origin as to transcend the power of man to determine it. +But that, on the contrary, we are taught by every analogy around us, as +well as by divine precept, to use the visible things of creation as +stepping stones to the attainment of what is not so apparent. That we +have the volume of nature spread out in tempting characters, inviting us +to read, and, assuredly, it is not so spread in mockery of man's limited +powers. As science advances, strange things, it is true, are brought to +light, but the more _rational_ the queries we propound, in every case +the more satisfactory are the answers. It is only when man consults the +oracle in irrational terms that the response is ambiguous. Alchemy, with +its unnatural transmutations, has long since vanished before the +increasing light. Why should not attraction also? Experience and +experiment, if men would only follow their indications, are consistently +enforcing the necessity of erasing these antiquated chimeras from the +book of knowledge; and inculcating the great truth, that the physical +universe owes all its endless variety to differences in the form, size, +and density of planetary atoms in motion, according to simple mechanical +principles. These, combined with the existence of an all-pervading +medium filling space, between which and planetary matter no bond of +union subsists, other than that which arises from a continual +interchange of motion, are the materials from which the gems of nature +are elaborated. But, simplicity of means is what philosophy has ever +been reluctant to admit, preferring rather the occult and obscure. + +If action be equal to reaction, and all nature be vibrating with motion, +these motions must necessarily interfere, and some effect should be +produced. A body radiating its motion on every side into a physical +medium, produces waves. These waves are a mechanical effect, and the +body parts with some of its motion in producing them; but, should +another body be placed in juxtaposition, having the same motion, the +opposing waves neutralize each other, and the bodies lose no motion from +their contiguous sides, and, therefore, the reaction from the opposite +sides acts as a propelling power, and the bodies approach, or tend to +approach each other. If one body be of double the inertia, it moves only +half as far as the first; then, seeing that this atomic motion is +radiated, the law of force must be directly as the mass, and inversely +as the squares of the distances. There may be other atomic vibrations +besides those which we call light, heat, and chemical action, yet the +joint effect of all is infinitesimally small, when we disregard the +united _attraction_ of all the atoms of which the earth is composed. The +_attraction_ of the whole earth at the surface causes bodies to fall 16 +feet the first second of time; but, if two spheres of ice of one foot +diameter, were placed in an infinite space, uninfluenced by other +matter, and only 16 feet apart, they would require nearly 10,000 years +to fall together by virtue of their mutual attraction. Our conceptions, +or, rather, our misconceptions, concerning the force of gravity, arises +from our forgetting that every pound of matter on the earth contributes +its share of the force which, in the aggregate, is so powerful. Hence, +the cause we have suggested, is fully adequate to account for the +phenomena. Whether the harmony of vibrations between two bodies may not +have an influence in determining the amount of interference, and, +consequently, produce _some_ difference between the gravitating mass +and its inertia, is a question which, no doubt, will ultimately be +solved; but this harmony of vibrations must depend, in some degree, on +the atomic weight, temperature, and intensity of atomic motion. + +That a part of the mass of the earth is _latent_ may be inferred from +certain considerations: 1st, from the discrepancies existing in the +results obtained for the earth's compression by the pendulum and by +actual measurement; and, 2d, from the irregularity of that compression +in particular latitudes and longitudes. The same may also be deduced +from the different values of the moon's mass as derived from different +phenomena, dependent on the law of gravitation. Astronomers have +hitherto covered themselves with the very convenient shield of errors of +observation; but, the perfection of modern instruments now demand a +better account of all outstanding discrepancies. The world requires it +of them. + +The mass of the moon comes out much greater by our theory than nutation +gives. The mass deduced from the theory is only dependent on the +relative inertiæ of the earth and moon. That given by nutation depends +on gravity. If, then, a part of the mass be latent, nutation will give +too small a value. But, in addition to this, we are justified in +doubting the strict wording of the Newtonian law, deriving our authority +from the very foundation stone of the Newtonian theory. + +It is well known that Newton suspected that the moon was retained in her +orbit by the same force which is usually called weight upon the surface, +sixteen years before the fact was confirmed, by finding a correspondence +in the fall of the moon and the fall of bodies on the earth. Usually, in +all elementary works, this problem is considered accurately solved. +Having formed a different idea of the mechanism of nature, this fact +presented itself as a barrier beyond which it was impossible to pass, +until suspicions, derived from other sources, induced the author to +inquire: Whether the phenomenon did exactly accord with the theory? We +are aware that it is easy to place the moon at such a distance, that the +result shall strictly correspond with the fact; but, from the parallax, +as derived from observation (and if this cannot be depended on +certainly, no magnitudes in astronomy can), we find, _that the moon does +not fall from the tangent of her orbit, as much as the theory requires_. +As this is of vital importance to the integrity of the theory we are +advocating, we have made the computation on Newton's own data, except +such as were necessarily inaccurate at the time he wrote; and we have +done it arithmetically, without logarithmic tables, that, if possible, +no error should creep in to vitiate the result. We take the moon's +elements from no less an authority than Sir John Herschel, as well as +the value of the earth's diameter. + + Mass of the moon 1/80 + Mean distance in equatorial radii 59.96435 + Sidereal period in seconds 2360591 + +The vibrations of the pendulum give the force of gravity at the surface +of the earth, and it is found to vary in different latitudes. The +intensity in any place being as the squares of the number of vibrations +in a given time. This inequality depends on the centrifugal force of +rotation, and on the spheroidal figure of the earth due to that +rotation. At the equator the fall of a heavy body is found to be +16.045223 feet, per second, and in that latitude the squares of whose +sine is ⅓, it is 16.0697 feet. The effect in this last-named latitude +is the same as if the earth were a perfect sphere. This does not, +however, express the whole force of gravity, as the rotation of the +earth causes a centrifugal tendency which is a maximum at the equator, +and there amounts to 1/289 of the whole gravitating force. In other +latitudes it is diminished in the ratio of the squares of the cosines of +the latitude; it therefore becomes 1/434 in that latitude the square of +whose sine is ⅓. Hence the fall per second becomes 16.1067 feet for +the true gravitating force of the earth, or for that force which retains +the moon in her orbit. + +The moon's mean distance is 59.96435 equatorial radii of the earth, +which radius is, according to Sir John Herschel, 20.923.713 +feet. Her mean distance as derived from the parallax is not to be +considered the radius vector of the orbit, inasmuch as the earth also +describes a small orbit around the common centre of gravity of the earth +and moon; neither is radius vector to be considered as her distance from +this common centre; for the attracting power is in the centre of the +earth. But the mean distance of the moon moving around a movable centre, +is to the same mean distance when the centre of attraction is fixed, as +the sum of the masses of the two bodies, to the first of two mean +proportionals between this sum and the largest of the two bodies +inversely. (Vid. Prin. Prop. 60 Lib. Prim.) The ratio of the masses +being as above 80 to 1 the mean proportional sought is 80.666 and in +this ratio must the moon's mean distance be diminished to get the force +of gravity at the moon. Therefore as 81 is to 80.666, so is 59.96435 to +59.71657 for the moon's distance in equatorial radii of the earth. +Multiply this last by 20.923,713 to bring the semi-diameter of the lunar +orbit into feet = 1.249.492.373, and this by 6.283185, the ratio of the +circumference to the radius, gives 7.850.791.736 feet, for the mean +circumference of the lunar orbit. + +Further, the mean sidereal period of the moon is 2360591 seconds and the +1/2360591th part of 7.850.791.736 is the arc the moon describes in one +second = 3325.77381 feet, the square of which divided by the diameter +of the orbit, gives the fall of the moon from the tangent or versed +size of that arc. + + 1106771.36876644 + = ---------------- = 0.004426106 feet. + 2498984746 + +This fraction is, however, too small, as the ablatitious action of the +sun diminishes the attraction of the earth on the moon, in the ratio of +178 29/40 to 177 29/40. So that we must increase the fall of the moon +in the ratio of 711 to 715, and hence the true fall of the moon from the +tangent of her orbit becomes 0.00451 feet per second. + +We have found the fall of a body at the surface of the earth, considered +as a sphere, 16.1067 feet per second, and the force of gravity +diminishes as the squares of the distances increases. The polar diameter +of the earth is set down as 7899.170 miles, and the equatorial diameter +7925.648 miles; therefore, the mean diameter is 7916.189 miles.[36] So +that, reckoning in mean radii of the earth, the moon's distance is +59.787925, which squared, is equal to 3574.595975805625. At one mean +radius distance, that is, at the surface, the force of gravity, or fall +per second, is as above, 16.1067 feet. Divide this by the square of the +distance, it is 16.1067/3574.595975805625 = 0.0045058 feet for the force +of gravity at the moon. But, from the preceding calculation, it appears, +that the moon only falls 0.0044510 feet in a second, showing a +deficiency of 1/82d part of the principal force that retains the moon in +her orbit, being more than double the whole disturbing power of the sun, +which is only 1/178th of the earth's gravity at the moon; yet, on this +1/178th depends the revolution of the lunar apogee and nodes, and all +those variations which clothe the lunar theory with such formidable +difficulties. The moon's mass cannot be less than 1/80, and if we +consider it greater, as it no doubt is, the results obtained will be +still more discrepant. Much of this discrepancy is owing to the +expulsive power of the radial stream of the terral vortex; yet, it may +be suspected that the effect is too great to be attributed to this, and, +for this reason, we have suggested that the fused matter of the moon's +centre may not gravitate with the same force as the exterior parts, and +thus contribute to increase the discrepancy. + +As there must be a similar effect produced by the radial stream of every +vortex, the masses of all the planets will appear too small, as derived +from their gravitating force; and the inertia of the sun will also be +greater than his apparent mass; and if, in addition to this, there be a +portion of these masses latent, we shall have an ample explanation of +the connection between the planetary densities and distances. We must +therefore inquire what is the particular law of force which governs the +radial stream of the solar vortex. It will be necessary to enter into +this question a little more in detail than our limits will justify; but +it is the resisting influence of the ether, and its consequences, which +will appear to present a vulnerable point in the present theory, and to +be incompatible with the perfection of astronomical science. + + +LAW OF DENSITY IN SOLAR VORTEX. + +Reverting to the dynamical principle, that the product of every particle +of matter in a fluid vortex, moving around a given axis, by its distance +from the centre and angular velocity, must ever be a constant quantity, +it follows that if the ethereal medium be uniformly dense, the periodic +times of the parts of the vortex will be directly as the distances from +the centre or axis; but the angular velocities being inversely as the +times, the absolute velocities will be equal at all distances from the +centre. + +Newton, in examining the doctrine of the Cartesian vortices, supposes +the case of a globe in motion, gradually communicating that motion to +the surrounding fluid, and finds that the periodic times will be in the +duplicate ratio of the distances from the centre of the globe. He and +his successors have always assumed that it was impossible for the +principle of gravity to be true, and a Cartesian plenum also; +consequently, the question has not been fairly treated. It is true that +Descartes sought to explain the motions of the planets, by the +mechanical action of a fluid vortex _solely_; and to Newton belongs the +glorious honor of determining, the existence of a centripetal force, +competent to explain these motions mathematically, (but not physically,) +and rashly rejected an intelligible principle for a miraculous virtue. +If our theory be true, the visible creation depends on the existence of +both working together in harmony, and that a physical medium is +absolutely necessary to the existence of gravitation. + +If space be filled with a fluid medium, analogy would teach us that it +is in motion, and that there must be inequalities in the direction and +velocity of that motion, and consequently there must be vortices. And if +we ascend into the history of the past, we shall find ample testimony +that the planetary matter now composing the members of the solar system, +was once one vast nebulous cloud of atoms, partaking of the vorticose +motion of the fluid involving them. Whether the gradual accumulation of +these atoms round a central nucleus from the surrounding space, and thus +having their tangential motion of translation converted into vorticose +motion, first produced the vortex in the ether; or whether the vortex +had previously existed, in consequence of conflicting currents in the +ether, and the scattered atoms of space were drawn into the vortex by +the polar current, thus forming a nucleus at the centre, as a necessary +result of the eddy which would obtain there, is of little consequence. +The ultimate result would be the same. A nucleus, once formed, would +give rise to a central force, tending more and more to counteract the +centripulsive power of the radial stream; and in consequence of this +continually increasing central power, the heaviest atoms would be best +enabled to withstand the radial stream, while the lighter atoms might be +carried away to the outer boundaries of the vortex, to congregate at +leisure, and, after the lapse of a thousand years, to again face the +radial stream in a more condensed mass, and to force a passage to the +very centre of the vortex, in an almost parabolic curve. That space is +filled with isolated atoms or planetary dust, is rendered very probable +by a fact discovered by Struve, that there is a gradual extinction in +the light of the stars, amounting to a loss of 1/107 of the whole, in +the distance which separates Sirius from the sun. According to Struve, +this can be accounted for, "by admitting as very probable that space is +filled with an _ether_, capable of intercepting in some degree the +light." Is it not as probable that this extinction is due to planetary +dust, scattered through the pure ether, whose vibrations convey the +light,--the material atoms of future worlds,--the debris of dilapidated +comets? Does not the Scripture teach the same thing, in asserting that +the heavens are not clean? + +The theory of vortices has had many staunch supporters amongst those +deeply versed in the science of the schools. The Bernoullis proposed +several ingenious hypothesis, to free the Cartesian system from the +objections urged against it, viz.: that the velocities of the planets, +in accordance with the three great laws of Kepler, cannot be made to +correspond with the motion of a fluid vortex; but they, and all others, +gave the vantage ground to the defenders of the Newtonian philosophy, by +seeking to refer the principle of gravitation to conditions dependent on +the density and vorticose motion of the ether. When we admit that the +ether is imponderable and yet material, and planetary matter subject to +the law of gravitation, the objections urged against the theory of +vortices become comparatively trivial, and we shall not stop to refute +them, but proceed with the investigation, and consider that the ether is +the original source of the planetary motions and arrangements. + +On the supposition that the ether is uniformly dense, we have shown that +the periodic times will be directly as the distances from the axis. If +the density be inversely as the distances, the periodic times will be +equal. If the density be inversely as the square roots of the distances, +the times will be directly in the same ratio. The celebrated J. +Bernoulli assumed this last ratio; but seeking the source of motion in +the rotating central globe, he was led into a hypothesis at variance +with analogy. The ellipticity of the orbit, according to this view, +was caused by the planet oscillating about a mean position,--sinking +first into the dense ether,--then, on account of superior buoyancy, +rising into too light a medium. Even if no other objection could be +urged to this view, the difficulty of explaining why the ether should be +denser near the sun, would still remain. We might make other +suppositions; for whatever ratio of the distances we assume for the +density of the medium, the periodic times will be compounded of those +distances and the assumed ratio. Seeing, therefore, that the periodic +times of the planets observe the direct ses-plicate ratio of the +distances, and that it is consonant to all analogy to suppose the +contiguous parts of the vortex to have the same ratio, we find that the +density of the ethereal medium in the solar vortex, is directly as the +square roots of the distances from the axis. + +Against this view, it may be urged that if the inertia of the medium is +so small, as is supposed, and its elasticity so great, there can be no +condensation by centrifugal force of rotation. It is true that when we +say the ether is condensed by this force, we speak incorrectly. If in an +infinite space of imponderable fluid a vortex is generated, the central +parts are rarefied, and the exterior parts are unchanged. But in all +finite vortices there must be a limit, outside of which the motion is +null, or perhaps contrary. In this case there may be a cylindrical ring, +where the medium will be somewhat denser than outside. Just as in water, +every little vortex is surrounded by a circular wave, visible by +reflection. As the density of the planet Neptune appears, from present +indications, to be a little denser than Uranus, and Uranus is denser +than Saturn, we may conceive that there is such a wave in the solar +vortex, near which rides this last magnificent planet, whose ring would +thus be an appropriate emblem of the peculiar position occupied by +Saturn. This may be the case, although the probability is, that the +density of Saturn is much greater than it appears, as we shall presently +explain. + +In order to show that there is nothing extravagant in the supposition of +the density of the ether being directly as the square roots of the +distances from the axis, we will take a fluid whose law of density is +known, and calculate the effect of the centrifugal force, considered as +a compressing power. Let us assume our atmosphere to be 47 miles high, +and the compressing power of the earth's gravity to be 289 times greater +than the centrifugal force of the equator, and the periodic time of +rotation necessary to give a centrifugal force at the equator equal to +the gravitating force to be 83 minutes. Now, considering the gravitating +force to be uniform, from the surface of the earth upwards, and knowing +from observation that at 18,000 feet above the surface, the density of +the air is only ½, it follows, (in accordance with the principle that +the density is as the compressing force,) that at 43½ miles high, or +18,000 feet _below_ the surface of the atmosphere, the density is only +1/8000 part of the density at the surface of the earth. Let us +take this density as being near the limit of expansion, and conceive a +hollow tube, reaching from the sun to the orbit of Neptune, and that +this end of the tube is closed, and the end at the sun communicates with +an inexhaustible reservoir of such an attenuated gas as composes the +upper-layer of our atmosphere; and further, that the tube is infinitely +strong to resist pressure, without offering resistance to the passage of +the air within the tube; then we say, that, if the air within the tube +be continually acted on by a force equal to the mean centrifugal force +of the solar vortex, reckoning from the sun to the orbit of Neptune, the +density of the air at that extremity of the tube, would be greater than +the density of a fluid formed by the compression of the ocean into one +single drop. For the centrifugal force of the vortex at 2,300,000 miles +from the centre of the sun, is equal to gravity at the surface of the +earth, and taking the mean centrifugal force of the whole vortex as +one-millionth of this last force; so that at 3,500,000 miles from the +surface of the sun, the density of the air in the tube (supposing it +obstructed at that distance) would be double the density of the +attenuated air in the reservoir. And the air at the extremity of the +tube reaching to the orbit of Neptune, would be as much denser than the +air we breathe, as a number expressed by 273 with 239 ciphers annexed, +is greater than unity. This is on the supposition of infinite +compressibility. Now, in the solar vortex there is no physical barrier +to oppose the passage of the ether from the centre to the circumference, +and the density of the ethereal ocean must be considered uniform, except +in the interior of the stellar vortices, where it will be rarefied; and +the rarefaction will depend on the centrifugal force and the length of +the axis of the vortex. If this axis be very long, and the centrifugal +velocity very great, the polar influx will not be sufficient, and the +central parts will be rarefied. We see, therefore, no reason why the +density of the ether may not be three times greater at Saturn than at +the earth, or as the square roots of the distances directly. + + +BODES' LAW OF PLANETARY DISTANCES. + +Thus, in the solar vortex, there will be two polar currents meeting at +the sun, and thence being deflected at right angles, in planes parallel +to the central plane of the vortex, and strongest in that central plane. +The velocity of expansion must, therefore, diminish from the divergence +of the radii, as the distances increase; but in advancing along these +planes, the ether of the vortex is continually getting more dense, +which operate by absorption or condensation on the radial stream; so +that the velocity is still more diminished, and this in the ratio of the +square roots of the distances directly. By combining these two ratios, +we find that the velocity of the radial stream will be in the +ses-plicate ratio of the distances inversely. But the force of this +stream is not as the velocity, but as the square of the velocity. The +_force_ of the radial stream is consequently as the cubes of the +distances inversely, from the axis of the vortex, reckoned in the same +plane. If the ether, however, loses in velocity by the increasing +density of the medium, it becomes also more dense; therefore the true +force of the radial stream will be as its density and the square of its +velocity, or directly as the square roots of the distances, and +inversely as the cubes of the distances, or as the 2.5 power of the +distances inversely. + +If we consider the central plane of the vortex as coincident with the +plane of the ecliptic, and the planetary orbits, also, in the same +plane; and had the force of the radial stream been inversely as the +square of the distances, there could be no disturbance produced by the +action of the radial stream. It would only counteract the gravitation of +the central body by a certain amount, and would be exactly proportioned +at all distances. As it is, there is an outstanding force as a +disturbing force, which is in the inverse ratio of the square roots of +the distances from the sun; and to this is, no doubt, owing, in part, +the fact, that the planetary distances are arranged in the inverse order +of their densities. + +Suppose two planets to have the same diameter to be placed in the same +orbit, they will only be in equilibrium when their densities are equal. +If their densities are unequal, the lighter planet will continually +enlarge its orbit, until the force of the radial stream becomes +proportional to the planets' resisting energy. This, however, is on the +hypothesis that the planets are not permeable by the radial stream, +which, perhaps, is more consistent with analogy than with the reality. +And it is more probable that the mean atomic weight of a planet's +elements tends more to fix the position of equilibrium for each. Under +the law of gravity, a planet may revolve at any distance from the sun, +but if we superadd a centripulsive force, whose law is not that of +gravity, but yet in some inverse ratio of the distances, and this force +acts only superficially, it would be possible to make up in volume what +is wanted in density, and a lighter planet might thus be found occupying +the position of a dense planet. So the planet Jupiter, respecting only +his resisting surface, is better able to withstand the force of the +radial stream at the earth than the earth itself. To understand this, it +is necessary to bear in mind, that, as far as planetary matter is +concerned, the earth would revolve in Jupiter's orbit in the same +periodic time as Jupiter, under the law of gravity: but that, in +reality, the whole of the gravitating force is not effective, and that +the equilibrium of a planet is due to a nice balance of interfering +forces arising from the planet's physical peculiarities. As in a +refracting body, the density of the ether may be considered inversely as +the refraction, and this as the atomic weight of the refracting +material, so, also, in a planet, the density of the ether will be +inversely in the same ratio of the density of the matter approximately. +Hence, the density of the ether within the planet Jupiter is greater +than that within the earth; and, on this ethereal matter, the sun has no +power to restrain it in its orbit, so that the centrifugal momentum of +Jupiter would be relatively greater than the centrifugal momentum of the +earth, were it also in Jupiter's orbit with the same periodic time. +Hence, to make an equilibrium, the earth should revolve in a medium of +less density, that there may be the same proportion between the external +ether, and the ether within the earth, as there is between the ether +around Jupiter and the ether within; so that the centrifugal tendency of +the dense ether at Jupiter shall counteract the greater momentum of the +dense ether within Jupiter; or, that the lack of centrifugal momentum in +the earth should be rendered equal to the centrifugal momentum of +Jupiter, by the deficiency of the centrifugal momentum of the ether at +the distance of the earth. + +If then, the diameters of all the planets were the same (supposing the +ether to act only superficially), the densities would be as the +distances inversely;[37] for the force due to the radial stream is as +the square roots of the distance inversely, and the force due to the +momentum, if the density of the ether within a planet be inversely as +the square root of a planet's distance, will also be inversely as the +square roots of the distances approximately. We offer these views, +however, only as suggestions to others more competent to grapple with +the question, as promising a satisfactory solution of Bode's empirical +formula. + +If there be a wave of denser ether cylindrically disposed around the +vortex at the distance of Saturn, or between Saturn and Uranus, we see +why the law of densities and distances is not continuous. For, if the +law of density changes, it must be owing to such a ring or wave. Inside +this wave, the two forces will be inverse; but outside, one will be +inverse, and the other direct: hence, there should also be a change in +the law of distances. As this change does not take place until we pass +Uranus, it may be suspected that the great disparity in the density of +Saturn may be more apparent than real. The density of a planet is the +relation between its mass and volume or extension, no matter what the +form of the body may be. From certain observations of Sir Wm. +Herschel--the Titan of practical astronomers--the figure of Saturn was +suspected to be that of a square figure, with the corners rounded off, +so as to leave both the equatorial and polar zones flatter than +pertained to a true spheroidal figure. The existence of an unbroken ring +around Saturn, certainly attaches a peculiarity to this planet which +prepares us to meet other departures from the usual order. And when we +reflect on the small density, and rapid rotation, the formation of this +ring, and the figure suspected by Sir Wm. Herschel, it is neither +impossible nor improbable, that there may be a cylindrical vacant space +surrounding the axis of Saturn, or at least, that his solid parts may be +cylindrical, and his globular form be due to elastic gases and vapors, +which effectually conceal his polar openings. And also, by dilating and +contracting at the poles, in consequence of inclination to the radial +stream, (just as the earth's atmosphere is bulged out sufficiently to +affect the barometer at certain hours every day,) give that peculiarity +of form in certain positions of the planet in its orbit. Justice to Sir +Wm. Herschel requires that _his_ observations shall not be attributed to +optical illusions. This view, however, which may be true in the case of +Saturn, would be absurd when applied to the earth, as has been done +within the present century. From these considerations, it is at least +possible, that the density of Saturn may be very little less, or even +greater than the density of Uranus, and be in harmony with the law of +distances. + +It is now apparently satisfactorily determined, that Neptune is denser +than Uranus, and the law being changed, we must look for transneptunean +planets at distances corresponding with the new law of arrangement. But +there are other modifying causes which have an influence in fixing the +precise position of equilibrium of a planet. Each planet of the system +possessing rotation, is surrounded by an ethereal vortex, and each +vortex has its own radial stream, the force of which in opposing the +radial stream of the sun, depends on the diameter and density of the +planet, on the velocity of rotation, on the inclination of its axis, and +on the density of the ether at each particular vortex; but the numerical +verification of the position of each planet with the forces we have +mentioned, cannot be made in the present state of the question. There is +one fact worthy of note, as bearing on the theory of vortices in +connection with the rotation of the planets, viz.: that observation has +determined that the axial rotation and sidereal revolution of the +secondaries, are identical; thus showing that they are without vortices, +and are motionless relative to the ether of the vortex to which they +belong. We may also advert to the theory of Doctor Olbers, that the +asteroidal group, are the fragments of a larger planet which once +filled the vacancy between Mars and Jupiter. Although this idea is not +generally received, it is gathering strength every year by the discovery +of other _fragments_, whose number now amounts to twenty-six. If the +idea be just, our theory offers an explanation of the great differences +observable in the mean distances of these bodies, and which would +otherwise form a strong objection against the hypothesis. For if these +little planets be fragments, there will be differences of density +according as they belonged to the central or superficial parts of the +quondam planet, and their mean distances must consequently vary also. + +There are some other peculiarities connecting the distances and +densities, to which we shall devote a few words. In the primordial state +of the system, when the nebulous masses agglomerated into spheres, the +diameter of these nebulous spheres would be determined by the relation +existing between the rotation of the mass, and the gravitating force at +the centre; for as long as the centrifugal force at the equator exceeded +the gravitating force, there would be a continual throwing off of matter +from the equator, as fast as it was brought from the poles, until a +balance was produced. It is also extremely probable, (especially if the +elementary components of water are as abundant in other planets as we +have reason to suppose them to be on the earth,) that the condensation +of the gaseous planets into liquids and solids, was effected in a _brief +period of time_,[38] leaving the lighter and more elastic substances as +a nebulous atmosphere around globes of semi-fluid matter, whose +diameters have never been much increased by the subsequent condensation +of their gaseous envelopes. The extent of these atmospheres being (in +the way pointed out) determined by the rotation, their subsequent +condensation has not therefore changed the original rotation of the +central globe by any appreciable quantity. The present rotation of the +planets, is therefore competent to determine the former diameters of the +nebulous planets, _i.e._, the limit where the present central force +would be balanced by the centrifugal force of rotation. If we make the +calculation for the planets, and take for the unit of each planet its +present diameter, we shall find that they have condensed from their +original nebulous state, by a quantity dependent on the distance, from +the centre of the system; and therefore on the original temperature of +the nebulous mass at that particular distance. Let us make the +calculation for Jupiter and the earth, and call the original nebulous +planets the nucleus of the vortex. We find the Equatorial diameter of +Jupiter's nucleus in equatorial diameters of Jupiter = 2.21, and the +equatorial diameter of the earth's nucleus, in equatorial diameters of +the earth = 6.59. Now, if we take the original temperature of the +nebulous planets to be inversely, as the squares of the distances from +the sun, and their volumes directly as the cubes of the diameters in the +unit of each, we find that these cubes are to each other, in the inverse +ratio of the squares of the planet's distances; for, + + 2.21³ : 6.59³ :: 1² : 5.2², + +showing that both planets have condensed equally, allowing for the +difference of temperature at the beginning. And we shall find, beginning +at the sun, that the diameters of the nebulous planets, _ceteris +paribus_, diminish outwards, giving for the nebulous sun a diameter of +16,000,000 miles,[39] thus indicating his original great temperature. + +That the original nebulous planets did rotate in the same time as they +do at present, is proved by Saturn's ring; for if we make the +calculation, about twice the diameter of Saturn. Now, the diameter of +the planet is about 80,000 miles, which will also be the semi-diameter +of the nebulous planet; and the middle of the outer ring has also a +semi-diameter of 80,000 miles; therefore, the ring is the equatorial +portion of the original nebulous planet, and ought, on this theory, to +rotate in the same time as Saturn. According to Sir John Herschel, +Saturn rotates in 10 hours, 29 minutes, and 17 seconds, and the ring +rotates in 10 hours, 29 minutes, and 17 seconds: yet this is not the +periodic time of a satellite, at the distance of the middle of the ring; +neither ought the rings to rotate in the same time; yet as far as +observation can be trusted, both the inner and outer ring do actually +rotate in the same time. The truth is, the ring rotates too fast, if we +derive its centrifugal force from the analogy of its satellites; but it +is, no doubt, in equilibrium; and the effective mass of Saturn on the +satellites is less than the true mass, in consequence of his radial +stream being immensely increased by the additional force impressed on +the ether, by the centrifugal velocity of the ring. If this be so, the +mass of Saturn, derived from one of the inner satellites, will be less +than the same mass derived from the great satellite, whose orbit is +considerably inclined. The analogy we have mentioned, between the +diameters of the nebulous planets and their distances, does not hold +good in the case of Saturn, for the reason already assigned, viz.: that +the nebulous planet was probably not a globe, but a cylindrical ring, +vacant around the axis, as there is reason to suppose is the case at +present. + +And now we have to ask the question, Did the ether involved in the +nebulous planets rotate in the same time? This does not necessarily +follow. The ether will undoubtedly tend to move with increasing velocity +to the very centre of motion, obeying the great dynamical principle when +unresisted. If resisted, the law will perhaps be modified; but in this +case, its motion of translation will be converted into atomic motion or +heat, according to the motion lost by the resistance of atomic matter. +This question has a bearing on many geological phenomena. As regards the +general effect, however, the present velocity of the ether circulating +round the planets, may be considered much greater than the velocities of +the planets themselves. + + +PERTURBATIONS DUE TO THE ETHER. + +In these investigations it is necessary to bear in mind that the whole +resisting power of the ether, in disturbing the planetary movements, is +but small, in comparison with gravitation. We will, however, show that, +in the case of the planets, there is a compensation continually made by +this resistance, which leaves but a very small outstanding balance as a +disturbing power. If we suppose all the planets to move in the central +plane of the vortex in circular orbits, and the force of the radial +stream, (or that portion which is not in accordance with the law of +gravitation,) to be inversely as the square roots of the distances from +the sun, it is evident, from what has been advanced, that an equilibrium +could still obtain, by variations in the densities, distances and +diameter of the planets. Supposing, again, that the planets still move +in the same plane, but in elliptical orbits, and that they are in +equilibrium at their mean distances, under the influence or action of +the tangential current, the radial stream, and the density of the ether; +we see that the force of the radial stream is too great at the +perihelion, and too small at the aphelion. At the perihelion the planet +is urged from the sun and at the aphelion towards the sun. The density +and consequent momentum is also relatively too great at the perihelion, +which also urges the planet from the sun, and at the aphelion, +relatively too small, which urges the planet towards sun; and the law is +the same in both cases, being null at the mean distance of the planet, +at a maximum at the apsides; it is, consequently, as the cosine of the +planet's eccentric anomaly at other distances, and is positive or +negative, according as the planet's distance is above or below the mean. + +At the planet's mean distance, the circular velocity of the vortex is +equal to the circular velocity of the planet, and, at different +distances, is inversely in the sub-duplicate ratio of those distances. +But the circular velocity of a planet in the same orbit, is in the +simple ratio of the distances inversely. At the perihelion, the planet +therefore moves faster than the ether of the vortex, and at the +aphelion, slower; and the difference is as the square roots of the +distances; but the force of resistance is as the square of the velocity, +and is therefore in the simple ratio of the distances, as we have +already found for the effect of the radial stream, and centrifugal +momentum of the internal ether. At the perihelion this excess of +tangential velocity creates a resistance, which urges the planet towards +the sun, and at the aphelion, the deficiency of tangential velocity +urges the planet from the sun,--the maximum effect being at the apsides +of the orbit, and null at the mean distances. In other positions it is, +therefore, as the cosines of the eccentric anomaly, as in the former +case; but in this last case it is an addititious force at the +perihelion, and an ablatitious force at the aphelion, whereas the first +disturbing force was an ablatitious force at the perihelion, and an +addititious force at the aphelion; therefore, as we must suppose the +planet to be in equilibrium at its mean distance, it is in equilibrium +at all distances. Hence, a planet moving in the central plane of the +vortex, experiences no disturbance from the resistance of the ether. + +As the eccentricities of the planetary orbits are continually changing +under the influence of the law of gravitation, we must inquire whether, +under these circumstances, such a change would not produce a permanent +derangement by a change in the mean force of the radial stream, so as to +increase or diminish the mean distance of the planet from the sun. The +law of force deduced from the theory for the radial stream is as the 2.5 +power of the distances inversely. But, by dividing this ratio, we may +make the investigation easier; for it is equivalent to two forces, one +being as the squares of the distances, and another as the square roots +of the distances. For the former force, we find that in orbits having +the same major axis the mean effect will be as the minor axis of the +ellipse _inversely_, so that two planets moving in different orbits, but +at the same mean distance, experience a less or greater amount of +centripulsive force from this radial stream, according as their orbits +are of less or greater eccentricity, and this in the ratio of the minor +axis. On the other hand, under the influence of a force acting +centripulsively in the inverse ratio of the square roots of the +distances, we find the mean effect to be as the minor axis of the +ellipse _directly_, so that two planets in orbits of different +eccentricity, but having the same major axis, experience a different +amount from the action of this radial stream, the least eccentric orbit +being that which receives the greatest mean effect. By combining these +two results, we get a ratio of equality; and, consequently, the action +of the radial stream will be the same for the same orbit, whatever +change may take place in the eccentricity, and the mean distance of the +planet will be unchanged. A little consideration will also show that the +effect of the centrifugal momentum due to the density of ether will also +be the same by change of eccentricity; for the positive will always +balance the negative effect at the greatest and least distances of the +planet. The same remark applies to the effect of the tangential current, +so that no change can be produced in the major axes of the planetary +orbits by change of eccentricity, as an effect of the resistance of the +ether. + +We will now suppose a planet's orbit to be inclined to the central plane +of the vortex, and in this case, also, we find, that the action of the +radial stream tends to increase the inclination in one quadrant as much +as it diminishes it in the next quadrant, so that no change of +inclination will result. But, if the inclination of the orbit be changed +by planetary perturbations, the mean effect of the radial stream will +also be changed, and this will tell on the major axis of the orbit, +enlarging the orbit when the inclination diminishes, and contracting it +when it increases. The change of inclination, however, must be referred +to the central plane of the vortex. Notwithstanding the perfection of +modern analysis, it is confessed that the recession of the moon's nodes +does yet differ from the theory by its 350th part, and a similar +discrepancy is found for the advance of the perigee.[40] This theory is +yet far too imperfect to say that the action of the ethereal medium will +account for these discrepancies; but it certainly wears a promising +aspect, worthy the notice of astronomers. There are other minute +discordancies between theory and observation in many astronomical +phenomena, which theory _is_ competent to remove. Some of these we shall +notice presently; and, it may be remarked, that it is in those minute +quantities which, in astronomy, are usually attributed to errors of +observation, that this theory will eventually find the surest evidence +of its truth. + + +KEPLER'S THIRD LAW ONLY APPROXIMATELY TRUE. + +But it may be asked: If there be a modifying force in astronomy derived +from another source than that of gravitation, why is it that the +elements of the various members of the system derived solely from +gravitation should be so perfect? To this it may be answered, that +although astronomers have endeavored to derive every movement in the +heavens from that great principle, they have but partially succeeded. +Let us not surrender our right of examining Nature to the authority of a +great name, nor call any man master, either in moral or physical +science. It is well known that Kepler's law of the planetary distances +and periods, is a direct consequence of the Newtonian Law of +gravitation, and that the squares of the periodic times ought to be +proportional to the cubes of the mean distances. These times are given +accurately by the planets themselves, by the interval elapsing between +two consecutive passages of the node, and as in the case of the ancient +planets we have observations for more than two thousand years past, +these times are known to the fraction of the second. The determination +of the distances however, depends on the astronomer, and a tyro in the +science might suppose that these distances were actually measured; and +so they are roughly; but the astronomer does not depend on his +instruments, he trusts to _analogy_, and the mathematical perfection of +a law, which in the abstract is true; but which he does not know is +rigidly exact when applied to physical phenomena. From the immense +distance of the planets and the smallness of the earth, man is unable to +command a base line sufficiently long, to make the horizontal parallax a +sensible angle for the more distant planets; and there are difficulties +of no small magnitude to contend with, with those that are the nearest. +In the occasional transit of Venus across the sun, however, he is +presented with a means of measuring on an enlarged scale, from which the +distance of the sun is determined; and by _analogy_ the distance of all +the planets. Even the parallax of the sun itself is only correct, by +supposing that the square of the periodic time of Venus is in the same +proportion to the square of the periodic time of the earth as the cube +of her distance is to the cube of the earth's distance. Our next nearest +planet is Mars, and observations on this planet at its opposition to the +sun, invariably give a larger parallax for the sun--Venus giving 8.5776″ +while Mars gives about 10″. It is true that the first is obtained under +more favorable circumstances; but this does not prove the last to be +incorrect. It is well known that the British Nautical Almanac contains a +list of stars lying in the path of the planet Mars about opposition, +(for the very purpose of obtaining a correct parallax,) that minute +differences of declination may be detected by simultaneous observations +in places having great differences of latitude. Yet strange to say, the +result is discredited when not conformable to the parallax given by +Venus. If then, we cannot trust the parallax of Mars, _à fortiori_, how +can we trust the parallax of Jupiter, and say that his mean distance +exactly corresponds to his periodic time? Let us suppose, for instance, +that the radius vector of Jupiter fell short of that indicated by +analogy by 10,000 miles, we say that it would be extremely difficult, +nay, utterly impossible, to detect it by instrumental means. Let not +astronomers, therefore, be too sure that there is not a modifying cause, +independent of gravitation, which they will yet have to recognize. The +moon's distance is about one-fourth of a million of miles, and Neptune's +2854 millions, or in the ratio of 10,000 to 1; yet even the moon's +parallax is not trusted in determining her mass, how then shall we +determine the parallax of Neptune? It is therefore _possible_ that the +effective action of the sun is in some small degree different, on the +different planets, whether due to the action of the ether, to the +similarity or dissimilarity of material elements, to the temperature of +the different bodies, or to all combined, is a question yet to be +considered. + +As another evidence of the necessity of modifying the strict wording of +the Newtonian law, it is found that the disturbing action of Jupiter on +different bodies, gives different values for the mass of Jupiter. The +mass deduced from Jupiter's action on his satellites, is different from +that derived from the perturbations of Saturn, and this last does not +correspond with that given by Juno: Vesta also gives a different mass +from the comet of Encke, and both vary from the preceding values.[41] + +In the analytical investigation of planetary disturbances, the +disturbing force is usually divided into a radial and tangential force; +the first changing the law of gravitation, to which law the elliptic +form of the orbit is due. The radial disturbing force, therefore, being +directed to or from the centre, can have no influence over the first law +of Kepler, which teaches that the radius vector of each planet having +the sun as the centre, describes equal areas in equal times. If the +radial disturbing force be exterior to the disturbed body, it will +diminish the central force, and cause a progressive motion in the +aphelion point of the orbit. In the case of the moon this motion is very +rapid, the apogee making an entire revolution in 3232 days. Does this, +however, correspond with the law of gravitation? Sir Isaac Newton, in +calculating the effect of the sun's disturbing force on the motion of +the moon's apogee, candidly concludes thus: "Idoque apsis summa singulis +revolutionibus progrediendo conficit 1° 31′ 28″. Apsis lunæ est duplo +velocior circiter." As there was a necessity for reconciling this +stubborn fact with the theory, his followers have made up the deficiency +by resorting to the tangential force, or, as Clairant proposed, by +continuing the approximations to terms of a higher order, or to the +square of the disturbing force. + +Now, in a circular orbit, this tangential force will alternately +increase and diminish the velocity of the disturbed body, without +producing any permanent derangement, the same result would obtain in an +elliptical orbit, if the position of the major axis were stationary. In +the case of the moon, the apogee is caused to advance by the disturbing +power of the radial force, and, consequently, an exact compensation is +not effected: there remains a small excess of velocity which geometers +have considered equivalent to a doubling of the radial force, and have +thus obviated the difficulty. To those not imbued with the profound +penetration of the modern analyst, there must ever appear a little +inconsistency in this result. The major axis of a planet's orbit depends +solely on the velocity of the planet at a given distance from the sun, +and the tangential portion of the disturbance due to the sun, and +impressed upon the moon, must necessarily increase and diminish +alternately the velocity of the moon, and interfere with the equable +description of the areas. If, then, there be left outstanding a small +excess of velocity over and above the elliptical velocity of the moon, +at the end of each synodical revolution, in consequence of the motion +impressed on the moon's apogee by the radial force, the _legitimate_ +effect would be a small enlargement of the lunar orbit every revolution +in a rapidly-increasing ratio, until the moon would at last be taken +entirely away. In the great inequality of Jupiter and Saturn, this +tangential force is not compensated at each revolution, in consequence +of continual changes in the configuration of the two planets at their +heliocentric conjunctions, with respect to the perihelion of their +orbits, and the near commensurability of their periods; and the effect +of the tangential force is, in this case, legitimately impressed on the +major axes of the orbits. But why (we may ask) should not this also be +expended on the motion of the aphelion as well as in the case of the +moon? Astronomy can make no distinctions between the orbit of a planet +and the orbit of a satellite. And, we might also ask, why the tangential +resistance to the comet of Encke should not also produce a retrograde +motion in the apsides of the orbit, instead of diminishing its period? +To the honor of Newton, be it remembered, that he never resorted to an +explanation of this phenomenon, which would vitiate that fundamental +proposition of his theory, in which the major axis of the orbit is shown +to depend on the velocity at any given distance from the focus. + +Some cause, however, exists to double the motion of the apogee, and +that there is an outstanding excess of orbital velocity due to the +tangential force, is also true. This excess may tell in the way +proposed, provided some other arrangement exists to _prevent_ a +permanent dilation of the lunar orbit; and this provision may be found +in the increasing density of the ether, which prevents the moon +overstepping the bounds prescribed by her own density, and the force of +the radial stream of the terral vortex. In the case of Jupiter and +Saturn, their mutual action is much less interfered with by change of +density in the ether in the enlarged or contracted orbit, and, +consequently, the effect is natural. Thus, we have in the law of density +of the ethereal medium a better safeguard to the stability of the +dynamical balance of the system, than in the profound and beautiful +Theorems of La Grange. It will, of course, occur to every one, that we +are not to look for the same law in every vortex, and it will, +therefore, appear as if the satellites of Jupiter, whose theory is so +well known, should render apparent any deviation between their periodic +times and the periodic times of the contiguous parts of the vortex, +which would obtain, if the density of the ether in the Jovian vortex +were not as the square roots of the distances directly. But, we have +shown how there can be a balance preserved, if the tangential resistance +of the vortex shall be equal and contrary at the different distances at +which the satellites are placed; that is, if these two forces shall +follow the same law. These are matters, however, for future +investigation. + + +LIGHT AND HEAT. + +But will not the admission of a vorticose motion of the ethereal medium, +affect the aberration of light? It is well known that the question has +been mooted, whether the velocity of reflected light is the same as that +of direct light. The value of aberration having been considered 20″.25, +from the eclipses of Jupiter's satellites, while later determinations, +from observations on Polaris, give 20″.45. It cannot be doubted that +light, in traversing the central parts of the solar vortex, that is, +having to cross the whole orbit of the earth, should pass this distance +in a portion of time somewhat different to a similar distance outside +the earth's orbit, where the density is greater, and consequently induce +an error in the aberration, determined by the eclipses of Jupiter's +satellites. In the case of Polaris, the circumstances are more equal; +still, a difference ought to be detected between the deduced aberration +in summer and in winter, as, in the first case, the light passes near +the axis of the solar vortex, where (according to the theory) a change +of density occurs. This is an important practical question, and the +suggestion is worthy attention. Now, the question occurs, will light +pass through the rarefied space with greater velocity than through the +denser ether beyond? From recent experiments, first instituted by Arago, +it is determined that light passes with less velocity through water than +through air; and one result of these experiments is the confirmation +they give to the theory of Fresnel, that the medium which conveys the +action of light partly partakes of the motion of the refracting body. +This of itself is a strong confirmation of this theory of an ethereal +medium. It may also be remarked, that every test applied to the +phenomenon of light, adds additional strength to the undulatory theory, +at the expense of the Newtonian theory of emission. As light occupies +time in traversing space, it must follow from the theory that it does +not come from the radiant point exactly in straight lines, inasmuch as +the ether itself is in motion tangentially,--the velocity being in the +sub-duplicate ratio of the distances from the sun inversely. + +May not that singular phenomenon,--the projection of a star on the +moon's disc, at the time of an occultation,--be due to this curvature of +the path of a ray of light, by considering that the rays from the moon +have less intensity, but more mechanical momentum, and consequently +more power to keep a straight direction? Let us explain: we have urged +that light, as well as heat, is a mechanical effect of atomic motion, +propagated through an elastic medium; that, _ceteris paribus_, the +product of matter by its motion is ever a constant quantity for equal +spaces throughout the universe,--in a word, that it is, and must +necessarily be, a fundamental law of nature. All departures from this +law are consequences of accidental arrangements, which can only be +considered of temporary duration. Our knowledge of planetary matter +requires the admission of differences in the density, form, and size of +ultimate atoms, and, according to the above law, when the atoms are of +uniform temperature or motion, the product of the matter of each by its +motion, when reduced to the same space, will be constant. The momentum +of two different atoms, therefore, we will consider equal, for the sake +of illustration; yet this momentum is made up of two different +elements,--matter and motion. Let us exaggerate the difference, and +assign a ratio of 1000 to 1. Suppose a ball of iron of 1000 lbs., +resting upon a horizontal plane, should be struck by another ball of 1 +lb., having a motion of 1000 feet in a second, and, in a second case, +should be struck by a ball of 1000 lbs., having a velocity of 1 foot per +second, the momentum of each ball is similar; but experience proves that +the motion impressed on the ball at rest is not similar; the ponderous +weight and slow motion is far more effective in displacing this ball, +for the reason that time is essential to the distribution of the motion. +If the body to be struck be small as, for instance, a nail, a greater +motion and less matter is more effective than much matter and little +motion. Hence, we have a _distinction_ applicable to the difference of +momentum of luminous and calorific rays. The velocity of a wave of sound +through the atmosphere, is the same for the deep-toned thunder and the +shrillest whistle,--being dependent on the density of the medium, and +not on the source from which it emanates. So it is in the ethereal +medium. + +This view is in accordance with the experiments of M. Delaroche and +Melloni, on the transmission of light and heat through diaphanous +bodies--the more calorific rays feeling more and more the influence of +thickness, showing that more motion was imparted to the particles of the +diaphanous substance by the rays possessing more material momentum, and +still more when the temperature of the radiating body was low, evidently +analogous to the illustration we have cited. Light may therefore be +regarded as the effect of the vibration of atoms having little mass, and +as this mass increases, the rays become more calorific, and finally the +calorific effect is the only evidence of their existence; as towards the +extreme red end of the spectrum they cease to be visible, owing to their +inability to impart their vibrations to the optic nerve. This may also +influence the law of gravitation. In this we have also an explanation of +the dispersion of light. The rays proceeding from atoms of small mass +having less material momentum, are the most refrangible, and those +possessing greater material momentum, are the least refrangible; so that +instead of presenting a difficulty in the undulatory theory of light, +this dispersion is a necessary consequence of its first principles. + +It is inferred from the experiments cited, and the facts ascertained by +them, viz.: that the velocity of light in water is less than its +velocity in air; that the density of the ether is greater in the first +case; but this by no means follows. We have advocated the idea, that the +ethereal medium is less dense within a refracting body than without. We +regard it as a fundamental principle. Taking the free ether of heaven; +the vibrations in the denser ether will no doubt be slowest; but within +a refracting body we must consider there is motion lost, or _light +absorbed_, and the time of the transmission is thus increased. + +There has been a phenomenon observed in transits of Mercury and Venus +across the sun, of which no explanation has been rendered by +astronomers. When these planets are visible on the solar disc, they are +seen surrounded by rings, as if the light was intercepted and increased +alternately. This is no doubt due to a small effect of interference, +caused by change of velocity in passing through the rarefied nucleus of +these planetary vortices, near the body of the planet, and through the +denser ether beyond, acting first as a concave, and secondly as a convex +refracting body; always considering that the ray will deviate _towards_ +the side of least insistence, and thus interfere. + +That heat is simply atomic motion, and altogether mechanical, is a +doctrine which ought never to have been questioned. The interest excited +by the bold experiments of Ericson, has caused the scientific to +_suspect_, that heat can be converted into motion, and motion into +heat--a fact which the author has considered too palpable to deny for +the last twenty years. He has ever regarded matter and motion as the two +great principles of nature, ever inseparable, yet variously combined; +and that without these two elements, we could have no conception of +anything existing. + +It may be thought by some, who are afraid to follow truth up the rugged +precipices of the hill of knowledge, that this theory of an +interplanetary plenum leads to materialism; forgetting, that He who made +the world, formed it of matter, and pronounced it "very good." We may +consider ethereal matter, in one sense, _purer_ than planetary matter, +because unaffected by chemical laws. Whether still purer matter exists, +it is not for us to aver or deny. The Scriptures teach us that "there is +a natural body and there is a spiritual body." Beyond this we know +nothing. We, however, believe that the _invisible_ world of matter, can +only be comprehended by the indications of that which is visible; yet +while humbly endeavoring to connect by one common tie, the various +phenomena of matter and motion, we protest against those doctrines which +teach the eternal duration of the present order of things, as being +incompatible with the analogies of the past, as well as with the +revelations of the future. + + +FOOTNOTES: + +[35] Silliman's Journal, vol xxxv., page 283. + +[36] The real diameter of the earth in that latitude, whose sine is +one-third, is a little greater than this; but the true mean is more +favorable for the Newtonian law. + +[37] This is, perhaps, the nearest ratio of the densities and distances. + +[38] This is an important consideration, as bearing on the geology of +the earth. + +[39] It is not as likely that the condensation of the sun was so sudden +as that of the planets, and therefore in this case this distance is only +approximate. + +[40] Mechanique Celeste. Theory of the Moon. + +[41] Mechanique Celeste. Masses of the planets. + + + + +SECTION FIFTH. + + +COMETARY PHENOMENA. + +The planetary arrangements of the solar system are all _à priori_ +indications of the theory of vortices, not only by the uniform direction +of the motions, the circular orbits in which these motions are +performed, the near coincidence of the planes of these orbits, and the +uniform direction of the rotation of the planets themselves; but, also, +by the law of densities and distances, which we have already attempted +to explain. In the motions of comets we find no such agreement. These +bodies move in planes at all possible inclinations in orbits extremely +eccentrical and without any general direction--as many moving contrary +to the direction of the planets as in the opposite direction; and when +we consider their great volume, and their want of mass, it appears, at +first sight, that comets do present a serious objection to the theory. +We shall point out, however, a number of _facts_ which tend to +invalidate this objection, and which will ultimately give the +preponderance to the opposite argument. + +Every fact indicative of the nature of comets proves that the nuclei are +masses of material gases, similar, perhaps (at least in the case of the +short-period comets), to the elementary gases of our own planet, and, +consequently, these masses must be but small. In the nascent state of +the system, the radial stream of the vortex would operate as a fan, +purging the planetary materials of the least ponderable atoms, and, as +it were, separating the wheat from the chaff. It is thus we conceive +that the average atomic density of each planet has been first determined +by the radial stream, and, subsequently, that the solidification of the +nebulous planets has, by their atomic density, assigned to each its +position in the system, from the consequent relation which it +established between the density of the ether within the planet, and the +density of the ether external to it, so that, according to this view, a +single isolated atom of the same density as the mean atomic density of +the earth could (_ceteris paribus_) revolve in an orbit at the distance +of the earth, and in the same periodic time. This, however, is only +advanced by way of illustration. + +The expulsive force of the radial stream would thus drive off this +cometary dust to distances in some inverse ratio of the density of the +atoms; but, a limit would ultimately be reached, when gravitation would +be relatively the strongest--the last force diminishing only as the +squares of the distances, and the first diminishing in the compound +ratio of the squares and the square roots of the distances. At the +extreme verge of the system, this cometary matter would accumulate, and, +by accumulation, would still further gather up the scattered atoms--the +sweepings of the inner space--and, in this condensed form, would again +visit the sun in an extremely elongated ellipse. It does not, however, +follow, that all comets are composed of such unsubstantial materials. +There may be comets moving in parabolas, or even in hyperbolas--bodies +which may have been accumulating for ages in the unknown regions of +space, far removed from the sun and stars, drifting on the mighty +currents of the great ethereal ocean, and thus brought within the sphere +of the sun's attraction; and these bodies may have no analogy to the +periodical comets of our system, which last are those with which we are +more immediately concerned. + +The periodical comets known are clearly arranged into two distinct +classes--one having a mean distance between Saturn and Uranus, with a +period of about seventy-five years, and another class, whose mean +distance assigns their position between the smaller planets and Jupiter, +having periods of about six years. These last may be considered the +siftings of the smaller planets, and the first the refuse of the +Saturnian system. In this light we may look for comets having a mean +distance corresponding to the intervals of the planets, rather than to +the distances of the planets themselves. One remarkable fact, however, +to be observed in these bodies is, that all their motions are in the +same direction as the planets, and, with one exception, there is no +periodical comet positively known whose motion is retrograde. + +The exception we have mentioned is the celebrated comet of Halley, whose +period is also about seventy-five years. In reasoning on the resistance +of the ether, we must consider that the case can have very little +analogy with the theory of projectiles in air; nor can we estimate the +inertia of an infinitely divisible fluid, from its resisting influence +on atomic matter, by a comparison of the resistance of an atomic fluid +on an atomic solid. Analogy will only justify comparisons of like with +like. The tangent of a comet's orbit, also, can only be tangential to +the circular motion of the ether at and near perihelion, which is a very +small portion of its period of revolution. As far as the tangential +resistance is concerned, therefore, it matters little whether its motion +be direct or retrograde. If a retrograde comet, of short period and +small eccentricity, were discovered moving also near the central plane +of the vortex, it would present a very serious objection, as being +indicative of contrary motions in the nascent state of the system. There +is no such case known. So, also, with the inclinations of the orbits; if +these be great, it matters little whether the comet moves in one way or +the other, as far as the tangential current of the vortex is concerned. +Yet, when we consider the average inclination of the orbit, and not of +its plane, we find that the major axes of nearly all known cometary +orbits are very little inclined to the plane of the ecliptic. + +In the following table of all the periodical comets known, the +inclination of the major axis of the orbit is calculated to the nearest +degree; but all cometary orbits with very few exceptions, will be found +to respect the ecliptic, and never to deviate far from that plane: + + +--------------------------------------------------------------------+ + | Designations | Periodic | Inclination | Motion | Planetary | + | of the Comets. | times. | of | in Orbit. | Intervals. | + | | | Major Axes | | | + |--------------------------------------------------------------------| + |Encke | 1818 | 3 years. | 1° | Direct |Mars & Ceres.| + |--------------------------------------------------------------------| + |De Vico | 1814 | | 2 | Direct | | + |Fayo | 1843 | | 4 | Direct | Ceres | + |De Avrest| 1851 | From | 1 | Direct | | + |Brorsen | 1846 | five | 7 | Direct | and | + |Messier | 1766 | to | 0 | Direct | | + |Clausen | 1743 | six | 0 | Direct | Jupiter. | + |Pigott | 1783 | or | 4 | Direct | | + |Pous | 1819 | seven | 3 | Direct | | + |Biela | 1826 | years. | 9 | Direct | | + |Blaupain | 1819 | | 2 | Direct | | + |Lexell | 1770 | | 1 | Direct | | + |--------------------------------------------------------------------| + |Pous | 1812 | | 17 | Direct | | + |Olbers | 1816 | about | 40 | Direct | Saturn | + |De Vico | 1846 | 75 | 13 | Direct | and | + |Brorsen | 1847 | years. | 12 | Direct | Uranus. | + |Westphal | 1852 | | 21 | Direct | | + |Halley | 1682 | | 16 | Retrograde| | + +--------------------------------------------------------------------+ + +From which it appears, that the objection arising from the great +inclination of the _planes_ of these orbits is much less important than +at first it appears to be. + +Regarding then, that a comet's mean distance depends on its mean atomic +density, as in the case of the planets, the undue enlargement of their +orbits by planetary perturbations is inadmissible. In 1770 Messier +discovered a comet which approached nearer the earth than any comet +known, and it was found to move in a small ellipse with a period of five +and a half years; but although repeatedly sought for, it was the +opinion of many, that it has never been since seen. The cause of this +seeming anomaly is found by astronomers in the disturbing power of +Jupiter,--near which planet the comet must have passed in 1779, but the +comet was not seen in 1776 before it passed near Jupiter, although a +very close search was kept up about this time. Now there are two +suppositions in reference to this body: the comet either moved in a +larger orbit previous to 1767, and was then caused by Jupiter to +diminish its velocity sufficiently to give it a period of five and a +half years, and that after perihelion it recovered a portion of its +velocity in endeavoring to get back into its natural orbit; or if moving +in the natural orbit in 1770, and by passing near Jupiter in 1779 this +orbit was deranged, the comet will ultimately return to that mean +distance although not necessarily having elements even approximating +those of 1770. In 1844, September 15th, the author discovered a comet in +the constellation Cetus, (the same previously discovered by De Vico at +Home,) and from positions _estimated with the naked eye_ approximately +determined the form of its orbit and its periodic time to be very +similar to the lost comet of 1770. These conclusions were published in a +western paper in October 1844, on which occasion he expressed the +conviction, that this was no other than the comet of 1770. As the +question bore strongly on his theory he paid the greater attention to +it, and had, previously to this time, often searched in hopes of finding +that very comet. Since then, M. Le Verrier has examined the question of +identity and given his decision against it; but the author is still +sanguine that the comet of 1844 is the same as that of 1770, once more +settled at its natural distance from the sun. This comet returns to its +perihelion on the 6th of August, 1855, according to Dr. Brünnow, when, +it is hoped, the question of identity will be reconsidered with +reference to the author's principles; and, that when astronomers become +satisfied of this, they will do him the justice of acknowledging that +he was the first who gave publicity to the fact, that the "Lost Comet" +was found. + +That comets do experience a resistance, is undeniable; but not in the +way astronomers suppose, if these views be correct. The investigations +of Professor Encke, of Berlin, on the comet which bears his name, has +determined the necessity of a correction, which has been applied for +several returns with apparent success. But there is this peculiarity +about it, which adds strength to our theory: "The Constant of +Resistance" requires a change after perihelion. The necessity for this +change shows the action of the radial stream. From the law of this +force, (reckoning on the central plane of the vortex,) there is an +outstanding portion, acting as a disturbing power, in the sub-duplicate +ratio of the distances inversely. If we only consider the mean or +average effect in orbits nearly circular, this force may be considered +as an ablatitious force at all distances below the mean, counterbalanced +by an opposite effect at all distances above the mean. But when the +orbits become very eccentrical, we must consider this force as +momentarily affecting a comet's velocity, diminishing it as it +approaches the perihelion, and increasing it when leaving the +perihelion. A resolution of this force is also requisite for the comet's +distance above the central plane of the vortex, and a correction, +likewise, for the intensity of the force estimated in that plane. There +is also a correction necessary for the perihelion distance, and another +for the tangential current; but we are only considering here the general +effect. By diminishing the comet's proper velocity in its orbit, if we +consider the attraction of the sun to remain the same, the general +effect _may_ be (for this depends on the tangential portion of the +resolved force preponderating) that the absolute velocity will be +increased, and the periodic time shortened; but after passing the +perihelion, with the velocity of a smaller orbit, there is also +superadded to this already undue velocity, the expulsive power of the +radial stream, adding additional velocity to the comet; the orbit is +therefore enlarged, and the periodic time increased. Hence the necessity +of changing the "Constant of Resistance" after perihelion, and this will +generally be found necessary in all cometary orbits, if this theory be +true. But this question is one which may be emphatically called the most +difficult of dynamical problems, and it may be long before it is fully +understood. + +According to the calculations of Professor Encke, the comet's period is +accelerated about 2 hours, 30 minutes, at each return, which he +considers due to a resisting medium. May it not rather be owing to _the +change of inclination of the major axis of the orbit, to the central +plane of the vortex_? Suppose the inclination of the _plane_ of the +orbit to remain unchanged, and the eccentricity of the orbit also, if +the longitude of the perihelion coincides with that of either node, the +major axis of the orbit lies in the ecliptic, and the comet then +experiences the greatest mean effect from the radial stream; its mean +distance is then, _ceteris paribus_, the greatest. When the angle +between the perihelion and the nearest node increases, the mean force of +the radial stream is diminished, and the mean distance is diminished +also. When the angle is 90°, the effect is least, and the mean distance +least. This is supposing the ecliptic the central plane of the vortex. +When Encke's formula was applied to Biela's comet, it was inadequate to +account for a tenth part of the acceleration; and although Biela moves +in a much denser medium, and is of less dense materials, even this taken +into account will not satisfy the observations,--making no other change +in Encke's formula. We must therefore attribute it to changes in the +elements of the orbits of these comets. Now, the effect of resistance +should also have been noticed, as an acceleration of Halley's comet in +1835, yet the period was prolonged. To show, that our theory of the +_cause_ of these anomalies corresponds with facts, we subjoin the +elements in the following tables, taken from Mr. Hind's catalogue: + +THE ELEMENTS OF ENCKE'S COMET. + + Date of Longitude of Longitude of Difference of + Perihelion. Perihelion. nearest Node Longitude. + 1822 157° 11′ 44″ 154° 25′ 9″ 2° 46′ 35″ + 1825 157 14 31 154 27 30 2 47 1 + 1829 157 17 53 154 29 32 2 48 21 + 1832[42] 157 21 1 154 32 9 2 41 52 + 1835 157 23 29 154 34 59 2 48 30 + 1838 157 27 4 154 36 41 2 50 23 + 1842 157 29 27 154 39 10 2 50 17 + 1845 157 44 21 154 19 33 3 24 48 + 1848 157 47 8 154 22 12 3 24 56 + 1852 157 51 2 154 23 21 3 27 41 + +In this we see a regular increase of the angle, which ought to be +attended with a small acceleration of the comet; but the change of +inclination of the orbit ought also to be taken into consideration, to +get the mean distance of the comet above the plane of the vortex, and, +by this, the mean force of the radial stream. + +In the following table, the same comparison is made for Biela's comet:-- + +ELEMENTS OF BIELA'S COMET. + + Date of Longitude of Longitude of Difference of + Perihelion. Perihelion. nearest Node. Longitude. + 1772 110° 14′ 54″ 74° 0′ 1″ 36° 14′ 53″ + 1806 109 32 23 71 15 15 38 17 8 + 1826 109 45 50 71 28 12 38 17 38[43] + 1832 110 55 55 68 15 36 41 45 19 + 1846 109 2 20 65 54 39 43 7 41 + +Between 1832 and 1846, the increase of the angle is twice as great for +Biela as for Encke, and the angle itself throws the major axis of Biela +10° above the ecliptic, whereas the angle made by Encke's major axis, is +only about 1°; the cosine of the first angle, diminishes much faster +therefore, and consequently the same difference of longitude between the +perihelion and node, will cause a greater acceleration of Biela; and +according to Prof. Encke's theory, Biela would require a resisting +medium twenty-five times greater than the comet of Encke to reconcile +observation with the theory. Halley's comet can scarcely be considered +to have had an orbit with perfect elements before 1835. If they were +known accurately for 1759, we should no doubt find, that the angle +between the node and perihelion _diminished_ in the interval between +1750 and 1835, as according to the calculations of M. Rosenberg, the +comet was six days behind its time--a fact fatal to the common ideas of +a resisting medium; but this amount of error must be received as only +approximate. + +No comet that has revisited the sun, has given astronomers more trouble +than the great comet of 1843. Various orbits have been tried, +elliptical, parabolic and hyperbolic; yet none will accord with all the +observations. The day before this comet was seen in Europe and the +United States, it was seen close to the body of the sun at Conception, +in South America; yet this observation, combined with those following, +would give an orbital velocity due to a very moderate mean distance. +Subsequent observations best accorded with a hyperbolic orbit; and it +was in view of this anomaly, that the late Sears C. Walker considered +that the comet came into collision with the sun in an elliptical orbit, +and its _debris_ passed off again in a hyperbola. That a concussion +would not add to its velocity is certain, and the departure in a +hyperbolic orbit would be contrary to the law of gravitation. This +principle is thus stated by Newton:--"In parabola velocitas ubiquo +equalis est velocitati corporis revolventis in circulo ad dimidiam +distantiam; in ellipsi minor est in hyperbola major." (Vid. Prin. Lib. +1. Prop. 6 Cor. 7.) + +But as regards the _fact_, it is probable that Mr. Walker's views are +correct, so far as the change from an ellipse to an hyperbola is +considered. The Conception observation cannot be summarily set aside, +and Professor Peirce acknowledges, that "If it was made with anything of +the accuracy which might be expected from Captain Ray, it exhibits a +decided anomaly in the nature of the forces to which the comet was +subjected during its perihelion passage." The comet came up to the sun +almost in a straight line against the full force of the radial stream; +its velocity must therefore necessarily have been diminished. After its +perihelion, its path was directly _from_ the sun, and an undue velocity +would be kept up by the auxiliary force impressed upon it by the same +radial stream; and hence, the later observations give orbits much larger +than the early ones, and there can be no chance of identifying this +comet with any of its former appearances, even should its orbit be +elliptical. This unexpected confirmation of the theory by the +observation of Capt. Ray, cannot easily be surmounted. + +We must now endeavor to explain the physical peculiarities of comets, in +accordance with the principles laid down. The most prominent phenomenon +of this class is the change of diameter of the visible nebulosity. It is +a most singular circumstance, but well established as a fact, that a +comet contracts in its dimensions on approaching the sun, and expands on +leaving it. In 1829, accurate measures were taken on different days, of +the diameter of Encke's comet, and again in 1838. The comet of 1618 was +also observed by Kepler with this very object, and also the comet of +1807; but without multiplying instances, it may be asserted that it is +one of those facts in cometary phenomena, to which there are no +exceptions. According to all analogy, the very reverse of this ought to +obtain. If a comet is chiefly vaporous, (as this change of volume would +seem to indicate,) its approach to the sun ought to be attended by a +corresponding expansion by increase of temperature. When the contrary is +observed, and invariably so, it ought to be regarded as an index of the +existence of other forces besides gravitation, increasing rapidly in the +neighborhood of the sun; for the disturbing power of the sun's +attraction would be to enlarge the diameter of a comet in proportion to +its proximity. Now, the force of the radial stream, as we have shown, is +as the 2.5th power of the distances inversely. If this alternate +contraction and expansion be due to the action of this force, there +ought to be an approximate correspondence of the law of the effect with +the law of the cause. Arago, in speaking of the comet of 1829, states, +"that between the 28th of October and the 24th of December, the volume +of the comet was reduced as 16000 to 1, the change of distance in the +meantime only varying about 3 to 1." To account for this, a memoir was +published on the subject by M. Valz, in which he supposes an atmosphere +around the sun, whose condensation increases rapidly from superincumbent +pressure; so that the deeper the comet penetrates into this atmosphere +the greater will be the pressure, and the less the volume. In this it is +evident, that the ponderous nature of a resisting medium is not yet +banished from the schools. In commenting on this memoir, Arago justly +observes, that "there would be no difficulty in this if it could be +admitted that the exterior envelope of the nebulosity were not permeable +to the ether; but this difficulty seems insurmountable, and merits our +sincere regret; for M. Valz's ingenious hypothesis has laid down the law +of variation of the bulk of the nebulosity, as well for the short-period +comet as for that of 1618, with a truly wonderful exactness." Now, if we +make the calculation, we shall find that the diameter of the nebulosity +of a comet is inversely as the force of the radial stream. This force is +inversely as the 2.5 power of the distances from the axis, and not from +the sun: it will, therefore, be in the inverse ratio of the cosine of +the comet's heliocentric latitude to radius, and to this ratio the +comet's distance ought to be reduced. But, this will only be correct for +the same plane or for equal distances above the ecliptic plane, +considering this last as approximately the central plane of the vortex. +From the principles already advanced, the radial stream is far more +powerful on the central plane than in more remote planes; therefore, if +a comet, by increase of latitude, approaches near the axis, thus +receiving a larger amount of force from the radial stream in that plane +than pertains to its actual distance from the sun, it will also receive +a less amount of force in that plane than it would in the central plane +at the same distance from the axis. Now, we do not know the difference +of force at different elevations above the central plane of the vortex; +but as the two differences due to elevation are contrary in their +effects and tend to neutralize each other, we shall make the calculation +as if the distances were truly reckoned from the centre of the sun. + +The following table is extracted from Arago's tract on Comets, and +represents the variations of the diameter of Encke's comet at different +distances from the sun,--the radius of the orbis magnus being taken as +unity. + + Times of observation, Distances of the Real diameters + 1828. comet from the sun. in radii of the earth. + Oct. 28 1.4617 79.4 + Nov. 7 1.3217 64.8 + Nov. 30 0.9668 29.8 + Dec. 7 0.8473 19.9 + Dec. 14 0.7285 11.3 + Dec. 24 0.6419 3.1 + +In order the better to compare the diameters with the force, we will +reduce them by making the first numbers equal. + + Distances. Diameters. The 2.5th power Reduced + of the Distances. Diameters. + 1.4617 79.4 2.58 2.58 + 1.3217 64.8 2.10 2.10 + 0.9668 29.8 0.92 0.97 + 0.8473 19.9 0.66 0.65 + 0.7285 11.3 0.45 0.37 + 0.5419 3.1 0.21 0.10 + +This is a very close approximation, when we consider the difficulty of +micrometric measurement, and the fact, that as the comet gets nearer to +the sun, as at the last date of the table, the diameter is more than +proportionally diminished by the fainter nebulosity becoming invisible. +But, there may be a reality in the discrepancy apparent at the last +date, as the comet was then very near the plane of the ecliptic, and +was, consequently, exposed to the more violent action of the radial +stream. + +To attempt to explain the _modus agendi_ is, perhaps, premature. Our +principal aim is to pioneer the way into the labyrinth, and it is +sufficient to connect this seeming anomaly with the same general law we +have deduced from other phenomena. Still, an explanation may be given in +strict accordance with the general principles of the theory. + +Admitting the _nucleus_ of a comet to be gaseous, there is no difficulty +about the solution. According to Sir John Herschel, "stars of the +smallest magnitude remain distinctly visible, though covered by what +appears the densest portion of their substances; and since it is an +observed fact, that the large comets which have presented the appearance +of a nucleus, have yet exhibited no phases, though we cannot doubt that +they shine by the reflected solar light, it follows that even these can +only be regarded as great masses of thin vapor." That comets shine +solely by reflected solar light, is a position that we shall presently +question; but that they are masses of vapor is too evident to dispute. +According to the same authority quoted above, "If the earth were reduced +to the one thousandth part of its actual mass, its coercive power over +the atmosphere would be diminished in the same proportion, and in +consequence the latter would expand to a thousand times its actual +_bulk_." If this were so, and comets composed of the elementary gases, +some of them would have very respectable masses, as the nuclei are +frequently not more than 5,000 miles in diameter, and consequently it +becomes important to examine the principle. From all experiments the +density of an elastic fluid is directly as the compressing force; and if +a cylinder reached to the top of our atmosphere, compressed by the +gravitation of the earth, considered equal at each end of the cylinder, +it would represent the actual compressing force to which it owes its +density. If the gravitation of the earth were diminished one thousand +times this atmospheric column would expand one thousand times,[44] +(taking no account of the decrease of gravitation by increase of +distance;) so that the diameter of the aërial globe would be increased +to 108,000 miles, taking the atmosphere at 50 miles. But the mere +increasing the _bulk_ of the atmosphere 1000 times would increase the +diameter to little more than double. Even giving the correct expansion, +a comet's mass must be much greater than is generally supposed, or the +diameters of the nuclei would be greater if composed of any gas lighter +than atmospheric air. + +It is very improbable that a comet is composed of only one elementary +gas, and if of many, their specific gravities will vary; the lighter, of +course, occupying the exterior layers. With such a small mass, +therefore, the upper portion of its atmosphere must be very attenuated. +Now let us remember that the density of the ether at a comet's aphelion, +is greater than at the perihelion, in the direct ratio of the square +roots of the distances from the sun nearly. At the aphelion the comet +lingers through half his period, giving ample time for the nucleus to be +permeated by ether proportionally dense with the surrounding ether of +the vortex at that distance. Thus situated, the comet descends to its +perihelion, getting faster and faster into a medium far less dense, and +there must consequently be an escape from the nucleus, or in common +parlance, the comet is positively electric. This escaping ether, in +passing through the attenuated layers composing the surface of the +nucleus, impels the lighter atoms of cometic dust further from the +centre, and as for as this _doubly_ attenuated atmosphere of isolated +particles extends, so far will the escaping ether be rendered luminous. +It may be objected here, that a contrary effect ought to be produced +when the comet is forsaking, its perihelion; but the objection is +premature, as the heat received from the sun will have the same effect +in increasing the elasticity, as change of density, and the comet will +probably part with its internal ether as long as it is visible to the +earth; and not fully regain it perhaps, until after it arrives at its +aphelion. Suppose that we admit that a comet continues to expand in the +same ratio for all distances, as is laid down for the comet of Encke +when near its perihelion; it would follow, that the comet of 1811, would +have a diameter at its aphelion of fifty millions of millions of miles, +that is, its outside would extend one thousand times further from the +sun, at the opposite side to that occupied by the centre of the comet, +than the distance of the comet's centre from the sun, at its enormous +aphelion distance. Such an absurdity shows us that there is a limit of +expansion due to natural causes, and that if there were no radial stream +the volume of a comet would be greatest when nearest the sun. + +But while the comet is shortening its distance and hastening to the sun +in the form of a huge globular mass of diffuse light, it is continually +encountering another force, increasing in a far more rapid ratio than +the law of gravitation. At great distances from the sun, the force of +the radial stream was insufficient to detach any portion of the comet's +atmosphere; presently, however, the globular form is changed to an +ellipsoid, the radial stream begins to strip the comet of that doubly +attenuated atmosphere of which we have spoken, and the diameter of the +comet is diminished, merely because the luminosity of the escaping ether +is terminated at the limit of that atmosphere. Meanwhile the mass of the +comet has suffered only an infinitely small diminution; but if the +perihelion distance be small, the force may become powerful enough to +detach the heavier particles of the nucleus, and thus a comet may suffer +in mass by this denudating process. We regard, therefore, the nucleus of +a comet to represent the mass of the comet and the coma, as auroral rays +passing through a very attenuated envelope of detached particles. The +individual gravitating force of these particles to the comet's centre, +may be therefore considered as inversely as the squares of the +distances, and directly as the density of the particles; and this +density will, according to analogical reasoning, be as the distances or +square roots of the distances;--grant the last ratio, and the +gravitating force of the particles composing the exterior envelope of a +comet, becomes inversely as the 2.5th power of the distances from the +comet's centre.[45] This being the law of the radial stream, it follows, +of course, that a comet's diameter is inversely as the force of the +radial stream. It must, however, be borne in mind, that we are speaking +of the atomic density, and not of density by compression; for this +cometary dust, which renders luminous the escaping ether of the nucleus, +must be far too much diffused to merit the name of an elastic fluid. May +not the concentric rings, which were so conspicuous in the comet of +1811, be owing to differences in the gravitating forces of such +particles, sifted, as it were, and thus arranged, according to some +ratio of the distances, by the centripulsive force of the electric coma, +leaving vacant intervals, through which the ether passed without +becoming luminous? This at least is the explanation given by our theory. +We may, indeed, consider it possible that the escaping ether, when very +intense, might be rendered luminous by passing into the surrounding +ether, and, as it became more diffused by radiation, at last become +invisible. In this case, as the law of radiation is as the squares of +the distances from the centre inversely, the rays would be more and more +bent at right angles, or apparently shortened, as the power of the +radial stream increased, and the apparent diameters of the coma would +be diminished faster than the ratio of the 2.5th power of the distances. +But whichever view we adopt, the diameter would again increase in the +same ratio on leaving the sun, if we make allowance for increase of +temperature, as well as for diminution of density, for the ordinary +distance of a comet's visibility. We, however, regard the change of +diameter, as due to both these nodes of action, as best agreeing with +the indications afforded by their tails. + +From the preceding remarks, it results that the density of the particles +producing the nebulous envelope of a comet, renders the variations of +diameter only approximate to the law of the radial stream; a comet's own +electric energy, or the intensity of the escaping ether, may also modify +this expression, and many other causes may be suggested. That the radial +stream is the cause, in the way we have pointed out, is proved by the +positions of the major axis of the short-period comet, making frequently +nearly a right angle with the radius vector of the orbit in 1828. A soap +bubble gently blown aside, without detaching it from the pipe, will +afford a good illustration of the mode, and a confirmation of the cause. +The angles measured by Struve, reckoned from the radius vector, +prolonged towards the sun, are subjoined: + + November 7 99°.7 | December 7 154°.0 + November 30 145 .3 | December 14 149 .4 + +At this last date, the comet was getting pretty close to the sun. When +the angle was greater, as on November 7th, the comet appeared to make +almost a right angle with the radius vector; and in this position of the +earth and comet, the longer axis of the elliptical comet was directed to +the axis of the vortex, as may be verified by experiment. At the later +dates, the comet was more rapidly descending, and, at the same time, the +axis of the comet was getting more directed towards the earth; so that +the angle increased between this axis and the radius vector, and +consequently became more coincident with it. We have now to consider the +luminous appendage of a comet, commonly called a tail. + +The various theories hitherto proposed to account for this appendage are +liable to grave objections. That it is not refracted light needs not a +word of comment. Newton supposes the tail to partake of the nature of +vapor, rising from the sun by its extreme levity, as smoke in a chimney, +and rendered visible by the reflected light of the sun. But, how vapor +should rise towards opposition in a vacuum, is utterly inexplicable. In +speaking of the greater number of comets near the sun than on the +opposite side, he observes: "Hinc etiam manifestum est quod cœli +resistentiâ destituuntur."[46] And again, in another place, speaking of +the tail moving with the same velocity of the comet, he says: "Et hinc +rursus colligitur spatia cœlestia vi resistendi destitui; utpote in +quibus non solum solida planetarum et cometarum corpora, sed etiam +rarissimi candarum vapores motus suos velocissimos liberrimè peragunt ac +diutissimè conservant." On what _principle_, therefore, Newton relied to +cause the vapors to ascend, does not appear. Hydrogen rises in our +atmosphere because specifically lighter. If there were no atmosphere, +hydrogen would not rise, but merely expand on all sides. But, a comet's +tail shoots off into space in a straight line of one hundred millions of +miles, and frequently as much as ten millions of miles in a single day, +as in the case of the comet of 1843. Sir John Herschel observes, that +"no rational or even plausible account has yet been rendered of those +immensely luminous appendages which they bear about with them, and which +are known as their tails." Yet, he believes, and astronomers generally +believe, that a comet shines by reflected light. This theory of +reflexion is the incubus which clogs the question with such formidable +difficulties; for, it follows, that the reflecting matter must come +from the comet. But, what wonderful elements must a comet be made of, to +project themselves into space with such immense velocity, and in such +enormous quantities as to exceed in volume the body from which they +emanate many millions of times. This theory may be, therefore, safely +rejected. + +From what we have already advanced concerning the coma or nebulosity of +the comet, we pass by an easy path to an explanation of the tail. In the +short-period comets, the density of the elementary atoms is too great to +be detached in the gross from the nucleus, or, rather, the density of +the atoms composing the nucleus is too great to permit the radiating +stream of the comet carrying them to a sufficient distance to be +detached by the radial stream of the sun. Hence, these comets exhibit +but very little tails. We may also conceive, that the continual siftings +which the nucleus undergoes at each successive perihelion passage, have +left but little of those lighter elements in comets whose mean distances +are so small. Yet, again, if by any chance the eccentricity is +increased, there are two causes--the density of the ether, and the heat +of the sun--which may make a comet assume quite an imposing appearance +when apparently reduced to the comparatively passive state above +mentioned. + +According to our theory, then, the coma of a comet is due to the +elasticity of the ethereal medium within the nucleus, caused both by the +diminished pressure of the external ether near the sun, and also by the +increased temperature acting on the nucleus, and thus on the involved +ether. The tail, on the contrary, is caused by the lighter particles of +the comet's attenuated atmosphere being blown off by the electric blast +of the radial stream of the solar vortex, in sufficient quantities to +render its passage visible. It is not, therefore, reflected light, but +an ethereal stream rendered luminous by this detached matter still held +in check by the gravitating force of the sun, whose centre each +particle still respects, and endeavors to describe such an orbit as +results from its own atomic density, and the resultant action of both +the acting forces. From the law of density of the ether, the coma ought +to be brightest and the radiating stream of the comet's nucleus +strongest on the side of least pressure: from this cause, and the fact +that the body of the comet affords a certain protection to the particles +immediately behind it, there will be an interval between the comet and +the tail less luminous, as is almost invariably observed. We thus have +an explanation of the fact noticed by Sir John Herschel, "that the +structure of a comet, as seen in section in the direction of its length, +must be that of a hollow envelope of a parabolic form, enclosing near +its vertex the nucleus or head." We have, also, a satisfactory +explanation of the rapid formation of the tail; of its being wider and +fainter at its extremity; of its occasional curvature; and of its +greater length after perihelion than before. But, more especially may we +point to the explanation which this theory gives of the fact, that, +_ceteris paribus_, the long-period comets, when their perihelion +distances are small, have tails of such exaggerated dimensions. + +A comet, whose mean distance is considerable, is supposed by the theory +to be composed of elements less dense, and, during its long sojourn at +its aphelion, it may be also supposed that it there receives continual +accessions to its volume from the diffused siftings of the system, and +from the scattered debris of other comets. On approaching the +perihelion, the rapidity of the change in the density of the ether in a +given time, depends on the eccentricity of the orbit, and so does the +change of temperature; so that, from both causes, both the length of the +tail and the brilliancy of the comet measurably depends on the magnitude +of the period and of the eccentricity. + +If the nuclei of comets be gaseous as we suppose, and that the smallest +stars are visible through them, it is an outrage on common sense, to +refer that light, which renders a comet visible at noon-day, within six +minutes of space of the sun itself, to the reflected light of the sun. +When a small star has been seen through the nucleus of a comet, without +any perceptible diminution of light, it indicates perfect transparency; +but there can be no reflection from a perfectly transparent body, and +therefore, a comet does not shine by reflected light. It is true that +Arago discovered traces of polarized light in the comet of 1819, and +also in more recent comets, but they are mere traces, and Arago himself +admits, that they do not permit "the conclusion decidedly that these +stars shine only with a borrowed light." But it still does not follow +that a comet (even if independent of reflected light) is in an +incandescent state. The auroral light is not polarized, nor any other +electric light, neither is it owing to a state of incandescence, yet it +is luminous. The intense light of a comet at perihelion is analogous to +the charcoal points of a galvanic battery, caused by a rapid current of +ether from the nucleus, and assisted by the radial stream of the vortex. +This will account for the phenomenon in all its shades of intensity, as +well as for the absence of any perceptible phase. It will also account +for the non-combustion of such comets as those of the years 1680 and +1843. We shall also be at no loss to understand, why there is no +refraction when a ray of light from a star passes through the nebulosity +of a comet; and if, as we may reasonably suppose, the gaseous matter +composing the nucleus be very attenuated, instruments are yet too +imperfect to determine whether these also have any refracting power. On +this point, however, it is safest to suspend our judgment, as there may +be comets not belonging to our system, with even liquid or solid nuclei, +or of matter widely different to those elements composing the members of +the solar system. + +In addition to what has been already advanced on this subject of a +comet's light, we may appeal to the well-known fact that the visibility +of a comet is not reciprocally as the squares of the distances from the +earth and sun as it ought to be, if shining by reflected light. In +Mr. Hind's late work on comets, the fact is stated that "Dr. Olbers +found that the comet of 1780 attained its greatest brightness on the 8th +of November, thirteen days subsequent to its discovery, whereas +according to the law of reflected light, it should have become gradually +fainter from the day of its discovery; and supposing the comet +self-luminous, the intensity of light should have increased each day +until November 26th; yet in the interval between the 8th and 26th of +that month, it grew rapidly less." Now this theory teaches, that a comet +is neither self-luminous nor dependent on the sun, but on its distance +from the axis of the vortex, and a certain amount of elapsed time from +the perihelion, varying somewhat in each particular case. This fact is +therefore a very strong argument in favor of our theory. + +Amidst the many anomalous peculiarities of comets, it has been noticed +that a short tail is sometimes seen at right angles to the principal +tail, and in a few cases pointing directly towards the sun. Much of this +may be owing to perspective, but granting the reality of the fact, it is +still explicable on the same general principles. + +In speaking of the modifying causes which influence the weather, we +mentioned the effect due to the position of the sun with respect to the +axis of the vortex. This will be found to have a sensible effect on the +action of the radial stream. The natural direction of a comet's electric +stream is _towards_ the axis of the vortex, and in the central plane of +the vortex it will be also towards the sun. But this stream is met by +the stronger radial stream from the axis, and as Mr. Hind describes it, +"is driven _backward_ in two streams passing on either side of the head, +and ultimately blending into one to form the tail." Now, if the body of +the sun be situated between the comet and the axis of the vortex, it +will shield the comet from the action of the radial stream, and thus a +tail may really point towards the sun. + +In 1744 a brilliant comet exhibited six distinct tails spread out like a +fan, some seven days after its perihelion passage; its distance from +the sun at the time not being more than a third of the earth's distance. +The comet was then rapidly approaching the plane of the ecliptic, and if +we make the calculation for the position of the sun, we shall find that +the body of the sun was on the same side of the axis of the vortex as +the comet, and that the comet was then situated at the boundaries of the +conical space, enclosed by the radial stream in its deflected passage +round the body of the sun. In this position there are numerous cross +currents of the stream, and hence the phenomenon in question. As this +fact rests on the testimony of one individual, and is an occurrence +never recorded before or since, many are disposed to doubt the fact, yet +our theory explains even this peculiarity, and shows that there is no +necessity for impugning the statement of Cheseaux. + +Another unexplained phenomenon is the corruscation of the tail. It has +been attempted to explode this fact also, by referring it to conditions +of our own atmosphere; and it is generally considered the argument of +Olbers, founded on the great length of the tail and the velocity of +light, is sufficient to prove that these corruscations are not actually +in the tail. Now, it is undoubtedly true, that as light travels less +than two hundred thousand miles in a second, and a comet's tail is +frequently one hundred millions long, it is impossible to see an +instantaneous motion along the whole line of the tail; but granting that +there are such flickerings in the tail as are described by so many, it +must necessarily be, that these flickerings will be _visible_. It would +be wonderful indeed, if a series of waves passing from the comet to the +extremity of the tail, should have their phases so exactly harmonizing +with their respective distances as to produce a uniform steady light +from a light in rapid motion. The argument, therefore, proves too much, +and as it is in the very nature of electric light thus to corruscate, as +we see frequently in the northern lights, we must be permitted still to +believe that not only the tails, but also the heads of comets do really +corruscate as described. + +With respect to the direction of the tail, astronomers have been forced +to abandon the antiquated notion, that the tail always pointed directly +from the sun; yet they still pertinaciously cling to the idea, that +although this is not always the case, the tail only deviates from this +direction _in the plane of the orbit_. As this is a most important +question, it is necessary formally to protest against such a conclusion. +If the earth should happen to be in the plane of the comet's orbit and +the tail appears in that plane, it must of course be in that plane +_really_; but if the earth is not in the plane of the comet's orbit, the +tail is not _necessarily_ in the same plane, whatever its apparent +direction may indicate. It is true there is a tendency of every particle +of the tail, moving under the restraining influence of the sun's +attraction, to continue in the plane of the orbit; and in certain +positions there is no oblique action arising from the force of the +radial stream to cause it to deviate from that plane; yet in other +positions of the comet, the action of the radial stream may be oblique, +forcing it out of that plane, and still such a direction might be +assigned to it as to make it conform. In the comet of 1843, P. Smythe +observed a forked tail 25° long on March 3d, and from the end of the +forked tail, and from its _north_ side, a streamer diverged at an angle +of 6° or 7° to the _north_. As this was contrary to the _direction_ of +the curvature, if the tail had been curved, it could only arise from a +portion being driven off by the radial stream, or bent towards the plane +of the ecliptic. The curvature observed by others at a later date, was +concave to the south. Towards the middle and close of March, the tail +became straight, and with the above exception, might be considered to +move in the plane of the orbit. + +The celebrated comet of Halley, as observed by Dr. Bessel in 1835, +showed that a more or less well-defined tuft of rays emanated from that +part of the nucleus which was turned towards the sun; and the rays being +_bent backward_ formed a part of the tail. The nucleus, with its +emanations, presented the appearance of a burning rocket, the end of +which was turned sideways by the force of the wind. And, Bessel +concludes: "That the cone of light issuing from the comet deviated +considerably both to the right and left of the true direction of the +sun, but that it always returned to that direction, and passed over to +the opposite side; so that the cone of light, and the body of the comet +from whence it emanated, experienced a rotatory, or, rather, a vibrating +motion _in the plane of the orbit_." It is impossible that Bessel should +here mean that this motion was certainly in the plane of the orbit; for +the orbit was then viewed sideways, and he had no means of ascertaining +the fact. His meaning must be that it was apparently in the plane of the +orbit. If a plane be made to pass through the earth, the comet, and the +sun, the tail might be placed in any position in that plane, and yet +appear to be at the intersection of the two; that is, in the plane of +the comet's orbit. The vibration of the tail, in this case, is another +strong proof of the correctness of our theory. To make it more +intelligible, we shall resort to a diagram. + +In the following diagram, the comet's orbit, represented by the dotted +line, is drawn on the plane of the ecliptic; it is, therefore, necessary +to bear in mind, that it is tilted up from the line of nodes SN, at an +angle of 17° 45′. The position of the comet, October 9th, is at C, +approaching its perihelion; that of the earth at the same time at T; +while S represents the sun, and SQ the line of equinoxes. Now, from a +cause already explained, the tail always tends to lay behind the comet, +in the direction indicated by the lower tail in the diagram at 1, and, +if produced, would pass to the left of the sun, as seen from the earth: +the force of the radial stream, however, will not allow this lagging of +the tail, and it is straightened out by this force; but, being directed +to the axis of the vortex, and not to the sun, it is not really in the +plane of the orbit, but is seen in the direction of the upper tail +depicted in the diagram at 3, and, if produced, would pass to the right +of the sun, as seen from T. Now, there is an intermediate position of +the tail, in which it will appear in the prolongation of the radius +vector SC; this position is represented by the middle or central tail of +the comet at 2, yet this is not in the plane of the orbit, it only +appears to be, as may be readily understood by remembering that the +earth at this time is under this plane, and the comet is seen at a +considerable elevation above the plane of the ecliptic. When the comet's +tail becomes directed to the axis of the vortex, or in the _apparent_ +position of No. 3, the comet, rapidly careering on its way to the sun, +again leaves the tail behind, and again it is strengthened out by the +radial stream oscillating about the mean position at 2, as observed by +Bessel. From this, it appears, that there is no necessity to make +confusion worse confounded, by resorting to polar forces, which are +about as intelligible as the foundations of the pillars of Atlas. + +[Illustration: Fig. 25] + +It may be objected that the continued action of the radial stream with +that velocity we have contended for, ought to keep the tail invariably +directed from the axis of the vortex; but, where there are two forces or +tendencies, as in this case, analogy would teach us that a certain +degree of oscillation is a necessary result. There may, also, be slight +and transient changes in the direction of the radial stream. In the +hurricane there are short and fitful blasts inclined to the general +direction of the wind, which must arise from the inertia of the moving +mass of atmosphere, causing temporary condensations and rarefactions. Be +this as it may, we have assigned a cause which satisfies the phenomenon, +without coming into collision with a single principle of celestial +mechanics. + +Prof. Struve compared the tail of this comet to a flame, or "ray of fire +shot out from the nucleus, as from some engine of artillery, and driven +on one side by the wind." At the same time, he saw a second emanation +nearly in the opposite direction. This last might arise from a momentary +fluctuation in the relative intensities of the electric radiation of the +comet, and of the radial stream, owing to the probable irregularities +just alluded to. Such and kindred phenomena are utterly inexplicable, +without we adopt the theory we are advocating. One other feature, and we +will leave the subject. + +From our explanation of the solar spots, we inferred the existence of +another large planet in the system. Might not the same effect be +produced by a comet? Or may there not be so many comets, whose great +elongation, combined with even a moderate mass, may render it impossible +to calculate the position of the sun with respect to the central axis of +the vortex,--always considering this last as the axis of equilibrium? In +a general way, we might say that the very number of comets in all +directions and all distances, would tend to neutralize each other's +effects; but we are not under this necessity. A comet, moving in a +parabola, does not belong to the system or to the rotating vortex; and +the periodic comets, if of gaseous elements, (as seems so probable,) +must, from the size of their nuclei, which the theory considers the only +part constituting their mass, have far less mass than the very smallest +of the asteroids, and consequently could have very little effect on the +mechanical balance of the vortex, even if elongated as far as the orbit +of Neptune. Did we know the influence of cold in limiting the +expansibility of the elementary gases, we might approximately determine +the mass of a comet, from the size of its nucleus; but this is a problem +that has never yet been solved; and astronomers ought to avail +themselves of every indication which promises to realize this great +desideratum. The grand comet of 1556 is now probably approaching, and, +from recent investigations, it appears that it will arrive at its +perihelion in 1858,--subject to an error either way of about two years. +An opportunity may thus be presented of determining the mass of one of +the largest comets on record, which may not again occur. This arises +from the possible appulse of the comet to the planet Pallas, whose mass, +being so small, would more sensibly be disturbed by such an appulse than +the earth. As the inclinations and ascending nodes of the two orbits +approximately coincide, and as Pallas will be near the comet's path, on +the approach of the latter to the sun, at the beginning of the year +1857, should the comet become visible about that time, a very close +appulse is possible. It is not unlikely, also, that if the elements of +Pallas were so far perfected as to afford reliable indications, that the +near approach of the comet might thus be heralded in advance, and lead +to an earlier detection of its presence. Would it not be a worthy +contribution to science, for some one possessing the necessary leisure, +to give an ephemeris of the planet for that epoch; as a very slight +change in Mr. Hind's elements of the comet, would cause an actual +intersection of the two orbits in about heliocentric longitude 153°? The +subsequent nodal passage of Pallas will take place near opposition, and +be very favorably situated for determining the instant of its passage; +and, of all the elements, this would be more likely to be affected than +any other.[47] + + +THE ZODIAL LIGHT. + +A phenomenon, akin to that which we have just been considering, is +presented by that great cone of diffused light which accompanies the +sun, and which in tropical climes displays a brilliancy seldom witnessed +in high latitudes, on account of its greater deviation from the +perpendicular. Sir John Herschel conjectures that it may be "no other +than the denser part of that medium, which, as we have reason to +believe, resists the motion, 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 passages, and which +may be slowly subsiding into the sun." If these materials have been +stripped, it is due to some force; and the same force would scarcely +permit them to subside into the sun. Once stripped, these portions must +be borne outwards, by the radial stream, to the outer verge of the +system. Still, there are, no doubt, denser particles of matter, of the +average atomic density of Mercury and Venus, which can maintain their +ground against the radial stream, and continue to circulate near the +central plane of the vortex, in all that space between the earth and the +sun. But if the zodial light be the denser part of that medium, which +astronomers now generally recognize as a resisting medium, how happens +it that it should be confined to the plane of the ecliptic? Why should +it not be a globular atmosphere? Here, again, our theory steps in with a +triumphant explanation; for while it permits the accumulation of such +particles around the equatorial plane of the sun, it allows no +resting-place very far removed from this plane. The zodial light, +therefore, is not the resisting medium, but the passage of the radial +stream through a diffuse nebula of atoms, brought down the poles of the +vortex by the polar current, and held in check along the central plane +by gravitation. + +If these atoms partook of the velocity of the ether, they would not be +luminous; but being held back by gravitation, they are opposed to the +radial stream, and hence the light. + +Many stars are also nebulous. In some cases we see the nebulosity +edgewise, or along the equatorial planes of the stellar vortices; in +others we look down the poles, and the nebulosities are circular, and +there is an endless variety in the shape and intensity of this light. +But the universe seems full of motion, and we are not justified in +supposing, because a star shows no such light, that it is without +rotation. The parallax of the nearest star is only one second, the whole +lenticular mass of light which surrounds our sun would therefore only +subtend an angle of a single second at the nearest fixed star. Seeing +its extreme faintness, therefore, the effulgence of the star would +render it totally invisible, provided that it _could_ traverse the vast +immensity of intervening space, without feeling the influence of that +extinction, which Struve has proved does actually diminish the number of +visible stars. + +Corruscations and flickerings have also been noticed in the zodial +light, and as usual, the learned have suggested atmospheric conditions +as the cause, instead of trusting to the evidence of their own senses. +How prone is philosophy to cling to that which is enveloped in the mist +of uncertainty, rather than embrace the _too simple_ indications of +nature. As if God had only intended her glories to be revealed to a +favored few, and not to mankind at large. Blessed will be the day when +_all_ will appreciate their own powers and privileges, and no longer +regard the oracles which emanate from a professional priesthood, whose +dicta have so often tended to darken the simple counsels of truth! To +set the question of pulsations in the zodial light, as well as in the +tails of comets, at rest, only requires previously concerted +observations, in places not very widely apart; for it is scarcely +possible, that atmospheric conditions should produce simultaneous +pulsations in two distant places. If the pulsations are found to be +simultaneous, they are real; if not simultaneous, they may depend on +such conditions; but from the nature of the cause, we should look for +them as much in the zodial light, as in the aurora borealis, regarding +the different intensities. + +There is also reason to suspect that the northern side is always the +brightest, both in spring and autumn. On the morning of October 4th, +1853, the light was very vivid and well defined, its northern margin +grazing Regulus and terminating at Mars, which was also to the north of +it. Now, although the _northern side_ was the brightest, the great mass +of light was to the south of the ecliptic, as far down as the cone shape +was preserved; but at 10° from the horizon, a still brighter mass +protruded from the cone towards the north, which was all _north_ of the +ecliptic, and of an irregular form, extending along the horizon. The +time was 4 A.M., and consequently was not due to any crepuscular light. +An explanation of the general fact of the brightest light being _always_ +on the north side, is given in the present section, in connection with +another phenomenon. If, as some suppose, the light does not reach to the +sun, the annulus must at least fill all the space between Venus and the +earth, but it is far more in accordance with facts as well as with our +theory, to suppose it increases in density to the body of the sun. + +Observations made at the observatory of the British Association, +detected, in 1850, sudden brightenings of the light, altogether +different from pulsations. The theory would refer these to that fitful +irregularity in the momentary intensity of the radial stream, which +gives the flickering and tremulous motion to comets' tails. But, the +steady variations in the intensity of this light must be due to other +causes. The longitude of the sun will here come in as a modifying cause; +for the obstruction caused by the body of the sun, when displaced from +the axis of the vortex, must necessarily exercise an influence on the +force and direction of the radial stream. A sudden influx of cometary +matter down the poles of the vortex, in more than usual quantities, will +also tend to brighten and enlarge the zodial light; and, in this last +cause, we have an explanation not only of ancient obscurations of the +solar light, but, also, of those phosphorescent mists, such as occurred +in 1743 and 1831, rendering moonless nights so light that the smallest +print could be read at midnight. + +In total eclipses of the sun, the denser portion of the zodial light is +visible as a brilliant corona; but, on such occasions, the brightest +stars only are to be seen, and, consequently, the fainter portions of +the light must be invisible. Hind mentions as many as ten stars visible +in the total eclipse of 1842. According to the same authority, the color +of the corona was like tarnished silver, and rays of light diverged in +every direction, and appeared shining through the light of the corona in +the total eclipse of 1851. In this year on the day of the eclipse (July +28th), the longitude of the sun was about 340°, and, therefore, the body +of the sun obstructed the radial stream as seen from the earth on the +right side; but, in 1842, the longitude of the sun was, according to our +table, about 116°, the sun's centre then being 700,000 miles from the +axis of the vortex, and on the opposite side with respect to the earth; +the position was, therefore, not so favorable for the appearance of +these rays which, in many cases, have given the appearance of a whirling +motion to the corona. + +At this date, July 7th, 1842, the corona, according to Prof. Airy, +"possibly had a somewhat radial appearance, but not sufficiently marked +to interfere with the general annular structure." Mr. Baily, on the +contrary, says, the corona had the appearance of brilliant rays; and, at +Milan, long jets of light were particularly noticed. There can be no +doubt but that the passage of the radial stream past the outer margin of +the moon must also give rise to the same phenomena as when passing the +sun, and in this we have an explanation of the fact, that, previous to +the moment of first contact, an appearance resembling a +faintly-illuminated limb of the moon, has been perceived near the body +of the sun; as well as of those flashes of light which have been +observed in the lunar disc as the eclipse advances. One important fact, +worthy of note, is, that these luminous streaks are more nearly parallel +than is due to a radiation from the centre. These streaks have, also, +been seen bent at right angles at the middle of their height, as a flame +is by means of a blowpipe, precisely analogous to cometary rays being +driven backwards to form the tail, as already described, thus indicating +a common origin. If the moon had an atmosphere, we should, no doubt, see +a greater display; but, having no rotating vortex to protect her from +the radial stream, her atmosphere must have been long since stripped +off, leaving her exposed to the withering winter blast of the great +stream of the solar vortex. In this connection, we may also allude to +the appearance of the moon when totally eclipsed. Instead of +disappearing at these times, she sometimes shines bright enough to +reveal her smallest spots. This has been generally referred to the +refraction of the earth's atmosphere bending inwards the solar rays. May +it not be owing to the brilliancy of the solar corona, which, in 1842, +was described as so intense that the eye was scarcely able to support +it? This is a far more palpable cause for the production of this +phenomenon, but of which astronomers cannot avail themselves, as long as +they are uncertain of the origin of this corona. + + +SHOOTING STARS. + +The continual influx of cosmical matter into the heart of the vortex in +ever-varying quantities, and speedily dispersed along the central plane, +according to its density, must necessarily give rise to another +phenomenon to which we have not yet alluded. Scarcely a night passes +without exhibiting this phenomena in some degree, and it is generally +supposed that the hourly average of shooting stars is from five to ten, +taking the whole year round. The matter composing these meteors we +regard as identical with that mass of diffused atoms which forms a +stratum conforming to the central plane of the vortex, and whose partial +resistance to the radial stream occasions that luminosity which we call +the zodial light. These atoms may coalesce into spherical aggregations, +either as elastic gas, or as planetary dust, and, passing outward on the +radial stream, will occasionally become involved in the vortex of our +own globe; and being drawn inwards by the polar current, and acted on by +the earth's gravity, be impelled with great velocity through the +rarefied air of the upper atmosphere. That meteors are more abundant +about the time of meridian passage of a vortex (or, perhaps, more +correctly speaking, from six to twelve hours afterwards, when the +current of restoration penetrates the atmosphere), well accords with the +author's observations. It is about this time that high winds may be +looked for, according to the theory; and it has ever been a popular +opinion, that these meteors are a sign of windy weather. Even in +Virgil's time, the same belief prevailed, as a passage in his Georgics +would seem to indicate. + + "Sape etiam stellas, vento impendente, videbis + Præcipites cœlo labi; noctisque per umbram + Flammarum longos à tergo albescere tractus;" + +Virgil was a close observer of nature, and commences a storm with the +wind at south, "Quo signo caderent Austri;" just as we have represented +the usual course when these vortices pass near the observer's latitude. +It is also a well-known fact, that after a display of meteors, (and we +are now speaking of ordinary displays, and not of the great showers,) +the temperature falls considerably. It is not uncommon also, that +meteors are more abundant during an auroral display, as they ought to be +by the theory. We must, however, exempt from this influence those solid +meteors which sometimes come into collision with the earth, and +afterwards grace the cabinets of the curious. These bodies may be +considered microscopic planets, moving in stated orbits with planetary +velocity, and bear strongly on the explosive theory of Olbers, as fully +detailed by Sir David Brewster. + +It is a very remarkable fact, first noticed by Olbers, that no fossil +meteoric stones have yet been discovered. If this fact be coupled with +the hypothesis advanced by Olbers, in reference to the origin of the +asteroidal group, we should have to date that tremendous catastrophe +since the deposition of our tertiary formations, and therefore it might +possibly be subsequent to the introduction of the present race into the +world. May not some of the legendary myths of the ancient world as +mystified by the Greeks, have for a foundation the disappearance of a +former great planet from the system? The idea of the existence of seven +planets is one of the oldest records of antiquity; but the earth of +course would not be counted one, and therefore in after times, the sun +was included to make up the number; just as the signs of the Zodiac have +been explained in accordance with the seasons of far later times than we +can possibly assign for the invention of this division of the heavens. +Let those who have the leisure, try how far the contraction and dilation +of the asteroidal orbits, to some average mean distance, will restore +them to a common intersection or node, as the point of divergence of the +different fragments. The question is interesting in many of its aspects, +and may yet be satisfactorily answered. + +The composition of aërolites may also be taken as indications of the +common origin and elementary texture of the planets, whether they are +independently formed or have originally pertained to a former planet; +for no hypothesis of telluric or selenic origin yet advanced, can stand +against the weight of evidence against it. Their fragmentary character +rather favors the views of Sir David Brewster, and when we consider that +they have been revolving for thousands of years with planetary velocity, +and in very eccentric orbits, through the ether of space, continually +scathed by the electric blast of the radial stream, their rounded +angles, and black glossy crust of an apparently fused envelope, may be +accounted for, without difficulty, from the non-vitrified appearance of +the interior. The composition of aërolites as far as known, embrace +nearly one-third of all known simple substances according to Humboldt, +and are as follows: iron, nickel, cobalt, manganese, chromium, copper, +arsenic, zinc, potash, soda, sulphur, phosphorus, and carbon. + +The theory we have thus given of the common occurrence of shooting +stars, will render a satisfactory general account of their sporadic +appearance; but there are other phenomena of greater interest, viz.: the +occasional recurrence of swarms of such meteors, which defy all +numerical estimates, being more like a fiery rain than anything they can +be compared to. The most interesting feature of this phenomena, is the +_apparent_ periodicity of their return. In the following table we have +set down the most remarkable epochs mentioned by Humboldt, (and no man +has devoted more attention to the subject,) as worthy of notice: + + About April 22 to 25 + " July 17 to 26 + " August 9 to 11 + " November 12 to 14 + " November 27 to 29 + " December 6 to 12 + +Besides these, he mentions two showers, from Arabian authority, in +October; one in October, observed in Bohemia; one observed by himself, +in the Pacific, on March 15; one February 4, just preceding the terrible +earthquake of Riobamba, in 1797. The Chinese annals also contain many +showers of stars, before the present era commenced. Some were in March, +more in July, and others in different months. How, then, in view of +these numerous dates, can we attach so much importance to the +periodicity of these showers? The great shower of 1833, in the United +States, on the 12th and 13th of November, brought to mind the great +shower at Cumana, observed by Humboldt and Bonpland just thirty-three +years before, to a day; and it must be confessed that more than ordinary +displays have been seen on this date. Yet, on the strength of this, +every meteoric shower is supposed to be periodical, and has resulted in +a theory which becomes more complicated as the phenomenon is more +observed, and can never lead to any useful and practical results. To +cite the numerous instances of discrepant results, would only encumber +this brief notice with facts neither interesting to the general reader, +nor convincing to those who hold a contrary opinion. The author of these +pages has watched for many years, and, in view of all the facts, has +concluded that the doctrine of periodicity (as held by present +meteorologists) is not tenable. The celebrated August shower failed, +also, this year, at least in this place, as for four hours each night, +on the 9th, 10th, and 11th, there were fewer bright meteors than at the +close of July. + +Professor Olmsted, who has paid considerable attention to the subject, +has indeed attempted to connect the great November shower with the +zodial light, which last he considers a nebulous body, of an elongated +form, whose external portions, at this time of the year, lie across the +earth's path. (See Silliman's Journal for 1837, vol. xxxiii. No. 2, +p. 392.) He even gives its periods, (about six months,) the aphelion of +the orbit being near the earth's orbit, and the perihelion within +Mercury's. In this way he attempts to explain both phenomena; but as the +zodial light is seen unchanged all the year round in tropical latitudes, +it is not the kind of body supposed by Olmsted, and the theory adds +nothing to our knowledge. Others have imagined rings of nebulous matter, +in which all the separate parts are moving in the same orbit around the +sun, with a retrograde motion, and this, with some modifications, is the +current theory of the day. The principal arguments rested on, for the +support of this view, are derived from the great shower of 1833, in +which a common radiant point was observed, and confirmed subsequently by +the radiant of other years, in the same month of November. As this point +is almost tangential to the earth's orbit at this season, the earth +meets the nebulous ring moving in the contrary direction, and thus +confers on these meteors the necessary velocity that is thought to be +demanded by observation. + +Now, our theory gives a totally different explanation of the phenomenon. +We contend that a retrograde motion of such a nebulous mass, is +subversive of our whole theory; and we must be permitted to examine +certain points, hitherto disregarded by those entertaining antagonist +views. It is supposed that the meteors in 1833 fell for eight or nine +hours. The orbital velocity of the earth is more than 1,000 miles per +minute, and the orbital velocity of the nebulous zone must have had a +similar velocity. During the nine hours of meteoric display, therefore, +the earth traversed 500,000 miles of her orbit, which would give +1,000,000 miles for the depth of the nebulous stratum. But if of such +vast extent, how happened it that the only part of the earth in which +these were visible in great density, was the United States, or a space +embraced between the latitudes of 50° and 20° north, and the longitudes +60° and 100° west, (and these are the widest limits,) comprising only +1/40 of the surface of the globe? To a calm inquirer, this difficulty +seems insurmountable. The author was then in the Mediterranean, on deck +the greatest part of the night,--the weather fine, and nothing unusual +visible in the heavens; from other sources he has also derived similar +information. Yet, were the earth then passing through a stratum of +meteors 1,000,000 miles in extent, it is utterly inconceivable that +other portions of the earth escaped. Much stress is also laid on the +fact that these meteors in 1833, passed from east to west generally, as +they ought to do, if tangential to the earth in her orbit; but on the +same phenomenon occurring in 1799, when the earth was in precisely the +same part of her orbit, Humboldt says distinctly, "the direction (of the +meteors) was very regular from north to south." How could this possibly +happen, and at the same time be moving tangentially to the orbit? + +There is also another fact of importance not duly weighed in forming +such a theory. In 1833 the meteors evidently differed in velocity; one +class, consisting of luminous points, passed like a shower of fire with +great velocity to the westward, another class were like large fire-balls +with luminous trains moving with less rapidity, while a third class +consisted of nebulous patches which remained stationary for a long time, +and frequently emitting large streams of light. These last, at least, do +not deport themselves as planetary bodies moving 2,000 miles per minute. +But the fact still remains, that unusual displays have occurred about +the 12th and 14th of November; and also as a general thing when there +are no unusual displays, the meteors are more abundant about this time. +Let us try if we can reconcile these facts with the theory of vortices. + +We will first confine our remarks to the increased number of meteors +about November 12th and 14th. The cosmical matter composing the zodial +light, or at least the lighter parts of it, is continually driven +outwards by the radial stream, just as the matter of a comet's tail is +stripped from the nucleus. This matter becomes involved in the terral +vortex by descending the poles, and is again passed out along the +equatorial plane. The form of the zodial light, as seen edgewise, gives +a lenticular form for the stratum of planetary particles composing it, +and its central plane has been considered as coinciding with the plane +of the sun's equator. At the orbit of the earth, this lenticular space +is narrowed to a very thin stratum, but undoubtedly reaches beyond the +earth's orbit with a rapidly diminishing density. As the axis of the sun +is inclined about 7° to the ecliptic, and the ascending node is in the +20th degree of Gemini, the earth can only pass through the plane of the +sun's equator about the 12th of December and the 12th of June. If, +therefore, the central plane of the vortex coincides with the plane of +the sun's equator, meteors ought to be more numerous about the dates +above mentioned. But the observed times are on November 12th and 13th. +Now, from actual measurements, a computation has been made by M. +Houzeau, that the elements of the zodial light are materially different +from those of the sun's equator. He fixes the node of the light +(according to Mr. Hind) in 2° heliocentric longitude, subject to an +uncertainty of 12° or 13°, and its inclination to the plane of the +ecliptic, 3° 35′, subject to an uncertainty of about 2°. The truth is, +astronomers have argued the coincidence of the two planes from +considerations connecting the zodial light with the sun's equator, as if +it were a solar atmosphere; but such an atmosphere is impossible, and it +is high time such measures should be taken as will lead to some certain +conclusion. If in the present state of the question, we were to take the +mean, we should find the node in about longitude 40°, which is the +position of the earth on November 2d. But in the absence of +measurements, we will assume, for the sake of argument, that the +ascending node of the central plane of the vortex was, in 1833, in 50° +heliocentric longitude, and consequently the earth was passing through +the meteoric stratum or central plane of the zodial light, on the night +of November 12th. The opposite period of the year is May 12th--a date, +it is true, on which no great shower of stars is recorded, but sporadic +meteors are very plentiful at that time, and what is more important to +observe is, that the 11th, 12th, and 13th of May, are the three noted +_cold days_ which we have before mentioned. Thus truly indicating that +the earth is then in or near the central plane of the vortex along which +the radial stream is at its maximum of power at any given distance from +the axis. + +But the question occurs, does the node of this plane remain stationary, +and is there no variation of the inclination of the axis of the solar +vortex? We have found from observation, that the axis of the terral +vortex is continually oscillating about a mean position by the action of +the moon; and reasoning from this analogy, and the constant tendency of +a material vortex to preserve a dynamical balance, the same tendency +must obtain in the solar vortex under the action of the great planets, +whose orbits do not coincide with the central plane of the vortex. The +ascending node of Jupiter's orbit is in longitude 98°, Saturn's 112°, +Uranus' 72°, Neptune's 131°; so that this plane does not correspond with +the plane of greatest inertia discovered by La Place, and from the +non-coincidence of these planes with the central plane of the vortex, +must produce the same oscillation in the axis of the solar vortex, as +the moon does in the terral vortex, but to what amount, observation can +alone determine. Jupiter and Saturn will of course exert the greatest +influence, and when these two planets are in conjunction, the ascending +node of the central plane of the vortex will vary in longitude perhaps +sufficiently to bring the meteoric maximum at the ascending node into +October on the one hand, and to the close of November on the other, and +at the descending node to April 25th on the one hand, and the close of +May on the other. + +The great showers of stars which have been recorded, must be therefore +considered as an accidental exaggeration of a perennial phenomenon, +attaining its maximum when the earth passes through the central plane of +the vortex, whose ascending node in 1833 we will suppose was in +longitude 50°. This theory will therefore account for those great +showers which have occurred about the 24th of April, as well as those +occurring in October and November; for it is far more consonant to all +analogy, to suppose the influx of planetary atoms into the solar vortex +to be in irregular, than in regular quantities. Yet, whether in the one +case or in the other, the matter will pass along the central plane of +the vortex, either diffusely scattered or in denser clouds, and will be +encountered by the earth when near the nodes _more frequently than at +other times_. The phenomenon of 1833, may then be attributed to the +earth encountering an unformed comet on the 12th of November; but we +must reflect, that the medium of the vortex is also in motion, and the +cometary matter drifting along with it; and that this motion corresponds +with the earth's motion. By becoming involved in the terral vortex, it +will in a measure be carried along with the earth in her orbit as a +temporary occupant of the terral vortex. But we are here met with the +objection that the radiant being nearly stationary amongst the stars, +demonstrated conclusively, that the source of these meteors did not +partake of the earth's motion. There is no difficulty in this. We +suppose as a general thing, that the meteors descended to the surface of +our atmosphere down the axis of the vortex (at least in the greatest +numbers), and the geocentric longitude of this axis was nearly the same +during the whole time of the display. We say nearly, for the motion of +the moon in her orbit in nine hours, would change the longitude of the +axis three or four degrees, and this is about the change in the +position of the radiant noted at the time. This objection, therefore, +falls to the ground; for the axis of the vortex, although carried along +with the earth in her orbit, was unaffected by the earth's rotation, and +would therefore appear nearly as stationary in the heavens as Gamma +Leonis. But it is again urged, that the moon was near conjunction with +the sun, and consequently the central vortex was on the opposite side of +the globe. This is true; but the outer vortex must have been near the +meridian about three hours after midnight, or about the time when the +radiant was vertical and the display the greatest. When the axis was to +the eastward, the stars would shoot westward, when on the meridian, they +would pass in all directions, but principally to the south, on account +of the inclination of the axis of the vortex; but this would only be +true for places situated to the southward of the central latitude. +During the great shower of stars seen by Humboldt, in Cumana, the +direction was to the south uniformly. Now, the latitude of Cumana is +above 10° north, yet still too low for the general limits of the +vortices; but from the same inclination of the axis (from 30° to 36° to +the surface), the meteors would pass far south of the limit, and might +even reach to the equator. The latitude of the _outer vortex ascending_ +on November 12th, must have been near the line of greatest display, from +the position of the moon at the time. We thus see why the phenomenon was +limited to so small a fraction of the earth's surface; why these meteors +should be intermingled with nebulous patches stationary in the heavens +for an hour together, and why, notwithstanding these facts, they were +independent of the earth's rotation. + +We have yet another objection to answer, viz.: the planetary velocity of +some of these bodies. Let us be understood. The velocity of a solid +aërolite is due to gravitation, and is planetary, on the other hand, +voluminous collections of cometary dust united by accident, and +remaining so by mere inertia, are borne passively on the ethereal +currents with _electric_ velocity, and probably never penetrate far, +even into the attenuated atmosphere, which may be supposed (from the +facts connected with the aurora) to extend far above the denser stratum +which refracts and reflects light, and from which the assigned limits of +our atmosphere have been derived. + +It is generally considered that sporadic meteors are more numerous in +the summer and autumn than in the winter and spring, and we have, +likewise, in the tenth of August, a date which corresponds to many great +displays and meteoric showers, both in recent and remote times. This +would seem to vitiate our theory; for we cannot suppose that there are +two _central_ planes in the vortex intersecting the ecliptic in +longitude 320° and 50°. We must remember, however, that as these great +displays are accidental, and as the stratum composing the zodial light +is manifestly of sufficient thickness to envelope the whole orbit of the +earth, that it does not necessarily follow that the dense portions to +which meteoric showers are due, should be always confined to the central +plane of the vortex. And, besides, we have similar displays recorded in +other months, which invalidates the theory of a regularly-recurring +phenomenon. We shall, therefore, only aim at explaining why meteors are +generally more abundant in summer and autumn than in the opposite +seasons. + +The axis of the solar vortex, considered as cylindrical, must be +admitted to run out to a great depth on either side from the sun, and +reach far into that unoccupied space intervening between our system and +the nearest fixed stars, and from these opposite points the solar vortex +is supplied with that stream of ether which passes down either pole to +restore a partial equilibrium in the density of the ether of the vortex, +rarefied by centrifugal force. As certain portions of the heavens are +crowded with stars, and other parts comparatively vacant, we may expect +a similar inequality in the distribution of that cometic dust, which +causes a certain amount of extinction in the light of the stars, and, +therefore, seeing that the two extremities of the axis of the solar +vortex are so widely separated, it would not be wonderful if different +quantities of such matter were brought down into the vortex from these +extremities. + +From recent observations made by H. R. Birt, at the observatory of the +British Association, it would appear that the brightest portion of the +zodial light is always north of the ecliptic. Others have also remarked +the same, and if we couple this fact with the suggestion just made, we +are justified in suspecting that a greater quantity of cometic dust +comes down the northern pole of the vortex than down the southern. This +matter, in passing outward, does not, of course, immediately attain to +the central plane of the vortex, but is more thickly distributed along a +plane parallel to this plane. And the same will be observed by that +matter coming down the southern pole; it will be, in a certain degree, +retained in a plane south of the central plane, but still parallel with +it. This would account for the greater brightness of the northern side +of the zodial light. It would, also, account for the greater frequency +of meteors in summer and autumn than in the opposite seasons. From May to +November the earth is above the central plane of the vortex, and, +consequently, on the northern side; but after passing the node in +November, she is on the under or southern side, and the meteors are less +frequent. With this general explanation we shall close. If what we have +advanced be an approximation to the truth, the theory itself affords +ample indications of what observations are requisite to prove or +disprove it; and, on this account, a theory is of great benefit, as +suggestive of many questions and combinations of facts which otherwise +might never be thought of. + +We have thus taken a cursory glance at the prominent physical phenomena +of the world, and attempted to link them together in the bonds of one +all-pervading principle. We have fearlessly taken a new path, and claim +originality for the whole, disclaiming all intention of retailing +second-hand wares, or of compiling an ingenious theory from +heterogeneous scraps. If it be true, or if it be partially true, let +those professionally engaged in such pursuits enter the wide field of +investigation we have discovered for them; for if the whole theory be +true, it only shows in a clearer light that the great work which has +been fancied so near completion is scarcely yet begun; while the +prospect of an ultimate and final completion of the temple which so many +zealous votaries are erecting, is rendered mournfully hopeless by the +contemplation of what yet remains to be performed. + +FOOTNOTES: + +[42] The orbit this year was determined under very unfavorable +circumstances. + +[43] According to other tables, this angle would be much greater than is +given in Mr. Hind's catalogue. + +[44] Prin. Prop. xx Lib. Sec. + +[45] With reference to the resisting power of the atoms. + +[46] Prin. Lib. Tor. Prop, xxxix., also Prop, xli. + +[47] In making this suggestion, the author is well aware that +Ephemerides of the four chief asteroids have been given annually in the +Greenwich Nautical Almanac; but for the object proposed they are utterly +useless. Will any astronomer contend that these Ephemerides are true to +ten seconds of arc? If not, they are useless for the purpose suggested +above, and the theory wants revision. And it is evident that any +objection against its practicability, founded on the uncertainty of the +number of the asteroids themselves, as has already been urged in answer +to this suggestion, is an evidence that the objector weighed the subject +in the scales of his imagination only. + + + + +SECTION SIXTH. + + +THE POLAR ICE. + +We shall conclude these pages by again referring to our theory of the +weather, in connection with an event which every friend of humanity and +every lover of natural science is bound deeply to deplore. + +From the present position of the lunar nodes and apogee, the vortices of +our earth do not ascend into very high latitudes. Now, according to the +principles laid down, the frequency of storms tends to lower the +temperature in the warm regions of the earth, and to elevate it in the +polar regions. Let us suppose the northern limit of the vortices to be +in latitude 70°. There will be, in this case, a greater prevalence of +northerly winds _within_ this circle of latitude, to supply the drain to +the southward, and the back currents by passing above will descend at +the pole, partaking of the temperature due to that elevation. The +character of the arctic seasons may therefore be considered as partly +dependent on the average direction of the wind. Suppose again, the +extreme limits of the vortices to be about latitude 80°, the relative +areas of the two circles are as 4 to 1; so that in this last case the +exclusive range of the northerly winds is limited to one-fourth of the +first area. South of 80° the wind will frequently come from the south, +and by mixing with the local atmosphere of that latitude, will tend to +ameliorate the small area to the northward. And the greater atmospheric +commotion when confined to such a small circle of latitude, must assist +materially to break up the polar ice; which would tend still more to +equalize the temperature. + +By referring to our table, we see that the mean conjunction of the pole +of the lunar orbit and the moon's apogee, was in longitude 128° on April +10, 1846, and let it be remembered that when the conjunction takes place +due south or in longitude 270°, the vortices attain their greatest +latitude north. When, on the contrary, the conjunction takes place due +north or in longitude 90°,[48] the northern limits of the vortices are +then in the lowest latitude possible. + +Sir John Franklin sailed in May 1845, and was certainly at the entrance +of Wellington sound, near latitude 75°, April 3d, 1846, as the dates on +the graves testify. That season, according to the theory, was a cold +one; for the vortices could not reach so far to the northward in that +year, and consequently there were no storms, properly speaking. It would +probably be late in the summer of 1846, before the expedition was +liberated, and as the prevailing winds would be from the northward, he +would have little choice, but to stand to the westward if the state of +the ice permitted. In his instructions he was to use every effort to +penetrate to the southward and westward of Cape Walker, and he probably +conformed to them under the circumstances, and passed the winter in the +ice, in that neighborhood. And in 1847 we do not anticipate, from the +theory, that he would make much progress westward. + +In 1848, Sir James Ross was sent out with the first relief-ship; but was +not able to reach the entrance of Wellington channel because of compact +ice from there to Leopold Island. This was about the beginning of +September--a time when the northern channels are usually the most open. +On the 11th, they ran the ships into Port Leopold, and the next day the +ice shut them in for the winter. From the character of the season, we +may infer that if Franklin did not enter Wellington channel in 1847, as +is most probable, neither did he in 1848. Perhaps he was not able to get +his ships far to the westward, as we infer from the theory. Still, as +the time was not very protracted, he would wait patiently another season +and husband his resources. + +In 1849, Sir James Ross cut his ships clear of the ice August 28th, and +crossed over to Wellington channel, where he found the land-ice still +fast, showing that this season was also a bad one in accordance with the +theory. On the 1st of September he met the first gale of wind, at which +time the _Inner Vortex_ was at its extreme north latitude, and rapidly +extending its limits by the motion of the perigee. + +This vortex describes a smaller orbit than either the central or the +outer vortex, and consequently reaches into higher latitudes. But the +time was badly chosen, as the whole series of years since Franklin left +has been unfavorable for the early rupture of the ice. Sir James Ross +having been drifted out of Lancaster sound by the gale, finally bore up +for England towards the close of September 1849. + +The same year, the North Star with additional supplies was working up +Baffin's bay; but on account of the unusual quantities of ice, and the +frosts "which glued the floes together," she was unable to force a +passage through the middle ice, and wintered on the east side of +Baffin's bay, in latitude 76° 33′--her thermometer marking 64° below +zero, as the coldest of the winter. In 1850, the perigee of the moon +attained its northern limit, but the position of the node was bad; still +this year and 1851, were the best of the series. The North Star +succeeded in getting out of the ice on the 1st of August--a very early +date for that high latitude--and on the 8th had crossed over to +Possession bay; but being prevented by the land-ice, she bore up for +Pond bay and there landed the provisions. The same year (1850) several +vessels entered Lancaster sound. Sir John Ross also reached Melville +Island; from which it is evident that this season was far better than +any preceding. According to Captain Penny, this year a floe of ice at +least two years old, filled Wellington strait; but was diminished in +breadth at a subsequent visit. He also saw a boundless open sea from the +_western_ entrance of Wellington strait; but of course the ships could +not reach it, for the floe before mentioned. Following the indications +of the theory, we consider it almost certain that Franklin went to the +westward and not through Wellington channel; that he made but slow +progress until 1850, when finding the sea more open to the northward, +and attributing it more to local influences than to any change in the +season, he considered it a better course to extricate the expedition, by +pushing on towards Behring's straits than to attempt the frozen channels +he had already passed through. But the seasons again getting worse after +1850, he was again arrested in the polar basin by the ice and islands +off the northern coast of America. + +Regarding the old and new continents as in reality a connected body of +land, with a polar depression, we may expect that the great range of +American mountains is continued in a straight line, from the mouth of +the McKenzie river, obliquely across the Polar sea, and connects with +the Ural; and that along the axis of the chain, protuberant masses will +emerge above the sea level, constituting an archipelago of islands, from +Nova Zembla to the McKenzie; and that these islands, causing an +accumulation of ice, and arresting its general tendency to the +southward, is the barrier which Sir John Franklin was finally stopped +by, in a situation where he could neither advance nor return. With the +map before us, and the data afforded by former voyages, and guided by +these theoretical views, respecting the prevailing direction of the +winds and the character of the seasons, we should locate Sir John +Franklin near latitude 80°, and longitude 145°, in 1851; and as the +seasons would afterwards become more severe, we may consider that he +has not been since able to change his locality, and dare not desert his +ships. + +No mere stranger can feel a deeper interest than the author, in view of +the hard fortunes of these hardy explorers, and he would not lightly +advance such opinions, did he not suppose they were in some degree +reliable. In 1832, he himself crossed the Atlantic, for the purpose of +offering himself to the Geographical Society of London, intending to be +landed as far northward as possible, with a single companion,[49] from +which point he purposed to follow the coast line on foot, with cautious +discretion as to seasons, confident that, with arms and ammunition, he +could support himself for many years. It has always been a grave error +in all these northern land expeditions, that they have been too +unwieldy, too much encumbered with the comforts and luxuries of +civilization at the outset, and too much loaded with a philosophical +paraphernalia, for a pioneering survey,--and cherishing too fondly the +idea that the wide shores of the Arctic sea could be explored in a +single season. Had the British government established a few posts in the +Arctic regions in the beginning,--one, for instance, in Lancaster sound, +another in Behring's Straits, and a third near the mouth of the +Coppermine, volunteers of sufficient scientific attainments might have +been procured, to banish themselves to these inhospitable regions for a +term of years, if assured of triennial supplies; and in this way, by +summer boat-parties and winter expeditions, over land or ice, the +explorations could have been gradually extended, and a greater knowledge +of the polar regions might have been acquired, with an immense saving +both of life and money. In 1832 the author's plan was deranged, by +finding that Captain Back was about setting out in quest of Ross, who +had then been some four years absent. This officer had all his party +engaged when the author waited upon him in Liverpool, and no notice was +taken of a modified plan which he forwarded to the Society at his +suggestion. It was therefore abandoned. + +The above fact is alluded to, in order to show the author's sincerity in +expressing his belief that, with a previous preparation of mind and body +for a sojourn in those frigid climes, a sufficient subsistence may be +derived from the country itself. Advantage must, of course, be taken of +the times of abundance, and due preparation made for the season of +scarcity. Averaging the extremes, there is little doubt but that both +land, and air, and water, afford an abundance of food for man in the +Arctic zone, and that, when spurred by necessity, it is within his power +to obtain it. We ought not therefore to despond, or give up efforts to +rescue those who have well earned the sympathy of the world, by what +they must have already suffered. _These northern seas will yet be +explored._ The very difficulty of accomplishing it, will itself give it +a charm, which in this restless age will operate with increasing power. +And should efforts now be relaxed, and in some future time the evidence +be brought to light that some of the party yet existed, long after all +efforts to rescue them had been abandoned, the fact would be a dark spot +on the escutcheon of England, which time could not erase. + +Since these pages were written, accounts have been received from Captain +McClure, of H. M. ship Investigator, which fully confirm the preceding +remarks on the character of the seasons in the Arctic circle; and, more +recently, despatches have been received from the discovery-ship, +Amphytrite, in relation to the past season in Behring's straits, which +also confirms the theory. + +The Investigator (now supposed to be frozen up in lat. 74° 5′ N., and +long 117° 54′ W.,--the last despatch being dated April 10, 1853) passed +round the northern shores of America into the channels communicating +with Lancaster sound, in 1850, but was unable to extricate herself in +1852, and, probably, yet remains in the harbor she made in the winter of +1851, in the position above named. No trace of Sir John Franklin's +expedition was, however, found, and, indeed, according to our theory, +the Investigator was not on the most promising ground. We contend that +Franklin has penetrated the pack of apparently perennial ice, which is +continually pressing to the southward, and blocking up the passages +between the northern islands, or skirting the coast line of the +continent; which pack has since increased, and effectually stopped all +egress from the open central portions of the polar sea. If Sir John +Franklin is ever heard from, this pack _must be penetrated_, and a +powerful steamer ought to be sent immediately by the British government, +to be ready in Behring's straits early enough to take advantage of the +first openings, and make a bold push _due north_, so as to get as +speedily as possible into the open waters to the north of the pack. + +If the author could make himself heard at Washington, he would also urge +the government to lose no time in following our own expedition under Dr. +Kane, who, if he finds a clear entrance from Smith's sound into the +Arctic sea, may be induced to push on, and endeavor to make his way +through the pack towards Behring's straits, and thus fall into the same +snare as Franklin. According to the theory, the higher the passage into +the Arctic sea, the less will it be incumbered with ice, and, +consequently, Smith's sound is the best both to enter and return by; and +had the author not already smarted enough by having his professions +derided, he would have submitted these views to the patrons of that +expedition before it sailed. + +The scientific world is, in reality, chargeable with the disastrous +results of Franklin's expedition. The polar basin is hemmed in by the +coast line of Europe, Asia, and America, in about latitude 70° north, +for the greatest part of the entire circumference. And this coast line, +and the islands adjacent, will cause the polar ice to accumulate and +form a frozen belt along these shores, in consequence of the constant +tendency of the earth's rotation to press the ice to the southward. The +fact that an open passage exists between this belt and the shore in +summer time, is no objection, as the tides, river currents, and warm +land breezes, may very well explain this. The learned have insisted, and +do yet insist, that the earth's rotation can produce no motions in the +Arctic sea, and, under this delusion, Franklin has passed into the +comparatively open waters inside the pack, perhaps has lost his ships; +yet it is very possible that the party may have escaped, and derived a +subsistence from the more genial waters of the central portion of that +ocean unto this day. + +We have already alluded to the difference of level between the Atlantic +and Pacific waters. It is well known that the currents in the +Spitzbergen and Greenland seas is to the southward, and that Parry, in +his attempt to reach the pole, was foiled by this very current, +frequently setting him back in twenty-four hours more than his party +could travel in the same time over the ice. Through Baffin's and +Hudson's bay the northern waters are also continually bearing their +frozen freight southward. We are, therefore, entitled to ask, what +supplies this immense drain? Behring's straits are only about sixty +miles wide, and twenty-five fathoms deep; the supply, therefore, through +this channel is totally inadequate, yet there is no other channel into +the Arctic sea where the current is inward. We have already explained +the reason why the current through Behring's straits is an exception to +the general rule, yet still confirming the principle by referring it to +the configuration of the land enclosing the Pacific ocean. The whole +south Pacific lies open to the pole, and the inertia of the immense mass +of mobile waters pressing northward, and continually contracted by the +form of the American and Asiatic coasts, is not balanced by a contrary +impulse of the waters of the north Pacific, inasmuch as this ocean +becomes narrower as it extends northward, and the only passage to the +frozen ocean is through the narrow straits of Behring. The axifugal +force of rotation due to the northern waters is, therefore, overborne +by the vast preponderance due to the southern waters, and, hence, the +northern Pacific may be considered as relatively at a higher level, and +there will be a current northward through Behring's straits, as we find +it. The same cause accumulates the waters under the equator, thus giving +a higher level to the Pacific than to the Atlantic at the isthmus of +Panama, where the difference of level is found by actual measurement to +be five or six feet. This fact has never before been explained; but the +cause is too obvious to admit of question. + +That the sea is deeper than was formerly admitted, is now fully +confirmed. We have before alluded to the results obtained by Captain +Denham, of H. M. ship Herald, who found bottom at 7,706 fathoms, or +about nine English miles. Now, whether that spherical shell, which we +have contended to be the true form of the solid earth, be continuous and +entire; or, whether it may not be wanting in localities of limited +extent where the ocean would be absolutely unfathomable, we know not; +but if such be the internal constitution of our globe, there will be, no +doubt, many channels of communication between the internal and external +ocean, and, as a consequence of the earth's rotation, the axifugal +current of the Arctic sea may be supplied by an upward current from the +interior of the globe; and this current may have a higher temperature +than the surface waters of that sea, and thus the middle portions may, +in truth, remain open the whole year round, and be teeming with animal +life. According to Captain Penny's observations in 1850, whales and +other northern animals existed to the westward, where he saw the open +sea stretch out without a bound before him. + +It has been a question mooted by some, that Franklin's ships might be +overtaken, at an early stage of the voyage, by a storm, and foundered +amidst the ice. The theory would give a negative answer to this +question. Stiff gales may prevail far to the north when the vortices do +not reach so high; but no storm, properly speaking, will be found far +beyond their northern limit. After the coming winter (1853), the +vortices will gradually penetrate farther and farther to the northward, +and the years 1857, 1858, and 1859, will be highly favorable for +northern discovery, accompanied, however, with the necessary draw-back +of tempestuous weather. + + +FOOTNOTES: + +[48] The reader will of course understand these as celestial longitudes, +and the latitudes as terrestrial. + +[49] Mr. William McDonald, of Canada. + + + + +CONCLUSION. + + +Our theory has thus extended itself beyond those limits which we at +first had drawn, and our apology must consist in the necessity existing +for reconciling the most remarkable phenomena of meteorology to its +principles. Yet, after all, what has been said is but an outline of what +remains, but this outline is a part of our theory of the weather, and it +could not well do without its aid. In some points we may not have +correctly interpreted facts; but the facts remain. The numerical +elements of the theory may also be in error--we know not; but we think +that they are as perfect as the many contingencies on which they depend +will permit. What is _certain_ however, is of ample value to compensate +for trivial errors. We have hitherto experienced but little courtesy +from those intrusted with the keys of knowledge, and cannot consequently +anticipate a very lenient verdict. But we now tell them before the +world, that they have a duty to perform, and an examination to make, and +a decision to come to, "whether these things are so." Our theory may be +called an ingenious speculation, but WE CHALLENGE THE SCIENTIFIC TO +PROVE IT--NOTHING ELSE. The theory furnishes them with tests of daily +occurrence, to prove or to disprove it. By such a trial we are willing +to be judged; but let it be conducted in the spirit recommended in the +opening address before the American Association for the Advancement of +Science, to expose all false developments, and to do it generously and +without prejudice; and to remember, "that the temple of science belongs +to no country or clime. It is the world's temple, and all men are free +of its communion. Let its beauty not be marred by writing names upon its +walls."[50] The _great_ objection, of friction and resistance of an +all-pervading medium, which will be urged against it, we regard as +rather the offspring of a bewildered imagination, than of scientific +induction. We can discover no such consequences as final ruin to our +system through its agency; but even if such were discovered, we may +answer, that nature nowhere tells us that her arrangements are eternal; +but rather, that decay is stamped with the seal of the Almighty on every +created thing. Change may be one of the great laws of matter and motion, +and yet matter and motion be indestructible. The earth was called into +existence for a specific object, and when that object is accomplished, +we are assured that another change awaits her. But when earth, and sun, +and planets, are again redissolved into their primitive state, their +atoms will still float on the ever-rolling billows of the great ethereal +ocean, to be again cast up, on the shore of time, whenever it pleaseth +Him to say, "Let there be light." + + +FOOTNOTES: + +[50] Prof. Pierce's Address, 1853. + + + + +APPENDIX. + + +Since the author's arrival in New York for the purpose of publishing his +outlines, the third and fourth volume of the Cosmos has been placed in +his hands, containing the latest uranological discoveries and +speculations. It is now more than twenty years since he began to +investigate the subject he has treated of, and fifteen since he first +announced to the world, that he had satisfactory evidence of his theory +being true. Luckily, perhaps, he has been cut off from the great streams +of knowledge; and he may confess that it was with pardonable feelings of +gratification that he discovered in 1853, by the acquisition of the two +first volumes of the Cosmos, that the philosophic mind of Humboldt had +also pondered deeply on the planetary peculiarities of size, density, +distance, inclination of axes and eccentricities of orbits, without +eliciting any satisfactory relations. + +From the tenor of the third and fourth volume of this learned summary of +scientific knowledge, it is evident that the question of a medium +filling space is more and more occupying the learned world; but the +author is unable to discover any consistent theory respecting it. The +increasing interest attaching to it, however, is evidently preparing the +world for some radical change in preconceived views. The explanation +given by this present theory to many prominent phenomena, is so totally +contrary to that of the learned world, as to leave it untouched by +anything yet advanced. What the fifth volume of the Cosmos will +contain, is not yet known in this country, neither has the author been +favored with any glimpse of the progress of science as developed before +the British Association; he supposes, however, that he yet stands alone +in the position he has defined. + +As a question of practical importance, the reader will find in the work +cited, the various opinions of the temperature of space. Both Fourier +and Poisson regard this as the result of radiated heat from the sun and +all the stars, minus the quantity lost by absorption in traversing the +regions of space filled with ether.[51] But why should we regard the +stars as the source of all motions? Why cannot physicists admit the idea +of an infinite space filled (if we may use the expression) with an +infinite medium, possessing an unchangeable mean temperature long before +the formation of a single star. A star equal to our sun at the distance +of Sirius, would give about one million of million times less heat than +our present sun, which is only able to give an average temperature to +the whole globe--about twenty degrees above freezing--then let us +remember that there are only about fifty stars of the first and second +magnitude, which give more light (and by analogy heat also) than all the +rest of the stars visible. Such labored theories as this of Poisson's is +a lamentable instance of the aberrations of human wisdom. + +We would also call the reader's attention to a late conclusion of +Professor Dove, viz.: That differences of temperature in different +longitudes frequently exist on the same parallel of latitude, or, in +other words, are laterally disposed. This may be thought adverse to the +theory, but it should be borne in mind that the annual mean temperature +of the whole parallel of latitude should be taken when comparing the +temperatures of different years. + +Another fact cited in the Cosmos apparently adverse to the theory, is +the idea entertained by Sir John Herschel, that the full-moon +dissipates the clouds. This question has been fully examined by +Professor Loomis before the American Association, and he concludes that +there is not the slightest foundation for the assertion--taking as data +the Greenwich observations themselves. + + +FOOTNOTES: + +[51] See _Cosmos_, p. 41, vol. III. + + + + + + +End of the Project Gutenberg EBook of Outlines of a Mechanical Theory of +Storms, by T. Bassnett + +*** END OF THIS PROJECT GUTENBERG EBOOK THEORY OF STORMS *** + +***** This file should be named 18791-0.txt or 18791-0.zip ***** +This and all associated files of various formats will be found in: + http://www.gutenberg.org/1/8/7/9/18791/ + +Produced by Curtis Weyant, Laura Wisewell and the Online +Distributed Proofreading Team at http://www.pgdp.net + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + http://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. diff --git a/18791-0.zip b/18791-0.zip Binary files differnew file mode 100644 index 0000000..cb85167 --- /dev/null +++ b/18791-0.zip diff --git a/18791-8.txt b/18791-8.txt new file mode 100644 index 0000000..4b25bb3 --- /dev/null +++ b/18791-8.txt @@ -0,0 +1,8049 @@ +Project Gutenberg's Outlines of a Mechanical Theory of Storms, by T. Bassnett + +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: Outlines of a Mechanical Theory of Storms + Containing the True Law of Lunar Influence + +Author: T. Bassnett + +Release Date: July 8, 2006 [EBook #18791] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK THEORY OF STORMS *** + + + + +Produced by Curtis Weyant, Laura Wisewell and the Online +Distributed Proofreading Team at http://www.pgdp.net + + + + + + +------------------------------------------------------------------+ + | | + | Transcriber's Note | + | | + | Transliterations: The Greek phrase on the title page has been | + | transliterated. The book also used special symbols for planets, | + | etc; this version renders these in capitals surrounded by | + | square brackets, e.g. [NEPTUNE]. [VOLCANO] represents an unknown | + | planet, in the original denoted by a right-angled triangle which | + | the author wrote represented a volcano. The UTF-8 text and HTML | + | versions of this ebook use no transliterations but display the | + | symbols originally used. | + | | + | Special characters: This ISO-8859-1 text file uses the following | + | special characters: | + | | + | If these do not display, you may prefer the plain ASCII text | + | versin of this ebook. | + | | + | Printer errors: Obvious typographical errors in the original | + | have been corrected in this version, and full details of the | + | corrections can be found in the HTML version of this ebook. | + | However, the inconsistent spelling of Ottawa/Ottowa, and the | + | inconsistent use of comma or full-stop as thousands separator | + | has been left as in the original. The value given for the | + | eccentricity of Uranus may also be a printer error. | + | | + +------------------------------------------------------------------+ + + + + OUTLINES + + OF + + A MECHANICAL THEORY OF STORMS, + + CONTAINING + + THE TRUE LAW OF LUNAR INFLUENCE, + + WITH + + PRACTICAL INSTRUCTIONS TO THE NAVIGATOR, TO ENABLE + HIM APPROXIMATELY TO CALCULATE THE COMING + CHANGES OF THE WIND AND WEATHER, + FOR ANY GIVEN DAY, AND FOR + ANY PART OF THE OCEAN. + + + BY T. BASSNETT. + + H de mesots en pasin asphalestera + + NEW YORK: + D. APPLETON & COMPANY, + 346 & 348 BROADWAY, + AND 16 LITTLE BRITAIN, LONDON. + 1854. + + + + Entered, according to Act of Congress, in the year 1853, by + T. BASSNETT, + In the Clerk's Office of the Southern District of New York. + + + + +CONTENTS. + + +SECTION FIRST. + +Present State of the Science of Meteorology--Primordial Condition of the + Solar System--Theory of Gravitation the great key of Nature--Bessell's + doubts of its perfect adequacy--the Newtonian Vacuum: its + difficulties--Nature of the element called Ether--The Medium of Space + and the Electric Fluid--Ponderosity of Matter--Dynamical law of + Equilibrium--Specific heat and its relation to space--A Plenum not + opposed to Gravitation--The medium of space in motion--Formation of + Vortices--A new principle developed--Elements of the problem--Hutton's + theory of the production of rain--Indications of change and the + cause--Action of the Ethereal Current--Physical process of Atmospheric + Derangement--Redfield's theory of Storms: its difficulties--All storms + are of brief duration and limited extent. 13 + + +SECTION SECOND. + +Mechanical action of the Moon--The Moon's mass--Axis of the Terral + Vortex affected by the Moon: its inclination and position: its + displacement--An example of the principle--Corrections + necessary--Milwaukie storm--New York storm--Ottawa storm--Liverpool + storm--Names and recurring order of the storm-producing agents--Record + of the weather--Second New York storm. 58 + + +SECTION THIRD. + +Lunar influence rejected by the learned--Their conclusions not + valid--Modifying causes in accordance with these principles--Years and + seasons vary in character--Superficial temperature of different + Planets--No storms on the planet Mars--Rotation the cause of Ocean and + Atmospheric Currents--Pressure of the atmosphere and its regular and + irregular variations--Terrestrial Magnetism--Internal Constitution of + the Globe--Magnetic variations--Cause of these variations--Magnetic + storms--Aurora Borealis: its altitude--Earthquakes; their possible + connection with Storms. 101 + + +SECTION FOURTH. + +The solar spots--Law of periodicity compared with the theory--Existence + of another planet beyond Neptune probable--Masses of the Sun and + Planet yet uncertain--The Law of Gravitation not above + suspicion--Proofs of this--The full of the Moon--Density of the + Ethereal Medium: its law in the Solar Vortex--Bode's law of the + planetary distances--Law of planetary density--Law connecting the + present and former diameters of the planets--Disturbing action of the + Ether--Kepler's third law not rigidly exact--Inconsistencies of + Astronomers--Nature of light and heat--Distinction between light and + heat. 147 + + +SECTION FIFTH. + +Comets--Their small inclinations--Their motions chiefly direct--Comet of + 1770 and 1844--Cause of acceleration in the case of Encke--Anomalous + motions of the comet of 1843--Change of diameter at different + distances of a comet from the sun--Cause of this change--Nature of the + nebulosity--Formation of the tail--Compound nature of a comet's + light--motion and direction of a comet's tail--Phenomena presented by + the great comet of Halley--Mass of a comet--The Zodial light--Nebulous + stars--Shooting stars--Periodic showers--Periodicity doubtful--Cause + of the apparent periodicity--Cause for being more numerous in Autumn + than in Spring. 187 + + +SECTION SIXTH. + +State of the polar ice since 1845--Sir John Franklin's track--Probable + existence of islands north of Behring's Straits--Possibility of + subsisting in the Arctic islands--News from the + Investigator--Necessity of searching in a higher latitude than the + Investigator visited--Franklin's misfortunes due to Scientific + Errors--Relative levels of the Atlantic and Pacific Oceans--The Arctic + seas more accessible in a few years--Conclusion. 233 + + + + +PREFACE. + + +On presenting to the public a work of this novel character, +overstepping, as it does, the barriers erected by modern systems to the +further progress of knowledge, a few words of explanation may not be +inappropriate. Early imbued with a desire to understand the _causes_ of +natural phenomena, the author devoured with avidity the interpretations +contained in the elementary works of orthodox science, until reason and +observation rendered him dissatisfied with the repast. To him it +appeared that there was an evident tendency in scholastic instruction, +to make the knowledge of nature inaccessible to the many, that the world +might be made more dependent on the few; while many of the _established +principles_, on which the learned rested, seemed to be at variance with +the simplicity and consistency of truth. Thus situated, he ventured to +think for himself, and looking back on the history of the past, and +finding so many cases in which the philosophy of to-day was supplanted +by a different system on the morrow, he was led to suspect the +possibility of future revolutions, and was thus determined to be no +longer embarrassed by previous systems, nor deterred by opinions +however learned, which conflicted with a rational recognition of the +mechanical nature of all physical phenomena. + +The science of meteorology, to which the following pages are devoted, +is, and always has been, a confessedly complex subject; and on this +account, any suggestions and facts which observation gleans,--no matter +how humble the source may be, should not be denied a hearing by those +professedly engaged in the pursuit of truth. Step by step, the author +became more and more confirmed in his doubts of the soundness of many +modern theories; and in 1838 he had attained a position which enabled +him to allege in the public prints of the day, that there did exist +certain erroneous dogmas in the schools, which stood in the way of a +fuller development of the causes of many meteorological phenomena. This +annunciation was made in general terms, and no notice was taken of it. +Subsequently, he forwarded to the British Association of Science, then +convened at Birmingham, a communication of similar tenor; and at a later +date still, a more particular statement of the advantages of his +discoveries to the navigator and agriculturist, was sent to the British +admiralty. The first of these communications was treated with silent +contempt; the last elicited some unimportant reply. In 1844 a memorial +was presented to Congress, accompanied with a certified copy of +_predictions_ of the weather, written several weeks before the event, +and attested in due form by two impartial witnesses; but neither did +this result in any inquiry as to its truth. During the time since +elapsed, he has been engaged in pursuits which prevented him from +pressing the subject elsewhere, until the spring of 1853, he brought +his theory under the notice of the Smithsonian Institution. This led to +a correspondence between himself and the gentlemanly Secretary of the +Institution, whose doubts of the truth of his allegations were expressed +with kindness, and whose courtesy was in strange contrast with the +conduct of others. In the communications which he forwarded to that +Institution, he gave a detailed statement of the difficulties he had met +with, and expressed the hope that an Institution, created for the +purpose of increasing and diffusing knowledge, would feel justified in +lending the influence of its name to facilitate the completion of a +theory which was yet undeniably imperfect. In view of this, a test was +proposed.[1] "Give us, for example, a prediction of the weather for one +month in each season of the year 1854, for the City of Washington." This +test the author refused, for the reason that he did not consider it +necessary to wait so long; but he informed the Secretary of the +Institution, that he would prepare an outline of his theory, which would +enable him to decide upon the merits of the discoveries claimed. This +outline is contained in the following pages. During the summer of 1853 +he called upon Professor Henry, then at Chicago, with his manuscript; +but a sudden indisposition prevented that gentleman from having it read. +He, however, strongly recommended its publication from such impressions +he then received.[2] This the author had resolved on, from a sense of +duty to the world at large, although the promise was rather of +prospective loss than of present benefit. The peculiar form under which +the theory appears, is, therefore, a result of the circumstances above +stated, and of the author's present inability to enter into the minute +details of a subject, which embraces in its range the whole visible +creation. + +In extending the theory to other phenomena, he has only fearlessly +followed out the same principles which have conducted him to a knowledge +of a disturbing cause, to which atmospheric storms owe their origin, and +in doing so he has conferred with no one. For whatever of merit or of +blame may therefore justly attach to these views, he alone is +responsible. If he has charged the scientific with inconsistency, or +with sometimes forgetting that the truth of their unnecessarily abstruse +investigations depends on the truth of the data, he at least is +conscientious; for he is too well aware that to provoke an unfavorable +verdict by contending against such fearful odds, is not the surest way +to either wealth or fame, or even to an acknowledgment of at least _the +mite_, which he cannot but feel that he has contributed to the treasury +of knowledge. That the scientific organisations of the day do tend to +curb the aberrations of a fanciful philosophy, cannot be denied; but at +the same time there is engendered such a slavish subordination as checks +the originality of thought, and destroys that perfect freedom from the +trammels of system, so necessary to success in the pursuit of truth. Of +such an influence the author explicitly asserts his entire independence. + +In thus introducing his theory, the reader is forewarned that he will +not find it dressed in the fascinating garb of the popular literature of +the day, whose chief characteristic is to promise much when possessing +little. It is, however, a plant of the author's own raising, unpropped, +unpruned, with none of the delicate tendrils or graceful festoons of the +trellissed vine; yet he flatters himself that its roots are watered by +the springs of truth, and hopes that he who is in quest of _that_, will +not find, amidst its many clusters, any fruit to set his teeth on +edge. + + +FOOTNOTES: + +[1] Extract from a letter from Professor Henry. + +[2] This gentleman kindly offered to contribute from his own private +means, to forward the publication, but he could do nothing officially +without submitting the manuscript to three different censors. He who +claims a new discovery, will seldom be satisfied to have it judged by +men who are engaged in the same investigations, however pure and +honorable they may be. Is this Institution adopting the best plan of +aiding truth, in its struggles against error? Should any man sit as +judge in his own trial? If there had been a powerful Institution to +stand between Galileo and the scientific of his day, his doctrines would +not have been condemned, and the world would have been fifty years more +in advance. + + + + +MECHANICAL THEORY OF STORMS. + + + +SECTION FIRST. + + +PRESENT STATE OF METEOROLOGY. + +The present state of the science of which we are about to treat, cannot +be better defined than in the words of the celebrated Humboldt, who has +devoted a long life to the investigation of this department of Physics. +He says: "The processes of the absorption of light, the liberation of +heat, and the variations in the elastic and electric tension, and in the +hygrometric condition of the vast arial ocean, are all so intimately +connected together, that each individual meteorological process is +modified by the action of all the others. The complicated nature of +these disturbing causes, increases the difficulty of giving a full +explanation of these involved meteorological phenomena; and likewise +limits, or _wholly precludes_ the possibility of that predetermination +of atmospheric changes, which would be so important for horticulture, +agriculture, and navigation, no less than for the comfort and enjoyment +of life. Those who place the value of meteorology in this problematic +species of prediction, rather than in the knowledge of the phenomena +themselves, are firmly convinced that this branch of science, on account +of which so many expeditions to distant mountainous regions have been +undertaken, has not made any very considerable progress for centuries +past. The confidence which they refuse to the physicist they yield to +changes of the moon, and to certain days marked in the calender by the +superstition of a by-gone age." + +The charge thus skilfully repelled, contains, however, much truth; there +has been no adequate return of the vast amount of labor and expense thus +far devoted to this branch of knowledge. And it is not wonderful that +the popular mind should expect a result which is so much in accordance +with the wants of mankind. Who is there whose happiness, and health, and +comfort, _and_ safety, and prosperity, may not be more or less affected +by reducing to law, the apparently irregular fluctuations of the +weather, and the predetermination of the storm? To do this would be the +crowning triumph of the age; and the present theory has pioneered the +way for its speedy accomplishment. + + +ORIGINAL CONDITION OF THE EARTH. + +That the present order of things had a beginning, is taught by every +analogy around us, and as we have the glaring fact forced upon us, that +our globe has experienced a far higher temperature on its surface than +obtains at present, and moreover, as it is demonstrated beyond a cavil, +that the interior is now of far higher temperature than is due to solar +radiation, we are justified in concluding, not only that the condition +of the interior of our globe is that of fusion, but that its original +temperature was far higher than at present; so that the inference is +allowable that there has been a time when the whole globe was _perhaps_ +in this state. But why should we stop here? There are three states of +matter, the solid, the fluid, and the gaseous; and with this passing +glance at the question, we will jump at once to the theory of La +Place,--that not only our own globe, but the whole solar system, has +been once in the nebulous state. + +In justice to himself, the author ought to remark, that he had reasoned +his way up to this starting point, before even the name of La Place had +reached his ears. He makes the remark in order to disclaim any desire to +appropriate that which belongs to another; as he may innocently speak of +things hereafter, the idea of which has occurred to others. It is not +his intention here to say a word _pro_ or _con_ on the nebular +hypothesis; it is sufficient to allude to the facts, that the direction +of rotation and of revolution is the same for all the planets and +satellites of our system; and that the planes on which these motions are +performed, are nearly coincident. That this concordance is due to one +common cause, no one acquainted with the theory of probabilities will +pretend to deny. + + +GREAT OBJECT OF LA PLACE. + +The science of Astronomy occupies a pre-eminent rank in the physical +circle, not only on account of that dignity conferred upon it in the +most remote antiquity, or as being the grand starting point--the +earliest born of science--from whence we must contemplate the visible +creation, if we would reduce its numerous details into one harmonious +whole; but also on account of its practical fruits, of the value of +which modern commerce is an instance. Accordingly we will glance at its +past history. In the earliest ages there was no doubt a rational view +entertained of the movements of the planets in space. From the Chaldeans +to the Arabs, a belief prevailed, that space was filled with a pure +ethereal fluid, whose existence probably did not rest on any more solid +foundation than analogy or tradition. One hundred years after Copernicus +had given to the world the true arrangements of our planetary system, +Descartes advanced his theory of vortices in the ethereal medium, in +which the planets were borne in orbits around the sun, and the +satellites around their primaries. This idea retained its ground with +various additions, until the Geometry of Newton reconciled the laws of +Kepler with the existence of a power pertaining to matter, varying +inversely as the squares of the distances, to which power he showed the +weight of terrestrial bodies was owing, and also the revolution of +the moon about the earth. Since Newton's day, those deviations from the +strict wording of Kepler's laws, have been referred to the same law, +and the avowed object of the author of the "Mechanique Celeste," was to +bring all the great phenomena of nature within the grasp of analysis, by +referring them to one single principle, and one simple law. And in his +Introduction to the Theory of the Moon, he remarks: "Hence it +incontestibly follows, that the law of gravitation is the sole cause of +the lunar inequalities." + + +BESSEL'S OPINION. + +However beautiful the conception, it must be admitted that in its _ +priori_ aspect, it was not in accordance with human experience and +analogy to anticipate a successful issue. In nature law re-acts upon +law, and change induces change, through an almost endless chain of +consequences; and it might be asked, why a simple law of matter should +thus be exempt from the common lot? Why, in a word, there should be no +intrinsic difference in matter, by which the gravitation of similar or +dissimilar substances should be affected? But experiment has detected no +such differences; a globe of lead and a globe of wood, of equal weight, +attract contiguous bodies with equal force. It is evident, therefore, +that if there be such differences, human means are not yet refined +enough to detect them. Was the issue successful then? Generally +speaking, we may say yes. But where there is a discrepancy between +theory and observation, however small that may be, it shows there is +still something wanting; and a high authority (Professor Bessel) says in +relation to this: "But I think that the certainty that the theory based +upon this law, _perfectly_ explains all the observations, is not +correctly inferred." We will not here enumerate the cases to which +suspicion might be directed, neither will we more than just allude to +the fact, that the Theory of Newton requires a vacuum, in order that the +planetary motions may be mathematically exact, and permanent in their +stability. + + +A VACUUM REQUIRED BY MODERN SYSTEMS. + +Whatever may be the practical belief of the learned, their fundamental +principles forbid the avowal of a plenum, although the undulatory theory +of light renders a plenum necessary, and is so far virtually recognized +by them, and a correction for resistance is applied to the Comet of +Encke. Yet there has been no attempt made to reconcile these opposing +principles, other than by supposing that the celestial regions are +filled with an extremely rare and elastic fluid. That no definite view +has been agreed on, is not denied, and Sir John Herschel speculates on +the reality of a resisting medium, by suggesting questions that will +ultimately have to be considered, as: "What is the law of density of the +resisting medium which _surrounds_ the sun? Is it in rest or in motion? +If the latter, in what direction does it move?" In these queries he +still clings to the idea of Encke, that the resistance is confined to +the neighborhood of the sun and planets, like a ponderable fluid. But +the most profound analyst the world has ever boasted, speaks less +cautiously, (Poisson Rech.) "It is difficult to attribute, as is usually +done, the incandescence of arolites to friction against the molecules +of the atmosphere, at an elevation above the earth where the density of +the air is almost null. May we not suppose that the electric fluid, in a +neutral condition, forms a kind of atmosphere, extending far beyond the +mass of our atmosphere, yet _subject to terrestrial attraction_, yet +_physically imponderable_, and, consequently, following our globe in its +motion?" The incandescence of arolites must, therefore, be owing to +friction against the molecules of the electric fluid which forms an +atmosphere around the globe. According to this view, some force keeps it +there, yet it is not ponderable. As it is of limited extent, this is not +the medium whose undulations brings to light the existence of the stars; +neither is Encke's, nor Herschel's, nor any other resisting medium. +Where shall we find the present established principles of science? If we +grant the Newtonians a plenum, they still cling to attraction of _all +matter_ in some shape. If we confine them to a vacuum, they will +virtually deny it. Is not this solemn trifling? How much more noble +would it be to exhibit a little more tolerance, seeing that they +themselves know not what to believe? We do not offer these remarks as +argument, but merely as indications of that course of reasoning by which +we conclude that the upholders of the present systems of science are not +entitled to any other ground than the pure Newtonian basis of an +interplanetary vacuum. + + +DIFFICULTIES OF THIS VIEW. + +This, then, is the state of the case: Matter attracts matter directly as +the mass, and inversely as the squares of the distances. This law is +derived from the planetary motions; space is, consequently, a void; and, +therefore, the power which gives mechanical momentum to matter, is +transferred from one end of creation to the other, without any physical +medium to convey the impulse. At the present day the doctrines of +Descartes are considered absurd; yet here is an absurdity of a far +deeper dye, without we resort to the miraculous, which at once +obliterates the connection between cause and effect, which it is the +peculiar province of physical science to develop. Let us take another +view. The present doctrine of light teaches that light is an undulation +of an elastic medium necessarily filling all space; and this branch of +science probably rests on higher and surer grounds than any other. Every +test applied to it by the refinements of modern skill, strengthens its +claims. Here then the Newtonian vacuum is no longer a void. If we get +over this difficulty, by attributing to this medium a degree of tenuity +almost spiritual, we shall run upon Scylla while endeavoring to shun +Charybdis. Light and heat come bound together from the sun, by the same +path, and with the same velocity. Heat is therefore due also to an +excitement of this attenuated medium. Yet this heat puts our atmosphere +in motion, impels onward the waves of the sea, wafts our ships to +distant climes, grinds our corn, and in various ways does the work of +man. If we expose a mass of metal to the sun's rays for a single hour +the temperature will be raised. To do the same by an artificial fire, +would consume fuel, and this fuel would generate the strength or force +of a horse. Estimate, therefore, the amount of force received from the +sun in a single day for the whole globe, and we shall find that nothing +but a material medium will suffice to convey this force. + +Let us appeal to analogy. The undulations of our atmosphere produce +sound; that is, convey to the ear a part of a mechanical force imparted +to a solid body--a bell for instance. Let us suppose this force to equal +one pound. On account of the elasticity of the bell, the whole of the +force is not instantaneously imparted to the surrounding air; but the +denser the air the sooner it loses its motion. In a dense fluid like +water, the motion is imparted quickly, and the sound is not a ring but a +click. If we diminish the density of the air, the loss of motion is +retarded; so that we might conceive it possible, provided the bell could +be suspended in a _perfect vacuum_, without a mechanical tie, and there +was no friction to overcome from the rigidity of its particles, that the +bell would vibrate forever, although its sound could never reach the +ear. We see, therefore, that the mechanical effect in a given time, is +owing to the density of the medium. But can we resort to such an +analogy? Every discovery in the science confirms more and more the +analogy between the motions of air and the medium of space; the angle of +reflexion and incidence follows the same law in both; the law of +radiation and interference; and if experiments were instituted, there +can be but little doubt that sound has also got its spectrum. + + +ETHER IMPONDERABLE. + +The medium of space, therefore, is capable of conveying a mechanical +force from one body to another; it therefore possesses inertia. Does it +also possess gravity? If we forsake not the principles of science, it is +but right that we expect science shall abide by her own principles. +Condensation in every elastic medium is as the compressing power, +according to all experiments. In the case of our atmosphere under the +law of gravitation, the density of air, (supposing it to be infinitely +expansible,) at a height only of ten semidiameters of the earth above +its surface, would have only a density equal to the density of one cubic +inch of such air we breathe, if that cubic inch was to be expanded so as +to fill a globular space whose centre should be the earth, and whose +surface should take inside the whole visible creation. Such a medium +could convey no mechanical force from the sun, and therefore the medium +of space cannot be ponderable. Simple as the argument is, it is +unassailable. + + +ELECTRIC FLUID THE MEDIUM OF SPACE. + +Let us take yet another view. All experiments prove that the phenomenon +we call electricity, is owing to a disturbance of the equilibrium or +natural condition of a highly elastic fluid. In certain conditions of +the atmosphere, this fluid is accumulated in the region of the clouds, +and by its tension is enabled to force a passage through opposing +obstacles, in order to restore the equilibrium. By experiment it is +found that dry dense air opposes the greatest obstacle to its escape. As +the air is rarefied, this obstacle diminishes; until in a vacuum the +transmission may be considered instantaneous. There ought to be, +therefore, a greater escape of electricity from the clouds upwards than +downwards; and, if space be void, or only filled with an extremely +attenuated matter, the electricity of the earth, considered as an +elastic fluid without ponderosity, (and no law of condensation from the +law of gravity in harmony with its other attributes, will allow us to +consider it otherwise,) _would long since have left the earth_. The same +objection applies in the case of the galvanic and magnetic fluids. If we +entertain the idea that electricity is a mere disturbance of natural +condition, wherein two fluids are united, and that an excess of one is +necessarily attended by deficiency in the other, we depart from the +first rule of philosophy, which teaches us to admit no greater number of +causes than are sufficient to explain the phenomenon. For we fearlessly +assert that not a single fact exists in electrical science, which can be +explained better on Dufoy's theory than on Franklin's; and the former +objections would still apply. + + +NEWTONIAN GRAVITY. + +But what is gravity? According to Newton: "Hc est qualitas omnium in +quibus experimenta instituere licet, et propterea per Reg.3 de +universes affirmanda est." _Vide_ Prin. Lib. Ter. Cor.2. Prop.vi. + +Now the other primary qualities of matter are unaffected by +circumstances. The inertia of a particle of matter is the same at +Jupiter as on the earth, so also is its extension; but not so with +gravity. It depends on other matter, and on its distance from it; and +may be less or greater at different times, and in different places. It +is, therefore, not philosophical to say that all matter is necessarily +ponderous, inasmuch as it is a virtue not residing in itself alone, but +needs the existence of other matter to call it into action. If an atom +were isolated in space it would have no weight. If influenced by other +matter, there must be some physical medium to convey the influence, or +gravity is not in accordance with the laws of force and motion. Which +horn of the dilemma shall we take? Let us first admit that there is a +principle of gravitation, affecting all planetary or atomic matter, and +that there exists a highly elastic medium, pervading all space, +conveying to us the light of the most distant stars, and that this +medium is not affected by gravity. In this summary way, therefore, we +have arrived at the pivot on which this theory turns. + +The prominent feature of the theory, therefore, is the necessity it will +show for the existence of an all-pervading medium, and that it possesses +inertia without ponderosity. That electricity is nothing more than the +effects of the condensation and rarefaction of this medium by force. +That it also pervades all atomic matter, whose motions necessarily move +the medium; and, consequently, that there can be no motion without some +degree of electricity. That no change can take place in bodies either by +chemical decomposition, by increase or decrease of temperature, by +friction or contact, without in some measure exciting electricity or +motion of the ether. That galvanism and magnetism are but ethereal +currents without condensation, induced by peculiar superficial and +internal molecular arrangement of the particles of certain substances. +That light and heat are effects of the vibrations of atoms, propagated +through this universal medium from body to body. That the atomic motion +of heat can be produced by the motion of translation or momentum of +bodies in the gross, that is, by friction, by compression, &c.; and can +be reconverted into momentum at our pleasure. Hence the latent heat or +specific atomic motion of combustibles, originally derived from the sun, +is transferred to atoms, which are capable of being inclosed in +cylinders, so as to make use of their force of expansion, which is thus +converted into momentum available for all the wants of man. + + +GRAVITY MECHANICAL. + +When we come to a full examination of this theory, we shall further +reason that this _ether_ so far from being of that quasi spiritual +nature which astronomers would have us believe, is a fearfully energetic +fluid, possessing considerable inertia and elasticity; that its law of +condensation is that of all other fluids, that is, as the compressing +force directly; and that its effects are simply a product of matter and +motion. We will next endeavor to prove that the gravity of planetary +matter could not exist without this ethereal medium, by showing that it +is an effect produced by the interference of _opposing waves_, whereby a +body is prevented from radiating into space its own atomic motion, from +the side opposite which another body is placed, as much as on the +opposite side, and consequently it is propelled by its own motion +towards the other body. And this effect following the simple law of +inertia and radiation, is directly as the mass, and inversely as the +squares of the distances. + + +GREAT PRINCIPLE OF DYNAMICS. + +One great principle to be kept in view in this investigation, is that +which teaches that the product of matter, angular velocity, and distance +from the centre of motion, must ever be a constant quality in every +balanced system. Yet this principle does not seem to be observed in the +case of the planets. We will, however, endeavor to show that it is +rigidly observed. And we will extend the principle further, and contend +that all the phenomena of nature are consequences of the constant +tendency of matter to conform to this principle of equilibrium, when +suffering temporary derangement from the operation of other laws. That +throughout the system of nature, equal spaces possess equal force. That +what we call temperature, is nothing more than the motion of equilibrium +or atomic momentum of space; or, in other words, that if all space were +fluid, and in a state of equilibrium, the product of each atom of equal +volume, by its motion would be a constant quality. From this it would +seem to follow, that the specific heat of bodies should be inversely as +their atomic weights; and this does, no doubt, _approximately_ obtain as +was proved by Dulong and Petit, for metallic substances, more recently +by Regnault, and has since been extended by Garnier to other substances. +But it is to the gaseous state that we must look for confirmation of the +principle that equal spaces possess equal power; and in doing so, it +will be necessary to bear in mind, that the ether also is affected by +temperature. + + +SPECIFIC HEAT. + +It has been contended by some that the medium which conveys the +impression of light through transparent, bodies, is necessarily more +dense within the body than without; but according to this theory the +converse is true. A ray of light is a mechanical impulse, propagated +through an elastic medium, and, like a wave in water, tends to the side +of least resistance. Within a refracting body the ether is rarefied, not +only by the proximity of the atoms of the body (or its density), but +also by the motions of those atoms; so that if two _simple_ gases of +different specific gravity be made equal in density by compression, +their refraction will be approximately as their specific heats. In the +case of solids and liquids, or even compound gases, there is a continual +absorption of motion to produce the cohesion of composition and +aggregation. And the specific heats of compound gases will be found +greater than those of simple gases, in proportion to the loss of volume +by combination, _ceteris paribus_. If impenetrability be a law of +matter, the more a portion of atomic matter is condensed, the less ether +will be found in the same space. The same is also true when the natural +density or specific gravity of a gas is greater than that of another. +And the lighter the gas, the more will this circumstance vitiate the +experiments to determine its specific heat. There is, therefore, this +great source of fallacy in such experiments, viz.: that the ether +permeates all fluids and solids, and that _its specific heat probably +far exceeds that of all other matter_. This is a fundamental position of +the theory, in support of which we will introduce a fact announced by +M.V. Regnault, which was published in the Comptes Rendus of the French +Academy for April, 1853. He says: "In the course of my researches I have +encountered, indeed, at every step, anomalies which appeared to me +inexplicable, in accordance with the theories formally recognized. For +the sake of illustration I will quote one instance: 1st, a mass of gas, +under a pressure of ten atmospheres, is contained in a space which is +suddenly doubled; the pressure falls to five atmospheres. 2d. Two +reservoirs of equal capacity are placed in a calorimeter; the one is +filled with a gas, under a pressure of ten atmospheres; the second is +perfectly empty. In these two experiments, the initial and final +conditions of the gas are the same; but this identity of condition is +accompanied by calorific results which are very different; for while in +the former experiment there is a reduction of temperature, in the second +the calorimeter does not indicate the slightest alteration of +temperature." This experiment tends to confirm the theory. In the first +experiment, the sudden doubling of the space causes the ether also to +expand, inasmuch as the sides of the vessel prevent the instantaneous +passage of the external ether. In the second, both vessels are full, one +of ether, and the other of air mixed with ether; so that there is no +actual expansion of the space, and consequently no derangement of the +quantity of motion in that space. + + +LAW OF SPECIFIC HEAT. + +From this view it is evident that the specific heat of elastic fluids +can only be considered as approximately determined. If equal spaces +possess equal momenta, and the ethereal or _tomic_ matter be inversely +as the weight of the atomic matter in the same space, it follows that +the product of the specific gravities and specific heats of the simple +gases should be constant; or that the specific heats should be inversely +as the specific gravities,--taking pound for pound in determining those +specific heats. If we test the matter by the data now afforded, it is +best to obey the injunction, "_In medio tutissimus ibis_." In the +following table, the first column are the values obtained by Regnault; +in the second, the former values; and in the third, the mean of the two. + + Gases. Reg. specific heats. Former specific heats. Mean. + Atmospheric air, .237 .267 .252 + Oxygen, .218 .236 .227 + Nitrogen, .244 .275 .260 + Hydrogen, 3.405 3.294 3.350 + +The specific gravities of these gases, according to the best tables in +our possession, are: + + Specific gravities. Mean. Products. + Atmospheric air, 1.0000 .252 = .252 + Oxygen, 1.1111 .227 = .252 + Nitrogen, 0.9722 .260 = .252 + Hydrogen, 0.0745 3.350 = .249 + +As might be expected, there is a greater discrepancy in the case of +hydrogen. + +If we test the principle by the vapor of water, we must consider that it +is composed of two volumes of hydrogen and one volume of oxygen, and +that one volume disappears; or that one-third of the whole atomic +motion is consumed by the interference of the vibrations of the ether, +necessary to unite the atoms, and form an atom of water. We must +therefore form this product from its specific gravity and two-thirds of +its specific heat. On no one subject in chemistry has there been so much +labor expended, as in determining the specific heat of watery vapor. In +relation to this, Regnault observes: "It is important to remark that an +immense number of experiments have been made, to find the specific heat +of steam, and that it is about one-half of what it was thought to be." +He gives its value .475; but this is vitiated still, by the +non-recognition of the specific heat of the ether. Former experiments +give .847. Perhaps Regnault's numbers are entitled to the most weight. +Instead of taking the mean, therefore, we will give double weight to his +results; so that we get .600 for the specific heat of vapor, and as its +specific gravity is .625, the product .400 .625 is .250, the same as +for hydrogen. Little importance, however, should be attached to such +coincidences, owing to the uncertainty of the numbers. If our position +be correct, the specific heat of hydrogen should be 10 times greater +than of oxygen. The atomic weights are as 1 to 8, while their volumes +are as 2 to 1; therefore, for equal spaces, the matter is as 1 to 16. +Calling the specific heat 10 to 1, and taking the amount due to half the +space, the product becomes as 8 to 16; but in the rarer gas there is +_8times_ as much ethereal momentum or matter, which, added to the +atomic matter, renders the spaces equal.[3] Regnault's results give a +ratio of specific heats= 1 to 3.405/.215= 1 to 15.6. + + +THE GOLDEN MEAN. + +The history of science proves how few have practically respected the +adage of the ancients, which we have chosen for our motto; words which +ought to be written in letters of gold in every language under the sun. +Descartes, by considering the mechanical impulse of the ether sufficient +to explain the planetary motions, failed to detect the force of gravity +in the heavens. Newton, on the other hand, feeling that his law was +sufficient to explain them, and requiring a vacuum for its mathematical +accuracy, rejected the notion of an ethereal medium. His successors, +following too closely in his footsteps, and forgetting the golden law, +have forced themselves into a position by no means enviable. The +short-period comet has driven them to a resisting medium, which, while +according to Encke's hypothesis of increasing density around the sun, it +explains the anomalies of one periodical comet, requires a different +law of density for another, and a negative resistance for a third. + + +OUTLINES OF THE PROBLEM. + +From the position we now occupy, we can see the outlines of the problem +before us, viz.: To reconcile the existence of an ethereal medium with +the law of gravitation, and to show the harmony between them. We shall +thus occupy the middle ground, and endeavor to be just to the genius of +Descartes, without detracting from the glory of Newton, by demonstrating +the reality of the Cartesian vortices, and by showing that the ether is +not affected by gravitation, but on the other hand is _least dense_ in +the centre of our system. But what (it may be asked) has this to do with +the theory of storms? Much every way. And we may so far anticipate our +subject as to _assert_ that every phenomenon in meteorology where force +is concerned, is dependent on the motions of the great sea of electric +fluid which surrounds us, in connection with its great specific, +caloric. If we are chargeable with overweening pretensions, let it be +attributed to the fact that for the last fifteen years we have treated +the weather as an astronomical phenomenon, calculated by simple formul, +and that the evidence of its truth has been almost daily presented to +us, so as to render it by this time one of the most familiar and +palpable of all the great fundamental laws of nature. True, we have +neither had means nor leisure to render the theory as perfect as we +might have done, the reason of which we have already communicated. + + +MOTIONS OF THE STARS. + +In investigating the question now before us, we shall first take the +case of an ethereal vortex without any reference to the ponderable +bodies which it contains, considering the ether to possess only inertia. +If there be a vortex around the sun, it is of finite extent; for if the +ether be co-extensive with space, and the stars likewise suns with +surrounding vortices, the solar vortex cannot be infinite. That there is +an activity in the heavens which the mere law of attraction is +incompetent to account for, is an admitted fact. The proper motions of +the fixed stars have occupied the attention of the greatest names in +astronomy, and motions have been detected, which according to the theory +of gravity, requires the admission of invisible masses of matter in +their neighborhood, compared with which the stars themselves are +insignificant. But this is not the only difficulty. No law of +arrangement in the stars can exist that will save the Stellar system +from ultimate destruction. The case assumed by Sir John Herschel, of a +cluster, wherein the periods shall be equal, cannot be made to fulfil +the conditions of being very numerous, without infringing the other +condition--the non-intersection of their orbits; while the outside stars +would have to obey another law of gravitation, and consequently would be +still more liable to derangement from their ever-changing distances +from each other, and from those next outside; in brief, the stability of +those stars composing the cluster would necessarily depend on the +existence of outside stars, and plenty of them. But those outside stars +would follow the common law of gravity, and must ultimately bring ruin +on the whole. We know such clusters do exist in the heavens, and that +the law of gravity alone must bring destruction upon them. This is a +case wherein modern science has been instrumental in drawing a veil over +the fair proportions of nature. That such collections of stars are not +designed thus to derange the order of nature, proves _ priori_, that +some other conservative principle must exist; that the medium of space +must contain many vortices--eddies, as it were, in the great ethereal +ocean, whose currents are sweeping along the whole body of stars. We +shall consider, (as a faint shadowing of the glorious empire of +Omnipotence,) that the whole infinite extent of space is full of motion +and power to its farthest verge; and it may be an allowable stretch of +the imagination to conceive that the whole comprises one infinite +cylindrical vortex, whose axis is the only thing in the universe in a +state of absolute unchangeableness. + + +VORTICOSE MOTION. + +Let us for a moment admit the idea of an infinite ocean of fluid matter, +having inertia without gravity, and rotating around an infinite axis, in +this case there is nothing to counteract the effect of the centrifugal +force. The elasticity of the medium would only oppose resistance in a +vortex of finite diameter. Where it is infinite, each cylindrical layer +is urged outward by its own motion, and impelled also by those behind. +The result would be that all the fluid would at last have left the axis, +around which would exist an absolute and eternal void; into which +neither sound, nor light, nor aught material, could enter. The case of +a finite vortex is very different. However great the velocity of +rotation, and the tendency of the central parts to recede from the axis, +there would be an inward current down either pole, and meeting at the +equatorial plane to be thence deflected in radii. But this radiation +would be general from every part of the axis, and would be kept up as +long as the rotation continued, if the polar currents can supply the +drain of the radial stream, that is, if the axis of the vortex is not +too long for the velocity of rotation and the elasticity of the ether, +there will be no derangement of the density, only a tendency. And in +this case the periodic times of the parts of the vortex will be directly +as the distances from the axis, and the absolute velocities will be +equal. + + +FORMATION OF VORTICES. + +There is reason to suspect that Newton looked at this question with a +jaundiced eye. To do it justice, we must consider the planetary matter +in a vortex, as the exponent of its motion, and not as originating or +directing it. If planetary matter becomes involved in any vortex, it +introduces the law of gravitation, which counteracts the expulsive force +of the radial stream, and is thus enabled to retain its position in the +centre. A predominating mass in the centre will, by its influence, +retain other masses of matter at a distance from the centre, even when +exposed to the full power of the radial stream. If the power of the +central mass is harmoniously adjusted to the rotation of the vortex, +(and the co-existence of the phenomena is itself the proof that such an +adjustment does obtain,) the two principles will not clash or interfere +with each other. Or in other words, that whatever might have been the +initial condition of the solar vortex, the ultimate condition was +necessarily one of equilibrium, or the system of the planets would not +now exist. With this view of its constitution, we must consider that the +periodic times of the planets approximately correspond to the times of +the contiguous parts of the vortex. Consequently, in the solar vortex, +the density of the ether is directly as the square roots of the +distances from the axis. This is not the place fully to enter into a +discussion of the question, or to show that the position of each planet +in the system is due to the outstanding, uncompensated, portion of the +expulsive force of the radial stream, modified by the density of the +ether within the planets, and also by their own densities, diameters, +inclinations of axis, and periods of rotation. That Jupiter could not +remain in the orbit of Mercury, nor Mercury in that of Jupiter, by +merely exchanging periods and distances, but that each planet can only +be in equilibrio in its own orbit. That any change in the eccentricities +of the planetary orbits will neither increase nor diminish the action of +the radial stream of the vortex, and consequently will not interfere +with the law of gravitation. In relation to the numerous questions that +will spring up from such a position, it is sufficient here to say, that +it is believed all objections can be satisfactorily answered; while, by +this light, a long range of phenomena that have hitherto baffled the +sagacity of the wise, come out plainly, and discover their parentage. + +In cometary astronomy we shall find much to substantiate these views. +The anomalies in their motions, the discrepancies in their periods, +calculated from different sets of observations, their nebulosities and +appendages, will all receive a satisfactory solution; and these lawless +wanderers of the deep be placed in a more interesting light. + + +TEST OF A THEORY. + +It has been remarked that the best evidence of the truth of a theory, is +its ability to refer to some general principle, the greatest number of +relevant phenomena, that, like the component masses of the chiselled +arch, they may mutually bind and strengthen each other. This we claim +to be the characteristic of this theory. At the outset it was not +intended to allude to more than was actually necessary to give an +outline of the theory, and to introduce the main question, yet +untouched. We have exhibited the stones of which the arch is composed; +but they may be pasteboard,--for the reader has not handled them. We +will now produce the keystone, and put it in its place. This he shall +handle and weigh. He will find it hard,--a block of granite, cut from +the quarry of observed facts, and far too heavy to be held in its place +by a mere pasteboard structure. + + +ENUNCIATION OF THE THEORY. + +Quitting, therefore, the region of the planets, we will come down to the +surface of our own globe, to seek for some more palpable evidence of the +truth of the following propositions: + +1st. That space is filled with an elastic fluid, possessing inertia +without weight. + +2d. That the parts of this fluid in the solar system circulate, after +the manner of a vortex, with a direct motion. + +3d. That there are also secondary vortices, in which the planets are +placed. + +4th. That the earth is also placed in a vortex of the ethereal medium. + +5th. That the satellites are passively carried around their primaries, +with the ethereal current, and have no rotation relative to the ether, +and therefore they always present the same face to their primaries, and +have no vortex. + +The consideration of these propositions involves many others, many +difficulties, many apparent anomalies and contradictions, which should +bespeak for such a theory,--the offspring of observation, without the +aid afforded by the knowledge of others, and of toil without leisure,--a +large share of indulgence. With this we will close these preliminary +remarks, and present our theory of the physical cause which disturbs +the equilibrium of our atmosphere, and which appears the principal agent +in the production of storms, in the following words: + +The dynamical axis of the terral vortex passes through the centre of +gravity of the earth and moon, and is continually circulating over the +earth's surface in both hemispheres, in a spiral,--its latitude and +longitude, at any particular time, being dependent,-- + +1st. On the relative mass of the moon. + +2d. On the inclination of the axis of the vortex to the earth's axis. + +3d. On the longitude of the ascending node of the vortex on the lunar +orbit. + +4th. On the longitude of the ascending node of the lunar orbit on the +ecliptic. + +5th. On the eccentricity of the lunar orbit at the time. + +6th. On the longitude of the perigee of the lunar orbit at the time. + +7th. On the moon's true anomaly at the time. + + +MASS OF THE MOON. + +Those elements which represent the moon's distance and motion are +accurately known, and may be taken from the Nautical Almanac, being all +embodied in the moon's parallax or semi-diameter, and in the declination +and right ascension; but for the most important element,--the moon's +mass, we in vain look to astronomy. In fact, it may be averred that the +importance attached to astronomical authority, concerning the mass of +the moon, has caused more trouble than any other question of the whole +theory, until we trusted implicitly to the theory itself to determine +it. The determination of three unknown elements, viz.: the moon's mass, +the inclination of the axis of the vortex, and the right ascension of +that axis, is a more difficult problem than at first sight appears, +owing to the nature of the phenomena, which affords the only clue for +its solution. There are six principal vortices ever in operation on the +surface of the earth, and their disturbing influence extends from 200 to +400 miles. To find the precise centre, by one observer confined to one +place, is difficult; and to separate them, so as to be fully assured +that you have the right one, is perhaps still more so. Happily this +tedious labor is accomplished, and we are able with confidence to give +the following important elements, as very close approximations to the +truth: + + Mass of the moon 1/72.3 + Obliquity of the axis of the vortex 15 to 32 variable. + Right ascension of ditto 250 to 290 variable. + +It must be borne in mind that we are now discussing the main or central +vortex of the earth; but before applying them to the calculation, we +will explain the _modus operandi_, waiving for the present the +consideration of the law of density in the Terral vortex. It is evident +at first sight that if the periodic times of the parts of the vortex +contiguous to the moon, are equal to the moon's period approximately, +that the velocity of the ether is greater at the surface of the earth +than the velocity of that surface. Now, we have before argued that the +ether possesses inertia, it therefore would under such circumstances +exert some mechanical action. Consequently, the arial envelope of our +globe, or its superior stratum, is impelled eastward by _convection_[4] +of the more rapidly rotating ether. And from the extreme tenuity of its +upper layers, is probably forced into immense waves, which will observe +to a certain degree, a general parallelism north and south. + + +ATMOSPHERIC CURRENTS. + +It is a well-known fact, that the prevailing current of the atmosphere +in high latitudes is from the westward. The cause of this is ascribed by +Professor Dove to the transfer of the equatorial portions to a higher +latitude, by which the excess of its rotative velocity is made apparent, +by outstripping the slower moving surface in its progress eastward. No +doubt some effect is due to this, but still a difficulty remains. Let us +follow this current. The polar current reaches the surface on the +borders of the trades with less rotative velocity than the surface, and +is, therefore, met by the surface as a current partaking of both +motions. In the northern hemisphere it is north-east deflected to east +as it approaches the southern trades. By the same reasoning, coming from +the north before it readies the surface, it ought to be also a +north-east wind above the lower westerly currents. Now it is an observed +fact, that while in the latitude of New York, for instance, the lower +westerly winds are to the easterly, as 3 or 4 to 1, in the highest +regions of observed clouds, the ratio is much increased; and according +to our own observations in this place,[5] we have never seen the highest +cirrus clouds moving westward. How then is this continual interchange +kept up? Assuredly we cannot have a current from the poles without a +contrary current to the poles. If we go into the arctic circle, we again +find the westerly and northerly winds predominating. If the current from +the equator follows the surface, the westerly winds ought to be +south-west. If it be above the surface wind, then the surface wind is +the polar current, and ought to be north-east. Whereas, from the +testimony of all who have visited these regions, the prevailing winds +are north-west. How can this be? + +Again, it is proved that the upper current near the equator is also from +the westward--as near due west as possible. Take the latitude of St +Vincent. The difference between the cosine of 13 and radius applied +to the circumference, is about 600 miles, which would give 25 miles per +hour to the eastward, in lat.13. But to do this, it is necessary to +transfer it suddenly from the equator; for by a slow motion the easterly +tendency would be lost. Give it 24 hours from the equator to lat.13, +without any loss of easterly tendency, and it comes to that latitude +with a velocity of 38 miles per hour to the northward, and only 25 to +the eastward; we have, therefore, a wind from south-west by south. Yet +it is known that in the tropics the highest visible clouds move from the +westward. But as no such case could occur as a transfer in twenty-four +hours without loss, and if we diminish the time, the wind is still more +southerly. Meteorologists usually cite the falling of ashes at Jamaica +during the eruption of Coseguina, in Guatamala, in February 1835, as +coming from south-west, whereas the true direction was about west +south-west, and the trade wind below was about north. But do we deny +that there is an interchange between the frigid and torrid zones? By no +means; but we would show that the great controlling power is external to +our atmosphere, and that the relative velocities of the earth and the +atmosphere is not alone adequate to account for it. By this view the +polar current is a north-west wind (which is impossible by Professor +Dove's theory), or is carried eastward by electric convection. + + +HUTTON'S THEORY. + +Whether we adopt the views of Fourier or Poullet, as to the temperature +of the planetary spaces, it is certain that it is at least equal to, or +less than, the lowest temperature of our globe. It is also a well-known +fact, that the capacity of air to hold vapor in solution, increases in a +higher ratio than the temperature, so that the intermingling of +saturated portions of air, at different temperatures, must _necessarily_ +be attended by precipitation of moisture. This idea was advanced by +Doctor Hutton, and considered competent to account for the prominent +meteorological phenomena, until Professor Espy broached a questionable +principle, (and which is rendered still more so by the late +investigations of Regnault,) in opposition to Hutton's theory. That the +theory is deficient, no one can gainsay. That Espy has rendered the +question clearer, is equally hazardous to assert. Hutton failed in +showing a cause for such intermingling on a sufficient scale; while +Espy, it may be suspected, has misinterpreted facts, and incautiously +rejected the only element possessing the power of raising the storm. + + +GREAT SPECIFIC HEAT OF THE ETHER. + +Whatever may be the degree of condensation or rarefaction in the terral +vortex, there must necessarily be a current down the pole or axis, +thence to be deflected along the equatorial plane of the vortex, and +this drain will be as perpetual as the rarefaction of the centre, +(caused by the centrifugal force of rotation,) which calls it forth. It +will now be perceived that the fluid of the vortex, which we shall still +term ether, is neither more nor less than the electric fluid,--the +mighty energising principle of space,--the source of motion,--the cause +of magnetism, galvanism, light, heat, gravity, of the aurora, the +lightning, the zodiacal light, of the tails and nebulosities of comets, +of the great currents of our atmosphere, of the samiel, the hurricane, +and the earthquake. It will be perceived that we treat it as any other +fluid, in relation to its law of motion and condensation. But we have no +right to base our calculations on its resistance, by the analogies +presented by ponderable or atomic matter. Atomic fluids,--even pure air, +may be considered viscid and tenacious when compared to an infinitely +divisible fluid, between whose particles (if we may use the term) no +_attraction_ of any kind exists. No ponderable matter can come in close +contact without feeling the influence of the gravitating force which, at +insensible distances,--such as the breadth of a wave of ether, is +increased in power, and becomes a cohering and combining force. We +contend that this fluid is the only fluid of space; when condensed it is +positive, and seeks to escape; when rarefied it is negative, and +receives from the contiguous space a restoration of its power. That it +can give and receive, from planetary matter, what we call motion; and +consequently can affect the temperature of such matter, and be in turn +affected by it. And finally that, for its degree of inertia, it exceeds +in elasticity and specific heat all other matter. + + +PROCESS OF DERANGEMENT. + +This premised, we see that as the axis of the vortex traverses the +surface of the earth, there is a tendency to derange the electric state +of the parts travelled over, by bringing the atmosphere and surface of +the earth under the rarefied centre of the vortex. For it is not the +ether of the atmosphere alone that is affected. It is called forth from +the earth itself, and partakes of the temperature of the +crust,--carrying up into the upper regions the vapor-loaded atmosphere +of the surface. The weather now feels close and warm; even in winter +there is a balmy change in the feelings. The atmosphere then fills with +haze, even to the highest regions of the clouds; the clouds themselves +are ill defined; generally the wind comes in at E.S-E., or S., getting +very fresh by the time it chops round to W. In from six to twelve hours +from the time of the meridian passage, in this latitude, the Big Cumuli +have formed, and commenced their march eastward. In summer time there is +always thunder and lightning, when the passage is attended or followed +by a storm. In winter, generally, but not always. In summer, the +diameter of the storm is contracted; in winter, dilated; in consequence +of this, summer is the best season to trace the vortices of the earth +through their revolutions. Let us now attend a little to the results. +The ether of the surface atmosphere partakes of the temperature of that +atmosphere, so also the ether of the earth's crust partakes of the +temperature of the crust; and its escape is rapid, compared with the +ascent of the air. When it arrives at the colder layers of air above, +its temperature sinks, and, on account of the greater specific caloric, +it imparts a much higher temperature to those layers than is due to +their position; an elevation consequently takes place,--begetting a +drain from below, until the upper regions are loaded with a warm and +vapory atmosphere. If the action of the sun conspires at the same time +to increase the effect, the storm will be more violent. In twelve hours +after the meridian passage of the vortex, the storm is brought under the +parts of the ethereal atmosphere of the earth most remote from the axis; +a reaction now takes place; the cold ether of space rushes in, and, on +account of its great specific caloric, it abstracts from the warm +atmosphere more than pertains to the difference of temperature, and +there is a great condensation. Rain and hail may form in fearful +quantities; and when the equilibrium is restored, the temperature will +have fallen many degrees. + +As it is important that we should have a clear view of the character of +the ether, we will revert to the principle we have advocated, viz.: that +in equal spaces there are equal momenta. What the ether wants in +inertia, is made up by its motion or specific heat, considering in this +case inertia to stand for weight when compared with ponderable matter; +so that to raise an equivalent amount of inertia of ether to the same +temperature as atmospheric air, will require as much more motion or +specific heat as its matter is less. And this we conceive to be a law of +space in relation to all free or gaseous matter. To apply it to solids +would require a knowledge of the amount of force constituting the +cohesion of the solid. + + +INFLUENCE OF DIMINISHED PRESSURE. + +But there is another principle which modifies these effects. We have +already adverted to the action of the tangential current of the vortex +forcing the outer layers of the atmosphere into waves. These waves will +be interfered with by the different vortices, sometimes being increased +and sometimes diminished by them.[6] If these waves are supposed very +wide, (which would be the case in the attenuated outside layers of the +atmosphere,) the action of the vortex will be greater in its passage +over a place, which at the time corresponded to the depression point of +the wave, that is, to the line of low barometer; because here there +would be less resistance to overcome in the passage of the ether from +the surface of the earth into space; so that we may conceive each vortex +making a line of storms each day around the earth, separated by less +disturbed intervals. After the formation of the storm, it of course has +nothing to do with the vortex that produced it; it travels in the +general direction of the local atmosphere of the place--in intratropical +latitudes westward, in extratropical latitudes eastward. If, therefore, +the disturbance forms at the place of observation, there will probably +be no storm; but further eastward its action would be more apparent or +violent. It is impossible, of course, to lay down any general +description which shall meet every case. It is a knowledge that can only +be acquired by observation, and then is not readily or easily +communicated. There are many contingencies to be allowed for, and many +modifying causes to keep sight of, to enter into which would only be +tedious; we shall, therefore, confine ourselves to the prominent +phenomena. + + +ACTION OF THE POLAR CURRENT. + +We have seen how the passage of the axis of the vortex may derange the +electric tension of the parts passed over; but there is another mode of +action not yet adverted to. + +[Illustration: Fig. 1] + +When the moon is at her perigee, the axis of the vortex passes through +the centre of gravity of the earth and moon at C, and cuts off the +segment RR. At the apogee, on account of her greater distance, and of +her consequent power to _push_ the earth out from the axis of the vortex +XX, the segment R'R' is only cut off by the axis; and the angle which +the axis makes with the surface will vary with the arcs AR and A'R'; for +these arcs will measure the inclination from the nature of the circle. +In passing from the perigee to the apogee the axis will pass over the +latitudes intermediate between R and R' in both hemispheres, neither +reaching to the equator E, nor to the pole P. Let us now suppose a +meridian of the earth, represented by the line NRS, N being north, and S +south, and the surface of the atmosphere by N'S'; XX still representing +the axis of the vortex, ordinarily inclined 34 or 35 to the surface. +Let us also conceive the rotation of the earth to cease, (the action of +the vortex remaining the same,) thus leaving the axis over a particular +longitude. If the ether possesses inertia, there will be an actual +scooping out of the upper portions, driving them southward to a certain +distance, where the atmosphere will be piled up above the ordinary +level. There will, therefore, be a strong contrary current at the +surface of the earth to restore the equilibrium, and if the action be +violent, the surface wind will be increased; so that if it be considered +tangential to the surface at S, its own momentum will tend to make it +leave the surface and mount up to T; and in this way increase the action +due to the ether. Now, although the axis is never stationary, but +travels round the earth in less than twenty-five hours, yet there is a +tendency to this mode of action; and it is even sometimes palpable to +the observer when the axis has passed immediately to the northward; for +the pinnate shafts and branching plumes of the cirri often reach far to +the south of the southern boundary of the storm. These shafts are always +longer when radiating from the northward than when proceeding from the +southward. The cause is understood by the above figure. At such a time, +after dark, the auroral shafts will also be seen over the storm to the +northward, but will be invisible to those beneath. There is this to be +observed, however, that the visibility of the ethereal current (or the +aurora) is more frequent when the passage of the vortex is not attended +with any great commotion, its free passage being perhaps obstructed by +too dry an atmosphere; hence it becomes more visible. But it may be +asserted that a great aurora is never seen except when a vortex is near, +and to the northward, and within a few hours of its passage over the +meridian. We have, however, seen partial auroras to the south when none +existed north, and also cases when the radiation was from west, but they +are never as bright as in the north. They are all due, however, to the +same cause; and we have frequently followed a vortex for three days to +the northward, (that is, seen the effects of its meridian passage,) at +700 miles distance, by the aurora, and even by the lightning, which +proves plainly that the _exterior layers_ of our atmosphere can reflect +a flash of lightning, assisted by the horizontal refraction, otherwise +the curvature of the earth would sink it ten miles below the horizon. + +[Illustration: Fig. 2] + + +LIMITS OF THE VORTEX. + +The action of the polar current of the ether, therefore, tends to cause +a depression of the barometer, and an elevation to the _northward_ and +southward, and there is a general set of the wind below to the point of +greatest depression. The action of the tangential current works the +outer surface of the atmosphere into great ridges and hollows, whose +distances apart as well as actual dimensions, are continually changing +under the influences of causes not yet alluded to, and it is in the +hollows where the action of the polar current will be principally +expended. Luckily for the earth, the axis of the vortex is never long in +passing over any particular place. In this latitude, whose natural +cosine is three-fourths, the velocity _westward_ is over 700 miles per +hour; but at its extreme limits north, the motion is much slower, and is +repeated for two or three days in nearly the same latitude, for then it +begins to return to the south; thus oscillating in about one sidereal +period of the moon. At its southern limit, the vortex varies but slowly +in latitude for the same time, but the velocity is much greater. The +extreme latitudes vary at different times with the eccentricity of the +lunar orbit, with the place or longitude of the perigee, and with the +longitude of the moon's ascending node, but in no case can the _central +vortex_ reach within 5 of the equator, or higher than about 75 of +latitude north or south. Hence there are no storms strictly speaking +beyond 88[7] of latitude; although a storm may be raging close by, at +the turning point south, and draw in a very strong gale from the +northward with a clear sky above. So also, although rains and short +squalls may be frequent in the vapor-loaded atmosphere of the equator, +yet the hurricane does not reach there, owing to the adjustment of the +mass and distance of the moon, and the inclination of the axes of the +vortices to the axis of the earth. If the temperature of the upper limit +or highest latitude of the vortex, was equal to the temperature which +obtains at its lowest limit, and the daily extremes of the solar +influence as great, the hurricanes would be as violent at the one as the +other, and even more so on account of the smaller velocity. But the +deficiency of temperature and moisture, (which last is all-important,) +prevents the full development of the effect. And even in the tropics, +the progress of the sun, by its power in directing the great annual +currents of the atmosphere, only conspires in the summer and autumn +months, to bring an atmosphere in the track of the vortices, possessing +the full degree of moisture and deficiency of electric tension, to +produce the derangement necessary to call forth the hurricane in its +greatest activity. + + +ROUTINE OF A STORM. + +The novelty and originality of this theory will perhaps justify us in +dwelling a little longer on what observation has detected. The vortex +(and we are now speaking only of the central vortex) does not derange +every place alike, but _skips_ over large tracts of longitude in its +progress westward. We speak here of the immovable axis of the vortex as +in motion; in reality it is the rotation of the earth which brings every +meridian under its influence in some latitude once every twenty-four +hours. The centre of greatest derangement forms the nucleus, towards +which the surface currents, under certain restrictions, flow. The +strongest current will, however, usually be from the south, on account +of the inclination of the axis of the vortex to the surface of the +earth.[8] These currents continuing onwards by their vires inerti, +according to the first law of motion, assist somewhat in conveying the +warm surface wind, loaded with moisture, into the region of cloud; and +the diminution of temperature causes the condensation of large masses of +vapor, according to Hutton's views; and the partial vacuum thus +produced, causes a still greater intermingling. But we have already +shown that this is not the sole cause, nor is it ever more than +partially accomplished. The ether of the lower atmosphere, and of the +crust of the earth, is disturbed, and rushes towards the rarefied axis +from the surface, and with the temperature of the surface, thus +conveying the surface atmosphere, in a measure, along with it. In the +upper regions, this ether (or electric fluid) cools down, or parts with +some of its heat, to the air of those regions, and, by its great +specific caloric, necessarily and unduly increases the temperature of +the air. This, by its expansion and ascension will cause a further +influx from below, until the upper atmosphere becomes loaded with vapor. +In twelve hours, at least, a reaction must take place, as that part of +the earth's surface is carried six or seven thousand miles from the +axis, where the ether is more dense. This in turn descends to the +surface, carrying with it the temperature of space, at least 60 below +zero; a great condensation must follow; local derangements of the +electric equilibrium in the centre of large clouds, when the +condensation is active, must now take place, while partially +nonconducting masses intervene, to prevent an instantaneous restoration +of the equilibrium, until the derangement is sufficient to cause the +necessary tension, when all obstacles are rent asunder, and the ether +issues forth, clothed in the power and sublimity of the lightning. It is +a fearfully-energetic fluid, and, when sufficiently disturbed, competent +to produce the most violent tornado, or the most destructive earthquake. +That these two phenomena have simultaneously occurred, seems well +authenticated; but the earthquake, of course, must be referred generally +to derangements of the electric equilibrium of the earth's interior, of +which at present we know but little. + +The day or morning previous to the passage of the vortex, is frequently +very fine, calm, mild, and sleepy weather,--commonly called a weather +breeder. After the storm has fully matured, there is an approach of the +clouds to the surface, a reduction of the temperature above, and the +human body feels the change far more than is due to the fall of +temperature. This is owing to the cold ether requiring so much heat to +raise its temperature to that of surrounding bodies, or, in other words, +is due to its great specific caloric. In summer, this falling of the +upper layers in front of the storm is so apparent, that every part is +seen to expand under the eye by perspective,--swelling, and curling, and +writhing, like the surface of water or oil when just commenced boiling. +The wind now partakes of the motion of the external ether, and moves +with the storm eastward (in this latitude), or from N-E. to S-E., until +the action ceases. + + +CONDITIONS NECESSARY TO PRODUCE A STORM. + +The vortex, in its passage round the earth, may only meet with a few +localities favorable for producing a very violent storm; but these +nuclei will generally be connected by bands of cloudy atmosphere; so +that could we view them from the moon, the earth would be belted like +the planet Jupiter. There is reason to suspect, also, that there are +variations in the energy of the ethereal motions, independent of the +conditions of the earth and its atmosphere, which affects even the +radial stream of the sun. For the zodiacal light, which is caused by +this radial stream, is at times much more vivid than at others. Also in +the case of the aurora, on our own globe. On this point there is much to +say, but here is not the place. The conditions favorable for the +production of a storm at the _central_ passage of a vortex, are a +previous exemption from excitement _ceteris paribus_, a high temperature +and dew point, a depression of the barometer, and local accumulation of +electric tension, positive or negative; and these are influenced by the +storms in other places controlling the arial currents, and thus +determining the atmosphere of the place. + + +LATERAL VORTICES. + +We have already alluded to the lateral vortices of the terral system. We +must now resort to a diagram. + +In the following figure, the arrows represent the ethereal current of +the terral vortex; the linear circle, the earth; C the centre of gravity +of the earth and moon, and, consequently, the central vortex or axis of +the vortex of the earth, I represents the position of the inner vortex, +and O that of the outer vortex. These two last are eddies, caused by the +obstacle presented by the earth in being _pushed_ out from the centre by +the moon, and are called lateral vortices. There are, therefore, two +lateral vortices, and one central, in both hemispheres, and by this +simple arrangement is the earth watered, and the atmospheric circulation +produced. + +[Illustration: Fig. 3] + + +ILLUSTRATION OF THEIR ACTION. + +If we place a globe in a vessel of water, so that the vertex shall only +just be covered, and place the globe eccentrically in the vessel so that +the centre of the vessel may not be too far from the outside of the +globe, and then impart an equable but slow motion to the water, in the +manner of a vortex; by viewing the reflected light of the sky from the +surface of the water above the globe, we shall be able to trace a +succession of dimples, originating at I and O, and passing off with the +current, and dying away. The direction of the fluid in these little +eddies, will be the same as the direction of the current in the main +vortex. If we displace the globe, so as to remove it far from the centre +of the vessel, and impart the same motion, the vortex I will be found at +E, and the direction of the current will be contrary to the direction +of the fluid in the vessel. In the case of the earth and moon, the +displacement can never change the position of the inner vortex much. It +will always be to the right hand of the central vortex in north +latitudes, and in consequence of the ether striking our globe in such a +position, the current that is deflected from its true path, by the +protuberance of the earth forcing it inside, is prevented by the +circular current of the parts nearer the axis of the vortex, from +passing off; so that a vortex is formed, and is more violent, _ceteris +paribus_, than the vortex at O. + + +ORDER OF OCCURRENCE. + +Whether this mode of action has been correctly inferred, matters little; +the lateral vortices follow the law of such a position. The inner vortex +always precedes the central from five to eight days, when ascending in +this latitude, and comes to the meridian after the moon. The outer +vortex, on the contrary, follows the central in its monthly round, and +comes to the meridian before the moon. It will be readily understood +that if the axes of these lateral vortices be produced through the +earth, they will pass through similar vortices in the opposite +hemisphere; but as the greatest latitude of the one, corresponds to the +least latitude of the other, the same calculation will not answer for +both. The same remark applies to the central vortex also. + +Thus there are six passages each month over latitude 41; but as there +are intervals of 3 to 6 between two consecutive passages of the same +vortex, it may happen that an observer in the middle latitude, would +perhaps see nothing of their effects without looking for them. Generally +speaking, they are not only seen, but felt. The time of the passage of +the outer vortex ascending, corresponds so nearly (in 38 of latitude) +at certain times, with the passage of the central vortex descending, +that the two may be considered one if attention is not directed to it. +The orbits of these lateral vortices depend, like that of the central +vortex, on the orbit of the moon for eccentricity, but the longitudes of +the perigee will not correspond with the longitude of the moon's +perigee. This follows from the theory. As the elements of these orbits +are only approximately determined, we shall confine our calculations to +the orbit of the central vortex. + + +REDFIELD'S THEORY OF STORMS. + +It will now appear plainly to the reader, that this theory of storms +differs in every particular from the rival theories of Redfield and +Espy, both as to the cause and the _modus agendi_. It would appear at +first sight, as if the discovery of these vortices would at once remedy +the great defect in the theory of Redfield, viz.: that no adequate cause +is assigned for the commencement and continuation of the vorticose +motion, in the great circular whirlwinds which compose a storm. The +facts, however, are adverse to such an application. According to +Mr.Redfield, the rotation of a circular storm in the northern +hemisphere is from right to left, and the reverse in the southern. The +author's attention has, of course, been considerably directed to this +point; but in every case he has been unfortunate in finding in the +clouds a rotation from left to right. Some cases are mentioned in the +appended record of the weather. He has also noticed many of those small +whirlwinds on arid plains, in Egypt, in Mexico, and in California, +which, in the great majority of cases, were also from left to right. His +opportunities, however, have not extended to the southern hemisphere. +This theory has not, however, been formed on theoretic views, but by +looking nature in the face for years, and following her indications. +Accordingly, we find that the changes of the wind in a storm forbid the +adoption of the circular hypothesis. + + +WHIRLWINDS VERY LIMITED IN DIAMETER. + +The theory, as extended by Col.Reid, rests on a simple rotation around +a progressing centre, and is found sometimes supported by evidence of +the most violent action at the centre, and sometimes by showing that the +central portion is often in a state of calm. We do not attempt to +reconcile these views; but would merely observe, that an atmospheric +vortex must be subject to the same dynamical laws as all other vortices; +and inasmuch as the medium cannot differ greatly in density, from the +centre to the circumference, the periodic times of the parts of the +vortex, must be directly as their distances from the axis, and +consequently the absolute velocities must be equal. If Mr.Redfield +resorts to a spirally inward current, it would be a centripetal instead +of a centrifugal current, and therefore could not cause the barometer to +fall, which was the best feature of the theory in its primitive form. +The absolute velocity of the wind is the important element which most +concerns us. In the case of a tornado of a few yards in diameter, there +is no doubt a circular motion, caused by the meeting of opposing +currents; but this may be considered a circle of a very small diameter. +The cause is due to a rapid escape of electric or ethereal matter, from +the crust of the earth, called forth by the progressing, disturbed space +above; this involves the air, and an ascending column in rotation begets +the rush on all sides to that column in straight lines: consequently, +the velocities will be inversely as the distances from the axis, and the +force of the current as the squares of the velocities. On the circular +theory, no increase of velocity would be conferred by the approach of +the centre, and consequently no increase of power. + + +OBJECTION TO CIRCULAR STORMS. + +Another objection to the circular theory of storms, is the uniformity of +phase. If that theory be true, we see no reason why a person should not +be sometimes on the northern side of the gale. By referring to a +diagram, we perceive that on the northern side the changes of the wind +pursue a contrary direction to what they do on the south, yet in nine +cases out of ten, each vessel meeting a hurricane will find the same +changes of wind as are due to the southern side of the storm. It is +true, that if a vessel be to the northward of a great hurricane, there +will almost certainly be a north-east gale drawn in, and this might be +set down as the outer limits of a circular storm. But when the storm +really begins, the wind comes round south-east, south, south-west, +ending at north-west, and frequently is succeeded, on the following day, +(if in middle latitude,) by a moderate breeze from the northward. Now, +if the north-east gale spoken of above, was the outer limits of an +atmospheric vortex, a vessel sailing west ought not to meet the +hurricane, as a north-east wind is indicative of being already on the +west side, or behind the storm. + +Again, the characters of the winds, and appearances at the different +changes, are opposed to the circular theory. At a distance of fifty +miles from the centre of a storm, the wind which passes over a ship as a +southerly wind, will have made a rotation and a half, with the hurricane +velocity, before the same wind can again pass the ship as a northerly +wind, (supposing the progress eastward, and the ship lying to,) that is, +the same wind which in another place was a south wind two hours before, +and after only going one degree north, becomes a northerly +wind,--changed in character and temperature, as every seaman is well +aware. In a storm, if the circular theory be true, the character and +temperature should be the same, no matter from what point the wind is +blowing. This should be a conclusive argument. + +Mr.Espy has also changed his ground on the storms of the United States; +he does not now contend that the winds blow inwards to a centre, but to +a line either directly or obliquely. Thus we see that while Mr.Redfield +concedes to Mr.Espy a spirally inward current, the latter also gives up +a direct current to the centre, to Mr.Redfield. This shows at least an +approximation to the truth. + +It is not necessary for the support of this theory, that we should +derive any materials from the ruins of others; we shall therefore not +avail ourselves of certain discrepant results, which can be found in +many of the storms cited by Colonel Reid. With respect to Mr.Espy's +_cause_ of storms, the experiments of Regnault may be considered as +decisive of the question:--1st, because the specific heat of vapor is so +much less than Espy assumed it to be; and 2d, because the expansion of +air in a free space does not suffer any change of volume by ascending, +except what is due to diminished pressure, and the natural temperature +of that elevation. + + +INDICATIONS OF A STORM. + +In accordance with our theory, the direction and force of the wind in a +storm are due to ascending columns of air, supplied from the upper +portion of the atmospheric stratum beneath the clouds. The commotion +begins at the highest limits of the cirri, and even at greater +elevations. Hence, the hazy appearance of the sky is a legitimate +precursor of the coming gale. As a general thing, the wind will blow (at +the surface) towards the centre of greatest commotion, but it is too +dependent on the ever-varying position and power of temporary nuclei of +disturbance, to be long steady, except when the disturbance is so remote +that its different centres of induction are, as it were, merged into one +common focus. When a vortex is descending, or passing from north to +south, and withal very energetic at the time, the southerly wind (which +may always be considered the principal wind of the storm in this +hemisphere) may blow steadily towards the vortex for three or even four +days. When a vortex is ascending, the induced northerly current will be +comparatively moderate, and be frequently checked by the southerly wind +overblowing the storm, and arriving the day before the vortex which +produced it. + +The important point for the navigator, is to know the time of meridian +passage of the vortex, and its latitude at the time of the passage, and +then be guided by the indications of the weather and the state of +barometer. If it commences storming the day before the passage, he may +expect it much worse soon after the passage; and again, if the weather +looks bad when no vortex is near, he may have a steady gale setting +towards a storm, but no storm until the arrival of a vortex. Again, if +the barometer is low the day before the vortex passes, there may be high +barometer to the west, and the passage be attended by no great +commotion, as it requires time for the storm to mature, and consequently +its greatest violence will be to the east. If at the ship the barometer +is high, the vortex may still produce a storm on a line of low barometer +to the west, and this line may reach the ship at the time of the +passage. In tropical climates the trouble must be looked for to the +eastward; as a storm, once excited, will travel westward with that +stratum of atmosphere in which the great mass of vapor is lodged, and in +which, of course, the greatest derangement of electric tension is +produced. + +It will now be seen that we do not admit, with Col.Reid, that a storm +continues in existence for a week together. Suppose a hurricane to +originate in the Antilles at the southern limits of a vortex, the +hurricane would die away, according to our theory, if the vortex did not +come round again and take up the same nucleus of disturbance. On the +third day the vortex is found still further north, and the apparent path +of the hurricane becomes more curved. In latitude 30 the vortex passes +over 3 or 5 of latitude in a day; and here being the latitude where +the lower atmospheric current changes its course, the storm passes due +north, and afterwards north-east. Now, each day of the series there is a +distinct hurricane, (caused by an increase of energy in a particular +vortex, as we have before hinted,) each one overlapping on the remains +of the preceding; but in each the same changes of the wind are gone +through, and the same general features preserved, as if it were truly a +progressive whirlwind, except that each vessel has the violent part of +it, as if she was in the southern half of the whirl. The apparent +regularity of the Atlantic storms in direction, as exhibited by Col. +Reid, are owing in a great degree to the course of the Gulf Stream, in +which a vortex, in its successive passages in different latitudes, finds +more favorable conditions for the development of its power, than in +other parts of the same ocean; thus showing the importance of regarding +the established character of storms in each locality, as determined by +observation. In this connection, also, we may remark, that the meridians +of greatest magnetic intensity are, _ceteris paribus_, also the +meridians of greatest atmospheric commotion. The discovery of this fact +is due to Capt.Sabine. The cause is explained by the theory. + +As it is the author's intention to embody the practical application of +this theory to navigation, with the necessary rules and tables, in a +separate work, sufficient has been said to familiarize the reader with +the general idea of a cause external to the earth, as the active motor +in all atmospheric phenomena. We will therefore only allude in a general +way to the principal distinguishing feature of the theory. We say, then, +that the wind in a storm is not in rotation, and it is a dangerous +doctrine to teach the navigator. We also assert as distinctly, that the +wind _in_ a storm does not blow from all sides towards the centre, which +is just as dangerous to believe. If it were wise to pin our faith to any +Procrustean formula, we might endorse the following propositions: That +at the beginning of a storm the wind is from the equator towards the +poles in every part of the storm; that, at a later date, another current +(really a polar current deflected by convection) sets in at right angles +to the first one; and that at the end of the storm there is only _one_ +wind blowing at right angles to the direction at the beginning. Outside +the storm, considered as a hundred, or two or three hundred miles in +diameter, there is, under certain limitations, a surface wind setting +towards the general focus of motion and condensation, and this surface +wind will be strongest from the westward, on account of the motion of +the whole atmosphere in which these other motions are performed being to +the eastward.[9] The whole phenomenon is electrical or magnetic, or +electro-magnetic or ethereal, whichever name pleases best. The vortex, +by its action, causes a current of induction below, from the equator, as +may be understood by inspecting Fig.2, which in the northern hemisphere +brings in a southerly current by convection: the regular circular +current, however, finally penetrates below, as soon as the process of +induction has ceased; and thus the polar current of the atmosphere at +last overcomes the equatorial current in a furious squall, which ceases +by degrees, and the equilibrium is restored. + +Every locality will have its peculiar features; in each, the prevailing +wind will be at right angles to the magnetic meridian, and the progress +of the storm will tend to follow the magnetic parallel, which is one +reason why the Atlantic and Indian Ocean storms have been mistaken for +progressive whirlwinds. When these views are developed in full, the +mariner can pretty certainly decide his position in the storm, the +direction of its progress, and its probable duration. + + +FOOTNOTES: + +[3] The specific heat of the ether being a constant factor, it may be +divided out. + +[4] A term adopted by Prof. Faraday to denote the mode in which bodies +are carried along by an electrical current. + +[5] Ottawa, Ill. + +[6] The principal cause of these waves is, no doubt, due to the +vortices, and the eastern progress of the waves due to the rotating +ether; but, at present, it will not be necessary to separate these +effects. + +[7] The inner vortex may reach as high as 83 when the moon's orbit is +favorably situated. + +[8] The curvature of the earth is more than 10 miles in a distance of +300 miles. + +[9] In middle latitudes. + + + + +SECTION SECOND. + + +MECHANICAL ACTION OF THE MOON. + +We will now proceed to give the method of determining the latitude of +the axis of the vortex, at the time of its passage over any given +meridian, and at any given time. And afterwards we will give a brief +abstract from the record of the weather, for one sidereal period of the +moon, in order to compare the theory with observation. + +[Illustration: Fig. 4] + +In the above figure, the circle PER represents the earth, E the equator, +PP' the poles, T the centre of the earth, C the mechanical centre of the +terral vortex, M the moon, XX' the axis of the vortex, and A the point +where the radius vector of the moon pierces the surface of the earth. If +we consider the axis of the vortex to be the axis of equilibrium in the +system, it is evident that TC will be to CM, as the mass of the moon to +the mass of the earth. Now, if we take these masses respectively as 1 to +72.3, and the moon's mean distance at 238,650 miles, the mean value of +TC is equal to this number, divided by the sum of these masses,--_i.e._ +the mean radius vector of the little orbit, described by the earth's +centre around the centre of gravity of the earth and moon, is equal +238650/(72.3+1)=3,256 miles; and at any other distance of the moon, is +equal to that distance, divided by the same sum. Therefore, by taking CT +in the inverse ratio of the mean semi-diameter of the moon to the true +semi-diameter, we shall have the value of CT at that time. But TA is to +TC as radius to the cosine of the arcAR, and RR' are the points on the +earth's surface pierced by the axis of the vortex, supposing this axis +coincident with the pole of the lunar orbit. If this were so, the +calculation would be very short and simple; and it will, perhaps, +facilitate the investigation, by considering, for the present, that the +two axes do coincide. + +In order, also, to simplify the question, we will consider the earth a +perfect sphere, having a diameter of 7,900 miles, equal to the actual +polar diameter, and therefore TA is equal to 3,950 miles. + +In the spherical triangle given on next page, we have given the point A, +being the position of the moon in right ascension and declination in the +heavens, and considered as terrestrial latitude and longitude. + +Therefore, PA is equal to the complement of the moon's declination, P +being the pole of the earth, and L being the pole of the lunar orbit; PL +is equal to the obliquity of the lunar orbit, with respect to the earth, +and is therefore given by finding the true inclination of the lunar +orbit at the time, equal EL, (E being the pole of the ecliptic,) also +the true longitude of the ascending node, and the obliquity of the +ecliptic PE. Now, as we are supposing the axis of the vortex parallel +to the pole of the lunar orbit, and to pierce the earth's surface at R, +ARL will evidently all be in the same plane; and, as in the case of A +and L, this plane passes through the earth's centre, ARL must all lie in +the same great circle. Having, therefore, the right ascension of A, and +the right ascension of L, we have the angleP. This gives us two sides, +and the included angle, to find the side LA. But we have before found +the arcAR; we therefore know LR. But in finding LA, we found both the +angles L and A, and therefore can find PR, which is equal to the +complement of the latitude sought. + +[Illustration: Fig. 5] + +We have thus indicated briefly the simple process by which we could find +the latitude of the axis of the central vortex, supposing it to be +always coincident with the pole of the lunar orbit. The true problem is +more complicated, and the principal modifications, indicated by the +theory, are abundantly confirmed by observation. The determination of +the inclination of the axis of the vortex, its position in space at a +given time, and the law of its motion, was a work of cheerless labor for +a long time. He that has been tantalized by hope for years, and ever on +the eve of realization, has found the vision vanish, can understand the +feeling which proceeds from frequent disappointment in not finding that, +whose existence is almost demonstrated; and more especially when the +approximation differs but slightly from the actual phenomena. + +The chief difficulty at the outset of these investigations, arose from +the conflicting authority of astronomers in relation to the mass of the +moon. We are too apt to confound the precision of the laws of nature, +with the perfection of human theories. Man observes the phenomena of the +heavens, and derives his means of predicting what will be, from what has +been. Hence the motions of the heavenly bodies are known to within a +trifling amount of the truth; but it does not follow that the true +explanation is always given by theory. If this were so, the mass of the +moon (for instance) ought to be the same, whether deduced from the +principle of gravitation or from some other source. This is not so. +Newton found it 1/40 of that of the earth. La Place, from a profound +theoretical discussion of the tides, gave it as 1/58.6, while from other +sources he found a necessity of diminishing it still more, to 1/68, and +finally as low as 1/75. Bailly, Herschel, and others, from the nutation +of the earth's axis, only found 1/80, and the Baron Lindenau deduced the +mass from the same phenomenon 1/88. In a very recent work by Mr.Hind, +he uses this last value in certain computations, and remarks, that we +shall not be very far wrong in considering it as 1/80 of the mass of the +earth. This shows the uncertainty of the matter in 1852. If astronomy is +so perfect as to determine the parallax of a fixed star, which is almost +always less than one second, why is it that the mass of the moon is not +more nearly approximated? Every two weeks the sun's longitude is +affected by the position of the moon, alternately increasing and +diminishing it, by a quantity depending solely upon the relative mass of +the earth and moon, and is a gross quantity compared to the parallax of +a star. So, also, the horizontal parallax--the most palpable of all +methods--taken by different observers at Berlin, and the Cape of Good +Hope, (a very respectable base line, one would suppose,) makes the mass +of the moon greater than its value derived from nutation; the first +giving about 1/70, the last about 1/74.2. Does not this declare that it +is unsafe to depend too absolutely on the strict wording of the +Newtonian law of gravitation. Happily our theory furnishes us with the +correct value of the moon's mass, written legibly on the surface of the +earth; and it comes out nearly what these two phenomena always gave it, +viz.: 1/72.3 of that of the earth. In another place we shall inquire +into the cause of the discrepancy as given by the nutation of the earth. + + +MOTION OF THE AXIS OF THE VORTEX. + +If the axis of the terral vortex does not coincide with the axis of the +lunar orbit, we must derive this position from observation, which can +only be done by long and careful attention. This difficulty is increased +by the uncertainty about the mass of the moon, already alluded to, and +by the fact that there are three vortices in each hemisphere which pass +over _twice_ in each month, and it is not _always_ possible to decide by +observation, whether a vortex is ascending or descending, or even to +discriminate between them, so as to be assured that this is the central +descending, and that the outer vortex ascending. A better acquaintance, +however, with the phenomenon, at last dissipates this uncertainty, and +the vortices are then found to pursue their course with that regularity +which varies only according to law. The position of the vortex (the +central vortex is the one under consideration) then depends on the +inclination of its axis to the axis of the earth, and the right +ascension of that axis at the given time. For we shall see that an +assumed immobility of the axis of the vortex, would be in direct +collision with the principles of the theory. + +Let the following figure represent a globe of wood of uniform density +throughout. Let this globe be rotated round the axis. It is evident that +no change of position of the axis would be produced by the rotation. If +we add two equal masses of lead at m and m', on opposite sides of the +axis, the globe is still in equilibrium, as far as gravity is concerned, +and if perfectly spherical and homogeneous it might be suspended from +its centre in any position, or assume indifferently any position in a +vessel of water. If, however, the globe is now put into a state of rapid +rotation round the axis, and then allowed to float freely in the water, +we perceive that it is no longer in a state of equilibrium. The mass m +being more dense than its antagonist particle at n, and having equal +velocity, its momentum is greater, and it now tends continually to pull +the pole from its perpendicular, without affecting the position of the +centre. The same effect is produced by m', and consequently the axis +describes the surface of a double cone, whose vertices are at the centre +of the globe. If these masses of lead had been placed at opposite sides +of the axis on the _equator_ of the globe, no such motion would be +produced; for we are supposing the globe formed of a hard and unyielding +material. In the case of the ethereal vortex of the earth, we must +remember there are two different kinds of matter,--one ponderable, the +other not ponderable; yet both subject to the same dynamical laws. If we +consider the axis of the terral vortex to coincide with the axis of the +lunar orbit, the moon and earth are placed in the equatorial plane of +the vortex, and consequently there can be no derangement of the +equilibrium of the vortex by its own rotation. But even in this case, +seeing that the moon's orbit is inclined to the ecliptic, the +gravitating power of the sun is exerted on the moon, and of necessity +she must quit the equatorial plane of the vortex; for the sun can exert +no influence on the _matter_ of the vortex by his attracting power. The +moment, however, the moon has left the equatorial plane of the vortex, +the principle of momentum comes into play, and a conical motion of the +axis of the vortex is produced, by its seeking to follow the moon in her +monthly revolution. This case is, however, very different to the +illustration we gave. The vortex is a fluid, through which the moon +freely wends her way, passing through the equatorial plane of the vortex +twice in each revolution. These points constitute the moon's nodes on +the plane of the vortex, and, from the principles laid down, the force +of the moon to disturb the equilibrium of the axis of the vortex, +vanishes at these points, and attains a maximum 90 from them. And the +effect produced, in passing from her ascending to her descending node, +is equal and contrary to the effect produced in passing from her +descending to her ascending node,--reckoning these points on the plane +of the vortex. + +[Illustration: Fig. 6] + + +INCLINATION OF THE AXIS. + +By whatever means the two planes first became permanently inclined, we +see that it is a necessary consequence of the admission of these +principles, not only that the axis of the vortex should be drawn aside +by the momentum of the earth and moon, ever striving, as it were, to +maintain a dynamical balance in the system, in accordance with the +simple laws of motion, and ever disturbed by the action of gravitation +exerted on the grosser matter of the system; but also, that this axis +should follow, the axis of the lunar orbit, at the same mean +inclination, during the complete revolution of the node. The mean +inclination of the two axes, determined by observation, is 2 45', and +the monthly equation, at a maximum, is about 15', being a plus +correction in the northern hemisphere, where the moon is between her +descending and ascending node, reckoned on the plane of the vortex, and +a minus correction, when between her ascending and descending node. And +the mean longitude of the node will be the same as the true longitude of +the moon's orbit node,--the maximum correction for the true longitude +being only about 5. + +[Illustration: Fig. 7] + +In the following figure, P is the pole of the earth; E the pole of the +ecliptic; L the pole of the lunar orbit; V the mean position of the pole +of the vortex at the time; the angle[ARIES]EL the true longitude of the pole +of the lunar orbit, equal to the _true_ longitude of the ascending node + 90. VL is therefore the mean inclination 2 45'; and the little +circle, the orbit described by the pole of the vortex _twice_ in each +sidereal revolution of the moon. The distance of the pole of the vortex +from the mean position V, may be approximately estimated, by multiplying +the maximum value 15' by the sine of twice the moon's distance from the +node of the vortex, or from its mean position, viz.: the true longitude +of the ascending node of the moon on the ecliptic. From this we may +calculate the true place of the node, the true obliquity, and the true +inclination to the lunar orbit. Having indicated the necessity for this +correction, and its numerical coefficient, we shall no longer embarrass +the computation by such minuti, but consider the mean inclination as +the true inclination, and the mean place of the node as the true place +of the node, and coincident with the ascending node of the moon's orbit +on the ecliptic. + + +POSITION OF THE AXIS OF THE VORTEX. + +It is now necessary to prove that the axis of the vortex will still pass +through the centre of gravity of the earth and moon. + +[Illustration: Fig. 8] + +Let XX now represent the axis of the lunar orbit, and C the centre of +gravity of the earth and moon, X'X' the axis of the vortex, and KCR the +inclination of this axis. Then from + + similarity Ct : Tt :: Cm : Mm + but Tt : Mm :: Moon's mass : Earth's mass. + That is Tt : Mm :: TC : MC. + +Therefore the system is still balanced; and in no other point but the +point C, can the intersection of the axes be made without destroying +this balance. + +It will be observed by inspecting the figure, that the arc R'K' is +greater than the arcRK. That the first increases the arcAR, and the +second diminishes that arc. The arcR'K' is a plus correction therefore, +and the smaller arcRK a minus correction. If the moon is between her +descending and ascending node, (taking now the node on the ecliptic,) +the correction is negative, and we take the smaller arc. If the moon is +between her ascending and descending node, the correction is positive, +and we take the larger arc. If the moon is 90 from the node, the +correction is a maximum. If the moon is at the node, the correction is +null. In all other positions it is as the sine of the moon's distance +from the nodes. We must now find the maximum value of these arcs of +correction corresponding to the mean inclination of 2 45'. + +To do this we may reduce TC to Tt in the ratio of radius to cosine of +the inclination, and taking TS for radius. + +[Illustration: Fig. 9] + +{TC Cos &c. (inclination 2 45')}/R is equal the cosine of the arc SK' +and SK' + AS = AK' and AK' + AR' = R'K'. But from the nature of the +circle, arcRK + arcR'K' = angle RCK + angleR'CK', or equal to double +the inclination; and therefore, by subtracting either arc from double +the inclination, we may get the other arc. + +The maximum value of these arcs can, however, be found by a simple +proportion, by saying; as the arcAR, plus the inclination, is to the +inclination, so is the inclination to the difference between them; and +therefore, the inclination, plus half the difference, is equal the +greater arc, and the inclination, minus half the difference, is equal +the lesser; the greater being positive, and the lesser negative. + +Having found the arcAR, and knowing the moon's distance from either +node, we must reduce these values of the arcs RK and R'K' just found, in +the ratio of radius to the sine of that distance, and apply it to the +arcAR or A'R', and we shall get the first correction equal to the +arcAK or AK'. + + Call the arcAR = a + " inclination = n + " distance from the node = d + " arcAK = k + +and supposing the value of AK be wanted for the northern hemisphere when +the moon is between her descending and ascending node, we have + + n + ------- + a+n + (n- ------- )sin d. + 2 + k=a----------------------- + R + +If the moon is between her ascending and descending node, then + + n + ------- + a+n + (n- ------- )sin d. + 2 + k=a+---------------------- + R + +The computation will be shorter, however, if we merely reduce the +inclination to the sine of the distance from the node for the first +correction of the arcAR, if we neglect the semi-monthly motion of the +axis; for this last correction diminishes the plus corrections, and the +first one increases it. If, therefore, one is neglected, it is better to +neglect the other also; especially as it might be deemed affectation to +notice trifling inequalities in the present state of the elements of the +question. + +There is one inequality, however, which it will not do to neglect. This +arises from the displacement of the axis of the vortex. + + +DISPLACEMENT OF THE AXIS. + +We have represented the axis of the terral vortex as continually passing +through the centre of gravity of the earth and moon. Now, by following +out the principles of the theory, we shall see that this cannot be the +case, except when the moon is in quadrature with the sun. To explain +this: + +[Illustration: Fig. 10] + +Let the curve passing through C represent a portion of the orbit of the +earth, and S the sun. From the principles laid down, the density of the +ethereal medium increases outward as the square roots of the distances +from the sun. Now, if we consider the circle whose centre is C to +represent the whole terral vortex, it must be that the medium composing +it varies also in density at different distances from the sun, and at +the same time is rotating round the centre. That half of the vortex +which is exterior to the orbit of the earth, being most dense, has +consequently most inertia, and if we conceive the centre of gravity of +the earth and moon to be in the orbit (as it must be) at C, there will +not be dynamical balance in the terral system, if the centre of the +vortex is also found at C. To preserve the equilibrium the centre of the +vortex will necessarily come nearer the sun, and thus be found between T +and C, T representing the earth, and [MOON] the moon, and C the centre of +gravity of the two bodies. If the moon is in opposition, the centre of +the vortex will fall between the centre of gravity and the centre of the +earth, and have the apparent effect of diminishing the mass of the moon. +If, on the other hand, the moon is in conjunction, the centre of the +vortex will fall between the centre of gravity and the moon, and have +the apparent effect of increasing the mass of the moon. If the moon is +in quadrature, the effect will be null. The coefficient of this +inequality is 90', and depends on the sun's distance from the moon. When +the moon is more than 90 from the sun, this correction is positive, and +when less than 90 from the sun, it is negative. If we call this second +correction C, and the moon's distance from her quadratures Q, we have +the value of C=(90' sin Q)/R. + +[Illustration: Fig. 11] + +This correction, however, does not affect the inclination of the axis of +the vortex, as will be understood by the subjoined figure. If the moon +is in opposition, the axis of the vortex will not pass through C, but +through C', and QQ' will be parallel to KK'. If the moon is in +conjunction, the axis will be still parallel to KK', as represented by +the dotted line qq'. The correction, therefore, for displacement, is +equal to the arcKQ or Kq, and the correct position of the vortex on the +surface of the earth at a given time will be at the points Q or q and Q' +or q', considering the earth as a sphere. + +[Illustration: Fig. 12] + +In the spherical triangleAPV, P is the pole of the earth, V the pole of +the vortex, A the point of the earth's surface pierced by the radius +vector of the moon, AQ is the corrected arc, and PV is the obliquity of +the vortex. Now, as the axis of the vortex is parallel to the pole V, +and the earth's centre, and the line MA also passes through the earth's +centre, consequently AQV will all lie in the same great circle, and as +PV is known, and PA is equal to the complement of the moon's declination +at the time, and the right, ascensions of A and V give the angleP, we +have two sides and the included angle to find the rest, PQ being the +complement of the latitude sought. + +We will now give an example of the application of these principles. + +_Example._[10] Required the latitude of the central vortex at the time +of its meridian passage in longitude 88 50' west, July 2d, 1853. + +CENTRAL VORTEX ASCENDING. + + Greenwich time of passage 2d. 3h. 1m. + Mean longitude of moon's node 78 29' + True " " 79 32 + Mean inclination of lunar orbit 5 9 + True " " 5 13 + Obliquity of ecliptic 23 27 32" + Mean inclination of vortex 2 45 0 + +Then in the spherical trianglePEV, + + PE is equal 23 27' 32" + EV " 7 58 0 + E " 100 28 0 + P " 18 5 7 + PV " 26 2 32 + +Calling P the polar angle and PV the obliquity of vortex. + +[Illustration: Fig. 13] + +To find the arcAR. + +By combining the two proportions already given, we have by logarithms: + + M.R.V. minor = 3256 Log. 3.512683 + M.S.D. of moon = 940" " 2.973128 + P.S.D. of earth = 3950 A.C. 6.403403 + Radius 10.000000 + T.S.D. of moon 885".5 A.C. 7.052811 + Log. Cosine arcAR = 28 57' 3" 9.942025 + --------- + +As the only variable quantity in the above formula is the "True" +semi-diameter of the moon at the time, we may add the Constant logarithm +2.889214 to the arithmetical complement of the logarithm of the true +semi-diameter, and we have in two lines the log. cosine of the arcAR. + +We must now find the arcRK equal at a maximum to 2 45'. The true +longitude of the moon's node being 79 32', and the moon's longitude, +per Nautical Almanac, being 58 30', the distance from the node is 21 +2', therefore, the correction is + + -2 45' sin 21 2' + -arcRK=--------------------- = -59' 13" + R + +To find the correction for displacement. + + True longitude of sun at date 100 30' + " of moon " 58 30 + Moon's distance from quadrature 48 0 + +As the moon is less than 90 from the sun this correction is also +negative, or + + -90' sin 48 + Arc Kq= --------------- = -1 6' 46". + R + + ArcAR= 28 57' 3" + RK= - 0 39' 13" + Kq= - 1 6' 46" + Sum= 26 51' 4" = corrected arcAQ. + +We have now the necessary elements in the Nautical Almanac, which we +must reduce for the instant of the vortex passing the meridian in +Greenwich time. + + July 2d. + Meridian passage, local time, at 9h. 5m. A.M. + " in Greenwich time 2d. 3h. 1m. + Right ascension same time 56 42' 45" + Declination north " 18 00 1 + Obliquity of the vortex " 26 2 32 + Polar angle " 18 5 7 + ArcAQ " 26 51 4 + +[Illustration: Fig. 14] + + PA = 17 59' 59" } P = 128 37' 38" + PV = 26 2 32 } + VA = 89 3 0 V = 47 59 44 + VQ = 62 11 56 A = 20 3 42 + PQ = 47 14 22 Q = 26 22 55 + Latitude of Q on the sphere = 42 45' 38" + + +CORRECTION FOR PROTUBERANCE. + +We have hitherto considered the earth a perfect sphere with a diameter +of 7,900 miles. It is convenient to regard it thus, and afterwards make +the correction for protuberance. We will now indicate the process for +obtaining this correction by the aid of the following diagram. + +[Illustration: Fig. 15] + +Let B bisect the chord ZZ'. Then, by geometry, the angleFQY is equal to +the angleBTF, and the protuberance FY is equal the sine of that angle, +making QF radius. This angle, made by the axis of the vortex and the +surface of the sphere, is commonly between 30 and 40, according as the +moon is near her apogee or perigee; and the correction will be greatest +when the angle is least, as at the apogee. At the equator, the whole +protuberance of the earth is about 13 miles. Multiply this by the cosine +of the angle and divide by the sine, and we shall get the value of the +arcQY for the equator. For the smallest angle, when the correction is a +maximum, this correction will be about 20' of latitude at the equator; +for other latitudes it is diminished as the squares of the cosines of +the latitude. Then add this amount to the latitude EQ, equal the +latitude EY. This, however, is only correct when the axis of the vortex +is in the same plane as the axis of the earth; it is, therefore, subject +to a minus correction, which can be found by saying, as radius to cosine +of obliquity so is the correction to a fourth--the difference of these +corrections is the maximum minus correction, and needs reducing in the +ratio of radius to the cosine of the angle of the moon's distance from +the node; but as it can only amount to about 2' at a maximum under the +most favorable circumstances, it is not necessary to notice it. The +correction previously noticed is on the supposition that the earth is +like a sphere having TF for radius; as it is a spheroid, we must correct +again. From the evolute, draw the line SF, and parallel to it, draw TW; +then EW is the latitude of the point F on the surface of the spheroid. +This second correction is also a plus correction, subject to the same +error as the first on account of the obliquity, its maximum value for an +angle of 30 is about 6', and is greatest in latitude 45; for other +latitudes, it is equal {6' sin(double the lat.)}/R. + +The three principal corrections for protuberance may be _estimated_ from +the following table, calculated for every 15 of latitude for an angle +of 30, or when the correction is greatest. + + Latitude. 1st Corr. 2d Corr. 3d Corr. + 0 + 20' + 0 - 2 + 15 + 19 + 3 - 1.5 + 30 + 15 + 5 - 1.5 + 45 + 10 + 6 - 1. + 60 + 5 + 5 - 1 + 70 + 1 + 3 - 0.5 + +We can now apply this correction to the latitude of the vortex just +found: + + Latitude on the sphere 42 45' 38" n. + Correction for protuberance + 14 22 + ---------- + Correct latitude 43 00 00 + + +MILWAUKIE STORM, JULY 2. + +As this example was calculated about ten days before the actual date, we +have appended an extract from the Milwaukie papers, which is in the same +longitude as Ottawa, in which place the calculation was made. It is +needless to remark that the latitude of Milwaukie corresponds to the +calculated latitude of the centre of the vortex. It is not intended, +however, to convey the idea that the central line is always the most +subject to the greatest violence--a storm may have several centres or +nuclei of disturbance, which are frequently waning and reviving as the +storm progresses. Generally speaking, however, the greatest action is +developed along the line previously passed over by the axis of the +vortex. + + "SUMMIT, Waukesha Co., Wis., July 4, 1853. + + "Our town, on Saturday, the 2d, was visited by a terrible storm, + which will long be remembered by those who witnessed its effects and + suffered from its fury. It arose in the south-west, and came + scowling in blackness, sufficient to indicate its anger, for the + space of eighty or a hundred rods in _width_, covering our usually + quiet village; and for nearly half an hour's duration, the rain fell + in torrents, the heavens blazed with the lightning's flashes, trees + fell and were uprooted by the fury of the blast, fragments of gates + and of buildings, shingles, roof-boards, rafters, circled through + the air, the playthings of the wind--and buildings themselves were + moved entire from their foundations, and deposited at different + distances from their original positions. A barn, fifty-five feet + square on the ground, owned by Mr.B.R. Hinckley, is moved from its + position some ten feet to the eastward; and a house, some fifteen by + eighteen feet on the ground, owned by the same person, fronting the + east, was driven by the wind to the opposite side of the street, and + now fronts nearly west; and what is most strange, is that the grass, + in the route the house must have passed over, stands straight as + usual, and gives no evidence that the building was pushed along on + the ground. A lady running from a house unroofed by the storm, took + an arial flight over two fences, and finally caught against a tree, + which arrested her passage for a moment only, when, giving way, she + renewed her journey for a few rods, and was set down unhurt in + Mr.O.Reed's wheat field, where, clinging to the growing grain, she + remained till the gale went by."[11] + +The weather at this place is briefly recorded in the accompanying +abstract from the journal, as well as in an extract from a note to +Professor Henry, of the Smithsonian Institution, from a friend of the +authors, who has long occupied a high official station in Illinois. But +such coincidences are of no value in deciding on the merits of such a +theory, it must be tried before the tribunal of the world, and applied +to phenomena in other countries with success, before its merits can be +fully appreciated. The accompanying record, therefore, is only given to +show how these vortices render themselves apparent, and what ought to be +observed, and also to exhibit the order of their recurrence and their +positions at a given time. + +_Extract of a note addressed to the Secretary of the Smithsonian +Institution, by Hon. John Dean Caton, on this subject._ + + "As a striking instance of the remarkable coincidences confirmatory + of these calculations, I will state, that on Friday, the first of + July last, this gentleman[12] stated that on the next day a storm + would pass north of us, being central a little south of Milwaukie, + and that he thought, from the state of the atmosphere, the storm + would be severe, and that its greatest violence would be felt on the + afternoon or night of the next day. At this time the weather was + fine, without any indications of a storm, so far as I could judge. + At noon on the following day he pointed out the indications of a + storm at the north and north-west, consisting of a dark, hazy belt + in that direction, extending up a few degrees above the horizon, + although so indistinct as to have escaped my observation. At five + o'clock a violent storm visited us, which lasted half an hour, + although a clear sky was visible at the south the whole time. On + Monday morning I learned, from the telegraph office at Chicago, that + early on Saturday afternoon communication with Milwaukie had been + interrupted by atmospheric electricity, and that the line had been + broken by a storm." + + +NEW YORK STORM. + +After this was written, the author discovered that the vortex was +equally violent the day before at New York, July 1st, 1853. An account +of this storm follows. The calculation has not been made, but it is easy +to perceive that the latitude of the vortex, on July 1st, must be very +nearly that of New York--being in latitude 43 next day and ascending. + +"At a meeting of the American Association, convened at Cleveland, +Professor Loomis presented a long notice of the terrible hail storm in +New York on the 1st of July. He traced its course, and minutely examined +all the phenomena relating to it, from a mile and a half south-east of +Paterson, N.J., to the east side of Long Island, where it appeared +nearly to have spent its force. It passed over the village of Aqueenac, +striking the Island of New York in the vicinity of the Crystal Palace. +It was not much more than half a mile wide. The size of the hail-stones +was almost incredibly large, many of them being as large as a hen's egg, +and the Professor saw several which he thought as large as his fist. +Some of them weighed nearly half a pound. The principal facts in +relation to this storm were published at the time, and need not be +repeated. The discussions arising among the members as to the origin and +the size of these hail-stones, and the phenomena of the storm, were +exceedingly interesting. They were participated in by Professors Heustus +and Hosford, of Cambridge University, Professor Loomis, and Professors +Bache and Redfield. The latter two gentlemen differ somewhat, we should +suppose radically, in their meteorological theories, and had some very +sharp but very pleasant "shooting" between them."[13] + + +CENTRAL VORTEX DESCENDING. + +We will now make the calculation for the central vortex _descending_, +for longitude 88 50' west, August 7, 1853,--putting down the necessary +elements for the time of the meridian passage in order: + + Meridian passage in local time at 2h. 25m. P.M. + " " in Greenwich time 7d. 8h. 18m. + Mass of the moon 1/12.3 M.R.V. minor 3,256 miles. + Obliquity of the vortex, same time 26 5' 0" + Polar angle of " " 17 41 47 + True longitude of moon's node " 78 42 0 + " inclination of orbit " 5 5 0 + " longitude of the sun " 135 20 0 + Moon's longitude " 169 44 0 + " distance from node " 91 2 0 + " distance from quadrature " 55 36 0 + " true semi-diameter " 943 + " right ascension " 172 30 0 + " declination north " 8 42 20 + Constant logarithm 2.889214 + Arith. comp. of log. of 943 7.025488 + Log. cos. arc. AR 9.914702 = 34 44' 48" + 1st. correction, + 2 45 0 + 2d. correction, - 1 14 15 + -------------- + Corrected arc AQ = 36 15 33 + PA = 81 17' 40" + PV = 26 5 0 + P = 115 11 47 + V = 63 34 26 + A = 23 28 24 + AV = 92 48 39 + Q = 31 32 18 + Complement of lat.= PQ = 48 49' 41" + The latitude is therefore for + the earth, as a sphere 41 10 18 + Correction for protuberance + 0 16 0 + ------------ + True latitude of centre 41 26 18 north. + ------------ + Latitude of Ottowa 41 20 0 " + ------------ + Vortex passed 6 18 north of Ottowa. + +[Illustration: Fig. 16] + +As this was nearly a central passage, and as the influence was less +extensive than usual, on account of great atmospheric pressure with a +low dew point, the central disturbance could the more readily be +located, and was certainly to the north, and but a few miles. The +following is from the record of the weather: + +_August_ 6th. Very fine and clear all day; wind from S.-W.; a light +breeze; 8P.M. frequent flashes of lightning in the northern sky; +10P.M. a _low bank of dense clouds in north_, fringed with cirri, +visible during the flash of the lightning; 12 P.M. same continues. + +7th. Very line and clear morning; wind S.-W. moderate; noon, clouds +accumulating in the northern half of the sky; wind fresher S.-W.; 3P.M. +a clap of thunder overhead, and black cumuli in west, north, and east; +4P.M. much thunder, and scattered showers; six miles west rained very +heavily; 6P.M. the heavy clouds passing over to the south; 10 P.M. +clear again in north. + +_August_ 8th. Clear all day; wind the same (S.-W.); a hazy bank visible +all along on _southern horizon_. + +This was not a storm, in the ordinary acceptation of the term; but the +same cause, under other circumstances, would have produced one; and let +it be borne in mind, that although the moon is the chief disturbing +cause, and the passages of the vortices are the periods of greatest +commotion in both settled and unsettled weather, still the sun is +powerful in predisposing the circumstances, whether favorable or +unfavorable; and as there is no periodic connection between the passage +of a vortex and the concurrence of the great atmospheric waves, it will, +of course, happen only occasionally that all the circumstances will +conspire to make a storm. There are also other modifying causes, to +which we have not yet alluded, which influence the storms at different +seasons of the year,--exaggerating their activity in some latitudes, and +diminishing it in other latitudes. In this latitude, the months of May, +June, and July are marked by more energetic action than August, +September, and October. The activity of one vortex also, in one place, +seems to modify the activity of another vortex in another place. But the +great question to decide is: Do these vortices really exist? Do they +follow each other in the _order_ indicated by the theory? Do they pass +from south to north, and from north to south, at the _times_ indicated +by the theory? Do they obey, in their monthly revolutions, a +mathematical law connecting them with the motions of the moon? We answer +emphatically, Yes! And the non-discovery of these facts, is one of the +most humiliating features of the present age. + + +OTTOWA STORM, DECEMBER 22, 1852. + +To show that the same calculations are applicable for other times, we +will make the calculation for the _centre ascending_, for the 22d +December, 1852, taking the following elements: + + Moon's mer. passage, Dec. 22d 15h. 16m. G. time. + " right ascension, same time 51 57' + " declination north 15 42 + " true S. Diameter 886.6" + " distance from node 37 + " " " quadrature 52 + -------- + Which gives the arcAR 29 5 + 1st correction -1 51 + 2d +1 11 + -------- + Corrected arcAQ 28 25 + -------- + +And the latitude at the time of the meridian passage = 42 north, or +about forty miles north of Ottawa. + +Abstract from the record:-- + +[14]_Dec._ 21st, 1852. Wind N.-E., fine +weather. + +_Dec._ 22d. Thick, hazy morning, wind east, much lighter in S.-E. than +in N.-W.; 8A.M., a clear arch in S.-E. getting more to south; noon, +very black in W.N.-W.; above, a broken layer of cir. cumulus, the sun +visible sometimes through the waves; wind round to S.-E., and fresher; +getting thicker all day; 10P.M., wind south, strong; thunder, +lightning, and heavy rain all night, with strong squalls from south. + +_Dec._ 23d. Wind S.-W., moderate, drizzly day; 10P.M., wind west, and +getting clearer. + +The next day the vortex passed the latitude of Montreal (the moon being +on the meridian about 10P.M.) + + +MAGNETIC STORM, DECEMBER 23, 1852. + +In the July number of Vol.XVI. of Silliman's Journal, we find certain +notices of the weather in 1852, by Charles Smallwood, of St. Martins, +nine miles east of Montreal. He mentions "two remarkable electrical +storms (which) occurred on the 23d and 31st of December, (in which) +sparks 5/40 of an inch were constantly passing from the conductor to the +discharger for several hours each day." At 10P.M. (23d) the vortex +passed over Montreal, and again descending on the 31st North, and was +visible at Ottowa on the morning of the 1st of January, with southerly +wind setting towards it. On the 29th of December, Mr.Smallwood records +"a low auroral arch, sky clear." On the 20th, the vortex was 5 to the +northward of Montreal, and the aurora was consequently low--the +brightest auroras being when the vortex is immediately north without +storm, or one day to the northward, although we have seen it _very low_ +when the vortex was three days to the north, and no other vortex near. + + +LIVERPOOL STORM. + +On the night of the 24th of December, the same central vortex ascending +passed between Cape Clear and Liverpool. + +On the 25th, at midnight, the vortex passed to the north of Liverpool: +its northerly progress being very slow, being confined for three days +between the parallel of Liverpool and its extreme northern limit in +latitude about 57. The accompanying account of the weather will show +the result of a long-continued disturbance near the same latitude: + +The Baltic, three days out from Liverpool, encountered the vortex on the +night of the 23d. On the morning of the 25th, very early, the gale +commenced at Liverpool, and did much damage. On the 26th, the vortex +attained its northern limit; but we have not been able to procure any +account of its effects to the northward of Liverpool, although there can +be but little doubt that it was violent on the coast of Scotland on the +26th; for the next day (27th) the vortex having made the turn, was near +the latitude of Liverpool, and caused a _tremendous_ storm, thus showing +a continued state of activity for several days, or a peculiarly +favorable local atmosphere in those parts. It is very probable, also, +that there was a conjunction of the central and inner vortex on the +27th. The inner vortex precedes the central in passing latitude 41; but +as the mean radius of its orbit is less than that of the central, it +attains to a higher latitude, and has, consequently, to cross the path +of the central, in order again to precede it descending in latitude 41. +As a very trifling change in the elements of the problem will cause +great changes in the positions of the vortices on the surface of the +earth, it cannot now be asserted that such a conjunction did positively +occur at that time; but, it maybe suspected, that a double disturbance +would produce a greater commotion, or, in other words, a more violent, +storm. + +It is on this account, combined with other auxiliary causes, that the +vicinity of Cape Horn is so proverbially stormy, as well as for the low +standard of the barometer in that latitude, it is the stationary point +of the vortices in ordinary positions of the nodes and perigee of the +moon. We have already alluded to the fact, that none of the vortices +scarcely ever pass much beyond latitude 80, and then only under +favorable circumstances, so that we ought to infer, that gales in high +latitudes should set from the poles towards the storms in lower +latitudes. This is, no doubt, the fact, but, nevertheless, a hard +southerly blow _may possibly_ occur in high northern latitudes, if a +storm should be raging very violently in a lower latitude on the +opposite side of the pole, the distance across the circle of 80 being +only about 1,400 miles. As the different vortices have a different limit +in latitude every year, the determination of this turning point is +obviously of great practical utility, as the fact may yet be connected +with other phenomena, so as to give us the probable character of the +polar ice at any assigned time. On this point we have more to say. + + +PASSAGES OF ALL THE VORTICES. + +Our remarks have hitherto been confined to the central vortex. We shall +now show from the record, that the other vortices are as effective in +deranging the equilibrium of our atmosphere. In the following table we +have given the passages of the different vortices, which will serve as +their true positions within moderate limits, to calculate from, for all +future time. + + +PASSAGES OF THE CENTRAL AND LATERAL VORTICES, OBSERVED IN JUNE AND JULY, +1853, IN LATITUDE 41 20' NORTH. + +I signifying Inner; O, outer; C, central; A, ascending; D, descending. + + ____________________________________________________________________ + | | | | | | | + | Order.|Vortex.| Date. | Meridian |Passage.| Calculated latitude | + | | | | Passage. | | and Remarks. | + |_______|_______|_________|__________|________|______________________| + | | | | | | | + | 1st | I.A. | June 22 | 7A.M. | south | Centre. About 40. | + | | | 23 | 8A.M. | north | Warsaw. Storm. | + | 2d | O.D. | 27 | 0 noon | north | | + | | | 28 | 1A.M. | south | See record. | + | 3d | C.A. | July 1 | 9A.M. | south | | + | | | 2 | 10A.M. | north | Lat. 43. Storm. | + | 4th | I.D. | 7 | 5P.M. | north | | + | | | 8 | 6P.M. | south | Lat. New York. Storm.| + | 5th | C.D. | 12 | 5P.M. | north | Aurora. | + | | | 13 | 6P.M. | south | Stormy, very. | + | 6th | O.A. | 14 | 10A.M. | south | | + | | | 15 | 11A.M. | north | See Record. | + |_______|_______|_________|__________|________|______________________| + +The intervals between the ascending and descending passages of the +different vortices, are + + Between I.A. and I.D. from 11 to 14 days. + " O.A. " O.D. " 10 " 12 " + " C.A. " C.D. " 9 " 11 " + +and the effect is greatest when the vortex comes to the meridian before +the sun, and least when after the sun; in which case the full effect is +not developed, sometimes until the following day. + +A brief abstract from a journal of the weather for one sidereal period +of the moon, in 1853. + +_June_ 21st. Fine clear morning (S. fresh)[15]: noon very warm 88; +4P.M. plumous _cirri in south_; ends clear. + +22d. Hazy morning (S. very fresh) arch of cirrus in west; 2P.M., black +in W.-N.-W.; 3P.M., overcast and rainy; 4P.M., a heavy gust from +south; 4.30P.M., blowing furiously (S. by W.); 5P.M., tremendous +squall, uprooting trees and scattering chimneys; 6P.M., more moderate +(W.) + +23d. Clearing up (N.-W.); 8A.M., quite clear; 11A.M., bands of mottled +cirri pointing N.-E. and S.-W.; ends cold (W.N.-W.); the cirri seem to +rotate from left to right, or with the sun. + +24th. Fine clear cool day, begins and ends (N.-W.) + +25th. Clear morning (N.-W, light); 2P.M. (E.) calm; tufts of tangled +cirri in north intermixed with radiating streaks, all passing eastward; +ends clear. + +26th. Hazy morning (S.-E) cloudy; noon, a heavy windy looking bank in +north (S. fresh), with dense cirrus fringe above on its upper edge; +clear in S. + +27th. Clear, warm, (W.); bank in north; noon bank covered all the +northern sky, and fresh breeze; 10P.M., a few flashes to the northward. + +28th. Uniform dense cirro-stratus, (S. fresh); noon showers all round; +2P.M., a heavy squall of wind, with thunder and rain (S.-W. to N.-W.); +8P.M., a line of heavy cumuli in south; 8.30P.M., a very bright and +high cumulus in S.-W., protruding through a layer of dark stratus; +8.50P.M., the cloud bearing E. by S., with three rays of electric +light.[16] + +[Illustration: Fig. 17] + +_June_ 29th. A stationary stratus over all, (S.-W. light); clear at +night, but distant lightning in S. + +30th. Stratus clouds (N.-E. almost calm); 8A.M., raining gently; +3P.M., stratus passing off to S; 8P.M., clear, pleasant. + +_July_ 1st. Fine and clear; 8A.M., cirrus in sheets, curls, wisps, and +gauzy wreathes, with patches beneath of darker shade, all nearly +motionless; close and warm (N.-E.); a long, low bank of haze in S., with +one large cumulus in S.-W., but very distant. + +_July_ 2d. At 5A.M., overcast generally with hazy clouds and fog of +prismatic shades, chiefly greenish-yellow; 7A.M., (S.-S.-E. +freshening,) thick in W; 8A.M., (S. fresh) much cirrus, thick and +gloomy; 9A.M., a clap of thunder, and clouds hurrying to N.; a reddish +haze all around; at noon the margin of a line of yellowish-red cumuli +just visible above a gloomy-looking bank of haze in N.-N.-W., (S. very +fresh;) warm, 86; more cumuli in N.-W.--the whole line of cumuli N. are +separated from the clouds south by a clear space. These clouds are borne +rapidly past the zenith, but never get into the clear space--they seem +to melt or to be turned off N.-E. The cumuli in N. and N.-W., slowly +spreading E. and S.; 3P.M., the bank hidden by small cumuli; 4P.M., +very thick in north, magnificent cumuli visible sometimes through the +breaks, and beyond them a dark, watery back-ground, (S. strong); +4.30P.M., wind round to N.-W. in a severe squall; 5P.M., heavy rain, +with thunder, &c.--all this time there is a bright sky in the south +visible through the rain 15 high; 7P.M., clearing, (S.-W. mod.) + +_July_ 3d. Very fine and clear, (N.-W.); noon, a line of large cumuli in +N., and dark lines of stratus below, the cumuli moving eastward; 6P.M., +their altitude 2 40'. Velocity 1 per minute; 9P.M., much lightning in +the bank north.[17] + +_July_ 4th. 6A.M., a line of small cumulo-stratus, extending east and +west, with a clear horizon north and south 10 high. This band[18] seems +to have been thrown off by the central yesterday, as it moves slowly +south, preserving its parallelism, although the clouds composing it move +eastward. Fine and cool all day--(N.-W. mod.)--Lightning in N. + +_July_ 5th. Cloudy (N. almost calm), thick in E., clear in W.; same all +day. + +6th. Fine and clear (E. light); small cumuli at noon; clear night. + +7th. Warm (S.E. light); cirrus bank N.W.; noon (S.) thickening in N.; +6P.M., hazy but fine; 8P.M., lightning in N.; 10P.M., the lightning +shows a heavy line of cumuli along the northern horizon; calm and very +dark and incessant lightning in N. + +8th. Last night after midnight commencing raining, slowly and steadily, +but leaving a line of lighter sky south; much lightning all night, but +little thunder. + +8th. 6A.M. Very low scud (500 feet high) driving south, still calm +below, (N. light); 10A.M., clearing a little; a bank north with cirrus +spreading south; same all day; 9P.M., wind freshening (N. stormy); +heavy cumuli visible in S.; 10.30P.M., quite clear, but a dense watery +haze obscuring the stars; 12 P.M., again overcast: much lightning in S. +and N.-W. + +9th. Last night (2A.M. of 9th) squall from N.-W. very black; 4A.M., +still raining and blowing hard, the sky a perfect blaze, but very few +flashes reach the ground; 7A.M., raining hard; 8A.M. (N.-W. strong); a +constant roll of thunder; noon (N.-E.); 2P.M. (N.); 4P.M. clearing; +8P.M., a line of heavy cumuli in S., but clear in N-W., N., and +N.-E.[19] + + +NEW YORK STORM, JULY 8, 1853. + +"At 5 o'clock Friday afternoon, a terrible storm of rain, hail, and +lightning, rose suddenly from the north-west, and passed over the upper +part of the city and neighborhood. It was quite moderate in the lower +part of the town, and probably scarcely felt on Staten Island. The whole +affair lasted not more than a quarter of an hour, yet the results were +most disastrous, as will be seen by the following accounts from our +reporters: + +"Happening to be in the neighborhood of the Palace about 5 o'clock +Friday evening, we sought shelter under its ample roof from an impending +thunder storm, of very threatening appearance, rapidly approaching from +the west. We had scarcely passed the northern entrance, and reached the +gallery by the nearest flight of steps, when the torrent--it was not +rain, but an avalanche of water--struck the building; the gutters were +filled on the windward side in a moment, and poured over an almost +unbroken sheet of water, which was driven through the Venetian blind +ventilators, into and half way across the north-west gallery, and also +through the upper ventilators, falling upon the main floor of the north +transept. Workmen hastened to close the blinds, but that did not prevent +the deluge. The tinning of the dome being unfinished, the water, of +course, came down in showers all over the centre. Many workmen were +engaged on the dome when the shower struck it; several of them, in their +haste to escape such dangerous proximity to the terrific lightning, came +down single ropes, hand over hand. Large number of workmen were engaged +all over the exterior, and such a scampering will rarely be witnessed +but once in a lifetime. It was found impossible to close a north window, +used for ingress and egress of workmen upon the rod, and the water came +in, in almost solid columns. For a time the water was nearly two inches +deep on the gallery floor, and poured down the stairs in miniature +cascades. + +"A great number of boxes, bales, and packages of goods lay upon the main +floor, among which the water poured down from the edge of the gallery +floor in destructive quantities; Fortunately but few goods were opened, +and were upon the tables, or the damage would have been irreparable. As +it is, we fear some of the goods are injured. In the height of the +storm, the centre portion of the fanlight over the western entrance +burst in, and several single lights were broken, by staging or +otherwise. + +"About ten minutes after the storm burst, the most terrific hailstorm we +ever saw began to rattle, like discharges of musketry, upon the tin roof +and glass sides. Some of the masses of ice were as large as hen's eggs. +There were probably a thousand excited workmen in the building, and a +good many exhibitors and visitors, among whom there were some twenty +ladies, some of whom appeared a good deal alarmed at the awful din. A +portion of the frame-work of the addition next to 42d street, went down +with a terrible crash, and a part of the brick wall of the engine-house +on the opposite side of the street, was blown over, crushing two or +three shanties, fortunately without any other injury than driving the +occupants out into the storm. But an awful scene occurred on the north +side of 43d street, directly opposite the Latting Tower. Here two large +unfinished frame buildings were blown, or rather, we should judge from +appearances, were crushed down into a mass of ruins, such as may be +imagined by supposing a great weight had fallen, with a circular, +grinding motion, upon the first fine fabrics. One of them was partly +sided, and had the rafters up, but no roof; the other was sided and +rooted with tin, and was being plastered. We were told it was three +stories high, 50 by 98 feet. + +"We reached the ruins among the first, after the burst of the storm +subsided a little. The scene was such as we pray God we may never +witness again. A small portion of the roof and upper part of the front +of the building stood or rather partly hung over the side-walk. The +chamber and lower floor of the front rooms lay flat together. The sides +were standing. In the rear all were down. In this building, besides the +workmen, there were numerous laborers who had taken shelter under its +roof when the storm drove them hurriedly from their work. How so many +persons escaped death is truly wonderful. It can only be accounted for +by supposing that they had a moment's warning, and rushed into the +street. The first alarm was from the tearing off a portion of the tin +roof, which was carried high over another building, and fell in the +street. A horse and cart barely escaped being buried under this. It +seems the frame of the other building came down with a deafening crash +at the same time, confusing instead of warning those in danger. At any +rate, before they could escape, they were buried in a mass of timber, +and three of them instantly killed, and four or five dangerously +wounded; and others slightly bruised and badly frightened. Several would +have perished but for timely assistance to extricate them. In this they +were greatly assisted by Jacob Steinant, boss carpenter of the Tower, +who with his men rushed to the rescue, notwithstanding the pouring down +torrents. + +"In Williamsburgh, the storm lasted about fifteen minutes, doing an +incalculable amount of damage to dwellings, foliage, &c. Hailstones came +down in sizes from that of a hickory-nut to a large apple, some with +such force as to drive them through the cloth awnings. + +"The storm passed over Brooklyn lightly, in comparison with the effects +across the Williamsburgh line. On Flushing avenue, beyond the Naval +Hospital, a number of trees were uprooted, and the window-panes of the +houses shattered. On the corner of Fulton and Portland avenues, three +buildings were unroofed, and the walls of the houses were sprung to the +foundation. + +"On Spencer street, a new frame building was levelled with the ground. +Along Myrtle, Classon, and other streets and avenues of East Brooklyn, +many of the shade trees were uprooted, and the windows smashed. In Jay +street, two trees were struck by lightning, but no other damage ensued. + +"Several schooners at the foot of Jay street were forced from their +moorings, but were soon after secured. A small frame house in Spencer +street, just put under roof, was prostrated to the ground. + +"We understand that a large barn filled with hay, situated on the road +between Bushwick and Flushing, was struck by lightning and destroyed +with its contents, embracing several head of live stock."[20] + +_July_ 10th, 3A.M. Overcast and much lightning in south (N. mod.); +7A.M., clear except in south; 6P.M. (E.); 10P.M., lightning south; +11P.M., auroral rays long but faint, converging to a point between +Epsilon Virginis and Denebola, in west; low down in west thick with +haze; on the north the rays converged to a point still lower; lightning +still visible in south. This is an aurora in the west. + +11th. Fine clear morning (N.-E.); same all day; no lightning visible +to-night, but a bank of clouds low down in south, 2 high, and streaks +of dark stratus below the upper margin. + +12th. Fine and clear (N.-E.); noon, a well defined arch in S.-W., rising +slowly; the bank yellowish, with prismatic shades of greenish yellow on +its borders. This is the O.A. At 6P.M., the bank spreading to the +northward. At 9P.M., thick bank of haze in north, with bright auroral +margin; one heavy pyramid of light passed through Cassiopa, travelling +_westward_ 1 per minute. This moves to the other side of the pole, +but not more inclined towards it than is due to prospective, if the +shaft is very long; 11.10P.M., saw a mass of light more diffuse due +east, reaching to _Markab_, then on the prime vertical. It appears +evident this is seen in profile, as it inclines downwards at an angle of +10 or 12 from the perpendicular. It does not seem very distant. +12P.M., the aurora still bright, but the brightest part is now west of +the pole, before it was east. + +13th, 6A.M. Clear, east and north; bank of cirrus in N.-W., _i.e._, +from N.-N.-E. to W. by S.; irregular branches of cirrus clouds, reaching +almost to south-eastern horizon; wind changed (S.-E. fresh); 8A.M., the +sky a perfect picture; heavy regular shafts of dense cirrus radiating +all around, and diverging from a thick nucleus in north-west, the spaces +between being of clear blue sky. The shafts are rotating from north to +south, the nucleus advancing eastward. + +Appearance of the central vortex descending at 8A.M., July 13th, 1853: + +In Fig.18, the circle represents the whole sky from the zenith to the +horizon, yet it can convey but a very faint idea of the regularity and +vividness of this display. The reflected image of the sky was received +from a vessel of turbid water, which will be found better than a mirror, +when the wind will permit. + +[Illustration: Fig. 18] + +At noon (same day) getting thicker (S.-E. very fresh); 6P.M., moon on +meridian, a prismatic gloom in south, and very thick stratus of all +shades; 9P.M., very gloomy; wind stronger (S.-E.): 10P.M., very black +in south, and overcast generally. + +14th. Last night about 12P.M. commenced raining; 3A.M., rained +steadily; 7A.M., same weather; 8.20A.M., a line of low storm-cloud, or +seud, showing very sharp and white on the dark back ground all along the +southern sky. This line continues until noon about 10 at the highest, +showing the northern boundary of the storm to the southward; 8P.M., +same bank visible, although in rapid motion eastward; same time clear +overhead, with cirrus fringe pointing north from the bank; much +lightning in south (W. fresh); so ends. + +15th. Last night a black squall from N.-W. passed south without rain; at +3A.M. clear above, but very black in south (calm below all the time); +9A.M., the bank in south again throwing off rays of cirri in a +well-defined arch, whose vortex is south: these pass east, but continue +to form and preserve their linear direction to the north; no lightning +in south to-night. + +16th. Clear all day, without a stain, and calm. + +17th. Fine and clear (N.-E. light); 6P.M., calm. + +18th. Fair and cloudy (N.-E. light); 6P.M., calm. + +19th. Fine and clear (N. fresh); I.V. visible in S.-W. + +20th. 8A.M., bank in N.-W. with beautiful cirrus radiations; 10A.M., +getting thick with dense plates of cream-colored cirrus visible through +the breaks; gloomy looking all day (N.-E. light).[21] + +Appearance of the Inner Vortex at 8A.M., July 20th, 1853, including the +whole sky. (See Fig.19.) + +[Illustration: Fig. 19] + +This was a different passage of the Inner Vortex ascending as compared +with the same 28 days before. At that date (June 22) it did great damage +in the central parts of Illinois. Still this last passage was very +palpable--the clouds were very irregularly assorted--plates of cirrus +above and beneath cumulus--various kinds of cirrus clouds, and that +peculiar prismatic haze which is a common sign of the passage of a +vortex. The appearance depicted above is a very common, although a very +evanescent appearance. When the sky appears of a clear blue through the +cirri, there will be generally fresh gales without any great electrical +derangement; but if the clear spaces are hazy, gradually thickening +towards the nucleus, a storm may be expected. Any one who wishes to +understand the indications of the clouds, must watch them closely for +many years, before he can place much reliance upon them. But we shall +again advert to this point. + +We have now passed through one sidereal period of the moon. We might +continue the record, but it would be tedious. The passages of these +vortices vary in violence at different times, as we might expect; but +they never cease to circulate, and never will as long as the moon +remains a satellite to the earth; and if we take the passage of any of +these vortices, and add thereto the time of one sidereal period of the +moon, we get approximately the time of the next passage. When the +elements of the lunar orbit tend to accelerate the passages, they may +come in 26 days; and when to retard, in 28 days; and these are about the +limits of the theory. + +Having begun and ended this record of the weather with the passage of +the Inner vortex ascending, it may not be amiss to notice one more, (the +August passage,) as it offers a peculiarity not often so distinctly +marked. We have alluded to the greater force of the storms when the +passage of the vortex corresponds to the passage of the line of low +barometer or the depression point of a great atmospheric wave, which is +also due to the action of the ether. In consequence of these waves +passing from west to east, the storm will only be violent when formed a +little to the westward. If the storm forms to the eastward, we neither +see it nor feel it, as it requires time to develop its strength, and +always in this latitude travels eastward; so that storms may generally +be said to come from the west, although the exciting cause travels from +east to west. In the case now alluded to, the weather indicated a high +barometer, and the storm formed immediately to the eastward, even +showing a distinct circular outline. We subjoin a description. + +_August_ 15th. Clear morning (N.-E.), a bank of cumuli in south: noon +quite cloudy in S. and clear in north. (N.-E.) + +16th. Clear morning (N.-E.); 3P.M., getting very black in E. and S.-E., +very _clear_ to the _westward_; 4P.M., much thunder and lightning in +east, and evidently raining hard; 5P.M., a violent squall from _east_ +for 10 minutes; tore up several trees; 6P.M., the storm passing +eastward, clear in west all this time; 6.30P.M., the storm forming a +regular arch, the vertex being in _S.-E._; the arch of hazy cirrus and +heavy cumulus much lower in S.-E., wind still moderate from east; +10P.M., clear all around, but lightning in S.-E. and E. + +17th. Fine clear morning (W.); noon, scattered cumuli in north; 6P.M., +a beautifully regular arch of dense cumuli and cirrus margin in _N.-E._, +with a constant glimmer of lightning; 7P.M., very clear to the west, +and north-west, and south; along the northern horizon a line of high +peaked cumuli terminating in N.-N.-W.; a continued roll of distant +thunder in the circular bank in N.-E., and not a moment's cessation to +the lightning; the electric excitement advancing westward along the +lines of cumuli; the cirrus haze also rising and passing towards S.-W.; +8P.M., the sky alive with lightning, the cirrus now reaches the zenith; +no streaks of lightning coming to the earth; they seem to radiate from +the heaviest mass of cumuli, and spread slowly (sufficiently so to +follow them) in innumerable fibres over the cloudy cirrus portion of the +sky; every flash seems to originate in the same cloud; 8.30P.M., one +branching flash covered the whole north-eastern half of the sky, no +leafless tree of the forest could show so many branches; 9.30P.M., all +passed to S.-W. without rain, leaving behind a large cumulus, as if it +lagged behind. From this cumulus a straight line of lightning shot up +10 above the cloud into a perfectly clear sky, and terminated abruptly +without branching. + +We have been thus particular in giving these details, as this was a +clear case confirming the principles advanced, that the vortices do not +form a continuous line of disturbance, in their daily passage around the +earth. It shows also that the barometer, in connection with these +principles, will be a far more useful instrument than it has yet proved +itself, for practical service as an indicator of the weather. + + +FOOTNOTES: + +[10] For convenience to those wishing to verify the calculation of these +triangles, we have put down each side and angle as found. Also, as an +aid to the navigator. + +[11] Daily Wisconsin, July 7. + +[12] The author. + +[13] Chicago Democrat. + +[14] This was also calculated before the event. + +[15] The letters in a parenthesis signify the direction of the wind. + +[16] Giving this cloud the average velocity of thirty miles per hour, +its altitude was determined by the sextant at twelve miles, and we think +under-estimated. While measuring, the author's attention was drawn to +the fact, that although it appeared equally dense above and below, yet +its middle part was the brightest, and as there was only a faint glimmer +of twilight in the N.-W., he concluded that the cloud was self-luminous; +for when the smallest stars were visible, it glowed about as bright as +the milky-way in Sagittarius. Occasionally the whole cloud was lit up +internally by the lightning, and about this time it sent off three rays: +one horizontally, westward, which was the faintest; one about N.-W., +towards Jupiter, and the brightest of the three; and another towards the +north. These were not cirrus streaks, but veritable streams of electric +matter, and had a very decided rotation from left to right, and +continued visible about twenty minutes, as represented above. + +[17] This day the central vortex passed in about latitude 47 N.--the +southern margin cannot be nearer than 250 miles, throwing off the 40' +for the horizontal refraction, would give eight miles of altitude above +a tangential plane. Then another seven miles, for curvature, will give +an altitude of fifteen miles for the cumuli. The height of these +thunder-clouds has been much under-estimated. They seem to rise in +unbroken folds to a height of ten and twelve miles frequently; from the +data afforded by the theory, we believe they will be found much higher +sometimes--even as much as sixteen miles. + +[18] These parallel bands, and bands lying east and west, are frequent +in fine weather between two vortices. Sailors consider them a sign of +settled weather. After dark there was frequently seen along the northern +horizon flashes of lightning in a perfectly clear sky. But they were +both faint and low, not reaching more than 4 or 5 above the horizon. +After sunset there were very distinct rays proceeding from the sun, but +they were shorter than on the evening of the 3d. These are caused by the +tops of the great cumuli of the storm, when sunk below the horizon, +intercepting the sun's rays, which still shine on the upper atmosphere. +The gradation was very marked, and accorded with the different distances +of the central vortex on the 3d and 4th--although, on the 4th, the +nearest distance must have been over four hundred miles to the southern +boundary of the storm. + +[19] It is worthy of notice here, that New York, which only differs by +about 40 miles of latitude and 800 in longitude, had the storm earlier, +near the time of the passage, as appears by the appended account of it. +This proves, that a storm affects a particular latitude simultaneously, +or approximately so. If this had to travel eastward to reach New York, +it would have been the 10th instead of the 8th. The principal trouble +was, however, in the early part of the evening of the 8th, to the south +of Ottawa, where the strong wind was drawn in from the northward. If a +vortex passes from north to south, leaving the observer between the +passages, there must, nearly always, be a winding up squall from the +north to clear away the vapory atmosphere. + +[20] From the _New York Tribune_, July 9, 1853. + +[21] These pages are now in the compositors' hands, (Nov. 21st,) and up +to the last moment the Author has observed carefully in New York the +passages of these vortices. October 24th, in the inner vortex descending +produced a violent storm on the coast, and much damage ensued. November +7th, the same vortex ascending was also severe. And on November 13th, +early, the passage of the central vortex ascending, caused a flood in +Connecticut of a very disastrous nature. Would it not pay the insurance +offices to patronize such investigations in view of such palpable facts +as these? + + + + +SECTION THIRD. + + +OBJECTIONS TO LUNAR INFLUENCE. + +We have now presented a theory of the weather, which accounts for many +prominent phenomena, a few of which we shall enumerate. It is an +observed fact, that in all great storms electrical action is more or +less violent, and that without this element it seems impossible to +explain the velocity of the wind in the tornado, its limited track, and +the formation of large masses of ice or hail in the upper regions of the +atmosphere. It is also an observed fact, that the barometer is in +continued motion, which can only be legitimately referred to a change in +the weight of the atmospheric column. This we have explained as due to +atmospheric waves, caused by the greater velocity of rotation of the +external ether, as well as to the action of the three great vortices. +These causes, however, only partially produce the effect--the greater +portion of the daily oscillations is produced by the action of the great +radial stream of the solar vortex, as we shall presently explain. It is +an observed fact, that, although the storm is frequently violent, +according to the depression of the barometer, it is not always so. +According to the theory, the storm will be violent, _ceteris paribus_, +on a line of low barometer, but may still be violent, when the contrary +obtains. Another fact is the disturbance of the magnetic needle during a +storm. Storms are also preceded generally by a rise in the thermometer, +and succeeded by a fall; also by a fall in the barometer, and succeded +by a rise. It is also well known, that hurricanes are unknown at the +equator, and probably at the poles also. At all events, they are rare in +lat.80, and, according to Capt.Scoresby, storms are there frequently +raging to the south, while above, there is clear sky and fine weather, +with a stiff breeze from the northward. The greater violence of storms +in those regions where the magnetic intensity is greater in the same +latitude, the probable connection of peculiarities in the electric state +of the atmosphere with earthquakes, and the indications of the latter +afforded by the magnet; the preponderance of westerly winds at a great +elevation in every latitude on the globe visited by man; and the +frequent superposition of warm layers of air above cold ones at those +elevations, are all facts worthy of note. And the connection of cirrus +clouds with storms, as well as with the aurora, indicates that the +producing cause is external to the atmosphere, and gradually penetrates +below. The theory fully explains this, and is confirmed by the fantastic +wreathings and rapid formation of these clouds in straight lines of a +hundred miles and upwards. But time would fail us in pointing out a +tithe of the phenomena, traceable to the same cause, which keeps our +atmosphere in a perpetual state of change, and we shall only advert to +one more peculiarity of the theory. It places meteorology on a +mathematical basis, and explains why it is that a storm may be raging at +one place, while in another, not very remote, the weather may be fine, +and yet be dependent on the position of the moon. + +That the moon has exerted an influence on the weather has been the +popular creed from time immemorial; but, ignorant of the mode in which +this influence was exerted, men have often been found who have fostered +the popular belief for their own vanity or advantage; and, on the other +hand, philosophers have assailed it more by ridicule than by argument, +as a relic of a barbarian age. Not so with all; for we believe we are +not wrong in stating, that the celebrated Olbers compared the moon's +positions with the weather for fifty years, before he gave his verdict +against it. He found the average amount of rain at the perigee about +equal to the amount at the apogee, as much at the full as at the change, +and no difference at the quadratures. But this fact does not throw a +feather in the scale by which this theory is weighed. Popular opinions, +of remote origin, have almost always some foundation in fact, and it is +not much more wise to reject them, than to receive them. The Baron Von +Humboldt--a man possessing that rare ingredient of learning, a practical +common sense--observes: "That arrogant spirit of incredulity which +rejects facts, without attempting to investigate them, is, in some +cases, more injurious than an unquestioning credulity."[22] If a popular +belief or prejudice be absurd, its traditional preservation for a +thousand years or more may very well account for the absurdity. + +The present system of astronomy still retains the motley garniture of +the celestial sphere, as handed down from the most remote antiquity; and +granting that ages of ignorance and superstition have involved the +history of the different constellations in a chaos of contradictory +traditions, there is no doubt at the foundation some seeds of truth +which may even yet emerge from the rubbish of fable, and bear fruit most +precious. That the zodial[23] signs are significant records of something +worthy of being preserved, is prejudice to deny; and we must be allowed +to regard the Gorgons and Hydras of the skies as interesting problems +yet unsolved, as well as to consider that the belief in lunar influence +is a fragment of a true system of natural philosophy which has become +more and more debased in postdiluvian times. Amongst those who have not +summarily ignored the influence of the moon, is Toaldo, a Spanish +physicist, who endeavored to show the connection between the recurrence +of warm and cold seasons, and the semi-revolution of the lunar nodes and +apogee, and proposed six of those periods, or about fifty-four years, as +the cycle in which the changes of the weather would run through their +course. According to the present theory, it is not likely such a cycle +will ever be discovered. There are too many secular, as well as periodic +influences combining, to produce the effect; and the times are too +incommensurable. Lately, Mr.Glaisher has presented a paper to the Royal +Society, giving about fourteen years from observation. Others have +lately attempted to connect the changes of the seasons with the solar +spots, as well as with the variations of the magnetism of the earth, but +without any marked result. + +It may, however, be urged, that if the sidereal period of the moon be +approximately a cycle of change, it would have been detected long ago. +One reason why this has been so long concealed, is the high latitude of +the observers. Spain, Italy, and Turkey, are better situated than other +European countries; but the scientific nations lie further north; and +from these the law has gone forth to regulate more southern lands. In +the United States, particularly in the great plains of the west, the +weather can be better compared; not only on account of the latitude +being more favorable, but also on account of the greater magnetic +intensity of the western hemisphere. + +It must also be remembered that there are in latitude 40, five or six +distinct passages of the disturbing cause in one sidereal period of the +moon. If two of these periods are drawn closer together by the change of +the elements, the interval between two others must necessarily be +increased. Besides, the effect produced is not always the same, for +reasons already adverted to. One vortex may be more violent one month, +or for a few days in one month, while another may be more active the +next. It may also happen that for several successive passages, the +passage shall be central in one latitude, while two or three degrees +north or south, another place shall be passed by. In different months +and in different years, as well as in different seasons of the year, the +energy of the ether may be augmented or diminished. But it may be said, +that, supposing the theory true, if its indications are so uncertain, it +is of little value. By no means. It is true there are many things to be +inquired into; but it is a great thing in this science to be able to +take the first step in the right direction,--to find even the _key_ of +the portal. It is a great stride to be able to say, a storm may happen +at such a time, but cannot happen at another; that a storm, when raging, +will go in this direction, rather than in that; that it will be central +here, and less violent yonder; and when we consider its bearing on +astronomical and other science, it is difficult to exaggerate its value +to the world at large. + +Again, it may be said that rain, and cloudy days, and fresh breezes, and +even strong winds, sometimes occur, when the vortices do not pass +centrally. This is true; yet only indicating that where the vortices are +central, an unusual disturbance is taking place. But there is another +cause, which was purposely omitted in considering the prominent features +of the theory, in order not to encumber the question with secondary +influences. By referring to Fig.3, section1, we see that the lateral +vortices of the globe are continually passing off to the southward, in +the northern hemisphere, in a succession of dimples, and continually +reforming. We will now represent this mode of action in profile, as it +actually occurs in the illustration we have used. + +The vortex passing off from O, (Fig.20,) although it does not actually +reach the surface of the atmosphere, affects the equilibrium of the +ether, and, for a short distance from the parent vortex, may cause an +ascensional movement of the air. If to this is conjoined a northerly +wind from the vortex, a band of clouds will be produced, and perhaps +rain; but violent storms never occur in the intervals, except as a +steady gale, caused by the violence of a distant storm. Thus, it will +frequently be noticed that these vortices are flanked by bands of +clouds, which pass southward, although the individual clouds may be +moving eastward. Hence, instead of disproving the theory, they offer +strong evidence of its truth; and could we view the earth from the moon +with a telescope, we should no doubt see her beautifully belted. + +[Illustration: Fig. 20] + +But it may be again asked, why should not the weather be the same +generally, in the same latitude, if this theory be true? If the earth +were a globe of level land, or altogether of water, no doubt it would be +similar; but it must be remembered, that both land and water are very +unequally distributed: that the land is of varying extent and +elevation--here a vast plain, far removed from the ocean, and there a +mountain chain, interposing a barrier to the free course of the +atmospheric currents; sometimes penetrating in full width into the +frigid zone, and again dwindling to a few miles under the equator. One +very important distinction is also to be remarked, in the superficial +area of the different zones, reckoning from the equator, and taking the +hemisphere as 100 parts: + + Frigid zone 8 parts. + Temperate " 52 " + Torrid " 40 " + +For as the time of rotation in every latitude is the same, the area to +be disturbed in the same time, is less in high latitudes, and there a +greater similarity will obtain, _ceteris paribus_. In lower latitudes, +where both land and water stretch away for thousands of miles, it is not +wonderful that great differences should exist in the electrical and +hygrometric state of the air. + +The summer of many countries is always dry--California for instance. In +winter, in the same country, the rains are apparently incessant. This of +course depends on the power of the sun, in diverting the great annual +currents of the atmosphere. As long as the dry north-west trade sets +down the coast of California, the circumstances are not favorable for +giving full development to the action of the vortices. When the trade +wind ceases, and the prevailing winds come from the south, loaded with +vapor, the vortices produce storms of any magnitude; but (and we speak +from two years' observation) the passages of the vortices are as +distinctly marked there in winter time, as they are in the eastern +States; and in summer time, also, they are very perceptible. The same +remark applies to Mediterranean countries, particularly to Syria and +Asia Minor; although the author's opportunity for observing lasted only +from April to December, during one season. If we are told it never rains +on the coast of Peru, or in Upper Egypt, it does not seriously militate +against the theory. The cause is local, and the Samiel and the sand +storm of the desert, is but another phase of the question, explicable on +the same general principles. From the preceding remarks it will be seen, +that in order to foretell the character of particular days, a previous +knowledge of the weather at that particular place, and for some +considerable time, is requisite; and hence the difficulty of laying down +general rules, until the theory is more fully understood. + + +MODIFYING CAUSES. + +We now come to the causes which are auxiliary and interfering. It is +natural that we should regard the sun as the first and most influential +of these causes, as being the source of that variation in the +temperature of the globe, which alternately clothes the colder regions +in snow and verdure. The heat of the sun undoubtedly causes the ether of +the lower atmosphere to ascend, not by diminution of its specific +gravity; for it has no ponderosity; but precisely by increase of +tension, due to increase of motion. This aids the ascensional movement +of the air, and therefore, when a vortex is in conjunction with the sun, +its action is increased--the greatest effect being produced when the +vortex comes to the meridian a little before the sun. This has a +tendency to make the period of action to appear dependent on the phases +of the moon, which being the most palpable of all the moon's variations, +has been naturally regarded by mankind as the true _cause_ of the +changes of the weather. Thus Virgil in his Georgics, speaking of the +moon's influence and its signs: + + "Sin ortu in quarto (Namque is certissimus auctor) + Pura, nec obtusis per coelum cornibus ibit; + Totus et ille dies, et qui nascentur ab illo, + Exactum ad mensem, pluvi ventisque carebunt." + +Hence, also, in the present day we hear sailors speak of the full and +change, or the quartering of the moon, in connection with a gale at sea; +thus showing, at least, their faith in the influence of the phenomenon. +Yet it is actually the case, at certain times, that in about latitude +40 and 41, the storms appear about a week apart. + +There is some reason, also, to suspect, that there is a difference of +temperature on opposite sides of the sun. As the synodical rotation is +nearly identical with the siderent period of the moon, this would +require about forty-four years to run its course, so as to bring the +phenomena to exact coincidence again. Since these observations were +made, it is understood that Sig. Secchi has determined that the +equatorial regions of the sun are hotter than his polar regions. It may +be owing to this fact, that we have inferred a necessity for a change, +whose period is a multiple of the sun's synodical rotation, but it is +worthy of examination by those who possess the necessary conveniences. + +Another period which must influence the character of different years, +depends on the conjunction of the perigee of the lunar orbit with the +node. Taking the mean direct motion of the moon's perigee, and the mean +retrograde motion of the node, we find that it takes six years and one +day nearly from conjunction to conjunction. Now, from the principles +laid down, it follows, that when the perigee of the orbit is due north, +and the ascending node in Aries, that the vortices of the earth will +attain their greatest north latitude; and when these conditions are +reversed, the vortices will reach their highest limit in the lowest +latitude. This will materially affect the temperature of the polar +regions. In the following table, we have calculated the times of the +conjunctions of the apogee and pole of the orbit, taking the mean +motions. It may be convenient to refer to by-and-bye, remembering that +when the conjunction takes place due south, the vortices reach the +highest, but when due north, the vortices in the northern hemisphere +have their lowest upper limit: + + CONJUNCTION OF APOGEE AND POLE OF ORBIT.[24] + + Year. Month and Day. Longitude. + 1804, April 18th, 220 + 1810, " 17th, 104 + 1816, " 16th, 348 + 1822, " 15th, 232 + 1828, " 14th, 116 + 1834, " 12th, 360 + 1840, " 11th, 244 + 1846, " 10th, 128 + 1852, " 9th, 12 + 1858, " 8th, 255 + 1864, " 7th, 139 + 1870, " 6th, 23 + 1876, " 5th, 267 + +By this we see that the vortices have never attained their highest limit +during the present century, but that in 1858 their range will be in a +tolerable high latitude, and still higher in 1876--neglecting the +eccentricity of the orbit. + +A very potent influence is also due to the heliocentric longitude of the +sun, in determining the character of any given year. Let us explain: + +The moon's inertia forces the earth from the mechanical centre of the +terral system, but is never able to force her clear from the central +axis. With the sun it is different. He possesses many satellites +(planets). Jupiter alone, from his great mass and distance, is able to +displace the whole body of the sun. If other planets conspire at the +same side, the centre of the sun may be displaced a million of miles +from the mechanical centre of the solar system. Considering this centre, +therefore, as the centre of an imaginary sun, from which heliocentric +longitudes are reckoned, the longitude of the real sun will vary with +the positions of the great planets of the system. Now, although this +_systematic_ longitude will not be exactly similar to the heliocentric +longitude reckoned from the sun's centre, yet, for the purposes +intended, it will correspond sufficiently, and we shall speak of the +longitude of the sun as if we reckoned heliocentric longitudes from the +mechanical centre of the system. When we come to consider the solar +spots, we shall enter into this more fully. In the following diagram we +shall be able to perceive a cause for variation of seasons in a given +year, as well as for the general character of that year. + +[Illustration: Fig. 21] + +Let S represent the centre of the sun, and the circle a vertical section +of the sun, cutting; through the centre,--SJ being in the equatorial +plane of the vortex, of which ZZ' represents the axis. As the ether +descends the poles or axis at Z, it is met by the current down the +opposite pole, and is thence deflected in radii along the equatorial +plane to J. But on the side S, the ether is opposed by the body of the +sun; its direction is consequently changed, and cross currents are +produced, assuming it as a principle, that the ethereal fluid is +permeable by other currents of similar matter, and that it tends always +to move in right lines. This granted, it is evident that, in passing the +sun, the quick moving ether forms a conical shell, (the sun being at the +apex,) so that the strongest current of ether is in this conical shell, +or at the surface of this conical space. As the plane of the ecliptic is +not much inclined to the sun's equator, and this last probably not much +inclined to the plane of the vortex, should the earth have the same +_heliocentric_ longitude at the time, (or nearly the same,) she would +be in an eddy, as respects the radial stream, and be protected from its +full force by the body of the sun. + +Now, the ether comes down the axis with the temperature of space, and +may possibly derive a _little_ additional temperature in passing over +the body of the sun; so that in this position the earth is protected +from the chilling influence of the radial stream, by being protected by +the body of the sun. And although, from the immense velocity of the +ether, it cannot derive much additional temperature, there may still be +an appreciable difference, due to this cause. + +It is the chilling influence of the ethereal stream which originated the +idea among philosophers, of _frigorific impressions, darted from a clear +sky_. In some years the sun will be nearly in the centre of the system; +in other years the axis of the vortex will not come near the sun. And as +the sun's longitude may vary through the entire circle, it may happen +that the earth's longitude shall coincide in winter or summer, or spring +or autumn. When, however, the earth emerges from the protection of the +sun, and enters the conical shell, considered as a space of considerable +depth, she will again be exposed to the full force of the radial stream, +rendered more active by the previous deflection, and by the numerous +cross currents pervading it; so that a mild and calm winter may be +succeeded by a cold and stormy spring. The present season, (1853) the +earth's longitude coincided with the sun's longitude in about 135, and +consequently was in the conical space spoken of, during February and +March; but the radius vector of the sun's centre, being then less +than 300,000 miles, the protection was not as complete as it is +sometimes. Still, the general fineness of these months was remarkable; +yet in April and May, when the earth became again exposed to the action +of the solar stream, the effect was to retard the spring, and disappoint +the prognostications of the weather-wise. In applying these principles, +we must consider the effect in those latitudes which are more readily +affected,--that is, in the temperate zone, midway between the two +extreme zones of heat and cold. + +In 1837 and 1838, the longitude of the sun's centre corresponded with +the earth's, in August and September, when there was neither rain nor +electrical excitement; and consequently those seasons were sickly over +the whole country. Now, there is another cause which renders the months +of August, September, and October, deficient in electrical energy, and +consequently more prone to be sickly. If, therefore, the two causes +unite their influence, the autumnal months will be more sickly at those +times. This last cause, however, only affects the _northern latitudes_ +in autumn, and consequently, _ceteris paribus_, the autumnal months +should not be so proverbially sickly in the southern hemisphere. This +is, however, only suggestive. + +Again, in 1843, the winter was very mild in January and February; but in +March it turned cold and stormy, and continued through April. In this +year the longitude of the sun was nearly the same as in 1853,--the two +longitudes of the earth and sun corresponding about the last of January; +but in March, the earth forsook the comparative calm produced by the +sun's position, and hence the greater cold.[25] + +Thus it appears at every step we take, that the different members of the +solar system do indeed belong to the same family, whose least motions +have their influence on the rest. Who could have anticipated that the +position of Jupiter in his orbit had anything to do with the health of +this remote planet, or with the mildness of its seasons? In this we have +a clue to the origin of that astrological jargon about planetary aspects +being propitious or malign. Philosophers are even yet too prone to wrap +themselves in their mantle of academic lore, and despise the knowledge +of the ancients, while there is reason to believe that the world once +possessed a true insight into the structure of the solar system. As war +became the occupation of mankind, under the despotic rule of ambition, +so truth retired, and ignorance seizing upon her treasures, has so +mutilated and defaced them, that their original beauty no longer +appears. Let us hope that the dawn of a better day is approaching. + +There is yet another cause (just alluded to) which modifies the action +of the vortices. + +We have shown that, if the periodic times of the planets are +approximately equal to the periodic times of the contiguous parts of the +solar vortex, the density of the ether is directly as the square roots +of the distances from the centre. As the earth is at her perihelion +about the first of January, the density of the surrounding ether is then +less than in other parts of the orbit; consequently, if we suppose that +there is a continual tendency to equilibrium, the ether of space must +press inwards, during the time between the perihelion and aphelion, +(_i.e._ from January to July,) lowering the temperature and increasing +the electrical action of those months. As the distance from the sun is +most rapidly augmenting about the first of April, and the effective +power of the sun's radiation is most rapidly increasing in May; by +combining the two we shall find, that about the first of May we shall +have considerable electrical action, and cold weather. This explains +also, in part, the prevalent tradition of certain days in May being very +cold.[26] When the earth leaves the aphelion, a reaction takes place, +being most rapid in September. There is then an _escape_ of ether from +the earth, which keeps up the temperature, and causes these months to be +sickly, from the negative electrical state of the atmosphere. In the +southern hemisphere, the effects in the same season will be reversed, +which may partly account for the greater degree of cold in that +hemisphere, and for accelerating the approach of both summer and winter, +while in the north they were both retarded. + +We must now advert to another cause, which of all others is probably the +most important, at least to the other members of the solar system. + +In every part of the solar vortex the ether is continually pressing +outwards. We are not now speaking of the radial stream, but of the +slower spiral motion of the ether around the axis of the vortex, whose +centrifugal force is bearing the whole body of the ether outwards, thus +rarefying the central parts, and thus giving rise to the polar influx, +from which arises the radial stream. This may be made more intelligible, +by reflecting that the polar current is comparatively dense ether, and +that the length of the axis of the vortex prevents this influx current +coming in sufficient quantities to restore an equilibrium in the density +of the medium. Yet, what does come down the poles, is distributed +rapidly along the equatorial plane, leaving the space still rarefied. +Now we perceive, that in order for the radial stream to continue in +action, requires the whole medium of the vortex to be also moving +outward; it is therefore continually condensed as it proceeds. This +condensation necessarily converts much of the specific heat of the ether +into sensible heat; so that the _temperature_ of the medium is +continually increasing, as the distance from the sun increases. + +When we contemplate the solar system as the emanation of one Great Mind, +we naturally seek for evidence of the wisdom of a supreme intelligence +in _all_ the arrangements of that system. But, however humbly and +reverently we may speak of these arrangements, we can scarcely avoid the +wish, that the planetary distances had been differently arranged, if +Newton's doctrine be true, that space is a vacuum, and that the heat of +a planet, is inversely as the squares of the distances from the sun. +For, to speak of the temperature of space, except as dependent on this +law, is one of those many incomprehensible inconsistencies with which +philosophers are chargeable. If the Newtonian philosophy is literally +true, space has _no temperature_, and the surface heat of the planet +Neptune is nearly 1,000 times less than on our own globe. Again, on +Mercury it is seven times greater, which heat would scorch and consume +every organic substance on the earth, and speedily envelope the boiling +ocean in a shroud of impermeable vapor. Granting even that space may not +be a vacuum, and yet the law of gravitation be true, we may still be +allowed to consider both Saturn and Uranus and Neptune, as inhospitable +abodes for intelligent creatures; and, seeing the immensity of room in +the system, there is no reason why these planets might not have been +permitted to revolve nearer the great source of light and life and +cheering emanations. To suggest the resources of Omnipotence is no +argument. He has surrounded us with analogies which are seen, by which +we may attain a knowledge of those which are not seen; and we have every +reason to suppose that the great Author of nature is not indifferent to +the aspects under which his works reveal him unto his creatures. Yet +there is (on the above hypothesis) an apparent want of harmony in the +planetary distances; and if frail mortality may be permitted to speak +out, an explanation is needed to obviate this seeming anomaly in the +economy of the world. The more we learn of the physical arrangements of +the universe, the more do they correspond with our experience of the +nice adaptation of the means to the end which obtains in our own globe, +and we can only judge of other planets by the analogies around us. Here, +there, are extremes of temperature it is true: it is necessary there +should be, and we can see and understand the necessity in all such +cases, and how they conduce to the general average of good. But, +astronomers can give no reason why it is necessary that some planets of +our system should be placed so remote that the sun is frittered down to +a star, whose heatless light is but a mockery to those frigid realms. + +Now, according to this theory, the temperature of Neptune may be far +more uniform and conducive to life than that of our own globe. The +chilling influence of the solar stream at that planet being nearly null, +and the temperature of the surrounding space far greater. So also +Mercury, instead of being the burning planet of the schools, may suffer +the most from cold. + +The planet Mars is generally considered, of all the members of the +system, most nearly to resemble our own world. The telescope not only +reveals seas and continents, but the snowy circles round his poles, +which appear to increase and diminish, as his winter is beginning or +ending. This planet's ecliptic is similar to our own in inclination or +obliquity, his distance, also, is far greater, and his winter longer; +yet, for all this, his snow zones are less than on our own globe. This +anomalous fact has, we believe, never been noticed before; but it is +explicable on the theory, and therefore confirms it. Mars has no +satellite, and therefore his centre will be coincident with the centre +of the marsial vortex. There will be no _lateral vortices_ to derange +his atmosphere, and if the axis of his vortex coincides also with the +axis of the planet, the central vortex will be continually over the +poles, _and there will be no storms on the planet Mars_. A capital fact +connected with this, is the want of belts, as in Jupiter and Saturn; for +these planets have satellites, and if _they_ are not massive enough, the +belts may be produced by an obliquity in the axis of the Jovial and +Saturnial vortices. If Mars had an aurora like the earth, it is fair to +presume the telescope would ere this have shown it. He is, therefore, in +equilibrium. In applying this reasoning to the earth, we perceive that a +certain influence is due to the difference of temperature of the +ethereal medium surrounding the earth, at perihelion and aphelion, being +least at the former, and greatest at the latter. + +As a modifying and interfering cause in the action of the vortices, we +must mention the great natural currents of the atmosphere, due to the +earth's rotation. + +It is considered that the sun is the principal cause of these great +currents. By elevating the surface atmosphere of the equator, a lateral +current is induced from the north and south; but on account of the +enlarging circles of latitude, their direction tends more from the +north-east and south-east. These currents are usually called the trades. +Without disputing the correctness of this, it may be doubted whether the +whole effect is due to the sun. As this principle affects the ocean +likewise, it is necessary to look into it; and in order to simplify the +question, we will first suppose our globe covered entirely by the ocean, +without any protuberant land. + +Let us assign a uniform depth of ten miles to this ocean. In the Fig. +following, the two circles will represent the surface and bottom of the +ocean respectively. The axis of rotation is thus represented by the line +PP'. Let us consider two particles of water at m and n, as feeling the +influence of this rotation; they will, of course, be both urged towards +the equator by the axifugal force. Now, every particle in the ocean +being also urged by the same force, it might be supposed that after a +protuberant mass of water had accumulated at the equator EE', the whole +ocean would be in equilibrium. This would not follow. The particle at m +is urged by a greater force than n; consequently the particle at n is +overborne by the pressure at m. Considering both in the same direction, +yet the particle at n must give way, and move in the opposite direction. +Just as the heaviest scale of the balance bears up the lightest, +although both gravitate towards the same point. This is so self-evident +that it would seem unnecessary to dwell upon it, had not the scientific +world decided that the rotation of the earth can cause no currents +either in the atmosphere or in the ocean. + +[Illustration: Fig. 22] + +The axifugal forces of the two particles m and n are directly as the +lines Mm and Nn, and if the gravitating forces were also as the radii Tm +and Tn, no motion would be produced. Admitting even the Newtonian law to +be rigidly exact, the earth cannot be considered a homogeneous globe, +but, on the contrary, the density of the central parts must be nearly +thirty times greater than the density of the surface of the ocean. The +ratio of the gravitating forces of these two particles is, therefore, +less than the ratio of their respective radii, and the axifugal tendency +of the particle at n is more than proportionally restrained by the +central gravitation; and hence m will move towards the equator, and n +towards the poles, as represented in the Fig. + +It is on account of the overwhelming momentum of the surface waters of +the South Pacific over the North, that the Pacific, at Panama, stands +six or seven feet higher than the Atlantic. We shall again allude to +this interesting fact. + +According to newspaper reports of a lecture, delivered in New York, by +Lieut. Maury, U.S.N., this gentleman endeavors to explain the currents +of the ocean, by referring them to evaporation in the tropics. The vapor +leaves the salt of the water behind, and thus, by continual +accumulation, the specific gravity of the tropical waters is greater +than that of the superficial waters nearer the poles; the lighter +water, therefore, passes towards the equator, and the heavier water +below, towards the poles. If this be a correct statement of that +gentleman's theory, fidelity to our standards compels us to question the +soundness of the conclusion. The mere fact of the surface water of the +ocean being lighter than that of the bottom, cannot on any known +principles of science cause any movement of the surface waters towards +the equator. When such an acute and practical physicist is driven, by +the palpability of the fact that the polar waters are continually +tending towards the equator, to seek the cause in the tropical +evaporation, it shows that the dogma, which teaches that rotation can +produce no motion, is unsound. + +Sir John Herschel, in speaking of the solar spots, says: "We may also +observe that the tranquillity of the sun's polar, as compared with his +equatorial regions (if his spots be really atmospheric), cannot be +accounted for by its rotation on its axis only, but must arise from some +cause external to the sun, as we see the belts of Jupiter and Saturn and +our trade winds arise from a cause external to these planets combining +itself with their rotations, which _alone_ (and he lays an emphasis on +the word) can produce no motions when once the form of equilibrium is +attained." + +With respect to the origin of the solar spots, we have no disposition to +question the conclusion; but, as regards the _principle_ laid down, that +rotation can produce no motions when once the form of equilibrium is +attained, we must unequivocally dispute it. If our atmosphere were of +uniform density, the rotation of the earth would cause no current such +as we have described; with our atmosphere as it is, the result will be +different. The momenta of two portions of matter are the products of +their inerti by their motions, and, in the present case, we must take +the inerti of equal spaces. A cubic inch of air at the surface, and at +three miles above the surface, is as 2 to 1; but their centrifugal +velocity varies only as the radii of the respective spheres, or as 1320 +to 1321. In the polar regions, therefore, the momentum of the surface +air preponderates, and, in this case, the _surface_ current is towards +the equator, and the upper current towards the poles. When, however, the +centrifugal velocity is considerably increased in a lower latitude, and +the curvature of the surface becomes more and more inclined to the +direction of that resolved part of the centrifugal force, which is +always _from_ the axis, the surface layers will evince a tendency to +leave the surface, and an intermingling will then take place in the +space between latitude 70 and 50, or in latitude 60. As this layer is +continually urged on in the same direction by the surface layer of +latitudes above 60, the upper layer now becomes a current setting +_towards_ the equator, and, consequently, the back current occupies the +surface. Now, considering that the rarefying action of the sun is +elevating the air under the equator, there must necessarily be an upper +current from the equator to the poles; so that if we conceive the two +currents to meet about latitude 30, there will be a second +intermingling, and the current from the poles will again occupy the +surface. Thus, we regard a part of the effect of the trades to the +rotation of the earth, which is the chief impelling power at the poles, +as the sun is at the equator; and the latitudes 60 and 30 will be +marked by some especial phenomena of temperature, and other +meteorological features which do actually obtain. These would be much +more marked if the irregular configuration of land and sea, the +existence of mountain chains, and the different heating power of +different latitudes, owing to the unequal distribution of the land, did +not interfere; and the currents of the air (disregarding the deflection +east and west) might then be represented by a treble link or loop, whose +nodes would vary but little from latitudes 30 and 60. As it is, it +has, no doubt, its influence, although unimportant, when compared with +the disturbing action of the ethereal vortices. + +There is another phenomenon due to the action of the radial stream, +which has given much trouble to the physicist, and which has yet never +been explained. This is the horary oscillations of the atmospheric +pressure which, in some countries are so regular that the time of day +may be ascertained by the height of the barometer. According to +Humboldt, the regularity of the ebb and flow in the torrid regions of +America, is undisturbed by storms or earthquake. It is supposed that the +maxima occur at 9A.M. and 10P.M., and the minima at 4 A.M. and +4P.M. From the morning minimum to the morning maximum is, +therefore, five hours; from the evening minimum to the evening maximum +is 6 hours; from the evening maximum to the morning minimum is 5 +hours, and from the morning maximum to the evening minimum is 7 +hours. Again, these oscillations are greatest at the equator, and +diminish with the increase of latitude. + +[Illustration: Fig. 23] + +If we suppose the earth's axis perpendicular to the plane of the vortex, +and P the pole in the above figure, and SP the line joining the centre +of the earth and sun, M and m will represent the points in the earth's +equator where it is midday and midnight respectively. The solar stream +penetrates the terral vortex; and strikes the earth's atmosphere along +the lines parallel to SP. The direct effect would be to pile up the +atmosphere at N and n; and therefore, were the earth at rest, the +maximum would be at 6A.M. and 6P.M., and the minimum at midday and +midnight; but the earth rotating from N towards M, carries along the +accumulated atmosphere, being more sluggish in its motions than the +producing cause, which cause is still exercised to force it back to N. +From this cause the maximum is now found at K. For a like reason the +minimum at M would be found at L, but on account of the motion of the +earth being now in the same direction as the solar stream, the minimum +is found still more in advance at k; so that, according to the theory, +the interval between the morning maximum and the evening maximum, should +be greater than the interval between the evening maximum and the morning +maximum; and so it is, the first being 13 hours and the last 10 +hours. The morning minimum should also be less marked than the evening +minimum, and this also is a fact. The effect also should be greater in +the tropics than in high latitudes, which again also obtains; being 1.32 +French lines at the equator, and only 0.18 at latitude 70. Had the +earth no obliquity, the effect would be as the squares of the cosines of +the latitude; but the ratio is diminished by the inclination of the +axis. But there are other variations of the barometer of longer period, +apparently depending on the phases of the moon, but which cannot be +reconciled to the attracting power of the moon as an atmospheric tide; +and Arago concluded that they were due to some _special cause_, of which +the nature and mode of action are unknown. Perhaps this theory will +obviate the difficulty, as although the central vortex comes to the +meridian at the same time as the moon, its effect will be different on +the inferior meridian to what it is on the superior one; whereas the +moon's attraction should be the same on both. That the passage of a +vortex over or near a particular place should affect the barometer, is +too obvious to need explanation, and therefore we may say that the +theory will explain all those varieties both small and great, which have +caused so much speculation for the last fifty years. + + +TERRESTRIAL MAGNETISM. + +In applying the theory to the magnetism of the earth, we must bear in +mind that the earth is probably magnetic by induction, and not in virtue +of its own specific action. The rotation of the surrounding ether, and +the consequent production of a radial stream, calls the ether into +motion within the earth's interior, as well as on the surface; but it +does not follow that the ether shall also enter the earth at its poles +and escape at its equator, for the obliquity of the vortex would +interfere with this result. It is sufficient that this does occur in the +terral vortex immediately surrounding the earth. From late experiments +it is pretty well established that the axial direction of the needle, +(and of other bodies also,) is due to peculiar internal arrangement in +lamin or layers, the existence of which is favorable to the passage of +the magnetic current. + +According to the experiments[27] of Dr. Tyndal, it is found that the +magnetism of a body is strongest along the line of greatest density. As, +therefore, the lamin of bodies may be considered planes of pressure, +when these planes are suspended horizontally, the directive force is +greatest, and the longest diameter of the body sets axial. On the other +hand, when the body was suspended so that the lamin were vertical, the +longest diameter set equatorial. Now, we know that the crust of the +earth is composed of lamin, just as the piece of shale in Doctor +Tyndal's experiments, and that these layers are disposed horizontally. +And whatever force originally arranged the land and water on our globe, +it is evident that the continents are longest from north to south, and +therefore correspond to the natural direction of the magnetic force. + +In consequence of the intrinsic difficulties of this question, and the +mystery yet attaching to it, we may be permitted to enter a little more +minutely into it, and jointly consider other questions of interest, that +will enable us to refer the principal phenomena of terrestrial magnetism +to our theory. + +We have before adverted to the discrepancies in the earth's compression, +as determined by the pendulum, and also to the uncertainty of the moon's +mass, as deduced from the nutation of the earth's axis. It is also +suspected that the southern hemisphere is more compressed than the +northern; and other phenomena also point out the inadequacy of the law +of gravitation, to account for the figure of the earth. + +From the invariability of the axis of rotation, we must conclude that +whatever form is the true form, it is one of equilibrium. In casting our +eyes over the map of the world, we perceive that the surface is very +unequally divided into land and sea; and that the land is very unequally +arranged, both north and south, and east and west. If we compare the +northern and southern hemisphere, we find the land to the water about 3 +to 1. If we take the Pacific portion, and consider the north end of New +Zealand as a centre, we can describe a great circle taking in one half +the globe, which shall not include one-tenth of the whole land. Yet the +average height of the remaining nine-tenths, above the level of the sea, +is nearly 1,000 feet. Call this nine-tenths nearly equal to one-fourth +of the whole surface, and the protuberant land in the hemisphere, +opposite the South Pacific, amounts to 1/30,000 part of the whole mass +of the earth, or about 1/700 of the mass of the moon. Again, the mean +density of the earth is about 5--water being unity,--and the mean +density of the surface land is only about half this: but three-fourths +of the whole surface is water. Hence, we see that the materials of the +interior of the earth must be either metallic or very compressible. To +assign a metallic nucleus to the earth, is repugnant to analogy; and it +is not rendered even probable by facts, as we find volcanic emissions to +contain no heavier elements than the sedimentary layers. Besides, there +are indications of a gradual increase of density downwards, such as +would arise from the compressibility of the layers. Seeing, therefore, +the equilibrium of the whole mass, and the consequent hydrostatic +balance of the land in the sea,--seeing also the small compressibility +of the solid portions, and the great compressibility of the fluid, the +inference is legitimate that the whole is hydrostatically balanced, and +that our globe is a globe of water, with an intermediate shell of land, +specifically lighter than the fluid in which it is suspended. Where this +shell is of great thickness, it penetrates to greater depths, and +attains to greater elevations above the surface of the aqueous globe; +where it is less thick, it is found below the surface, and forms the +bottom of the upper ocean. Recent soundings give much greater depths to +some parts of the ocean, than the most elevated land upon the globe. +Captain Denham, of H.B.M. ship Herald, lately sounded in 37 south and +37 west, and found bottom at 7,706 fathoms, or about nine English +miles. + +As the interior portions of our globe are totally unknown, and the +compressibility of water is well established, it is just as sane to +consider water the most abundant element of nature, as solid land. The +great question to ask is, whether there may not be other phenomena +incompatible with this supposition? It is plain that the permanency of +terrestrial latitudes and longitudes would be unaffected by the +conditions we have supposed. Would the precession of the equinoxes be +also unaffected? Mr. Hopkins has entered into such an investigation, and +concludes: "Upon the whole, then, we may venture to assert that the +minimum thickness of the crust of the globe, which can be deemed +consistent with the observed amount of precession, cannot be less than +one-fourth or one-fifth of the radius of the earth." These +investigations were made on the hypothesis of the interior fluidity +being caused by the fusion of the central portions of a solid globe; but +it is evident that the analytical result would be the same if these +central parts were water, inclosed by an irregularly-spherical shell of +land. Nor would the result be affected, if we considered certain +portions of the interior of this solid shell to be in a state of fusion, +as no doubt is the case. + +May not the uncertainty of the mass of the moon, be owing to the fact +that this shell is not so rigidly compacted but that it may yield a +little to external force, and thus also account for the tides in the +Pacific groups, rather obeying the centrifugal force due to the orbit +velocity of the earth, than the attraction of the moon? + +Since the days of Hipparchus the sidereal day has not diminished by the +hundredth part of a second; and, consequently, seeing that the +contraction of the mass must be limited by the time of rotation, it is +inferred that the earth has not lost 1/508th of one degree of heat since +that time. This conclusion, sound as it is, is scarcely credible, when +we reflect on the constant radiation into a space 60 below zero. Admit +that the globe is a globe of water, whose average temperature is the +temperature it receives from the sun, and the difficulty vanishes at +once. Its diameter will be invariable, and the only effect of the +cooling of the solid parts will be to immerse them deeper in the water, +to change the _relative_ level of the sea without changing its volume. +This is no puerile argument when rightly considered; but there is +another phenomenon which, if fairly weighed, will also conduct us to the +same views. + +It is now a fact uncontroverted, that the sea does actually change its +level, or rather, that the elevation of continents is not only apparent +but real. The whole coast of Sweden and Finland is rising at the present +day at the rate of four feet in a century, while on the south a contrary +effect is produced. Various hypotheses have been formed concerning this +interesting fact. Yet from the indications of geology, it must have been +an universal phenomenon in the early ages of the world, in order to +account for the emersion of sedimentary deposits from the fluid which +deposited them. May not internal fires be yet spreading, and the +continents expanding instead of contracting? And may there not be an +inequality in this process, so as necessarily to immerse in one +direction nearly as much as to elevate in another? One fact is certain, +the elements are scattering the materials of the land along its Oceanic +coasts, which of itself must produce a very minute effect in disturbing +the hydrostatic balance; but a more efficient agent is the earthquake +and volcano. + +The upheaving of tracts of land by earthquakes, as on the coast of Chili +would thus be satisfactorily explained, by attributing a certain +resistance due to cohesion or friction preventing a _gradual_ change of +level, but producing it suddenly by the jar of the earthquakes. May we +not inquire also, whether the facility with which the earth seems moved +by this destructive agent, does not point to the same solution as the +irregularity of the figure of the earth? + +This is a subject on which it is allowable to speculate, especially if +any light can be thereby thrown on the still more mysterious source of +terrestrial magnetism. It is for such a purpose that we have permitted +ourselves to digress from that subject. In this connection we also may +acknowledge our indebtedness to the sacred volume for the first germ of +this theory of the weather. + +Believing in the authenticity of the Mosaic history of the deluge, the +author found it difficult to refer that event to other than natural +causes, called into action by the operation of other causes, and all +simultaneous with the going forth of the fiat of Omnipotence. Thus +reasoning, he was led to regard the deluge as a physical phenomenon +inviting solution, and as a promising exponent to the climatology of +the early world. He looked upon the bow of promise, as the autograph of +the Creator, the signature to a solemn bond, upon which the eye of man +had never before rested. But if there was no rainbow before the deluge, +there was no rain; and following up this clue, he was not only enabled +to solve the problem, but also led to the true cause, which produces the +principal commotions in our atmosphere. + +Science boasts of being the handmaid of religion; yet there are names of +note in her ranks who have labored rather to invest this phenomenon with +the mantle of fable, and to force it into collision with the records +graven on the rocky pages of geognosy. But the world is ever prone to be +captivated by the brilliancy of misapplied talents, instead of weighing +merit by its zeal in reconciling the teachings of those things which are +seen, with those which are revealed. + +If our globe be constituted as we suppose, the land might experience +repeated submersions, without involving the necessity of any great +departure from established laws. And we might refer to the historical +record of one of these, with all the minute particulars as positive +data, imposing on us the necessity of admitting that the solid parts of +the globe are hydrostatically balanced in the sea. But, modern science +is not always correctly defined when called the pursuit of truth, nor +human learning the means of discovering it. + +If we could divest ourselves of this prejudice, we should have a ready +solution of the difficulty presented by the earth having two north +magnetic poles, and probably two also in the south. For, by regarding +the old and new continents as two distinct masses of land whose bases +are separated by 6,000 miles of water, we recognize two great magnets, +dependent, however, for their magnetism, on the rotation of the terral +vortex. + +This is no place to enter into a lengthy discussion of such a difficult +subject as magnetism, but we may be allowed to enter a protest against +the current theory of electro-magnetism, viz.: that a force is generated +by a galvanic current at right angles to the producing cause, which is +contrary to the fundamental principles of mechanics. We may conceive +that a current is induced from or to the surrounding space by the +rarefaction or condensation attending the transmission of such a current +along a wire, and that rotation should follow, just as a bent pipe full +of small holes at the lower end, and immersed in water as a syphon, will +generate a vorticose motion in the water; but mere juxtaposition, +without participation and communication with the general current, is +irrational, and, therefore, not true. + +We have always regarded a magnetic needle as a part of the great natural +magnet, the earth; that its north pole actually points to the north, and +its south pole to the south; and, being free to move, it is affected by +the circular motion of the surrounding ether, and by every motion by +which the ether is directed. If there was any attraction between the +earth and the needle, opposite poles would be presented, but it is not +so--the force is merely directive. + + +MAGNETIC VARIATIONS. + +Let us now see whether we cannot assign an adequate cause for the +secular and periodic variations in the inclination and declination of +the needle. These have been generally referred to changes of +temperature, as in fact, also, the magnetism of the earth is sometimes +ascribed to galvanic or electric currents, called forth by a daily +change of temperature. Our theory gives a totally different explanation +of these variations. + +In the northern hemisphere, the north point of the needle moves from +east to west in the morning from about 8A.M. to 1P.M., and +returns to its mean position about 10P.M. It then passes over to the +east, and again returns to its mean position about 8 or 9A.M. The +analogy of this motion, with the horary changes in the barometer, +indicate a common origin. Humboldt, in the instructions he drew up for +the Antarctic Expedition under Sir James Ross, says: "The phenomena +of periodical variations depend manifestly on the action of _solar +heat_, operating probably through the medium of thermo electric currents +induced on the earth's surface. Beyond this rude guess, however, +_nothing is yet known of their physical cause_. It is even still a +matter of speculation whether the solar influence be a principal or only +a subordinate cause." That the sun may exert a modifying influence on +the phenomenon is not unlikely, but that he cannot be the principal +cause, is evident from the following considerations. These horary +variations of the magnetic needle are as great at the bottom of deep +mines far removed from solar influence, as on the surface. They are as +great, _ceteris paribus_ on a small island in the midst of the ocean, as +in the interior of continents, where the heating power of the surface is +vastly greater. They are extremely regular, so that between the tropics, +according to the sagacious Humboldt, "the time of the day may be known +by the direction of the needle, as well as by the height of the +barometer." + +But what is the cause of these variations? This question is the most +difficult of all physical problems, and we shall only aim at indicating +the causes which are yet perhaps too intricately involved to afford a +positive numerical determination. Admitting the existence of two +principal solid masses whose general direction is from south to north, +and that these masses are more susceptible of permeation by the ethereal +fluid than the waters in which they are suspended, we have a general +solution of the position of the magnetic poles, and of the isogonic, +isoclinic, and isodynamic lines. Considering, too, that the southern +poles of these masses are the points of ingress, and the northern poles +the points of egress, it is easily understood that the ethereal medium +having the temperature of space, will cause the southern hemisphere to +be colder than the northern, and also that the magnetic poles will be +the poles of maximum cold, and the centres respected by the isothermal +and isogeothermal lines. + +The general direction of the magnetism of the earth may be considered as +the controlling influence, therefore, in determining the position of the +magnetic needle; but there are other causes which, to some extent, will +modify the result. That half of the globe turned away from the sun will +partake of the density of the ether at that distance, which is greater +than on the side next the sun; the magnetic intensity ought, therefore, +to be greater in the night than in the day. The poles of the great +terrestrial magnets, or even the position of a magnetic needle on the +surface, are continually placed by the earth's rotation in a different +relation to the axes of the terral vortex, and the tangential current, +which is continually circulating around the globe, has its inclination +to a given meridian in a perpetual state of change. If we conceive that +there is a tendency to force the needle at right angles to this current, +we shall have an influence which varies during the day, during the year, +and during the time occupied by a complete revolution of the node. The +principal effect, however, of the horary variation of the needle is due +to the radial stream of the sun, which not only penetrates the +atmosphere, but also the solid crust of the earth. Its principal +influence is, however, an indirect influence, as we shall endeavor to +explain. + +No fact in the science of electro-magnetism is, perhaps, better +established than the disposition of an ethereal current to place itself +at right angles to the magnetic meridian, and conversely, when the +current is not free to move, to place the needle at right angles to the +current. Now, the terrestrial magnet or magnets, may be considered to be +surrounded by a body of ether in rotation, which, in the earth, on its +surface, and for some distance from the surface, is made to conform to +the general rule, that is, to circulate at right angles to the magnetic +meridian. Outside this again, the ether more and more conforms to the +position of the axis of the vortex, and this position varying, it must +exert _some_ influence on the surface currents, and, therefore, change +in some degree the position of the magnetic meridian. The radial stream +comes from the sun in parallel lines, and strikes the globe and its +superficial ethereal envelope just as we have shown its action on the +atmosphere; but in this last case the magnetic equator is not a great +circle, neither can we suppose its effects to be an accumulation of a +fluid which is imponderable at points 90 from the plane passing through +the centre of the earth and sun, and coincident with the plane of the +central meridian, and a depressing effect on that meridian. Its precise +influence must be, from the nature of the cause, to deflect the circular +current towards the poles, in places less than 90 from the meridian, +and a contrary effect must be produced in places greater than 90 from +the meridian. Let us assume, for argument's sake, that the magnetic +poles of the earth correspond to the poles of rotation, the parallels of +latitude will, therefore, represent the ethereal currents circulating +around the globe. Now, at sunrise, the radial stream of the solar vortex +is tangential to the surface, and, therefore, can produce no change in +these currents. As the sun ascends say about 8 or 9A.M., the radial +stream striking only the surface of the earth perpendicularly in that +place where the sun is vertical (which we will suppose at the equator), +streams off on every side, as the meridians do from the pole, and the +circles of latitude (that is the ethereal currents) being parallel to +the equator, they are met by the radial stream obliquely, and deflected +towards either pole. By this deflection they are no longer at right +angles to the meridians. But, from the principle of reaction above +noticed, the magnetic meridians will place themselves at right angles to +the current, or, in other words, the magnetic pole will change its +position on the surface of the earth with respect to that particular +place. But, in other parts of the world, the meridians are in opposite +phases at the same instant of absolute time; therefore, the magnetic +poles are not points, but wide areas enclosing the magnetic poles of all +the countries under the sun. As this conforms to observation, it is +worthy our especial attention, and may be understood by the subjoined +figure, in which the oblique curves represent the course of the +tangential current in the different positions of the sun, the parallel +lines representing the solar radial stream. + +[Illustration: Fig. 24] + +As the sun gains altitude the action of the radial stream is at a +greater and greater angle to the circular currents, and attains its +maximum at noon, still acting, however, after noon; but seeing that the +circular current possesses a force of re-action, that is, that the +magnetism of the earth is ever striving to bring these currents to their +natural direction, an hour or two after noon, the currents tend again to +the equator, and the maximum deflection is passed, and finally ceases a +few hours after sunset. Now let us attend to what is going on on the +opposite side of the world. The radial stream passing over the polar +regions, now produces a contrary effect; the ethereal atmosphere of the +great magnet is accumulated on the farthest side from the sun, by the +action of the radial stream passing over the polar region, the parallel +currents are now bent towards the equator, being at a maximum in places +where it is an hour or two past midnight. Before they were concave to +the equator, and now they are convex; the magnetic meridian is therefore +deflected the contrary way to what it was in the day time, by the same +principle of reaction. After the maximum, say at 4A.M., the deflection +gradually ceases, and the magnetic meridian returns to its mean position +at 8 or 9A.M. These times, however, of maximum and minimum, must vary +with the time of the year, or with the declination of the sun, with the +position of the moon in her orbit, with the perigee of the orbit, and +with the place of the ascending node; there are also minor influences +which have an effect, which present instrumental means cannot render +appreciable. + +What says observation? The needle declines from its mean position in the +whole northern hemisphere to the westward, from about 8.30A.M., until +1.30P.M.; it then gradually returns to its mean position by 10A.M. +After 10P.M., it passes over to the eastward, and attains its maximum +deflection about three or four hours after midnight, and is found again +at its mean position about 9A.M. Now, this is precisely the direction +of the deviation of the magnetic meridian, the needle therefore only +follows the meridian, or still continues to point to the temporary +magnetic pole. And although we have assumed, for the sake of simplicity, +that the mean magnetic pole corresponds to the pole of rotation; in +truth there are two magnetic poles, neither of which correspond; yet +still the general effect will be the same, although the numerical +verification will be rendered more difficult. + +In the southern hemisphere the effect is the reverse, (this southern +hemisphere, however, must be considered separated from the northern by +the magnetic equator, and not by the geographical one,) the needle +declines to the eastward in the morning, and goes through the same +changes, substituting east for west, and west for east. Does observation +decide this to be to be a fact also? Most decidedly it does; and this +alone may be considered a positive demonstration, that the theory which +explains it is true. The contrary deflection of the needle in the +northern and southern hemisphere may be formally proclaimed as utterly +beyond the reach of the common theory of magnetism to explain. This +difficulty arises from considering the needle as the disturbed body +instead of the earth; and also from the fact that the effect of solar +heat must be common to needles in both hemispheres, and act upon similar +poles, and consequently the deflection must be in the same direction. + +But a still more capital feature is presented by the discovery of +Colonel Sabine, that the deflection is in contrary directions at the +Cape of Good Hope, at the epoch of the two equinoxes. This arises from +the great angle made by the magnetic meridian at this place, with the +terrestrial meridian--the variation being by Barlow's tables, 30 to the +westward. The sun varies in declination 47 throughout the year. At the +southern solstice, therefore the radial stream strikes the circular +current on the southern side, and deflects it towards the equator, +rendering the declination to the westward in the morning; but at the +northern solstice the radial stream strikes the current on its northern +side, and the deflection is eastward in the morning. And the vicinity of +the Cape of Good Hope is, perhaps, the only part of the world where this +anomaly will obtain; as it is necessary not only that the declination +shall be considerable, but also that the latitude shall not be very +great. + +Observation also determines that the amount of the horary variation +increases with the latitude. Near the equator, according to Humboldt, it +scarcely amounts to three or four minutes, whilst it is from thirteen to +fourteen minutes in the middle of Europe. The theory explains this also; +for as the circles recede from the equator, the angles made by their +planes with the direction of the radial stream increases, and hence the +force of deflection is greater, and the effect is proportioned to the +cause. We have also a satisfactory explanation of the fact that there +has not yet been discovered a line of _no variation of horary +declination_ as we might reasonably anticipate from the fact that the +declinations are in _contrary directions_ in the northern and southern +hemisphere. This is owing to the ever-varying declination of the sun. +There would be such a line, no doubt, if the axis of the earth were +perpendicular to the plane of the orbit, and the magnetic pole coincided +with the pole of rotation: for then the equator would be such a line. + + +MAGNETIC STORMS. + +But there are also irregular fluctuations in the direction of the +magnetic needle. These depend on the moon, and are caused by the passage +of the vortices over or near to the place of observation. The action of +these vortices is proved to be of variable force, whether arising from +atmospheric conditions, or due to an increased activity of the ethereal +medium throughout the whole system, is at present immaterial. They do +vary, and sometimes the passage of a vortex will deflect the needle a +whole degree. At other times, there are magnetic storms extending over a +great part of the earth's surface; but there is reason to suppose, that +the extent of these storms has been over estimated. Thus, on the 25th of +September, 1841, a magnetic storm was observed in Toronto, and at the +same time there was one felt at the Cape of Good Hope. There is no great +mystery in this. If we suppose the axis of the central vortex, for +instance, to have passed Toronto in latitude 43 33' north, in ordinary +positions of the moon, in her orbit, the southern portion of the axis +would be in 33 or 34 south latitude, and consequently would have +passed near the Cape of Good Hope on the same night. Now, we certainly +could not expect the northern portion of the vortex to be intensely +active, without the southern portion being in the same state of +activity. That this is the true explanation is proved by magnetic storms +in the same hemisphere being comparatively limited in extent; as, +according to Gauss and Weber, magnetic storms which were simultaneously +felt from Sicily to Upsala, did not extend from Upsala to Alten. Still +it would not be wonderful if they were felt over a vast area of +thousands of miles as a consequence of _great_ disturbance in the +elasticity of the ether in the terral vortex; as the solid earth must be +permeable to all its motions, and thus be explicable on the general +principles we have advanced. + +But besides these variations which we have mentioned, there are changes +steadily going on, by which the isodynamic, isogonic and isoclinic lines +are permanently displaced on the surface of our planet. These must be +attributed to changes of temperature in the interior of the globe, and +to the direction in the progress of subterranean fires, which it may +also be expected will change the isogeothermal lines. But there are +changes, which although of long period, are yet periodic, one of which +is obviously due to the revolution of the lunar nodes in eighteen and a +half years, and the revolution of the apogee in nine years. The first is +continually changing the obliquity of the axis of the vortex, and they +both tend to limit the vortices in their extreme latitudes; but the +planet Jupiter has an indirect influence, which is probably equal, if +not greater, than the action of the moon, in changing the magnetic +declination. + +From the investigations of Lamont, it would appear, that the period of +the variations of magnetic declination is about 101/3 years, while, +more recently, R. Wolfe has suggested the connection between this +variation and the solar spots, and assigns a period of 11.11 years, and +remarks, that it "corresponds more exactly with the variations in +magnetic declination than the period of 101/3 years established by +Lamont. The magnetic variations accompany the solar spots, not only in +their regular changes, but even in their minor irregularities: this +latter fact is itself sufficient to prove definitely the important +relations between them."[28] + +As the planet Jupiter exerts the greatest influence on the sun, in +forcing the centre from the mechanical centre of the system, the +longitude of the sun will in a great measure depend on the position of +this planet; and, in consequence, the sun will generally revolve around +this centre in a period nearly equal to the period of Jupiter. The +sidereal period of Jupiter is about twelve years, but the action of the +other planets tend to shorten this period (at least, that has been the +effect for the last twenty or thirty years), and bring it nearly to the +period assigned by M. Wolfe to the variations in the magnetic +declinations. As this has its influence on the radial stream, and the +radial stream on the declination, we see at once the connection between +them. When we come to a consideration of the solar spots, we shall +exhibit this influence more fully. + + +AURORA BOREALIS. + +Let us now examine another phenomenon. The Aurora Borealis has been +generally considered to be in some way connected with the magnetism of +the earth, and with the position of the magnetic pole. It is certain +that the appearance of this meteor does affect the needle in a way not +to be mistaken, and (although not invariably) the vertex of the luminous +arch will usually conform to the magnetic meridian. Yet (and this is +worthy of attention), the observations made in the North Polar +Expeditions[29] "appear to prove, that in the immediate vicinity of the +magnetic pole the development of light is not in the least degree more +intense or frequent than at some distance from it." In fact, as the +American magnetic pole is, as stated, in latitude 73, the central +vortex will seldom reach so high, and, consequently, the aurora ought +at such times to be more frequent in a lower latitude. In a late work by +M. de la Rive, this gentleman expresses the opinion, that the cause of +the aurora is not due to a radiation of polar magnetism, but to a purely +electrical action.[30] His explanation, however, is not so satisfactory +as his opinion. Now, we have examined numerous cases of auroral +displays, and never yet found one which could not be legitimately +referred to the action of ethereal vortices. Generally, the aurora will +not be visible, when the upper surface of the atmosphere of that +latitude in which the vortex is known to be (reckoning in the direction +of the magnetic meridian) is below the horizon, which shows that the +brightest portion is in the atmosphere. In latitude 41 even, it may +show itself when the vortex is three days north, more frequently when +one or two days north; but when the vortex passes centrally, or south, +it rarely is seen, and this is the only difficulty in explaining it by +the theory. But, when we reflect that the ether shoots out in straight +lines, and at an angle corresponding to the magnetic dip, we are at no +loss to perceive the reason of this. If each minute line composing the +light were seen endwise, it would be invisible; if there were millions +such in the same position, they could add nothing to the general effect; +but, when viewed sideways, the case would be different, there would be a +continued reduplication of ray upon ray, until in the range of some +hundreds of miles an effect might be produced amounting to any degree of +intensity on record. Now, this is the case when the aurora is +immediately overhead, it will be invisible to those below, but may be +seen by persons a hundred miles south; so, also, when it is to the +south, it is too oblique to the line of vision to be seen, especially as +all the rays to the northward of the observer can contribute nothing to +increase the effect. That it is of the nature of rays very much +diffused, can hardly be doubted; and, therefore, if only of a few miles +in depth, its impressions are too faint to be sensible. By referring to +the record of the weather in the second section of this work, an auroral +display will be found on July 12th, the central vortex having passed a +little to the northward the same evening, and the next day passing south +_descending_. On that occasion the author saw an inclined column, in +profile, due east, and between himself and a line of bluffs and timber, +about eight miles distant; And, he has not any doubt that the mass of +rays began where he stood. As in a shower, every drop, passing through a +conical surface, whose axis passes through the sun and through the eye, +contributes to form the apparently distant rainbow. + +The altitude of this meteor has been much exaggerated, especially of +those rings or luminous arches, which are often detached completely from +the luminous bank. On the 24th of May, a bright aurora was visible at +Ottawa, but the author's attention was engrossed by the most brilliant +arch of light he had ever seen. It was all the time south of the zenith, +and had no visible connection with the aurora north. At 9 hours, 59 +minutes, 30 seconds mean solar time, Arcturus was in the exact centre of +the band, at which time it was very bright, and full 7 wide. At the +same time, Prof. G.W. Wheeler observed the aurora in Perryville, in the +State of Missouri, only 1 of longitude to the westward, but did not see +the arch.[31] The difference of latitude between the two places being 3 +30', and the weather, as he states, clear and still, there is only one +reason why he did not see the arch: it must have been too _low_, and had +become merged in the bank of light. At the time mentioned, the altitude +of Arcturus was 68 30', and, as Prof. Wheeler assigns only 10 as the +altitude of the bank, the maximum elevation of the arch, on the +supposition of its composing a part of the bank, was 43 miles. At +Perryville, the bank and streamers had disappeared at 10 o'clock. At +Ottawa, the arch or bow disappeared at 10h. 5m., differing only the +fraction of a minute from the time at Perryville; but, the bank was +still visible, but low and faint, the greatest altitude having been over +30. To show the rapid fluctuations in width and position of this bow, +we will add a few of the minutes taken at the time with great care, in +hopes some other observer had been equally precise. When first seen, +there were three luminous patches, or elongated clouds of light; one in +Leo, one in Bootes, and another in Ophinchus, all in line. This was +about 9h. 15m. The times following are correct to 30 seconds: + + 9h. 42m. 30s. Bow complete; south edge 2 north of Arcturus. + + 9 45 30 Northern edge diffuse south; edge bright, and well + defined; 10 wide in zenith; north edge on Alphacca. + + 9 47 30 South edge 5 north of Arcturus; north edge close to + Cor. Caroli. + + 9 53 30 Eastern half composed of four detached bands + _shingling_ over each other. + + 58 30 Arcturus on south; bow narrower. + + 9 59 30 Arcturus in the middle of the band; very bright and + regular in outline, and widest at the zenith. + + 10 0 30 Arcturus on northern edge; north side better defined + than the southern. + + 10 2 0 Arcturus 1 north; very bright. + + 10 2 30 Gamma and Delta Leonis, northern edge. + + 10 3 Regulus on southern age; getting faint. + + 10 5 Fast fading away. + + 10 5 30 Scarcely visible; bank in north faint. + +This aurora was due to the _inner vortex ascending_, whose period was at +this time 28 days. + +There are several circumstances to be observed in this case. The bow +brightened and faded simultaneously with the aurora, and respected the +vertex of the auroral bank, being apparently concentric with it. The +bow, therefore, depends on the same cause, but differs from the aurora +in being limited to the _surface_ of the atmosphere in which the vortex +has produced a wave to the southward of its central path, as may be +understood by inspecting Fig.2, Sec.1,--the figure representing the +polar current of the central vortex. On the 29th of May, 1840,[32] the +author saw a similar phenomenon, at the same time of night, and passing +over the same stars southward until it reached within 5 of Jupiter and +Saturn, to which it was parallel. This atmospheric wave offers a greater +resistance to the passage of the ether: hence the light. On this account +it is, also, that when the passage of a vortex is attended by an auroral +display there will be no thunder-storm. There may be an increase of +wind; but the atmosphere at such times is too dry to make a violent +storm, and there is a silent restoration of the equilibrium, by the +ether passing through the dry atmosphere, without meeting any +condensable vapor, and becoming luminous on account of the greater +resistance of the air when unmixed with vapor. We thus see also the +connection between the aurora and the linear cirri, and we have a +triumphant explanation of the fact, that when the observer is north of +the northern limit of the vortices, he sees the aurora to the south and +not to the north; for, to see it to the northward, he would have to see +it in the same latitude as it appears in the south, and, consequently, +have to see across twice the complement of the latitude. We thus see, +also, why the temperature falls after an aurora; for, the passage of +electricity in any shape, must have this effect on account of the great +specific caloric of this fluid. We see, also, why the aurora should be +more frequent where the magnetic intensity is greatest and be +consequently invisible at the equator, and why the magnetic needle is so +sensibly affected at the time of its occurrence. We may, perhaps, here +be allowed to allude to another phenomenon connected with terrestrial +magnetism and electricity. + + +EARTHQUAKES. + +The awful and destructive concussions which sometimes are produced at +great depths beneath the surface of the soil, would seem to indicate +that no force but that of electricity is adequate to account for the +almost instantaneous desolation of wide tracts of the earth's surface. +But we do not mean to say that the action of the terral vortices, +combined with the internal conditions of our planet, is the only cause; +although it is far from improbable that the same activity of the ether, +which generates through these vortices, the full fury of the hurricane +in the tropics, may be simultaneously accompanied by a _subterranean_ +storm. And physicists are too rash to reject the evidence on which the +connection of the phenomena rests. + +In the extract given by Colonel Reid, in his "Law of Storms," from Sir +George Rodney's official report of the great hurricane of 1780, it is +stated, that, "Nothing but an earthquake could have occasioned the +_foundations_ of the strongest buildings to be rent; and I am convinced +that the violence of the wind must have prevented the inhabitants from +feeling the earthquake which certainly attended the storm."[33] Again, +in the Savannah-la-Mar hurricane, which occurred the same year and +month, the Annual Register, published at Jamaica, states, that at the +same time, "a smart shock of an earthquake was felt." The general +serenity of equatorial regions is due to the fact that they are beyond +the limit of the vortices, as in Peru, where neither rain nor lightning +nor storm is ever seen. Thunder and rain, without storms, however, are +common in other tropical countries, also out of the reach of the +vortices. But even in those parts, (as the Antilles,) lying in the track +of these vortices, the weather is not as _frequently_ disturbed as in +higher latitudes. The storms of the Antilles, when they do occur, +however, are fearful beyond any conception, showing the presence of some +cause, auxiliary to the ordinary disturbing action of the vortices, +which, when simultaneously occurring, adds tremendously to their force. + +That earthquakes are preceded _sometimes_ by a peculiar haziness and +oppressiveness, similar to that which sometimes precedes a storm, is a +current opinion in volcanic countries. And Humboldt, who doubts the +connection, has to confess that sudden changes of weather have +_succeeded_ violent earthquakes, and that "during the great earthquake +of Cumana, he found the inclination of the needle was diminished 48'." +He also mentions the simultaneous occurrence of shocks, from +earthquakes, and a clap of thunder, and the agitation of the +electrometer during the earthquake, which lasted from the 2d of April to +the 17th of May, 1808; but concluding that "these indications presented +by clouds, by modifications of atmospheric electricity, or by calms, +cannot be regarded as _generally_ or _necessarily_ connected with +earthquakes, since in Peru, Canada, and Italy, earthquakes are observed, +along with the purest and clearest skies, and with the freshest land and +sea breezes. But if no meteorological phenomena indicates the coming +earthquake, either on the morning of the shock or a few days previously, +the influence of certain periods of the year, (the vernal and autumnal +equinoxes,) the commencement of the rainy season in the tropics, after +long drought, cannot be overlooked, even though the genetic connection +of meteorological processes, with those going on in the interior of our +globe, is still enveloped in obscurity."[34] + +It is at the equinoxes that the earth changes her distances from the sun +most rapidly, and whether she is passing from her perihelion or from +her aphelion, the density of the ether externally is changing in the +subduplicate ratio of these distances and consequently at these times +there will be the greatest disturbance of the electric equilibrium. How +far our views of the internal structure of our globe, (considered along +a diameter as a solid crust, then a fused mass separated from the lower +ocean by another solid crust, and separated from a similar arrangement +on the opposite side by an interposed mass of water, perhaps also +possessing a solid nucleus,) may affect this question, is difficult to +say; but that the agent is electric, appears highly probable; and very +recently it has been discovered, by M. Ratio Menton, that a piece of +iron, suspended by attraction to a magnet, will fall on the approach of +an earthquake; thus indicating that the power of the magnet is +temporarily weakened by the action of some disturbing force. + + +FOOTNOTES: + +[22] Hum. Cosmos, art Aerolites. + +[23] We shall in all cases use this abbreviation for the extremely +awkward word zodiacal. + +[24] It is here assumed, that all the vortices are at their apogee at +the same time, and, consequently, they lie in different longitudes, but +the central being between, its position is taken for the average +position of the three. + +[25] It is far from improbable that the effect produced in one zone of +climate, may be reversed in another, from the nature of the cause. + +[26] That the 11th, 12th, and 13th of May should recede 2 in +temperature as determined by Mdler from observations of 86 years, at a +time when the power of the sun so rapidly augments, is strongly +confirmatory of the theory. See _Cosmos_, p.121. + +[27] Plucker first discovered that a plate of tourmaline suspended with +its axis vertical, set axial. + +[28] Silliman's Journal for March and April, 1853. + +[29] Humboldt, _Cosmos_ p.193, London ed. + +[30] See Silliman's Journal for September, 1853. + +[31] See Silliman's Journal for September, 1853. + +[32] This was the central vortex ascending. + +[33] Reid's Law of Storms, p.350. + +[34] Humboldt, _Cosmos_, p.203. + + + + +SECTION FOURTH. + + +THE SOLAR SPOTS. + +We have yet many phenomena to investigate by the aid of the theory, and +we will develop them in that order which will best exhibit their mutual +dependence. The solar spots have long troubled astronomers, and to this +day no satisfactory solution of the question has been proposed; but we +shall not examine theories. It is sufficient that we can explain them on +the same general principles that we have applied to terrestrial +phenomena. There can be but little doubt about the existence of a solar +atmosphere, and, reasoning from analogy, the constituent elements of the +sun must partake of the nature of other planetary matter. That there are +bodies in our system possessing the same elements as our earth, is +proved by the composition of meteoric masses, which, whether they are +independent bodies of the system, or fragments of an exploded planet, or +projected from lunar volcanoes, is of little consequence; they show that +the same elements are distributed to other bodies of the system, +although not necessarily in the same proportions. The gaseous matter of +the sun's atmosphere may, therefore, be safely considered as vapors +condensable by cold, and the formation of vortices over the surface of +this atmosphere, brings down the ether, and causes it to intermingle +with this atmosphere. But, from the immensely rapid motion of the polar +current of the solar vortex, this ether may be considered to enter the +atmosphere of the sun with the temperature of space. + +Sir John Herschel, in commenting on the theory of Mr. Redfield before +the British Association, convened at Newcastle in 1838,[35] suggested an +analogy to terrestrial hurricanes, from a suspected rotation and +progressive motion in these spots. From their rapid formation, change of +shape, and diameter, this view is allowable, and, taken in conjunction +with the action of the ethereal currents, will account for all the +phenomena. The nucleus of the spot is dense, like the nucleus of a storm +on the earth, and surrounded by a penumbon precisely as our storms are +fringed with lighter clouds, permitting the light of the sun to +penetrate. And, it has been observed, that these spots seem to follow +one another in lines on the same parallel of solar latitude (or nearly +the same), exactly as we have determined the action of the vortices on +the surface of the earth from observation. These spots are never found +in very high latitudes--not much above 30 from the solar equator. If we +consider this equator to be but slightly inclined to the plane of the +vortex, this latitude would be the general position of the lateral solar +vortices, and, in fact, be confined principally to a belt on each side +of the equator, between 15 and 30 of solar latitude, rather than at +the equator itself. This, it is needless to say, is actually the case. +But, a more capital feature still has been more recently brought to +light by observation, although previously familiar to the author, who, +in endeavoring to verify the theory, seriously injured his sight, by +observing with inadequate instrumental means. This is the periodicity of +the spots. + +We have already observed, that there is reason to suppose that the +action of the inner vortex of the earth is probably greater than that of +the outer vortex, on account of the conflicting currents by which it is +caused. And the full development of this vortex requires, that the +central vortex or mechanical axis of the system shall be nearly +tangential to the surface. In this position, the action of the central +vortex is itself at a maximum; and, when the planets of the system are +so arranged as to produce this result, we may expect the greatest number +of spots. If the axis or central vortex approaches to coincidence with +the axis of the sun, the lateral vortices disappear, and the central +vortex being then perpendicular to the surface, is rendered ineffective. +Under these circumstances, there will be no spots on the sun's disc. +When, on the other hand, all the planets conspire at the same side to +force the sun out from the mechanical centre of the system, the surface +is too distant to be acted on by the central vortex, and the lateral +vortices are also thrown clear of the sun's surface, on account of the +greater velocity of the parts of the vortex, in sweeping past the body +of the sun. In this case, there will be but few spots. The case in which +the axis of the vortex coincides with the axis of the sun, is much more +transient than the first position, and hence, although the interval +between the maxima will be tolerably uniform, there will be an +irregularity between a particular maximum, and the preceding and +subsequent minimum. + +The following table exhibits the solar spots, as determined by Schwabe, +of Dessau: + + Year of observation. Groups of spots observed. Number of days. + 1826 118 277 + 1827 161 273 + 1828 225 282 + 1829 199 244 + 1830 190 217 + 1831 149 239 + 1832 84 270 + 1833 33 267 + 1834 51 273 + 1835 173 244 + 1836 272 200 + 1837 333 168 + 1838 282 202 + 1839 162 205 + 1840 152 263 + 1841 102 283 + 1842 68 307 + 1843 34 324 + +Previous to the publication of this table, the author had inferred the +necessity of admitting the existence of another planet in the solar +system, from the phenomenon of which we are speaking. He found a +sufficient correspondence between the minima of spots to confirm the +explanation given by the theory, and this was still more confirmed by +the more exact determination of Schwabe; yet there was a little +discrepancy in the synchronous values of the ordinates, when the theory +was graphically compared with the table. Previous to the discovery of +Neptune, the theory corresponded much better than afterwards, and as no +doubt could be entertained that the anomalous movements of Uranus were +caused by an exterior planet, he adopted the notion that there were two +planets exterior to Uranus, whose positions at the time were such, that +their mechanical affects on the system were about equal and contrary. +Consequently, when Neptune became known, the existence of another planet +seemed a conclusion necessary to adopt. Accordingly, he calculated the +heliocentric longitudes and true anomalies, and the values of radius +vector, for all the planets during the present century, but not having +any planetary tables, he contented himself with computing for the +nearest degree of true anomaly, and the nearest thousand miles of +distance. Then by a composition and resolution of all the forces, he +deduced the radius vector of the sun, and the longitude of his centre, +for each past year of the century. It was in view of a little +outstanding discrepancy in the times of the minima, as determined by +theory and observation, that he was induced to consider as almost +certain the existence of a theoretical planet, whose longitude, in 1828, +was about 90, and whose period is from the theory about double that of +Neptune. And for convenience of computation and reference, he has been +in the habit of symbolizing it by a volcano. The following table of the +radii vectores of the sun, and the longitude of his centre, for the +years designated in Schwabe's table, is calculated from the following +data for each planet: + + Long. of + Planets. Masses. Mean distances. Eccentricities. Perihelion. + [JUPITER] 1/1648 494.800.000 0.0481 11 + [SATURN] 1/3310 907.162.000 0.0561 89 + [URANUS] 1/23000 1824.290.000 0.0166 167 + [NEPTUNE] 1/20000 2854.000.000 0.0088 0 + [VOLCANO] 1/28000 4464.000.000 + + No. of spots in + Dates. Rad. vector. Sun's long. Ordinates. Schwabe's table. + Jan. 1, 1826 528,000 320 + 84 118 + " 1827 480,000 339 + 36 161 + " 1828 432,000 352 - 12 Max. 225 Max. + " 1829 397,000 38 - 47 199 + " 1830 858,000 71 - 86 190 + " 1831 324,000 104 -120 149 + " 1832 311,000 144 -133 84 + " 1833 300,000 183 -144 Min. 33 Min. + " 1834 307,000 220 -137 51 + " 1835 338,000 263 -106 173 + " 1836 380,000 302 - 55 272 + " 1837 419,000 337 + 25 Max. 333 Max. + " 1838 488,000 3 + 44 282 + " 1839 651,000 29 +107 162 + " 1840 632,000 51 +188 152 + " 1841 680,000 80 +236 102 + " 1842 730,000 105 +286 68 + " 1843 160,000 128 +322 34 Min. + " 1844 188,000 152 +339 Min. 52 + " 1845 772,000 174 +328 114 + " 1846 728,000 196 +284 157 + " 1847 660,000 218 +216 + " 1848 563,000 240 +119 Observed. Max. + " 1849 447,000 261 + 3 Max. + " 1850 309,000 283 -135 + " 1851 170,000 323 -274 + " 1852 53,000 41 -391 Min. + " 1853 167,000 133 -277 + " 1854 315,000 160 -129 + " 1855 475,000 183 + 31 Max. + " 1856 611,000 203 +167 + " 1857 720,000 225 +276 + +It is necessary to observe here, that the values of the numbers in +Schwabe's table are the numbers for the whole year, and, therefore, the +1st of July would have been a better date for the comparison; but, as +the table was calculated before the author was cognizant of the fact, +and being somewhat tedious to calculate, he has left it as it was, viz., +for January 1st of each year. Hence, the minimum for 1843 appears as +pertaining to 1844. The number of spots ought to be inversely as the +ordinates approximately--these last being derived from the Radii +Vectores minus, the semi-diameter of the sun=444,000 miles. + +In passing judgment on this relation, it must also be borne in mind, +that the recognized masses of the planets cannot be the true masses, if +the theory be true. Both sun and planets are under-estimated, yet, as +they are, probably, all to a certain degree proportionally undervalued, +it will not vitiate the above calculation much. + +The spots being considered as solar storms, they ought also to vary in +number at different times of the year, according to the longitude of the +earth and sun, and from their transient character, and the slow rotation +of the sun, they ought, _ceteris paribus_, to be more numerous when the +producing vortex is over a visible portion of the sun's surface. + +The difficulty of reconciling the solar spots, and their periodicity to +any known principle of physics, ought to produce a more tolerant spirit +amongst the scientific for speculations even which may afford the +slightest promise of a solution, although emanating from the humblest +inquirer after truth. The hypothesis of an undiscovered planet, exterior +to Neptune, is of a nature to startle the cautions timidity of many; +but, if the general theory be true, this hypothesis becomes extremely +probable. We may not have located it exactly. There may be even two such +planets, whose joint effect shall be equivalent to one in the position +we have assigned. There may even be a comet of great mass, capable of +producing an effect on the position of the sun's centre (although it +follows from the theory that comets have very little mass). Yet, in view +of all these suppositions, there can be but little doubt that the solar +spots are caused by the solar vortices, and these last made effective on +the sun by the positions of the great planets, and, therefore, we have +indicated a new method of determining the existence and position of all +the planets exterior to Neptune. On the supposition that there is only +one more in the system, from its deduced distance and mass, it will +appear only as a star of the eleventh magnitude, and, consequently, will +only be recognizable by its motion, which, at the greatest, will only be +ten or eleven seconds per day. + + +MASSES OF THE SUN AND PLANETS. + +We have alluded to the fact of the radial stream of the sun necessarily +diminishing the sun's power, and, consequently, diminishing his apparent +mass. The radial stream of all the planets will do the same, so that +each planet whose mass is derived from the periodic times of the +satellites, will also appear too small. But, there is also a great +probability that some modification must be made in the wording of the +Newtonian law. The experiments of Newton on the pendulum, with every +variety of substance, was sufficient justification to entitle him to +infer, that inertia was as the weight of matter universally. But, there +was one condition which could not be observed in experimenting on these +substances, viz., the difference of temperature existing between the +interior and surface of a planet. + +We have already expressed the idea, that the cause of gravity has no +such mysterious origin as to transcend the power of man to determine it. +But that, on the contrary, we are taught by every analogy around us, as +well as by divine precept, to use the visible things of creation as +stepping stones to the attainment of what is not so apparent. That we +have the volume of nature spread out in tempting characters, inviting us +to read, and, assuredly, it is not so spread in mockery of man's limited +powers. As science advances, strange things, it is true, are brought to +light, but the more _rational_ the queries we propound, in every case +the more satisfactory are the answers. It is only when man consults the +oracle in irrational terms that the response is ambiguous. Alchemy, with +its unnatural transmutations, has long since vanished before the +increasing light. Why should not attraction also? Experience and +experiment, if men would only follow their indications, are consistently +enforcing the necessity of erasing these antiquated chimeras from the +book of knowledge; and inculcating the great truth, that the physical +universe owes all its endless variety to differences in the form, size, +and density of planetary atoms in motion, according to simple mechanical +principles. These, combined with the existence of an all-pervading +medium filling space, between which and planetary matter no bond of +union subsists, other than that which arises from a continual +interchange of motion, are the materials from which the gems of nature +are elaborated. But, simplicity of means is what philosophy has ever +been reluctant to admit, preferring rather the occult and obscure. + +If action be equal to reaction, and all nature be vibrating with motion, +these motions must necessarily interfere, and some effect should be +produced. A body radiating its motion on every side into a physical +medium, produces waves. These waves are a mechanical effect, and the +body parts with some of its motion in producing them; but, should +another body be placed in juxtaposition, having the same motion, the +opposing waves neutralize each other, and the bodies lose no motion from +their contiguous sides, and, therefore, the reaction from the opposite +sides acts as a propelling power, and the bodies approach, or tend to +approach each other. If one body be of double the inertia, it moves only +half as far as the first; then, seeing that this atomic motion is +radiated, the law of force must be directly as the mass, and inversely +as the squares of the distances. There may be other atomic vibrations +besides those which we call light, heat, and chemical action, yet the +joint effect of all is infinitesimally small, when we disregard the +united _attraction_ of all the atoms of which the earth is composed. The +_attraction_ of the whole earth at the surface causes bodies to fall 16 +feet the first second of time; but, if two spheres of ice of one foot +diameter, were placed in an infinite space, uninfluenced by other +matter, and only 16 feet apart, they would require nearly 10,000 years +to fall together by virtue of their mutual attraction. Our conceptions, +or, rather, our misconceptions, concerning the force of gravity, arises +from our forgetting that every pound of matter on the earth contributes +its share of the force which, in the aggregate, is so powerful. Hence, +the cause we have suggested, is fully adequate to account for the +phenomena. Whether the harmony of vibrations between two bodies may not +have an influence in determining the amount of interference, and, +consequently, produce _some_ difference between the gravitating mass +and its inertia, is a question which, no doubt, will ultimately be +solved; but this harmony of vibrations must depend, in some degree, on +the atomic weight, temperature, and intensity of atomic motion. + +That a part of the mass of the earth is _latent_ may be inferred from +certain considerations: 1st, from the discrepancies existing in the +results obtained for the earth's compression by the pendulum and by +actual measurement; and, 2d, from the irregularity of that compression +in particular latitudes and longitudes. The same may also be deduced +from the different values of the moon's mass as derived from different +phenomena, dependent on the law of gravitation. Astronomers have +hitherto covered themselves with the very convenient shield of errors of +observation; but, the perfection of modern instruments now demand a +better account of all outstanding discrepancies. The world requires it +of them. + +The mass of the moon comes out much greater by our theory than nutation +gives. The mass deduced from the theory is only dependent on the +relative inerti of the earth and moon. That given by nutation depends +on gravity. If, then, a part of the mass be latent, nutation will give +too small a value. But, in addition to this, we are justified in +doubting the strict wording of the Newtonian law, deriving our authority +from the very foundation stone of the Newtonian theory. + +It is well known that Newton suspected that the moon was retained in her +orbit by the same force which is usually called weight upon the surface, +sixteen years before the fact was confirmed, by finding a correspondence +in the fall of the moon and the fall of bodies on the earth. Usually, in +all elementary works, this problem is considered accurately solved. +Having formed a different idea of the mechanism of nature, this fact +presented itself as a barrier beyond which it was impossible to pass, +until suspicions, derived from other sources, induced the author to +inquire: Whether the phenomenon did exactly accord with the theory? We +are aware that it is easy to place the moon at such a distance, that the +result shall strictly correspond with the fact; but, from the parallax, +as derived from observation (and if this cannot be depended on +certainly, no magnitudes in astronomy can), we find, _that the moon does +not fall from the tangent of her orbit, as much as the theory requires_. +As this is of vital importance to the integrity of the theory we are +advocating, we have made the computation on Newton's own data, except +such as were necessarily inaccurate at the time he wrote; and we have +done it arithmetically, without logarithmic tables, that, if possible, +no error should creep in to vitiate the result. We take the moon's +elements from no less an authority than Sir John Herschel, as well as +the value of the earth's diameter. + + Mass of the moon 1/80 + Mean distance in equatorial radii 59.96435 + Sidereal period in seconds 2360591 + +The vibrations of the pendulum give the force of gravity at the surface +of the earth, and it is found to vary in different latitudes. The +intensity in any place being as the squares of the number of vibrations +in a given time. This inequality depends on the centrifugal force of +rotation, and on the spheroidal figure of the earth due to that +rotation. At the equator the fall of a heavy body is found to be +16.045223 feet, per second, and in that latitude the squares of whose +sine is 1/3, it is 16.0697 feet. The effect in this last-named latitude +is the same as if the earth were a perfect sphere. This does not, +however, express the whole force of gravity, as the rotation of the +earth causes a centrifugal tendency which is a maximum at the equator, +and there amounts to 1/289 of the whole gravitating force. In other +latitudes it is diminished in the ratio of the squares of the cosines of +the latitude; it therefore becomes 1/434 in that latitude the square of +whose sine is 1/3. Hence the fall per second becomes 16.1067 feet for +the true gravitating force of the earth, or for that force which retains +the moon in her orbit. + +The moon's mean distance is 59.96435 equatorial radii of the earth, +which radius is, according to Sir John Herschel, 20.923.713 +feet. Her mean distance as derived from the parallax is not to be +considered the radius vector of the orbit, inasmuch as the earth also +describes a small orbit around the common centre of gravity of the earth +and moon; neither is radius vector to be considered as her distance from +this common centre; for the attracting power is in the centre of the +earth. But the mean distance of the moon moving around a movable centre, +is to the same mean distance when the centre of attraction is fixed, as +the sum of the masses of the two bodies, to the first of two mean +proportionals between this sum and the largest of the two bodies +inversely. (Vid. Prin. Prop. 60 Lib. Prim.) The ratio of the masses +being as above 80 to 1 the mean proportional sought is 80.666 and in +this ratio must the moon's mean distance be diminished to get the force +of gravity at the moon. Therefore as 81 is to 80.666, so is 59.96435 to +59.71657 for the moon's distance in equatorial radii of the earth. +Multiply this last by 20.923,713 to bring the semi-diameter of the lunar +orbit into feet = 1.249.492.373, and this by 6.283185, the ratio of the +circumference to the radius, gives 7.850.791.736 feet, for the mean +circumference of the lunar orbit. + +Further, the mean sidereal period of the moon is 2360591 seconds and the +1/2360591th part of 7.850.791.736 is the arc the moon describes in one +second = 3325.77381 feet, the square of which divided by the diameter +of the orbit, gives the fall of the moon from the tangent or versed +size of that arc. + + 1106771.36876644 + = ---------------- = 0.004426106 feet. + 2498984746 + +This fraction is, however, too small, as the ablatitious action of the +sun diminishes the attraction of the earth on the moon, in the ratio of +17829/40 to 17729/40. So that we must increase the fall of the moon +in the ratio of 711 to 715, and hence the true fall of the moon from the +tangent of her orbit becomes 0.00451 feet per second. + +We have found the fall of a body at the surface of the earth, considered +as a sphere, 16.1067 feet per second, and the force of gravity +diminishes as the squares of the distances increases. The polar diameter +of the earth is set down as 7899.170 miles, and the equatorial diameter +7925.648 miles; therefore, the mean diameter is 7916.189 miles.[36] So +that, reckoning in mean radii of the earth, the moon's distance is +59.787925, which squared, is equal to 3574.595975805625. At one mean +radius distance, that is, at the surface, the force of gravity, or fall +per second, is as above, 16.1067 feet. Divide this by the square of the +distance, it is 16.1067/3574.595975805625 = 0.0045058feet for the force +of gravity at the moon. But, from the preceding calculation, it appears, +that the moon only falls 0.0044510 feet in a second, showing a +deficiency of 1/82d part of the principal force that retains the moon in +her orbit, being more than double the whole disturbing power of the sun, +which is only 1/178th of the earth's gravity at the moon; yet, on this +1/178th depends the revolution of the lunar apogee and nodes, and all +those variations which clothe the lunar theory with such formidable +difficulties. The moon's mass cannot be less than 1/80, and if we +consider it greater, as it no doubt is, the results obtained will be +still more discrepant. Much of this discrepancy is owing to the +expulsive power of the radial stream of the terral vortex; yet, it may +be suspected that the effect is too great to be attributed to this, and, +for this reason, we have suggested that the fused matter of the moon's +centre may not gravitate with the same force as the exterior parts, and +thus contribute to increase the discrepancy. + +As there must be a similar effect produced by the radial stream of every +vortex, the masses of all the planets will appear too small, as derived +from their gravitating force; and the inertia of the sun will also be +greater than his apparent mass; and if, in addition to this, there be a +portion of these masses latent, we shall have an ample explanation of +the connection between the planetary densities and distances. We must +therefore inquire what is the particular law of force which governs the +radial stream of the solar vortex. It will be necessary to enter into +this question a little more in detail than our limits will justify; but +it is the resisting influence of the ether, and its consequences, which +will appear to present a vulnerable point in the present theory, and to +be incompatible with the perfection of astronomical science. + + +LAW OF DENSITY IN SOLAR VORTEX. + +Reverting to the dynamical principle, that the product of every particle +of matter in a fluid vortex, moving around a given axis, by its distance +from the centre and angular velocity, must ever be a constant quantity, +it follows that if the ethereal medium be uniformly dense, the periodic +times of the parts of the vortex will be directly as the distances from +the centre or axis; but the angular velocities being inversely as the +times, the absolute velocities will be equal at all distances from the +centre. + +Newton, in examining the doctrine of the Cartesian vortices, supposes +the case of a globe in motion, gradually communicating that motion to +the surrounding fluid, and finds that the periodic times will be in the +duplicate ratio of the distances from the centre of the globe. He and +his successors have always assumed that it was impossible for the +principle of gravity to be true, and a Cartesian plenum also; +consequently, the question has not been fairly treated. It is true that +Descartes sought to explain the motions of the planets, by the +mechanical action of a fluid vortex _solely_; and to Newton belongs the +glorious honor of determining, the existence of a centripetal force, +competent to explain these motions mathematically, (but not physically,) +and rashly rejected an intelligible principle for a miraculous virtue. +If our theory be true, the visible creation depends on the existence of +both working together in harmony, and that a physical medium is +absolutely necessary to the existence of gravitation. + +If space be filled with a fluid medium, analogy would teach us that it +is in motion, and that there must be inequalities in the direction and +velocity of that motion, and consequently there must be vortices. And if +we ascend into the history of the past, we shall find ample testimony +that the planetary matter now composing the members of the solar system, +was once one vast nebulous cloud of atoms, partaking of the vorticose +motion of the fluid involving them. Whether the gradual accumulation of +these atoms round a central nucleus from the surrounding space, and thus +having their tangential motion of translation converted into vorticose +motion, first produced the vortex in the ether; or whether the vortex +had previously existed, in consequence of conflicting currents in the +ether, and the scattered atoms of space were drawn into the vortex by +the polar current, thus forming a nucleus at the centre, as a necessary +result of the eddy which would obtain there, is of little consequence. +The ultimate result would be the same. A nucleus, once formed, would +give rise to a central force, tending more and more to counteract the +centripulsive power of the radial stream; and in consequence of this +continually increasing central power, the heaviest atoms would be best +enabled to withstand the radial stream, while the lighter atoms might be +carried away to the outer boundaries of the vortex, to congregate at +leisure, and, after the lapse of a thousand years, to again face the +radial stream in a more condensed mass, and to force a passage to the +very centre of the vortex, in an almost parabolic curve. That space is +filled with isolated atoms or planetary dust, is rendered very probable +by a fact discovered by Struve, that there is a gradual extinction in +the light of the stars, amounting to a loss of 1/107 of the whole, in +the distance which separates Sirius from the sun. According to Struve, +this can be accounted for, "by admitting as very probable that space is +filled with an _ether_, capable of intercepting in some degree the +light." Is it not as probable that this extinction is due to planetary +dust, scattered through the pure ether, whose vibrations convey the +light,--the material atoms of future worlds,--the debris of dilapidated +comets? Does not the Scripture teach the same thing, in asserting that +the heavens are not clean? + +The theory of vortices has had many staunch supporters amongst those +deeply versed in the science of the schools. The Bernoullis proposed +several ingenious hypothesis, to free the Cartesian system from the +objections urged against it, viz.: that the velocities of the planets, +in accordance with the three great laws of Kepler, cannot be made to +correspond with the motion of a fluid vortex; but they, and all others, +gave the vantage ground to the defenders of the Newtonian philosophy, by +seeking to refer the principle of gravitation to conditions dependent on +the density and vorticose motion of the ether. When we admit that the +ether is imponderable and yet material, and planetary matter subject to +the law of gravitation, the objections urged against the theory of +vortices become comparatively trivial, and we shall not stop to refute +them, but proceed with the investigation, and consider that the ether is +the original source of the planetary motions and arrangements. + +On the supposition that the ether is uniformly dense, we have shown that +the periodic times will be directly as the distances from the axis. If +the density be inversely as the distances, the periodic times will be +equal. If the density be inversely as the square roots of the distances, +the times will be directly in the same ratio. The celebrated J. +Bernoulli assumed this last ratio; but seeking the source of motion in +the rotating central globe, he was led into a hypothesis at variance +with analogy. The ellipticity of the orbit, according to this view, +was caused by the planet oscillating about a mean position,--sinking +first into the dense ether,--then, on account of superior buoyancy, +rising into too light a medium. Even if no other objection could be +urged to this view, the difficulty of explaining why the ether should be +denser near the sun, would still remain. We might make other +suppositions; for whatever ratio of the distances we assume for the +density of the medium, the periodic times will be compounded of those +distances and the assumed ratio. Seeing, therefore, that the periodic +times of the planets observe the direct ses-plicate ratio of the +distances, and that it is consonant to all analogy to suppose the +contiguous parts of the vortex to have the same ratio, we find that the +density of the ethereal medium in the solar vortex, is directly as the +square roots of the distances from the axis. + +Against this view, it may be urged that if the inertia of the medium is +so small, as is supposed, and its elasticity so great, there can be no +condensation by centrifugal force of rotation. It is true that when we +say the ether is condensed by this force, we speak incorrectly. If in an +infinite space of imponderable fluid a vortex is generated, the central +parts are rarefied, and the exterior parts are unchanged. But in all +finite vortices there must be a limit, outside of which the motion is +null, or perhaps contrary. In this case there may be a cylindrical ring, +where the medium will be somewhat denser than outside. Just as in water, +every little vortex is surrounded by a circular wave, visible by +reflection. As the density of the planet Neptune appears, from present +indications, to be a little denser than Uranus, and Uranus is denser +than Saturn, we may conceive that there is such a wave in the solar +vortex, near which rides this last magnificent planet, whose ring would +thus be an appropriate emblem of the peculiar position occupied by +Saturn. This may be the case, although the probability is, that the +density of Saturn is much greater than it appears, as we shall presently +explain. + +In order to show that there is nothing extravagant in the supposition of +the density of the ether being directly as the square roots of the +distances from the axis, we will take a fluid whose law of density is +known, and calculate the effect of the centrifugal force, considered as +a compressing power. Let us assume our atmosphere to be 47 miles high, +and the compressing power of the earth's gravity to be 289 times greater +than the centrifugal force of the equator, and the periodic time of +rotation necessary to give a centrifugal force at the equator equal to +the gravitating force to be 83 minutes. Now, considering the gravitating +force to be uniform, from the surface of the earth upwards, and knowing +from observation that at 18,000 feet above the surface, the density of +the air is only , it follows, (in accordance with the principle that +the density is as the compressing force,) that at 43 miles high, or +18,000 feet _below_ the surface of the atmosphere, the density is only +1/8000 part of the density at the surface of the earth. Let us +take this density as being near the limit of expansion, and conceive a +hollow tube, reaching from the sun to the orbit of Neptune, and that +this end of the tube is closed, and the end at the sun communicates with +an inexhaustible reservoir of such an attenuated gas as composes the +upper-layer of our atmosphere; and further, that the tube is infinitely +strong to resist pressure, without offering resistance to the passage of +the air within the tube; then we say, that, if the air within the tube +be continually acted on by a force equal to the mean centrifugal force +of the solar vortex, reckoning from the sun to the orbit of Neptune, the +density of the air at that extremity of the tube, would be greater than +the density of a fluid formed by the compression of the ocean into one +single drop. For the centrifugal force of the vortex at 2,300,000 miles +from the centre of the sun, is equal to gravity at the surface of the +earth, and taking the mean centrifugal force of the whole vortex as +one-millionth of this last force; so that at 3,500,000 miles from the +surface of the sun, the density of the air in the tube (supposing it +obstructed at that distance) would be double the density of the +attenuated air in the reservoir. And the air at the extremity of the +tube reaching to the orbit of Neptune, would be as much denser than the +air we breathe, as a number expressed by 273 with 239 ciphers annexed, +is greater than unity. This is on the supposition of infinite +compressibility. Now, in the solar vortex there is no physical barrier +to oppose the passage of the ether from the centre to the circumference, +and the density of the ethereal ocean must be considered uniform, except +in the interior of the stellar vortices, where it will be rarefied; and +the rarefaction will depend on the centrifugal force and the length of +the axis of the vortex. If this axis be very long, and the centrifugal +velocity very great, the polar influx will not be sufficient, and the +central parts will be rarefied. We see, therefore, no reason why the +density of the ether may not be three times greater at Saturn than at +the earth, or as the square roots of the distances directly. + + +BODES' LAW OF PLANETARY DISTANCES. + +Thus, in the solar vortex, there will be two polar currents meeting at +the sun, and thence being deflected at right angles, in planes parallel +to the central plane of the vortex, and strongest in that central plane. +The velocity of expansion must, therefore, diminish from the divergence +of the radii, as the distances increase; but in advancing along these +planes, the ether of the vortex is continually getting more dense, +which operate by absorption or condensation on the radial stream; so +that the velocity is still more diminished, and this in the ratio of the +square roots of the distances directly. By combining these two ratios, +we find that the velocity of the radial stream will be in the +ses-plicate ratio of the distances inversely. But the force of this +stream is not as the velocity, but as the square of the velocity. The +_force_ of the radial stream is consequently as the cubes of the +distances inversely, from the axis of the vortex, reckoned in the same +plane. If the ether, however, loses in velocity by the increasing +density of the medium, it becomes also more dense; therefore the true +force of the radial stream will be as its density and the square of its +velocity, or directly as the square roots of the distances, and +inversely as the cubes of the distances, or as the 2.5 power of the +distances inversely. + +If we consider the central plane of the vortex as coincident with the +plane of the ecliptic, and the planetary orbits, also, in the same +plane; and had the force of the radial stream been inversely as the +square of the distances, there could be no disturbance produced by the +action of the radial stream. It would only counteract the gravitation of +the central body by a certain amount, and would be exactly proportioned +at all distances. As it is, there is an outstanding force as a +disturbing force, which is in the inverse ratio of the square roots of +the distances from the sun; and to this is, no doubt, owing, in part, +the fact, that the planetary distances are arranged in the inverse order +of their densities. + +Suppose two planets to have the same diameter to be placed in the same +orbit, they will only be in equilibrium when their densities are equal. +If their densities are unequal, the lighter planet will continually +enlarge its orbit, until the force of the radial stream becomes +proportional to the planets' resisting energy. This, however, is on the +hypothesis that the planets are not permeable by the radial stream, +which, perhaps, is more consistent with analogy than with the reality. +And it is more probable that the mean atomic weight of a planet's +elements tends more to fix the position of equilibrium for each. Under +the law of gravity, a planet may revolve at any distance from the sun, +but if we superadd a centripulsive force, whose law is not that of +gravity, but yet in some inverse ratio of the distances, and this force +acts only superficially, it would be possible to make up in volume what +is wanted in density, and a lighter planet might thus be found occupying +the position of a dense planet. So the planet Jupiter, respecting only +his resisting surface, is better able to withstand the force of the +radial stream at the earth than the earth itself. To understand this, it +is necessary to bear in mind, that, as far as planetary matter is +concerned, the earth would revolve in Jupiter's orbit in the same +periodic time as Jupiter, under the law of gravity: but that, in +reality, the whole of the gravitating force is not effective, and that +the equilibrium of a planet is due to a nice balance of interfering +forces arising from the planet's physical peculiarities. As in a +refracting body, the density of the ether may be considered inversely as +the refraction, and this as the atomic weight of the refracting +material, so, also, in a planet, the density of the ether will be +inversely in the same ratio of the density of the matter approximately. +Hence, the density of the ether within the planet Jupiter is greater +than that within the earth; and, on this ethereal matter, the sun has no +power to restrain it in its orbit, so that the centrifugal momentum of +Jupiter would be relatively greater than the centrifugal momentum of the +earth, were it also in Jupiter's orbit with the same periodic time. +Hence, to make an equilibrium, the earth should revolve in a medium of +less density, that there may be the same proportion between the external +ether, and the ether within the earth, as there is between the ether +around Jupiter and the ether within; so that the centrifugal tendency of +the dense ether at Jupiter shall counteract the greater momentum of the +dense ether within Jupiter; or, that the lack of centrifugal momentum in +the earth should be rendered equal to the centrifugal momentum of +Jupiter, by the deficiency of the centrifugal momentum of the ether at +the distance of the earth. + +If then, the diameters of all the planets were the same (supposing the +ether to act only superficially), the densities would be as the +distances inversely;[37] for the force due to the radial stream is as +the square roots of the distance inversely, and the force due to the +momentum, if the density of the ether within a planet be inversely as +the square root of a planet's distance, will also be inversely as the +square roots of the distances approximately. We offer these views, +however, only as suggestions to others more competent to grapple with +the question, as promising a satisfactory solution of Bode's empirical +formula. + +If there be a wave of denser ether cylindrically disposed around the +vortex at the distance of Saturn, or between Saturn and Uranus, we see +why the law of densities and distances is not continuous. For, if the +law of density changes, it must be owing to such a ring or wave. Inside +this wave, the two forces will be inverse; but outside, one will be +inverse, and the other direct: hence, there should also be a change in +the law of distances. As this change does not take place until we pass +Uranus, it may be suspected that the great disparity in the density of +Saturn may be more apparent than real. The density of a planet is the +relation between its mass and volume or extension, no matter what the +form of the body may be. From certain observations of Sir Wm. +Herschel--the Titan of practical astronomers--the figure of Saturn was +suspected to be that of a square figure, with the corners rounded off, +so as to leave both the equatorial and polar zones flatter than +pertained to a true spheroidal figure. The existence of an unbroken ring +around Saturn, certainly attaches a peculiarity to this planet which +prepares us to meet other departures from the usual order. And when we +reflect on the small density, and rapid rotation, the formation of this +ring, and the figure suspected by Sir Wm. Herschel, it is neither +impossible nor improbable, that there may be a cylindrical vacant space +surrounding the axis of Saturn, or at least, that his solid parts may be +cylindrical, and his globular form be due to elastic gases and vapors, +which effectually conceal his polar openings. And also, by dilating and +contracting at the poles, in consequence of inclination to the radial +stream, (just as the earth's atmosphere is bulged out sufficiently to +affect the barometer at certain hours every day,) give that peculiarity +of form in certain positions of the planet in its orbit. Justice to Sir +Wm. Herschel requires that _his_ observations shall not be attributed to +optical illusions. This view, however, which may be true in the case of +Saturn, would be absurd when applied to the earth, as has been done +within the present century. From these considerations, it is at least +possible, that the density of Saturn may be very little less, or even +greater than the density of Uranus, and be in harmony with the law of +distances. + +It is now apparently satisfactorily determined, that Neptune is denser +than Uranus, and the law being changed, we must look for transneptunean +planets at distances corresponding with the new law of arrangement. But +there are other modifying causes which have an influence in fixing the +precise position of equilibrium of a planet. Each planet of the system +possessing rotation, is surrounded by an ethereal vortex, and each +vortex has its own radial stream, the force of which in opposing the +radial stream of the sun, depends on the diameter and density of the +planet, on the velocity of rotation, on the inclination of its axis, and +on the density of the ether at each particular vortex; but the numerical +verification of the position of each planet with the forces we have +mentioned, cannot be made in the present state of the question. There is +one fact worthy of note, as bearing on the theory of vortices in +connection with the rotation of the planets, viz.: that observation has +determined that the axial rotation and sidereal revolution of the +secondaries, are identical; thus showing that they are without vortices, +and are motionless relative to the ether of the vortex to which they +belong. We may also advert to the theory of Doctor Olbers, that the +asteroidal group, are the fragments of a larger planet which once +filled the vacancy between Mars and Jupiter. Although this idea is not +generally received, it is gathering strength every year by the discovery +of other _fragments_, whose number now amounts to twenty-six. If the +idea be just, our theory offers an explanation of the great differences +observable in the mean distances of these bodies, and which would +otherwise form a strong objection against the hypothesis. For if these +little planets be fragments, there will be differences of density +according as they belonged to the central or superficial parts of the +quondam planet, and their mean distances must consequently vary also. + +There are some other peculiarities connecting the distances and +densities, to which we shall devote a few words. In the primordial state +of the system, when the nebulous masses agglomerated into spheres, the +diameter of these nebulous spheres would be determined by the relation +existing between the rotation of the mass, and the gravitating force at +the centre; for as long as the centrifugal force at the equator exceeded +the gravitating force, there would be a continual throwing off of matter +from the equator, as fast as it was brought from the poles, until a +balance was produced. It is also extremely probable, (especially if the +elementary components of water are as abundant in other planets as we +have reason to suppose them to be on the earth,) that the condensation +of the gaseous planets into liquids and solids, was effected in a _brief +period of time_,[38] leaving the lighter and more elastic substances as +a nebulous atmosphere around globes of semi-fluid matter, whose +diameters have never been much increased by the subsequent condensation +of their gaseous envelopes. The extent of these atmospheres being (in +the way pointed out) determined by the rotation, their subsequent +condensation has not therefore changed the original rotation of the +central globe by any appreciable quantity. The present rotation of the +planets, is therefore competent to determine the former diameters of the +nebulous planets, _i.e._, the limit where the present central force +would be balanced by the centrifugal force of rotation. If we make the +calculation for the planets, and take for the unit of each planet its +present diameter, we shall find that they have condensed from their +original nebulous state, by a quantity dependent on the distance, from +the centre of the system; and therefore on the original temperature of +the nebulous mass at that particular distance. Let us make the +calculation for Jupiter and the earth, and call the original nebulous +planets the nucleus of the vortex. We find the Equatorial diameter of +Jupiter's nucleus in equatorial diameters of Jupiter=2.21, and the +equatorial diameter of the earth's nucleus, in equatorial diameters of +the earth =6.59. Now, if we take the original temperature of the +nebulous planets to be inversely, as the squares of the distances from +the sun, and their volumes directly as the cubes of the diameters in the +unit of each, we find that these cubes are to each other, in the inverse +ratio of the squares of the planet's distances; for, + + 2.21 : 6.59 :: 1 : 5.2, + +showing that both planets have condensed equally, allowing for the +difference of temperature at the beginning. And we shall find, beginning +at the sun, that the diameters of the nebulous planets, _ceteris +paribus_, diminish outwards, giving for the nebulous sun a diameter of +16,000,000 miles,[39] thus indicating his original great temperature. + +That the original nebulous planets did rotate in the same time as they +do at present, is proved by Saturn's ring; for if we make the +calculation, about twice the diameter of Saturn. Now, the diameter of +the planet is about 80,000 miles, which will also be the semi-diameter +of the nebulous planet; and the middle of the outer ring has also a +semi-diameter of 80,000 miles; therefore, the ring is the equatorial +portion of the original nebulous planet, and ought, on this theory, to +rotate in the same time as Saturn. According to Sir John Herschel, +Saturn rotates in 10 hours, 29 minutes, and 17 seconds, and the ring +rotates in 10 hours, 29 minutes, and 17 seconds: yet this is not the +periodic time of a satellite, at the distance of the middle of the ring; +neither ought the rings to rotate in the same time; yet as far as +observation can be trusted, both the inner and outer ring do actually +rotate in the same time. The truth is, the ring rotates too fast, if we +derive its centrifugal force from the analogy of its satellites; but it +is, no doubt, in equilibrium; and the effective mass of Saturn on the +satellites is less than the true mass, in consequence of his radial +stream being immensely increased by the additional force impressed on +the ether, by the centrifugal velocity of the ring. If this be so, the +mass of Saturn, derived from one of the inner satellites, will be less +than the same mass derived from the great satellite, whose orbit is +considerably inclined. The analogy we have mentioned, between the +diameters of the nebulous planets and their distances, does not hold +good in the case of Saturn, for the reason already assigned, viz.: that +the nebulous planet was probably not a globe, but a cylindrical ring, +vacant around the axis, as there is reason to suppose is the case at +present. + +And now we have to ask the question, Did the ether involved in the +nebulous planets rotate in the same time? This does not necessarily +follow. The ether will undoubtedly tend to move with increasing velocity +to the very centre of motion, obeying the great dynamical principle when +unresisted. If resisted, the law will perhaps be modified; but in this +case, its motion of translation will be converted into atomic motion or +heat, according to the motion lost by the resistance of atomic matter. +This question has a bearing on many geological phenomena. As regards the +general effect, however, the present velocity of the ether circulating +round the planets, may be considered much greater than the velocities of +the planets themselves. + + +PERTURBATIONS DUE TO THE ETHER. + +In these investigations it is necessary to bear in mind that the whole +resisting power of the ether, in disturbing the planetary movements, is +but small, in comparison with gravitation. We will, however, show that, +in the case of the planets, there is a compensation continually made by +this resistance, which leaves but a very small outstanding balance as a +disturbing power. If we suppose all the planets to move in the central +plane of the vortex in circular orbits, and the force of the radial +stream, (or that portion which is not in accordance with the law of +gravitation,) to be inversely as the square roots of the distances from +the sun, it is evident, from what has been advanced, that an equilibrium +could still obtain, by variations in the densities, distances and +diameter of the planets. Supposing, again, that the planets still move +in the same plane, but in elliptical orbits, and that they are in +equilibrium at their mean distances, under the influence or action of +the tangential current, the radial stream, and the density of the ether; +we see that the force of the radial stream is too great at the +perihelion, and too small at the aphelion. At the perihelion the planet +is urged from the sun and at the aphelion towards the sun. The density +and consequent momentum is also relatively too great at the perihelion, +which also urges the planet from the sun, and at the aphelion, +relatively too small, which urges the planet towards sun; and the law is +the same in both cases, being null at the mean distance of the planet, +at a maximum at the apsides; it is, consequently, as the cosine of the +planet's eccentric anomaly at other distances, and is positive or +negative, according as the planet's distance is above or below the mean. + +At the planet's mean distance, the circular velocity of the vortex is +equal to the circular velocity of the planet, and, at different +distances, is inversely in the sub-duplicate ratio of those distances. +But the circular velocity of a planet in the same orbit, is in the +simple ratio of the distances inversely. At the perihelion, the planet +therefore moves faster than the ether of the vortex, and at the +aphelion, slower; and the difference is as the square roots of the +distances; but the force of resistance is as the square of the velocity, +and is therefore in the simple ratio of the distances, as we have +already found for the effect of the radial stream, and centrifugal +momentum of the internal ether. At the perihelion this excess of +tangential velocity creates a resistance, which urges the planet towards +the sun, and at the aphelion, the deficiency of tangential velocity +urges the planet from the sun,--the maximum effect being at the apsides +of the orbit, and null at the mean distances. In other positions it is, +therefore, as the cosines of the eccentric anomaly, as in the former +case; but in this last case it is an addititious force at the +perihelion, and an ablatitious force at the aphelion, whereas the first +disturbing force was an ablatitious force at the perihelion, and an +addititious force at the aphelion; therefore, as we must suppose the +planet to be in equilibrium at its mean distance, it is in equilibrium +at all distances. Hence, a planet moving in the central plane of the +vortex, experiences no disturbance from the resistance of the ether. + +As the eccentricities of the planetary orbits are continually changing +under the influence of the law of gravitation, we must inquire whether, +under these circumstances, such a change would not produce a permanent +derangement by a change in the mean force of the radial stream, so as to +increase or diminish the mean distance of the planet from the sun. The +law of force deduced from the theory for the radial stream is as the 2.5 +power of the distances inversely. But, by dividing this ratio, we may +make the investigation easier; for it is equivalent to two forces, one +being as the squares of the distances, and another as the square roots +of the distances. For the former force, we find that in orbits having +the same major axis the mean effect will be as the minor axis of the +ellipse _inversely_, so that two planets moving in different orbits, but +at the same mean distance, experience a less or greater amount of +centripulsive force from this radial stream, according as their orbits +are of less or greater eccentricity, and this in the ratio of the minor +axis. On the other hand, under the influence of a force acting +centripulsively in the inverse ratio of the square roots of the +distances, we find the mean effect to be as the minor axis of the +ellipse _directly_, so that two planets in orbits of different +eccentricity, but having the same major axis, experience a different +amount from the action of this radial stream, the least eccentric orbit +being that which receives the greatest mean effect. By combining these +two results, we get a ratio of equality; and, consequently, the action +of the radial stream will be the same for the same orbit, whatever +change may take place in the eccentricity, and the mean distance of the +planet will be unchanged. A little consideration will also show that the +effect of the centrifugal momentum due to the density of ether will also +be the same by change of eccentricity; for the positive will always +balance the negative effect at the greatest and least distances of the +planet. The same remark applies to the effect of the tangential current, +so that no change can be produced in the major axes of the planetary +orbits by change of eccentricity, as an effect of the resistance of the +ether. + +We will now suppose a planet's orbit to be inclined to the central plane +of the vortex, and in this case, also, we find, that the action of the +radial stream tends to increase the inclination in one quadrant as much +as it diminishes it in the next quadrant, so that no change of +inclination will result. But, if the inclination of the orbit be changed +by planetary perturbations, the mean effect of the radial stream will +also be changed, and this will tell on the major axis of the orbit, +enlarging the orbit when the inclination diminishes, and contracting it +when it increases. The change of inclination, however, must be referred +to the central plane of the vortex. Notwithstanding the perfection of +modern analysis, it is confessed that the recession of the moon's nodes +does yet differ from the theory by its 350th part, and a similar +discrepancy is found for the advance of the perigee.[40] This theory is +yet far too imperfect to say that the action of the ethereal medium will +account for these discrepancies; but it certainly wears a promising +aspect, worthy the notice of astronomers. There are other minute +discordancies between theory and observation in many astronomical +phenomena, which theory _is_ competent to remove. Some of these we shall +notice presently; and, it may be remarked, that it is in those minute +quantities which, in astronomy, are usually attributed to errors of +observation, that this theory will eventually find the surest evidence +of its truth. + + +KEPLER'S THIRD LAW ONLY APPROXIMATELY TRUE. + +But it may be asked: If there be a modifying force in astronomy derived +from another source than that of gravitation, why is it that the +elements of the various members of the system derived solely from +gravitation should be so perfect? To this it may be answered, that +although astronomers have endeavored to derive every movement in the +heavens from that great principle, they have but partially succeeded. +Let us not surrender our right of examining Nature to the authority of a +great name, nor call any man master, either in moral or physical +science. It is well known that Kepler's law of the planetary distances +and periods, is a direct consequence of the Newtonian Law of +gravitation, and that the squares of the periodic times ought to be +proportional to the cubes of the mean distances. These times are given +accurately by the planets themselves, by the interval elapsing between +two consecutive passages of the node, and as in the case of the ancient +planets we have observations for more than two thousand years past, +these times are known to the fraction of the second. The determination +of the distances however, depends on the astronomer, and a tyro in the +science might suppose that these distances were actually measured; and +so they are roughly; but the astronomer does not depend on his +instruments, he trusts to _analogy_, and the mathematical perfection of +a law, which in the abstract is true; but which he does not know is +rigidly exact when applied to physical phenomena. From the immense +distance of the planets and the smallness of the earth, man is unable to +command a base line sufficiently long, to make the horizontal parallax a +sensible angle for the more distant planets; and there are difficulties +of no small magnitude to contend with, with those that are the nearest. +In the occasional transit of Venus across the sun, however, he is +presented with a means of measuring on an enlarged scale, from which the +distance of the sun is determined; and by _analogy_ the distance of all +the planets. Even the parallax of the sun itself is only correct, by +supposing that the square of the periodic time of Venus is in the same +proportion to the square of the periodic time of the earth as the cube +of her distance is to the cube of the earth's distance. Our next nearest +planet is Mars, and observations on this planet at its opposition to the +sun, invariably give a larger parallax for the sun--Venus giving 8.5776" +while Mars gives about 10". It is true that the first is obtained under +more favorable circumstances; but this does not prove the last to be +incorrect. It is well known that the British Nautical Almanac contains a +list of stars lying in the path of the planet Mars about opposition, +(for the very purpose of obtaining a correct parallax,) that minute +differences of declination may be detected by simultaneous observations +in places having great differences of latitude. Yet strange to say, the +result is discredited when not conformable to the parallax given by +Venus. If then, we cannot trust the parallax of Mars, _ fortiori_, how +can we trust the parallax of Jupiter, and say that his mean distance +exactly corresponds to his periodic time? Let us suppose, for instance, +that the radius vector of Jupiter fell short of that indicated by +analogy by 10,000 miles, we say that it would be extremely difficult, +nay, utterly impossible, to detect it by instrumental means. Let not +astronomers, therefore, be too sure that there is not a modifying cause, +independent of gravitation, which they will yet have to recognize. The +moon's distance is about one-fourth of a million of miles, and Neptune's +2854 millions, or in the ratio of 10,000 to 1; yet even the moon's +parallax is not trusted in determining her mass, how then shall we +determine the parallax of Neptune? It is therefore _possible_ that the +effective action of the sun is in some small degree different, on the +different planets, whether due to the action of the ether, to the +similarity or dissimilarity of material elements, to the temperature of +the different bodies, or to all combined, is a question yet to be +considered. + +As another evidence of the necessity of modifying the strict wording of +the Newtonian law, it is found that the disturbing action of Jupiter on +different bodies, gives different values for the mass of Jupiter. The +mass deduced from Jupiter's action on his satellites, is different from +that derived from the perturbations of Saturn, and this last does not +correspond with that given by Juno: Vesta also gives a different mass +from the comet of Encke, and both vary from the preceding values.[41] + +In the analytical investigation of planetary disturbances, the +disturbing force is usually divided into a radial and tangential force; +the first changing the law of gravitation, to which law the elliptic +form of the orbit is due. The radial disturbing force, therefore, being +directed to or from the centre, can have no influence over the first law +of Kepler, which teaches that the radius vector of each planet having +the sun as the centre, describes equal areas in equal times. If the +radial disturbing force be exterior to the disturbed body, it will +diminish the central force, and cause a progressive motion in the +aphelion point of the orbit. In the case of the moon this motion is very +rapid, the apogee making an entire revolution in 3232 days. Does this, +however, correspond with the law of gravitation? Sir Isaac Newton, in +calculating the effect of the sun's disturbing force on the motion of +the moon's apogee, candidly concludes thus: "Idoque apsis summa singulis +revolutionibus progrediendo conficit 1 31' 28". Apsis lun est duplo +velocior circiter." As there was a necessity for reconciling this +stubborn fact with the theory, his followers have made up the deficiency +by resorting to the tangential force, or, as Clairant proposed, by +continuing the approximations to terms of a higher order, or to the +square of the disturbing force. + +Now, in a circular orbit, this tangential force will alternately +increase and diminish the velocity of the disturbed body, without +producing any permanent derangement, the same result would obtain in an +elliptical orbit, if the position of the major axis were stationary. In +the case of the moon, the apogee is caused to advance by the disturbing +power of the radial force, and, consequently, an exact compensation is +not effected: there remains a small excess of velocity which geometers +have considered equivalent to a doubling of the radial force, and have +thus obviated the difficulty. To those not imbued with the profound +penetration of the modern analyst, there must ever appear a little +inconsistency in this result. The major axis of a planet's orbit depends +solely on the velocity of the planet at a given distance from the sun, +and the tangential portion of the disturbance due to the sun, and +impressed upon the moon, must necessarily increase and diminish +alternately the velocity of the moon, and interfere with the equable +description of the areas. If, then, there be left outstanding a small +excess of velocity over and above the elliptical velocity of the moon, +at the end of each synodical revolution, in consequence of the motion +impressed on the moon's apogee by the radial force, the _legitimate_ +effect would be a small enlargement of the lunar orbit every revolution +in a rapidly-increasing ratio, until the moon would at last be taken +entirely away. In the great inequality of Jupiter and Saturn, this +tangential force is not compensated at each revolution, in consequence +of continual changes in the configuration of the two planets at their +heliocentric conjunctions, with respect to the perihelion of their +orbits, and the near commensurability of their periods; and the effect +of the tangential force is, in this case, legitimately impressed on the +major axes of the orbits. But why (we may ask) should not this also be +expended on the motion of the aphelion as well as in the case of the +moon? Astronomy can make no distinctions between the orbit of a planet +and the orbit of a satellite. And, we might also ask, why the tangential +resistance to the comet of Encke should not also produce a retrograde +motion in the apsides of the orbit, instead of diminishing its period? +To the honor of Newton, be it remembered, that he never resorted to an +explanation of this phenomenon, which would vitiate that fundamental +proposition of his theory, in which the major axis of the orbit is shown +to depend on the velocity at any given distance from the focus. + +Some cause, however, exists to double the motion of the apogee, and +that there is an outstanding excess of orbital velocity due to the +tangential force, is also true. This excess may tell in the way +proposed, provided some other arrangement exists to _prevent_ a +permanent dilation of the lunar orbit; and this provision may be found +in the increasing density of the ether, which prevents the moon +overstepping the bounds prescribed by her own density, and the force of +the radial stream of the terral vortex. In the case of Jupiter and +Saturn, their mutual action is much less interfered with by change of +density in the ether in the enlarged or contracted orbit, and, +consequently, the effect is natural. Thus, we have in the law of density +of the ethereal medium a better safeguard to the stability of the +dynamical balance of the system, than in the profound and beautiful +Theorems of La Grange. It will, of course, occur to every one, that we +are not to look for the same law in every vortex, and it will, +therefore, appear as if the satellites of Jupiter, whose theory is so +well known, should render apparent any deviation between their periodic +times and the periodic times of the contiguous parts of the vortex, +which would obtain, if the density of the ether in the Jovian vortex +were not as the square roots of the distances directly. But, we have +shown how there can be a balance preserved, if the tangential resistance +of the vortex shall be equal and contrary at the different distances at +which the satellites are placed; that is, if these two forces shall +follow the same law. These are matters, however, for future +investigation. + + +LIGHT AND HEAT. + +But will not the admission of a vorticose motion of the ethereal medium, +affect the aberration of light? It is well known that the question has +been mooted, whether the velocity of reflected light is the same as that +of direct light. The value of aberration having been considered 20".25, +from the eclipses of Jupiter's satellites, while later determinations, +from observations on Polaris, give 20".45. It cannot be doubted that +light, in traversing the central parts of the solar vortex, that is, +having to cross the whole orbit of the earth, should pass this distance +in a portion of time somewhat different to a similar distance outside +the earth's orbit, where the density is greater, and consequently induce +an error in the aberration, determined by the eclipses of Jupiter's +satellites. In the case of Polaris, the circumstances are more equal; +still, a difference ought to be detected between the deduced aberration +in summer and in winter, as, in the first case, the light passes near +the axis of the solar vortex, where (according to the theory) a change +of density occurs. This is an important practical question, and the +suggestion is worthy attention. Now, the question occurs, will light +pass through the rarefied space with greater velocity than through the +denser ether beyond? From recent experiments, first instituted by Arago, +it is determined that light passes with less velocity through water than +through air; and one result of these experiments is the confirmation +they give to the theory of Fresnel, that the medium which conveys the +action of light partly partakes of the motion of the refracting body. +This of itself is a strong confirmation of this theory of an ethereal +medium. It may also be remarked, that every test applied to the +phenomenon of light, adds additional strength to the undulatory theory, +at the expense of the Newtonian theory of emission. As light occupies +time in traversing space, it must follow from the theory that it does +not come from the radiant point exactly in straight lines, inasmuch as +the ether itself is in motion tangentially,--the velocity being in the +sub-duplicate ratio of the distances from the sun inversely. + +May not that singular phenomenon,--the projection of a star on the +moon's disc, at the time of an occultation,--be due to this curvature of +the path of a ray of light, by considering that the rays from the moon +have less intensity, but more mechanical momentum, and consequently +more power to keep a straight direction? Let us explain: we have urged +that light, as well as heat, is a mechanical effect of atomic motion, +propagated through an elastic medium; that, _ceteris paribus_, the +product of matter by its motion is ever a constant quantity for equal +spaces throughout the universe,--in a word, that it is, and must +necessarily be, a fundamental law of nature. All departures from this +law are consequences of accidental arrangements, which can only be +considered of temporary duration. Our knowledge of planetary matter +requires the admission of differences in the density, form, and size of +ultimate atoms, and, according to the above law, when the atoms are of +uniform temperature or motion, the product of the matter of each by its +motion, when reduced to the same space, will be constant. The momentum +of two different atoms, therefore, we will consider equal, for the sake +of illustration; yet this momentum is made up of two different +elements,--matter and motion. Let us exaggerate the difference, and +assign a ratio of 1000 to 1. Suppose a ball of iron of 1000 lbs., +resting upon a horizontal plane, should be struck by another ball of 1 +lb., having a motion of 1000 feet in a second, and, in a second case, +should be struck by a ball of 1000 lbs., having a velocity of 1 foot per +second, the momentum of each ball is similar; but experience proves that +the motion impressed on the ball at rest is not similar; the ponderous +weight and slow motion is far more effective in displacing this ball, +for the reason that time is essential to the distribution of the motion. +If the body to be struck be small as, for instance, a nail, a greater +motion and less matter is more effective than much matter and little +motion. Hence, we have a _distinction_ applicable to the difference of +momentum of luminous and calorific rays. The velocity of a wave of sound +through the atmosphere, is the same for the deep-toned thunder and the +shrillest whistle,--being dependent on the density of the medium, and +not on the source from which it emanates. So it is in the ethereal +medium. + +This view is in accordance with the experiments of M. Delaroche and +Melloni, on the transmission of light and heat through diaphanous +bodies--the more calorific rays feeling more and more the influence of +thickness, showing that more motion was imparted to the particles of the +diaphanous substance by the rays possessing more material momentum, and +still more when the temperature of the radiating body was low, evidently +analogous to the illustration we have cited. Light may therefore be +regarded as the effect of the vibration of atoms having little mass, and +as this mass increases, the rays become more calorific, and finally the +calorific effect is the only evidence of their existence; as towards the +extreme red end of the spectrum they cease to be visible, owing to their +inability to impart their vibrations to the optic nerve. This may also +influence the law of gravitation. In this we have also an explanation of +the dispersion of light. The rays proceeding from atoms of small mass +having less material momentum, are the most refrangible, and those +possessing greater material momentum, are the least refrangible; so that +instead of presenting a difficulty in the undulatory theory of light, +this dispersion is a necessary consequence of its first principles. + +It is inferred from the experiments cited, and the facts ascertained by +them, viz.: that the velocity of light in water is less than its +velocity in air; that the density of the ether is greater in the first +case; but this by no means follows. We have advocated the idea, that the +ethereal medium is less dense within a refracting body than without. We +regard it as a fundamental principle. Taking the free ether of heaven; +the vibrations in the denser ether will no doubt be slowest; but within +a refracting body we must consider there is motion lost, or _light +absorbed_, and the time of the transmission is thus increased. + +There has been a phenomenon observed in transits of Mercury and Venus +across the sun, of which no explanation has been rendered by +astronomers. When these planets are visible on the solar disc, they are +seen surrounded by rings, as if the light was intercepted and increased +alternately. This is no doubt due to a small effect of interference, +caused by change of velocity in passing through the rarefied nucleus of +these planetary vortices, near the body of the planet, and through the +denser ether beyond, acting first as a concave, and secondly as a convex +refracting body; always considering that the ray will deviate _towards_ +the side of least insistence, and thus interfere. + +That heat is simply atomic motion, and altogether mechanical, is a +doctrine which ought never to have been questioned. The interest excited +by the bold experiments of Ericson, has caused the scientific to +_suspect_, that heat can be converted into motion, and motion into +heat--a fact which the author has considered too palpable to deny for +the last twenty years. He has ever regarded matter and motion as the two +great principles of nature, ever inseparable, yet variously combined; +and that without these two elements, we could have no conception of +anything existing. + +It may be thought by some, who are afraid to follow truth up the rugged +precipices of the hill of knowledge, that this theory of an +interplanetary plenum leads to materialism; forgetting, that He who made +the world, formed it of matter, and pronounced it "very good." We may +consider ethereal matter, in one sense, _purer_ than planetary matter, +because unaffected by chemical laws. Whether still purer matter exists, +it is not for us to aver or deny. The Scriptures teach us that "there is +a natural body and there is a spiritual body." Beyond this we know +nothing. We, however, believe that the _invisible_ world of matter, can +only be comprehended by the indications of that which is visible; yet +while humbly endeavoring to connect by one common tie, the various +phenomena of matter and motion, we protest against those doctrines which +teach the eternal duration of the present order of things, as being +incompatible with the analogies of the past, as well as with the +revelations of the future. + + +FOOTNOTES: + +[35] Silliman's Journal, vol xxxv., page 283. + +[36] The real diameter of the earth in that latitude, whose sine is +one-third, is a little greater than this; but the true mean is more +favorable for the Newtonian law. + +[37] This is, perhaps, the nearest ratio of the densities and distances. + +[38] This is an important consideration, as bearing on the geology of +the earth. + +[39] It is not as likely that the condensation of the sun was so sudden +as that of the planets, and therefore in this case this distance is only +approximate. + +[40] Mechanique Celeste. Theory of the Moon. + +[41] Mechanique Celeste. Masses of the planets. + + + + +SECTION FIFTH. + + +COMETARY PHENOMENA. + +The planetary arrangements of the solar system are all _ priori_ +indications of the theory of vortices, not only by the uniform direction +of the motions, the circular orbits in which these motions are +performed, the near coincidence of the planes of these orbits, and the +uniform direction of the rotation of the planets themselves; but, also, +by the law of densities and distances, which we have already attempted +to explain. In the motions of comets we find no such agreement. These +bodies move in planes at all possible inclinations in orbits extremely +eccentrical and without any general direction--as many moving contrary +to the direction of the planets as in the opposite direction; and when +we consider their great volume, and their want of mass, it appears, at +first sight, that comets do present a serious objection to the theory. +We shall point out, however, a number of _facts_ which tend to +invalidate this objection, and which will ultimately give the +preponderance to the opposite argument. + +Every fact indicative of the nature of comets proves that the nuclei are +masses of material gases, similar, perhaps (at least in the case of the +short-period comets), to the elementary gases of our own planet, and, +consequently, these masses must be but small. In the nascent state of +the system, the radial stream of the vortex would operate as a fan, +purging the planetary materials of the least ponderable atoms, and, as +it were, separating the wheat from the chaff. It is thus we conceive +that the average atomic density of each planet has been first determined +by the radial stream, and, subsequently, that the solidification of the +nebulous planets has, by their atomic density, assigned to each its +position in the system, from the consequent relation which it +established between the density of the ether within the planet, and the +density of the ether external to it, so that, according to this view, a +single isolated atom of the same density as the mean atomic density of +the earth could (_ceteris paribus_) revolve in an orbit at the distance +of the earth, and in the same periodic time. This, however, is only +advanced by way of illustration. + +The expulsive force of the radial stream would thus drive off this +cometary dust to distances in some inverse ratio of the density of the +atoms; but, a limit would ultimately be reached, when gravitation would +be relatively the strongest--the last force diminishing only as the +squares of the distances, and the first diminishing in the compound +ratio of the squares and the square roots of the distances. At the +extreme verge of the system, this cometary matter would accumulate, and, +by accumulation, would still further gather up the scattered atoms--the +sweepings of the inner space--and, in this condensed form, would again +visit the sun in an extremely elongated ellipse. It does not, however, +follow, that all comets are composed of such unsubstantial materials. +There may be comets moving in parabolas, or even in hyperbolas--bodies +which may have been accumulating for ages in the unknown regions of +space, far removed from the sun and stars, drifting on the mighty +currents of the great ethereal ocean, and thus brought within the sphere +of the sun's attraction; and these bodies may have no analogy to the +periodical comets of our system, which last are those with which we are +more immediately concerned. + +The periodical comets known are clearly arranged into two distinct +classes--one having a mean distance between Saturn and Uranus, with a +period of about seventy-five years, and another class, whose mean +distance assigns their position between the smaller planets and Jupiter, +having periods of about six years. These last may be considered the +siftings of the smaller planets, and the first the refuse of the +Saturnian system. In this light we may look for comets having a mean +distance corresponding to the intervals of the planets, rather than to +the distances of the planets themselves. One remarkable fact, however, +to be observed in these bodies is, that all their motions are in the +same direction as the planets, and, with one exception, there is no +periodical comet positively known whose motion is retrograde. + +The exception we have mentioned is the celebrated comet of Halley, whose +period is also about seventy-five years. In reasoning on the resistance +of the ether, we must consider that the case can have very little +analogy with the theory of projectiles in air; nor can we estimate the +inertia of an infinitely divisible fluid, from its resisting influence +on atomic matter, by a comparison of the resistance of an atomic fluid +on an atomic solid. Analogy will only justify comparisons of like with +like. The tangent of a comet's orbit, also, can only be tangential to +the circular motion of the ether at and near perihelion, which is a very +small portion of its period of revolution. As far as the tangential +resistance is concerned, therefore, it matters little whether its motion +be direct or retrograde. If a retrograde comet, of short period and +small eccentricity, were discovered moving also near the central plane +of the vortex, it would present a very serious objection, as being +indicative of contrary motions in the nascent state of the system. There +is no such case known. So, also, with the inclinations of the orbits; if +these be great, it matters little whether the comet moves in one way or +the other, as far as the tangential current of the vortex is concerned. +Yet, when we consider the average inclination of the orbit, and not of +its plane, we find that the major axes of nearly all known cometary +orbits are very little inclined to the plane of the ecliptic. + +In the following table of all the periodical comets known, the +inclination of the major axis of the orbit is calculated to the nearest +degree; but all cometary orbits with very few exceptions, will be found +to respect the ecliptic, and never to deviate far from that plane: + + +--------------------------------------------------------------------+ + | Designations | Periodic | Inclination | Motion | Planetary | + | of the Comets. | times. | of | in Orbit. | Intervals. | + | | | Major Axes | | | + |--------------------------------------------------------------------| + |Encke | 1818 | 3 years. | 1 | Direct |Mars & Ceres.| + |--------------------------------------------------------------------| + |De Vico | 1814 | | 2 | Direct | | + |Fayo | 1843 | | 4 | Direct | Ceres | + |De Avrest| 1851 | From | 1 | Direct | | + |Brorsen | 1846 | five | 7 | Direct | and | + |Messier | 1766 | to | 0 | Direct | | + |Clausen | 1743 | six | 0 | Direct | Jupiter. | + |Pigott | 1783 | or | 4 | Direct | | + |Pous | 1819 | seven | 3 | Direct | | + |Biela | 1826 | years. | 9 | Direct | | + |Blaupain | 1819 | | 2 | Direct | | + |Lexell | 1770 | | 1 | Direct | | + |--------------------------------------------------------------------| + |Pous | 1812 | | 17 | Direct | | + |Olbers | 1816 | about | 40 | Direct | Saturn | + |De Vico | 1846 | 75 | 13 | Direct | and | + |Brorsen | 1847 | years. | 12 | Direct | Uranus. | + |Westphal | 1852 | | 21 | Direct | | + |Halley | 1682 | | 16 | Retrograde| | + +--------------------------------------------------------------------+ + +From which it appears, that the objection arising from the great +inclination of the _planes_ of these orbits is much less important than +at first it appears to be. + +Regarding then, that a comet's mean distance depends on its mean atomic +density, as in the case of the planets, the undue enlargement of their +orbits by planetary perturbations is inadmissible. In 1770 Messier +discovered a comet which approached nearer the earth than any comet +known, and it was found to move in a small ellipse with a period of five +and a half years; but although repeatedly sought for, it was the +opinion of many, that it has never been since seen. The cause of this +seeming anomaly is found by astronomers in the disturbing power of +Jupiter,--near which planet the comet must have passed in 1779, but the +comet was not seen in 1776 before it passed near Jupiter, although a +very close search was kept up about this time. Now there are two +suppositions in reference to this body: the comet either moved in a +larger orbit previous to 1767, and was then caused by Jupiter to +diminish its velocity sufficiently to give it a period of five and a +half years, and that after perihelion it recovered a portion of its +velocity in endeavoring to get back into its natural orbit; or if moving +in the natural orbit in 1770, and by passing near Jupiter in 1779 this +orbit was deranged, the comet will ultimately return to that mean +distance although not necessarily having elements even approximating +those of 1770. In 1844, September 15th, the author discovered a comet in +the constellation Cetus, (the same previously discovered by De Vico at +Home,) and from positions _estimated with the naked eye_ approximately +determined the form of its orbit and its periodic time to be very +similar to the lost comet of 1770. These conclusions were published in a +western paper in October 1844, on which occasion he expressed the +conviction, that this was no other than the comet of 1770. As the +question bore strongly on his theory he paid the greater attention to +it, and had, previously to this time, often searched in hopes of finding +that very comet. Since then, M. Le Verrier has examined the question of +identity and given his decision against it; but the author is still +sanguine that the comet of 1844 is the same as that of 1770, once more +settled at its natural distance from the sun. This comet returns to its +perihelion on the 6th of August, 1855, according to Dr.Brnnow, when, +it is hoped, the question of identity will be reconsidered with +reference to the author's principles; and, that when astronomers become +satisfied of this, they will do him the justice of acknowledging that +he was the first who gave publicity to the fact, that the "Lost Comet" +was found. + +That comets do experience a resistance, is undeniable; but not in the +way astronomers suppose, if these views be correct. The investigations +of Professor Encke, of Berlin, on the comet which bears his name, has +determined the necessity of a correction, which has been applied for +several returns with apparent success. But there is this peculiarity +about it, which adds strength to our theory: "The Constant of +Resistance" requires a change after perihelion. The necessity for this +change shows the action of the radial stream. From the law of this +force, (reckoning on the central plane of the vortex,) there is an +outstanding portion, acting as a disturbing power, in the sub-duplicate +ratio of the distances inversely. If we only consider the mean or +average effect in orbits nearly circular, this force may be considered +as an ablatitious force at all distances below the mean, counterbalanced +by an opposite effect at all distances above the mean. But when the +orbits become very eccentrical, we must consider this force as +momentarily affecting a comet's velocity, diminishing it as it +approaches the perihelion, and increasing it when leaving the +perihelion. A resolution of this force is also requisite for the comet's +distance above the central plane of the vortex, and a correction, +likewise, for the intensity of the force estimated in that plane. There +is also a correction necessary for the perihelion distance, and another +for the tangential current; but we are only considering here the general +effect. By diminishing the comet's proper velocity in its orbit, if we +consider the attraction of the sun to remain the same, the general +effect _may_ be (for this depends on the tangential portion of the +resolved force preponderating) that the absolute velocity will be +increased, and the periodic time shortened; but after passing the +perihelion, with the velocity of a smaller orbit, there is also +superadded to this already undue velocity, the expulsive power of the +radial stream, adding additional velocity to the comet; the orbit is +therefore enlarged, and the periodic time increased. Hence the necessity +of changing the "Constant of Resistance" after perihelion, and this will +generally be found necessary in all cometary orbits, if this theory be +true. But this question is one which may be emphatically called the most +difficult of dynamical problems, and it may be long before it is fully +understood. + +According to the calculations of Professor Encke, the comet's period is +accelerated about 2 hours, 30 minutes, at each return, which he +considers due to a resisting medium. May it not rather be owing to _the +change of inclination of the major axis of the orbit, to the central +plane of the vortex_? Suppose the inclination of the _plane_ of the +orbit to remain unchanged, and the eccentricity of the orbit also, if +the longitude of the perihelion coincides with that of either node, the +major axis of the orbit lies in the ecliptic, and the comet then +experiences the greatest mean effect from the radial stream; its mean +distance is then, _ceteris paribus_, the greatest. When the angle +between the perihelion and the nearest node increases, the mean force of +the radial stream is diminished, and the mean distance is diminished +also. When the angle is 90, the effect is least, and the mean distance +least. This is supposing the ecliptic the central plane of the vortex. +When Encke's formula was applied to Biela's comet, it was inadequate to +account for a tenth part of the acceleration; and although Biela moves +in a much denser medium, and is of less dense materials, even this taken +into account will not satisfy the observations,--making no other change +in Encke's formula. We must therefore attribute it to changes in the +elements of the orbits of these comets. Now, the effect of resistance +should also have been noticed, as an acceleration of Halley's comet in +1835, yet the period was prolonged. To show, that our theory of the +_cause_ of these anomalies corresponds with facts, we subjoin the +elements in the following tables, taken from Mr.Hind's catalogue: + +THE ELEMENTS OF ENCKE'S COMET. + + Date of Longitude of Longitude of Difference of + Perihelion. Perihelion. nearest Node Longitude. + 1822 157 11' 44" 154 25' 9" 2 46' 35" + 1825 157 14 31 154 27 30 2 47 1 + 1829 157 17 53 154 29 32 2 48 21 + 1832[42] 157 21 1 154 32 9 2 41 52 + 1835 157 23 29 154 34 59 2 48 30 + 1838 157 27 4 154 36 41 2 50 23 + 1842 157 29 27 154 39 10 2 50 17 + 1845 157 44 21 154 19 33 3 24 48 + 1848 157 47 8 154 22 12 3 24 56 + 1852 157 51 2 154 23 21 3 27 41 + +In this we see a regular increase of the angle, which ought to be +attended with a small acceleration of the comet; but the change of +inclination of the orbit ought also to be taken into consideration, to +get the mean distance of the comet above the plane of the vortex, and, +by this, the mean force of the radial stream. + +In the following table, the same comparison is made for Biela's comet:-- + +ELEMENTS OF BIELA'S COMET. + + Date of Longitude of Longitude of Difference of + Perihelion. Perihelion. nearest Node. Longitude. + 1772 110 14' 54" 74 0' 1" 36 14' 53" + 1806 109 32 23 71 15 15 38 17 8 + 1826 109 45 50 71 28 12 38 17 38[43] + 1832 110 55 55 68 15 36 41 45 19 + 1846 109 2 20 65 54 39 43 7 41 + +Between 1832 and 1846, the increase of the angle is twice as great for +Biela as for Encke, and the angle itself throws the major axis of Biela +10 above the ecliptic, whereas the angle made by Encke's major axis, is +only about 1; the cosine of the first angle, diminishes much faster +therefore, and consequently the same difference of longitude between the +perihelion and node, will cause a greater acceleration of Biela; and +according to Prof. Encke's theory, Biela would require a resisting +medium twenty-five times greater than the comet of Encke to reconcile +observation with the theory. Halley's comet can scarcely be considered +to have had an orbit with perfect elements before 1835. If they were +known accurately for 1759, we should no doubt find, that the angle +between the node and perihelion _diminished_ in the interval between +1750 and 1835, as according to the calculations of M. Rosenberg, the +comet was six days behind its time--a fact fatal to the common ideas of +a resisting medium; but this amount of error must be received as only +approximate. + +No comet that has revisited the sun, has given astronomers more trouble +than the great comet of 1843. Various orbits have been tried, +elliptical, parabolic and hyperbolic; yet none will accord with all the +observations. The day before this comet was seen in Europe and the +United States, it was seen close to the body of the sun at Conception, +in South America; yet this observation, combined with those following, +would give an orbital velocity due to a very moderate mean distance. +Subsequent observations best accorded with a hyperbolic orbit; and it +was in view of this anomaly, that the late Sears C. Walker considered +that the comet came into collision with the sun in an elliptical orbit, +and its _debris_ passed off again in a hyperbola. That a concussion +would not add to its velocity is certain, and the departure in a +hyperbolic orbit would be contrary to the law of gravitation. This +principle is thus stated by Newton:--"In parabola velocitas ubiquo +equalis est velocitati corporis revolventis in circulo ad dimidiam +distantiam; in ellipsi minor est in hyperbola major." (Vid. Prin. Lib. +1. Prop. 6 Cor. 7.) + +But as regards the _fact_, it is probable that Mr.Walker's views are +correct, so far as the change from an ellipse to an hyperbola is +considered. The Conception observation cannot be summarily set aside, +and Professor Peirce acknowledges, that "If it was made with anything of +the accuracy which might be expected from Captain Ray, it exhibits a +decided anomaly in the nature of the forces to which the comet was +subjected during its perihelion passage." The comet came up to the sun +almost in a straight line against the full force of the radial stream; +its velocity must therefore necessarily have been diminished. After its +perihelion, its path was directly _from_ the sun, and an undue velocity +would be kept up by the auxiliary force impressed upon it by the same +radial stream; and hence, the later observations give orbits much larger +than the early ones, and there can be no chance of identifying this +comet with any of its former appearances, even should its orbit be +elliptical. This unexpected confirmation of the theory by the +observation of Capt.Ray, cannot easily be surmounted. + +We must now endeavor to explain the physical peculiarities of comets, in +accordance with the principles laid down. The most prominent phenomenon +of this class is the change of diameter of the visible nebulosity. It is +a most singular circumstance, but well established as a fact, that a +comet contracts in its dimensions on approaching the sun, and expands on +leaving it. In 1829, accurate measures were taken on different days, of +the diameter of Encke's comet, and again in 1838. The comet of 1618 was +also observed by Kepler with this very object, and also the comet of +1807; but without multiplying instances, it may be asserted that it is +one of those facts in cometary phenomena, to which there are no +exceptions. According to all analogy, the very reverse of this ought to +obtain. If a comet is chiefly vaporous, (as this change of volume would +seem to indicate,) its approach to the sun ought to be attended by a +corresponding expansion by increase of temperature. When the contrary is +observed, and invariably so, it ought to be regarded as an index of the +existence of other forces besides gravitation, increasing rapidly in the +neighborhood of the sun; for the disturbing power of the sun's +attraction would be to enlarge the diameter of a comet in proportion to +its proximity. Now, the force of the radial stream, as we have shown, is +as the 2.5th power of the distances inversely. If this alternate +contraction and expansion be due to the action of this force, there +ought to be an approximate correspondence of the law of the effect with +the law of the cause. Arago, in speaking of the comet of 1829, states, +"that between the 28th of October and the 24th of December, the volume +of the comet was reduced as 16000 to 1, the change of distance in the +meantime only varying about 3 to 1." To account for this, a memoir was +published on the subject by M. Valz, in which he supposes an atmosphere +around the sun, whose condensation increases rapidly from superincumbent +pressure; so that the deeper the comet penetrates into this atmosphere +the greater will be the pressure, and the less the volume. In this it is +evident, that the ponderous nature of a resisting medium is not yet +banished from the schools. In commenting on this memoir, Arago justly +observes, that "there would be no difficulty in this if it could be +admitted that the exterior envelope of the nebulosity were not permeable +to the ether; but this difficulty seems insurmountable, and merits our +sincere regret; for M. Valz's ingenious hypothesis has laid down the law +of variation of the bulk of the nebulosity, as well for the short-period +comet as for that of 1618, with a truly wonderful exactness." Now, if we +make the calculation, we shall find that the diameter of the nebulosity +of a comet is inversely as the force of the radial stream. This force is +inversely as the 2.5 power of the distances from the axis, and not from +the sun: it will, therefore, be in the inverse ratio of the cosine of +the comet's heliocentric latitude to radius, and to this ratio the +comet's distance ought to be reduced. But, this will only be correct for +the same plane or for equal distances above the ecliptic plane, +considering this last as approximately the central plane of the vortex. +From the principles already advanced, the radial stream is far more +powerful on the central plane than in more remote planes; therefore, if +a comet, by increase of latitude, approaches near the axis, thus +receiving a larger amount of force from the radial stream in that plane +than pertains to its actual distance from the sun, it will also receive +a less amount of force in that plane than it would in the central plane +at the same distance from the axis. Now, we do not know the difference +of force at different elevations above the central plane of the vortex; +but as the two differences due to elevation are contrary in their +effects and tend to neutralize each other, we shall make the calculation +as if the distances were truly reckoned from the centre of the sun. + +The following table is extracted from Arago's tract on Comets, and +represents the variations of the diameter of Encke's comet at different +distances from the sun,--the radius of the orbis magnus being taken as +unity. + + Times of observation, Distances of the Real diameters + 1828. comet from the sun. in radii of the earth. + Oct. 28 1.4617 79.4 + Nov. 7 1.3217 64.8 + Nov. 30 0.9668 29.8 + Dec. 7 0.8473 19.9 + Dec. 14 0.7285 11.3 + Dec. 24 0.6419 3.1 + +In order the better to compare the diameters with the force, we will +reduce them by making the first numbers equal. + + Distances. Diameters. The 2.5th power Reduced + of the Distances. Diameters. + 1.4617 79.4 2.58 2.58 + 1.3217 64.8 2.10 2.10 + 0.9668 29.8 0.92 0.97 + 0.8473 19.9 0.66 0.65 + 0.7285 11.3 0.45 0.37 + 0.5419 3.1 0.21 0.10 + +This is a very close approximation, when we consider the difficulty of +micrometric measurement, and the fact, that as the comet gets nearer to +the sun, as at the last date of the table, the diameter is more than +proportionally diminished by the fainter nebulosity becoming invisible. +But, there may be a reality in the discrepancy apparent at the last +date, as the comet was then very near the plane of the ecliptic, and +was, consequently, exposed to the more violent action of the radial +stream. + +To attempt to explain the _modus agendi_ is, perhaps, premature. Our +principal aim is to pioneer the way into the labyrinth, and it is +sufficient to connect this seeming anomaly with the same general law we +have deduced from other phenomena. Still, an explanation may be given in +strict accordance with the general principles of the theory. + +Admitting the _nucleus_ of a comet to be gaseous, there is no difficulty +about the solution. According to Sir John Herschel, "stars of the +smallest magnitude remain distinctly visible, though covered by what +appears the densest portion of their substances; and since it is an +observed fact, that the large comets which have presented the appearance +of a nucleus, have yet exhibited no phases, though we cannot doubt that +they shine by the reflected solar light, it follows that even these can +only be regarded as great masses of thin vapor." That comets shine +solely by reflected solar light, is a position that we shall presently +question; but that they are masses of vapor is too evident to dispute. +According to the same authority quoted above, "If the earth were reduced +to the one thousandth part of its actual mass, its coercive power over +the atmosphere would be diminished in the same proportion, and in +consequence the latter would expand to a thousand times its actual +_bulk_." If this were so, and comets composed of the elementary gases, +some of them would have very respectable masses, as the nuclei are +frequently not more than 5,000 miles in diameter, and consequently it +becomes important to examine the principle. From all experiments the +density of an elastic fluid is directly as the compressing force; and if +a cylinder reached to the top of our atmosphere, compressed by the +gravitation of the earth, considered equal at each end of the cylinder, +it would represent the actual compressing force to which it owes its +density. If the gravitation of the earth were diminished one thousand +times this atmospheric column would expand one thousand times,[44] +(taking no account of the decrease of gravitation by increase of +distance;) so that the diameter of the arial globe would be increased +to 108,000 miles, taking the atmosphere at 50 miles. But the mere +increasing the _bulk_ of the atmosphere 1000 times would increase the +diameter to little more than double. Even giving the correct expansion, +a comet's mass must be much greater than is generally supposed, or the +diameters of the nuclei would be greater if composed of any gas lighter +than atmospheric air. + +It is very improbable that a comet is composed of only one elementary +gas, and if of many, their specific gravities will vary; the lighter, of +course, occupying the exterior layers. With such a small mass, +therefore, the upper portion of its atmosphere must be very attenuated. +Now let us remember that the density of the ether at a comet's aphelion, +is greater than at the perihelion, in the direct ratio of the square +roots of the distances from the sun nearly. At the aphelion the comet +lingers through half his period, giving ample time for the nucleus to be +permeated by ether proportionally dense with the surrounding ether of +the vortex at that distance. Thus situated, the comet descends to its +perihelion, getting faster and faster into a medium far less dense, and +there must consequently be an escape from the nucleus, or in common +parlance, the comet is positively electric. This escaping ether, in +passing through the attenuated layers composing the surface of the +nucleus, impels the lighter atoms of cometic dust further from the +centre, and as for as this _doubly_ attenuated atmosphere of isolated +particles extends, so far will the escaping ether be rendered luminous. +It may be objected here, that a contrary effect ought to be produced +when the comet is forsaking, its perihelion; but the objection is +premature, as the heat received from the sun will have the same effect +in increasing the elasticity, as change of density, and the comet will +probably part with its internal ether as long as it is visible to the +earth; and not fully regain it perhaps, until after it arrives at its +aphelion. Suppose that we admit that a comet continues to expand in the +same ratio for all distances, as is laid down for the comet of Encke +when near its perihelion; it would follow, that the comet of 1811, would +have a diameter at its aphelion of fifty millions of millions of miles, +that is, its outside would extend one thousand times further from the +sun, at the opposite side to that occupied by the centre of the comet, +than the distance of the comet's centre from the sun, at its enormous +aphelion distance. Such an absurdity shows us that there is a limit of +expansion due to natural causes, and that if there were no radial stream +the volume of a comet would be greatest when nearest the sun. + +But while the comet is shortening its distance and hastening to the sun +in the form of a huge globular mass of diffuse light, it is continually +encountering another force, increasing in a far more rapid ratio than +the law of gravitation. At great distances from the sun, the force of +the radial stream was insufficient to detach any portion of the comet's +atmosphere; presently, however, the globular form is changed to an +ellipsoid, the radial stream begins to strip the comet of that doubly +attenuated atmosphere of which we have spoken, and the diameter of the +comet is diminished, merely because the luminosity of the escaping ether +is terminated at the limit of that atmosphere. Meanwhile the mass of the +comet has suffered only an infinitely small diminution; but if the +perihelion distance be small, the force may become powerful enough to +detach the heavier particles of the nucleus, and thus a comet may suffer +in mass by this denudating process. We regard, therefore, the nucleus of +a comet to represent the mass of the comet and the coma, as auroral rays +passing through a very attenuated envelope of detached particles. The +individual gravitating force of these particles to the comet's centre, +may be therefore considered as inversely as the squares of the +distances, and directly as the density of the particles; and this +density will, according to analogical reasoning, be as the distances or +square roots of the distances;--grant the last ratio, and the +gravitating force of the particles composing the exterior envelope of a +comet, becomes inversely as the 2.5th power of the distances from the +comet's centre.[45] This being the law of the radial stream, it follows, +of course, that a comet's diameter is inversely as the force of the +radial stream. It must, however, be borne in mind, that we are speaking +of the atomic density, and not of density by compression; for this +cometary dust, which renders luminous the escaping ether of the nucleus, +must be far too much diffused to merit the name of an elastic fluid. May +not the concentric rings, which were so conspicuous in the comet of +1811, be owing to differences in the gravitating forces of such +particles, sifted, as it were, and thus arranged, according to some +ratio of the distances, by the centripulsive force of the electric coma, +leaving vacant intervals, through which the ether passed without +becoming luminous? This at least is the explanation given by our theory. +We may, indeed, consider it possible that the escaping ether, when very +intense, might be rendered luminous by passing into the surrounding +ether, and, as it became more diffused by radiation, at last become +invisible. In this case, as the law of radiation is as the squares of +the distances from the centre inversely, the rays would be more and more +bent at right angles, or apparently shortened, as the power of the +radial stream increased, and the apparent diameters of the coma would +be diminished faster than the ratio of the 2.5th power of the distances. +But whichever view we adopt, the diameter would again increase in the +same ratio on leaving the sun, if we make allowance for increase of +temperature, as well as for diminution of density, for the ordinary +distance of a comet's visibility. We, however, regard the change of +diameter, as due to both these nodes of action, as best agreeing with +the indications afforded by their tails. + +From the preceding remarks, it results that the density of the particles +producing the nebulous envelope of a comet, renders the variations of +diameter only approximate to the law of the radial stream; a comet's own +electric energy, or the intensity of the escaping ether, may also modify +this expression, and many other causes may be suggested. That the radial +stream is the cause, in the way we have pointed out, is proved by the +positions of the major axis of the short-period comet, making frequently +nearly a right angle with the radius vector of the orbit in 1828. A soap +bubble gently blown aside, without detaching it from the pipe, will +afford a good illustration of the mode, and a confirmation of the cause. +The angles measured by Struve, reckoned from the radius vector, +prolonged towards the sun, are subjoined: + + November 7 99.7 | December 7 154.0 + November 30 145 .3 | December 14 149 .4 + +At this last date, the comet was getting pretty close to the sun. When +the angle was greater, as on November 7th, the comet appeared to make +almost a right angle with the radius vector; and in this position of the +earth and comet, the longer axis of the elliptical comet was directed to +the axis of the vortex, as may be verified by experiment. At the later +dates, the comet was more rapidly descending, and, at the same time, the +axis of the comet was getting more directed towards the earth; so that +the angle increased between this axis and the radius vector, and +consequently became more coincident with it. We have now to consider the +luminous appendage of a comet, commonly called a tail. + +The various theories hitherto proposed to account for this appendage are +liable to grave objections. That it is not refracted light needs not a +word of comment. Newton supposes the tail to partake of the nature of +vapor, rising from the sun by its extreme levity, as smoke in a chimney, +and rendered visible by the reflected light of the sun. But, how vapor +should rise towards opposition in a vacuum, is utterly inexplicable. In +speaking of the greater number of comets near the sun than on the +opposite side, he observes: "Hinc etiam manifestum est quod coeli +resistenti destituuntur."[46] And again, in another place, speaking of +the tail moving with the same velocity of the comet, he says: "Et hinc +rursus colligitur spatia coelestia vi resistendi destitui; utpote in +quibus non solum solida planetarum et cometarum corpora, sed etiam +rarissimi candarum vapores motus suos velocissimos liberrim peragunt ac +diutissim conservant." On what _principle_, therefore, Newton relied to +cause the vapors to ascend, does not appear. Hydrogen rises in our +atmosphere because specifically lighter. If there were no atmosphere, +hydrogen would not rise, but merely expand on all sides. But, a comet's +tail shoots off into space in a straight line of one hundred millions of +miles, and frequently as much as ten millions of miles in a single day, +as in the case of the comet of 1843. Sir John Herschel observes, that +"no rational or even plausible account has yet been rendered of those +immensely luminous appendages which they bear about with them, and which +are known as their tails." Yet, he believes, and astronomers generally +believe, that a comet shines by reflected light. This theory of +reflexion is the incubus which clogs the question with such formidable +difficulties; for, it follows, that the reflecting matter must come +from the comet. But, what wonderful elements must a comet be made of, to +project themselves into space with such immense velocity, and in such +enormous quantities as to exceed in volume the body from which they +emanate many millions of times. This theory may be, therefore, safely +rejected. + +From what we have already advanced concerning the coma or nebulosity of +the comet, we pass by an easy path to an explanation of the tail. In the +short-period comets, the density of the elementary atoms is too great to +be detached in the gross from the nucleus, or, rather, the density of +the atoms composing the nucleus is too great to permit the radiating +stream of the comet carrying them to a sufficient distance to be +detached by the radial stream of the sun. Hence, these comets exhibit +but very little tails. We may also conceive, that the continual siftings +which the nucleus undergoes at each successive perihelion passage, have +left but little of those lighter elements in comets whose mean distances +are so small. Yet, again, if by any chance the eccentricity is +increased, there are two causes--the density of the ether, and the heat +of the sun--which may make a comet assume quite an imposing appearance +when apparently reduced to the comparatively passive state above +mentioned. + +According to our theory, then, the coma of a comet is due to the +elasticity of the ethereal medium within the nucleus, caused both by the +diminished pressure of the external ether near the sun, and also by the +increased temperature acting on the nucleus, and thus on the involved +ether. The tail, on the contrary, is caused by the lighter particles of +the comet's attenuated atmosphere being blown off by the electric blast +of the radial stream of the solar vortex, in sufficient quantities to +render its passage visible. It is not, therefore, reflected light, but +an ethereal stream rendered luminous by this detached matter still held +in check by the gravitating force of the sun, whose centre each +particle still respects, and endeavors to describe such an orbit as +results from its own atomic density, and the resultant action of both +the acting forces. From the law of density of the ether, the coma ought +to be brightest and the radiating stream of the comet's nucleus +strongest on the side of least pressure: from this cause, and the fact +that the body of the comet affords a certain protection to the particles +immediately behind it, there will be an interval between the comet and +the tail less luminous, as is almost invariably observed. We thus have +an explanation of the fact noticed by Sir John Herschel, "that the +structure of a comet, as seen in section in the direction of its length, +must be that of a hollow envelope of a parabolic form, enclosing near +its vertex the nucleus or head." We have, also, a satisfactory +explanation of the rapid formation of the tail; of its being wider and +fainter at its extremity; of its occasional curvature; and of its +greater length after perihelion than before. But, more especially may we +point to the explanation which this theory gives of the fact, that, +_ceteris paribus_, the long-period comets, when their perihelion +distances are small, have tails of such exaggerated dimensions. + +A comet, whose mean distance is considerable, is supposed by the theory +to be composed of elements less dense, and, during its long sojourn at +its aphelion, it may be also supposed that it there receives continual +accessions to its volume from the diffused siftings of the system, and +from the scattered debris of other comets. On approaching the +perihelion, the rapidity of the change in the density of the ether in a +given time, depends on the eccentricity of the orbit, and so does the +change of temperature; so that, from both causes, both the length of the +tail and the brilliancy of the comet measurably depends on the magnitude +of the period and of the eccentricity. + +If the nuclei of comets be gaseous as we suppose, and that the smallest +stars are visible through them, it is an outrage on common sense, to +refer that light, which renders a comet visible at noon-day, within six +minutes of space of the sun itself, to the reflected light of the sun. +When a small star has been seen through the nucleus of a comet, without +any perceptible diminution of light, it indicates perfect transparency; +but there can be no reflection from a perfectly transparent body, and +therefore, a comet does not shine by reflected light. It is true that +Arago discovered traces of polarized light in the comet of 1819, and +also in more recent comets, but they are mere traces, and Arago himself +admits, that they do not permit "the conclusion decidedly that these +stars shine only with a borrowed light." But it still does not follow +that a comet (even if independent of reflected light) is in an +incandescent state. The auroral light is not polarized, nor any other +electric light, neither is it owing to a state of incandescence, yet it +is luminous. The intense light of a comet at perihelion is analogous to +the charcoal points of a galvanic battery, caused by a rapid current of +ether from the nucleus, and assisted by the radial stream of the vortex. +This will account for the phenomenon in all its shades of intensity, as +well as for the absence of any perceptible phase. It will also account +for the non-combustion of such comets as those of the years 1680 and +1843. We shall also be at no loss to understand, why there is no +refraction when a ray of light from a star passes through the nebulosity +of a comet; and if, as we may reasonably suppose, the gaseous matter +composing the nucleus be very attenuated, instruments are yet too +imperfect to determine whether these also have any refracting power. On +this point, however, it is safest to suspend our judgment, as there may +be comets not belonging to our system, with even liquid or solid nuclei, +or of matter widely different to those elements composing the members of +the solar system. + +In addition to what has been already advanced on this subject of a +comet's light, we may appeal to the well-known fact that the visibility +of a comet is not reciprocally as the squares of the distances from the +earth and sun as it ought to be, if shining by reflected light. In +Mr.Hind's late work on comets, the fact is stated that "Dr. Olbers +found that the comet of 1780 attained its greatest brightness on the 8th +of November, thirteen days subsequent to its discovery, whereas +according to the law of reflected light, it should have become gradually +fainter from the day of its discovery; and supposing the comet +self-luminous, the intensity of light should have increased each day +until November 26th; yet in the interval between the 8th and 26th of +that month, it grew rapidly less." Now this theory teaches, that a comet +is neither self-luminous nor dependent on the sun, but on its distance +from the axis of the vortex, and a certain amount of elapsed time from +the perihelion, varying somewhat in each particular case. This fact is +therefore a very strong argument in favor of our theory. + +Amidst the many anomalous peculiarities of comets, it has been noticed +that a short tail is sometimes seen at right angles to the principal +tail, and in a few cases pointing directly towards the sun. Much of this +may be owing to perspective, but granting the reality of the fact, it is +still explicable on the same general principles. + +In speaking of the modifying causes which influence the weather, we +mentioned the effect due to the position of the sun with respect to the +axis of the vortex. This will be found to have a sensible effect on the +action of the radial stream. The natural direction of a comet's electric +stream is _towards_ the axis of the vortex, and in the central plane of +the vortex it will be also towards the sun. But this stream is met by +the stronger radial stream from the axis, and as Mr.Hind describes it, +"is driven _backward_ in two streams passing on either side of the head, +and ultimately blending into one to form the tail." Now, if the body of +the sun be situated between the comet and the axis of the vortex, it +will shield the comet from the action of the radial stream, and thus a +tail may really point towards the sun. + +In 1744 a brilliant comet exhibited six distinct tails spread out like a +fan, some seven days after its perihelion passage; its distance from +the sun at the time not being more than a third of the earth's distance. +The comet was then rapidly approaching the plane of the ecliptic, and if +we make the calculation for the position of the sun, we shall find that +the body of the sun was on the same side of the axis of the vortex as +the comet, and that the comet was then situated at the boundaries of the +conical space, enclosed by the radial stream in its deflected passage +round the body of the sun. In this position there are numerous cross +currents of the stream, and hence the phenomenon in question. As this +fact rests on the testimony of one individual, and is an occurrence +never recorded before or since, many are disposed to doubt the fact, yet +our theory explains even this peculiarity, and shows that there is no +necessity for impugning the statement of Cheseaux. + +Another unexplained phenomenon is the corruscation of the tail. It has +been attempted to explode this fact also, by referring it to conditions +of our own atmosphere; and it is generally considered the argument of +Olbers, founded on the great length of the tail and the velocity of +light, is sufficient to prove that these corruscations are not actually +in the tail. Now, it is undoubtedly true, that as light travels less +than two hundred thousand miles in a second, and a comet's tail is +frequently one hundred millions long, it is impossible to see an +instantaneous motion along the whole line of the tail; but granting that +there are such flickerings in the tail as are described by so many, it +must necessarily be, that these flickerings will be _visible_. It would +be wonderful indeed, if a series of waves passing from the comet to the +extremity of the tail, should have their phases so exactly harmonizing +with their respective distances as to produce a uniform steady light +from a light in rapid motion. The argument, therefore, proves too much, +and as it is in the very nature of electric light thus to corruscate, as +we see frequently in the northern lights, we must be permitted still to +believe that not only the tails, but also the heads of comets do really +corruscate as described. + +With respect to the direction of the tail, astronomers have been forced +to abandon the antiquated notion, that the tail always pointed directly +from the sun; yet they still pertinaciously cling to the idea, that +although this is not always the case, the tail only deviates from this +direction _in the plane of the orbit_. As this is a most important +question, it is necessary formally to protest against such a conclusion. +If the earth should happen to be in the plane of the comet's orbit and +the tail appears in that plane, it must of course be in that plane +_really_; but if the earth is not in the plane of the comet's orbit, the +tail is not _necessarily_ in the same plane, whatever its apparent +direction may indicate. It is true there is a tendency of every particle +of the tail, moving under the restraining influence of the sun's +attraction, to continue in the plane of the orbit; and in certain +positions there is no oblique action arising from the force of the +radial stream to cause it to deviate from that plane; yet in other +positions of the comet, the action of the radial stream may be oblique, +forcing it out of that plane, and still such a direction might be +assigned to it as to make it conform. In the comet of 1843, P. Smythe +observed a forked tail 25 long on March 3d, and from the end of the +forked tail, and from its _north_ side, a streamer diverged at an angle +of 6 or 7 to the _north_. As this was contrary to the _direction_ of +the curvature, if the tail had been curved, it could only arise from a +portion being driven off by the radial stream, or bent towards the plane +of the ecliptic. The curvature observed by others at a later date, was +concave to the south. Towards the middle and close of March, the tail +became straight, and with the above exception, might be considered to +move in the plane of the orbit. + +The celebrated comet of Halley, as observed by Dr. Bessel in 1835, +showed that a more or less well-defined tuft of rays emanated from that +part of the nucleus which was turned towards the sun; and the rays being +_bent backward_ formed a part of the tail. The nucleus, with its +emanations, presented the appearance of a burning rocket, the end of +which was turned sideways by the force of the wind. And, Bessel +concludes: "That the cone of light issuing from the comet deviated +considerably both to the right and left of the true direction of the +sun, but that it always returned to that direction, and passed over to +the opposite side; so that the cone of light, and the body of the comet +from whence it emanated, experienced a rotatory, or, rather, a vibrating +motion _in the plane of the orbit_." It is impossible that Bessel should +here mean that this motion was certainly in the plane of the orbit; for +the orbit was then viewed sideways, and he had no means of ascertaining +the fact. His meaning must be that it was apparently in the plane of the +orbit. If a plane be made to pass through the earth, the comet, and the +sun, the tail might be placed in any position in that plane, and yet +appear to be at the intersection of the two; that is, in the plane of +the comet's orbit. The vibration of the tail, in this case, is another +strong proof of the correctness of our theory. To make it more +intelligible, we shall resort to a diagram. + +In the following diagram, the comet's orbit, represented by the dotted +line, is drawn on the plane of the ecliptic; it is, therefore, necessary +to bear in mind, that it is tilted up from the line of nodes SN, at an +angle of 17 45'. The position of the comet, October 9th, is at C, +approaching its perihelion; that of the earth at the same time at T; +while S represents the sun, and SQ the line of equinoxes. Now, from a +cause already explained, the tail always tends to lay behind the comet, +in the direction indicated by the lower tail in the diagram at 1, and, +if produced, would pass to the left of the sun, as seen from the earth: +the force of the radial stream, however, will not allow this lagging of +the tail, and it is straightened out by this force; but, being directed +to the axis of the vortex, and not to the sun, it is not really in the +plane of the orbit, but is seen in the direction of the upper tail +depicted in the diagram at 3, and, if produced, would pass to the right +of the sun, as seen from T. Now, there is an intermediate position of +the tail, in which it will appear in the prolongation of the radius +vector SC; this position is represented by the middle or central tail of +the comet at 2, yet this is not in the plane of the orbit, it only +appears to be, as may be readily understood by remembering that the +earth at this time is under this plane, and the comet is seen at a +considerable elevation above the plane of the ecliptic. When the comet's +tail becomes directed to the axis of the vortex, or in the _apparent_ +position of No.3, the comet, rapidly careering on its way to the sun, +again leaves the tail behind, and again it is strengthened out by the +radial stream oscillating about the mean position at 2, as observed by +Bessel. From this, it appears, that there is no necessity to make +confusion worse confounded, by resorting to polar forces, which are +about as intelligible as the foundations of the pillars of Atlas. + +[Illustration: Fig. 25] + +It may be objected that the continued action of the radial stream with +that velocity we have contended for, ought to keep the tail invariably +directed from the axis of the vortex; but, where there are two forces or +tendencies, as in this case, analogy would teach us that a certain +degree of oscillation is a necessary result. There may, also, be slight +and transient changes in the direction of the radial stream. In the +hurricane there are short and fitful blasts inclined to the general +direction of the wind, which must arise from the inertia of the moving +mass of atmosphere, causing temporary condensations and rarefactions. Be +this as it may, we have assigned a cause which satisfies the phenomenon, +without coming into collision with a single principle of celestial +mechanics. + +Prof. Struve compared the tail of this comet to a flame, or "ray of fire +shot out from the nucleus, as from some engine of artillery, and driven +on one side by the wind." At the same time, he saw a second emanation +nearly in the opposite direction. This last might arise from a momentary +fluctuation in the relative intensities of the electric radiation of the +comet, and of the radial stream, owing to the probable irregularities +just alluded to. Such and kindred phenomena are utterly inexplicable, +without we adopt the theory we are advocating. One other feature, and we +will leave the subject. + +From our explanation of the solar spots, we inferred the existence of +another large planet in the system. Might not the same effect be +produced by a comet? Or may there not be so many comets, whose great +elongation, combined with even a moderate mass, may render it impossible +to calculate the position of the sun with respect to the central axis of +the vortex,--always considering this last as the axis of equilibrium? In +a general way, we might say that the very number of comets in all +directions and all distances, would tend to neutralize each other's +effects; but we are not under this necessity. A comet, moving in a +parabola, does not belong to the system or to the rotating vortex; and +the periodic comets, if of gaseous elements, (as seems so probable,) +must, from the size of their nuclei, which the theory considers the only +part constituting their mass, have far less mass than the very smallest +of the asteroids, and consequently could have very little effect on the +mechanical balance of the vortex, even if elongated as far as the orbit +of Neptune. Did we know the influence of cold in limiting the +expansibility of the elementary gases, we might approximately determine +the mass of a comet, from the size of its nucleus; but this is a problem +that has never yet been solved; and astronomers ought to avail +themselves of every indication which promises to realize this great +desideratum. The grand comet of 1556 is now probably approaching, and, +from recent investigations, it appears that it will arrive at its +perihelion in 1858,--subject to an error either way of about two years. +An opportunity may thus be presented of determining the mass of one of +the largest comets on record, which may not again occur. This arises +from the possible appulse of the comet to the planet Pallas, whose mass, +being so small, would more sensibly be disturbed by such an appulse than +the earth. As the inclinations and ascending nodes of the two orbits +approximately coincide, and as Pallas will be near the comet's path, on +the approach of the latter to the sun, at the beginning of the year +1857, should the comet become visible about that time, a very close +appulse is possible. It is not unlikely, also, that if the elements of +Pallas were so far perfected as to afford reliable indications, that the +near approach of the comet might thus be heralded in advance, and lead +to an earlier detection of its presence. Would it not be a worthy +contribution to science, for some one possessing the necessary leisure, +to give an ephemeris of the planet for that epoch; as a very slight +change in Mr.Hind's elements of the comet, would cause an actual +intersection of the two orbits in about heliocentric longitude 153? The +subsequent nodal passage of Pallas will take place near opposition, and +be very favorably situated for determining the instant of its passage; +and, of all the elements, this would be more likely to be affected than +any other.[47] + + +THE ZODIAL LIGHT. + +A phenomenon, akin to that which we have just been considering, is +presented by that great cone of diffused light which accompanies the +sun, and which in tropical climes displays a brilliancy seldom witnessed +in high latitudes, on account of its greater deviation from the +perpendicular. Sir John Herschel conjectures that it may be "no other +than the denser part of that medium, which, as we have reason to +believe, resists the motion, 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 passages, and which +may be slowly subsiding into the sun." If these materials have been +stripped, it is due to some force; and the same force would scarcely +permit them to subside into the sun. Once stripped, these portions must +be borne outwards, by the radial stream, to the outer verge of the +system. Still, there are, no doubt, denser particles of matter, of the +average atomic density of Mercury and Venus, which can maintain their +ground against the radial stream, and continue to circulate near the +central plane of the vortex, in all that space between the earth and the +sun. But if the zodial light be the denser part of that medium, which +astronomers now generally recognize as a resisting medium, how happens +it that it should be confined to the plane of the ecliptic? Why should +it not be a globular atmosphere? Here, again, our theory steps in with a +triumphant explanation; for while it permits the accumulation of such +particles around the equatorial plane of the sun, it allows no +resting-place very far removed from this plane. The zodial light, +therefore, is not the resisting medium, but the passage of the radial +stream through a diffuse nebula of atoms, brought down the poles of the +vortex by the polar current, and held in check along the central plane +by gravitation. + +If these atoms partook of the velocity of the ether, they would not be +luminous; but being held back by gravitation, they are opposed to the +radial stream, and hence the light. + +Many stars are also nebulous. In some cases we see the nebulosity +edgewise, or along the equatorial planes of the stellar vortices; in +others we look down the poles, and the nebulosities are circular, and +there is an endless variety in the shape and intensity of this light. +But the universe seems full of motion, and we are not justified in +supposing, because a star shows no such light, that it is without +rotation. The parallax of the nearest star is only one second, the whole +lenticular mass of light which surrounds our sun would therefore only +subtend an angle of a single second at the nearest fixed star. Seeing +its extreme faintness, therefore, the effulgence of the star would +render it totally invisible, provided that it _could_ traverse the vast +immensity of intervening space, without feeling the influence of that +extinction, which Struve has proved does actually diminish the number of +visible stars. + +Corruscations and flickerings have also been noticed in the zodial +light, and as usual, the learned have suggested atmospheric conditions +as the cause, instead of trusting to the evidence of their own senses. +How prone is philosophy to cling to that which is enveloped in the mist +of uncertainty, rather than embrace the _too simple_ indications of +nature. As if God had only intended her glories to be revealed to a +favored few, and not to mankind at large. Blessed will be the day when +_all_ will appreciate their own powers and privileges, and no longer +regard the oracles which emanate from a professional priesthood, whose +dicta have so often tended to darken the simple counsels of truth! To +set the question of pulsations in the zodial light, as well as in the +tails of comets, at rest, only requires previously concerted +observations, in places not very widely apart; for it is scarcely +possible, that atmospheric conditions should produce simultaneous +pulsations in two distant places. If the pulsations are found to be +simultaneous, they are real; if not simultaneous, they may depend on +such conditions; but from the nature of the cause, we should look for +them as much in the zodial light, as in the aurora borealis, regarding +the different intensities. + +There is also reason to suspect that the northern side is always the +brightest, both in spring and autumn. On the morning of October 4th, +1853, the light was very vivid and well defined, its northern margin +grazing Regulus and terminating at Mars, which was also to the north of +it. Now, although the _northern side_ was the brightest, the great mass +of light was to the south of the ecliptic, as far down as the cone shape +was preserved; but at 10 from the horizon, a still brighter mass +protruded from the cone towards the north, which was all _north_ of the +ecliptic, and of an irregular form, extending along the horizon. The +time was 4A.M., and consequently was not due to any crepuscular light. +An explanation of the general fact of the brightest light being _always_ +on the north side, is given in the present section, in connection with +another phenomenon. If, as some suppose, the light does not reach to the +sun, the annulus must at least fill all the space between Venus and the +earth, but it is far more in accordance with facts as well as with our +theory, to suppose it increases in density to the body of the sun. + +Observations made at the observatory of the British Association, +detected, in 1850, sudden brightenings of the light, altogether +different from pulsations. The theory would refer these to that fitful +irregularity in the momentary intensity of the radial stream, which +gives the flickering and tremulous motion to comets' tails. But, the +steady variations in the intensity of this light must be due to other +causes. The longitude of the sun will here come in as a modifying cause; +for the obstruction caused by the body of the sun, when displaced from +the axis of the vortex, must necessarily exercise an influence on the +force and direction of the radial stream. A sudden influx of cometary +matter down the poles of the vortex, in more than usual quantities, will +also tend to brighten and enlarge the zodial light; and, in this last +cause, we have an explanation not only of ancient obscurations of the +solar light, but, also, of those phosphorescent mists, such as occurred +in 1743 and 1831, rendering moonless nights so light that the smallest +print could be read at midnight. + +In total eclipses of the sun, the denser portion of the zodial light is +visible as a brilliant corona; but, on such occasions, the brightest +stars only are to be seen, and, consequently, the fainter portions of +the light must be invisible. Hind mentions as many as ten stars visible +in the total eclipse of 1842. According to the same authority, the color +of the corona was like tarnished silver, and rays of light diverged in +every direction, and appeared shining through the light of the corona in +the total eclipse of 1851. In this year on the day of the eclipse (July +28th), the longitude of the sun was about 340, and, therefore, the body +of the sun obstructed the radial stream as seen from the earth on the +right side; but, in 1842, the longitude of the sun was, according to our +table, about 116, the sun's centre then being 700,000 miles from the +axis of the vortex, and on the opposite side with respect to the earth; +the position was, therefore, not so favorable for the appearance of +these rays which, in many cases, have given the appearance of a whirling +motion to the corona. + +At this date, July 7th, 1842, the corona, according to Prof. Airy, +"possibly had a somewhat radial appearance, but not sufficiently marked +to interfere with the general annular structure." Mr.Baily, on the +contrary, says, the corona had the appearance of brilliant rays; and, at +Milan, long jets of light were particularly noticed. There can be no +doubt but that the passage of the radial stream past the outer margin of +the moon must also give rise to the same phenomena as when passing the +sun, and in this we have an explanation of the fact, that, previous to +the moment of first contact, an appearance resembling a +faintly-illuminated limb of the moon, has been perceived near the body +of the sun; as well as of those flashes of light which have been +observed in the lunar disc as the eclipse advances. One important fact, +worthy of note, is, that these luminous streaks are more nearly parallel +than is due to a radiation from the centre. These streaks have, also, +been seen bent at right angles at the middle of their height, as a flame +is by means of a blowpipe, precisely analogous to cometary rays being +driven backwards to form the tail, as already described, thus indicating +a common origin. If the moon had an atmosphere, we should, no doubt, see +a greater display; but, having no rotating vortex to protect her from +the radial stream, her atmosphere must have been long since stripped +off, leaving her exposed to the withering winter blast of the great +stream of the solar vortex. In this connection, we may also allude to +the appearance of the moon when totally eclipsed. Instead of +disappearing at these times, she sometimes shines bright enough to +reveal her smallest spots. This has been generally referred to the +refraction of the earth's atmosphere bending inwards the solar rays. May +it not be owing to the brilliancy of the solar corona, which, in 1842, +was described as so intense that the eye was scarcely able to support +it? This is a far more palpable cause for the production of this +phenomenon, but of which astronomers cannot avail themselves, as long as +they are uncertain of the origin of this corona. + + +SHOOTING STARS. + +The continual influx of cosmical matter into the heart of the vortex in +ever-varying quantities, and speedily dispersed along the central plane, +according to its density, must necessarily give rise to another +phenomenon to which we have not yet alluded. Scarcely a night passes +without exhibiting this phenomena in some degree, and it is generally +supposed that the hourly average of shooting stars is from five to ten, +taking the whole year round. The matter composing these meteors we +regard as identical with that mass of diffused atoms which forms a +stratum conforming to the central plane of the vortex, and whose partial +resistance to the radial stream occasions that luminosity which we call +the zodial light. These atoms may coalesce into spherical aggregations, +either as elastic gas, or as planetary dust, and, passing outward on the +radial stream, will occasionally become involved in the vortex of our +own globe; and being drawn inwards by the polar current, and acted on by +the earth's gravity, be impelled with great velocity through the +rarefied air of the upper atmosphere. That meteors are more abundant +about the time of meridian passage of a vortex (or, perhaps, more +correctly speaking, from six to twelve hours afterwards, when the +current of restoration penetrates the atmosphere), well accords with the +author's observations. It is about this time that high winds may be +looked for, according to the theory; and it has ever been a popular +opinion, that these meteors are a sign of windy weather. Even in +Virgil's time, the same belief prevailed, as a passage in his Georgics +would seem to indicate. + + "Sape etiam stellas, vento impendente, videbis + Prcipites coelo labi; noctisque per umbram + Flammarum longos tergo albescere tractus;" + +Virgil was a close observer of nature, and commences a storm with the +wind at south, "Quo signo caderent Austri;" just as we have represented +the usual course when these vortices pass near the observer's latitude. +It is also a well-known fact, that after a display of meteors, (and we +are now speaking of ordinary displays, and not of the great showers,) +the temperature falls considerably. It is not uncommon also, that +meteors are more abundant during an auroral display, as they ought to be +by the theory. We must, however, exempt from this influence those solid +meteors which sometimes come into collision with the earth, and +afterwards grace the cabinets of the curious. These bodies may be +considered microscopic planets, moving in stated orbits with planetary +velocity, and bear strongly on the explosive theory of Olbers, as fully +detailed by Sir David Brewster. + +It is a very remarkable fact, first noticed by Olbers, that no fossil +meteoric stones have yet been discovered. If this fact be coupled with +the hypothesis advanced by Olbers, in reference to the origin of the +asteroidal group, we should have to date that tremendous catastrophe +since the deposition of our tertiary formations, and therefore it might +possibly be subsequent to the introduction of the present race into the +world. May not some of the legendary myths of the ancient world as +mystified by the Greeks, have for a foundation the disappearance of a +former great planet from the system? The idea of the existence of seven +planets is one of the oldest records of antiquity; but the earth of +course would not be counted one, and therefore in after times, the sun +was included to make up the number; just as the signs of the Zodiac have +been explained in accordance with the seasons of far later times than we +can possibly assign for the invention of this division of the heavens. +Let those who have the leisure, try how far the contraction and dilation +of the asteroidal orbits, to some average mean distance, will restore +them to a common intersection or node, as the point of divergence of the +different fragments. The question is interesting in many of its aspects, +and may yet be satisfactorily answered. + +The composition of arolites may also be taken as indications of the +common origin and elementary texture of the planets, whether they are +independently formed or have originally pertained to a former planet; +for no hypothesis of telluric or selenic origin yet advanced, can stand +against the weight of evidence against it. Their fragmentary character +rather favors the views of Sir David Brewster, and when we consider that +they have been revolving for thousands of years with planetary velocity, +and in very eccentric orbits, through the ether of space, continually +scathed by the electric blast of the radial stream, their rounded +angles, and black glossy crust of an apparently fused envelope, may be +accounted for, without difficulty, from the non-vitrified appearance of +the interior. The composition of arolites as far as known, embrace +nearly one-third of all known simple substances according to Humboldt, +and are as follows: iron, nickel, cobalt, manganese, chromium, copper, +arsenic, zinc, potash, soda, sulphur, phosphorus, and carbon. + +The theory we have thus given of the common occurrence of shooting +stars, will render a satisfactory general account of their sporadic +appearance; but there are other phenomena of greater interest, viz.: the +occasional recurrence of swarms of such meteors, which defy all +numerical estimates, being more like a fiery rain than anything they can +be compared to. The most interesting feature of this phenomena, is the +_apparent_ periodicity of their return. In the following table we have +set down the most remarkable epochs mentioned by Humboldt, (and no man +has devoted more attention to the subject,) as worthy of notice: + + About April 22 to 25 + " July 17 to 26 + " August 9 to 11 + " November 12 to 14 + " November 27 to 29 + " December 6 to 12 + +Besides these, he mentions two showers, from Arabian authority, in +October; one in October, observed in Bohemia; one observed by himself, +in the Pacific, on March 15; one February 4, just preceding the terrible +earthquake of Riobamba, in 1797. The Chinese annals also contain many +showers of stars, before the present era commenced. Some were in March, +more in July, and others in different months. How, then, in view of +these numerous dates, can we attach so much importance to the +periodicity of these showers? The great shower of 1833, in the United +States, on the 12th and 13th of November, brought to mind the great +shower at Cumana, observed by Humboldt and Bonpland just thirty-three +years before, to a day; and it must be confessed that more than ordinary +displays have been seen on this date. Yet, on the strength of this, +every meteoric shower is supposed to be periodical, and has resulted in +a theory which becomes more complicated as the phenomenon is more +observed, and can never lead to any useful and practical results. To +cite the numerous instances of discrepant results, would only encumber +this brief notice with facts neither interesting to the general reader, +nor convincing to those who hold a contrary opinion. The author of these +pages has watched for many years, and, in view of all the facts, has +concluded that the doctrine of periodicity (as held by present +meteorologists) is not tenable. The celebrated August shower failed, +also, this year, at least in this place, as for four hours each night, +on the 9th, 10th, and 11th, there were fewer bright meteors than at the +close of July. + +Professor Olmsted, who has paid considerable attention to the subject, +has indeed attempted to connect the great November shower with the +zodial light, which last he considers a nebulous body, of an elongated +form, whose external portions, at this time of the year, lie across the +earth's path. (See Silliman's Journal for 1837, vol.xxxiii. No.2, +p.392.) He even gives its periods, (about six months,) the aphelion of +the orbit being near the earth's orbit, and the perihelion within +Mercury's. In this way he attempts to explain both phenomena; but as the +zodial light is seen unchanged all the year round in tropical latitudes, +it is not the kind of body supposed by Olmsted, and the theory adds +nothing to our knowledge. Others have imagined rings of nebulous matter, +in which all the separate parts are moving in the same orbit around the +sun, with a retrograde motion, and this, with some modifications, is the +current theory of the day. The principal arguments rested on, for the +support of this view, are derived from the great shower of 1833, in +which a common radiant point was observed, and confirmed subsequently by +the radiant of other years, in the same month of November. As this point +is almost tangential to the earth's orbit at this season, the earth +meets the nebulous ring moving in the contrary direction, and thus +confers on these meteors the necessary velocity that is thought to be +demanded by observation. + +Now, our theory gives a totally different explanation of the phenomenon. +We contend that a retrograde motion of such a nebulous mass, is +subversive of our whole theory; and we must be permitted to examine +certain points, hitherto disregarded by those entertaining antagonist +views. It is supposed that the meteors in 1833 fell for eight or nine +hours. The orbital velocity of the earth is more than 1,000 miles per +minute, and the orbital velocity of the nebulous zone must have had a +similar velocity. During the nine hours of meteoric display, therefore, +the earth traversed 500,000 miles of her orbit, which would give +1,000,000 miles for the depth of the nebulous stratum. But if of such +vast extent, how happened it that the only part of the earth in which +these were visible in great density, was the United States, or a space +embraced between the latitudes of 50 and 20 north, and the longitudes +60 and 100 west, (and these are the widest limits,) comprising only +1/40 of the surface of the globe? To a calm inquirer, this difficulty +seems insurmountable. The author was then in the Mediterranean, on deck +the greatest part of the night,--the weather fine, and nothing unusual +visible in the heavens; from other sources he has also derived similar +information. Yet, were the earth then passing through a stratum of +meteors 1,000,000 miles in extent, it is utterly inconceivable that +other portions of the earth escaped. Much stress is also laid on the +fact that these meteors in 1833, passed from east to west generally, as +they ought to do, if tangential to the earth in her orbit; but on the +same phenomenon occurring in 1799, when the earth was in precisely the +same part of her orbit, Humboldt says distinctly, "the direction (of the +meteors) was very regular from north to south." How could this possibly +happen, and at the same time be moving tangentially to the orbit? + +There is also another fact of importance not duly weighed in forming +such a theory. In 1833 the meteors evidently differed in velocity; one +class, consisting of luminous points, passed like a shower of fire with +great velocity to the westward, another class were like large fire-balls +with luminous trains moving with less rapidity, while a third class +consisted of nebulous patches which remained stationary for a long time, +and frequently emitting large streams of light. These last, at least, do +not deport themselves as planetary bodies moving 2,000 miles per minute. +But the fact still remains, that unusual displays have occurred about +the 12th and 14th of November; and also as a general thing when there +are no unusual displays, the meteors are more abundant about this time. +Let us try if we can reconcile these facts with the theory of vortices. + +We will first confine our remarks to the increased number of meteors +about November 12th and 14th. The cosmical matter composing the zodial +light, or at least the lighter parts of it, is continually driven +outwards by the radial stream, just as the matter of a comet's tail is +stripped from the nucleus. This matter becomes involved in the terral +vortex by descending the poles, and is again passed out along the +equatorial plane. The form of the zodial light, as seen edgewise, gives +a lenticular form for the stratum of planetary particles composing it, +and its central plane has been considered as coinciding with the plane +of the sun's equator. At the orbit of the earth, this lenticular space +is narrowed to a very thin stratum, but undoubtedly reaches beyond the +earth's orbit with a rapidly diminishing density. As the axis of the sun +is inclined about 7 to the ecliptic, and the ascending node is in the +20th degree of Gemini, the earth can only pass through the plane of the +sun's equator about the 12th of December and the 12th of June. If, +therefore, the central plane of the vortex coincides with the plane of +the sun's equator, meteors ought to be more numerous about the dates +above mentioned. But the observed times are on November 12th and 13th. +Now, from actual measurements, a computation has been made by M. +Houzeau, that the elements of the zodial light are materially different +from those of the sun's equator. He fixes the node of the light +(according to Mr.Hind) in 2 heliocentric longitude, subject to an +uncertainty of 12 or 13, and its inclination to the plane of the +ecliptic, 3 35', subject to an uncertainty of about 2. The truth is, +astronomers have argued the coincidence of the two planes from +considerations connecting the zodial light with the sun's equator, as if +it were a solar atmosphere; but such an atmosphere is impossible, and it +is high time such measures should be taken as will lead to some certain +conclusion. If in the present state of the question, we were to take the +mean, we should find the node in about longitude 40, which is the +position of the earth on November 2d. But in the absence of +measurements, we will assume, for the sake of argument, that the +ascending node of the central plane of the vortex was, in 1833, in 50 +heliocentric longitude, and consequently the earth was passing through +the meteoric stratum or central plane of the zodial light, on the night +of November 12th. The opposite period of the year is May 12th--a date, +it is true, on which no great shower of stars is recorded, but sporadic +meteors are very plentiful at that time, and what is more important to +observe is, that the 11th, 12th, and 13th of May, are the three noted +_cold days_ which we have before mentioned. Thus truly indicating that +the earth is then in or near the central plane of the vortex along which +the radial stream is at its maximum of power at any given distance from +the axis. + +But the question occurs, does the node of this plane remain stationary, +and is there no variation of the inclination of the axis of the solar +vortex? We have found from observation, that the axis of the terral +vortex is continually oscillating about a mean position by the action of +the moon; and reasoning from this analogy, and the constant tendency of +a material vortex to preserve a dynamical balance, the same tendency +must obtain in the solar vortex under the action of the great planets, +whose orbits do not coincide with the central plane of the vortex. The +ascending node of Jupiter's orbit is in longitude 98, Saturn's 112, +Uranus' 72, Neptune's 131; so that this plane does not correspond with +the plane of greatest inertia discovered by La Place, and from the +non-coincidence of these planes with the central plane of the vortex, +must produce the same oscillation in the axis of the solar vortex, as +the moon does in the terral vortex, but to what amount, observation can +alone determine. Jupiter and Saturn will of course exert the greatest +influence, and when these two planets are in conjunction, the ascending +node of the central plane of the vortex will vary in longitude perhaps +sufficiently to bring the meteoric maximum at the ascending node into +October on the one hand, and to the close of November on the other, and +at the descending node to April 25th on the one hand, and the close of +May on the other. + +The great showers of stars which have been recorded, must be therefore +considered as an accidental exaggeration of a perennial phenomenon, +attaining its maximum when the earth passes through the central plane of +the vortex, whose ascending node in 1833 we will suppose was in +longitude 50. This theory will therefore account for those great +showers which have occurred about the 24th of April, as well as those +occurring in October and November; for it is far more consonant to all +analogy, to suppose the influx of planetary atoms into the solar vortex +to be in irregular, than in regular quantities. Yet, whether in the one +case or in the other, the matter will pass along the central plane of +the vortex, either diffusely scattered or in denser clouds, and will be +encountered by the earth when near the nodes _more frequently than at +other times_. The phenomenon of 1833, may then be attributed to the +earth encountering an unformed comet on the 12th of November; but we +must reflect, that the medium of the vortex is also in motion, and the +cometary matter drifting along with it; and that this motion corresponds +with the earth's motion. By becoming involved in the terral vortex, it +will in a measure be carried along with the earth in her orbit as a +temporary occupant of the terral vortex. But we are here met with the +objection that the radiant being nearly stationary amongst the stars, +demonstrated conclusively, that the source of these meteors did not +partake of the earth's motion. There is no difficulty in this. We +suppose as a general thing, that the meteors descended to the surface of +our atmosphere down the axis of the vortex (at least in the greatest +numbers), and the geocentric longitude of this axis was nearly the same +during the whole time of the display. We say nearly, for the motion of +the moon in her orbit in nine hours, would change the longitude of the +axis three or four degrees, and this is about the change in the +position of the radiant noted at the time. This objection, therefore, +falls to the ground; for the axis of the vortex, although carried along +with the earth in her orbit, was unaffected by the earth's rotation, and +would therefore appear nearly as stationary in the heavens as Gamma +Leonis. But it is again urged, that the moon was near conjunction with +the sun, and consequently the central vortex was on the opposite side of +the globe. This is true; but the outer vortex must have been near the +meridian about three hours after midnight, or about the time when the +radiant was vertical and the display the greatest. When the axis was to +the eastward, the stars would shoot westward, when on the meridian, they +would pass in all directions, but principally to the south, on account +of the inclination of the axis of the vortex; but this would only be +true for places situated to the southward of the central latitude. +During the great shower of stars seen by Humboldt, in Cumana, the +direction was to the south uniformly. Now, the latitude of Cumana is +above 10 north, yet still too low for the general limits of the +vortices; but from the same inclination of the axis (from 30 to 36 to +the surface), the meteors would pass far south of the limit, and might +even reach to the equator. The latitude of the _outer vortex ascending_ +on November 12th, must have been near the line of greatest display, from +the position of the moon at the time. We thus see why the phenomenon was +limited to so small a fraction of the earth's surface; why these meteors +should be intermingled with nebulous patches stationary in the heavens +for an hour together, and why, notwithstanding these facts, they were +independent of the earth's rotation. + +We have yet another objection to answer, viz.: the planetary velocity of +some of these bodies. Let us be understood. The velocity of a solid +arolite is due to gravitation, and is planetary, on the other hand, +voluminous collections of cometary dust united by accident, and +remaining so by mere inertia, are borne passively on the ethereal +currents with _electric_ velocity, and probably never penetrate far, +even into the attenuated atmosphere, which may be supposed (from the +facts connected with the aurora) to extend far above the denser stratum +which refracts and reflects light, and from which the assigned limits of +our atmosphere have been derived. + +It is generally considered that sporadic meteors are more numerous in +the summer and autumn than in the winter and spring, and we have, +likewise, in the tenth of August, a date which corresponds to many great +displays and meteoric showers, both in recent and remote times. This +would seem to vitiate our theory; for we cannot suppose that there are +two _central_ planes in the vortex intersecting the ecliptic in +longitude 320 and 50. We must remember, however, that as these great +displays are accidental, and as the stratum composing the zodial light +is manifestly of sufficient thickness to envelope the whole orbit of the +earth, that it does not necessarily follow that the dense portions to +which meteoric showers are due, should be always confined to the central +plane of the vortex. And, besides, we have similar displays recorded in +other months, which invalidates the theory of a regularly-recurring +phenomenon. We shall, therefore, only aim at explaining why meteors are +generally more abundant in summer and autumn than in the opposite +seasons. + +The axis of the solar vortex, considered as cylindrical, must be +admitted to run out to a great depth on either side from the sun, and +reach far into that unoccupied space intervening between our system and +the nearest fixed stars, and from these opposite points the solar vortex +is supplied with that stream of ether which passes down either pole to +restore a partial equilibrium in the density of the ether of the vortex, +rarefied by centrifugal force. As certain portions of the heavens are +crowded with stars, and other parts comparatively vacant, we may expect +a similar inequality in the distribution of that cometic dust, which +causes a certain amount of extinction in the light of the stars, and, +therefore, seeing that the two extremities of the axis of the solar +vortex are so widely separated, it would not be wonderful if different +quantities of such matter were brought down into the vortex from these +extremities. + +From recent observations made by H.R. Birt, at the observatory of the +British Association, it would appear that the brightest portion of the +zodial light is always north of the ecliptic. Others have also remarked +the same, and if we couple this fact with the suggestion just made, we +are justified in suspecting that a greater quantity of cometic dust +comes down the northern pole of the vortex than down the southern. This +matter, in passing outward, does not, of course, immediately attain to +the central plane of the vortex, but is more thickly distributed along a +plane parallel to this plane. And the same will be observed by that +matter coming down the southern pole; it will be, in a certain degree, +retained in a plane south of the central plane, but still parallel with +it. This would account for the greater brightness of the northern side +of the zodial light. It would, also, account for the greater frequency +of meteors in summer and autumn than in the opposite seasons. From May to +November the earth is above the central plane of the vortex, and, +consequently, on the northern side; but after passing the node in +November, she is on the under or southern side, and the meteors are less +frequent. With this general explanation we shall close. If what we have +advanced be an approximation to the truth, the theory itself affords +ample indications of what observations are requisite to prove or +disprove it; and, on this account, a theory is of great benefit, as +suggestive of many questions and combinations of facts which otherwise +might never be thought of. + +We have thus taken a cursory glance at the prominent physical phenomena +of the world, and attempted to link them together in the bonds of one +all-pervading principle. We have fearlessly taken a new path, and claim +originality for the whole, disclaiming all intention of retailing +second-hand wares, or of compiling an ingenious theory from +heterogeneous scraps. If it be true, or if it be partially true, let +those professionally engaged in such pursuits enter the wide field of +investigation we have discovered for them; for if the whole theory be +true, it only shows in a clearer light that the great work which has +been fancied so near completion is scarcely yet begun; while the +prospect of an ultimate and final completion of the temple which so many +zealous votaries are erecting, is rendered mournfully hopeless by the +contemplation of what yet remains to be performed. + +FOOTNOTES: + +[42] The orbit this year was determined under very unfavorable +circumstances. + +[43] According to other tables, this angle would be much greater than is +given in Mr.Hind's catalogue. + +[44] Prin. Prop.xx Lib. Sec. + +[45] With reference to the resisting power of the atoms. + +[46] Prin. Lib. Tor. Prop, xxxix., also Prop, xli. + +[47] In making this suggestion, the author is well aware that +Ephemerides of the four chief asteroids have been given annually in the +Greenwich Nautical Almanac; but for the object proposed they are utterly +useless. Will any astronomer contend that these Ephemerides are true to +ten seconds of arc? If not, they are useless for the purpose suggested +above, and the theory wants revision. And it is evident that any +objection against its practicability, founded on the uncertainty of the +number of the asteroids themselves, as has already been urged in answer +to this suggestion, is an evidence that the objector weighed the subject +in the scales of his imagination only. + + + + +SECTION SIXTH. + + +THE POLAR ICE. + +We shall conclude these pages by again referring to our theory of the +weather, in connection with an event which every friend of humanity and +every lover of natural science is bound deeply to deplore. + +From the present position of the lunar nodes and apogee, the vortices of +our earth do not ascend into very high latitudes. Now, according to the +principles laid down, the frequency of storms tends to lower the +temperature in the warm regions of the earth, and to elevate it in the +polar regions. Let us suppose the northern limit of the vortices to be +in latitude 70. There will be, in this case, a greater prevalence of +northerly winds _within_ this circle of latitude, to supply the drain to +the southward, and the back currents by passing above will descend at +the pole, partaking of the temperature due to that elevation. The +character of the arctic seasons may therefore be considered as partly +dependent on the average direction of the wind. Suppose again, the +extreme limits of the vortices to be about latitude 80, the relative +areas of the two circles are as 4 to 1; so that in this last case the +exclusive range of the northerly winds is limited to one-fourth of the +first area. South of 80 the wind will frequently come from the south, +and by mixing with the local atmosphere of that latitude, will tend to +ameliorate the small area to the northward. And the greater atmospheric +commotion when confined to such a small circle of latitude, must assist +materially to break up the polar ice; which would tend still more to +equalize the temperature. + +By referring to our table, we see that the mean conjunction of the pole +of the lunar orbit and the moon's apogee, was in longitude 128 on April +10, 1846, and let it be remembered that when the conjunction takes place +due south or in longitude 270, the vortices attain their greatest +latitude north. When, on the contrary, the conjunction takes place due +north or in longitude 90,[48] the northern limits of the vortices are +then in the lowest latitude possible. + +Sir John Franklin sailed in May 1845, and was certainly at the entrance +of Wellington sound, near latitude 75, April 3d, 1846, as the dates on +the graves testify. That season, according to the theory, was a cold +one; for the vortices could not reach so far to the northward in that +year, and consequently there were no storms, properly speaking. It would +probably be late in the summer of 1846, before the expedition was +liberated, and as the prevailing winds would be from the northward, he +would have little choice, but to stand to the westward if the state of +the ice permitted. In his instructions he was to use every effort to +penetrate to the southward and westward of Cape Walker, and he probably +conformed to them under the circumstances, and passed the winter in the +ice, in that neighborhood. And in 1847 we do not anticipate, from the +theory, that he would make much progress westward. + +In 1848, Sir James Ross was sent out with the first relief-ship; but was +not able to reach the entrance of Wellington channel because of compact +ice from there to Leopold Island. This was about the beginning of +September--a time when the northern channels are usually the most open. +On the 11th, they ran the ships into Port Leopold, and the next day the +ice shut them in for the winter. From the character of the season, we +may infer that if Franklin did not enter Wellington channel in 1847, as +is most probable, neither did he in 1848. Perhaps he was not able to get +his ships far to the westward, as we infer from the theory. Still, as +the time was not very protracted, he would wait patiently another season +and husband his resources. + +In 1849, Sir James Ross cut his ships clear of the ice August 28th, and +crossed over to Wellington channel, where he found the land-ice still +fast, showing that this season was also a bad one in accordance with the +theory. On the 1st of September he met the first gale of wind, at which +time the _Inner Vortex_ was at its extreme north latitude, and rapidly +extending its limits by the motion of the perigee. + +This vortex describes a smaller orbit than either the central or the +outer vortex, and consequently reaches into higher latitudes. But the +time was badly chosen, as the whole series of years since Franklin left +has been unfavorable for the early rupture of the ice. Sir James Ross +having been drifted out of Lancaster sound by the gale, finally bore up +for England towards the close of September 1849. + +The same year, the North Star with additional supplies was working up +Baffin's bay; but on account of the unusual quantities of ice, and the +frosts "which glued the floes together," she was unable to force a +passage through the middle ice, and wintered on the east side of +Baffin's bay, in latitude 76 33'--her thermometer marking 64 below +zero, as the coldest of the winter. In 1850, the perigee of the moon +attained its northern limit, but the position of the node was bad; still +this year and 1851, were the best of the series. The North Star +succeeded in getting out of the ice on the 1st of August--a very early +date for that high latitude--and on the 8th had crossed over to +Possession bay; but being prevented by the land-ice, she bore up for +Pond bay and there landed the provisions. The same year (1850) several +vessels entered Lancaster sound. Sir John Ross also reached Melville +Island; from which it is evident that this season was far better than +any preceding. According to Captain Penny, this year a floe of ice at +least two years old, filled Wellington strait; but was diminished in +breadth at a subsequent visit. He also saw a boundless open sea from the +_western_ entrance of Wellington strait; but of course the ships could +not reach it, for the floe before mentioned. Following the indications +of the theory, we consider it almost certain that Franklin went to the +westward and not through Wellington channel; that he made but slow +progress until 1850, when finding the sea more open to the northward, +and attributing it more to local influences than to any change in the +season, he considered it a better course to extricate the expedition, by +pushing on towards Behring's straits than to attempt the frozen channels +he had already passed through. But the seasons again getting worse after +1850, he was again arrested in the polar basin by the ice and islands +off the northern coast of America. + +Regarding the old and new continents as in reality a connected body of +land, with a polar depression, we may expect that the great range of +American mountains is continued in a straight line, from the mouth of +the McKenzie river, obliquely across the Polar sea, and connects with +the Ural; and that along the axis of the chain, protuberant masses will +emerge above the sea level, constituting an archipelago of islands, from +Nova Zembla to the McKenzie; and that these islands, causing an +accumulation of ice, and arresting its general tendency to the +southward, is the barrier which Sir John Franklin was finally stopped +by, in a situation where he could neither advance nor return. With the +map before us, and the data afforded by former voyages, and guided by +these theoretical views, respecting the prevailing direction of the +winds and the character of the seasons, we should locate Sir John +Franklin near latitude 80, and longitude 145, in 1851; and as the +seasons would afterwards become more severe, we may consider that he +has not been since able to change his locality, and dare not desert his +ships. + +No mere stranger can feel a deeper interest than the author, in view of +the hard fortunes of these hardy explorers, and he would not lightly +advance such opinions, did he not suppose they were in some degree +reliable. In 1832, he himself crossed the Atlantic, for the purpose of +offering himself to the Geographical Society of London, intending to be +landed as far northward as possible, with a single companion,[49] from +which point he purposed to follow the coast line on foot, with cautious +discretion as to seasons, confident that, with arms and ammunition, he +could support himself for many years. It has always been a grave error +in all these northern land expeditions, that they have been too +unwieldy, too much encumbered with the comforts and luxuries of +civilization at the outset, and too much loaded with a philosophical +paraphernalia, for a pioneering survey,--and cherishing too fondly the +idea that the wide shores of the Arctic sea could be explored in a +single season. Had the British government established a few posts in the +Arctic regions in the beginning,--one, for instance, in Lancaster sound, +another in Behring's Straits, and a third near the mouth of the +Coppermine, volunteers of sufficient scientific attainments might have +been procured, to banish themselves to these inhospitable regions for a +term of years, if assured of triennial supplies; and in this way, by +summer boat-parties and winter expeditions, over land or ice, the +explorations could have been gradually extended, and a greater knowledge +of the polar regions might have been acquired, with an immense saving +both of life and money. In 1832 the author's plan was deranged, by +finding that Captain Back was about setting out in quest of Ross, who +had then been some four years absent. This officer had all his party +engaged when the author waited upon him in Liverpool, and no notice was +taken of a modified plan which he forwarded to the Society at his +suggestion. It was therefore abandoned. + +The above fact is alluded to, in order to show the author's sincerity in +expressing his belief that, with a previous preparation of mind and body +for a sojourn in those frigid climes, a sufficient subsistence may be +derived from the country itself. Advantage must, of course, be taken of +the times of abundance, and due preparation made for the season of +scarcity. Averaging the extremes, there is little doubt but that both +land, and air, and water, afford an abundance of food for man in the +Arctic zone, and that, when spurred by necessity, it is within his power +to obtain it. We ought not therefore to despond, or give up efforts to +rescue those who have well earned the sympathy of the world, by what +they must have already suffered. _These northern seas will yet be +explored._ The very difficulty of accomplishing it, will itself give it +a charm, which in this restless age will operate with increasing power. +And should efforts now be relaxed, and in some future time the evidence +be brought to light that some of the party yet existed, long after all +efforts to rescue them had been abandoned, the fact would be a dark spot +on the escutcheon of England, which time could not erase. + +Since these pages were written, accounts have been received from Captain +McClure, of H.M. ship Investigator, which fully confirm the preceding +remarks on the character of the seasons in the Arctic circle; and, more +recently, despatches have been received from the discovery-ship, +Amphytrite, in relation to the past season in Behring's straits, which +also confirms the theory. + +The Investigator (now supposed to be frozen up in lat.74 5' N., and +long 117 54' W.,--the last despatch being dated April 10, 1853) passed +round the northern shores of America into the channels communicating +with Lancaster sound, in 1850, but was unable to extricate herself in +1852, and, probably, yet remains in the harbor she made in the winter of +1851, in the position above named. No trace of Sir John Franklin's +expedition was, however, found, and, indeed, according to our theory, +the Investigator was not on the most promising ground. We contend that +Franklin has penetrated the pack of apparently perennial ice, which is +continually pressing to the southward, and blocking up the passages +between the northern islands, or skirting the coast line of the +continent; which pack has since increased, and effectually stopped all +egress from the open central portions of the polar sea. If Sir John +Franklin is ever heard from, this pack _must be penetrated_, and a +powerful steamer ought to be sent immediately by the British government, +to be ready in Behring's straits early enough to take advantage of the +first openings, and make a bold push _due north_, so as to get as +speedily as possible into the open waters to the north of the pack. + +If the author could make himself heard at Washington, he would also urge +the government to lose no time in following our own expedition under Dr. +Kane, who, if he finds a clear entrance from Smith's sound into the +Arctic sea, may be induced to push on, and endeavor to make his way +through the pack towards Behring's straits, and thus fall into the same +snare as Franklin. According to the theory, the higher the passage into +the Arctic sea, the less will it be incumbered with ice, and, +consequently, Smith's sound is the best both to enter and return by; and +had the author not already smarted enough by having his professions +derided, he would have submitted these views to the patrons of that +expedition before it sailed. + +The scientific world is, in reality, chargeable with the disastrous +results of Franklin's expedition. The polar basin is hemmed in by the +coast line of Europe, Asia, and America, in about latitude 70 north, +for the greatest part of the entire circumference. And this coast line, +and the islands adjacent, will cause the polar ice to accumulate and +form a frozen belt along these shores, in consequence of the constant +tendency of the earth's rotation to press the ice to the southward. The +fact that an open passage exists between this belt and the shore in +summer time, is no objection, as the tides, river currents, and warm +land breezes, may very well explain this. The learned have insisted, and +do yet insist, that the earth's rotation can produce no motions in the +Arctic sea, and, under this delusion, Franklin has passed into the +comparatively open waters inside the pack, perhaps has lost his ships; +yet it is very possible that the party may have escaped, and derived a +subsistence from the more genial waters of the central portion of that +ocean unto this day. + +We have already alluded to the difference of level between the Atlantic +and Pacific waters. It is well known that the currents in the +Spitzbergen and Greenland seas is to the southward, and that Parry, in +his attempt to reach the pole, was foiled by this very current, +frequently setting him back in twenty-four hours more than his party +could travel in the same time over the ice. Through Baffin's and +Hudson's bay the northern waters are also continually bearing their +frozen freight southward. We are, therefore, entitled to ask, what +supplies this immense drain? Behring's straits are only about sixty +miles wide, and twenty-five fathoms deep; the supply, therefore, through +this channel is totally inadequate, yet there is no other channel into +the Arctic sea where the current is inward. We have already explained +the reason why the current through Behring's straits is an exception to +the general rule, yet still confirming the principle by referring it to +the configuration of the land enclosing the Pacific ocean. The whole +south Pacific lies open to the pole, and the inertia of the immense mass +of mobile waters pressing northward, and continually contracted by the +form of the American and Asiatic coasts, is not balanced by a contrary +impulse of the waters of the north Pacific, inasmuch as this ocean +becomes narrower as it extends northward, and the only passage to the +frozen ocean is through the narrow straits of Behring. The axifugal +force of rotation due to the northern waters is, therefore, overborne +by the vast preponderance due to the southern waters, and, hence, the +northern Pacific may be considered as relatively at a higher level, and +there will be a current northward through Behring's straits, as we find +it. The same cause accumulates the waters under the equator, thus giving +a higher level to the Pacific than to the Atlantic at the isthmus of +Panama, where the difference of level is found by actual measurement to +be five or six feet. This fact has never before been explained; but the +cause is too obvious to admit of question. + +That the sea is deeper than was formerly admitted, is now fully +confirmed. We have before alluded to the results obtained by Captain +Denham, of H.M. ship Herald, who found bottom at 7,706 fathoms, or +about nine English miles. Now, whether that spherical shell, which we +have contended to be the true form of the solid earth, be continuous and +entire; or, whether it may not be wanting in localities of limited +extent where the ocean would be absolutely unfathomable, we know not; +but if such be the internal constitution of our globe, there will be, no +doubt, many channels of communication between the internal and external +ocean, and, as a consequence of the earth's rotation, the axifugal +current of the Arctic sea may be supplied by an upward current from the +interior of the globe; and this current may have a higher temperature +than the surface waters of that sea, and thus the middle portions may, +in truth, remain open the whole year round, and be teeming with animal +life. According to Captain Penny's observations in 1850, whales and +other northern animals existed to the westward, where he saw the open +sea stretch out without a bound before him. + +It has been a question mooted by some, that Franklin's ships might be +overtaken, at an early stage of the voyage, by a storm, and foundered +amidst the ice. The theory would give a negative answer to this +question. Stiff gales may prevail far to the north when the vortices do +not reach so high; but no storm, properly speaking, will be found far +beyond their northern limit. After the coming winter (1853), the +vortices will gradually penetrate farther and farther to the northward, +and the years 1857, 1858, and 1859, will be highly favorable for +northern discovery, accompanied, however, with the necessary draw-back +of tempestuous weather. + + +FOOTNOTES: + +[48] The reader will of course understand these as celestial longitudes, +and the latitudes as terrestrial. + +[49] Mr.William McDonald, of Canada. + + + + +CONCLUSION. + + +Our theory has thus extended itself beyond those limits which we at +first had drawn, and our apology must consist in the necessity existing +for reconciling the most remarkable phenomena of meteorology to its +principles. Yet, after all, what has been said is but an outline of what +remains, but this outline is a part of our theory of the weather, and it +could not well do without its aid. In some points we may not have +correctly interpreted facts; but the facts remain. The numerical +elements of the theory may also be in error--we know not; but we think +that they are as perfect as the many contingencies on which they depend +will permit. What is _certain_ however, is of ample value to compensate +for trivial errors. We have hitherto experienced but little courtesy +from those intrusted with the keys of knowledge, and cannot consequently +anticipate a very lenient verdict. But we now tell them before the +world, that they have a duty to perform, and an examination to make, and +a decision to come to, "whether these things are so." Our theory may be +called an ingenious speculation, but WE CHALLENGE THE SCIENTIFIC TO +PROVE IT--NOTHING ELSE. The theory furnishes them with tests of daily +occurrence, to prove or to disprove it. By such a trial we are willing +to be judged; but let it be conducted in the spirit recommended in the +opening address before the American Association for the Advancement of +Science, to expose all false developments, and to do it generously and +without prejudice; and to remember, "that the temple of science belongs +to no country or clime. It is the world's temple, and all men are free +of its communion. Let its beauty not be marred by writing names upon its +walls."[50] The _great_ objection, of friction and resistance of an +all-pervading medium, which will be urged against it, we regard as +rather the offspring of a bewildered imagination, than of scientific +induction. We can discover no such consequences as final ruin to our +system through its agency; but even if such were discovered, we may +answer, that nature nowhere tells us that her arrangements are eternal; +but rather, that decay is stamped with the seal of the Almighty on every +created thing. Change may be one of the great laws of matter and motion, +and yet matter and motion be indestructible. The earth was called into +existence for a specific object, and when that object is accomplished, +we are assured that another change awaits her. But when earth, and sun, +and planets, are again redissolved into their primitive state, their +atoms will still float on the ever-rolling billows of the great ethereal +ocean, to be again cast up, on the shore of time, whenever it pleaseth +Him to say, "Let there be light." + + +FOOTNOTES: + +[50] Prof. Pierce's Address, 1853. + + + + +APPENDIX. + + +Since the author's arrival in New York for the purpose of publishing his +outlines, the third and fourth volume of the Cosmos has been placed in +his hands, containing the latest uranological discoveries and +speculations. It is now more than twenty years since he began to +investigate the subject he has treated of, and fifteen since he first +announced to the world, that he had satisfactory evidence of his theory +being true. Luckily, perhaps, he has been cut off from the great streams +of knowledge; and he may confess that it was with pardonable feelings of +gratification that he discovered in 1853, by the acquisition of the two +first volumes of the Cosmos, that the philosophic mind of Humboldt had +also pondered deeply on the planetary peculiarities of size, density, +distance, inclination of axes and eccentricities of orbits, without +eliciting any satisfactory relations. + +From the tenor of the third and fourth volume of this learned summary of +scientific knowledge, it is evident that the question of a medium +filling space is more and more occupying the learned world; but the +author is unable to discover any consistent theory respecting it. The +increasing interest attaching to it, however, is evidently preparing the +world for some radical change in preconceived views. The explanation +given by this present theory to many prominent phenomena, is so totally +contrary to that of the learned world, as to leave it untouched by +anything yet advanced. What the fifth volume of the Cosmos will +contain, is not yet known in this country, neither has the author been +favored with any glimpse of the progress of science as developed before +the British Association; he supposes, however, that he yet stands alone +in the position he has defined. + +As a question of practical importance, the reader will find in the work +cited, the various opinions of the temperature of space. Both Fourier +and Poisson regard this as the result of radiated heat from the sun and +all the stars, minus the quantity lost by absorption in traversing the +regions of space filled with ether.[51] But why should we regard the +stars as the source of all motions? Why cannot physicists admit the idea +of an infinite space filled (if we may use the expression) with an +infinite medium, possessing an unchangeable mean temperature long before +the formation of a single star. A star equal to our sun at the distance +of Sirius, would give about one million of million times less heat than +our present sun, which is only able to give an average temperature to +the whole globe--about twenty degrees above freezing--then let us +remember that there are only about fifty stars of the first and second +magnitude, which give more light (and by analogy heat also) than all the +rest of the stars visible. Such labored theories as this of Poisson's is +a lamentable instance of the aberrations of human wisdom. + +We would also call the reader's attention to a late conclusion of +Professor Dove, viz.: That differences of temperature in different +longitudes frequently exist on the same parallel of latitude, or, in +other words, are laterally disposed. This may be thought adverse to the +theory, but it should be borne in mind that the annual mean temperature +of the whole parallel of latitude should be taken when comparing the +temperatures of different years. + +Another fact cited in the Cosmos apparently adverse to the theory, is +the idea entertained by Sir John Herschel, that the full-moon +dissipates the clouds. This question has been fully examined by +Professor Loomis before the American Association, and he concludes that +there is not the slightest foundation for the assertion--taking as data +the Greenwich observations themselves. + + +FOOTNOTES: + +[51] See _Cosmos_, p.41, vol.III. + + + + + + +End of the Project Gutenberg EBook of Outlines of a Mechanical Theory of +Storms, by T. 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Bassnett. + </title> + <style type="text/css"> +/*<![CDATA[ XML blockout */ +<!-- +body{margin-left: 10%; + margin-right: 10%; + } +p { margin-top: .75em; + margin-bottom: .75em; + text-align: justify; + line-height:1.3em; + } +p.title {font-size: 150%; + text-align:center; + font-weight:bold; + } +small {font-size:60%;} +h1,h2,h3,h4,h5,h6 { + text-align: center; /* all headings centered */ + clear: both; + } +hr { width: 33%; + margin-top: 2em; + margin-bottom: 2em; + margin-left: auto; + margin-right: auto; + clear: both; + } + +table {margin-left: auto; margin-right: auto; + border-collapse:collapse;} + table.toc td {vertical-align:bottom;} + table.toc p {margin:0.75em 0.5em 0 2em; + text-indent:-1.5em;} + table.toc th {padding-top:1em;} +th {padding: 0.25em 0.5em 0.25em 0.5em; + font-weight:normal;} +td {vertical-align:bottom;} +td[rowspan] {vertical-align:middle;} +.tdr0 {text-align:right; padding-right: 0.25em;} +.tdr {text-align:right; padding-right:2em;} +.tdr1 {text-align:right; padding-right:4em;} +.tdl0 {text-align:left; padding-left:0.25em;} +.tdl {text-align:left; padding-left:2em;} +.tdl1{text-align:left; padding-left:4em;} +.tdc {text-align:center;} +table.space td {padding-left:0.5em; padding-right:0.5em; } +table.cols td, table.cols th {border-left:thin solid black; border-right:thin solid black; } + table.cols td.l {border-right:none;} + table.cols td.r {border-left:none;} +caption {margin-bottom:0.3em; margin-left:auto; margin-right:auto;} +ins.correction { text-decoration:none; + border-bottom: thin dotted gray; } +ins.info {text-decoration:none; + border-bottom: thin dotted #0000DD; } +.transnote {background-color: #E6E6FA; + color: black; + font-size:smaller; + padding:0.5em; + margin-bottom:5em;} +.transnote h4, .transnote p.sf {font-family:sans-serif, serif;} +.pagenum { + position: absolute; + left: 92%; + font-size: 13px; /* same font size for page nums inside <h>, regular <p> or in the index */ + font-weight: normal; /* prevent bolding in <h> */ + font-variant:normal; + font-style:normal; + text-indent: 0em; text-align:right; + color: silver; + background-color:inherit; + } + span[title].pagenum:after { + content: "[" attr(title) "]"; + } +a[name] { position:absolute; } /* Fix Opera bug */ +p.hang {text-indent:-0.4em; } +.center {text-align: center;} +.smcap {font-variant: small-caps;} +span.time {text-transform:lowercase; font-variant:small-caps;} +.figcenter {margin:1em auto 1em auto; text-align: center;} +p img {vertical-align:middle; border:none;} +.footnotes {border: dashed 1px;} +.footnote {margin-left: 10%; margin-right: 10%; font-size: 0.9em;} +.footnote .label {position: absolute; right: 85%; text-align: right;} +.fnanchor {vertical-align: super; font-size: .8em; text-decoration: none;} +p .fnanchor {line-height:0.1;} +// --> +/* XML end ]]>*/ +</style> + </head> + +<body> + + +<pre> + +Project Gutenberg's Outlines of a Mechanical Theory of Storms, by T. Bassnett + +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: Outlines of a Mechanical Theory of Storms + Containing the True Law of Lunar Influence + +Author: T. Bassnett + +Release Date: July 8, 2006 [EBook #18791] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK THEORY OF STORMS *** + + + + +Produced by Curtis Weyant, Laura Wisewell and the Online +Distributed Proofreading Team at http://www.pgdp.net + + + + + + +</pre> + +<div class="transnote"> + +<h4>Transcriber’s Note</h4> + +<p class="sf"><b>Special characters:</b> This file uses a number of special characters, which +may not display in your browser or font. Some, such as Greek letters and +special symbols to denote planets, occur infrequently and a +transliteration is given with a mouse-hover like this: <ins class="info" title="Neptune.">♆</ins>. However, +the following mathematical symbols occur often:</p> + +<p class="center" style="letter-spacing:0.5em;">× − ± ½ ¼ ⅓ ⁄ ′ +″.</p> + +<p class="sf">If these do not display, you may prefer to use a plain text version of +this ebook.</p> + +<p class="sf"><b>Printer errors:</b> Obvious typographical errors in the original have been +corrected in this version, and are marked with mouse-hovers <ins +class="correction" title="Description of the error.">like this</ins>. However, +the inconsistent spelling of Ottawa/Ottowa, and the inconsistent use of +comma or full-stop as thousands separator has been left as in the +original. The value given for the eccentricity of Uranus may also be a +printer error.</p> +</div> + + + +<h1><span style="letter-spacing:0.4em;">OUTLINES</span><span class="pagenum" title="Page 1"> </span><a name="Page_1" id="Page_1"></a> +<br /> +<small>OF</small><br /> +<br /> +A MECHANICAL THEORY OF STORMS,</h1> +<p class="title"> +<small>CONTAINING</small><br /> +<br /> +THE TRUE LAW OF LUNAR INFLUENCE,<br /> +<br /> +<small>WITH<br /> +<br /> +PRACTICAL INSTRUCTIONS TO THE NAVIGATOR, TO ENABLE HIM<br /> +APPROXIMATELY TO CALCULATE THE COMING<br /> +CHANGES OF THE WIND AND WEATHER,<br /> +FOR ANY GIVEN DAY, AND FOR<br /> +ANY PART OF THE OCEAN.</small> +</p> +<h2>BY T. BASSNETT.</h2> +<p class="title"><small> +<ins class="info" title="Greek: H de mesots en pasin asphalestera.">Ἡ δε μεσοτης εν πασιν ασφαλεϛερα</ins> +</small></p> +<p class="title" style="line-height:0.8;"><small>NEW YORK:<br /> +D. APPLETON & COMPANY,<br /> +346 & 348 BROADWAY,<br /> +AND 16 LITTLE BRITAIN, LONDON.<br /> +1854.</small></p> + + + +<hr style="width: 65%;" /> +<p class="center"><span class="pagenum" title="Page 2"> </span><a name="Page_2" id="Page_2"></a> +Entered, according to Act of Congress, in the year 1853, by +<br /> +T. BASSNETT, +<br /> +In the Clerk’s Office of the Southern District of New York.</p> + + + +<hr style="width: 65%;" /> +<h2><a name="CONTENTS" id="CONTENTS"></a><span class="pagenum" title="Page 3"> </span><a name="Page_3" id="Page_3"></a>CONTENTS.</h2> + + +<table class="toc" summary="Table of Contents"> +<tr><th colspan="2"><a href="#SECTION_FIRST">SECTION FIRST.</a></th></tr> +<tr> +<td><p>Present State of the Science of Meteorology—Primordial Condition of the +Solar System—Theory of Gravitation the great key of Nature—Bessell’s +doubts of its perfect adequacy—the Newtonian Vacuum: its +difficulties—Nature of the element called Ether—The Medium of Space +and the Electric Fluid—Ponderosity of Matter—Dynamical law of +Equilibrium—Specific heat and its relation to space—A Plenum not +opposed to Gravitation—The medium of space in motion—Formation of +Vortices—A new principle developed—Elements of the problem—Hutton’s +theory of the production of rain—Indications of change and the +cause—Action of the Ethereal Current—Physical process of Atmospheric +Derangement—Redfield’s theory of Storms: its difficulties—All storms +are of brief duration and limited extent.</p></td><td><a href="#Page_13">13</a></td></tr> + + +<tr><th colspan="2"><a href="#SECTION_SECOND">SECTION SECOND.</a></th></tr> +<tr> +<td><p>Mechanical action of the Moon—The Moon’s mass—Axis of the Terral +Vortex affected by the Moon: its inclination and position: its +displacement—An example of the principle—Corrections +necessary—Milwaukie storm—New York storm—Ottawa storm—Liverpool +storm—Names and recurring order of the storm-producing agents—Record +of the weather—Second New York storm.</p></td><td><a href="#Page_58">58</a></td></tr> + + +<tr><th colspan="2"><span class="pagenum" title="Page 4"> </span><a name="Page_4" id="Page_4"></a><a href="#SECTION_THIRD">SECTION THIRD.</a></th></tr> +<tr> +<td><p>Lunar influence rejected by the learned—Their conclusions not +valid—Modifying causes in accordance with these principles—Years and +seasons vary in character—Superficial temperature of different +Planets—No storms on the planet Mars—Rotation the cause of Ocean and +Atmospheric Currents—Pressure of the atmosphere and its regular and +irregular variations—Terrestrial Magnetism—Internal Constitution of +the Globe—Magnetic variations—Cause of these variations—Magnetic +storms—Aurora Borealis: its altitude—Earthquakes; their possible +connection with Storms.</p></td><td><a href="#Page_101">101</a></td></tr> + + +<tr><th colspan="2"><a href="#SECTION_FOURTH">SECTION FOURTH.</a></th></tr> +<tr> +<td><p>The solar spots—Law of periodicity compared with the theory—Existence +of another planet beyond Neptune probable—Masses of the Sun and +Planet yet uncertain—The Law of Gravitation not above +suspicion—Proofs of this—The full of the Moon—Density of the +Ethereal Medium: its law in the Solar Vortex—Bode’s law of the +planetary distances—Law of planetary density—Law connecting the +present and former diameters of the planets—Disturbing action of the +Ether—Kepler’s third law not rigidly exact—Inconsistencies of +Astronomers—Nature of light and heat—Distinction between light and +heat.</p></td><td><a href="#Page_147">147</a></td></tr> + + +<tr><th colspan="2"><a href="#SECTION_FIFTH">SECTION FIFTH.</a></th></tr> +<tr> +<td><p>Comets—Their small inclinations—Their motions chiefly direct—Comet of +1770 and 1844—Cause of acceleration in the case of Encke—Anomalous +motions of the comet of 1843—Change of diameter at different +distances of a comet from the sun—Cause of this change—Nature of the +nebulosity—Form<span class="pagenum" title="Page 5"> </span><a name="Page_5" id="Page_5"></a>ation of the tail—Compound nature of a comet’s +light—motion and direction of a comet’s tail—Phenomena presented by +the great comet of Halley—Mass of a comet—The Zodial light—Nebulous +stars—Shooting stars—Periodic showers—Periodicity doubtful—Cause +of the apparent periodicity—Cause for being more numerous in Autumn +than in Spring.</p></td><td><a href="#Page_187">187</a></td></tr> + + +<tr><th colspan="2"><a href="#SECTION_SIXTH">SECTION SIXTH.</a></th></tr> +<tr> +<td><p>State of the polar ice since 1845—Sir John Franklin’s track—Probable +existence of islands north of Behring’s Straits—Possibility of +subsisting in the Arctic islands—News from the +Investigator—Necessity of searching in a higher latitude than the +Investigator visited—Franklin’s misfortunes due to Scientific +Errors—Relative levels of the Atlantic and Pacific Oceans—The Arctic +seas more accessible in a few years—Conclusion.</p></td><td><a href="#Page_233">233</a><span class="pagenum" title="Page 6"> </span><a name="Page_6" id="Page_6"></a></td></tr> +</table> + + +<hr style="width: 65%;" /> +<h2><a name="PREFACE" id="PREFACE"></a><span class="pagenum" title="Page 7"> </span><a name="Page_7" id="Page_7"></a>PREFACE.</h2> + + +<p>On presenting to the public a work of this novel character, +overstepping, as it does, the barriers erected by modern systems to the +further progress of knowledge, a few words of explanation may not be +inappropriate. Early imbued with a desire to understand the <i>causes</i> of +natural phenomena, the author devoured with avidity the interpretations +contained in the elementary works of orthodox science, until reason and +observation rendered him dissatisfied with the repast. To him it +appeared that there was an evident tendency in scholastic instruction, +to make the knowledge of nature inaccessible to the many, that the world +might be made more dependent on the few; while many of the <i>established +principles</i>, on which the learned rested, seemed to be at variance with +the simplicity and consistency of truth. Thus situated, he ventured to +think for himself, and looking back on the history of the past, and +finding so many cases in which the philosophy of to-day was supplanted +by a different system on the morrow, he was led to suspect the +possibility of future revolutions, and was thus determined to be no +longer embarrassed by previous systems, nor deterred by opinions +however<span class="pagenum" title="Page 8"> </span><a name="Page_8" id="Page_8"></a> learned, which conflicted with a rational recognition of the +mechanical nature of all physical phenomena.</p> + +<p>The science of meteorology, to which the following pages are devoted, +is, and always has been, a confessedly complex subject; and on this +account, any suggestions and facts which observation gleans,—no matter +how humble the source may be, should not be denied a hearing by those +professedly engaged in the pursuit of truth. Step by step, the author +became more and more confirmed in his doubts of the soundness of many +modern theories; and in 1838 he had attained a position which enabled +him to allege in the public prints of the day, that there did exist +certain erroneous dogmas in the schools, which stood in the way of a +fuller development of the causes of many meteorological phenomena. This +annunciation was made in general terms, and no notice was taken of it. +Subsequently, he forwarded to the British Association of Science, then +convened at Birmingham, a communication of similar tenor; and at a later +date still, a more particular statement of the advantages of his +discoveries to the navigator and agriculturist, was sent to the British +admiralty. The first of these communications was treated with silent +contempt; the last elicited some unimportant reply. In 1844 a memorial +was presented to Congress, accompanied with a certified copy of +<i>predictions</i> of the weather, written several weeks before the event, +and attested in due form by two impartial witnesses; but neither did +this result in any inquiry as to its truth. During the time since +elapsed, he has been engaged in pursuits which prevented him from +pressing the subject elsewhere, until the spring of 1853, he brought +his<span class="pagenum" title="Page 9"> </span><a name="Page_9" id="Page_9"></a> theory under the notice of the Smithsonian Institution. This led to +a correspondence between himself and the gentlemanly Secretary of the +Institution, whose doubts of the truth of his allegations were expressed +with kindness, and whose courtesy was in strange contrast with the +conduct of others. In the communications which he forwarded to that +Institution, he gave a detailed statement of the difficulties he had met +with, and expressed the hope that an Institution, created for the +purpose of increasing and diffusing knowledge, would feel justified in +lending the influence of its name to facilitate the completion of a +theory which was yet undeniably imperfect. In view of this, a test was +proposed.<a name="FNanchor_1_1" id="FNanchor_1_1"></a><a href="#Footnote_1_1" class="fnanchor">[1]</a> “Give us, for example, a prediction of the weather for one +month in each season of the year 1854, for the City of Washington.” This +test the author refused, for the reason that he did not consider it +necessary to wait so long; but he informed the Secretary of the +Institution, that he would prepare an outline of his theory, which would +enable him to decide upon the merits of the discoveries claimed. This +outline is contained in the following pages. During the summer of 1853 +he called upon Professor Henry, then at Chicago, with his manuscript; +but a sudden indisposition prevented that gentleman from having it read. +He, however, strongly recommended its publication from such impressions +he then received.<a name="FNanchor_2_2" id="FNanchor_2_2"></a><a href="#Footnote_2_2" class="fnanchor">[2]</a> This the author had<span class="pagenum" title="Page 10"> </span><a name="Page_10" id="Page_10"></a> resolved on, from a sense of +duty to the world at large, although the promise was rather of +prospective loss than of present benefit. The peculiar form under which +the theory appears, is, therefore, a result of the circumstances above +stated, and of the author’s present inability to enter into the minute +details of a subject, which embraces in its range the whole visible +creation.</p> + +<p>In extending the theory to other phenomena, he has only fearlessly +followed out the same principles which have conducted him to a knowledge +of a disturbing cause, to which atmospheric storms owe their origin, and +in doing so he has conferred with no one. For whatever of merit or of +blame may therefore justly attach to these views, he alone is +responsible. If he has charged the scientific with inconsistency, or +with sometimes forgetting that the truth of their unnecessarily abstruse +investigations depends on the truth of the data, he at least is +conscientious; for he is too well aware that to provoke an unfavorable +verdict by contending against such fearful odds, is not the surest way +to either wealth or fame, or even to an acknowledgment of at least <i>the +mite</i>, which he cannot but feel that he has contributed to the treasury +of knowledge. That the scientific organisations of the day do tend to +curb the aberrations of a fanciful philosophy, cannot be denied;<span class="pagenum" title="Page 11"> </span><a name="Page_11" id="Page_11"></a> but at +the same time there is engendered such a slavish subordination as checks +the originality of thought, and destroys that perfect freedom from the +trammels of system, so necessary to success in the pursuit of truth. Of +such an influence the author explicitly asserts his entire independence.</p> + +<p>In thus introducing his theory, the reader is forewarned that he will +not find it dressed in the fascinating garb of the popular literature of +the day, whose chief characteristic is to promise much when possessing +little. It is, however, a plant of the author’s own raising, unpropped, +unpruned, with none of the delicate tendrils or graceful festoons of the +trellissed vine; yet he flatters himself that its roots are watered by +the springs of truth, and hopes that he who is in quest of <i>that</i>, will +not find, amidst its many clusters, any fruit to set his teeth on +edge.</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_1_1" id="Footnote_1_1"></a><a href="#FNanchor_1_1">[1]</a></span>Extract from a letter from Professor Henry.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_2_2" id="Footnote_2_2"></a><a href="#FNanchor_2_2">[2]</a></span>This gentleman kindly offered to contribute from his own +private means, to forward the publication, but he could do nothing +officially without submitting the manuscript to three different censors. +He who claims a new discovery, will seldom be satisfied to have it +judged by men who are engaged in the same investigations, however pure +and honorable they may be. Is this Institution adopting the best plan of +aiding truth, in its struggles against error? Should any man sit as +judge in his own trial? If there had been a powerful Institution to +stand between Galileo and the scientific of his day, his doctrines would +not have been condemned, and the world would have been fifty years more +in advance.</p></div> +</div> + + +<hr style="width: 65%;" /> +<h1><span class="pagenum" title="Page 12"> </span><a name="Page_12" id="Page_12"></a><a name="MECHANICAL_THEORY_OF_STORMS" id="MECHANICAL_THEORY_OF_STORMS"></a>MECHANICAL THEORY OF STORMS.</h1> + + + +<hr style="width: 65%;" /> +<h2><span class="pagenum" title="Page 13"> </span><a name="Page_13" id="Page_13"></a><a name="SECTION_FIRST" id="SECTION_FIRST"></a>SECTION FIRST.</h2> + +<h3>PRESENT STATE OF METEOROLOGY.</h3> + + +<p>The present state of the science of which we are about to treat, cannot +be better defined than in the words of the celebrated Humboldt, who has +devoted a long life to the investigation of this department of Physics. +He says: “The processes of the absorption of light, the liberation of +heat, and the variations in the elastic and electric tension, and in the +hygrometric condition of the vast aërial ocean, are all so intimately +connected together, that each individual meteorological process is +modified by the action of all the others. The complicated nature of +these disturbing causes, increases the difficulty of giving a full +explanation of these involved meteorological phenomena; and likewise +limits, or <i>wholly precludes</i> the possibility of that predetermination +of atmospheric changes, which would be so important for horticulture, +agriculture, and navigation, no less than for the comfort and enjoyment +of life. Those who place the value of meteorology in this problematic +species of prediction, rather than in the knowledge of the phenomena +themselves, are firmly convinced that this branch of science, on account +of which so many expeditions to distant mountainous regions have been +undertaken, has not made any very considerable progress for<span class="pagenum" title="Page 14"> </span><a name="Page_14" id="Page_14"></a> centuries +past. The confidence which they refuse to the physicist they yield to +changes of the moon, and to certain days marked in the calender by the +superstition of a by-gone age.”</p> + +<p>The charge thus skilfully repelled, contains, however, much truth; there +has been no adequate return of the vast amount of labor and expense thus +far devoted to this branch of knowledge. And it is not wonderful that +the popular mind should expect a result which is so much in accordance +with the wants of mankind. Who is there whose happiness, and health, and +comfort, <i>and</i> safety, and prosperity, may not be more or less affected +by reducing to law, the apparently irregular fluctuations of the +weather, and the predetermination of the storm? To do this would be the +crowning triumph of the age; and the present theory has pioneered the +way for its speedy accomplishment.</p> + + +<h3>ORIGINAL CONDITION OF THE EARTH.</h3> + +<p>That the present order of things had a beginning, is taught by every +analogy around us, and as we have the glaring fact forced upon us, that +our globe has experienced a far higher temperature on its surface than +obtains at present, and moreover, as it is demonstrated beyond a cavil, +that the interior is now of far higher temperature than is due to solar +radiation, we are justified in concluding, not only that the condition +of the interior of our globe is that of fusion, but that its original +temperature was far higher than at present; so that the inference is +allowable that there has been a time when the whole globe was <i>perhaps</i> +in this state. But why should we stop here? There are three states of +matter, the solid, the fluid, and the gaseous; and with this passing +glance at the question, we will jump at once to the theory of La +Place,—that not only our own globe, but the whole solar system, has +been once in the nebulous state.</p> + +<p>In justice to himself, the author ought to remark, that he<span class="pagenum" title="Page 15"> </span><a name="Page_15" id="Page_15"></a> had reasoned +his way up to this starting point, before even the name of La Place had +reached his ears. He makes the remark in order to disclaim any desire to +appropriate that which belongs to another; as he may innocently speak of +things hereafter, the idea of which has occurred to others. It is not +his intention here to say a word <i>pro</i> or <i>con</i> on the nebular +hypothesis; it is sufficient to allude to the facts, that the direction +of rotation and of revolution is the same for all the planets and +satellites of our system; and that the planes on which these motions are +performed, are nearly coincident. That this concordance is due to one +common cause, no one acquainted with the theory of probabilities will +pretend to deny.</p> + + +<h3>GREAT OBJECT OF LA PLACE.</h3> + +<p>The science of Astronomy occupies a pre-eminent rank in the physical +circle, not only on account of that dignity conferred upon it in the +most remote antiquity, or as being the grand starting point—the +earliest born of science—from whence we must contemplate the visible +creation, if we would reduce its numerous details into one harmonious +whole; but also on account of its practical fruits, of the value of +which modern commerce is an instance. Accordingly we will glance at its +past history. In the earliest ages there was no doubt a rational view +entertained of the movements of the planets in space. From the Chaldeans +to the Arabs, a belief prevailed, that space was filled with a pure +ethereal fluid, whose existence probably did not rest on any more solid +foundation than analogy or tradition. One hundred years after Copernicus +had given to the world the true arrangements of our planetary system, +Descartes advanced his theory of vortices in the ethereal medium, in +which the planets were borne in orbits around the sun, and the +satellites around their primaries. This idea retained its ground with +various additions, until the Geometry of Newton recon<span class="pagenum" title="Page 16"> </span><a name="Page_16" id="Page_16"></a>ciled the laws of +Kepler with the existence of a power pertaining to matter, varying +inversely as the squares of the distances, to which power he showed the +weight of <ins class="correction" title="Transcriber’s note: Original reads ‘terrestial’.">terrestrial</ins> bodies was owing, and also the revolution of +the moon about the earth. Since Newton’s day, those deviations from the +strict wording of Kepler’s laws, have been referred to the same law, +and the avowed object of the author of the “Mechanique Celeste,” was to +bring all the great phenomena of nature within the grasp of analysis, by +referring them to one single principle, and one simple law. And in his +Introduction to the Theory of the Moon, he remarks: “Hence it +incontestibly follows, that the law of gravitation is the sole cause of +the lunar inequalities.”</p> + + +<h3>BESSEL’S OPINION.</h3> + +<p>However beautiful the conception, it must be admitted that in its <i>à +priori</i> aspect, it was not in accordance with human experience and +analogy to anticipate a successful issue. In nature law re-acts upon +law, and change induces change, through an almost endless chain of +consequences; and it might be asked, why a simple law of matter should +thus be exempt from the common lot? Why, in a word, there should be no +intrinsic difference in matter, by which the gravitation of similar or +dissimilar substances should be affected? But experiment has detected no +such differences; a globe of lead and a globe of wood, of equal weight, +attract contiguous bodies with equal force. It is evident, therefore, +that if there be such differences, human means are not yet refined +enough to detect them. Was the issue successful then? Generally +speaking, we may say yes. But where there is a discrepancy between +theory and observation, however small that may be, it shows there is +still something wanting; and a high authority (Professor Bessel) says in +relation to this: “But I think that the certainty that the theory based +upon this law, <i>perfectly</i> explains all the observations, is<span class="pagenum" title="Page 17"> </span><a name="Page_17" id="Page_17"></a> not +correctly inferred.” We will not here enumerate the cases to which +suspicion might be directed, neither will we more than just allude to +the fact, that the Theory of Newton requires a vacuum, in order that the +planetary motions may be mathematically exact, and permanent in their +stability.</p> + + +<h3>A VACUUM REQUIRED BY MODERN SYSTEMS.</h3> + +<p>Whatever may be the practical belief of the learned, their fundamental +principles forbid the avowal of a plenum, although the undulatory theory +of light renders a plenum necessary, and is so far virtually recognized +by them, and a correction for resistance is applied to the Comet of +Encke. Yet there has been no attempt made to reconcile these opposing +principles, other than by supposing that the celestial regions are +filled with an extremely rare and elastic fluid. That no definite view +has been agreed on, is not denied, and Sir John Herschel speculates on +the reality of a resisting medium, by suggesting questions that will +ultimately have to be considered, as: “What is the law of density of the +resisting medium which <i>surrounds</i> the sun? Is it in rest or in motion? +If the latter, in what direction does it move?” In these queries he +still clings to the idea of Encke, that the resistance is confined to +the neighborhood of the sun and planets, like a ponderable fluid. But +the most profound analyst the world has ever boasted, speaks less +cautiously, (Poisson Rech.) “It is difficult to attribute, as is usually +done, the incandescence of aërolites to friction against the molecules +of the atmosphere, at an elevation above the earth where the density of +the air is almost null. May we not suppose that the electric fluid, in a +neutral condition, forms a kind of atmosphere, extending far beyond the +mass of our atmosphere, yet <i>subject to terrestrial attraction</i>, yet +<i>physically imponderable</i>, and, consequently, following our globe in its +motion?” The incandescence of aërolites must, therefore, be owing to +friction against the<span class="pagenum" title="Page 18"> </span><a name="Page_18" id="Page_18"></a> molecules of the electric fluid which forms an +atmosphere around the globe. According to this view, some force keeps it +there, yet it is not ponderable. As it is of limited extent, this is not +the medium whose undulations brings to light the existence of the stars; +neither is Encke’s, nor Herschel’s, nor any other resisting medium. +Where shall we find the present established principles of science? If we +grant the Newtonians a plenum, they still cling to attraction of <i>all +matter</i> in some shape. If we confine them to a vacuum, they will +virtually deny it. Is not this solemn trifling? How much more noble +would it be to exhibit a little more tolerance, seeing that they +themselves know not what to believe? We do not offer these remarks as +argument, but merely as indications of that course of reasoning by which +we conclude that the upholders of the present systems of science are not +entitled to any other ground than the pure Newtonian basis of an +interplanetary vacuum.</p> + + +<h3>DIFFICULTIES OF THIS VIEW.</h3> + +<p>This, then, is the state of the case: Matter attracts matter directly as +the mass, and inversely as the squares of the distances. This law is +derived from the planetary motions; space is, consequently, a void; and, +therefore, the power which gives mechanical momentum to matter, is +transferred from one end of creation to the other, without any physical +medium to convey the impulse. At the present day the doctrines of +Descartes are considered absurd; yet here is an absurdity of a far +deeper dye, without we resort to the miraculous, which at once +obliterates the connection between cause and effect, which it is the +peculiar province of physical science to develop. Let us take another +view. The present doctrine of light teaches that light is an undulation +of an elastic medium necessarily filling all space; and this branch of +science probably rests on higher and surer grounds than any other. Every +test applied to it by the<span class="pagenum" title="Page 19"> </span><a name="Page_19" id="Page_19"></a> refinements of modern skill, strengthens its +claims. Here then the Newtonian vacuum is no longer a void. If we get +over this difficulty, by attributing to this medium a degree of tenuity +almost spiritual, we shall run upon Scylla while endeavoring to shun +Charybdis. Light and heat come bound together from the sun, by the same +path, and with the same velocity. Heat is therefore due also to an +excitement of this attenuated medium. Yet this heat puts our atmosphere +in motion, impels onward the waves of the sea, wafts our ships to +distant climes, grinds our corn, and in various ways does the work of +man. If we expose a mass of metal to the sun’s rays for a single hour +the temperature will be raised. To do the same by an artificial fire, +would consume fuel, and this fuel would generate the strength or force +of a horse. Estimate, therefore, the amount of force received from the +sun in a single day for the whole globe, and we shall find that nothing +but a material medium will suffice to convey this force.</p> + +<p>Let us appeal to analogy. The undulations of our atmosphere produce +sound; that is, convey to the ear a part of a mechanical force imparted +to a solid body—a bell for instance. Let us suppose this force to equal +one pound. On account of the elasticity of the bell, the whole of the +force is not instantaneously imparted to the surrounding air; but the +denser the air the sooner it loses its motion. In a dense fluid like +water, the motion is imparted quickly, and the sound is not a ring but a +click. If we diminish the density of the air, the loss of motion is +retarded; so that we might conceive it possible, provided the bell could +be suspended in a <i>perfect vacuum</i>, without a mechanical tie, and there +was no friction to overcome from the rigidity of its particles, that the +bell would vibrate forever, although its sound could never reach the +ear. We see, therefore, that the mechanical effect in a given time, is +owing to the density of the medium. But can we resort to such an +analogy? Every discovery in the science confirms more and more the<span class="pagenum" title="Page 20"> </span><a name="Page_20" id="Page_20"></a> +analogy between the motions of air and the medium of space; the angle of +reflexion and incidence follows the same law in both; the law of +radiation and interference; and if experiments were instituted, there +can be but little doubt that sound has also got its spectrum.</p> + + +<h3>ETHER IMPONDERABLE.</h3> + +<p>The medium of space, therefore, is capable of conveying a mechanical +force from one body to another; it therefore possesses inertia. Does it +also possess gravity? If we forsake not the principles of science, it is +but right that we expect science shall abide by her own principles. +Condensation in every elastic medium is as the compressing power, +according to all experiments. In the case of our atmosphere under the +law of gravitation, the density of air, (supposing it to be infinitely +expansible,) at a height only of ten semidiameters of the earth above +its surface, would have only a density equal to the density of one cubic +inch of such air we breathe, if that cubic inch was to be expanded so as +to fill a globular space whose centre should be the earth, and whose +surface should take inside the whole visible creation. Such a medium +could convey no mechanical force from the sun, and therefore the medium +of space cannot be ponderable. Simple as the argument is, it is +unassailable.</p> + + +<h3>ELECTRIC FLUID THE MEDIUM OF SPACE.</h3> + +<p>Let us take yet another view. All experiments prove that the phenomenon +we call electricity, is owing to a disturbance of the equilibrium or +natural condition of a highly elastic fluid. In certain conditions of +the atmosphere, this fluid is accumulated in the region of the clouds, +and by its tension is enabled to force a passage through opposing +obstacles, in order to restore the equilibrium. By experiment it is +found that dry dense air opposes the greatest obstacle to its escape. As +the air is rarefied,<span class="pagenum" title="Page 21"> </span><a name="Page_21" id="Page_21"></a> this obstacle diminishes; until in a vacuum the +transmission may be considered instantaneous. There ought to be, +therefore, a greater escape of electricity from the clouds upwards than +downwards; and, if space be void, or only filled with an extremely +attenuated matter, the electricity of the earth, considered as an +elastic fluid without ponderosity, (and no law of condensation from the +law of gravity in harmony with its other attributes, will allow us to +consider it otherwise,) <i>would long since have left the earth</i>. The same +objection applies in the case of the galvanic and magnetic fluids. If we +entertain the idea that electricity is a mere disturbance of natural +condition, wherein two fluids are united, and that an excess of one is +necessarily attended by deficiency in the other, we depart from the +first rule of philosophy, which teaches us to admit no greater number of +causes than are sufficient to explain the phenomenon. For we fearlessly +assert that not a single fact exists in electrical science, which can be +explained better on Dufoy’s theory than on Franklin’s; and the former +objections would still apply.</p> + + +<h3>NEWTONIAN GRAVITY.</h3> + +<p>But what is gravity? According to Newton: “Hæc est qualitas omnium in +quibus experimenta instituere licet, et propterea per Reg. 3 de +universes affirmanda est.” <i>Vide</i> Prin. Lib. Ter. Cor. 2. Prop. vi.</p> + +<p>Now the other primary qualities of matter are unaffected by +circumstances. The inertia of a particle of matter is the same at +Jupiter as on the earth, so also is its extension; but not so with +gravity. It depends on other matter, and on its distance from it; and +may be less or greater at different times, and in different places. It +is, therefore, not philosophical to say that all matter is necessarily +ponderous, inasmuch as it is a virtue not residing in itself alone, but +needs the existence of other matter to call it into action. If an atom +were isolated in space<span class="pagenum" title="Page 22"> </span><a name="Page_22" id="Page_22"></a> it would have no weight. If influenced by other +matter, there must be some physical medium to convey the influence, or +gravity is not in accordance with the laws of force and motion. Which +horn of the dilemma shall we take? Let us first admit that there is a +principle of gravitation, affecting all planetary or atomic matter, and +that there exists a highly elastic medium, pervading all space, +conveying to us the light of the most distant stars, and that this +medium is not affected by gravity. In this summary way, therefore, we +have arrived at the pivot on which this theory turns.</p> + +<p>The prominent feature of the theory, therefore, is the necessity it will +show for the existence of an all-pervading medium, and that it possesses +inertia without ponderosity. That electricity is nothing more than the +effects of the condensation and rarefaction of this medium by force. +That it also pervades all atomic matter, whose motions necessarily move +the medium; and, consequently, that there can be no motion without some +degree of electricity. That no change can take place in bodies either by +chemical decomposition, by increase or decrease of temperature, by +friction or contact, without in some measure exciting electricity or +motion of the ether. That galvanism and magnetism are but ethereal +currents without condensation, induced by peculiar superficial and +internal molecular arrangement of the particles of certain substances. +That light and heat are effects of the vibrations of atoms, propagated +through this universal medium from body to body. That the atomic motion +of heat can be produced by the motion of translation or momentum of +bodies in the gross, that is, by friction, by compression, &c.; and can +be reconverted into momentum at our pleasure. Hence the latent heat or +specific atomic motion of combustibles, originally derived from the sun, +is transferred to atoms, which are capable of being inclosed in +cylinders, so as to make use of their force of expansion, which is thus +converted into momentum available for all the wants of man.</p> + + +<h3><span class="pagenum" title="Page 23"> </span><a name="Page_23" id="Page_23"></a>GRAVITY MECHANICAL.</h3> + +<p>When we come to a full examination of this theory, we shall further +reason that this <i>ether</i> so far from being of that quasi spiritual +nature which astronomers would have us believe, is a fearfully energetic +fluid, possessing considerable inertia and elasticity; that its law of +condensation is that of all other fluids, that is, as the compressing +force directly; and that its effects are simply a product of matter and +motion. We will next endeavor to prove that the gravity of planetary +matter could not exist without this ethereal medium, by showing that it +is an effect produced by the interference of <i>opposing waves</i>, whereby a +body is prevented from radiating into space its own atomic motion, from +the side opposite which another body is placed, as much as on the +opposite side, and consequently it is propelled by its own motion +towards the other body. And this effect following the simple law of +inertia and radiation, is directly as the mass, and inversely as the +squares of the distances.</p> + + +<h3>GREAT PRINCIPLE OF DYNAMICS.</h3> + +<p>One great principle to be kept in view in this investigation, is that +which teaches that the product of matter, angular velocity, and distance +from the centre of motion, must ever be a constant quality in every +balanced system. Yet this principle does not seem to be observed in the +case of the planets. We will, however, endeavor to show that it is +rigidly observed. And we will extend the principle further, and contend +that all the phenomena of nature are consequences of the constant +tendency of matter to conform to this principle of equilibrium, when +suffering temporary derangement from the operation of other laws. That +throughout the system of nature, equal spaces possess equal force. That +what we call temperature, is nothing more than the motion of equilibrium +or atomic momentum of<span class="pagenum" title="Page 24"> </span><a name="Page_24" id="Page_24"></a> space; or, in other words, that if all space were +fluid, and in a state of equilibrium, the product of each atom of equal +volume, by its motion would be a constant quality. From this it would +seem to follow, that the specific heat of bodies should be inversely as +their atomic weights; and this does, no doubt, <i>approximately</i> obtain as +was proved by Dulong and Petit, for metallic substances, more recently +by Regnault, and has since been extended by Garnier to other substances. +But it is to the gaseous state that we must look for confirmation of the +principle that equal spaces possess equal power; and in doing so, it +will be necessary to bear in mind, that the ether also is affected by +temperature.</p> + + +<h3>SPECIFIC HEAT.</h3> + +<p>It has been contended by some that the medium which conveys the +impression of light through transparent, bodies, is necessarily more +dense within the body than without; but according to this theory the +converse is true. A ray of light is a mechanical impulse, propagated +through an elastic medium, and, like a wave in water, tends to the side +of least resistance. Within a refracting body the ether is rarefied, not +only by the proximity of the atoms of the body (or its density), but +also by the motions of those atoms; so that if two <i>simple</i> gases of +different specific gravity be made equal in density by compression, +their refraction will be approximately as their specific heats. In the +case of solids and liquids, or even compound gases, there is a continual +absorption of motion to produce the cohesion of composition and +aggregation. And the specific heats of compound gases will be found +greater than those of simple gases, in proportion to the loss of volume +by combination, <i>ceteris paribus</i>. If impenetrability be a law of +matter, the more a portion of atomic matter is condensed, the less ether +will be found in the same space. The same is also true when the natural +density or specific gravity of a gas is greater than that<span class="pagenum" title="Page 25"> </span><a name="Page_25" id="Page_25"></a> of another. +And the lighter the gas, the more will this circumstance vitiate the +experiments to determine its specific heat. There is, therefore, this +great source of fallacy in such experiments, viz.: that the ether +permeates all fluids and solids, and that <i>its specific heat probably +far exceeds that of all other matter</i>. This is a fundamental position of +the theory, in support of which we will introduce a fact announced by +M. V. Regnault, which was published in the Comptes Rendus of the French +Academy for April, 1853. He says: “In the course of my researches I have +encountered, indeed, at every step, anomalies which appeared to me +inexplicable, in accordance with the theories formally recognized. For +the sake of illustration I will quote one instance: 1st, a mass of gas, +under a pressure of ten atmospheres, is contained in a space which is +suddenly doubled; the pressure falls to five atmospheres. 2d. Two +reservoirs of equal capacity are placed in a calorimeter; the one is +filled with a gas, under a pressure of ten atmospheres; the second is +perfectly empty. In these two experiments, the initial and final +conditions of the gas are the same; but this identity of condition is +accompanied by calorific results which are very different; for while in +the former experiment there is a reduction of temperature, in the second +the calorimeter does not indicate the slightest alteration of +temperature.” This experiment tends to confirm the theory. In the first +experiment, the sudden doubling of the space causes the <ins class="correction" title="Transcriber’s note: Original reads ‘either’.">ether</ins> also to +expand, inasmuch as the sides of the vessel prevent the instantaneous +passage of the external ether. In the second, both vessels are full, one +of ether, and the other of air mixed with ether; so that there is no +actual expansion of the space, and consequently no derangement of the +quantity of motion in that space.</p> + + +<h3><span class="pagenum" title="Page 26"> </span><a name="Page_26" id="Page_26"></a>LAW OF SPECIFIC HEAT.</h3> + +<p>From this view it is evident that the specific heat of elastic fluids +can only be considered as approximately determined. If equal spaces +possess equal momenta, and the ethereal or <i>tomic</i> matter be inversely +as the weight of the atomic matter in the same space, it follows that +the product of the specific gravities and specific heats of the simple +gases should be constant; or that the specific heats should be inversely +as the specific gravities,—taking pound for pound in determining those +specific heats. If we test the matter by the data now afforded, it is +best to obey the injunction, “<i>In medio tutissimus ibis</i>.” In the +following table, the first column are the values obtained by <ins class="correction" title="Transcriber’s note: Original reads ‘Reynault’.">Regnault</ins>; +in the second, the former values; and in the third, the mean of the two.</p> + +<table summary="Specific heats of gases."> +<tr> + <th>Gases.</th> + <th>Reg.<br />specific heats.</th> + <th>Former<br />specific heats.</th> + <th>Mean.</th> +</tr> +<tr> + <td>Atmospheric air,</td> + <td class="tdr">.237</td> + <td class="tdr">.267</td> + <td class="tdr">.252</td> +</tr> +<tr> + <td>Oxygen,</td> + <td class="tdr">.218</td> + <td class="tdr">.236</td> + <td class="tdr">.227</td> +</tr> +<tr> + <td>Nitrogen,</td> + <td class="tdr">.244</td> + <td class="tdr">.275</td> + <td class="tdr">.260</td> +</tr> +<tr> + <td>Hydrogen,</td> + <td class="tdr">3.405</td> + <td class="tdr">3.294</td> + <td class="tdr"> 3.350</td> +</tr> +</table> + +<p>The specific gravities of these gases, according to the best tables in +our possession, are:</p> + +<table summary="Specific gravities of gases."> +<tr> + <th></th> + <th>Specific gravities.</th> + <th></th> + <th>Mean. </th> + <th></th> + <th>Products.</th> +</tr> +<tr> + <td>Atmospheric air,</td> + <td class="tdr">1.0000</td> + <td>×</td> + <td class="tdr">.252</td> + <td>=</td> + <td class="tdc">.252</td> +</tr> +<tr> + <td>Oxygen,</td> + <td class="tdr">1.1111</td> + <td>×</td> + <td class="tdr">.227</td> + <td>=</td> + <td class="tdc">.252</td> +</tr> +<tr> + <td>Nitrogen,</td> + <td class="tdr">0.9722</td> + <td>×</td> + <td class="tdr">.260</td> + <td>=</td> + <td class="tdc">.252</td> +</tr> +<tr> + <td>Hydrogen,</td> + <td class="tdr">0.0745</td> + <td>×</td> + <td class="tdr">3.350</td> + <td>=</td> + <td class="tdc">.249</td> +</tr> +</table> + +<p>As might be expected, there is a greater discrepancy in the case of +hydrogen.</p> + +<p>If we test the principle by the vapor of water, we must consider that it +is composed of two volumes of hydrogen and one volume of oxygen, and +that one volume disappears; or that<span class="pagenum" title="Page 27"> </span><a name="Page_27" id="Page_27"></a> one-third of the whole atomic +motion is consumed by the interference of the vibrations of the ether, +necessary to unite the atoms, and form an atom of water. We must +therefore form this product from its specific gravity and two-thirds of +its specific heat. On no one subject in chemistry has there been so much +labor expended, as in determining the specific heat of watery vapor. In +relation to this, Regnault observes: “It is important to remark that an +immense number of experiments have been made, to find the specific heat +of steam, and that it is about one-half of what it was thought to be.” +He gives its value .475; but this is vitiated still, by the +non-recognition of the specific heat of the ether. Former experiments +give .847. Perhaps Regnault’s numbers are entitled to the most weight. +Instead of taking the mean, therefore, we will give double weight to his +results; so that we get .600 for the specific heat of vapor, and as its +specific gravity is .625, the product .400 × .625 is .250, the same as +for hydrogen. Little importance, however, should be attached to such +coincidences, owing to the uncertainty of the numbers. If our position +be correct, the specific heat of hydrogen should be 10 times greater +than of oxygen. The atomic weights are as 1 to 8, while their volumes +are as 2 to 1; therefore, for equal spaces, the matter is as 1 to 16. +Calling the specific heat 10 to 1, and taking the amount due to half the +space, the product becomes as 8 to 16; but in the rarer gas there is <i>8 +times</i> as much ethereal momentum or matter, which, added to the atomic +matter, renders the spaces equal.<a name="FNanchor_3_3" id="FNanchor_3_3"></a><a href="#Footnote_3_3" class="fnanchor">[3]</a> <ins class="correction" title="Transcriber’s note: Original reads ‘Reynault’.">Regnault</ins>’s results give a ratio of +specific heats = 1 to 3.405 ⁄ .215 = 1 to 15.6.</p> + + +<h3><span class="pagenum" title="Page 28"> </span><a name="Page_28" id="Page_28"></a>THE GOLDEN MEAN.</h3> + +<p>The history of science proves how few have practically respected the +adage of the ancients, which we have chosen for our motto; words which +ought to be written in letters of gold in every language under the sun. +Descartes, by considering the mechanical impulse of the ether sufficient +to explain the planetary motions, failed to detect the force of gravity +in the heavens. Newton, on the other hand, feeling that his law was +sufficient to explain them, and requiring a vacuum for its mathematical +accuracy, rejected the notion of an ethereal medium. His successors, +following too closely in his footsteps, and forgetting the golden law, +have forced themselves into a position by no means enviable. The +short-period comet has driven them to a resisting medium, which, while +according to Encke’s hypothesis of increasing density around the sun, it +explains the anomalies of one periodical comet, requires a different +law of density for another, and a negative resistance for a third.</p> + + +<h3>OUTLINES OF THE PROBLEM.</h3> + +<p>From the position we now occupy, we can see the outlines of the problem +before us, viz.: To reconcile the existence of an ethereal medium with +the law of gravitation, and to show the harmony between them. We shall +thus occupy the middle ground, and endeavor to be just to the genius of +Descartes, without detracting from the glory of Newton, by demonstrating +the reality of the Cartesian vortices, and by showing that the ether is +not affected by gravitation, but on the other hand is <i>least dense</i> in +the centre of our system. But what (it may be asked) has this to do with +the theory of storms? Much every way. And we may so far anticipate our +subject as to <i>assert</i> that every phenomenon in meteorology where force +is concerned, is dependent on the motions of the great sea of electric +fluid<span class="pagenum" title="Page 29"> </span><a name="Page_29" id="Page_29"></a> which surrounds us, in connection with its great specific, +caloric. If we are chargeable with overweening pretensions, let it be +attributed to the fact that for the last fifteen years we have treated +the weather as an astronomical phenomenon, calculated by simple formulæ, +and that the evidence of its truth has been almost daily presented to +us, so as to render it by this time one of the most familiar and +palpable of all the great fundamental laws of nature. True, we have +neither had means nor leisure to render the theory as perfect as we +might have done, the reason of which we have already communicated.</p> + + +<h3>MOTIONS OF THE STARS.</h3> + +<p>In investigating the question now before us, we shall first take the +case of an ethereal vortex without any reference to the ponderable +bodies which it contains, considering the ether to possess only inertia. +If there be a vortex around the sun, it is of finite extent; for if the +ether be co-extensive with space, and the stars likewise suns with +surrounding vortices, the solar vortex cannot be infinite. That there is +an activity in the heavens which the mere law of attraction is +incompetent to account for, is an admitted fact. The proper motions of +the fixed stars have occupied the attention of the greatest names in +astronomy, and motions have been detected, which according to the theory +of gravity, requires the admission of invisible masses of matter in +their neighborhood, compared with which the stars themselves are +insignificant. But this is not the only difficulty. No law of +arrangement in the stars can exist that will save the Stellar system +from ultimate destruction. The case assumed by Sir John Herschel, of a +cluster, wherein the periods shall be equal, cannot be made to fulfil +the conditions of being very numerous, without infringing the other +condition—the non-intersection of their orbits; while the outside stars +would have to obey another law of gravitation, and consequently would be +still more liable<span class="pagenum" title="Page 30"> </span><a name="Page_30" id="Page_30"></a> to derangement from their ever-changing distances +from each other, and from those next outside; in brief, the stability of +those stars composing the cluster would necessarily depend on the +existence of outside stars, and plenty of them. But those outside stars +would follow the common law of gravity, and must ultimately bring ruin +on the whole. We know such clusters do exist in the heavens, and that +the law of gravity alone must bring destruction upon them. This is a +case wherein modern science has been instrumental in drawing a veil over +the fair proportions of nature. That such collections of stars are not +designed thus to derange the order of nature, proves <i>à priori</i>, that +some other conservative principle must exist; that the medium of space +must contain many vortices—eddies, as it were, in the great ethereal +ocean, whose currents are sweeping along the whole body of stars. We +shall consider, (as a faint shadowing of the glorious empire of +Omnipotence,) that the whole infinite extent of space is full of motion +and power to its farthest verge; and it may be an allowable stretch of +the imagination to conceive that the whole comprises one infinite +cylindrical vortex, whose axis is the only thing in the universe in a +state of absolute unchangeableness.</p> + + +<h3>VORTICOSE MOTION.</h3> + +<p>Let us for a moment admit the idea of an infinite ocean of fluid matter, +having inertia without gravity, and rotating around an infinite axis, in +this case there is nothing to counteract the effect of the centrifugal +force. The elasticity of the medium would only oppose resistance in a +vortex of finite diameter. Where it is infinite, each cylindrical layer +is urged outward by its own motion, and impelled also by those behind. +The result would be that all the fluid would at last have left the axis, +around which would exist an absolute and eternal void; into which +neither sound, nor light, nor aught material, could enter.<span class="pagenum" title="Page 31"> </span><a name="Page_31" id="Page_31"></a> The case of +a finite vortex is very different. However great the velocity of +rotation, and the tendency of the central parts to recede from the axis, +there would be an inward current down either pole, and meeting at the +equatorial plane to be thence deflected in radii. But this radiation +would be general from every part of the axis, and would be kept up as +long as the rotation continued, if the polar currents can supply the +drain of the radial stream, that is, if the axis of the vortex is not +too long for the velocity of rotation and the elasticity of the ether, +there will be no derangement of the density, only a tendency. And in +this case the periodic times of the parts of the vortex will be directly +as the distances from the axis, and the absolute velocities will be +equal.</p> + + +<hr style="width: 65%;" /> +<h3>FORMATION OF VORTICES.</h3> + +<p>There is reason to suspect that Newton looked at this question with a +jaundiced eye. To do it justice, we must consider the planetary matter +in a vortex, as the exponent of its motion, and not as originating or +directing it. If planetary matter becomes involved in any vortex, it +introduces the law of gravitation, which counteracts the expulsive force +of the radial stream, and is thus enabled to retain its position in the +centre. A predominating mass in the centre will, by its influence, +retain other masses of matter at a distance from the centre, even when +exposed to the full power of the radial stream. If the power of the +central mass is harmoniously adjusted to the rotation of the vortex, +(and the co-existence of the phenomena is itself the proof that such an +adjustment does obtain,) the two principles will not clash or interfere +with each other. Or in other words, that whatever might have been the +initial condition of the solar vortex, the ultimate condition was +necessarily one of equilibrium, or the system of the planets would not +now exist. With this view of its constitution, we must consider that the +periodic times<span class="pagenum" title="Page 32"> </span><a name="Page_32" id="Page_32"></a> of the planets approximately correspond to the times of +the contiguous parts of the vortex. Consequently, in the solar vortex, +the density of the ether is directly as the square roots of the +distances from the axis. This is not the place fully to enter into a +discussion of the question, or to show that the position of each planet +in the system is due to the outstanding, uncompensated, portion of the +expulsive force of the radial stream, modified by the density of the +ether within the planets, and also by their own densities, diameters, +inclinations of axis, and periods of rotation. That Jupiter could not +remain in the orbit of Mercury, nor Mercury in that of Jupiter, by +merely exchanging periods and distances, but that each planet can only +be in equilibrio in its own orbit. That any change in the eccentricities +of the planetary orbits will neither increase nor diminish the action of +the radial stream of the vortex, and consequently will not interfere +with the law of gravitation. In relation to the numerous questions that +will spring up from such a position, it is sufficient here to say, that +it is believed all objections can be satisfactorily answered; while, by +this light, a long range of phenomena that have hitherto baffled the +sagacity of the wise, come out plainly, and discover their parentage.</p> + +<p>In cometary astronomy we shall find much to substantiate these views. +The anomalies in their motions, the discrepancies in their periods, +calculated from different sets of observations, their nebulosities and +appendages, will all receive a satisfactory solution; and these lawless +wanderers of the deep be placed in a more interesting light.</p> + + +<h3>TEST OF A THEORY.</h3> + +<p>It has been remarked that the best evidence of the truth of a theory, is +its ability to refer to some general principle, the greatest number of +relevant phenomena, that, like the component masses of the chiselled +arch, they may mutually bind<span class="pagenum" title="Page 33"> </span><a name="Page_33" id="Page_33"></a> and strengthen each other. This we claim +to be the characteristic of this theory. At the outset it was not +intended to allude to more than was actually necessary to give an +outline of the theory, and to introduce the main question, yet +untouched. We have exhibited the stones of which the arch is composed; +but they may be pasteboard,—for the reader has not handled them. We +will now produce the keystone, and put it in its place. This he shall +handle and weigh. He will find it hard,—a block of granite, cut from +the quarry of observed facts, and far too heavy to be held in its place +by a mere pasteboard structure.</p> + + +<h3>ENUNCIATION OF THE THEORY.</h3> + +<p>Quitting, therefore, the region of the planets, we will come down to the +surface of our own globe, to seek for some more palpable evidence of the +truth of the following propositions:</p> + +<p>1st. That space is filled with an elastic fluid, possessing inertia +without weight.</p> + +<p>2d. That the parts of this fluid in the solar system circulate, after +the manner of a vortex, with a direct motion.</p> + +<p>3d. That there are also secondary vortices, in which the planets are +placed.</p> + +<p>4th. That the earth is also placed in a vortex of the ethereal medium.</p> + +<p>5th. That the satellites are passively carried around their primaries, +with the ethereal current, and have no rotation relative to the ether, +and therefore they always present the same face to their primaries, and +have no vortex.</p> + +<p>The consideration of these propositions involves many others, many +difficulties, many apparent anomalies and contradictions, which should +bespeak for such a theory,—the offspring of observation, without the +aid afforded by the knowledge of others, and of toil without leisure,—a +large share of indulgence. With this we will close these preliminary +remarks, and present our<span class="pagenum" title="Page 34"> </span><a name="Page_34" id="Page_34"></a> theory of the physical cause which disturbs +the equilibrium of our atmosphere, and which appears the principal agent +in the production of storms, in the following words:</p> + +<p>The dynamical axis of the terral vortex passes through the centre of +gravity of the earth and moon, and is continually circulating over the +earth’s surface in both hemispheres, in a spiral,—its latitude and +longitude, at any particular time, being dependent,—</p> + +<p>1st. On the relative mass of the moon.</p> + +<p>2d. On the inclination of the axis of the vortex to the earth’s axis.</p> + +<p>3d. On the longitude of the ascending node of the vortex on the lunar +orbit.</p> + +<p>4th. On the longitude of the ascending node of the lunar orbit on the +ecliptic.</p> + +<p>5th. On the eccentricity of the lunar orbit at the time.</p> + +<p>6th. On the longitude of the perigee of the lunar orbit at the time.</p> + +<p>7th. On the moon’s true anomaly at the time.</p> + + +<h3>MASS OF THE MOON.</h3> + +<p>Those elements which represent the moon’s distance and motion are +accurately known, and may be taken from the Nautical Almanac, being all +embodied in the moon’s <ins class="correction" title="Transcriber’s note: Original reads ‘parrallax’.">parallax</ins> or semi-diameter, and in the +declination and right ascension; but for the most important +element,—the moon’s mass, we in vain look to astronomy. In fact, it may +be averred that the importance attached to astronomical authority, +concerning the mass of the moon, has caused more trouble than any other +question of the whole theory, until we trusted implicitly to the theory +itself to determine it. The determination of three unknown elements, +viz.: the moon’s mass, the inclination of the axis of the vortex, and +the right ascension of that axis, is a more difficult problem than at<span class="pagenum" title="Page 35"> </span><a name="Page_35" id="Page_35"></a> +first sight appears, owing to the nature of the phenomena, which affords +the only clue for its solution. There are six principal vortices ever in +operation on the surface of the earth, and their disturbing influence +extends from 200 to 400 miles. To find the precise centre, by one +observer confined to one place, is difficult; and to separate them, so +as to be fully assured that you have the right one, is perhaps still +more so. Happily this tedious labor is accomplished, and we are able +with confidence to give the following important elements, as very close +approximations to the truth:</p> + +<table summary="Facts about the moon."> +<tr> + <td>Mass of the moon</td> + <td>1 ⁄ 72.3</td> +</tr> +<tr> + <td style="padding-right:2em;">Obliquity of the axis of the vortex</td> + <td>15° to 32° variable.</td> +</tr> +<tr> + <td>Right ascension of ditto</td> + <td>250° to 290° variable.</td> +</tr> +</table> + +<p>It must be borne in mind that we are now discussing the main or central +vortex of the earth; but before applying them to the calculation, we +will explain the <i>modus operandi</i>, waiving for the present the +consideration of the law of density in the Terral vortex. It is evident +at first sight that if the periodic times of the parts of the vortex +contiguous to the moon, are equal to the moon’s period approximately, +that the velocity of the ether is greater at the surface of the earth +than the velocity of that surface. Now, we have before argued that the +ether possesses inertia, it therefore would under such circumstances +exert some mechanical action. Consequently, the aërial envelope of our +globe, or its superior stratum, is impelled eastward by <i>convection</i><a name="FNanchor_4_4" id="FNanchor_4_4"></a><a href="#Footnote_4_4" class="fnanchor">[4]</a> +of the more rapidly rotating ether. And from the extreme tenuity of its +upper layers, is probably forced into immense waves, which will observe +to a certain degree, a general <ins class="correction" title="Transcriber’s note: Original reads ‘paralellism’.">parallelism</ins> north and south.</p> + + +<h3><span class="pagenum" title="Page 36"> </span><a name="Page_36" id="Page_36"></a>ATMOSPHERIC CURRENTS.</h3> + +<p>It is a well-known fact, that the prevailing current of the atmosphere +in high latitudes is from the westward. The cause of this is ascribed by +Professor Dove to the transfer of the equatorial portions to a higher +latitude, by which the excess of its rotative velocity is made apparent, +by outstripping the slower moving surface in its progress eastward. No +doubt some effect is due to this, but still a difficulty remains. Let us +follow this current. The polar current reaches the surface on the +borders of the trades with less rotative velocity than the surface, and +is, therefore, met by the surface as a current partaking of both +motions. In the northern hemisphere it is north-east deflected to east +as it approaches the southern trades. By the same reasoning, coming from +the north before it readies the surface, it ought to be also a +north-east wind above the lower westerly currents. Now it is an observed +fact, that while in the latitude of New York, for instance, the lower +westerly winds are to the easterly, as 3 or 4 to 1, in the highest +regions of observed clouds, the ratio is much increased; and according +to our own observations in this place,<a name="FNanchor_5_5" id="FNanchor_5_5"></a><a href="#Footnote_5_5" class="fnanchor">[5]</a> we have never seen the highest +cirrus clouds moving westward. How then is this continual interchange +kept up? Assuredly we cannot have a current from the poles without a +contrary current to the poles. If we go into the arctic circle, we again +find the westerly and northerly winds predominating. If the current from +the equator follows the surface, the westerly winds ought to be +south-west. If it be above the surface wind, then the surface wind is +the polar current, and ought to be north-east. Whereas, from the +testimony of all who have visited these regions, the prevailing winds +are north-west. How can this be?</p> + +<p>Again, it is proved that the upper current near the equator is also from +the westward—as near due west as possible. Take<span class="pagenum" title="Page 37"> </span><a name="Page_37" id="Page_37"></a> the latitude of St +Vincent. The difference between the <ins class="correction" title="Transcriber’s note: Original reads ‘cosein’.">cosine</ins> of 13° and radius applied +to the circumference, is about 600 miles, which would give 25 miles per +hour to the eastward, in lat. 13°. But to do this, it is necessary to +transfer it suddenly from the equator; for by a slow motion the easterly +tendency would be lost. Give it 24 hours from the equator to lat. 13°, +without any loss of easterly tendency, and it comes to that latitude +with a velocity of 38 miles per hour to the northward, and only 25 to +the eastward; we have, therefore, a wind from south-west by south. Yet +it is known that in the tropics the highest visible clouds move from the +westward. But as no such case could occur as a transfer in twenty-four +hours without loss, and if we diminish the time, the wind is still more +southerly. Meteorologists usually cite the falling of ashes at Jamaica +during the eruption of Coseguina, in Guatamala, in February 1835, as +coming from south-west, whereas the true direction was about west +south-west, and the trade wind below was about north. But do we deny +that there is an interchange between the frigid and torrid zones? By no +means; but we would show that the great controlling power is external to +our atmosphere, and that the relative velocities of the earth and the +atmosphere is not alone adequate to account for it. By this view the +polar current is a north-west wind (which is impossible by Professor +Dove’s theory), or is carried eastward by electric convection.</p> + + +<h3>HUTTON’S THEORY.</h3> + +<p>Whether we adopt the views of Fourier or Poullet, as to the temperature +of the planetary spaces, it is certain that it is at least equal to, or +less than, the lowest temperature of our globe. It is also a well-known +fact, that the capacity of air to hold vapor in solution, increases in a +higher ratio than the temperature, so that the intermingling of +saturated portions of air, at different temperatures, must <i>necessarily</i> +be attended by precipi<span class="pagenum" title="Page 38"> </span><a name="Page_38" id="Page_38"></a>tation of moisture. This idea was advanced by +Doctor Hutton, and considered competent to account for the prominent +meteorological phenomena, until Professor Espy broached a questionable +principle, (and which is rendered still more so by the late +investigations of Regnault,) in opposition to Hutton’s theory. That the +theory is deficient, no one can gainsay. That Espy has rendered the +question clearer, is equally hazardous to assert. Hutton failed in +showing a cause for such intermingling on a sufficient scale; while +Espy, it may be suspected, has misinterpreted facts, and incautiously +rejected the only element possessing the power of raising the storm.</p> + + +<h3>GREAT SPECIFIC HEAT OF THE ETHER.</h3> + +<p>Whatever may be the degree of condensation or rarefaction in the terral +vortex, there must necessarily be a current down the pole or axis, +thence to be deflected along the equatorial plane of the vortex, and +this drain will be as perpetual as the rarefaction of the centre, +(caused by the centrifugal force of rotation,) which calls it forth. It +will now be perceived that the fluid of the vortex, which we shall still +term ether, is neither more nor less than the electric fluid,—the +mighty energising principle of space,—the source of motion,—the cause +of magnetism, galvanism, light, heat, gravity, of the aurora, the +lightning, the zodiacal light, of the tails and nebulosities of comets, +of the great currents of our atmosphere, of the samiel, the hurricane, +and the earthquake. It will be perceived that we treat it as any other +fluid, in relation to its law of motion and condensation. But we have no +right to base our calculations on its resistance, by the analogies +presented by ponderable or atomic matter. Atomic fluids,—even pure air, +may be considered viscid and tenacious when compared to an infinitely +divisible fluid, between whose particles (if we may use the term) no +<i>attraction</i> of any kind exists. No ponderable matter can<span class="pagenum" title="Page 39"> </span><a name="Page_39" id="Page_39"></a> come in close +contact without feeling the influence of the gravitating force which, at +insensible distances,—such as the breadth of a wave of ether, is +increased in power, and becomes a cohering and combining force. We +contend that this fluid is the only fluid of space; when condensed it is +positive, and seeks to escape; when rarefied it is negative, and +receives from the contiguous space a restoration of its power. That it +can give and receive, from planetary matter, what we call motion; and +consequently can affect the temperature of such matter, and be in turn +affected by it. And finally that, for its degree of inertia, it exceeds +in elasticity and specific heat all other matter.</p> + + +<h3>PROCESS OF DERANGEMENT.</h3> + +<p>This premised, we see that as the axis of the vortex traverses the +surface of the earth, there is a tendency to derange the electric state +of the parts travelled over, by bringing the atmosphere and surface of +the earth under the rarefied centre of the vortex. For it is not the +ether of the atmosphere alone that is affected. It is called forth from +the earth itself, and partakes of the temperature of the +crust,—carrying up into the upper regions the vapor-loaded atmosphere +of the surface. The weather now feels close and warm; even in winter +there is a balmy change in the feelings. The atmosphere then fills with +haze, even to the highest regions of the clouds; the clouds themselves +are ill defined; generally the wind comes in at E. S-E., or S., getting +very fresh by the time it chops round to W. In from six to twelve hours +from the time of the meridian passage, in this latitude, the Big Cumuli +have formed, and commenced their march eastward. In summer time there is +always thunder and lightning, when the passage is attended or followed +by a storm. In winter, generally, but not always. In summer, the +diameter of the storm is contracted; in winter, dilated; in consequence +of this, summer is the best season to trace the vortices<span class="pagenum" title="Page 40"> </span><a name="Page_40" id="Page_40"></a> of the earth +through their revolutions. Let us now attend a little to the results. +The ether of the surface atmosphere partakes of the temperature of that +atmosphere, so also the ether of the earth’s crust partakes of the +temperature of the crust; and its escape is rapid, compared with the +ascent of the air. When it arrives at the colder layers of air above, +its temperature sinks, and, on account of the greater specific caloric, +it imparts a much higher temperature to those layers than is due to +their position; an elevation consequently takes <ins class="correction" title="Transcriber’s note: Original reads ‘places’.">place</ins>,—begetting a +drain from below, until the upper regions are loaded with a warm and +vapory atmosphere. If the action of the sun conspires at the same time +to increase the effect, the storm will be more violent. In twelve hours +after the meridian passage of the vortex, the storm is brought under the +parts of the ethereal atmosphere of the earth most remote from the axis; +a reaction now takes place; the cold ether of space rushes in, and, on +account of its great specific caloric, it abstracts from the warm +atmosphere more than pertains to the difference of temperature, and +there is a great condensation. Rain and hail may form in fearful +quantities; and when the equilibrium is restored, the temperature will +have fallen many degrees.</p> + +<p>As it is important that we should have a clear view of the character of +the ether, we will revert to the principle we have advocated, viz.: that +in equal spaces there are equal momenta. What the ether wants in +inertia, is made up by its motion or specific heat, considering in this +case inertia to stand for weight when compared with ponderable matter; +so that to raise an equivalent amount of inertia of ether to the same +temperature as atmospheric air, will require as much more motion or +specific heat as its matter is less. And this we conceive to be a law of +space in relation to all free or gaseous matter. To apply it to solids +would require a knowledge of the amount of force constituting the +cohesion of the solid.</p> + + +<h3><span class="pagenum" title="Page 41"> </span><a name="Page_41" id="Page_41"></a>INFLUENCE OF DIMINISHED PRESSURE.</h3> + +<p>But there is another principle which modifies these effects. We have +already adverted to the action of the tangential current of the vortex +forcing the outer layers of the atmosphere into waves. These waves will +be interfered with by the different vortices, sometimes being increased +and sometimes diminished by them.<a name="FNanchor_6_6" id="FNanchor_6_6"></a><a href="#Footnote_6_6" class="fnanchor">[6]</a> If these waves are supposed very +wide, (which would be the case in the attenuated outside layers of the +atmosphere,) the action of the vortex will be greater in its passage +over a place, which at the time corresponded to the depression point of +the wave, that is, to the line of low barometer; because here there +would be less resistance to overcome in the passage of the ether from +the surface of the earth into space; so that we may conceive each vortex +making a line of storms each day around the earth, separated by less +disturbed intervals. After the formation of the storm, it of course has +nothing to do with the vortex that produced it; it travels in the +general direction of the local atmosphere of the place—in intratropical +latitudes westward, in extratropical latitudes eastward. If, therefore, +the disturbance forms at the place of observation, there will probably +be no storm; but further eastward its action would be more apparent or +violent. It is impossible, of course, to lay down any general +description which shall meet every case. It is a knowledge that can only +be acquired by observation, and then is not readily or easily +communicated. There are many contingencies to be allowed for, and many +modifying causes to keep sight of, to enter into which would only be +tedious; we shall, therefore, confine ourselves to the prominent +phenomena.</p> + + +<h3><span class="pagenum" title="Page 42"> </span><a name="Page_42" id="Page_42"></a>ACTION OF THE POLAR CURRENT.</h3> + +<p>We have seen how the passage of the axis of the vortex may derange the +electric tension of the parts passed over; but there is another mode of +action not yet adverted to.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig01" id="fig01"></a> +<img src="images/fig01.png" width="350" height="204" alt="Fig. 1" title="" /> +</div> + +<p>When the moon is at her perigee, the axis of the vortex passes through +the centre of gravity of the earth and moon at C, and cuts off the +segment RR. At the apogee, on account of her greater distance, and of +her consequent power to <i>push</i> the earth out from the axis of the vortex +XX, the segment R′R′ is only cut off by the axis; and the angle which +the axis makes with the surface will vary with the arcs AR and A′R′; for +these arcs will measure the inclination from the nature of the circle. +In passing from the perigee to the apogee the axis will pass over the +latitudes intermediate between R and R′ in both hemispheres, neither +reaching to the equator E, nor to the pole P. Let us now suppose a +meridian of the earth, represented by the line NRS, N being north, and S +south, and the surface of the atmosphere by N′S′; XX still representing +the axis of the vortex, ordinarily inclined 34° or 35° to the surface. +Let us also conceive the rotation of the earth to cease, (the action of +the vortex remaining the same,) thus leaving the axis over a particular +longitude. If the ether possesses inertia, there will be an actual<span class="pagenum" title="Page 43"> </span><a name="Page_43" id="Page_43"></a> +scooping out of the upper portions, driving them southward to a certain +distance, where the atmosphere will be piled up above the ordinary +level. There will, therefore, be a strong contrary current at the +surface of the earth to restore the equilibrium, and if the action be +violent, the surface wind will be increased; so that if it be considered +tangential to the surface at S, its own momentum will tend to make it +leave the surface and mount up to T; and in this way increase the action +due to the ether. Now, although the axis is never stationary, but +travels round the earth in less than twenty-five hours, yet there is a +tendency to this mode of action; and it is even sometimes palpable to +the observer when the axis has passed immediately to the northward; for +the pinnate shafts and branching plumes of the cirri often reach far to +the south of the southern boundary of the storm. These shafts are always +longer when radiating from the northward than when proceeding from the +southward. The cause is understood by the <a href="#fig02">above figure</a>. At such a time, +after dark, the auroral shafts will also be seen over the storm to the +northward, but will be invisible to those beneath. There is this to be +observed, however, that the visibility of the ethereal cur<span class="pagenum" title="Page 44"> </span><a name="Page_44" id="Page_44"></a>rent (or the +aurora) is more frequent when the passage of the vortex is not attended +with any great commotion, its free passage being perhaps obstructed by +too dry an atmosphere; hence it becomes more visible. But it may be +asserted that a great aurora is never seen except when a vortex is near, +and to the northward, and within a few hours of its passage over the +meridian. We have, however, seen partial auroras to the south when none +existed north, and also cases when the radiation was from west, but they +are never as bright as in the north. They are all due, however, to the +same cause; and we have frequently followed a vortex for three days to +the northward, (that is, seen the effects of its meridian passage,) at +700 miles distance, by the aurora, and even by the lightning, which +proves plainly that the <i>exterior layers</i> of our atmosphere can reflect +a flash of lightning, assisted by the horizontal refraction, otherwise +the curvature of the earth would sink it ten miles below the horizon.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig02" id="fig02"></a> +<img src="images/fig02.png" width="350" height="239" alt="Fig. 2" title="" /> +</div> + + +<h3>LIMITS OF THE VORTEX.</h3> + +<p>The action of the polar current of the ether, therefore, tends to cause +a depression of the barometer, and an elevation to the <i>northward</i> and +southward, and there is a general set of the wind below to the point of +greatest depression. The action of the tangential current works the +outer surface of the atmosphere into great ridges and hollows, whose +distances apart as well as actual dimensions, are continually changing +under the influences of causes not yet alluded to, and it is in the +hollows where the action of the polar current will be principally +expended. Luckily for the earth, the axis of the vortex is never long in +passing over any particular place. In this latitude, whose natural +cosine is three-fourths, the velocity <i>westward</i> is over 700 miles per +hour; but at its extreme limits north, the motion is much slower, and is +repeated for two or three days in nearly the same latitude, for then it +begins to return to the south; thus<span class="pagenum" title="Page 45"> </span><a name="Page_45" id="Page_45"></a> oscillating in about one sidereal +period of the moon. At its southern limit, the vortex varies but slowly +in latitude for the same time, but the velocity is much greater. The +extreme latitudes vary at different times with the eccentricity of the +lunar orbit, with the place or longitude of the <ins class="correction" title="Transcriber’note: Original reads ‘perigree’.">perigee</ins>, and with the +longitude of the moon’s ascending node, but in no case can the <i>central +vortex</i> reach within 5° of the equator, or higher than about 75° of +latitude north or south. Hence there are no storms strictly speaking +beyond 88°<a name="FNanchor_7_7" id="FNanchor_7_7"></a><a href="#Footnote_7_7" class="fnanchor">[7]</a> of latitude; although a storm may be raging close by, at +the turning point south, and draw in a very strong gale from the +northward with a clear sky above. So also, although rains and short +squalls may be frequent in the vapor-loaded atmosphere of the equator, +yet the hurricane does not reach there, owing to the adjustment of the +mass and distance of the moon, and the inclination of the axes of the +vortices to the axis of the earth. If the temperature of the upper limit +or highest latitude of the vortex, was equal to the temperature which +obtains at its lowest limit, and the daily extremes of the solar +influence as great, the hurricanes would be as violent at the one as the +other, and even more so on account of the smaller velocity. But the +deficiency of temperature and moisture, (which last is all-important,) +prevents the full development of the effect. And even in the tropics, +the progress of the sun, by its power in directing the great annual +currents of the atmosphere, only conspires in the summer and autumn +months, to bring an atmosphere in the track of the vortices, possessing +the full degree of moisture and deficiency of electric tension, to +produce the derangement necessary to call forth the hurricane in its +greatest activity.</p> + + +<h3><span class="pagenum" title="Page 46"> </span><a name="Page_46" id="Page_46"></a>ROUTINE OF A STORM.</h3> + +<p>The novelty and originality of this theory will perhaps justify us in +dwelling a little longer on what observation has detected. The vortex +(and we are now speaking only of the central vortex) does not derange +every place alike, but <i>skips</i> over large tracts of longitude in its +progress westward. We speak here of the immovable axis of the vortex as +in motion; in reality it is the rotation of the earth which brings every +meridian under its influence in some latitude once every twenty-four +hours. The centre of greatest derangement forms the nucleus, towards +which the surface currents, under certain restrictions, flow. The +strongest current will, however, usually be from the south, on account +of the inclination of the axis of the vortex to the surface of the +earth.<a name="FNanchor_8_8" id="FNanchor_8_8"></a><a href="#Footnote_8_8" class="fnanchor">[8]</a> These currents continuing onwards by their vires inertiæ, +according to the first law of motion, assist somewhat in conveying the +warm surface wind, loaded with moisture, into the region of cloud; and +the diminution of temperature causes the condensation of large masses of +vapor, according to Hutton’s views; and the partial vacuum thus +produced, causes a still greater intermingling. But we have already +shown that this is not the sole cause, nor is it ever more than +partially accomplished. The ether of the lower atmosphere, and of the +crust of the earth, is disturbed, and rushes towards the rarefied axis +from the surface, and with the temperature of the surface, thus +conveying the surface atmosphere, in a measure, along with it. In the +upper regions, this ether (or electric fluid) cools down, or parts with +some of its heat, to the air of those regions, and, by its great +specific caloric, necessarily and unduly increases the temperature of +the air. This, by its expansion and ascension will cause a further +influx from below, until the upper atmosphere becomes loaded with vapor. +In twelve hours, at least, a<span class="pagenum" title="Page 47"> </span><a name="Page_47" id="Page_47"></a> reaction must take place, as that part of +the earth’s surface is carried six or seven thousand miles from the +axis, where the ether is more dense. This in turn descends to the +surface, carrying with it the temperature of space, at least 60° below +zero; a great condensation must follow; local derangements of the +electric equilibrium in the centre of large clouds, when the +condensation is active, must now take place, while partially +nonconducting masses intervene, to prevent an instantaneous restoration +of the equilibrium, until the derangement is sufficient to cause the +necessary tension, when all obstacles are rent asunder, and the ether +issues forth, clothed in the power and sublimity of the lightning. It is +a fearfully-energetic fluid, and, when sufficiently disturbed, competent +to produce the most violent tornado, or the most destructive earthquake. +That these two phenomena have simultaneously occurred, seems well +authenticated; but the earthquake, of course, must be referred generally +to derangements of the electric equilibrium of the earth’s interior, of +which at present we know but little.</p> + +<p>The day or morning previous to the passage of the vortex, is frequently +very fine, calm, mild, and sleepy weather,—commonly called a weather +breeder. After the storm has fully matured, there is an approach of the +clouds to the surface, a reduction of the temperature above, and the +human body feels the change far more than is due to the fall of +temperature. This is owing to the cold ether requiring so much heat to +raise its temperature to that of surrounding bodies, or, in other words, +is due to its great specific caloric. In summer, this falling of the +upper layers in front of the storm is so apparent, that every part is +seen to expand under the eye by perspective,—swelling, and curling, and +writhing, like the surface of water or oil when just commenced boiling. +The wind now partakes of the motion of the external ether, and moves +with the storm eastward (in this latitude), or from N-E. to S-E., until +the action ceases.</p> + + +<h3><span class="pagenum" title="Page 48"> </span><a name="Page_48" id="Page_48"></a>CONDITIONS NECESSARY TO PRODUCE A STORM.</h3> + +<p>The vortex, in its passage round the earth, may only meet with a few +localities favorable for producing a very violent storm; but these +nuclei will generally be connected by bands of cloudy atmosphere; so +that could we view them from the moon, the earth would be belted like +the planet Jupiter. There is reason to suspect, also, that there are +variations in the energy of the ethereal motions, independent of the +conditions of the earth and its atmosphere, which affects even the +radial stream of the sun. For the zodiacal light, which is caused by +this radial stream, is at times much more vivid than at others. Also in +the case of the aurora, on our own globe. On this point there is much to +say, but here is not the place. The conditions favorable for the +production of a storm at the <i>central</i> passage of a vortex, are a +previous exemption from excitement <i>ceteris paribus</i>, a high temperature +and dew point, a depression of the barometer, and local accumulation of +electric tension, positive or negative; and these are influenced by the +storms in other places controlling the aërial currents, and thus +determining the atmosphere of the place.</p> + + +<h3>LATERAL VORTICES.</h3> + +<p>We have already alluded to the lateral vortices of the terral system. We +must now resort to a diagram.</p> + +<p>In the <a href="#fig03">following figure</a>, the arrows represent the ethereal current of +the terral vortex; the linear circle, the earth; C the centre of gravity +of the earth and moon, and, consequently, the central vortex or axis of +the vortex of the earth, I represents the position of the inner vortex, +and O that of the outer vortex. These two last are eddies, caused by the +obstacle presented by the earth in being <i>pushed</i> out from the centre by +the moon, and are called lateral vortices. There are, therefore, two +lateral vor<span class="pagenum" title="Page 49"> </span><a name="Page_49" id="Page_49"></a>tices, and one central, in both hemispheres, and by this +simple arrangement is the earth watered, and the atmospheric circulation +produced.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig03" id="fig03"></a> +<img src="images/fig03.png" width="350" height="236" alt="Fig. 3" title="" /> +</div> + + +<h3>ILLUSTRATION OF THEIR ACTION.</h3> + +<p>If we place a globe in a vessel of water, so that the vertex shall only +just be covered, and place the globe eccentrically in the vessel so that +the centre of the vessel may not be too far from the outside of the +globe, and then impart an equable but slow motion to the water, in the +manner of a vortex; by viewing the reflected light of the sky from the +surface of the water above the globe, we shall be able to trace a +succession of dimples, originating at I and O, and passing off with the +current, and dying away. The direction of the fluid in these little +eddies, will be the same as the direction of the current in the main +vortex. If we displace the globe, so as to remove it far from the centre +of the vessel, and impart the same motion, the vortex I will be found at +E, and the direction of the current<span class="pagenum" title="Page 50"> </span><a name="Page_50" id="Page_50"></a> will be contrary to the direction +of the fluid in the vessel. In the case of the earth and moon, the +displacement can never change the position of the inner vortex much. It +will always be to the right hand of the central vortex in north +latitudes, and in consequence of the ether striking our globe in such a +position, the current that is deflected from its true path, by the +protuberance of the earth forcing it inside, is prevented by the +circular current of the parts nearer the axis of the vortex, from +passing off; so that a vortex is formed, and is more violent, <i>ceteris +paribus</i>, than the vortex at O.</p> + + +<h3>ORDER OF OCCURRENCE.</h3> + +<p>Whether this mode of action has been correctly inferred, matters little; +the lateral vortices follow the law of such a position. The inner vortex +always precedes the central from five to eight days, when ascending in +this latitude, and comes to the meridian after the moon. The outer +vortex, on the contrary, follows the central in its monthly round, and +comes to the meridian before the moon. It will be readily understood +that if the axes of these lateral vortices be produced through the +earth, they will pass through similar vortices in the opposite +hemisphere; but as the greatest latitude of the one, corresponds to the +least latitude of the other, the same calculation will not answer for +both. The same remark applies to the central vortex also.</p> + +<p>Thus there are six passages each month over latitude 41°; but as there +are intervals of 3° to 6° between two consecutive passages of the same +vortex, it may happen that an observer in the middle latitude, would +perhaps see nothing of their effects without looking for them. Generally +speaking, they are not only seen, but felt. The time of the passage of +the outer vortex ascending, corresponds so nearly (in 38° of latitude) +at certain times, with the passage of the central vortex descending, +that<span class="pagenum" title="Page 51"> </span><a name="Page_51" id="Page_51"></a> the two may be considered one if attention is not directed to it. +The orbits of these lateral vortices depend, like that of the central +vortex, on the orbit of the moon for eccentricity, but the longitudes of +the perigee will not correspond with the longitude of the moon’s +perigee. This follows from the theory. As the elements of these orbits +are only approximately determined, we shall confine our calculations to +the orbit of the central vortex.</p> + + +<h3>REDFIELD’S THEORY OF STORMS.</h3> + +<p>It will now appear plainly to the reader, that this theory of storms +differs in every particular from the rival theories of Redfield and +Espy, both as to the cause and the <i>modus agendi</i>. It would appear at +first sight, as if the discovery of these vortices would at once remedy +the great defect in the theory of Redfield, viz.: that no adequate cause +is assigned for the commencement and continuation of the vorticose +motion, in the great circular whirlwinds which compose a storm. The +facts, however, are adverse to such an application. According to +Mr. Redfield, the rotation of a circular storm in the northern +hemisphere is from right to left, and the reverse in the southern. The +author’s attention has, of course, been considerably directed to this +point; but in every case he has been unfortunate in finding in the +clouds a rotation from left to right. Some cases are mentioned in the +appended record of the weather. He has also noticed many of those small +whirlwinds on arid plains, in Egypt, in Mexico, and in California, +which, in the great majority of cases, were also from left to right. His +opportunities, however, have not extended to the southern hemisphere. +This theory has not, however, been formed on theoretic views, but by +looking nature in the face for years, and following her indications. +Accordingly, we find that the changes of the wind in a storm forbid the +adoption of the circular hypothesis.</p> + + +<h3><span class="pagenum" title="Page 52"> </span><a name="Page_52" id="Page_52"></a>WHIRLWINDS VERY LIMITED IN DIAMETER.</h3> + +<p>The theory, as extended by Col. Reid, rests on a simple rotation around +a progressing centre, and is found sometimes supported by evidence of +the most violent action at the centre, and sometimes by showing that the +central portion is often in a state of calm. We do not attempt to +reconcile these views; but would merely observe, that an atmospheric +vortex must be subject to the same dynamical laws as all other vortices; +and inasmuch as the medium cannot differ greatly in density, from the +centre to the circumference, the periodic times of the parts of the +vortex, must be directly as their distances from the axis, and +consequently the absolute velocities must be equal. If Mr. Redfield +resorts to a spirally inward current, it would be a centripetal instead +of a centrifugal current, and therefore could not cause the barometer to +fall, which was the best feature of the theory in its primitive form. +The absolute velocity of the wind is the important element which most +concerns us. In the case of a tornado of a few yards in diameter, there +is no doubt a circular motion, caused by the meeting of opposing +currents; but this may be considered a circle of a very small diameter. +The cause is due to a rapid escape of electric or ethereal matter, from +the crust of the earth, called forth by the progressing, disturbed space +above; this involves the air, and an ascending column in rotation begets +the rush on all sides to that column in straight lines: consequently, +the velocities will be inversely as the distances from the axis, and the +force of the current as the squares of the velocities. On the circular +theory, no increase of velocity would be conferred by the approach of +the centre, and consequently no increase of power.</p> + + +<h3><span class="pagenum" title="Page 53"> </span><a name="Page_53" id="Page_53"></a>OBJECTION TO CIRCULAR STORMS.</h3> + +<p>Another objection to the circular theory of storms, is the uniformity of +phase. If that theory be true, we see no reason why a person should not +be sometimes on the northern side of the gale. By referring to a +diagram, we perceive that on the northern side the changes of the wind +pursue a contrary direction to what they do on the south, yet in nine +cases out of ten, each vessel meeting a hurricane will find the same +changes of wind as are due to the southern side of the storm. It is +true, that if a vessel be to the northward of a great hurricane, there +will almost certainly be a north-east gale drawn in, and this might be +set down as the outer limits of a circular storm. But when the storm +really begins, the wind comes round south-east, south, south-west, +ending at north-west, and frequently is succeeded, on the following day, +(if in middle latitude,) by a moderate breeze from the northward. Now, +if the north-east gale spoken of above, was the outer limits of an +atmospheric vortex, a vessel sailing west ought not to meet the +hurricane, as a north-east wind is indicative of being already on the +west side, or behind the storm.</p> + +<p>Again, the characters of the winds, and appearances at the different +changes, are opposed to the circular theory. At a distance of fifty +miles from the centre of a storm, the wind which passes over a ship as a +southerly wind, will have made a rotation and a half, with the hurricane +velocity, before the same wind can again pass the ship as a northerly +wind, (supposing the progress eastward, and the ship lying to,) that is, +the same wind which in another place was a south wind two hours before, +and after only going one degree north, becomes a northerly +wind,—changed in character and temperature, as every seaman is well +aware. In a storm, if the circular theory be true, the character and +temperature should be the same, no matter from what point the wind is +blowing. This should be a conclusive argument.</p> + +<p><span class="pagenum" title="Page 54"> </span><a name="Page_54" id="Page_54"></a>Mr. Espy has also changed his ground on the storms of the United States; +he does not now contend that the winds blow inwards to a centre, but to +a line either directly or obliquely. Thus we see that while Mr. Redfield +concedes to Mr. Espy a spirally inward current, the latter also gives up +a direct current to the centre, to Mr. Redfield. This shows at least an +approximation to the truth.</p> + +<p>It is not necessary for the support of this theory, that we should +derive any materials from the ruins of others; we shall therefore not +avail ourselves of certain discrepant results, which can be found in +many of the storms cited by Colonel Reid. With respect to Mr. Espy’s +<i>cause</i> of storms, the experiments of Regnault may be considered as +decisive of the question:—1st, because the specific heat of vapor is so +much less than Espy assumed it to be; and 2d, because the expansion of +air in a free space does not suffer any change of volume by ascending, +except what is due to diminished pressure, and the natural temperature +of that elevation.</p> + + +<h3>INDICATIONS OF A STORM.</h3> + +<p>In accordance with our theory, the direction and force of the wind in a +storm are due to ascending columns of air, supplied from the upper +portion of the atmospheric stratum beneath the clouds. The commotion +begins at the highest limits of the cirri, and even at greater +elevations. Hence, the hazy appearance of the sky is a legitimate +precursor of the coming gale. As a general thing, the wind will blow (at +the surface) towards the centre of greatest commotion, but it is too +dependent on the ever-varying position and power of temporary nuclei of +disturbance, to be long steady, except when the disturbance is so remote +that its different centres of induction are, as it were, merged into one +common focus. When a vortex is descending, or passing from north to +south, and withal very energetic at the<span class="pagenum" title="Page 55"> </span><a name="Page_55" id="Page_55"></a> time, the southerly wind (which +may always be considered the principal wind of the storm in this +hemisphere) may blow steadily towards the vortex for three or even four +days. When a vortex is ascending, the induced northerly current will be +comparatively moderate, and be frequently checked by the southerly wind +overblowing the storm, and arriving the day before the vortex which +produced it.</p> + +<p>The important point for the navigator, is to know the time of meridian +passage of the vortex, and its latitude at the time of the passage, and +then be guided by the indications of the weather and the state of +barometer. If it commences storming the day before the passage, he may +expect it much worse soon after the passage; and again, if the weather +looks bad when no vortex is near, he may have a steady gale setting +towards a storm, but no storm until the arrival of a vortex. Again, if +the barometer is low the day before the vortex passes, there may be high +barometer to the west, and the passage be attended by no great +commotion, as it requires time for the storm to mature, and consequently +its greatest violence will be to the east. If at the ship the barometer +is high, the vortex may still produce a storm on a line of low barometer +to the west, and this line may reach the ship at the time of the +passage. In tropical climates the trouble must be looked for to the +eastward; as a storm, once excited, will travel westward with that +stratum of atmosphere in which the great mass of vapor is lodged, and in +which, of course, the greatest derangement of electric tension is +produced.</p> + +<p>It will now be seen that we do not admit, with Col. Reid, that a storm +continues in existence for a week together. Suppose a hurricane to +originate in the Antilles at the southern limits of a vortex, the +hurricane would die away, according to our theory, if the vortex did not +come round again and take up the same nucleus of disturbance. On the +third day the vortex is found still further north, and the apparent path +of the hurricane<span class="pagenum" title="Page 56"> </span><a name="Page_56" id="Page_56"></a> becomes more curved. In latitude 30° the vortex passes +over 3° or 5° of latitude in a day; and here being the latitude where +the lower atmospheric current changes its course, the storm passes due +north, and afterwards north-east. Now, each day of the series there is a +distinct hurricane, (caused by an increase of energy in a particular +vortex, as we have before hinted,) each one overlapping on the remains +of the preceding; but in each the same changes of the wind are gone +through, and the same general features preserved, as if it were truly a +progressive whirlwind, except that each vessel has the violent part of +it, as if she was in the southern half of the whirl. The apparent +regularity of the Atlantic storms in direction, as exhibited by Col. +Reid, are owing in a great degree to the course of the Gulf Stream, in +which a vortex, in its successive passages in different latitudes, finds +more favorable conditions for the development of its power, than in +other parts of the same ocean; thus showing the importance of regarding +the established character of storms in each locality, as determined by +observation. In this connection, also, we may remark, that the meridians +of greatest magnetic intensity are, <i>ceteris paribus</i>, also the +meridians of greatest atmospheric commotion. The discovery of this fact +is due to Capt. Sabine. The cause is explained by the theory.</p> + +<p>As it is the author’s intention to embody the practical application of +this theory to navigation, with the necessary rules and tables, in a +separate work, sufficient has been said to familiarize the reader with +the general idea of a cause external to the earth, as the active motor +in all atmospheric phenomena. We will therefore only allude in a general +way to the principal distinguishing feature of the theory. We say, then, +that the wind in a storm is not in rotation, and it is a dangerous +doctrine to teach the navigator. We also assert as distinctly, that the +wind <i>in</i> a storm does not blow from all sides towards the centre, which +is just as dangerous to believe. If it were wise to pin our faith to any +Procrustean formula, we might endorse the following<span class="pagenum" title="Page 57"> </span><a name="Page_57" id="Page_57"></a> propositions: That +at the beginning of a storm the wind is from the equator towards the +poles in every part of the storm; that, at a later date, another current +(really a polar current deflected by convection) sets in at right angles +to the first one; and that at the end of the storm there is only <i>one</i> +wind blowing at right angles to the direction at the beginning. Outside +the storm, considered as a hundred, or two or three hundred miles in +diameter, there is, under certain limitations, a surface wind setting +towards the general focus of motion and condensation, and this surface +wind will be strongest from the westward, on account of the motion of +the whole atmosphere in which these other motions are performed being to +the eastward.<a name="FNanchor_9_9" id="FNanchor_9_9"></a><a href="#Footnote_9_9" class="fnanchor">[9]</a> The whole phenomenon is electrical or magnetic, or +electro-magnetic or ethereal, whichever name pleases best. The vortex, +by its action, causes a current of induction below, from the equator, as +may be understood by inspecting <a href="#fig02">Fig. 2</a>, which in the northern hemisphere +brings in a southerly current by convection: the regular circular +current, however, finally penetrates below, as soon as the process of +induction has ceased; and thus the polar current of the atmosphere at +last overcomes the equatorial current in a furious squall, which ceases +by degrees, and the equilibrium is restored.</p> + +<p>Every locality will have its peculiar features; in each, the prevailing +wind will be at right angles to the magnetic meridian, and the progress +of the storm will tend to follow the magnetic parallel, which is one +reason why the Atlantic and Indian Ocean storms have been mistaken for +progressive whirlwinds. When these views are developed in full, the +mariner can pretty certainly decide his position in the storm, the +direction of its progress, and its probable duration.</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_3_3" id="Footnote_3_3"></a><a href="#FNanchor_3_3">[3]</a></span>The specific heat of the ether being a constant factor, it +may be divided out.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_4_4" id="Footnote_4_4"></a><a href="#FNanchor_4_4">[4]</a></span>A term adopted by Prof. Faraday to denote the mode in which +bodies are carried along by an electrical current.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_5_5" id="Footnote_5_5"></a><a href="#FNanchor_5_5">[5]</a></span>Ottawa, Ill.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_6_6" id="Footnote_6_6"></a><a href="#FNanchor_6_6">[6]</a></span>The principal cause of these waves is, no doubt, due to the +vortices, and the eastern progress of the waves due to the rotating +ether; but, at present, it will not be necessary to separate these +effects.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_7_7" id="Footnote_7_7"></a><a href="#FNanchor_7_7">[7]</a></span>The inner vortex may reach as high as 83° when the moon’s +orbit is favorably situated.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_8_8" id="Footnote_8_8"></a><a href="#FNanchor_8_8">[8]</a></span>The curvature of the earth is more than 10 miles in a +distance of 300 miles.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_9_9" id="Footnote_9_9"></a><a href="#FNanchor_9_9">[9]</a></span>In middle latitudes.</p></div> + +</div> + + +<hr style="width: 65%;" /> +<h2><span class="pagenum" title="Page 58"> </span><a name="Page_58" id="Page_58"></a><a name="SECTION_SECOND" id="SECTION_SECOND"></a>SECTION SECOND.</h2> + + +<h3>MECHANICAL ACTION OF THE MOON.</h3> + +<p>We will now proceed to give the method of determining the latitude of +the axis of the vortex, at the time of its passage over any given +meridian, and at any given time. And afterwards we will give a brief +abstract from the record of the weather, for one sidereal period of the +moon, in order to compare the theory with observation.</p> + +<div class="figcenter" style="width: 366px;"> +<a name="fig04" id="fig04"></a> +<img src="images/fig04.png" width="366" height="200" alt="Fig. 4" title="" /> +</div> + +<p>In the <a href="#fig04">above figure</a>, the circle PER represents the earth, E the equator, +PP′ the poles, T the centre of the earth, C the mechanical centre of the +terral vortex, M the moon, XX′ the axis of the vortex, and A the point +where the radius <ins class="correction" title="Transcriber’s note: Original reads ‘rector’.">vector</ins> of the moon pierces the surface of the earth. If +we consider the<span class="pagenum" title="Page 59"> </span><a name="Page_59" id="Page_59"></a> axis of the vortex to be the axis of equilibrium in the +system, it is evident that TC will be to CM, as the mass of the moon to +the mass of the earth. Now, if we take these masses respectively as 1 to +72.3, and the moon’s mean distance at 238,650 miles, the mean value of +TC is equal to this number, divided by the sum of these masses,—<i>i.e.</i> +the mean radius vector of the little orbit, described by the earth’s +centre around the centre of gravity of the earth and moon, is equal +238650 ⁄ (72.3 + 1) = 3,256 miles; and at any other +distance of the moon, is equal to that distance, divided by the same +sum. Therefore, by taking CT in the inverse ratio of the mean +semi-diameter of the moon to the true semi-diameter, we shall have the +value of CT at that time. But TA is to TC as radius to the cosine of the +arc AR, and RR′ are the points on the earth’s surface pierced by the +axis of the vortex, supposing this axis coincident with the pole of the +lunar orbit. If this were so, the calculation would be very short and +simple; and it will, perhaps, facilitate the investigation, by +considering, for the present, that the two axes do coincide.</p> + +<p>In order, also, to simplify the question, we will consider the earth a +perfect sphere, having a diameter of 7,900 miles, equal to the actual +polar diameter, and therefore TA is equal to 3,950 miles.</p> + +<p>In the spherical triangle given on next page, we have given the point A, +being the position of the moon in right ascension and declination in the +heavens, and considered as terrestrial latitude and longitude.</p> + +<p>Therefore, PA is equal to the complement of the moon’s declination, P +being the pole of the earth, and L being the pole of the lunar orbit; PL +is equal to the obliquity of the lunar orbit, with respect to the earth, +and is therefore given by finding the true inclination of the lunar +orbit at the time, equal EL, (E being the pole of the ecliptic,) also +the true longitude of the ascending node, and the obliquity of the +ecliptic PE.<span class="pagenum" title="Page 60"> </span><a name="Page_60" id="Page_60"></a> Now, as we are supposing the axis of the vortex parallel +to the pole of the lunar orbit, and to pierce the earth’s surface at R, +ARL will evidently all be in the same plane; and, as in the case of A +and L, this plane passes through the earth’s centre, ARL must all lie in +the same great circle. Having, therefore, the right ascension of A, and +the right ascension of L, we have the angle P. This gives us two sides, +and the included angle, to find the side LA. But we have before found +the arc AR; we therefore know LR. But in finding LA, we found both the +angles L and A, and therefore can find PR, which is equal to the +complement of the latitude sought.</p> + +<div class="figcenter" style="width: 373px;"> +<a name="fig05" id="fig05"></a> +<img src="images/fig05.png" width="373" height="200" alt="Fig. 5" title="" /> +</div> + +<p>We have thus indicated briefly the simple process by which we could find +the latitude of the axis of the central vortex, supposing it to be +always coincident with the pole of the lunar orbit. The true problem is +more complicated, and the principal modifications, indicated by the +theory, are abundantly confirmed by observation. The determination of +the inclination of the axis of the vortex, its position in space at a +given time, and the law of its motion, was a work of cheerless labor for +a long time. He that has been tantalized by hope for years, and ever on +the eve of realization, has found the vision vanish, can understand the +feeling which proceeds from frequent disappointment in not finding that, +whose existence is almost demonstrated;<span class="pagenum" title="Page 61"> </span><a name="Page_61" id="Page_61"></a> and more especially when the +approximation differs but slightly from the actual phenomena.</p> + +<p>The chief difficulty at the outset of these investigations, arose from +the conflicting authority of astronomers in relation to the mass of the +moon. We are too apt to confound the precision of the laws of nature, +with the perfection of human theories. Man observes the phenomena of the +heavens, and derives his means of predicting what will be, from what has +been. Hence the motions of the heavenly bodies are known to within a +trifling amount of the truth; but it does not follow that the true +explanation is always given by theory. If this were so, the mass of the +moon (for instance) ought to be the same, whether deduced from the +principle of gravitation or from some other source. This is not so. +Newton found it 1 ⁄ 40 of that of the earth. La Place, from a +profound theoretical discussion of the tides, gave it as +1 ⁄ 58.6, while from other sources he found a necessity of +diminishing it still more, to 1 ⁄ 68, and finally as low as +1 ⁄ 75. Bailly, Herschel, and others, from the nutation of the +earth’s axis, only found 1 ⁄ 80, and the Baron Lindenau deduced +the mass from the same phenomenon 1 ⁄ 88. In a very recent work +by Mr. Hind, he uses this last value in certain computations, and +remarks, that we shall not be very far wrong in considering it <ins class="correction" title="Transcriber’s note: Original reads ‘as as’.">as</ins> +1 ⁄ 80 of the mass of the earth. This shows the uncertainty of +the matter in 1852. If astronomy is so perfect as to determine the +parallax of a fixed star, which is almost always less than one second, +why is it that the mass of the moon is not more nearly approximated? +Every two weeks the sun’s longitude is affected by the position of the +moon, alternately increasing and diminishing it, by a quantity depending +solely upon the relative mass of the earth and moon, and is a gross +quantity compared to the parallax of a star. So, also, the horizontal +parallax—the most palpable of all methods—taken by different observers +at Berlin, and the Cape of Good Hope, (a very respectable base line, one +would suppose,) makes the mass of the moon greater than its value<span class="pagenum" title="Page 62"> </span><a name="Page_62" id="Page_62"></a> +derived from nutation; the first giving about 1 ⁄ 70, the last +about 1 ⁄ 74.2. Does not this declare that it is unsafe to +depend too absolutely on the strict wording of the Newtonian law of +gravitation. Happily our theory furnishes us with the correct value of +the moon’s mass, written legibly on the surface of the earth; and it +comes out nearly what these two phenomena always gave it, viz.: +1 ⁄ 72.3 of that of the earth. In another place we shall inquire +into the cause of the discrepancy as given by the nutation of the earth.</p> + + +<h3>MOTION OF THE AXIS OF THE VORTEX.</h3> + +<p>If the axis of the terral vortex does not coincide with the axis of the +lunar orbit, we must derive this position from observation, which can +only be done by long and careful attention. This difficulty is increased +by the uncertainty about the mass of the moon, already alluded to, and +by the fact that there are three vortices in each hemisphere which pass +over <i>twice</i> in each month, and it is not <i>always</i> possible to decide by +observation, whether a vortex is ascending or descending, or even to +discriminate between them, so as to be assured that this is the central +descending, and that the outer vortex ascending. A better acquaintance, +however, with the phenomenon, at last dissipates this uncertainty, and +the vortices are then found to pursue their course with that regularity +which varies only according to law. The position of the vortex (the +central vortex is the one under consideration) then depends on the +inclination of its axis to the axis of the earth, and the right +ascension of that axis at the given time. For we shall see that an +assumed immobility of the axis of the vortex, would be in direct +collision with the principles of the theory.</p> + +<p>Let the <a href="#fig06">following figure</a> represent a globe of wood of uniform density +throughout. Let this globe be rotated round the axis. It is evident that +no change of position of the axis would be<span class="pagenum" title="Page 63"> </span><a name="Page_63" id="Page_63"></a> produced by the rotation. If +we add two equal masses of lead at <i>m</i> and <i>m</i>′, on opposite sides of the +axis, the globe is still in equilibrium, as far as gravity is concerned, +and if perfectly spherical and homogeneous it might be suspended from +its centre in any position, or assume indifferently any position in a +vessel of water. If, however, the globe is now put into a state of rapid +rotation round the axis, and then allowed to float freely in the water, +we perceive that it is no longer in a state of equilibrium. The mass <i>m</i> +being more dense than its antagonist particle at <i>n</i>, and having equal +velocity, its momentum is greater, and it now tends continually to pull +the pole from its perpendicular, without affecting the position of the +centre. The same effect is produced by <i>m</i>′, and consequently the axis +describes the surface of a double cone, whose vertices are at the centre +of the globe. If these masses of lead had been placed at opposite sides +of the axis on the <i>equator</i> of the globe, no such motion would be +produced; for we are supposing the globe formed of a hard and unyielding +material. In the case of the ethereal vortex of the earth, we must +remember there are two different kinds of matter,—one ponderable, the +other not ponderable; yet both subject to the same dynamical laws. If we +consider the axis of the terral vortex to coincide with the axis of the +lunar orbit, the moon and earth are placed in the equatorial plane of +the vortex,<span class="pagenum" title="Page 64"> </span><a name="Page_64" id="Page_64"></a> and consequently there can be no derangement of the +equilibrium of the vortex by its own rotation. But even in this case, +seeing that the moon’s orbit is inclined to the ecliptic, the +gravitating power of the sun is exerted on the moon, and of necessity +she must quit the equatorial plane of the vortex; for the sun can exert +no influence on the <i>matter</i> of the vortex by his attracting power. The +moment, however, the moon has left the equatorial plane of the vortex, +the principle of momentum comes into play, and a conical motion of the +axis of the vortex is produced, by its seeking to follow the moon in her +monthly revolution. This case is, however, very different to the +illustration we gave. The vortex is a fluid, through which the moon +freely wends her way, passing through the equatorial plane of the vortex +twice in each revolution. These points <ins class="correction" title="Transcriber’s note: Original reads ‘constitutes’.">constitute</ins> the moon’s nodes on +the plane of the vortex, and, from the principles laid down, the force +of the moon to disturb the equilibrium of the axis of the vortex, +vanishes at these points, and attains a maximum 90° from them. And the +effect produced, in passing from her ascending to her descending node, +is equal and contrary to the effect produced in passing from her +descending to her ascending node,—reckoning these points on the plane +of the vortex.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig06" id="fig06"></a> +<img src="images/fig06.png" width="350" height="250" alt="Fig. 6" title="" /> +</div> + + +<h3>INCLINATION OF THE AXIS.</h3> + +<p>By whatever means the two planes first became permanently inclined, we +see that it is a necessary consequence of the admission of these +principles, not only that the axis of the vortex should be drawn aside +by the momentum of the earth and moon, ever striving, as it were, to +maintain a dynamical balance in the system, in accordance with the +simple laws of motion, and ever disturbed by the action of gravitation +exerted on the grosser matter of the system; but also, that this axis +should follow, the axis of the lunar orbit, at the same mean +inclination, during the complete revolution of the node. The mean +inclination<span class="pagenum" title="Page 65"> </span><a name="Page_65" id="Page_65"></a> of the two axes, determined by observation, is 2° 45′, and +the monthly equation, at a maximum, is about 15′, being a plus +correction in the northern hemisphere, where the moon is between her +descending and ascending node, reckoned on the plane of the vortex, and +a minus correction, when between her ascending and descending node. And +the mean longitude of the node will be the same as the true longitude of +the moon’s orbit node,—the maximum correction for the true longitude +being only about 5° ±.</p> + +<div class="figcenter" style="width: 200px;"> +<a name="fig07" id="fig07"></a> +<img src="images/fig07.png" width="200" height="377" alt="Fig. 7" title="" /> +</div> + +<p>In the <a href="#fig07">following figure</a>, P is the pole of the earth; E the pole of the +ecliptic; L the pole of the lunar orbit; V the mean position of the pole +of the vortex at the time; the angle <ins class="info" title="Aries.">♈</ins>EL the true longitude of the pole +of the lunar orbit, equal to the <i>true</i> longitude of the ascending node +± 90°. VL is therefore the mean inclination ± 2° 45′; and the little +circle, the orbit described by the pole of the vortex <i>twice</i> in each +sidereal revolution of the moon. The distance of the pole of the vortex +from the mean position V, may be approximately estimated, by multiplying +the maximum value 15′ by the sine of twice the moon’s distance from the +node of the vortex, or from its mean position, viz.: the true longitude +of the ascending node of the moon on the ecliptic. From this we may +calculate the true place of the node, the true<span class="pagenum" title="Page 66"> </span><a name="Page_66" id="Page_66"></a> obliquity, and the true +inclination to the lunar orbit. Having indicated the necessity for this +correction, and its numerical coefficient, we shall no longer embarrass +the computation by such minutiæ, but consider the mean inclination as +the true inclination, and the mean place of the node as the true place +of the node, and coincident with the ascending node of the moon’s orbit +on the ecliptic.</p> + + +<h3>POSITION OF THE AXIS OF THE VORTEX.</h3> + +<p>It is now necessary to prove that the axis of the vortex will still pass +through the centre of gravity of the earth and moon.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig08" id="fig08"></a> +<img src="images/fig08.png" width="350" height="181" alt="Fig. 8" title="" /> +</div> + +<p>Let XX now represent the axis of the lunar orbit, and C the centre of +gravity of the earth and moon, X′X′ the axis of the vortex, and KCR the +inclination of this axis. Then from</p> + +<table class="space" summary="Finding the position of the axis of the vortex."> +<tr> + <td class="tdc">similarity</td> + <td class="tdc">C<i>t</i></td> + <td class="tdc">:</td> + <td class="tdc">T<i>t</i></td> + <td class="tdc">: :</td> + <td class="tdc">C<i>m</i></td> + <td class="tdc">:</td> + <td class="tdc">M<i>m</i></td> +</tr> +<tr> + <td class="tdc">but</td> + <td class="tdc">T<i>t</i></td> + <td class="tdc">:</td> + <td class="tdc">M<i>m</i></td> + <td class="tdc">: :</td> + <td class="tdc">Moon’s mass</td> + <td class="tdc">:</td> + <td class="tdc">Earth’s mass.</td> +</tr> +<tr> + <td class="tdc">That is</td> + <td class="tdc">T<i>t</i></td> + <td class="tdc">:</td> + <td class="tdc">M<i>m</i></td> + <td class="tdc">: :</td> + <td class="tdc">TC</td> + <td class="tdc">:</td> + <td class="tdc">MC.</td> +</tr> +</table> + +<p>Therefore the system is still balanced; and in no other point but the +point C, can the intersection of the axes be made without destroying +this balance.</p> + +<p><span class="pagenum" title="Page 67"> </span><a name="Page_67" id="Page_67"></a>It will be observed by inspecting the <a href="#fig09">figure</a>, that the arc R′K′ is +greater than the arc RK. That the first increases the arc AR, and the +second diminishes that arc. The arc R′K′ is a plus correction therefore, +and the smaller arc RK a minus correction. If the moon is between her +descending and ascending node, (taking now the node on the ecliptic,) +the correction is negative, and we take the smaller arc. If the moon is +between her ascending and descending node, the correction is positive, +and we take the larger arc. If the moon is 90° from the node, the +correction is a maximum. If the moon is at the node, the correction is +null. In all other positions it is as the sine of the moon’s distance +from the nodes. We must now find the maximum value of these arcs of +correction corresponding to the mean inclination of 2° 45′.</p> + +<p>To do this we may reduce TC to T<i>t</i> in the ratio of radius to cosine of +the inclination, and taking TS for radius.</p> + +<div class="figcenter" style="width: 360px;"> +<a name="fig09" id="fig09"></a> +<img src="images/fig09.png" width="360" height="200" alt="Fig. 9" title="" /> +</div> + + +<p><a href="images/eqp67.png"><img src="images/eqp67_s.png" width="214" height="35" +alt="TC × Cos &c. (inclination 2° 45′) ⁄ R" +title="TC × Cos &c. (inclination 2° 45′) ⁄ R" /></a> + is equal the +cosine of the arc SK′ and SK′ + AS = AK′ and AK′ + AR′ = R′K′. But from +the nature of the circle, arc RK + arc R′K′ = angle RCK + angle R′CK′, +or equal to double the inclination; and therefore, by subtracting either +arc from double the inclination, we may get the other arc.</p> + +<p><span class="pagenum" title="Page 68"> </span><a name="Page_68" id="Page_68"></a>The maximum value of these arcs can, however, be found by a simple +proportion, by saying; as the arc AR, plus the inclination, is to the +inclination, so is the inclination to the difference between them; and +therefore, the inclination, plus half the difference, is equal the +greater arc, and the inclination, minus half the difference, is equal +the lesser; the greater being positive, and the lesser negative.</p> + +<p>Having found the arc AR, and knowing the moon’s distance from either +node, we must reduce these values of the arcs RK and R′K′ just found, in +the ratio of radius to the sine of that distance, and apply it to the +arc AR or A′R′, and we shall get the first correction equal to the +arc AK or AK′.</p> + +<table summary="Notation."> +<tr> + <td>Call the</td> + <td>arc AR</td> + <td>= <i>a</i></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>inclination</td> + <td>= <i>n</i></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>distance from the node</td> + <td>= <i>d</i></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>arc AK</td> + <td>= <i>k</i></td> +</tr> +</table> + +<p>and supposing the value of AK be wanted for the northern hemisphere when +the moon is between her descending and ascending node, we have</p> + +<p class="center"><a href="images/eqp68a.png"><img src="images/eqp68a_s.png" width="175" height="73" +alt="k = a − (n − n² ⁄ {(a+n) ⁄ 2}sin d) ⁄ R." +title="k = a − (n − n² ⁄ {(a+n) ⁄ 2}sin d) ⁄ R." /></a> +</p> + +<p>If the moon is between her ascending and descending node, then</p> + +<p class="center"><a href="images/eqp68b.png"><img src="images/eqp68b_s.png" width="175" height="74" +alt="k = a + (n − n² ⁄ {(a+n) ⁄ 2}sin d) ⁄ R." +title="k = a + (n − n² ⁄ {(a+n) ⁄ 2}sin d) ⁄ R." /></a> +</p> + +<p>The computation will be shorter, however, if we merely reduce the +inclination to the sine of the distance from the node for the first +correction of the arc AR, if we neglect the semi-<span class="pagenum" title="Page 69"> </span><a name="Page_69" id="Page_69"></a>monthly motion of the +axis; for this last correction diminishes the plus corrections, and the +first one increases it. If, therefore, one is neglected, it is better to +neglect the other also; especially as it might be deemed affectation to +notice trifling inequalities in the present state of the elements of the +question.</p> + +<p>There is one inequality, however, which it will not do to neglect. This +arises from the displacement of the axis of the vortex.</p> + + +<h3>DISPLACEMENT OF THE AXIS.</h3> + +<p>We have represented the axis of the terral vortex as continually passing +through the centre of gravity of the earth and moon. Now, by following +out the principles of the theory, we shall see that this cannot be the +case, except when the moon is in quadrature with the sun. To explain +this:</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig10" id="fig10"></a> +<img src="images/fig10.png" width="350" height="187" alt="Fig. 10" title="" /> +</div> + +<p>Let the curve passing through C represent a portion of the orbit of the +earth, and S the sun. From the principles laid down, the density of the +ethereal medium increases outward as the square roots of the distances +from the sun. Now, if we consider the circle whose centre is C to +represent the whole terral vortex, it must be that the medium composing +it varies also in density at different distances from the sun, and at +the same time is rotating round the centre. That half of the<span class="pagenum" title="Page 70"> </span><a name="Page_70" id="Page_70"></a> vortex +which is exterior to the orbit of the earth, being most dense, has +consequently most inertia, and if we conceive the centre of gravity of +the earth and moon to be in the orbit (as it must be) at C, there will +not be dynamical balance in the terral system, if the centre of the +vortex is also found at C. To preserve the equilibrium the centre of the +vortex will necessarily come nearer the sun, and thus be found between T +and C, T representing the earth, and <ins class="info" title="Crescent moon (last quarter).">☾</ins> the moon, and C the centre of +gravity of the two bodies. If the moon is in opposition, the centre of +the vortex will fall between the centre of gravity and the centre of the +earth, and have the apparent effect of diminishing the mass of the moon. +If, on the other hand, the moon is in conjunction, the centre of the +vortex will fall between the centre of gravity and the moon, and have +the apparent effect of increasing the mass of the moon. If the moon is +in quadrature, the effect will be null. The coefficient of this +inequality is 90′, and depends on the sun’s distance from the moon. When +the moon is more than 90° from the sun, this correction is positive, and +when less than 90° from the sun, it is negative. If we call this second +correction C, and the moon’s distance from her quadratures Q, we have +the value of C = ±(90′ × sin Q) ⁄ R.</p> + +<div class="figcenter" style="width: 200px;"> +<a name="fig11" id="fig11"></a> +<img src="images/fig11.png" width="200" height="392" alt="Fig. 11" title="" /> +</div> + +<p><span class="pagenum" title="Page 71"> </span><a name="Page_71" id="Page_71"></a>This correction, however, does not affect the inclination of the axis of +the vortex, as will be understood by the subjoined <a href="#fig12">figure</a>. If the moon +is in opposition, the axis of the vortex will not pass through C, but +through C′, and QQ′ will be parallel to KK′. If the moon is in +conjunction, the axis will be still parallel to KK′, as represented by +the dotted line <i>qq</i>′. The correction, therefore, for displacement, is +equal to the arc KQ or K<i>q</i>, and the correct position of the vortex on the +surface of the earth at a given time will be at the points Q or <i>q</i> and Q′ +or <i>q</i>′, considering the earth as a sphere.</p> + +<div class="figcenter" style="width: 370px;"> +<a name="fig12" id="fig12"></a> +<img src="images/fig12.png" width="370" height="180" alt="Fig. 12" title="" /> +</div> + +<p>In the spherical triangle APV, P is the pole of the earth, V the pole of +the vortex, A the point of the earth’s surface pierced by the radius +vector of the moon, AQ is the corrected arc, and PV is the obliquity of +the vortex. Now, as the axis of the vortex is parallel to the pole V, +and the earth’s centre, and the line MA also passes through the earth’s +centre, consequently AQV will all lie in the same great circle, and as +PV is known, and PA is equal to the complement of the moon’s declination +at the time, and the right, ascensions of A and V give the angle P, we +have two sides and the included angle to find the rest, PQ being the +complement of the latitude sought.</p> + +<p>We will now give an example of the application of these principles.</p> + +<p><span class="pagenum" title="Page 72"> </span><a name="Page_72" id="Page_72"></a><i>Example.</i><a name="FNanchor_10_10" id="FNanchor_10_10"></a><a href="#Footnote_10_10" class="fnanchor">[10]</a> Required the latitude of the central vortex at the time +of its meridian passage in longitude 88° 50′ west, July 2d, 1853.</p> + + +<h3>CENTRAL VORTEX ASCENDING.</h3> + +<table summary="Calculations for central vortex ascending."> +<tr> + <td>Greenwich time of passage</td> + <td class="tdr0">2d.</td> + <td class="tdr0">3h.</td> + <td class="tdr0">1m.</td> +</tr> +<tr> + <td style="padding-right:2em;">Mean longitude of moon’s node</td> + <td class="tdr0">78°</td> + <td class="tdr0">29′</td> + <td></td> +</tr> +<tr> + <td>True<span style="margin-left:3em;">"</span><span style= + "margin-left:3em;">"</span></td> + <td class="tdr0">79°</td> + <td class="tdr0">32′</td> + <td></td> +</tr> +<tr> + <td>Mean inclination of lunar orbit</td> + <td class="tdr0">5°</td> + <td class="tdr0">9′</td> + <td></td> +</tr> +<tr> + <td>True<span style="margin-left:3em;">"</span><span style= + "margin-left:3em;">"</span></td> + <td class="tdr0">5°</td> + <td class="tdr0">13′</td> + <td></td> +</tr> +<tr> + <td>Obliquity of ecliptic</td> + <td class="tdr0">23°</td> + <td class="tdr0">27′</td> + <td class="tdr0">32″</td> +</tr> +<tr> + <td>Mean inclination of vortex</td> + <td class="tdr0">2°</td> + <td class="tdr0">45′</td> + <td class="tdr0">0″</td> +</tr> +</table> + +<p>Then in the spherical triangle PEV,</p> + +<table summary="Calculating arcs of the triangle."> +<tr> + <td>PE</td> + <td style="padding-left:0.5em; padding-right:0.5em;">is equal</td> + <td class="tdr0">23°</td> + <td class="tdr0">27′</td> + <td class="tdr0">32″</td> +</tr> +<tr> + <td>EV</td> + <td class="tdc">"</td> + <td class="tdr0">7°</td> + <td class="tdr0">58′</td> + <td class="tdr0">0″</td> +</tr> +<tr> + <td>E</td> + <td class="tdc">"</td> + <td class="tdr0">100°</td> + <td class="tdr0">28′</td> + <td class="tdr0">0″</td> +</tr> +<tr> + <td>P</td> + <td class="tdc">"</td> + <td class="tdr0">18°</td> + <td class="tdr0">5′</td> + <td class="tdr0">7″</td> +</tr> +<tr> + <td>PV</td> + <td class="tdc">"</td> + <td class="tdr0">26°</td> + <td class="tdr0">2′</td> + <td class="tdr0">32″</td> +</tr> +</table> + +<p>Calling P the polar angle and PV the obliquity of vortex.</p> + +<div class="figcenter" style="width: 300px;"> +<a name="fig13" id="fig13"></a> +<img src="images/fig13.png" width="300" height="211" alt="Fig. 13" title="" /> +</div> + +<p><span class="pagenum" title="Page 73"> </span><a name="Page_73" id="Page_73"></a>To find the arc AR.</p> + +<p>By combining the two proportions already given, we have by logarithms:</p> + +<table summary="Calculating the arc AR."> +<tr> + <td>M. R. V. minor</td> + <td>=</td> + <td>3256 Log.</td> + <td class="tdr0">3.512683</td> +</tr> +<tr> + <td>M. S. D. of moon</td> + <td>=</td> + <td>940″<span style="margin-left:1em;">"</span></td> + <td class="tdr0">2.973128</td> +</tr> +<tr> + <td>P. S. D. of earth</td> + <td>=</td> + <td>3950 A. C.</td> + <td class="tdr0">6.403403</td> +</tr><tr> + <td>Radius</td> + <td></td> + <td></td> + <td class="tdr0">10.000000</td> +</tr><tr> + <td>T. S. D. of moon</td> + <td></td> + <td>885″.5 A. C.</td> + <td class="tdr0">7.052811</td> +</tr><tr> + <td>Log. Cosine arc AR</td> + <td>=</td> + <td>28° 57′ 3″</td> + <td class="tdr0" style="border-top:thin solid black; border-bottom:thin solid black;">9.942025</td> +</tr> +</table> + +<p>As the only variable quantity in the above formula is the “True” +semi-diameter of the moon at the time, we may add the Constant logarithm +2.889214 to the arithmetical complement of the logarithm of the true +semi-diameter, and we have in two lines the log. cosine of the arc AR.</p> + +<p>We must now find the arc RK equal at a maximum to 2° 45′. The true +longitude of the moon’s node being 79° 32′, and the moon’s longitude, +per Nautical Almanac, being 58° 30′, the distance from the node is 21° 2′, therefore, the correction is</p> + +<p class="center"><a href="images/eqp73a.png"><img src="images/eqp73a_s.png" width="284" height="35" +alt="−arc RK = (−2° 45′ × sin 21° 2′) ⁄ R = −59′ 13″" +title="−arc RK = (−2° 45′ × sin 21° 2′) ⁄ R = −59′ 13″" /></a> +</p> + +<p>To find the correction for displacement.</p> + +<table summary="Calculating the correction for displacement."> +<tr> + <td>True longitude</td> + <td style="padding-right:3em;"> of sun at date</td> + <td class="tdr0">100°</td> + <td class="tdr0">30′</td> +</tr> +<tr> + <td class="tdc">"</td> + <td> of moon<span style="margin-left:1em;">"</span></td> + <td class="tdr0">58°</td> + <td class="tdr0">30′</td> +</tr> +<tr> + <td colspan="2">Moon’s distance from quadrature</td> + <td class="tdr0">48°</td> + <td class="tdr0">0′</td> +</tr> +</table> + +<p>As the moon is less than 90° from the sun this correction is also +negative, or</p> + +<p class="center"><a href="images/eqp73b.png"><img src="images/eqp73b_s.png" width="314" height="124" +alt="Arc Kq = (−90′ × sin 48°) ⁄ R = −1° 6′ 46″. +Arc AR = 28° 57′ 3″ +RK = −0° 39′ 13″ +Kq = −1° 6′ 46″ +Sum = 26° 51′ 4″ = corrected arc AQ." +title="Arc Kq = (−90′ × sin 48°) ⁄ R = −1° 6′ 46″. +Arc AR = 28° 57′ 3″ +RK = −0° 39′ 13″ +Kq = −1° 6′ 46″ +Sum = 26° 51′ 4″ = corrected arc AQ." /></a> +</p> + +<p><span class="pagenum" title="Page 74"> </span><a name="Page_74" id="Page_74"></a>We have now the necessary elements in the Nautical Almanac, which we +must reduce for the instant of the vortex passing the meridian in +Greenwich time.</p> + +<table summary="Further calculations for central vortex ascending."> +<caption>July 2d.</caption> +<tr> + <td>Meridian passage,</td> + <td>local time, at</td> + <td class="tdr0" style="padding-left:2em;">9h.</td> + <td class="tdr0">5m.</td> + <td><span class="time">A. M.</span></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>in Greenwich time </td> + <td class="tdr0">2d.</td> + <td class="tdr0">3h.</td> + <td class="tdr0">1m.</td> +</tr> +<tr> + <td>Right ascension</td> + <td>same time</td> + <td class="tdr0">56°</td> + <td class="tdr0">42′</td> + <td class="tdr0">45″</td> +</tr> +<tr> + <td>Declination north</td> + <td class="tdc">"</td> + <td class="tdr0">18°</td> + <td class="tdr0">00′</td> + <td class="tdr0">1″</td> +</tr> +<tr> + <td>Obliquity of the vortex</td> + <td class="tdc">"</td> + <td class="tdr0">26°</td> + <td class="tdr0">2′</td> + <td class="tdr0">32″</td> +</tr> +<tr> + <td>Polar angle</td> + <td class="tdc">"</td> + <td class="tdr0">18°</td> + <td class="tdr0">5′</td> + <td class="tdr0">7″</td> +</tr> +<tr> + <td>Arc AQ</td> + <td class="tdc">"</td> + <td class="tdr0">26°</td> + <td class="tdr0">51′</td> + <td class="tdr0">4″</td> +</tr> +</table> + +<div class="figcenter" style="width: 350px;"> +<a name="fig14" id="fig14"></a> +<img src="images/fig14.png" width="350" height="159" alt="Fig. 14" title="" /> +</div> + +<table summary="Further calculations for central vortex ascending."> +<tr> + <td>PA</td> + <td>= 17°</td> + <td class="tdr0">59′</td> + <td class="tdr0">59″</td> + <td rowspan="2"><big style="font-size:200%;">}</big></td> + <td class="tdr0" style="padding-left:2em;">P</td> + <td>=</td> + <td class="tdr0">128°</td> + <td class="tdr0">37′</td> + <td class="tdr0">38″</td> +</tr> +<tr> + <td>PV</td> + <td>= 26°</td> + <td class="tdr0">2′</td> + <td class="tdr0">32″</td> + <td colspan="5" style="border-bottom:thin solid black;"></td> +</tr> +<tr> + <td>VA</td> + <td>= 89°</td> + <td class="tdr0">3′</td> + <td class="tdr0">0″</td> + <td></td> + <td class="tdr0">V</td> + <td>=</td> + <td class="tdr0">47°</td> + <td class="tdr0">59′</td> + <td class="tdr0">44″</td> +</tr> +<tr> + <td>VQ</td> + <td>= 62°</td> + <td class="tdr0">11′</td> + <td class="tdr0">56″</td> + <td></td> + <td class="tdr0">A</td> + <td>=</td> + <td class="tdr0">20°</td> + <td class="tdr0">3′</td> + <td class="tdr0">42″</td> +</tr> +<tr> + <td>PQ</td> + <td>= 47°</td> + <td class="tdr0">14′</td> + <td class="tdr0">22″</td> + <td></td> + <td class="tdr0">Q</td> + <td>=</td> + <td class="tdr0">26°</td> + <td class="tdr0">22′</td> + <td class="tdr0">55″</td> +</tr> +<tr> + <td colspan="6">Latitude of Q on the sphere</td> + <td>=</td> + <td class="tdr0">42°</td> + <td class="tdr0">45′</td> + <td class="tdr0">38″</td> +</tr> +</table> + + +<h3>CORRECTION FOR PROTUBERANCE.</h3> + +<p>We have hitherto considered the earth a perfect sphere with a diameter +of 7,900 miles. It is convenient to regard it thus, and afterwards make +the correction for protuberance. We will<span class="pagenum" title="Page 75"> </span><a name="Page_75" id="Page_75"></a> now indicate the process for +obtaining this correction by the aid of the following diagram.</p> + +<div class="figcenter" style="width: 200px;"> +<a name="fig15" id="fig15"></a> +<img src="images/fig15.png" width="200" height="385" alt="Fig. 15" title="" /> +</div> + +<p>Let B bisect the chord ZZ′. Then, by geometry, the angle FQY is equal to +the angle BTF, and the protuberance FY is equal the sine of that angle, +making QF radius. This angle, made by the axis of the vortex and the +surface of the sphere, is commonly between 30° and 40°, according as the +moon is near her apogee or perigee; and the correction will be greatest +when the angle is least, as at the apogee. At the equator, the whole +protuberance of the earth is about 13 miles. Multiply this by the cosine +of the angle and divide by the sine, and we shall get the value of the +arc QY for the equator. For the smallest angle, when the correction is a +maximum, this correction will be about 20′ of latitude at the equator; +for other latitudes it is diminished as the squares of the cosines of +the latitude. Then add this amount to the latitude EQ, equal the +latitude EY. This, however, is only correct when the axis of the vortex +is in the same plane as the axis of the earth; it is, therefore, subject +to a minus correction, which can be found by saying, as radius to cosine +of obliquity so is the correction to a fourth—the difference of these +corrections is the maximum minus correction, and needs reducing in<span class="pagenum" title="Page 76"> </span><a name="Page_76" id="Page_76"></a> the +ratio of radius to the cosine of the angle of the moon’s distance from +the node; but as it can only amount to about 2′ at a maximum under the +most favorable circumstances, it is not necessary to notice it. The +correction previously noticed is on the supposition that the earth is +like a sphere having TF for radius; as it is a spheroid, we must correct +again. From the evolute, draw the line SF, and parallel to it, draw TW; +then EW is the latitude of the point F on the surface of the spheroid. +This second correction is also a plus correction, subject to the same +error as the first on account of the obliquity, its maximum value for an +angle of 30° is about 6′, and is greatest in latitude 45°; for other +latitudes, it is equal +<a href="images/eqp76.png"><img src="images/eqp76_s.png" width="155" height="35" +alt="(6′ × sin (double the lat.) ⁄ R." +title="(6′ × sin (double the lat.) ⁄ R." /></a> +</p> + +<p>The three principal corrections for protuberance may be <i>estimated</i> from +the following table, calculated for every 15° of latitude for an angle +of 30°, or when the correction is greatest.</p> + +<table summary="Three principal corrections for protuberance."> +<tr> + <th>Latitude.</th> + <th colspan="2">1st Corr.</th> + <th>2d Corr.</th> + <th>3d Corr.</th> +</tr> +<tr> + <td class="tdr">0</td> + <td class="tdl">+</td> + <td class="tdr">20′</td> + <td class="tdl">+ 0</td> + <td class="tdl">−2</td> +</tr> +<tr> + <td class="tdr">15</td> + <td class="tdl">+</td> + <td class="tdr">19′</td> + <td class="tdl">+ 3</td> + <td class="tdl">−1.5</td> +</tr> +<tr> + <td class="tdr">30</td> + <td class="tdl">+</td> + <td class="tdr">15′</td> + <td class="tdl">+ 5</td> + <td class="tdl">−1.5</td> +</tr> +<tr> + <td class="tdr">45</td> + <td class="tdl">+</td> + <td class="tdr">10′</td> + <td class="tdl">+ 6</td> + <td class="tdl">−1.</td> +</tr> +<tr> + <td class="tdr">60</td> + <td class="tdl">+</td> + <td class="tdr">5′</td> + <td class="tdl">+ 5</td> + <td class="tdl">−1</td> +</tr> +<tr> + <td class="tdr">70</td> + <td class="tdl">+</td> + <td class="tdr">1′</td> + <td class="tdl">+ 3</td> + <td class="tdl">−0.5</td> +</tr> +</table> + +<p>We can now apply this correction to the latitude of the vortex just +found:</p> + +<table summary="Applying the correction."> +<tr> + <td style="padding-right:4em;">Latitude on the sphere</td> + <td class="tdr0">42°</td> + <td class="tdr0">45′</td> + <td class="tdr0">38″</td> + <td>n.</td> +</tr> +<tr> + <td>Correction for protuberance</td> + <td class="tdr0">+</td> + <td class="tdr0">14′</td> + <td class="tdr0">22″</td> +</tr> +<tr> + <td>Correct latitude</td> + <td class="tdr0" style="border-top:thin solid black;">43°</td> + <td class="tdr0" style="border-top:thin solid black;">00′</td> + <td class="tdr0" style="border-top:thin solid black;">00″</td> +</tr> +</table> + +<h3>MILWAUKIE STORM, JULY 2.</h3> + +<p>As this example was calculated about ten days before the actual date, we +have appended an extract from the Milwaukie papers, which is in the same +longitude as Ottawa, in which place<span class="pagenum" title="Page 77"> </span><a name="Page_77" id="Page_77"></a> the calculation was made. It is +needless to remark that the latitude of Milwaukie corresponds to the +calculated latitude of the centre of the vortex. It is not intended, +however, to convey the idea that the central line is always the most +subject to the greatest violence—a storm may have several centres or +nuclei of disturbance, which are frequently waning and reviving as the +storm progresses. Generally speaking, however, the greatest action is +developed along the line previously passed over by the axis of the +vortex.</p> + +<blockquote><p>“<span class="smcap">Summit</span>, Waukesha Co., Wis., July 4, 1853.</p> + +<p>“Our town, on Saturday, the 2d, was visited by a terrible storm, +which will long be remembered by those who witnessed its effects and +suffered from its fury. It arose in the south-west, and came +scowling in blackness, sufficient to indicate its anger, for the +space of eighty or a hundred rods in <i>width</i>, covering our usually +quiet village; and for nearly half an hour’s duration, the rain fell +in torrents, the heavens blazed with the lightning’s flashes, trees +fell and were uprooted by the fury of the blast, fragments of gates +and of buildings, shingles, roof-boards, rafters, circled through +the air, the playthings of the wind—and buildings themselves were +moved entire from their foundations, and deposited at different +distances from their original positions. A barn, fifty-five feet +square on the ground, owned by Mr. B. R. Hinckley, is moved from its +position some ten feet to the eastward; and a house, some fifteen by +eighteen feet on the ground, owned by the same person, fronting the +east, was driven by the wind to the opposite side of the street, and +now fronts nearly west; and what is most strange, is that the grass, +in the route the house must have passed over, stands straight as +usual, and gives no evidence that the building was pushed along on +the ground. A lady running from a house unroofed by the storm, took +an aërial flight over two fences, and finally caught against a tree, +which arrested her passage for a moment only, when, giving way, she +renewed her journey for a few rods, and was<span class="pagenum" title="Page 78"> </span><a name="Page_78" id="Page_78"></a> set down unhurt in +Mr. O. Reed’s wheat field, where, clinging to the growing grain, she +remained till the gale went by.”<a name="FNanchor_11_11" id="FNanchor_11_11"></a><a href="#Footnote_11_11" class="fnanchor">[11]</a></p></blockquote> + +<p>The weather at this place is briefly recorded in the accompanying +abstract from the journal, as well as in an extract from a note to +Professor Henry, of the Smithsonian Institution, from a friend of the +authors, who has long occupied a high official station in Illinois. But +such coincidences are of no value in deciding on the merits of such a +theory, it must be tried before the tribunal of the world, and applied +to phenomena in other countries with success, before its merits can be +fully appreciated. The accompanying record, therefore, is only given to +show how these vortices render themselves apparent, and what ought to be +observed, and also to exhibit the order of their recurrence and their +positions at a given time.</p> + +<blockquote><p><i>Extract of a note addressed to the Secretary of the Smithsonian +Institution, by Hon. John Dean Caton, on this subject.</i></p> + +<p>“As a striking instance of the remarkable coincidences confirmatory +of these calculations, I will state, that on Friday, the first of +July last, this gentleman<a name="FNanchor_12_12" id="FNanchor_12_12"></a><a href="#Footnote_12_12" class="fnanchor">[12]</a> stated that on the next day a storm +would pass north of us, being central a little south of Milwaukie, +and that he thought, from the state of the atmosphere, the storm +would be severe, and that its greatest violence would be felt on the +afternoon or night of the next day. At this time the weather was +fine, without any indications of a storm, so far as I could judge. +At noon on the following day he pointed out the indications of a +storm at the north and north-west, consisting of a dark, hazy belt +in that direction, extending up a few degrees above the horizon, +although so indistinct as to have escaped my observation. At five o’clock a violent storm visited us, which lasted half an hour, +although a clear sky was visible at the south the whole time. On +Monday morning I learned, from the telegraph office at Chicago, that +early on Saturday<span class="pagenum" title="Page 79"> </span><a name="Page_79" id="Page_79"></a> afternoon communication with Milwaukie had been +interrupted by atmospheric electricity, and that the line had been +broken by a storm.”</p></blockquote> + + +<h3>NEW YORK STORM.</h3> + +<p>After this was written, the author discovered that the vortex was +equally violent the day before at New York, July 1st, 1853. An account +of this storm follows. The calculation has not been made, but it is easy +to perceive that the latitude of the vortex, on July 1st, must be very +nearly that of New York—being in latitude 43° next day and ascending.</p> + +<blockquote><p>“At a meeting of the American Association, convened at Cleveland, +Professor Loomis presented a long notice of the terrible hail storm in +New York on the 1st of July. He traced its course, and minutely examined +all the phenomena relating to it, from a mile and a half south-east of +Paterson, N. J., to the east side of Long Island, where it appeared +nearly to have spent its force. It passed over the village of Aqueenac, +striking the Island of New York in the vicinity of the Crystal Palace. +It was not much more than half a mile wide. The size of the hail-stones +was almost incredibly large, many of them being as large as a hen’s egg, +and the Professor saw several which he thought as large as his fist. +Some of them weighed nearly half a pound. The principal facts in +relation to this storm were published at the time, and need not be +repeated. The discussions arising among the members as to the origin and +the size of these hail-stones, and the phenomena of the storm, were +exceedingly interesting. They were participated in by Professors Heustus +and Hosford, of Cambridge University, Professor Loomis, and Professors +Bache and Redfield. The latter two gentlemen differ somewhat, we should +suppose radically, in their meteorological theories, and had some very +sharp but very pleasant “shooting” between them.”<a name="FNanchor_13_13" id="FNanchor_13_13"></a><a href="#Footnote_13_13" class="fnanchor">[13]</a></p></blockquote> + + +<h3><span class="pagenum" title="Page 80"> </span><a name="Page_80" id="Page_80"></a>CENTRAL VORTEX DESCENDING.</h3> + +<p>We will now make the calculation for the central vortex <i>descending</i>, +for longitude 88° 50′ west, August 7, 1853,—putting down the necessary +elements for the time of the meridian passage in order:</p> + +<table summary="Calculations for central vortex descending."> +<tr> + <td>Meridian passage</td> + <td class="tdr0">in local time at</td> + <td></td> + <td></td> + <td class="tdr0">2h.</td> + <td class="tdr0">25m.</td> + <td><span class="time">P. M.</span></td> +</tr> +<tr> + <td><span style="margin-left:2em; margin-right:1em;">"</span><span style="margin-left:1em; margin-right:2em;">"</span></td> + <td class="tdr0">in Greenwich time</td> + <td></td> + <td class="tdr0">7d.</td> + <td class="tdr0">8h.</td> + <td class="tdr0">18m.</td> + <td></td> +</tr> +<tr> + <td colspan="2">Mass of the moon 1 ⁄ 12.3 M. R. V. minor</td> + <td></td> + <td colspan="3" class="tdr0">3,256</td> + <td>miles.</td> +</tr> +<tr> + <td>Obliquity of the vortex,</td> + <td class="tdr0">same time</td> + <td></td> + <td class="tdr0">26°</td> + <td class="tdr0">5′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td>Polar angle of<span style="margin-left:2em; margin-right:1em;">"</span></td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0">17°</td> + <td class="tdr0">41′</td> + <td class="tdr0">47″</td> + <td></td> +</tr> +<tr> + <td>True longitude of moon’s node </td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0">78°</td> + <td class="tdr0">42′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td><span style="margin-left:1em; margin-right:1em;">"</span>inclination of orbit </td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0">5°</td> + <td class="tdr0">5′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td><span style="margin-left:1em; margin-right:1em;">"</span>longitude of the sun </td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0">135°</td> + <td class="tdr0">20′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td>Moon’s longitude </td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0">169°</td> + <td class="tdr0">44′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td><span style="margin-left:1em; margin-right:1em;">"</span>distance from node </td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0">91°</td> + <td class="tdr0">2′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td><span style="margin-left:1em; margin-right:1em;">"</span>distance from quadrature </td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0">55°</td> + <td class="tdr0">36′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td><span style="margin-left:1em; margin-right:1em;">"</span>true semi-diameter </td> + <td class="tdr">"</td> + <td></td> + <td></td> + <td></td> + <td class="tdr0">943″</td> + <td></td> +</tr> +<tr> + <td><span style="margin-left:1em; margin-right:1em;">"</span>right ascension </td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0">172°</td> + <td class="tdr0">30′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td><span style="margin-left:1em; margin-right:1em;">"</span>declination north </td> + <td class="tdr">"</td> + <td></td> + <td class="tdr0" style="border-bottom:thin solid black;">8°</td> + <td class="tdr0" style="border-bottom:thin solid black;">42′</td> + <td class="tdr0" style="border-bottom:thin solid black;">20″</td> + <td></td> +</tr> +<tr> + <td>Constant logarithm</td> + <td class="tdr0">2.889214</td> + <td colspan="5"></td> +</tr> +<tr> + <td>Arith. comp. of log. of 943</td> + <td class="tdr0">7.025488</td> + <td colspan="5"></td> +</tr> +<tr> + <td>Log. cos. arc. AR</td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">9.914702</td> + <td>=</td> + <td class="tdr0">34°</td> + <td class="tdr0">44′</td> + <td class="tdr0">48″</td> + <td></td> +</tr> +<tr> + <td colspan="2">1st. correction,</td> + <td>+</td> + <td class="tdr0">2°</td> + <td class="tdr0">45′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td colspan="2">2d. correction,</td> + <td>−</td> + <td class="tdr0">1°</td> + <td class="tdr0">14′</td> + <td class="tdr0">15″</td> + <td></td> +</tr> +<tr> + <td class="tdr0">Corrected arc</td> + <td>AQ</td> + <td>=</td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">36°</td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">15′</td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">33″</td> + <td></td> +</tr> +<tr> + <td></td> + <td>PA</td> + <td>=</td> + <td class="tdr0">81°</td> + <td class="tdr0">17′</td> + <td class="tdr0">40″</td> + <td></td> +</tr> +<tr> + <td></td> + <td>PV</td> + <td>=</td> + <td class="tdr0">26°</td> + <td class="tdr0">5′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td></td> + <td>P</td> + <td>=</td> + <td class="tdr0">115°</td> + <td class="tdr0">11′</td> + <td class="tdr0">47″</td> + <td></td> +</tr> +<tr> + <td></td> + <td>V</td> + <td>=</td> + <td class="tdr0">63°</td> + <td class="tdr0">34′</td> + <td class="tdr0">26″</td> + <td></td> +</tr> +<tr> + <td></td> + <td>A</td> + <td>=</td> + <td class="tdr0">23°</td> + <td class="tdr0">28′</td> + <td class="tdr0">24″</td> + <td></td> +</tr> +<tr> + <td></td> + <td>AV</td> + <td>=</td> + <td class="tdr0">92°</td> + <td class="tdr0">48′</td> + <td class="tdr0">39″</td> + <td></td> +</tr> +<tr> + <td></td> + <td>Q</td> + <td>=</td> + <td class="tdr0">31°</td> + <td class="tdr0">32′</td> + <td class="tdr0">18″</td> + <td></td> +</tr> +<tr> + <td><a name="Page_81" id="Page_81"></a>Complement of lat. =</td> + <td>PQ</td> + <td>=</td> + <td class="tdr0">48°</td> + <td class="tdr0">49′</td> + <td class="tdr0">41″</td> + <td></td> +</tr> +<tr> + <td colspan="2">The latitude is therefore for the earth, as a sphere</td> + <td></td> + <td class="tdr0">41°</td> + <td class="tdr0">10′</td> + <td class="tdr0">18″</td> + <td></td> +</tr> +<tr> + <td colspan="2">Correction for protuberance</td> + <td>+</td> + <td class="tdr0">0°</td> + <td class="tdr0">16′</td> + <td class="tdr0">0″</td> + <td></td> +</tr> +<tr> + <td colspan="2">True latitude of centre</td> + <td></td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">41°</td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">26′</td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">18″</td> + <td>north.</td> +</tr> +<tr> + <td colspan="2">Latitude of Ottowa</td> + <td></td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">41°</td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">20′</td> + <td class="tdr0" style="border-bottom:thin solid black; border-top:thin solid black;">0″</td> + <td><span style="margin-left:1em;">"</span></td> +</tr> +<tr> + <td colspan="2">Vortex passed</td> + <td></td> + <td></td> + <td class="tdr0">6′</td> + <td class="tdr0">18″</td> + <td>north of Ottowa.</td> +</tr> +</table> + +<div class="figcenter" style="width: 350px;"> +<a name="fig16" id="fig16"></a> +<img src="images/fig16.png" width="350" height="187" alt="Fig. 16" title="" /> +</div> + +<p>As this was nearly a central passage, and as the influence was less +extensive than usual, on account of great atmospheric pressure with a +low dew point, the central disturbance could the more readily be +located, and was certainly to the north, and but a few miles. The +following is from the record of the weather:</p> + +<p><i>August</i> 6th. Very fine and clear all day; wind from S.-W.; a light +breeze; 8 <span class="time">P. M.</span> frequent flashes of lightning in the northern sky; +10 <span class="time">P. M.</span> a <i>low bank of dense clouds in north</i>, fringed with cirri, +visible during the flash of the lightning; 12 <span class="time">P. M.</span> same continues.</p> + +<p>7th. Very line and clear morning; wind S.-W. moderate; noon, clouds +accumulating in the northern half of the sky; wind fresher S.-W.; 3 <span class="time">P. M.</span> +a clap of thunder overhead, and black cumuli in west, north, and east; +4 <span class="time">P. M.</span> much thunder, and scattered showers; six miles west rained very<span class="pagenum" title="Page 82"> </span><a name="Page_82" id="Page_82"></a> +heavily; 6 <span class="time">P. M.</span> the heavy clouds passing over to the south; 10 <span class="time">P. M.</span> +clear again in north.</p> + +<p><i>August</i> 8th. Clear all day; wind the same (S.-W.); a hazy bank visible +all along on <i>southern horizon</i>.</p> + +<p>This was not a storm, in the ordinary acceptation of the term; but the +same cause, under other circumstances, would have produced one; and let +it be borne in mind, that although the moon is the chief disturbing +cause, and the passages of the vortices are the periods of greatest +commotion in both settled and unsettled weather, still the sun is +powerful in predisposing the circumstances, whether favorable or +unfavorable; and as there is no periodic connection between the passage +of a vortex and the concurrence of the great atmospheric waves, it will, +of course, happen only occasionally that all the circumstances will +conspire to make a storm. There are also other modifying causes, to +which we have not yet alluded, which influence the storms at different +seasons of the year,—exaggerating their activity in some latitudes, and +diminishing it in other latitudes. In this latitude, the months of May, +June, and July are marked by more energetic action than August, +September, and October. The activity of one vortex also, in one place, +seems to modify the activity of another vortex in another place. But the +great question to decide is: Do these vortices really exist? Do they +follow each other in the <i>order</i> indicated by the theory? Do they pass +from south to north, and from north to south, at the <i>times</i> indicated +by the theory? Do they obey, in their monthly revolutions, a +mathematical law connecting them with the motions of the moon? We answer +emphatically, Yes! And the non-discovery of these facts, is one of the +most humiliating features of the present age.</p> + + +<h3><span class="pagenum" title="Page 83"> </span><a name="Page_83" id="Page_83"></a>OTTOWA STORM, DECEMBER 22, 1852.</h3> + +<p>To show that the same calculations are applicable for other times, we +will make the calculation for the <i>centre ascending</i>, for the 22d +December, 1852, taking the following elements:</p> + +<table summary="Calculation for the centre ascending."> +<tr> + <td>Moon’s</td> + <td style="padding-right:3em;">mer. passage, Dec. 22d</td> + <td>15h.</td> + <td>16m.</td> + <td>G. time.</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>right ascension, same time</td> + <td>51°</td> + <td>57′</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>declination north</td> + <td>15°</td> + <td>42′</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>true S. Diameter</td> + <td colspan="3">886.6″</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>distance from node</td> + <td>37°</td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td><span style="margin-left:1.5em;">"</span><span style="margin-left:2.3em; margin-right:1em;">"</span>quadrature</td> + <td style="border-bottom:thin solid black;">52°</td> + <td style="border-bottom:thin solid black;"></td> + <td></td> +</tr> +<tr> + <td colspan="2">Which gives the arc AR</td> + <td>29°</td> + <td>5′</td> + <td></td> +</tr> +<tr> + <td colspan="2">1st correction</td> + <td>−1°</td> + <td>51′</td> + <td></td> +</tr> +<tr> + <td colspan="2">2d<span style="margin-left:2em;">"</span></td> + <td>+1°</td> + <td>11′</td> + <td></td> +</tr> +<tr> + <td colspan="2">Corrected arc AQ</td> + <td style="border-bottom:thin solid black; border-top:thin solid black;">28°</td> + <td style="border-bottom:thin solid black; border-top:thin solid black;">25′</td> + <td></td> +</tr> +</table> + +<p>And the latitude at the time of the meridian passage = 42° north, or +about forty miles north of Ottawa.</p> + +<p>Abstract from the record:—</p> + +<p><a name="FNanchor_14_14" id="FNanchor_14_14"></a><a href="#Footnote_14_14" class="fnanchor">[14]</a><i>Dec.</i> 21st, 1852. Wind N.-E., fine +weather.</p> + +<p><i>Dec.</i> 22d. Thick, hazy morning, wind east, much lighter in S.-E. than +in N.-W.; 8 <span class="time">A. M.</span>, a clear arch in S.-E. getting more to south; noon, +very black in W. N.-W.; above, a broken layer of cir. cumulus, the sun +visible sometimes through the waves; wind round to S.-E., and fresher; +getting thicker all day; 10 <span class="time">P. M.</span>, wind south, strong; thunder, +lightning, and heavy rain all night, with strong squalls from south.</p> + +<p><i>Dec.</i> 23d. Wind S.-W., moderate, drizzly day; 10 <span class="time">P. M.</span>, wind west, and +getting clearer.</p> + +<p>The next day the vortex passed the latitude of Montreal (the moon being +on the meridian about 10 <span class="time">P. M.</span>)</p> + + +<h3><span class="pagenum" title="Page 84"> </span><a name="Page_84" id="Page_84"></a>MAGNETIC STORM, DECEMBER 23, 1852.</h3> + +<p>In the July number of Vol. XVI. of Silliman’s Journal, we find certain +notices of the weather in 1852, by Charles Smallwood, of St. Martins, +nine miles east of Montreal. He mentions “two remarkable electrical +storms (which) occurred on the 23d and 31st of December, (in which) +sparks 5 ⁄ 40 of an inch were constantly passing from the +conductor to the discharger for several hours each day.” At 10 <span class="time">P. M.</span> +(23d) the vortex passed over Montreal, and again descending on the 31st +North, and was visible at Ottowa on the morning of the 1st of January, +with southerly wind setting towards it. On the 29th of December, +Mr. Smallwood records “a low auroral arch, sky clear.” On the 20th, the +vortex was 5° to the northward of Montreal, and the aurora was +consequently low—the brightest auroras being when the vortex is +immediately north without storm, or one day to the northward, although +we have seen it <i>very low</i> when the vortex was three days to the north, +and no other vortex near.</p> + + +<h3>LIVERPOOL STORM.</h3> + +<p>On the night of the 24th of December, the same central vortex ascending +passed between Cape Clear and Liverpool.</p> + +<p>On the 25th, at midnight, the vortex passed to the north of Liverpool: +its northerly progress being very slow, being confined for three days +between the parallel of Liverpool and its extreme northern limit in +latitude about 57°. The accompanying account of the weather will show +the result of a long-continued disturbance near the same latitude:</p> + +<p>The Baltic, three days out from Liverpool, encountered the vortex on the +night of the 23d. On the morning of the 25th, very early, the gale +commenced at Liverpool, and did much damage. On the 26th, the vortex +attained its northern limit;<span class="pagenum" title="Page 85"> </span><a name="Page_85" id="Page_85"></a> but we have not been able to procure any +account of its effects to the northward of Liverpool, although there can +be but little doubt that it was violent on the coast of Scotland on the +26th; for the next day (27th) the vortex having made the turn, was near +the latitude of Liverpool, and caused a <i>tremendous</i> storm, thus showing +a continued state of activity for several days, or a peculiarly +favorable local atmosphere in those parts. It is very probable, also, +that there was a conjunction of the central and inner vortex on the +27th. The inner vortex precedes the central in passing latitude 41°; but +as the mean radius of its orbit is less than that of the central, it +attains to a higher latitude, and has, consequently, to cross the path +of the central, in order again to precede it descending in latitude 41°. +As a very trifling change in the elements of the problem will cause +great changes in the positions of the vortices on the surface of the +earth, it cannot now be asserted that such a conjunction did positively +occur at that time; but, it maybe suspected, that a double disturbance +would produce a greater commotion, or, in other words, a more violent, +storm.</p> + +<p>It is on this account, combined with other auxiliary causes, that the +vicinity of Cape Horn is so proverbially stormy, as well as for the low +standard of the barometer in that latitude, it is the stationary point +of the vortices in ordinary positions of the nodes and perigee of the +moon. We have already alluded to the fact, that none of the vortices +scarcely ever pass much beyond latitude 80°, and then only under +favorable circumstances, so that we ought to infer, that gales in high +latitudes should set from the poles towards the storms in lower +latitudes. This is, no doubt, the fact, but, nevertheless, a hard +southerly blow <i>may possibly</i> occur in high northern latitudes, if a +storm should be raging very violently in a lower latitude on the +opposite side of the pole, the distance across the circle of 80° being +only about 1,400 miles. As the different vortices have a different limit +in latitude every year, the determination of this<span class="pagenum" title="Page 86"> </span><a name="Page_86" id="Page_86"></a> turning point is +obviously of great practical utility, as the fact may yet be connected +with other phenomena, so as to give us the probable character of the +polar ice at any assigned time. On this point we have more to say.</p> + + +<h3>PASSAGES OF ALL THE VORTICES.</h3> + +<p>Our remarks have hitherto been confined to the central vortex. We shall +now show from the record, that the other vortices are as effective in +deranging the equilibrium of our atmosphere. In the following table we +have given the passages of the different vortices, which will serve as +their true positions within moderate limits, to calculate from, for all +future time.</p> + +<table class="center cols" summary="Passages of the Central and Lateral Vortices."> +<caption> + <span class="smcap">Passages of the Central and Lateral Vortices, + observed in June and July, 1853, in latitude 41° 20′ north.</span><br /> + I signifying Inner; O, outer; C, central; A, ascending; D, + descending. +</caption> +<col span="3" style="border-left:thin solid black;" /> +<col style="border-right:thin solid black;" /> +<col /> +<col span="3" style="border-right:thin solid black;" /> +<tr style="border-top: thin solid black; border-bottom:thin solid black;"> + <th>Order.</th> + <th>Vortex.</th> + <th colspan="2">Date.</th> + <th colspan="2">Meridian<br />Passage.</th> + <th>Passage.</th> + <th>Calculated latitude and<br />Remarks.</th> +</tr> +<tr> + <td>1st</td> + <td>I. A.</td> + <td class="l" style="padding-left:0.25em;">June </td> + <td class="tdr0 r">22</td> + <td class="tdr0 l">7</td> + <td class="tdr r"><span class="time">A. M.</span></td> + <td>south</td> + <td class="tdl0">Centre. About 40°.</td> +</tr> +<tr> + <td></td> + <td></td> + <td class="l"></td> + <td class="tdr0 r">23</td> + <td class="tdr0 l">8</td> + <td class="tdr r"><span class="time">A. M.</span></td> + <td>north</td> + <td class="tdl0">Warsaw. Storm.</td> +</tr> +<tr> + <td>2d</td> + <td>O. D.</td> + <td class="l"></td> + <td class="tdr0 r">27</td> + <td class="tdr0 l">0</td> + <td class="tdr r"><ins class="correction" title="Transcriber’s note: Original reads ‘moon’.">noon</ins></td> + <td>north</td> + <td></td> +</tr> +<tr> + <td></td> + <td></td> + <td class="l"></td> + <td class="tdr0 r">28</td> + <td class="tdr0 l">1</td> + <td class="tdr r"><span class="time">A. M.</span></td> + <td>south</td> + <td class="tdl0">See record.</td> +</tr> +<tr> + <td>3d</td> + <td>C. A.</td> + <td class="l">July</td> + <td class="tdr0 r">1</td> + <td class="tdr0 l">9</td> + <td class="tdr r"><span class="time">A. M.</span></td> + <td>south</td> + <td></td> +</tr> +<tr> + <td></td> + <td></td> + <td class="l"></td> + <td class="tdr0 r">2</td> + <td class="tdr0 l">10</td> + <td class="tdr r"><span class="time">A. M.</span></td> + <td>north</td> + <td class="tdl0">Lat. 43°. Storm.</td> +</tr> +<tr> + <td>4th</td> + <td>I. D.</td> + <td class="l"></td> + <td class="tdr0 r">7</td> + <td class="tdr0 l">5</td> + <td class="tdr r"><span class="time">P. M.</span></td> + <td>north</td> + <td></td> +</tr> +<tr> + <td></td> + <td></td> + <td class="l"></td> + <td class="tdr0 r">8</td> + <td class="tdr0 l">6</td> + <td class="tdr r"><span class="time">P. M.</span></td> + <td>south</td> + <td class="tdl0">Lat. New York. Storm.</td> +</tr> +<tr> + <td>5th</td> + <td>C. D.</td> + <td class="l"></td> + <td class="tdr0 r">12</td> + <td class="tdr0 l">5</td> + <td class="tdr r"><span class="time">P. M.</span></td> + <td>north</td> + <td class="tdl0">Aurora.</td> +</tr> +<tr> + <td></td> + <td></td> + <td class="l"></td> + <td class="tdr0 r">13</td> + <td class="tdr0 l">6</td> + <td class="tdr r"><span class="time">P. M.</span></td> + <td>south</td> + <td class="tdl0">Stormy, very.</td> +</tr> +<tr> + <td>6th</td> + <td>O. A.</td> + <td class="l"></td> + <td class="tdr0 r">14</td> + <td class="tdr0 l">10</td> + <td class="tdr r"><span class="time">A. M.</span></td> + <td>south</td> + <td></td> +</tr> +<tr style="border-bottom:thin solid black;"> + <td></td> + <td></td> + <td class="l"></td> + <td class="tdr0 r">15</td> + <td class="tdr0 l"> 11</td> + <td class="tdr r"><span class="time">A. M.</span></td> + <td>north</td> + <td class="tdl0">See Record.</td> +</tr> +</table> + +<p>The intervals between the ascending and descending passages of the +different vortices, are</p> + +<table class="center" summary="Intervals between the ascending and descending passages of the different vortices."> +<tr> + <td style="padding-right:0.5em; padding-left:0.5em;">Between</td> + <td>I. A.</td> + <td style="padding-right:0.5em; padding-left:0.5em;">and</td> + <td>I. D.</td> + <td style="padding-right:0.5em; padding-left:0.5em;">from</td> + <td>11</td> + <td style="padding-right:0.5em; padding-left:0.5em;">to</td> + <td>14</td> + <td style="padding-right:0.5em; padding-left:0.5em;">days.</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>O. A.</td> + <td class="tdc">"</td> + <td>O. D.</td> + <td class="tdc">"</td> + <td>10</td> + <td class="tdc">"</td> + <td>12</td> + <td class="tdc">"</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>C. A.</td> + <td class="tdc">"</td> + <td>C. D.</td> + <td class="tdc">"</td> + <td>9</td> + <td class="tdc">"</td> + <td>11</td> + <td class="tdc">"</td> +</tr> +</table> + +<p>and the effect is greatest when the vortex comes to the meridian<span class="pagenum" title="Page 87"> </span><a name="Page_87" id="Page_87"></a> before +the sun, and least when after the sun; in which case the full effect is +not developed, sometimes until the following day.</p> + +<p>A brief abstract from a journal of the weather for one sidereal period +of the moon, in 1853.</p> + +<p><i>June</i> 21st. Fine clear morning (S. fresh)<a name="FNanchor_15_15" id="FNanchor_15_15"></a><a href="#Footnote_15_15" class="fnanchor">[15]</a>: noon very warm 88°; +4 <span class="time">P. M.</span> plumous <i>cirri in south</i>; ends clear.</p> + +<p>22d. Hazy morning (S. very fresh) arch of cirrus in west; 2 <span class="time">P. M.</span>, black +in W.-N.-W.; 3 <span class="time">P. M.</span>, overcast and rainy; 4 <span class="time">P. M.</span>, a heavy gust from +south; 4.30 <span class="time">P. M.</span>, blowing furiously (S. by W.); 5 <span class="time">P. M.</span>, tremendous +squall, uprooting trees and scattering chimneys; 6 <span class="time">P. M.</span>, more moderate +(W.)</p> + +<p>23d. Clearing up (N.-W.); 8 <span class="time">A. M.</span>, quite clear; 11 <span class="time">A. M.</span>, bands of mottled +cirri pointing N.-E. and S.-W.; ends cold (W. N.-W.); the cirri seem to +rotate from left to right, or with the sun.</p> + +<p>24th. Fine clear cool day, begins and ends (N.-W.)</p> + +<p>25th. Clear morning (N.-W, light); 2 <span class="time">P. M.</span> (E.) calm; tufts of tangled +cirri in north intermixed with radiating streaks, all passing eastward; +ends clear.</p> + +<p>26th. Hazy morning (S.-E) cloudy; noon, a heavy windy looking bank in +north (S. fresh), with dense cirrus fringe above on its upper edge; +clear in S.</p> + +<p>27th. Clear, warm, (W.); bank in north; noon bank covered all the +northern sky, and fresh breeze; 10 <span class="time">P. M.</span>, a few flashes to the northward.</p> + +<p>28th. Uniform dense cirro-stratus, (S. fresh); noon showers all round; +2 <span class="time">P. M.</span>, a heavy squall of wind, with thunder and rain (S.-W. to N.-W.); +8 <span class="time">P. M.</span>, a line of heavy cumuli in south; 8.30 <span class="time">P. M.</span>, a very bright and +high cumulus in S.-W., protruding through a layer of dark stratus; +8.50 <span class="time">P. M.</span>, the cloud bearing E. by S., with three rays of electric +light.<a name="FNanchor_16_16" id="FNanchor_16_16"></a><a href="#Footnote_16_16" class="fnanchor">[16]</a><span class="pagenum" title="Page 88"> </span><a name="Page_88" id="Page_88"></a></p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig17" id="fig17"></a> +<img src="images/fig17.png" width="350" height="211" alt="Fig. 17" title="" /> +</div> + +<p><i>June</i> 29th. A stationary stratus over all, (S.-W. light); clear at +night, but distant lightning in S.</p> + +<p>30th. Stratus clouds (N.-E. almost calm); 8 <span class="time">A. M.</span>, raining gently; +3 <span class="time">P. M.</span>, stratus passing off to S; 8 <span class="time">P. M.</span>, clear, pleasant.</p> + +<p><i>July</i> 1st. Fine and clear; 8 <span class="time">A. M.</span>, cirrus in sheets, curls, wisps, and +gauzy wreathes, with patches beneath of darker shade,<span class="pagenum" title="Page 89"> </span><a name="Page_89" id="Page_89"></a> all nearly +motionless; close and warm (N.-E.); a long, low bank of haze in S., with +one large cumulus in S.-W., but very distant.</p> + +<p><i>July</i> 2d. At 5 <span class="time">A. M.</span>, overcast generally with hazy clouds and fog of +prismatic shades, chiefly greenish-yellow; 7 <span class="time">A. M.</span>, (S.-S.-E. +freshening,) <ins class="correction" title="Transcriber’s note: Original reads ‘think’">thick</ins> in W; 8 <span class="time">A. M.</span>, (S. fresh) much cirrus, thick and +gloomy; 9 <span class="time">A. M.</span>, a clap of thunder, and clouds hurrying to N.; a reddish +haze all around; at noon the margin of a line of yellowish-red cumuli +just visible above a gloomy-looking bank of haze in N.-N.-W., (S. very +fresh;) warm, 86°; more cumuli in N.-W.—the whole line of cumuli N. are +separated from the clouds south by a clear space. These clouds are borne +rapidly past the zenith, but never get into the clear space—they seem +to melt or to be turned off N.-E. The cumuli in N. and N.-W., slowly +spreading E. and S.; 3 <span class="time">P. M.</span>, the bank hidden by small cumuli; 4 <span class="time">P. M.</span>, +very thick in north, magnificent cumuli visible sometimes through the +breaks, and beyond them a dark, watery back-ground, (S. strong); +4.30 <span class="time">P. M.</span>, wind round to N.-W. in a severe squall; 5 <span class="time">P. M.</span>, heavy rain, +with thunder, &c.—all this time there is a bright sky in the south +visible through the rain 15° high; 7 <span class="time">P. M.</span>, clearing, (S.-W. mod.)</p> + +<p><i>July</i> 3d. Very fine and clear, (N.-W.); noon, a line of large cumuli in +N., and dark lines of stratus below, the cumuli moving eastward; 6 <span class="time">P. M.</span>, +their altitude 2° 40′. Velocity 1° per minute; 9 <span class="time">P. M.</span>, much lightning in +the bank north.<a name="FNanchor_17_17" id="FNanchor_17_17"></a><a href="#Footnote_17_17" class="fnanchor">[17]</a></p> + +<p><i>July</i> 4th. 6 <span class="time">A. M.</span>, a line of small cumulo-stratus, extending<span class="pagenum" title="Page 90"> </span><a name="Page_90" id="Page_90"></a> east and +west, with a clear horizon north and south 10° high. This band<a name="FNanchor_18_18" id="FNanchor_18_18"></a><a href="#Footnote_18_18" class="fnanchor">[18]</a> seems +to have been thrown off by the central yesterday, as it moves slowly +south, preserving its parallelism, although the clouds composing it move +eastward. Fine and cool all day—(N.-W. mod.)—Lightning in N.</p> + +<p><i>July</i> 5th. Cloudy (N. almost calm), thick in E., clear in W.; same all +day.</p> + +<p>6th. Fine and clear (E. light); small cumuli at noon; clear night.</p> + +<p>7th. Warm (S. E. light); cirrus bank N. W.; noon (S.) thickening in N.; +6 <span class="time">P. M.</span>, hazy but fine; 8 <span class="time">P. M.</span>, lightning in N.; 10 <span class="time">P. M.</span>, the lightning +shows a heavy line of cumuli along the northern horizon; calm and very +dark and incessant lightning in N.</p> + +<p>8th. Last night after midnight commencing raining, slowly and steadily, +but leaving a line of lighter sky south; much lightning all night, but +little thunder.</p> + +<p>8th. 6 <span class="time">A. M.</span> Very low scud (500 feet high) driving south, still calm +below, (N. light); 10 <span class="time">A. M.</span>, clearing a little; a bank north with cirrus +spreading south; same all day; 9 <span class="time">P. M.</span>, wind freshening (N. stormy); +heavy cumuli visible in S.; 10.30 <span class="time">P. M.</span>, quite clear, but a dense watery +haze obscuring the stars; 12 <span class="time">P. M.</span>, again overcast: much lightning in S. +and N.-W.</p> + +<p><span class="pagenum" title="Page 91"> </span><a name="Page_91" id="Page_91"></a>9th. Last night (2 <span class="time">A. M.</span> of 9th) squall from N.-W. very black; 4 <span class="time">A. M.</span>, +still raining and blowing hard, the sky a perfect blaze, but very few +flashes reach the ground; 7 <span class="time">A. M.</span>, raining hard; 8 <span class="time">A. M.</span> (N.-W. strong); a +constant roll of thunder; noon (N.-E.); 2 <span class="time">P. M.</span> (N.); 4 <span class="time">P. M.</span> clearing; +8 <span class="time">P. M.</span>, a line of heavy cumuli in S., but clear in N-W., N., and +N.-E.<a name="FNanchor_19_19" id="FNanchor_19_19"></a><a href="#Footnote_19_19" class="fnanchor">[19]</a></p> + + +<h3>NEW YORK STORM, JULY 8, 1853.</h3> + +<p>“At 5 o’clock Friday afternoon, a terrible storm of rain, hail, and +lightning, rose suddenly from the north-west, and passed over the upper +part of the city and neighborhood. It was quite moderate in the lower +part of the town, and probably scarcely felt on Staten Island. The whole +affair lasted not more than a quarter of an hour, yet the results were +most disastrous, as will be seen by the following accounts from our +reporters:</p> + +<p>“Happening to be in the neighborhood of the Palace about 5 o’clock +Friday evening, we sought shelter under its ample roof from an impending +thunder storm, of very threatening appearance, rapidly approaching from +the west. We had scarcely passed the northern entrance, and reached the +gallery by the nearest flight of steps, when the torrent—it was not +rain, but an avalanche of water—struck the building; the gutters were +filled on the windward side in a moment, and poured over<span class="pagenum" title="Page 92"> </span><a name="Page_92" id="Page_92"></a> an almost +unbroken sheet of water, which was driven through the Venetian blind +ventilators, into and half way across the north-west gallery, and also +through the upper ventilators, falling upon the main floor of the north +transept. Workmen hastened to close the blinds, but that did not prevent +the deluge. The tinning of the dome being unfinished, the water, of +course, came down in showers all over the centre. Many workmen were +engaged on the dome when the shower struck it; several of them, in their +haste to escape such dangerous proximity to the terrific lightning, came +down single ropes, hand over hand. Large number of workmen were engaged +all over the exterior, and such a scampering will rarely be witnessed +but once in a lifetime. It was found impossible to close a north window, +used for ingress and egress of workmen upon the rod, and the water came +in, in almost solid columns. For a time the water was nearly two inches +deep on the gallery floor, and poured down the stairs in miniature +cascades.</p> + +<p>“A great number of boxes, bales, and packages of goods lay upon the main +floor, among which the water poured down from the edge of the gallery +floor in destructive quantities; Fortunately but few goods were opened, +and were upon the tables, or the damage would have been irreparable. As +it is, we fear some of the goods are injured. In the height of the +storm, the centre portion of the fanlight over the western entrance +burst in, and several single lights were broken, by staging or +otherwise.</p> + +<p>“About ten minutes after the storm burst, the most terrific hailstorm we +ever saw began to rattle, like discharges of musketry, upon the tin roof +and glass sides. Some of the masses of ice were as large as hen’s eggs. +There were probably a thousand excited workmen in the building, and a +good many exhibitors and visitors, among whom there were some twenty +ladies, some of whom appeared a good deal alarmed at the awful din. A +portion of the frame-work of the addition next to 42d street, went down +with a terrible crash, and a part of the<span class="pagenum" title="Page 93"> </span><a name="Page_93" id="Page_93"></a> brick wall of the engine-house +on the opposite side of the street, was blown over, crushing two or +three shanties, fortunately without any other injury than driving the +occupants out into the storm. But an awful scene occurred on the north +side of 43d street, directly opposite the Latting Tower. Here two large +unfinished frame buildings were blown, or rather, we should judge from +appearances, were crushed down into a mass of ruins, such as may be +imagined by supposing a great weight had fallen, with a circular, +grinding motion, upon the first fine fabrics. One of them was partly +sided, and had the rafters up, but no roof; the other was sided and +rooted with tin, and was being plastered. We were told it was three +stories high, 50 by 98 feet.</p> + +<p>“We reached the ruins among the first, after the burst of the storm +subsided a little. The scene was such as we pray God we may never +witness again. A small portion of the roof and upper part of the front +of the building stood or rather partly hung over the side-walk. The +chamber and lower floor of the front rooms lay flat together. The sides +were standing. In the rear all were down. In this building, besides the +workmen, there were numerous laborers who had taken shelter under its +roof when the storm drove them hurriedly from their work. How so many +persons escaped death is truly wonderful. It can only be accounted for +by supposing that they had a moment’s warning, and rushed into the +street. The first alarm was from the tearing off a portion of the tin +roof, which was carried high over another building, and fell in the +street. A horse and cart barely escaped being buried under this. It +seems the frame of the other building came down with a deafening crash +at the same time, confusing instead of warning those in danger. At any +rate, before they could escape, they were buried in a mass of timber, +and three of them instantly killed, and four or five dangerously +wounded; and others slightly bruised and badly frightened. Several would +have perished but for timely assist<span class="pagenum" title="Page 94"> </span><a name="Page_94" id="Page_94"></a>ance to extricate them. In this they +were greatly assisted by Jacob Steinant, boss carpenter of the Tower, +who with his men rushed to the rescue, notwithstanding the pouring down +torrents.</p> + +<p>“In Williamsburgh, the storm lasted about fifteen minutes, doing an +incalculable amount of damage to dwellings, foliage, &c. Hailstones came +down in sizes from that of a hickory-nut to a large apple, some with +such force as to drive them through the cloth awnings.</p> + +<p>“The storm passed over Brooklyn lightly, in comparison with the effects +across the Williamsburgh line. On Flushing avenue, beyond the Naval +Hospital, a number of trees were uprooted, and the window-panes of the +houses shattered. On the corner of Fulton and Portland avenues, three +<ins class="correction" title="Transcriber’s note: Original reads ‘building’.">buildings</ins> were unroofed, and the walls of the houses were sprung to the +foundation.</p> + +<p>“On Spencer street, a new frame building was levelled with the ground. +Along Myrtle, Classon, and other streets and avenues of East Brooklyn, +many of the shade trees were uprooted, and the windows smashed. In Jay +street, two trees were struck by lightning, but no other damage ensued.</p> + +<p>“Several schooners at the foot of Jay street were forced from their +moorings, but were soon after secured. A small frame house in Spencer +street, just put under roof, was prostrated to the ground.</p> + +<p>“We understand that a large barn filled with hay, situated on the road +between Bushwick and Flushing, was struck by lightning and destroyed +with its contents, embracing several head of live stock.”<a name="FNanchor_20_20" id="FNanchor_20_20"></a><a href="#Footnote_20_20" class="fnanchor">[20]</a></p> + +<p><i>July</i> 10th, 3 <span class="time">A. M.</span> Overcast and much lightning in south (N. mod.); +7 <span class="time">A. M.</span>, clear except in south; 6 <span class="time">P. M.</span> (E.); 10 <span class="time">P. M.</span>, lightning south; +11 <span class="time">P. M.</span>, auroral rays long but faint, converging to a point between +Epsilon Virginis and Denebola, in west; low down in west thick with +haze; on the north the rays con<span class="pagenum" title="Page 95"> </span><a name="Page_95" id="Page_95"></a>verged to a point still lower; lightning +still visible in south. This is an aurora in the west.</p> + +<p>11th. Fine clear morning (N.-E.); same all day; no lightning visible +to-night, but a bank of clouds low down in south, 2° high, and streaks +of dark stratus below the upper margin.</p> + +<p>12th. Fine and clear (N.-E.); noon, a well defined arch in S.-W., rising +slowly; the bank yellowish, with prismatic shades of greenish yellow on +its borders. This is the O. A. At 6 <span class="time">P. M.</span>, the bank spreading to the +northward. At 9 <span class="time">P. M.</span>, thick bank of haze in north, with bright auroral +margin; one heavy pyramid of light passed through Cassiopæa, travelling +<i>westward</i> 1½° per minute. This moves to the other side of the pole, +but not more inclined towards it than is due to prospective, if the +shaft is very long; 11.10 <span class="time">P. M.</span>, saw a mass of light more diffuse due +east, reaching to <i>Markab</i>, then on the prime vertical. It appears +evident this is seen in profile, as it inclines downwards at an angle of +10° or 12° from the perpendicular. It does not seem very distant. +12 <span class="time">P. M.</span>, the aurora still bright, but the brightest part is now west of +the pole, before it was east.</p> + +<p>13th, 6 <span class="time">A. M.</span> Clear, east and north; bank of cirrus in N.-W., <i>i.e.</i>, +from N.-N.-E. to W. by S.; irregular branches of cirrus clouds, reaching +almost to south-eastern horizon; wind changed (S.-E. fresh); 8 <span class="time">A. M.</span>, the +sky a perfect picture; heavy regular shafts of dense cirrus radiating +all around, and diverging from a thick nucleus in north-west, the spaces +between being of clear blue sky. The shafts are rotating from north to +south, the nucleus advancing eastward.</p> + +<p>Appearance of the central vortex descending at 8 <span class="time">A. M.</span>, July 13th, 1853:</p> + +<p>In <a href="#fig18">Fig. 18</a>, the circle represents the whole sky from the zenith to the +horizon, yet it can convey but a very faint idea of the regularity and +vividness of this display. The reflected image of the sky was received +from a vessel of turbid water, which will be found better than a mirror, +when the wind will permit.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig18" id="fig18"></a> +<img src="images/fig18.png" width="350" height="347" alt="Fig. 18" title="" /> +</div> + +<p><span class="pagenum" title="Page 96"> </span><a name="Page_96" id="Page_96"></a>At noon (same day) getting thicker (S.-E. very fresh); 6 <span class="time">P. M.</span>, moon on +meridian, a prismatic gloom in south, and very thick stratus of all +shades; 9 <span class="time">P. M.</span>, very gloomy; wind stronger (S.-E.): 10 <span class="time">P. M.</span>, very black +in south, and overcast generally.</p> + +<p>14th. Last night about 12 <span class="time">P. M.</span> commenced raining; 3 <span class="time">A. M.</span>, rained +steadily; 7 <span class="time">A. M.</span>, same weather; 8.20 <span class="time">A. M.</span>, a line of low storm-cloud, or +seud, showing very sharp and white on the dark back ground all along the +southern sky. This line continues until noon about 10° at the highest, +showing the northern boundary of the storm to the southward; 8 <span class="time">P. M.</span>, +same bank visible, although in rapid motion eastward; same time<span class="pagenum" title="Page 97"> </span><a name="Page_97" id="Page_97"></a> clear +overhead, with cirrus fringe pointing north from the bank; much +lightning in south (W. fresh); so ends.</p> + +<p>15th. Last night a black squall from N.-W. passed south without rain; at +3 <span class="time">A. M.</span> clear above, but very black in south (calm below all the time); +9 <span class="time">A. M.</span>, the bank in south again throwing off rays of cirri in a +well-defined arch, whose vortex is south: these pass east, but continue +to form and preserve their linear direction to the north; no lightning +in south to-night.</p> + +<p>16th. Clear all day, without a stain, and calm.</p> + +<p>17th. Fine and clear (N.-E. light); 6 <span class="time">P. M.</span>, calm.</p> + +<p>18th. Fair and cloudy (N.-E. light); 6 <span class="time">P. M.</span>, calm.</p> + +<p>19th. Fine and clear (N. fresh); I. V. visible in S.-W.</p> + +<p>20th. 8 <span class="time">A. M.</span>, bank in N.-W. with beautiful cirrus radiations; 10 <span class="time">A. M.</span>, +getting thick with dense plates of cream-colored cirrus visible through +the breaks; gloomy looking all day (N.-E. light).<a name="FNanchor_21_21" id="FNanchor_21_21"></a><a href="#Footnote_21_21" class="fnanchor">[21]</a></p> + +<p>Appearance of the Inner Vortex at 8 <span class="time">A. M.</span>, July 20th, 1853, including the +whole sky. (See <a href="#fig19">Fig. 19</a>.)</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig19" id="fig19"></a> +<img src="images/fig19.png" width="350" height="350" alt="Fig. 19" title="" /> +</div> + +<p>This was a different passage of the Inner Vortex ascending as compared +with the same 28 days before. At that date (June 22) it did great damage +in the central parts of Illinois. Still this last passage was very +palpable—the clouds were very irregularly assorted—plates of cirrus +above and beneath cumulus—various kinds of cirrus clouds, and that +peculiar prismatic haze<span class="pagenum" title="Page 98"> </span><a name="Page_98" id="Page_98"></a> which is a common sign of the passage of a +vortex. The appearance depicted above is a very common, although a very +evanescent appearance. When the sky appears of a clear blue through the +cirri, there will be generally fresh gales without any great electrical +derangement; but if the clear spaces are hazy, gradually thickening +towards the nucleus, a storm may be expected. Any one who wishes to +understand the indications of the clouds, must watch them closely for +many years, before he can place much reliance upon them. But we shall +again advert to this point.</p> + +<p>We have now passed through one sidereal period of the moon. We might +continue the record, but it would be tedious.<span class="pagenum" title="Page 99"> </span><a name="Page_99" id="Page_99"></a> The passages of these +vortices vary in violence at different times, as we might expect; but +they never cease to circulate, and never will as long as the moon +remains a satellite to the earth; and if we take the passage of any of +these vortices, and add thereto the time of one sidereal period of the +moon, we get approximately the time of the next passage. When the +elements of the lunar orbit tend to accelerate the passages, they may +come in 26 days; and when to retard, in 28 days; and these are about the +limits of the theory.</p> + +<p>Having begun and ended this record of the weather with the passage of +the Inner vortex ascending, it may not be amiss to notice one more, (the +August passage,) as it offers a peculiarity not often so distinctly +marked. We have alluded to the greater force of the storms when the +passage of the vortex corresponds to the passage of the line of low +barometer or the depression point of a great atmospheric wave, which is +also due to the action of the ether. In consequence of these waves +passing from west to east, the storm will only be violent when formed a +little to the westward. If the storm forms to the eastward, we neither +see it nor feel it, as it requires time to develop its strength, and +always in this latitude travels eastward; so that storms may generally +be said to come from the west, although the exciting cause travels from +east to west. In the case now alluded to, the weather indicated a high +barometer, and the storm formed immediately to the eastward, even +showing a distinct circular outline. We subjoin a description.</p> + +<p><i>August</i> 15th. Clear morning (N.-E.), a bank of cumuli in south: noon +quite cloudy in S. and clear in north. (N.-E.)</p> + +<p>16th. Clear morning (N.-E.); 3 <span class="time">P. M.</span>, getting very black in E. and S.-E., +very <i>clear</i> to the <i>westward</i>; 4 <span class="time">P. M.</span>, much thunder and lightning in +east, and evidently raining hard; 5 <span class="time">P. M.</span>, a violent squall from <i>east</i> +for 10 minutes; tore up several trees; 6 <span class="time">P. M.</span>, the storm passing +eastward, clear in west all this time; 6.30 <span class="time">P. M.</span>, the storm forming a +regular arch, the<span class="pagenum" title="Page 100"> </span><a name="Page_100" id="Page_100"></a> vertex being in <i>S.-E.</i>; the arch of hazy cirrus and +heavy cumulus much lower in S.-E., wind still moderate from east; +10 <span class="time">P. M.</span>, clear all around, but lightning in S.-E. and E.</p> + +<p>17th. Fine clear morning (W.); noon, scattered cumuli in north; 6 <span class="time">P. M.</span>, +a beautifully regular arch of dense cumuli and cirrus margin in <i>N.-E.</i>, +with a constant glimmer of lightning; 7 <span class="time">P. M.</span>, very clear to the west, +and north-west, and south; along the northern horizon a line of high +peaked cumuli terminating in N.-N.-W.; a continued roll of distant +thunder in the circular bank in N.-E., and not a moment’s cessation to +the lightning; the electric excitement advancing westward along the +lines of cumuli; the cirrus haze also rising and passing towards S.-W.; +8 <span class="time">P. M.</span>, the sky alive with lightning, the cirrus now reaches the zenith; +no streaks of lightning coming to the earth; they seem to radiate from +the heaviest mass of cumuli, and spread slowly (sufficiently so to +follow them) in innumerable fibres over the cloudy cirrus portion of the +sky; every flash seems to originate in the same cloud; 8.30 <span class="time">P. M.</span>, one +branching flash covered the whole north-eastern half of the sky, no +leafless tree of the forest could show so many branches; 9.30 <span class="time">P. M.</span>, all +passed to S.-W. without rain, leaving behind a large cumulus, as if it +lagged behind. From this cumulus a straight line of lightning shot up +10° above the cloud into a perfectly clear sky, and terminated abruptly +without branching.</p> + +<p>We have been thus particular in giving these details, as this was a +clear case confirming the principles advanced, that the vortices do not +form a continuous line of disturbance, in their daily passage around the +earth. It shows also that the barometer, in connection with these +principles, will be a far more useful instrument than it has yet proved +itself, for practical service as an indicator of the weather.</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_10_10" id="Footnote_10_10"></a><a href="#FNanchor_10_10">[10]</a></span>For convenience to those wishing to verify the calculation +of these triangles, we have put down each side and angle as found. Also, +as an aid to the navigator.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_11_11" id="Footnote_11_11"></a><a href="#FNanchor_11_11">[11]</a></span>Daily Wisconsin, July 7.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_12_12" id="Footnote_12_12"></a><a href="#FNanchor_12_12">[12]</a></span>The author.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_13_13" id="Footnote_13_13"></a><a href="#FNanchor_13_13">[13]</a></span>Chicago Democrat.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_14_14" id="Footnote_14_14"></a><a href="#FNanchor_14_14">[14]</a></span>This was also calculated before the event.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_15_15" id="Footnote_15_15"></a><a href="#FNanchor_15_15">[15]</a></span>The letters in a parenthesis signify the direction of the +wind.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_16_16" id="Footnote_16_16"></a><a href="#FNanchor_16_16">[16]</a></span>Giving this cloud the average velocity of thirty miles per +hour, its altitude was determined by the sextant at twelve miles, and we +think under-estimated. While measuring, the author’s attention was drawn +to the fact, that although it appeared equally dense above and below, +yet its middle part was the brightest, and as there was only a faint +glimmer of twilight in the N.-W., he concluded that the cloud was +self-luminous; for when the smallest stars were visible, it glowed about +as bright as the milky-way in Sagittarius. Occasionally the whole cloud +was lit up internally by the lightning, and about this time it sent off +three rays: one horizontally, westward, which was the faintest; one +about N.-W., towards Jupiter, and the brightest of the three; and +another towards the north. These were not cirrus streaks, but veritable +streams of electric matter, and had a very decided rotation from left to +right, and continued visible about twenty minutes, as represented +above.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_17_17" id="Footnote_17_17"></a><a href="#FNanchor_17_17">[17]</a></span>This day the central vortex passed in about latitude 47° N.—the southern margin cannot be nearer than 250 miles, throwing off +the 40′ for the horizontal refraction, would give eight miles of +altitude above a tangential plane. Then another seven miles, for +curvature, will give an altitude of fifteen miles for the cumuli. The +height of these thunder-clouds has been much under-estimated. They seem +to rise in unbroken folds to a height of ten and twelve miles +frequently; from the data afforded by the theory, we believe they will +be found much higher sometimes—even as much as sixteen miles.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_18_18" id="Footnote_18_18"></a><a href="#FNanchor_18_18">[18]</a></span>These parallel bands, and bands lying east and west, are +frequent in fine weather between two vortices. Sailors consider them a +sign of settled weather. After dark there was frequently seen along the +northern horizon flashes of lightning in a perfectly clear sky. But they +were both faint and low, not reaching more than 4° or 5° above the +horizon. After sunset there were very distinct rays proceeding from the +sun, but they were shorter than on the evening of the 3d. These are +caused by the tops of the great cumuli of the storm, when sunk below the +horizon, intercepting the sun’s rays, which still shine on the upper +atmosphere. The gradation was very marked, and accorded with the +different distances of the central vortex on the 3d and 4th—although, +on the 4th, the nearest distance must have been over four hundred miles +to the southern boundary of the storm.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_19_19" id="Footnote_19_19"></a><a href="#FNanchor_19_19">[19]</a></span>It is worthy of notice here, that New York, which only +differs by about 40 miles of latitude and 800 in longitude, had the +storm earlier, near the time of the passage, as appears by the appended +account of it. This proves, that a storm affects a particular latitude +simultaneously, or approximately so. If this had to travel eastward to +reach New York, it would have been the 10th instead of the 8th. The +principal trouble was, however, in the early part of the evening of the +8th, to the south of Ottawa, where the strong wind was drawn in from the +northward. If a vortex passes from north to south, leaving the observer +between the passages, there must, nearly always, be a winding up squall +from the north to clear away the vapory atmosphere.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_20_20" id="Footnote_20_20"></a><a href="#FNanchor_20_20">[20]</a></span>From the <i>New York Tribune</i>, July 9, 1853.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_21_21" id="Footnote_21_21"></a><a href="#FNanchor_21_21">[21]</a></span>These pages are now in the compositors’ hands, (Nov. +21st,) and up to the last moment the Author has observed carefully in +New York the passages of these vortices. October 24th, in the inner +vortex descending produced a violent storm on the coast, and much damage +ensued. November 7th, the same vortex ascending was also severe. And on +November 13th, early, the passage of the central vortex ascending, +caused a flood in Connecticut of a very disastrous nature. Would it not +pay the insurance offices to patronize such investigations in view of +such palpable facts as these?</p></div> +</div> + + +<hr style="width: 65%;" /> +<h2><span class="pagenum" title="Page 101"> </span><a name="Page_101" id="Page_101"></a><a name="SECTION_THIRD" id="SECTION_THIRD"></a>SECTION THIRD.</h2> + + +<h3>OBJECTIONS TO LUNAR INFLUENCE.</h3> + +<p>We have now presented a theory of the weather, which accounts for many +prominent phenomena, a few of which we shall enumerate. It is an +observed fact, that in all great storms electrical action is more or +less violent, and that without this element it seems impossible to +explain the velocity of the wind in the tornado, its limited track, and +the formation of large masses of ice or hail in the upper regions of the +atmosphere. It is also an observed fact, that the barometer is in +continued motion, which can only be legitimately referred to a change in +the weight of the atmospheric column. This we have explained as due to +atmospheric waves, caused by the greater velocity of rotation of the +external ether, as well as to the action of the three great vortices. +These causes, however, only partially produce the effect—the greater +portion of the daily oscillations is produced by the action of the great +radial stream of the solar vortex, as we shall presently explain. It is +an observed fact, that, although the storm is frequently violent, +according to the depression of the barometer, it is not always so. +According to the theory, the storm will be violent, <i>ceteris paribus</i>, +on a line of low barometer, but may still be violent, when the contrary +obtains. Another fact <ins class="correction" title="Transcriber’s note: Original reads ‘in’.">is</ins> the disturbance of the magnetic needle during a +storm. Storms are also preceded generally by a rise in the thermometer, +and succeeded by a fall; also by a fall in the<span class="pagenum" title="Page 102"> </span><a name="Page_102" id="Page_102"></a> barometer, and succeded +by a rise. It is also well known, that hurricanes are unknown at the +equator, and probably at the poles also. At all events, they are rare in +lat. 80°, and, according to Capt. Scoresby, storms are there frequently +raging to the south, while above, there is clear sky and fine weather, +with a stiff breeze from the northward. The greater violence of storms +in those regions where the magnetic intensity is greater in the same +latitude, the probable connection of peculiarities in the electric state +of the atmosphere with earthquakes, and the indications of the latter +afforded by the magnet; the preponderance of westerly winds at a great +elevation in every latitude on the globe visited by man; and the +frequent superposition of warm layers of air above cold ones at those +elevations, are all facts worthy of note. And the connection of cirrus +clouds with storms, as well as with the aurora, indicates that the +producing cause is external to the atmosphere, and gradually penetrates +below. The theory fully explains this, and is confirmed by the fantastic +wreathings and rapid formation of these clouds in straight lines of a +hundred miles and upwards. But time would fail us in pointing out a +tithe of the phenomena, traceable to the same cause, which keeps our +atmosphere in a perpetual state of change, and we shall only advert to +one more peculiarity of the theory. It places meteorology on a +mathematical basis, and explains why it is that a storm may be raging at +one place, while in another, not very remote, the weather may be fine, +and yet be dependent on the position of the moon.</p> + +<p>That the moon has exerted an influence on the weather has been the +popular creed from time immemorial; but, ignorant of the mode in which +this influence was exerted, men have often been found who have fostered +the popular belief for their own vanity or advantage; and, on the other +hand, philosophers have assailed it more by ridicule than by argument, +as a relic of a barbarian age. Not so with all; for we believe we are +not wrong in stating, that the celebrated Olbers compared the<span class="pagenum" title="Page 103"> </span><a name="Page_103" id="Page_103"></a> moon’s +positions with the weather for fifty years, before he gave his verdict +against it. He found the average amount of rain at the perigee about +equal to the amount at the apogee, as much at the full as at the change, +and no difference at the quadratures. But this fact does not throw a +feather in the scale by which this theory is weighed. Popular opinions, +of remote origin, have almost always some foundation in fact, and it is +not much more wise to reject them, than to receive them. The Baron Von +Humboldt—a man possessing that rare ingredient of learning, a practical +common sense—observes: “That arrogant spirit of incredulity which +rejects facts, without attempting to investigate them, is, in some +cases, more injurious than an unquestioning credulity.”<a name="FNanchor_22_22" id="FNanchor_22_22"></a><a href="#Footnote_22_22" class="fnanchor">[22]</a> If a popular +belief or prejudice be absurd, its traditional preservation for a +thousand years or more may very well account for the absurdity.</p> + +<p>The present system of astronomy still retains the motley garniture of +the celestial sphere, as handed down from the most remote antiquity; and +granting that ages of ignorance and superstition have involved the +history of the different constellations in a chaos of contradictory +traditions, there is no doubt at the foundation some seeds of truth +which may even yet emerge from the rubbish of fable, and bear fruit most +precious. That the zodial<a name="FNanchor_23_23" id="FNanchor_23_23"></a><a href="#Footnote_23_23" class="fnanchor">[23]</a> signs are significant records of something +worthy of being preserved, is prejudice to deny; and we must be allowed +to regard the Gorgons and Hydras of the skies as interesting problems +yet unsolved, as well as to consider that the belief in lunar influence +is a fragment of a true system of natural philosophy which has become +more and more debased in postdiluvian times. Amongst those who have not +summarily ignored the influence of the moon, is Toaldo, a Spanish +physicist, who endeavored to show the connection<span class="pagenum" title="Page 104"> </span><a name="Page_104" id="Page_104"></a> between the recurrence +of warm and cold seasons, and the semi-revolution of the lunar nodes and +apogee, and proposed six of those periods, or about fifty-four years, as +the cycle in which the changes of the weather would run through their +course. According to the present theory, it is not likely such a cycle +will ever be discovered. There are too many secular, as well as periodic +influences combining, to produce the effect; and the times are too +incommensurable. Lately, Mr. Glaisher has presented a paper to the Royal +Society, giving about fourteen years from observation. Others have +lately attempted to connect the changes of the seasons with the solar +spots, as well as with the variations of the magnetism of the earth, but +without any marked result.</p> + +<p>It may, however, be urged, that if the sidereal period of the moon be +approximately a cycle of change, it would have been detected long ago. +One reason why this has been so long concealed, is the high latitude of +the observers. Spain, Italy, and Turkey, are better situated than other +European countries; but the scientific nations lie further north; and +from these the law has gone forth to regulate more southern lands. In +the United States, particularly in the great plains of the west, the +weather can be better compared; not only on account of the latitude +being more favorable, but also on account of the greater magnetic +intensity of the western hemisphere.</p> + +<p>It must also be remembered that there are in latitude 40°, five or six +distinct passages of the disturbing cause in one sidereal period of the +moon. If two of these periods are drawn closer together by the change of +the elements, the interval between two others must necessarily be +increased. Besides, the effect produced is not always the same, for +reasons already adverted to. One vortex may be more violent one month, +or for a few days in one month, while another may be more active the +next. It may also happen that for several successive passages, the +passage shall be central in one latitude, while two or three<span class="pagenum" title="Page 105"> </span><a name="Page_105" id="Page_105"></a> degrees +north or south, another place shall be passed by. In different months +and in different years, as well as in different seasons of the year, the +energy of the ether may be augmented or diminished. But it may be said, +that, supposing the theory true, if its indications are so uncertain, it +is of little value. By no means. It is true there are many things to be +inquired into; but it is a great thing in this science to be able to +take the first step in the right direction,—to find even the <i>key</i> of +the portal. It is a great stride to be able to say, a storm may happen +at such a time, but cannot happen at another; that a storm, when raging, +will go in this direction, rather than in that; that it will be central +here, and less violent yonder; and when we consider its bearing on +astronomical and other science, it is difficult to exaggerate its value +to the world at large.</p> + +<p>Again, it may be said that rain, and cloudy days, and fresh breezes, and +even strong winds, sometimes occur, when the vortices do not pass +centrally. This is true; yet only indicating that where the vortices are +central, an unusual disturbance is taking place. But there is another +cause, which was purposely omitted in considering the prominent features +of the theory, in order not to encumber the question with secondary +influences. By referring to <a href="#fig03">Fig. 3</a>, <a href="#SECTION_FIRST">section 1</a>, we see that the lateral +vortices of the globe are continually passing off to the southward, in +the northern hemisphere, in a succession of dimples, and continually +reforming. We will now represent this mode of action in profile, as it +actually occurs in the illustration we have used.</p> + +<p>The vortex passing off from O, (<a href="#fig20">Fig. 20</a>,) although it does not actually +reach the surface of the atmosphere, affects the equilibrium of the +ether, and, for a short distance from the parent vortex, may cause an +ascensional movement of the air. If to this is conjoined a northerly +wind from the vortex, a band of clouds will be produced, and perhaps +rain; but violent storms never occur in the intervals, except as a +steady gale, caused by the violence of a distant storm. Thus, it will +frequently be noticed that<span class="pagenum" title="Page 106"> </span><a name="Page_106" id="Page_106"></a> these vortices are flanked by bands of +clouds, which pass southward, although the individual clouds may be +moving eastward. Hence, instead of disproving the theory, they offer +strong evidence of its truth; and could we view the earth from the moon +with a telescope, we should no doubt see her beautifully belted.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig20" id="fig20"></a> +<img src="images/fig20.png" width="350" height="204" alt="Fig. 20" title="" /> +</div> + +<p>But it may be again asked, why should not the weather be the same +generally, in the same latitude, if this theory be true? If the earth +were a globe of level land, or altogether of water, no doubt it would be +similar; but it must be remembered, that both land and water are very +unequally distributed: that the land is of varying extent and +elevation—here a vast plain, far removed from the ocean, and there a +mountain chain, interposing a barrier to the free course of the +atmospheric currents; sometimes penetrating in full width into the +frigid zone, and again dwindling to a few miles under the equator. One +very important distinction is also to be remarked, in the superficial +area of the different zones, reckoning from the equator, and taking the +hemisphere as 100 parts:</p> + +<table summary="Relative areas of different zones of the earth."> +<tr> + <td>Frigid</td> + <td class="tdc">zone</td> + <td class="tdr0" style="padding-left:3em;">8</td> + <td>parts.</td> +</tr> +<tr> + <td>Temperate</td> + <td class="tdc">"</td> + <td class="tdr0">52</td> + <td class="tdc">"</td></tr> +<tr> + <td>Torrid</td> + <td class="tdc">"</td> + <td class="tdr0">40</td> + <td class="tdc">"</td> +</tr> +</table> + +<p><span class="pagenum" title="Page 107"> </span><a name="Page_107" id="Page_107"></a>For as the time of rotation in every latitude is the same, the area to +be disturbed in the same time, is less in high latitudes, and there a +greater similarity will obtain, <i>ceteris paribus</i>. In lower latitudes, +where both land and water stretch away for thousands of miles, it is not +wonderful that great differences should exist in the electrical and +hygrometric state of the air.</p> + +<p>The summer of many countries is always dry—California for instance. In +winter, in the same country, the rains are apparently incessant. This of +course depends on the power of the sun, in diverting the great annual +currents of the atmosphere. As long as the dry north-west trade sets +down the coast of California, the circumstances are not favorable for +giving full development to the action of the vortices. When the trade +wind ceases, and the prevailing winds come from the south, loaded with +vapor, the vortices produce storms of any magnitude; but (and we speak +from two years’ observation) the passages of the vortices are as +distinctly marked there in winter time, as they are in the eastern +States; and in summer time, also, they are very perceptible. The same +remark applies to Mediterranean countries, particularly to Syria and +Asia Minor; although the author’s opportunity for observing lasted only +from April to December, during one season. If we are told it never rains +on the coast of Peru, or in Upper Egypt, it does not seriously militate +against the theory. The cause is local, and the Samiel and the sand +storm of the desert, is but another phase of the question, explicable on +the same general principles. From the preceding remarks it will be seen, +that in order to foretell the character of particular days, a previous +knowledge of the weather at that particular place, and for some +considerable time, is requisite; and hence the difficulty of laying down +general rules, until the theory is more fully understood.</p> + + +<h3><span class="pagenum" title="Page 108"> </span><a name="Page_108" id="Page_108"></a>MODIFYING CAUSES.</h3> + +<p>We now come to the causes which are auxiliary and interfering. It is +natural that we should regard the sun as the first and most influential +of these causes, as being the source of that variation in the +temperature of the globe, which alternately clothes the colder regions +in snow and verdure. The heat of the sun undoubtedly causes the ether of +the lower atmosphere to ascend, not by diminution of its specific +gravity; for it has no ponderosity; but precisely by increase of +tension, due to increase of motion. This aids the ascensional movement +of the air, and therefore, when a vortex is in conjunction with the sun, +its action is increased—the greatest effect being produced when the +vortex comes to the meridian a little before the sun. This has a +tendency to make the period of action to appear dependent on the phases +of the moon, which being the most palpable of all the moon’s variations, +has been naturally regarded by mankind as the true <i>cause</i> of the +changes of the weather. Thus Virgil in his Georgics, speaking of the +moon’s influence and its signs:</p> + +<blockquote> +<p class="hang">“Sin ortu in quarto (Namque is certissimus auctor)<br /> +Pura, nec obtusis per cœlum cornibus ibit;<br /> +Totus et ille dies, et qui nascentur ab illo,<br /> +Exactum ad mensem, pluviâ ventisque carebunt.”</p> +</blockquote> + +<p>Hence, also, in the present day we hear sailors speak of the full and +change, or the quartering of the moon, in connection with a gale at sea; +thus showing, at least, their faith in the influence of the phenomenon. +Yet it is actually the case, at certain times, that in about latitude +40° and 41°, the storms appear about a week apart.</p> + +<p>There is some reason, also, to suspect, that there is a difference of +temperature on opposite sides of the sun. As the synodical rotation is +nearly identical with the siderent period of the moon, this would +require about forty-four years to run its<span class="pagenum" title="Page 109"> </span><a name="Page_109" id="Page_109"></a> course, so as to bring the +phenomena to exact coincidence again. Since these observations were +made, it is understood that Sig. Secchi has determined that the +equatorial regions of the sun are hotter than his polar regions. It may +be owing to this fact, that we have inferred a necessity for a change, +whose period is a multiple of the sun’s synodical rotation, but it is +worthy of examination by those who possess the necessary conveniences.</p> + +<p>Another period which must influence the character of different years, +depends on the conjunction of the perigee of the lunar orbit with the +node. Taking the mean direct motion of the moon’s perigee, and the mean +retrograde motion of the node, we find that it takes six years and one +day nearly from conjunction to conjunction. Now, from the principles +laid down, it follows, that when the perigee of the orbit is due north, +and the ascending node in Aries, that the vortices of the earth will +attain their greatest north latitude; and when these conditions are +reversed, the vortices will reach their highest limit in the lowest +latitude. This will materially affect the temperature of the polar +regions. In the following table, we have calculated the times of the +conjunctions of the apogee and pole of the orbit, taking the mean +motions. It may be convenient to refer to by-and-bye, remembering that +when the conjunction takes place due south, the vortices reach the +highest, but when due north, the vortices in the northern hemisphere +have their lowest upper limit:</p> + +<table summary="Times of the conjunctions of the apogee and pole of the orbit, from 1804 to 1876."> +<caption> + <span class="smcap">Conjunction of Apogee and Pole of + Orbit.</span><a name="FNanchor_24_24" id= + "FNanchor_24_24"></a><a href="#Footnote_24_24" class= + "fnanchor">[24]</a> +</caption> +<tr> + <th>Year.</th> + <th colspan="2">Month and Day.</th> + <th>Longitude.</th> +</tr> +<tr> + <td class="tdc">1804,</td> + <td class="tdl">April</td> + <td class="tdr">18th,</td> + <td class="tdr">220°</td> +</tr> +<tr> + <td class="tdc">1810,</td> + <td class="tdr0">" </td> + <td class="tdr">17th,</td> + <td class="tdr">104°</td> +</tr> +<tr> + <td class="tdc"><span class="pagenum" title="Page 110"> </span><a name="Page_110" id="Page_110"></a>1816,</td> + <td class="tdr0">" </td> + <td class="tdr">16th,</td> + <td class="tdr">348°</td> +</tr> +<tr> + <td class="tdc">1822,</td> + <td class="tdr0">" </td> + <td class="tdr">15th,</td> + <td class="tdr">232°</td> +</tr> +<tr> + <td class="tdc">1828,</td> + <td class="tdr0">" </td> + <td class="tdr">14th,</td> + <td class="tdr">116°</td> +</tr> +<tr> + <td class="tdc">1834,</td> + <td class="tdr0">" </td> + <td class="tdr">12th,</td> + <td class="tdr">360°</td> +</tr> +<tr> + <td class="tdc">1840,</td> + <td class="tdr0">" </td> + <td class="tdr">11th,</td> + <td class="tdr">244°</td> +</tr> +<tr> + <td class="tdc">1846,</td> + <td class="tdr0">" </td> + <td class="tdr">10th,</td> + <td class="tdr">128°</td> +</tr> +<tr> + <td class="tdc">1852,</td> + <td class="tdr0">" </td> + <td class="tdr">9th,</td> + <td class="tdr">12°</td> +</tr> +<tr> + <td class="tdc">1858,</td> + <td class="tdr0">" </td> + <td class="tdr">8th,</td> + <td class="tdr">255°</td> +</tr> +<tr> + <td class="tdc">1864,</td> + <td class="tdr0">" </td> + <td class="tdr">7th,</td> + <td class="tdr">139°</td> +</tr> +<tr> + <td class="tdc">1870,</td> + <td class="tdr0">" </td> + <td class="tdr">6th,</td> + <td class="tdr">23°</td> +</tr> +<tr> + <td class="tdc">1876,</td> + <td class="tdr0">" </td> + <td class="tdr">5th,</td> + <td class="tdr">267°</td> +</tr> +</table> + +<p>By this we see that the vortices have never attained their highest limit +during the present century, but that in 1858 their range will be in a +tolerable high latitude, and still higher in 1876—neglecting the +eccentricity of the orbit.</p> + +<p>A very potent influence is also due to the heliocentric longitude of the +sun, in determining the character of any given year. Let us explain:</p> + +<p>The moon’s inertia forces the earth from the mechanical centre of the +terral system, but is never able to force her clear from the central +axis. With the sun it is different. He possesses many satellites +(planets). Jupiter alone, from his great mass and distance, is able to +displace the whole body of the sun. If other planets conspire at the +same side, the centre of the sun may be displaced a million of miles +from the mechanical centre of the solar system. Considering this centre, +therefore, as the centre of an imaginary sun, from which heliocentric +longitudes are reckoned, the longitude of the real sun will vary with +the positions of the great planets of the system. Now, although this +<i>systematic</i> longitude will not be exactly similar to the heliocentric +longitude reckoned from the sun’s centre, yet, for the purposes +intended, it will correspond sufficiently, and we shall speak of the +longitude of the sun as if we reckoned<span class="pagenum" title="Page 111"> </span><a name="Page_111" id="Page_111"></a> heliocentric longitudes from the +mechanical centre of the system. When we come to consider the solar +spots, we shall enter into this more fully. In the following diagram we +shall be able to perceive a cause for variation of seasons in a given +year, as well as for the general character of that year.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig21" id="fig21"></a> +<img src="images/fig21.png" width="350" height="193" alt="Fig. 21" title="" /> +</div> + +<p>Let S represent the centre of the sun, and the circle a vertical section +of the sun, cutting; through the centre,—SJ being in the equatorial +plane of the vortex, of which ZZ′ represents the axis. As the ether +descends the poles or axis at Z, it is met by the current down the +opposite pole, and is thence deflected in radii along the equatorial +plane to J. But on the side S, the ether is opposed by the body of the +sun; its direction is consequently changed, and cross currents are +produced, assuming it as a principle, that the ethereal fluid is +permeable by other currents of similar matter, and that it tends always +to move in right lines. This granted, it is evident that, in passing the +sun, the quick moving ether forms a conical shell, (the sun being at the +apex,) so that the strongest current of ether is in this conical shell, +or at the surface of this conical space. As the plane of the ecliptic is +not much inclined to the sun’s equator, and this last probably not much +inclined to the plane of the vortex, should the earth have the same +<i>heliocentric</i> longitude<span class="pagenum" title="Page 112"> </span><a name="Page_112" id="Page_112"></a> at the time, (or nearly the same,) she would +be in an eddy, as respects the radial stream, and be protected from its +full force by the body of the sun.</p> + +<p>Now, the ether comes down the axis with the temperature of space, and +may possibly derive a <i>little</i> additional temperature in passing over +the body of the sun; so that in this position the earth is protected +from the chilling influence of the radial stream, by being protected by +the body of the sun. And although, from the immense velocity of the +ether, it cannot derive much additional temperature, there may still be +an appreciable difference, due to this cause.</p> + +<p>It is the chilling influence of the ethereal stream which originated the +idea among philosophers, of <i>frigorific impressions, darted from a clear +sky</i>. In some years the sun will be nearly in the centre of the system; +in other years the axis of the vortex will not come near the sun. And as +the sun’s longitude may vary through the entire circle, it may happen +that the earth’s longitude shall coincide in winter or summer, or spring +or autumn. When, however, the earth emerges from the protection of the +sun, and enters the conical shell, considered as a space of considerable +depth, she will again be exposed to the full force of the radial stream, +rendered more active by the previous deflection, and by the numerous +cross currents pervading it; so that a mild and calm winter may be +succeeded by a cold and stormy spring. The present season, (1853) the +earth’s longitude coincided with the sun’s longitude in about 135°, and +consequently was in the conical space spoken of, during February and +March; but the radius <ins class="correction" title="Transcriber’s note: Original reads ‘rector’.">vector</ins> of the sun’s centre, being then less +than 300,000 miles, the protection was not as complete as it is +sometimes. Still, the general fineness of these months was remarkable; +yet in April and May, when the earth became again exposed to the action +of the solar stream, the effect was to retard the spring, and disappoint +the prognostications of the weather-wise. In applying these principles, +we<span class="pagenum" title="Page 113"> </span><a name="Page_113" id="Page_113"></a> must consider the effect in those latitudes which are more readily +affected,—that is, in the temperate zone, midway between the two +extreme zones of heat and cold.</p> + +<p>In 1837 and 1838, the longitude of the sun’s centre corresponded with +the earth’s, in August and September, when there was neither rain nor +electrical excitement; and consequently those seasons were sickly over +the whole country. Now, there is another cause which renders the months +of August, September, and October, deficient in electrical energy, and +consequently more prone to be sickly. If, therefore, the two causes +unite their influence, the autumnal months will be more sickly at those +times. This last cause, however, only affects the <i>northern latitudes</i> +in autumn, and consequently, <i>ceteris paribus</i>, the autumnal months +should not be so proverbially sickly in the southern hemisphere. This +is, however, only suggestive.</p> + +<p>Again, in 1843, the winter was very mild in January and February; but in +March it turned cold and stormy, and continued through April. In this +year the longitude of the sun was nearly the same as in 1853,—the two +longitudes of the earth and sun corresponding about the last of January; +but in March, the earth forsook the comparative calm produced by the +sun’s position, and hence the greater cold.<a name="FNanchor_25_25" id="FNanchor_25_25"></a><a href="#Footnote_25_25" class="fnanchor">[25]</a></p> + +<p>Thus it appears at every step we take, that the different members of the +solar system do indeed belong to the same family, whose least motions +have their influence on the rest. Who could have anticipated that the +position of Jupiter in his orbit had anything to do with the health of +this remote planet, or with the mildness of its seasons? In this we have +a clue to the origin of that astrological jargon about planetary aspects +being propitious or malign. Philosophers are even yet too prone to wrap +themselves in their mantle of academic lore, and despise the knowledge +of the ancients, while there is reason to<span class="pagenum" title="Page 114"> </span><a name="Page_114" id="Page_114"></a> believe that the world once +possessed a true insight into the structure of the solar system. As war +became the occupation of mankind, under the despotic rule of ambition, +so truth retired, and ignorance seizing upon her treasures, has so +mutilated and defaced them, that their original beauty no longer +appears. Let us hope that the dawn of a better day is approaching.</p> + +<p>There is yet another cause (just alluded to) which modifies the action +of the vortices.</p> + +<p>We have shown that, if the periodic times of the planets are +approximately equal to the periodic times of the contiguous parts of the +solar vortex, the density of the ether is directly as the square roots +of the distances from the centre. As the earth is at her perihelion +about the first of January, the density of the surrounding ether is then +less than in other parts of the orbit; consequently, if we suppose that +there is a continual tendency to equilibrium, the ether of space must +press inwards, during the time between the perihelion and aphelion, +(<i>i.e.</i> from January to July,) lowering the temperature and increasing +the electrical action of those months. As the distance from the sun is +most rapidly augmenting about the first of April, and the effective +power of the sun’s radiation is most rapidly increasing in May; by +combining the two we shall find, that about the first of May we shall +have considerable electrical action, and cold weather. This explains +also, in part, the prevalent tradition of certain days in May being very +cold.<a name="FNanchor_26_26" id="FNanchor_26_26"></a><a href="#Footnote_26_26" class="fnanchor">[26]</a> When the earth leaves the aphelion, a reaction takes place, +being most rapid in September. There is then an <i>escape</i> of ether from +the earth, which keeps up the temperature, and causes these months to be +sickly, from the negative electrical state of the atmosphere. In the +southern hemisphere, the effects in the same season will<span class="pagenum" title="Page 115"> </span><a name="Page_115" id="Page_115"></a> be reversed, +which may partly account for the greater degree of cold in that +hemisphere, and for accelerating the approach of both summer and winter, +while in the north they were both retarded.</p> + +<p>We must now advert to another cause, which of all others is probably the +most important, at least to the other members of the solar system.</p> + +<p>In every part of the solar vortex the ether is continually pressing +outwards. We are not now speaking of the radial stream, but of the +slower spiral motion of the ether around the axis of the vortex, whose +centrifugal force is bearing the whole body of the ether outwards, thus +rarefying the central parts, and thus giving rise to the polar influx, +from which arises the radial stream. This may be made more intelligible, +by reflecting that the polar current is comparatively dense ether, and +that the length of the axis of the vortex prevents this influx current +coming in sufficient quantities to restore an equilibrium in the density +of the medium. Yet, what does come down the poles, is distributed +rapidly along the equatorial plane, leaving the space still rarefied. +Now we perceive, that in order for the radial stream to continue in +action, requires the whole medium of the vortex to be also moving +outward; it is therefore continually condensed as it proceeds. This +condensation necessarily converts much of the specific heat of the ether +into sensible heat; so that the <i>temperature</i> of the medium is +continually increasing, as the distance from the sun increases.</p> + +<p>When we contemplate the solar system as the emanation of one Great Mind, +we naturally seek for evidence of the wisdom of a supreme intelligence +in <i>all</i> the arrangements of that system. But, however humbly and +reverently we may speak of these arrangements, we can scarcely avoid the +wish, that the planetary distances had been differently arranged, if +Newton’s doctrine be true, that space is a vacuum, and that the heat of +a planet, is inversely as the squares of the distances from the sun.<span class="pagenum" title="Page 116"> </span><a name="Page_116" id="Page_116"></a> +For, to speak of the temperature of space, except as dependent on this +law, is one of those many incomprehensible inconsistencies with which +philosophers are chargeable. If the Newtonian philosophy is literally +true, space has <i>no temperature</i>, and the surface heat of the planet +Neptune is nearly 1,000 times less than on our own globe. Again, on +Mercury it is seven times greater, which heat would scorch and consume +every organic substance on the earth, and speedily envelope the boiling +ocean in a shroud of impermeable vapor. Granting even that space may not +be a vacuum, and yet the law of gravitation be true, we may still be +allowed to consider both Saturn and Uranus and Neptune, as inhospitable +abodes for intelligent creatures; and, seeing the immensity of room in +the system, there is no reason why these planets might not have been +permitted to revolve nearer the great source of light and life and +cheering emanations. To suggest the resources of Omnipotence is no +argument. He has surrounded us with analogies which are seen, by which +we may attain a knowledge of those which are not seen; and we have every +reason to suppose that the great Author of nature is not indifferent to +the aspects under which his works reveal him unto his creatures. Yet +there is (on the above hypothesis) an apparent want of harmony in the +planetary distances; and if frail mortality may be permitted to speak +out, an explanation is needed to obviate this seeming anomaly in the +economy of the world. The more we learn of the physical arrangements of +the universe, the more do they correspond with our experience of the +nice adaptation of the means to the end which obtains in our own globe, +and we can only judge of other planets by the analogies around us. Here, +there, are extremes of temperature it is true: it is necessary there +should be, and we can see and understand the necessity in all such +cases, and how they conduce to the general average of good. But, +astronomers can give no reason why it is necessary that some planets of +our system should be placed so<span class="pagenum" title="Page 117"> </span><a name="Page_117" id="Page_117"></a> remote that the sun is frittered down to +a star, whose heatless light is but a mockery to those frigid realms.</p> + +<p>Now, according to this theory, the temperature of Neptune may be far +more uniform and conducive to life than that of our own globe. The +chilling influence of the solar stream at that planet being nearly null, +and the temperature of the surrounding space far greater. So also +Mercury, instead of being the burning planet of the schools, may suffer +the most from cold.</p> + +<p>The planet Mars is generally considered, of all the members of the +system, most nearly to resemble our own world. The telescope not only +reveals seas and continents, but the snowy circles round his poles, +which appear to increase and diminish, as his winter is beginning or +ending. This planet’s ecliptic is similar to our own in inclination or +obliquity, his distance, also, is far greater, and his winter longer; +yet, for all this, his snow zones are less than on our own globe. This +anomalous fact has, we believe, never been noticed before; but it is +explicable on the theory, and therefore confirms it. Mars has no +satellite, and therefore his centre will be coincident with the centre +of the marsial vortex. There will be no <i>lateral vortices</i> to derange +his atmosphere, and if the axis of his vortex coincides also with the +axis of the planet, the central vortex will be continually over the +poles, <i>and there will be no storms on the planet Mars</i>. A capital fact +connected with this, is the want of belts, as in Jupiter and Saturn; for +these planets have satellites, and if <i>they</i> are not massive enough, the +belts may be produced by an obliquity in the axis of the Jovial and +Saturnial vortices. If Mars had an aurora like the earth, it is fair to +presume the telescope would ere this have shown it. He is, therefore, in +equilibrium. In applying this reasoning to the earth, we perceive that a +certain influence is due to the difference of temperature of the +ethereal medium surrounding the earth, at perihelion and aphelion, being +least at the former, and greatest at the latter.</p> + +<p><span class="pagenum" title="Page 118"> </span><a name="Page_118" id="Page_118"></a>As a modifying and interfering cause in the action of the vortices, we +must mention the great natural currents of the atmosphere, due to the +earth’s rotation.</p> + +<p>It is considered that the sun is the principal cause of these great +currents. By elevating the surface atmosphere of the equator, a lateral +current is induced from the north and south; but on account of the +enlarging circles of latitude, their direction tends more from the +north-east and south-east. These currents are usually called the trades. +Without disputing the correctness of this, it may be doubted whether the +whole effect is due to the sun. As this principle affects the ocean +likewise, it is necessary to look into it; and in order to simplify the +question, we will first suppose our globe covered entirely by the ocean, +without any protuberant land.</p> + +<p>Let us assign a uniform depth of ten miles to this ocean. In the <a href="#fig22">Fig. +following</a>, the two circles will represent the surface and bottom of the +ocean respectively. The axis of rotation is thus represented by the line +PP′. Let us consider two particles of water at <i>m</i> and <i>n</i>, as feeling the +influence of this rotation; they will, of course, be both urged towards +the equator by the axifugal force. Now, every particle in the ocean +being also urged by the same force, it might be supposed that<span class="pagenum" title="Page 119"> </span><a name="Page_119" id="Page_119"></a> after a +protuberant mass of water had accumulated at the equator EE′, the whole +ocean would be in equilibrium. This would not follow. The particle at <i>m</i> is urged by a greater force than n; consequently the particle at <i>n</i> is +overborne by the pressure at <i>m</i>. Considering both in the same direction, +yet the particle at <i>n</i> must give way, and move in the opposite direction. +Just as the heaviest scale of the balance bears up the lightest, +although both gravitate towards the same point. This is so self-evident +that it would seem unnecessary to dwell upon it, had not the scientific +world decided that the rotation of the earth can cause no currents +either in the atmosphere or in the ocean.</p> + +<div class="figcenter" style="width: 300px;"> +<a name="fig22" id="fig22"></a> +<img src="images/fig22.png" width="300" height="229" alt="Fig. 22" title="" /> +</div> + +<p>The axifugal forces of the two particles <i>m</i> and <i>n</i> are directly as the +lines M<i>m</i> and N<i>n</i>, and if the gravitating forces were also as the radii T<i>m</i> +and T<i>n</i>, no motion would be produced. Admitting even the Newtonian law to +be rigidly exact, the earth cannot be considered a homogeneous globe, +but, on the contrary, the density of the central parts must be nearly +thirty times greater than the density of the surface of the ocean. The +ratio of the gravitating forces of these two particles is, therefore, +less than the ratio of their respective radii, and the axifugal tendency +of the particle at <i>n</i> is more than proportionally restrained by the +central gravitation; and hence <i>m</i> will move towards the equator, and <i>n</i> towards the poles, as represented in the <a href="#fig22">Fig</a>.</p> + +<p>It is on account of the overwhelming momentum of the surface waters of +the South Pacific over the North, that the Pacific, at Panama, stands +six or seven feet higher than the Atlantic. We shall again allude to +this interesting fact.</p> + +<p>According to newspaper reports of a lecture, delivered in New York, by +Lieut. Maury, U. S. N., this gentleman endeavors to explain the currents +of the ocean, by referring them to evaporation in the tropics. The vapor +leaves the salt of the water behind, and thus, by continual +accumulation, the specific gravity of the tropical waters is greater +than that of the superficial<span class="pagenum" title="Page 120"> </span><a name="Page_120" id="Page_120"></a> waters nearer the poles; the lighter +water, therefore, passes towards the equator, and the heavier water +below, towards the poles. If this be a correct statement of that +gentleman’s theory, fidelity to our standards compels us to question the +soundness of the conclusion. The mere fact of the surface water of the +ocean being lighter than that of the bottom, cannot on any known +principles of science cause any movement of the surface waters towards +the equator. When such an acute and practical physicist is driven, by +the palpability of the fact that the polar waters are continually +tending towards the equator, to seek the cause in the tropical +evaporation, it shows that the dogma, which teaches that rotation can +produce no motion, is unsound.</p> + +<p>Sir John Herschel, in speaking of the solar spots, says: “We may also +observe that the tranquillity of the sun’s polar, as compared with his +equatorial regions (if his spots be really atmospheric), cannot be +accounted for by its rotation on its axis only, but must arise from some +cause external to the sun, as we see the belts of Jupiter and Saturn and +our trade winds arise from a cause external to these planets combining +itself with their rotations, which <i>alone</i> (and he lays an emphasis on +the word) can produce no motions when once the form of equilibrium is +attained.”</p> + +<p>With respect to the origin of the solar spots, we have no disposition to +question the conclusion; but, as regards the <i>principle</i> laid down, that +rotation can produce no motions when once the form of equilibrium is +attained, we must unequivocally dispute it. If our atmosphere were of +uniform density, the rotation of the earth would cause no current such +as we have described; with our atmosphere as it is, the result will be +different. The momenta of two portions of matter are the products of +their inertiæ by their motions, and, in the present case, we must take +the inertiæ of equal spaces. A cubic inch of air at the surface, and at +three miles above the surface, is as 2 to 1; but their centrifugal +velocity varies only as the radii<span class="pagenum" title="Page 121"> </span><a name="Page_121" id="Page_121"></a> of the respective spheres, or as 1320 +to 1321. In the polar regions, therefore, the momentum of the surface +air preponderates, and, in this case, the <i>surface</i> current is towards +the equator, and the upper current towards the poles. When, however, the +centrifugal velocity is considerably increased in a lower latitude, and +the curvature of the surface becomes more and more inclined to the +direction of that resolved part of the centrifugal force, which is +always <i>from</i> the axis, the surface layers will evince a tendency to +leave the surface, and an intermingling will then take place in the +space between latitude 70° and 50°, or in latitude 60°. As this layer is +continually urged on in the same direction by the surface layer of +latitudes above 60°, the upper layer now becomes a current setting +<i>towards</i> the equator, and, consequently, the back current occupies the +surface. Now, considering that the rarefying action of the sun is +elevating the air under the equator, there must necessarily be an upper +current from the equator to the poles; so that if we conceive the two +currents to meet about latitude 30°, there will be a second +intermingling, and the current from the poles will again occupy the +surface. Thus, we regard a part of the effect of the trades to the +rotation of the earth, which is the chief impelling power at the poles, +as the sun is at the equator; and the latitudes 60° and 30° will be +marked by some especial phenomena of temperature, and other +meteorological features which do actually obtain. These would be much +more marked if the irregular configuration of land and sea, the +existence of mountain chains, and the different heating power of +different latitudes, owing to the unequal distribution of the land, did +not interfere; and the currents of the air (disregarding the deflection +east and west) might then be represented by a treble link or loop, whose +nodes would vary but little from latitudes 30° and 60°. As it is, it +has, no doubt, its influence, although unimportant, when compared with +the disturbing action of the ethereal vortices.</p> + +<p><span class="pagenum" title="Page 122"> </span><a name="Page_122" id="Page_122"></a>There is another phenomenon due to the action of the radial stream, +which has given much trouble to the physicist, and which has yet never +been explained. This is the horary oscillations of the atmospheric +pressure which, in some countries are so regular that the time of day +may be ascertained by the height of the barometer. According to +Humboldt, the regularity of the ebb and flow in the torrid regions of +America, is undisturbed by storms or earthquake. It is supposed that the +maxima occur at 9 <span class="time">A. M.</span> and 10 ½ <span class="time">P. M.</span>, and the minima at 4 <span class="time">A. M.</span> and +4 ¼ <span class="time">P. M.</span> From the morning minimum to the morning maximum is, +therefore, five hours; from the evening minimum to the evening maximum +is 6 ¼ hours; from the evening maximum to the morning minimum is 5 ½ +hours, and from the morning maximum to the evening minimum is 7 ¼ +hours. Again, these oscillations are greatest at the equator, and +diminish with the increase of latitude.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig23" id="fig23"></a> +<img src="images/fig23.png" width="350" height="193" alt="Fig. 23" title="" /> +</div> + +<p>If we suppose the earth’s axis perpendicular to the plane of the vortex, +and P the pole in the <a href="#fig23">above figure</a>, and SP the line joining the centre +of the earth and sun, M and <i>m</i> will represent the points in the earth’s +equator where it is midday and midnight respectively. The solar stream +penetrates the terral vortex; and strikes the earth’s atmosphere along +the lines par<span class="pagenum" title="Page 123"> </span><a name="Page_123" id="Page_123"></a>allel to SP. The direct effect would be to pile up the +atmosphere at N and n; and therefore, were the earth at rest, the +maximum would be at 6 <span class="time">A. M.</span> and 6 <span class="time">P. M.</span>, and the minimum at midday and +midnight; but the earth rotating from N towards M, carries along the +accumulated atmosphere, being more sluggish in its motions than the +producing cause, which cause is still exercised to force it back to N. +From this cause the maximum is now found at K. For a like reason the +minimum at M would be found at L, but on account of the motion of the +earth being now in the same direction as the solar stream, the minimum +is found still more in advance at k; so that, according to the theory, +the interval between the morning maximum and the evening maximum, should +be greater than the interval between the evening maximum and the morning +maximum; and so it is, the first being 13 ½ hours and the last 10 ½ +hours. The morning minimum should also be less marked than the evening +minimum, and this also is a fact. The effect also should be greater in +the tropics than in high latitudes, which again also obtains; being 1.32 +French lines at the equator, and only 0.18 at latitude 70°. Had the +earth no obliquity, the effect would be as the squares of the cosines of +the latitude; but the ratio is diminished by the inclination of the +axis. But there are other variations of the barometer of longer period, +apparently depending on the phases of the moon, but which cannot be +reconciled to the attracting power of the moon as an atmospheric tide; +and Arago concluded that they were due to some <i>special cause</i>, of which +the nature and mode of action are unknown. Perhaps this theory will +obviate the difficulty, as although the central vortex comes to the +meridian at the same time as the moon, its effect will be different on +the inferior meridian to what it is on the superior one; whereas the +moon’s attraction should be the same on both. That the passage of a +vortex over or near a particular place should affect the barometer, is +too obvious to need explanation, and therefore<span class="pagenum" title="Page 124"> </span><a name="Page_124" id="Page_124"></a> we may say that the +theory will explain all those varieties both small and great, which have +caused so much speculation for the last fifty years.</p> + + +<h3>TERRESTRIAL MAGNETISM.</h3> + +<p>In applying the theory to the magnetism of the earth, we must bear in +mind that the earth is probably magnetic by induction, and not in virtue +of its own specific action. The rotation of the surrounding ether, and +the consequent production of a radial stream, calls the ether into +motion within the earth’s interior, as well as on the surface; but it +does not follow that the ether shall also enter the earth at its poles +and escape at its equator, for the obliquity of the vortex would +interfere with this result. It is sufficient that this does occur in the +terral vortex immediately surrounding the earth. From late experiments +it is pretty well established that the axial direction of the needle, +(and of other bodies also,) is due to peculiar internal arrangement in +laminæ or layers, the existence of which is favorable to the passage of +the magnetic current.</p> + +<p>According to the experiments<a name="FNanchor_27_27" id="FNanchor_27_27"></a><a href="#Footnote_27_27" class="fnanchor">[27]</a> of Dr. Tyndal, it is found that the +magnetism of a body is strongest along the line of greatest density. As, +therefore, the laminæ of bodies may be considered planes of pressure, +when these planes are suspended horizontally, the directive force is +greatest, and the longest diameter of the body sets axial. On the other +hand, when the body was suspended so that the laminæ were vertical, the +longest diameter set equatorial. Now, we know that the crust of the +earth is composed of laminæ, just as the piece of shale in Doctor +Tyndal’s experiments, and that these layers are disposed horizontally. +And whatever force originally arranged the land and water on our globe, +it is evident that the continents are longest<span class="pagenum" title="Page 125"> </span><a name="Page_125" id="Page_125"></a> from north to south, and +therefore correspond to the natural direction of the magnetic force.</p> + +<p>In consequence of the intrinsic difficulties of this question, and the +mystery yet attaching to it, we may be permitted to enter a little more +minutely into it, and jointly consider other questions of interest, that +will enable us to refer the principal phenomena of terrestrial magnetism +to our theory.</p> + +<p>We have before adverted to the discrepancies in the earth’s compression, +as determined by the pendulum, and also to the uncertainty of the moon’s +mass, as deduced from the nutation of the earth’s axis. It is also +suspected that the southern hemisphere is more compressed than the +northern; and other phenomena also point out the inadequacy of the law +of gravitation, to account for the figure of the earth.</p> + +<p>From the invariability of the axis of rotation, we must conclude that +whatever form is the true form, it is one of equilibrium. In casting our +eyes over the map of the world, we perceive that the surface is very +unequally divided into land and sea; and that the land is very unequally +arranged, both north and south, and east and west. If we compare the +northern and southern hemisphere, we find the land to the water about 3 +to 1. If we take the Pacific portion, and consider the north end of New +Zealand as a centre, we can describe a great circle taking in one half +the globe, which shall not include one-tenth of the whole land. Yet the +average height of the remaining nine-tenths, above the level of the sea, +is nearly 1,000 feet. Call this nine-tenths nearly equal to one-fourth +of the whole surface, and the protuberant land in the hemisphere, +opposite the South Pacific, amounts to 1 ⁄ 30,000 part of the whole mass +of the earth, or about 1 ⁄ 700 of the mass of the moon. Again, the mean +density of the earth is about 5 ½—water being unity,—and the mean +density of the surface land is only about half this: but three-fourths +of the whole surface is water. Hence, we see that the materials of the +interior of the earth must be either<span class="pagenum" title="Page 126"> </span><a name="Page_126" id="Page_126"></a> metallic or very compressible. To +assign a metallic nucleus to the earth, is repugnant to analogy; and it +is not rendered even probable by facts, as we find volcanic emissions to +contain no heavier elements than the sedimentary layers. Besides, there +are indications of a gradual increase of density downwards, such as +would arise from the compressibility of the layers. Seeing, therefore, +the equilibrium of the whole mass, and the consequent hydrostatic +balance of the land in the sea,—seeing also the small compressibility +of the solid portions, and the great compressibility of the fluid, the +inference is legitimate that the whole is hydrostatically balanced, and +that our globe is a globe of water, with an intermediate shell of land, +specifically lighter than the fluid in which it is suspended. Where this +shell is of great thickness, it penetrates to greater depths, and +attains to greater elevations above the surface of the aqueous globe; +where it is less thick, it is found below the surface, and forms the +bottom of the upper ocean. Recent soundings give much greater depths to +some parts of the ocean, than the most elevated land upon the globe. +Captain Denham, of H. B. M. ship Herald, lately sounded in 37° south and +37° west, and found bottom at 7,706 fathoms, or about nine English +miles.</p> + +<p>As the interior portions of our globe are totally unknown, and the +compressibility of water is well established, it is just as sane to +consider water the most abundant element of nature, as solid land. The +great question to ask is, whether there may not be other phenomena +incompatible with this supposition? It is plain that the permanency of +terrestrial latitudes and longitudes would be unaffected by the +conditions we have supposed. Would the precession of the equinoxes be +also unaffected? Mr. Hopkins has entered into such an investigation, and +concludes: “Upon the whole, then, we may venture to assert that the +minimum thickness of the crust of the globe, which can be deemed +consistent with the observed amount of precession, cannot be less than +one-fourth or one-fifth of the radius of the<span class="pagenum" title="Page 127"> </span><a name="Page_127" id="Page_127"></a> earth.”These +investigations were made on the hypothesis of the interior fluidity +being caused by the fusion of the central portions of a solid globe; but +it is evident that the analytical result would be the same if these +central parts were water, inclosed by an irregularly-spherical shell of +land. Nor would the result be affected, if we considered certain +portions of the interior of this solid shell to be in a state of fusion, +as no doubt is the case.</p> + +<p>May not the uncertainty of the mass of the moon, be owing to the fact +that this shell is not so rigidly compacted but that it may yield a +little to external force, and thus also account for the tides in the +Pacific groups, rather obeying the centrifugal force due to the orbit +velocity of the earth, than the attraction of the moon?</p> + +<p>Since the days of Hipparchus the sidereal day has not diminished by the +<ins class="correction" title="Transcriber’s note: Original reads ‘hundreth’.">hundredth</ins> part of a second; and, consequently, seeing that the +contraction of the mass must be limited by the time of rotation, it is +inferred that the earth has not lost 1 ⁄ 508th of one degree of heat since +that time. This conclusion, sound as it is, is scarcely credible, when +we reflect on the constant radiation into a space 60° below zero. Admit +that the globe is a globe of water, whose average temperature is the +temperature it receives from the sun, and the difficulty vanishes at +once. Its diameter will be invariable, and the only effect of the +cooling of the solid parts will be to immerse them deeper in the water, +to change the <i>relative</i> level of the sea without changing its volume. +This is no puerile argument when rightly considered; but there is +another phenomenon which, if fairly weighed, will also conduct us to the +same views.</p> + +<p>It is now a fact uncontroverted, that the sea does actually change its +level, or rather, that the elevation of continents is not only apparent +but real. The whole coast of Sweden and Finland is rising at the present +day at the rate of four feet in a century, while on the south a contrary +effect is produced. Vari<span class="pagenum" title="Page 128"> </span><a name="Page_128" id="Page_128"></a>ous hypotheses have been formed concerning this +interesting fact. Yet from the indications of geology, it must have been +an universal phenomenon in the early ages of the world, in order to +account for the emersion of sedimentary deposits from the fluid which +deposited them. May not internal fires be yet spreading, and the +continents expanding instead of contracting? And may there not be an +inequality in this process, so as necessarily to immerse in one +direction nearly as much as to elevate in another? One fact is certain, +the elements are scattering the materials of the land along its Oceanic +coasts, which of itself must produce a very minute effect in disturbing +the hydrostatic balance; but a more efficient agent is the earthquake +and volcano.</p> + +<p>The upheaving of tracts of land by earthquakes, as on the coast of Chili +would thus be satisfactorily explained, by attributing a certain +resistance due to cohesion or friction preventing a <i>gradual</i> change of +level, but producing it suddenly by the jar of the earthquakes. May we +not inquire also, whether the facility with which the earth seems moved +by this destructive agent, does not point to the same solution as the +irregularity of the figure of the earth?</p> + +<p>This is a subject on which it is allowable to speculate, especially if +any light can be thereby thrown on the still more mysterious source of +terrestrial magnetism. It is for such a purpose that we have permitted +ourselves to digress from that subject. In this connection we also may +acknowledge our indebtedness to the sacred volume for the first germ of +this theory of the weather.</p> + +<p>Believing in the authenticity of the Mosaic history of the deluge, the +author found it difficult to refer that event to other than natural +causes, called into action by the operation of other causes, and all +simultaneous with the going forth of the fiat of Omnipotence. Thus +reasoning, he was led to regard the deluge as a physical phenomenon +inviting solution, and as a promising<span class="pagenum" title="Page 129"> </span><a name="Page_129" id="Page_129"></a> exponent to the climatology of +the early world. He looked upon the bow of promise, as the autograph of +the Creator, the signature to a solemn bond, upon which the eye of man +had never before rested. But if there was no rainbow before the deluge, +there was no rain; and following up this clue, he was not only enabled +to solve the problem, but also led to the true cause, which produces the +principal commotions in our atmosphere.</p> + +<p>Science boasts of being the handmaid of religion; yet there are names of +note in her ranks who have labored rather to invest this phenomenon with +the mantle of fable, and to force it into collision with the records +graven on the rocky pages of geognosy. But the world is ever prone to be +captivated by the brilliancy of misapplied talents, instead of weighing +merit by its zeal in reconciling the teachings of those things which are +seen, with those which are revealed.</p> + +<p>If our globe be constituted as we suppose, the land might experience +repeated submersions, without involving the necessity of any great +departure from established laws. And we might refer to the historical +record of one of these, with all the minute particulars as positive +data, imposing on us the necessity of admitting that the solid parts of +the globe are hydrostatically balanced in the sea. But, modern science +is not always correctly defined when called the pursuit of truth, nor +human learning the means of discovering it.</p> + +<p>If we could divest ourselves of this prejudice, we should have a ready +solution of the difficulty presented by the earth having two north +magnetic poles, and probably two also in the south. For, by regarding +the old and new continents as two distinct masses of land whose bases +are separated by 6,000 miles of water, we recognize two great magnets, +dependent, however, for their magnetism, on the rotation of the terral +vortex.</p> + +<p>This is no place to enter into a lengthy discussion of such a difficult +subject as magnetism, but we may be allowed to enter<span class="pagenum" title="Page 130"> </span><a name="Page_130" id="Page_130"></a> a protest against +the current theory of electro-magnetism, viz.: that a force is generated +by a galvanic current at right angles to the producing cause, which is +contrary to the fundamental principles of mechanics. We may conceive +that a current is induced from or to the surrounding space by the +rarefaction or condensation attending the transmission of such a current +along a wire, and that rotation should follow, just as a bent pipe full +of small holes at the lower end, and immersed in water as a syphon, will +generate a vorticose motion in the water; but mere juxtaposition, +without participation and communication with the general current, is +irrational, and, therefore, not true.</p> + +<p>We have always regarded a magnetic needle as a part of the great natural +magnet, the earth; that its north pole actually points to the north, and +its south pole to the south; and, being free to move, it is affected by +the circular motion of the surrounding ether, and by every motion by +which the ether is directed. If there was any attraction between the +earth and the needle, opposite poles would be presented, but it is not +so—the force is merely directive.</p> + + +<h3>MAGNETIC VARIATIONS.</h3> + +<p>Let us now see whether we cannot assign an adequate cause for the +secular and periodic variations in the inclination and declination of +the needle. These have been generally referred to changes of +temperature, as in fact, also, the magnetism of the earth is sometimes +ascribed to galvanic or electric currents, called forth by a daily +change of temperature. Our theory gives a totally different explanation +of these variations.</p> + +<p>In the northern hemisphere, the north point of the needle moves from +east to west in the morning from about 8 ½ <span class="time">A. M.</span> to 1 ½ <span class="time">P. M.</span>, and +returns to its mean position about 10 <span class="time">P. M.</span> It then passes over to the +east, and again returns to its mean position about 8 or 9 <span class="time">A. M.</span> The +analogy of this motion, with<span class="pagenum" title="Page 131"> </span><a name="Page_131" id="Page_131"></a> the horary changes in the barometer, +indicate a common origin. Humboldt, in the instructions he drew up for +the <ins class="correction" title="Transcriber’s note: Original reads ‘Antartic’.">Antarctic</ins> Expedition under Sir James Ross, says: “The phenomena +of periodical variations depend manifestly on the action of <i>solar +heat</i>, operating probably through the medium of thermo electric currents +induced on the earth’s surface. Beyond this rude guess, however, +<i>nothing is yet known of their physical cause</i>. It is even still a +matter of speculation whether the solar influence be a principal or only +a subordinate cause.” That the sun may exert a modifying influence on +the phenomenon is not unlikely, but that he cannot be the principal +cause, is evident from the following considerations. These horary +variations of the magnetic needle are as great at the bottom of deep +mines far removed from solar influence, as on the surface. They are as +great, <i>ceteris paribus</i> on a small island in the midst of the ocean, as +in the interior of continents, where the heating power of the surface is +vastly greater. They are extremely regular, so that between the tropics, +according to the sagacious Humboldt, “the time of the day may be known +by the direction of the needle, as well as by the height of the +barometer.”</p> + +<p>But what is the cause of these variations? This question is the most +difficult of all physical problems, and we shall only aim at indicating +the causes which are yet perhaps too intricately involved to afford a +positive numerical determination. Admitting the existence of two +principal solid masses whose general direction is from south to north, +and that these masses are more susceptible of permeation by the ethereal +fluid than the waters in which they are suspended, we have a general +solution of the position of the magnetic poles, and of the isogonic, +isoclinic, and isodynamic lines. Considering, too, that the southern +poles of these masses are the points of ingress, and the northern poles +the points of egress, it is easily understood that the ethereal medium +having the temperature of<span class="pagenum" title="Page 132"> </span><a name="Page_132" id="Page_132"></a> space, will cause the southern hemisphere to +be colder than the northern, and also that the magnetic poles will be +the poles of maximum cold, and the centres respected by the isothermal +and isogeothermal lines.</p> + +<p>The general direction of the magnetism of the earth may be considered as +the controlling influence, therefore, in determining the position of the +magnetic needle; but there are other causes which, to some extent, will +modify the result. That half of the globe turned away from the sun will +partake of the density of the ether at that distance, which is greater +than on the side next the sun; the magnetic intensity ought, therefore, +to be greater in the night than in the day. The poles of the great +terrestrial magnets, or even the position of a magnetic needle on the +surface, are continually placed by the earth’s rotation in a different +relation to the axes of the terral vortex, and the tangential current, +which is continually circulating around the globe, has its inclination +to a given meridian in a perpetual state of change. If we conceive that +there is a tendency to force the needle at right angles to this current, +we shall have an influence which varies during the day, during the year, +and during the time occupied by a complete revolution of the node. The +principal effect, however, of the horary variation of the needle is due +to the radial stream of the sun, which not only penetrates the +atmosphere, but also the solid crust of the earth. Its principal +influence is, however, an indirect influence, as we shall endeavor to +explain.</p> + +<p>No fact in the science of electro-magnetism is, perhaps, better +established than the disposition of an ethereal current to place itself +at right angles to the magnetic meridian, and conversely, when the +current is not free to move, to place the needle at right angles to the +current. Now, the terrestrial magnet or magnets, may be considered to be +surrounded by a body of ether in rotation, which, in the earth, on its +surface, and for some distance from the surface, is made to conform to +the<span class="pagenum" title="Page 133"> </span><a name="Page_133" id="Page_133"></a> general rule, that is, to circulate at right angles to the magnetic +meridian. Outside this again, the ether more and more conforms to the +position of the axis of the vortex, and this position varying, it must +exert <i>some</i> influence on the surface currents, and, therefore, change +in some degree the position of the magnetic meridian. The radial stream +comes from the sun in parallel lines, and strikes the globe and its +superficial ethereal envelope just as we have shown its action on the +atmosphere; but in this last case the magnetic equator is not a great +circle, neither can we suppose its effects to be an accumulation of a +fluid which is imponderable at points 90° from the plane passing through +the centre of the earth and sun, and coincident with the plane of the +central meridian, and a depressing effect on that meridian. Its precise +influence must be, from the nature of the cause, to deflect the circular +current towards the poles, in places less than 90° from the meridian, +and a contrary effect must be produced in places greater than 90° from +the meridian. Let us assume, for argument’s sake, that the magnetic +poles of the earth correspond to the poles of rotation, the parallels of +latitude will, therefore, represent the ethereal currents circulating +around the globe. Now, at sunrise, the radial stream of the solar vortex +is tangential to the surface, and, therefore, can produce no change in +these currents. As the sun ascends say about 8 or 9 <span class="time">A. M.</span>, the radial +stream striking only the surface of the earth perpendicularly in that +place where the sun is vertical (which we will suppose at the equator), +streams off on every side, as the meridians do from the pole, and the +circles of latitude (that is the ethereal currents) being parallel to +the equator, they are met by the radial stream obliquely, and deflected +towards either pole. By this deflection they are no longer at right +angles to the meridians. But, from the principle of reaction above +noticed, the magnetic meridians will place themselves at right angles to +the current, or, in other words, the magnetic pole will change its +position on the surface<span class="pagenum" title="Page 134"> </span><a name="Page_134" id="Page_134"></a> of the earth with respect to that particular +place. But, in other parts of the world, the meridians are in opposite +phases at the same instant of absolute time; therefore, the magnetic +poles are not points, but wide areas enclosing the magnetic poles of all +the countries under the sun. As this conforms to observation, it is +worthy our especial attention, and may be understood by the subjoined +<a href="#fig24">figure</a>, in which the oblique curves represent the course of the +tangential current in the different positions of the sun, the parallel +lines representing the solar radial stream.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig24" id="fig24"></a> +<img src="images/fig24.png" width="350" height="187" alt="Fig. 24" title="" /> +</div> + +<p>As the sun gains altitude the action of the radial stream is at a +greater and greater angle to the circular currents, and attains its +maximum at noon, still acting, however, after noon; but seeing that the +circular current possesses a force of re-action, that is, that the +magnetism of the earth is ever striving to bring these currents to their +natural direction, an hour or two after noon, the currents tend again to +the equator, and the maximum deflection is passed, and finally ceases a +few hours after sunset. Now let us attend to what is going on on the +opposite side of the world. The radial stream passing over the polar +regions, now produces a contrary effect; the ethereal atmosphere of the +great magnet is accumulated on the farthest side from the sun,<span class="pagenum" title="Page 135"> </span><a name="Page_135" id="Page_135"></a> by the +action of the radial stream passing over the polar region, the parallel +currents are now bent towards the equator, being at a maximum in places +where it is an hour or two past midnight. Before they were concave to +the equator, and now they are convex; the magnetic meridian is therefore +deflected the contrary way to what it was in the day time, by the same +principle of reaction. After the maximum, say at 4 <span class="time">A. M.</span>, the deflection +gradually ceases, and the magnetic meridian returns to its mean position +at 8 or 9 <span class="time">A. M.</span> These times, however, of maximum and minimum, must vary +with the time of the year, or with the declination of the sun, with the +position of the moon in her orbit, with the perigee of the orbit, and +with the place of the ascending node; there are also minor influences +which have an effect, which present instrumental means cannot render +appreciable.</p> + +<p>What says observation? The needle declines from its mean position in the +whole northern hemisphere to the westward, from about 8.30 <span class="time">A. M.</span>, until +1.30 <span class="time">P. M.</span>; it then gradually returns to its mean position by 10 <span class="time">A. M.</span> +After 10 <span class="time">P. M.</span>, it passes over to the eastward, and attains its maximum +deflection about three or four hours after midnight, and is found again +at its mean position about 9 <span class="time">A. M.</span> Now, this is precisely the direction +of the deviation of the magnetic meridian, the needle therefore only +follows the meridian, or still continues to point to the temporary +magnetic pole. And although we have assumed, for the sake of simplicity, +that the mean magnetic pole corresponds to the pole of rotation; in +truth there are two magnetic poles, neither of which correspond; yet +still the general effect will be the same, although the numerical +verification will be rendered more difficult.</p> + +<p>In the southern hemisphere the effect is the reverse, (this southern +hemisphere, however, must be considered separated from the northern by +the magnetic equator, and not by the geographical one,) the needle +declines to the eastward in the<span class="pagenum" title="Page 136"> </span><a name="Page_136" id="Page_136"></a> morning, and goes through the same +changes, substituting east for west, and west for east. Does observation +decide this to be to be a fact also? Most decidedly it does; and this +alone may be considered a positive demonstration, that the theory which +explains it is true. The contrary deflection of the needle in the +northern and southern hemisphere may be formally proclaimed as utterly +beyond the reach of the common theory of magnetism to explain. This +difficulty arises from considering the needle as the disturbed body +instead of the earth; and also from the fact that the effect of solar +heat must be common to needles in both hemispheres, and act upon similar +poles, and consequently the deflection must be in the same direction.</p> + +<p>But a still more capital feature is presented by the discovery of +Colonel Sabine, that the deflection is in contrary directions at the +Cape of Good Hope, at the epoch of the two equinoxes. This arises from +the great angle made by the magnetic meridian at this place, with the +terrestrial meridian—the variation being by Barlow’s tables, 30° to the +westward. The sun varies in declination 47° throughout the year. At the +southern solstice, therefore the radial stream strikes the circular +current on the southern side, and deflects it towards the equator, +rendering the declination to the westward in the morning; but at the +northern solstice the radial stream strikes the current on its northern +side, and the deflection is eastward in the morning. And the vicinity of +the Cape of Good Hope is, perhaps, the only part of the world where this +anomaly will obtain; as it is necessary not only that the declination +shall be considerable, but also that the latitude shall not be very +great.</p> + +<p>Observation also determines that the amount of the horary variation +increases with the latitude. Near the equator, according to Humboldt, it +scarcely amounts to three or four minutes, whilst it is from thirteen to +fourteen minutes in the middle of Europe. The theory explains this also; +for as the circles recede from the equator, the angles made by their +planes with the<span class="pagenum" title="Page 137"> </span><a name="Page_137" id="Page_137"></a> direction of the radial stream increases, and hence the +force of deflection is greater, and the effect is proportioned to the +cause. We have also a satisfactory explanation of the fact that there +has not yet been discovered a line of <i>no variation of horary +declination</i> as we might reasonably anticipate from the fact that the +declinations are in <i>contrary directions</i> in the northern and southern +hemisphere. This is owing to the ever-varying declination of the sun. +There would be such a line, no doubt, if the axis of the earth were +perpendicular to the plane of the orbit, and the magnetic pole coincided +with the pole of rotation: for then the equator would be such a line.</p> + + +<h3>MAGNETIC STORMS.</h3> + +<p>But there are also irregular fluctuations in the direction of the +magnetic needle. These depend on the moon, and are caused by the passage +of the vortices over or near to the place of observation. The action of +these vortices is proved to be of variable force, whether arising from +atmospheric conditions, or due to an increased activity of the ethereal +medium throughout the whole system, is at present immaterial. They do +vary, and sometimes the passage of a vortex will deflect the needle a +whole degree. At other times, there are magnetic storms extending over a +great part of the earth’s surface; but there is reason to suppose, that +the extent of these storms has been over estimated. Thus, on the 25th of +September, 1841, a magnetic storm was observed in Toronto, and at the +same time there was one felt at the Cape of Good Hope. There is no great +mystery in this. If we suppose the axis of the central vortex, for +instance, to have passed Toronto in latitude 43° 33′ north, in ordinary +positions of the moon, in her orbit, the southern portion of the axis +would be in 33° or 34° south latitude, and consequently would have +passed near the Cape of Good Hope on the same night. Now, we certainly +could not expect the northern portion of the vortex to be intensely +active,<span class="pagenum" title="Page 138"> </span><a name="Page_138" id="Page_138"></a> without the southern portion being in the same state of +activity. That this is the true explanation is proved by magnetic storms +in the same hemisphere being comparatively limited in extent; as, +according to Gauss and Weber, magnetic storms which were simultaneously +felt from Sicily to Upsala, did not extend from Upsala to Alten. Still +it would not be wonderful if they were felt over a vast area of +thousands of miles as a consequence of <i>great</i> disturbance in the +elasticity of the ether in the terral vortex; as the solid earth must be +permeable to all its motions, and thus be explicable on the general +principles we have advanced.</p> + +<p>But besides these variations which we have mentioned, there are changes +steadily going on, by which the isodynamic, isogonic and isoclinic lines +are permanently displaced on the surface of our planet. These must be +attributed to changes of temperature in the interior of the globe, and +to the direction in the progress of subterranean fires, which it may +also be expected will change the isogeothermal lines. But there are +changes, which although of long period, are yet periodic, one of which +is obviously due to the revolution of the lunar nodes in eighteen and a +half years, and the revolution of the apogee in nine years. The first is +continually changing the obliquity of the axis of the vortex, and they +both tend to limit the vortices in their extreme latitudes; but the +planet Jupiter has an indirect influence, which is probably equal, if +not greater, than the action of the moon, in changing the magnetic +declination.</p> + +<p>From the investigations of Lamont, it would appear, that the period of +the variations of magnetic declination is about 10⅓ years, while, +more recently, R. Wolfe has suggested the connection between this +variation and the solar spots, and assigns a period of 11.11 years, and +remarks, that it “corresponds more exactly with the variations in +magnetic declination than the period of 10⅓ years established by +Lamont. The magnetic variations accompany the solar spots, not only in<span class="pagenum" title="Page 139"> </span><a name="Page_139" id="Page_139"></a> +their regular changes, but even in their minor irregularities: this +latter fact is itself sufficient to prove definitely the important +relations between them.”<a name="FNanchor_28_28" id="FNanchor_28_28"></a><a href="#Footnote_28_28" class="fnanchor">[28]</a></p> + +<p>As the planet Jupiter exerts the greatest influence on the sun, in +forcing the centre from the mechanical centre of the system, the +longitude of the sun will in a great measure depend on the position of +this planet; and, in consequence, the sun will generally revolve around +this centre in a period nearly equal to the period of Jupiter. The +sidereal period of Jupiter is about twelve years, but the action of the +other planets tend to shorten this period (at least, that has been the +effect for the last twenty or thirty years), and bring it nearly to the +period assigned by M. Wolfe to the variations in the magnetic +declinations. As this has its influence on the radial stream, and the +radial stream on the declination, we see at once the connection between +them. When we come to a consideration of the solar spots, we shall +exhibit this influence more fully.</p> + + +<h3>AURORA BOREALIS.</h3> + +<p>Let us now examine another phenomenon. The Aurora Borealis has been +generally considered to be in some way connected with the magnetism of +the earth, and with the position of the magnetic pole. It is certain +that the appearance of this meteor does affect the needle in a way not +to be mistaken, and (although not invariably) the vertex of the luminous +arch will usually conform to the magnetic meridian. Yet (and this is +worthy of attention), the observations made in the North Polar +Expeditions<a name="FNanchor_29_29" id="FNanchor_29_29"></a><a href="#Footnote_29_29" class="fnanchor">[29]</a> “appear to prove, that in the immediate vicinity of the +magnetic pole the development of light is not in the least degree more +intense or frequent than at some distance from it.” In fact, as the +American magnetic pole is, as stated, in latitude 73°, the central +vortex will seldom reach so high,<span class="pagenum" title="Page 140"> </span><a name="Page_140" id="Page_140"></a> and, consequently, the aurora ought +at such times to be more frequent in a lower latitude. In a late work by +M. de la Rive, this gentleman expresses the opinion, that the cause of +the aurora is not due to a radiation of polar magnetism, but to a purely +electrical action.<a name="FNanchor_30_30" id="FNanchor_30_30"></a><a href="#Footnote_30_30" class="fnanchor">[30]</a> His explanation, however, is not so satisfactory +as his opinion. Now, we have examined numerous cases of auroral +displays, and never yet found one which could not be legitimately +referred to the action of ethereal vortices. Generally, the aurora will +not be visible, when the upper surface of the atmosphere of that +latitude in which the vortex is known to be (reckoning in the direction +of the magnetic meridian) is below the horizon, which shows that the +brightest portion is in the atmosphere. In latitude 41° even, it may +show itself when the vortex is three days north, more frequently when +one or two days north; but when the vortex passes centrally, or south, +it rarely is seen, and this is the only difficulty in explaining it by +the theory. But, when we reflect that the ether shoots out in straight +lines, and at an angle corresponding to the magnetic dip, we are at no +loss to perceive the reason of this. If each minute line composing the +light were seen endwise, it would be invisible; if there were millions +such in the same position, they could add nothing to the general effect; +but, when viewed sideways, the case would be different, there would be a +continued reduplication of ray upon ray, until in the range of some +hundreds of miles an effect might be produced amounting to any degree of +intensity on record. Now, this is the case when the aurora is +immediately overhead, it will be invisible to those below, but may be +seen by persons a hundred miles south; so, also, when it is to the +south, it is too oblique to the line of vision to be seen, especially as +all the rays to the northward of the observer can contribute nothing to +increase the effect. That it is of the nature of rays very much +diffused, can hardly be doubted; and, therefore, if only<span class="pagenum" title="Page 141"> </span><a name="Page_141" id="Page_141"></a> of a few miles +in depth, its impressions are too faint to be sensible. By referring to +the record of the weather in the second section of this work, an auroral +display will be found on July 12th, the central vortex having passed a +little to the northward the same evening, and the next day passing south +<i>descending</i>. On that occasion the author saw an inclined column, in +profile, due east, and between himself and a line of bluffs and timber, +about eight miles distant; And, he has not any doubt that the mass of +rays began where he stood. As in a shower, every drop, passing through a +conical surface, whose axis passes through the sun and through the eye, +contributes to form the apparently distant rainbow.</p> + +<p>The altitude of this meteor has been much exaggerated, especially of +those rings or luminous arches, which are often detached completely from +the luminous bank. On the 24th of May, a bright aurora was visible at +Ottawa, but the author’s attention was engrossed by the most brilliant +arch of light he had ever seen. It was all the time south of the zenith, +and had no visible connection with the aurora north. At 9 hours, 59 minutes, 30 seconds mean solar time, Arcturus was in the exact centre of +the band, at which time it was very bright, and full 7° wide. At the +same time, Prof. G. W. Wheeler observed the aurora in Perryville, in the +State of Missouri, only 1° of longitude to the westward, but did not see +the arch.<a name="FNanchor_31_31" id="FNanchor_31_31"></a><a href="#Footnote_31_31" class="fnanchor">[31]</a> The difference of latitude between the two places being 3° 30′, and the weather, as he states, clear and still, there is only one +reason why he did not see the arch: it must have been too <i>low</i>, and had +become merged in the bank of light. At the time mentioned, the altitude +of Arcturus was 68° 30′, and, as Prof. Wheeler assigns only 10° as the +altitude of the bank, the maximum elevation of the arch, on the +supposition of its composing a part of the bank, was 43 miles. At +Perryville, the bank and streamers had disappeared at 10 o’clock. At +Ottawa,<span class="pagenum" title="Page 142"> </span><a name="Page_142" id="Page_142"></a> the arch or bow disappeared at 10 h. 5 m., differing only the +fraction of a minute from the time at Perryville; but, the bank was +still visible, but low and faint, the greatest altitude having been over +30°. To show the rapid fluctuations in width and position of this bow, +we will add a few of the minutes taken at the time with great care, in +hopes some other observer had been equally precise. When first seen, +there were three luminous patches, or elongated clouds of light; one in +Leo, one in Bootes, and another in Ophinchus, all in line. This was +about 9h. 15m. The times following are correct to 30 seconds:</p> + +<table summary="Observations of the aurora."> +<tr> + <td class="tdr0">9h.</td> + <td class="tdr0">42m.</td> + <td class="tdr">30s.</td> + <td>Bow complete; south edge 2° north of Arcturus.</td> +</tr> +<tr> + <td class="tdr0">9h.</td> + <td class="tdr0">45m.</td> + <td class="tdr">30s.</td> + <td>Northern edge diffuse south; edge bright, and well defined; + 10° wide in zenith; north edge on Alphacca.</td> +</tr> +<tr> + <td class="tdr0">9h.</td> + <td class="tdr0">47m.</td> + <td class="tdr">30s.</td> + <td>South edge 5° north of Arcturus; north edge close to Cor. + Caroli.</td> +</tr> +<tr> + <td class="tdr0">9h.</td> + <td class="tdr0">53m.</td> + <td class="tdr">30s.</td> + <td>Eastern half composed of four detached bands <i>shingling</i> + over each other.</td> +</tr> +<tr> + <td class="tdr0">0h.</td> + <td class="tdr0">58m.</td> + <td class="tdr">30s.</td> + <td>Arcturus on south; bow narrower.</td> +</tr> +<tr> + <td class="tdr0">9h.</td> + <td class="tdr0">59m.</td> + <td class="tdr">30s.</td> + <td>Arcturus in the middle of the band; very bright and regular in + outline, and widest at the zenith.</td> +</tr> +<tr> + <td class="tdr0">10h.</td> + <td class="tdr0">0m.</td> + <td class="tdr">30s.</td> + <td>Arcturus on northern edge; north side better defined than the + southern.</td> +</tr> +<tr> + <td class="tdr0">10h.</td> + <td class="tdr0">2m.</td> + <td class="tdr">0s.</td> + <td>Arcturus 1° north; very bright.</td> +</tr> +<tr> + <td class="tdr0">10h.</td> + <td class="tdr0">2m.</td> + <td class="tdr">30s.</td> + <td><ins class="correction" title="Transcriber’s note: Original reads ‘Glamma’.">Gamma</ins> and Delta Leonis, northern edge.</td> +</tr> +<tr> + <td class="tdr0">10h.</td> + <td class="tdr0">3m.</td> + <td class="tdr">0s.</td> + <td>Regulus on southern age; getting faint.</td> +</tr> +<tr> + <td class="tdr0">10h.</td> + <td class="tdr0">5m.</td> + <td class="tdr">0s.</td> + <td>Fast fading away.</td> +</tr> +<tr> + <td class="tdr0">10h.</td> + <td class="tdr0">5m.</td> + <td class="tdr">30s.</td> + <td>Scarcely visible; bank in north faint.</td> +</tr> +</table> + +<p>This aurora was due to the <i>inner vortex ascending</i>, whose period was at +this time 28 days.</p> + +<p><span class="pagenum" title="Page 143"> </span><a name="Page_143" id="Page_143"></a>There are several circumstances to be observed in this case. The bow +brightened and faded simultaneously with the aurora, and respected the +vertex of the auroral bank, being apparently concentric with it. The +bow, therefore, depends on the same cause, but differs from the aurora +in being limited to the <i>surface</i> of the atmosphere in which the vortex +has produced a wave to the southward of its central path, as may be +understood by inspecting <a href="#fig02">Fig. 2</a>, <a href="#SECTION_FIRST">Sec. 1</a>,—the figure representing the +polar current of the central vortex. On the 29th of May, 1840,<a name="FNanchor_32_32" id="FNanchor_32_32"></a><a href="#Footnote_32_32" class="fnanchor">[32]</a> the +author saw a similar phenomenon, at the same time of night, and passing +over the same stars southward until it reached within 5° of Jupiter and +Saturn, to which it was parallel. This atmospheric wave offers a greater +resistance to the passage of the ether: hence the light. On this account +it is, also, that when the passage of a vortex is attended by an auroral +display there will be no thunder-storm. There may be an increase of +wind; but the atmosphere at such times is too dry to make a violent +storm, and there is a silent restoration of the equilibrium, by the +ether passing through the dry atmosphere, without meeting any +condensable vapor, and becoming luminous on account of the greater +resistance of the air when unmixed with vapor. We thus see also the +connection between the aurora and the linear cirri, and we have a +triumphant explanation of the fact, that when the observer is north of +the northern limit of the vortices, he sees the aurora to the south and +not to the north; for, to see it to the northward, he would have to see +it in the same latitude as it appears in the south, and, consequently, +have to see across twice the complement of the latitude. We thus see, +also, why the temperature falls after an aurora; for, the passage of +electricity in any shape, must have this effect on account of the great +specific caloric of this fluid. We see, also, why the aurora should be +more frequent where the magnetic intensity is great<span class="pagenum" title="Page 144"> </span><a name="Page_144" id="Page_144"></a>est and be +consequently invisible at the equator, and why the magnetic needle is so +sensibly affected at the time of its occurrence. We may, perhaps, here +be allowed to allude to another phenomenon connected with terrestrial +magnetism and electricity.</p> + + +<h3>EARTHQUAKES.</h3> + +<p>The awful and destructive concussions which sometimes are produced at +great depths beneath the surface of the soil, would seem to indicate +that no force but that of electricity is adequate to account for the +almost instantaneous desolation of wide tracts of the earth’s surface. +But we do not mean to say that the action of the terral vortices, +combined with the internal conditions of our planet, is the only cause; +although it is far from improbable that the same activity of the ether, +which generates through these vortices, the full fury of the hurricane +in the tropics, may be simultaneously accompanied by a <i>subterranean</i> +storm. And physicists are too rash to reject the evidence on which the +connection of the phenomena rests.</p> + +<p>In the extract given by Colonel Reid, in his “Law of Storms,” from Sir +George Rodney’s official report of the great hurricane of 1780, it is +stated, that, “Nothing but an earthquake could have occasioned the +<i>foundations</i> of the strongest buildings to be rent; and I am convinced +that the violence of the wind must have prevented the inhabitants from +feeling the earthquake which certainly attended the storm.”<a name="FNanchor_33_33" id="FNanchor_33_33"></a><a href="#Footnote_33_33" class="fnanchor">[33]</a> Again, +in the Savannah-la-Mar hurricane, which occurred the same year and +month, the Annual Register, published at Jamaica, states, that at the +same time, “a smart shock of an earthquake was felt.” The general +serenity of equatorial regions is due to the fact that they are beyond +the limit of the vortices, as in Peru, where neither rain nor lightning +nor storm is ever seen. Thunder and rain, without storms, however, are +common in other tropical countries,<span class="pagenum" title="Page 145"> </span><a name="Page_145" id="Page_145"></a> also out of the reach of the +vortices. But even in those parts, (as the Antilles,) lying in the track +of these vortices, the weather is not as <i>frequently</i> disturbed as in +higher latitudes. The storms of the Antilles, when they do occur, +however, are fearful beyond any conception, showing the presence of some +cause, auxiliary to the ordinary disturbing action of the vortices, +which, when simultaneously occurring, adds tremendously to their force.</p> + +<p>That earthquakes are preceded <i>sometimes</i> by a peculiar haziness and +oppressiveness, similar to that which sometimes precedes a storm, is a +current opinion in volcanic countries. And Humboldt, who doubts the +connection, has to confess that sudden changes of weather have +<i>succeeded</i> violent earthquakes, and that “during the great earthquake +of Cumana, he found the inclination of the needle was diminished 48′.” +He also mentions the simultaneous occurrence of shocks, from +earthquakes, and a clap of thunder, and the agitation of the +electrometer during the earthquake, which lasted from the 2d of April to +the 17th of May, 1808; but concluding that “these indications presented +by clouds, by modifications of atmospheric electricity, or by calms, +cannot be regarded as <i>generally</i> or <i>necessarily</i> connected with +earthquakes, since in Peru, Canada, and Italy, earthquakes are observed, +along with the purest and clearest skies, and with the freshest land and +sea breezes. But if no meteorological phenomena indicates the coming +earthquake, either on the morning of the shock or a few days previously, +the influence of certain periods of the year, (the vernal and autumnal +equinoxes,) the commencement of the rainy season in the tropics, after +long drought, cannot be overlooked, even though the genetic connection +of meteorological processes, with those going on in the interior of our +globe, is still enveloped in obscurity.”<a name="FNanchor_34_34" id="FNanchor_34_34"></a><a href="#Footnote_34_34" class="fnanchor">[34]</a></p> + +<p>It is at the equinoxes that the earth changes her distances from the sun +most rapidly, and whether she is passing from her<span class="pagenum" title="Page 146"> </span><a name="Page_146" id="Page_146"></a> perihelion or from +her aphelion, the density of the ether externally is changing in the +subduplicate ratio of these distances and consequently at these times +there will be the greatest disturbance of the electric equilibrium. How +far our views of the internal structure of our globe, (considered along +a diameter as a solid crust, then a fused mass separated from the lower +ocean by another solid crust, and separated from a similar arrangement +on the opposite side by an interposed mass of water, perhaps also +possessing a solid nucleus,) may affect this question, is difficult to +say; but that the agent is electric, appears highly probable; and very +recently it has been discovered, by M. Ratio Menton, that a piece of +iron, suspended by attraction to a magnet, will fall on the approach of +an earthquake; thus indicating that the power of the magnet is +temporarily weakened by the action of some disturbing force.</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_22_22" id="Footnote_22_22"></a><a href="#FNanchor_22_22">[22]</a></span>Hum. Cosmos, art Aerolites.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_23_23" id="Footnote_23_23"></a><a href="#FNanchor_23_23">[23]</a></span>We shall in all cases use this abbreviation for the +extremely awkward word zodiacal.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_24_24" id="Footnote_24_24"></a><a href="#FNanchor_24_24">[24]</a></span>It is here assumed, that all the vortices are at their +apogee at the same time, and, consequently, they lie in different +longitudes, but the central being between, its position is taken for the +average position of the three.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_25_25" id="Footnote_25_25"></a><a href="#FNanchor_25_25">[25]</a></span>It is far from improbable that the effect produced in one +zone of climate, may be reversed in another, from the nature of the +cause.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_26_26" id="Footnote_26_26"></a><a href="#FNanchor_26_26">[26]</a></span>That the 11th, 12th, and 13th of May should recede 2° in +temperature as determined by Mædler from observations of 86 years, at a +time when the power of the sun so rapidly augments, is strongly +confirmatory of the theory. See <i>Cosmos</i>, p. 121.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_27_27" id="Footnote_27_27"></a><a href="#FNanchor_27_27">[27]</a></span>Plucker first discovered that a plate of tourmaline +suspended with its axis vertical, set axial.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_28_28" id="Footnote_28_28"></a><a href="#FNanchor_28_28">[28]</a></span>Silliman’s Journal for March and April, 1853.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_29_29" id="Footnote_29_29"></a><a href="#FNanchor_29_29">[29]</a></span>Humboldt, <i>Cosmos</i> p. 193, London ed.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_30_30" id="Footnote_30_30"></a><a href="#FNanchor_30_30">[30]</a></span>See Silliman’s Journal for September, 1853.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_31_31" id="Footnote_31_31"></a><a href="#FNanchor_31_31">[31]</a></span>See Silliman’s Journal for September, 1853.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_32_32" id="Footnote_32_32"></a><a href="#FNanchor_32_32">[32]</a></span>This was the central vortex ascending.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_33_33" id="Footnote_33_33"></a><a href="#FNanchor_33_33">[33]</a></span>Reid’s Law of Storms, p. 350.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_34_34" id="Footnote_34_34"></a><a href="#FNanchor_34_34">[34]</a></span>Humboldt, <i>Cosmos</i>, p. 203.</p></div> +</div> + + +<hr style="width: 65%;" /> +<h2><span class="pagenum" title="Page 147"> </span><a name="Page_147" id="Page_147"></a><a name="SECTION_FOURTH" id="SECTION_FOURTH"></a>SECTION FOURTH.</h2> + + +<h3>THE SOLAR SPOTS.</h3> + +<p>We have yet many phenomena to investigate by the aid of the theory, and +we will develop them in that order which will best exhibit their mutual +dependence. The solar spots have long troubled astronomers, and to this +day no satisfactory solution of the question has been proposed; but we +shall not examine theories. It is sufficient that we can explain them on +the same general principles that we have applied to terrestrial +phenomena. There can be but little doubt about the existence of a solar +atmosphere, and, reasoning from analogy, the constituent elements of the +sun must partake of the nature of other planetary matter. That there are +bodies in our system possessing the same elements as our earth, is +proved by the composition of meteoric masses, which, whether they are +independent bodies of the system, or fragments of an exploded planet, or +projected from lunar volcanoes, is of little consequence; they show that +the same elements are distributed to other bodies of the system, +although not necessarily in the same proportions. The gaseous matter of +the sun’s atmosphere may, therefore, be safely considered as vapors +condensable by cold, and the formation of vortices over the surface of +this atmosphere, brings down the ether, and causes it to intermingle +with this atmosphere. But, from the immensely rapid motion of the polar +current of the solar vortex, this ether may be<span class="pagenum" title="Page 148"> </span><a name="Page_148" id="Page_148"></a> considered to enter the +atmosphere of the sun with the temperature of space.</p> + +<p>Sir John Herschel, in commenting on the theory of Mr. Redfield before +the British Association, convened at Newcastle in 1838,<a name="FNanchor_35_35" id="FNanchor_35_35"></a><a href="#Footnote_35_35" class="fnanchor">[35]</a> suggested an +analogy to terrestrial hurricanes, from a suspected rotation and +progressive motion in these spots. From their rapid formation, change of +shape, and diameter, this view is allowable, and, taken in conjunction +with the action of the ethereal currents, will account for all the +phenomena. The nucleus of the spot is dense, like the nucleus of a storm +on the earth, and surrounded by a penumbon precisely as our storms are +fringed with lighter clouds, permitting the light of the sun to +penetrate. And, it has been observed, that these spots seem to follow +one another in lines on the same parallel of solar latitude (or nearly +the same), exactly as we have determined the action of the vortices on +the surface of the earth from observation. These spots are never found +in very high latitudes—not much above 30° from the solar equator. If we +consider this equator to be but slightly inclined to the plane of the +vortex, this latitude would be the general position of the lateral solar +vortices, and, in fact, be confined principally to a belt on each side +of the equator, between 15° and 30° of solar latitude, rather than at +the equator itself. This, it is needless to say, is actually the case. +But, a more capital feature still has been more recently brought to +light by observation, although previously familiar to the author, who, +in endeavoring to verify the theory, seriously injured his sight, by +observing with inadequate instrumental means. This is the periodicity of +the spots.</p> + +<p>We have already observed, that there is reason to suppose that the +action of the inner vortex of the earth is probably greater than that of +the outer vortex, on account of the conflicting currents by which it is +caused. And the full development of this vortex requires, that the +central vortex or<span class="pagenum" title="Page 149"> </span><a name="Page_149" id="Page_149"></a> mechanical axis of the system shall be nearly +tangential to the surface. In this position, the action of the central +vortex is itself at a maximum; and, when the planets of the system are +so arranged as to produce this result, we may expect the greatest number +of spots. If the axis or central vortex approaches to coincidence with +the axis of the sun, the lateral vortices disappear, and the central +vortex being then perpendicular to the surface, is rendered ineffective. +Under these circumstances, there will be no spots on the sun’s disc. +When, on the other hand, all the planets conspire at the same side to +force the sun out from the mechanical centre of the system, the surface +is too distant to be acted on by the central vortex, and the lateral +vortices are also thrown clear of the sun’s surface, on account of the +greater velocity of the parts of the vortex, in sweeping past the body +of the sun. In this case, there will be but few spots. The case in which +the axis of the vortex coincides with the axis of the sun, is much more +transient than the first position, and hence, although the interval +between the maxima will be tolerably uniform, there will be an +irregularity between a particular maximum, and the preceding and +subsequent minimum.</p> + +<p>The following table exhibits the solar spots, as determined by Schwabe, +of Dessau:</p> + +<table style="text-align:center;" summary= +"Observations of solar spots."> +<tr> + <th><span class="pagenum" title= + "Page 150"> </span><a name="Page_150" id= + "Page_150"></a>Year of observation.</th> + <th>Groups of spots observed.</th> + <th>Number of days.</th> +</tr> +<tr> + <td>1826</td> + <td class="tdr1">118</td> + <td>277</td> +</tr> +<tr> + <td>1827</td> + <td class="tdr1">161</td> + <td>273</td> +</tr> +<tr> + <td>1828</td> + <td class="tdr1">225</td> + <td>282</td> +</tr> +<tr> + <td>1829</td> + <td class="tdr1">199</td> + <td>244</td> +</tr> +<tr> + <td>1830</td> + <td class="tdr1">190</td> + <td>217</td> +</tr> +<tr> + <td>1831</td> + <td class="tdr1">149</td> + <td>239</td> +</tr> +<tr> + <td>1832</td> + <td class="tdr1">84</td> + <td>270</td> +</tr> +<tr> + <td>1833</td> + <td class="tdr1">33</td> + <td>267</td> +</tr> +<tr> + <td>1834</td> + <td class="tdr1">51</td> + <td>273</td> +</tr> +<tr> + <td>1835</td> + <td class="tdr1">173</td> + <td>244</td> +</tr> +<tr> + <td>1836</td> + <td class="tdr1">272</td> + <td>200</td> +</tr> +<tr> + <td>1837</td> + <td class="tdr1">333</td> + <td>168</td> +</tr> +<tr> + <td>1838</td> + <td class="tdr1">282</td> + <td>202</td> +</tr> +<tr> + <td>1839</td> + <td class="tdr1">162</td> + <td>205</td> +</tr> +<tr> + <td>1840</td> + <td class="tdr1">152</td> + <td>263</td> +</tr> +<tr> + <td>1841</td> + <td class="tdr1">102</td> + <td>283</td> +</tr> +<tr> + <td>1842</td> + <td class="tdr1">68</td> + <td>307</td> +</tr> +<tr> + <td>1843</td> + <td class="tdr1">34</td> + <td>324</td> +</tr> +</table> + +<p>Previous to the publication of this table, the author had inferred the +necessity of admitting the existence of another planet in the solar +system, from the phenomenon of which we are speaking. He found a +sufficient correspondence between the minima of spots to confirm the +explanation given by the theory, and this was still more confirmed by +the more exact determination of Schwabe; yet there was a little +discrepancy in the synchronous values of the ordinates, when the theory +was graphically compared with the table. Previous to the discovery of +Neptune, the theory corresponded much better than afterwards, and as no +doubt could be entertained that the anomalous movements of Uranus were +caused by an exterior planet, he adopted the notion that there were two +planets exterior to Uranus, whose positions at the time were such, that +their mechanical affects on the system were about equal and contrary. +Consequently, when Neptune became known, the existence of another planet +seemed a conclusion necessary to adopt. Accordingly, he calculated the +heliocentric longitudes and true anomalies, and the values of radius +vector, for all the planets during the present century, but not having +any planetary tables, he contented himself with computing for the +nearest degree of true anomaly, and the nearest thousand miles of +distance. Then by a composition and resolution of all the forces, he +deduced the radius vector of the sun, and the longitude of his centre, +for each past year of the century. It was in view of a little +outstanding<span class="pagenum" title="Page 151"> </span><a name="Page_151" id="Page_151"></a> discrepancy in the times of the minima, as determined by +theory and observation, that he was induced to consider as almost +certain the existence of a theoretical planet, whose longitude, in 1828, +was about 90°, and whose period is from the theory about double that of +Neptune. And for convenience of computation and reference, he has been +in the habit of symbolizing it by a volcano. The following table of the +radii vectores of the sun, and the longitude of his centre, for the +years designated in Schwabe’s table, is calculated from the following +data for each planet:</p> + +<table summary="Data on five planets."> +<tr> + <th>Planets.</th> + <th>Masses.</th> + <th style="padding-right:0;">Mean distances.</th> + <th>Eccentricities.</th> + <th>Long. of<br />Perihelion.</th> +</tr> +<tr> + <td class="tdc"><ins class="info" title="Jupiter.">♃</ins></td> + <td class="tdc">1 ⁄ 1648</td> + <td class="tdr0">494.800.000</td> + <td class="tdr">0.0481</td> + <td class="tdr">11°</td> +</tr> +<tr> + <td class="tdc"><ins class="info" title="Saturn.">♄</ins></td> + <td class="tdc">1 ⁄ 3310</td> + <td class="tdr0">907.162.000</td> + <td class="tdr">0.0561</td> + <td class="tdr">89°</td> +</tr> +<tr> + <td class="tdc"><ins class="info" title="Uranus.">♅</ins></td> + <td class="tdc">1 ⁄ 23000</td> + <td class="tdr0">1824.290.000</td> + <td class="tdr">0.0166</td> + <td class="tdr">167°</td> +</tr> +<tr> + <td class="tdc"><ins class="info" title="Neptune.">♆</ins></td> + <td class="tdc">1 ⁄ 20000</td> + <td class="tdr0">2854.000.000</td> + <td class="tdr">0.0088</td> + <td class="tdr">0°</td> +</tr> +<tr> + <td class="tdc"><ins class="info" title="Right-angled triangle notation.">⊿</ins></td> + <td class="tdc">1 ⁄ 28000</td> + <td class="tdr0">4464.000.000</td> + <td></td> + <td></td> +</tr> +</table> + +<table summary="Table comparing the number of solar spots with data on the radius vector and longitude." style="margin-top:2em;"> +<tr> + <th colspan="2">Dates.</th> + <th>Rad. vector.</th> + <th>Sun’s long.</th> + <th colspan="3">Ordinates.</th> + <th colspan="2">No. of spots in<br />Schwabe’s table.</th> +</tr> +<tr> + <td class="tdc">Jan. 1,</td> + <td>1826</td> + <td class="tdc">528,000</td> + <td class="tdr">320°</td> + <td class="tdc">+</td> + <td class="tdr0">84</td> + <td></td> + <td class="tdr0">118</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1827</td> + <td class="tdc">480,000</td> + <td class="tdr">339°</td> + <td class="tdc">+</td> + <td class="tdr0">36</td> + <td></td> + <td class="tdr0">161</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1828</td> + <td class="tdc">432,000</td> + <td class="tdr">352°</td> + <td class="tdc">−</td> + <td class="tdr0">12</td> + <td>Max.</td> + <td class="tdr0">225</td> + <td>Max.</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1829</td> + <td class="tdc">397,000</td> + <td class="tdr">38°</td> + <td class="tdc">−</td> + <td class="tdr0">47</td> + <td></td> + <td class="tdr0">199</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1830</td> + <td class="tdc">858,000</td> + <td class="tdr">71°</td> + <td class="tdc">−</td> + <td class="tdr0">86</td> + <td></td> + <td class="tdr0">190</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1831</td> + <td class="tdc">324,000</td> + <td class="tdr">104°</td> + <td class="tdc">−</td> + <td class="tdr0">120</td> + <td></td> + <td class="tdr0">149</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1832</td> + <td class="tdc">311,000</td> + <td class="tdr">144°</td> + <td class="tdc">−</td> + <td class="tdr0">133</td> + <td></td> + <td class="tdr0">84</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1833</td> + <td class="tdc">300,000</td> + <td class="tdr">183°</td> + <td class="tdc">−</td> + <td class="tdr0">144</td> + <td>Min.</td> + <td class="tdr0">33</td> + <td>Min.</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1834</td> + <td class="tdc">307,000</td> + <td class="tdr">220°</td> + <td class="tdc">−</td> + <td class="tdr0">137</td> + <td></td> + <td class="tdr0">51</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1835</td> + <td class="tdc">338,000</td> + <td class="tdr">263°</td> + <td class="tdc">−</td> + <td class="tdr0">106</td> + <td></td> + <td class="tdr0">173</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1836</td> + <td class="tdc">380,000</td> + <td class="tdr">302°</td> + <td class="tdc">−</td> + <td class="tdr0">55</td> + <td></td> + <td class="tdr0">272</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1837</td> + <td class="tdc">419,000</td> + <td class="tdr">337°</td> + <td class="tdc">+</td> + <td class="tdr0">25</td> + <td>Max.</td> + <td class="tdr0">333</td> + <td>Max.</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1838</td> + <td class="tdc">488,000</td> + <td class="tdr">3°</td> + <td class="tdc">+</td> + <td class="tdr0">44</td> + <td></td> + <td class="tdr0">282</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1839</td> + <td class="tdc">651,000</td> + <td class="tdr">29°</td> + <td class="tdc">+</td> + <td class="tdr0">107</td> + <td></td> + <td class="tdr0">162</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1840</td> + <td class="tdc">632,000</td> + <td class="tdr">51°</td> + <td class="tdc">+</td> + <td class="tdr0">188</td> + <td></td> + <td class="tdr0">152</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1841</td> + <td class="tdc">680,000</td> + <td class="tdr">80°</td> + <td class="tdc">+</td> + <td class="tdr0">236</td> + <td></td> + <td class="tdr0">102</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1842</td> + <td class="tdc">730,000</td> + <td class="tdr">105°</td> + <td class="tdc">+</td> + <td class="tdr0">286</td> + <td></td> + <td class="tdr0">68</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1843</td> + <td class="tdc">160,000</td> + <td class="tdr">128°</td> + <td class="tdc">+</td> + <td class="tdr0">322</td> + <td></td> + <td class="tdr0">34</td> + <td>Min.</td> +</tr> +<tr> + <td class="tdc"><span class="pagenum" title="Page 152"> </span><a name="Page_152" id="Page_152"></a>"</td> + <td>1844</td> + <td class="tdc">188,000</td> + <td class="tdr">152°</td> + <td class="tdc">+</td> + <td class="tdr0">339</td> + <td>Min.</td> + <td class="tdr0">52</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1845</td> + <td class="tdc">772,000</td> + <td class="tdr">174°</td> + <td class="tdc">+</td> + <td class="tdr0">328</td> + <td></td> + <td class="tdr0">114</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1846</td> + <td class="tdc">728,000</td> + <td class="tdr">196°</td> + <td class="tdc">+</td> + <td class="tdr0">284</td> + <td></td> + <td class="tdr0">157</td> + <td></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1847</td> + <td class="tdc">660,000</td> + <td class="tdr">218°</td> + <td class="tdc">+</td> + <td class="tdr0">216</td> + <td></td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1848</td> + <td class="tdc">563,000</td> + <td class="tdr">240°</td> + <td class="tdc">+</td> + <td class="tdr0">119</td> + <td></td> + <td colspan="2">Observed. Max.</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1849</td> + <td class="tdc">447,000</td> + <td class="tdr">261°</td> + <td class="tdc">+</td> + <td class="tdr0">3</td> + <td>Max.</td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1850</td> + <td class="tdc">309,000</td> + <td class="tdr">283°</td> + <td class="tdc">−</td> + <td class="tdr0">135</td> + <td></td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1851</td> + <td class="tdc">170,000</td> + <td class="tdr">323°</td> + <td class="tdc">−</td> + <td class="tdr0">274</td> + <td></td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1852</td> + <td class="tdc"> 53,000</td> + <td class="tdr">41°</td> + <td class="tdc">−</td> + <td class="tdr0">391</td> + <td>Min.</td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1853</td> + <td class="tdc">167,000</td> + <td class="tdr">133°</td> + <td class="tdc">−</td> + <td class="tdr0">277</td> + <td></td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1854</td> + <td class="tdc">315,000</td> + <td class="tdr">160°</td> + <td class="tdc">−</td> + <td class="tdr0">129</td> + <td></td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1855</td> + <td class="tdc">475,000</td> + <td class="tdr">183°</td> + <td class="tdc">+</td> + <td class="tdr0">31</td> + <td>Max.</td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1856</td> + <td class="tdc">611,000</td> + <td class="tdr">203°</td> + <td class="tdc">+</td> + <td class="tdr0">167</td> + <td></td> + <td colspan="2"></td> +</tr> +<tr> + <td class="tdc">"</td> + <td>1857</td> + <td class="tdc">720,000</td> + <td class="tdr">225°</td> + <td class="tdc">+</td> + <td class="tdr0">276</td> + <td></td> + <td colspan="2"></td> +</tr> +</table> + +<p>It is necessary to observe here, that the values of the numbers in +Schwabe’s table are the numbers for the whole year, and, therefore, the +1st of July would have been a better date for the comparison; but, as +the table was calculated before the author was cognizant of the fact, +and being somewhat tedious to calculate, he has left it as it was, viz., +for January 1st of each year. Hence, the minimum for 1843 appears as +pertaining to 1844. The number of spots ought to be inversely as the +ordinates approximately—these last being derived from the Radii +Vectores minus, the semi-diameter of the sun = 444,000 miles.</p> + +<p>In passing judgment on this relation, it must also be borne in mind, +that the recognized masses of the planets cannot be the true masses, if +the theory be true. Both sun and planets are under-estimated, yet, as +they are, probably, all to a certain degree proportionally undervalued, +it will not vitiate the above calculation much.</p> + +<p>The spots being considered as solar storms, they ought also to vary in +number at different times of the year, according to the longitude of the +earth and sun, and from their transient character, and the slow rotation +of the sun, they ought, <i>ceteris<span class="pagenum" title="Page 153"> </span><a name="Page_153" id="Page_153"></a> paribus</i>, to be more numerous when the +producing vortex is over a visible portion of the sun’s surface.</p> + +<p>The difficulty of reconciling the solar spots, and their periodicity to +any known principle of physics, ought to produce a more tolerant spirit +amongst the scientific for speculations even which may afford the +slightest promise of a solution, although emanating from the humblest +inquirer after truth. The hypothesis of an undiscovered planet, exterior +to Neptune, is of a nature to startle the cautions timidity of many; +but, if the general theory be true, this hypothesis becomes extremely +probable. We may not have located it exactly. There may be even two such +planets, whose joint effect shall be equivalent to one in the position +we have assigned. There may even be a comet of great mass, capable of +producing an effect on the position of the sun’s centre (although it +follows from the theory that comets have very little mass). Yet, in view +of all these suppositions, there can be but little doubt that the solar +spots are caused by the solar vortices, and these last made effective on +the sun by the positions of the great planets, and, therefore, we have +indicated a new method of determining the existence and position of all +the planets exterior to Neptune. On the supposition that there is only +one more in the system, from its deduced distance and mass, it will +appear only as a star of the eleventh magnitude, and, consequently, will +only be recognizable by its motion, which, at the greatest, will only be +ten or eleven seconds per day.</p> + + +<h3>MASSES OF THE SUN AND PLANETS.</h3> + +<p>We have alluded to the fact of the radial stream of the sun necessarily +diminishing the sun’s power, and, consequently, diminishing his apparent +mass. The radial stream of all the planets will do the same, so that +each planet whose mass is derived from the periodic times of the +satellites, will also appear<span class="pagenum" title="Page 154"> </span><a name="Page_154" id="Page_154"></a> too small. But, there is also a great +probability that some modification must be made in the wording of the +Newtonian law. The experiments of Newton on the pendulum, with every +variety of substance, was sufficient justification to entitle him to +infer, that inertia was as the weight of matter universally. But, there +was one condition which could not be observed in experimenting on these +substances, viz., the difference of temperature existing between the +interior and surface of a planet.</p> + +<p>We have already expressed the idea, that the cause of gravity has no +such mysterious origin as to transcend the power of man to determine it. +But that, on the contrary, we are taught by every analogy around us, as +well as by divine precept, to use the visible things of creation as +stepping stones to the attainment of what is not so apparent. That we +have the volume of nature spread out in tempting characters, inviting us +to read, and, assuredly, it is not so spread in mockery of man’s limited +powers. As science advances, strange things, it is true, are brought to +light, but the more <i>rational</i> the queries we propound, in every case +the more satisfactory are the answers. It is only when man consults the +oracle in irrational terms that the response is ambiguous. Alchemy, with +its unnatural transmutations, has long since vanished before the +increasing light. Why should not attraction also? Experience and +experiment, if men would only follow their indications, are consistently +enforcing the necessity of erasing these antiquated chimeras from the +book of knowledge; and inculcating the great truth, that the physical +universe owes all its endless variety to differences in the form, size, +and density of planetary atoms in motion, according to simple mechanical +principles. These, combined with the existence of an all-pervading +medium filling space, between which and planetary matter no bond of +union subsists, other than that which arises from a continual +interchange of motion, are the materials from which the gems of nature +are elaborated. But, simplicity of means is what phil<span class="pagenum" title="Page 155"> </span><a name="Page_155" id="Page_155"></a>osophy has ever +been reluctant to admit, preferring rather the occult and obscure.</p> + +<p>If action be equal to reaction, and all nature be vibrating with motion, +these motions must necessarily interfere, and some effect should be +produced. A body radiating its motion on every side into a physical +medium, produces waves. These waves are a mechanical effect, and the +body parts with some of its motion in producing them; but, should +another body be placed in juxtaposition, having the same motion, the +opposing waves neutralize each other, and the bodies lose no motion from +their contiguous sides, and, therefore, the reaction from the opposite +sides acts as a propelling power, and the bodies approach, or tend to +approach each other. If one body be of double the inertia, it moves only +half as far as the first; then, seeing that this atomic motion is +radiated, the law of force must be directly as the mass, and inversely +as the squares of the distances. There may be other atomic vibrations +besides those which we call light, heat, and chemical action, yet the +joint effect of all is infinitesimally small, when we disregard the +united <i>attraction</i> of all the atoms of which the earth is composed. The +<i>attraction</i> of the whole earth at the surface causes bodies to fall 16 feet +the first second of time; but, if two spheres of ice of one foot +diameter, were placed in an infinite space, uninfluenced by other +matter, and only 16 feet apart, they would require nearly 10,000 years +to fall together by virtue of their mutual attraction. Our conceptions, +or, rather, our misconceptions, concerning the force of gravity, arises +from our forgetting that every pound of matter on the earth contributes +its share of the force which, in the aggregate, is so powerful. Hence, +the cause we have suggested, is fully adequate to account for the +phenomena. Whether the harmony of vibrations between two bodies may not +have an influence in determining the amount of interference, and, +consequently, produce <i>some</i> difference between the gravitating mass<span class="pagenum" title="Page 156"> </span><a name="Page_156" id="Page_156"></a> +and its inertia, is a question which, no doubt, will ultimately be +solved; but this harmony of vibrations must depend, in some degree, on +the atomic weight, temperature, and intensity of atomic motion.</p> + +<p>That a part of the mass of the earth is <i>latent</i> may be inferred from +certain considerations: 1st, from the discrepancies existing in the +results obtained for the earth’s compression by the pendulum and by +actual measurement; and, 2d, from the irregularity of that compression +in particular latitudes and longitudes. The same may also be deduced +from the different values of the moon’s mass as derived from different +phenomena, dependent on the law of gravitation. Astronomers have +hitherto covered themselves with the very convenient shield of errors of +observation; but, the perfection of modern instruments now demand a +better account of all outstanding discrepancies. The world requires it +of them.</p> + +<p>The mass of the moon comes out much greater by our theory than nutation +gives. The mass deduced from the theory is only dependent on the +relative inertiæ of the earth and moon. That given by nutation depends +on gravity. If, then, a part of the mass be latent, nutation will give +too small a value. But, in addition to this, we are justified in +doubting the strict wording of the Newtonian law, deriving our authority +from the very foundation stone of the Newtonian theory.</p> + +<p>It is well known that Newton suspected that the moon was retained in her +orbit by the same force which is usually called weight upon the surface, +sixteen years before the fact was confirmed, by finding a correspondence +in the fall of the moon and the fall of bodies on the earth. Usually, in +all elementary works, this problem is considered accurately solved. +Having formed a different idea of the mechanism of nature, this fact +presented itself as a barrier beyond which it was impossible to pass, +until suspicions, derived from other sources, induced the author to +inquire: Whether the phenomenon did exactly<span class="pagenum" title="Page 157"> </span><a name="Page_157" id="Page_157"></a> accord with the theory? We +are aware that it is easy to place the moon at such a distance, that the +result shall strictly correspond with the fact; but, from the parallax, +as derived from observation (and if this cannot be depended on +certainly, no magnitudes in astronomy can), we find, <i>that the moon does +not fall from the tangent of her orbit, as much as the theory requires</i>. +As this is of vital importance to the integrity of the theory we are +advocating, we have made the computation on Newton’s own data, except +such as were necessarily inaccurate at the time he wrote; and we have +done it arithmetically, without logarithmic tables, that, if possible, +no error should creep in to vitiate the result. We take the moon’s +elements from no less an authority than Sir John Herschel, as well as +the value of the earth’s diameter.</p> + +<table summary="Facts about the moon."> +<tr> + <td>Mass of the moon</td> + <td>1 ⁄ 80</td> +</tr> +<tr> + <td style="padding-right:2em;">Mean distance in equatorial radii</td> + <td>59.96435</td> +</tr> +<tr> + <td>Sidereal period in seconds</td> + <td>2360591</td> +</tr> +</table> + +<p>The vibrations of the pendulum give the force of gravity at the surface +of the earth, and it is found to vary in different latitudes. The +intensity in any place being as the squares of the number of vibrations +in a given time. This inequality depends on the centrifugal force of +rotation, and on the spheroidal figure of the earth due to that +rotation. At the equator the fall of a heavy body is found to be +16.045223 feet, per second, and in that latitude the squares of whose +sine is ⅓, it is 16.0697 feet. The effect in this last-named +latitude is the same as if the earth were a perfect sphere. This does +not, however, express the whole force of gravity, as the rotation of the +earth causes a centrifugal tendency which is a maximum at the equator, +and there amounts to 1 ⁄ 289 of the whole gravitating force. In +other latitudes it is diminished in the ratio of the squares of the +cosines of the latitude; it therefore becomes 1 ⁄ 434 in that +latitude the square of whose sine is ⅓. Hence<span class="pagenum" title="Page 158"> </span><a name="Page_158" id="Page_158"></a> the fall per +second becomes 16.1067 feet for the true gravitating force of the earth, +or for that force which retains the moon in her orbit.</p> + +<p>The moon’s mean distance is 59.96435 equatorial radii of the earth, +which radius is, according to Sir John <ins class="correction" title="Transcriber’s note: Original reads ‘Herschell’.">Herschel</ins>, 20.923.713 feet. Her mean distance as derived from the <ins class="correction" title="Transcriber’s note: Original reads ‘parrallax’.">parallax</ins> is not to be +considered the radius vector of the orbit, inasmuch as the earth also +describes a small orbit around the common centre of gravity of the earth +and moon; neither is radius vector to be considered as her distance from +this common centre; for the attracting power is in the centre of the +earth. But the mean distance of the moon moving around a movable centre, +is to the same mean distance when the centre of attraction is fixed, as +the sum of the masses of the two bodies, to the first of two mean +proportionals between this sum and the largest of the two bodies +inversely. (Vid. Prin. Prop. 60 Lib. Prim.) The ratio of the masses +being as above 80 to 1 the mean proportional sought is 80.666 and in +this ratio must the moon’s mean distance be diminished to get the force +of gravity at the moon. Therefore as 81 is to 80.666, so is 59.96435 to +59.71657 for the moon’s distance in equatorial radii of the earth. +Multiply this last by 20.923.713 to bring the semi-diameter of the lunar +orbit into feet = 1.249.492.373, and this by 6.283185, the ratio of the +circumference to the radius, gives 7.850.791.736 feet, for the mean +circumference of the lunar orbit.</p> + +<p>Further, the mean sidereal period of the moon is 2360591 seconds and the +1 ⁄ 2360591th part of 7.850.791.736 is the arc the moon +describes in one second = 3325.77381 feet, the square of which divided +by the diameter of the orbit, gives the fall of the moon from the +tangent or versed size of that arc. += <a href="images/eqp158.png"><img src="images/eqp158_s.png" width="127" height="34" +alt="1106771.36876644 ⁄ 2498984746" +title="1106771.36876644 ⁄ 2498984746" /></a> += 0.004426106 feet.</p> + +<p>This fraction is, however, too small, as the ablatitious action<span class="pagenum" title="Page 159"> </span><a name="Page_159" id="Page_159"></a> of the +sun diminishes the attraction of the earth on the moon, in the ratio of +<a href="images/eqp159a.png"><img src="images/eqp159a_s.png" width="37" height="21" +alt="178 29 ⁄ 40" +title="178 29 ⁄ 40" /></a> +to +<a href="images/eqp159b.png"><img src="images/eqp159b_s.png" width="37" height="21" +alt="177 29 ⁄ 40" +title="177 29 ⁄ 40" /></a>. +So that we must increase the +fall of the moon in the ratio of 711 to 715, and hence the true fall of +the moon from the tangent of her orbit becomes 0.00451 feet per second.</p> + +<p>We have found the fall of a body at the surface of the earth, considered +as a sphere, 16.1067 feet per second, and the force of gravity +diminishes as the squares of the distances increases. The polar diameter +of the earth is set down as 7899.170 miles, and the equatorial diameter +7925.648 miles; therefore, the mean diameter is 7916.189 miles.<a name="FNanchor_36_36" id="FNanchor_36_36"></a><a href="#Footnote_36_36" class="fnanchor">[36]</a> So +that, reckoning in mean radii of the earth, the moon’s distance is +59.787925, which squared, is equal to 3574.595975805625. At one mean +radius distance, that is, at the surface, the force of gravity, or fall +per second, is as above, 16.1067 feet. Divide this by the square of the +distance, it is +<a href="images/eqp159c.png"><img src="images/eqp159c_s.png" style="height:2em;" +alt="16.1067 ⁄ 3574.595975805625" +title="16.1067 ⁄ 3574.595975805625" /></a> += 0.0045058 feet for +the force of gravity at the moon. But, from the preceding calculation, +it appears, that the moon only falls 0.0044510 feet in a second, showing +a deficiency of 1 ⁄ 82d part of the principal force that retains +the moon in her orbit, being more than double the whole disturbing power +of the sun, which is only 1 ⁄ 178th of the earth’s gravity at +the moon; yet, on this 1 ⁄ 178th depends the revolution of the +lunar apogee and nodes, and all those variations which clothe the lunar +theory with such formidable difficulties. The moon’s mass cannot be less +than 1 ⁄ 80, and if we consider it greater, as it no doubt is, +the results obtained will be still more discrepant. Much of this +discrepancy is owing to the expulsive power of the radial stream of the +terral vortex; yet, it may be suspected that the effect is too great to +be attributed to this, and, for this<span class="pagenum" title="Page 160"> </span><a name="Page_160" id="Page_160"></a> reason, we have suggested that the +fused matter of the moon’s centre may not gravitate with the same force +as the exterior parts, and thus contribute to increase the discrepancy.</p> + +<p>As there must be a similar effect produced by the radial stream of every +vortex, the masses of all the planets will appear too small, as derived +from their gravitating force; and the inertia of the sun will also be +greater than his apparent mass; and if, in addition to this, there be a +portion of these masses latent, we shall have an ample explanation of +the connection between the planetary densities and distances. We must +therefore inquire what is the particular law of force which governs the +radial stream of the solar vortex. It will be necessary to enter into +this question a little more in detail than our limits will justify; but +it is the resisting influence of the ether, and its consequences, which +will appear to present a vulnerable point in the present theory, and to +be incompatible with the perfection of astronomical science.</p> + + +<h3>LAW OF DENSITY IN SOLAR VORTEX.</h3> + +<p>Reverting to the dynamical principle, that the product of every particle +of matter in a fluid vortex, moving around a given axis, by its distance +from the centre and angular velocity, must ever be a constant quantity, +it follows that if the ethereal medium be uniformly dense, the periodic +times of the parts of the vortex will be directly as the distances from +the centre or axis; but the angular velocities being inversely as the +times, the absolute velocities will be equal at all distances from the +centre.</p> + +<p>Newton, in examining the doctrine of the Cartesian vortices, supposes +the case of a globe in motion, gradually communicating that motion to +the surrounding fluid, and finds that the periodic times will be in the +duplicate ratio of the distances from the centre of the globe. He and +his successors have always assumed that it was impossible for the +principle of gravity to<span class="pagenum" title="Page 161"> </span><a name="Page_161" id="Page_161"></a> be true, and a Cartesian plenum also; +consequently, the question has not been fairly treated. It is true that +Descartes sought to explain the motions of the planets, by the +mechanical action of a fluid vortex <i>solely</i>; and to Newton belongs the +glorious honor of determining, the existence of a centripetal force, +competent to explain these motions mathematically, (but not physically,) +and rashly rejected an intelligible principle for a miraculous virtue. +If our theory be true, the visible creation depends on the existence of +both working together in harmony, and that a physical medium is +absolutely necessary to the existence of gravitation.</p> + +<p>If space be filled with a fluid medium, analogy would teach us that it +is in motion, and that there must be inequalities in the direction and +velocity of that motion, and consequently there must be vortices. And if +we ascend into the history of the past, we shall find ample testimony +that the planetary matter now composing the members of the solar system, +was once one vast nebulous cloud of atoms, partaking of the vorticose +motion of the fluid involving them. Whether the gradual accumulation of +these atoms round a central nucleus from the surrounding space, and thus +having their tangential motion of translation converted into vorticose +motion, first produced the vortex in the ether; or whether the vortex +had previously existed, in consequence of conflicting currents in the +ether, and the scattered atoms of space were drawn into the vortex by +the polar current, thus forming a nucleus at the centre, as a necessary +result of the eddy which would obtain there, is of little consequence. +The ultimate result would be the same. A nucleus, once formed, would +give rise to a central force, tending more and more to counteract the +centripulsive power of the radial stream; and in consequence of this +continually increasing central power, the heaviest atoms would be best +enabled to withstand the radial stream, while the lighter atoms might be +carried away to the outer boundaries of the vortex, to congregate at +leisure, and,<span class="pagenum" title="Page 162"> </span><a name="Page_162" id="Page_162"></a> after the lapse of a thousand years, to again face the +radial stream in a more condensed mass, and to force a passage to the +very centre of the vortex, in an almost parabolic curve. That space is +filled with isolated atoms or planetary dust, is rendered very probable +by a fact discovered by Struve, that there is a gradual extinction in +the light of the stars, amounting to a loss of 1 ⁄ 107 of the whole, in +the distance which separates Sirius from the sun. According to Struve, +this can be accounted for, “by admitting as very probable that space is +filled with an <i>ether</i>, capable of intercepting in some degree the +light.” Is it not as probable that this extinction is due to planetary +dust, scattered through the pure ether, whose vibrations convey the +light,—the material atoms of future worlds,—the debris of dilapidated +comets? Does not the Scripture teach the same thing, in asserting that +the heavens are not clean?</p> + +<p>The theory of vortices has had many staunch supporters amongst those +deeply versed in the science of the schools. The Bernoullis proposed +several ingenious hypothesis, to free the Cartesian system from the +objections urged against it, viz.: that the velocities of the planets, +in accordance with the three great laws of Kepler, cannot be made to +correspond with the motion of a fluid vortex; but they, and all others, +gave the vantage ground to the defenders of the Newtonian philosophy, by +seeking to refer the principle of gravitation to conditions dependent on +the density and vorticose motion of the ether. When we admit that the +ether is imponderable and yet material, and planetary matter subject to +the law of gravitation, the objections urged against the theory of +vortices become comparatively trivial, and we shall not stop to refute +them, but proceed with the investigation, and consider that the ether is +the original source of the planetary motions and arrangements.</p> + +<p>On the supposition that the ether is uniformly dense, we have shown that +the periodic times will be directly as the distances from the axis. If +the density be inversely as the distances, the<span class="pagenum" title="Page 163"> </span><a name="Page_163" id="Page_163"></a> periodic times will be +equal. If the density be inversely as the square roots of the distances, +the times will be directly in the same ratio. The celebrated J. +Bernoulli assumed this last ratio; but seeking the source of motion in +the rotating central globe, he was led into a hypothesis at variance +with <ins class="correction" title="Transcriber’s note: Original reads ‘anology’.">analogy</ins>. The ellipticity of the orbit, according to this view, +was caused by the planet oscillating about a mean position,—sinking +first into the dense ether,—then, on account of superior buoyancy, +rising into too light a medium. Even if no other objection could be +urged to this view, the difficulty of explaining why the ether should be +denser near the sun, would still remain. We might make other +suppositions; for whatever ratio of the distances we assume for the +density of the medium, the periodic times will be compounded of those +distances and the assumed ratio. Seeing, therefore, that the periodic +times of the planets observe the direct ses-plicate ratio of the +distances, and that it is consonant to all analogy to suppose the +contiguous parts of the vortex to have the same ratio, we find that the +density of the ethereal medium in the solar vortex, is directly as the +square roots of the distances from the axis.</p> + +<p>Against this view, it may be urged that if the inertia of the medium is +so small, as is supposed, and its elasticity so great, there can be no +condensation by centrifugal force of rotation. It is true that when we +say the ether is condensed by this force, we speak incorrectly. If in an +infinite space of imponderable fluid a vortex is generated, the central +parts are rarefied, and the exterior parts are unchanged. But in all +finite vortices there must be a limit, outside of which the motion is +null, or perhaps contrary. In this case there may be a cylindrical ring, +where the medium will be somewhat denser than outside. Just as in water, +every little vortex is surrounded by a circular wave, visible by +reflection. As the density of the planet Neptune appears, from present +indications, to be a little denser than Uranus, and Uranus is denser +than Saturn, we may conceive that there is<span class="pagenum" title="Page 164"> </span><a name="Page_164" id="Page_164"></a> such a wave in the solar +vortex, near which rides this last magnificent planet, whose ring would +thus be an appropriate emblem of the peculiar position occupied by +Saturn. This may be the case, although the probability is, that the +density of Saturn is much greater than it appears, as we shall presently +explain.</p> + +<p>In order to show that there is nothing extravagant in the supposition of +the density of the ether being directly as the square roots of the +distances from the axis, we will take a fluid whose law of density is +known, and calculate the effect of the centrifugal force, considered as +a compressing power. Let us assume our atmosphere to be 47 miles high, +and the compressing power of the earth’s gravity to be 289 times greater +than the centrifugal force of the equator, and the periodic time of +rotation necessary to give a centrifugal force at the equator equal to +the gravitating force to be 83 minutes. Now, considering the gravitating +force to be uniform, from the surface of the earth upwards, and knowing +from observation that at 18,000 feet above the surface, the density of +the air is only ½, it follows, (in accordance with the principle that +the density is as the compressing force,) that at 43½ miles high, or +18,000 feet <i>below</i> the surface of the atmosphere, the density is only +1 ⁄ 8000 part of the density at the surface of the earth. Let us +take this density as being near the limit of expansion, and conceive a +hollow tube, reaching from the sun to the orbit of Neptune, and that +this end of the tube is closed, and the end at the sun communicates with +an inexhaustible reservoir of such an attenuated gas as composes the +upper-layer of our atmosphere; and further, that the tube is infinitely +strong to resist pressure, without offering resistance to the passage of +the air within the tube; then we say, that, if the air within the tube +be continually acted on by a force equal to the mean centrifugal force +of the solar vortex, reckoning from the sun to the orbit of Neptune, the +density of the air at that extremity of the tube, would be<span class="pagenum" title="Page 165"> </span><a name="Page_165" id="Page_165"></a> greater than +the density of a fluid formed by the compression of the ocean into one +single drop. For the centrifugal force of the vortex at 2,300,000 miles +from the centre of the sun, is equal to gravity at the surface of the +earth, and taking the mean centrifugal force of the whole vortex as +one-millionth of this last force; so that at 3,500,000 miles from the +surface of the sun, the density of the air in the tube (supposing it +obstructed at that distance) would be double the density of the +attenuated air in the reservoir. And the air at the extremity of the +tube reaching to the orbit of Neptune, would be as much denser than the +air we breathe, as a number expressed by 273 with 239 ciphers annexed, +is greater than unity. This is on the supposition of infinite +compressibility. Now, in the solar vortex there is no physical barrier +to oppose the passage of the ether from the centre to the circumference, +and the density of the ethereal ocean must be considered uniform, except +in the interior of the stellar vortices, where it will be rarefied; and +the rarefaction will depend on the centrifugal force and the length of +the axis of the vortex. If this axis be very long, and the centrifugal +velocity very great, the polar influx will not be sufficient, and the +central parts will be rarefied. We see, therefore, no reason why the +density of the ether may not be three times greater at Saturn than at +the earth, or as the square roots of the distances directly.</p> + + +<h3>BODES’ LAW OF PLANETARY DISTANCES.</h3> + +<p>Thus, in the solar vortex, there will be two polar currents meeting at +the sun, and thence being deflected at right angles, in planes parallel +to the central plane of the vortex, and strongest in that central plane. +The velocity of expansion must, therefore, diminish from the divergence +of the radii, as the distances increase; but in advancing along these +planes, the ether of the vortex is continually getting more dense, +which<span class="pagenum" title="Page 166"> </span><a name="Page_166" id="Page_166"></a> operate by absorption or condensation on the radial stream; so +that the velocity is still more diminished, and this in the ratio of the +square roots of the distances directly. By combining these two ratios, +we find that the velocity of the radial stream will be in the +ses-plicate ratio of the distances inversely. But the force of this +stream is not as the velocity, but as the square of the velocity. The +<i>force</i> of the radial stream is consequently as the cubes of the +distances inversely, from the axis of the vortex, reckoned in the same +plane. If the ether, however, loses in velocity by the increasing +density of the medium, it becomes also more dense; therefore the true +force of the radial stream will be as its density and the square of its +velocity, or directly as the square roots of the distances, and +inversely as the cubes of the distances, or as the 2.5 power of the +distances inversely.</p> + +<p>If we consider the central plane of the vortex as coincident with the +plane of the ecliptic, and the planetary orbits, also, in the same +plane; and had the force of the radial stream been inversely as the +square of the distances, there could be no disturbance produced by the +action of the radial stream. It would only counteract the gravitation of +the central body by a certain amount, and would be exactly proportioned +at all distances. As it is, there is an outstanding force as a +disturbing force, which is in the inverse ratio of the square roots of +the distances from the sun; and to this is, no doubt, owing, in part, +the fact, that the planetary distances are arranged in the inverse order +of their densities.</p> + +<p>Suppose two planets to have the same diameter to be placed in the same +orbit, they will only be in equilibrium when their densities are equal. +If their densities are unequal, the lighter planet will continually +enlarge its orbit, until the force of the radial stream becomes +proportional to the <ins class="correction" title="Transcriber’s note: Original omitted the apostrophe.">planets’</ins> resisting energy. This, however, is on the +hypothesis that the planets are not permeable by the radial stream, +which, perhaps, is more<span class="pagenum" title="Page 167"> </span><a name="Page_167" id="Page_167"></a> consistent with analogy than with the reality. +And it is more probable that the mean atomic weight of a planet’s +elements tends more to fix the position of equilibrium for each. Under +the law of gravity, a planet may revolve at any distance from the sun, +but if we superadd a centripulsive force, whose law is not that of +gravity, but yet in some inverse ratio of the distances, and this force +acts only superficially, it would be possible to make up in volume what +is wanted in density, and a lighter planet might thus be found occupying +the position of a dense planet. So the planet Jupiter, respecting only +his resisting surface, is better able to withstand the force of the +radial stream at the earth than the earth itself. To understand this, it +is necessary to bear in mind, that, as far as planetary matter is +concerned, the earth would revolve in Jupiter’s orbit in the same +periodic time as Jupiter, under the law of gravity: but that, in +reality, the whole of the gravitating force is not effective, and that +the equilibrium of a planet is due to a nice balance of interfering +forces arising from the planet’s physical peculiarities. As in a +refracting body, the density of the ether may be considered inversely as +the refraction, and this as the atomic weight of the refracting +material, so, also, in a planet, the density of the ether will be +inversely in the same ratio of the density of the matter approximately. +Hence, the density of the ether within the planet Jupiter is greater +than that within the earth; and, on this ethereal matter, the sun has no +power to restrain it in its orbit, so that the centrifugal momentum of +Jupiter would be relatively greater than the centrifugal momentum of the +earth, were it also in Jupiter’s orbit with the same periodic time. +Hence, to make an equilibrium, the earth should revolve in a medium of +less density, that there may be the same proportion between the external +ether, and the ether within the earth, as there is between the ether +around Jupiter and the ether within; so that the centrifugal tendency of +the dense ether at Jupiter shall counteract the greater momentum of the<span class="pagenum" title="Page 168"> </span><a name="Page_168" id="Page_168"></a> +dense ether within Jupiter; or, that the lack of centrifugal momentum in +the earth should be rendered equal to the centrifugal momentum of +Jupiter, by the deficiency of the centrifugal momentum of the ether at +the distance of the earth.</p> + +<p>If then, the diameters of all the planets were the same (supposing the +ether to act only superficially), the densities would be as the +distances inversely;<a name="FNanchor_37_37" id="FNanchor_37_37"></a><a href="#Footnote_37_37" class="fnanchor">[37]</a> for the force due to the radial stream is as +the square roots of the distance inversely, and the force due to the +momentum, if the density of the ether within a planet be inversely as +the square root of a planet’s distance, will also be inversely as the +square roots of the distances approximately. We offer these views, +however, only as suggestions to others more competent to grapple with +the question, as promising a satisfactory solution of Bode’s empirical +formula.</p> + +<p>If there be a wave of denser ether cylindrically disposed around the +vortex at the distance of Saturn, or between Saturn and Uranus, we see +why the law of densities and distances is not continuous. For, if the +law of density changes, it must be owing to such a ring or wave. Inside +this wave, the two forces will be inverse; but outside, one will be +inverse, and the other direct: hence, there should also be a change in +the law of distances. As this change does not take place until we pass +Uranus, it may be suspected that the great disparity in the density of +Saturn may be more apparent than real. The density of a planet is the +relation between its mass and volume or extension, no matter what the +form of the body may be. From certain observations of Sir Wm. +Herschel—the Titan of practical astronomers—the figure of Saturn was +suspected to be that of a square figure, with the corners rounded off, +so as to leave both the equatorial and polar zones flatter than +pertained to a true spheroidal figure. The existence of an unbroken ring +around Saturn, certainly attaches a peculiarity to this planet which +prepares us to meet other departures from the usual<span class="pagenum" title="Page 169"> </span><a name="Page_169" id="Page_169"></a> order. And when we +reflect on the small density, and rapid rotation, the formation of this +ring, and the figure suspected by Sir Wm. Herschel, it is neither +impossible nor improbable, that there may be a cylindrical vacant space +surrounding the axis of Saturn, or at least, that his solid parts may be +cylindrical, and his globular form be due to elastic gases and vapors, +which effectually conceal his polar openings. And also, by dilating and +contracting at the poles, in consequence of inclination to the radial +stream, (just as the earth’s atmosphere is bulged out sufficiently to +affect the barometer at certain hours every day,) give that peculiarity +of form in certain positions of the planet in its orbit. Justice to Sir +Wm. Herschel requires that <i>his</i> observations shall not be attributed to +optical illusions. This view, however, which may be true in the case of +Saturn, would be absurd when applied to the earth, as has been done +within the present century. From these considerations, it is at least +possible, that the density of Saturn may be very little less, or even +greater than the density of Uranus, and be in harmony with the law of +distances.</p> + +<p>It is now apparently satisfactorily determined, that Neptune is denser +than Uranus, and the law being changed, we must look for transneptunean +planets at distances corresponding with the new law of arrangement. But +there are other modifying causes which have an influence in fixing the +precise position of equilibrium of a planet. Each planet of the system +possessing rotation, is surrounded by an ethereal vortex, and each +vortex has its own radial stream, the force of which in opposing the +radial stream of the sun, depends on the diameter and density of the +planet, on the velocity of rotation, on the inclination of its axis, and +on the density of the ether at each particular vortex; but the numerical +verification of the position of each planet with the forces we have +mentioned, cannot be made in the present state of the question. There is +one fact worthy of note, as bearing on the theory of vortices in +connection with<span class="pagenum" title="Page 170"> </span><a name="Page_170" id="Page_170"></a> the rotation of the planets, viz.: that observation has +determined that the axial rotation and sidereal revolution of the +secondaries, are identical; thus showing that they are without vortices, +and are motionless relative to the ether of the vortex to which they +belong. We may also advert to the theory of Doctor Olbers, that the +<ins class="correction" title="Transcriber’s note: Original reads ‘asterodial’.">asteroidal</ins> group, are the fragments of a larger planet which once +filled the vacancy between Mars and Jupiter. Although this idea is not +generally received, it is gathering strength every year by the discovery +of other <i>fragments</i>, whose number now amounts to twenty-six. If the +idea be just, our theory offers an explanation of the great differences +observable in the mean distances of these bodies, and which would +otherwise form a strong objection against the hypothesis. For if these +little planets be fragments, there will be differences of density +according as they belonged to the central or superficial parts of the +quondam planet, and their mean distances must consequently vary also.</p> + +<p>There are some other peculiarities connecting the distances and +densities, to which we shall devote a few words. In the primordial state +of the system, when the nebulous masses agglomerated into spheres, the +diameter of these nebulous spheres would be determined by the relation +existing between the rotation of the mass, and the gravitating force at +the centre; for as long as the centrifugal force at the equator exceeded +the gravitating force, there would be a continual throwing off of matter +from the equator, as fast as it was brought from the poles, until a +balance was produced. It is also extremely probable, (especially if the +elementary components of water are as abundant in other planets as we +have reason to suppose them to be on the earth,) that the condensation +of the gaseous planets into liquids and solids, was effected in a <i>brief +period of time</i>,<a name="FNanchor_38_38" id="FNanchor_38_38"></a><a href="#Footnote_38_38" class="fnanchor">[38]</a> leaving the lighter and more elastic substances as +a nebulous<span class="pagenum" title="Page 171"> </span><a name="Page_171" id="Page_171"></a> atmosphere around globes of semi-fluid matter, whose +diameters have never been much increased by the subsequent condensation +of their gaseous envelopes. The extent of these atmospheres being (in +the way pointed out) determined by the rotation, their subsequent +condensation has not therefore changed the original rotation of the +central globe by any appreciable quantity. The present rotation of the +planets, is therefore competent to determine the former diameters of the +nebulous planets, <ins class="correction" title="Transcriber’s note: This instance, unlike the others, was not italicized in the original."><i>i.e.</i></ins>, the limit where the present central force +would be balanced by the centrifugal force of rotation. If we make the +calculation for the planets, and take for the unit of each planet its +present diameter, we shall find that they have condensed from their +original nebulous state, by a quantity dependent on the distance, from +the centre of the system; and therefore on the original temperature of +the nebulous mass at that particular distance. Let us make the +calculation for Jupiter and the earth, and call the original nebulous +planets the nucleus of the vortex. We find <ins class="correction" title="Transcriber’s note: Original has a paragraph break here.">the +Equatorial</ins> diameter of Jupiter’s nucleus in equatorial diameters of +Jupiter = 2.21, and the equatorial diameter of the earth’s nucleus, in +equatorial diameters of the earth = 6.59. Now, if we take the original +temperature of the nebulous planets to be inversely, as the squares of +the distances from the sun, and their volumes directly as the cubes of +the diameters in the unit of each, we find that these cubes are to each +other, in the inverse ratio of the squares of the planet’s distances; +for,</p> + +<p class="center">2.21<sup>3</sup> : 6.59<sup>3</sup> : : 1<sup>2</sup> : 5.2<sup>2</sup>,</p> + +<p>showing that both planets have condensed equally, allowing for the +difference of temperature at the beginning. And we shall find, beginning +at the sun, that the diameters of the nebulous planets, <i>ceteris +paribus</i>, diminish outwards, giving for the nebulous sun a diameter of +16,000,000 miles,<a name="FNanchor_39_39" id="FNanchor_39_39"></a><a href="#Footnote_39_39" class="fnanchor">[39]</a> thus indicating his original great temperature.</p> + +<p><span class="pagenum" title="Page 172"> </span><a name="Page_172" id="Page_172"></a>That the original nebulous planets did rotate in the same time as they +do at present, is proved by Saturn’s ring; for if we make the +calculation, about twice the diameter of Saturn. Now, the diameter of +the planet is about 80,000 miles, which will also be the semi-diameter +of the nebulous planet; and the middle of the outer ring has also a +semi-diameter of 80,000 miles; therefore, the ring is the equatorial +portion of the original nebulous planet, and ought, on this theory, to +rotate in the same time as Saturn. According to Sir John Herschel, +Saturn rotates in 10 hours, 29 minutes, and 17 seconds, and the ring +rotates in 10 hours, 29 minutes, and 17 seconds: yet this is not the +periodic time of a satellite, at the distance of the middle of the ring; +neither ought the rings to rotate in the same time; yet as far as +observation can be trusted, both the inner and outer ring do actually +rotate in the same time. The truth is, the ring rotates too fast, if we +derive its centrifugal force from the analogy of its satellites; but it +is, no doubt, in equilibrium; and the effective mass of Saturn on the +satellites is less than the true mass, in consequence of his radial +stream being immensely increased by the additional force impressed on +the ether, by the centrifugal velocity of the ring. If this be so, the +mass of Saturn, derived from one of the inner satellites, will be less +than the same mass derived from the great satellite, whose orbit is +considerably inclined. The analogy we have mentioned, between the +diameters of the nebulous planets and their distances, does not hold +good in the case of Saturn, for the reason already assigned, viz.: that +the nebulous planet was probably not a globe, but a cylindrical ring, +vacant around the axis, as there is reason to suppose is the case at +present.</p> + +<p>And now we have to ask the question, Did the ether involved in the +nebulous planets rotate in the same time? This does not<span class="pagenum" title="Page 173"> </span><a name="Page_173" id="Page_173"></a> necessarily +follow. The ether will undoubtedly tend to move with increasing velocity +to the very centre of motion, obeying the great dynamical principle when +unresisted. If resisted, the law will perhaps be modified; but in this +case, its motion of translation will be converted into atomic motion or +heat, according to the motion lost by the resistance of atomic matter. +This question has a bearing on many geological phenomena. As regards the +general effect, however, the present velocity of the ether circulating +round the planets, may be considered much greater than the velocities of +the planets themselves.</p> + + +<h3>PERTURBATIONS DUE TO THE ETHER.</h3> + +<p>In these investigations it is necessary to bear in mind that the whole +resisting power of the ether, in disturbing the planetary movements, is +but small, in comparison with gravitation. We will, however, show that, +in the case of the planets, there is a compensation continually made by +this resistance, which leaves but a very small outstanding balance as a +disturbing power. If we suppose all the planets to move in the central +plane of the vortex in circular orbits, and the force of the radial +stream, (or that portion which is not in accordance with the law of +gravitation,) to be inversely as the square roots of the distances from +the sun, it is evident, from what has been advanced, that an equilibrium +could still obtain, by variations in the densities, distances and +diameter of the planets. Supposing, again, that the planets still move +in the same plane, but in elliptical orbits, and that they are in +equilibrium at their mean distances, under the influence or action of +the tangential current, the radial stream, and the density of the ether; +we see that the force of the radial stream is too great at the +perihelion, and too small at the aphelion. At the perihelion the planet +is urged from the sun and at the aphelion towards the sun. The density +and consequent momentum is also relatively too great at the<span class="pagenum" title="Page 174"> </span><a name="Page_174" id="Page_174"></a> perihelion, +which also urges the planet from the sun, and at the aphelion, +relatively too small, which urges the planet towards sun; and the law is +the same in both cases, being null at the mean distance of the planet, +at a maximum at the apsides; it is, consequently, as the cosine of the +<ins class="correction" title="Transcriber’s note: Original omitted the apostrophe.">planet’s</ins> eccentric anomaly at other distances, and is positive or +negative, according as the planet’s distance is above or below the mean.</p> + +<p>At the planet’s mean distance, the circular velocity of the vortex is +equal to the circular velocity of the planet, and, at different +distances, is inversely in the sub-duplicate ratio of those distances. +But the circular velocity of a planet in the same orbit, is in the +simple ratio of the distances inversely. At the perihelion, the planet +therefore moves faster than the ether of the vortex, and at the +aphelion, slower; and the difference is as the square roots of the +distances; but the force of resistance is as the square of the velocity, +and is therefore in the simple ratio of the distances, as we have +already found for the effect of the radial stream, and centrifugal +momentum of the internal ether. At the perihelion this excess of +tangential velocity creates a resistance, which urges the planet towards +the sun, and at the aphelion, the deficiency of tangential velocity +urges the planet from the sun,—the maximum effect being at the apsides +of the orbit, and null at the mean distances. In other positions it is, +therefore, as the cosines of the eccentric anomaly, as in the former +case; but in this last case it is an addititious force at the +perihelion, and an ablatitious force at the aphelion, whereas the first +disturbing force was an ablatitious force at the perihelion, and an +addititious force at the aphelion; therefore, as we must suppose the +planet to be in equilibrium at its mean distance, it is in equilibrium +at all distances. Hence, a planet moving in the central plane of the +vortex, experiences no disturbance from the resistance of the ether.</p> + +<p>As the eccentricities of the planetary orbits are continually changing +under the influence of the law of gravitation, we<span class="pagenum" title="Page 175"> </span><a name="Page_175" id="Page_175"></a> must inquire whether, +under these circumstances, such a change would not produce a permanent +derangement by a change in the mean force of the radial stream, so as to +increase or diminish the mean distance of the planet from the sun. The +law of force deduced from the theory for the radial stream is as the 2.5 +power of the distances inversely. But, by dividing this ratio, we may +make the investigation easier; for it is equivalent to two forces, one +being as the squares of the distances, and another as the square roots +of the distances. For the former force, we find that in orbits having +the same major axis the mean effect will be as the minor axis of the +ellipse <i>inversely</i>, so that two planets moving in different orbits, but +at the same mean distance, experience a less or greater amount of +centripulsive force from this radial stream, according as their orbits +are of less or greater eccentricity, and this in the ratio of the minor +axis. On the other hand, under the influence of a force acting +centripulsively in the inverse ratio of the square roots of the +distances, we find the mean effect to be as the minor axis of the +ellipse <i>directly</i>, so that two planets in orbits of different +eccentricity, but having the same major axis, experience a different +amount from the action of this radial stream, the least eccentric orbit +being that which receives the greatest mean effect. By combining these +two results, we get a ratio of equality; and, consequently, the action +of the radial stream will be the same for the same orbit, whatever +change may take place in the eccentricity, and the mean distance of the +planet will be unchanged. A little consideration will also show that the +effect of the centrifugal momentum due to the density of ether will also +be the same by change of eccentricity; for the positive will always +balance the negative effect at the greatest and least distances of the +planet. The same remark applies to the effect of the tangential current, +so that no change can be produced in the major axes of the planetary +orbits by change of eccentricity, as an effect of the resistance of the +ether.</p> + +<p><span class="pagenum" title="Page 176"> </span><a name="Page_176" id="Page_176"></a>We will now suppose a planet’s orbit to be inclined to the central plane +of the vortex, and in this case, also, we find, that the action of the +radial stream tends to increase the inclination in one quadrant as much +as it diminishes it in the next quadrant, so that no change of +inclination will result. But, if the inclination of the orbit be changed +by planetary perturbations, the mean effect of the radial stream will +also be changed, and this will tell on the major axis of the orbit, +enlarging the orbit when the inclination diminishes, and contracting it +when it increases. The change of inclination, however, must be referred +to the central plane of the vortex. Notwithstanding the perfection of +modern analysis, it is confessed that the recession of the moon’s nodes +does yet differ from the theory by its 350th part, and a similar +discrepancy is found for the advance of the perigee.<a name="FNanchor_40_40" id="FNanchor_40_40"></a><a href="#Footnote_40_40" class="fnanchor">[40]</a> This theory is +yet far too imperfect to say that the action of the ethereal medium will +account for these discrepancies; but it certainly wears a promising +aspect, worthy the notice of astronomers. There are other minute +discordancies between theory and observation in many astronomical +phenomena, which theory <i>is</i> competent to remove. Some of these we shall +notice presently; and, it may be remarked, that it is in those minute +quantities which, in astronomy, are usually attributed to errors of +observation, that this theory will eventually find the surest evidence +of its truth.</p> + + +<h3>KEPLER’S THIRD LAW ONLY APPROXIMATELY TRUE.</h3> + +<p>But it may be asked: If there be a modifying force in astronomy derived +from another source than that of gravitation, why is it that the +elements of the various members of the system derived solely from +gravitation should be so perfect? To this it may be answered, that +although astronomers have endeavored to derive every movement in the +heavens from that<span class="pagenum" title="Page 177"> </span><a name="Page_177" id="Page_177"></a> great principle, they have but partially succeeded. +Let us not surrender our right of examining Nature to the authority of a +great name, nor call any man master, either in moral or physical +science. It is well known that Kepler’s law of the planetary distances +and periods, is a direct consequence of the Newtonian Law of +gravitation, and that the squares of the periodic times ought to be +proportional to the cubes of the mean distances. These times are given +accurately by the planets themselves, by the interval elapsing between +two consecutive passages of the node, and as in the case of the ancient +planets we have observations for more than two thousand years past, +these times are known to the fraction of the second. The determination +of the distances however, depends on the astronomer, and a tyro in the +science might suppose that these distances were actually measured; and +so they are roughly; but the astronomer does not depend on his +instruments, he trusts to <i>analogy</i>, and the mathematical perfection of +a law, which in the abstract is true; but which he does not know is +rigidly exact when applied to physical phenomena. From the immense +distance of the planets and the smallness of the earth, man is unable to +command a base line sufficiently long, to make the horizontal parallax a +sensible angle for the more distant planets; and there are difficulties +of no small magnitude to contend with, with those that are the nearest. +In the occasional transit of Venus across the sun, however, he is +presented with a means of measuring on an enlarged scale, from which the +distance of the sun is determined; and by <i>analogy</i> the distance of all +the planets. Even the parallax of the sun itself is only correct, by +supposing that the square of the periodic time of Venus is in the same +proportion to the square of the periodic time of the earth as the cube +of her distance is to the cube of the earth’s distance. Our next nearest +planet is Mars, and observations on this planet at its opposition to the +sun, invariably give a larger parallax for the sun—Venus giving 8.5776″ +while Mars gives about 10″. It<span class="pagenum" title="Page 178"> </span><a name="Page_178" id="Page_178"></a> is true that the first is obtained under +more favorable circumstances; but this does not prove the last to be +incorrect. It is well known that the British Nautical Almanac contains a +list of stars lying in the path of the planet Mars about opposition, +(for the very purpose of obtaining a correct parallax,) that minute +differences of declination may be detected by simultaneous observations +in places having great differences of latitude. Yet strange to say, the +result is discredited when not conformable to the parallax given by +Venus. If then, we cannot trust the parallax of Mars, <i>à fortiori</i>, how +can we trust the parallax of Jupiter, and say that his mean distance +exactly corresponds to his periodic time? Let us suppose, for instance, +that the radius vector of Jupiter fell short of that indicated by +analogy by 10,000 miles, we say that it would be extremely difficult, +nay, utterly impossible, to detect it by instrumental means. Let not +astronomers, therefore, be too sure that there is not a modifying cause, +independent of gravitation, which they will yet have to recognize. The +moon’s distance is about one-fourth of a million of miles, and Neptune’s +2854 millions, or in the ratio of 10,000 to 1; yet even the moon’s +parallax is not trusted in determining her mass, how then shall we +determine the parallax of Neptune? It is therefore <i>possible</i> that the +effective action of the sun is in some small degree different, on the +different planets, whether due to the action of the ether, to the +similarity or dissimilarity of material elements, to the temperature of +the different bodies, or to all combined, is a question yet to be +considered.</p> + +<p>As another evidence of the necessity of modifying the strict wording of +the Newtonian law, it is found that the disturbing action of Jupiter on +different bodies, gives different values for the mass of Jupiter. The +mass deduced from Jupiter’s action on his satellites, is different from +that derived from the perturbations of Saturn, and this last does not +correspond with that<span class="pagenum" title="Page 179"> </span><a name="Page_179" id="Page_179"></a> given by Juno: Vesta also gives a different mass +from the comet of Encke, and both vary from the preceding values.<a name="FNanchor_41_41" id="FNanchor_41_41"></a><a href="#Footnote_41_41" class="fnanchor">[41]</a></p> + +<p>In the analytical investigation of planetary disturbances, the +disturbing force is usually divided into a radial and tangential force; +the first changing the law of gravitation, to which law the elliptic +form of the orbit is due. The radial disturbing force, therefore, being +directed to or from the centre, can have no influence over the first law +of Kepler, which teaches that the radius vector of each planet having +the sun as the centre, describes equal areas in equal times. If the +radial disturbing force be exterior to the disturbed body, it will +diminish the central force, and cause a progressive motion in the +aphelion point of the orbit. In the case of the moon this motion is very +rapid, the apogee making an entire revolution in 3232 days. Does this, +however, correspond with the law of gravitation? Sir Isaac Newton, in +calculating the effect of the sun’s disturbing force on the motion of +the moon’s apogee, candidly concludes thus: “Idoque apsis summa singulis +revolutionibus progrediendo conficit 1° 31′ 28″. Apsis lunæ est duplo +velocior circiter.” As there was a necessity for reconciling this +stubborn fact with the theory, his followers have made up the deficiency +by resorting to the tangential force, or, as Clairant proposed, by +continuing the approximations to terms of a higher order, or to the +square of the disturbing force.</p> + +<p>Now, in a circular orbit, this tangential force will alternately +increase and diminish the velocity of the disturbed body, without +producing any permanent derangement, the same result would obtain in an +elliptical orbit, if the position of the major axis were stationary. In +the case of the moon, the apogee is caused to advance by the disturbing +power of the radial force, and, consequently, an exact compensation is +not effected: there remains a small excess of velocity which geometers +have considered equivalent to a doubling of the radial force, and have<span class="pagenum" title="Page 180"> </span><a name="Page_180" id="Page_180"></a> +thus obviated the difficulty. To those not imbued with the profound +penetration of the modern analyst, there must ever appear a little +inconsistency in this result. The major axis of a planet’s orbit depends +solely on the velocity of the planet at a given distance from the sun, +and the tangential portion of the disturbance due to the sun, and +impressed upon the moon, must necessarily increase and diminish +alternately the velocity of the moon, and interfere with the equable +description of the areas. If, then, there be left outstanding a small +excess of velocity over and above the elliptical velocity of the moon, +at the end of each synodical revolution, in consequence of the motion +impressed on the moon’s apogee by the radial force, the <i>legitimate</i> +effect would be a small enlargement of the lunar orbit every revolution +in a rapidly-increasing ratio, until the moon would at last be taken +entirely away. In the great inequality of Jupiter and Saturn, this +tangential force is not compensated at each revolution, in consequence +of continual changes in the configuration of the two planets at their +heliocentric conjunctions, with respect to the perihelion of their +orbits, and the near commensurability of their periods; and the effect +of the tangential force is, in this case, legitimately impressed on the +major axes of the orbits. But why (we may ask) should not this also be +expended on the motion of the aphelion as well as in the case of the +moon? Astronomy can make no distinctions between the orbit of a planet +and the orbit of a satellite. And, we might also ask, why the tangential +resistance to the comet of Encke should not also produce a retrograde +motion in the apsides of the orbit, instead of diminishing its period? +To the honor of Newton, be it remembered, that he never resorted to an +explanation of this phenomenon, which would vitiate that fundamental +proposition of his theory, in which the major axis of the orbit is shown +to depend on the velocity at any given distance from the focus.</p> + +<p>Some cause, however, exists to double the motion of the<span class="pagenum" title="Page 181"> </span><a name="Page_181" id="Page_181"></a> apogee, and +that there is an outstanding excess of orbital velocity due to the +tangential force, is also true. This excess may tell in the way +proposed, provided some other arrangement exists to <i>prevent</i> a +permanent dilation of the lunar orbit; and this provision may be found +in the increasing density of the ether, which prevents the moon +overstepping the bounds prescribed by her own density, and the force of +the radial stream of the terral vortex. In the case of Jupiter and +Saturn, their mutual action is much less interfered with by change of +density in the ether in the enlarged or contracted orbit, and, +consequently, the effect is natural. Thus, we have in the law of density +of the ethereal medium a better safeguard to the stability of the +dynamical balance of the system, than in the profound and beautiful +Theorems of La Grange. It will, of course, occur to every one, that we +are not to look for the same law in every vortex, and it will, +therefore, appear as if the satellites of Jupiter, whose theory is so +well known, should render apparent any deviation between their periodic +times and the periodic times of the contiguous parts of the vortex, +which would obtain, if the density of the ether in the Jovian vortex +were not as the square roots of the distances directly. But, we have +shown how there can be a balance preserved, if the tangential resistance +of the vortex shall be equal and contrary at the different distances at +which the satellites are placed; that is, if these two forces shall +follow the same law. These are matters, however, for future +investigation.</p> + + +<h3>LIGHT AND HEAT.</h3> + +<p>But will not the admission of a vorticose motion of the ethereal medium, +affect the aberration of light? It is well known that the question has +been mooted, whether the velocity of reflected light is the same as that +of direct light. The value of aberration having been considered 20″.25, +from the eclipses<span class="pagenum" title="Page 182"> </span><a name="Page_182" id="Page_182"></a> of Jupiter’s satellites, while later determinations, +from observations on Polaris, give 20″.45. It cannot be doubted that +light, in traversing the central parts of the solar vortex, that is, +having to cross the whole orbit of the earth, should pass this distance +in a portion of time somewhat different to a similar distance outside +the earth’s orbit, where the density is greater, and consequently induce +an error in the aberration, determined by the eclipses of Jupiter’s +satellites. In the case of Polaris, the circumstances are more equal; +still, a difference ought to be detected between the deduced aberration +in summer and in winter, as, in the first case, the light passes near +the axis of the solar vortex, where (according to the theory) a change +of density occurs. This is an important practical question, and the +suggestion is worthy attention. Now, the <ins class="correction" title="Transcriber’s note: Original reads ‘questions’">question</ins> occurs, will light +pass through the rarefied space with greater velocity than through the +denser ether beyond? From recent experiments, first instituted by Arago, +it is determined that light passes with less velocity through water than +through air; and one result of these experiments is the confirmation +they give to the theory of Fresnel, that the medium which conveys the +action of light partly partakes of the motion of the refracting body. +This of itself is a strong confirmation of this theory of an ethereal +medium. It may also be remarked, that every test applied to the +phenomenon of light, adds additional strength to the undulatory theory, +at the expense of the Newtonian theory of emission. As light occupies +time in traversing space, it must follow from the theory that it does +not come from the radiant point exactly in straight lines, inasmuch as +the ether itself is in motion tangentially,—the velocity being in the +sub-duplicate ratio of the distances from the sun inversely.</p> + +<p>May not that singular phenomenon,—the projection of a star on the +moon’s disc, at the time of an occultation,—be due to this curvature of +the path of a ray of light, by considering that the rays from the moon +have less intensity, but more mechanical<span class="pagenum" title="Page 183"> </span><a name="Page_183" id="Page_183"></a> momentum, and consequently +more power to keep a straight direction? Let us explain: we have urged +that light, as well as heat, is a mechanical effect of atomic motion, +propagated through an elastic medium; that, <i>ceteris paribus</i>, the +product of matter by its motion is ever a constant quantity for equal +spaces throughout the universe,—in a word, that it is, and must +necessarily be, a fundamental law of nature. All departures from this +law are consequences of accidental arrangements, which can only be +considered of temporary duration. Our knowledge of planetary matter +requires the admission of differences in the density, form, and size of +ultimate atoms, and, according to the above law, when the atoms are of +uniform temperature or motion, the product of the matter of each by its +motion, when reduced to the same space, will be constant. The momentum +of two different atoms, therefore, we will consider equal, for the sake +of illustration; yet this momentum is made up of two different +elements,—matter and motion. Let us exaggerate the difference, and +assign a ratio of 1000 to 1. Suppose a ball of iron of 1000 lbs., +resting upon a horizontal plane, should be struck by another ball of 1 lb., having a motion of 1000 feet in a second, and, in a second case, +should be struck by a ball of 1000 lbs., having a velocity of 1 foot per +second, the momentum of each ball is similar; but experience proves that +the motion impressed on the ball at rest is not similar; the ponderous +weight and slow motion is far more effective in displacing this ball, +for the reason that time is essential to the distribution of the motion. +If the body to be struck be small as, for instance, a nail, a greater +motion and less matter is more effective than much matter and little +motion. Hence, we have a <i>distinction</i> applicable to the difference of +momentum of luminous and calorific rays. The velocity of a wave of sound +through the atmosphere, is the same for the deep-toned thunder and the +shrillest whistle,—being dependent on the density<span class="pagenum" title="Page 184"> </span><a name="Page_184" id="Page_184"></a> of the medium, and +not on the source from which it emanates. So it is in the ethereal +medium.</p> + +<p>This view is in accordance with the experiments of M. Delaroche and +Melloni, on the transmission of light and heat through diaphanous +bodies—the more calorific rays feeling more and more the influence of +thickness, showing that more motion was imparted to the particles of the +diaphanous substance by the rays possessing more material momentum, and +still more when the temperature of the radiating body was low, evidently +analogous to the illustration we have cited. Light may therefore be +regarded as the effect of the vibration of atoms having little mass, and +as this mass increases, the rays become more calorific, and finally the +calorific effect is the only evidence of their existence; as towards the +extreme red end of the spectrum they cease to be visible, owing to their +inability to impart their vibrations to the optic nerve. This may also +influence the law of gravitation. In this we have also an explanation of +the dispersion of light. The rays proceeding from atoms of small mass +having less material momentum, are the most refrangible, and those +possessing greater material momentum, are the least refrangible; so that +instead of presenting a difficulty in the undulatory theory of light, +this dispersion is a necessary consequence of its first principles.</p> + +<p>It is inferred from the experiments cited, and the facts ascertained by +them, viz.: that the velocity of light in water is less than its +velocity in air; that the density of the ether is greater in the first +case; but this by no means follows. We have advocated the idea, that the +ethereal medium is less dense within a refracting body than without. We +regard it as a fundamental principle. Taking the free ether of heaven; +the vibrations in the denser ether will no doubt be slowest; but within +a refracting body we must consider there is motion lost, or <i>light +absorbed</i>, and the time of the transmission is thus increased.</p> + +<p>There has been a phenomenon observed in transits of Mer<span class="pagenum" title="Page 185"> </span><a name="Page_185" id="Page_185"></a>cury and Venus +across the sun, of which no explanation has been rendered by +astronomers. When these planets are visible on the solar disc, they are +seen surrounded by rings, as if the light was intercepted and increased +alternately. This is no doubt due to a small effect of interference, +caused by change of velocity in passing through the rarefied nucleus of +these planetary vortices, near the body of the planet, and through the +denser ether beyond, acting first as a concave, and secondly as a convex +refracting body; always considering that the ray will deviate <i>towards</i> +the side of least insistence, and thus interfere.</p> + +<p>That heat is simply atomic motion, and altogether mechanical, is a +doctrine which ought never to have been questioned. The interest excited +by the bold experiments of Ericson, has caused the scientific to +<i>suspect</i>, that heat can be converted into motion, and motion into +heat—a fact which the author has considered too palpable to deny for +the last twenty years. He has ever regarded matter and motion as the two +great principles of nature, ever inseparable, yet variously combined; +and that without these two elements, we could have no conception of +anything existing.</p> + +<p>It may be thought by some, who are afraid to follow truth up the rugged +precipices of the hill of knowledge, that this theory of an +interplanetary plenum leads to materialism; forgetting, that He who made +the world, formed it of matter, and pronounced it “very good.” We may +consider ethereal matter, in one sense, <i>purer</i> than planetary matter, +because unaffected by chemical laws. Whether still purer matter exists, +it is not for us to aver or deny. The Scriptures teach us that “there is +a natural body and there is a spiritual body.” Beyond this we know +nothing. We, however, believe that the <i>invisible</i> world of matter, can +only be comprehended by the indications of that which is visible; yet +while humbly endeavoring to connect by<span class="pagenum" title="Page 186"> </span><a name="Page_186" id="Page_186"></a> one common tie, the various +phenomena of matter and motion, we protest against those doctrines which +teach the eternal duration of the present order of things, as being +incompatible with the analogies of the past, as well as with the +revelations of the future.</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_35_35" id="Footnote_35_35"></a><a href="#FNanchor_35_35">[35]</a></span>Silliman’s Journal, vol xxxv., page 283.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_36_36" id="Footnote_36_36"></a><a href="#FNanchor_36_36">[36]</a></span>The real diameter of the earth in that latitude, whose +sine is one-third, is a little greater than this; but the true mean is +more favorable for the Newtonian law.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_37_37" id="Footnote_37_37"></a><a href="#FNanchor_37_37">[37]</a></span>This is, perhaps, the nearest ratio of the densities and +distances.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_38_38" id="Footnote_38_38"></a><a href="#FNanchor_38_38">[38]</a></span>This is an important consideration, as bearing on the +geology of the earth.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_39_39" id="Footnote_39_39"></a><a href="#FNanchor_39_39">[39]</a></span>It is not as likely that the condensation of the sun was +so sudden as that of the planets, and therefore in this case this +distance is only approximate.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_40_40" id="Footnote_40_40"></a><a href="#FNanchor_40_40">[40]</a></span>Mechanique Celeste. Theory of the Moon.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_41_41" id="Footnote_41_41"></a><a href="#FNanchor_41_41">[41]</a></span>Mechanique Celeste. Masses of the planets.</p></div> +</div> + + +<hr style="width: 65%;" /> +<h2><span class="pagenum" title="Page 187"> </span><a name="Page_187" id="Page_187"></a><a name="SECTION_FIFTH" id="SECTION_FIFTH"></a>SECTION FIFTH.</h2> + + +<h3>COMETARY PHENOMENA.</h3> + +<p>The planetary arrangements of the solar system are all <i>à priori</i> +indications of the theory of vortices, not only by the uniform direction +of the motions, the circular orbits in which these motions are +performed, the near coincidence of the planes of these orbits, and the +uniform direction of the rotation of the planets themselves; but, also, +by the law of densities and distances, which we have already attempted +to explain. In the motions of comets we find no such agreement. These +bodies move in planes at all possible inclinations in orbits extremely +eccentrical and without any general direction—as many moving contrary +to the direction of the planets as in the opposite direction; and when +we consider their great volume, and their want of mass, it appears, at +first sight, that comets do present a serious objection to the theory. +We shall point out, however, a number of <i>facts</i> which tend to +invalidate this objection, and which will ultimately give the +preponderance to the opposite argument.</p> + +<p>Every fact indicative of the nature of comets proves that the nuclei are +masses of material gases, similar, perhaps (at least in the case of the +short-period comets), to the elementary gases of our own planet, and, +consequently, these masses must be but small. In the nascent state of +the system, the radial stream of the vortex would operate as a fan, +purging the planetary materials of the least ponderable atoms, and, as +it were, separating<span class="pagenum" title="Page 188"> </span><a name="Page_188" id="Page_188"></a> the wheat from the chaff. It is thus we conceive +that the average atomic density of each planet has been first determined +by the radial stream, and, subsequently, that the solidification of the +nebulous planets has, by their atomic density, assigned to each its +position in the system, from the consequent relation which it +established between the density of the ether within the planet, and the +density of the ether external to it, so that, according to this view, a +single isolated atom of the same density as the mean atomic density of +the earth could (<i>ceteris paribus</i>) revolve in an orbit at the distance +of the earth, and in the same periodic time. This, however, is only +advanced by way of illustration.</p> + +<p>The expulsive force of the radial stream would thus drive off this +cometary dust to distances in some inverse ratio of the density of the +atoms; but, a limit would ultimately be reached, when gravitation would +be relatively the strongest—the last force diminishing only as the +squares of the distances, and the first diminishing in the compound +ratio of the squares and the square roots of the distances. At the +extreme verge of the system, this cometary matter would accumulate, and, +by accumulation, would still further gather up the scattered atoms—the +sweepings of the inner space—and, in this condensed form, would again +visit the sun in an extremely elongated ellipse. It does not, however, +follow, that all comets are composed of such unsubstantial materials. +There may be comets moving in parabolas, or even in hyperbolas—bodies +which may have been accumulating for ages in the unknown regions of +space, far removed from the sun and stars, drifting on the mighty +currents of the great ethereal ocean, and thus brought within the sphere +of the sun’s attraction; and these bodies may have no analogy to the +periodical comets of our system, which last are those with which we are +more immediately concerned.</p> + +<p>The periodical comets known are clearly arranged into two distinct +classes—one having a mean distance between Saturn<span class="pagenum" title="Page 189"> </span><a name="Page_189" id="Page_189"></a> and Uranus, with a +period of about seventy-five years, and another class, whose mean +distance assigns their position between the smaller planets and Jupiter, +having periods of about six years. These last may be considered the +siftings of the smaller planets, and the first the refuse of the +Saturnian system. In this light we may look for comets having a mean +distance corresponding to the intervals of the planets, rather than to +the distances of the planets themselves. One remarkable fact, however, +to be observed in these bodies is, that all their motions are in the +same direction as the planets, and, with one exception, there is no +periodical comet positively known whose motion is retrograde.</p> + +<p>The exception we have mentioned is the celebrated comet of Halley, whose +period is also about seventy-five years. In reasoning on the resistance +of the ether, we must consider that the case can have very little +analogy with the theory of projectiles in air; nor can we estimate the +inertia of an infinitely divisible fluid, from its resisting influence +on atomic matter, by a comparison of the resistance of an atomic fluid +on an atomic solid. Analogy will only justify comparisons of like with +like. The tangent of a comet’s orbit, also, can only be tangential to +the circular motion of the ether at and near perihelion, which is a very +small portion of its period of revolution. As far as the tangential +resistance is concerned, therefore, it matters little whether its motion +be direct or retrograde. If a retrograde comet, of short period and +small eccentricity, were discovered moving also near the central plane +of the vortex, it would present a very serious objection, as being +indicative of contrary motions in the nascent state of the system. There +is no such case known. So, also, with the inclinations of the orbits; if +these be great, it matters little whether the comet moves in one way or +the other, as far as the tangential current of the vortex is concerned. +Yet, when we consider the average inclination of the orbit, and not of +its plane, we find that the major axes<span class="pagenum" title="Page 190"> </span><a name="Page_190" id="Page_190"></a> of nearly all known cometary +orbits are very little inclined to the plane of the ecliptic.</p> + +<p>In the following table of all the periodical comets known, the +inclination of the major axis of the orbit is calculated to the nearest +degree; but all cometary orbits with very few exceptions, will be found +to respect the ecliptic, and never to deviate far from that plane:</p> + + +<table class="tdc" summary="List of comets with details of their motion. It is seen that those with a longer period have a greater inclination of the major axis."> +<col style="border-right:thin solid black; border-left:thin solid black;" span="6" /> +<tr style="border:thin solid black;"> + <th colspan="2">Designations of the Comets.</th> + <th>Periodic times.</th> + <th>Inclination of Major Axes.</th> + <th>Motion in Orbit.</th> + <th>Planetary Intervals.</th> +</tr> +<tr style="border-bottom:thin solid black;"> + <td class="tdl0">Encke</td> + <td>1818</td> + <td>3 years.</td> + <td class="tdr1">1°</td> + <td>Direct</td> + <td>Mars & Ceres.</td> +</tr> +<tr> + <td class="tdl0">De Vico</td> + <td>1814</td> + <td rowspan="11">From<br />five<br />to<br />six<br />or<br />seven<br />years.</td> + <td class="tdr1">2°</td> + <td>Direct</td> + <td rowspan="11">Ceres<br />and<br />Jupiter.</td> +</tr> +<tr> + <td class="tdl0">Fayo</td> + <td>1843</td> + <td class="tdr1">4°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">De Avrest</td> + <td>1851</td> + <td class="tdr1">1°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Brorsen</td> + <td>1846</td> + <td class="tdr1">7°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Messier</td> + <td>1766</td> + <td class="tdr1">0°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Clausen</td> + <td>1743</td> + <td class="tdr1">0°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Pigott</td> + <td>1783</td> + <td class="tdr1">4°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Pous</td> + <td>1819</td> + <td class="tdr1">3°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Biela</td> + <td>1826</td> + <td class="tdr1">9°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Blaupain</td> + <td>1819</td> + <td class="tdr1">2°</td> + <td>Direct</td> +</tr> +<tr style="border-bottom:thin solid black;"> + <td class="tdl0">Lexell</td> + <td>1770</td> + <td class="tdr1">1°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Pous</td> + <td>1812</td> + <td rowspan="6" style="border-bottom:thin solid black;">about<br />75<br />years</td> + <td class="tdr1">17°</td> + <td>Direct</td> + <td rowspan="6" style="border-bottom:thin solid black;">Saturn<br />and<br />Uranus.</td> +</tr> +<tr> + <td class="tdl0">Olbers</td> + <td>1816</td> + <td class="tdr1">40°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">De Vico</td> + <td>1846</td> + <td class="tdr1">13°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Brorsen</td> + <td>1847</td> + <td class="tdr1">12°</td> + <td>Direct</td> +</tr> +<tr> + <td class="tdl0">Westphal</td> + <td>1852</td> + <td class="tdr1">21°</td> + <td>Direct</td> +</tr> +<tr style="border-bottom:thin solid black;"> + <td class="tdl0">Halley</td> + <td>1682</td> + <td class="tdr1">16°</td> + <td>Retrograde</td> +</tr> +</table> + +<p>From which it appears, that the objection arising from the great +inclination of the <i>planes</i> of these orbits is much less important than +at first it appears to be.</p> + +<p>Regarding then, that a comet’s mean distance depends on its mean atomic +density, as in the case of the planets, the undue enlargement of their +orbits by planetary perturbations is inadmissible. In 1770 Messier +discovered a comet which approached nearer the earth than any comet +known, and it was found to move in a small ellipse with a period of five +and a half years; but although repeatedly sought for, it was the +opinion<span class="pagenum" title="Page 191"> </span><a name="Page_191" id="Page_191"></a> of many, that it has never been since seen. The cause of this +seeming anomaly is found by astronomers in the disturbing power of +Jupiter,—near which planet the comet must have passed in 1779, but the +comet was not seen in 1776 before it passed near Jupiter, although a +very close search was kept up about this time. Now there are two +suppositions in reference to this body: the comet either moved in a +larger orbit previous to 1767, and was then caused by Jupiter to +diminish its velocity sufficiently to give it a period of five and a +half years, and that after perihelion it recovered a portion of its +velocity in endeavoring to get back into its natural orbit; or if moving +in the natural orbit in 1770, and by passing near Jupiter in 1779 this +orbit was deranged, the comet will ultimately return to that mean +distance although not <ins class="correction" title="Transcriber’s note: Original reads ‘necesarily’.">necessarily</ins> having elements even approximating +those of 1770. In 1844, September 15th, the author discovered a comet in +the constellation Cetus, (the same previously discovered by De Vico at +Home,) and from positions <i>estimated with the naked eye</i> approximately +determined the form of its orbit and its periodic time to be very +similar to the lost comet of 1770. These conclusions were published in a +western paper in October 1844, on which occasion he expressed the +conviction, that this was no other than the comet of 1770. As the +question bore strongly on his theory he paid the greater attention to +it, and had, previously to this time, often searched in hopes of finding +that very comet. Since then, M. Le Verrier has examined the question of +identity and given his decision against it; but the author is still +sanguine that the comet of 1844 is the same as that of 1770, once more +settled at its natural distance from the sun. This comet returns to its +perihelion on the 6th of August, 1855, according to Dr. Brünnow, when, +it is hoped, the question of identity will be reconsidered with +reference to the author’s principles; and, that when astronomers become +satisfied of this, they will do him the justice of<span class="pagenum" title="Page 192"> </span><a name="Page_192" id="Page_192"></a> acknowledging that +he was the first who gave publicity to the fact, that the “Lost Comet” +was found.</p> + +<p>That comets do experience a resistance, is undeniable; but not in the +way astronomers suppose, if these views be correct. The investigations +of Professor Encke, of Berlin, on the comet which bears his name, has +determined the necessity of a correction, which has been applied for +several returns with apparent success. But there is this peculiarity +about it, which adds strength to our theory: “The Constant of +Resistance” requires a change after perihelion. The necessity for this +change shows the action of the radial stream. From the law of this +force, (reckoning on the central plane of the vortex,) there is an +outstanding portion, acting as a disturbing power, in the sub-duplicate +ratio of the distances inversely. If we only consider the mean or +average effect in orbits nearly circular, this force may be considered +as an ablatitious force at all distances below the mean, counterbalanced +by an opposite effect at all distances above the mean. But when the +orbits become very eccentrical, we must consider this force as +momentarily affecting a comet’s velocity, diminishing it as it +approaches the perihelion, and increasing it when leaving the +perihelion. A resolution of this force is also requisite for the comet’s +distance above the central plane of the vortex, and a correction, +likewise, for the intensity of the force estimated in that plane. There +is also a correction necessary for the perihelion distance, and another +for the tangential current; but we are only considering here the general +effect. By diminishing the comet’s proper velocity in its orbit, if we +consider the attraction of the sun to remain the same, the general +effect <i>may</i> be (for this depends on the tangential portion of the +resolved force preponderating) that the absolute velocity will be +increased, and the periodic time shortened; but after passing the +perihelion, with the velocity of a smaller orbit, there is also +superadded to this already undue velocity, the expulsive power of the +radial stream, adding additional velocity to the<span class="pagenum" title="Page 193"> </span><a name="Page_193" id="Page_193"></a> comet; the orbit is +therefore enlarged, and the periodic time increased. Hence the necessity +of changing the “Constant of Resistance” after perihelion, and this will +generally be found necessary in all cometary orbits, if this theory be +true. But this question is one which may be emphatically called the most +difficult of dynamical problems, and it may be long before it is fully +understood.</p> + +<p>According to the calculations of Professor Encke, the comet’s period is +accelerated about 2 hours, 30 minutes, at each return, which he +considers due to a resisting medium. May it not rather be owing to <i>the +change of inclination of the major axis of the orbit, to the central +plane of the vortex</i>? Suppose the inclination of the <i>plane</i> of the +orbit to remain unchanged, and the eccentricity of the orbit also, if +the longitude of the perihelion coincides with that of either node, the +major axis of the orbit lies in the ecliptic, and the comet then +experiences the greatest mean effect from the radial stream; its mean +distance is then, <i>ceteris paribus</i>, the greatest. When the angle +between the perihelion and the nearest node increases, the mean force of +the radial stream is diminished, and the mean distance is diminished +also. When the angle is 90°, the effect is least, and the mean distance +least. This is supposing the ecliptic the central plane of the vortex. +When Encke’s formula was applied to Biela’s comet, it was inadequate to +account for a tenth part of the acceleration; and although Biela moves +in a much denser medium, and is of less dense materials, even this taken +into account will not satisfy the observations,—making no other change +in Encke’s formula. We must therefore attribute it to changes in the +elements of the orbits of these comets. Now, the effect of resistance +should also have been noticed, as an acceleration of Halley’s comet in +1835, yet the period was prolonged. To show, that our theory of the +<i>cause</i> of these anomalies corresponds with facts, we subjoin the +elements in the following tables, taken from Mr. Hind’s catalogue:</p> + +<table summary="Data on Encke’s comet."> +<caption><span class="pagenum" title="Page 194"> </span><a name="Page_194" id="Page_194"></a>THE ELEMENTS OF ENCKE’S COMET.</caption> +<tr> + <th>Date of<br />Perihelion.</th> + <th colspan="3">Longitude of<br />Perihelion.</th> + <th colspan="3">Longitude of<br />nearest Node.</th> + <th colspan="3">Difference of<br />Longitude.</th> +</tr> +<tr> + <td class="tdl">1822</td> + <td class="tdl">157°</td> + <td class="tdr0">11′</td> + <td class="tdr">44″</td> + <td class="tdl">154°</td> + <td class="tdr0">25′</td> + <td class="tdr">9″</td> + <td class="tdl">2°</td> + <td class="tdr0">46′</td> + <td class="tdr">35″</td> +</tr> +<tr> + <td class="tdl">1825</td> + <td class="tdl">157°</td> + <td class="tdr0">14′</td> + <td class="tdr">31″</td> + <td class="tdl">154°</td> + <td class="tdr0">27′</td> + <td class="tdr">30″</td> + <td class="tdl">2°</td> + <td class="tdr0">47′</td> + <td class="tdr">1″</td> +</tr> +<tr> + <td class="tdl">1829</td> + <td class="tdl">157°</td> + <td class="tdr0">17′</td> + <td class="tdr">53″</td> + <td class="tdl">154°</td> + <td class="tdr0">29′</td> + <td class="tdr">32″</td> + <td class="tdl">2°</td> + <td class="tdr0">48′</td> + <td class="tdr">21″</td> +</tr> +<tr> + <td class="tdl">1832<a name="FNanchor_42_42" id="FNanchor_42_42"></a><a href= + "#Footnote_42_42" class="fnanchor">[42]</a></td> + <td class="tdl" style="vertical-align:bottom;">157°</td> + <td class="tdr0" style="vertical-align:bottom;">21′</td> + <td class="tdr" style="vertical-align:bottom;">1″</td> + <td class="tdl" style="vertical-align:bottom;">154°</td> + <td class="tdr0" style="vertical-align:bottom;">32′</td> + <td class="tdr" style="vertical-align:bottom;">9″</td> + <td class="tdl" style="vertical-align:bottom;">2°</td> + <td class="tdr0" style="vertical-align:bottom;">41′</td> + <td class="tdr" style="vertical-align:bottom;">52″</td> +</tr> +<tr> + <td class="tdl">1835</td> + <td class="tdl">157°</td> + <td class="tdr0">23′</td> + <td class="tdr">29″</td> + <td class="tdl">154°</td> + <td class="tdr0">34′</td> + <td class="tdr">59″</td> + <td class="tdl">2°</td> + <td class="tdr0">48′</td> + <td class="tdr">30″</td> +</tr> +<tr> + <td class="tdl">1838</td> + <td class="tdl">157°</td> + <td class="tdr0">27′</td> + <td class="tdr">4″</td> + <td class="tdl">154°</td> + <td class="tdr0">36′</td> + <td class="tdr">41″</td> + <td class="tdl">2°</td> + <td class="tdr0">50′</td> + <td class="tdr">23″</td> +</tr> +<tr> + <td class="tdl">1842</td> + <td class="tdl">157°</td> + <td class="tdr0">29′</td> + <td class="tdr">27″</td> + <td class="tdl">154°</td> + <td class="tdr0">39′</td> + <td class="tdr">10″</td> + <td class="tdl">2°</td> + <td class="tdr0">50′</td> + <td class="tdr">17″</td> +</tr> +<tr> + <td class="tdl">1845</td> + <td class="tdl">157°</td> + <td class="tdr0">44′</td> + <td class="tdr">21″</td> + <td class="tdl">154°</td> + <td class="tdr0">19′</td> + <td class="tdr">33″</td> + <td class="tdl">3°</td> + <td class="tdr0">24′</td> + <td class="tdr">48″</td> +</tr> +<tr> + <td class="tdl">1848</td> + <td class="tdl">157°</td> + <td class="tdr0">47′</td> + <td class="tdr">8″</td> + <td class="tdl">154°</td> + <td class="tdr0">22′</td> + <td class="tdr">12″</td> + <td class="tdl">3°</td> + <td class="tdr0">24′</td> + <td class="tdr">56″</td> +</tr> +<tr> + <td class="tdl">1852</td> + <td class="tdl">157°</td> + <td class="tdr0">51′</td> + <td class="tdr">2″</td> + <td class="tdl">154°</td> + <td class="tdr0">23′</td> + <td class="tdr">21″</td> + <td class="tdl">3°</td> + <td class="tdr0">27′</td> + <td class="tdr">41″</td> +</tr> +</table> + +<p>In this we see a regular increase of the angle, which ought to be +attended with a small acceleration of the comet; but the change of +inclination of the orbit ought also to be taken into consideration, to +get the mean distance of the comet above the plane of the vortex, and, +by this, the mean force of the radial stream.</p> + +<p>In the following table, the same comparison is made for Biela’s comet:—</p> + + +<table summary="Data on Biela’s comet."> +<caption>ELEMENTS OF BIELA’S COMET.</caption> +<tr> + <th>Date of<br />Perihelion.</th> + <th colspan="3">Longitude of the<br />Perihelion.</th> + <th colspan="3">Longitude of the<br />nearest Node.</th> + <th colspan="3">Difference of<br />Longitude.</th> +</tr> +<tr> + <td class="tdc">1772</td> + <td class="tdl">110°</td> + <td class="tdr0">14′</td> + <td class="tdr">54″</td> + <td class="tdl">74°</td> + <td class="tdr0">0′</td> + <td class="tdr">1″</td> + <td class="tdl">36°</td> + <td class="tdr0">14′</td> + <td class="tdr">53″</td> +</tr> +<tr> + <td class="tdc">1806</td> + <td class="tdl">109°</td> + <td class="tdr0">32′</td> + <td class="tdr">23″</td> + <td class="tdl">71°</td> + <td class="tdr0">15′</td> + <td class="tdr">15″</td> + <td class="tdl">38°</td> + <td class="tdr0">17′</td> + <td class="tdr">8″</td> +</tr> +<tr> + <td class="tdc" style="vertical-align:bottom;">1826</td> + <td class="tdl" style="vertical-align:bottom;">109°</td> + <td class="tdr0" style="vertical-align:bottom;">45′</td> + <td class="tdr" style="vertical-align:bottom;">50″</td> + <td class="tdl" style="vertical-align:bottom;">71°</td> + <td class="tdr0" style="vertical-align:bottom;">28′</td> + <td class="tdr" style="vertical-align:bottom;">12″</td> + <td class="tdl" style="vertical-align:bottom;">38°</td> + <td class="tdr0" style="vertical-align:bottom;">17′</td> + <td style="vertical-align:bottom;">38″<a name="FNanchor_43_43" id="FNanchor_43_43"></a><a href= + "#Footnote_43_43" class="fnanchor">[43]</a></td> +</tr> +<tr> + <td class="tdc">1832</td> + <td class="tdl">110°</td> + <td class="tdr0">55′</td> + <td class="tdr">55″</td> + <td class="tdl">68°</td> + <td class="tdr0">15′</td> + <td class="tdr">36″</td> + <td class="tdl">41°</td> + <td class="tdr0">45′</td> + <td class="tdr">19″</td> +</tr> +<tr> + <td class="tdc">1846</td> + <td class="tdl">109°</td> + <td class="tdr0">2′</td> + <td class="tdr">20″</td> + <td class="tdl">65°</td> + <td class="tdr0">54′</td> + <td class="tdr">39″</td> + <td class="tdl">43°</td> + <td class="tdr0">7′</td> + <td class="tdr">41″</td> +</tr> +</table> + +<p>Between 1832 and 1846, the increase of the angle is twice as great for +Biela as for Encke, and the angle itself throws the major axis of Biela +10° above the ecliptic, whereas the angle made by Encke’s major axis, is +only about 1°; the cosine of the<span class="pagenum" title="Page 195"> </span><a name="Page_195" id="Page_195"></a> first angle, diminishes much faster +therefore, and consequently the same difference of longitude between the +perihelion and node, will cause a greater acceleration of Biela; and +according to Prof. Encke’s theory, Biela would require a resisting +medium twenty-five times greater than the comet of Encke to reconcile +observation with the theory. Halley’s comet can scarcely be considered +to have had an orbit with perfect elements before 1835. If they were +known accurately for 1759, we should no doubt find, that the angle +between the node and perihelion <i>diminished</i> in the interval between +1750 and 1835, as according to the calculations of M. Rosenberg, the +comet was six days behind its time—a fact fatal to the common ideas of +a resisting medium; but this amount of error must be received as only +approximate.</p> + +<p>No comet that has revisited the sun, has given astronomers more trouble +than the great comet of 1843. Various orbits have been tried, +elliptical, parabolic and hyperbolic; yet none will accord with all the +observations. The day before this comet was seen in Europe and the +United States, it was seen close to the body of the sun at Conception, +in South America; yet this observation, combined with those following, +would give an orbital velocity due to a very moderate mean distance. +Subsequent observations best accorded with a hyperbolic orbit; and it +was in view of this anomaly, that the late Sears C. Walker considered +that the comet came into collision with the sun in an elliptical orbit, +and its <i>debris</i> passed off again in a hyperbola. That a concussion +would not add to its velocity is certain, and the departure in a +hyperbolic orbit would be contrary to the law of gravitation. This +principle is thus stated by Newton:—“In parabola velocitas ubiquo +equalis est velocitati corporis revolventis in circulo ad dimidiam +distantiam; in ellipsi minor est in hyperbola major.” (Vid. Prin. Lib. +1. Prop. 6 Cor. 7.)</p> + +<p>But as regards the <i>fact</i>, it is probable that Mr. Walker’s<span class="pagenum" title="Page 196"> </span><a name="Page_196" id="Page_196"></a> views are +correct, so far as the change from an ellipse to an hyperbola is +considered. The Conception observation cannot be summarily set aside, +and Professor Peirce acknowledges, that “If it was made with anything of +the accuracy which might be expected from Captain Ray, it exhibits a +decided anomaly in the nature of the forces to which the comet was +subjected during its perihelion passage.” The comet came up to the sun +almost in a straight line against the full force of the radial stream; +its velocity must therefore necessarily have been diminished. After its +perihelion, its path was directly <i>from</i> the sun, and an undue velocity +would be kept up by the auxiliary force impressed upon it by the same +radial stream; and hence, the later observations give orbits much larger +than the early ones, and there can be no chance of identifying this +comet with any of its former appearances, even should its orbit be +elliptical. This unexpected confirmation of the theory by the +observation of Capt. Ray, cannot easily be surmounted.</p> + +<p>We must now endeavor to explain the physical peculiarities of comets, in +accordance with the principles laid down. The most prominent phenomenon +of this class is the change of diameter of the visible nebulosity. It is +a most singular circumstance, but well established as a fact, that a +comet contracts in its dimensions on approaching the sun, and expands on +leaving it. In 1829, accurate measures were taken on different days, of +the diameter of Encke’s comet, and again in 1838. The comet of 1618 was +also observed by Kepler with this very object, and also the comet of +1807; but without multiplying instances, it may be asserted that it is +one of those facts in cometary phenomena, to which there are no +exceptions. According to all analogy, the very reverse of this ought to +obtain. If a comet is chiefly vaporous, (as this change of volume would +seem to indicate,) its approach to the sun ought to be attended by a +corresponding expansion by increase of temperature. When the contrary is +observed, and invariably so, it ought to<span class="pagenum" title="Page 197"> </span><a name="Page_197" id="Page_197"></a> be regarded as an index of the +existence of other forces besides gravitation, increasing rapidly in the +neighborhood of the sun; for the disturbing power of the sun’s +attraction would be to enlarge the diameter of a comet in proportion to +its proximity. Now, the force of the radial stream, as we have shown, is +as the 2.5th power of the distances inversely. If this alternate +contraction and expansion be due to the action of this force, there +ought to be an approximate correspondence of the law of the effect with +the law of the cause. Arago, in speaking of the comet of 1829, states, +“that between the 28th of October and the 24th of December, the volume +of the comet was reduced as 16000 to 1, the change of distance in the +meantime only varying about 3 to 1.” To account for this, a memoir was +published on the subject by M. Valz, in which he supposes an atmosphere +around the sun, whose condensation increases rapidly from superincumbent +pressure; so that the deeper the comet penetrates into this atmosphere +the greater will be the pressure, and the less the volume. In this it is +evident, that the ponderous nature of a resisting medium is not yet +banished from the schools. In commenting on this memoir, Arago justly +observes, that “there would be no difficulty in this if it could be +admitted that the exterior envelope of the nebulosity were not permeable +to the ether; but this difficulty seems insurmountable, and merits our +sincere regret; for M. Valz’s ingenious hypothesis has laid down the law +of variation of the bulk of the nebulosity, as well for the short-period +comet as for that of 1618, with a truly wonderful exactness.” Now, if we +make the calculation, we shall find that the diameter of the nebulosity +of a comet is inversely as the force of the radial stream. This force is +inversely as the 2.5 power of the distances from the axis, and not from +the sun: it will, therefore, be in the inverse ratio of the cosine of +the comet’s heliocentric latitude to radius, and to this ratio the +comet’s distance ought to be reduced. But, this will only be correct for +the same<span class="pagenum" title="Page 198"> </span><a name="Page_198" id="Page_198"></a> plane or for equal distances above the ecliptic plane, +considering this last as approximately the central plane of the vortex. +From the principles already advanced, the radial stream is far more +powerful on the central plane than in more remote planes; therefore, if +a comet, by increase of latitude, approaches near the axis, thus +receiving a larger amount of force from the radial stream in that plane +than pertains to its actual distance from the sun, it will also receive +a less amount of force in that plane than it would in the central plane +at the same distance from the axis. Now, we do not know the difference +of force at different elevations above the central plane of the vortex; +but as the two differences due to elevation are contrary in their +effects and tend to neutralize each other, we shall make the calculation +as if the distances were truly reckoned from the centre of the sun.</p> + +<p>The following table is extracted from Arago’s tract on Comets, and +represents the variations of the diameter of Encke’s comet at different +distances from the sun,—the radius of the orbis magnus being taken as +unity.</p> + +<table summary="Table showing the diameter of the comet and its distance from the sun on various dates. Both diameter and distance are seen to decrease over the time period."> +<tr> + <th colspan="2">Times of<br />observation, 1828.</th> + <th>Distances of the<br />comet from the sun.</th> + <th style="padding-left:2em;">Real diameters<br />in radii of the earth.</th> +</tr> +<tr> + <td class="tdl1">Oct.</td> + <td class="tdr1">28</td> + <td class="tdc">1.4617</td> + <td class="tdr1">79.4</td> +</tr> +<tr> + <td class="tdl1">Nov.</td> + <td class="tdr1">7</td> + <td class="tdc">1.3217</td> + <td class="tdr1">64.8</td> +</tr> +<tr> + <td class="tdl1">Nov.</td> + <td class="tdr1">30</td> + <td class="tdc">0.9668</td> + <td class="tdr1">29.8</td> +</tr> +<tr> + <td class="tdl1">Dec.</td> + <td class="tdr1">7</td> + <td class="tdc">0.8473</td> + <td class="tdr1">19.9</td> +</tr> +<tr> + <td class="tdl1">Dec.</td> + <td class="tdr1">14</td> + <td class="tdc">0.7285</td> + <td class="tdr1">11.3</td> +</tr> +<tr> + <td class="tdl1">Dec.</td> + <td class="tdr1">24</td> + <td class="tdc">0.6419</td> + <td class="tdr1">3.1</td> +</tr> +</table> +<p>In order the better to compare the diameters with the force, we will +reduce them by making the first numbers equal.</p> + +<table summary="Reducing the diameters."> +<tr> + <th>Distances.</th> + <th>Diameters.</th> + <th>The 2.5th power<br />of the Distances.</th> + <th>Reduced<br />Diameters.</th> +</tr> +<tr> + <td class="tdc">1.4617</td> + <td class="tdr">79.4</td> + <td class="tdc">2.58</td> + <td class="tdc">2.58</td> +</tr> +<tr> + <td class="tdc">1.3217</td> + <td class="tdr">64.8</td> + <td class="tdc">2.10</td> + <td class="tdc">2.10</td> +</tr> +<tr> + <td class="tdc">0.9668</td> + <td class="tdr">29.8</td> + <td class="tdc">0.92</td> + <td class="tdc">0.97</td> +</tr> +<tr> + <td class="tdc">0.8473</td> + <td class="tdr">19.9</td> + <td class="tdc">0.66</td> + <td class="tdc">0.65</td> +</tr> +<tr> + <td class="tdc">0.7285</td> + <td class="tdr">11.3</td> + <td class="tdc">0.45</td> + <td class="tdc">0.37</td> +</tr> +<tr> + <td class="tdc">0.5419</td> + <td class="tdr">3.1</td> + <td class="tdc">0.21</td> + <td class="tdc">0.10</td> +</tr> +</table> + +<p><span class="pagenum" title="Page 199"> </span><a name="Page_199" id="Page_199"></a>This is a very close approximation, when we consider the difficulty of +micrometric measurement, and the fact, that as the comet gets nearer to +the sun, as at the last date of the table, the diameter is more than +proportionally diminished by the fainter nebulosity becoming invisible. +But, there may be a reality in the discrepancy apparent at the last +date, as the comet was then very near the plane of the ecliptic, and +was, consequently, exposed to the more violent action of the radial +stream.</p> + +<p>To attempt to explain the <i>modus agendi</i> is, perhaps, premature. Our +principal aim is to pioneer the way into the labyrinth, and it is +sufficient to connect this seeming anomaly with the same general law we +have deduced from other phenomena. Still, an explanation may be given in +strict accordance with the general principles of the theory.</p> + +<p>Admitting the <i>nucleus</i> of a comet to be gaseous, there is no difficulty +about the solution. According to Sir John Herschel, “stars of the +smallest magnitude remain distinctly <ins class="correction" title="Transcriber’s note: Original reads ‘vissible’.">visible</ins>, though covered by +what appears the densest portion of their substances; and since it is an +observed fact, that the large comets which have presented the appearance +of a nucleus, have yet exhibited no phases, though we cannot doubt that +they shine by the reflected solar light, it follows that even these can +only be regarded as great masses of thin vapor.” That comets shine +solely by reflected solar light, is a position that we shall presently +question; but that they are masses of vapor is too evident to dispute. +According to the same authority quoted above, “If the earth were reduced +to the one thousandth part of its actual mass, its coercive power over +the atmosphere would be diminished in the same proportion, and in +consequence the latter would expand to a thousand times its actual +<i>bulk</i>.” If this were so, and comets composed of the elementary gases, +some of them would have very respectable masses, as the nuclei are +frequently not more than 5,000 miles in diameter, and consequently<span class="pagenum" title="Page 200"> </span><a name="Page_200" id="Page_200"></a> it +becomes important to examine the principle. From all experiments the +density of an elastic fluid is directly as the compressing force; and if +a cylinder reached to the top of our atmosphere, compressed by the +gravitation of the earth, considered equal at each end of the cylinder, +it would represent the actual compressing force to which it owes its +density. If the gravitation of the earth were diminished one thousand +times this atmospheric column would expand one thousand times,<a name="FNanchor_44_44" id="FNanchor_44_44"></a><a href="#Footnote_44_44" class="fnanchor">[44]</a> +(taking no account of the decrease of gravitation by increase of +distance;) so that the diameter of the aërial globe would be increased +to 108,000 miles, taking the atmosphere at 50 miles. But the mere +increasing the <i>bulk</i> of the atmosphere 1000 times would increase the +diameter to little more than double. Even giving the correct expansion, +a comet’s mass must be much greater than is generally supposed, or the +diameters of the nuclei would be greater if composed of any gas lighter +than atmospheric air.</p> + +<p>It is very improbable that a comet is composed of only one elementary +gas, and if of many, their specific gravities will vary; the lighter, of +course, occupying the exterior layers. With such a small mass, +therefore, the upper portion of its atmosphere must be very attenuated. +Now let us remember that the density of the ether at a comet’s aphelion, +is greater than at the perihelion, in the direct ratio of the square +roots of the distances from the sun nearly. At the aphelion the comet +lingers through half his period, giving ample time for the nucleus to be +permeated by ether proportionally dense with the surrounding ether of +the vortex at that distance. Thus situated, the comet descends to its +perihelion, getting faster and faster into a medium far less dense, and +there must consequently be an escape from the nucleus, or in common +parlance, the comet is positively electric. This escaping ether, in +passing through the attenuated layers composing the surface of the<span class="pagenum" title="Page 201"> </span><a name="Page_201" id="Page_201"></a> +nucleus, impels the lighter atoms of cometic dust further from the +centre, and as for as this <i>doubly</i> attenuated atmosphere of isolated +particles extends, so far will the escaping ether be rendered luminous. +It may be objected here, that a contrary effect ought to be produced +when the comet is forsaking, its perihelion; but the objection is +premature, as the heat received from the sun will have the same effect +in increasing the elasticity, as change of density, and the comet will +probably part with its internal ether as long as it is visible to the +earth; and not fully regain it perhaps, until after it arrives at its +aphelion. Suppose that we admit that a comet continues to expand in the +same ratio for all distances, as is laid down for the comet of Encke +when near its perihelion; it would follow, that the comet of 1811, would +have a diameter at its aphelion of fifty millions of millions of miles, +that is, its outside would extend one thousand times further from the +sun, at the opposite side to that occupied by the centre of the comet, +than the distance of the comet’s centre from the sun, at its enormous +aphelion distance. Such an absurdity shows us that there is a limit of +expansion due to natural causes, and that if there were no radial stream +the volume of a comet would be greatest when nearest the sun.</p> + +<p>But while the comet is shortening its distance and hastening to the sun +in the form of a huge globular mass of diffuse light, it is continually +encountering another force, increasing in a far more rapid ratio than +the law of gravitation. At great distances from the sun, the force of +the radial stream was insufficient to detach any portion of the comet’s +atmosphere; presently, however, the globular form is changed to an +ellipsoid, the radial stream begins to strip the comet of that doubly +attenuated atmosphere of which we have spoken, and the diameter of the +comet is diminished, merely because the luminosity of the escaping ether +is terminated at the limit of that atmosphere. Meanwhile the mass of the +comet has suffered only an infinitely small diminution; but if the +perihelion distance be<span class="pagenum" title="Page 202"> </span><a name="Page_202" id="Page_202"></a> small, the force may become powerful enough to +detach the heavier particles of the nucleus, and thus a comet may suffer +in mass by this denudating process. We regard, therefore, the nucleus of +a comet to represent the mass of the comet and the coma, as auroral rays +passing through a very attenuated envelope of detached particles. The +individual gravitating force of these particles to the comet’s centre, +may be therefore considered as inversely as the squares of the +distances, and directly as the density of the particles; and this +density will, according to analogical reasoning, be as the distances or +square roots of the distances;—grant the last ratio, and the +gravitating force of the particles composing the exterior envelope of a +comet, becomes inversely as the 2.5th power of the distances from the +comet’s centre.<a name="FNanchor_45_45" id="FNanchor_45_45"></a><a href="#Footnote_45_45" class="fnanchor">[45]</a> This being the law of the radial stream, it follows, +of course, that a comet’s diameter is inversely as the force of the +radial stream. It must, however, be borne in mind, that we are speaking +of the atomic density, and not of density by compression; for this +cometary dust, which renders luminous the escaping ether of the nucleus, +must be far too much diffused to merit the name of an elastic fluid. May +not the concentric rings, which were so conspicuous in the comet of +1811, be owing to differences in the gravitating forces of such +particles, sifted, as it were, and thus arranged, according to some +ratio of the distances, by the centripulsive force of the electric coma, +leaving vacant intervals, through which the ether passed without +becoming luminous? This at least is the explanation given by our theory. +We may, indeed, consider it possible that the escaping ether, when very +intense, might be rendered luminous by passing into the surrounding +ether, and, as it became more diffused by radiation, at last become +invisible. In this case, as the law of radiation is as the squares of +the distances from the centre inversely, the rays would be more and more +bent at right angles, or apparently shortened, as the power of the +radial stream in<span class="pagenum" title="Page 203"> </span><a name="Page_203" id="Page_203"></a>creased, and the apparent diameters of the coma would +be diminished faster than the ratio of the 2.5th power of the distances. +But whichever view we adopt, the diameter would again increase in the +same ratio on leaving the sun, if we make allowance for increase of +temperature, as well as for diminution of density, for the ordinary +distance of a comet’s visibility. We, however, regard the change of +diameter, as due to both these nodes of action, as best agreeing with +the indications afforded by their tails.</p> + +<p>From the preceding remarks, it results that the density of the particles +producing the nebulous envelope of a comet, renders the variations of +diameter only approximate to the law of the radial stream; a comet’s own +electric energy, or the intensity of the escaping ether, may also modify +this expression, and many other causes may be suggested. That the radial +stream is the cause, in the way we have pointed out, is proved by the +positions of the major axis of the short-period comet, making frequently +nearly a right angle with the radius vector of the orbit in 1828. A soap +bubble gently blown aside, without detaching it from the pipe, will +afford a good illustration of the mode, and a confirmation of the cause. +The angles measured by Struve, reckoned from the radius vector, +prolonged towards the sun, are subjoined:</p> + +<table summary="Angle made by the comet with the radius vector, measured on four dates."> +<col /><col style="border-right:thin solid black;" /><col /><col /> +<tr> + <td>November 7</td> + <td class="tdr">99°.7</td> + <td style="padding-left:2em;">December 7</td> + <td class="tdr">154°.0</td> +</tr> +<tr> + <td style="padding-right:1em;">November 30</td> + <td class="tdr">145°.3</td> + <td style="padding-left:2em; padding-right:1em;">December 14</td> + <td class="tdr">149°.4</td> +</tr> +</table> + +<p>At this last date, the comet was getting pretty close to the sun. When +the angle was greater, as on November 7th, the comet appeared to make +almost a right angle with the radius vector; and in this position of the +earth and comet, the longer axis of the elliptical comet was directed to +the axis of the vortex, as may be verified by experiment. At the later +dates, the comet was more rapidly descending, and, at the same time, the +axis of the comet was getting more directed towards the earth; so that +the angle increased between this axis and the radius<span class="pagenum" title="Page 204"> </span><a name="Page_204" id="Page_204"></a> vector, and +consequently became more coincident with it. We have now to consider the +luminous appendage of a comet, commonly called a tail.</p> + +<p>The various theories hitherto proposed to account for this appendage are +liable to grave objections. That it is not refracted light needs not a +word of comment. Newton supposes the tail to partake of the nature of +vapor, rising from the sun by its extreme levity, as smoke in a chimney, +and rendered visible by the reflected light of the sun. But, how vapor +should rise towards opposition in a vacuum, is utterly inexplicable. In +speaking of the greater number of comets near the sun than on the +opposite side, he observes: “Hinc etiam manifestum est quod cœli +resistentiâ destituuntur.”<a name="FNanchor_46_46" id="FNanchor_46_46"></a><a href="#Footnote_46_46" class="fnanchor">[46]</a> And again, in another place, speaking of +the tail moving with the same velocity of the comet, he says: “Et hinc +rursus colligitur spatia cœlestia vi resistendi destitui; utpote in +quibus non solum solida planetarum et cometarum corpora, sed etiam +rarissimi candarum vapores motus suos velocissimos liberrimè +peragunt ac diutissimè conservant.” On what <i>principle</i>, therefore, +Newton relied to cause the vapors to ascend, does not appear. Hydrogen +rises in our atmosphere because specifically lighter. If there were no +atmosphere, hydrogen would not rise, but merely expand on all sides. +But, a comet’s tail shoots off into space in a straight line of one +hundred millions of miles, and frequently as much as ten millions of +miles in a single day, as in the case of the comet of 1843. Sir John +Herschel observes, that “no rational or even plausible account has yet +been rendered of those immensely luminous appendages which they bear +about with them, and which are known as their tails.” Yet, he believes, +and astronomers generally believe, that a comet shines by reflected +light. This theory of reflexion is the incubus which clogs the question +with such formidable difficulties; for, it follows, that the reflecting +matter<span class="pagenum" title="Page 205"> </span><a name="Page_205" id="Page_205"></a> must come from the comet. But, what wonderful elements must a +comet be made of, to project themselves into space with such immense +velocity, and in such enormous quantities as to exceed in volume the +body from which they emanate many millions of times. This theory may be, +therefore, safely rejected.</p> + +<p>From what we have already advanced concerning the coma or nebulosity of +the comet, we pass by an easy path to an explanation of the tail. In the +short-period comets, the density of the elementary atoms is too great to +be detached in the gross from the nucleus, or, rather, the density of +the atoms composing the nucleus is too great to permit the radiating +stream of the comet carrying them to a sufficient distance to be +detached by the radial stream of the sun. Hence, these comets exhibit +but very little tails. We may also conceive, that the continual siftings +which the nucleus undergoes at each successive perihelion passage, have +left but little of those lighter elements in comets whose mean distances +are so small. Yet, again, if by any chance the eccentricity is +increased, there are two causes—the density of the ether, and the heat +of the sun—which may make a comet assume quite an imposing appearance +when apparently reduced to the comparatively passive state above +mentioned.</p> + +<p>According to our theory, then, the coma of a comet is due to the +elasticity of the ethereal medium within the nucleus, caused both by the +diminished pressure of the external ether near the sun, and also by the +increased temperature acting on the nucleus, and thus on the involved +ether. The tail, on the contrary, is caused by the lighter particles of +the comet’s attenuated atmosphere being blown off by the electric blast +of the radial stream of the solar vortex, in sufficient quantities to +render its passage visible. It is not, therefore, reflected light, but +an ethereal stream rendered luminous by this detached matter still held +in check by the gravitating force of the sun,<span class="pagenum" title="Page 206"> </span><a name="Page_206" id="Page_206"></a> whose centre each +particle still respects, and endeavors to describe such an orbit as +results from its own atomic density, and the resultant action of both +the acting forces. From the law of density of the ether, the coma ought +to be brightest and the radiating stream of the comet’s nucleus +strongest on the side of least pressure: from this cause, and the fact +that the body of the comet affords a certain protection to the particles +immediately behind it, there will be an interval between the comet and +the tail less luminous, as is almost invariably observed. We thus have +an explanation of the fact noticed by Sir John Herschel, “that the +structure of a comet, as seen in section in the direction of its length, +must be that of a hollow envelope of a parabolic form, enclosing near +its vertex the nucleus or head.” We have, also, a satisfactory +explanation of the rapid formation of the tail; of its being wider and +fainter at its extremity; of its occasional curvature; and of its +greater length after perihelion than before. But, more especially may we +point to the explanation which this theory gives of the fact, that, +<i>ceteris paribus</i>, the long-period comets, when their perihelion +distances are small, have tails of such exaggerated dimensions.</p> + +<p>A comet, whose mean distance is considerable, is supposed by the theory +to be composed of elements less dense, and, during its long sojourn at +its aphelion, it may be also supposed that it there receives continual +accessions to its volume from the diffused siftings of the system, and +from the scattered debris of other comets. On approaching the +perihelion, the rapidity of the change in the density of the ether in a +given time, depends on the eccentricity of the orbit, and so does the +change of temperature; so that, from both causes, both the length of the +tail and the brilliancy of the comet measurably depends on the magnitude +of the period and of the eccentricity.</p> + +<p>If the nuclei of comets be gaseous as we suppose, and that the smallest +stars are visible through them, it is an outrage on<span class="pagenum" title="Page 207"> </span><a name="Page_207" id="Page_207"></a> common sense, to +refer that light, which renders a comet visible at noon-day, within six +minutes of space of the sun itself, to the reflected light of the sun. +When a small star has been seen through the nucleus of a comet, without +any perceptible diminution of light, it indicates perfect transparency; +but there can be no reflection from a perfectly transparent body, and +therefore, a comet does not shine by reflected light. It is true that +Arago discovered traces of polarized light in the comet of 1819, and +also in more recent comets, but they are mere traces, and Arago himself +admits, that they do not permit “the conclusion decidedly that these +stars shine only with a borrowed light.” But it still does not follow +that a comet (even if independent of reflected light) is in an +incandescent state. The auroral light is not polarized, nor any other +electric light, neither is it owing to a state of incandescence, yet it +is luminous. The intense light of a comet at perihelion is analogous to +the charcoal points of a galvanic battery, caused by a rapid current of +ether from the nucleus, and assisted by the radial stream of the vortex. +This will account for the phenomenon in all its shades of intensity, as +well as for the absence of any perceptible phase. It will also account +for the non-combustion of such comets as those of the years 1680 and +1843. We shall also be at no loss to understand, why there is no +refraction when a ray of light from a star passes through the nebulosity +of a comet; and if, as we may reasonably suppose, the gaseous matter +composing the nucleus be very attenuated, instruments are yet too +imperfect to determine whether these also have any refracting power. On +this point, however, it is safest to suspend our judgment, as there may +be comets not belonging to our system, with even liquid or solid nuclei, +or of matter widely different to those elements composing the members of +the solar system.</p> + +<p>In addition to what has been already advanced on this subject of a +comet’s light, we may appeal to the well-known fact that the visibility +of a comet is not reciprocally as the squares<span class="pagenum" title="Page 208"> </span><a name="Page_208" id="Page_208"></a> of the distances from the +earth and sun as it ought to be, if shining by reflected light. In +Mr. Hind’s late work on comets, the fact is stated that “Dr. Olbers +found that the comet of 1780 attained its greatest brightness on the 8th +of November, thirteen days subsequent to its discovery, whereas +according to the law of reflected light, it should have become gradually +fainter from the day of its discovery; and supposing the comet +self-luminous, the intensity of light should have increased each day +until November 26th; yet in the interval between the 8th and 26th of +that month, it grew rapidly less.” Now this theory teaches, that a comet +is neither self-luminous nor dependent on the sun, but on its distance +from the axis of the vortex, and a certain amount of elapsed time from +the perihelion, varying somewhat in each particular case. This fact is +therefore a very strong argument in favor of our theory.</p> + +<p>Amidst the many anomalous peculiarities of comets, it has been noticed +that a short tail is sometimes seen at right angles to the principal +tail, and in a few cases pointing directly towards the sun. Much of this +may be owing to perspective, but granting the reality of the fact, it is +still explicable on the same general principles.</p> + +<p>In speaking of the modifying causes which influence the weather, we +mentioned the effect due to the position of the sun with respect to the +axis of the vortex. This will be found to have a sensible effect on the +action of the radial stream. The natural direction of a comet’s electric +stream is <i>towards</i> the axis of the vortex, and in the central plane of +the vortex it will be also towards the sun. But this stream is met by +the stronger radial stream from the axis, and as Mr. Hind describes it, +“is driven <i>backward</i> in two streams passing on either side of the head, +and ultimately blending into one to form the tail.” Now, if the body of +the sun be situated between the comet and the axis of the vortex, it +will shield the comet from the action of the radial stream, and thus a +tail may really point towards the sun.</p> + +<p><span class="pagenum" title="Page 209"> </span><a name="Page_209" id="Page_209"></a>In 1744 a brilliant comet exhibited six distinct tails spread out like a +fan, some seven days after its perihelion passage; its distance from +the sun at the time not being more than a third of the earth’s distance. +The comet was then rapidly approaching the plane of the ecliptic, and if +we make the calculation for the position of the sun, we shall find that +the body of the sun was on the same side of the axis of the vortex as +the comet, and that the comet was then situated at the boundaries of the +conical space, enclosed by the radial stream in its deflected passage +round the body of the sun. In this position there are numerous cross +currents of the stream, and hence the phenomenon in question. As this +fact rests on the testimony of one individual, and is an occurrence +never recorded before or since, many are disposed to doubt the fact, yet +our theory explains even this peculiarity, and shows that there is no +necessity for impugning the statement of Cheseaux.</p> + +<p>Another unexplained phenomenon is the corruscation of the tail. It has +been attempted to explode this fact also, by referring it to conditions +of our own atmosphere; and it is generally considered the argument of +Olbers, founded on the great length of the tail and the velocity of +light, is sufficient to prove that these corruscations are not actually +in the tail. Now, it is undoubtedly true, that as light travels less +than two hundred thousand miles in a second, and a comet’s tail is +frequently one hundred millions long, it is impossible to see an +instantaneous motion along the whole line of the tail; but granting that +there are such flickerings in the tail as are described by so many, it +must necessarily be, that these flickerings will be <i>visible</i>. It would +be wonderful indeed, if a series of waves passing from the comet to the +extremity of the tail, should have their phases so exactly harmonizing +with their respective distances as to produce a uniform steady light +from a light in rapid motion. The argument, therefore, proves too much, +and as it is in the very nature of electric light thus to corruscate, as +we see frequently<span class="pagenum" title="Page 210"> </span><a name="Page_210" id="Page_210"></a> in the northern lights, we must be permitted still to +believe that not only the tails, but also the heads of comets do really +corruscate as described.</p> + +<p>With respect to the direction of the tail, astronomers have been forced +to abandon the antiquated notion, that the tail always pointed directly +from the sun; yet they still pertinaciously cling to the idea, that +although this is not always the case, the tail only deviates from this +direction <i>in the plane of the orbit</i>. As this is a most important +question, it is necessary formally to protest against such a conclusion. +If the earth should happen to be in the plane of the comet’s orbit and +the tail appears in that plane, it must of course be in that plane +<i>really</i>; but if the earth is not in the plane of the comet’s orbit, the +tail is not <i>necessarily</i> in the same plane, whatever its apparent +direction may indicate. It is true there is a tendency of every particle +of the tail, moving under the restraining influence of the sun’s +attraction, to continue in the plane of the orbit; and in certain +positions there is no oblique action arising from the force of the +radial stream to cause it to deviate from that plane; yet in other +positions of the comet, the action of the radial stream may be oblique, +forcing it out of that plane, and still such a direction might be +assigned to it as to make it conform. In the comet of 1843, P. Smythe +observed a forked tail 25° long on March 3d, and from the end of the +forked tail, and from its <i>north</i> side, a streamer diverged at an angle +of 6° or 7° to the <i>north</i>. As this was contrary to the <i>direction</i> of +the curvature, if the tail had been curved, it could only arise from a +portion being driven off by the radial stream, or bent towards the plane +of the ecliptic. The curvature observed by others at a later date, was +concave to the south. Towards the middle and close of March, the tail +became straight, and with the above exception, might be considered to +move in the plane of the orbit.</p> + +<p>The celebrated comet of Halley, as observed by Dr. Bessel in 1835, +showed that a more or less well-defined tuft of rays ema<span class="pagenum" title="Page 211"> </span><a name="Page_211" id="Page_211"></a>nated from that +part of the nucleus which was turned towards the sun; and the rays being +<i>bent backward</i> formed a part of the tail. The nucleus, with its +emanations, presented the appearance of a burning rocket, the end of +which was turned sideways by the force of the wind. And, Bessel +concludes: “That the cone of light issuing from the comet deviated +considerably both to the right and left of the true direction of the +sun, but that it always returned to that direction, and passed over to +the opposite side; so that the cone of light, and the body of the comet +from whence it emanated, experienced a rotatory, or, rather, a vibrating +motion <i>in the plane of the orbit</i>.” It is impossible that Bessel should +here mean that this motion was certainly in the plane of the orbit; for +the orbit was then viewed sideways, and he had no means of ascertaining +the fact. His meaning must be that it was apparently in the plane of the +orbit. If a plane be made to pass through the earth, the comet, and the +sun, the tail might be placed in any position in that plane, and yet +appear to be at the intersection of the two; that is, in the plane of +the comet’s orbit. The vibration of the tail, in this case, is another +strong proof of the correctness of our theory. To make it more +intelligible, we shall resort to a diagram.</p> + +<p>In the following diagram, the comet’s orbit, represented by the dotted +line, is drawn on the plane of the ecliptic; it is, therefore, necessary +to bear in mind, that it is tilted up from the line of nodes SN, at an +angle of 17° 45′. The position of the comet, October 9th, is at C, +approaching its perihelion; that of the earth at the same time at T; +while S represents the sun, and SQ the line of equinoxes. Now, from a +cause already explained, the tail always tends to lay behind the comet, +in the direction indicated by the lower tail in the diagram at 1, and, +if produced, would pass to the left of the sun, as seen from the earth: +the force of the radial stream, however, will not allow this lagging of +the tail, and it is straightened out by this force;<span class="pagenum" title="Page 212"> </span><a name="Page_212" id="Page_212"></a> but, being directed +to the axis of the vortex, and not to the sun, it is not really in the +plane of the orbit, but is seen in the direction of the upper tail +depicted in the diagram at 3, and, if produced, would pass to the right +of the sun, as seen from T. Now, there is an intermediate position of +the tail, in which it will appear in the prolongation of the radius +vector SC; this position is represented by the middle or central tail of +the comet at 2, yet this is not in the plane of the orbit, it only +appears to be, as may be readily understood by remembering that the +earth at this time is under this plane, and the comet is seen at a +considerable elevation above the plane of the ecliptic. When the comet’s +tail becomes directed to the axis of the vortex, or in the <i>apparent</i> +position of No. 3, the comet, rapidly careering on its way to the sun, +again leaves the tail behind, and again it is strengthened out by the +radial stream oscillating about the mean position at 2, as observed by +Bessel. From this, it appears, that there is no necessity to make +confusion worse confounded, by resorting to polar forces, which are +about as intelligible as the foundations of the pillars of Atlas.</p> + +<div class="figcenter" style="width: 350px;"> +<a name="fig25" id="fig25"></a> +<img src="images/fig25.png" width="350" height="251" alt="Fig. 25" title="" /> +</div> + +<p><span class="pagenum" title="Page 213"> </span><a name="Page_213" id="Page_213"></a>It may be objected that the continued action of the radial stream with +that velocity we have contended for, ought to keep the tail invariably +directed from the axis of the vortex; but, where there are two forces or +tendencies, as in this case, analogy would teach us that a certain +degree of oscillation is a necessary result. There may, also, be slight +and transient changes in the direction of the radial stream. In the +hurricane there are short and fitful blasts inclined to the general +direction of the wind, which must arise from the inertia of the moving +mass of atmosphere, causing temporary condensations and +<ins class="correction" title="Transcriber’s note: Original reads ‘rarefractions’.">rarefactions</ins>. Be this as it may, we have assigned a cause which +satisfies the phenomenon, without coming into collision with a single +principle of celestial mechanics.</p> + +<p>Prof. Struve compared the tail of this comet to a flame, or “ray of fire +shot out from the nucleus, as from some engine of artillery, and driven +on one side by the wind.” At the same time, he saw a second emanation +nearly in the opposite direction. This last might arise from a momentary +fluctuation in the relative intensities of the electric radiation of the +comet, and of the radial stream, owing to the probable irregularities +just alluded to. Such and kindred phenomena are utterly inexplicable, +without we adopt the theory we are advocating. One other feature, and we +will leave the subject.</p> + +<p>From our explanation of the solar spots, we inferred the existence of +another large planet in the system. Might not the same effect be +produced by a comet? Or may there not be so many comets, whose great +elongation, combined with even a moderate mass, may render it impossible +to calculate the position of the sun with respect to the central axis of +the vortex,—always considering this last as the axis of equilibrium? In +a general way, we might say that the very number of comets in all +directions and all distances, would tend to neutralize each other’s +effects; but we are not under this necessity. A comet, moving in a +parabola, does not belong to the system or to the<span class="pagenum" title="Page 214"> </span><a name="Page_214" id="Page_214"></a> rotating vortex; and +the periodic comets, if of gaseous elements, (as seems so probable,) +must, from the size of their nuclei, which the theory considers the only +part constituting their mass, have far less mass than the very smallest +of the asteroids, and consequently could have very little effect on the +mechanical balance of the vortex, even if elongated as far as the orbit +of Neptune. Did we know the influence of cold in limiting the +expansibility of the elementary gases, we might approximately determine +the mass of a comet, from the size of its nucleus; but this is a problem +that has never yet been solved; and astronomers ought to avail +themselves of every indication which promises to realize this great +desideratum. The grand comet of 1556 is now probably approaching, and, +from recent investigations, it appears that it will arrive at its +perihelion in 1858,—subject to an error either way of about two years. +An opportunity may thus be presented of determining the mass of one of +the largest comets on record, which may not again occur. This arises +from the possible appulse of the comet to the planet Pallas, whose mass, +being so small, would more sensibly be disturbed by such an appulse than +the earth. As the inclinations and ascending nodes of the two orbits +approximately coincide, and as Pallas will be near the comet’s path, on +the approach of the latter to the sun, at the beginning of the year +1857, should the comet become visible about that time, a very close +appulse is possible. It is not unlikely, also, that if the elements of +Pallas were so far perfected as to afford reliable indications, that the +near approach of the comet might thus be heralded in advance, and lead +to an earlier detection of its presence. Would it not be a worthy +contribution to science, for some one possessing the necessary leisure, +to give an ephemeris of the planet for that epoch; as a very slight +change in Mr. Hind’s elements of the comet, would cause an actual +intersection of the two orbits in about heliocentric longitude 153°? The +subsequent nodal passage of Pallas will take place near opposition, and +be very<span class="pagenum" title="Page 215"> </span><a name="Page_215" id="Page_215"></a> favorably situated for determining the instant of its passage; +and, of all the elements, this would be more likely to be affected than +any other.<a name="FNanchor_47_47" id="FNanchor_47_47"></a><a href="#Footnote_47_47" class="fnanchor">[47]</a></p> + + +<h3>THE ZODIAL LIGHT.</h3> + +<p>A phenomenon, akin to that which we have just been considering, is +presented by that great cone of diffused light which accompanies the +sun, and which in tropical climes displays a brilliancy seldom witnessed +in high latitudes, on account of its greater deviation from the +perpendicular. Sir John Herschel conjectures that it may be “no other +than the denser part of that medium, which, as we have reason to +believe, resists the motion, 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 passages, and which +may be slowly subsiding into the sun.” If these materials have been +stripped, it is due to some force; and the same force would scarcely +permit them to subside into the sun. Once stripped, these portions must +be borne outwards, by the radial stream, to the outer verge of the +system. Still, there are, no doubt, denser particles of matter, of the +average atomic density of Mercury and Venus, which can maintain their +ground against the radial stream, and continue to circulate near the +central plane of the vortex, in all that space between the earth and the +sun. But<span class="pagenum" title="Page 216"> </span><a name="Page_216" id="Page_216"></a> if the zodial light be the denser part of that medium, which +astronomers now generally recognize as a resisting medium, how happens +it that it should be confined to the plane of the ecliptic? Why should +it not be a globular atmosphere? Here, again, our theory steps in with a +triumphant explanation; for while it permits the accumulation of such +particles around the equatorial plane of the sun, it allows no +resting-place very far removed from this plane. The zodial light, +therefore, is not the resisting medium, but the passage of the radial +stream through a diffuse nebula of atoms, brought down the poles of the +vortex by the polar current, and held in check along the central plane +by gravitation.</p> + +<p>If these atoms partook of the velocity of the ether, they would not be +luminous; but being held back by gravitation, they are opposed to the +radial stream, and hence the light.</p> + +<p>Many stars are also nebulous. In some cases we see the nebulosity +edgewise, or along the equatorial planes of the stellar vortices; in +others we look down the poles, and the nebulosities are circular, and +there is an endless variety in the shape and intensity of this light. +But the universe seems full of motion, and we are not justified in +supposing, because a star shows no such light, that it is without +rotation. The parallax of the nearest star is only one second, the whole +lenticular mass of light which surrounds our sun would therefore only +subtend an angle of a single second at the nearest fixed star. Seeing +its extreme faintness, therefore, the effulgence of the star would +render it totally invisible, provided that it <i>could</i> traverse the vast +immensity of intervening space, without feeling the influence of that +extinction, which Struve has proved does actually diminish the number of +visible stars.</p> + +<p>Corruscations and flickerings have also been noticed in the zodial +light, and as usual, the learned have suggested atmospheric conditions +as the cause, instead of trusting to the evidence of their own senses. +How prone is philosophy to cling<span class="pagenum" title="Page 217"> </span><a name="Page_217" id="Page_217"></a> to that which is enveloped in the mist +of uncertainty, rather than embrace the <i>too simple</i> indications of +nature. As if God had only intended her glories to be revealed to a +favored few, and not to mankind at large. Blessed will be the day when +<i>all</i> will appreciate their own powers and privileges, and no longer +regard the oracles which emanate from a professional priesthood, whose +dicta have so often tended to darken the simple counsels of truth! To +set the question of pulsations in the zodial light, as well as in the +tails of comets, at rest, only requires previously concerted +observations, in places not very widely apart; for it is scarcely +possible, that atmospheric conditions should produce simultaneous +pulsations in two distant places. If the pulsations are found to be +simultaneous, they are real; if not simultaneous, they may depend on +such conditions; but from the nature of the cause, we should look for +them as much in the zodial light, as in the aurora borealis, regarding +the different intensities.</p> + +<p>There is also reason to suspect that the northern side is always the +brightest, both in spring and autumn. On the morning of October 4th, +1853, the light was very vivid and well defined, its northern margin +grazing Regulus and terminating at Mars, which was also to the north of +it. Now, although the <i>northern side</i> was the brightest, the great mass +of light was to the south of the ecliptic, as far down as the cone shape +was preserved; but at 10° from the horizon, a still brighter mass +protruded from the cone towards the north, which was all <i>north</i> of the +ecliptic, and of an irregular form, extending along the horizon. The +time was 4 <span class="time">A. M.</span>, and consequently was not due to any crepuscular light. +An explanation of the general fact of the brightest light being <i>always</i> +on the north side, is given in the present section, in connection with +another phenomenon. If, as some suppose, the light does not reach to the +sun, the annulus must at least fill all the space between Venus and the +earth, but it is far more in accordance with facts as well as with<span class="pagenum" title="Page 218"> </span><a name="Page_218" id="Page_218"></a> our +theory, to suppose it increases in density to the body of the sun.</p> + +<p>Observations made at the observatory of the British Association, +detected, in 1850, sudden brightenings of the light, altogether +different from pulsations. The theory would refer these to that fitful +irregularity in the momentary intensity of the radial stream, which +gives the flickering and tremulous motion to comets’ tails. But, the +steady variations in the intensity of this light must be due to other +causes. The longitude of the sun will here come in as a modifying cause; +for the obstruction caused by the body of the sun, when displaced from +the axis of the vortex, must necessarily exercise an influence on the +force and direction of the radial stream. A sudden influx of cometary +matter down the poles of the vortex, in more than usual quantities, will +also tend to brighten and enlarge the zodial light; and, in this last +cause, we have an explanation not only of ancient obscurations of the +solar light, but, also, of those phosphorescent mists, such as occurred +in 1743 and 1831, rendering moonless nights so light that the smallest +print could be read at midnight.</p> + +<p>In total eclipses of the sun, the denser portion of the zodial light is +visible as a brilliant corona; but, on such occasions, the brightest +stars only are to be seen, and, consequently, the fainter portions of +the light must be invisible. Hind mentions as many as ten stars visible +in the total eclipse of 1842. According to the same authority, the color +of the corona was like tarnished silver, and rays of light diverged in +every direction, and appeared shining through the light of the corona in +the total eclipse of 1851. In this year on the day of the eclipse (July +28th), the longitude of the sun was about 340°, and, therefore, the body +of the sun obstructed the radial stream as seen from the earth on the +right side; but, in 1842, the longitude of the sun was, according to our +table, about 116°, the sun’s centre then being 700,000 miles from the +axis of the<span class="pagenum" title="Page 219"> </span><a name="Page_219" id="Page_219"></a> vortex, and on the opposite side with respect to the earth; +the position was, therefore, not so favorable for the appearance of +these rays which, in many cases, have given the appearance of a whirling +motion to the corona.</p> + +<p>At this date, July 7th, 1842, the corona, according to Prof. Airy, +“possibly had a somewhat radial appearance, but not sufficiently marked +to interfere with the general annular <ins class="correction" title="Transcriber’s note: Original omits closing quote mark.">structure.“</ins> Mr. Baily, on the +contrary, says, the corona had the appearance of brilliant rays; and, at +Milan, long jets of light were particularly noticed. There can be no +doubt but that the passage of the radial stream past the outer margin of +the moon must also give rise to the same phenomena as when passing the +sun, and in this we have an explanation of the fact, that, previous to +the moment of first contact, an appearance resembling a +faintly-illuminated limb of the moon, has been perceived near the body +of the sun; as well as of those flashes of light which have been +observed in the lunar disc as the eclipse advances. One important fact, +worthy of note, is, that these luminous streaks are more nearly parallel +than is due to a radiation from the centre. These streaks have, also, +been seen bent at right angles at the middle of their height, as a flame +is by means of a blowpipe, precisely analogous to cometary rays being +driven backwards to form the tail, as already described, thus indicating +a common origin. If the moon had an atmosphere, we should, no doubt, see +a greater display; but, having no rotating vortex to protect her from +the radial stream, her atmosphere must have been long since stripped +off, leaving her exposed to the withering winter blast of the great +stream of the solar vortex. In this connection, we may also allude to +the appearance of the moon when totally eclipsed. Instead of +disappearing at these times, she sometimes shines bright enough to +reveal her smallest spots. This has been generally referred to the +refraction of the earth’s atmosphere bending inwards the solar rays. May +it not be owing to the brilliancy of the solar<span class="pagenum" title="Page 220"> </span><a name="Page_220" id="Page_220"></a> corona, which, in 1842, +was described as so intense that the eye was scarcely able to support +it? This is a far more palpable cause for the production of this +phenomenon, but of which astronomers cannot avail themselves, as long as +they are uncertain of the origin of this corona.</p> + + +<h3>SHOOTING STARS.</h3> + +<p>The continual influx of cosmical matter into the heart of the vortex in +ever-varying quantities, and speedily dispersed along the central plane, +according to its density, must necessarily give rise to another +phenomenon to which we have not yet alluded. Scarcely a night passes +without exhibiting this phenomena in some degree, and it is generally +supposed that the hourly average of shooting stars is from five to ten, +taking the whole year round. The matter composing these meteors we +regard as identical with that mass of diffused atoms which forms a +stratum conforming to the central plane of the vortex, and whose partial +resistance to the radial stream occasions that luminosity which we call +the zodial light. These atoms may coalesce into spherical aggregations, +either as elastic gas, or as planetary dust, and, passing outward on the +radial stream, will occasionally become involved in the vortex of our +own globe; and being drawn inwards by the polar current, and acted on by +the earth’s gravity, be impelled with great velocity through the +rarefied air of the upper atmosphere. That meteors are more abundant +about the time of meridian passage of a vortex (or, perhaps, more +correctly speaking, from six to twelve hours afterwards, when the +current of restoration penetrates the atmosphere), well accords with the +author’s observations. It is about this time that high winds may be +looked for, according to the theory; and it has ever been a popular +opinion, that these meteors are a sign of windy weather. Even in +Virgil’s<span class="pagenum" title="Page 221"> </span><a name="Page_221" id="Page_221"></a> time, the same belief prevailed, as a passage in his Georgics +would seem to indicate.</p> + +<blockquote> +<p class="hang">“Sape etiam stellas, vento impendente, videbis<br /> +Præcipites cœlo labi; noctisque per umbram<br /> +Flammarum longos à tergo albescere tractus;”</p> +</blockquote> + +<p>Virgil was a close observer of nature, and commences a storm with the +wind at south, “Quo signo caderent Austri;” just as we have represented +the usual course when these vortices pass near the observer’s latitude. +It is also a well-known fact, that after a display of meteors, (and we +are now speaking of ordinary displays, and not of the great showers,) +the temperature falls considerably. It is not uncommon also, that +meteors are more abundant during an auroral display, as they ought to be +by the theory. We must, however, exempt from this influence those solid +meteors which sometimes come into collision with the earth, and +afterwards grace the cabinets of the curious. These bodies may be +considered microscopic planets, moving in stated orbits with planetary +velocity, and bear strongly on the explosive theory of Olbers, as fully +detailed by Sir David Brewster.</p> + +<p>It is a very remarkable fact, first noticed by Olbers, that no fossil +meteoric stones have yet been discovered. If this fact be coupled with +the hypothesis advanced by Olbers, in reference to the origin of the +asteroidal group, we should have to date that tremendous catastrophe +since the deposition of our tertiary formations, and therefore it might +possibly be subsequent to the introduction of the present race into the +world. May not some of the legendary myths of the ancient world as +mystified by the Greeks, have for a foundation the disappearance of a +former great planet from the system? The idea of the existence of seven +planets is one of the oldest records of antiquity; but the earth of +course would not be counted one, and therefore in after times, the sun +was included to make up the number; just as the signs of the Zodiac have +been explained in accordance with the seasons of far later times than we +can possibly assign for<span class="pagenum" title="Page 222"> </span><a name="Page_222" id="Page_222"></a> the invention of this division of the heavens. +Let those who have the leisure, try how far the contraction and dilation +of the asteroidal orbits, to some average mean distance, will restore +them to a common intersection or node, as the point of divergence of the +different fragments. The question is interesting in many of its aspects, +and may yet be satisfactorily answered.</p> + +<p>The composition of aërolites may also be taken as indications of the +common origin and elementary texture of the planets, whether they are +independently formed or have originally pertained to a former planet; +for no hypothesis of telluric or selenic origin yet advanced, can stand +against the weight of evidence against it. Their fragmentary character +rather favors the views of Sir David Brewster, and when we consider that +they have been revolving for thousands of years with planetary velocity, +and in very eccentric orbits, through the ether of space, continually +scathed by the electric blast of the radial stream, their rounded +angles, and black glossy crust of an apparently fused envelope, may be +accounted for, without difficulty, from the non-vitrified appearance of +the interior. The composition of aërolites as far as known, embrace +nearly one-third of all known simple substances according to Humboldt, +and are as follows: iron, nickel, cobalt, manganese, chromium, copper, +arsenic, zinc, potash, soda, sulphur, phosphorus, and carbon.</p> + +<p>The theory we have thus given of the common occurrence of shooting +stars, will render a satisfactory general account of their sporadic +appearance; but there are other phenomena of greater interest, viz.: the +occasional recurrence of swarms of such meteors, which defy all +numerical estimates, being more like a fiery rain than anything they can +be compared to. The most interesting feature of this phenomena, is the +<i>apparent</i> periodicity of their return. In the following table we have +set down the most remarkable epochs mentioned by Humboldt, (and no man +has devoted more attention to the subject,) as worthy of notice:</p> + +<table summary="Dates of showers between April and December."> +<tr> + <td><span class="pagenum" title= + "Page 223"> </span><a name="Page_223" id= + "Page_223"></a> About </td> + <td style="padding-right:4em;">April</td> + <td>22</td> + <td>to</td> + <td>25</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>July</td> + <td class="tdr0">17</td> + <td>to</td> + <td>26</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>August</td> + <td class="tdr0">9</td> + <td>to</td> + <td>11</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>November</td> + <td class="tdr0">12</td> + <td>to</td> + <td>14</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>November</td> + <td class="tdr0">27</td> + <td>to</td> + <td>29</td> +</tr> +<tr> + <td class="tdc">"</td> + <td>December</td> + <td class="tdr0">6</td> + <td>to</td> + <td>12</td> +</tr> +</table> + +<p>Besides these, he mentions two showers, from Arabian authority, in +October; one in October, observed in Bohemia; one observed by himself, +in the Pacific, on March 15; one February 4, just preceding the terrible +earthquake of Riobamba, in 1797. The Chinese annals also contain many +showers of stars, before the present era commenced. Some were in March, +more in July, and others in different months. How, then, in view of +these numerous dates, can we attach so much importance to the +periodicity of these showers? The great shower of 1833, in the United +States, on the 12th and 13th of November, brought to mind the great +shower at Cumana, observed by Humboldt and Bonpland just thirty-three +years before, to a day; and it must be confessed that more than ordinary +displays have been seen on this date. Yet, on the strength of this, +every meteoric shower is supposed to be periodical, and has resulted in +a theory which becomes more complicated as the phenomenon is more +observed, and can never lead to any useful and practical results. To +cite the numerous instances of discrepant results, would only encumber +this brief notice with facts neither interesting to the general reader, +nor convincing to those who hold a contrary opinion. The author of these +pages has watched for many years, and, in view of all the facts, has +concluded that the doctrine of periodicity (as held by present +meteorologists) is not tenable. The celebrated August shower failed, +also, this year, at least in this place, as for four hours each night, +on the 9th, 10th, and 11th, there were fewer bright meteors than at the +close of July.</p> + +<p>Professor Olmsted, who has paid considerable attention to the<span class="pagenum" title="Page 224"> </span><a name="Page_224" id="Page_224"></a> subject, +has indeed attempted to connect the great November shower with the +zodial light, which last he considers a nebulous body, of an elongated +form, whose external portions, at this time of the year, lie across the +earth’s path. (See Silliman’s Journal for 1837, vol. xxxiii. No. 2, +p. 392.) He even gives its periods, (about six months,) the aphelion of +the orbit being near the earth’s orbit, and the perihelion within +Mercury’s. In this way he attempts to explain both phenomena; but as the +zodial light is seen unchanged all the year round in tropical latitudes, +it is not the kind of body supposed by Olmsted, and the theory adds +nothing to our knowledge. Others have imagined rings of nebulous matter, +in which all the separate parts are moving in the same orbit around the +sun, with a retrograde motion, and this, with some modifications, is the +current theory of the day. The principal arguments rested on, for the +support of this view, are derived from the great shower of 1833, in +which a common radiant point was observed, and confirmed subsequently by +the radiant of other years, in the same month of November. As this point +is almost tangential to the earth’s orbit at this season, the earth +meets the nebulous ring moving in the contrary direction, and thus +confers on these meteors the necessary velocity that is thought to be +demanded by observation.</p> + +<p>Now, our theory gives a totally different explanation of the phenomenon. +We contend that a retrograde motion of such a nebulous mass, is +subversive of our whole theory; and we must be permitted to examine +certain points, hitherto disregarded by those entertaining antagonist +views. It is supposed that the meteors in 1833 fell for eight or nine +hours. The orbital velocity of the earth is more than 1,000 miles per +minute, and the orbital velocity of the nebulous zone must have had a +similar velocity. During the nine hours of meteoric display, therefore, +the earth traversed 500,000 miles of her orbit, which would give +1,000,000 miles for the depth of the nebulous stratum. But if<span class="pagenum" title="Page 225"> </span><a name="Page_225" id="Page_225"></a> of such +vast extent, how happened it that the only part of the earth in which +these were visible in great density, was the United States, or a space +embraced between the latitudes of 50° and 20° north, and the longitudes +60° and 100° west, (and these are the widest limits,) comprising only +1 ⁄ 40 of the surface of the globe? To a calm inquirer, this difficulty +seems insurmountable. The author was then in the Mediterranean, on deck +the greatest part of the night,—the weather fine, and nothing unusual +visible in the heavens; from other sources he has also derived similar +information. Yet, were the earth then passing through a stratum of +meteors 1,000,000 miles in extent, it is utterly inconceivable that +other portions of the earth escaped. Much stress is also laid on the +fact that these meteors in 1833, passed from east to west generally, as +they ought to do, if tangential to the earth in her orbit; but on the +same phenomenon occurring in 1799, when the earth was in precisely the +same part of her orbit, Humboldt says distinctly, “the direction (of the +meteors) was very regular from north to south.” How could this possibly +happen, and at the same time be moving tangentially to the orbit?</p> + +<p>There is also another fact of importance not duly weighed in forming +such a theory. In 1833 the meteors evidently differed in velocity; one +class, consisting of luminous points, passed like a shower of fire with +great velocity to the westward, another class were like large fire-balls +with luminous trains moving with less rapidity, while a third class +consisted of nebulous patches which remained stationary for a long time, +and frequently emitting large streams of light. These last, at least, do +not deport themselves as planetary bodies moving 2,000 miles per minute. +But the fact still remains, that unusual displays have occurred about +the 12th and 14th of November; and also as a general thing when there +are no unusual displays, the meteors are more abundant about this time. +Let us try if we can reconcile these facts with the theory of vortices.</p> + +<p><span class="pagenum" title="Page 226"> </span><a name="Page_226" id="Page_226"></a>We will first confine our remarks to the increased number of meteors +about November 12th and 14th. The cosmical matter composing the zodial +light, or at least the lighter parts of it, is continually driven +outwards by the radial stream, just as the matter of a comet’s tail is +stripped from the nucleus. This matter becomes involved in the terral +vortex by descending the poles, and is again passed out along the +equatorial plane. The form of the zodial light, as seen edgewise, gives +a lenticular form for the stratum of planetary particles composing it, +and its central plane has been considered as coinciding with the plane +of the sun’s equator. At the orbit of the earth, this lenticular space +is narrowed to a very thin stratum, but undoubtedly reaches beyond the +earth’s orbit with a rapidly diminishing density. As the axis of the sun +is inclined about 7° to the ecliptic, and the ascending node is in the +20th degree of Gemini, the earth can only pass through the plane of the +sun’s equator about the 12th of December and the 12th of June. If, +therefore, the central plane of the vortex coincides with the plane of +the sun’s equator, meteors ought to be more numerous about the dates +above mentioned. But the observed times are on November 12th and 13th. +Now, from actual measurements, a computation has been made by M. +Houzeau, that the elements of the zodial light are materially different +from those of the sun’s equator. He fixes the node of the light +(according to Mr. Hind) in 2° heliocentric longitude, subject to an +uncertainty of 12° or 13°, and its inclination to the plane of the +ecliptic, 3° 35′, subject to an uncertainty of about 2°. The truth is, +astronomers have argued the coincidence of the two planes from +considerations connecting the zodial light with the sun’s equator, as if +it were a solar atmosphere; but such an atmosphere is impossible, and it +is high time such measures should be taken as will lead to some certain +conclusion. If in the present state of the question, we were to take the +mean, we should find the node in about longitude 40°, which is the +posi<span class="pagenum" title="Page 227"> </span><a name="Page_227" id="Page_227"></a>tion of the earth on November 2d. But in the absence of +measurements, we will assume, for the sake of argument, that the +ascending node of the central plane of the vortex was, in 1833, in 50° +heliocentric longitude, and consequently the earth was passing through +the meteoric stratum or central plane of the zodial light, on the night +of November 12th. The opposite period of the year is May 12th—a date, +it is true, on which no great shower of stars is recorded, but sporadic +meteors are very plentiful at that time, and what is more important to +observe is, that the 11th, 12th, and 13th of May, are the three noted +<i>cold days</i> which we have before mentioned. Thus truly indicating that +the earth is then in or near the central plane of the vortex along which +the radial stream is at its maximum of power at any given distance from +the axis.</p> + +<p>But the question occurs, does the node of this plane remain stationary, +and is there no variation of the inclination of the axis of the solar +vortex? We have found from observation, that the axis of the terral +vortex is continually oscillating about a mean position by the action of +the moon; and reasoning from this analogy, and the constant tendency of +a material vortex to preserve a dynamical balance, the same tendency +must obtain in the solar vortex under the action of the great planets, +whose orbits do not coincide with the central plane of the vortex. The +ascending node of Jupiter’s orbit is in longitude 98°, Saturn’s 112°, +Uranus’ 72°, Neptune’s 131°; so that this plane does not correspond with +the plane of greatest inertia discovered by La Place, and from the +non-coincidence of these planes with the central plane of the vortex, +must produce the same oscillation in the axis of the solar vortex, as +the moon does in the terral vortex, but to what amount, observation can +alone determine. Jupiter and Saturn will of course exert the greatest +influence, and when these two planets are in conjunction, the ascending +node of the central plane of the vortex will vary in longitude perhaps +sufficiently to bring the meteoric maximum<span class="pagenum" title="Page 228"> </span><a name="Page_228" id="Page_228"></a> at the ascending node into +October on the one hand, and to the close of November on the other, and +at the descending node to April 25th on the one hand, and the close of +May on the other.</p> + +<p>The great showers of stars which have been recorded, must be therefore +considered as an accidental exaggeration of a perennial phenomenon, +attaining its maximum when the earth passes through the central plane of +the vortex, whose ascending node in 1833 we will suppose was in +longitude 50°. This theory will therefore account for those great +showers which have occurred about the 24th of April, as well as those +occurring in October and November; for it is far more consonant to all +analogy, to suppose the influx of planetary atoms into the solar vortex +to be in irregular, than in regular quantities. Yet, whether in the one +case or in the other, the matter will pass along the central plane of +the vortex, either diffusely scattered or in denser clouds, and will be +encountered by the earth when near the nodes <i>more frequently than at +other times</i>. The phenomenon of 1833, may then be attributed to the +earth encountering an unformed comet on the 12th of November; but we +must reflect, that the medium of the vortex is also in motion, and the +cometary matter drifting along with it; and that this motion corresponds +with the earth’s motion. By becoming involved in the terral vortex, it +will in a measure be carried along with the earth in her orbit as a +temporary occupant of the terral vortex. But we are here met with the +objection that the radiant being nearly stationary amongst the stars, +demonstrated conclusively, that the source of these meteors did not +partake of the earth’s motion. There is no difficulty in this. We +suppose as a general thing, that the meteors descended to the surface of +our atmosphere down the axis of the vortex (at least in the greatest +numbers), and the geocentric longitude of this axis was nearly the same +during the whole time of the display. We say nearly, for the motion of +the moon in her orbit in nine hours, would change the longitude of the +axis three or four de<span class="pagenum" title="Page 229"> </span><a name="Page_229" id="Page_229"></a>grees, and this is about the change in the +position of the radiant noted at the time. This objection, therefore, +falls to the ground; for the axis of the vortex, although carried along +with the earth in her orbit, was unaffected by the earth’s rotation, and +would therefore appear nearly as stationary in the heavens as Gamma +Leonis. But it is again urged, that the moon was near conjunction with +the sun, and consequently the central vortex was on the opposite side of +the globe. This is true; but the outer vortex must have been near the +meridian about three hours after midnight, or about the time when the +radiant was vertical and the display the greatest. When the axis was to +the eastward, the stars would shoot westward, when on the meridian, they +would pass in all directions, but principally to the south, on account +of the inclination of the axis of the vortex; but this would only be +true for places situated to the southward of the central latitude. +During the great shower of stars seen by Humboldt, in Cumana, the +direction was to the south uniformly. Now, the latitude of Cumana is +above 10° north, yet still too low for the general limits of the +vortices; but from the same inclination of the axis (from 30° to 36° to +the surface), the meteors would pass far south of the limit, and might +even reach to the equator. The latitude of the <i>outer vortex ascending</i> +on November 12th, must have been near the line of greatest display, from +the position of the moon at the time. We thus see why the phenomenon was +limited to so small a fraction of the earth’s surface; why these meteors +should be intermingled with nebulous patches stationary in the heavens +for an hour together, and why, notwithstanding these facts, they were +independent of the earth’s rotation.</p> + +<p>We have yet another objection to answer, viz.: the planetary velocity of +some of these bodies. Let us be understood. The velocity of a solid +aërolite is due to gravitation, and is planetary, on the other hand, +voluminous collections of cometary dust united by accident, and +remaining so by mere inertia, are borne<span class="pagenum" title="Page 230"> </span><a name="Page_230" id="Page_230"></a> passively on the ethereal +currents with <i>electric</i> velocity, and probably never penetrate far, +even into the attenuated atmosphere, which may be supposed (from the +facts connected with the aurora) to extend far above the denser stratum +which refracts and reflects light, and from which the assigned limits of +our atmosphere have been derived.</p> + +<p>It is generally considered that sporadic meteors are more numerous in +the summer and autumn than in the winter and spring, and we have, +likewise, in the tenth of August, a date which corresponds to many great +displays and meteoric showers, both in recent and remote times. This +would seem to vitiate our theory; for we cannot suppose that there are +two <i>central</i> planes in the vortex intersecting the ecliptic in +longitude 320° and 50°. We must remember, however, that as these great +displays are accidental, and as the stratum composing the zodial light +is manifestly of sufficient thickness to envelope the whole orbit of the +earth, that it does not necessarily follow that the dense portions to +which meteoric showers are due, should be always confined to the central +plane of the vortex. And, besides, we have similar displays recorded in +other months, which invalidates the theory of a regularly-recurring +phenomenon. We shall, therefore, only aim at explaining why meteors are +generally more abundant in summer and autumn than in the opposite +seasons.</p> + +<p>The axis of the solar vortex, considered as cylindrical, must be +admitted to run out to a great depth on either side from the sun, and +reach far into that unoccupied space intervening between our system and +the nearest fixed stars, and from these opposite points the solar vortex +is supplied with that stream of ether which passes down either pole to +restore a partial equilibrium in the density of the ether of the vortex, +rarefied by centrifugal force. As certain portions of the heavens are +crowded with stars, and other parts comparatively vacant, we may expect +a similar inequality in the distribution of that<span class="pagenum" title="Page 231"> </span><a name="Page_231" id="Page_231"></a> cometic dust, which +causes a certain amount of extinction in the light of the stars, and, +therefore, seeing that the two extremities of the axis of the solar +vortex are so widely separated, it would not be wonderful if different +quantities of such matter were brought down into the vortex from these +extremities.</p> + +<p>From recent observations made by H. R. Birt, at the observatory of the +British Association, it would appear that the brightest portion of the +zodial light is always north of the ecliptic. Others have also remarked +the same, and if we couple this fact with the suggestion just made, we +are justified in suspecting that a greater quantity of cometic dust +comes down the northern pole of the vortex than down the southern. This +matter, in passing outward, does not, of course, immediately attain to +the central plane of the vortex, but is more thickly distributed along a +plane parallel to this plane. And the same will be observed by that +matter coming down the southern pole; it will be, in a certain degree, +retained in a plane south of the central plane, but still parallel with +it. This would account for the greater brightness of the northern side +of the zodial light. It would, also, account for the greater frequency +of meteors in summer and autumn than in the opposite seasons. From May to +November the earth is above the central plane of the vortex, and, +consequently, on the northern side; but after passing the node in +November, she is on the under or southern side, and the meteors are less +frequent. With this general explanation we shall close. If what we have +advanced be an approximation to the truth, the theory itself affords +ample indications of what observations are requisite to prove or +disprove it; and, on this account, a theory is of great benefit, as +suggestive of many questions and combinations of facts which otherwise +might never be thought of.</p> + +<p>We have thus taken a cursory glance at the prominent physical phenomena +of the world, and attempted to link them<span class="pagenum" title="Page 232"> </span><a name="Page_232" id="Page_232"></a> together in the bonds of one +all-pervading principle. We have fearlessly taken a new path, and claim +originality for the whole, disclaiming all intention of retailing +second-hand wares, or of compiling an ingenious theory from +heterogeneous scraps. If it be true, or if it be partially true, let +those professionally engaged in such pursuits enter the wide field of +investigation we have discovered for them; for if the whole theory be +true, it only shows in a clearer light that the great work which has +been fancied so near completion is scarcely yet begun; while the +prospect of an ultimate and final completion of the temple which so many +zealous votaries are erecting, is rendered mournfully hopeless by the +contemplation of what yet remains to be performed.</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_42_42" id="Footnote_42_42"></a><a href="#FNanchor_42_42">[42]</a></span>The orbit this year was determined under very unfavorable +circumstances.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_43_43" id="Footnote_43_43"></a><a href="#FNanchor_43_43">[43]</a></span>According to other tables, this angle would be much +greater than is given in Mr. Hind’s catalogue.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_44_44" id="Footnote_44_44"></a><a href="#FNanchor_44_44">[44]</a></span>Prin. Prop. xx Lib. Sec.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_45_45" id="Footnote_45_45"></a><a href="#FNanchor_45_45">[45]</a></span>With reference to the resisting power of the atoms.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_46_46" id="Footnote_46_46"></a><a href="#FNanchor_46_46">[46]</a></span>Prin. Lib. Tor. Prop, xxxix., also Prop, xli.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_47_47" id="Footnote_47_47"></a><a href="#FNanchor_47_47">[47]</a></span>In making this suggestion, the author is well aware that +Ephemerides of the four chief asteroids have been given annually in the +Greenwich Nautical Almanac; but for the object proposed they are utterly +useless. Will any astronomer contend that these Ephemerides are true to +ten seconds of arc? If not, they are useless for the purpose suggested +above, and the theory wants revision. And it is evident that any +objection against its practicability, founded on the uncertainty of the +number of the asteroids themselves, as has already been urged in answer +to this suggestion, is an evidence that the objector weighed the subject +in the scales of his imagination only.</p></div> +</div> + + +<hr style="width: 65%;" /> +<h2><span class="pagenum" title="Page 233"> </span><a name="Page_233" id="Page_233"></a><a name="SECTION_SIXTH" id="SECTION_SIXTH"></a>SECTION SIXTH.</h2> + + +<h3>THE POLAR ICE.</h3> + +<p>We shall conclude these pages by again referring to our theory of the +weather, in connection with an event which every friend of humanity and +every lover of natural science is bound deeply to deplore.</p> + +<p>From the present position of the lunar nodes and apogee, the vortices of +our earth do not ascend into very high latitudes. Now, according to the +principles laid down, the frequency of storms tends to lower the +temperature in the warm regions of the earth, and to elevate it in the +polar regions. Let us suppose the northern limit of the vortices to be +in latitude 70°. There will be, in this case, a greater prevalence of +northerly winds <i>within</i> this circle of latitude, to supply the drain to +the southward, and the back currents by passing above will descend at +the pole, partaking of the temperature due to that elevation. The +character of the arctic seasons may therefore be considered as partly +dependent on the average direction of the wind. Suppose again, the +extreme limits of the vortices to be about latitude 80°, the relative +areas of the two circles are as 4 to 1; so that in this last case the +exclusive range of the northerly winds is limited to one-fourth of the +first area. South of 80° the wind will frequently come from the south, +and by mixing with the local atmosphere of that latitude, will tend to +ameliorate the small area to the northward. And the greater atmos<span class="pagenum" title="Page 234"> </span><a name="Page_234" id="Page_234"></a>pheric +commotion when confined to such a small circle of latitude, must assist +materially to break up the polar ice; which would tend still more to +equalize the temperature.</p> + +<p>By referring to our table, we see that the mean conjunction of the pole +of the lunar orbit and the moon’s apogee, was in longitude 128° on April +10, 1846, and let it be remembered that when the conjunction takes place +due south or in longitude 270°, the vortices attain their greatest +latitude north. When, on the contrary, the conjunction takes place due +north or in longitude 90°,<a name="FNanchor_48_48" id="FNanchor_48_48"></a><a href="#Footnote_48_48" class="fnanchor">[48]</a> the northern limits of the vortices are +then in the lowest latitude possible.</p> + +<p>Sir John Franklin sailed in May 1845, and was certainly at the entrance +of Wellington sound, near latitude 75°, April 3d, 1846, as the dates on +the graves testify. That season, according to the theory, was a cold +one; for the vortices could not reach so far to the northward in that +year, and consequently there were no storms, properly speaking. It would +probably be late in the summer of 1846, before the expedition was +liberated, and as the prevailing winds would be from the northward, he +would have little choice, but to stand to the westward if the state of +the ice permitted. In his instructions he was to use every effort to +penetrate to the southward and westward of Cape Walker, and he probably +conformed to them under the circumstances, and passed the winter in the +ice, in that neighborhood. And in 1847 we do not anticipate, from the +theory, that he would make much progress westward.</p> + +<p>In 1848, Sir James Ross was sent out with the first relief-ship; but was +not able to reach the entrance of Wellington channel because of compact +ice from there to Leopold Island. This was about the beginning of +September—a time when the northern channels are usually the most open. +On the 11th, they ran the ships into Port Leopold, and the next day the +ice<span class="pagenum" title="Page 235"> </span><a name="Page_235" id="Page_235"></a> shut them in for the winter. From the character of the season, we +may infer that if Franklin did not enter Wellington channel in 1847, as +is most probable, neither did he in 1848. Perhaps he was not able to get +his ships far to the westward, as we infer from the theory. Still, as +the time was not very protracted, he would wait patiently another season +and husband his resources.</p> + +<p>In 1849, Sir James Ross cut his ships clear of the ice August 28th, and +crossed over to Wellington channel, where he found the land-ice still +fast, showing that this season was also a bad one in accordance with the +theory. On the 1st of September he met the first gale of wind, at which +time the <i>Inner Vortex</i> was at its extreme north latitude, and rapidly +extending its limits by the motion of the perigee.</p> + +<p>This vortex describes a smaller orbit than either the central or the +outer vortex, and consequently reaches into higher latitudes. But the +time was badly chosen, as the whole series of years since Franklin left +has been unfavorable for the early rupture of the ice. Sir James Ross +having been drifted out of Lancaster sound by the gale, finally bore up +for England towards the close of September 1849.</p> + +<p>The same year, the North Star with additional supplies was working up +Baffin’s bay; but on account of the unusual quantities of ice, and the +frosts “which glued the floes together,” she was unable to force a +passage through the middle ice, and wintered on the east side of +Baffin’s bay, in latitude 76° 33′—her thermometer marking 64° below +zero, as the coldest of the winter. In 1850, the perigee of the moon +attained its northern limit, but the position of the node was bad; still +this year and 1851, were the best of the series. The North Star +succeeded in getting out of the ice on the 1st of August—a very early +date for that high latitude—and on the 8th had crossed over to +Possession bay; but being prevented by the land-ice, she bore up for +Pond bay and there landed the provisions. The same year (1850) several +vessels entered Lancaster sound. Sir John<span class="pagenum" title="Page 236"> </span><a name="Page_236" id="Page_236"></a> Ross also reached Melville +Island; from which it is evident that this season was far better than +any preceding. According to Captain Penny, this year a floe of ice at +least two years old, filled Wellington strait; but was diminished in +breadth at a subsequent visit. He also saw a boundless open sea from the +<i>western</i> entrance of Wellington strait; but of course the ships could +not reach it, for the floe before mentioned. Following the indications +of the theory, we consider it almost certain that Franklin went to the +westward and not through Wellington channel; that he made but slow +progress until 1850, when finding the sea more open to the northward, +and attributing it more to local influences than to any change in the +season, he considered it a better course to extricate the expedition, by +pushing on towards Behring’s straits than to attempt the frozen channels +he had already passed through. But the seasons again getting worse after +1850, he was again arrested in the polar basin by the ice and islands +off the northern coast of America.</p> + +<p>Regarding the old and new continents as in reality a connected body of +land, with a polar depression, we may expect that the great range of +American mountains is continued in a straight line, from the mouth of +the McKenzie river, obliquely across the Polar sea, and connects with +the Ural; and that along the axis of the chain, protuberant masses will +emerge above the sea level, constituting an archipelago of islands, from +Nova Zembla to the McKenzie; and that these islands, causing an +accumulation of ice, and arresting its general tendency to the +southward, is the barrier which Sir John Franklin was finally stopped +by, in a situation where he could neither advance nor return. With the +map before us, and the data afforded by former voyages, and guided by +these theoretical views, respecting the prevailing direction of the +winds and the character of the seasons, we should locate Sir John +Franklin near latitude 80°, and longitude 145°, in 1851; and as the +seasons would<span class="pagenum" title="Page 237"> </span><a name="Page_237" id="Page_237"></a> afterwards become more severe, we may consider that he +has not been since able to change his locality, and dare not desert his +ships.</p> + +<p>No mere stranger can feel a deeper interest than the author, in view of +the hard fortunes of these hardy explorers, and he would not lightly +advance such opinions, did he not suppose they were in some degree +reliable. In 1832, he himself crossed the Atlantic, for the purpose of +offering himself to the Geographical Society of London, intending to be +landed as far northward as possible, with a single companion,<a name="FNanchor_49_49" id="FNanchor_49_49"></a><a href="#Footnote_49_49" class="fnanchor">[49]</a> from +which point he purposed to follow the coast line on foot, with cautious +discretion as to seasons, confident that, with arms and ammunition, he +could support himself for many years. It has always been a grave error +in all these northern land expeditions, that they have been too +unwieldy, too much encumbered with the comforts and luxuries of +civilization at the outset, and too much loaded with a philosophical +paraphernalia, for a pioneering survey,—and cherishing too fondly the +idea that the wide shores of the Arctic sea could be explored in a +single season. Had the British government established a few posts in the +Arctic regions in the beginning,—one, for instance, in Lancaster sound, +another in Behring’s Straits, and a third near the mouth of the +Coppermine, volunteers of sufficient scientific attainments might have +been procured, to banish themselves to these inhospitable regions for a +term of years, if assured of triennial supplies; and in this way, by +summer boat-parties and winter expeditions, over land or ice, the +explorations could have been gradually extended, and a greater knowledge +of the polar regions might have been acquired, with an immense saving +both of life and money. In 1832 the author’s plan was deranged, by +finding that Captain Back was about setting out in quest of Ross, who +had then been some four years absent. This officer had all his party +engaged when the author waited upon him in Liverpool,<span class="pagenum" title="Page 238"> </span><a name="Page_238" id="Page_238"></a> and no notice was +taken of a modified plan which he forwarded to the Society at his +suggestion. It was therefore abandoned.</p> + +<p>The above fact is alluded to, in order to show the author’s sincerity in +expressing his belief that, with a previous preparation of mind and body +for a sojourn in those frigid climes, a sufficient subsistence may be +derived from the country itself. Advantage must, of course, be taken of +the times of abundance, and due preparation made for the season of +scarcity. Averaging the extremes, there is little doubt but that both +land, and air, and water, afford an abundance of food for man in the +Arctic zone, and that, when spurred by necessity, it is within his power +to obtain it. We ought not therefore to despond, or give up efforts to +rescue those who have well earned the sympathy of the world, by what +they must have already suffered. <i>These northern seas will yet be +explored.</i> The very difficulty of accomplishing it, will itself give it +a charm, which in this restless age will operate with increasing power. +And should efforts now be relaxed, and in some future time the evidence +be brought to light that some of the party yet existed, long after all +efforts to rescue them had been abandoned, the fact would be a dark spot +on the escutcheon of England, which time could not erase.</p> + +<p>Since these pages were written, accounts have been received from Captain +McClure, of H. M. ship Investigator, which fully confirm the preceding +remarks on the character of the seasons in the Arctic circle; and, more +recently, despatches have been received from the discovery-ship, +Amphytrite, in relation to the past season in Behring’s straits, which +also confirms the theory.</p> + +<p>The Investigator (now supposed to be frozen up in lat. 74° 5′ N., and +long 117° 54′ W.,—the last despatch being dated April 10, 1853) passed +round the northern shores of America into the channels communicating +with Lancaster sound, in 1850, but was unable to extricate herself in +1852, and, probably, yet remains in the harbor she made in the winter of +1851, in the position above named. No trace of Sir John Franklin’s<span class="pagenum" title="Page 239"> </span><a name="Page_239" id="Page_239"></a> +expedition was, however, found, and, indeed, according to our theory, +the Investigator was not on the most promising ground. We contend that +Franklin has penetrated the pack of apparently perennial ice, which is +continually pressing to the southward, and blocking up the passages +between the northern islands, or skirting the coast line of the +continent; which pack has since increased, and effectually stopped all +egress from the open central portions of the polar sea. If Sir John +Franklin is ever heard from, this pack <i>must be penetrated</i>, and a +powerful steamer ought to be sent immediately by the British government, +to be ready in Behring’s straits early enough to take advantage of the +first openings, and make a bold push <i>due north</i>, so as to get as +speedily as possible into the open waters to the north of the pack.</p> + +<p>If the author could make himself heard at Washington, he would also urge +the government to lose no time in following our own expedition under Dr. +Kane, who, if he finds a clear entrance from Smith’s sound into the +Arctic sea, may be induced to push on, and endeavor to make his way +through the pack towards Behring’s straits, and thus fall into the same +snare as Franklin. According to the theory, the higher the passage into +the Arctic sea, the less will it be incumbered with ice, and, +consequently, Smith’s sound is the best both to enter and return by; and +had the author not already smarted enough by having his professions +derided, he would have submitted these views to the patrons of that +expedition before it sailed.</p> + +<p>The scientific world is, in reality, chargeable with the disastrous +results of Franklin’s expedition. The polar basin is hemmed in by the +coast line of Europe, Asia, and America, in about latitude 70° north, +for the greatest part of the entire circumference. And this coast line, +and the islands adjacent, will cause the polar ice to accumulate and +form a frozen belt along these shores, in consequence of the constant +tendency of the earth’s rotation to press the ice to the southward. The<span class="pagenum" title="Page 240"> </span><a name="Page_240" id="Page_240"></a> +fact that an open passage exists between this belt and the shore in +summer time, is no objection, as the tides, river currents, and warm +land breezes, may very well explain this. The learned have insisted, and +do yet insist, that the earth’s rotation can produce no motions in the +Arctic sea, and, under this delusion, Franklin has passed into the +comparatively open waters inside the pack, perhaps has lost his ships; +yet it is very possible that the party may have escaped, and derived a +subsistence from the more genial waters of the central portion of that +ocean unto this day.</p> + +<p>We have already alluded to the difference of level between the Atlantic +and Pacific waters. It is well known that the currents in the +Spitzbergen and Greenland seas is to the southward, and that Parry, in +his attempt to reach the pole, was foiled by this very current, +frequently setting him back in twenty-four hours more than his party +could travel in the same time over the ice. Through Baffin’s and +Hudson’s bay the northern waters are also continually bearing their +frozen freight southward. We are, therefore, entitled to ask, what +supplies this immense drain? Behring’s straits are only about sixty +miles wide, and twenty-five fathoms deep; the supply, therefore, through +this channel is totally inadequate, yet there is no other channel into +the Arctic sea where the current is inward. We have already explained +the reason why the current through Behring’s straits is an exception to +the general rule, yet still confirming the principle by referring it to +the configuration of the land enclosing the Pacific ocean. The whole +south Pacific lies open to the pole, and the inertia of the immense mass +of mobile waters pressing northward, and continually contracted by the +form of the American and Asiatic coasts, is not balanced by a contrary +impulse of the waters of the north Pacific, inasmuch as this ocean +becomes narrower as it extends northward, and the only passage to the +frozen ocean is through the narrow straits of Behring. The axifugal +force of rotation due to the<span class="pagenum" title="Page 241"> </span><a name="Page_241" id="Page_241"></a> northern waters is, therefore, overborne +by the vast preponderance due to the southern waters, and, hence, the +northern Pacific may be considered as relatively at a higher level, and +there will be a current northward through Behring’s straits, as we find +it. The same cause accumulates the waters under the equator, thus giving +a higher level to the Pacific than to the Atlantic at the isthmus of +Panama, where the difference of level is found by actual measurement to +be five or six feet. This fact has never before been explained; but the +cause is too obvious to admit of question.</p> + +<p>That the sea is deeper than was formerly admitted, is now fully +confirmed. We have before alluded to the results obtained by Captain +Denham, of H. M. ship Herald, who found bottom at 7,706 fathoms, or +about nine English miles. Now, whether that spherical shell, which we +have contended to be the true form of the solid earth, be continuous and +entire; or, whether it may not be wanting in localities of limited +extent where the ocean would be absolutely unfathomable, we know not; +but if such be the internal constitution of our globe, there will be, no +doubt, many channels of communication between the internal and external +ocean, and, as a consequence of the earth’s rotation, the axifugal +current of the Arctic sea may be supplied by an upward current from the +interior of the globe; and this current may have a higher temperature +than the surface waters of that sea, and thus the middle portions may, +in truth, remain open the whole year round, and be teeming with animal +life. According to Captain Penny’s observations in 1850, whales and +other northern animals existed to the westward, where he saw the open +sea stretch out without a bound before him.</p> + +<p>It has been a question mooted by some, that Franklin’s ships might be +overtaken, at an early stage of the voyage, by a storm, and foundered +amidst the ice. The theory would give a negative answer to this +question. Stiff gales may prevail far to the north when the vortices do +not reach so high; but no<span class="pagenum" title="Page 242"> </span><a name="Page_242" id="Page_242"></a> storm, properly speaking, will be found far +beyond their northern limit. After the coming winter (1853), the +vortices will gradually penetrate farther and farther to the northward, +and the years 1857, 1858, and 1859, will be highly favorable for +northern discovery, accompanied, however, with the necessary draw-back +of tempestuous weather.</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_48_48" id="Footnote_48_48"></a><a href="#FNanchor_48_48">[48]</a></span>The reader will of course understand these as celestial +longitudes, and the latitudes as terrestrial.</p></div> + +<div class="footnote"><p><span class="label"><a name="Footnote_49_49" id="Footnote_49_49"></a><a href="#FNanchor_49_49">[49]</a></span>Mr. William McDonald, of Canada.</p></div> +</div> + + +<hr style="width: 65%;" /> +<h2><a name="CONCLUSION" id="CONCLUSION"></a>CONCLUSION.</h2> + + +<p>Our theory has thus extended itself beyond those limits which we at +first had drawn, and our apology must consist in the necessity existing +for reconciling the most remarkable phenomena of meteorology to its +principles. Yet, after all, what has been said is but an outline of what +remains, but this outline is a part of our theory of the weather, and it +could not well do without its aid. In some points we may not have +correctly interpreted facts; but the facts remain. The numerical +elements of the theory may also be in error—we know not; but we think +that they are as perfect as the many contingencies on which they depend +will permit. What is <i>certain</i> however, is of ample value to compensate +for trivial errors. We have hitherto experienced but little courtesy +from those intrusted with the keys of knowledge, and cannot consequently +anticipate a very lenient verdict. But we now tell them before the +world, that they have a duty to perform, and an examination to make, and +a decision to come to, “whether these things are so.” Our theory may be +called an ingenious speculation, but WE CHALLENGE THE SCIENTIFIC TO +PROVE IT—NOTHING ELSE. The theory furnishes them with tests of daily +occurrence, to prove or to disprove it. By such a trial we are willing +to be judged; but let it be conducted in the spirit recommended<span class="pagenum" title="Page 243"> </span><a name="Page_243" id="Page_243"></a> in the +opening address before the American Association for the Advancement of +Science, to expose all false developments, and to do it generously and +without prejudice; and to remember, “that the temple of science belongs +to no country or clime. It is the world’s temple, and all men are free +of its communion. Let its beauty not be marred by writing names upon its +walls.”<a name="FNanchor_50_50" id="FNanchor_50_50"></a><a href="#Footnote_50_50" class="fnanchor">[50]</a> The <i>great</i> objection, of friction and resistance of an +all-pervading medium, which will be urged against it, we regard as +rather the offspring of a bewildered imagination, than of scientific +induction. We can discover no such consequences as final ruin to our +system through its agency; but even if such were discovered, we may +answer, that nature nowhere tells us that her arrangements are eternal; +but rather, that decay is stamped with the seal of the Almighty on every +created thing. Change may be one of the great laws of matter and motion, +and yet matter and motion be indestructible. The earth was called into +existence for a specific object, and when that object is accomplished, +we are assured that another change awaits her. But when earth, and sun, +and planets, are again redissolved into their primitive state, their +atoms will still float on the ever-rolling billows of the great ethereal +ocean, to be again cast up, on the shore of time, whenever it pleaseth +Him to say, “Let there be light.”</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_50_50" id="Footnote_50_50"></a><a href="#FNanchor_50_50">[50]</a></span>Prof. Pierce’s Address, 1853.</p></div> +</div> + + +<hr style="width: 65%;" /> +<h2><span class="pagenum" title="Page 244"> </span><a name="Page_244" id="Page_244"></a><a name="APPENDIX" id="APPENDIX"></a>APPENDIX.</h2> + + +<p>Since the author’s arrival in New York for the purpose of publishing his +outlines, the third and fourth volume of the Cosmos has been placed in +his hands, containing the latest uranological discoveries and +speculations. It is now more than twenty years since he began to +investigate the subject he has treated of, and fifteen since he first +announced to the world, that he had satisfactory evidence of his theory +being true. Luckily, perhaps, he has been cut off from the great streams +of knowledge; and he may confess that it was with pardonable feelings of +gratification that he discovered in 1853, by the acquisition of the two +first volumes of the Cosmos, that the philosophic mind of Humboldt had +also pondered deeply on the planetary peculiarities of size, density, +distance, inclination of axes and eccentricities of orbits, without +eliciting any satisfactory relations.</p> + +<p>From the tenor of the third and fourth volume of this learned summary of +scientific knowledge, it is evident that the question of a medium +filling space is more and more occupying the learned world; but the +author is unable to discover any consistent theory respecting it. The +increasing interest attaching to it, however, is evidently preparing the +world for some radical change in preconceived views. The explanation +given by this present theory to many prominent phenomena, is so totally +contrary to that of the learned world, as to leave it untouched by +anything yet advanced. What the fifth volume of the Cosmos<span class="pagenum" title="Page 245"> </span><a name="Page_245" id="Page_245"></a> will +contain, is not yet known in this country, neither has the author been +favored with any glimpse of the progress of science as developed before +the British Association; he supposes, however, that he yet stands alone +in the position he has defined.</p> + +<p>As a question of practical importance, the reader will find in the work +cited, the various opinions of the temperature of space. Both Fourier +and Poisson regard this as the result of radiated heat from the sun and +all the stars, minus the quantity lost by absorption in traversing the +regions of space filled with ether.<a name="FNanchor_51_51" id="FNanchor_51_51"></a><a href="#Footnote_51_51" class="fnanchor">[51]</a> But why should we regard the +stars as the source of all motions? Why cannot physicists admit the idea +of an infinite space filled (if we may use the expression) with an +infinite medium, possessing an unchangeable mean temperature long before +the formation of a single star. A star equal to our sun at the distance +of Sirius, would give about one million of million times less heat than +our present sun, which is only able to give an average temperature to +the whole globe—about twenty degrees above freezing—then let us +remember that there are only about fifty stars of the first and second +magnitude, which give more light (and by analogy heat also) than all the +rest of the stars visible. Such labored theories as this of Poisson’s is +a lamentable instance of the aberrations of human wisdom.</p> + +<p>We would also call the reader’s attention to a late conclusion of +Professor Dove, viz.: That differences of temperature in different +longitudes frequently exist on the same parallel of latitude, or, in +other words, are laterally disposed. This may be thought adverse to the +theory, but it should be borne in mind that the annual mean temperature +of the whole parallel of latitude should be taken when comparing the +temperatures of different years.</p> + +<p>Another fact cited in the Cosmos apparently adverse to the theory, is +the idea entertained by Sir John Herschel, that the<span class="pagenum" title="Page 246"> </span><a name="Page_246" id="Page_246"></a> full-moon +dissipates the clouds. This question has been fully examined by +Professor Loomis before the American Association, and he concludes that +there is not the slightest foundation for the assertion—taking as data +the Greenwich observations themselves.</p> + +<div class="footnotes"><h3>FOOTNOTES:</h3> + +<div class="footnote"><p><span class="label"><a name="Footnote_51_51" id="Footnote_51_51"></a><a href="#FNanchor_51_51">[51]</a></span>See <i>Cosmos</i>, p. 41, vol. III.</p></div> + +</div> + + + + + + + +<pre> + + + + + +End of the Project Gutenberg EBook of Outlines of a Mechanical Theory of +Storms, by T. 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Bassnett + +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: Outlines of a Mechanical Theory of Storms + Containing the True Law of Lunar Influence + +Author: T. Bassnett + +Release Date: July 8, 2006 [EBook #18791] + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK THEORY OF STORMS *** + + + + +Produced by Curtis Weyant, Laura Wisewell and the Online +Distributed Proofreading Team at http://www.pgdp.net + + + + + + +------------------------------------------------------------------+ + | | + | Transcriber's Note | + | | + | Transliterations: The original book used a number of special | + | characters. Most have been replaced by obvious text equivalents. | + | The Greek phrase on the title page has been transliterated. | + | The book also used special symbols for planets, etc; this | + | version renders these in capitals surrounded by square brackets, | + | e.g. [NEPTUNE]. [VOLCANO] represents an unknown planet, in the | + | original denoted by a right-angled triangle which the author | + | wrote represented a volcano. | + | The degree symbol is here rendered as d. It is hoped that no | + | confusion will result from the author's use of "2d" and "3d" for | + | "second" and "third". | + | The plus-or-minus sign is rendered +/-. | + | | + | The ISO-8859-1 text version preserves more symbols, including | + | the latter two. The UTF-8 text and HTML versions preserve all of | + | the symbols originally used. | + | | + | Printer errors: Obvious typographical errors in the original | + | have been corrected in this version, and full details of the | + | corrections can be found in the HTML version of this ebook. | + | However, the inconsistent spelling of Ottawa/Ottowa, and the | + | inconsistent use of comma or full-stop as thousands separator | + | has been left as in the original. The value given for the | + | eccentricity of Uranus may also be a printer error. | + | | + +------------------------------------------------------------------+ + + + + + OUTLINES + + OF + + A MECHANICAL THEORY OF STORMS, + + CONTAINING + + THE TRUE LAW OF LUNAR INFLUENCE, + + WITH + + PRACTICAL INSTRUCTIONS TO THE NAVIGATOR, TO ENABLE + HIM APPROXIMATELY TO CALCULATE THE COMING + CHANGES OF THE WIND AND WEATHER, + FOR ANY GIVEN DAY, AND FOR + ANY PART OF THE OCEAN. + + + BY T. BASSNETT. + + He de mesotes en pasin asphalestera + + NEW YORK: + D. APPLETON & COMPANY, + 346 & 348 BROADWAY, + AND 16 LITTLE BRITAIN, LONDON. + 1854. + + + + Entered, according to Act of Congress, in the year 1853, by + T. BASSNETT, + In the Clerk's Office of the Southern District of New York. + + + + +CONTENTS. + + +SECTION FIRST. + +Present State of the Science of Meteorology--Primordial Condition of the + Solar System--Theory of Gravitation the great key of Nature--Bessell's + doubts of its perfect adequacy--the Newtonian Vacuum: its + difficulties--Nature of the element called Ether--The Medium of Space + and the Electric Fluid--Ponderosity of Matter--Dynamical law of + Equilibrium--Specific heat and its relation to space--A Plenum not + opposed to Gravitation--The medium of space in motion--Formation of + Vortices--A new principle developed--Elements of the problem--Hutton's + theory of the production of rain--Indications of change and the + cause--Action of the Ethereal Current--Physical process of Atmospheric + Derangement--Redfield's theory of Storms: its difficulties--All storms + are of brief duration and limited extent. 13 + + +SECTION SECOND. + +Mechanical action of the Moon--The Moon's mass--Axis of the Terral + Vortex affected by the Moon: its inclination and position: its + displacement--An example of the principle--Corrections + necessary--Milwaukie storm--New York storm--Ottawa storm--Liverpool + storm--Names and recurring order of the storm-producing agents--Record + of the weather--Second New York storm. 58 + + +SECTION THIRD. + +Lunar influence rejected by the learned--Their conclusions not + valid--Modifying causes in accordance with these principles--Years and + seasons vary in character--Superficial temperature of different + Planets--No storms on the planet Mars--Rotation the cause of Ocean and + Atmospheric Currents--Pressure of the atmosphere and its regular and + irregular variations--Terrestrial Magnetism--Internal Constitution of + the Globe--Magnetic variations--Cause of these variations--Magnetic + storms--Aurora Borealis: its altitude--Earthquakes; their possible + connection with Storms. 101 + + +SECTION FOURTH. + +The solar spots--Law of periodicity compared with the theory--Existence + of another planet beyond Neptune probable--Masses of the Sun and + Planet yet uncertain--The Law of Gravitation not above + suspicion--Proofs of this--The full of the Moon--Density of the + Ethereal Medium: its law in the Solar Vortex--Bode's law of the + planetary distances--Law of planetary density--Law connecting the + present and former diameters of the planets--Disturbing action of the + Ether--Kepler's third law not rigidly exact--Inconsistencies of + Astronomers--Nature of light and heat--Distinction between light and + heat. 147 + + +SECTION FIFTH. + +Comets--Their small inclinations--Their motions chiefly direct--Comet of + 1770 and 1844--Cause of acceleration in the case of Encke--Anomalous + motions of the comet of 1843--Change of diameter at different + distances of a comet from the sun--Cause of this change--Nature of the + nebulosity--Formation of the tail--Compound nature of a comet's + light--motion and direction of a comet's tail--Phenomena presented by + the great comet of Halley--Mass of a comet--The Zodial light--Nebulous + stars--Shooting stars--Periodic showers--Periodicity doubtful--Cause + of the apparent periodicity--Cause for being more numerous in Autumn + than in Spring. 187 + + +SECTION SIXTH. + +State of the polar ice since 1845--Sir John Franklin's track--Probable + existence of islands north of Behring's Straits--Possibility of + subsisting in the Arctic islands--News from the + Investigator--Necessity of searching in a higher latitude than the + Investigator visited--Franklin's misfortunes due to Scientific + Errors--Relative levels of the Atlantic and Pacific Oceans--The Arctic + seas more accessible in a few years--Conclusion. 233 + + + + +PREFACE. + + +On presenting to the public a work of this novel character, +overstepping, as it does, the barriers erected by modern systems to the +further progress of knowledge, a few words of explanation may not be +inappropriate. Early imbued with a desire to understand the _causes_ of +natural phenomena, the author devoured with avidity the interpretations +contained in the elementary works of orthodox science, until reason and +observation rendered him dissatisfied with the repast. To him it +appeared that there was an evident tendency in scholastic instruction, +to make the knowledge of nature inaccessible to the many, that the world +might be made more dependent on the few; while many of the _established +principles_, on which the learned rested, seemed to be at variance with +the simplicity and consistency of truth. Thus situated, he ventured to +think for himself, and looking back on the history of the past, and +finding so many cases in which the philosophy of to-day was supplanted +by a different system on the morrow, he was led to suspect the +possibility of future revolutions, and was thus determined to be no +longer embarrassed by previous systems, nor deterred by opinions +however learned, which conflicted with a rational recognition of the +mechanical nature of all physical phenomena. + +The science of meteorology, to which the following pages are devoted, +is, and always has been, a confessedly complex subject; and on this +account, any suggestions and facts which observation gleans,--no matter +how humble the source may be, should not be denied a hearing by those +professedly engaged in the pursuit of truth. Step by step, the author +became more and more confirmed in his doubts of the soundness of many +modern theories; and in 1838 he had attained a position which enabled +him to allege in the public prints of the day, that there did exist +certain erroneous dogmas in the schools, which stood in the way of a +fuller development of the causes of many meteorological phenomena. This +annunciation was made in general terms, and no notice was taken of it. +Subsequently, he forwarded to the British Association of Science, then +convened at Birmingham, a communication of similar tenor; and at a later +date still, a more particular statement of the advantages of his +discoveries to the navigator and agriculturist, was sent to the British +admiralty. The first of these communications was treated with silent +contempt; the last elicited some unimportant reply. In 1844 a memorial +was presented to Congress, accompanied with a certified copy of +_predictions_ of the weather, written several weeks before the event, +and attested in due form by two impartial witnesses; but neither did +this result in any inquiry as to its truth. During the time since +elapsed, he has been engaged in pursuits which prevented him from +pressing the subject elsewhere, until the spring of 1853, he brought +his theory under the notice of the Smithsonian Institution. This led to +a correspondence between himself and the gentlemanly Secretary of the +Institution, whose doubts of the truth of his allegations were expressed +with kindness, and whose courtesy was in strange contrast with the +conduct of others. In the communications which he forwarded to that +Institution, he gave a detailed statement of the difficulties he had met +with, and expressed the hope that an Institution, created for the +purpose of increasing and diffusing knowledge, would feel justified in +lending the influence of its name to facilitate the completion of a +theory which was yet undeniably imperfect. In view of this, a test was +proposed.[1] "Give us, for example, a prediction of the weather for one +month in each season of the year 1854, for the City of Washington." This +test the author refused, for the reason that he did not consider it +necessary to wait so long; but he informed the Secretary of the +Institution, that he would prepare an outline of his theory, which would +enable him to decide upon the merits of the discoveries claimed. This +outline is contained in the following pages. During the summer of 1853 +he called upon Professor Henry, then at Chicago, with his manuscript; +but a sudden indisposition prevented that gentleman from having it read. +He, however, strongly recommended its publication from such impressions +he then received.[2] This the author had resolved on, from a sense of +duty to the world at large, although the promise was rather of +prospective loss than of present benefit. The peculiar form under which +the theory appears, is, therefore, a result of the circumstances above +stated, and of the author's present inability to enter into the minute +details of a subject, which embraces in its range the whole visible +creation. + +In extending the theory to other phenomena, he has only fearlessly +followed out the same principles which have conducted him to a knowledge +of a disturbing cause, to which atmospheric storms owe their origin, and +in doing so he has conferred with no one. For whatever of merit or of +blame may therefore justly attach to these views, he alone is +responsible. If he has charged the scientific with inconsistency, or +with sometimes forgetting that the truth of their unnecessarily abstruse +investigations depends on the truth of the data, he at least is +conscientious; for he is too well aware that to provoke an unfavorable +verdict by contending against such fearful odds, is not the surest way +to either wealth or fame, or even to an acknowledgment of at least _the +mite_, which he cannot but feel that he has contributed to the treasury +of knowledge. That the scientific organisations of the day do tend to +curb the aberrations of a fanciful philosophy, cannot be denied; but at +the same time there is engendered such a slavish subordination as checks +the originality of thought, and destroys that perfect freedom from the +trammels of system, so necessary to success in the pursuit of truth. Of +such an influence the author explicitly asserts his entire independence. + +In thus introducing his theory, the reader is forewarned that he will +not find it dressed in the fascinating garb of the popular literature of +the day, whose chief characteristic is to promise much when possessing +little. It is, however, a plant of the author's own raising, unpropped, +unpruned, with none of the delicate tendrils or graceful festoons of the +trellissed vine; yet he flatters himself that its roots are watered by +the springs of truth, and hopes that he who is in quest of _that_, will +not find, amidst its many clusters, any fruit to set his teeth on +edge. + + +FOOTNOTES: + +[1] Extract from a letter from Professor Henry. + +[2] This gentleman kindly offered to contribute from his own private +means, to forward the publication, but he could do nothing officially +without submitting the manuscript to three different censors. He who +claims a new discovery, will seldom be satisfied to have it judged by +men who are engaged in the same investigations, however pure and +honorable they may be. Is this Institution adopting the best plan of +aiding truth, in its struggles against error? Should any man sit as +judge in his own trial? If there had been a powerful Institution to +stand between Galileo and the scientific of his day, his doctrines would +not have been condemned, and the world would have been fifty years more +in advance. + + + + +MECHANICAL THEORY OF STORMS. + + + +SECTION FIRST. + + +PRESENT STATE OF METEOROLOGY. + +The present state of the science of which we are about to treat, cannot +be better defined than in the words of the celebrated Humboldt, who has +devoted a long life to the investigation of this department of Physics. +He says: "The processes of the absorption of light, the liberation of +heat, and the variations in the elastic and electric tension, and in the +hygrometric condition of the vast aerial ocean, are all so intimately +connected together, that each individual meteorological process is +modified by the action of all the others. The complicated nature of +these disturbing causes, increases the difficulty of giving a full +explanation of these involved meteorological phenomena; and likewise +limits, or _wholly precludes_ the possibility of that predetermination +of atmospheric changes, which would be so important for horticulture, +agriculture, and navigation, no less than for the comfort and enjoyment +of life. Those who place the value of meteorology in this problematic +species of prediction, rather than in the knowledge of the phenomena +themselves, are firmly convinced that this branch of science, on account +of which so many expeditions to distant mountainous regions have been +undertaken, has not made any very considerable progress for centuries +past. The confidence which they refuse to the physicist they yield to +changes of the moon, and to certain days marked in the calender by the +superstition of a by-gone age." + +The charge thus skilfully repelled, contains, however, much truth; there +has been no adequate return of the vast amount of labor and expense thus +far devoted to this branch of knowledge. And it is not wonderful that +the popular mind should expect a result which is so much in accordance +with the wants of mankind. Who is there whose happiness, and health, and +comfort, _and_ safety, and prosperity, may not be more or less affected +by reducing to law, the apparently irregular fluctuations of the +weather, and the predetermination of the storm? To do this would be the +crowning triumph of the age; and the present theory has pioneered the +way for its speedy accomplishment. + + +ORIGINAL CONDITION OF THE EARTH. + +That the present order of things had a beginning, is taught by every +analogy around us, and as we have the glaring fact forced upon us, that +our globe has experienced a far higher temperature on its surface than +obtains at present, and moreover, as it is demonstrated beyond a cavil, +that the interior is now of far higher temperature than is due to solar +radiation, we are justified in concluding, not only that the condition +of the interior of our globe is that of fusion, but that its original +temperature was far higher than at present; so that the inference is +allowable that there has been a time when the whole globe was _perhaps_ +in this state. But why should we stop here? There are three states of +matter, the solid, the fluid, and the gaseous; and with this passing +glance at the question, we will jump at once to the theory of La +Place,--that not only our own globe, but the whole solar system, has +been once in the nebulous state. + +In justice to himself, the author ought to remark, that he had reasoned +his way up to this starting point, before even the name of La Place had +reached his ears. He makes the remark in order to disclaim any desire to +appropriate that which belongs to another; as he may innocently speak of +things hereafter, the idea of which has occurred to others. It is not +his intention here to say a word _pro_ or _con_ on the nebular +hypothesis; it is sufficient to allude to the facts, that the direction +of rotation and of revolution is the same for all the planets and +satellites of our system; and that the planes on which these motions are +performed, are nearly coincident. That this concordance is due to one +common cause, no one acquainted with the theory of probabilities will +pretend to deny. + + +GREAT OBJECT OF LA PLACE. + +The science of Astronomy occupies a pre-eminent rank in the physical +circle, not only on account of that dignity conferred upon it in the +most remote antiquity, or as being the grand starting point--the +earliest born of science--from whence we must contemplate the visible +creation, if we would reduce its numerous details into one harmonious +whole; but also on account of its practical fruits, of the value of +which modern commerce is an instance. Accordingly we will glance at its +past history. In the earliest ages there was no doubt a rational view +entertained of the movements of the planets in space. From the Chaldeans +to the Arabs, a belief prevailed, that space was filled with a pure +ethereal fluid, whose existence probably did not rest on any more solid +foundation than analogy or tradition. One hundred years after Copernicus +had given to the world the true arrangements of our planetary system, +Descartes advanced his theory of vortices in the ethereal medium, in +which the planets were borne in orbits around the sun, and the +satellites around their primaries. This idea retained its ground with +various additions, until the Geometry of Newton reconciled the laws of +Kepler with the existence of a power pertaining to matter, varying +inversely as the squares of the distances, to which power he showed the +weight of terrestrial bodies was owing, and also the revolution of +the moon about the earth. Since Newton's day, those deviations from the +strict wording of Kepler's laws, have been referred to the same law, +and the avowed object of the author of the "Mechanique Celeste," was to +bring all the great phenomena of nature within the grasp of analysis, by +referring them to one single principle, and one simple law. And in his +Introduction to the Theory of the Moon, he remarks: "Hence it +incontestibly follows, that the law of gravitation is the sole cause of +the lunar inequalities." + + +BESSEL'S OPINION. + +However beautiful the conception, it must be admitted that in its _a +priori_ aspect, it was not in accordance with human experience and +analogy to anticipate a successful issue. In nature law re-acts upon +law, and change induces change, through an almost endless chain of +consequences; and it might be asked, why a simple law of matter should +thus be exempt from the common lot? Why, in a word, there should be no +intrinsic difference in matter, by which the gravitation of similar or +dissimilar substances should be affected? But experiment has detected no +such differences; a globe of lead and a globe of wood, of equal weight, +attract contiguous bodies with equal force. It is evident, therefore, +that if there be such differences, human means are not yet refined +enough to detect them. Was the issue successful then? Generally +speaking, we may say yes. But where there is a discrepancy between +theory and observation, however small that may be, it shows there is +still something wanting; and a high authority (Professor Bessel) says in +relation to this: "But I think that the certainty that the theory based +upon this law, _perfectly_ explains all the observations, is not +correctly inferred." We will not here enumerate the cases to which +suspicion might be directed, neither will we more than just allude to +the fact, that the Theory of Newton requires a vacuum, in order that the +planetary motions may be mathematically exact, and permanent in their +stability. + + +A VACUUM REQUIRED BY MODERN SYSTEMS. + +Whatever may be the practical belief of the learned, their fundamental +principles forbid the avowal of a plenum, although the undulatory theory +of light renders a plenum necessary, and is so far virtually recognized +by them, and a correction for resistance is applied to the Comet of +Encke. Yet there has been no attempt made to reconcile these opposing +principles, other than by supposing that the celestial regions are +filled with an extremely rare and elastic fluid. That no definite view +has been agreed on, is not denied, and Sir John Herschel speculates on +the reality of a resisting medium, by suggesting questions that will +ultimately have to be considered, as: "What is the law of density of the +resisting medium which _surrounds_ the sun? Is it in rest or in motion? +If the latter, in what direction does it move?" In these queries he +still clings to the idea of Encke, that the resistance is confined to +the neighborhood of the sun and planets, like a ponderable fluid. But +the most profound analyst the world has ever boasted, speaks less +cautiously, (Poisson Rech.) "It is difficult to attribute, as is usually +done, the incandescence of aerolites to friction against the molecules +of the atmosphere, at an elevation above the earth where the density of +the air is almost null. May we not suppose that the electric fluid, in a +neutral condition, forms a kind of atmosphere, extending far beyond the +mass of our atmosphere, yet _subject to terrestrial attraction_, yet +_physically imponderable_, and, consequently, following our globe in its +motion?" The incandescence of aerolites must, therefore, be owing to +friction against the molecules of the electric fluid which forms an +atmosphere around the globe. According to this view, some force keeps it +there, yet it is not ponderable. As it is of limited extent, this is not +the medium whose undulations brings to light the existence of the stars; +neither is Encke's, nor Herschel's, nor any other resisting medium. +Where shall we find the present established principles of science? If we +grant the Newtonians a plenum, they still cling to attraction of _all +matter_ in some shape. If we confine them to a vacuum, they will +virtually deny it. Is not this solemn trifling? How much more noble +would it be to exhibit a little more tolerance, seeing that they +themselves know not what to believe? We do not offer these remarks as +argument, but merely as indications of that course of reasoning by which +we conclude that the upholders of the present systems of science are not +entitled to any other ground than the pure Newtonian basis of an +interplanetary vacuum. + + +DIFFICULTIES OF THIS VIEW. + +This, then, is the state of the case: Matter attracts matter directly as +the mass, and inversely as the squares of the distances. This law is +derived from the planetary motions; space is, consequently, a void; and, +therefore, the power which gives mechanical momentum to matter, is +transferred from one end of creation to the other, without any physical +medium to convey the impulse. At the present day the doctrines of +Descartes are considered absurd; yet here is an absurdity of a far +deeper dye, without we resort to the miraculous, which at once +obliterates the connection between cause and effect, which it is the +peculiar province of physical science to develop. Let us take another +view. The present doctrine of light teaches that light is an undulation +of an elastic medium necessarily filling all space; and this branch of +science probably rests on higher and surer grounds than any other. Every +test applied to it by the refinements of modern skill, strengthens its +claims. Here then the Newtonian vacuum is no longer a void. If we get +over this difficulty, by attributing to this medium a degree of tenuity +almost spiritual, we shall run upon Scylla while endeavoring to shun +Charybdis. Light and heat come bound together from the sun, by the same +path, and with the same velocity. Heat is therefore due also to an +excitement of this attenuated medium. Yet this heat puts our atmosphere +in motion, impels onward the waves of the sea, wafts our ships to +distant climes, grinds our corn, and in various ways does the work of +man. If we expose a mass of metal to the sun's rays for a single hour +the temperature will be raised. To do the same by an artificial fire, +would consume fuel, and this fuel would generate the strength or force +of a horse. Estimate, therefore, the amount of force received from the +sun in a single day for the whole globe, and we shall find that nothing +but a material medium will suffice to convey this force. + +Let us appeal to analogy. The undulations of our atmosphere produce +sound; that is, convey to the ear a part of a mechanical force imparted +to a solid body--a bell for instance. Let us suppose this force to equal +one pound. On account of the elasticity of the bell, the whole of the +force is not instantaneously imparted to the surrounding air; but the +denser the air the sooner it loses its motion. In a dense fluid like +water, the motion is imparted quickly, and the sound is not a ring but a +click. If we diminish the density of the air, the loss of motion is +retarded; so that we might conceive it possible, provided the bell could +be suspended in a _perfect vacuum_, without a mechanical tie, and there +was no friction to overcome from the rigidity of its particles, that the +bell would vibrate forever, although its sound could never reach the +ear. We see, therefore, that the mechanical effect in a given time, is +owing to the density of the medium. But can we resort to such an +analogy? Every discovery in the science confirms more and more the +analogy between the motions of air and the medium of space; the angle of +reflexion and incidence follows the same law in both; the law of +radiation and interference; and if experiments were instituted, there +can be but little doubt that sound has also got its spectrum. + + +ETHER IMPONDERABLE. + +The medium of space, therefore, is capable of conveying a mechanical +force from one body to another; it therefore possesses inertia. Does it +also possess gravity? If we forsake not the principles of science, it is +but right that we expect science shall abide by her own principles. +Condensation in every elastic medium is as the compressing power, +according to all experiments. In the case of our atmosphere under the +law of gravitation, the density of air, (supposing it to be infinitely +expansible,) at a height only of ten semidiameters of the earth above +its surface, would have only a density equal to the density of one cubic +inch of such air we breathe, if that cubic inch was to be expanded so as +to fill a globular space whose centre should be the earth, and whose +surface should take inside the whole visible creation. Such a medium +could convey no mechanical force from the sun, and therefore the medium +of space cannot be ponderable. Simple as the argument is, it is +unassailable. + + +ELECTRIC FLUID THE MEDIUM OF SPACE. + +Let us take yet another view. All experiments prove that the phenomenon +we call electricity, is owing to a disturbance of the equilibrium or +natural condition of a highly elastic fluid. In certain conditions of +the atmosphere, this fluid is accumulated in the region of the clouds, +and by its tension is enabled to force a passage through opposing +obstacles, in order to restore the equilibrium. By experiment it is +found that dry dense air opposes the greatest obstacle to its escape. As +the air is rarefied, this obstacle diminishes; until in a vacuum the +transmission may be considered instantaneous. There ought to be, +therefore, a greater escape of electricity from the clouds upwards than +downwards; and, if space be void, or only filled with an extremely +attenuated matter, the electricity of the earth, considered as an +elastic fluid without ponderosity, (and no law of condensation from the +law of gravity in harmony with its other attributes, will allow us to +consider it otherwise,) _would long since have left the earth_. The same +objection applies in the case of the galvanic and magnetic fluids. If we +entertain the idea that electricity is a mere disturbance of natural +condition, wherein two fluids are united, and that an excess of one is +necessarily attended by deficiency in the other, we depart from the +first rule of philosophy, which teaches us to admit no greater number of +causes than are sufficient to explain the phenomenon. For we fearlessly +assert that not a single fact exists in electrical science, which can be +explained better on Dufoy's theory than on Franklin's; and the former +objections would still apply. + + +NEWTONIAN GRAVITY. + +But what is gravity? According to Newton: "Haec est qualitas omnium in +quibus experimenta instituere licet, et propterea per Reg. 3 de +universes affirmanda est." _Vide_ Prin. Lib. Ter. Cor. 2. Prop. vi. + +Now the other primary qualities of matter are unaffected by +circumstances. The inertia of a particle of matter is the same at +Jupiter as on the earth, so also is its extension; but not so with +gravity. It depends on other matter, and on its distance from it; and +may be less or greater at different times, and in different places. It +is, therefore, not philosophical to say that all matter is necessarily +ponderous, inasmuch as it is a virtue not residing in itself alone, but +needs the existence of other matter to call it into action. If an atom +were isolated in space it would have no weight. If influenced by other +matter, there must be some physical medium to convey the influence, or +gravity is not in accordance with the laws of force and motion. Which +horn of the dilemma shall we take? Let us first admit that there is a +principle of gravitation, affecting all planetary or atomic matter, and +that there exists a highly elastic medium, pervading all space, +conveying to us the light of the most distant stars, and that this +medium is not affected by gravity. In this summary way, therefore, we +have arrived at the pivot on which this theory turns. + +The prominent feature of the theory, therefore, is the necessity it will +show for the existence of an all-pervading medium, and that it possesses +inertia without ponderosity. That electricity is nothing more than the +effects of the condensation and rarefaction of this medium by force. +That it also pervades all atomic matter, whose motions necessarily move +the medium; and, consequently, that there can be no motion without some +degree of electricity. That no change can take place in bodies either by +chemical decomposition, by increase or decrease of temperature, by +friction or contact, without in some measure exciting electricity or +motion of the ether. That galvanism and magnetism are but ethereal +currents without condensation, induced by peculiar superficial and +internal molecular arrangement of the particles of certain substances. +That light and heat are effects of the vibrations of atoms, propagated +through this universal medium from body to body. That the atomic motion +of heat can be produced by the motion of translation or momentum of +bodies in the gross, that is, by friction, by compression, &c.; and can +be reconverted into momentum at our pleasure. Hence the latent heat or +specific atomic motion of combustibles, originally derived from the sun, +is transferred to atoms, which are capable of being inclosed in +cylinders, so as to make use of their force of expansion, which is thus +converted into momentum available for all the wants of man. + + +GRAVITY MECHANICAL. + +When we come to a full examination of this theory, we shall further +reason that this _ether_ so far from being of that quasi spiritual +nature which astronomers would have us believe, is a fearfully energetic +fluid, possessing considerable inertia and elasticity; that its law of +condensation is that of all other fluids, that is, as the compressing +force directly; and that its effects are simply a product of matter and +motion. We will next endeavor to prove that the gravity of planetary +matter could not exist without this ethereal medium, by showing that it +is an effect produced by the interference of _opposing waves_, whereby a +body is prevented from radiating into space its own atomic motion, from +the side opposite which another body is placed, as much as on the +opposite side, and consequently it is propelled by its own motion +towards the other body. And this effect following the simple law of +inertia and radiation, is directly as the mass, and inversely as the +squares of the distances. + + +GREAT PRINCIPLE OF DYNAMICS. + +One great principle to be kept in view in this investigation, is that +which teaches that the product of matter, angular velocity, and distance +from the centre of motion, must ever be a constant quality in every +balanced system. Yet this principle does not seem to be observed in the +case of the planets. We will, however, endeavor to show that it is +rigidly observed. And we will extend the principle further, and contend +that all the phenomena of nature are consequences of the constant +tendency of matter to conform to this principle of equilibrium, when +suffering temporary derangement from the operation of other laws. That +throughout the system of nature, equal spaces possess equal force. That +what we call temperature, is nothing more than the motion of equilibrium +or atomic momentum of space; or, in other words, that if all space were +fluid, and in a state of equilibrium, the product of each atom of equal +volume, by its motion would be a constant quality. From this it would +seem to follow, that the specific heat of bodies should be inversely as +their atomic weights; and this does, no doubt, _approximately_ obtain as +was proved by Dulong and Petit, for metallic substances, more recently +by Regnault, and has since been extended by Garnier to other substances. +But it is to the gaseous state that we must look for confirmation of the +principle that equal spaces possess equal power; and in doing so, it +will be necessary to bear in mind, that the ether also is affected by +temperature. + + +SPECIFIC HEAT. + +It has been contended by some that the medium which conveys the +impression of light through transparent, bodies, is necessarily more +dense within the body than without; but according to this theory the +converse is true. A ray of light is a mechanical impulse, propagated +through an elastic medium, and, like a wave in water, tends to the side +of least resistance. Within a refracting body the ether is rarefied, not +only by the proximity of the atoms of the body (or its density), but +also by the motions of those atoms; so that if two _simple_ gases of +different specific gravity be made equal in density by compression, +their refraction will be approximately as their specific heats. In the +case of solids and liquids, or even compound gases, there is a continual +absorption of motion to produce the cohesion of composition and +aggregation. And the specific heats of compound gases will be found +greater than those of simple gases, in proportion to the loss of volume +by combination, _ceteris paribus_. If impenetrability be a law of +matter, the more a portion of atomic matter is condensed, the less ether +will be found in the same space. The same is also true when the natural +density or specific gravity of a gas is greater than that of another. +And the lighter the gas, the more will this circumstance vitiate the +experiments to determine its specific heat. There is, therefore, this +great source of fallacy in such experiments, viz.: that the ether +permeates all fluids and solids, and that _its specific heat probably +far exceeds that of all other matter_. This is a fundamental position of +the theory, in support of which we will introduce a fact announced by +M. V. Regnault, which was published in the Comptes Rendus of the French +Academy for April, 1853. He says: "In the course of my researches I have +encountered, indeed, at every step, anomalies which appeared to me +inexplicable, in accordance with the theories formally recognized. For +the sake of illustration I will quote one instance: 1st, a mass of gas, +under a pressure of ten atmospheres, is contained in a space which is +suddenly doubled; the pressure falls to five atmospheres. 2d. Two +reservoirs of equal capacity are placed in a calorimeter; the one is +filled with a gas, under a pressure of ten atmospheres; the second is +perfectly empty. In these two experiments, the initial and final +conditions of the gas are the same; but this identity of condition is +accompanied by calorific results which are very different; for while in +the former experiment there is a reduction of temperature, in the second +the calorimeter does not indicate the slightest alteration of +temperature." This experiment tends to confirm the theory. In the first +experiment, the sudden doubling of the space causes the ether also to +expand, inasmuch as the sides of the vessel prevent the instantaneous +passage of the external ether. In the second, both vessels are full, one +of ether, and the other of air mixed with ether; so that there is no +actual expansion of the space, and consequently no derangement of the +quantity of motion in that space. + + +LAW OF SPECIFIC HEAT. + +From this view it is evident that the specific heat of elastic fluids +can only be considered as approximately determined. If equal spaces +possess equal momenta, and the ethereal or _tomic_ matter be inversely +as the weight of the atomic matter in the same space, it follows that +the product of the specific gravities and specific heats of the simple +gases should be constant; or that the specific heats should be inversely +as the specific gravities,--taking pound for pound in determining those +specific heats. If we test the matter by the data now afforded, it is +best to obey the injunction, "_In medio tutissimus ibis_." In the +following table, the first column are the values obtained by Regnault; +in the second, the former values; and in the third, the mean of the two. + + Gases. Reg. specific heats. Former specific heats. Mean. + Atmospheric air, .237 .267 .252 + Oxygen, .218 .236 .227 + Nitrogen, .244 .275 .260 + Hydrogen, 3.405 3.294 3.350 + +The specific gravities of these gases, according to the best tables in +our possession, are: + + Specific gravities. Mean. Products. + Atmospheric air, 1.0000 x .252 = .252 + Oxygen, 1.1111 x .227 = .252 + Nitrogen, 0.9722 x .260 = .252 + Hydrogen, 0.0745 x 3.350 = .249 + +As might be expected, there is a greater discrepancy in the case of +hydrogen. + +If we test the principle by the vapor of water, we must consider that it +is composed of two volumes of hydrogen and one volume of oxygen, and +that one volume disappears; or that one-third of the whole atomic +motion is consumed by the interference of the vibrations of the ether, +necessary to unite the atoms, and form an atom of water. We must +therefore form this product from its specific gravity and two-thirds of +its specific heat. On no one subject in chemistry has there been so much +labor expended, as in determining the specific heat of watery vapor. In +relation to this, Regnault observes: "It is important to remark that an +immense number of experiments have been made, to find the specific heat +of steam, and that it is about one-half of what it was thought to be." +He gives its value .475; but this is vitiated still, by the +non-recognition of the specific heat of the ether. Former experiments +give .847. Perhaps Regnault's numbers are entitled to the most weight. +Instead of taking the mean, therefore, we will give double weight to his +results; so that we get .600 for the specific heat of vapor, and as its +specific gravity is .625, the product .400 x .625 is .250, the same as +for hydrogen. Little importance, however, should be attached to such +coincidences, owing to the uncertainty of the numbers. If our position +be correct, the specific heat of hydrogen should be 10 times greater +than of oxygen. The atomic weights are as 1 to 8, while their volumes +are as 2 to 1; therefore, for equal spaces, the matter is as 1 to 16. +Calling the specific heat 10 to 1, and taking the amount due to half the +space, the product becomes as 8 to 16; but in the rarer gas there is +_8 times_ as much ethereal momentum or matter, which, added to the +atomic matter, renders the spaces equal.[3] Regnault's results give a +ratio of specific heats = 1 to 3.405/.215 = 1 to 15.6. + + +THE GOLDEN MEAN. + +The history of science proves how few have practically respected the +adage of the ancients, which we have chosen for our motto; words which +ought to be written in letters of gold in every language under the sun. +Descartes, by considering the mechanical impulse of the ether sufficient +to explain the planetary motions, failed to detect the force of gravity +in the heavens. Newton, on the other hand, feeling that his law was +sufficient to explain them, and requiring a vacuum for its mathematical +accuracy, rejected the notion of an ethereal medium. His successors, +following too closely in his footsteps, and forgetting the golden law, +have forced themselves into a position by no means enviable. The +short-period comet has driven them to a resisting medium, which, while +according to Encke's hypothesis of increasing density around the sun, it +explains the anomalies of one periodical comet, requires a different +law of density for another, and a negative resistance for a third. + + +OUTLINES OF THE PROBLEM. + +From the position we now occupy, we can see the outlines of the problem +before us, viz.: To reconcile the existence of an ethereal medium with +the law of gravitation, and to show the harmony between them. We shall +thus occupy the middle ground, and endeavor to be just to the genius of +Descartes, without detracting from the glory of Newton, by demonstrating +the reality of the Cartesian vortices, and by showing that the ether is +not affected by gravitation, but on the other hand is _least dense_ in +the centre of our system. But what (it may be asked) has this to do with +the theory of storms? Much every way. And we may so far anticipate our +subject as to _assert_ that every phenomenon in meteorology where force +is concerned, is dependent on the motions of the great sea of electric +fluid which surrounds us, in connection with its great specific, +caloric. If we are chargeable with overweening pretensions, let it be +attributed to the fact that for the last fifteen years we have treated +the weather as an astronomical phenomenon, calculated by simple formulae, +and that the evidence of its truth has been almost daily presented to +us, so as to render it by this time one of the most familiar and +palpable of all the great fundamental laws of nature. True, we have +neither had means nor leisure to render the theory as perfect as we +might have done, the reason of which we have already communicated. + + +MOTIONS OF THE STARS. + +In investigating the question now before us, we shall first take the +case of an ethereal vortex without any reference to the ponderable +bodies which it contains, considering the ether to possess only inertia. +If there be a vortex around the sun, it is of finite extent; for if the +ether be co-extensive with space, and the stars likewise suns with +surrounding vortices, the solar vortex cannot be infinite. That there is +an activity in the heavens which the mere law of attraction is +incompetent to account for, is an admitted fact. The proper motions of +the fixed stars have occupied the attention of the greatest names in +astronomy, and motions have been detected, which according to the theory +of gravity, requires the admission of invisible masses of matter in +their neighborhood, compared with which the stars themselves are +insignificant. But this is not the only difficulty. No law of +arrangement in the stars can exist that will save the Stellar system +from ultimate destruction. The case assumed by Sir John Herschel, of a +cluster, wherein the periods shall be equal, cannot be made to fulfil +the conditions of being very numerous, without infringing the other +condition--the non-intersection of their orbits; while the outside stars +would have to obey another law of gravitation, and consequently would be +still more liable to derangement from their ever-changing distances +from each other, and from those next outside; in brief, the stability of +those stars composing the cluster would necessarily depend on the +existence of outside stars, and plenty of them. But those outside stars +would follow the common law of gravity, and must ultimately bring ruin +on the whole. We know such clusters do exist in the heavens, and that +the law of gravity alone must bring destruction upon them. This is a +case wherein modern science has been instrumental in drawing a veil over +the fair proportions of nature. That such collections of stars are not +designed thus to derange the order of nature, proves _a priori_, that +some other conservative principle must exist; that the medium of space +must contain many vortices--eddies, as it were, in the great ethereal +ocean, whose currents are sweeping along the whole body of stars. We +shall consider, (as a faint shadowing of the glorious empire of +Omnipotence,) that the whole infinite extent of space is full of motion +and power to its farthest verge; and it may be an allowable stretch of +the imagination to conceive that the whole comprises one infinite +cylindrical vortex, whose axis is the only thing in the universe in a +state of absolute unchangeableness. + + +VORTICOSE MOTION. + +Let us for a moment admit the idea of an infinite ocean of fluid matter, +having inertia without gravity, and rotating around an infinite axis, in +this case there is nothing to counteract the effect of the centrifugal +force. The elasticity of the medium would only oppose resistance in a +vortex of finite diameter. Where it is infinite, each cylindrical layer +is urged outward by its own motion, and impelled also by those behind. +The result would be that all the fluid would at last have left the axis, +around which would exist an absolute and eternal void; into which +neither sound, nor light, nor aught material, could enter. The case of +a finite vortex is very different. However great the velocity of +rotation, and the tendency of the central parts to recede from the axis, +there would be an inward current down either pole, and meeting at the +equatorial plane to be thence deflected in radii. But this radiation +would be general from every part of the axis, and would be kept up as +long as the rotation continued, if the polar currents can supply the +drain of the radial stream, that is, if the axis of the vortex is not +too long for the velocity of rotation and the elasticity of the ether, +there will be no derangement of the density, only a tendency. And in +this case the periodic times of the parts of the vortex will be directly +as the distances from the axis, and the absolute velocities will be +equal. + + +FORMATION OF VORTICES. + +There is reason to suspect that Newton looked at this question with a +jaundiced eye. To do it justice, we must consider the planetary matter +in a vortex, as the exponent of its motion, and not as originating or +directing it. If planetary matter becomes involved in any vortex, it +introduces the law of gravitation, which counteracts the expulsive force +of the radial stream, and is thus enabled to retain its position in the +centre. A predominating mass in the centre will, by its influence, +retain other masses of matter at a distance from the centre, even when +exposed to the full power of the radial stream. If the power of the +central mass is harmoniously adjusted to the rotation of the vortex, +(and the co-existence of the phenomena is itself the proof that such an +adjustment does obtain,) the two principles will not clash or interfere +with each other. Or in other words, that whatever might have been the +initial condition of the solar vortex, the ultimate condition was +necessarily one of equilibrium, or the system of the planets would not +now exist. With this view of its constitution, we must consider that the +periodic times of the planets approximately correspond to the times of +the contiguous parts of the vortex. Consequently, in the solar vortex, +the density of the ether is directly as the square roots of the +distances from the axis. This is not the place fully to enter into a +discussion of the question, or to show that the position of each planet +in the system is due to the outstanding, uncompensated, portion of the +expulsive force of the radial stream, modified by the density of the +ether within the planets, and also by their own densities, diameters, +inclinations of axis, and periods of rotation. That Jupiter could not +remain in the orbit of Mercury, nor Mercury in that of Jupiter, by +merely exchanging periods and distances, but that each planet can only +be in equilibrio in its own orbit. That any change in the eccentricities +of the planetary orbits will neither increase nor diminish the action of +the radial stream of the vortex, and consequently will not interfere +with the law of gravitation. In relation to the numerous questions that +will spring up from such a position, it is sufficient here to say, that +it is believed all objections can be satisfactorily answered; while, by +this light, a long range of phenomena that have hitherto baffled the +sagacity of the wise, come out plainly, and discover their parentage. + +In cometary astronomy we shall find much to substantiate these views. +The anomalies in their motions, the discrepancies in their periods, +calculated from different sets of observations, their nebulosities and +appendages, will all receive a satisfactory solution; and these lawless +wanderers of the deep be placed in a more interesting light. + + +TEST OF A THEORY. + +It has been remarked that the best evidence of the truth of a theory, is +its ability to refer to some general principle, the greatest number of +relevant phenomena, that, like the component masses of the chiselled +arch, they may mutually bind and strengthen each other. This we claim +to be the characteristic of this theory. At the outset it was not +intended to allude to more than was actually necessary to give an +outline of the theory, and to introduce the main question, yet +untouched. We have exhibited the stones of which the arch is composed; +but they may be pasteboard,--for the reader has not handled them. We +will now produce the keystone, and put it in its place. This he shall +handle and weigh. He will find it hard,--a block of granite, cut from +the quarry of observed facts, and far too heavy to be held in its place +by a mere pasteboard structure. + + +ENUNCIATION OF THE THEORY. + +Quitting, therefore, the region of the planets, we will come down to the +surface of our own globe, to seek for some more palpable evidence of the +truth of the following propositions: + +1st. That space is filled with an elastic fluid, possessing inertia +without weight. + +2d. That the parts of this fluid in the solar system circulate, after +the manner of a vortex, with a direct motion. + +3d. That there are also secondary vortices, in which the planets are +placed. + +4th. That the earth is also placed in a vortex of the ethereal medium. + +5th. That the satellites are passively carried around their primaries, +with the ethereal current, and have no rotation relative to the ether, +and therefore they always present the same face to their primaries, and +have no vortex. + +The consideration of these propositions involves many others, many +difficulties, many apparent anomalies and contradictions, which should +bespeak for such a theory,--the offspring of observation, without the +aid afforded by the knowledge of others, and of toil without leisure,--a +large share of indulgence. With this we will close these preliminary +remarks, and present our theory of the physical cause which disturbs +the equilibrium of our atmosphere, and which appears the principal agent +in the production of storms, in the following words: + +The dynamical axis of the terral vortex passes through the centre of +gravity of the earth and moon, and is continually circulating over the +earth's surface in both hemispheres, in a spiral,--its latitude and +longitude, at any particular time, being dependent,-- + +1st. On the relative mass of the moon. + +2d. On the inclination of the axis of the vortex to the earth's axis. + +3d. On the longitude of the ascending node of the vortex on the lunar +orbit. + +4th. On the longitude of the ascending node of the lunar orbit on the +ecliptic. + +5th. On the eccentricity of the lunar orbit at the time. + +6th. On the longitude of the perigee of the lunar orbit at the time. + +7th. On the moon's true anomaly at the time. + + +MASS OF THE MOON. + +Those elements which represent the moon's distance and motion are +accurately known, and may be taken from the Nautical Almanac, being all +embodied in the moon's parallax or semi-diameter, and in the declination +and right ascension; but for the most important element,--the moon's +mass, we in vain look to astronomy. In fact, it may be averred that the +importance attached to astronomical authority, concerning the mass of +the moon, has caused more trouble than any other question of the whole +theory, until we trusted implicitly to the theory itself to determine +it. The determination of three unknown elements, viz.: the moon's mass, +the inclination of the axis of the vortex, and the right ascension of +that axis, is a more difficult problem than at first sight appears, +owing to the nature of the phenomena, which affords the only clue for +its solution. There are six principal vortices ever in operation on the +surface of the earth, and their disturbing influence extends from 200 to +400 miles. To find the precise centre, by one observer confined to one +place, is difficult; and to separate them, so as to be fully assured +that you have the right one, is perhaps still more so. Happily this +tedious labor is accomplished, and we are able with confidence to give +the following important elements, as very close approximations to the +truth: + + Mass of the moon 1/72.3 + Obliquity of the axis of the vortex 15d to 32d variable. + Right ascension of ditto 250d to 290d variable. + +It must be borne in mind that we are now discussing the main or central +vortex of the earth; but before applying them to the calculation, we +will explain the _modus operandi_, waiving for the present the +consideration of the law of density in the Terral vortex. It is evident +at first sight that if the periodic times of the parts of the vortex +contiguous to the moon, are equal to the moon's period approximately, +that the velocity of the ether is greater at the surface of the earth +than the velocity of that surface. Now, we have before argued that the +ether possesses inertia, it therefore would under such circumstances +exert some mechanical action. Consequently, the aerial envelope of our +globe, or its superior stratum, is impelled eastward by _convection_[4] +of the more rapidly rotating ether. And from the extreme tenuity of its +upper layers, is probably forced into immense waves, which will observe +to a certain degree, a general parallelism north and south. + + +ATMOSPHERIC CURRENTS. + +It is a well-known fact, that the prevailing current of the atmosphere +in high latitudes is from the westward. The cause of this is ascribed by +Professor Dove to the transfer of the equatorial portions to a higher +latitude, by which the excess of its rotative velocity is made apparent, +by outstripping the slower moving surface in its progress eastward. No +doubt some effect is due to this, but still a difficulty remains. Let us +follow this current. The polar current reaches the surface on the +borders of the trades with less rotative velocity than the surface, and +is, therefore, met by the surface as a current partaking of both +motions. In the northern hemisphere it is north-east deflected to east +as it approaches the southern trades. By the same reasoning, coming from +the north before it readies the surface, it ought to be also a +north-east wind above the lower westerly currents. Now it is an observed +fact, that while in the latitude of New York, for instance, the lower +westerly winds are to the easterly, as 3 or 4 to 1, in the highest +regions of observed clouds, the ratio is much increased; and according +to our own observations in this place,[5] we have never seen the highest +cirrus clouds moving westward. How then is this continual interchange +kept up? Assuredly we cannot have a current from the poles without a +contrary current to the poles. If we go into the arctic circle, we again +find the westerly and northerly winds predominating. If the current from +the equator follows the surface, the westerly winds ought to be +south-west. If it be above the surface wind, then the surface wind is +the polar current, and ought to be north-east. Whereas, from the +testimony of all who have visited these regions, the prevailing winds +are north-west. How can this be? + +Again, it is proved that the upper current near the equator is also from +the westward--as near due west as possible. Take the latitude of St +Vincent. The difference between the cosine of 13d and radius applied +to the circumference, is about 600 miles, which would give 25 miles per +hour to the eastward, in lat. 13d. But to do this, it is necessary to +transfer it suddenly from the equator; for by a slow motion the easterly +tendency would be lost. Give it 24 hours from the equator to lat. 13d, +without any loss of easterly tendency, and it comes to that latitude +with a velocity of 38 miles per hour to the northward, and only 25 to +the eastward; we have, therefore, a wind from south-west by south. Yet +it is known that in the tropics the highest visible clouds move from the +westward. But as no such case could occur as a transfer in twenty-four +hours without loss, and if we diminish the time, the wind is still more +southerly. Meteorologists usually cite the falling of ashes at Jamaica +during the eruption of Coseguina, in Guatamala, in February 1835, as +coming from south-west, whereas the true direction was about west +south-west, and the trade wind below was about north. But do we deny +that there is an interchange between the frigid and torrid zones? By no +means; but we would show that the great controlling power is external to +our atmosphere, and that the relative velocities of the earth and the +atmosphere is not alone adequate to account for it. By this view the +polar current is a north-west wind (which is impossible by Professor +Dove's theory), or is carried eastward by electric convection. + + +HUTTON'S THEORY. + +Whether we adopt the views of Fourier or Poullet, as to the temperature +of the planetary spaces, it is certain that it is at least equal to, or +less than, the lowest temperature of our globe. It is also a well-known +fact, that the capacity of air to hold vapor in solution, increases in a +higher ratio than the temperature, so that the intermingling of +saturated portions of air, at different temperatures, must _necessarily_ +be attended by precipitation of moisture. This idea was advanced by +Doctor Hutton, and considered competent to account for the prominent +meteorological phenomena, until Professor Espy broached a questionable +principle, (and which is rendered still more so by the late +investigations of Regnault,) in opposition to Hutton's theory. That the +theory is deficient, no one can gainsay. That Espy has rendered the +question clearer, is equally hazardous to assert. Hutton failed in +showing a cause for such intermingling on a sufficient scale; while +Espy, it may be suspected, has misinterpreted facts, and incautiously +rejected the only element possessing the power of raising the storm. + + +GREAT SPECIFIC HEAT OF THE ETHER. + +Whatever may be the degree of condensation or rarefaction in the terral +vortex, there must necessarily be a current down the pole or axis, +thence to be deflected along the equatorial plane of the vortex, and +this drain will be as perpetual as the rarefaction of the centre, +(caused by the centrifugal force of rotation,) which calls it forth. It +will now be perceived that the fluid of the vortex, which we shall still +term ether, is neither more nor less than the electric fluid,--the +mighty energising principle of space,--the source of motion,--the cause +of magnetism, galvanism, light, heat, gravity, of the aurora, the +lightning, the zodiacal light, of the tails and nebulosities of comets, +of the great currents of our atmosphere, of the samiel, the hurricane, +and the earthquake. It will be perceived that we treat it as any other +fluid, in relation to its law of motion and condensation. But we have no +right to base our calculations on its resistance, by the analogies +presented by ponderable or atomic matter. Atomic fluids,--even pure air, +may be considered viscid and tenacious when compared to an infinitely +divisible fluid, between whose particles (if we may use the term) no +_attraction_ of any kind exists. No ponderable matter can come in close +contact without feeling the influence of the gravitating force which, at +insensible distances,--such as the breadth of a wave of ether, is +increased in power, and becomes a cohering and combining force. We +contend that this fluid is the only fluid of space; when condensed it is +positive, and seeks to escape; when rarefied it is negative, and +receives from the contiguous space a restoration of its power. That it +can give and receive, from planetary matter, what we call motion; and +consequently can affect the temperature of such matter, and be in turn +affected by it. And finally that, for its degree of inertia, it exceeds +in elasticity and specific heat all other matter. + + +PROCESS OF DERANGEMENT. + +This premised, we see that as the axis of the vortex traverses the +surface of the earth, there is a tendency to derange the electric state +of the parts travelled over, by bringing the atmosphere and surface of +the earth under the rarefied centre of the vortex. For it is not the +ether of the atmosphere alone that is affected. It is called forth from +the earth itself, and partakes of the temperature of the +crust,--carrying up into the upper regions the vapor-loaded atmosphere +of the surface. The weather now feels close and warm; even in winter +there is a balmy change in the feelings. The atmosphere then fills with +haze, even to the highest regions of the clouds; the clouds themselves +are ill defined; generally the wind comes in at E. S-E., or S., getting +very fresh by the time it chops round to W. In from six to twelve hours +from the time of the meridian passage, in this latitude, the Big Cumuli +have formed, and commenced their march eastward. In summer time there is +always thunder and lightning, when the passage is attended or followed +by a storm. In winter, generally, but not always. In summer, the +diameter of the storm is contracted; in winter, dilated; in consequence +of this, summer is the best season to trace the vortices of the earth +through their revolutions. Let us now attend a little to the results. +The ether of the surface atmosphere partakes of the temperature of that +atmosphere, so also the ether of the earth's crust partakes of the +temperature of the crust; and its escape is rapid, compared with the +ascent of the air. When it arrives at the colder layers of air above, +its temperature sinks, and, on account of the greater specific caloric, +it imparts a much higher temperature to those layers than is due to +their position; an elevation consequently takes place,--begetting a +drain from below, until the upper regions are loaded with a warm and +vapory atmosphere. If the action of the sun conspires at the same time +to increase the effect, the storm will be more violent. In twelve hours +after the meridian passage of the vortex, the storm is brought under the +parts of the ethereal atmosphere of the earth most remote from the axis; +a reaction now takes place; the cold ether of space rushes in, and, on +account of its great specific caloric, it abstracts from the warm +atmosphere more than pertains to the difference of temperature, and +there is a great condensation. Rain and hail may form in fearful +quantities; and when the equilibrium is restored, the temperature will +have fallen many degrees. + +As it is important that we should have a clear view of the character of +the ether, we will revert to the principle we have advocated, viz.: that +in equal spaces there are equal momenta. What the ether wants in +inertia, is made up by its motion or specific heat, considering in this +case inertia to stand for weight when compared with ponderable matter; +so that to raise an equivalent amount of inertia of ether to the same +temperature as atmospheric air, will require as much more motion or +specific heat as its matter is less. And this we conceive to be a law of +space in relation to all free or gaseous matter. To apply it to solids +would require a knowledge of the amount of force constituting the +cohesion of the solid. + + +INFLUENCE OF DIMINISHED PRESSURE. + +But there is another principle which modifies these effects. We have +already adverted to the action of the tangential current of the vortex +forcing the outer layers of the atmosphere into waves. These waves will +be interfered with by the different vortices, sometimes being increased +and sometimes diminished by them.[6] If these waves are supposed very +wide, (which would be the case in the attenuated outside layers of the +atmosphere,) the action of the vortex will be greater in its passage +over a place, which at the time corresponded to the depression point of +the wave, that is, to the line of low barometer; because here there +would be less resistance to overcome in the passage of the ether from +the surface of the earth into space; so that we may conceive each vortex +making a line of storms each day around the earth, separated by less +disturbed intervals. After the formation of the storm, it of course has +nothing to do with the vortex that produced it; it travels in the +general direction of the local atmosphere of the place--in intratropical +latitudes westward, in extratropical latitudes eastward. If, therefore, +the disturbance forms at the place of observation, there will probably +be no storm; but further eastward its action would be more apparent or +violent. It is impossible, of course, to lay down any general +description which shall meet every case. It is a knowledge that can only +be acquired by observation, and then is not readily or easily +communicated. There are many contingencies to be allowed for, and many +modifying causes to keep sight of, to enter into which would only be +tedious; we shall, therefore, confine ourselves to the prominent +phenomena. + + +ACTION OF THE POLAR CURRENT. + +We have seen how the passage of the axis of the vortex may derange the +electric tension of the parts passed over; but there is another mode of +action not yet adverted to. + +[Illustration: Fig. 1] + +When the moon is at her perigee, the axis of the vortex passes through +the centre of gravity of the earth and moon at C, and cuts off the +segment RR. At the apogee, on account of her greater distance, and of +her consequent power to _push_ the earth out from the axis of the vortex +XX, the segment R'R' is only cut off by the axis; and the angle which +the axis makes with the surface will vary with the arcs AR and A'R'; for +these arcs will measure the inclination from the nature of the circle. +In passing from the perigee to the apogee the axis will pass over the +latitudes intermediate between R and R' in both hemispheres, neither +reaching to the equator E, nor to the pole P. Let us now suppose a +meridian of the earth, represented by the line NRS, N being north, and S +south, and the surface of the atmosphere by N'S'; XX still representing +the axis of the vortex, ordinarily inclined 34d or 35d to the surface. +Let us also conceive the rotation of the earth to cease, (the action of +the vortex remaining the same,) thus leaving the axis over a particular +longitude. If the ether possesses inertia, there will be an actual +scooping out of the upper portions, driving them southward to a certain +distance, where the atmosphere will be piled up above the ordinary +level. There will, therefore, be a strong contrary current at the +surface of the earth to restore the equilibrium, and if the action be +violent, the surface wind will be increased; so that if it be considered +tangential to the surface at S, its own momentum will tend to make it +leave the surface and mount up to T; and in this way increase the action +due to the ether. Now, although the axis is never stationary, but +travels round the earth in less than twenty-five hours, yet there is a +tendency to this mode of action; and it is even sometimes palpable to +the observer when the axis has passed immediately to the northward; for +the pinnate shafts and branching plumes of the cirri often reach far to +the south of the southern boundary of the storm. These shafts are always +longer when radiating from the northward than when proceeding from the +southward. The cause is understood by the above figure. At such a time, +after dark, the auroral shafts will also be seen over the storm to the +northward, but will be invisible to those beneath. There is this to be +observed, however, that the visibility of the ethereal current (or the +aurora) is more frequent when the passage of the vortex is not attended +with any great commotion, its free passage being perhaps obstructed by +too dry an atmosphere; hence it becomes more visible. But it may be +asserted that a great aurora is never seen except when a vortex is near, +and to the northward, and within a few hours of its passage over the +meridian. We have, however, seen partial auroras to the south when none +existed north, and also cases when the radiation was from west, but they +are never as bright as in the north. They are all due, however, to the +same cause; and we have frequently followed a vortex for three days to +the northward, (that is, seen the effects of its meridian passage,) at +700 miles distance, by the aurora, and even by the lightning, which +proves plainly that the _exterior layers_ of our atmosphere can reflect +a flash of lightning, assisted by the horizontal refraction, otherwise +the curvature of the earth would sink it ten miles below the horizon. + +[Illustration: Fig. 2] + + +LIMITS OF THE VORTEX. + +The action of the polar current of the ether, therefore, tends to cause +a depression of the barometer, and an elevation to the _northward_ and +southward, and there is a general set of the wind below to the point of +greatest depression. The action of the tangential current works the +outer surface of the atmosphere into great ridges and hollows, whose +distances apart as well as actual dimensions, are continually changing +under the influences of causes not yet alluded to, and it is in the +hollows where the action of the polar current will be principally +expended. Luckily for the earth, the axis of the vortex is never long in +passing over any particular place. In this latitude, whose natural +cosine is three-fourths, the velocity _westward_ is over 700 miles per +hour; but at its extreme limits north, the motion is much slower, and is +repeated for two or three days in nearly the same latitude, for then it +begins to return to the south; thus oscillating in about one sidereal +period of the moon. At its southern limit, the vortex varies but slowly +in latitude for the same time, but the velocity is much greater. The +extreme latitudes vary at different times with the eccentricity of the +lunar orbit, with the place or longitude of the perigee, and with the +longitude of the moon's ascending node, but in no case can the _central +vortex_ reach within 5d of the equator, or higher than about 75d of +latitude north or south. Hence there are no storms strictly speaking +beyond 88d[7] of latitude; although a storm may be raging close by, at +the turning point south, and draw in a very strong gale from the +northward with a clear sky above. So also, although rains and short +squalls may be frequent in the vapor-loaded atmosphere of the equator, +yet the hurricane does not reach there, owing to the adjustment of the +mass and distance of the moon, and the inclination of the axes of the +vortices to the axis of the earth. If the temperature of the upper limit +or highest latitude of the vortex, was equal to the temperature which +obtains at its lowest limit, and the daily extremes of the solar +influence as great, the hurricanes would be as violent at the one as the +other, and even more so on account of the smaller velocity. But the +deficiency of temperature and moisture, (which last is all-important,) +prevents the full development of the effect. And even in the tropics, +the progress of the sun, by its power in directing the great annual +currents of the atmosphere, only conspires in the summer and autumn +months, to bring an atmosphere in the track of the vortices, possessing +the full degree of moisture and deficiency of electric tension, to +produce the derangement necessary to call forth the hurricane in its +greatest activity. + + +ROUTINE OF A STORM. + +The novelty and originality of this theory will perhaps justify us in +dwelling a little longer on what observation has detected. The vortex +(and we are now speaking only of the central vortex) does not derange +every place alike, but _skips_ over large tracts of longitude in its +progress westward. We speak here of the immovable axis of the vortex as +in motion; in reality it is the rotation of the earth which brings every +meridian under its influence in some latitude once every twenty-four +hours. The centre of greatest derangement forms the nucleus, towards +which the surface currents, under certain restrictions, flow. The +strongest current will, however, usually be from the south, on account +of the inclination of the axis of the vortex to the surface of the +earth.[8] These currents continuing onwards by their vires inertiae, +according to the first law of motion, assist somewhat in conveying the +warm surface wind, loaded with moisture, into the region of cloud; and +the diminution of temperature causes the condensation of large masses of +vapor, according to Hutton's views; and the partial vacuum thus +produced, causes a still greater intermingling. But we have already +shown that this is not the sole cause, nor is it ever more than +partially accomplished. The ether of the lower atmosphere, and of the +crust of the earth, is disturbed, and rushes towards the rarefied axis +from the surface, and with the temperature of the surface, thus +conveying the surface atmosphere, in a measure, along with it. In the +upper regions, this ether (or electric fluid) cools down, or parts with +some of its heat, to the air of those regions, and, by its great +specific caloric, necessarily and unduly increases the temperature of +the air. This, by its expansion and ascension will cause a further +influx from below, until the upper atmosphere becomes loaded with vapor. +In twelve hours, at least, a reaction must take place, as that part of +the earth's surface is carried six or seven thousand miles from the +axis, where the ether is more dense. This in turn descends to the +surface, carrying with it the temperature of space, at least 60d below +zero; a great condensation must follow; local derangements of the +electric equilibrium in the centre of large clouds, when the +condensation is active, must now take place, while partially +nonconducting masses intervene, to prevent an instantaneous restoration +of the equilibrium, until the derangement is sufficient to cause the +necessary tension, when all obstacles are rent asunder, and the ether +issues forth, clothed in the power and sublimity of the lightning. It is +a fearfully-energetic fluid, and, when sufficiently disturbed, competent +to produce the most violent tornado, or the most destructive earthquake. +That these two phenomena have simultaneously occurred, seems well +authenticated; but the earthquake, of course, must be referred generally +to derangements of the electric equilibrium of the earth's interior, of +which at present we know but little. + +The day or morning previous to the passage of the vortex, is frequently +very fine, calm, mild, and sleepy weather,--commonly called a weather +breeder. After the storm has fully matured, there is an approach of the +clouds to the surface, a reduction of the temperature above, and the +human body feels the change far more than is due to the fall of +temperature. This is owing to the cold ether requiring so much heat to +raise its temperature to that of surrounding bodies, or, in other words, +is due to its great specific caloric. In summer, this falling of the +upper layers in front of the storm is so apparent, that every part is +seen to expand under the eye by perspective,--swelling, and curling, and +writhing, like the surface of water or oil when just commenced boiling. +The wind now partakes of the motion of the external ether, and moves +with the storm eastward (in this latitude), or from N-E. to S-E., until +the action ceases. + + +CONDITIONS NECESSARY TO PRODUCE A STORM. + +The vortex, in its passage round the earth, may only meet with a few +localities favorable for producing a very violent storm; but these +nuclei will generally be connected by bands of cloudy atmosphere; so +that could we view them from the moon, the earth would be belted like +the planet Jupiter. There is reason to suspect, also, that there are +variations in the energy of the ethereal motions, independent of the +conditions of the earth and its atmosphere, which affects even the +radial stream of the sun. For the zodiacal light, which is caused by +this radial stream, is at times much more vivid than at others. Also in +the case of the aurora, on our own globe. On this point there is much to +say, but here is not the place. The conditions favorable for the +production of a storm at the _central_ passage of a vortex, are a +previous exemption from excitement _ceteris paribus_, a high temperature +and dew point, a depression of the barometer, and local accumulation of +electric tension, positive or negative; and these are influenced by the +storms in other places controlling the aerial currents, and thus +determining the atmosphere of the place. + + +LATERAL VORTICES. + +We have already alluded to the lateral vortices of the terral system. We +must now resort to a diagram. + +In the following figure, the arrows represent the ethereal current of +the terral vortex; the linear circle, the earth; C the centre of gravity +of the earth and moon, and, consequently, the central vortex or axis of +the vortex of the earth, I represents the position of the inner vortex, +and O that of the outer vortex. These two last are eddies, caused by the +obstacle presented by the earth in being _pushed_ out from the centre by +the moon, and are called lateral vortices. There are, therefore, two +lateral vortices, and one central, in both hemispheres, and by this +simple arrangement is the earth watered, and the atmospheric circulation +produced. + +[Illustration: Fig. 3] + + +ILLUSTRATION OF THEIR ACTION. + +If we place a globe in a vessel of water, so that the vertex shall only +just be covered, and place the globe eccentrically in the vessel so that +the centre of the vessel may not be too far from the outside of the +globe, and then impart an equable but slow motion to the water, in the +manner of a vortex; by viewing the reflected light of the sky from the +surface of the water above the globe, we shall be able to trace a +succession of dimples, originating at I and O, and passing off with the +current, and dying away. The direction of the fluid in these little +eddies, will be the same as the direction of the current in the main +vortex. If we displace the globe, so as to remove it far from the centre +of the vessel, and impart the same motion, the vortex I will be found at +E, and the direction of the current will be contrary to the direction +of the fluid in the vessel. In the case of the earth and moon, the +displacement can never change the position of the inner vortex much. It +will always be to the right hand of the central vortex in north +latitudes, and in consequence of the ether striking our globe in such a +position, the current that is deflected from its true path, by the +protuberance of the earth forcing it inside, is prevented by the +circular current of the parts nearer the axis of the vortex, from +passing off; so that a vortex is formed, and is more violent, _ceteris +paribus_, than the vortex at O. + + +ORDER OF OCCURRENCE. + +Whether this mode of action has been correctly inferred, matters little; +the lateral vortices follow the law of such a position. The inner vortex +always precedes the central from five to eight days, when ascending in +this latitude, and comes to the meridian after the moon. The outer +vortex, on the contrary, follows the central in its monthly round, and +comes to the meridian before the moon. It will be readily understood +that if the axes of these lateral vortices be produced through the +earth, they will pass through similar vortices in the opposite +hemisphere; but as the greatest latitude of the one, corresponds to the +least latitude of the other, the same calculation will not answer for +both. The same remark applies to the central vortex also. + +Thus there are six passages each month over latitude 41d; but as there +are intervals of 3d to 6d between two consecutive passages of the same +vortex, it may happen that an observer in the middle latitude, would +perhaps see nothing of their effects without looking for them. Generally +speaking, they are not only seen, but felt. The time of the passage of +the outer vortex ascending, corresponds so nearly (in 38d of latitude) +at certain times, with the passage of the central vortex descending, +that the two may be considered one if attention is not directed to it. +The orbits of these lateral vortices depend, like that of the central +vortex, on the orbit of the moon for eccentricity, but the longitudes of +the perigee will not correspond with the longitude of the moon's +perigee. This follows from the theory. As the elements of these orbits +are only approximately determined, we shall confine our calculations to +the orbit of the central vortex. + + +REDFIELD'S THEORY OF STORMS. + +It will now appear plainly to the reader, that this theory of storms +differs in every particular from the rival theories of Redfield and +Espy, both as to the cause and the _modus agendi_. It would appear at +first sight, as if the discovery of these vortices would at once remedy +the great defect in the theory of Redfield, viz.: that no adequate cause +is assigned for the commencement and continuation of the vorticose +motion, in the great circular whirlwinds which compose a storm. The +facts, however, are adverse to such an application. According to +Mr. Redfield, the rotation of a circular storm in the northern +hemisphere is from right to left, and the reverse in the southern. The +author's attention has, of course, been considerably directed to this +point; but in every case he has been unfortunate in finding in the +clouds a rotation from left to right. Some cases are mentioned in the +appended record of the weather. He has also noticed many of those small +whirlwinds on arid plains, in Egypt, in Mexico, and in California, +which, in the great majority of cases, were also from left to right. His +opportunities, however, have not extended to the southern hemisphere. +This theory has not, however, been formed on theoretic views, but by +looking nature in the face for years, and following her indications. +Accordingly, we find that the changes of the wind in a storm forbid the +adoption of the circular hypothesis. + + +WHIRLWINDS VERY LIMITED IN DIAMETER. + +The theory, as extended by Col. Reid, rests on a simple rotation around +a progressing centre, and is found sometimes supported by evidence of +the most violent action at the centre, and sometimes by showing that the +central portion is often in a state of calm. We do not attempt to +reconcile these views; but would merely observe, that an atmospheric +vortex must be subject to the same dynamical laws as all other vortices; +and inasmuch as the medium cannot differ greatly in density, from the +centre to the circumference, the periodic times of the parts of the +vortex, must be directly as their distances from the axis, and +consequently the absolute velocities must be equal. If Mr. Redfield +resorts to a spirally inward current, it would be a centripetal instead +of a centrifugal current, and therefore could not cause the barometer to +fall, which was the best feature of the theory in its primitive form. +The absolute velocity of the wind is the important element which most +concerns us. In the case of a tornado of a few yards in diameter, there +is no doubt a circular motion, caused by the meeting of opposing +currents; but this may be considered a circle of a very small diameter. +The cause is due to a rapid escape of electric or ethereal matter, from +the crust of the earth, called forth by the progressing, disturbed space +above; this involves the air, and an ascending column in rotation begets +the rush on all sides to that column in straight lines: consequently, +the velocities will be inversely as the distances from the axis, and the +force of the current as the squares of the velocities. On the circular +theory, no increase of velocity would be conferred by the approach of +the centre, and consequently no increase of power. + + +OBJECTION TO CIRCULAR STORMS. + +Another objection to the circular theory of storms, is the uniformity of +phase. If that theory be true, we see no reason why a person should not +be sometimes on the northern side of the gale. By referring to a +diagram, we perceive that on the northern side the changes of the wind +pursue a contrary direction to what they do on the south, yet in nine +cases out of ten, each vessel meeting a hurricane will find the same +changes of wind as are due to the southern side of the storm. It is +true, that if a vessel be to the northward of a great hurricane, there +will almost certainly be a north-east gale drawn in, and this might be +set down as the outer limits of a circular storm. But when the storm +really begins, the wind comes round south-east, south, south-west, +ending at north-west, and frequently is succeeded, on the following day, +(if in middle latitude,) by a moderate breeze from the northward. Now, +if the north-east gale spoken of above, was the outer limits of an +atmospheric vortex, a vessel sailing west ought not to meet the +hurricane, as a north-east wind is indicative of being already on the +west side, or behind the storm. + +Again, the characters of the winds, and appearances at the different +changes, are opposed to the circular theory. At a distance of fifty +miles from the centre of a storm, the wind which passes over a ship as a +southerly wind, will have made a rotation and a half, with the hurricane +velocity, before the same wind can again pass the ship as a northerly +wind, (supposing the progress eastward, and the ship lying to,) that is, +the same wind which in another place was a south wind two hours before, +and after only going one degree north, becomes a northerly +wind,--changed in character and temperature, as every seaman is well +aware. In a storm, if the circular theory be true, the character and +temperature should be the same, no matter from what point the wind is +blowing. This should be a conclusive argument. + +Mr. Espy has also changed his ground on the storms of the United States; +he does not now contend that the winds blow inwards to a centre, but to +a line either directly or obliquely. Thus we see that while Mr. Redfield +concedes to Mr. Espy a spirally inward current, the latter also gives up +a direct current to the centre, to Mr. Redfield. This shows at least an +approximation to the truth. + +It is not necessary for the support of this theory, that we should +derive any materials from the ruins of others; we shall therefore not +avail ourselves of certain discrepant results, which can be found in +many of the storms cited by Colonel Reid. With respect to Mr. Espy's +_cause_ of storms, the experiments of Regnault may be considered as +decisive of the question:--1st, because the specific heat of vapor is so +much less than Espy assumed it to be; and 2d, because the expansion of +air in a free space does not suffer any change of volume by ascending, +except what is due to diminished pressure, and the natural temperature +of that elevation. + + +INDICATIONS OF A STORM. + +In accordance with our theory, the direction and force of the wind in a +storm are due to ascending columns of air, supplied from the upper +portion of the atmospheric stratum beneath the clouds. The commotion +begins at the highest limits of the cirri, and even at greater +elevations. Hence, the hazy appearance of the sky is a legitimate +precursor of the coming gale. As a general thing, the wind will blow (at +the surface) towards the centre of greatest commotion, but it is too +dependent on the ever-varying position and power of temporary nuclei of +disturbance, to be long steady, except when the disturbance is so remote +that its different centres of induction are, as it were, merged into one +common focus. When a vortex is descending, or passing from north to +south, and withal very energetic at the time, the southerly wind (which +may always be considered the principal wind of the storm in this +hemisphere) may blow steadily towards the vortex for three or even four +days. When a vortex is ascending, the induced northerly current will be +comparatively moderate, and be frequently checked by the southerly wind +overblowing the storm, and arriving the day before the vortex which +produced it. + +The important point for the navigator, is to know the time of meridian +passage of the vortex, and its latitude at the time of the passage, and +then be guided by the indications of the weather and the state of +barometer. If it commences storming the day before the passage, he may +expect it much worse soon after the passage; and again, if the weather +looks bad when no vortex is near, he may have a steady gale setting +towards a storm, but no storm until the arrival of a vortex. Again, if +the barometer is low the day before the vortex passes, there may be high +barometer to the west, and the passage be attended by no great +commotion, as it requires time for the storm to mature, and consequently +its greatest violence will be to the east. If at the ship the barometer +is high, the vortex may still produce a storm on a line of low barometer +to the west, and this line may reach the ship at the time of the +passage. In tropical climates the trouble must be looked for to the +eastward; as a storm, once excited, will travel westward with that +stratum of atmosphere in which the great mass of vapor is lodged, and in +which, of course, the greatest derangement of electric tension is +produced. + +It will now be seen that we do not admit, with Col. Reid, that a storm +continues in existence for a week together. Suppose a hurricane to +originate in the Antilles at the southern limits of a vortex, the +hurricane would die away, according to our theory, if the vortex did not +come round again and take up the same nucleus of disturbance. On the +third day the vortex is found still further north, and the apparent path +of the hurricane becomes more curved. In latitude 30d the vortex passes +over 3d or 5d of latitude in a day; and here being the latitude where +the lower atmospheric current changes its course, the storm passes due +north, and afterwards north-east. Now, each day of the series there is a +distinct hurricane, (caused by an increase of energy in a particular +vortex, as we have before hinted,) each one overlapping on the remains +of the preceding; but in each the same changes of the wind are gone +through, and the same general features preserved, as if it were truly a +progressive whirlwind, except that each vessel has the violent part of +it, as if she was in the southern half of the whirl. The apparent +regularity of the Atlantic storms in direction, as exhibited by Col. +Reid, are owing in a great degree to the course of the Gulf Stream, in +which a vortex, in its successive passages in different latitudes, finds +more favorable conditions for the development of its power, than in +other parts of the same ocean; thus showing the importance of regarding +the established character of storms in each locality, as determined by +observation. In this connection, also, we may remark, that the meridians +of greatest magnetic intensity are, _ceteris paribus_, also the +meridians of greatest atmospheric commotion. The discovery of this fact +is due to Capt. Sabine. The cause is explained by the theory. + +As it is the author's intention to embody the practical application of +this theory to navigation, with the necessary rules and tables, in a +separate work, sufficient has been said to familiarize the reader with +the general idea of a cause external to the earth, as the active motor +in all atmospheric phenomena. We will therefore only allude in a general +way to the principal distinguishing feature of the theory. We say, then, +that the wind in a storm is not in rotation, and it is a dangerous +doctrine to teach the navigator. We also assert as distinctly, that the +wind _in_ a storm does not blow from all sides towards the centre, which +is just as dangerous to believe. If it were wise to pin our faith to any +Procrustean formula, we might endorse the following propositions: That +at the beginning of a storm the wind is from the equator towards the +poles in every part of the storm; that, at a later date, another current +(really a polar current deflected by convection) sets in at right angles +to the first one; and that at the end of the storm there is only _one_ +wind blowing at right angles to the direction at the beginning. Outside +the storm, considered as a hundred, or two or three hundred miles in +diameter, there is, under certain limitations, a surface wind setting +towards the general focus of motion and condensation, and this surface +wind will be strongest from the westward, on account of the motion of +the whole atmosphere in which these other motions are performed being to +the eastward.[9] The whole phenomenon is electrical or magnetic, or +electro-magnetic or ethereal, whichever name pleases best. The vortex, +by its action, causes a current of induction below, from the equator, as +may be understood by inspecting Fig. 2, which in the northern hemisphere +brings in a southerly current by convection: the regular circular +current, however, finally penetrates below, as soon as the process of +induction has ceased; and thus the polar current of the atmosphere at +last overcomes the equatorial current in a furious squall, which ceases +by degrees, and the equilibrium is restored. + +Every locality will have its peculiar features; in each, the prevailing +wind will be at right angles to the magnetic meridian, and the progress +of the storm will tend to follow the magnetic parallel, which is one +reason why the Atlantic and Indian Ocean storms have been mistaken for +progressive whirlwinds. When these views are developed in full, the +mariner can pretty certainly decide his position in the storm, the +direction of its progress, and its probable duration. + + +FOOTNOTES: + +[3] The specific heat of the ether being a constant factor, it may be +divided out. + +[4] A term adopted by Prof. Faraday to denote the mode in which bodies +are carried along by an electrical current. + +[5] Ottawa, Ill. + +[6] The principal cause of these waves is, no doubt, due to the +vortices, and the eastern progress of the waves due to the rotating +ether; but, at present, it will not be necessary to separate these +effects. + +[7] The inner vortex may reach as high as 83d when the moon's orbit is +favorably situated. + +[8] The curvature of the earth is more than 10 miles in a distance of +300 miles. + +[9] In middle latitudes. + + + + +SECTION SECOND. + + +MECHANICAL ACTION OF THE MOON. + +We will now proceed to give the method of determining the latitude of +the axis of the vortex, at the time of its passage over any given +meridian, and at any given time. And afterwards we will give a brief +abstract from the record of the weather, for one sidereal period of the +moon, in order to compare the theory with observation. + +[Illustration: Fig. 4] + +In the above figure, the circle PER represents the earth, E the equator, +PP' the poles, T the centre of the earth, C the mechanical centre of the +terral vortex, M the moon, XX' the axis of the vortex, and A the point +where the radius vector of the moon pierces the surface of the earth. If +we consider the axis of the vortex to be the axis of equilibrium in the +system, it is evident that TC will be to CM, as the mass of the moon to +the mass of the earth. Now, if we take these masses respectively as 1 to +72.3, and the moon's mean distance at 238,650 miles, the mean value of +TC is equal to this number, divided by the sum of these masses,--_i.e._ +the mean radius vector of the little orbit, described by the earth's +centre around the centre of gravity of the earth and moon, is equal +238650/(72.3+1) = 3,256 miles; and at any other distance of the moon, is +equal to that distance, divided by the same sum. Therefore, by taking CT +in the inverse ratio of the mean semi-diameter of the moon to the true +semi-diameter, we shall have the value of CT at that time. But TA is to +TC as radius to the cosine of the arc AR, and RR' are the points on the +earth's surface pierced by the axis of the vortex, supposing this axis +coincident with the pole of the lunar orbit. If this were so, the +calculation would be very short and simple; and it will, perhaps, +facilitate the investigation, by considering, for the present, that the +two axes do coincide. + +In order, also, to simplify the question, we will consider the earth a +perfect sphere, having a diameter of 7,900 miles, equal to the actual +polar diameter, and therefore TA is equal to 3,950 miles. + +In the spherical triangle given on next page, we have given the point A, +being the position of the moon in right ascension and declination in the +heavens, and considered as terrestrial latitude and longitude. + +Therefore, PA is equal to the complement of the moon's declination, P +being the pole of the earth, and L being the pole of the lunar orbit; PL +is equal to the obliquity of the lunar orbit, with respect to the earth, +and is therefore given by finding the true inclination of the lunar +orbit at the time, equal EL, (E being the pole of the ecliptic,) also +the true longitude of the ascending node, and the obliquity of the +ecliptic PE. Now, as we are supposing the axis of the vortex parallel +to the pole of the lunar orbit, and to pierce the earth's surface at R, +ARL will evidently all be in the same plane; and, as in the case of A +and L, this plane passes through the earth's centre, ARL must all lie in +the same great circle. Having, therefore, the right ascension of A, and +the right ascension of L, we have the angle P. This gives us two sides, +and the included angle, to find the side LA. But we have before found +the arc AR; we therefore know LR. But in finding LA, we found both the +angles L and A, and therefore can find PR, which is equal to the +complement of the latitude sought. + +[Illustration: Fig. 5] + +We have thus indicated briefly the simple process by which we could find +the latitude of the axis of the central vortex, supposing it to be +always coincident with the pole of the lunar orbit. The true problem is +more complicated, and the principal modifications, indicated by the +theory, are abundantly confirmed by observation. The determination of +the inclination of the axis of the vortex, its position in space at a +given time, and the law of its motion, was a work of cheerless labor for +a long time. He that has been tantalized by hope for years, and ever on +the eve of realization, has found the vision vanish, can understand the +feeling which proceeds from frequent disappointment in not finding that, +whose existence is almost demonstrated; and more especially when the +approximation differs but slightly from the actual phenomena. + +The chief difficulty at the outset of these investigations, arose from +the conflicting authority of astronomers in relation to the mass of the +moon. We are too apt to confound the precision of the laws of nature, +with the perfection of human theories. Man observes the phenomena of the +heavens, and derives his means of predicting what will be, from what has +been. Hence the motions of the heavenly bodies are known to within a +trifling amount of the truth; but it does not follow that the true +explanation is always given by theory. If this were so, the mass of the +moon (for instance) ought to be the same, whether deduced from the +principle of gravitation or from some other source. This is not so. +Newton found it 1/40 of that of the earth. La Place, from a profound +theoretical discussion of the tides, gave it as 1/58.6, while from other +sources he found a necessity of diminishing it still more, to 1/68, and +finally as low as 1/75. Bailly, Herschel, and others, from the nutation +of the earth's axis, only found 1/80, and the Baron Lindenau deduced the +mass from the same phenomenon 1/88. In a very recent work by Mr. Hind, +he uses this last value in certain computations, and remarks, that we +shall not be very far wrong in considering it as 1/80 of the mass of the +earth. This shows the uncertainty of the matter in 1852. If astronomy is +so perfect as to determine the parallax of a fixed star, which is almost +always less than one second, why is it that the mass of the moon is not +more nearly approximated? Every two weeks the sun's longitude is +affected by the position of the moon, alternately increasing and +diminishing it, by a quantity depending solely upon the relative mass of +the earth and moon, and is a gross quantity compared to the parallax of +a star. So, also, the horizontal parallax--the most palpable of all +methods--taken by different observers at Berlin, and the Cape of Good +Hope, (a very respectable base line, one would suppose,) makes the mass +of the moon greater than its value derived from nutation; the first +giving about 1/70, the last about 1/74.2. Does not this declare that it +is unsafe to depend too absolutely on the strict wording of the +Newtonian law of gravitation. Happily our theory furnishes us with the +correct value of the moon's mass, written legibly on the surface of the +earth; and it comes out nearly what these two phenomena always gave it, +viz.: 1/72.3 of that of the earth. In another place we shall inquire +into the cause of the discrepancy as given by the nutation of the earth. + + +MOTION OF THE AXIS OF THE VORTEX. + +If the axis of the terral vortex does not coincide with the axis of the +lunar orbit, we must derive this position from observation, which can +only be done by long and careful attention. This difficulty is increased +by the uncertainty about the mass of the moon, already alluded to, and +by the fact that there are three vortices in each hemisphere which pass +over _twice_ in each month, and it is not _always_ possible to decide by +observation, whether a vortex is ascending or descending, or even to +discriminate between them, so as to be assured that this is the central +descending, and that the outer vortex ascending. A better acquaintance, +however, with the phenomenon, at last dissipates this uncertainty, and +the vortices are then found to pursue their course with that regularity +which varies only according to law. The position of the vortex (the +central vortex is the one under consideration) then depends on the +inclination of its axis to the axis of the earth, and the right +ascension of that axis at the given time. For we shall see that an +assumed immobility of the axis of the vortex, would be in direct +collision with the principles of the theory. + +Let the following figure represent a globe of wood of uniform density +throughout. Let this globe be rotated round the axis. It is evident that +no change of position of the axis would be produced by the rotation. If +we add two equal masses of lead at m and m', on opposite sides of the +axis, the globe is still in equilibrium, as far as gravity is concerned, +and if perfectly spherical and homogeneous it might be suspended from +its centre in any position, or assume indifferently any position in a +vessel of water. If, however, the globe is now put into a state of rapid +rotation round the axis, and then allowed to float freely in the water, +we perceive that it is no longer in a state of equilibrium. The mass m +being more dense than its antagonist particle at n, and having equal +velocity, its momentum is greater, and it now tends continually to pull +the pole from its perpendicular, without affecting the position of the +centre. The same effect is produced by m', and consequently the axis +describes the surface of a double cone, whose vertices are at the centre +of the globe. If these masses of lead had been placed at opposite sides +of the axis on the _equator_ of the globe, no such motion would be +produced; for we are supposing the globe formed of a hard and unyielding +material. In the case of the ethereal vortex of the earth, we must +remember there are two different kinds of matter,--one ponderable, the +other not ponderable; yet both subject to the same dynamical laws. If we +consider the axis of the terral vortex to coincide with the axis of the +lunar orbit, the moon and earth are placed in the equatorial plane of +the vortex, and consequently there can be no derangement of the +equilibrium of the vortex by its own rotation. But even in this case, +seeing that the moon's orbit is inclined to the ecliptic, the +gravitating power of the sun is exerted on the moon, and of necessity +she must quit the equatorial plane of the vortex; for the sun can exert +no influence on the _matter_ of the vortex by his attracting power. The +moment, however, the moon has left the equatorial plane of the vortex, +the principle of momentum comes into play, and a conical motion of the +axis of the vortex is produced, by its seeking to follow the moon in her +monthly revolution. This case is, however, very different to the +illustration we gave. The vortex is a fluid, through which the moon +freely wends her way, passing through the equatorial plane of the vortex +twice in each revolution. These points constitute the moon's nodes on +the plane of the vortex, and, from the principles laid down, the force +of the moon to disturb the equilibrium of the axis of the vortex, +vanishes at these points, and attains a maximum 90d from them. And the +effect produced, in passing from her ascending to her descending node, +is equal and contrary to the effect produced in passing from her +descending to her ascending node,--reckoning these points on the plane +of the vortex. + +[Illustration: Fig. 6] + + +INCLINATION OF THE AXIS. + +By whatever means the two planes first became permanently inclined, we +see that it is a necessary consequence of the admission of these +principles, not only that the axis of the vortex should be drawn aside +by the momentum of the earth and moon, ever striving, as it were, to +maintain a dynamical balance in the system, in accordance with the +simple laws of motion, and ever disturbed by the action of gravitation +exerted on the grosser matter of the system; but also, that this axis +should follow, the axis of the lunar orbit, at the same mean +inclination, during the complete revolution of the node. The mean +inclination of the two axes, determined by observation, is 2d 45', and +the monthly equation, at a maximum, is about 15', being a plus +correction in the northern hemisphere, where the moon is between her +descending and ascending node, reckoned on the plane of the vortex, and +a minus correction, when between her ascending and descending node. And +the mean longitude of the node will be the same as the true longitude of +the moon's orbit node,--the maximum correction for the true longitude +being only about 5d +/-. + +[Illustration: Fig. 7] + +In the following figure, P is the pole of the earth; E the pole of the +ecliptic; L the pole of the lunar orbit; V the mean position of the pole +of the vortex at the time; the angle [ARIES]EL the true longitude of the +pole of the lunar orbit, equal to the _true_ longitude of the ascending +node +/- 90d. VL is therefore the mean inclination +/- 2d 45'; and the +little circle, the orbit described by the pole of the vortex _twice_ in +each sidereal revolution of the moon. The distance of the pole of the +vortex from the mean position V, may be approximately estimated, by +multiplying the maximum value 15' by the sine of twice the moon's +distance from the node of the vortex, or from its mean position, viz.: +the true longitude of the ascending node of the moon on the ecliptic. +From this we may calculate the true place of the node, the true +obliquity, and the true inclination to the lunar orbit. Having indicated +the necessity for this correction, and its numerical coefficient, we +shall no longer embarrass the computation by such minutiae, but consider +the mean inclination as the true inclination, and the mean place of the +node as the true place of the node, and coincident with the ascending +node of the moon's orbit on the ecliptic. + + +POSITION OF THE AXIS OF THE VORTEX. + +It is now necessary to prove that the axis of the vortex will still pass +through the centre of gravity of the earth and moon. + +[Illustration: Fig. 8] + +Let XX now represent the axis of the lunar orbit, and C the centre of +gravity of the earth and moon, X'X' the axis of the vortex, and KCR the +inclination of this axis. Then from + + similarity Ct : Tt :: Cm : Mm + but Tt : Mm :: Moon's mass : Earth's mass. + That is Tt : Mm :: TC : MC. + +Therefore the system is still balanced; and in no other point but the +point C, can the intersection of the axes be made without destroying +this balance. + +It will be observed by inspecting the figure, that the arc R'K' is +greater than the arc RK. That the first increases the arc AR, and the +second diminishes that arc. The arc R'K' is a plus correction therefore, +and the smaller arc RK a minus correction. If the moon is between her +descending and ascending node, (taking now the node on the ecliptic,) +the correction is negative, and we take the smaller arc. If the moon is +between her ascending and descending node, the correction is positive, +and we take the larger arc. If the moon is 90d from the node, the +correction is a maximum. If the moon is at the node, the correction is +null. In all other positions it is as the sine of the moon's distance +from the nodes. We must now find the maximum value of these arcs of +correction corresponding to the mean inclination of 2d 45'. + +To do this we may reduce TC to Tt in the ratio of radius to cosine of +the inclination, and taking TS for radius. + +[Illustration: Fig. 9] + +{TC x Cos &c. (inclination 2d 45')}/R is equal the cosine of the arc SK' +and SK' + AS = AK' and AK' + AR' = R'K'. But from the nature of the +circle, arc RK + arc R'K' = angle RCK + angle R'CK', or equal to double +the inclination; and therefore, by subtracting either arc from double +the inclination, we may get the other arc. + +The maximum value of these arcs can, however, be found by a simple +proportion, by saying; as the arc AR, plus the inclination, is to the +inclination, so is the inclination to the difference between them; and +therefore, the inclination, plus half the difference, is equal the +greater arc, and the inclination, minus half the difference, is equal +the lesser; the greater being positive, and the lesser negative. + +Having found the arc AR, and knowing the moon's distance from either +node, we must reduce these values of the arcs RK and R'K' just found, in +the ratio of radius to the sine of that distance, and apply it to the +arc AR or A'R', and we shall get the first correction equal to the +arc AK or AK'. + + Call the arc AR = a + " inclination = n + " distance from the node = d + " arc AK = k + +and supposing the value of AK be wanted for the northern hemisphere when +the moon is between her descending and ascending node, we have + + n^2 + ------- + a + n + (n - ------- ) sin d. + 2 + k = a - ---------------------- + R + +If the moon is between her ascending and descending node, then + + n^2 + ------- + a + n + (n - ------- ) sin d. + 2 + k = a + ---------------------- + R + +The computation will be shorter, however, if we merely reduce the +inclination to the sine of the distance from the node for the first +correction of the arc AR, if we neglect the semi-monthly motion of the +axis; for this last correction diminishes the plus corrections, and the +first one increases it. If, therefore, one is neglected, it is better to +neglect the other also; especially as it might be deemed affectation to +notice trifling inequalities in the present state of the elements of the +question. + +There is one inequality, however, which it will not do to neglect. This +arises from the displacement of the axis of the vortex. + + +DISPLACEMENT OF THE AXIS. + +We have represented the axis of the terral vortex as continually passing +through the centre of gravity of the earth and moon. Now, by following +out the principles of the theory, we shall see that this cannot be the +case, except when the moon is in quadrature with the sun. To explain +this: + +[Illustration: Fig. 10] + +Let the curve passing through C represent a portion of the orbit of the +earth, and S the sun. From the principles laid down, the density of the +ethereal medium increases outward as the square roots of the distances +from the sun. Now, if we consider the circle whose centre is C to +represent the whole terral vortex, it must be that the medium composing +it varies also in density at different distances from the sun, and at +the same time is rotating round the centre. That half of the vortex +which is exterior to the orbit of the earth, being most dense, has +consequently most inertia, and if we conceive the centre of gravity of +the earth and moon to be in the orbit (as it must be) at C, there will +not be dynamical balance in the terral system, if the centre of the +vortex is also found at C. To preserve the equilibrium the centre of the +vortex will necessarily come nearer the sun, and thus be found between T +and C, T representing the earth, and [MOON] the moon, and C the centre of +gravity of the two bodies. If the moon is in opposition, the centre of +the vortex will fall between the centre of gravity and the centre of the +earth, and have the apparent effect of diminishing the mass of the moon. +If, on the other hand, the moon is in conjunction, the centre of the +vortex will fall between the centre of gravity and the moon, and have +the apparent effect of increasing the mass of the moon. If the moon is +in quadrature, the effect will be null. The coefficient of this +inequality is 90', and depends on the sun's distance from the moon. When +the moon is more than 90d from the sun, this correction is positive, and +when less than 90d from the sun, it is negative. If we call this second +correction C, and the moon's distance from her quadratures Q, we have +the value of C = +/-(90' x sin Q)/R. + +[Illustration: Fig. 11] + +This correction, however, does not affect the inclination of the axis of +the vortex, as will be understood by the subjoined figure. If the moon +is in opposition, the axis of the vortex will not pass through C, but +through C', and QQ' will be parallel to KK'. If the moon is in +conjunction, the axis will be still parallel to KK', as represented by +the dotted line qq'. The correction, therefore, for displacement, is +equal to the arc KQ or Kq, and the correct position of the vortex on the +surface of the earth at a given time will be at the points Q or q and Q' +or q', considering the earth as a sphere. + +[Illustration: Fig. 12] + +In the spherical triangle APV, P is the pole of the earth, V the pole of +the vortex, A the point of the earth's surface pierced by the radius +vector of the moon, AQ is the corrected arc, and PV is the obliquity of +the vortex. Now, as the axis of the vortex is parallel to the pole V, +and the earth's centre, and the line MA also passes through the earth's +centre, consequently AQV will all lie in the same great circle, and as +PV is known, and PA is equal to the complement of the moon's declination +at the time, and the right, ascensions of A and V give the angle P, we +have two sides and the included angle to find the rest, PQ being the +complement of the latitude sought. + +We will now give an example of the application of these principles. + +_Example._[10] Required the latitude of the central vortex at the time +of its meridian passage in longitude 88d 50' west, July 2d, 1853. + +CENTRAL VORTEX ASCENDING. + + Greenwich time of passage 2d. 3h. 1m. + Mean longitude of moon's node 78d 29' + True " " 79 32 + Mean inclination of lunar orbit 5 9 + True " " 5 13 + Obliquity of ecliptic 23 27 32" + Mean inclination of vortex 2 45 0 + +Then in the spherical triangle PEV, + + PE is equal 23d 27' 32" + EV " 7 58 0 + E " 100 28 0 + P " 18 5 7 + PV " 26 2 32 + +Calling P the polar angle and PV the obliquity of vortex. + +[Illustration: Fig. 13] + +To find the arc AR. + +By combining the two proportions already given, we have by logarithms: + + M.R.V. minor = 3256 Log. 3.512683 + M.S.D. of moon = 940" " 2.973128 + P.S.D. of earth = 3950 A. C. 6.403403 + Radius 10.000000 + T.S.D. of moon 885".5 A. C. 7.052811 + Log. Cosine arc AR = 28d 57' 3" 9.942025 + --------- + +As the only variable quantity in the above formula is the "True" +semi-diameter of the moon at the time, we may add the Constant logarithm +2.889214 to the arithmetical complement of the logarithm of the true +semi-diameter, and we have in two lines the log. cosine of the arc AR. + +We must now find the arc RK equal at a maximum to 2d 45'. The true +longitude of the moon's node being 79d 32', and the moon's longitude, +per Nautical Almanac, being 58d 30', the distance from the node is 21d +2', therefore, the correction is + + -2d 45' x sin 21d 2' + -arc RK = --------------------- = -59' 13" + R + +To find the correction for displacement. + + True longitude of sun at date 100d 30' + " of moon " 58 30 + Moon's distance from quadrature 48 0 + +As the moon is less than 90d from the sun this correction is also +negative, or + + -90' x sin 48d + Arc Kq = --------------- = -1d 6' 46". + R + + Arc AR = 28d 57' 3" + RK = - 0d 39' 13" + Kq = - 1d 6' 46" + Sum = 26d 51' 4" = corrected arc AQ. + +We have now the necessary elements in the Nautical Almanac, which we +must reduce for the instant of the vortex passing the meridian in +Greenwich time. + + July 2d. + Meridian passage, local time, at 9h. 5m. A.M. + " in Greenwich time 2d. 3h. 1m. + Right ascension same time 56d 42' 45" + Declination north " 18 00 1 + Obliquity of the vortex " 26 2 32 + Polar angle " 18 5 7 + Arc AQ " 26 51 4 + +[Illustration: Fig. 14] + + PA = 17d 59' 59" } P = 128d 37' 38" + PV = 26 2 32 } + VA = 89 3 0 V = 47 59 44 + VQ = 62 11 56 A = 20 3 42 + PQ = 47 14 22 Q = 26 22 55 + Latitude of Q on the sphere = 42d 45' 38" + + +CORRECTION FOR PROTUBERANCE. + +We have hitherto considered the earth a perfect sphere with a diameter +of 7,900 miles. It is convenient to regard it thus, and afterwards make +the correction for protuberance. We will now indicate the process for +obtaining this correction by the aid of the following diagram. + +[Illustration: Fig. 15] + +Let B bisect the chord ZZ'. Then, by geometry, the angle FQY is equal to +the angle BTF, and the protuberance FY is equal the sine of that angle, +making QF radius. This angle, made by the axis of the vortex and the +surface of the sphere, is commonly between 30d and 40d, according as the +moon is near her apogee or perigee; and the correction will be greatest +when the angle is least, as at the apogee. At the equator, the whole +protuberance of the earth is about 13 miles. Multiply this by the cosine +of the angle and divide by the sine, and we shall get the value of the +arc QY for the equator. For the smallest angle, when the correction is a +maximum, this correction will be about 20' of latitude at the equator; +for other latitudes it is diminished as the squares of the cosines of +the latitude. Then add this amount to the latitude EQ, equal the +latitude EY. This, however, is only correct when the axis of the vortex +is in the same plane as the axis of the earth; it is, therefore, subject +to a minus correction, which can be found by saying, as radius to cosine +of obliquity so is the correction to a fourth--the difference of these +corrections is the maximum minus correction, and needs reducing in the +ratio of radius to the cosine of the angle of the moon's distance from +the node; but as it can only amount to about 2' at a maximum under the +most favorable circumstances, it is not necessary to notice it. The +correction previously noticed is on the supposition that the earth is +like a sphere having TF for radius; as it is a spheroid, we must correct +again. From the evolute, draw the line SF, and parallel to it, draw TW; +then EW is the latitude of the point F on the surface of the spheroid. +This second correction is also a plus correction, subject to the same +error as the first on account of the obliquity, its maximum value for an +angle of 30d is about 6', and is greatest in latitude 45d; for other +latitudes, it is equal {6' x sin(double the lat.)}/R. + +The three principal corrections for protuberance may be _estimated_ from +the following table, calculated for every 15d of latitude for an angle +of 30d, or when the correction is greatest. + + Latitude. 1st Corr. 2d Corr. 3d Corr. + 0 + 20' + 0 - 2 + 15 + 19 + 3 - 1.5 + 30 + 15 + 5 - 1.5 + 45 + 10 + 6 - 1. + 60 + 5 + 5 - 1 + 70 + 1 + 3 - 0.5 + +We can now apply this correction to the latitude of the vortex just +found: + + Latitude on the sphere 42d 45' 38" n. + Correction for protuberance + 14 22 + ---------- + Correct latitude 43 00 00 + + +MILWAUKIE STORM, JULY 2. + +As this example was calculated about ten days before the actual date, we +have appended an extract from the Milwaukie papers, which is in the same +longitude as Ottawa, in which place the calculation was made. It is +needless to remark that the latitude of Milwaukie corresponds to the +calculated latitude of the centre of the vortex. It is not intended, +however, to convey the idea that the central line is always the most +subject to the greatest violence--a storm may have several centres or +nuclei of disturbance, which are frequently waning and reviving as the +storm progresses. Generally speaking, however, the greatest action is +developed along the line previously passed over by the axis of the +vortex. + + "SUMMIT, Waukesha Co., Wis., July 4, 1853. + + "Our town, on Saturday, the 2d, was visited by a terrible storm, + which will long be remembered by those who witnessed its effects and + suffered from its fury. It arose in the south-west, and came + scowling in blackness, sufficient to indicate its anger, for the + space of eighty or a hundred rods in _width_, covering our usually + quiet village; and for nearly half an hour's duration, the rain fell + in torrents, the heavens blazed with the lightning's flashes, trees + fell and were uprooted by the fury of the blast, fragments of gates + and of buildings, shingles, roof-boards, rafters, circled through + the air, the playthings of the wind--and buildings themselves were + moved entire from their foundations, and deposited at different + distances from their original positions. A barn, fifty-five feet + square on the ground, owned by Mr. B. R. Hinckley, is moved from its + position some ten feet to the eastward; and a house, some fifteen by + eighteen feet on the ground, owned by the same person, fronting the + east, was driven by the wind to the opposite side of the street, and + now fronts nearly west; and what is most strange, is that the grass, + in the route the house must have passed over, stands straight as + usual, and gives no evidence that the building was pushed along on + the ground. A lady running from a house unroofed by the storm, took + an aerial flight over two fences, and finally caught against a tree, + which arrested her passage for a moment only, when, giving way, she + renewed her journey for a few rods, and was set down unhurt in + Mr. O. Reed's wheat field, where, clinging to the growing grain, she + remained till the gale went by."[11] + +The weather at this place is briefly recorded in the accompanying +abstract from the journal, as well as in an extract from a note to +Professor Henry, of the Smithsonian Institution, from a friend of the +authors, who has long occupied a high official station in Illinois. But +such coincidences are of no value in deciding on the merits of such a +theory, it must be tried before the tribunal of the world, and applied +to phenomena in other countries with success, before its merits can be +fully appreciated. The accompanying record, therefore, is only given to +show how these vortices render themselves apparent, and what ought to be +observed, and also to exhibit the order of their recurrence and their +positions at a given time. + +_Extract of a note addressed to the Secretary of the Smithsonian +Institution, by Hon. John Dean Caton, on this subject._ + + "As a striking instance of the remarkable coincidences confirmatory + of these calculations, I will state, that on Friday, the first of + July last, this gentleman[12] stated that on the next day a storm + would pass north of us, being central a little south of Milwaukie, + and that he thought, from the state of the atmosphere, the storm + would be severe, and that its greatest violence would be felt on the + afternoon or night of the next day. At this time the weather was + fine, without any indications of a storm, so far as I could judge. + At noon on the following day he pointed out the indications of a + storm at the north and north-west, consisting of a dark, hazy belt + in that direction, extending up a few degrees above the horizon, + although so indistinct as to have escaped my observation. At five + o'clock a violent storm visited us, which lasted half an hour, + although a clear sky was visible at the south the whole time. On + Monday morning I learned, from the telegraph office at Chicago, that + early on Saturday afternoon communication with Milwaukie had been + interrupted by atmospheric electricity, and that the line had been + broken by a storm." + + +NEW YORK STORM. + +After this was written, the author discovered that the vortex was +equally violent the day before at New York, July 1st, 1853. An account +of this storm follows. The calculation has not been made, but it is easy +to perceive that the latitude of the vortex, on July 1st, must be very +nearly that of New York--being in latitude 43d next day and ascending. + +"At a meeting of the American Association, convened at Cleveland, +Professor Loomis presented a long notice of the terrible hail storm in +New York on the 1st of July. He traced its course, and minutely examined +all the phenomena relating to it, from a mile and a half south-east of +Paterson, N.J., to the east side of Long Island, where it appeared +nearly to have spent its force. It passed over the village of Aqueenac, +striking the Island of New York in the vicinity of the Crystal Palace. +It was not much more than half a mile wide. The size of the hail-stones +was almost incredibly large, many of them being as large as a hen's egg, +and the Professor saw several which he thought as large as his fist. +Some of them weighed nearly half a pound. The principal facts in +relation to this storm were published at the time, and need not be +repeated. The discussions arising among the members as to the origin and +the size of these hail-stones, and the phenomena of the storm, were +exceedingly interesting. They were participated in by Professors Heustus +and Hosford, of Cambridge University, Professor Loomis, and Professors +Bache and Redfield. The latter two gentlemen differ somewhat, we should +suppose radically, in their meteorological theories, and had some very +sharp but very pleasant "shooting" between them."[13] + + +CENTRAL VORTEX DESCENDING. + +We will now make the calculation for the central vortex _descending_, +for longitude 88d 50' west, August 7, 1853,--putting down the necessary +elements for the time of the meridian passage in order: + + Meridian passage in local time at 2h. 25m. P.M. + " " in Greenwich time 7d. 8h. 18m. + Mass of the moon 1/12.3 M. R. V. minor 3,256 miles. + Obliquity of the vortex, same time 26d 5' 0" + Polar angle of " " 17 41 47 + True longitude of moon's node " 78 42 0 + " inclination of orbit " 5 5 0 + " longitude of the sun " 135 20 0 + Moon's longitude " 169 44 0 + " distance from node " 91 2 0 + " distance from quadrature " 55 36 0 + " true semi-diameter " 943 + " right ascension " 172 30 0 + " declination north " 8 42 20 + Constant logarithm 2.889214 + Arith. comp. of log. of 943 7.025488 + Log. cos. arc. AR 9.914702 = 34d 44' 48" + 1st. correction, + 2 45 0 + 2d. correction, - 1 14 15 + -------------- + Corrected arc AQ = 36 15 33 + PA = 81d 17' 40" + PV = 26 5 0 + P = 115 11 47 + V = 63 34 26 + A = 23 28 24 + AV = 92 48 39 + Q = 31 32 18 + Complement of lat. = PQ = 48d 49' 41" + The latitude is therefore for + the earth, as a sphere 41 10 18 + Correction for protuberance + 0 16 0 + ------------ + True latitude of centre 41 26 18 north. + ------------ + Latitude of Ottowa 41 20 0 " + ------------ + Vortex passed 6 18 north of Ottowa. + +[Illustration: Fig. 16] + +As this was nearly a central passage, and as the influence was less +extensive than usual, on account of great atmospheric pressure with a +low dew point, the central disturbance could the more readily be +located, and was certainly to the north, and but a few miles. The +following is from the record of the weather: + +_August_ 6th. Very fine and clear all day; wind from S.-W.; a light +breeze; 8 P.M. frequent flashes of lightning in the northern sky; +10 P.M. a _low bank of dense clouds in north_, fringed with cirri, +visible during the flash of the lightning; 12 P.M. same continues. + +7th. Very line and clear morning; wind S.-W. moderate; noon, clouds +accumulating in the northern half of the sky; wind fresher S.-W.; 3 P.M. +a clap of thunder overhead, and black cumuli in west, north, and east; +4 P.M. much thunder, and scattered showers; six miles west rained very +heavily; 6 P.M. the heavy clouds passing over to the south; 10 P.M. +clear again in north. + +_August_ 8th. Clear all day; wind the same (S.-W.); a hazy bank visible +all along on _southern horizon_. + +This was not a storm, in the ordinary acceptation of the term; but the +same cause, under other circumstances, would have produced one; and let +it be borne in mind, that although the moon is the chief disturbing +cause, and the passages of the vortices are the periods of greatest +commotion in both settled and unsettled weather, still the sun is +powerful in predisposing the circumstances, whether favorable or +unfavorable; and as there is no periodic connection between the passage +of a vortex and the concurrence of the great atmospheric waves, it will, +of course, happen only occasionally that all the circumstances will +conspire to make a storm. There are also other modifying causes, to +which we have not yet alluded, which influence the storms at different +seasons of the year,--exaggerating their activity in some latitudes, and +diminishing it in other latitudes. In this latitude, the months of May, +June, and July are marked by more energetic action than August, +September, and October. The activity of one vortex also, in one place, +seems to modify the activity of another vortex in another place. But the +great question to decide is: Do these vortices really exist? Do they +follow each other in the _order_ indicated by the theory? Do they pass +from south to north, and from north to south, at the _times_ indicated +by the theory? Do they obey, in their monthly revolutions, a +mathematical law connecting them with the motions of the moon? We answer +emphatically, Yes! And the non-discovery of these facts, is one of the +most humiliating features of the present age. + + +OTTOWA STORM, DECEMBER 22, 1852. + +To show that the same calculations are applicable for other times, we +will make the calculation for the _centre ascending_, for the 22d +December, 1852, taking the following elements: + + Moon's mer. passage, Dec. 22d 15h. 16m. G. time. + " right ascension, same time 51d 57' + " declination north 15 42 + " true S. Diameter 886.6" + " distance from node 37 + " " " quadrature 52 + -------- + Which gives the arc AR 29 5 + 1st correction -1 51 + 2d +1 11 + -------- + Corrected arc AQ 28 25 + -------- + +And the latitude at the time of the meridian passage = 42d north, or +about forty miles north of Ottawa. + +Abstract from the record:-- + +[14]_Dec._ 21st, 1852. Wind N.-E., fine +weather. + +_Dec._ 22d. Thick, hazy morning, wind east, much lighter in S.-E. than +in N.-W.; 8 A.M., a clear arch in S.-E. getting more to south; noon, +very black in W. N.-W.; above, a broken layer of cir. cumulus, the sun +visible sometimes through the waves; wind round to S.-E., and fresher; +getting thicker all day; 10 P.M., wind south, strong; thunder, +lightning, and heavy rain all night, with strong squalls from south. + +_Dec._ 23d. Wind S.-W., moderate, drizzly day; 10 P.M., wind west, and +getting clearer. + +The next day the vortex passed the latitude of Montreal (the moon being +on the meridian about 10 P.M.) + + +MAGNETIC STORM, DECEMBER 23, 1852. + +In the July number of Vol. XVI. of Silliman's Journal, we find certain +notices of the weather in 1852, by Charles Smallwood, of St. Martins, +nine miles east of Montreal. He mentions "two remarkable electrical +storms (which) occurred on the 23d and 31st of December, (in which) +sparks 5/40 of an inch were constantly passing from the conductor to the +discharger for several hours each day." At 10 P.M. (23d) the vortex +passed over Montreal, and again descending on the 31st North, and was +visible at Ottowa on the morning of the 1st of January, with southerly +wind setting towards it. On the 29th of December, Mr. Smallwood records +"a low auroral arch, sky clear." On the 20th, the vortex was 5d to the +northward of Montreal, and the aurora was consequently low--the +brightest auroras being when the vortex is immediately north without +storm, or one day to the northward, although we have seen it _very low_ +when the vortex was three days to the north, and no other vortex near. + + +LIVERPOOL STORM. + +On the night of the 24th of December, the same central vortex ascending +passed between Cape Clear and Liverpool. + +On the 25th, at midnight, the vortex passed to the north of Liverpool: +its northerly progress being very slow, being confined for three days +between the parallel of Liverpool and its extreme northern limit in +latitude about 57d. The accompanying account of the weather will show +the result of a long-continued disturbance near the same latitude: + +The Baltic, three days out from Liverpool, encountered the vortex on the +night of the 23d. On the morning of the 25th, very early, the gale +commenced at Liverpool, and did much damage. On the 26th, the vortex +attained its northern limit; but we have not been able to procure any +account of its effects to the northward of Liverpool, although there can +be but little doubt that it was violent on the coast of Scotland on the +26th; for the next day (27th) the vortex having made the turn, was near +the latitude of Liverpool, and caused a _tremendous_ storm, thus showing +a continued state of activity for several days, or a peculiarly +favorable local atmosphere in those parts. It is very probable, also, +that there was a conjunction of the central and inner vortex on the +27th. The inner vortex precedes the central in passing latitude 41d; but +as the mean radius of its orbit is less than that of the central, it +attains to a higher latitude, and has, consequently, to cross the path +of the central, in order again to precede it descending in latitude 41d. +As a very trifling change in the elements of the problem will cause +great changes in the positions of the vortices on the surface of the +earth, it cannot now be asserted that such a conjunction did positively +occur at that time; but, it maybe suspected, that a double disturbance +would produce a greater commotion, or, in other words, a more violent, +storm. + +It is on this account, combined with other auxiliary causes, that the +vicinity of Cape Horn is so proverbially stormy, as well as for the low +standard of the barometer in that latitude, it is the stationary point +of the vortices in ordinary positions of the nodes and perigee of the +moon. We have already alluded to the fact, that none of the vortices +scarcely ever pass much beyond latitude 80d, and then only under +favorable circumstances, so that we ought to infer, that gales in high +latitudes should set from the poles towards the storms in lower +latitudes. This is, no doubt, the fact, but, nevertheless, a hard +southerly blow _may possibly_ occur in high northern latitudes, if a +storm should be raging very violently in a lower latitude on the +opposite side of the pole, the distance across the circle of 80d being +only about 1,400 miles. As the different vortices have a different limit +in latitude every year, the determination of this turning point is +obviously of great practical utility, as the fact may yet be connected +with other phenomena, so as to give us the probable character of the +polar ice at any assigned time. On this point we have more to say. + + +PASSAGES OF ALL THE VORTICES. + +Our remarks have hitherto been confined to the central vortex. We shall +now show from the record, that the other vortices are as effective in +deranging the equilibrium of our atmosphere. In the following table we +have given the passages of the different vortices, which will serve as +their true positions within moderate limits, to calculate from, for all +future time. + + +PASSAGES OF THE CENTRAL AND LATERAL VORTICES, OBSERVED IN JUNE AND JULY, +1853, IN LATITUDE 41d 20' NORTH. + +I signifying Inner; O, outer; C, central; A, ascending; D, descending. + + ____________________________________________________________________ + | | | | | | | + | Order.|Vortex.| Date. | Meridian |Passage.| Calculated latitude | + | | | | Passage. | | and Remarks. | + |_______|_______|_________|__________|________|______________________| + | | | | | | | + | 1st | I. A. | June 22 | 7 A.M. | south | Centre. About 40d. | + | | | 23 | 8 A.M. | north | Warsaw. Storm. | + | 2d | O. D. | 27 | 0 noon | north | | + | | | 28 | 1 A.M. | south | See record. | + | 3d | C. A. | July 1 | 9 A.M. | south | | + | | | 2 | 10 A.M. | north | Lat. 43d. Storm. | + | 4th | I. D. | 7 | 5 P.M. | north | | + | | | 8 | 6 P.M. | south | Lat. New York. Storm.| + | 5th | C. D. | 12 | 5 P.M. | north | Aurora. | + | | | 13 | 6 P.M. | south | Stormy, very. | + | 6th | O. A. | 14 | 10 A.M. | south | | + | | | 15 | 11 A.M. | north | See Record. | + |_______|_______|_________|__________|________|______________________| + +The intervals between the ascending and descending passages of the +different vortices, are + + Between I. A. and I. D. from 11 to 14 days. + " O. A. " O. D. " 10 " 12 " + " C. A. " C. D. " 9 " 11 " + +and the effect is greatest when the vortex comes to the meridian before +the sun, and least when after the sun; in which case the full effect is +not developed, sometimes until the following day. + +A brief abstract from a journal of the weather for one sidereal period +of the moon, in 1853. + +_June_ 21st. Fine clear morning (S. fresh)[15]: noon very warm 88d; +4 P.M. plumous _cirri in south_; ends clear. + +22d. Hazy morning (S. very fresh) arch of cirrus in west; 2 P.M., black +in W.-N.-W.; 3 P.M., overcast and rainy; 4 P.M., a heavy gust from +south; 4.30 P.M., blowing furiously (S. by W.); 5 P.M., tremendous +squall, uprooting trees and scattering chimneys; 6 P.M., more moderate +(W.) + +23d. Clearing up (N.-W.); 8 A.M., quite clear; 11 A.M., bands of mottled +cirri pointing N.-E. and S.-W.; ends cold (W. N.-W.); the cirri seem to +rotate from left to right, or with the sun. + +24th. Fine clear cool day, begins and ends (N.-W.) + +25th. Clear morning (N.-W, light); 2 P.M. (E.) calm; tufts of tangled +cirri in north intermixed with radiating streaks, all passing eastward; +ends clear. + +26th. Hazy morning (S.-E) cloudy; noon, a heavy windy looking bank in +north (S. fresh), with dense cirrus fringe above on its upper edge; +clear in S. + +27th. Clear, warm, (W.); bank in north; noon bank covered all the +northern sky, and fresh breeze; 10 P.M., a few flashes to the northward. + +28th. Uniform dense cirro-stratus, (S. fresh); noon showers all round; +2 P.M., a heavy squall of wind, with thunder and rain (S.-W. to N.-W.); +8 P.M., a line of heavy cumuli in south; 8.30 P.M., a very bright and +high cumulus in S.-W., protruding through a layer of dark stratus; +8.50 P.M., the cloud bearing E. by S., with three rays of electric +light.[16] + +[Illustration: Fig. 17] + +_June_ 29th. A stationary stratus over all, (S.-W. light); clear at +night, but distant lightning in S. + +30th. Stratus clouds (N.-E. almost calm); 8 A.M., raining gently; +3 P.M., stratus passing off to S; 8 P.M., clear, pleasant. + +_July_ 1st. Fine and clear; 8 A.M., cirrus in sheets, curls, wisps, and +gauzy wreathes, with patches beneath of darker shade, all nearly +motionless; close and warm (N.-E.); a long, low bank of haze in S., with +one large cumulus in S.-W., but very distant. + +_July_ 2d. At 5 A.M., overcast generally with hazy clouds and fog of +prismatic shades, chiefly greenish-yellow; 7 A.M., (S.-S.-E. +freshening,) thick in W; 8 A.M., (S. fresh) much cirrus, thick and +gloomy; 9 A.M., a clap of thunder, and clouds hurrying to N.; a reddish +haze all around; at noon the margin of a line of yellowish-red cumuli +just visible above a gloomy-looking bank of haze in N.-N.-W., (S. very +fresh;) warm, 86d; more cumuli in N.-W.--the whole line of cumuli N. are +separated from the clouds south by a clear space. These clouds are borne +rapidly past the zenith, but never get into the clear space--they seem +to melt or to be turned off N.-E. The cumuli in N. and N.-W., slowly +spreading E. and S.; 3 P.M., the bank hidden by small cumuli; 4 P.M., +very thick in north, magnificent cumuli visible sometimes through the +breaks, and beyond them a dark, watery back-ground, (S. strong); +4.30 P.M., wind round to N.-W. in a severe squall; 5 P.M., heavy rain, +with thunder, &c.--all this time there is a bright sky in the south +visible through the rain 15d high; 7 P.M., clearing, (S.-W. mod.) + +_July_ 3d. Very fine and clear, (N.-W.); noon, a line of large cumuli in +N., and dark lines of stratus below, the cumuli moving eastward; 6 P.M., +their altitude 2d 40'. Velocity 1d per minute; 9 P.M., much lightning in +the bank north.[17] + +_July_ 4th. 6 A.M., a line of small cumulo-stratus, extending east and +west, with a clear horizon north and south 10d high. This band[18] seems +to have been thrown off by the central yesterday, as it moves slowly +south, preserving its parallelism, although the clouds composing it move +eastward. Fine and cool all day--(N.-W. mod.)--Lightning in N. + +_July_ 5th. Cloudy (N. almost calm), thick in E., clear in W.; same all +day. + +6th. Fine and clear (E. light); small cumuli at noon; clear night. + +7th. Warm (S. E. light); cirrus bank N. W.; noon (S.) thickening in N.; +6 P.M., hazy but fine; 8 P.M., lightning in N.; 10 P.M., the lightning +shows a heavy line of cumuli along the northern horizon; calm and very +dark and incessant lightning in N. + +8th. Last night after midnight commencing raining, slowly and steadily, +but leaving a line of lighter sky south; much lightning all night, but +little thunder. + +8th. 6 A.M. Very low scud (500 feet high) driving south, still calm +below, (N. light); 10 A.M., clearing a little; a bank north with cirrus +spreading south; same all day; 9 P.M., wind freshening (N. stormy); +heavy cumuli visible in S.; 10.30 P.M., quite clear, but a dense watery +haze obscuring the stars; 12 P.M., again overcast: much lightning in S. +and N.-W. + +9th. Last night (2 A.M. of 9th) squall from N.-W. very black; 4 A.M., +still raining and blowing hard, the sky a perfect blaze, but very few +flashes reach the ground; 7 A.M., raining hard; 8 A.M. (N.-W. strong); a +constant roll of thunder; noon (N.-E.); 2 P.M. (N.); 4 P.M. clearing; +8 P.M., a line of heavy cumuli in S., but clear in N-W., N., and +N.-E.[19] + + +NEW YORK STORM, JULY 8, 1853. + +"At 5 o'clock Friday afternoon, a terrible storm of rain, hail, and +lightning, rose suddenly from the north-west, and passed over the upper +part of the city and neighborhood. It was quite moderate in the lower +part of the town, and probably scarcely felt on Staten Island. The whole +affair lasted not more than a quarter of an hour, yet the results were +most disastrous, as will be seen by the following accounts from our +reporters: + +"Happening to be in the neighborhood of the Palace about 5 o'clock +Friday evening, we sought shelter under its ample roof from an impending +thunder storm, of very threatening appearance, rapidly approaching from +the west. We had scarcely passed the northern entrance, and reached the +gallery by the nearest flight of steps, when the torrent--it was not +rain, but an avalanche of water--struck the building; the gutters were +filled on the windward side in a moment, and poured over an almost +unbroken sheet of water, which was driven through the Venetian blind +ventilators, into and half way across the north-west gallery, and also +through the upper ventilators, falling upon the main floor of the north +transept. Workmen hastened to close the blinds, but that did not prevent +the deluge. The tinning of the dome being unfinished, the water, of +course, came down in showers all over the centre. Many workmen were +engaged on the dome when the shower struck it; several of them, in their +haste to escape such dangerous proximity to the terrific lightning, came +down single ropes, hand over hand. Large number of workmen were engaged +all over the exterior, and such a scampering will rarely be witnessed +but once in a lifetime. It was found impossible to close a north window, +used for ingress and egress of workmen upon the rod, and the water came +in, in almost solid columns. For a time the water was nearly two inches +deep on the gallery floor, and poured down the stairs in miniature +cascades. + +"A great number of boxes, bales, and packages of goods lay upon the main +floor, among which the water poured down from the edge of the gallery +floor in destructive quantities; Fortunately but few goods were opened, +and were upon the tables, or the damage would have been irreparable. As +it is, we fear some of the goods are injured. In the height of the +storm, the centre portion of the fanlight over the western entrance +burst in, and several single lights were broken, by staging or +otherwise. + +"About ten minutes after the storm burst, the most terrific hailstorm we +ever saw began to rattle, like discharges of musketry, upon the tin roof +and glass sides. Some of the masses of ice were as large as hen's eggs. +There were probably a thousand excited workmen in the building, and a +good many exhibitors and visitors, among whom there were some twenty +ladies, some of whom appeared a good deal alarmed at the awful din. A +portion of the frame-work of the addition next to 42d street, went down +with a terrible crash, and a part of the brick wall of the engine-house +on the opposite side of the street, was blown over, crushing two or +three shanties, fortunately without any other injury than driving the +occupants out into the storm. But an awful scene occurred on the north +side of 43d street, directly opposite the Latting Tower. Here two large +unfinished frame buildings were blown, or rather, we should judge from +appearances, were crushed down into a mass of ruins, such as may be +imagined by supposing a great weight had fallen, with a circular, +grinding motion, upon the first fine fabrics. One of them was partly +sided, and had the rafters up, but no roof; the other was sided and +rooted with tin, and was being plastered. We were told it was three +stories high, 50 by 98 feet. + +"We reached the ruins among the first, after the burst of the storm +subsided a little. The scene was such as we pray God we may never +witness again. A small portion of the roof and upper part of the front +of the building stood or rather partly hung over the side-walk. The +chamber and lower floor of the front rooms lay flat together. The sides +were standing. In the rear all were down. In this building, besides the +workmen, there were numerous laborers who had taken shelter under its +roof when the storm drove them hurriedly from their work. How so many +persons escaped death is truly wonderful. It can only be accounted for +by supposing that they had a moment's warning, and rushed into the +street. The first alarm was from the tearing off a portion of the tin +roof, which was carried high over another building, and fell in the +street. A horse and cart barely escaped being buried under this. It +seems the frame of the other building came down with a deafening crash +at the same time, confusing instead of warning those in danger. At any +rate, before they could escape, they were buried in a mass of timber, +and three of them instantly killed, and four or five dangerously +wounded; and others slightly bruised and badly frightened. Several would +have perished but for timely assistance to extricate them. In this they +were greatly assisted by Jacob Steinant, boss carpenter of the Tower, +who with his men rushed to the rescue, notwithstanding the pouring down +torrents. + +"In Williamsburgh, the storm lasted about fifteen minutes, doing an +incalculable amount of damage to dwellings, foliage, &c. Hailstones came +down in sizes from that of a hickory-nut to a large apple, some with +such force as to drive them through the cloth awnings. + +"The storm passed over Brooklyn lightly, in comparison with the effects +across the Williamsburgh line. On Flushing avenue, beyond the Naval +Hospital, a number of trees were uprooted, and the window-panes of the +houses shattered. On the corner of Fulton and Portland avenues, three +buildings were unroofed, and the walls of the houses were sprung to the +foundation. + +"On Spencer street, a new frame building was levelled with the ground. +Along Myrtle, Classon, and other streets and avenues of East Brooklyn, +many of the shade trees were uprooted, and the windows smashed. In Jay +street, two trees were struck by lightning, but no other damage ensued. + +"Several schooners at the foot of Jay street were forced from their +moorings, but were soon after secured. A small frame house in Spencer +street, just put under roof, was prostrated to the ground. + +"We understand that a large barn filled with hay, situated on the road +between Bushwick and Flushing, was struck by lightning and destroyed +with its contents, embracing several head of live stock."[20] + +_July_ 10th, 3 A.M. Overcast and much lightning in south (N. mod.); +7 A.M., clear except in south; 6 P.M. (E.); 10 P.M., lightning south; +11 P.M., auroral rays long but faint, converging to a point between +Epsilon Virginis and Denebola, in west; low down in west thick with +haze; on the north the rays converged to a point still lower; lightning +still visible in south. This is an aurora in the west. + +11th. Fine clear morning (N.-E.); same all day; no lightning visible +to-night, but a bank of clouds low down in south, 2d high, and streaks +of dark stratus below the upper margin. + +12th. Fine and clear (N.-E.); noon, a well defined arch in S.-W., rising +slowly; the bank yellowish, with prismatic shades of greenish yellow on +its borders. This is the O. A. At 6 P.M., the bank spreading to the +northward. At 9 P.M., thick bank of haze in north, with bright auroral +margin; one heavy pyramid of light passed through Cassiopaea, travelling +_westward_ 1 1/2d per minute. This moves to the other side of the pole, +but not more inclined towards it than is due to prospective, if the +shaft is very long; 11.10 P.M., saw a mass of light more diffuse due +east, reaching to _Markab_, then on the prime vertical. It appears +evident this is seen in profile, as it inclines downwards at an angle of +10d or 12d from the perpendicular. It does not seem very distant. +12 P.M., the aurora still bright, but the brightest part is now west of +the pole, before it was east. + +13th, 6 A.M. Clear, east and north; bank of cirrus in N.-W., _i.e._, +from N.-N.-E. to W. by S.; irregular branches of cirrus clouds, reaching +almost to south-eastern horizon; wind changed (S.-E. fresh); 8 A.M., the +sky a perfect picture; heavy regular shafts of dense cirrus radiating +all around, and diverging from a thick nucleus in north-west, the spaces +between being of clear blue sky. The shafts are rotating from north to +south, the nucleus advancing eastward. + +Appearance of the central vortex descending at 8 A.M., July 13th, 1853: + +In Fig. 18, the circle represents the whole sky from the zenith to the +horizon, yet it can convey but a very faint idea of the regularity and +vividness of this display. The reflected image of the sky was received +from a vessel of turbid water, which will be found better than a mirror, +when the wind will permit. + +[Illustration: Fig. 18] + +At noon (same day) getting thicker (S.-E. very fresh); 6 P.M., moon on +meridian, a prismatic gloom in south, and very thick stratus of all +shades; 9 P.M., very gloomy; wind stronger (S.-E.): 10 P.M., very black +in south, and overcast generally. + +14th. Last night about 12 P.M. commenced raining; 3 A.M., rained +steadily; 7 A.M., same weather; 8.20 A.M., a line of low storm-cloud, or +seud, showing very sharp and white on the dark back ground all along the +southern sky. This line continues until noon about 10d at the highest, +showing the northern boundary of the storm to the southward; 8 P.M., +same bank visible, although in rapid motion eastward; same time clear +overhead, with cirrus fringe pointing north from the bank; much +lightning in south (W. fresh); so ends. + +15th. Last night a black squall from N.-W. passed south without rain; at +3 A.M. clear above, but very black in south (calm below all the time); +9 A.M., the bank in south again throwing off rays of cirri in a +well-defined arch, whose vortex is south: these pass east, but continue +to form and preserve their linear direction to the north; no lightning +in south to-night. + +16th. Clear all day, without a stain, and calm. + +17th. Fine and clear (N.-E. light); 6 P.M., calm. + +18th. Fair and cloudy (N.-E. light); 6 P.M., calm. + +19th. Fine and clear (N. fresh); I. V. visible in S.-W. + +20th. 8 A.M., bank in N.-W. with beautiful cirrus radiations; 10 A.M., +getting thick with dense plates of cream-colored cirrus visible through +the breaks; gloomy looking all day (N.-E. light).[21] + +Appearance of the Inner Vortex at 8 A.M., July 20th, 1853, including the +whole sky. (See Fig. 19.) + +[Illustration: Fig. 19] + +This was a different passage of the Inner Vortex ascending as compared +with the same 28 days before. At that date (June 22) it did great damage +in the central parts of Illinois. Still this last passage was very +palpable--the clouds were very irregularly assorted--plates of cirrus +above and beneath cumulus--various kinds of cirrus clouds, and that +peculiar prismatic haze which is a common sign of the passage of a +vortex. The appearance depicted above is a very common, although a very +evanescent appearance. When the sky appears of a clear blue through the +cirri, there will be generally fresh gales without any great electrical +derangement; but if the clear spaces are hazy, gradually thickening +towards the nucleus, a storm may be expected. Any one who wishes to +understand the indications of the clouds, must watch them closely for +many years, before he can place much reliance upon them. But we shall +again advert to this point. + +We have now passed through one sidereal period of the moon. We might +continue the record, but it would be tedious. The passages of these +vortices vary in violence at different times, as we might expect; but +they never cease to circulate, and never will as long as the moon +remains a satellite to the earth; and if we take the passage of any of +these vortices, and add thereto the time of one sidereal period of the +moon, we get approximately the time of the next passage. When the +elements of the lunar orbit tend to accelerate the passages, they may +come in 26 days; and when to retard, in 28 days; and these are about the +limits of the theory. + +Having begun and ended this record of the weather with the passage of +the Inner vortex ascending, it may not be amiss to notice one more, (the +August passage,) as it offers a peculiarity not often so distinctly +marked. We have alluded to the greater force of the storms when the +passage of the vortex corresponds to the passage of the line of low +barometer or the depression point of a great atmospheric wave, which is +also due to the action of the ether. In consequence of these waves +passing from west to east, the storm will only be violent when formed a +little to the westward. If the storm forms to the eastward, we neither +see it nor feel it, as it requires time to develop its strength, and +always in this latitude travels eastward; so that storms may generally +be said to come from the west, although the exciting cause travels from +east to west. In the case now alluded to, the weather indicated a high +barometer, and the storm formed immediately to the eastward, even +showing a distinct circular outline. We subjoin a description. + +_August_ 15th. Clear morning (N.-E.), a bank of cumuli in south: noon +quite cloudy in S. and clear in north. (N.-E.) + +16th. Clear morning (N.-E.); 3 P.M., getting very black in E. and S.-E., +very _clear_ to the _westward_; 4 P.M., much thunder and lightning in +east, and evidently raining hard; 5 P.M., a violent squall from _east_ +for 10 minutes; tore up several trees; 6 P.M., the storm passing +eastward, clear in west all this time; 6.30 P.M., the storm forming a +regular arch, the vertex being in _S.-E._; the arch of hazy cirrus and +heavy cumulus much lower in S.-E., wind still moderate from east; +10 P.M., clear all around, but lightning in S.-E. and E. + +17th. Fine clear morning (W.); noon, scattered cumuli in north; 6 P.M., +a beautifully regular arch of dense cumuli and cirrus margin in _N.-E._, +with a constant glimmer of lightning; 7 P.M., very clear to the west, +and north-west, and south; along the northern horizon a line of high +peaked cumuli terminating in N.-N.-W.; a continued roll of distant +thunder in the circular bank in N.-E., and not a moment's cessation to +the lightning; the electric excitement advancing westward along the +lines of cumuli; the cirrus haze also rising and passing towards S.-W.; +8 P.M., the sky alive with lightning, the cirrus now reaches the zenith; +no streaks of lightning coming to the earth; they seem to radiate from +the heaviest mass of cumuli, and spread slowly (sufficiently so to +follow them) in innumerable fibres over the cloudy cirrus portion of the +sky; every flash seems to originate in the same cloud; 8.30 P.M., one +branching flash covered the whole north-eastern half of the sky, no +leafless tree of the forest could show so many branches; 9.30 P.M., all +passed to S.-W. without rain, leaving behind a large cumulus, as if it +lagged behind. From this cumulus a straight line of lightning shot up +10d above the cloud into a perfectly clear sky, and terminated abruptly +without branching. + +We have been thus particular in giving these details, as this was a +clear case confirming the principles advanced, that the vortices do not +form a continuous line of disturbance, in their daily passage around the +earth. It shows also that the barometer, in connection with these +principles, will be a far more useful instrument than it has yet proved +itself, for practical service as an indicator of the weather. + + +FOOTNOTES: + +[10] For convenience to those wishing to verify the calculation of these +triangles, we have put down each side and angle as found. Also, as an +aid to the navigator. + +[11] Daily Wisconsin, July 7. + +[12] The author. + +[13] Chicago Democrat. + +[14] This was also calculated before the event. + +[15] The letters in a parenthesis signify the direction of the wind. + +[16] Giving this cloud the average velocity of thirty miles per hour, +its altitude was determined by the sextant at twelve miles, and we think +under-estimated. While measuring, the author's attention was drawn to +the fact, that although it appeared equally dense above and below, yet +its middle part was the brightest, and as there was only a faint glimmer +of twilight in the N.-W., he concluded that the cloud was self-luminous; +for when the smallest stars were visible, it glowed about as bright as +the milky-way in Sagittarius. Occasionally the whole cloud was lit up +internally by the lightning, and about this time it sent off three rays: +one horizontally, westward, which was the faintest; one about N.-W., +towards Jupiter, and the brightest of the three; and another towards the +north. These were not cirrus streaks, but veritable streams of electric +matter, and had a very decided rotation from left to right, and +continued visible about twenty minutes, as represented above. + +[17] This day the central vortex passed in about latitude 47d N.--the +southern margin cannot be nearer than 250 miles, throwing off the 40' +for the horizontal refraction, would give eight miles of altitude above +a tangential plane. Then another seven miles, for curvature, will give +an altitude of fifteen miles for the cumuli. The height of these +thunder-clouds has been much under-estimated. They seem to rise in +unbroken folds to a height of ten and twelve miles frequently; from the +data afforded by the theory, we believe they will be found much higher +sometimes--even as much as sixteen miles. + +[18] These parallel bands, and bands lying east and west, are frequent +in fine weather between two vortices. Sailors consider them a sign of +settled weather. After dark there was frequently seen along the northern +horizon flashes of lightning in a perfectly clear sky. But they were +both faint and low, not reaching more than 4d or 5d above the horizon. +After sunset there were very distinct rays proceeding from the sun, but +they were shorter than on the evening of the 3d. These are caused by the +tops of the great cumuli of the storm, when sunk below the horizon, +intercepting the sun's rays, which still shine on the upper atmosphere. +The gradation was very marked, and accorded with the different distances +of the central vortex on the 3d and 4th--although, on the 4th, the +nearest distance must have been over four hundred miles to the southern +boundary of the storm. + +[19] It is worthy of notice here, that New York, which only differs by +about 40 miles of latitude and 800 in longitude, had the storm earlier, +near the time of the passage, as appears by the appended account of it. +This proves, that a storm affects a particular latitude simultaneously, +or approximately so. If this had to travel eastward to reach New York, +it would have been the 10th instead of the 8th. The principal trouble +was, however, in the early part of the evening of the 8th, to the south +of Ottawa, where the strong wind was drawn in from the northward. If a +vortex passes from north to south, leaving the observer between the +passages, there must, nearly always, be a winding up squall from the +north to clear away the vapory atmosphere. + +[20] From the _New York Tribune_, July 9, 1853. + +[21] These pages are now in the compositors' hands, (Nov. 21st,) and up +to the last moment the Author has observed carefully in New York the +passages of these vortices. October 24th, in the inner vortex descending +produced a violent storm on the coast, and much damage ensued. November +7th, the same vortex ascending was also severe. And on November 13th, +early, the passage of the central vortex ascending, caused a flood in +Connecticut of a very disastrous nature. Would it not pay the insurance +offices to patronize such investigations in view of such palpable facts +as these? + + + + +SECTION THIRD. + + +OBJECTIONS TO LUNAR INFLUENCE. + +We have now presented a theory of the weather, which accounts for many +prominent phenomena, a few of which we shall enumerate. It is an +observed fact, that in all great storms electrical action is more or +less violent, and that without this element it seems impossible to +explain the velocity of the wind in the tornado, its limited track, and +the formation of large masses of ice or hail in the upper regions of the +atmosphere. It is also an observed fact, that the barometer is in +continued motion, which can only be legitimately referred to a change in +the weight of the atmospheric column. This we have explained as due to +atmospheric waves, caused by the greater velocity of rotation of the +external ether, as well as to the action of the three great vortices. +These causes, however, only partially produce the effect--the greater +portion of the daily oscillations is produced by the action of the great +radial stream of the solar vortex, as we shall presently explain. It is +an observed fact, that, although the storm is frequently violent, +according to the depression of the barometer, it is not always so. +According to the theory, the storm will be violent, _ceteris paribus_, +on a line of low barometer, but may still be violent, when the contrary +obtains. Another fact is the disturbance of the magnetic needle during a +storm. Storms are also preceded generally by a rise in the thermometer, +and succeeded by a fall; also by a fall in the barometer, and succeded +by a rise. It is also well known, that hurricanes are unknown at the +equator, and probably at the poles also. At all events, they are rare in +lat. 80d, and, according to Capt. Scoresby, storms are there frequently +raging to the south, while above, there is clear sky and fine weather, +with a stiff breeze from the northward. The greater violence of storms +in those regions where the magnetic intensity is greater in the same +latitude, the probable connection of peculiarities in the electric state +of the atmosphere with earthquakes, and the indications of the latter +afforded by the magnet; the preponderance of westerly winds at a great +elevation in every latitude on the globe visited by man; and the +frequent superposition of warm layers of air above cold ones at those +elevations, are all facts worthy of note. And the connection of cirrus +clouds with storms, as well as with the aurora, indicates that the +producing cause is external to the atmosphere, and gradually penetrates +below. The theory fully explains this, and is confirmed by the fantastic +wreathings and rapid formation of these clouds in straight lines of a +hundred miles and upwards. But time would fail us in pointing out a +tithe of the phenomena, traceable to the same cause, which keeps our +atmosphere in a perpetual state of change, and we shall only advert to +one more peculiarity of the theory. It places meteorology on a +mathematical basis, and explains why it is that a storm may be raging at +one place, while in another, not very remote, the weather may be fine, +and yet be dependent on the position of the moon. + +That the moon has exerted an influence on the weather has been the +popular creed from time immemorial; but, ignorant of the mode in which +this influence was exerted, men have often been found who have fostered +the popular belief for their own vanity or advantage; and, on the other +hand, philosophers have assailed it more by ridicule than by argument, +as a relic of a barbarian age. Not so with all; for we believe we are +not wrong in stating, that the celebrated Olbers compared the moon's +positions with the weather for fifty years, before he gave his verdict +against it. He found the average amount of rain at the perigee about +equal to the amount at the apogee, as much at the full as at the change, +and no difference at the quadratures. But this fact does not throw a +feather in the scale by which this theory is weighed. Popular opinions, +of remote origin, have almost always some foundation in fact, and it is +not much more wise to reject them, than to receive them. The Baron Von +Humboldt--a man possessing that rare ingredient of learning, a practical +common sense--observes: "That arrogant spirit of incredulity which +rejects facts, without attempting to investigate them, is, in some +cases, more injurious than an unquestioning credulity."[22] If a popular +belief or prejudice be absurd, its traditional preservation for a +thousand years or more may very well account for the absurdity. + +The present system of astronomy still retains the motley garniture of +the celestial sphere, as handed down from the most remote antiquity; and +granting that ages of ignorance and superstition have involved the +history of the different constellations in a chaos of contradictory +traditions, there is no doubt at the foundation some seeds of truth +which may even yet emerge from the rubbish of fable, and bear fruit most +precious. That the zodial[23] signs are significant records of something +worthy of being preserved, is prejudice to deny; and we must be allowed +to regard the Gorgons and Hydras of the skies as interesting problems +yet unsolved, as well as to consider that the belief in lunar influence +is a fragment of a true system of natural philosophy which has become +more and more debased in postdiluvian times. Amongst those who have not +summarily ignored the influence of the moon, is Toaldo, a Spanish +physicist, who endeavored to show the connection between the recurrence +of warm and cold seasons, and the semi-revolution of the lunar nodes and +apogee, and proposed six of those periods, or about fifty-four years, as +the cycle in which the changes of the weather would run through their +course. According to the present theory, it is not likely such a cycle +will ever be discovered. There are too many secular, as well as periodic +influences combining, to produce the effect; and the times are too +incommensurable. Lately, Mr. Glaisher has presented a paper to the Royal +Society, giving about fourteen years from observation. Others have +lately attempted to connect the changes of the seasons with the solar +spots, as well as with the variations of the magnetism of the earth, but +without any marked result. + +It may, however, be urged, that if the sidereal period of the moon be +approximately a cycle of change, it would have been detected long ago. +One reason why this has been so long concealed, is the high latitude of +the observers. Spain, Italy, and Turkey, are better situated than other +European countries; but the scientific nations lie further north; and +from these the law has gone forth to regulate more southern lands. In +the United States, particularly in the great plains of the west, the +weather can be better compared; not only on account of the latitude +being more favorable, but also on account of the greater magnetic +intensity of the western hemisphere. + +It must also be remembered that there are in latitude 40d, five or six +distinct passages of the disturbing cause in one sidereal period of the +moon. If two of these periods are drawn closer together by the change of +the elements, the interval between two others must necessarily be +increased. Besides, the effect produced is not always the same, for +reasons already adverted to. One vortex may be more violent one month, +or for a few days in one month, while another may be more active the +next. It may also happen that for several successive passages, the +passage shall be central in one latitude, while two or three degrees +north or south, another place shall be passed by. In different months +and in different years, as well as in different seasons of the year, the +energy of the ether may be augmented or diminished. But it may be said, +that, supposing the theory true, if its indications are so uncertain, it +is of little value. By no means. It is true there are many things to be +inquired into; but it is a great thing in this science to be able to +take the first step in the right direction,--to find even the _key_ of +the portal. It is a great stride to be able to say, a storm may happen +at such a time, but cannot happen at another; that a storm, when raging, +will go in this direction, rather than in that; that it will be central +here, and less violent yonder; and when we consider its bearing on +astronomical and other science, it is difficult to exaggerate its value +to the world at large. + +Again, it may be said that rain, and cloudy days, and fresh breezes, and +even strong winds, sometimes occur, when the vortices do not pass +centrally. This is true; yet only indicating that where the vortices are +central, an unusual disturbance is taking place. But there is another +cause, which was purposely omitted in considering the prominent features +of the theory, in order not to encumber the question with secondary +influences. By referring to Fig. 3, section 1, we see that the lateral +vortices of the globe are continually passing off to the southward, in +the northern hemisphere, in a succession of dimples, and continually +reforming. We will now represent this mode of action in profile, as it +actually occurs in the illustration we have used. + +The vortex passing off from O, (Fig. 20,) although it does not actually +reach the surface of the atmosphere, affects the equilibrium of the +ether, and, for a short distance from the parent vortex, may cause an +ascensional movement of the air. If to this is conjoined a northerly +wind from the vortex, a band of clouds will be produced, and perhaps +rain; but violent storms never occur in the intervals, except as a +steady gale, caused by the violence of a distant storm. Thus, it will +frequently be noticed that these vortices are flanked by bands of +clouds, which pass southward, although the individual clouds may be +moving eastward. Hence, instead of disproving the theory, they offer +strong evidence of its truth; and could we view the earth from the moon +with a telescope, we should no doubt see her beautifully belted. + +[Illustration: Fig. 20] + +But it may be again asked, why should not the weather be the same +generally, in the same latitude, if this theory be true? If the earth +were a globe of level land, or altogether of water, no doubt it would be +similar; but it must be remembered, that both land and water are very +unequally distributed: that the land is of varying extent and +elevation--here a vast plain, far removed from the ocean, and there a +mountain chain, interposing a barrier to the free course of the +atmospheric currents; sometimes penetrating in full width into the +frigid zone, and again dwindling to a few miles under the equator. One +very important distinction is also to be remarked, in the superficial +area of the different zones, reckoning from the equator, and taking the +hemisphere as 100 parts: + + Frigid zone 8 parts. + Temperate " 52 " + Torrid " 40 " + +For as the time of rotation in every latitude is the same, the area to +be disturbed in the same time, is less in high latitudes, and there a +greater similarity will obtain, _ceteris paribus_. In lower latitudes, +where both land and water stretch away for thousands of miles, it is not +wonderful that great differences should exist in the electrical and +hygrometric state of the air. + +The summer of many countries is always dry--California for instance. In +winter, in the same country, the rains are apparently incessant. This of +course depends on the power of the sun, in diverting the great annual +currents of the atmosphere. As long as the dry north-west trade sets +down the coast of California, the circumstances are not favorable for +giving full development to the action of the vortices. When the trade +wind ceases, and the prevailing winds come from the south, loaded with +vapor, the vortices produce storms of any magnitude; but (and we speak +from two years' observation) the passages of the vortices are as +distinctly marked there in winter time, as they are in the eastern +States; and in summer time, also, they are very perceptible. The same +remark applies to Mediterranean countries, particularly to Syria and +Asia Minor; although the author's opportunity for observing lasted only +from April to December, during one season. If we are told it never rains +on the coast of Peru, or in Upper Egypt, it does not seriously militate +against the theory. The cause is local, and the Samiel and the sand +storm of the desert, is but another phase of the question, explicable on +the same general principles. From the preceding remarks it will be seen, +that in order to foretell the character of particular days, a previous +knowledge of the weather at that particular place, and for some +considerable time, is requisite; and hence the difficulty of laying down +general rules, until the theory is more fully understood. + + +MODIFYING CAUSES. + +We now come to the causes which are auxiliary and interfering. It is +natural that we should regard the sun as the first and most influential +of these causes, as being the source of that variation in the +temperature of the globe, which alternately clothes the colder regions +in snow and verdure. The heat of the sun undoubtedly causes the ether of +the lower atmosphere to ascend, not by diminution of its specific +gravity; for it has no ponderosity; but precisely by increase of +tension, due to increase of motion. This aids the ascensional movement +of the air, and therefore, when a vortex is in conjunction with the sun, +its action is increased--the greatest effect being produced when the +vortex comes to the meridian a little before the sun. This has a +tendency to make the period of action to appear dependent on the phases +of the moon, which being the most palpable of all the moon's variations, +has been naturally regarded by mankind as the true _cause_ of the +changes of the weather. Thus Virgil in his Georgics, speaking of the +moon's influence and its signs: + + "Sin ortu in quarto (Namque is certissimus auctor) + Pura, nec obtusis per coelum cornibus ibit; + Totus et ille dies, et qui nascentur ab illo, + Exactum ad mensem, pluvia ventisque carebunt." + +Hence, also, in the present day we hear sailors speak of the full and +change, or the quartering of the moon, in connection with a gale at sea; +thus showing, at least, their faith in the influence of the phenomenon. +Yet it is actually the case, at certain times, that in about latitude +40d and 41d, the storms appear about a week apart. + +There is some reason, also, to suspect, that there is a difference of +temperature on opposite sides of the sun. As the synodical rotation is +nearly identical with the siderent period of the moon, this would +require about forty-four years to run its course, so as to bring the +phenomena to exact coincidence again. Since these observations were +made, it is understood that Sig. Secchi has determined that the +equatorial regions of the sun are hotter than his polar regions. It may +be owing to this fact, that we have inferred a necessity for a change, +whose period is a multiple of the sun's synodical rotation, but it is +worthy of examination by those who possess the necessary conveniences. + +Another period which must influence the character of different years, +depends on the conjunction of the perigee of the lunar orbit with the +node. Taking the mean direct motion of the moon's perigee, and the mean +retrograde motion of the node, we find that it takes six years and one +day nearly from conjunction to conjunction. Now, from the principles +laid down, it follows, that when the perigee of the orbit is due north, +and the ascending node in Aries, that the vortices of the earth will +attain their greatest north latitude; and when these conditions are +reversed, the vortices will reach their highest limit in the lowest +latitude. This will materially affect the temperature of the polar +regions. In the following table, we have calculated the times of the +conjunctions of the apogee and pole of the orbit, taking the mean +motions. It may be convenient to refer to by-and-bye, remembering that +when the conjunction takes place due south, the vortices reach the +highest, but when due north, the vortices in the northern hemisphere +have their lowest upper limit: + + CONJUNCTION OF APOGEE AND POLE OF ORBIT.[24] + + Year. Month and Day. Longitude. + 1804, April 18th, 220d + 1810, " 17th, 104 + 1816, " 16th, 348d + 1822, " 15th, 232 + 1828, " 14th, 116 + 1834, " 12th, 360 + 1840, " 11th, 244 + 1846, " 10th, 128 + 1852, " 9th, 12 + 1858, " 8th, 255 + 1864, " 7th, 139 + 1870, " 6th, 23 + 1876, " 5th, 267 + +By this we see that the vortices have never attained their highest limit +during the present century, but that in 1858 their range will be in a +tolerable high latitude, and still higher in 1876--neglecting the +eccentricity of the orbit. + +A very potent influence is also due to the heliocentric longitude of the +sun, in determining the character of any given year. Let us explain: + +The moon's inertia forces the earth from the mechanical centre of the +terral system, but is never able to force her clear from the central +axis. With the sun it is different. He possesses many satellites +(planets). Jupiter alone, from his great mass and distance, is able to +displace the whole body of the sun. If other planets conspire at the +same side, the centre of the sun may be displaced a million of miles +from the mechanical centre of the solar system. Considering this centre, +therefore, as the centre of an imaginary sun, from which heliocentric +longitudes are reckoned, the longitude of the real sun will vary with +the positions of the great planets of the system. Now, although this +_systematic_ longitude will not be exactly similar to the heliocentric +longitude reckoned from the sun's centre, yet, for the purposes +intended, it will correspond sufficiently, and we shall speak of the +longitude of the sun as if we reckoned heliocentric longitudes from the +mechanical centre of the system. When we come to consider the solar +spots, we shall enter into this more fully. In the following diagram we +shall be able to perceive a cause for variation of seasons in a given +year, as well as for the general character of that year. + +[Illustration: Fig. 21] + +Let S represent the centre of the sun, and the circle a vertical section +of the sun, cutting; through the centre,--SJ being in the equatorial +plane of the vortex, of which ZZ' represents the axis. As the ether +descends the poles or axis at Z, it is met by the current down the +opposite pole, and is thence deflected in radii along the equatorial +plane to J. But on the side S, the ether is opposed by the body of the +sun; its direction is consequently changed, and cross currents are +produced, assuming it as a principle, that the ethereal fluid is +permeable by other currents of similar matter, and that it tends always +to move in right lines. This granted, it is evident that, in passing the +sun, the quick moving ether forms a conical shell, (the sun being at the +apex,) so that the strongest current of ether is in this conical shell, +or at the surface of this conical space. As the plane of the ecliptic is +not much inclined to the sun's equator, and this last probably not much +inclined to the plane of the vortex, should the earth have the same +_heliocentric_ longitude at the time, (or nearly the same,) she would +be in an eddy, as respects the radial stream, and be protected from its +full force by the body of the sun. + +Now, the ether comes down the axis with the temperature of space, and +may possibly derive a _little_ additional temperature in passing over +the body of the sun; so that in this position the earth is protected +from the chilling influence of the radial stream, by being protected by +the body of the sun. And although, from the immense velocity of the +ether, it cannot derive much additional temperature, there may still be +an appreciable difference, due to this cause. + +It is the chilling influence of the ethereal stream which originated the +idea among philosophers, of _frigorific impressions, darted from a clear +sky_. In some years the sun will be nearly in the centre of the system; +in other years the axis of the vortex will not come near the sun. And as +the sun's longitude may vary through the entire circle, it may happen +that the earth's longitude shall coincide in winter or summer, or spring +or autumn. When, however, the earth emerges from the protection of the +sun, and enters the conical shell, considered as a space of considerable +depth, she will again be exposed to the full force of the radial stream, +rendered more active by the previous deflection, and by the numerous +cross currents pervading it; so that a mild and calm winter may be +succeeded by a cold and stormy spring. The present season, (1853) the +earth's longitude coincided with the sun's longitude in about 135d, and +consequently was in the conical space spoken of, during February and +March; but the radius vector of the sun's centre, being then less +than 300,000 miles, the protection was not as complete as it is +sometimes. Still, the general fineness of these months was remarkable; +yet in April and May, when the earth became again exposed to the action +of the solar stream, the effect was to retard the spring, and disappoint +the prognostications of the weather-wise. In applying these principles, +we must consider the effect in those latitudes which are more readily +affected,--that is, in the temperate zone, midway between the two +extreme zones of heat and cold. + +In 1837 and 1838, the longitude of the sun's centre corresponded with +the earth's, in August and September, when there was neither rain nor +electrical excitement; and consequently those seasons were sickly over +the whole country. Now, there is another cause which renders the months +of August, September, and October, deficient in electrical energy, and +consequently more prone to be sickly. If, therefore, the two causes +unite their influence, the autumnal months will be more sickly at those +times. This last cause, however, only affects the _northern latitudes_ +in autumn, and consequently, _ceteris paribus_, the autumnal months +should not be so proverbially sickly in the southern hemisphere. This +is, however, only suggestive. + +Again, in 1843, the winter was very mild in January and February; but in +March it turned cold and stormy, and continued through April. In this +year the longitude of the sun was nearly the same as in 1853,--the two +longitudes of the earth and sun corresponding about the last of January; +but in March, the earth forsook the comparative calm produced by the +sun's position, and hence the greater cold.[25] + +Thus it appears at every step we take, that the different members of the +solar system do indeed belong to the same family, whose least motions +have their influence on the rest. Who could have anticipated that the +position of Jupiter in his orbit had anything to do with the health of +this remote planet, or with the mildness of its seasons? In this we have +a clue to the origin of that astrological jargon about planetary aspects +being propitious or malign. Philosophers are even yet too prone to wrap +themselves in their mantle of academic lore, and despise the knowledge +of the ancients, while there is reason to believe that the world once +possessed a true insight into the structure of the solar system. As war +became the occupation of mankind, under the despotic rule of ambition, +so truth retired, and ignorance seizing upon her treasures, has so +mutilated and defaced them, that their original beauty no longer +appears. Let us hope that the dawn of a better day is approaching. + +There is yet another cause (just alluded to) which modifies the action +of the vortices. + +We have shown that, if the periodic times of the planets are +approximately equal to the periodic times of the contiguous parts of the +solar vortex, the density of the ether is directly as the square roots +of the distances from the centre. As the earth is at her perihelion +about the first of January, the density of the surrounding ether is then +less than in other parts of the orbit; consequently, if we suppose that +there is a continual tendency to equilibrium, the ether of space must +press inwards, during the time between the perihelion and aphelion, +(_i.e._ from January to July,) lowering the temperature and increasing +the electrical action of those months. As the distance from the sun is +most rapidly augmenting about the first of April, and the effective +power of the sun's radiation is most rapidly increasing in May; by +combining the two we shall find, that about the first of May we shall +have considerable electrical action, and cold weather. This explains +also, in part, the prevalent tradition of certain days in May being very +cold.[26] When the earth leaves the aphelion, a reaction takes place, +being most rapid in September. There is then an _escape_ of ether from +the earth, which keeps up the temperature, and causes these months to be +sickly, from the negative electrical state of the atmosphere. In the +southern hemisphere, the effects in the same season will be reversed, +which may partly account for the greater degree of cold in that +hemisphere, and for accelerating the approach of both summer and winter, +while in the north they were both retarded. + +We must now advert to another cause, which of all others is probably the +most important, at least to the other members of the solar system. + +In every part of the solar vortex the ether is continually pressing +outwards. We are not now speaking of the radial stream, but of the +slower spiral motion of the ether around the axis of the vortex, whose +centrifugal force is bearing the whole body of the ether outwards, thus +rarefying the central parts, and thus giving rise to the polar influx, +from which arises the radial stream. This may be made more intelligible, +by reflecting that the polar current is comparatively dense ether, and +that the length of the axis of the vortex prevents this influx current +coming in sufficient quantities to restore an equilibrium in the density +of the medium. Yet, what does come down the poles, is distributed +rapidly along the equatorial plane, leaving the space still rarefied. +Now we perceive, that in order for the radial stream to continue in +action, requires the whole medium of the vortex to be also moving +outward; it is therefore continually condensed as it proceeds. This +condensation necessarily converts much of the specific heat of the ether +into sensible heat; so that the _temperature_ of the medium is +continually increasing, as the distance from the sun increases. + +When we contemplate the solar system as the emanation of one Great Mind, +we naturally seek for evidence of the wisdom of a supreme intelligence +in _all_ the arrangements of that system. But, however humbly and +reverently we may speak of these arrangements, we can scarcely avoid the +wish, that the planetary distances had been differently arranged, if +Newton's doctrine be true, that space is a vacuum, and that the heat of +a planet, is inversely as the squares of the distances from the sun. +For, to speak of the temperature of space, except as dependent on this +law, is one of those many incomprehensible inconsistencies with which +philosophers are chargeable. If the Newtonian philosophy is literally +true, space has _no temperature_, and the surface heat of the planet +Neptune is nearly 1,000 times less than on our own globe. Again, on +Mercury it is seven times greater, which heat would scorch and consume +every organic substance on the earth, and speedily envelope the boiling +ocean in a shroud of impermeable vapor. Granting even that space may not +be a vacuum, and yet the law of gravitation be true, we may still be +allowed to consider both Saturn and Uranus and Neptune, as inhospitable +abodes for intelligent creatures; and, seeing the immensity of room in +the system, there is no reason why these planets might not have been +permitted to revolve nearer the great source of light and life and +cheering emanations. To suggest the resources of Omnipotence is no +argument. He has surrounded us with analogies which are seen, by which +we may attain a knowledge of those which are not seen; and we have every +reason to suppose that the great Author of nature is not indifferent to +the aspects under which his works reveal him unto his creatures. Yet +there is (on the above hypothesis) an apparent want of harmony in the +planetary distances; and if frail mortality may be permitted to speak +out, an explanation is needed to obviate this seeming anomaly in the +economy of the world. The more we learn of the physical arrangements of +the universe, the more do they correspond with our experience of the +nice adaptation of the means to the end which obtains in our own globe, +and we can only judge of other planets by the analogies around us. Here, +there, are extremes of temperature it is true: it is necessary there +should be, and we can see and understand the necessity in all such +cases, and how they conduce to the general average of good. But, +astronomers can give no reason why it is necessary that some planets of +our system should be placed so remote that the sun is frittered down to +a star, whose heatless light is but a mockery to those frigid realms. + +Now, according to this theory, the temperature of Neptune may be far +more uniform and conducive to life than that of our own globe. The +chilling influence of the solar stream at that planet being nearly null, +and the temperature of the surrounding space far greater. So also +Mercury, instead of being the burning planet of the schools, may suffer +the most from cold. + +The planet Mars is generally considered, of all the members of the +system, most nearly to resemble our own world. The telescope not only +reveals seas and continents, but the snowy circles round his poles, +which appear to increase and diminish, as his winter is beginning or +ending. This planet's ecliptic is similar to our own in inclination or +obliquity, his distance, also, is far greater, and his winter longer; +yet, for all this, his snow zones are less than on our own globe. This +anomalous fact has, we believe, never been noticed before; but it is +explicable on the theory, and therefore confirms it. Mars has no +satellite, and therefore his centre will be coincident with the centre +of the marsial vortex. There will be no _lateral vortices_ to derange +his atmosphere, and if the axis of his vortex coincides also with the +axis of the planet, the central vortex will be continually over the +poles, _and there will be no storms on the planet Mars_. A capital fact +connected with this, is the want of belts, as in Jupiter and Saturn; for +these planets have satellites, and if _they_ are not massive enough, the +belts may be produced by an obliquity in the axis of the Jovial and +Saturnial vortices. If Mars had an aurora like the earth, it is fair to +presume the telescope would ere this have shown it. He is, therefore, in +equilibrium. In applying this reasoning to the earth, we perceive that a +certain influence is due to the difference of temperature of the +ethereal medium surrounding the earth, at perihelion and aphelion, being +least at the former, and greatest at the latter. + +As a modifying and interfering cause in the action of the vortices, we +must mention the great natural currents of the atmosphere, due to the +earth's rotation. + +It is considered that the sun is the principal cause of these great +currents. By elevating the surface atmosphere of the equator, a lateral +current is induced from the north and south; but on account of the +enlarging circles of latitude, their direction tends more from the +north-east and south-east. These currents are usually called the trades. +Without disputing the correctness of this, it may be doubted whether the +whole effect is due to the sun. As this principle affects the ocean +likewise, it is necessary to look into it; and in order to simplify the +question, we will first suppose our globe covered entirely by the ocean, +without any protuberant land. + +Let us assign a uniform depth of ten miles to this ocean. In the Fig. +following, the two circles will represent the surface and bottom of the +ocean respectively. The axis of rotation is thus represented by the line +PP'. Let us consider two particles of water at m and n, as feeling the +influence of this rotation; they will, of course, be both urged towards +the equator by the axifugal force. Now, every particle in the ocean +being also urged by the same force, it might be supposed that after a +protuberant mass of water had accumulated at the equator EE', the whole +ocean would be in equilibrium. This would not follow. The particle at m +is urged by a greater force than n; consequently the particle at n is +overborne by the pressure at m. Considering both in the same direction, +yet the particle at n must give way, and move in the opposite direction. +Just as the heaviest scale of the balance bears up the lightest, +although both gravitate towards the same point. This is so self-evident +that it would seem unnecessary to dwell upon it, had not the scientific +world decided that the rotation of the earth can cause no currents +either in the atmosphere or in the ocean. + +[Illustration: Fig. 22] + +The axifugal forces of the two particles m and n are directly as the +lines Mm and Nn, and if the gravitating forces were also as the radii Tm +and Tn, no motion would be produced. Admitting even the Newtonian law to +be rigidly exact, the earth cannot be considered a homogeneous globe, +but, on the contrary, the density of the central parts must be nearly +thirty times greater than the density of the surface of the ocean. The +ratio of the gravitating forces of these two particles is, therefore, +less than the ratio of their respective radii, and the axifugal tendency +of the particle at n is more than proportionally restrained by the +central gravitation; and hence m will move towards the equator, and n +towards the poles, as represented in the Fig. + +It is on account of the overwhelming momentum of the surface waters of +the South Pacific over the North, that the Pacific, at Panama, stands +six or seven feet higher than the Atlantic. We shall again allude to +this interesting fact. + +According to newspaper reports of a lecture, delivered in New York, by +Lieut. Maury, U. S. N., this gentleman endeavors to explain the currents +of the ocean, by referring them to evaporation in the tropics. The vapor +leaves the salt of the water behind, and thus, by continual +accumulation, the specific gravity of the tropical waters is greater +than that of the superficial waters nearer the poles; the lighter +water, therefore, passes towards the equator, and the heavier water +below, towards the poles. If this be a correct statement of that +gentleman's theory, fidelity to our standards compels us to question the +soundness of the conclusion. The mere fact of the surface water of the +ocean being lighter than that of the bottom, cannot on any known +principles of science cause any movement of the surface waters towards +the equator. When such an acute and practical physicist is driven, by +the palpability of the fact that the polar waters are continually +tending towards the equator, to seek the cause in the tropical +evaporation, it shows that the dogma, which teaches that rotation can +produce no motion, is unsound. + +Sir John Herschel, in speaking of the solar spots, says: "We may also +observe that the tranquillity of the sun's polar, as compared with his +equatorial regions (if his spots be really atmospheric), cannot be +accounted for by its rotation on its axis only, but must arise from some +cause external to the sun, as we see the belts of Jupiter and Saturn and +our trade winds arise from a cause external to these planets combining +itself with their rotations, which _alone_ (and he lays an emphasis on +the word) can produce no motions when once the form of equilibrium is +attained." + +With respect to the origin of the solar spots, we have no disposition to +question the conclusion; but, as regards the _principle_ laid down, that +rotation can produce no motions when once the form of equilibrium is +attained, we must unequivocally dispute it. If our atmosphere were of +uniform density, the rotation of the earth would cause no current such +as we have described; with our atmosphere as it is, the result will be +different. The momenta of two portions of matter are the products of +their inertiae by their motions, and, in the present case, we must take +the inertiae of equal spaces. A cubic inch of air at the surface, and at +three miles above the surface, is as 2 to 1; but their centrifugal +velocity varies only as the radii of the respective spheres, or as 1320 +to 1321. In the polar regions, therefore, the momentum of the surface +air preponderates, and, in this case, the _surface_ current is towards +the equator, and the upper current towards the poles. When, however, the +centrifugal velocity is considerably increased in a lower latitude, and +the curvature of the surface becomes more and more inclined to the +direction of that resolved part of the centrifugal force, which is +always _from_ the axis, the surface layers will evince a tendency to +leave the surface, and an intermingling will then take place in the +space between latitude 70d and 50d, or in latitude 60d. As this layer is +continually urged on in the same direction by the surface layer of +latitudes above 60d, the upper layer now becomes a current setting +_towards_ the equator, and, consequently, the back current occupies the +surface. Now, considering that the rarefying action of the sun is +elevating the air under the equator, there must necessarily be an upper +current from the equator to the poles; so that if we conceive the two +currents to meet about latitude 30d, there will be a second +intermingling, and the current from the poles will again occupy the +surface. Thus, we regard a part of the effect of the trades to the +rotation of the earth, which is the chief impelling power at the poles, +as the sun is at the equator; and the latitudes 60d and 30d will be +marked by some especial phenomena of temperature, and other +meteorological features which do actually obtain. These would be much +more marked if the irregular configuration of land and sea, the +existence of mountain chains, and the different heating power of +different latitudes, owing to the unequal distribution of the land, did +not interfere; and the currents of the air (disregarding the deflection +east and west) might then be represented by a treble link or loop, whose +nodes would vary but little from latitudes 30d and 60d. As it is, it +has, no doubt, its influence, although unimportant, when compared with +the disturbing action of the ethereal vortices. + +There is another phenomenon due to the action of the radial stream, +which has given much trouble to the physicist, and which has yet never +been explained. This is the horary oscillations of the atmospheric +pressure which, in some countries are so regular that the time of day +may be ascertained by the height of the barometer. According to +Humboldt, the regularity of the ebb and flow in the torrid regions of +America, is undisturbed by storms or earthquake. It is supposed that the +maxima occur at 9 A.M. and 10 1/2 P.M., and the minima at 4 A.M. and +4 1/4 P.M. From the morning minimum to the morning maximum is, +therefore, five hours; from the evening minimum to the evening maximum +is 6 1/4 hours; from the evening maximum to the morning minimum is 5 1/2 +hours, and from the morning maximum to the evening minimum is 7 1/4 +hours. Again, these oscillations are greatest at the equator, and +diminish with the increase of latitude. + +[Illustration: Fig. 23] + +If we suppose the earth's axis perpendicular to the plane of the vortex, +and P the pole in the above figure, and SP the line joining the centre +of the earth and sun, M and m will represent the points in the earth's +equator where it is midday and midnight respectively. The solar stream +penetrates the terral vortex; and strikes the earth's atmosphere along +the lines parallel to SP. The direct effect would be to pile up the +atmosphere at N and n; and therefore, were the earth at rest, the +maximum would be at 6 A.M. and 6 P.M., and the minimum at midday and +midnight; but the earth rotating from N towards M, carries along the +accumulated atmosphere, being more sluggish in its motions than the +producing cause, which cause is still exercised to force it back to N. +From this cause the maximum is now found at K. For a like reason the +minimum at M would be found at L, but on account of the motion of the +earth being now in the same direction as the solar stream, the minimum +is found still more in advance at k; so that, according to the theory, +the interval between the morning maximum and the evening maximum, should +be greater than the interval between the evening maximum and the morning +maximum; and so it is, the first being 13 1/2 hours and the last 10 1/2 +hours. The morning minimum should also be less marked than the evening +minimum, and this also is a fact. The effect also should be greater in +the tropics than in high latitudes, which again also obtains; being 1.32 +French lines at the equator, and only 0.18 at latitude 70d. Had the +earth no obliquity, the effect would be as the squares of the cosines of +the latitude; but the ratio is diminished by the inclination of the +axis. But there are other variations of the barometer of longer period, +apparently depending on the phases of the moon, but which cannot be +reconciled to the attracting power of the moon as an atmospheric tide; +and Arago concluded that they were due to some _special cause_, of which +the nature and mode of action are unknown. Perhaps this theory will +obviate the difficulty, as although the central vortex comes to the +meridian at the same time as the moon, its effect will be different on +the inferior meridian to what it is on the superior one; whereas the +moon's attraction should be the same on both. That the passage of a +vortex over or near a particular place should affect the barometer, is +too obvious to need explanation, and therefore we may say that the +theory will explain all those varieties both small and great, which have +caused so much speculation for the last fifty years. + + +TERRESTRIAL MAGNETISM. + +In applying the theory to the magnetism of the earth, we must bear in +mind that the earth is probably magnetic by induction, and not in virtue +of its own specific action. The rotation of the surrounding ether, and +the consequent production of a radial stream, calls the ether into +motion within the earth's interior, as well as on the surface; but it +does not follow that the ether shall also enter the earth at its poles +and escape at its equator, for the obliquity of the vortex would +interfere with this result. It is sufficient that this does occur in the +terral vortex immediately surrounding the earth. From late experiments +it is pretty well established that the axial direction of the needle, +(and of other bodies also,) is due to peculiar internal arrangement in +laminae or layers, the existence of which is favorable to the passage of +the magnetic current. + +According to the experiments[27] of Dr. Tyndal, it is found that the +magnetism of a body is strongest along the line of greatest density. As, +therefore, the laminae of bodies may be considered planes of pressure, +when these planes are suspended horizontally, the directive force is +greatest, and the longest diameter of the body sets axial. On the other +hand, when the body was suspended so that the laminae were vertical, the +longest diameter set equatorial. Now, we know that the crust of the +earth is composed of laminae, just as the piece of shale in Doctor +Tyndal's experiments, and that these layers are disposed horizontally. +And whatever force originally arranged the land and water on our globe, +it is evident that the continents are longest from north to south, and +therefore correspond to the natural direction of the magnetic force. + +In consequence of the intrinsic difficulties of this question, and the +mystery yet attaching to it, we may be permitted to enter a little more +minutely into it, and jointly consider other questions of interest, that +will enable us to refer the principal phenomena of terrestrial magnetism +to our theory. + +We have before adverted to the discrepancies in the earth's compression, +as determined by the pendulum, and also to the uncertainty of the moon's +mass, as deduced from the nutation of the earth's axis. It is also +suspected that the southern hemisphere is more compressed than the +northern; and other phenomena also point out the inadequacy of the law +of gravitation, to account for the figure of the earth. + +From the invariability of the axis of rotation, we must conclude that +whatever form is the true form, it is one of equilibrium. In casting our +eyes over the map of the world, we perceive that the surface is very +unequally divided into land and sea; and that the land is very unequally +arranged, both north and south, and east and west. If we compare the +northern and southern hemisphere, we find the land to the water about 3 +to 1. If we take the Pacific portion, and consider the north end of New +Zealand as a centre, we can describe a great circle taking in one half +the globe, which shall not include one-tenth of the whole land. Yet the +average height of the remaining nine-tenths, above the level of the sea, +is nearly 1,000 feet. Call this nine-tenths nearly equal to one-fourth +of the whole surface, and the protuberant land in the hemisphere, +opposite the South Pacific, amounts to 1/30,000 part of the whole mass +of the earth, or about 1/700 of the mass of the moon. Again, the mean +density of the earth is about 5 1/2--water being unity,--and the mean +density of the surface land is only about half this: but three-fourths +of the whole surface is water. Hence, we see that the materials of the +interior of the earth must be either metallic or very compressible. To +assign a metallic nucleus to the earth, is repugnant to analogy; and it +is not rendered even probable by facts, as we find volcanic emissions to +contain no heavier elements than the sedimentary layers. Besides, there +are indications of a gradual increase of density downwards, such as +would arise from the compressibility of the layers. Seeing, therefore, +the equilibrium of the whole mass, and the consequent hydrostatic +balance of the land in the sea,--seeing also the small compressibility +of the solid portions, and the great compressibility of the fluid, the +inference is legitimate that the whole is hydrostatically balanced, and +that our globe is a globe of water, with an intermediate shell of land, +specifically lighter than the fluid in which it is suspended. Where this +shell is of great thickness, it penetrates to greater depths, and +attains to greater elevations above the surface of the aqueous globe; +where it is less thick, it is found below the surface, and forms the +bottom of the upper ocean. Recent soundings give much greater depths to +some parts of the ocean, than the most elevated land upon the globe. +Captain Denham, of H. B. M. ship Herald, lately sounded in 37d south and +37d west, and found bottom at 7,706 fathoms, or about nine English +miles. + +As the interior portions of our globe are totally unknown, and the +compressibility of water is well established, it is just as sane to +consider water the most abundant element of nature, as solid land. The +great question to ask is, whether there may not be other phenomena +incompatible with this supposition? It is plain that the permanency of +terrestrial latitudes and longitudes would be unaffected by the +conditions we have supposed. Would the precession of the equinoxes be +also unaffected? Mr. Hopkins has entered into such an investigation, and +concludes: "Upon the whole, then, we may venture to assert that the +minimum thickness of the crust of the globe, which can be deemed +consistent with the observed amount of precession, cannot be less than +one-fourth or one-fifth of the radius of the earth." These +investigations were made on the hypothesis of the interior fluidity +being caused by the fusion of the central portions of a solid globe; but +it is evident that the analytical result would be the same if these +central parts were water, inclosed by an irregularly-spherical shell of +land. Nor would the result be affected, if we considered certain +portions of the interior of this solid shell to be in a state of fusion, +as no doubt is the case. + +May not the uncertainty of the mass of the moon, be owing to the fact +that this shell is not so rigidly compacted but that it may yield a +little to external force, and thus also account for the tides in the +Pacific groups, rather obeying the centrifugal force due to the orbit +velocity of the earth, than the attraction of the moon? + +Since the days of Hipparchus the sidereal day has not diminished by the +hundredth part of a second; and, consequently, seeing that the +contraction of the mass must be limited by the time of rotation, it is +inferred that the earth has not lost 1/508th of one degree of heat since +that time. This conclusion, sound as it is, is scarcely credible, when +we reflect on the constant radiation into a space 60d below zero. Admit +that the globe is a globe of water, whose average temperature is the +temperature it receives from the sun, and the difficulty vanishes at +once. Its diameter will be invariable, and the only effect of the +cooling of the solid parts will be to immerse them deeper in the water, +to change the _relative_ level of the sea without changing its volume. +This is no puerile argument when rightly considered; but there is +another phenomenon which, if fairly weighed, will also conduct us to the +same views. + +It is now a fact uncontroverted, that the sea does actually change its +level, or rather, that the elevation of continents is not only apparent +but real. The whole coast of Sweden and Finland is rising at the present +day at the rate of four feet in a century, while on the south a contrary +effect is produced. Various hypotheses have been formed concerning this +interesting fact. Yet from the indications of geology, it must have been +an universal phenomenon in the early ages of the world, in order to +account for the emersion of sedimentary deposits from the fluid which +deposited them. May not internal fires be yet spreading, and the +continents expanding instead of contracting? And may there not be an +inequality in this process, so as necessarily to immerse in one +direction nearly as much as to elevate in another? One fact is certain, +the elements are scattering the materials of the land along its Oceanic +coasts, which of itself must produce a very minute effect in disturbing +the hydrostatic balance; but a more efficient agent is the earthquake +and volcano. + +The upheaving of tracts of land by earthquakes, as on the coast of Chili +would thus be satisfactorily explained, by attributing a certain +resistance due to cohesion or friction preventing a _gradual_ change of +level, but producing it suddenly by the jar of the earthquakes. May we +not inquire also, whether the facility with which the earth seems moved +by this destructive agent, does not point to the same solution as the +irregularity of the figure of the earth? + +This is a subject on which it is allowable to speculate, especially if +any light can be thereby thrown on the still more mysterious source of +terrestrial magnetism. It is for such a purpose that we have permitted +ourselves to digress from that subject. In this connection we also may +acknowledge our indebtedness to the sacred volume for the first germ of +this theory of the weather. + +Believing in the authenticity of the Mosaic history of the deluge, the +author found it difficult to refer that event to other than natural +causes, called into action by the operation of other causes, and all +simultaneous with the going forth of the fiat of Omnipotence. Thus +reasoning, he was led to regard the deluge as a physical phenomenon +inviting solution, and as a promising exponent to the climatology of +the early world. He looked upon the bow of promise, as the autograph of +the Creator, the signature to a solemn bond, upon which the eye of man +had never before rested. But if there was no rainbow before the deluge, +there was no rain; and following up this clue, he was not only enabled +to solve the problem, but also led to the true cause, which produces the +principal commotions in our atmosphere. + +Science boasts of being the handmaid of religion; yet there are names of +note in her ranks who have labored rather to invest this phenomenon with +the mantle of fable, and to force it into collision with the records +graven on the rocky pages of geognosy. But the world is ever prone to be +captivated by the brilliancy of misapplied talents, instead of weighing +merit by its zeal in reconciling the teachings of those things which are +seen, with those which are revealed. + +If our globe be constituted as we suppose, the land might experience +repeated submersions, without involving the necessity of any great +departure from established laws. And we might refer to the historical +record of one of these, with all the minute particulars as positive +data, imposing on us the necessity of admitting that the solid parts of +the globe are hydrostatically balanced in the sea. But, modern science +is not always correctly defined when called the pursuit of truth, nor +human learning the means of discovering it. + +If we could divest ourselves of this prejudice, we should have a ready +solution of the difficulty presented by the earth having two north +magnetic poles, and probably two also in the south. For, by regarding +the old and new continents as two distinct masses of land whose bases +are separated by 6,000 miles of water, we recognize two great magnets, +dependent, however, for their magnetism, on the rotation of the terral +vortex. + +This is no place to enter into a lengthy discussion of such a difficult +subject as magnetism, but we may be allowed to enter a protest against +the current theory of electro-magnetism, viz.: that a force is generated +by a galvanic current at right angles to the producing cause, which is +contrary to the fundamental principles of mechanics. We may conceive +that a current is induced from or to the surrounding space by the +rarefaction or condensation attending the transmission of such a current +along a wire, and that rotation should follow, just as a bent pipe full +of small holes at the lower end, and immersed in water as a syphon, will +generate a vorticose motion in the water; but mere juxtaposition, +without participation and communication with the general current, is +irrational, and, therefore, not true. + +We have always regarded a magnetic needle as a part of the great natural +magnet, the earth; that its north pole actually points to the north, and +its south pole to the south; and, being free to move, it is affected by +the circular motion of the surrounding ether, and by every motion by +which the ether is directed. If there was any attraction between the +earth and the needle, opposite poles would be presented, but it is not +so--the force is merely directive. + + +MAGNETIC VARIATIONS. + +Let us now see whether we cannot assign an adequate cause for the +secular and periodic variations in the inclination and declination of +the needle. These have been generally referred to changes of +temperature, as in fact, also, the magnetism of the earth is sometimes +ascribed to galvanic or electric currents, called forth by a daily +change of temperature. Our theory gives a totally different explanation +of these variations. + +In the northern hemisphere, the north point of the needle moves from +east to west in the morning from about 8 1/2 A.M. to 1 1/2 P.M., and +returns to its mean position about 10 P.M. It then passes over to the +east, and again returns to its mean position about 8 or 9 A.M. The +analogy of this motion, with the horary changes in the barometer, +indicate a common origin. Humboldt, in the instructions he drew up for +the Antarctic Expedition under Sir James Ross, says: "The phenomena +of periodical variations depend manifestly on the action of _solar +heat_, operating probably through the medium of thermo electric currents +induced on the earth's surface. Beyond this rude guess, however, +_nothing is yet known of their physical cause_. It is even still a +matter of speculation whether the solar influence be a principal or only +a subordinate cause." That the sun may exert a modifying influence on +the phenomenon is not unlikely, but that he cannot be the principal +cause, is evident from the following considerations. These horary +variations of the magnetic needle are as great at the bottom of deep +mines far removed from solar influence, as on the surface. They are as +great, _ceteris paribus_ on a small island in the midst of the ocean, as +in the interior of continents, where the heating power of the surface is +vastly greater. They are extremely regular, so that between the tropics, +according to the sagacious Humboldt, "the time of the day may be known +by the direction of the needle, as well as by the height of the +barometer." + +But what is the cause of these variations? This question is the most +difficult of all physical problems, and we shall only aim at indicating +the causes which are yet perhaps too intricately involved to afford a +positive numerical determination. Admitting the existence of two +principal solid masses whose general direction is from south to north, +and that these masses are more susceptible of permeation by the ethereal +fluid than the waters in which they are suspended, we have a general +solution of the position of the magnetic poles, and of the isogonic, +isoclinic, and isodynamic lines. Considering, too, that the southern +poles of these masses are the points of ingress, and the northern poles +the points of egress, it is easily understood that the ethereal medium +having the temperature of space, will cause the southern hemisphere to +be colder than the northern, and also that the magnetic poles will be +the poles of maximum cold, and the centres respected by the isothermal +and isogeothermal lines. + +The general direction of the magnetism of the earth may be considered as +the controlling influence, therefore, in determining the position of the +magnetic needle; but there are other causes which, to some extent, will +modify the result. That half of the globe turned away from the sun will +partake of the density of the ether at that distance, which is greater +than on the side next the sun; the magnetic intensity ought, therefore, +to be greater in the night than in the day. The poles of the great +terrestrial magnets, or even the position of a magnetic needle on the +surface, are continually placed by the earth's rotation in a different +relation to the axes of the terral vortex, and the tangential current, +which is continually circulating around the globe, has its inclination +to a given meridian in a perpetual state of change. If we conceive that +there is a tendency to force the needle at right angles to this current, +we shall have an influence which varies during the day, during the year, +and during the time occupied by a complete revolution of the node. The +principal effect, however, of the horary variation of the needle is due +to the radial stream of the sun, which not only penetrates the +atmosphere, but also the solid crust of the earth. Its principal +influence is, however, an indirect influence, as we shall endeavor to +explain. + +No fact in the science of electro-magnetism is, perhaps, better +established than the disposition of an ethereal current to place itself +at right angles to the magnetic meridian, and conversely, when the +current is not free to move, to place the needle at right angles to the +current. Now, the terrestrial magnet or magnets, may be considered to be +surrounded by a body of ether in rotation, which, in the earth, on its +surface, and for some distance from the surface, is made to conform to +the general rule, that is, to circulate at right angles to the magnetic +meridian. Outside this again, the ether more and more conforms to the +position of the axis of the vortex, and this position varying, it must +exert _some_ influence on the surface currents, and, therefore, change +in some degree the position of the magnetic meridian. The radial stream +comes from the sun in parallel lines, and strikes the globe and its +superficial ethereal envelope just as we have shown its action on the +atmosphere; but in this last case the magnetic equator is not a great +circle, neither can we suppose its effects to be an accumulation of a +fluid which is imponderable at points 90d from the plane passing through +the centre of the earth and sun, and coincident with the plane of the +central meridian, and a depressing effect on that meridian. Its precise +influence must be, from the nature of the cause, to deflect the circular +current towards the poles, in places less than 90d from the meridian, +and a contrary effect must be produced in places greater than 90d from +the meridian. Let us assume, for argument's sake, that the magnetic +poles of the earth correspond to the poles of rotation, the parallels of +latitude will, therefore, represent the ethereal currents circulating +around the globe. Now, at sunrise, the radial stream of the solar vortex +is tangential to the surface, and, therefore, can produce no change in +these currents. As the sun ascends say about 8 or 9 A.M., the radial +stream striking only the surface of the earth perpendicularly in that +place where the sun is vertical (which we will suppose at the equator), +streams off on every side, as the meridians do from the pole, and the +circles of latitude (that is the ethereal currents) being parallel to +the equator, they are met by the radial stream obliquely, and deflected +towards either pole. By this deflection they are no longer at right +angles to the meridians. But, from the principle of reaction above +noticed, the magnetic meridians will place themselves at right angles to +the current, or, in other words, the magnetic pole will change its +position on the surface of the earth with respect to that particular +place. But, in other parts of the world, the meridians are in opposite +phases at the same instant of absolute time; therefore, the magnetic +poles are not points, but wide areas enclosing the magnetic poles of all +the countries under the sun. As this conforms to observation, it is +worthy our especial attention, and may be understood by the subjoined +figure, in which the oblique curves represent the course of the +tangential current in the different positions of the sun, the parallel +lines representing the solar radial stream. + +[Illustration: Fig. 24] + +As the sun gains altitude the action of the radial stream is at a +greater and greater angle to the circular currents, and attains its +maximum at noon, still acting, however, after noon; but seeing that the +circular current possesses a force of re-action, that is, that the +magnetism of the earth is ever striving to bring these currents to their +natural direction, an hour or two after noon, the currents tend again to +the equator, and the maximum deflection is passed, and finally ceases a +few hours after sunset. Now let us attend to what is going on on the +opposite side of the world. The radial stream passing over the polar +regions, now produces a contrary effect; the ethereal atmosphere of the +great magnet is accumulated on the farthest side from the sun, by the +action of the radial stream passing over the polar region, the parallel +currents are now bent towards the equator, being at a maximum in places +where it is an hour or two past midnight. Before they were concave to +the equator, and now they are convex; the magnetic meridian is therefore +deflected the contrary way to what it was in the day time, by the same +principle of reaction. After the maximum, say at 4 A.M., the deflection +gradually ceases, and the magnetic meridian returns to its mean position +at 8 or 9 A.M. These times, however, of maximum and minimum, must vary +with the time of the year, or with the declination of the sun, with the +position of the moon in her orbit, with the perigee of the orbit, and +with the place of the ascending node; there are also minor influences +which have an effect, which present instrumental means cannot render +appreciable. + +What says observation? The needle declines from its mean position in the +whole northern hemisphere to the westward, from about 8.30 A.M., until +1.30 P.M.; it then gradually returns to its mean position by 10 A.M. +After 10 P.M., it passes over to the eastward, and attains its maximum +deflection about three or four hours after midnight, and is found again +at its mean position about 9 A.M. Now, this is precisely the direction +of the deviation of the magnetic meridian, the needle therefore only +follows the meridian, or still continues to point to the temporary +magnetic pole. And although we have assumed, for the sake of simplicity, +that the mean magnetic pole corresponds to the pole of rotation; in +truth there are two magnetic poles, neither of which correspond; yet +still the general effect will be the same, although the numerical +verification will be rendered more difficult. + +In the southern hemisphere the effect is the reverse, (this southern +hemisphere, however, must be considered separated from the northern by +the magnetic equator, and not by the geographical one,) the needle +declines to the eastward in the morning, and goes through the same +changes, substituting east for west, and west for east. Does observation +decide this to be to be a fact also? Most decidedly it does; and this +alone may be considered a positive demonstration, that the theory which +explains it is true. The contrary deflection of the needle in the +northern and southern hemisphere may be formally proclaimed as utterly +beyond the reach of the common theory of magnetism to explain. This +difficulty arises from considering the needle as the disturbed body +instead of the earth; and also from the fact that the effect of solar +heat must be common to needles in both hemispheres, and act upon similar +poles, and consequently the deflection must be in the same direction. + +But a still more capital feature is presented by the discovery of +Colonel Sabine, that the deflection is in contrary directions at the +Cape of Good Hope, at the epoch of the two equinoxes. This arises from +the great angle made by the magnetic meridian at this place, with the +terrestrial meridian--the variation being by Barlow's tables, 30d to the +westward. The sun varies in declination 47d throughout the year. At the +southern solstice, therefore the radial stream strikes the circular +current on the southern side, and deflects it towards the equator, +rendering the declination to the westward in the morning; but at the +northern solstice the radial stream strikes the current on its northern +side, and the deflection is eastward in the morning. And the vicinity of +the Cape of Good Hope is, perhaps, the only part of the world where this +anomaly will obtain; as it is necessary not only that the declination +shall be considerable, but also that the latitude shall not be very +great. + +Observation also determines that the amount of the horary variation +increases with the latitude. Near the equator, according to Humboldt, it +scarcely amounts to three or four minutes, whilst it is from thirteen to +fourteen minutes in the middle of Europe. The theory explains this also; +for as the circles recede from the equator, the angles made by their +planes with the direction of the radial stream increases, and hence the +force of deflection is greater, and the effect is proportioned to the +cause. We have also a satisfactory explanation of the fact that there +has not yet been discovered a line of _no variation of horary +declination_ as we might reasonably anticipate from the fact that the +declinations are in _contrary directions_ in the northern and southern +hemisphere. This is owing to the ever-varying declination of the sun. +There would be such a line, no doubt, if the axis of the earth were +perpendicular to the plane of the orbit, and the magnetic pole coincided +with the pole of rotation: for then the equator would be such a line. + + +MAGNETIC STORMS. + +But there are also irregular fluctuations in the direction of the +magnetic needle. These depend on the moon, and are caused by the passage +of the vortices over or near to the place of observation. The action of +these vortices is proved to be of variable force, whether arising from +atmospheric conditions, or due to an increased activity of the ethereal +medium throughout the whole system, is at present immaterial. They do +vary, and sometimes the passage of a vortex will deflect the needle a +whole degree. At other times, there are magnetic storms extending over a +great part of the earth's surface; but there is reason to suppose, that +the extent of these storms has been over estimated. Thus, on the 25th of +September, 1841, a magnetic storm was observed in Toronto, and at the +same time there was one felt at the Cape of Good Hope. There is no great +mystery in this. If we suppose the axis of the central vortex, for +instance, to have passed Toronto in latitude 43d 33' north, in ordinary +positions of the moon, in her orbit, the southern portion of the axis +would be in 33d or 34d south latitude, and consequently would have +passed near the Cape of Good Hope on the same night. Now, we certainly +could not expect the northern portion of the vortex to be intensely +active, without the southern portion being in the same state of +activity. That this is the true explanation is proved by magnetic storms +in the same hemisphere being comparatively limited in extent; as, +according to Gauss and Weber, magnetic storms which were simultaneously +felt from Sicily to Upsala, did not extend from Upsala to Alten. Still +it would not be wonderful if they were felt over a vast area of +thousands of miles as a consequence of _great_ disturbance in the +elasticity of the ether in the terral vortex; as the solid earth must be +permeable to all its motions, and thus be explicable on the general +principles we have advanced. + +But besides these variations which we have mentioned, there are changes +steadily going on, by which the isodynamic, isogonic and isoclinic lines +are permanently displaced on the surface of our planet. These must be +attributed to changes of temperature in the interior of the globe, and +to the direction in the progress of subterranean fires, which it may +also be expected will change the isogeothermal lines. But there are +changes, which although of long period, are yet periodic, one of which +is obviously due to the revolution of the lunar nodes in eighteen and a +half years, and the revolution of the apogee in nine years. The first is +continually changing the obliquity of the axis of the vortex, and they +both tend to limit the vortices in their extreme latitudes; but the +planet Jupiter has an indirect influence, which is probably equal, if +not greater, than the action of the moon, in changing the magnetic +declination. + +From the investigations of Lamont, it would appear, that the period of +the variations of magnetic declination is about 10 1/3 years, while, +more recently, R. Wolfe has suggested the connection between this +variation and the solar spots, and assigns a period of 11.11 years, and +remarks, that it "corresponds more exactly with the variations in +magnetic declination than the period of 10 1/3 years established by +Lamont. The magnetic variations accompany the solar spots, not only in +their regular changes, but even in their minor irregularities: this +latter fact is itself sufficient to prove definitely the important +relations between them."[28] + +As the planet Jupiter exerts the greatest influence on the sun, in +forcing the centre from the mechanical centre of the system, the +longitude of the sun will in a great measure depend on the position of +this planet; and, in consequence, the sun will generally revolve around +this centre in a period nearly equal to the period of Jupiter. The +sidereal period of Jupiter is about twelve years, but the action of the +other planets tend to shorten this period (at least, that has been the +effect for the last twenty or thirty years), and bring it nearly to the +period assigned by M. Wolfe to the variations in the magnetic +declinations. As this has its influence on the radial stream, and the +radial stream on the declination, we see at once the connection between +them. When we come to a consideration of the solar spots, we shall +exhibit this influence more fully. + + +AURORA BOREALIS. + +Let us now examine another phenomenon. The Aurora Borealis has been +generally considered to be in some way connected with the magnetism of +the earth, and with the position of the magnetic pole. It is certain +that the appearance of this meteor does affect the needle in a way not +to be mistaken, and (although not invariably) the vertex of the luminous +arch will usually conform to the magnetic meridian. Yet (and this is +worthy of attention), the observations made in the North Polar +Expeditions[29] "appear to prove, that in the immediate vicinity of the +magnetic pole the development of light is not in the least degree more +intense or frequent than at some distance from it." In fact, as the +American magnetic pole is, as stated, in latitude 73d, the central +vortex will seldom reach so high, and, consequently, the aurora ought +at such times to be more frequent in a lower latitude. In a late work by +M. de la Rive, this gentleman expresses the opinion, that the cause of +the aurora is not due to a radiation of polar magnetism, but to a purely +electrical action.[30] His explanation, however, is not so satisfactory +as his opinion. Now, we have examined numerous cases of auroral +displays, and never yet found one which could not be legitimately +referred to the action of ethereal vortices. Generally, the aurora will +not be visible, when the upper surface of the atmosphere of that +latitude in which the vortex is known to be (reckoning in the direction +of the magnetic meridian) is below the horizon, which shows that the +brightest portion is in the atmosphere. In latitude 41d even, it may +show itself when the vortex is three days north, more frequently when +one or two days north; but when the vortex passes centrally, or south, +it rarely is seen, and this is the only difficulty in explaining it by +the theory. But, when we reflect that the ether shoots out in straight +lines, and at an angle corresponding to the magnetic dip, we are at no +loss to perceive the reason of this. If each minute line composing the +light were seen endwise, it would be invisible; if there were millions +such in the same position, they could add nothing to the general effect; +but, when viewed sideways, the case would be different, there would be a +continued reduplication of ray upon ray, until in the range of some +hundreds of miles an effect might be produced amounting to any degree of +intensity on record. Now, this is the case when the aurora is +immediately overhead, it will be invisible to those below, but may be +seen by persons a hundred miles south; so, also, when it is to the +south, it is too oblique to the line of vision to be seen, especially as +all the rays to the northward of the observer can contribute nothing to +increase the effect. That it is of the nature of rays very much +diffused, can hardly be doubted; and, therefore, if only of a few miles +in depth, its impressions are too faint to be sensible. By referring to +the record of the weather in the second section of this work, an auroral +display will be found on July 12th, the central vortex having passed a +little to the northward the same evening, and the next day passing south +_descending_. On that occasion the author saw an inclined column, in +profile, due east, and between himself and a line of bluffs and timber, +about eight miles distant; And, he has not any doubt that the mass of +rays began where he stood. As in a shower, every drop, passing through a +conical surface, whose axis passes through the sun and through the eye, +contributes to form the apparently distant rainbow. + +The altitude of this meteor has been much exaggerated, especially of +those rings or luminous arches, which are often detached completely from +the luminous bank. On the 24th of May, a bright aurora was visible at +Ottawa, but the author's attention was engrossed by the most brilliant +arch of light he had ever seen. It was all the time south of the zenith, +and had no visible connection with the aurora north. At 9 hours, 59 +minutes, 30 seconds mean solar time, Arcturus was in the exact centre of +the band, at which time it was very bright, and full 7d wide. At the +same time, Prof. G.W. Wheeler observed the aurora in Perryville, in the +State of Missouri, only 1d of longitude to the westward, but did not see +the arch.[31] The difference of latitude between the two places being 3d +30', and the weather, as he states, clear and still, there is only one +reason why he did not see the arch: it must have been too _low_, and had +become merged in the bank of light. At the time mentioned, the altitude +of Arcturus was 68d 30', and, as Prof. Wheeler assigns only 10d as the +altitude of the bank, the maximum elevation of the arch, on the +supposition of its composing a part of the bank, was 43 miles. At +Perryville, the bank and streamers had disappeared at 10 o'clock. At +Ottawa, the arch or bow disappeared at 10 h. 5 m., differing only the +fraction of a minute from the time at Perryville; but, the bank was +still visible, but low and faint, the greatest altitude having been over +30d. To show the rapid fluctuations in width and position of this bow, +we will add a few of the minutes taken at the time with great care, in +hopes some other observer had been equally precise. When first seen, +there were three luminous patches, or elongated clouds of light; one in +Leo, one in Bootes, and another in Ophinchus, all in line. This was +about 9h. 15m. The times following are correct to 30 seconds: + + 9h. 42m. 30s. Bow complete; south edge 2d north of Arcturus. + + 9 45 30 Northern edge diffuse south; edge bright, and well + defined; 10d wide in zenith; north edge on Alphacca. + + 9 47 30 South edge 5d north of Arcturus; north edge close to + Cor. Caroli. + + 9 53 30 Eastern half composed of four detached bands + _shingling_ over each other. + + 58 30 Arcturus on south; bow narrower. + + 9 59 30 Arcturus in the middle of the band; very bright and + regular in outline, and widest at the zenith. + + 10 0 30 Arcturus on northern edge; north side better defined + than the southern. + + 10 2 0 Arcturus 1d north; very bright. + + 10 2 30 Gamma and Delta Leonis, northern edge. + + 10 3 Regulus on southern age; getting faint. + + 10 5 Fast fading away. + + 10 5 30 Scarcely visible; bank in north faint. + +This aurora was due to the _inner vortex ascending_, whose period was at +this time 28 days. + +There are several circumstances to be observed in this case. The bow +brightened and faded simultaneously with the aurora, and respected the +vertex of the auroral bank, being apparently concentric with it. The +bow, therefore, depends on the same cause, but differs from the aurora +in being limited to the _surface_ of the atmosphere in which the vortex +has produced a wave to the southward of its central path, as may be +understood by inspecting Fig. 2, Sec. 1,--the figure representing the +polar current of the central vortex. On the 29th of May, 1840,[32] the +author saw a similar phenomenon, at the same time of night, and passing +over the same stars southward until it reached within 5d of Jupiter and +Saturn, to which it was parallel. This atmospheric wave offers a greater +resistance to the passage of the ether: hence the light. On this account +it is, also, that when the passage of a vortex is attended by an auroral +display there will be no thunder-storm. There may be an increase of +wind; but the atmosphere at such times is too dry to make a violent +storm, and there is a silent restoration of the equilibrium, by the +ether passing through the dry atmosphere, without meeting any +condensable vapor, and becoming luminous on account of the greater +resistance of the air when unmixed with vapor. We thus see also the +connection between the aurora and the linear cirri, and we have a +triumphant explanation of the fact, that when the observer is north of +the northern limit of the vortices, he sees the aurora to the south and +not to the north; for, to see it to the northward, he would have to see +it in the same latitude as it appears in the south, and, consequently, +have to see across twice the complement of the latitude. We thus see, +also, why the temperature falls after an aurora; for, the passage of +electricity in any shape, must have this effect on account of the great +specific caloric of this fluid. We see, also, why the aurora should be +more frequent where the magnetic intensity is greatest and be +consequently invisible at the equator, and why the magnetic needle is so +sensibly affected at the time of its occurrence. We may, perhaps, here +be allowed to allude to another phenomenon connected with terrestrial +magnetism and electricity. + + +EARTHQUAKES. + +The awful and destructive concussions which sometimes are produced at +great depths beneath the surface of the soil, would seem to indicate +that no force but that of electricity is adequate to account for the +almost instantaneous desolation of wide tracts of the earth's surface. +But we do not mean to say that the action of the terral vortices, +combined with the internal conditions of our planet, is the only cause; +although it is far from improbable that the same activity of the ether, +which generates through these vortices, the full fury of the hurricane +in the tropics, may be simultaneously accompanied by a _subterranean_ +storm. And physicists are too rash to reject the evidence on which the +connection of the phenomena rests. + +In the extract given by Colonel Reid, in his "Law of Storms," from Sir +George Rodney's official report of the great hurricane of 1780, it is +stated, that, "Nothing but an earthquake could have occasioned the +_foundations_ of the strongest buildings to be rent; and I am convinced +that the violence of the wind must have prevented the inhabitants from +feeling the earthquake which certainly attended the storm."[33] Again, +in the Savannah-la-Mar hurricane, which occurred the same year and +month, the Annual Register, published at Jamaica, states, that at the +same time, "a smart shock of an earthquake was felt." The general +serenity of equatorial regions is due to the fact that they are beyond +the limit of the vortices, as in Peru, where neither rain nor lightning +nor storm is ever seen. Thunder and rain, without storms, however, are +common in other tropical countries, also out of the reach of the +vortices. But even in those parts, (as the Antilles,) lying in the track +of these vortices, the weather is not as _frequently_ disturbed as in +higher latitudes. The storms of the Antilles, when they do occur, +however, are fearful beyond any conception, showing the presence of some +cause, auxiliary to the ordinary disturbing action of the vortices, +which, when simultaneously occurring, adds tremendously to their force. + +That earthquakes are preceded _sometimes_ by a peculiar haziness and +oppressiveness, similar to that which sometimes precedes a storm, is a +current opinion in volcanic countries. And Humboldt, who doubts the +connection, has to confess that sudden changes of weather have +_succeeded_ violent earthquakes, and that "during the great earthquake +of Cumana, he found the inclination of the needle was diminished 48'." +He also mentions the simultaneous occurrence of shocks, from +earthquakes, and a clap of thunder, and the agitation of the +electrometer during the earthquake, which lasted from the 2d of April to +the 17th of May, 1808; but concluding that "these indications presented +by clouds, by modifications of atmospheric electricity, or by calms, +cannot be regarded as _generally_ or _necessarily_ connected with +earthquakes, since in Peru, Canada, and Italy, earthquakes are observed, +along with the purest and clearest skies, and with the freshest land and +sea breezes. But if no meteorological phenomena indicates the coming +earthquake, either on the morning of the shock or a few days previously, +the influence of certain periods of the year, (the vernal and autumnal +equinoxes,) the commencement of the rainy season in the tropics, after +long drought, cannot be overlooked, even though the genetic connection +of meteorological processes, with those going on in the interior of our +globe, is still enveloped in obscurity."[34] + +It is at the equinoxes that the earth changes her distances from the sun +most rapidly, and whether she is passing from her perihelion or from +her aphelion, the density of the ether externally is changing in the +subduplicate ratio of these distances and consequently at these times +there will be the greatest disturbance of the electric equilibrium. How +far our views of the internal structure of our globe, (considered along +a diameter as a solid crust, then a fused mass separated from the lower +ocean by another solid crust, and separated from a similar arrangement +on the opposite side by an interposed mass of water, perhaps also +possessing a solid nucleus,) may affect this question, is difficult to +say; but that the agent is electric, appears highly probable; and very +recently it has been discovered, by M. Ratio Menton, that a piece of +iron, suspended by attraction to a magnet, will fall on the approach of +an earthquake; thus indicating that the power of the magnet is +temporarily weakened by the action of some disturbing force. + + +FOOTNOTES: + +[22] Hum. Cosmos, art Aerolites. + +[23] We shall in all cases use this abbreviation for the extremely +awkward word zodiacal. + +[24] It is here assumed, that all the vortices are at their apogee at +the same time, and, consequently, they lie in different longitudes, but +the central being between, its position is taken for the average +position of the three. + +[25] It is far from improbable that the effect produced in one zone of +climate, may be reversed in another, from the nature of the cause. + +[26] That the 11th, 12th, and 13th of May should recede 2d in +temperature as determined by Maedler from observations of 86 years, at a +time when the power of the sun so rapidly augments, is strongly +confirmatory of the theory. See _Cosmos_, p. 121. + +[27] Plucker first discovered that a plate of tourmaline suspended with +its axis vertical, set axial. + +[28] Silliman's Journal for March and April, 1853. + +[29] Humboldt, _Cosmos_ p. 193, London ed. + +[30] See Silliman's Journal for September, 1853. + +[31] See Silliman's Journal for September, 1853. + +[32] This was the central vortex ascending. + +[33] Reid's Law of Storms, p. 350. + +[34] Humboldt, _Cosmos_, p. 203. + + + + +SECTION FOURTH. + + +THE SOLAR SPOTS. + +We have yet many phenomena to investigate by the aid of the theory, and +we will develop them in that order which will best exhibit their mutual +dependence. The solar spots have long troubled astronomers, and to this +day no satisfactory solution of the question has been proposed; but we +shall not examine theories. It is sufficient that we can explain them on +the same general principles that we have applied to terrestrial +phenomena. There can be but little doubt about the existence of a solar +atmosphere, and, reasoning from analogy, the constituent elements of the +sun must partake of the nature of other planetary matter. That there are +bodies in our system possessing the same elements as our earth, is +proved by the composition of meteoric masses, which, whether they are +independent bodies of the system, or fragments of an exploded planet, or +projected from lunar volcanoes, is of little consequence; they show that +the same elements are distributed to other bodies of the system, +although not necessarily in the same proportions. The gaseous matter of +the sun's atmosphere may, therefore, be safely considered as vapors +condensable by cold, and the formation of vortices over the surface of +this atmosphere, brings down the ether, and causes it to intermingle +with this atmosphere. But, from the immensely rapid motion of the polar +current of the solar vortex, this ether may be considered to enter the +atmosphere of the sun with the temperature of space. + +Sir John Herschel, in commenting on the theory of Mr. Redfield before +the British Association, convened at Newcastle in 1838,[35] suggested an +analogy to terrestrial hurricanes, from a suspected rotation and +progressive motion in these spots. From their rapid formation, change of +shape, and diameter, this view is allowable, and, taken in conjunction +with the action of the ethereal currents, will account for all the +phenomena. The nucleus of the spot is dense, like the nucleus of a storm +on the earth, and surrounded by a penumbon precisely as our storms are +fringed with lighter clouds, permitting the light of the sun to +penetrate. And, it has been observed, that these spots seem to follow +one another in lines on the same parallel of solar latitude (or nearly +the same), exactly as we have determined the action of the vortices on +the surface of the earth from observation. These spots are never found +in very high latitudes--not much above 30d from the solar equator. If we +consider this equator to be but slightly inclined to the plane of the +vortex, this latitude would be the general position of the lateral solar +vortices, and, in fact, be confined principally to a belt on each side +of the equator, between 15d and 30d of solar latitude, rather than at +the equator itself. This, it is needless to say, is actually the case. +But, a more capital feature still has been more recently brought to +light by observation, although previously familiar to the author, who, +in endeavoring to verify the theory, seriously injured his sight, by +observing with inadequate instrumental means. This is the periodicity of +the spots. + +We have already observed, that there is reason to suppose that the +action of the inner vortex of the earth is probably greater than that of +the outer vortex, on account of the conflicting currents by which it is +caused. And the full development of this vortex requires, that the +central vortex or mechanical axis of the system shall be nearly +tangential to the surface. In this position, the action of the central +vortex is itself at a maximum; and, when the planets of the system are +so arranged as to produce this result, we may expect the greatest number +of spots. If the axis or central vortex approaches to coincidence with +the axis of the sun, the lateral vortices disappear, and the central +vortex being then perpendicular to the surface, is rendered ineffective. +Under these circumstances, there will be no spots on the sun's disc. +When, on the other hand, all the planets conspire at the same side to +force the sun out from the mechanical centre of the system, the surface +is too distant to be acted on by the central vortex, and the lateral +vortices are also thrown clear of the sun's surface, on account of the +greater velocity of the parts of the vortex, in sweeping past the body +of the sun. In this case, there will be but few spots. The case in which +the axis of the vortex coincides with the axis of the sun, is much more +transient than the first position, and hence, although the interval +between the maxima will be tolerably uniform, there will be an +irregularity between a particular maximum, and the preceding and +subsequent minimum. + +The following table exhibits the solar spots, as determined by Schwabe, +of Dessau: + + Year of observation. Groups of spots observed. Number of days. + 1826 118 277 + 1827 161 273 + 1828 225 282 + 1829 199 244 + 1830 190 217 + 1831 149 239 + 1832 84 270 + 1833 33 267 + 1834 51 273 + 1835 173 244 + 1836 272 200 + 1837 333 168 + 1838 282 202 + 1839 162 205 + 1840 152 263 + 1841 102 283 + 1842 68 307 + 1843 34 324 + +Previous to the publication of this table, the author had inferred the +necessity of admitting the existence of another planet in the solar +system, from the phenomenon of which we are speaking. He found a +sufficient correspondence between the minima of spots to confirm the +explanation given by the theory, and this was still more confirmed by +the more exact determination of Schwabe; yet there was a little +discrepancy in the synchronous values of the ordinates, when the theory +was graphically compared with the table. Previous to the discovery of +Neptune, the theory corresponded much better than afterwards, and as no +doubt could be entertained that the anomalous movements of Uranus were +caused by an exterior planet, he adopted the notion that there were two +planets exterior to Uranus, whose positions at the time were such, that +their mechanical affects on the system were about equal and contrary. +Consequently, when Neptune became known, the existence of another planet +seemed a conclusion necessary to adopt. Accordingly, he calculated the +heliocentric longitudes and true anomalies, and the values of radius +vector, for all the planets during the present century, but not having +any planetary tables, he contented himself with computing for the +nearest degree of true anomaly, and the nearest thousand miles of +distance. Then by a composition and resolution of all the forces, he +deduced the radius vector of the sun, and the longitude of his centre, +for each past year of the century. It was in view of a little +outstanding discrepancy in the times of the minima, as determined by +theory and observation, that he was induced to consider as almost +certain the existence of a theoretical planet, whose longitude, in 1828, +was about 90d, and whose period is from the theory about double that of +Neptune. And for convenience of computation and reference, he has been +in the habit of symbolizing it by a volcano. The following table of the +radii vectores of the sun, and the longitude of his centre, for the +years designated in Schwabe's table, is calculated from the following +data for each planet: + + Long. of + Planets. Masses. Mean distances. Eccentricities. Perihelion. + [JUPITER] 1/1648 494.800.000 0.0481 11d + [SATURN] 1/3310 907.162.000 0.0561 89 + [URANUS] 1/23000 1824.290.000 0.0166 167 + [NEPTUNE] 1/20000 2854.000.000 0.0088 0 + [VOLCANO] 1/28000 4464.000.000 + + No. of spots in + Dates. Rad. vector. Sun's long. Ordinates. Schwabe's table. + Jan. 1, 1826 528,000 320d + 84 118 + " 1827 480,000 339 + 36 161 + " 1828 432,000 352 - 12 Max. 225 Max. + " 1829 397,000 38 - 47 199 + " 1830 858,000 71 - 86 190 + " 1831 324,000 104 - 120 149 + " 1832 311,000 144 - 133 84 + " 1833 300,000 183 - 144 Min. 33 Min. + " 1834 307,000 220 - 137 51 + " 1835 338,000 263 - 106 173 + " 1836 380,000 302 - 55 272 + " 1837 419,000 337 + 25 Max. 333 Max. + " 1838 488,000 3 + 44 282 + " 1839 651,000 29 + 107 162 + " 1840 632,000 51 + 188 152 + " 1841 680,000 80 + 236 102 + " 1842 730,000 105 + 286 68 + " 1843 160,000 128 + 322 34 Min. + " 1844 188,000 152 + 339 Min. 52 + " 1845 772,000 174 + 328 114 + " 1846 728,000 196 + 284 157 + " 1847 660,000 218 + 216 + " 1848 563,000 240 + 119 Observed. Max. + " 1849 447,000 261 + 3 Max. + " 1850 309,000 283 - 135 + " 1851 170,000 323 - 274 + " 1852 53,000 41 - 391 Min. + " 1853 167,000 133 - 277 + " 1854 315,000 160 - 129 + " 1855 475,000 183 + 31 Max. + " 1856 611,000 203 + 167 + " 1857 720,000 225 + 276 + +It is necessary to observe here, that the values of the numbers in +Schwabe's table are the numbers for the whole year, and, therefore, the +1st of July would have been a better date for the comparison; but, as +the table was calculated before the author was cognizant of the fact, +and being somewhat tedious to calculate, he has left it as it was, viz., +for January 1st of each year. Hence, the minimum for 1843 appears as +pertaining to 1844. The number of spots ought to be inversely as the +ordinates approximately--these last being derived from the Radii +Vectores minus, the semi-diameter of the sun = 444,000 miles. + +In passing judgment on this relation, it must also be borne in mind, +that the recognized masses of the planets cannot be the true masses, if +the theory be true. Both sun and planets are under-estimated, yet, as +they are, probably, all to a certain degree proportionally undervalued, +it will not vitiate the above calculation much. + +The spots being considered as solar storms, they ought also to vary in +number at different times of the year, according to the longitude of the +earth and sun, and from their transient character, and the slow rotation +of the sun, they ought, _ceteris paribus_, to be more numerous when the +producing vortex is over a visible portion of the sun's surface. + +The difficulty of reconciling the solar spots, and their periodicity to +any known principle of physics, ought to produce a more tolerant spirit +amongst the scientific for speculations even which may afford the +slightest promise of a solution, although emanating from the humblest +inquirer after truth. The hypothesis of an undiscovered planet, exterior +to Neptune, is of a nature to startle the cautions timidity of many; +but, if the general theory be true, this hypothesis becomes extremely +probable. We may not have located it exactly. There may be even two such +planets, whose joint effect shall be equivalent to one in the position +we have assigned. There may even be a comet of great mass, capable of +producing an effect on the position of the sun's centre (although it +follows from the theory that comets have very little mass). Yet, in view +of all these suppositions, there can be but little doubt that the solar +spots are caused by the solar vortices, and these last made effective on +the sun by the positions of the great planets, and, therefore, we have +indicated a new method of determining the existence and position of all +the planets exterior to Neptune. On the supposition that there is only +one more in the system, from its deduced distance and mass, it will +appear only as a star of the eleventh magnitude, and, consequently, will +only be recognizable by its motion, which, at the greatest, will only be +ten or eleven seconds per day. + + +MASSES OF THE SUN AND PLANETS. + +We have alluded to the fact of the radial stream of the sun necessarily +diminishing the sun's power, and, consequently, diminishing his apparent +mass. The radial stream of all the planets will do the same, so that +each planet whose mass is derived from the periodic times of the +satellites, will also appear too small. But, there is also a great +probability that some modification must be made in the wording of the +Newtonian law. The experiments of Newton on the pendulum, with every +variety of substance, was sufficient justification to entitle him to +infer, that inertia was as the weight of matter universally. But, there +was one condition which could not be observed in experimenting on these +substances, viz., the difference of temperature existing between the +interior and surface of a planet. + +We have already expressed the idea, that the cause of gravity has no +such mysterious origin as to transcend the power of man to determine it. +But that, on the contrary, we are taught by every analogy around us, as +well as by divine precept, to use the visible things of creation as +stepping stones to the attainment of what is not so apparent. That we +have the volume of nature spread out in tempting characters, inviting us +to read, and, assuredly, it is not so spread in mockery of man's limited +powers. As science advances, strange things, it is true, are brought to +light, but the more _rational_ the queries we propound, in every case +the more satisfactory are the answers. It is only when man consults the +oracle in irrational terms that the response is ambiguous. Alchemy, with +its unnatural transmutations, has long since vanished before the +increasing light. Why should not attraction also? Experience and +experiment, if men would only follow their indications, are consistently +enforcing the necessity of erasing these antiquated chimeras from the +book of knowledge; and inculcating the great truth, that the physical +universe owes all its endless variety to differences in the form, size, +and density of planetary atoms in motion, according to simple mechanical +principles. These, combined with the existence of an all-pervading +medium filling space, between which and planetary matter no bond of +union subsists, other than that which arises from a continual +interchange of motion, are the materials from which the gems of nature +are elaborated. But, simplicity of means is what philosophy has ever +been reluctant to admit, preferring rather the occult and obscure. + +If action be equal to reaction, and all nature be vibrating with motion, +these motions must necessarily interfere, and some effect should be +produced. A body radiating its motion on every side into a physical +medium, produces waves. These waves are a mechanical effect, and the +body parts with some of its motion in producing them; but, should +another body be placed in juxtaposition, having the same motion, the +opposing waves neutralize each other, and the bodies lose no motion from +their contiguous sides, and, therefore, the reaction from the opposite +sides acts as a propelling power, and the bodies approach, or tend to +approach each other. If one body be of double the inertia, it moves only +half as far as the first; then, seeing that this atomic motion is +radiated, the law of force must be directly as the mass, and inversely +as the squares of the distances. There may be other atomic vibrations +besides those which we call light, heat, and chemical action, yet the +joint effect of all is infinitesimally small, when we disregard the +united _attraction_ of all the atoms of which the earth is composed. The +_attraction_ of the whole earth at the surface causes bodies to fall 16 +feet the first second of time; but, if two spheres of ice of one foot +diameter, were placed in an infinite space, uninfluenced by other +matter, and only 16 feet apart, they would require nearly 10,000 years +to fall together by virtue of their mutual attraction. Our conceptions, +or, rather, our misconceptions, concerning the force of gravity, arises +from our forgetting that every pound of matter on the earth contributes +its share of the force which, in the aggregate, is so powerful. Hence, +the cause we have suggested, is fully adequate to account for the +phenomena. Whether the harmony of vibrations between two bodies may not +have an influence in determining the amount of interference, and, +consequently, produce _some_ difference between the gravitating mass +and its inertia, is a question which, no doubt, will ultimately be +solved; but this harmony of vibrations must depend, in some degree, on +the atomic weight, temperature, and intensity of atomic motion. + +That a part of the mass of the earth is _latent_ may be inferred from +certain considerations: 1st, from the discrepancies existing in the +results obtained for the earth's compression by the pendulum and by +actual measurement; and, 2d, from the irregularity of that compression +in particular latitudes and longitudes. The same may also be deduced +from the different values of the moon's mass as derived from different +phenomena, dependent on the law of gravitation. Astronomers have +hitherto covered themselves with the very convenient shield of errors of +observation; but, the perfection of modern instruments now demand a +better account of all outstanding discrepancies. The world requires it +of them. + +The mass of the moon comes out much greater by our theory than nutation +gives. The mass deduced from the theory is only dependent on the +relative inertiae of the earth and moon. That given by nutation depends +on gravity. If, then, a part of the mass be latent, nutation will give +too small a value. But, in addition to this, we are justified in +doubting the strict wording of the Newtonian law, deriving our authority +from the very foundation stone of the Newtonian theory. + +It is well known that Newton suspected that the moon was retained in her +orbit by the same force which is usually called weight upon the surface, +sixteen years before the fact was confirmed, by finding a correspondence +in the fall of the moon and the fall of bodies on the earth. Usually, in +all elementary works, this problem is considered accurately solved. +Having formed a different idea of the mechanism of nature, this fact +presented itself as a barrier beyond which it was impossible to pass, +until suspicions, derived from other sources, induced the author to +inquire: Whether the phenomenon did exactly accord with the theory? We +are aware that it is easy to place the moon at such a distance, that the +result shall strictly correspond with the fact; but, from the parallax, +as derived from observation (and if this cannot be depended on +certainly, no magnitudes in astronomy can), we find, _that the moon does +not fall from the tangent of her orbit, as much as the theory requires_. +As this is of vital importance to the integrity of the theory we are +advocating, we have made the computation on Newton's own data, except +such as were necessarily inaccurate at the time he wrote; and we have +done it arithmetically, without logarithmic tables, that, if possible, +no error should creep in to vitiate the result. We take the moon's +elements from no less an authority than Sir John Herschel, as well as +the value of the earth's diameter. + + Mass of the moon 1/80 + Mean distance in equatorial radii 59.96435 + Sidereal period in seconds 2360591 + +The vibrations of the pendulum give the force of gravity at the surface +of the earth, and it is found to vary in different latitudes. The +intensity in any place being as the squares of the number of vibrations +in a given time. This inequality depends on the centrifugal force of +rotation, and on the spheroidal figure of the earth due to that +rotation. At the equator the fall of a heavy body is found to be +16.045223 feet, per second, and in that latitude the squares of whose +sine is 1/3, it is 16.0697 feet. The effect in this last-named latitude +is the same as if the earth were a perfect sphere. This does not, +however, express the whole force of gravity, as the rotation of the +earth causes a centrifugal tendency which is a maximum at the equator, +and there amounts to 1/289 of the whole gravitating force. In other +latitudes it is diminished in the ratio of the squares of the cosines of +the latitude; it therefore becomes 1/434 in that latitude the square of +whose sine is 1/3. Hence the fall per second becomes 16.1067 feet for +the true gravitating force of the earth, or for that force which retains +the moon in her orbit. + +The moon's mean distance is 59.96435 equatorial radii of the earth, +which radius is, according to Sir John Herschel, 20.923.713 +feet. Her mean distance as derived from the parallax is not to be +considered the radius vector of the orbit, inasmuch as the earth also +describes a small orbit around the common centre of gravity of the earth +and moon; neither is radius vector to be considered as her distance from +this common centre; for the attracting power is in the centre of the +earth. But the mean distance of the moon moving around a movable centre, +is to the same mean distance when the centre of attraction is fixed, as +the sum of the masses of the two bodies, to the first of two mean +proportionals between this sum and the largest of the two bodies +inversely. (Vid. Prin. Prop. 60 Lib. Prim.) The ratio of the masses +being as above 80 to 1 the mean proportional sought is 80.666 and in +this ratio must the moon's mean distance be diminished to get the force +of gravity at the moon. Therefore as 81 is to 80.666, so is 59.96435 to +59.71657 for the moon's distance in equatorial radii of the earth. +Multiply this last by 20.923,713 to bring the semi-diameter of the lunar +orbit into feet = 1.249.492.373, and this by 6.283185, the ratio of the +circumference to the radius, gives 7.850.791.736 feet, for the mean +circumference of the lunar orbit. + +Further, the mean sidereal period of the moon is 2360591 seconds and the +1/2360591th part of 7.850.791.736 is the arc the moon describes in one +second = 3325.77381 feet, the square of which divided by the diameter +of the orbit, gives the fall of the moon from the tangent or versed +size of that arc. + + 1106771.36876644 + = ---------------- = 0.004426106 feet. + 2498984746 + +This fraction is, however, too small, as the ablatitious action of the +sun diminishes the attraction of the earth on the moon, in the ratio of +178 29/40 to 177 29/40. So that we must increase the fall of the moon +in the ratio of 711 to 715, and hence the true fall of the moon from the +tangent of her orbit becomes 0.00451 feet per second. + +We have found the fall of a body at the surface of the earth, considered +as a sphere, 16.1067 feet per second, and the force of gravity +diminishes as the squares of the distances increases. The polar diameter +of the earth is set down as 7899.170 miles, and the equatorial diameter +7925.648 miles; therefore, the mean diameter is 7916.189 miles.[36] So +that, reckoning in mean radii of the earth, the moon's distance is +59.787925, which squared, is equal to 3574.595975805625. At one mean +radius distance, that is, at the surface, the force of gravity, or fall +per second, is as above, 16.1067 feet. Divide this by the square of the +distance, it is 16.1067/3574.595975805625 = 0.0045058 feet for the force +of gravity at the moon. But, from the preceding calculation, it appears, +that the moon only falls 0.0044510 feet in a second, showing a +deficiency of 1/82d part of the principal force that retains the moon in +her orbit, being more than double the whole disturbing power of the sun, +which is only 1/178th of the earth's gravity at the moon; yet, on this +1/178th depends the revolution of the lunar apogee and nodes, and all +those variations which clothe the lunar theory with such formidable +difficulties. The moon's mass cannot be less than 1/80, and if we +consider it greater, as it no doubt is, the results obtained will be +still more discrepant. Much of this discrepancy is owing to the +expulsive power of the radial stream of the terral vortex; yet, it may +be suspected that the effect is too great to be attributed to this, and, +for this reason, we have suggested that the fused matter of the moon's +centre may not gravitate with the same force as the exterior parts, and +thus contribute to increase the discrepancy. + +As there must be a similar effect produced by the radial stream of every +vortex, the masses of all the planets will appear too small, as derived +from their gravitating force; and the inertia of the sun will also be +greater than his apparent mass; and if, in addition to this, there be a +portion of these masses latent, we shall have an ample explanation of +the connection between the planetary densities and distances. We must +therefore inquire what is the particular law of force which governs the +radial stream of the solar vortex. It will be necessary to enter into +this question a little more in detail than our limits will justify; but +it is the resisting influence of the ether, and its consequences, which +will appear to present a vulnerable point in the present theory, and to +be incompatible with the perfection of astronomical science. + + +LAW OF DENSITY IN SOLAR VORTEX. + +Reverting to the dynamical principle, that the product of every particle +of matter in a fluid vortex, moving around a given axis, by its distance +from the centre and angular velocity, must ever be a constant quantity, +it follows that if the ethereal medium be uniformly dense, the periodic +times of the parts of the vortex will be directly as the distances from +the centre or axis; but the angular velocities being inversely as the +times, the absolute velocities will be equal at all distances from the +centre. + +Newton, in examining the doctrine of the Cartesian vortices, supposes +the case of a globe in motion, gradually communicating that motion to +the surrounding fluid, and finds that the periodic times will be in the +duplicate ratio of the distances from the centre of the globe. He and +his successors have always assumed that it was impossible for the +principle of gravity to be true, and a Cartesian plenum also; +consequently, the question has not been fairly treated. It is true that +Descartes sought to explain the motions of the planets, by the +mechanical action of a fluid vortex _solely_; and to Newton belongs the +glorious honor of determining, the existence of a centripetal force, +competent to explain these motions mathematically, (but not physically,) +and rashly rejected an intelligible principle for a miraculous virtue. +If our theory be true, the visible creation depends on the existence of +both working together in harmony, and that a physical medium is +absolutely necessary to the existence of gravitation. + +If space be filled with a fluid medium, analogy would teach us that it +is in motion, and that there must be inequalities in the direction and +velocity of that motion, and consequently there must be vortices. And if +we ascend into the history of the past, we shall find ample testimony +that the planetary matter now composing the members of the solar system, +was once one vast nebulous cloud of atoms, partaking of the vorticose +motion of the fluid involving them. Whether the gradual accumulation of +these atoms round a central nucleus from the surrounding space, and thus +having their tangential motion of translation converted into vorticose +motion, first produced the vortex in the ether; or whether the vortex +had previously existed, in consequence of conflicting currents in the +ether, and the scattered atoms of space were drawn into the vortex by +the polar current, thus forming a nucleus at the centre, as a necessary +result of the eddy which would obtain there, is of little consequence. +The ultimate result would be the same. A nucleus, once formed, would +give rise to a central force, tending more and more to counteract the +centripulsive power of the radial stream; and in consequence of this +continually increasing central power, the heaviest atoms would be best +enabled to withstand the radial stream, while the lighter atoms might be +carried away to the outer boundaries of the vortex, to congregate at +leisure, and, after the lapse of a thousand years, to again face the +radial stream in a more condensed mass, and to force a passage to the +very centre of the vortex, in an almost parabolic curve. That space is +filled with isolated atoms or planetary dust, is rendered very probable +by a fact discovered by Struve, that there is a gradual extinction in +the light of the stars, amounting to a loss of 1/107 of the whole, in +the distance which separates Sirius from the sun. According to Struve, +this can be accounted for, "by admitting as very probable that space is +filled with an _ether_, capable of intercepting in some degree the +light." Is it not as probable that this extinction is due to planetary +dust, scattered through the pure ether, whose vibrations convey the +light,--the material atoms of future worlds,--the debris of dilapidated +comets? Does not the Scripture teach the same thing, in asserting that +the heavens are not clean? + +The theory of vortices has had many staunch supporters amongst those +deeply versed in the science of the schools. The Bernoullis proposed +several ingenious hypothesis, to free the Cartesian system from the +objections urged against it, viz.: that the velocities of the planets, +in accordance with the three great laws of Kepler, cannot be made to +correspond with the motion of a fluid vortex; but they, and all others, +gave the vantage ground to the defenders of the Newtonian philosophy, by +seeking to refer the principle of gravitation to conditions dependent on +the density and vorticose motion of the ether. When we admit that the +ether is imponderable and yet material, and planetary matter subject to +the law of gravitation, the objections urged against the theory of +vortices become comparatively trivial, and we shall not stop to refute +them, but proceed with the investigation, and consider that the ether is +the original source of the planetary motions and arrangements. + +On the supposition that the ether is uniformly dense, we have shown that +the periodic times will be directly as the distances from the axis. If +the density be inversely as the distances, the periodic times will be +equal. If the density be inversely as the square roots of the distances, +the times will be directly in the same ratio. The celebrated J. +Bernoulli assumed this last ratio; but seeking the source of motion in +the rotating central globe, he was led into a hypothesis at variance +with analogy. The ellipticity of the orbit, according to this view, +was caused by the planet oscillating about a mean position,--sinking +first into the dense ether,--then, on account of superior buoyancy, +rising into too light a medium. Even if no other objection could be +urged to this view, the difficulty of explaining why the ether should be +denser near the sun, would still remain. We might make other +suppositions; for whatever ratio of the distances we assume for the +density of the medium, the periodic times will be compounded of those +distances and the assumed ratio. Seeing, therefore, that the periodic +times of the planets observe the direct ses-plicate ratio of the +distances, and that it is consonant to all analogy to suppose the +contiguous parts of the vortex to have the same ratio, we find that the +density of the ethereal medium in the solar vortex, is directly as the +square roots of the distances from the axis. + +Against this view, it may be urged that if the inertia of the medium is +so small, as is supposed, and its elasticity so great, there can be no +condensation by centrifugal force of rotation. It is true that when we +say the ether is condensed by this force, we speak incorrectly. If in an +infinite space of imponderable fluid a vortex is generated, the central +parts are rarefied, and the exterior parts are unchanged. But in all +finite vortices there must be a limit, outside of which the motion is +null, or perhaps contrary. In this case there may be a cylindrical ring, +where the medium will be somewhat denser than outside. Just as in water, +every little vortex is surrounded by a circular wave, visible by +reflection. As the density of the planet Neptune appears, from present +indications, to be a little denser than Uranus, and Uranus is denser +than Saturn, we may conceive that there is such a wave in the solar +vortex, near which rides this last magnificent planet, whose ring would +thus be an appropriate emblem of the peculiar position occupied by +Saturn. This may be the case, although the probability is, that the +density of Saturn is much greater than it appears, as we shall presently +explain. + +In order to show that there is nothing extravagant in the supposition of +the density of the ether being directly as the square roots of the +distances from the axis, we will take a fluid whose law of density is +known, and calculate the effect of the centrifugal force, considered as +a compressing power. Let us assume our atmosphere to be 47 miles high, +and the compressing power of the earth's gravity to be 289 times greater +than the centrifugal force of the equator, and the periodic time of +rotation necessary to give a centrifugal force at the equator equal to +the gravitating force to be 83 minutes. Now, considering the gravitating +force to be uniform, from the surface of the earth upwards, and knowing +from observation that at 18,000 feet above the surface, the density of +the air is only 1/2, it follows, (in accordance with the principle that +the density is as the compressing force,) that at 43 1/2 miles high, or +18,000 feet _below_ the surface of the atmosphere, the density is only +1/8000 part of the density at the surface of the earth. Let us +take this density as being near the limit of expansion, and conceive a +hollow tube, reaching from the sun to the orbit of Neptune, and that +this end of the tube is closed, and the end at the sun communicates with +an inexhaustible reservoir of such an attenuated gas as composes the +upper-layer of our atmosphere; and further, that the tube is infinitely +strong to resist pressure, without offering resistance to the passage of +the air within the tube; then we say, that, if the air within the tube +be continually acted on by a force equal to the mean centrifugal force +of the solar vortex, reckoning from the sun to the orbit of Neptune, the +density of the air at that extremity of the tube, would be greater than +the density of a fluid formed by the compression of the ocean into one +single drop. For the centrifugal force of the vortex at 2,300,000 miles +from the centre of the sun, is equal to gravity at the surface of the +earth, and taking the mean centrifugal force of the whole vortex as +one-millionth of this last force; so that at 3,500,000 miles from the +surface of the sun, the density of the air in the tube (supposing it +obstructed at that distance) would be double the density of the +attenuated air in the reservoir. And the air at the extremity of the +tube reaching to the orbit of Neptune, would be as much denser than the +air we breathe, as a number expressed by 273 with 239 ciphers annexed, +is greater than unity. This is on the supposition of infinite +compressibility. Now, in the solar vortex there is no physical barrier +to oppose the passage of the ether from the centre to the circumference, +and the density of the ethereal ocean must be considered uniform, except +in the interior of the stellar vortices, where it will be rarefied; and +the rarefaction will depend on the centrifugal force and the length of +the axis of the vortex. If this axis be very long, and the centrifugal +velocity very great, the polar influx will not be sufficient, and the +central parts will be rarefied. We see, therefore, no reason why the +density of the ether may not be three times greater at Saturn than at +the earth, or as the square roots of the distances directly. + + +BODES' LAW OF PLANETARY DISTANCES. + +Thus, in the solar vortex, there will be two polar currents meeting at +the sun, and thence being deflected at right angles, in planes parallel +to the central plane of the vortex, and strongest in that central plane. +The velocity of expansion must, therefore, diminish from the divergence +of the radii, as the distances increase; but in advancing along these +planes, the ether of the vortex is continually getting more dense, +which operate by absorption or condensation on the radial stream; so +that the velocity is still more diminished, and this in the ratio of the +square roots of the distances directly. By combining these two ratios, +we find that the velocity of the radial stream will be in the +ses-plicate ratio of the distances inversely. But the force of this +stream is not as the velocity, but as the square of the velocity. The +_force_ of the radial stream is consequently as the cubes of the +distances inversely, from the axis of the vortex, reckoned in the same +plane. If the ether, however, loses in velocity by the increasing +density of the medium, it becomes also more dense; therefore the true +force of the radial stream will be as its density and the square of its +velocity, or directly as the square roots of the distances, and +inversely as the cubes of the distances, or as the 2.5 power of the +distances inversely. + +If we consider the central plane of the vortex as coincident with the +plane of the ecliptic, and the planetary orbits, also, in the same +plane; and had the force of the radial stream been inversely as the +square of the distances, there could be no disturbance produced by the +action of the radial stream. It would only counteract the gravitation of +the central body by a certain amount, and would be exactly proportioned +at all distances. As it is, there is an outstanding force as a +disturbing force, which is in the inverse ratio of the square roots of +the distances from the sun; and to this is, no doubt, owing, in part, +the fact, that the planetary distances are arranged in the inverse order +of their densities. + +Suppose two planets to have the same diameter to be placed in the same +orbit, they will only be in equilibrium when their densities are equal. +If their densities are unequal, the lighter planet will continually +enlarge its orbit, until the force of the radial stream becomes +proportional to the planets' resisting energy. This, however, is on the +hypothesis that the planets are not permeable by the radial stream, +which, perhaps, is more consistent with analogy than with the reality. +And it is more probable that the mean atomic weight of a planet's +elements tends more to fix the position of equilibrium for each. Under +the law of gravity, a planet may revolve at any distance from the sun, +but if we superadd a centripulsive force, whose law is not that of +gravity, but yet in some inverse ratio of the distances, and this force +acts only superficially, it would be possible to make up in volume what +is wanted in density, and a lighter planet might thus be found occupying +the position of a dense planet. So the planet Jupiter, respecting only +his resisting surface, is better able to withstand the force of the +radial stream at the earth than the earth itself. To understand this, it +is necessary to bear in mind, that, as far as planetary matter is +concerned, the earth would revolve in Jupiter's orbit in the same +periodic time as Jupiter, under the law of gravity: but that, in +reality, the whole of the gravitating force is not effective, and that +the equilibrium of a planet is due to a nice balance of interfering +forces arising from the planet's physical peculiarities. As in a +refracting body, the density of the ether may be considered inversely as +the refraction, and this as the atomic weight of the refracting +material, so, also, in a planet, the density of the ether will be +inversely in the same ratio of the density of the matter approximately. +Hence, the density of the ether within the planet Jupiter is greater +than that within the earth; and, on this ethereal matter, the sun has no +power to restrain it in its orbit, so that the centrifugal momentum of +Jupiter would be relatively greater than the centrifugal momentum of the +earth, were it also in Jupiter's orbit with the same periodic time. +Hence, to make an equilibrium, the earth should revolve in a medium of +less density, that there may be the same proportion between the external +ether, and the ether within the earth, as there is between the ether +around Jupiter and the ether within; so that the centrifugal tendency of +the dense ether at Jupiter shall counteract the greater momentum of the +dense ether within Jupiter; or, that the lack of centrifugal momentum in +the earth should be rendered equal to the centrifugal momentum of +Jupiter, by the deficiency of the centrifugal momentum of the ether at +the distance of the earth. + +If then, the diameters of all the planets were the same (supposing the +ether to act only superficially), the densities would be as the +distances inversely;[37] for the force due to the radial stream is as +the square roots of the distance inversely, and the force due to the +momentum, if the density of the ether within a planet be inversely as +the square root of a planet's distance, will also be inversely as the +square roots of the distances approximately. We offer these views, +however, only as suggestions to others more competent to grapple with +the question, as promising a satisfactory solution of Bode's empirical +formula. + +If there be a wave of denser ether cylindrically disposed around the +vortex at the distance of Saturn, or between Saturn and Uranus, we see +why the law of densities and distances is not continuous. For, if the +law of density changes, it must be owing to such a ring or wave. Inside +this wave, the two forces will be inverse; but outside, one will be +inverse, and the other direct: hence, there should also be a change in +the law of distances. As this change does not take place until we pass +Uranus, it may be suspected that the great disparity in the density of +Saturn may be more apparent than real. The density of a planet is the +relation between its mass and volume or extension, no matter what the +form of the body may be. From certain observations of Sir Wm. +Herschel--the Titan of practical astronomers--the figure of Saturn was +suspected to be that of a square figure, with the corners rounded off, +so as to leave both the equatorial and polar zones flatter than +pertained to a true spheroidal figure. The existence of an unbroken ring +around Saturn, certainly attaches a peculiarity to this planet which +prepares us to meet other departures from the usual order. And when we +reflect on the small density, and rapid rotation, the formation of this +ring, and the figure suspected by Sir Wm. Herschel, it is neither +impossible nor improbable, that there may be a cylindrical vacant space +surrounding the axis of Saturn, or at least, that his solid parts may be +cylindrical, and his globular form be due to elastic gases and vapors, +which effectually conceal his polar openings. And also, by dilating and +contracting at the poles, in consequence of inclination to the radial +stream, (just as the earth's atmosphere is bulged out sufficiently to +affect the barometer at certain hours every day,) give that peculiarity +of form in certain positions of the planet in its orbit. Justice to Sir +Wm. Herschel requires that _his_ observations shall not be attributed to +optical illusions. This view, however, which may be true in the case of +Saturn, would be absurd when applied to the earth, as has been done +within the present century. From these considerations, it is at least +possible, that the density of Saturn may be very little less, or even +greater than the density of Uranus, and be in harmony with the law of +distances. + +It is now apparently satisfactorily determined, that Neptune is denser +than Uranus, and the law being changed, we must look for transneptunean +planets at distances corresponding with the new law of arrangement. But +there are other modifying causes which have an influence in fixing the +precise position of equilibrium of a planet. Each planet of the system +possessing rotation, is surrounded by an ethereal vortex, and each +vortex has its own radial stream, the force of which in opposing the +radial stream of the sun, depends on the diameter and density of the +planet, on the velocity of rotation, on the inclination of its axis, and +on the density of the ether at each particular vortex; but the numerical +verification of the position of each planet with the forces we have +mentioned, cannot be made in the present state of the question. There is +one fact worthy of note, as bearing on the theory of vortices in +connection with the rotation of the planets, viz.: that observation has +determined that the axial rotation and sidereal revolution of the +secondaries, are identical; thus showing that they are without vortices, +and are motionless relative to the ether of the vortex to which they +belong. We may also advert to the theory of Doctor Olbers, that the +asteroidal group, are the fragments of a larger planet which once +filled the vacancy between Mars and Jupiter. Although this idea is not +generally received, it is gathering strength every year by the discovery +of other _fragments_, whose number now amounts to twenty-six. If the +idea be just, our theory offers an explanation of the great differences +observable in the mean distances of these bodies, and which would +otherwise form a strong objection against the hypothesis. For if these +little planets be fragments, there will be differences of density +according as they belonged to the central or superficial parts of the +quondam planet, and their mean distances must consequently vary also. + +There are some other peculiarities connecting the distances and +densities, to which we shall devote a few words. In the primordial state +of the system, when the nebulous masses agglomerated into spheres, the +diameter of these nebulous spheres would be determined by the relation +existing between the rotation of the mass, and the gravitating force at +the centre; for as long as the centrifugal force at the equator exceeded +the gravitating force, there would be a continual throwing off of matter +from the equator, as fast as it was brought from the poles, until a +balance was produced. It is also extremely probable, (especially if the +elementary components of water are as abundant in other planets as we +have reason to suppose them to be on the earth,) that the condensation +of the gaseous planets into liquids and solids, was effected in a _brief +period of time_,[38] leaving the lighter and more elastic substances as +a nebulous atmosphere around globes of semi-fluid matter, whose +diameters have never been much increased by the subsequent condensation +of their gaseous envelopes. The extent of these atmospheres being (in +the way pointed out) determined by the rotation, their subsequent +condensation has not therefore changed the original rotation of the +central globe by any appreciable quantity. The present rotation of the +planets, is therefore competent to determine the former diameters of the +nebulous planets, _i.e._, the limit where the present central force +would be balanced by the centrifugal force of rotation. If we make the +calculation for the planets, and take for the unit of each planet its +present diameter, we shall find that they have condensed from their +original nebulous state, by a quantity dependent on the distance, from +the centre of the system; and therefore on the original temperature of +the nebulous mass at that particular distance. Let us make the +calculation for Jupiter and the earth, and call the original nebulous +planets the nucleus of the vortex. We find the Equatorial diameter of +Jupiter's nucleus in equatorial diameters of Jupiter = 2.21, and the +equatorial diameter of the earth's nucleus, in equatorial diameters of +the earth = 6.59. Now, if we take the original temperature of the +nebulous planets to be inversely, as the squares of the distances from +the sun, and their volumes directly as the cubes of the diameters in the +unit of each, we find that these cubes are to each other, in the inverse +ratio of the squares of the planet's distances; for, + + 2.21^3 : 6.59^3 :: 1^2 : 5.2^2, + +showing that both planets have condensed equally, allowing for the +difference of temperature at the beginning. And we shall find, beginning +at the sun, that the diameters of the nebulous planets, _ceteris +paribus_, diminish outwards, giving for the nebulous sun a diameter of +16,000,000 miles,[39] thus indicating his original great temperature. + +That the original nebulous planets did rotate in the same time as they +do at present, is proved by Saturn's ring; for if we make the +calculation, about twice the diameter of Saturn. Now, the diameter of +the planet is about 80,000 miles, which will also be the semi-diameter +of the nebulous planet; and the middle of the outer ring has also a +semi-diameter of 80,000 miles; therefore, the ring is the equatorial +portion of the original nebulous planet, and ought, on this theory, to +rotate in the same time as Saturn. According to Sir John Herschel, +Saturn rotates in 10 hours, 29 minutes, and 17 seconds, and the ring +rotates in 10 hours, 29 minutes, and 17 seconds: yet this is not the +periodic time of a satellite, at the distance of the middle of the ring; +neither ought the rings to rotate in the same time; yet as far as +observation can be trusted, both the inner and outer ring do actually +rotate in the same time. The truth is, the ring rotates too fast, if we +derive its centrifugal force from the analogy of its satellites; but it +is, no doubt, in equilibrium; and the effective mass of Saturn on the +satellites is less than the true mass, in consequence of his radial +stream being immensely increased by the additional force impressed on +the ether, by the centrifugal velocity of the ring. If this be so, the +mass of Saturn, derived from one of the inner satellites, will be less +than the same mass derived from the great satellite, whose orbit is +considerably inclined. The analogy we have mentioned, between the +diameters of the nebulous planets and their distances, does not hold +good in the case of Saturn, for the reason already assigned, viz.: that +the nebulous planet was probably not a globe, but a cylindrical ring, +vacant around the axis, as there is reason to suppose is the case at +present. + +And now we have to ask the question, Did the ether involved in the +nebulous planets rotate in the same time? This does not necessarily +follow. The ether will undoubtedly tend to move with increasing velocity +to the very centre of motion, obeying the great dynamical principle when +unresisted. If resisted, the law will perhaps be modified; but in this +case, its motion of translation will be converted into atomic motion or +heat, according to the motion lost by the resistance of atomic matter. +This question has a bearing on many geological phenomena. As regards the +general effect, however, the present velocity of the ether circulating +round the planets, may be considered much greater than the velocities of +the planets themselves. + + +PERTURBATIONS DUE TO THE ETHER. + +In these investigations it is necessary to bear in mind that the whole +resisting power of the ether, in disturbing the planetary movements, is +but small, in comparison with gravitation. We will, however, show that, +in the case of the planets, there is a compensation continually made by +this resistance, which leaves but a very small outstanding balance as a +disturbing power. If we suppose all the planets to move in the central +plane of the vortex in circular orbits, and the force of the radial +stream, (or that portion which is not in accordance with the law of +gravitation,) to be inversely as the square roots of the distances from +the sun, it is evident, from what has been advanced, that an equilibrium +could still obtain, by variations in the densities, distances and +diameter of the planets. Supposing, again, that the planets still move +in the same plane, but in elliptical orbits, and that they are in +equilibrium at their mean distances, under the influence or action of +the tangential current, the radial stream, and the density of the ether; +we see that the force of the radial stream is too great at the +perihelion, and too small at the aphelion. At the perihelion the planet +is urged from the sun and at the aphelion towards the sun. The density +and consequent momentum is also relatively too great at the perihelion, +which also urges the planet from the sun, and at the aphelion, +relatively too small, which urges the planet towards sun; and the law is +the same in both cases, being null at the mean distance of the planet, +at a maximum at the apsides; it is, consequently, as the cosine of the +planet's eccentric anomaly at other distances, and is positive or +negative, according as the planet's distance is above or below the mean. + +At the planet's mean distance, the circular velocity of the vortex is +equal to the circular velocity of the planet, and, at different +distances, is inversely in the sub-duplicate ratio of those distances. +But the circular velocity of a planet in the same orbit, is in the +simple ratio of the distances inversely. At the perihelion, the planet +therefore moves faster than the ether of the vortex, and at the +aphelion, slower; and the difference is as the square roots of the +distances; but the force of resistance is as the square of the velocity, +and is therefore in the simple ratio of the distances, as we have +already found for the effect of the radial stream, and centrifugal +momentum of the internal ether. At the perihelion this excess of +tangential velocity creates a resistance, which urges the planet towards +the sun, and at the aphelion, the deficiency of tangential velocity +urges the planet from the sun,--the maximum effect being at the apsides +of the orbit, and null at the mean distances. In other positions it is, +therefore, as the cosines of the eccentric anomaly, as in the former +case; but in this last case it is an addititious force at the +perihelion, and an ablatitious force at the aphelion, whereas the first +disturbing force was an ablatitious force at the perihelion, and an +addititious force at the aphelion; therefore, as we must suppose the +planet to be in equilibrium at its mean distance, it is in equilibrium +at all distances. Hence, a planet moving in the central plane of the +vortex, experiences no disturbance from the resistance of the ether. + +As the eccentricities of the planetary orbits are continually changing +under the influence of the law of gravitation, we must inquire whether, +under these circumstances, such a change would not produce a permanent +derangement by a change in the mean force of the radial stream, so as to +increase or diminish the mean distance of the planet from the sun. The +law of force deduced from the theory for the radial stream is as the 2.5 +power of the distances inversely. But, by dividing this ratio, we may +make the investigation easier; for it is equivalent to two forces, one +being as the squares of the distances, and another as the square roots +of the distances. For the former force, we find that in orbits having +the same major axis the mean effect will be as the minor axis of the +ellipse _inversely_, so that two planets moving in different orbits, but +at the same mean distance, experience a less or greater amount of +centripulsive force from this radial stream, according as their orbits +are of less or greater eccentricity, and this in the ratio of the minor +axis. On the other hand, under the influence of a force acting +centripulsively in the inverse ratio of the square roots of the +distances, we find the mean effect to be as the minor axis of the +ellipse _directly_, so that two planets in orbits of different +eccentricity, but having the same major axis, experience a different +amount from the action of this radial stream, the least eccentric orbit +being that which receives the greatest mean effect. By combining these +two results, we get a ratio of equality; and, consequently, the action +of the radial stream will be the same for the same orbit, whatever +change may take place in the eccentricity, and the mean distance of the +planet will be unchanged. A little consideration will also show that the +effect of the centrifugal momentum due to the density of ether will also +be the same by change of eccentricity; for the positive will always +balance the negative effect at the greatest and least distances of the +planet. The same remark applies to the effect of the tangential current, +so that no change can be produced in the major axes of the planetary +orbits by change of eccentricity, as an effect of the resistance of the +ether. + +We will now suppose a planet's orbit to be inclined to the central plane +of the vortex, and in this case, also, we find, that the action of the +radial stream tends to increase the inclination in one quadrant as much +as it diminishes it in the next quadrant, so that no change of +inclination will result. But, if the inclination of the orbit be changed +by planetary perturbations, the mean effect of the radial stream will +also be changed, and this will tell on the major axis of the orbit, +enlarging the orbit when the inclination diminishes, and contracting it +when it increases. The change of inclination, however, must be referred +to the central plane of the vortex. Notwithstanding the perfection of +modern analysis, it is confessed that the recession of the moon's nodes +does yet differ from the theory by its 350th part, and a similar +discrepancy is found for the advance of the perigee.[40] This theory is +yet far too imperfect to say that the action of the ethereal medium will +account for these discrepancies; but it certainly wears a promising +aspect, worthy the notice of astronomers. There are other minute +discordancies between theory and observation in many astronomical +phenomena, which theory _is_ competent to remove. Some of these we shall +notice presently; and, it may be remarked, that it is in those minute +quantities which, in astronomy, are usually attributed to errors of +observation, that this theory will eventually find the surest evidence +of its truth. + + +KEPLER'S THIRD LAW ONLY APPROXIMATELY TRUE. + +But it may be asked: If there be a modifying force in astronomy derived +from another source than that of gravitation, why is it that the +elements of the various members of the system derived solely from +gravitation should be so perfect? To this it may be answered, that +although astronomers have endeavored to derive every movement in the +heavens from that great principle, they have but partially succeeded. +Let us not surrender our right of examining Nature to the authority of a +great name, nor call any man master, either in moral or physical +science. It is well known that Kepler's law of the planetary distances +and periods, is a direct consequence of the Newtonian Law of +gravitation, and that the squares of the periodic times ought to be +proportional to the cubes of the mean distances. These times are given +accurately by the planets themselves, by the interval elapsing between +two consecutive passages of the node, and as in the case of the ancient +planets we have observations for more than two thousand years past, +these times are known to the fraction of the second. The determination +of the distances however, depends on the astronomer, and a tyro in the +science might suppose that these distances were actually measured; and +so they are roughly; but the astronomer does not depend on his +instruments, he trusts to _analogy_, and the mathematical perfection of +a law, which in the abstract is true; but which he does not know is +rigidly exact when applied to physical phenomena. From the immense +distance of the planets and the smallness of the earth, man is unable to +command a base line sufficiently long, to make the horizontal parallax a +sensible angle for the more distant planets; and there are difficulties +of no small magnitude to contend with, with those that are the nearest. +In the occasional transit of Venus across the sun, however, he is +presented with a means of measuring on an enlarged scale, from which the +distance of the sun is determined; and by _analogy_ the distance of all +the planets. Even the parallax of the sun itself is only correct, by +supposing that the square of the periodic time of Venus is in the same +proportion to the square of the periodic time of the earth as the cube +of her distance is to the cube of the earth's distance. Our next nearest +planet is Mars, and observations on this planet at its opposition to the +sun, invariably give a larger parallax for the sun--Venus giving 8.5776" +while Mars gives about 10". It is true that the first is obtained under +more favorable circumstances; but this does not prove the last to be +incorrect. It is well known that the British Nautical Almanac contains a +list of stars lying in the path of the planet Mars about opposition, +(for the very purpose of obtaining a correct parallax,) that minute +differences of declination may be detected by simultaneous observations +in places having great differences of latitude. Yet strange to say, the +result is discredited when not conformable to the parallax given by +Venus. If then, we cannot trust the parallax of Mars, _a fortiori_, how +can we trust the parallax of Jupiter, and say that his mean distance +exactly corresponds to his periodic time? Let us suppose, for instance, +that the radius vector of Jupiter fell short of that indicated by +analogy by 10,000 miles, we say that it would be extremely difficult, +nay, utterly impossible, to detect it by instrumental means. Let not +astronomers, therefore, be too sure that there is not a modifying cause, +independent of gravitation, which they will yet have to recognize. The +moon's distance is about one-fourth of a million of miles, and Neptune's +2854 millions, or in the ratio of 10,000 to 1; yet even the moon's +parallax is not trusted in determining her mass, how then shall we +determine the parallax of Neptune? It is therefore _possible_ that the +effective action of the sun is in some small degree different, on the +different planets, whether due to the action of the ether, to the +similarity or dissimilarity of material elements, to the temperature of +the different bodies, or to all combined, is a question yet to be +considered. + +As another evidence of the necessity of modifying the strict wording of +the Newtonian law, it is found that the disturbing action of Jupiter on +different bodies, gives different values for the mass of Jupiter. The +mass deduced from Jupiter's action on his satellites, is different from +that derived from the perturbations of Saturn, and this last does not +correspond with that given by Juno: Vesta also gives a different mass +from the comet of Encke, and both vary from the preceding values.[41] + +In the analytical investigation of planetary disturbances, the +disturbing force is usually divided into a radial and tangential force; +the first changing the law of gravitation, to which law the elliptic +form of the orbit is due. The radial disturbing force, therefore, being +directed to or from the centre, can have no influence over the first law +of Kepler, which teaches that the radius vector of each planet having +the sun as the centre, describes equal areas in equal times. If the +radial disturbing force be exterior to the disturbed body, it will +diminish the central force, and cause a progressive motion in the +aphelion point of the orbit. In the case of the moon this motion is very +rapid, the apogee making an entire revolution in 3232 days. Does this, +however, correspond with the law of gravitation? Sir Isaac Newton, in +calculating the effect of the sun's disturbing force on the motion of +the moon's apogee, candidly concludes thus: "Idoque apsis summa singulis +revolutionibus progrediendo conficit 1d 31' 28". Apsis lunae est duplo +velocior circiter." As there was a necessity for reconciling this +stubborn fact with the theory, his followers have made up the deficiency +by resorting to the tangential force, or, as Clairant proposed, by +continuing the approximations to terms of a higher order, or to the +square of the disturbing force. + +Now, in a circular orbit, this tangential force will alternately +increase and diminish the velocity of the disturbed body, without +producing any permanent derangement, the same result would obtain in an +elliptical orbit, if the position of the major axis were stationary. In +the case of the moon, the apogee is caused to advance by the disturbing +power of the radial force, and, consequently, an exact compensation is +not effected: there remains a small excess of velocity which geometers +have considered equivalent to a doubling of the radial force, and have +thus obviated the difficulty. To those not imbued with the profound +penetration of the modern analyst, there must ever appear a little +inconsistency in this result. The major axis of a planet's orbit depends +solely on the velocity of the planet at a given distance from the sun, +and the tangential portion of the disturbance due to the sun, and +impressed upon the moon, must necessarily increase and diminish +alternately the velocity of the moon, and interfere with the equable +description of the areas. If, then, there be left outstanding a small +excess of velocity over and above the elliptical velocity of the moon, +at the end of each synodical revolution, in consequence of the motion +impressed on the moon's apogee by the radial force, the _legitimate_ +effect would be a small enlargement of the lunar orbit every revolution +in a rapidly-increasing ratio, until the moon would at last be taken +entirely away. In the great inequality of Jupiter and Saturn, this +tangential force is not compensated at each revolution, in consequence +of continual changes in the configuration of the two planets at their +heliocentric conjunctions, with respect to the perihelion of their +orbits, and the near commensurability of their periods; and the effect +of the tangential force is, in this case, legitimately impressed on the +major axes of the orbits. But why (we may ask) should not this also be +expended on the motion of the aphelion as well as in the case of the +moon? Astronomy can make no distinctions between the orbit of a planet +and the orbit of a satellite. And, we might also ask, why the tangential +resistance to the comet of Encke should not also produce a retrograde +motion in the apsides of the orbit, instead of diminishing its period? +To the honor of Newton, be it remembered, that he never resorted to an +explanation of this phenomenon, which would vitiate that fundamental +proposition of his theory, in which the major axis of the orbit is shown +to depend on the velocity at any given distance from the focus. + +Some cause, however, exists to double the motion of the apogee, and +that there is an outstanding excess of orbital velocity due to the +tangential force, is also true. This excess may tell in the way +proposed, provided some other arrangement exists to _prevent_ a +permanent dilation of the lunar orbit; and this provision may be found +in the increasing density of the ether, which prevents the moon +overstepping the bounds prescribed by her own density, and the force of +the radial stream of the terral vortex. In the case of Jupiter and +Saturn, their mutual action is much less interfered with by change of +density in the ether in the enlarged or contracted orbit, and, +consequently, the effect is natural. Thus, we have in the law of density +of the ethereal medium a better safeguard to the stability of the +dynamical balance of the system, than in the profound and beautiful +Theorems of La Grange. It will, of course, occur to every one, that we +are not to look for the same law in every vortex, and it will, +therefore, appear as if the satellites of Jupiter, whose theory is so +well known, should render apparent any deviation between their periodic +times and the periodic times of the contiguous parts of the vortex, +which would obtain, if the density of the ether in the Jovian vortex +were not as the square roots of the distances directly. But, we have +shown how there can be a balance preserved, if the tangential resistance +of the vortex shall be equal and contrary at the different distances at +which the satellites are placed; that is, if these two forces shall +follow the same law. These are matters, however, for future +investigation. + + +LIGHT AND HEAT. + +But will not the admission of a vorticose motion of the ethereal medium, +affect the aberration of light? It is well known that the question has +been mooted, whether the velocity of reflected light is the same as that +of direct light. The value of aberration having been considered 20".25, +from the eclipses of Jupiter's satellites, while later determinations, +from observations on Polaris, give 20".45. It cannot be doubted that +light, in traversing the central parts of the solar vortex, that is, +having to cross the whole orbit of the earth, should pass this distance +in a portion of time somewhat different to a similar distance outside +the earth's orbit, where the density is greater, and consequently induce +an error in the aberration, determined by the eclipses of Jupiter's +satellites. In the case of Polaris, the circumstances are more equal; +still, a difference ought to be detected between the deduced aberration +in summer and in winter, as, in the first case, the light passes near +the axis of the solar vortex, where (according to the theory) a change +of density occurs. This is an important practical question, and the +suggestion is worthy attention. Now, the question occurs, will light +pass through the rarefied space with greater velocity than through the +denser ether beyond? From recent experiments, first instituted by Arago, +it is determined that light passes with less velocity through water than +through air; and one result of these experiments is the confirmation +they give to the theory of Fresnel, that the medium which conveys the +action of light partly partakes of the motion of the refracting body. +This of itself is a strong confirmation of this theory of an ethereal +medium. It may also be remarked, that every test applied to the +phenomenon of light, adds additional strength to the undulatory theory, +at the expense of the Newtonian theory of emission. As light occupies +time in traversing space, it must follow from the theory that it does +not come from the radiant point exactly in straight lines, inasmuch as +the ether itself is in motion tangentially,--the velocity being in the +sub-duplicate ratio of the distances from the sun inversely. + +May not that singular phenomenon,--the projection of a star on the +moon's disc, at the time of an occultation,--be due to this curvature of +the path of a ray of light, by considering that the rays from the moon +have less intensity, but more mechanical momentum, and consequently +more power to keep a straight direction? Let us explain: we have urged +that light, as well as heat, is a mechanical effect of atomic motion, +propagated through an elastic medium; that, _ceteris paribus_, the +product of matter by its motion is ever a constant quantity for equal +spaces throughout the universe,--in a word, that it is, and must +necessarily be, a fundamental law of nature. All departures from this +law are consequences of accidental arrangements, which can only be +considered of temporary duration. Our knowledge of planetary matter +requires the admission of differences in the density, form, and size of +ultimate atoms, and, according to the above law, when the atoms are of +uniform temperature or motion, the product of the matter of each by its +motion, when reduced to the same space, will be constant. The momentum +of two different atoms, therefore, we will consider equal, for the sake +of illustration; yet this momentum is made up of two different +elements,--matter and motion. Let us exaggerate the difference, and +assign a ratio of 1000 to 1. Suppose a ball of iron of 1000 lbs., +resting upon a horizontal plane, should be struck by another ball of 1 +lb., having a motion of 1000 feet in a second, and, in a second case, +should be struck by a ball of 1000 lbs., having a velocity of 1 foot per +second, the momentum of each ball is similar; but experience proves that +the motion impressed on the ball at rest is not similar; the ponderous +weight and slow motion is far more effective in displacing this ball, +for the reason that time is essential to the distribution of the motion. +If the body to be struck be small as, for instance, a nail, a greater +motion and less matter is more effective than much matter and little +motion. Hence, we have a _distinction_ applicable to the difference of +momentum of luminous and calorific rays. The velocity of a wave of sound +through the atmosphere, is the same for the deep-toned thunder and the +shrillest whistle,--being dependent on the density of the medium, and +not on the source from which it emanates. So it is in the ethereal +medium. + +This view is in accordance with the experiments of M. Delaroche and +Melloni, on the transmission of light and heat through diaphanous +bodies--the more calorific rays feeling more and more the influence of +thickness, showing that more motion was imparted to the particles of the +diaphanous substance by the rays possessing more material momentum, and +still more when the temperature of the radiating body was low, evidently +analogous to the illustration we have cited. Light may therefore be +regarded as the effect of the vibration of atoms having little mass, and +as this mass increases, the rays become more calorific, and finally the +calorific effect is the only evidence of their existence; as towards the +extreme red end of the spectrum they cease to be visible, owing to their +inability to impart their vibrations to the optic nerve. This may also +influence the law of gravitation. In this we have also an explanation of +the dispersion of light. The rays proceeding from atoms of small mass +having less material momentum, are the most refrangible, and those +possessing greater material momentum, are the least refrangible; so that +instead of presenting a difficulty in the undulatory theory of light, +this dispersion is a necessary consequence of its first principles. + +It is inferred from the experiments cited, and the facts ascertained by +them, viz.: that the velocity of light in water is less than its +velocity in air; that the density of the ether is greater in the first +case; but this by no means follows. We have advocated the idea, that the +ethereal medium is less dense within a refracting body than without. We +regard it as a fundamental principle. Taking the free ether of heaven; +the vibrations in the denser ether will no doubt be slowest; but within +a refracting body we must consider there is motion lost, or _light +absorbed_, and the time of the transmission is thus increased. + +There has been a phenomenon observed in transits of Mercury and Venus +across the sun, of which no explanation has been rendered by +astronomers. When these planets are visible on the solar disc, they are +seen surrounded by rings, as if the light was intercepted and increased +alternately. This is no doubt due to a small effect of interference, +caused by change of velocity in passing through the rarefied nucleus of +these planetary vortices, near the body of the planet, and through the +denser ether beyond, acting first as a concave, and secondly as a convex +refracting body; always considering that the ray will deviate _towards_ +the side of least insistence, and thus interfere. + +That heat is simply atomic motion, and altogether mechanical, is a +doctrine which ought never to have been questioned. The interest excited +by the bold experiments of Ericson, has caused the scientific to +_suspect_, that heat can be converted into motion, and motion into +heat--a fact which the author has considered too palpable to deny for +the last twenty years. He has ever regarded matter and motion as the two +great principles of nature, ever inseparable, yet variously combined; +and that without these two elements, we could have no conception of +anything existing. + +It may be thought by some, who are afraid to follow truth up the rugged +precipices of the hill of knowledge, that this theory of an +interplanetary plenum leads to materialism; forgetting, that He who made +the world, formed it of matter, and pronounced it "very good." We may +consider ethereal matter, in one sense, _purer_ than planetary matter, +because unaffected by chemical laws. Whether still purer matter exists, +it is not for us to aver or deny. The Scriptures teach us that "there is +a natural body and there is a spiritual body." Beyond this we know +nothing. We, however, believe that the _invisible_ world of matter, can +only be comprehended by the indications of that which is visible; yet +while humbly endeavoring to connect by one common tie, the various +phenomena of matter and motion, we protest against those doctrines which +teach the eternal duration of the present order of things, as being +incompatible with the analogies of the past, as well as with the +revelations of the future. + + +FOOTNOTES: + +[35] Silliman's Journal, vol xxxv., page 283. + +[36] The real diameter of the earth in that latitude, whose sine is +one-third, is a little greater than this; but the true mean is more +favorable for the Newtonian law. + +[37] This is, perhaps, the nearest ratio of the densities and distances. + +[38] This is an important consideration, as bearing on the geology of +the earth. + +[39] It is not as likely that the condensation of the sun was so sudden +as that of the planets, and therefore in this case this distance is only +approximate. + +[40] Mechanique Celeste. Theory of the Moon. + +[41] Mechanique Celeste. Masses of the planets. + + + + +SECTION FIFTH. + + +COMETARY PHENOMENA. + +The planetary arrangements of the solar system are all _a priori_ +indications of the theory of vortices, not only by the uniform direction +of the motions, the circular orbits in which these motions are +performed, the near coincidence of the planes of these orbits, and the +uniform direction of the rotation of the planets themselves; but, also, +by the law of densities and distances, which we have already attempted +to explain. In the motions of comets we find no such agreement. These +bodies move in planes at all possible inclinations in orbits extremely +eccentrical and without any general direction--as many moving contrary +to the direction of the planets as in the opposite direction; and when +we consider their great volume, and their want of mass, it appears, at +first sight, that comets do present a serious objection to the theory. +We shall point out, however, a number of _facts_ which tend to +invalidate this objection, and which will ultimately give the +preponderance to the opposite argument. + +Every fact indicative of the nature of comets proves that the nuclei are +masses of material gases, similar, perhaps (at least in the case of the +short-period comets), to the elementary gases of our own planet, and, +consequently, these masses must be but small. In the nascent state of +the system, the radial stream of the vortex would operate as a fan, +purging the planetary materials of the least ponderable atoms, and, as +it were, separating the wheat from the chaff. It is thus we conceive +that the average atomic density of each planet has been first determined +by the radial stream, and, subsequently, that the solidification of the +nebulous planets has, by their atomic density, assigned to each its +position in the system, from the consequent relation which it +established between the density of the ether within the planet, and the +density of the ether external to it, so that, according to this view, a +single isolated atom of the same density as the mean atomic density of +the earth could (_ceteris paribus_) revolve in an orbit at the distance +of the earth, and in the same periodic time. This, however, is only +advanced by way of illustration. + +The expulsive force of the radial stream would thus drive off this +cometary dust to distances in some inverse ratio of the density of the +atoms; but, a limit would ultimately be reached, when gravitation would +be relatively the strongest--the last force diminishing only as the +squares of the distances, and the first diminishing in the compound +ratio of the squares and the square roots of the distances. At the +extreme verge of the system, this cometary matter would accumulate, and, +by accumulation, would still further gather up the scattered atoms--the +sweepings of the inner space--and, in this condensed form, would again +visit the sun in an extremely elongated ellipse. It does not, however, +follow, that all comets are composed of such unsubstantial materials. +There may be comets moving in parabolas, or even in hyperbolas--bodies +which may have been accumulating for ages in the unknown regions of +space, far removed from the sun and stars, drifting on the mighty +currents of the great ethereal ocean, and thus brought within the sphere +of the sun's attraction; and these bodies may have no analogy to the +periodical comets of our system, which last are those with which we are +more immediately concerned. + +The periodical comets known are clearly arranged into two distinct +classes--one having a mean distance between Saturn and Uranus, with a +period of about seventy-five years, and another class, whose mean +distance assigns their position between the smaller planets and Jupiter, +having periods of about six years. These last may be considered the +siftings of the smaller planets, and the first the refuse of the +Saturnian system. In this light we may look for comets having a mean +distance corresponding to the intervals of the planets, rather than to +the distances of the planets themselves. One remarkable fact, however, +to be observed in these bodies is, that all their motions are in the +same direction as the planets, and, with one exception, there is no +periodical comet positively known whose motion is retrograde. + +The exception we have mentioned is the celebrated comet of Halley, whose +period is also about seventy-five years. In reasoning on the resistance +of the ether, we must consider that the case can have very little +analogy with the theory of projectiles in air; nor can we estimate the +inertia of an infinitely divisible fluid, from its resisting influence +on atomic matter, by a comparison of the resistance of an atomic fluid +on an atomic solid. Analogy will only justify comparisons of like with +like. The tangent of a comet's orbit, also, can only be tangential to +the circular motion of the ether at and near perihelion, which is a very +small portion of its period of revolution. As far as the tangential +resistance is concerned, therefore, it matters little whether its motion +be direct or retrograde. If a retrograde comet, of short period and +small eccentricity, were discovered moving also near the central plane +of the vortex, it would present a very serious objection, as being +indicative of contrary motions in the nascent state of the system. There +is no such case known. So, also, with the inclinations of the orbits; if +these be great, it matters little whether the comet moves in one way or +the other, as far as the tangential current of the vortex is concerned. +Yet, when we consider the average inclination of the orbit, and not of +its plane, we find that the major axes of nearly all known cometary +orbits are very little inclined to the plane of the ecliptic. + +In the following table of all the periodical comets known, the +inclination of the major axis of the orbit is calculated to the nearest +degree; but all cometary orbits with very few exceptions, will be found +to respect the ecliptic, and never to deviate far from that plane: + + +--------------------------------------------------------------------+ + | Designations | Periodic | Inclination | Motion | Planetary | + | of the Comets. | times. | of | in Orbit. | Intervals. | + | | | Major Axes | | | + |--------------------------------------------------------------------| + |Encke | 1818 | 3 years. | 1d | Direct |Mars & Ceres.| + |--------------------------------------------------------------------| + |De Vico | 1814 | | 2 | Direct | | + |Fayo | 1843 | | 4 | Direct | Ceres | + |De Avrest| 1851 | From | 1 | Direct | | + |Brorsen | 1846 | five | 7 | Direct | and | + |Messier | 1766 | to | 0 | Direct | | + |Clausen | 1743 | six | 0 | Direct | Jupiter. | + |Pigott | 1783 | or | 4 | Direct | | + |Pous | 1819 | seven | 3 | Direct | | + |Biela | 1826 | years. | 9 | Direct | | + |Blaupain | 1819 | | 2 | Direct | | + |Lexell | 1770 | | 1 | Direct | | + |--------------------------------------------------------------------| + |Pous | 1812 | | 17 | Direct | | + |Olbers | 1816 | about | 40 | Direct | Saturn | + |De Vico | 1846 | 75 | 13 | Direct | and | + |Brorsen | 1847 | years. | 12 | Direct | Uranus. | + |Westphal | 1852 | | 21 | Direct | | + |Halley | 1682 | | 16 | Retrograde| | + +--------------------------------------------------------------------+ + +From which it appears, that the objection arising from the great +inclination of the _planes_ of these orbits is much less important than +at first it appears to be. + +Regarding then, that a comet's mean distance depends on its mean atomic +density, as in the case of the planets, the undue enlargement of their +orbits by planetary perturbations is inadmissible. In 1770 Messier +discovered a comet which approached nearer the earth than any comet +known, and it was found to move in a small ellipse with a period of five +and a half years; but although repeatedly sought for, it was the +opinion of many, that it has never been since seen. The cause of this +seeming anomaly is found by astronomers in the disturbing power of +Jupiter,--near which planet the comet must have passed in 1779, but the +comet was not seen in 1776 before it passed near Jupiter, although a +very close search was kept up about this time. Now there are two +suppositions in reference to this body: the comet either moved in a +larger orbit previous to 1767, and was then caused by Jupiter to +diminish its velocity sufficiently to give it a period of five and a +half years, and that after perihelion it recovered a portion of its +velocity in endeavoring to get back into its natural orbit; or if moving +in the natural orbit in 1770, and by passing near Jupiter in 1779 this +orbit was deranged, the comet will ultimately return to that mean +distance although not necessarily having elements even approximating +those of 1770. In 1844, September 15th, the author discovered a comet in +the constellation Cetus, (the same previously discovered by De Vico at +Home,) and from positions _estimated with the naked eye_ approximately +determined the form of its orbit and its periodic time to be very +similar to the lost comet of 1770. These conclusions were published in a +western paper in October 1844, on which occasion he expressed the +conviction, that this was no other than the comet of 1770. As the +question bore strongly on his theory he paid the greater attention to +it, and had, previously to this time, often searched in hopes of finding +that very comet. Since then, M. Le Verrier has examined the question of +identity and given his decision against it; but the author is still +sanguine that the comet of 1844 is the same as that of 1770, once more +settled at its natural distance from the sun. This comet returns to its +perihelion on the 6th of August, 1855, according to Dr. Brunnow, when, +it is hoped, the question of identity will be reconsidered with +reference to the author's principles; and, that when astronomers become +satisfied of this, they will do him the justice of acknowledging that +he was the first who gave publicity to the fact, that the "Lost Comet" +was found. + +That comets do experience a resistance, is undeniable; but not in the +way astronomers suppose, if these views be correct. The investigations +of Professor Encke, of Berlin, on the comet which bears his name, has +determined the necessity of a correction, which has been applied for +several returns with apparent success. But there is this peculiarity +about it, which adds strength to our theory: "The Constant of +Resistance" requires a change after perihelion. The necessity for this +change shows the action of the radial stream. From the law of this +force, (reckoning on the central plane of the vortex,) there is an +outstanding portion, acting as a disturbing power, in the sub-duplicate +ratio of the distances inversely. If we only consider the mean or +average effect in orbits nearly circular, this force may be considered +as an ablatitious force at all distances below the mean, counterbalanced +by an opposite effect at all distances above the mean. But when the +orbits become very eccentrical, we must consider this force as +momentarily affecting a comet's velocity, diminishing it as it +approaches the perihelion, and increasing it when leaving the +perihelion. A resolution of this force is also requisite for the comet's +distance above the central plane of the vortex, and a correction, +likewise, for the intensity of the force estimated in that plane. There +is also a correction necessary for the perihelion distance, and another +for the tangential current; but we are only considering here the general +effect. By diminishing the comet's proper velocity in its orbit, if we +consider the attraction of the sun to remain the same, the general +effect _may_ be (for this depends on the tangential portion of the +resolved force preponderating) that the absolute velocity will be +increased, and the periodic time shortened; but after passing the +perihelion, with the velocity of a smaller orbit, there is also +superadded to this already undue velocity, the expulsive power of the +radial stream, adding additional velocity to the comet; the orbit is +therefore enlarged, and the periodic time increased. Hence the necessity +of changing the "Constant of Resistance" after perihelion, and this will +generally be found necessary in all cometary orbits, if this theory be +true. But this question is one which may be emphatically called the most +difficult of dynamical problems, and it may be long before it is fully +understood. + +According to the calculations of Professor Encke, the comet's period is +accelerated about 2 hours, 30 minutes, at each return, which he +considers due to a resisting medium. May it not rather be owing to _the +change of inclination of the major axis of the orbit, to the central +plane of the vortex_? Suppose the inclination of the _plane_ of the +orbit to remain unchanged, and the eccentricity of the orbit also, if +the longitude of the perihelion coincides with that of either node, the +major axis of the orbit lies in the ecliptic, and the comet then +experiences the greatest mean effect from the radial stream; its mean +distance is then, _ceteris paribus_, the greatest. When the angle +between the perihelion and the nearest node increases, the mean force of +the radial stream is diminished, and the mean distance is diminished +also. When the angle is 90d, the effect is least, and the mean distance +least. This is supposing the ecliptic the central plane of the vortex. +When Encke's formula was applied to Biela's comet, it was inadequate to +account for a tenth part of the acceleration; and although Biela moves +in a much denser medium, and is of less dense materials, even this taken +into account will not satisfy the observations,--making no other change +in Encke's formula. We must therefore attribute it to changes in the +elements of the orbits of these comets. Now, the effect of resistance +should also have been noticed, as an acceleration of Halley's comet in +1835, yet the period was prolonged. To show, that our theory of the +_cause_ of these anomalies corresponds with facts, we subjoin the +elements in the following tables, taken from Mr. Hind's catalogue: + +THE ELEMENTS OF ENCKE'S COMET. + + Date of Longitude of Longitude of Difference of + Perihelion. Perihelion. nearest Node Longitude. + 1822 157d 11' 44" 154d 25' 9" 2d 46' 35" + 1825 157 14 31 154 27 30 2 47 1 + 1829 157 17 53 154 29 32 2 48 21 + 1832[42] 157 21 1 154 32 9 2 41 52 + 1835 157 23 29 154 34 59 2 48 30 + 1838 157 27 4 154 36 41 2 50 23 + 1842 157 29 27 154 39 10 2 50 17 + 1845 157 44 21 154 19 33 3 24 48 + 1848 157 47 8 154 22 12 3 24 56 + 1852 157 51 2 154 23 21 3 27 41 + +In this we see a regular increase of the angle, which ought to be +attended with a small acceleration of the comet; but the change of +inclination of the orbit ought also to be taken into consideration, to +get the mean distance of the comet above the plane of the vortex, and, +by this, the mean force of the radial stream. + +In the following table, the same comparison is made for Biela's comet:-- + +ELEMENTS OF BIELA'S COMET. + + Date of Longitude of Longitude of Difference of + Perihelion. Perihelion. nearest Node. Longitude. + 1772 110d 14' 54" 74d 0' 1" 36d 14' 53" + 1806 109 32 23 71 15 15 38 17 8 + 1826 109 45 50 71 28 12 38 17 38[43] + 1832 110 55 55 68 15 36 41 45 19 + 1846 109 2 20 65 54 39 43 7 41 + +Between 1832 and 1846, the increase of the angle is twice as great for +Biela as for Encke, and the angle itself throws the major axis of Biela +10d above the ecliptic, whereas the angle made by Encke's major axis, is +only about 1d; the cosine of the first angle, diminishes much faster +therefore, and consequently the same difference of longitude between the +perihelion and node, will cause a greater acceleration of Biela; and +according to Prof. Encke's theory, Biela would require a resisting +medium twenty-five times greater than the comet of Encke to reconcile +observation with the theory. Halley's comet can scarcely be considered +to have had an orbit with perfect elements before 1835. If they were +known accurately for 1759, we should no doubt find, that the angle +between the node and perihelion _diminished_ in the interval between +1750 and 1835, as according to the calculations of M. Rosenberg, the +comet was six days behind its time--a fact fatal to the common ideas of +a resisting medium; but this amount of error must be received as only +approximate. + +No comet that has revisited the sun, has given astronomers more trouble +than the great comet of 1843. Various orbits have been tried, +elliptical, parabolic and hyperbolic; yet none will accord with all the +observations. The day before this comet was seen in Europe and the +United States, it was seen close to the body of the sun at Conception, +in South America; yet this observation, combined with those following, +would give an orbital velocity due to a very moderate mean distance. +Subsequent observations best accorded with a hyperbolic orbit; and it +was in view of this anomaly, that the late Sears C. Walker considered +that the comet came into collision with the sun in an elliptical orbit, +and its _debris_ passed off again in a hyperbola. That a concussion +would not add to its velocity is certain, and the departure in a +hyperbolic orbit would be contrary to the law of gravitation. This +principle is thus stated by Newton:--"In parabola velocitas ubiquo +equalis est velocitati corporis revolventis in circulo ad dimidiam +distantiam; in ellipsi minor est in hyperbola major." (Vid. Prin. Lib. +1. Prop. 6 Cor. 7.) + +But as regards the _fact_, it is probable that Mr. Walker's views are +correct, so far as the change from an ellipse to an hyperbola is +considered. The Conception observation cannot be summarily set aside, +and Professor Peirce acknowledges, that "If it was made with anything of +the accuracy which might be expected from Captain Ray, it exhibits a +decided anomaly in the nature of the forces to which the comet was +subjected during its perihelion passage." The comet came up to the sun +almost in a straight line against the full force of the radial stream; +its velocity must therefore necessarily have been diminished. After its +perihelion, its path was directly _from_ the sun, and an undue velocity +would be kept up by the auxiliary force impressed upon it by the same +radial stream; and hence, the later observations give orbits much larger +than the early ones, and there can be no chance of identifying this +comet with any of its former appearances, even should its orbit be +elliptical. This unexpected confirmation of the theory by the +observation of Capt. Ray, cannot easily be surmounted. + +We must now endeavor to explain the physical peculiarities of comets, in +accordance with the principles laid down. The most prominent phenomenon +of this class is the change of diameter of the visible nebulosity. It is +a most singular circumstance, but well established as a fact, that a +comet contracts in its dimensions on approaching the sun, and expands on +leaving it. In 1829, accurate measures were taken on different days, of +the diameter of Encke's comet, and again in 1838. The comet of 1618 was +also observed by Kepler with this very object, and also the comet of +1807; but without multiplying instances, it may be asserted that it is +one of those facts in cometary phenomena, to which there are no +exceptions. According to all analogy, the very reverse of this ought to +obtain. If a comet is chiefly vaporous, (as this change of volume would +seem to indicate,) its approach to the sun ought to be attended by a +corresponding expansion by increase of temperature. When the contrary is +observed, and invariably so, it ought to be regarded as an index of the +existence of other forces besides gravitation, increasing rapidly in the +neighborhood of the sun; for the disturbing power of the sun's +attraction would be to enlarge the diameter of a comet in proportion to +its proximity. Now, the force of the radial stream, as we have shown, is +as the 2.5th power of the distances inversely. If this alternate +contraction and expansion be due to the action of this force, there +ought to be an approximate correspondence of the law of the effect with +the law of the cause. Arago, in speaking of the comet of 1829, states, +"that between the 28th of October and the 24th of December, the volume +of the comet was reduced as 16000 to 1, the change of distance in the +meantime only varying about 3 to 1." To account for this, a memoir was +published on the subject by M. Valz, in which he supposes an atmosphere +around the sun, whose condensation increases rapidly from superincumbent +pressure; so that the deeper the comet penetrates into this atmosphere +the greater will be the pressure, and the less the volume. In this it is +evident, that the ponderous nature of a resisting medium is not yet +banished from the schools. In commenting on this memoir, Arago justly +observes, that "there would be no difficulty in this if it could be +admitted that the exterior envelope of the nebulosity were not permeable +to the ether; but this difficulty seems insurmountable, and merits our +sincere regret; for M. Valz's ingenious hypothesis has laid down the law +of variation of the bulk of the nebulosity, as well for the short-period +comet as for that of 1618, with a truly wonderful exactness." Now, if we +make the calculation, we shall find that the diameter of the nebulosity +of a comet is inversely as the force of the radial stream. This force is +inversely as the 2.5 power of the distances from the axis, and not from +the sun: it will, therefore, be in the inverse ratio of the cosine of +the comet's heliocentric latitude to radius, and to this ratio the +comet's distance ought to be reduced. But, this will only be correct for +the same plane or for equal distances above the ecliptic plane, +considering this last as approximately the central plane of the vortex. +From the principles already advanced, the radial stream is far more +powerful on the central plane than in more remote planes; therefore, if +a comet, by increase of latitude, approaches near the axis, thus +receiving a larger amount of force from the radial stream in that plane +than pertains to its actual distance from the sun, it will also receive +a less amount of force in that plane than it would in the central plane +at the same distance from the axis. Now, we do not know the difference +of force at different elevations above the central plane of the vortex; +but as the two differences due to elevation are contrary in their +effects and tend to neutralize each other, we shall make the calculation +as if the distances were truly reckoned from the centre of the sun. + +The following table is extracted from Arago's tract on Comets, and +represents the variations of the diameter of Encke's comet at different +distances from the sun,--the radius of the orbis magnus being taken as +unity. + + Times of observation, Distances of the Real diameters + 1828. comet from the sun. in radii of the earth. + Oct. 28 1.4617 79.4 + Nov. 7 1.3217 64.8 + Nov. 30 0.9668 29.8 + Dec. 7 0.8473 19.9 + Dec. 14 0.7285 11.3 + Dec. 24 0.6419 3.1 + +In order the better to compare the diameters with the force, we will +reduce them by making the first numbers equal. + + Distances. Diameters. The 2.5th power Reduced + of the Distances. Diameters. + 1.4617 79.4 2.58 2.58 + 1.3217 64.8 2.10 2.10 + 0.9668 29.8 0.92 0.97 + 0.8473 19.9 0.66 0.65 + 0.7285 11.3 0.45 0.37 + 0.5419 3.1 0.21 0.10 + +This is a very close approximation, when we consider the difficulty of +micrometric measurement, and the fact, that as the comet gets nearer to +the sun, as at the last date of the table, the diameter is more than +proportionally diminished by the fainter nebulosity becoming invisible. +But, there may be a reality in the discrepancy apparent at the last +date, as the comet was then very near the plane of the ecliptic, and +was, consequently, exposed to the more violent action of the radial +stream. + +To attempt to explain the _modus agendi_ is, perhaps, premature. Our +principal aim is to pioneer the way into the labyrinth, and it is +sufficient to connect this seeming anomaly with the same general law we +have deduced from other phenomena. Still, an explanation may be given in +strict accordance with the general principles of the theory. + +Admitting the _nucleus_ of a comet to be gaseous, there is no difficulty +about the solution. According to Sir John Herschel, "stars of the +smallest magnitude remain distinctly visible, though covered by what +appears the densest portion of their substances; and since it is an +observed fact, that the large comets which have presented the appearance +of a nucleus, have yet exhibited no phases, though we cannot doubt that +they shine by the reflected solar light, it follows that even these can +only be regarded as great masses of thin vapor." That comets shine +solely by reflected solar light, is a position that we shall presently +question; but that they are masses of vapor is too evident to dispute. +According to the same authority quoted above, "If the earth were reduced +to the one thousandth part of its actual mass, its coercive power over +the atmosphere would be diminished in the same proportion, and in +consequence the latter would expand to a thousand times its actual +_bulk_." If this were so, and comets composed of the elementary gases, +some of them would have very respectable masses, as the nuclei are +frequently not more than 5,000 miles in diameter, and consequently it +becomes important to examine the principle. From all experiments the +density of an elastic fluid is directly as the compressing force; and if +a cylinder reached to the top of our atmosphere, compressed by the +gravitation of the earth, considered equal at each end of the cylinder, +it would represent the actual compressing force to which it owes its +density. If the gravitation of the earth were diminished one thousand +times this atmospheric column would expand one thousand times,[44] +(taking no account of the decrease of gravitation by increase of +distance;) so that the diameter of the aerial globe would be increased +to 108,000 miles, taking the atmosphere at 50 miles. But the mere +increasing the _bulk_ of the atmosphere 1000 times would increase the +diameter to little more than double. Even giving the correct expansion, +a comet's mass must be much greater than is generally supposed, or the +diameters of the nuclei would be greater if composed of any gas lighter +than atmospheric air. + +It is very improbable that a comet is composed of only one elementary +gas, and if of many, their specific gravities will vary; the lighter, of +course, occupying the exterior layers. With such a small mass, +therefore, the upper portion of its atmosphere must be very attenuated. +Now let us remember that the density of the ether at a comet's aphelion, +is greater than at the perihelion, in the direct ratio of the square +roots of the distances from the sun nearly. At the aphelion the comet +lingers through half his period, giving ample time for the nucleus to be +permeated by ether proportionally dense with the surrounding ether of +the vortex at that distance. Thus situated, the comet descends to its +perihelion, getting faster and faster into a medium far less dense, and +there must consequently be an escape from the nucleus, or in common +parlance, the comet is positively electric. This escaping ether, in +passing through the attenuated layers composing the surface of the +nucleus, impels the lighter atoms of cometic dust further from the +centre, and as for as this _doubly_ attenuated atmosphere of isolated +particles extends, so far will the escaping ether be rendered luminous. +It may be objected here, that a contrary effect ought to be produced +when the comet is forsaking, its perihelion; but the objection is +premature, as the heat received from the sun will have the same effect +in increasing the elasticity, as change of density, and the comet will +probably part with its internal ether as long as it is visible to the +earth; and not fully regain it perhaps, until after it arrives at its +aphelion. Suppose that we admit that a comet continues to expand in the +same ratio for all distances, as is laid down for the comet of Encke +when near its perihelion; it would follow, that the comet of 1811, would +have a diameter at its aphelion of fifty millions of millions of miles, +that is, its outside would extend one thousand times further from the +sun, at the opposite side to that occupied by the centre of the comet, +than the distance of the comet's centre from the sun, at its enormous +aphelion distance. Such an absurdity shows us that there is a limit of +expansion due to natural causes, and that if there were no radial stream +the volume of a comet would be greatest when nearest the sun. + +But while the comet is shortening its distance and hastening to the sun +in the form of a huge globular mass of diffuse light, it is continually +encountering another force, increasing in a far more rapid ratio than +the law of gravitation. At great distances from the sun, the force of +the radial stream was insufficient to detach any portion of the comet's +atmosphere; presently, however, the globular form is changed to an +ellipsoid, the radial stream begins to strip the comet of that doubly +attenuated atmosphere of which we have spoken, and the diameter of the +comet is diminished, merely because the luminosity of the escaping ether +is terminated at the limit of that atmosphere. Meanwhile the mass of the +comet has suffered only an infinitely small diminution; but if the +perihelion distance be small, the force may become powerful enough to +detach the heavier particles of the nucleus, and thus a comet may suffer +in mass by this denudating process. We regard, therefore, the nucleus of +a comet to represent the mass of the comet and the coma, as auroral rays +passing through a very attenuated envelope of detached particles. The +individual gravitating force of these particles to the comet's centre, +may be therefore considered as inversely as the squares of the +distances, and directly as the density of the particles; and this +density will, according to analogical reasoning, be as the distances or +square roots of the distances;--grant the last ratio, and the +gravitating force of the particles composing the exterior envelope of a +comet, becomes inversely as the 2.5th power of the distances from the +comet's centre.[45] This being the law of the radial stream, it follows, +of course, that a comet's diameter is inversely as the force of the +radial stream. It must, however, be borne in mind, that we are speaking +of the atomic density, and not of density by compression; for this +cometary dust, which renders luminous the escaping ether of the nucleus, +must be far too much diffused to merit the name of an elastic fluid. May +not the concentric rings, which were so conspicuous in the comet of +1811, be owing to differences in the gravitating forces of such +particles, sifted, as it were, and thus arranged, according to some +ratio of the distances, by the centripulsive force of the electric coma, +leaving vacant intervals, through which the ether passed without +becoming luminous? This at least is the explanation given by our theory. +We may, indeed, consider it possible that the escaping ether, when very +intense, might be rendered luminous by passing into the surrounding +ether, and, as it became more diffused by radiation, at last become +invisible. In this case, as the law of radiation is as the squares of +the distances from the centre inversely, the rays would be more and more +bent at right angles, or apparently shortened, as the power of the +radial stream increased, and the apparent diameters of the coma would +be diminished faster than the ratio of the 2.5th power of the distances. +But whichever view we adopt, the diameter would again increase in the +same ratio on leaving the sun, if we make allowance for increase of +temperature, as well as for diminution of density, for the ordinary +distance of a comet's visibility. We, however, regard the change of +diameter, as due to both these nodes of action, as best agreeing with +the indications afforded by their tails. + +From the preceding remarks, it results that the density of the particles +producing the nebulous envelope of a comet, renders the variations of +diameter only approximate to the law of the radial stream; a comet's own +electric energy, or the intensity of the escaping ether, may also modify +this expression, and many other causes may be suggested. That the radial +stream is the cause, in the way we have pointed out, is proved by the +positions of the major axis of the short-period comet, making frequently +nearly a right angle with the radius vector of the orbit in 1828. A soap +bubble gently blown aside, without detaching it from the pipe, will +afford a good illustration of the mode, and a confirmation of the cause. +The angles measured by Struve, reckoned from the radius vector, +prolonged towards the sun, are subjoined: + + November 7 99d.7 | December 7 154d.0 + November 30 145 .3 | December 14 149 .4 + +At this last date, the comet was getting pretty close to the sun. When +the angle was greater, as on November 7th, the comet appeared to make +almost a right angle with the radius vector; and in this position of the +earth and comet, the longer axis of the elliptical comet was directed to +the axis of the vortex, as may be verified by experiment. At the later +dates, the comet was more rapidly descending, and, at the same time, the +axis of the comet was getting more directed towards the earth; so that +the angle increased between this axis and the radius vector, and +consequently became more coincident with it. We have now to consider the +luminous appendage of a comet, commonly called a tail. + +The various theories hitherto proposed to account for this appendage are +liable to grave objections. That it is not refracted light needs not a +word of comment. Newton supposes the tail to partake of the nature of +vapor, rising from the sun by its extreme levity, as smoke in a chimney, +and rendered visible by the reflected light of the sun. But, how vapor +should rise towards opposition in a vacuum, is utterly inexplicable. In +speaking of the greater number of comets near the sun than on the +opposite side, he observes: "Hinc etiam manifestum est quod coeli +resistentia destituuntur."[46] And again, in another place, speaking of +the tail moving with the same velocity of the comet, he says: "Et hinc +rursus colligitur spatia coelestia vi resistendi destitui; utpote in +quibus non solum solida planetarum et cometarum corpora, sed etiam +rarissimi candarum vapores motus suos velocissimos liberrime peragunt ac +diutissime conservant." On what _principle_, therefore, Newton relied to +cause the vapors to ascend, does not appear. Hydrogen rises in our +atmosphere because specifically lighter. If there were no atmosphere, +hydrogen would not rise, but merely expand on all sides. But, a comet's +tail shoots off into space in a straight line of one hundred millions of +miles, and frequently as much as ten millions of miles in a single day, +as in the case of the comet of 1843. Sir John Herschel observes, that +"no rational or even plausible account has yet been rendered of those +immensely luminous appendages which they bear about with them, and which +are known as their tails." Yet, he believes, and astronomers generally +believe, that a comet shines by reflected light. This theory of +reflexion is the incubus which clogs the question with such formidable +difficulties; for, it follows, that the reflecting matter must come +from the comet. But, what wonderful elements must a comet be made of, to +project themselves into space with such immense velocity, and in such +enormous quantities as to exceed in volume the body from which they +emanate many millions of times. This theory may be, therefore, safely +rejected. + +From what we have already advanced concerning the coma or nebulosity of +the comet, we pass by an easy path to an explanation of the tail. In the +short-period comets, the density of the elementary atoms is too great to +be detached in the gross from the nucleus, or, rather, the density of +the atoms composing the nucleus is too great to permit the radiating +stream of the comet carrying them to a sufficient distance to be +detached by the radial stream of the sun. Hence, these comets exhibit +but very little tails. We may also conceive, that the continual siftings +which the nucleus undergoes at each successive perihelion passage, have +left but little of those lighter elements in comets whose mean distances +are so small. Yet, again, if by any chance the eccentricity is +increased, there are two causes--the density of the ether, and the heat +of the sun--which may make a comet assume quite an imposing appearance +when apparently reduced to the comparatively passive state above +mentioned. + +According to our theory, then, the coma of a comet is due to the +elasticity of the ethereal medium within the nucleus, caused both by the +diminished pressure of the external ether near the sun, and also by the +increased temperature acting on the nucleus, and thus on the involved +ether. The tail, on the contrary, is caused by the lighter particles of +the comet's attenuated atmosphere being blown off by the electric blast +of the radial stream of the solar vortex, in sufficient quantities to +render its passage visible. It is not, therefore, reflected light, but +an ethereal stream rendered luminous by this detached matter still held +in check by the gravitating force of the sun, whose centre each +particle still respects, and endeavors to describe such an orbit as +results from its own atomic density, and the resultant action of both +the acting forces. From the law of density of the ether, the coma ought +to be brightest and the radiating stream of the comet's nucleus +strongest on the side of least pressure: from this cause, and the fact +that the body of the comet affords a certain protection to the particles +immediately behind it, there will be an interval between the comet and +the tail less luminous, as is almost invariably observed. We thus have +an explanation of the fact noticed by Sir John Herschel, "that the +structure of a comet, as seen in section in the direction of its length, +must be that of a hollow envelope of a parabolic form, enclosing near +its vertex the nucleus or head." We have, also, a satisfactory +explanation of the rapid formation of the tail; of its being wider and +fainter at its extremity; of its occasional curvature; and of its +greater length after perihelion than before. But, more especially may we +point to the explanation which this theory gives of the fact, that, +_ceteris paribus_, the long-period comets, when their perihelion +distances are small, have tails of such exaggerated dimensions. + +A comet, whose mean distance is considerable, is supposed by the theory +to be composed of elements less dense, and, during its long sojourn at +its aphelion, it may be also supposed that it there receives continual +accessions to its volume from the diffused siftings of the system, and +from the scattered debris of other comets. On approaching the +perihelion, the rapidity of the change in the density of the ether in a +given time, depends on the eccentricity of the orbit, and so does the +change of temperature; so that, from both causes, both the length of the +tail and the brilliancy of the comet measurably depends on the magnitude +of the period and of the eccentricity. + +If the nuclei of comets be gaseous as we suppose, and that the smallest +stars are visible through them, it is an outrage on common sense, to +refer that light, which renders a comet visible at noon-day, within six +minutes of space of the sun itself, to the reflected light of the sun. +When a small star has been seen through the nucleus of a comet, without +any perceptible diminution of light, it indicates perfect transparency; +but there can be no reflection from a perfectly transparent body, and +therefore, a comet does not shine by reflected light. It is true that +Arago discovered traces of polarized light in the comet of 1819, and +also in more recent comets, but they are mere traces, and Arago himself +admits, that they do not permit "the conclusion decidedly that these +stars shine only with a borrowed light." But it still does not follow +that a comet (even if independent of reflected light) is in an +incandescent state. The auroral light is not polarized, nor any other +electric light, neither is it owing to a state of incandescence, yet it +is luminous. The intense light of a comet at perihelion is analogous to +the charcoal points of a galvanic battery, caused by a rapid current of +ether from the nucleus, and assisted by the radial stream of the vortex. +This will account for the phenomenon in all its shades of intensity, as +well as for the absence of any perceptible phase. It will also account +for the non-combustion of such comets as those of the years 1680 and +1843. We shall also be at no loss to understand, why there is no +refraction when a ray of light from a star passes through the nebulosity +of a comet; and if, as we may reasonably suppose, the gaseous matter +composing the nucleus be very attenuated, instruments are yet too +imperfect to determine whether these also have any refracting power. On +this point, however, it is safest to suspend our judgment, as there may +be comets not belonging to our system, with even liquid or solid nuclei, +or of matter widely different to those elements composing the members of +the solar system. + +In addition to what has been already advanced on this subject of a +comet's light, we may appeal to the well-known fact that the visibility +of a comet is not reciprocally as the squares of the distances from the +earth and sun as it ought to be, if shining by reflected light. In +Mr. Hind's late work on comets, the fact is stated that "Dr. Olbers +found that the comet of 1780 attained its greatest brightness on the 8th +of November, thirteen days subsequent to its discovery, whereas +according to the law of reflected light, it should have become gradually +fainter from the day of its discovery; and supposing the comet +self-luminous, the intensity of light should have increased each day +until November 26th; yet in the interval between the 8th and 26th of +that month, it grew rapidly less." Now this theory teaches, that a comet +is neither self-luminous nor dependent on the sun, but on its distance +from the axis of the vortex, and a certain amount of elapsed time from +the perihelion, varying somewhat in each particular case. This fact is +therefore a very strong argument in favor of our theory. + +Amidst the many anomalous peculiarities of comets, it has been noticed +that a short tail is sometimes seen at right angles to the principal +tail, and in a few cases pointing directly towards the sun. Much of this +may be owing to perspective, but granting the reality of the fact, it is +still explicable on the same general principles. + +In speaking of the modifying causes which influence the weather, we +mentioned the effect due to the position of the sun with respect to the +axis of the vortex. This will be found to have a sensible effect on the +action of the radial stream. The natural direction of a comet's electric +stream is _towards_ the axis of the vortex, and in the central plane of +the vortex it will be also towards the sun. But this stream is met by +the stronger radial stream from the axis, and as Mr. Hind describes it, +"is driven _backward_ in two streams passing on either side of the head, +and ultimately blending into one to form the tail." Now, if the body of +the sun be situated between the comet and the axis of the vortex, it +will shield the comet from the action of the radial stream, and thus a +tail may really point towards the sun. + +In 1744 a brilliant comet exhibited six distinct tails spread out like a +fan, some seven days after its perihelion passage; its distance from +the sun at the time not being more than a third of the earth's distance. +The comet was then rapidly approaching the plane of the ecliptic, and if +we make the calculation for the position of the sun, we shall find that +the body of the sun was on the same side of the axis of the vortex as +the comet, and that the comet was then situated at the boundaries of the +conical space, enclosed by the radial stream in its deflected passage +round the body of the sun. In this position there are numerous cross +currents of the stream, and hence the phenomenon in question. As this +fact rests on the testimony of one individual, and is an occurrence +never recorded before or since, many are disposed to doubt the fact, yet +our theory explains even this peculiarity, and shows that there is no +necessity for impugning the statement of Cheseaux. + +Another unexplained phenomenon is the corruscation of the tail. It has +been attempted to explode this fact also, by referring it to conditions +of our own atmosphere; and it is generally considered the argument of +Olbers, founded on the great length of the tail and the velocity of +light, is sufficient to prove that these corruscations are not actually +in the tail. Now, it is undoubtedly true, that as light travels less +than two hundred thousand miles in a second, and a comet's tail is +frequently one hundred millions long, it is impossible to see an +instantaneous motion along the whole line of the tail; but granting that +there are such flickerings in the tail as are described by so many, it +must necessarily be, that these flickerings will be _visible_. It would +be wonderful indeed, if a series of waves passing from the comet to the +extremity of the tail, should have their phases so exactly harmonizing +with their respective distances as to produce a uniform steady light +from a light in rapid motion. The argument, therefore, proves too much, +and as it is in the very nature of electric light thus to corruscate, as +we see frequently in the northern lights, we must be permitted still to +believe that not only the tails, but also the heads of comets do really +corruscate as described. + +With respect to the direction of the tail, astronomers have been forced +to abandon the antiquated notion, that the tail always pointed directly +from the sun; yet they still pertinaciously cling to the idea, that +although this is not always the case, the tail only deviates from this +direction _in the plane of the orbit_. As this is a most important +question, it is necessary formally to protest against such a conclusion. +If the earth should happen to be in the plane of the comet's orbit and +the tail appears in that plane, it must of course be in that plane +_really_; but if the earth is not in the plane of the comet's orbit, the +tail is not _necessarily_ in the same plane, whatever its apparent +direction may indicate. It is true there is a tendency of every particle +of the tail, moving under the restraining influence of the sun's +attraction, to continue in the plane of the orbit; and in certain +positions there is no oblique action arising from the force of the +radial stream to cause it to deviate from that plane; yet in other +positions of the comet, the action of the radial stream may be oblique, +forcing it out of that plane, and still such a direction might be +assigned to it as to make it conform. In the comet of 1843, P. Smythe +observed a forked tail 25d long on March 3d, and from the end of the +forked tail, and from its _north_ side, a streamer diverged at an angle +of 6d or 7d to the _north_. As this was contrary to the _direction_ of +the curvature, if the tail had been curved, it could only arise from a +portion being driven off by the radial stream, or bent towards the plane +of the ecliptic. The curvature observed by others at a later date, was +concave to the south. Towards the middle and close of March, the tail +became straight, and with the above exception, might be considered to +move in the plane of the orbit. + +The celebrated comet of Halley, as observed by Dr. Bessel in 1835, +showed that a more or less well-defined tuft of rays emanated from that +part of the nucleus which was turned towards the sun; and the rays being +_bent backward_ formed a part of the tail. The nucleus, with its +emanations, presented the appearance of a burning rocket, the end of +which was turned sideways by the force of the wind. And, Bessel +concludes: "That the cone of light issuing from the comet deviated +considerably both to the right and left of the true direction of the +sun, but that it always returned to that direction, and passed over to +the opposite side; so that the cone of light, and the body of the comet +from whence it emanated, experienced a rotatory, or, rather, a vibrating +motion _in the plane of the orbit_." It is impossible that Bessel should +here mean that this motion was certainly in the plane of the orbit; for +the orbit was then viewed sideways, and he had no means of ascertaining +the fact. His meaning must be that it was apparently in the plane of the +orbit. If a plane be made to pass through the earth, the comet, and the +sun, the tail might be placed in any position in that plane, and yet +appear to be at the intersection of the two; that is, in the plane of +the comet's orbit. The vibration of the tail, in this case, is another +strong proof of the correctness of our theory. To make it more +intelligible, we shall resort to a diagram. + +In the following diagram, the comet's orbit, represented by the dotted +line, is drawn on the plane of the ecliptic; it is, therefore, necessary +to bear in mind, that it is tilted up from the line of nodes SN, at an +angle of 17d 45'. The position of the comet, October 9th, is at C, +approaching its perihelion; that of the earth at the same time at T; +while S represents the sun, and SQ the line of equinoxes. Now, from a +cause already explained, the tail always tends to lay behind the comet, +in the direction indicated by the lower tail in the diagram at 1, and, +if produced, would pass to the left of the sun, as seen from the earth: +the force of the radial stream, however, will not allow this lagging of +the tail, and it is straightened out by this force; but, being directed +to the axis of the vortex, and not to the sun, it is not really in the +plane of the orbit, but is seen in the direction of the upper tail +depicted in the diagram at 3, and, if produced, would pass to the right +of the sun, as seen from T. Now, there is an intermediate position of +the tail, in which it will appear in the prolongation of the radius +vector SC; this position is represented by the middle or central tail of +the comet at 2, yet this is not in the plane of the orbit, it only +appears to be, as may be readily understood by remembering that the +earth at this time is under this plane, and the comet is seen at a +considerable elevation above the plane of the ecliptic. When the comet's +tail becomes directed to the axis of the vortex, or in the _apparent_ +position of No. 3, the comet, rapidly careering on its way to the sun, +again leaves the tail behind, and again it is strengthened out by the +radial stream oscillating about the mean position at 2, as observed by +Bessel. From this, it appears, that there is no necessity to make +confusion worse confounded, by resorting to polar forces, which are +about as intelligible as the foundations of the pillars of Atlas. + +[Illustration: Fig. 25] + +It may be objected that the continued action of the radial stream with +that velocity we have contended for, ought to keep the tail invariably +directed from the axis of the vortex; but, where there are two forces or +tendencies, as in this case, analogy would teach us that a certain +degree of oscillation is a necessary result. There may, also, be slight +and transient changes in the direction of the radial stream. In the +hurricane there are short and fitful blasts inclined to the general +direction of the wind, which must arise from the inertia of the moving +mass of atmosphere, causing temporary condensations and rarefactions. Be +this as it may, we have assigned a cause which satisfies the phenomenon, +without coming into collision with a single principle of celestial +mechanics. + +Prof. Struve compared the tail of this comet to a flame, or "ray of fire +shot out from the nucleus, as from some engine of artillery, and driven +on one side by the wind." At the same time, he saw a second emanation +nearly in the opposite direction. This last might arise from a momentary +fluctuation in the relative intensities of the electric radiation of the +comet, and of the radial stream, owing to the probable irregularities +just alluded to. Such and kindred phenomena are utterly inexplicable, +without we adopt the theory we are advocating. One other feature, and we +will leave the subject. + +From our explanation of the solar spots, we inferred the existence of +another large planet in the system. Might not the same effect be +produced by a comet? Or may there not be so many comets, whose great +elongation, combined with even a moderate mass, may render it impossible +to calculate the position of the sun with respect to the central axis of +the vortex,--always considering this last as the axis of equilibrium? In +a general way, we might say that the very number of comets in all +directions and all distances, would tend to neutralize each other's +effects; but we are not under this necessity. A comet, moving in a +parabola, does not belong to the system or to the rotating vortex; and +the periodic comets, if of gaseous elements, (as seems so probable,) +must, from the size of their nuclei, which the theory considers the only +part constituting their mass, have far less mass than the very smallest +of the asteroids, and consequently could have very little effect on the +mechanical balance of the vortex, even if elongated as far as the orbit +of Neptune. Did we know the influence of cold in limiting the +expansibility of the elementary gases, we might approximately determine +the mass of a comet, from the size of its nucleus; but this is a problem +that has never yet been solved; and astronomers ought to avail +themselves of every indication which promises to realize this great +desideratum. The grand comet of 1556 is now probably approaching, and, +from recent investigations, it appears that it will arrive at its +perihelion in 1858,--subject to an error either way of about two years. +An opportunity may thus be presented of determining the mass of one of +the largest comets on record, which may not again occur. This arises +from the possible appulse of the comet to the planet Pallas, whose mass, +being so small, would more sensibly be disturbed by such an appulse than +the earth. As the inclinations and ascending nodes of the two orbits +approximately coincide, and as Pallas will be near the comet's path, on +the approach of the latter to the sun, at the beginning of the year +1857, should the comet become visible about that time, a very close +appulse is possible. It is not unlikely, also, that if the elements of +Pallas were so far perfected as to afford reliable indications, that the +near approach of the comet might thus be heralded in advance, and lead +to an earlier detection of its presence. Would it not be a worthy +contribution to science, for some one possessing the necessary leisure, +to give an ephemeris of the planet for that epoch; as a very slight +change in Mr. Hind's elements of the comet, would cause an actual +intersection of the two orbits in about heliocentric longitude 153d? The +subsequent nodal passage of Pallas will take place near opposition, and +be very favorably situated for determining the instant of its passage; +and, of all the elements, this would be more likely to be affected than +any other.[47] + + +THE ZODIAL LIGHT. + +A phenomenon, akin to that which we have just been considering, is +presented by that great cone of diffused light which accompanies the +sun, and which in tropical climes displays a brilliancy seldom witnessed +in high latitudes, on account of its greater deviation from the +perpendicular. Sir John Herschel conjectures that it may be "no other +than the denser part of that medium, which, as we have reason to +believe, resists the motion, 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 passages, and which +may be slowly subsiding into the sun." If these materials have been +stripped, it is due to some force; and the same force would scarcely +permit them to subside into the sun. Once stripped, these portions must +be borne outwards, by the radial stream, to the outer verge of the +system. Still, there are, no doubt, denser particles of matter, of the +average atomic density of Mercury and Venus, which can maintain their +ground against the radial stream, and continue to circulate near the +central plane of the vortex, in all that space between the earth and the +sun. But if the zodial light be the denser part of that medium, which +astronomers now generally recognize as a resisting medium, how happens +it that it should be confined to the plane of the ecliptic? Why should +it not be a globular atmosphere? Here, again, our theory steps in with a +triumphant explanation; for while it permits the accumulation of such +particles around the equatorial plane of the sun, it allows no +resting-place very far removed from this plane. The zodial light, +therefore, is not the resisting medium, but the passage of the radial +stream through a diffuse nebula of atoms, brought down the poles of the +vortex by the polar current, and held in check along the central plane +by gravitation. + +If these atoms partook of the velocity of the ether, they would not be +luminous; but being held back by gravitation, they are opposed to the +radial stream, and hence the light. + +Many stars are also nebulous. In some cases we see the nebulosity +edgewise, or along the equatorial planes of the stellar vortices; in +others we look down the poles, and the nebulosities are circular, and +there is an endless variety in the shape and intensity of this light. +But the universe seems full of motion, and we are not justified in +supposing, because a star shows no such light, that it is without +rotation. The parallax of the nearest star is only one second, the whole +lenticular mass of light which surrounds our sun would therefore only +subtend an angle of a single second at the nearest fixed star. Seeing +its extreme faintness, therefore, the effulgence of the star would +render it totally invisible, provided that it _could_ traverse the vast +immensity of intervening space, without feeling the influence of that +extinction, which Struve has proved does actually diminish the number of +visible stars. + +Corruscations and flickerings have also been noticed in the zodial +light, and as usual, the learned have suggested atmospheric conditions +as the cause, instead of trusting to the evidence of their own senses. +How prone is philosophy to cling to that which is enveloped in the mist +of uncertainty, rather than embrace the _too simple_ indications of +nature. As if God had only intended her glories to be revealed to a +favored few, and not to mankind at large. Blessed will be the day when +_all_ will appreciate their own powers and privileges, and no longer +regard the oracles which emanate from a professional priesthood, whose +dicta have so often tended to darken the simple counsels of truth! To +set the question of pulsations in the zodial light, as well as in the +tails of comets, at rest, only requires previously concerted +observations, in places not very widely apart; for it is scarcely +possible, that atmospheric conditions should produce simultaneous +pulsations in two distant places. If the pulsations are found to be +simultaneous, they are real; if not simultaneous, they may depend on +such conditions; but from the nature of the cause, we should look for +them as much in the zodial light, as in the aurora borealis, regarding +the different intensities. + +There is also reason to suspect that the northern side is always the +brightest, both in spring and autumn. On the morning of October 4th, +1853, the light was very vivid and well defined, its northern margin +grazing Regulus and terminating at Mars, which was also to the north of +it. Now, although the _northern side_ was the brightest, the great mass +of light was to the south of the ecliptic, as far down as the cone shape +was preserved; but at 10d from the horizon, a still brighter mass +protruded from the cone towards the north, which was all _north_ of the +ecliptic, and of an irregular form, extending along the horizon. The +time was 4 A.M., and consequently was not due to any crepuscular light. +An explanation of the general fact of the brightest light being _always_ +on the north side, is given in the present section, in connection with +another phenomenon. If, as some suppose, the light does not reach to the +sun, the annulus must at least fill all the space between Venus and the +earth, but it is far more in accordance with facts as well as with our +theory, to suppose it increases in density to the body of the sun. + +Observations made at the observatory of the British Association, +detected, in 1850, sudden brightenings of the light, altogether +different from pulsations. The theory would refer these to that fitful +irregularity in the momentary intensity of the radial stream, which +gives the flickering and tremulous motion to comets' tails. But, the +steady variations in the intensity of this light must be due to other +causes. The longitude of the sun will here come in as a modifying cause; +for the obstruction caused by the body of the sun, when displaced from +the axis of the vortex, must necessarily exercise an influence on the +force and direction of the radial stream. A sudden influx of cometary +matter down the poles of the vortex, in more than usual quantities, will +also tend to brighten and enlarge the zodial light; and, in this last +cause, we have an explanation not only of ancient obscurations of the +solar light, but, also, of those phosphorescent mists, such as occurred +in 1743 and 1831, rendering moonless nights so light that the smallest +print could be read at midnight. + +In total eclipses of the sun, the denser portion of the zodial light is +visible as a brilliant corona; but, on such occasions, the brightest +stars only are to be seen, and, consequently, the fainter portions of +the light must be invisible. Hind mentions as many as ten stars visible +in the total eclipse of 1842. According to the same authority, the color +of the corona was like tarnished silver, and rays of light diverged in +every direction, and appeared shining through the light of the corona in +the total eclipse of 1851. In this year on the day of the eclipse (July +28th), the longitude of the sun was about 340d, and, therefore, the body +of the sun obstructed the radial stream as seen from the earth on the +right side; but, in 1842, the longitude of the sun was, according to our +table, about 116d, the sun's centre then being 700,000 miles from the +axis of the vortex, and on the opposite side with respect to the earth; +the position was, therefore, not so favorable for the appearance of +these rays which, in many cases, have given the appearance of a whirling +motion to the corona. + +At this date, July 7th, 1842, the corona, according to Prof. Airy, +"possibly had a somewhat radial appearance, but not sufficiently marked +to interfere with the general annular structure." Mr. Baily, on the +contrary, says, the corona had the appearance of brilliant rays; and, at +Milan, long jets of light were particularly noticed. There can be no +doubt but that the passage of the radial stream past the outer margin of +the moon must also give rise to the same phenomena as when passing the +sun, and in this we have an explanation of the fact, that, previous to +the moment of first contact, an appearance resembling a +faintly-illuminated limb of the moon, has been perceived near the body +of the sun; as well as of those flashes of light which have been +observed in the lunar disc as the eclipse advances. One important fact, +worthy of note, is, that these luminous streaks are more nearly parallel +than is due to a radiation from the centre. These streaks have, also, +been seen bent at right angles at the middle of their height, as a flame +is by means of a blowpipe, precisely analogous to cometary rays being +driven backwards to form the tail, as already described, thus indicating +a common origin. If the moon had an atmosphere, we should, no doubt, see +a greater display; but, having no rotating vortex to protect her from +the radial stream, her atmosphere must have been long since stripped +off, leaving her exposed to the withering winter blast of the great +stream of the solar vortex. In this connection, we may also allude to +the appearance of the moon when totally eclipsed. Instead of +disappearing at these times, she sometimes shines bright enough to +reveal her smallest spots. This has been generally referred to the +refraction of the earth's atmosphere bending inwards the solar rays. May +it not be owing to the brilliancy of the solar corona, which, in 1842, +was described as so intense that the eye was scarcely able to support +it? This is a far more palpable cause for the production of this +phenomenon, but of which astronomers cannot avail themselves, as long as +they are uncertain of the origin of this corona. + + +SHOOTING STARS. + +The continual influx of cosmical matter into the heart of the vortex in +ever-varying quantities, and speedily dispersed along the central plane, +according to its density, must necessarily give rise to another +phenomenon to which we have not yet alluded. Scarcely a night passes +without exhibiting this phenomena in some degree, and it is generally +supposed that the hourly average of shooting stars is from five to ten, +taking the whole year round. The matter composing these meteors we +regard as identical with that mass of diffused atoms which forms a +stratum conforming to the central plane of the vortex, and whose partial +resistance to the radial stream occasions that luminosity which we call +the zodial light. These atoms may coalesce into spherical aggregations, +either as elastic gas, or as planetary dust, and, passing outward on the +radial stream, will occasionally become involved in the vortex of our +own globe; and being drawn inwards by the polar current, and acted on by +the earth's gravity, be impelled with great velocity through the +rarefied air of the upper atmosphere. That meteors are more abundant +about the time of meridian passage of a vortex (or, perhaps, more +correctly speaking, from six to twelve hours afterwards, when the +current of restoration penetrates the atmosphere), well accords with the +author's observations. It is about this time that high winds may be +looked for, according to the theory; and it has ever been a popular +opinion, that these meteors are a sign of windy weather. Even in +Virgil's time, the same belief prevailed, as a passage in his Georgics +would seem to indicate. + + "Sape etiam stellas, vento impendente, videbis + Praecipites coelo labi; noctisque per umbram + Flammarum longos a tergo albescere tractus;" + +Virgil was a close observer of nature, and commences a storm with the +wind at south, "Quo signo caderent Austri;" just as we have represented +the usual course when these vortices pass near the observer's latitude. +It is also a well-known fact, that after a display of meteors, (and we +are now speaking of ordinary displays, and not of the great showers,) +the temperature falls considerably. It is not uncommon also, that +meteors are more abundant during an auroral display, as they ought to be +by the theory. We must, however, exempt from this influence those solid +meteors which sometimes come into collision with the earth, and +afterwards grace the cabinets of the curious. These bodies may be +considered microscopic planets, moving in stated orbits with planetary +velocity, and bear strongly on the explosive theory of Olbers, as fully +detailed by Sir David Brewster. + +It is a very remarkable fact, first noticed by Olbers, that no fossil +meteoric stones have yet been discovered. If this fact be coupled with +the hypothesis advanced by Olbers, in reference to the origin of the +asteroidal group, we should have to date that tremendous catastrophe +since the deposition of our tertiary formations, and therefore it might +possibly be subsequent to the introduction of the present race into the +world. May not some of the legendary myths of the ancient world as +mystified by the Greeks, have for a foundation the disappearance of a +former great planet from the system? The idea of the existence of seven +planets is one of the oldest records of antiquity; but the earth of +course would not be counted one, and therefore in after times, the sun +was included to make up the number; just as the signs of the Zodiac have +been explained in accordance with the seasons of far later times than we +can possibly assign for the invention of this division of the heavens. +Let those who have the leisure, try how far the contraction and dilation +of the asteroidal orbits, to some average mean distance, will restore +them to a common intersection or node, as the point of divergence of the +different fragments. The question is interesting in many of its aspects, +and may yet be satisfactorily answered. + +The composition of aerolites may also be taken as indications of the +common origin and elementary texture of the planets, whether they are +independently formed or have originally pertained to a former planet; +for no hypothesis of telluric or selenic origin yet advanced, can stand +against the weight of evidence against it. Their fragmentary character +rather favors the views of Sir David Brewster, and when we consider that +they have been revolving for thousands of years with planetary velocity, +and in very eccentric orbits, through the ether of space, continually +scathed by the electric blast of the radial stream, their rounded +angles, and black glossy crust of an apparently fused envelope, may be +accounted for, without difficulty, from the non-vitrified appearance of +the interior. The composition of aerolites as far as known, embrace +nearly one-third of all known simple substances according to Humboldt, +and are as follows: iron, nickel, cobalt, manganese, chromium, copper, +arsenic, zinc, potash, soda, sulphur, phosphorus, and carbon. + +The theory we have thus given of the common occurrence of shooting +stars, will render a satisfactory general account of their sporadic +appearance; but there are other phenomena of greater interest, viz.: the +occasional recurrence of swarms of such meteors, which defy all +numerical estimates, being more like a fiery rain than anything they can +be compared to. The most interesting feature of this phenomena, is the +_apparent_ periodicity of their return. In the following table we have +set down the most remarkable epochs mentioned by Humboldt, (and no man +has devoted more attention to the subject,) as worthy of notice: + + About April 22 to 25 + " July 17 to 26 + " August 9 to 11 + " November 12 to 14 + " November 27 to 29 + " December 6 to 12 + +Besides these, he mentions two showers, from Arabian authority, in +October; one in October, observed in Bohemia; one observed by himself, +in the Pacific, on March 15; one February 4, just preceding the terrible +earthquake of Riobamba, in 1797. The Chinese annals also contain many +showers of stars, before the present era commenced. Some were in March, +more in July, and others in different months. How, then, in view of +these numerous dates, can we attach so much importance to the +periodicity of these showers? The great shower of 1833, in the United +States, on the 12th and 13th of November, brought to mind the great +shower at Cumana, observed by Humboldt and Bonpland just thirty-three +years before, to a day; and it must be confessed that more than ordinary +displays have been seen on this date. Yet, on the strength of this, +every meteoric shower is supposed to be periodical, and has resulted in +a theory which becomes more complicated as the phenomenon is more +observed, and can never lead to any useful and practical results. To +cite the numerous instances of discrepant results, would only encumber +this brief notice with facts neither interesting to the general reader, +nor convincing to those who hold a contrary opinion. The author of these +pages has watched for many years, and, in view of all the facts, has +concluded that the doctrine of periodicity (as held by present +meteorologists) is not tenable. The celebrated August shower failed, +also, this year, at least in this place, as for four hours each night, +on the 9th, 10th, and 11th, there were fewer bright meteors than at the +close of July. + +Professor Olmsted, who has paid considerable attention to the subject, +has indeed attempted to connect the great November shower with the +zodial light, which last he considers a nebulous body, of an elongated +form, whose external portions, at this time of the year, lie across the +earth's path. (See Silliman's Journal for 1837, vol. xxxiii. No. 2, +p. 392.) He even gives its periods, (about six months,) the aphelion of +the orbit being near the earth's orbit, and the perihelion within +Mercury's. In this way he attempts to explain both phenomena; but as the +zodial light is seen unchanged all the year round in tropical latitudes, +it is not the kind of body supposed by Olmsted, and the theory adds +nothing to our knowledge. Others have imagined rings of nebulous matter, +in which all the separate parts are moving in the same orbit around the +sun, with a retrograde motion, and this, with some modifications, is the +current theory of the day. The principal arguments rested on, for the +support of this view, are derived from the great shower of 1833, in +which a common radiant point was observed, and confirmed subsequently by +the radiant of other years, in the same month of November. As this point +is almost tangential to the earth's orbit at this season, the earth +meets the nebulous ring moving in the contrary direction, and thus +confers on these meteors the necessary velocity that is thought to be +demanded by observation. + +Now, our theory gives a totally different explanation of the phenomenon. +We contend that a retrograde motion of such a nebulous mass, is +subversive of our whole theory; and we must be permitted to examine +certain points, hitherto disregarded by those entertaining antagonist +views. It is supposed that the meteors in 1833 fell for eight or nine +hours. The orbital velocity of the earth is more than 1,000 miles per +minute, and the orbital velocity of the nebulous zone must have had a +similar velocity. During the nine hours of meteoric display, therefore, +the earth traversed 500,000 miles of her orbit, which would give +1,000,000 miles for the depth of the nebulous stratum. But if of such +vast extent, how happened it that the only part of the earth in which +these were visible in great density, was the United States, or a space +embraced between the latitudes of 50d and 20d north, and the longitudes +60d and 100d west, (and these are the widest limits,) comprising only +1/40 of the surface of the globe? To a calm inquirer, this difficulty +seems insurmountable. The author was then in the Mediterranean, on deck +the greatest part of the night,--the weather fine, and nothing unusual +visible in the heavens; from other sources he has also derived similar +information. Yet, were the earth then passing through a stratum of +meteors 1,000,000 miles in extent, it is utterly inconceivable that +other portions of the earth escaped. Much stress is also laid on the +fact that these meteors in 1833, passed from east to west generally, as +they ought to do, if tangential to the earth in her orbit; but on the +same phenomenon occurring in 1799, when the earth was in precisely the +same part of her orbit, Humboldt says distinctly, "the direction (of the +meteors) was very regular from north to south." How could this possibly +happen, and at the same time be moving tangentially to the orbit? + +There is also another fact of importance not duly weighed in forming +such a theory. In 1833 the meteors evidently differed in velocity; one +class, consisting of luminous points, passed like a shower of fire with +great velocity to the westward, another class were like large fire-balls +with luminous trains moving with less rapidity, while a third class +consisted of nebulous patches which remained stationary for a long time, +and frequently emitting large streams of light. These last, at least, do +not deport themselves as planetary bodies moving 2,000 miles per minute. +But the fact still remains, that unusual displays have occurred about +the 12th and 14th of November; and also as a general thing when there +are no unusual displays, the meteors are more abundant about this time. +Let us try if we can reconcile these facts with the theory of vortices. + +We will first confine our remarks to the increased number of meteors +about November 12th and 14th. The cosmical matter composing the zodial +light, or at least the lighter parts of it, is continually driven +outwards by the radial stream, just as the matter of a comet's tail is +stripped from the nucleus. This matter becomes involved in the terral +vortex by descending the poles, and is again passed out along the +equatorial plane. The form of the zodial light, as seen edgewise, gives +a lenticular form for the stratum of planetary particles composing it, +and its central plane has been considered as coinciding with the plane +of the sun's equator. At the orbit of the earth, this lenticular space +is narrowed to a very thin stratum, but undoubtedly reaches beyond the +earth's orbit with a rapidly diminishing density. As the axis of the sun +is inclined about 7d to the ecliptic, and the ascending node is in the +20th degree of Gemini, the earth can only pass through the plane of the +sun's equator about the 12th of December and the 12th of June. If, +therefore, the central plane of the vortex coincides with the plane of +the sun's equator, meteors ought to be more numerous about the dates +above mentioned. But the observed times are on November 12th and 13th. +Now, from actual measurements, a computation has been made by M. +Houzeau, that the elements of the zodial light are materially different +from those of the sun's equator. He fixes the node of the light +(according to Mr. Hind) in 2d heliocentric longitude, subject to an +uncertainty of 12d or 13d, and its inclination to the plane of the +ecliptic, 3d 35', subject to an uncertainty of about 2d. The truth is, +astronomers have argued the coincidence of the two planes from +considerations connecting the zodial light with the sun's equator, as if +it were a solar atmosphere; but such an atmosphere is impossible, and it +is high time such measures should be taken as will lead to some certain +conclusion. If in the present state of the question, we were to take the +mean, we should find the node in about longitude 40d, which is the +position of the earth on November 2d. But in the absence of +measurements, we will assume, for the sake of argument, that the +ascending node of the central plane of the vortex was, in 1833, in 50d +heliocentric longitude, and consequently the earth was passing through +the meteoric stratum or central plane of the zodial light, on the night +of November 12th. The opposite period of the year is May 12th--a date, +it is true, on which no great shower of stars is recorded, but sporadic +meteors are very plentiful at that time, and what is more important to +observe is, that the 11th, 12th, and 13th of May, are the three noted +_cold days_ which we have before mentioned. Thus truly indicating that +the earth is then in or near the central plane of the vortex along which +the radial stream is at its maximum of power at any given distance from +the axis. + +But the question occurs, does the node of this plane remain stationary, +and is there no variation of the inclination of the axis of the solar +vortex? We have found from observation, that the axis of the terral +vortex is continually oscillating about a mean position by the action of +the moon; and reasoning from this analogy, and the constant tendency of +a material vortex to preserve a dynamical balance, the same tendency +must obtain in the solar vortex under the action of the great planets, +whose orbits do not coincide with the central plane of the vortex. The +ascending node of Jupiter's orbit is in longitude 98d, Saturn's 112d, +Uranus' 72d, Neptune's 131d; so that this plane does not correspond with +the plane of greatest inertia discovered by La Place, and from the +non-coincidence of these planes with the central plane of the vortex, +must produce the same oscillation in the axis of the solar vortex, as +the moon does in the terral vortex, but to what amount, observation can +alone determine. Jupiter and Saturn will of course exert the greatest +influence, and when these two planets are in conjunction, the ascending +node of the central plane of the vortex will vary in longitude perhaps +sufficiently to bring the meteoric maximum at the ascending node into +October on the one hand, and to the close of November on the other, and +at the descending node to April 25th on the one hand, and the close of +May on the other. + +The great showers of stars which have been recorded, must be therefore +considered as an accidental exaggeration of a perennial phenomenon, +attaining its maximum when the earth passes through the central plane of +the vortex, whose ascending node in 1833 we will suppose was in +longitude 50d. This theory will therefore account for those great +showers which have occurred about the 24th of April, as well as those +occurring in October and November; for it is far more consonant to all +analogy, to suppose the influx of planetary atoms into the solar vortex +to be in irregular, than in regular quantities. Yet, whether in the one +case or in the other, the matter will pass along the central plane of +the vortex, either diffusely scattered or in denser clouds, and will be +encountered by the earth when near the nodes _more frequently than at +other times_. The phenomenon of 1833, may then be attributed to the +earth encountering an unformed comet on the 12th of November; but we +must reflect, that the medium of the vortex is also in motion, and the +cometary matter drifting along with it; and that this motion corresponds +with the earth's motion. By becoming involved in the terral vortex, it +will in a measure be carried along with the earth in her orbit as a +temporary occupant of the terral vortex. But we are here met with the +objection that the radiant being nearly stationary amongst the stars, +demonstrated conclusively, that the source of these meteors did not +partake of the earth's motion. There is no difficulty in this. We +suppose as a general thing, that the meteors descended to the surface of +our atmosphere down the axis of the vortex (at least in the greatest +numbers), and the geocentric longitude of this axis was nearly the same +during the whole time of the display. We say nearly, for the motion of +the moon in her orbit in nine hours, would change the longitude of the +axis three or four degrees, and this is about the change in the +position of the radiant noted at the time. This objection, therefore, +falls to the ground; for the axis of the vortex, although carried along +with the earth in her orbit, was unaffected by the earth's rotation, and +would therefore appear nearly as stationary in the heavens as Gamma +Leonis. But it is again urged, that the moon was near conjunction with +the sun, and consequently the central vortex was on the opposite side of +the globe. This is true; but the outer vortex must have been near the +meridian about three hours after midnight, or about the time when the +radiant was vertical and the display the greatest. When the axis was to +the eastward, the stars would shoot westward, when on the meridian, they +would pass in all directions, but principally to the south, on account +of the inclination of the axis of the vortex; but this would only be +true for places situated to the southward of the central latitude. +During the great shower of stars seen by Humboldt, in Cumana, the +direction was to the south uniformly. Now, the latitude of Cumana is +above 10d north, yet still too low for the general limits of the +vortices; but from the same inclination of the axis (from 30d to 36d to +the surface), the meteors would pass far south of the limit, and might +even reach to the equator. The latitude of the _outer vortex ascending_ +on November 12th, must have been near the line of greatest display, from +the position of the moon at the time. We thus see why the phenomenon was +limited to so small a fraction of the earth's surface; why these meteors +should be intermingled with nebulous patches stationary in the heavens +for an hour together, and why, notwithstanding these facts, they were +independent of the earth's rotation. + +We have yet another objection to answer, viz.: the planetary velocity of +some of these bodies. Let us be understood. The velocity of a solid +aerolite is due to gravitation, and is planetary, on the other hand, +voluminous collections of cometary dust united by accident, and +remaining so by mere inertia, are borne passively on the ethereal +currents with _electric_ velocity, and probably never penetrate far, +even into the attenuated atmosphere, which may be supposed (from the +facts connected with the aurora) to extend far above the denser stratum +which refracts and reflects light, and from which the assigned limits of +our atmosphere have been derived. + +It is generally considered that sporadic meteors are more numerous in +the summer and autumn than in the winter and spring, and we have, +likewise, in the tenth of August, a date which corresponds to many great +displays and meteoric showers, both in recent and remote times. This +would seem to vitiate our theory; for we cannot suppose that there are +two _central_ planes in the vortex intersecting the ecliptic in +longitude 320d and 50d. We must remember, however, that as these great +displays are accidental, and as the stratum composing the zodial light +is manifestly of sufficient thickness to envelope the whole orbit of the +earth, that it does not necessarily follow that the dense portions to +which meteoric showers are due, should be always confined to the central +plane of the vortex. And, besides, we have similar displays recorded in +other months, which invalidates the theory of a regularly-recurring +phenomenon. We shall, therefore, only aim at explaining why meteors are +generally more abundant in summer and autumn than in the opposite +seasons. + +The axis of the solar vortex, considered as cylindrical, must be +admitted to run out to a great depth on either side from the sun, and +reach far into that unoccupied space intervening between our system and +the nearest fixed stars, and from these opposite points the solar vortex +is supplied with that stream of ether which passes down either pole to +restore a partial equilibrium in the density of the ether of the vortex, +rarefied by centrifugal force. As certain portions of the heavens are +crowded with stars, and other parts comparatively vacant, we may expect +a similar inequality in the distribution of that cometic dust, which +causes a certain amount of extinction in the light of the stars, and, +therefore, seeing that the two extremities of the axis of the solar +vortex are so widely separated, it would not be wonderful if different +quantities of such matter were brought down into the vortex from these +extremities. + +From recent observations made by H. R. Birt, at the observatory of the +British Association, it would appear that the brightest portion of the +zodial light is always north of the ecliptic. Others have also remarked +the same, and if we couple this fact with the suggestion just made, we +are justified in suspecting that a greater quantity of cometic dust +comes down the northern pole of the vortex than down the southern. This +matter, in passing outward, does not, of course, immediately attain to +the central plane of the vortex, but is more thickly distributed along a +plane parallel to this plane. And the same will be observed by that +matter coming down the southern pole; it will be, in a certain degree, +retained in a plane south of the central plane, but still parallel with +it. This would account for the greater brightness of the northern side +of the zodial light. It would, also, account for the greater frequency +of meteors in summer and autumn than in the opposite seasons. From May to +November the earth is above the central plane of the vortex, and, +consequently, on the northern side; but after passing the node in +November, she is on the under or southern side, and the meteors are less +frequent. With this general explanation we shall close. If what we have +advanced be an approximation to the truth, the theory itself affords +ample indications of what observations are requisite to prove or +disprove it; and, on this account, a theory is of great benefit, as +suggestive of many questions and combinations of facts which otherwise +might never be thought of. + +We have thus taken a cursory glance at the prominent physical phenomena +of the world, and attempted to link them together in the bonds of one +all-pervading principle. We have fearlessly taken a new path, and claim +originality for the whole, disclaiming all intention of retailing +second-hand wares, or of compiling an ingenious theory from +heterogeneous scraps. If it be true, or if it be partially true, let +those professionally engaged in such pursuits enter the wide field of +investigation we have discovered for them; for if the whole theory be +true, it only shows in a clearer light that the great work which has +been fancied so near completion is scarcely yet begun; while the +prospect of an ultimate and final completion of the temple which so many +zealous votaries are erecting, is rendered mournfully hopeless by the +contemplation of what yet remains to be performed. + +FOOTNOTES: + +[42] The orbit this year was determined under very unfavorable +circumstances. + +[43] According to other tables, this angle would be much greater than is +given in Mr. Hind's catalogue. + +[44] Prin. Prop. xx Lib. Sec. + +[45] With reference to the resisting power of the atoms. + +[46] Prin. Lib. Tor. Prop, xxxix., also Prop, xli. + +[47] In making this suggestion, the author is well aware that +Ephemerides of the four chief asteroids have been given annually in the +Greenwich Nautical Almanac; but for the object proposed they are utterly +useless. Will any astronomer contend that these Ephemerides are true to +ten seconds of arc? If not, they are useless for the purpose suggested +above, and the theory wants revision. And it is evident that any +objection against its practicability, founded on the uncertainty of the +number of the asteroids themselves, as has already been urged in answer +to this suggestion, is an evidence that the objector weighed the subject +in the scales of his imagination only. + + + + +SECTION SIXTH. + + +THE POLAR ICE. + +We shall conclude these pages by again referring to our theory of the +weather, in connection with an event which every friend of humanity and +every lover of natural science is bound deeply to deplore. + +From the present position of the lunar nodes and apogee, the vortices of +our earth do not ascend into very high latitudes. Now, according to the +principles laid down, the frequency of storms tends to lower the +temperature in the warm regions of the earth, and to elevate it in the +polar regions. Let us suppose the northern limit of the vortices to be +in latitude 70d. There will be, in this case, a greater prevalence of +northerly winds _within_ this circle of latitude, to supply the drain to +the southward, and the back currents by passing above will descend at +the pole, partaking of the temperature due to that elevation. The +character of the arctic seasons may therefore be considered as partly +dependent on the average direction of the wind. Suppose again, the +extreme limits of the vortices to be about latitude 80d, the relative +areas of the two circles are as 4 to 1; so that in this last case the +exclusive range of the northerly winds is limited to one-fourth of the +first area. South of 80d the wind will frequently come from the south, +and by mixing with the local atmosphere of that latitude, will tend to +ameliorate the small area to the northward. And the greater atmospheric +commotion when confined to such a small circle of latitude, must assist +materially to break up the polar ice; which would tend still more to +equalize the temperature. + +By referring to our table, we see that the mean conjunction of the pole +of the lunar orbit and the moon's apogee, was in longitude 128d on April +10, 1846, and let it be remembered that when the conjunction takes place +due south or in longitude 270d, the vortices attain their greatest +latitude north. When, on the contrary, the conjunction takes place due +north or in longitude 90d,[48] the northern limits of the vortices are +then in the lowest latitude possible. + +Sir John Franklin sailed in May 1845, and was certainly at the entrance +of Wellington sound, near latitude 75d, April 3d, 1846, as the dates on +the graves testify. That season, according to the theory, was a cold +one; for the vortices could not reach so far to the northward in that +year, and consequently there were no storms, properly speaking. It would +probably be late in the summer of 1846, before the expedition was +liberated, and as the prevailing winds would be from the northward, he +would have little choice, but to stand to the westward if the state of +the ice permitted. In his instructions he was to use every effort to +penetrate to the southward and westward of Cape Walker, and he probably +conformed to them under the circumstances, and passed the winter in the +ice, in that neighborhood. And in 1847 we do not anticipate, from the +theory, that he would make much progress westward. + +In 1848, Sir James Ross was sent out with the first relief-ship; but was +not able to reach the entrance of Wellington channel because of compact +ice from there to Leopold Island. This was about the beginning of +September--a time when the northern channels are usually the most open. +On the 11th, they ran the ships into Port Leopold, and the next day the +ice shut them in for the winter. From the character of the season, we +may infer that if Franklin did not enter Wellington channel in 1847, as +is most probable, neither did he in 1848. Perhaps he was not able to get +his ships far to the westward, as we infer from the theory. Still, as +the time was not very protracted, he would wait patiently another season +and husband his resources. + +In 1849, Sir James Ross cut his ships clear of the ice August 28th, and +crossed over to Wellington channel, where he found the land-ice still +fast, showing that this season was also a bad one in accordance with the +theory. On the 1st of September he met the first gale of wind, at which +time the _Inner Vortex_ was at its extreme north latitude, and rapidly +extending its limits by the motion of the perigee. + +This vortex describes a smaller orbit than either the central or the +outer vortex, and consequently reaches into higher latitudes. But the +time was badly chosen, as the whole series of years since Franklin left +has been unfavorable for the early rupture of the ice. Sir James Ross +having been drifted out of Lancaster sound by the gale, finally bore up +for England towards the close of September 1849. + +The same year, the North Star with additional supplies was working up +Baffin's bay; but on account of the unusual quantities of ice, and the +frosts "which glued the floes together," she was unable to force a +passage through the middle ice, and wintered on the east side of +Baffin's bay, in latitude 76d 33'--her thermometer marking 64d below +zero, as the coldest of the winter. In 1850, the perigee of the moon +attained its northern limit, but the position of the node was bad; still +this year and 1851, were the best of the series. The North Star +succeeded in getting out of the ice on the 1st of August--a very early +date for that high latitude--and on the 8th had crossed over to +Possession bay; but being prevented by the land-ice, she bore up for +Pond bay and there landed the provisions. The same year (1850) several +vessels entered Lancaster sound. Sir John Ross also reached Melville +Island; from which it is evident that this season was far better than +any preceding. According to Captain Penny, this year a floe of ice at +least two years old, filled Wellington strait; but was diminished in +breadth at a subsequent visit. He also saw a boundless open sea from the +_western_ entrance of Wellington strait; but of course the ships could +not reach it, for the floe before mentioned. Following the indications +of the theory, we consider it almost certain that Franklin went to the +westward and not through Wellington channel; that he made but slow +progress until 1850, when finding the sea more open to the northward, +and attributing it more to local influences than to any change in the +season, he considered it a better course to extricate the expedition, by +pushing on towards Behring's straits than to attempt the frozen channels +he had already passed through. But the seasons again getting worse after +1850, he was again arrested in the polar basin by the ice and islands +off the northern coast of America. + +Regarding the old and new continents as in reality a connected body of +land, with a polar depression, we may expect that the great range of +American mountains is continued in a straight line, from the mouth of +the McKenzie river, obliquely across the Polar sea, and connects with +the Ural; and that along the axis of the chain, protuberant masses will +emerge above the sea level, constituting an archipelago of islands, from +Nova Zembla to the McKenzie; and that these islands, causing an +accumulation of ice, and arresting its general tendency to the +southward, is the barrier which Sir John Franklin was finally stopped +by, in a situation where he could neither advance nor return. With the +map before us, and the data afforded by former voyages, and guided by +these theoretical views, respecting the prevailing direction of the +winds and the character of the seasons, we should locate Sir John +Franklin near latitude 80d, and longitude 145d, in 1851; and as the +seasons would afterwards become more severe, we may consider that he +has not been since able to change his locality, and dare not desert his +ships. + +No mere stranger can feel a deeper interest than the author, in view of +the hard fortunes of these hardy explorers, and he would not lightly +advance such opinions, did he not suppose they were in some degree +reliable. In 1832, he himself crossed the Atlantic, for the purpose of +offering himself to the Geographical Society of London, intending to be +landed as far northward as possible, with a single companion,[49] from +which point he purposed to follow the coast line on foot, with cautious +discretion as to seasons, confident that, with arms and ammunition, he +could support himself for many years. It has always been a grave error +in all these northern land expeditions, that they have been too +unwieldy, too much encumbered with the comforts and luxuries of +civilization at the outset, and too much loaded with a philosophical +paraphernalia, for a pioneering survey,--and cherishing too fondly the +idea that the wide shores of the Arctic sea could be explored in a +single season. Had the British government established a few posts in the +Arctic regions in the beginning,--one, for instance, in Lancaster sound, +another in Behring's Straits, and a third near the mouth of the +Coppermine, volunteers of sufficient scientific attainments might have +been procured, to banish themselves to these inhospitable regions for a +term of years, if assured of triennial supplies; and in this way, by +summer boat-parties and winter expeditions, over land or ice, the +explorations could have been gradually extended, and a greater knowledge +of the polar regions might have been acquired, with an immense saving +both of life and money. In 1832 the author's plan was deranged, by +finding that Captain Back was about setting out in quest of Ross, who +had then been some four years absent. This officer had all his party +engaged when the author waited upon him in Liverpool, and no notice was +taken of a modified plan which he forwarded to the Society at his +suggestion. It was therefore abandoned. + +The above fact is alluded to, in order to show the author's sincerity in +expressing his belief that, with a previous preparation of mind and body +for a sojourn in those frigid climes, a sufficient subsistence may be +derived from the country itself. Advantage must, of course, be taken of +the times of abundance, and due preparation made for the season of +scarcity. Averaging the extremes, there is little doubt but that both +land, and air, and water, afford an abundance of food for man in the +Arctic zone, and that, when spurred by necessity, it is within his power +to obtain it. We ought not therefore to despond, or give up efforts to +rescue those who have well earned the sympathy of the world, by what +they must have already suffered. _These northern seas will yet be +explored._ The very difficulty of accomplishing it, will itself give it +a charm, which in this restless age will operate with increasing power. +And should efforts now be relaxed, and in some future time the evidence +be brought to light that some of the party yet existed, long after all +efforts to rescue them had been abandoned, the fact would be a dark spot +on the escutcheon of England, which time could not erase. + +Since these pages were written, accounts have been received from Captain +McClure, of H. M. ship Investigator, which fully confirm the preceding +remarks on the character of the seasons in the Arctic circle; and, more +recently, despatches have been received from the discovery-ship, +Amphytrite, in relation to the past season in Behring's straits, which +also confirms the theory. + +The Investigator (now supposed to be frozen up in lat. 74d 5' N., and +long 117d 54' W.,--the last despatch being dated April 10, 1853) passed +round the northern shores of America into the channels communicating +with Lancaster sound, in 1850, but was unable to extricate herself in +1852, and, probably, yet remains in the harbor she made in the winter of +1851, in the position above named. No trace of Sir John Franklin's +expedition was, however, found, and, indeed, according to our theory, +the Investigator was not on the most promising ground. We contend that +Franklin has penetrated the pack of apparently perennial ice, which is +continually pressing to the southward, and blocking up the passages +between the northern islands, or skirting the coast line of the +continent; which pack has since increased, and effectually stopped all +egress from the open central portions of the polar sea. If Sir John +Franklin is ever heard from, this pack _must be penetrated_, and a +powerful steamer ought to be sent immediately by the British government, +to be ready in Behring's straits early enough to take advantage of the +first openings, and make a bold push _due north_, so as to get as +speedily as possible into the open waters to the north of the pack. + +If the author could make himself heard at Washington, he would also urge +the government to lose no time in following our own expedition under Dr. +Kane, who, if he finds a clear entrance from Smith's sound into the +Arctic sea, may be induced to push on, and endeavor to make his way +through the pack towards Behring's straits, and thus fall into the same +snare as Franklin. According to the theory, the higher the passage into +the Arctic sea, the less will it be incumbered with ice, and, +consequently, Smith's sound is the best both to enter and return by; and +had the author not already smarted enough by having his professions +derided, he would have submitted these views to the patrons of that +expedition before it sailed. + +The scientific world is, in reality, chargeable with the disastrous +results of Franklin's expedition. The polar basin is hemmed in by the +coast line of Europe, Asia, and America, in about latitude 70d north, +for the greatest part of the entire circumference. And this coast line, +and the islands adjacent, will cause the polar ice to accumulate and +form a frozen belt along these shores, in consequence of the constant +tendency of the earth's rotation to press the ice to the southward. The +fact that an open passage exists between this belt and the shore in +summer time, is no objection, as the tides, river currents, and warm +land breezes, may very well explain this. The learned have insisted, and +do yet insist, that the earth's rotation can produce no motions in the +Arctic sea, and, under this delusion, Franklin has passed into the +comparatively open waters inside the pack, perhaps has lost his ships; +yet it is very possible that the party may have escaped, and derived a +subsistence from the more genial waters of the central portion of that +ocean unto this day. + +We have already alluded to the difference of level between the Atlantic +and Pacific waters. It is well known that the currents in the +Spitzbergen and Greenland seas is to the southward, and that Parry, in +his attempt to reach the pole, was foiled by this very current, +frequently setting him back in twenty-four hours more than his party +could travel in the same time over the ice. Through Baffin's and +Hudson's bay the northern waters are also continually bearing their +frozen freight southward. We are, therefore, entitled to ask, what +supplies this immense drain? Behring's straits are only about sixty +miles wide, and twenty-five fathoms deep; the supply, therefore, through +this channel is totally inadequate, yet there is no other channel into +the Arctic sea where the current is inward. We have already explained +the reason why the current through Behring's straits is an exception to +the general rule, yet still confirming the principle by referring it to +the configuration of the land enclosing the Pacific ocean. The whole +south Pacific lies open to the pole, and the inertia of the immense mass +of mobile waters pressing northward, and continually contracted by the +form of the American and Asiatic coasts, is not balanced by a contrary +impulse of the waters of the north Pacific, inasmuch as this ocean +becomes narrower as it extends northward, and the only passage to the +frozen ocean is through the narrow straits of Behring. The axifugal +force of rotation due to the northern waters is, therefore, overborne +by the vast preponderance due to the southern waters, and, hence, the +northern Pacific may be considered as relatively at a higher level, and +there will be a current northward through Behring's straits, as we find +it. The same cause accumulates the waters under the equator, thus giving +a higher level to the Pacific than to the Atlantic at the isthmus of +Panama, where the difference of level is found by actual measurement to +be five or six feet. This fact has never before been explained; but the +cause is too obvious to admit of question. + +That the sea is deeper than was formerly admitted, is now fully +confirmed. We have before alluded to the results obtained by Captain +Denham, of H. M. ship Herald, who found bottom at 7,706 fathoms, or +about nine English miles. Now, whether that spherical shell, which we +have contended to be the true form of the solid earth, be continuous and +entire; or, whether it may not be wanting in localities of limited +extent where the ocean would be absolutely unfathomable, we know not; +but if such be the internal constitution of our globe, there will be, no +doubt, many channels of communication between the internal and external +ocean, and, as a consequence of the earth's rotation, the axifugal +current of the Arctic sea may be supplied by an upward current from the +interior of the globe; and this current may have a higher temperature +than the surface waters of that sea, and thus the middle portions may, +in truth, remain open the whole year round, and be teeming with animal +life. According to Captain Penny's observations in 1850, whales and +other northern animals existed to the westward, where he saw the open +sea stretch out without a bound before him. + +It has been a question mooted by some, that Franklin's ships might be +overtaken, at an early stage of the voyage, by a storm, and foundered +amidst the ice. The theory would give a negative answer to this +question. Stiff gales may prevail far to the north when the vortices do +not reach so high; but no storm, properly speaking, will be found far +beyond their northern limit. After the coming winter (1853), the +vortices will gradually penetrate farther and farther to the northward, +and the years 1857, 1858, and 1859, will be highly favorable for +northern discovery, accompanied, however, with the necessary draw-back +of tempestuous weather. + + +FOOTNOTES: + +[48] The reader will of course understand these as celestial longitudes, +and the latitudes as terrestrial. + +[49] Mr. William McDonald, of Canada. + + + + +CONCLUSION. + + +Our theory has thus extended itself beyond those limits which we at +first had drawn, and our apology must consist in the necessity existing +for reconciling the most remarkable phenomena of meteorology to its +principles. Yet, after all, what has been said is but an outline of what +remains, but this outline is a part of our theory of the weather, and it +could not well do without its aid. In some points we may not have +correctly interpreted facts; but the facts remain. The numerical +elements of the theory may also be in error--we know not; but we think +that they are as perfect as the many contingencies on which they depend +will permit. What is _certain_ however, is of ample value to compensate +for trivial errors. We have hitherto experienced but little courtesy +from those intrusted with the keys of knowledge, and cannot consequently +anticipate a very lenient verdict. But we now tell them before the +world, that they have a duty to perform, and an examination to make, and +a decision to come to, "whether these things are so." Our theory may be +called an ingenious speculation, but WE CHALLENGE THE SCIENTIFIC TO +PROVE IT--NOTHING ELSE. The theory furnishes them with tests of daily +occurrence, to prove or to disprove it. By such a trial we are willing +to be judged; but let it be conducted in the spirit recommended in the +opening address before the American Association for the Advancement of +Science, to expose all false developments, and to do it generously and +without prejudice; and to remember, "that the temple of science belongs +to no country or clime. It is the world's temple, and all men are free +of its communion. Let its beauty not be marred by writing names upon its +walls."[50] The _great_ objection, of friction and resistance of an +all-pervading medium, which will be urged against it, we regard as +rather the offspring of a bewildered imagination, than of scientific +induction. We can discover no such consequences as final ruin to our +system through its agency; but even if such were discovered, we may +answer, that nature nowhere tells us that her arrangements are eternal; +but rather, that decay is stamped with the seal of the Almighty on every +created thing. Change may be one of the great laws of matter and motion, +and yet matter and motion be indestructible. The earth was called into +existence for a specific object, and when that object is accomplished, +we are assured that another change awaits her. But when earth, and sun, +and planets, are again redissolved into their primitive state, their +atoms will still float on the ever-rolling billows of the great ethereal +ocean, to be again cast up, on the shore of time, whenever it pleaseth +Him to say, "Let there be light." + + +FOOTNOTES: + +[50] Prof. Pierce's Address, 1853. + + + + +APPENDIX. + + +Since the author's arrival in New York for the purpose of publishing his +outlines, the third and fourth volume of the Cosmos has been placed in +his hands, containing the latest uranological discoveries and +speculations. It is now more than twenty years since he began to +investigate the subject he has treated of, and fifteen since he first +announced to the world, that he had satisfactory evidence of his theory +being true. Luckily, perhaps, he has been cut off from the great streams +of knowledge; and he may confess that it was with pardonable feelings of +gratification that he discovered in 1853, by the acquisition of the two +first volumes of the Cosmos, that the philosophic mind of Humboldt had +also pondered deeply on the planetary peculiarities of size, density, +distance, inclination of axes and eccentricities of orbits, without +eliciting any satisfactory relations. + +From the tenor of the third and fourth volume of this learned summary of +scientific knowledge, it is evident that the question of a medium +filling space is more and more occupying the learned world; but the +author is unable to discover any consistent theory respecting it. The +increasing interest attaching to it, however, is evidently preparing the +world for some radical change in preconceived views. The explanation +given by this present theory to many prominent phenomena, is so totally +contrary to that of the learned world, as to leave it untouched by +anything yet advanced. What the fifth volume of the Cosmos will +contain, is not yet known in this country, neither has the author been +favored with any glimpse of the progress of science as developed before +the British Association; he supposes, however, that he yet stands alone +in the position he has defined. + +As a question of practical importance, the reader will find in the work +cited, the various opinions of the temperature of space. Both Fourier +and Poisson regard this as the result of radiated heat from the sun and +all the stars, minus the quantity lost by absorption in traversing the +regions of space filled with ether.[51] But why should we regard the +stars as the source of all motions? Why cannot physicists admit the idea +of an infinite space filled (if we may use the expression) with an +infinite medium, possessing an unchangeable mean temperature long before +the formation of a single star. A star equal to our sun at the distance +of Sirius, would give about one million of million times less heat than +our present sun, which is only able to give an average temperature to +the whole globe--about twenty degrees above freezing--then let us +remember that there are only about fifty stars of the first and second +magnitude, which give more light (and by analogy heat also) than all the +rest of the stars visible. Such labored theories as this of Poisson's is +a lamentable instance of the aberrations of human wisdom. + +We would also call the reader's attention to a late conclusion of +Professor Dove, viz.: That differences of temperature in different +longitudes frequently exist on the same parallel of latitude, or, in +other words, are laterally disposed. This may be thought adverse to the +theory, but it should be borne in mind that the annual mean temperature +of the whole parallel of latitude should be taken when comparing the +temperatures of different years. + +Another fact cited in the Cosmos apparently adverse to the theory, is +the idea entertained by Sir John Herschel, that the full-moon +dissipates the clouds. This question has been fully examined by +Professor Loomis before the American Association, and he concludes that +there is not the slightest foundation for the assertion--taking as data +the Greenwich observations themselves. + + +FOOTNOTES: + +[51] See _Cosmos_, p. 41, vol. 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