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+Project Gutenberg's The Philosophy of the Weather, by Thomas Belden Butler
+
+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: The Philosophy of the Weather
+       And a Guide to Its Changes
+
+Author: Thomas Belden Butler
+
+Release Date: August 14, 2010 [EBook #33429]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+*** START OF THIS PROJECT GUTENBERG EBOOK THE PHILOSOPHY OF THE WEATHER ***
+
+
+
+
+Produced by Robin Monks and the Online Distributed
+Proofreading Team at http://www.pgdp.net (This book was
+produced from scanned images of public domain material
+from the Google Print project and from The Internet Archive:
+American Libraries.)
+
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+
+
+
+
+  THE PHILOSOPHY OF THE WEATHER.
+  AND A GUIDE TO ITS CHANGES.
+
+
+  BY T. B. BUTLER.
+
+
+  NEW YORK:
+  D. APPLETON & COMPANY,
+  NOS. 346 & 348 BROADWAY.
+  1856.
+
+
+
+
+  Entered according to Act of Congress, in the year 1856, by
+  T. B. BUTLER,
+  In the Clerks Office of the District Court of the District of
+  Connecticut.
+
+
+  ELECTROTYPED BY
+  THOMAS B. SMITH,
+  82 & 84 Beekman Street.
+
+
+  PRINTED BY
+  J. F. TROW,
+  379 Broadway.
+
+
+
+
+INTRODUCTION.
+
+
+The atmospheric conditions and phenomena which constitute "The Weather"
+are of surpassing interest. Now, we rejoice in the genial air and warm
+rains of spring, which clothe the earth with verdure; in the alternating
+heat and showers of summer, which insure the bountiful harvest; in the
+milder, ripening sunshine of autumn; or the mantle of snow and the
+invigorating air of a moderate winter's-day. Now, again, we suffer from
+drenching rains and, devastating floods, or excessive and debilitating
+heat and parching drought, or sudden and unseasonable frost, or extreme
+cold. And now, death and destruction come upon us or our property, at any
+season, in the gale, the hurricane, or the tornado; or a succession of
+sudden or peculiar changes blight our expected crops, and plant in our
+systems the seeds of epidemic disease and death. These, and other normal
+conditions, and varied changes, and violent extremes, potent for good or
+evil, are continually alternating above and around us. They affect our
+health and personal comfort, and, through those with whom we are
+connected, our social and domestic enjoyments. They influence our business
+prosperity directly, or indirectly, through our near or remote dependence
+upon others. They limit our pleasures and amusements--they control the
+realities of to-day, and the anticipations of to-morrow. None can
+prudently disregard them; few can withhold from them a constant attention.
+Scientific men, and others, devote to them daily hours of careful
+observation and registration. Devout Christians regard them as the
+special agencies of an over-ruling Providence. The prudent, fear their
+sudden, or silent and mysterious changes; the timid, their awful
+manifestations of power; and they are, to each and all of us, ever present
+objects of unfailing interest.
+
+This _interest_ finds constant expression in our intercourse with each
+other. A recent English writer has said: "The germ of meteorology is, as
+it were, innate in the mind of every Englishman--the weather is his first
+thought after every salutation." In the qualified sense in which this was
+probably intended, it is, doubtless, equally true of us. Indeed, it is
+often not only a "first thought" _after_ a salutation, but a part of the
+salutation itself--an offspring of the same friendly feeling, or a part of
+the same habit, which dictates the salutation--an expression of sympathy
+in a subject of common and absorbing interest--a sorrowing or rejoicing
+with those who sorrow or rejoice in the frowns and smiles of an
+ever-changing, ever-influential atmosphere.
+
+If consistent with our purpose, it would be exceedingly interesting to
+trace the varied forms of expression in use among different classes and
+callings, and see how indicative they are of character and employment.
+
+The sailor deals mainly with the winds of the hour, and to him all the
+other phases of the weather are comparatively indifferent. He speaks of
+airs, and breezes, and squalls, and gales, and hurricanes; or of such
+appearances of the sky as prognosticate them. The citizens, whose lives
+are a succession of _days_, deal in such adjectives as characterize the
+weather of _the day_, according to their class, or temperament, or
+business; and it is pleasant, or fine, or _very_ pleasant or fine;
+beautiful, delightful, splendid, or glorious; or unpleasant, rainy,
+stormy, dismal, dreadful or horrible. The farmer deals with the weather
+of considerable periods; with forward or backward _seasons_, with "cold
+snaps" or "hot spells," and "wet spells" or "dry spells." And there are
+many intermediate varieties. The acute observer will find much in them to
+instruct and amuse him, and will probably be surprised to find how much
+they have to do with his "first impressions" of others.
+
+But I have a more important object in view. I propose to deal with "The
+PHILOSOPHY _of the Weather_"--to examine the nature and operation of the
+arrangements from which the phenomena result; to strip the subject, if
+possible, of some of the complication and mystery in which traditionary
+axioms and false theories continue to envelop it; to endeavor to grasp
+_its principles_, and unfold them in a plain, concise, and systematic
+manner, to the comprehension of "_the many_," who are equal partners with
+the scientific in its practical, if not in its philosophic interest; and
+to deduce a few general rules by which its changes may be understood, and,
+ultimately, to a considerable extent, foreseen.
+
+This is not an easy, perhaps not a prudent undertaking. Nor is my position
+exactly that of a volunteer. A few words seem necessary, therefore, by way
+of apology and explanation.
+
+In the fall of 1853, in the evening of a fair autumnal day, I started for
+Hartford, in the express train. Just above Meriden, an acquaintance
+sitting beside me, who had been felicitating himself on the prospect of
+fine weather for a journey to the north, called my attention to several
+small patches of scud--clouds he called them--to the eastward of us,
+between us and the full clear moon, which seemed to be enlarging and
+traveling south--and asked what they meant.
+
+"Ah!" said I, "they are scud, forming over the central and northern
+portions of Connecticut, induced and attracted by the influence of a
+storm which is passing from the westward to the eastward, over the
+northern parts of New England, and are traveling toward it in a southerly
+surface wind, which we have run into. They seem to go south, because we
+are running north faster than they. You see them at the eastward because
+they are forming successively as the storm and its influence passes in
+that direction, and are most readily seen in the range of the moon; but
+when we reach Hartford you will see them in every direction, more numerous
+and dense, running north to underlie that storm."
+
+I had seen such appearances too many times to be deceived. It was so. When
+we arrived at Hartford they were visible in all directions, running to the
+northward at the rate of twenty-five miles an hour. In the space of forty
+minutes we had passed from a clear, calm atmosphere (and which still
+remained so), into a cloudy, damp air, and brisk wind blowing in the same
+direction we were traveling, and toward a heavy storm. My friend passed
+on, and met the southern edge of the rain at Deerfield, and had a most
+unpleasant journey during the forenoon of the next day. Taking the cars
+soon afterwards, in the afternoon, for the south, I found him on his
+return.
+
+"Shall I have fair weather now till I get home?" said he.
+
+"There are no indications of a storm here, or at present," I replied, "but
+we may observe them elsewhere, and at nightfall."
+
+He kept a sharp look-out, and, as we neared New Haven, discovered faint
+lines of cirrus cloud low down in the west, extending in parallel bars,
+contracting into threads, up from the western horizon, in an E. N. E.
+direction toward the zenith.
+
+"Now, what is that?" said he.
+
+"The eastern outlying edge of a N. E. storm, approaching from the W. S. W.
+It is now raining from 150 to 200 miles to the westward of the eastern
+extremity of those bars of cirrus-condensation; perhaps more, perhaps
+less; and under those bars of condensation the wind is attracted, and is
+blowing from the N. E. toward the body of the storm, and where the
+condensation is sufficiently dense to drop rain. That dense portion will
+reach here, and it will rain from twelve to fifteen hours hence. As we
+pass along the shore, and run under that out-lying advance
+cirrus-condensation, we shall see that the vessels in the Sound have the
+wind from the N. E., freshening, but we shall continue to have this light
+and scarcely-perceptible air from the northward for a time--_the N. E.
+wind always setting in toward an approaching storm, out on the Sound, much
+sooner than upon the land_."
+
+As we approached the storm, and the storm us, the evidence of denser
+condensation at the west, and of wind from the east, blowing toward it,
+became more apparent. The fore and aft vessels were running "up Sound"
+with "sheet out and boom off," before a fresh N. E. breeze, and my friend
+was astonished.
+
+"I must understand this," said he; "how is it?"
+
+"All very simple. The page of nature spread out above us is intelligible
+to him who will attentively study it. The laws which produce the
+impressions and changes upon that page, are few and comprehensible.
+Although there is great variety, even upon the limited portion which is
+bounded by our horizon, there is also substantial uniformity; and,
+although the changes are always extensive, often covering an area of one
+thousand miles or more, and our vision can not extend in any direction
+more than from thirty to fifty, yet those changes are always, to a
+considerable extent, intelligible, and may often be foreseen."
+
+"Has meteorology made such progress?"
+
+"By no means. It has, indeed, been raised to the dignity of a science, and
+professorships endowed for its advancement. Some books have been written,
+and many theories broached in relation to it; and innumerable observations
+of the states of the barometer and thermometer, of the clouds, and the
+quantity of fallen rain, and the direction and force of the wind--made and
+recorded simultaneously in different countries--have been published and
+compared; and a great many important facts established, and tables of
+'_means_' constructed, and just inferences drawn, yet the _few and simple
+arrangements_ upon which all the phenomena depend, and _their philosophy_,
+have not yet been clearly elicited or understood."
+
+"Have not the 'American Association for the Advancement of Science'
+arrived at some definite and sound conclusion upon the subject?"
+
+"No; it has been with them, for many years, an interesting subject for
+papers and debate. Some very valuable articles, upon particular topics, or
+branches of the subject, have been read and published. But the
+_Cyclonologists_, as they term themselves, and who seem to think the great
+question is, '_Are storms whirlwinds?_' appear with new editions and
+phases of their favorite views as regularly as the annual meeting recurs;
+and, though they have not convinced, they seem to have silenced their
+opponents. The only conclusion, however, judging from their debates, to
+which the Association appear to have come with any considerable unanimity,
+is, that they are yet without sufficient _authentic observations_ and
+well-established facts, to authorize the adoption of the Huttonian,
+Daltonian, Gyratory, or Aspiratory, or any of the other numerous theories
+which abound. And they are right. The subject is mystified by these
+theories and speculations of the study, founded on barometrical and
+thermometrical records, and the direction and force of the surface winds.
+
+"The qualities of heat were among the earlier discoveries of science, and
+all the phenomena of the weather were forthwith attributed to its
+influence. Hastily-formed and erroneous views of its power, and the manner
+of its action in particular localities, and under particular
+circumstances, have retained the credence accorded to them when first
+announced, although subsequent discoveries have shown their fallacy; some
+new theory of _modification_ having been invented to reconcile the
+discrepancies as soon as they appeared. Perhaps it is not too much to say
+(however it may seem to one not thoroughly acquainted with the subject,
+who does not know that the _primary_ and secondary modifying hypotheses
+found in Kämtz, may be counted by hundreds) that there is not remaining in
+any other science, and possibly in all others, an equal amount of false
+and absurd theory, and of forced and unnatural grouping of admitted facts
+to sustain it, as in meteorology as at present taught and received.
+Astronomy, as a science, is almost perfected--the nature, and size, and
+orbits, of the distant worlds around us are known--while constant changes
+and alternating atmospheric conditions, which all occur _within less than
+six miles of us_, affecting all our important interests, and obvious to
+our senses, although much talked off, and made the objects of many
+theories, are but little understood."
+
+"How, then, did you acquire the information you seem to possess?"
+
+"By studying '_the countenance of the sky_,' for in no other way has such
+information ever been, or can it ever be, acquired. By a long-continued,
+daily, and sometimes hourly observation of the clouds and currents of the
+atmosphere, in connection with such reports of the then state of the
+weather elsewhere, as have fallen under my notice, and the effect of its
+changes upon the animal creation--for very much can be learned from them.
+Yonder flock of black ducks that sit on that inshore rock, above the
+tide--the wildest and most suspicious of all their tribe--although the
+air is calm about them, know well that a storm is at hand. They probably
+both see and feel it. As twilight approaches they will fly away inland,
+forty or fifty miles perhaps, and settle among the lilies or grass which
+surround some fresh-water pond, certain of remaining while the storm
+lasts, and for one day at least, out of danger, and undisturbed. Many a
+time, in my boyhood, have I heard, in the stillness of evening, the
+whistling of their wings, as they swept up the Connecticut valley, to
+seek, on the borders of the coves, and in the creeks of the meadows, a
+concealed and safe feeding-place during a coming storm. And many a time in
+the autumn, after they had all passed down for the season, when the
+indications of an approaching storm were clearly visible at nightfall,
+have I waited for them to return, on the eastern margin of a bend in the
+cove, on the eastern side of a creek, to shoot them, though invisible, by
+shooting across the head of the wake, which they made upon the water in
+alighting, and from which the few remaining rays of twilight that came
+from the western sky were reflected.
+
+"But I am far from being singular in this. That page is more extensively
+read than is generally supposed. Many plain, unassuming men--farmers,
+shipmasters, and others within the circle of my acquaintance--know more,
+practically, of the weather than the most learned closet-theorist, or the
+most indefatigable recorder of its changes. Every one, by studying the
+page of nature above him, as he would the page of any other science, and
+testing, by observation, the numerous theories invented to account for the
+varied phenomena, may learn much, very much, that will be useful and
+interesting to him, and which he can never learn from books, or
+instruments, or theories alone."
+
+"Well," said my friend, "I am too far advanced in life, as are many
+others, to commence such observations, and you must publish."
+
+I demurred, and he insisted.
+
+"It is difficult to spare the time; and I can not neglect my profession,"
+I urged.
+
+"Where there is a will there is a way," he replied.
+
+"It is difficult to make one's self understood without many
+illustrations."
+
+"Very well, they are easily obtained."
+
+"But they cost money, and it is said 'science will not pay its way' like
+fiction and humbug."
+
+"That," said he, "is a libel--such science will. Every one is interested
+in the weather--all talk about it--and thousands would carefully observe
+it, if they could be correctly guided in their observations."
+
+"I may get into unpleasant controversy."
+
+"Suppose you do; you can yield your position if wrong, and maintain it if
+right, and _magna est veritas_."
+
+"But I may be mistaken in some of the views to which it will be necessary
+to advert, if I attempt to systematize the subject."
+
+"Be it so--your mistakes may lead others to the discovery of the truth.
+Besides, the weather is _common property_, and every one has a right to
+theorize about it, or to talk about it, as they please--even to call a
+stormy day a pleasant one, or make any other mistaken remark concerning
+it; and every other person is entitled to a like latitude of reply. And
+further," said he, with some emphasis, "no important observation, in
+relation to a subject of such interest, should be lost; and, if you have
+observed one new fact, or drawn one new and just inference from those
+which have been observed by others; and especially if, from observation
+and reading, you can deduce from the phenomena an intelligible,
+_observable, general system_, it is not only your right, but duty, to make
+it known. Such a knowledge of the true system is greatly desired by every
+considerate man."
+
+To my friend's last argument I was compelled to yield. I could make no
+reply consistent with the great principles of fraternity, which I shall
+ever recognize. The promise was given. My friend went on his way, and I
+went to the daguerreotypist to procure a copy of the then appearance of
+the sky, as the first step toward its fulfillment. The fulfillment of that
+promise, reader, you will find in the following work. It was commenced as
+an article for a magazine, but it has grown on my hands to a volume.
+Justice could not well be done to the subject in less space. It has been
+written during occasional and distant intervals of relaxation from
+professional avocations, or during convalescence from sickness, and it is,
+for these reasons, somewhat imperfect in style and arrangement. But I have
+no time to rewrite. There is much in it which will be old to those who
+read journals of science, but new to those who do not. There is more which
+will be new to all classes of readers, and may, perhaps, be deemed
+heretical and revolutionary by conservative meteorologists; yet I feel
+assured that the work is a step in the right direction--that it contains a
+substantially accurate exposition of the Philosophy of the Weather, and
+valuable suggestions for the practical observer.
+
+I have inserted my name in the title-page, contrary to my original
+intention, and at the suggestion of others; for I have no scientific
+reputation which will aid the publisher to sell a copy. Nor do I desire to
+acquire such reputation. It can never form any part of my "capital in
+life." Nor has it influenced me at all in preparing the work. I have aimed
+to fulfill a promise, too hastily given, perhaps--to put on record the
+observations I have made, and the inferences I have drawn from those of
+others--to induce and assist further observations, and, if possible, of a
+_general_ and _connected character_--and to impress those who may read
+what I have written with the belief, that _they will derive a degree of
+pleasure from a daily familiarity with, and intelligent understanding of,
+the "countenance of the sky," not exceeded by that which any other science
+can afford them_.
+
+I have examined, with entire freedom and fearlessness (but I trust in a
+manner which will not be deemed censurable or in bad taste) the theories
+and supposed erroneous views of others, for, in my judgment, the
+advancement of the science requires it. Says Sir George Harvey, in his
+able article on Meteorology, written for the Encyclopædia Metropolitana:
+
+     "It is humiliating to those who have been most occupied in
+     cultivating the science of meteorology, to see an agriculturist or a
+     waterman, who has neither instruments nor theory, foretell the future
+     changes of the weather many days before they happen, with a precision
+     which the philosopher, aided by all the resources of science, would
+     be unable to attain."
+
+The admissions contained in this paragraph, in relation to the comparative
+uselessness of instruments and theories, and the value of practical
+observation, are both in a good measure true. And the time has come, or
+should speedily come, when "_pride of opinion_," and "_esprit du corps_,"
+among theorists and philosophers, should neither be indulged in, nor
+respected; and when their theories should be freely discussed, and rigidly
+tested by the observations of practical men. Such measure, therefore, as I
+have meted, I invite in return. Let whatever I have advanced, that is new,
+or adopted that is old, be _as_ rigidly tested, and _as_ freely discussed.
+Let the errors, if there be any--and doubtless there are--be detected and
+exposed. Let the TRUTH be sought by all; and meteorology, as a PRACTICAL
+SCIENCE, advance to that full measure of perfection and usefulness, of
+which it is unquestionably susceptible.
+
+
+
+
+TABLE OF CONTENTS.
+
+
+                                                                      PAGE
+
+  CHAPTER I.
+
+  Heat and moisture are indispensable to the fertillity of the
+  earth--Arrangements exist for their diffusion and distribution,
+  and all the phenomena of the weather result from their
+  operation--Heat furnished or produced mainly by the direct
+  action of the sun's rays--Manner in which it is diffused over
+  the earth--Other causes operate besides the sun's rays--The
+  earth intensely heated in its interior--Heat derived from the
+  great Oceanic currents, and the aerial currents which flow
+  from the tropics to the poles, and from magnetism and
+  electricity--Water distributed by an atmospheric machinery as
+  extensive as the globe--Evidences of this--Its distribution over
+  the continents of North America--Explanation of it--Source from
+  whence our supply of water is derived, and from which our rivers
+  return                                                                 1
+
+
+  CHAPTER II.
+
+  Our rivers return in the form of clouds, and in storms and
+  showers--Definition and character of storms--Differences in
+  the character of the clouds which constitute them--Nomenclature
+  of Howard--Its imperfections--New order of description--Low
+  fog--High fog--Storm fog--Storm scud--N. W. scud--Cumulus--
+  Stratus--Cirrus--Compounds of the two latter--recapitulation in
+  tabular form                                                          24
+
+
+  CHAPTER III.
+
+  Our rivers do not return from the North Atlantic--All storms and
+  showers move from the westward to the eastward--Seeming clouds
+  seen moving from the eastward to the westward are scud--They are
+  incidents of the storm, and not a necessary part of it--The
+  storm clouds are above them, moving to the eastward--Occasions
+  when this may be seen--Admitted facts prove it--Investigations
+  prove it--May be known from analogy--From the fact that there is
+  an aerial current pursuing the same course in which the storms
+  originate--Character of this current--Its influence upon our
+  country--Importance of a knowledge of its origin, cause, and the
+  reciprocal action between it and the earth--To this end necessary
+  to go down "to the chambers of the South"                             43
+
+
+  CHAPTER IV.
+
+  The trade wind region--Its extent and arrangements--Its belt of
+  daily rains and movable character--The trade winds--The extra
+  tropical belt of rains--Connection between them and their annual
+  movements--The counter-trades--Their origin and situation--One
+  of them constitutes our aerial current--It originates in the
+  South Atlantic as a surface-trade--Anomalies of the trade wind
+  region--Dry seasons--Humboldt's description of them--Exist where
+  the surface trades are situated--The rainless countries--
+  Concentrated counter-trade--Monsoons--Received theory in relation
+  to them a fallacy--Cause of the great central phenomena--
+  Calorific theory a fallacy--Land not hotter under the belt of
+  rains, nor sea materially so--Theory should be abandoned              52
+
+
+  CHAPTER V.
+
+  The agent, magnetism--Its character and currents--Oxygen
+  magnetic--Precipitation at the belt of rains occasioned by
+  depolarization--Storms originate in this central belt, and move
+  toward the poles                                                      82
+
+
+  CHAPTER VI.
+
+  Course and functions of the counter-trade--Ours come from the
+  South Atlantic--Reason why it can not come from the Pacific--
+  Mistake of Mr. Redfield and Lieutenant Maury in regard to it--
+  All our storms originate in it--Proofs of this--State of the
+  weather, whether hot or cold affected by it--Proofs of this--All
+  our surface winds are incidents of it, and due to its conditions
+  and attractions--Proofs of this--Character of the different
+  winds--Anomalies of Mr. Blodgett accounted for--Received theory
+  in regard to sea and land breezes a mistaken one--Proofs of
+  this--Peculiar character of the N. W. wind--Identity with the
+  winter Mexican northers--Character of the West India hurricanes--
+  Of the thunder-gust--Of the tornado--Sundry particulars in
+  relation to the latter--Due to currents of electricity--
+  Proportions of winds in different localities--Examination of the
+  work of Professor Coffin upon that subject--Examination of
+  Lieutenant Maury's theory of the monsoons                             92
+
+
+  CHAPTER VII.
+
+  Height of the counter-trade in different latitudes--Cause of the
+  Calms of Cancer--Influence of mountains upon the counter-trade--
+  Reports of Herndon and Gibbon--Focus of precipitation in the
+  extra-tropical belt north of its southern line--Evidences of
+  this--The elevation of the counter-trade above the earth varies
+  in the same latitude with the variations in the phenomena of the
+  weather--Temperature of the counter-trade--Rain dust, its origin
+  and indications--Volcanic ashes--How far they indicate its course
+  of progression--Question whether there is an eastern progression
+  of the body of the atmosphere above the machinery of distribution    179
+
+
+  CHAPTER VIII.
+
+  Important to understand the precise character of the reciprocal
+  action between the earth and the counter-trade--Connection
+  between the width and movements of the belt of inter-tropical
+  rains and the volume of the trades--Its peculiarities over
+  Africa, the Atlantic, and South America--The magnetic equator--
+  Character of the storms which originate in the inter-tropical
+  belt indicate local magnetic action--Supposed influence of
+  volcanic action--Gulf Stream changes its position--This the
+  result of magnetic action--Alternating contrasts of heat and
+  cold, and rain and drought--Dr. Webster's history of the
+  weather--Spots upon the sun--Their character and influence--Cold
+  or warm periods during the same decade, and during different
+  decades--Connection between the spots and magnetic disturbances
+  and variations--Influence of the moon upon the weather--No
+  decisive inference to be drawn from these facts, and a more
+  critical examination necessary                                       204
+
+
+  CHAPTER IX.
+
+  Examination of existing theories--Calorific theory the prevailing
+  one--Lateral overflow of Professor Dove--Absurdity of his views
+  in relation to them--His theory of hurricanes--Its absurdity--A
+  new theory by Mr. Dobson--Three theories advanced by
+  meteorologists of this country--Professor Espy's theory--Mr.
+  Bassnett's theory--Mr. Redfield's theory--Extended examination of
+  the latter--His theory in relation to the fall of the barometer
+  contradictory in its character--Philosophy of the barometric
+  change--No aid to be derived from these theories                     232
+
+
+  CHAPTER X.
+
+  Further inquiry in relation to the reciprocal action between the
+  earth and the counter-trade--Terrestrial magnetism, and what we
+  know of it--Its elements, and their variations--Their connection
+  with the variations of atmospheric condition--Magnetism acts
+  through its connection with electricity--Character of the latter
+  and its variations--Their connection with atmospheric conditions--
+  Electricity as well as magnetism in excess over this country--
+  Effects of it upon our climate--Closer consideration of the
+  atmospheric phenomena--Their diurnal changes and connections
+  compared with those of magnetism and electricity--Grouping of all
+  the diurnal variations--Particular and separate examination of
+  them--Classification of storms--Examination in detail of the
+  several classes and the primary influence of the earth or
+  counter-trade in relation to each                                    285
+
+
+  CHAPTER XI.
+
+  Prognostics                                                          340
+
+
+
+
+THE PHILOSOPHY OF THE WEATHER.
+
+
+
+
+CHAPTER I.
+
+
+Heat and moisture are indispensable to the fertility of the earth. Without
+suitable arrangements for their diffusion and distribution, and within the
+limits of certain minima and maxima, it would not have been habitable, or
+the design of its Creator perfected. These arrangements therefore exist,
+and "while the earth remaineth seed time and harvest shall not cease." Few
+and simple in their character, though necessarily somewhat complicated and
+irregular in their operation, the ultimate result is always attained. A
+beautiful system of compensations supplies the losses of every apparent
+irregularity in one section or crop, by the abundance of others.
+
+From the operation of these few, simple, connected, and intelligible
+arrangements for the diffusion of heat and the distribution of moisture
+over the earth, result all the phenomena which constitute the weather; and
+by studying them, and their operation, we may acquire an accurate
+knowledge of its "_Philosophy_."
+
+The necessary heat is furnished, or produced, mainly by the direct action
+of the sun's rays; and the most obvious feature in the arrangements for
+its diffusion is that by which the sun is made to shine successively and
+alternately upon different portions of the earth. Nothing animate or
+organic could endure his burning rays, if they shone continuously or
+vertically upon one point, or could exist without their occasional
+presence. Hence the provision for a diurnal rotation, to prevent the
+exposure of any portion of the globe to the action of those rays for
+twenty-four consecutive hours, except for a limited period, and at a
+considerable angle, in the polar regions. But the earth is spheroidal, and
+a diurnal revolution would still leave that portion which lies under the
+equator too much, and the other too little, exposed to the action of the
+sun. This is obviated by an annual revolution of the earth around the sun,
+and an obliquity of its axis, by reason of which the northern and southern
+portions are alternately and, as far as the tropics vertically, exposed to
+the sun; and it is made to travel (so to speak) from tropic to tropic,
+producing summer and winter, and other important phenomena.
+
+This obliquity and consequent change of exposure are in degree precisely
+what the wants of the earth would seem to require. If it was greater, the
+sun would travel further north and south, but the alternate winters would
+be longer and more severe. If it was less, the end would not be as
+perfectly attained.
+
+The direct action of the sun's rays upon the earth, particularly those
+portions which lie north and south of the tropics, is not the only source
+from which the supply of heat is derived. Although there is a general
+increase of heat in spring and summer when the sun travels north, and of
+cold when he travels south in winter, yet there are frequent
+irregularities attending both. Very sudden and great changes occur in each
+of them. Frost sometimes, cool weather often, occurs in midsummer, and
+considerable heat and tornadoes in midwinter. And ordinarily the maxima
+and minima of each month and, indeed, of each week are widely apart. Even
+in the polar regions, in midwinter, _where the sun does not shine at all_,
+the same moderating changes with which we are conversant occur in degree.
+An extract or two from the register found in Dr. Kane's narrative of the
+"Grinnell Expedition" will illustrate this.
+
+  JANUARY 1851, (LATITUDE ABOUT 74°, LONGITUDE ABOUT 70°).
+
+  Date.   Wind.     Force.       Ther.  Bar.   Sky and Weather.
+
+  Jan. 3            calm         -26.1  29.62  blue sky, m.
+   "   4  W.        gent breeze  -21.3  29.53  blue sky,
+                                                 detached clouds, m.
+   "   5  W. by N.  gent breeze   -3.9  29.59  blue sky, m.,
+                                                 clouded over.
+   "   6  W. by S.  light breeze  -0.8  29.67  clouded over, m.,
+                                                 snow.
+   "   7  W.        gent breeze  -14.4  29.96  blue sky, detached
+                                                 clouds, m.
+   "   8  W.S.W.    light air    -21.2  30.14  blue sky, m.
+   "  29  W.N.W.    light air    -18.9  30.19  blue sky.
+   "  30  NW. by W. light air    -13.5  30.17  clouded over, m.
+   "  31  NW. by W. gent breeze   -4.4  29.35  clouded over, snow.
+  Feb. 1  W.        light breeze -11.7  29.27  cloudy, blue sky, m.
+   "   2  W.        light air    -25.1  29.62  blue sky, detached
+                                                 clouds, m.
+
+These extracts are instructive. It will be seen that on the 3d of
+January, when the sun had been absent some weeks, it was calm, the
+thermometer stood at 26° below zero (the - or minus mark before the
+figures indicates that), and the barometer at 29.62, with blue sky,
+somewhat misty or hazy--(the letter "m." standing for misty or hazy)--a
+state of the air which existed most of the time when it did not snow or
+rain, and therefore is of no importance in this connection. The next day
+the thermometer began to rise, and the barometer to fall. On the 5th it
+clouded over, and the thermometer rose rapidly, and on the 6th it had
+risen more than 25°, and snow fell. On the 7th it cleared off, the
+thermometer fell rapidly, and the barometer rose. On the 8th the
+thermometer had fallen to 21° below zero, and the barometer had risen to
+30.14. Another instance, in all respects similar, occurred the latter part
+of the month. We shall see hereafter that these changes are precisely like
+those which occur with us, and every where. That, as in the polar regions,
+and whether the sun be present or absent, or obscured by clouds, and by
+night as well as by day, the changes from warm to cold and from cold to
+warm are sudden and great, and that the latter are connected with the fall
+of rain and snow--that every where in winter it _moderates to storm_.
+
+Many other instructive instances, especially in relation to the great
+difference in the seasons in our own country, and upon the same parallels
+elsewhere, might be cited if it were necessary. But they will more
+appropriately appear in the sequel.
+
+
+[Illustration: Fig. 1.
+
+In the above cut the isothermal lines are Centigrade. The zero of the
+Centigrade thermometer is the freezing point of water, or 32° of
+Fahrenheit. The boiling point of water is 100° Centigrade, or 212°
+Fahrenheit. A degree of Centigrade is equal to one degree and four-fifths,
+Fahrenheit. The 0° line of the cut, therefore, is 32° of Fahrenheit--the
+line of 5° above is 41° Fahrenheit--the line of 5° below is 23°
+Fahrenheit, and so on. The reader, who is not familiar with the difference
+in the scale of the thermometer, is desired to remember this; for we shall
+make occasional extracts in which the temperature is given in the
+Centigrade scale.]
+
+
+
+The cause of those irregularities, especially in the same seasons of
+different years, and when very great, is often sought and supposed to be
+found in the presence or absence of spots on the sun, ice floes and bergs
+in the Atlantic, etc., etc. But neither the spots, nor ice, nor other
+local causes produce them. The cause will be found in the character of the
+arrangements we are considering, and the irregular action of the power
+which controls them.
+
+Nor is the temperature of the northern hemisphere, north of the tropics,
+equal in the same latitudes. Very great diversities exist in the "annual
+mean" as well as the "mean" of the different seasons. Accurate
+observations at many points have enabled men of science to demonstrate
+this by drawing isothermal lines (_i. e._, lines of equal average annual
+heat) from point to point around the earth, which show at a glance these
+differences. The annexed cut is a polar projection of the isothermal lines
+of the northern hemisphere, as far down as the tropic, copied from
+Kaemtz's Meteorology. The dotted lines show the parallels of latitude, the
+dark lines the isothermal lines, or lines of equal annual average
+temperature. The reader is desired to observe how rarely they correspond
+with the parallels of latitude, and how they fall below in a few
+instances, and in others with great uniformity rise almost to the pole.
+
+Take, for example, the isothermal line of 0 or zero--that is, the line
+where the mean or _average_ height of the thermometer _for the year_ is at
+zero. At Behring's Straits this line is a little below the Arctic circle,
+or the parallel of 66.30 north latitude. Passing east over North America,
+it descends into Canada, almost to Lake Superior, and to about the 50th
+parallel: that is to say, it is on an average during the year as cold on
+our continent at the 50th parallel as it is near Behring's Straits at the
+65th parallel. Passing east, the line of zero rises again over the
+Atlantic Ocean until, in the meridian of Spitzbergen, it reaches, within
+the Arctic circle, up almost to the 75th parallel. So, too, the isothermal
+of 5° below zero, which is below the 60th parallel in Siberia, rises in
+the North Sea, above Behring's Straits, to the parallel of 75°, descending
+on the continent in North America to the 55th parallel, and rising again
+almost to the pole at Spitzbergen, to descend again in Siberia, while the
+isothermals of 10° and 15° below zero, which in North America are but just
+above the latitude of 60° and 75° respectively, ascend abruptly
+_surrounding the magnetic pole_, and _falling short of the geographical
+one_. Let this projection of the lines of equal temperature, and
+particularly the situation of the magnetic poles, be studied well, for we
+shall recur to it hereafter in illustration of many important portions of
+our subject.
+
+It is apparent from these facts, and were it necessary might be rendered
+still more so by referring to others, that other causes operate in the
+distribution of heat over the earth besides the direct action of the sun's
+rays upon it. Doubtless very considerable allowance is to be made for the
+difference of seasons, and difference during the same season upon the
+land and upon the ocean; in mountainous countries and level ones. But
+making every allowance for them, the fact that other causes have a
+_controlling_ influence in producing the deviations still remains most
+obvious. Neither the difference of temperature between the land and the
+ocean, or land surfaces of unequal elevations, will account for the
+elevation of the isothermal lines on different portions of the ocean, or
+their extension around the magnetic poles.
+
+Returning to a consideration of the arrangements for the diffusion of
+heat, we observe: First, that the earth itself is intensely heated in its
+interior. This is inferred, and justly, from the fact that the thermometer
+is found to rise about one degree for every fifty-five feet of
+descent--whether in boring artesian wells, exploring caves, or sinking
+shafts in mines. It is demonstrated, also, by the existence of hot springs
+and the action of volcanoes. Heat is supposed to be conducted from the
+center toward the surface every where, but with difficulty and slowly. It
+is also supposed to be conducted from the tropical regions toward the
+poles. Such is the opinion of Humboldt. (Cosmos, vol. i. p. 167.)
+
+Probably it reaches the surface and exerts an influence, also, upon the
+weather through the ocean, and by heating it in its greatest depths.
+Little attention has been paid, so far as I am informed, to the question
+how far the ocean is thus heated in _tropical latitudes_. Doubtless a
+portion of the warmth of the ocean there is derived from that source, and
+it has its influence in changing the temperature of the deep-seated cold
+polar currents of, the great oceans. Perhaps it may yet be found that the
+icebergs are detached by it in the polar seas--the observations of Dr.
+Kane point to such a result. (Grinnell Expedition, p. 113, and also chap.
+48.)
+
+Little need be said of the inconsiderable quantities of heat supposed to
+be derived by radiation from the stars, the planets, and from space. If
+any such are derived they are too inconsiderable to be of importance in
+this inquiry.
+
+Heat is also carried, and in quantities which exert very considerable
+influence upon the weather, from the tropics to the poles by the great
+oceanic currents which flow unceasingly from one to the other.
+
+The most important of these with which we are acquainted is the Gulf
+Stream of the Atlantic. Gathering in the South Atlantic, and passing north
+through the Caribbean Sea and the Gulf of Mexico, it issues out through
+the Bahama Channel, and flows north along the eastern coast of the United
+States, but some distance from it, to Newfoundland, and from thence
+continuing to the north-east and spreading out over the surface of the
+ocean--a portion of it mingling with the waters of the North Atlantic in
+passing--it flows up on the western coast of Europe, around the Faroe
+Islands, and Spitzbergen, to the polar sea; passing around Greenland, and
+perhaps through its Fiords, it descends again through the sounds and
+channels of the Arctic regions into Baffin's Bay, and through Davis's
+Straits, burdened with the icebergs and floes of the polar waters, to
+return again to the South Atlantic. For reasons which will appear in the
+sequel, it has comparatively little influence upon the weather of the
+United States. Western Europe, however, Greenland, the islands which lie
+in its course, and the polar seas, are most materially influenced.
+Although not the only cause, it has very much to do with the remarkable
+elevation of the isothermal lines over the Northern Atlantic, and upon
+Western Europe, as seen upon the map.
+
+A like oceanic current exists in the Pacific Ocean, the influence of which
+may also be traced upon the map by the elevation of the isothermal lines
+at the northern extremity of that ocean, and upon the north-west coast of
+North America. A vast amount of heat is transported from the tropical to
+the temperate and frozen regions of the earth by these great oceanic
+currents.
+
+Another supply is derived from aerial currents which flow from the tropics
+toward the poles. These currents exist every where over the entire surface
+of the earth, but in more concentrated volumes along the great "lines of
+no variation," and greater magnetic intensity, on the western side of the
+great oceans, over the eastern portions of the two continents of North
+America and Asia. Not, as meteorological writers suppose, in the upper
+portions of the atmosphere, having risen in the trade-wind region and run
+off at the top toward the poles by force of gravity, but near, and
+sometimes in contact with the earth. The influence of these aerial
+currents upon the temperature of the atmosphere, and in producing the
+phenomena we are to consider, is exceedingly important. We shall have
+occasion to examine them with great care and minuteness under another
+head, for upon them, more than any other portion of the arrangements,
+depend not only the diffusion of heat, but also the distribution of
+moisture.
+
+Still another supply of heat, during the sudden changes, at least, is
+produced by the action of terrestrial magnetism and electricity. Very
+great progress has been made within a short period, in the investigation
+of the nature of these agents. The identity, or at least intimate
+association or connection of heat, light, electricity, and magnetism,
+always suspected, has been in various ways, and by a variety of
+experiments demonstrated. The influence of magnetism if distinct from
+gravitation, is second only to that; and its agency in producing the
+phenomena we are considering is primary and controlling. We will only, in
+this connection, ask the reader to note the situation of the north
+magnetic poles (for there are two of them); the manner in which the
+isothermal lines _surround_ them; the fact that they are _poles of cold_,
+_i. e._, that it is colder there than even to the north of them. We shall
+recur to this part of the subject again.
+
+Such, briefly considered, are the principal arrangements by which heat is
+diffused over the earth.
+
+Equally marked by infinite wisdom, and equally interesting and important,
+are the arrangements by which moisture is distributed. Doubtless the
+general belief is that this is a simple process; that water evaporates
+and rises till it meets a colder stratum of atmosphere, and then condenses
+and falls again; or that, according to the Huttonian theory, currents of
+air of different temperatures mingle and equalize their heat, and the
+aggregate mass when equalized in temperature is cooler, and therefore is
+unable to hold as much moisture in solution as the most heated portion
+had, and the excess falls in rain. But the process is by no means so
+simple, nor is heat the sole or most powerful agent concerned in it.
+Currents of air do not mingle, but stratify. Evaporation from the surface
+of any given portion of the earth outside of the tropics does not alone
+supply that portion with rain. _Vast and wonderful, coextensive with the
+globe itself, and perfectly connected, is the machinery by which that
+supply is furnished even to the most inconsiderable portion of its
+surface._
+
+Take your map of North America and note, in this respect, its
+peculiarities. It extends from the Isthmus of Darien to the Arctic
+regions, and from the 65th to the 160th meridian of west longitude from
+Greenwich, and has upon its surface a type of every climate in the world.
+For the purpose of simplifying and illustrating the matter in hand, let us
+divide it into five sections. Let the first section embrace Central
+America and Southern Mexico, south of 28°; the second, Northern Mexico and
+Southern New Mexico, California, etc., between the parallels of 28° and
+32°; the third, Northern California, Utah, Southern Oregon, and Western
+New Mexico, north of the parallel of 32°; the fourth, the entire
+continent north of 42°; and the fifth, the eastern United States, east of
+the meridian of 100°. These divisions are not intended to be entirely
+accurate in their separation, but substantially so for the purpose of
+illustrating the differences which exist in each.
+
+The accompanying diagram shows approximately, by dotted lines, the
+divisions.
+
+
+[Illustration: Fig. 2.]
+
+
+Now let us see in what a diverse manner, and to what a different extent,
+they are severally supplied with moisture.
+
+Central America and Southern Mexico lie within the tropics--their rains
+are tropical rains. The season is divided into wet and dry, as are the
+seasons of all tropical countries which are not rainless. During the rainy
+season it rains a portion of nearly every day, and during the dry season
+the sky is clear, the air is pure, and rain seldom falls.
+
+All around the earth within the tropics, over the land and over the sea,
+there is a belt of almost daily rains, varying in width, north and south,
+in different sections, but averaging about five hundred miles. This belt
+of daily rains is formed at and by the meeting of N. E. and S. E. trades,
+and travels north and south with them, as they do with the sun,
+_encircling the globe_. By this narrow belt a portion of the earth's
+surface, an average of some 35° of latitude, is supplied with moisture.
+Wherever it is situated at any given period, the tropical rainy season
+exists; and when it is absent in its northern or southern transit, the dry
+season prevails. Southern Mexico is within the range of this moving belt,
+and in its course to the northward with the sun, in our summer from May to
+October, it arrives over, and covers that country with a rainy season.
+When the sun returns to the south, taking with it the trades and this belt
+of tropical rains, that portion of Mexico is without rain, and dry, and so
+continues until the rainy belt returns in the following year. While the
+belt is over Southern Mexico it is nearly all _precipitation_, and there
+is little _evaporation_; while that belt is _absent_ it is all
+_evaporation_, with little or no _rain_. Surely this is not consistent
+with the prevailing belief of simple evaporation, ascent to a colder
+stratum, commingling, and condensation, and rain. Southern Mexico at least
+is not supplied by mere evaporation from its surface, and must therefore
+form an exception to that belief, and to the Huttonian theory.
+
+But we shall recur again to the peculiarity of distribution within the
+tropics.
+
+Turn now for a brief space to Northern Mexico, Southern New Mexico, and
+Southern California. In Northern Mexico, Southern New Mexico, Utah, and
+California, between the parallels of 28° and 32°, and particularly west of
+the mountain ranges, we find an almost rainless region, sterile and
+worthless, resembling that which is found upon nearly the same parallels
+of north latitude in Northern Africa, Egypt, Arabia, Beloochistan,
+Afghanistan, and North-western India; and in corresponding latitudes south
+of the Equator, in Peru, a portion of Southern Africa, and the northern
+and middle portions of New Holland. Why Northern Mexico and the other
+countries named are thus sterile and comparatively rainless, we shall see
+hereafter, when we examine critically the machinery of distribution as it
+operates within the tropics. It is the fact that it is thus sterile and
+rainless to which we desire to call attention in this place.
+
+Mr. Bartlett thus describes it:
+
+     "On leaving the head waters of the Concho, nature assumes a new
+     aspect. Here shrubs and trees disappear, except the thorny chaparral
+     of the deserts; the water-courses all cease, nor does any stream
+     intervene until the Rio Grande is reached, three hundred and fifty
+     miles distant, except the muddy Pecos, which, rising in the Rocky
+     Mountains, near Santa Fé, crosses the great desert plain west of the
+     Llano Estacado, or Staked Plain.
+
+     "From the Rio Grande to the waters of the Pacific, pursuing a
+     westerly course along the 32d parallel, near El Paso Del Norte, there
+     is no stream of a higher grade than a small creek. I know of none but
+     the San Pedro and the Santa Cruz--the latter but a rivulet, losing
+     itself in the sands near the Gila--the other but a diminutive stream,
+     scarcely reaching that river. At the head-waters of the Concho,
+     therefore, begins that great desert region, which, with no
+     interruption save a limited valley or bottom-land along the Rio
+     Grande, and lesser ones near the small courses mentioned, extends
+     over a district embracing sixteen degrees of longitude, or about a
+     thousand miles, and is wholly unfit for agriculture. It is a
+     desolate, barren waste, which can never be rendered useful for man or
+     beast, save for a public highway."--_Bartlett's Personal Narrative_,
+     vol. i. p. 138.
+
+Turning now to Central and Upper California, and Utah, and Southern
+Oregon, we find still another peculiarity. Like Southern Mexico, they have
+a rainy and dry season, but at a different period, and for a different
+reason. The dry season of California, etc., is the summer of the northern
+hemisphere, and her rainy season the winter. _California_ is, therefore,
+_dry_ when Southern _Mexico_ is _wet_, and _vice versâ_. The belt of rains
+which supplies California with moisture during her rainy seasons is the
+belt of _extra-tropical_ rains, which extends from the northern limit of
+the north-east trades to the poles, encircling the earth. The southern
+edge of this extra-tropical belt is _carried up_ on the western coast of
+America, and in that portion of the continent in _summer_, when the sun
+and trades, and the inter-tropical rainy belt travel to the north, and
+uncover California, etc., leaving them without rain for a period of about
+six months.
+
+
+[Illustration: Fig. 3. IN SUMMER.]
+
+
+As the sun, with the trades, travels south, the southern edge of the belt
+of extra-tropical rain follows, and covers California, etc., again
+extending gradually from the north to the south, and thus their wet
+season returns. The annexed diagrams by the shading will show the
+situation of the rainy belts which cover Mexico, Utah, New Mexico, and
+California in summer and winter, and that the belts of rains are entirely
+distinct and different in character.
+
+
+[Illustration: Fig. 4. IN WINTER.]
+
+
+Here again in this section of the continent, as in Mexico, evaporation is
+going on for six months of the year, and were it not for the return of the
+belt of rains from the north, in the fall, would go on for the entire year
+without precipitation; and for the other six months precipitation is
+vastly in excess. Nor can this be reconciled with, or explained by, the
+Huttonian or any other received theory of rain. Here again it is obvious
+that evaporation alone, however great or long continued, will not furnish
+the evaporating section with rain.
+
+The northern portion of the continent lies beneath the zone of
+extra-tropical rains, and north of the northern limit of the N. E.
+trades--is never uncovered from it, and has no distinct rainy or dry
+season, although more rain falls at certain periods, and in certain
+localities, than at others. The climate of that part of Oregon which lies
+upon the Pacific, and the character of its rains, resemble those of
+North-western Europe, and will be further explained hereafter.
+
+Coming to the portion of the continent which we occupy, the 5th section,
+we find it different still--a most favored region. Portions of it--Eastern
+Texas, for instance--are upon the same parallels of latitude as the
+rainless regions of Northern Mexico, etc. Eastern Texas, however, is not
+rainless. Other portions are upon the same parallels as California, etc.,
+yet have no distinct rainy and dry season. We repeat, this section is a
+most favored region--without a parallel upon any portion of the earth's
+surface, except, in degree, in China and some other portions of Eastern
+Asia.
+
+It is not only without a distinct rainy and dry season, but it is watered
+by an average, annually, of more than forty inches of rain, while Europe,
+although bounded on three sides by seas and oceans, and apparently much
+more favorably situated, receives annually an average of only about
+twenty-five--if we except Norway, and one or two other places, where the
+fall is excessive. The distribution of this supply of moisture over the
+United States is, in other respects, wonderful. Iowa, in the interior of
+the continent, far away from the great oceans, on the east or west, or the
+Gulf of Mexico on the south, receives fifty inches; some ten or fifteen
+inches more than fall upon the slope east of the Alleghanies, and
+contiguous to the great Atlantic (from which all our storms are,
+erroneously, supposed to be derived), and the average over the entire
+great interior valley is about forty-five inches, falling at all seasons
+of the year.
+
+Observe, then, by way of recapitulation: Southern Mexico has a rainy
+season furnished by the belt of _inter_-tropical rains, which _travels up
+over it from the south_ in summer. California has a rainy season, which is
+furnished by the _extra_-tropical belt of rains, which travels _down from
+the north_, and covers it in winter. Northern Mexico and the adjoining
+regions west of the 100th meridian are between the limits of the two, and
+neither travels far enough to reach them, except for brief and uncertain
+periods; they are comparatively rainless; while the eastern portion of
+the continent, _in all latitudes_, unlike the others, is without a
+distinctly marked dry season, or a rainless region, and with the exception
+of occasional droughts, is abundantly supplied with rain at all seasons of
+the year.
+
+And now, what is the explanation of all this? What produces the
+extra-tropical belt of regular rains surrounding the earth, north of the
+parallel of 30° north, in some places, and 35° in others, extending to the
+pole, with its southern edge traveling up ten or more degrees in summer,
+leaving large portions of the earth subject to a dry season; and back
+again in the winter to give them a rainy one? What produces the narrow
+belt of inter-tropical rains, encircling the earth; traveling up and down
+every year over an average of 35° of latitude, supplying every portion of
+it alternately with rain? And what connects the two together over the
+eastern portion of North America, so as to leave no distinctly marked wet
+and dry season, and no rainless and sterile portion there? Are all these
+the result of simple evaporation, ascent to a colder region, condensation,
+and descent again? Demonstrably not. Of the forty inches which fall
+annually upon the middle and eastern portions of the United States, an
+average probably of one-half or twenty inches, runs off by the rivers to
+the ocean, or is carried away eastward by the westerly and north-westerly
+evaporating winds. The same is true, in degree, of the rain which falls
+upon the other portions. Evaporation, therefore, could not keep up the
+supply. From whence, then, does it come? this twenty inches, thus lost by
+the rivers and winds, and with such wonderful regularity every year.
+
+"All the rivers run into the sea, yet the sea is not full. _Note the place
+whence the rivers come, hither they return again._"
+
+But how is it that they thus return with such wonderful regularity, in a
+narrow traveling belt of daily rains within the tropics, and a movable
+belt of irregular rains without the tropics, extending to the poles,
+leaving a space on each side of the equator encircling the earth in like
+manner (except at two points, _viz._, Eastern Asia and Eastern North
+America), from which they do not go, and to which they do not return, and
+which is almost entirely unfurnished with rain? And all this without any
+relation, whatever, to the contiguity of the oceans? Obviously this is not
+the work of mere evaporation, or of the accidental or irregular
+commingling of winds with different dew points, or quantities of moisture
+in solution, or accidental, irregular changes of barometric pressure. _It
+is one vast, wonderful, connected, and regular system--co-extensive with
+the globe--necessary to the return of moisture from the oceans upon the
+most inconsiderable portion of it, and to the condensation of the local
+moisture of evaporation; and by it the waters are returned from the oceans
+as regularly and bountifully upon the far interior of the great continents
+in the same latitudes, as upon the "isles which rest in their bosoms."_
+
+
+
+
+CHAPTER II.
+
+
+Before proceeding to an examination of this connected atmospheric
+machinery, and an investigation of the particular ocean from which our
+rivers return, it may be well to look at the form in which they appear to
+return, that we may have a clear understanding of terms.
+
+They seem to return in the form of clouds, and in storms and showers,
+although, in truth, they return in regular, uniform, ordinarily invisible
+currents, and the storms and showers are but condensations in, and
+discharges from portions of those currents, aided by the local moisture of
+evaporation.
+
+The term _storms_, seems to be used by European meteorologists to denote
+what we term thunder showers or gusts, and tornados; while what we call
+storms are denominated by them regular rains. As the terms are extensively
+in use in this country, we must adhere to the meaning attached to them
+_here_ rather than _there_.
+
+Storms with us, then, are regular rains of from six to forty-eight or more
+hours' continuance: generally without lightning, or thunder, or gusts, and
+usually with wind of more or less force, from some easterly point. They
+are called north-east storms, or south-east storms, according to the
+point from which the surface winds blow. Practically we shall find that
+this distinction is of some importance, for the north-east storms are the
+longest, lasting generally twenty-four hours, or more, while the
+south-east ones seldom, if ever, continue as long.
+
+These storms extend over a considerable surface, rarely less than one
+hundred miles in one direction or another, and sometimes fifteen hundred,
+or more. Distinct showers cover but a small surface, sometimes not more
+than forty to one hundred rods, as in the tornado, and rarely more than
+ten miles. Belts of showers, each new one forming a little more to the
+south, often, in summer, pass across the country, following each other in
+succession; and these belts may be of considerable width, say thirty to
+one hundred and fifty miles.
+
+The clouds which constitute the storms and showers differ in appearance
+and character, as well in the active as in the forming state. Clouds are
+of distinct characters, alike, substantially, every where under like
+circumstances; and a distinct nomenclature has been applied to them by Dr.
+Howard, of London. He notes three kinds of primary clouds: _viz._, cirrus,
+stratus, and cumulus; and inasmuch as the boundary line between them is
+not very distinct, certain compounds of the three, _viz._: cirro-stratus,
+cirro-cumulus, and cumulo-stratus. This nomenclature is every where
+received, and portions of it are of great practical importance.
+
+The three principal descriptions of cloud, _viz._: the cirrus, the
+stratus, and the cumulus, we have very much as they have in Europe, and
+doubtless as they exist every where outside of the tropics. The nimbus,
+another cloud described by him, is not distinct from the cumulus or
+stratus. An isolated, limited thunder-shower in a clear sky, presents the
+appearance of a nimbus, as shown in the cuts, but the basis of it is a
+cumulus, and it differs from an ordinary fair-weather cumulus merely in
+the dark and fringe-like appearance of the rain as it is falling from its
+lower surface, and sometimes in the existence of a stratus above and in
+connection with it. A similar form is often assumed by the peculiar clouds
+of the N. W. winds in March or November, when they assume the form of
+_squalls_, and drop flurries of snow. The nimbus, therefore, is not a
+distinct cloud, but an appearance which the cumulus, stratus, or
+cirro-stratus has in a stormy or showery state, and does not deserve a
+distinct name. It is but a cumulus, or a stratus, or cirro-stratus
+dissolving in snow or rain. It is important that this term should be
+abandoned. It tends to confuse and prevent a clear understanding of the
+difference in the character of the clouds, and in relation to which
+precision is both difficult and desirable.
+
+The figures on pages 27 and 29, show the different kinds of clouds as
+designated by Howard. They are copied from the engravings in the sixth
+edition of Maury's "Sailing Directions."
+
+
+[Illustration: Fig. 5.]
+
+[Illustration: Fig. 6.]
+
+
+  Figure 5.
+    The cirrus is indicated by      1 bird.
+    The cirro-cumulus by            2  "
+    The cirro-stratus by            3  "
+    The cumulo-stratus by           4  "
+
+  Figure 6.
+    The cirrus by                   1  "
+    The cumulus by                  3  "
+    The stratus by                  2  "
+    The nimbus by                   4  "
+
+How far these representations correspond with the actual appearance of the
+different compound forms in England, I can not say. But although they
+convey a _general_ idea, _they are not sufficiently accurate for practical
+illustration or observation here_. Indeed Howard himself has omitted from
+his last edition his plate of the clouds, assigning as a reason, "that the
+real student will acquire his knowledge in a more solid manner by the
+observation of nature, without the aid of drawings, and that the _more
+superficial are liable to be led into error by them_." The collection of
+forms in the cuts _does not contain some very important ones_, and
+contains some which are not distinct forms; but they may aid us somewhat
+in this inquiry, and, therefore, I have copied them. It is well, also, for
+the reader to have the generally received description before him.
+
+But for the purpose of _practical_ illustration hereafter, and greater
+precision, I shall follow a somewhat different order in describing them,
+and introduce two forms of _scud_ quite as important, practically, as any
+other.
+
+First, then, commencing at the earth, we have what may be properly termed
+_fog_, or low fog. This forms, in still clear weather, in the valleys, and
+over the surface of the rivers and other bodies of water, during the
+night, and most frequently the latter part of it, and is at its acmé at
+sunrise, or soon after, limiting vision horizontally and perpendicularly,
+and dissolving away during the forenoon. It is rarely more than from two
+to four hundred feet in height at its upper surface, and often much less,
+and is composed of vesicular condensed vapor, sometimes sufficiently dense
+to fall in mist, and is doubtless in composition substantially what the
+clouds are in the other strata of the atmosphere, as observed by us, or
+passed through by aeronauts. I have never seen it carried up to any
+considerable height into the other strata by any of the supposed ascending
+currents, to form permanent clouds, and shall have occasion to allude to
+the fact in another connection. It disappears usually before mid-day, and
+has, when thus formed, no connection with any clouds which furnish rain.
+
+To this Dr. Howard originally gave the name of stratus, and so it is
+represented upon the cut; but the latter term may be with greater
+propriety applied to the smooth uniform cloud in the superior strata from
+which the rain or snow is known to fall, and I shall retain and so apply
+it.
+
+The next in order, ascending, is high fog. This is usually from one to
+two thousand feet in height at its lower surface. It forms, like low fog,
+during the night and in still weather; and is rarely, if ever, connected
+with clouds which furnish rain. It breaks away and disappears between ten
+and twelve in the forenoon, usually passing off to the eastward. This fog
+is most commonly seen in summer and autumn, particularly the latter, and
+unless distinguished from cloud will deceive the weather-watcher. It is
+readily distinguishable. Although often very dense, obscuring the light of
+the sun as perfectly as the clouds of a north-east storm, it differs from
+them. It forms in still clear weather, is present only in the morning, is
+perfectly uniform, and, before its dissolution commences, without breaks,
+or light and shade, or apparent motion, and unaccompanied by scud or
+surface wind. The storm clouds are never entirely uniform, or without
+spots of light and shade, by which their nature can be discerned, and
+rarely, when as dense as high fog, without scud running under them and
+surface winds.
+
+There is another fog still, connected with rain storms, but it does not
+often precede them; occurring at all seasons, but most commonly in
+connection with the warm S. E. thaws and rains of winter and spring; and
+which usually comes on _after_ the rain has commenced and continued for
+awhile, and the easterly wind has abated; occupying probably the entire
+space from the earth to the inferior surface of the rain clouds or
+stratus. Practically this does not require any further notice. It is an
+_incident_ of the storm. When formed it remains while the storm clouds
+remain, and passes off with them. It is sometimes exceedingly dense in
+February and March, when it accompanies a thaw, and if there is a
+considerable depth of snow, it has the credit of aiding essentially in its
+dissolution.
+
+Mingled with the smoke of London, it produced there the memorable _dark
+day_ of the 24th of February, 1832, and at various other times has
+produced others of like character. (See Howard's Climate of London, vol.
+iii. pp. 36, 207, 303.) These fogs have been so dense there that every
+kind of locomotion was dangerous, even _with lanterns, at mid-day_.
+
+The next in order, ascending, are the storm scud, which float in the
+north-east or easterly, south-east or southerly wind, before and during
+storms.
+
+These, as the reader will hereafter see, are, _practically_, very
+important forms of cloud condensation--although they have found no place
+in any practical or scientific description given of the clouds, and are
+not upon the cuts. They are patches of foggy seeming clouds of all sizes,
+more or less connected together by thin portions of similar condensation,
+often passing to the westward, south-westward, north-westward, or
+northward with great rapidity. Their average height is about half a mile,
+but they often run much lower. They are usually of an "ashy gray" color.
+The annexed cut shows one phase of them, from among many taken by
+daguerreotype. The arrows pointing to the west show the scud distinguished
+from the smooth partially formed stratus above. This view was taken a few
+hours prior to the setting in of a heavy S. E. rain storm. It is a
+northerly view.
+
+
+[Illustration: Fig. 7.]
+
+
+At about the same height, but in a _different state of the atmosphere_,
+float the peculiar fair-weather clouds of the N. W. wind. They usually
+form in a clear sky, and pass with considerable rapidity to the S. E.
+Sometimes they are quite large, approaching the cumulus in form, and
+white, with dark under surfaces, and at others, in the month of November
+particularly, are entirely dark, and assume the character of squalls and
+drop flurries of snow; and then resemble the nimbus of Howard. They assume
+at different times and in different seasons, different shapes like those
+of the scud, the cumulus, or the stratus.
+
+
+[Illustration: Fig. 8.]
+
+
+They form and float in the peculiar N. W. current which is usually a
+fair-weather wind, and are never connected with storms. In mild weather
+they are usually white, and in cold weather sometimes very black, and at
+all times differ _in color_ from the ashy gray scud of the storm. This
+variety is not represented upon the general cuts. The annexed diagram
+shows one phase of them, but they are readily observable at all seasons of
+the year, when the N. W. wind is prevailing; differing in appearance
+according to the season. Let these, as well as the storm scud, be
+carefully observed and studied by the reader, and let no opportunity to
+familiarize himself with their appearance be lost. A brief glance at
+each recurrence of easterly or north-westerly wind will suffice.
+
+
+[Illustration: SUMMER CUMULI.]
+
+
+The _cumuli_ appear in isolated clouds of every size, or in vast clouds
+composed of aggregated masses, as the peculiar cloud of the thunder
+shower. They form as low down as the scud or fair-weather cloud of the N.
+W. wind, which, for convenience, I will call N. W. _scud_; and often in
+violent showers, and particularly in hail storms, extend up as far as the
+density of the atmosphere will permit them to form. Professor Espy thinks
+he has measured their tops at an altitude of ten miles. Others have
+estimated their height, when most largely developed, at twelve miles; but
+it is very doubtful whether the atmosphere can contain the moisture
+necessary to form so dense a cloud at that elevation. It is their immense
+height, however, whether it be six, or eight, or ten miles, together with
+the sudden and violent electric action, condensing suddenly all the
+moisture contained in the atmosphere within the space occupied by the
+cloud, which produces such sudden and heavy falls of rain or hail. As the
+rain drops or hail, when formed at such an elevation, in falling through
+the partially condensed vapor of the cloud must necessarily enlarge by
+accretion from the particles with which they come in contact, and probably
+also by attraction, their size when they reach the earth, though
+frequently very considerable, is not a matter of astonishment. The cumulus
+is represented in the general plate with sufficient accuracy to show its
+peculiar character.
+
+In summer, when the air is calm, the weather warm, and no storm is
+approaching, there is always, in the day time, a tendency to the formation
+of cumuli. This tendency exhibits itself about ten o'clock in the
+forenoon, and they gradually form and enlarge until about two in the
+afternoon; and after that, if they do not continue to enlarge and form
+showers, they melt away and disappear before nightfall. Sometimes in July
+and August the atmosphere will be studded with them at mid-day, floating
+about three-quarters of a mile from the earth (in a level country), gently
+and slowly away to the eastward. At times it may seem as if they must
+coalesce and form showers, yet they frequently do not, but gradually melt
+away, as before stated.
+
+The cumulus is the principal cloud of the tropics, and is not often seen
+with us except in summer, or when our weather is tropical in character.
+
+The engraving on the preceding page, shows a phase of these fair-weather
+summer cumuli.
+
+The last in order occupying (with their compounds) the higher portions of
+the atmosphere, are the cirrus and stratus. The cirrus is often the
+skeleton of the other, and precedes it in formation.
+
+These are the proper clouds of the storm, in our sense of the term. While,
+however, the cirrus remains a cirrus, it furnishes no rain. When it
+extends and expands, and its threads widen and coalesce into cirro-stratus
+and stratus, or it induces a layer of stratus below it, the rain forms.
+
+The following is Dr. Howard's description of cirrus: "Parallel, flexuous
+or diverging fibers, extensible by increase in any or in all directions.
+Clouds in this modification appear to have the least density, the greatest
+elevation, and the greatest variety of extent and direction. They are the
+earliest appearance after serene weather. They are first indicated by a
+few threads penciled, as it were, on the sky. These increase in length,
+and new ones are in the mean time added to them. Often the first-formed
+threads serve as stems to support numerous branches, which in their turn,
+give rise to others."
+
+The illustrations in the general cut are imperfect, and do not represent
+the delicate fibers of the cloud, for it is a difficult cloud to
+daguerreotype or engrave, but the representation is sufficiently accurate
+to give the reader a general idea of the different varieties, and enable
+him to discover them readily by observation. They are the most elevated
+forms, always of a light color, and often illuminated about sunset by the
+rays of the sun shining upon their inferior surface; the sun, however,
+often illuminates, in like manner, the dense forms of cirro-stratus, and
+the latter, from their greater density, are susceptible of a brighter and
+more vivid illumination.
+
+The stratus is a smooth, uniform cloud--the true rain cloud of the storm;
+often forming without much cirrus above, or connected with it. It may be
+seen in its partially formed state in the bank in the west, at nightfall,
+or in the circle around the moon in the night. When it becomes
+sufficiently condensed, rain always falls from it, but in moderation. If
+there be large masses of scud running beneath it for its drops to fall
+through (especially as is sometimes the case, in two or more currents),
+the rain may be very heavy. But more of this hereafter.
+
+
+[Illustration: Fig. 10.]
+
+
+The annexed cut shows the forming stratus, light and thin, passing to the
+east, as indicated by the short arrows just before a storm, while the scud
+beneath is running to the west.
+
+It was copied from a daguerreotype view, facing northwardly.
+
+Intermediate between the fibrous, tufted, cirrus, and the smooth uniform
+stratus, there is a variety of forms partaking more or less of the
+character of one or the other, and termed _cirro-stratus_. No single
+correct representation of cirro-stratus as a distinct cloud, can be
+given--but several varieties will be hereafter alluded to, under the head
+of prognostics. Several modifications are represented with tolerable
+accuracy upon the cuts.
+
+The cirro-cumulus is a collection in patches of very small distinct heaps
+of white clouds; they are called fleecy clouds, from their resemblance to
+a collection of fleeces of wool, and are imperfectly represented on the
+general cut. They do not appear often, and are usually _fair-weather
+clouds_.
+
+This form has none of the characteristics of the cumulus, and does not
+appear in the same stratum. It was probably called cumulus because its
+small masses are distinct, as are those of the ordinary cumulus. It occurs
+in the same stratum as cirro-stratus, and properly belongs to that
+modification. I retain the name inasmuch as the cloud is of some practical
+importance.
+
+The cumulo-stratus is seldom seen in our climate, as it is represented in
+the cut. Stratus condensation _above_, and in connection with cumulus
+condensation, is not uncommon, but that precise form is rare.
+
+This, too, is practically of no consequence, and I shall take no further
+notice of it.
+
+Recapitulating, I give (in a tabular form) the three principal strata and
+their modifications, located with sufficient accuracy for illustration.
+The clouds which are found in an upper or lower portion of a stratum are
+so represented by the location of their names; those which appear at all
+heights in the stratum, with the names across. The elevation is the
+average one--although there is no limit to the cirrus above, except the
+absence of sufficient moisture. It was seen by Guy Lussac, and has been by
+other aeronauts, at an elevation of five miles, or more, when too delicate
+to be visible below.
+
+           +------------------------------------------------+
+           |                                                | 3 miles.
+           |Cirrus.                                         |
+           |                                Cirro-cumulus.  |
+           |                                Cirro-stratus.  |
+           |                                                |
+  Primary  |            { Cumulus extending up              |
+  stratum. |            { in violent showers.               |
+           |                                                |
+           |                                                |
+           |Stratus.                                        |
+           |------------------------------------------------|
+           |                                                | 1-1/2 miles.
+  Scud &   |N. W. scud.    { Cumulus           Storm scud.  |
+  cumulus  |Fair-weather   { ordinarily and                 |
+  stratum. |               { its base always.               |
+           |                                                |
+           |------------------------------------------------|
+           |                                                | 1/2 mile.
+  Fog      |High fog.                           Storm fog.  |
+  stratum. |                                                |
+           |     Low fog at the surface of the earth.       |
+           |                                                |
+           +------------------------------------------------+
+
+With the assistance of this table of elevations, and a careful
+observation, the reader can soon become familiar with the forms of clouds
+and their relative situations.
+
+
+
+
+CHAPTER III.
+
+
+Having thus taken a brief view of the different clouds, let us return to
+the inquiry, from what ocean, and by what machinery, _our_ "rivers
+return."
+
+Not wholly or mainly from the North Atlantic, although it lies adjacent to
+us, and they often _seem_ to do so; for, first, all storms, showers, and
+clouds, which furnish, _independently_, any appreciable quantity of rain
+to the United States, and even adjacent to the Atlantic, or indeed to the
+Atlantic itself, come from a westerly point, and pass to the eastward.
+_This is a general, uniform, and invariable law, although there is in
+different places, and in the same place at different times, some variation
+in their direction; ranging in storms from W. by S. to S. S. W., and in
+showers between S. W. and N. W., to the opposite easterly points of the
+compass; the most general direction, east of the Alleghanies, being from
+W. S. W. to E. N. E._
+
+But do we not see, you inquire--at least those of us who live east of the
+Alleghanies--that when it rains, the wind is from the eastward; and that
+the _clouds_ follow the wind from the east to the west? You do indeed,
+generally, in all considerable storms, observe that the wind blows from
+some easterly point, and that _seeming_ clouds are blown by it to the
+westward; but what you see, and call clouds, are not the clouds which
+furnish the rain. Far above the seeming clouds you notice, directly over
+your head when it rains or snows, are the rain or snow clouds, dense and
+dark, passing to the eastward, how strong soever the wind may blow from
+the quarter to which they tend, or any other quarter, between you and
+them. What you see below them are _scud_. So the sailors call them, and so
+I have termed them. It is a "dictionary name," and a good one, expressive
+of a distinction between them and _clouds_. They are thin, and the sun
+shines through them, although with some difficulty, when the rain clouds
+above are absent or broken. _This east wind and the scud are not the
+storm, or essential parts of it._ Storms occasionally exist, particularly
+in April, without either. They are but _incidents_, _useful_, but not
+_necessary incidents_, as all surface winds are.
+
+If you could see a section of the storm, you would see the rain cloud
+above, moving to the east, and the scud beneath running to the west, as
+indicated by the arrows in the cut on page 40. Opportunities frequently
+occur when these appearances may be seen. Storms are sometimes very long,
+a thousand miles, perhaps, from W. S. W. to E. N. E., and not more than
+one to three hundred miles wide from S. E. to N. W., and their sides,
+particularly the northern ones, regular, and without extensive partial
+condensation. Then the storm cloud above, moving to the eastward, and the
+scud running under to the westward, may be seen as in the cut.
+
+So they may be seen before, at the commencement, and at the conclusion of
+easterly storms, in a majority of cases, and the reader is desired to
+notice them particularly as opportunities occur.
+
+The term _running_, too, is a very expressive one, used by sailors as
+applicable to _scud_. For while the forming or formed storm clouds may be
+moving moderately along, at the rate of twelve to fifteen or twenty miles
+an hour, from about W. S. W. to E. N. E., the scud may be running under
+them in a different direction--opposite, or diagonal, or both--at the rate
+of twenty, fifty, sixty, and, in hurricanes, even ninety miles an hour.
+You have doubtless seen these scud running from N. E. to S. W., and
+without dropping any moisture, a day or sometimes two days, before the
+storm coming from the S. W. reached the place where you were; and then,
+sometimes the storm cloud slipped by to the southward, and the expected
+storm at that point proved "a dry northeaster." Sometimes the
+condensation, although sufficiently dense to influence and attract the
+surface atmosphere, and create an easterly wind and scud, does not become
+sufficiently dense to drop rain, and then, too, we have a dry northeaster,
+which may melt away or increase to a storm after it has passed over us. _I
+have never seen, except, perhaps, in a single instance, one of these
+masses of scud, however dense, which had not a rain (stratus) cloud above
+it, drop moisture enough to make the eaves run._ So you see it may be
+true, and if you will examine carefully, you may satisfy yourself that it
+is true, that the storms all move from a westerly point to the eastward,
+notwithstanding the wind under them is blowing, and the scud under them
+are running to the westward.
+
+There are many other methods by which the reader may determine this matter
+himself. He may catch an opportunity for a view, when there is a break in
+the stratus cloud above, and the sun or moon, no longer obscured by the
+_storm cloud_, shines through the scud beneath. Then he may see they are
+moving in different directions. _The upper cloud, if there be any of it
+left, always to the eastward._
+
+Again, we may see the storm approach from the westward, as it often does,
+before the wind commences to blow, and the scud to run from the eastward;
+particularly snow storms in winter, and the gentle showers and storms of
+spring.
+
+Again, thunder storms, we know, come from the westward, and apparently
+against an east wind. It is sometimes said they approach from the east,
+but it is a mistake. During thirty years attentive observation in
+different localities, I have never seen an instance. They sometimes _form_
+over us, or just east of us, or one may form at the east and another at
+the west, and as they _spread out in forming_, one may seem to be coming
+from the east, or there may be an easterly current, with dense flocculent
+scud at the under surface of the shower cloud running westward, but they
+finally pass off to the eastward, and never to the westward. It is
+possible that a _patch of scud_ may become sufficiently _dense_ and
+_electrified_ to make a _shower_, but I have never observed one. Such an
+_apparent_ instance may be found recorded in "Sillman's Journal," vol.
+xxxix. page 57. I have seen the scud assume a distinct cumulus form, but
+never to become sufficiently dense to make a thunder shower.
+
+Thunder and lightning sometimes attend portions of regular storms in
+spring and autumn, but the thunder is always heard first in the west, and
+last in the east.
+
+Again, there are admitted facts with which you are conversant, which prove
+this proposition. When it has been raining all day, and just at night the
+storm has nearly all passed over to the eastward, and the sun shines under
+the western edge of it, and "_sets clear_," as it is termed--you say that
+"_it will be clear the next day_." Why? Because the storm will not pass to
+the westward, covering the sun and continuing, how strong soever the wind
+may be from the east; and because it is passing, and will continue to pass
+off to the eastward, leaving the sky clear. _The easterly wind will stop
+as soon as the storm clouds have passed, and it will fall calm, or the
+wind will "come out" from the westward._
+
+So, too, when the clouds are dark in the west in the morning, and the sun
+rises clear, but "_goes into a cloud_," as it is expressed, you say that
+it will rain. And if the clouds are dense this generally proves true;
+because there is a storm or shower approaching from the west, and passing
+over to the east, the western edge of whose advance condensation has met
+the sun in his coming, and obscured him from your vision.
+
+When, too, it has been storming, and lights up in the N. W. you say it
+will clear off; the N. W. wind will blow all the clouds away. It is,
+indeed, generally true that when it so lights up it is about to clear off;
+although it sometimes shuts down again, in consequence of the approach of
+another storm from the westward, following closely behind the one which is
+passing off. It is a great mistake, however, to suppose the N. W. wind
+blows away the clouds. Watch the smooth stratus rain cloud at its lower
+edge, where the clear sky is seen, and you will see that it is moving on
+steadily to the N. E., in obedience to the laws of its current, and will
+do so, even when its retreating edge has passed up to the zenith, and down
+to the S. E.
+
+The storm uncovers us from the N. W. by the contraction of its width, _or_
+because it has a _southern lateral extension_ and _dissolution_, and not
+by being blown away by the N. W. wind; although that wind, by its peculiar
+fair-weather clouds, may be, perhaps, observed beneath, ready to follow
+its retreating edge.
+
+Again, when it has been clear all day, and the sun sets in a bank of
+cloud, you say--"_it will rain to-morrow, the sun did not set clear_," and
+unless that bank is a thunder cloud, merely, which will pass over or by
+you, with or without rain, before morning, it is generally true that it
+will. The bank will prove the eastern edge of an approaching storm.
+
+From these generally admitted and understood facts, you may know that
+storms pass from the west to the east.
+
+This proposition is also proved by all the investigations of storms, which
+have taken place since the settlement of this country. Storms of great
+severity attract particular attention, and are said to "back up" against
+the wind, because they are observed to commence storming first at the
+westward, although the wind is from the eastward. Doubtless you recollect
+many such instances recorded in the newspapers. No season occurs without
+such notices.
+
+Many storms have been investigated by Mr. Redfield, for the purpose of
+sustaining his theory. Many others by Professor Espy, to sustain his. One
+by Professor Loomis, with great research and ability--and some by others,
+accounts of all which have been published; and every one yet investigated,
+north of the parallel of 30°, has been shown to pass from a westerly to an
+easterly point.
+
+So, too, we may know it from analogy. The laws of nature are uniform.
+There is a great end to be accomplished, _viz._: the distribution of forty
+inches of water, at regular intervals, over a large extent of country. The
+rivers are to return, and the clouds are to drop fatness, and seed time
+and harvest are not to cease. It is to be done and is done, by means of
+storms and showers, and pursuant to general laws, as immutable as the
+result. Most of these storms and showers, it has been found, and may be
+observed, move from the westward to the eastward. Then we may know, from
+analogy, that they do so in obedience to a general, uniform law; and so I
+might say with confidence, if our inquiry stopped here, it will ever be
+found by those who may hereafter examine them.
+
+But, 2d. There is a current in the atmosphere, all over the continent
+north of the N. E. trades, but in great volume over the United States,
+east of the meridian of 105° W. from Greenwich--varying in different
+seasons, and upon different parallels, and flowing near the earth, when no
+surface wind interposes between them. In the vicinity of New York, the
+usual course of this current is from about W. S. W. to E. N. E. In the
+western and south-western portion of the United States, it is, doubtless,
+more southerly--varying somewhat according to the season--and in other
+sections varies in obedience to the general law of its origin, and
+progress.
+
+I have observed its course in many places, between the parallels of 38°
+and 44° N. _This current comes from the South Atlantic Ocean._ It is our
+portion of the aerial current, which flows every where from the tropics
+toward the poles, to which I have already alluded in connection with the
+distribution of heat. _It brings to us the twenty inches of rain which we
+lose by the rivers, and by the westerly winds, which carry off a portion
+of the local moisture of evaporation, and its action precipitates the
+remaining portion of that moisture. It spreads out over the face of our
+country, with considerable, but not entire uniformity. All our great
+storms originate in it, and all our showers originate in or are induced
+and controlled by it._
+
+_From the varied action, inherent or induced, of this current, most of our
+meteorological phenomena, whether of wet or dry, or cold or warm weather,
+result_; and a thorough knowledge of its origin, cause, and the reciprocal
+action between it and the earth, is essential to a knowledge of the
+"_Philosophy of the Weather_."
+
+Let us then go down to the "chambers of the south," to the inter-tropical
+regions, of which we have said something in connection with a notice of
+Southern Mexico, and see where, and how this great aerial current
+originates.
+
+
+
+
+CHAPTER IV.
+
+
+Between the parallels of 35° north latitude, and 35° south
+latitude--changing its location within this limit at different seasons of
+the year--encircling the earth, and covering about one-half of its
+area--we find the trade-wind region. In this region are the simple and
+uniform arrangements, which extend every where, and produce all the
+atmospheric phenomena. In the center of it we find that movable belt of
+continual or daily rains, and comparative calms, particularly _near its
+center_, about four hundred and fifty miles in width upon the Atlantic,
+and over Africa, and the eastern portions of the Pacific, and something
+more over South America and the West Indies, the western portion of the
+Pacific and the Indian Ocean, to which we have already alluded. This belt
+of rains and calms follows the trades and sun, in their transit north and
+south, from one tropic to the other--its width and extension depending
+upon the volume of trade-winds existing on the sides of it. Its southern
+edge, when the sun is at the southern solstice, extends to 7° south in the
+Atlantic, to 10° south in the Indian Ocean, and still further, probably,
+over South America: on this point I do not pretend to be accurate, for
+accuracy is not essential. When the sun is at the northern solstice the
+southern edge is carried up as far as 12° north, over the Atlantic, and
+still further over the northern portions of South America, the West
+Indies, and Mexico. It travels, therefore, from south to north, over from
+twenty to forty degrees of latitude. The presence of this belt of rains
+over any given portion of the inter-tropics, gives that portion its rainy
+season, and its absence, as it moves to the north, or the south, gives the
+portion from which it has moved, its dry season. It passes in its transit
+twice each year over some portions of the country, Bogota, for instance,
+and two corresponding rainy and dry seasons result. Its presence, and
+character, and movements, are as fixed and regular, over from twenty-five
+to forty degrees of the earth's surface, _and all around it_, as the
+presence and movements of the sun over the same area.
+
+At the northern edge of this movable belt of rain, and extending in some
+places, particularly in the Pacific Ocean, north about 20°, or about one
+thousand four hundred miles, and in other places a less distance, the N.
+E. trade winds prevail, blowing toward and into it from N. N. E., N. E.,
+and E. N. E., averaging about N. E. At the south line of this belt of
+rains, extending south from twenty-five to thirty degrees, or from sixteen
+hundred to two thousand miles, the S. E. trades blow toward and into it,
+from the S. E., S. S. E., or E. S. E., averaging about S. E. Of course the
+northern limit of the N. E. trades travels north and south with the belt
+of rain, toward which it blows; and so the southern limit of the S. E.
+trades travel in like manner with the rainy belt, or rather, to speak with
+entire accuracy, the belt of rain moves with the trades, and the trades
+follow the verticality of the sun. The following diagrams exhibit
+approximately, and with sufficient accuracy for illustration, the
+situations of the rainy belt and the trades, when at their northern and
+southern limit, as well as the manner in which it must give certain
+localities two rainy seasons each year, in its transit north and south.
+
+At the northern and southern limits of the trade-winds, and extending from
+them to the poles, are found the variable winds and irregular
+extra-tropical rains, all over the earth, which are shown by the shading
+on the maps. This line of extra-tropical rains descends to the south,
+following the retreating trades as they descend in our winter, and recedes
+north before the trades when they return in spring and summer, so that at
+the outer limit of the trades respectively, toward the poles, the line of
+extra-tropical rains will be found, receding or following that limit, as
+the trades pass up and down with the sun. From the north pole to the
+northern limit of the N. E. trade-winds, wherever found, whether at 38°
+north latitude, as in some places in summer when the sun is at the tropic
+of Cancer; or whether at 20° to 30° north latitude, as in our winter, when
+the sun is at the tropic of Capricorn; the extra-tropical rains prevail. A
+state of things precisely similar exists between the south pole and the
+southern limit of the S. E. trades. Between this northern limit of the
+N. E. trades and the northern line of the inter-tropical belt of
+rains, wherever situated (with two exceptions, to which we have alluded
+and shall allude again), there is, for the time being, a dry season; and a
+like dry season between the southern line of the belt of rains and the
+southern limit of the S. E. trades. We have, therefore, extending around
+the earth, a belt of daily tropical rains, near the center,--two belts of
+drought which are mainly trade-wind surfaces, one on each side of the
+central rainy belt,--extending to the outward limits of the trades and the
+line of extra-tropical rains; and these rainy and dry belts, moving up and
+down after the sun, a distance of from twenty to forty degrees of
+latitude, each year.
+
+
+[Illustration: Fig. 10. IN SUMMER.]
+
+[Illustration: Fig. 11. IN WINTER.]
+
+
+Such are the _main_ phenomena, _at the surface_, in the trade-wind region.
+Ascending a step higher in the atmosphere, we find, above the
+surface-trades, a counter-trade, running, not in the opposite direction,
+but at right angles, or nearly so. The counter-trade which issues from the
+northern side of the rainy belt, running to the N. W. or W. N. W., and the
+counter trade which issues from the southern side, running to the S. W. or
+W. S. W., varying, as the trades do in direction in different localities.
+These counter-trades are continuations of the surface trades, which,
+ascending in their course, have threaded their way through the opposite
+trade in the rainy belt, and are continuing on at the same angle, and in
+the same direction at which they blew upon the surface, and in obedience
+to the same law. This is apparent from several considerations.
+
+1st. They issue at the same angle, and over the top of the surface trades.
+In the West Indies and elsewhere, this has been ascertained and proved by
+the course of the storms, and the rotation of their surface winds, and
+observation.
+
+2d. We can not suppose the N. E. trade to be reflected, and turn back over
+itself at a right angle. That would be impossible, even if there were a
+wall of solid material there for it to blow against. Air is a peculiar
+fluid, and it stratifies with astonishing ease. He who supposes that a
+current of air put in motion can be turned aside by another current, or by
+the atmosphere at rest, or can be made to mingle, is mistaken. It will
+stratify, and force itself onward through the adjacent and opposing
+atmosphere, and in a right line. I have observed some remarkable instances
+of this character.
+
+3d. The cause which operates to produce the surface trades, still operates
+upon the current to carry it over into the other hemisphere; a
+counter-trade, as we shall see. It is impossible, therefore, to believe
+that the surface-trades as they arrive at the belt of rains and calms,
+turn at a right angle, or at any angle, and return: and impossible to
+doubt that they pass through each other in this belt, and out at the
+opposite side, as upper currents, at the same angle at which they entered.
+Of course the N. E. trade of the Atlantic becomes the N. E. counter-trade
+of South America, carrying their storms in a S. W. direction, and the S.
+E. trade of the Atlantic the S. E. counter-trade of the West Indies,
+carrying all their storms in a N. W. direction; and what is true of them
+is true of the trade winds _every where, all over the globe, over the land
+and over the sea_.
+
+Doubtless here some one will say, our upper current is a S. W. current.
+True, the S. E. trade which enters the belt of rains, and issues out on
+the north, a S. E. upper current or counter-trade, keeps that course until
+it arrives at the northern limit of the surface trade, when, in _obedience
+to another law_, which we shall notice, it gradually _decends near the
+surface, curves to the eastward_, and becomes _the S. W. current which
+passes over us_. And so we have the S. E. trade-wind of the South
+Atlantic, with its moisture, warmth, electricity, and polarity, over, and
+perhaps sometimes around us, dropping the electric rain which makes glad
+our fields; giving us, when not prevented by other conditions, the balmy
+air of spring, the Indian summer of autumn, and the mild mitigating
+changes of winter; and thus, _our rivers, which run into the sea, return
+to us again_.
+
+But let us go back to the trade-wind region--the region of regularity and
+uniformity--and examine somewhat more attentively its features, that we
+may more fully understand the character of this counter-trade.
+
+Here are 60° at least of the 180° of the earth's surface, and at its
+largest diameter, covered in the course of the year, and of their travels,
+by the trade-winds at the surface, the counter-trades above, and the belt
+of rains and comparative calms, formed by the action of the opposite
+trades, as they thread their way through each other, to assume the
+relation of counter-trades. Truly the magnitude, simplicity, and
+regularity of this machinery are most wonderful.
+
+There are, however, some _apparent_ anomalies which deserve attention.
+Here are most distinctly marked the _rainy_ and _dry seasons_, existing
+side by side. Here are the _rainless portions_ of the earth, already but
+briefly alluded to; here the _monsoons_, and another peculiarity, _viz._:
+the _gathering of the counter-trades_ upon the western sides of the two
+great oceans, into two _aerial currents of greater volume_, _analogous_
+somewhat to the two _gulf streams_ of those oceans. Let us examine these
+anomalies.
+
+The rainy and dry seasons depend, as we have seen, upon the transit north
+and south of the rainy belt, or belt of comparative calms. Wherever this
+belt may happen on any given day to be situated, each side of it the
+trades prevail, it is dry, the earth is parched, and vegetation withers.
+These changes are graphically described by Humboldt in his "Views of
+Nature," as they occur on the northern portions of South America, as
+follows: "When, beneath the vertical rays of the bright and cloudless sun
+of the tropics, the parched sward crumbles into dust, then the indurated
+soil cracks and bursts, as if rent asunder by some mighty earthquake. The
+hot and dusty earth forms a cloudy vail, which shrouds the heavens from
+view, and increases the stifling oppression of the atmosphere; while the
+east wind (_i. e._ trade-wind), when it blows over the long heated soil,
+instead of cooling, adds to the burning glow.
+
+"Gradually, too, the pools of water, which had been protected from
+evaporation by the now seared foliage of the fan-palm, disappear. As in
+the icy north animals become torpid from cold, so here the crocodile and
+the boa-constrictor lie wrapped in unbroken sleep, deeply buried in the
+dried soil. Every where the drought announces death, yet every where the
+thirsty wanderer is deluded by the phantom of a moving, undulating, watery
+surface, created by the deceptive play of the reflected rays of light (the
+mirage). A narrow stratum separates the ground from the distant
+palm-trees, which seem to hover aloft, owing to the contact of currents of
+air having different degrees of heat, and therefore of density. Shrouded
+in dark clouds of dust, and tortured by hunger and burning thirst, oxen
+and horses scour the plain, the one belowing dismally, the other with
+outstretched necks snuffing the wind, in the endeavor to detect, by the
+moisture in the air, the vicinity of some pool of water not yet wholly
+evaporated.
+
+"Even if the burning heat of day be succeeded by the cool freshness of the
+night, here always of equal length, the wearied ox and horse enjoy no
+repose. Huge bats now attack the animals during sleep, and vampyre-like
+suck their blood; or, fastening on their backs, raise festering wounds, in
+which mosquitos, hippobosces, and a host of other stinging insects, burrow
+and nestle. Such is the miserable existence of these poor animals, when
+the heat of the sun has absorbed the waters from the surface of the
+earth.
+
+"When, after a long drought, the genial season of rain arrives, the scene
+suddenly changes. The deep azure of the hitherto cloudless sky assumes a
+lighter hue. Scarcely can the dark space in the constellation of the
+Southern Cross be distinguished at night. The mild phosphorescence of the
+Magellanic clouds fades away. Even the vertical stars of the
+constellations Aquila and Ophiuchus, shine with a flickering and less
+planetary light. Like some distant mountain, a single cloud is seen rising
+perpendicularly on the southern horizon. Misty vapors collect and
+gradually overspread the heavens, while distant thunder proclaims the
+approach of the vivifying rain. Scarcely is the surface of the earth
+moistened, before the teeming steppe becomes covered with Killingiæ, with
+the many-panicled Paspalum, and a variety of grasses. Excited by the power
+of light, the herbaceous Mimosa unfolds its dormant, drooping leaves,
+hailing, as it were, the rising sun in chorus with the matin song of the
+birds, and the opening flowers of aquatics. Horses and oxen, buoyant with
+life and enjoyment, roam over and crop the plains. The luxuriant grass
+hides the beautiful and spotted jaguar, who, lurking in safe concealment,
+and carefully measuring the extent of the leap, darts, like the Asiatic
+tiger, with a cat-like bound on his passing prey."
+
+Such is Humboldt's description of the dry season on the Orinoco, and the
+return of the belt of rains from the south.
+
+Again, within this trade-wind region are the _rainless countries_. These
+are portions of the earth which the equatorial rainy belt does not ascend
+far enough north in summer to cover, nor does the southern edge of the
+extra-tropical regular rains descend, in winter, far enough south to cover
+them, and where, of course, rain seldom, if ever, falls. Such are the
+central parts of the Desert of Sahara, Egypt, Arabia, portions of
+Affghanistan, Beloochistan, and the western parts of Hindoostan, to the
+north of the inter-tropical belt, and a similar state of things exists
+south of the equator in parts of South America, Africa, and New Holland,
+although upon a comparatively small surface.
+
+Again, another anomaly is the gathering of the trade winds into greater
+volumes, on the westerly side of the great oceans, and the consequent
+carrying of the equatorial rainy belt up to the region of extra-tropical
+rains, on the eastern side of the great continents of Asia and North
+America, and the peculiar liability of these aerial gulfs to hurricanes
+and typhoons. Such an aerial gulf gathers over the Caribbean Sea, and the
+West Indies. Passing across the Gulf of Mexico, it enters over Texas, and
+Louisiana, and the other southern states; its western edge passing north
+in autumn and winter, on the eastern side of the highlands of Western
+Texas, New Mexico, and the Great Desert; curving, as all counter-trades
+do, to the eastward as soon as it passes the limit of the N. E. trades,
+and spreading out over our favored country, leaving the evidence of its
+pathway in the greater quantities of rain, which fall annually upon its
+surface. This gathering deprives a portion of the Atlantic, north of the
+tropics, of its share of the counter trade, and there, as every where,
+where the volume of counter-trade is small, storms and gales are
+infrequent, and of less force, and comparative calms prevail. That portion
+of the Atlantic has long been known as "the horse latitudes," a name given
+to it by our Yankee sailors, because, there, in former times, the
+old-fashioned, low-decked, flat-bottomed, horse-carrying craft of New
+England, bound for the West Indies, often floundered about in the calms
+and baffling winds, until their animals perished for want of water, and
+were thrown overboard. Lieutenant Maury, in his most praiseworthy and
+exceedingly useful investigation of "The Winds and Currents of the Ocean,"
+has defined the situation of these calms and baffling winds at different
+seasons--for they move up and down, of course, with the motion of the
+whole machinery--and enabled navigators to avoid them, by running _east_
+before they attempt to make _southing_; and very materially shortened the
+voyages to the equator.
+
+A like gathering, in volume, of the S. E. trade, on the western side of
+the Pacific, enters over Asia, and covers China and Malaysia, extending,
+in its western course, nearly as far as the western edge of Hindoostan. In
+this concentrated volume of counter-trade, and owing to its concentrated
+action, form and float the typhoons of the China Sea, and of the Bay of
+Bengal; and to this anomalous aerial gulf stream, the S. E. portions of
+Asia, from the western desert of Hindoostan, to the eastern portion of
+China, north of the rainy belt, owe their great supply of moisture and
+fertility, and their peculiar climate. The western line of this volume of
+counter-trade is marked by the eastern portion of the rainless region of
+Beloochistan, and the north-western deserts of India, as the western edge
+of our concentrated volume of counter-trade, is marked by the arid plains
+of northern Mexico, western Texas, and New Mexico. On the south of the
+equatorial rainy belt, there is no corresponding aerial gulf of equal
+volume, as there is no corresponding gulf stream of equal magnitude. On
+the western side of the Indian Ocean we find a gathering of the N. E.
+trades from the Bay of Bengal and the Indian Ocean, in which form and
+travel the hurricanes which prevail--traveling to the southward and
+westward--about the Isle of France or Mauritius; and the lagullus oceanic
+current, which runs down to the S. W. toward the Cape of Good Hope. But
+the extension of South America to the eastward, under, or just south of
+the N. E. trades, does not permit the formation of such a concentrated
+volume on the western side of the Atlantic, nor is the strength or
+regularity of the N. E. trades, on that ocean, equal to those of the S. E.
+
+Nor is the magnetic intensity on the eastern and middle portions of the
+Pacific, sufficient to produce such a concentration, in large volume,
+there. The trades over that ocean, therefore, curve without concentration,
+except a partial one, over the western groups of Polynesia, which the
+Asiatic line of magnetic intensity approaches and where hurricanes are
+sometimes found, until we arrive near the eastern line of magnetic
+intensity, on the eastern side of Asia. We shall, hereafter, have occasion
+to follow the anomalous concentrated volumes of the S. E. counter-trade,
+of the northern tropic, on the western side of the great oceans, in
+explanation of some of the phenomena which we find north of the trade-wind
+region. Suffice it here to add, that if it were not for the concentration
+of these counter-trades, on the western side of the great oceans, the
+rainless region between the parallels of 20° and 30° would encircle the
+earth; and China and the Eastern United States would have a distinctly
+marked rainy and dry season, as have California, the Barbary States,
+Syria, Persia, and other countries which lie north of the rainless region,
+within the summer range of the N. E. trades, but also within the winter
+descending range of the belt of extra-tropical rains.
+
+Another anomaly which we find in the trade-wind region, is the monsoon.
+There are several of them, but they are found, in the greatest strength
+and regularity, in the Indian Ocean. Another, defined by the
+investigations of Maury, is found on the west coast of Africa, extending
+out over the Atlantic. Another prevails on the western coast of South and
+Central America. The etesian winds of the Mediterranean are but the N. E.
+trades, whose northern limit is carried up in summer, by the transit of
+the connected machinery, to the north, over that sea. The N. E. and S. E.
+monsoons, so called, of the Indian Ocean, are but the regular trades,
+blowing when the belt of rains is absent, as they do all over the globe.
+The N. W. monsoon, south of the equator, in the vicinity of New Holland;
+the S. W. monsoon which blows from the Arabian Sea, in upon Hindoostan;
+the S. W. monsoon of the Atlantic, south of the Cape De Verde Islands; and
+the variable west monsoon winds of the west coast of Southern and Central
+America, and Southern Mexico (known under several different names, but
+chiefly by that of Tapayaguas), are all that deserve attention as such.
+
+At first sight they appear to be anomalies, but the facts declare their
+character with perfect certainty. First, they are not continuous, like the
+trades, but _prevailing_ winds, and are _storm winds_; _they always blow
+toward a region_, _or portion of the ocean_, _covered at the time by
+clouds and falling weather_.
+
+Second, they do not blow upon, or toward, heated surfaces of land or
+water--_i. e._, toward the dry and parched surfaces, where the dry season
+prevails, or from adjoining cold waters on to warm surfaces, but toward
+the land or water _situated under the rainy belt_. They are therefore
+incident storm winds, (as our easterly winds are incident storm winds) of
+the rain clouds of the tropics. They blow in upon the land, under the belt
+of rains, while that belt with its daily cloud, and inducing electric
+action, is over it, and follow that belt in its transit north and south.
+They blow from the warm south polar current of the Atlantic, which flows
+N. W. from the coast of Africa, toward the inshore north polar current,
+which is there flowing south, but under the belt of rains. In the Indian
+Ocean they blow from the center of that ocean, and the Arabian Sea, toward
+the belt which hangs over Hindoostan, from the S. W.; and when the rainy
+belt travels south they still blow toward, and under it, from the Indian
+Ocean, but of course from the N. W. The heated character of the waters of
+the Indian Ocean and Arabian Sea, which receive no polar currents, but
+heated waters from the Persian Gulf, and from rivers which flow into the
+Bay of Bengal over the heated plains of a tropical country, explain this.
+So, too, the monsoon of the Atlantic Ocean, does not blow north of the
+Cape De Verde Islands,--where the heated surface of Sahara, burning with
+the rays of a vertical sun, has a temperature sometimes ranging from one
+hundred and forty to one hundred and sixty degrees--but remains under the
+rainy belt, drawn from the heated waters which flow up from the South
+Atlantic, and travels north as the rainy belt travels north in summer, and
+south to the Gulf of Guinea, as that travels south in winter. The same is
+true of the Pacific monsoon, the Tapayaguas, the least marked of all,
+which blows in during the rainy season upon the west coast of Southern
+Mexico, and of Southern and Central America. They are all incident rain or
+storm winds, blowing in upon the land, or on to a colder surface of
+different polarity, _during the rainy season_; and if it were possible to
+catch one of our north-easters, in its passage over our country to the
+eastward, and anchor it to the Alleghanies, "paying out" so to have it
+reach in part over the Atlantic, and keep it there in operation six
+months, we should have a continual easterly wind under it; a _monsoon_
+more strongly marked than the monsoons of the Indian, or Atlantic Oceans.
+_The received theory in relation to them is a fallacy._
+
+Recapitulating, then, all the phenomena, we have,--_Surface-trades_,
+blowing toward the center, passing through each other, and continuing on
+as upper or counter-trades; a _belt of rains_, with calms near the center,
+formed by the trades where they meet and pass through each other, which
+travels with them north and south following the sun; _two belts of
+drought_, following the belt of rains and the trades, and followed by the
+_extra_-tropical line of rains, as it travels with the trades and the
+rainy belt, leaving a part of the earth which the equatorial rainy belt
+does not travel far enough north, nor the extra-tropical line of rains far
+enough south to cover, and which is consequently a _rainless region_; _the
+monsoons_, which are but incidents of the rainy belt, and the _gathered
+volumes_ of counter-trade, on the west of the two great oceans, which
+usurp the place of the N. E. trades, carrying the rainy belt up to the
+region of extra-tropical rain, and preventing the rainless region from
+encircling the earth.
+
+Upon _what cause_ do these great central phenomena, so vast, so regular,
+so wonderful, depend? What is the _motive power_ of this connected
+atmospheric machinery, whose action and influence extend over the entire
+globe?
+
+"_Heat, heat_," say the text books, the Professors, the votaries of
+meteorology. "All these phenomena are owing to the heat of the sun. It
+heats the ocean and the earth--the air is thereby heated and rises, the
+cold air rushes in from below, then the ascended current rolls off each
+way at the top toward the pole, acquiring a westerly motion from the
+rotation of the earth, slipping away from under it, and a different,
+_viz._: an easterly motion, after reaching the latitude of 30°, from the
+_same rotation_; and all the winds and disturbances of the atmosphere are
+produced in the same way. They are produced by the action of heated
+surfaces upon the adjacent atmosphere."
+
+This is the great theory of meteorologists, by which they attempt to
+account for the various atmospherical disturbances, of both tropical and
+extra-tropical regions.
+
+The whole theory is a fallacy--it will not stand the test of a careful
+examination. The bases of the theory, which are assumed to be facts, are
+not so. The agent has not the power claimed for it. A heated surface,
+alone, never caused any considerable ascending current, or if it did,
+never produced a mile of wind. I repeat it, the theory and all incidental
+ones--the thousand explanatory and modifying theories, and
+hypotheses--_the whole system_--is without foundation in fact, and will
+not bear a critical examination.
+
+Let us see if this language is stronger than the facts will warrant.
+
+The theory assumes that both the land and water, under this central belt,
+where the air is supposed to be rising are _materially hotter_ than the
+land and ocean are on _either side of it_. Now, how much hotter are the
+air and the land under the belt of rains and calms, upon Hindoostan, or
+Africa, or South America, where the former is supposed to be acquiring
+heat and expansion so rapidly, and to be ascending, than under, and in the
+dry belts on either side? None; it is cooler by the thermometer--_much
+cooler_.
+
+The central belt of rains in midsummer over Africa, extends up as far as
+17° north latitude, and perhaps further. North of this line over the whole
+surface of the desert, the Barbary States, a part of the Mediterranean,
+and some portion of Italy, the dry season extends, and from the entire
+surface the N. E. trade blow into the central belt.[1] Over the desert
+they all pass. Now this desert is a sea of sand, under a vertical sun,
+intensely heated, blistering the skin with which it comes in contact, and
+often acquiring a temperature of 150° to 160° of Fahrenheit. Under the
+central belt of rains neither the earth nor air exceed the temperature of
+84°. And yet the hot air of the desert does not ascend, but blows into
+this cooler central belt; and when it is felt as it blows off the western
+coast by the mariner, or even in Guinea, when the belt of rains has gone
+south in winter, as it often is as the _harmattan_, it is suffocating and
+intolerable. There, then, not only is it untrue, that the land and the air
+over it under the rainy belt are hotter, but it is true that intensely
+heated air blows horizontally from the Desert of Sahara. Nay, as it will
+appear in the sequel, this hottest of all surfaces not only can not have a
+vortex, but it can not induce a monsoon, and scarcely a sea breeze. The
+same is true in a great degree of the surface, and the air over it, on
+either side of the supposed vortex of the rainy belt upon South America.
+See the description of Humboldt, already given, where the thermometer
+stood as high as 115° of Fahrenheit in the shade, while the N. E. winds,
+the regular trades, were blowing over the land. And it is equally true of
+Arabia, and indeed of every portion of the earth. There is not a spot upon
+the globe where the land and the air are cooler _by the side_ of the
+central belt of rains, than _under it_. _And the opposite is true every
+where upon the land._
+
+How much hotter is the ocean and air under this supposed vortex? But
+little hotter than they are on the side where the sun is not vertical,
+_and none on the other_. Let us be a little more particular. The
+temperature of the Atlantic under the belt of rains in our winter, and on
+the south of the belt at the latitude of 3° south, and down to 9° or more
+south, is 82°. The air may range a degree, or possibly two, higher than
+the water at either point. On the north this difference is from nothing at
+the meeting of the trades and belt of rains, to about 4° at their northern
+limit. This is too _trifling_ to be worth one moment's consideration. It
+is less, far less than the difference between the water and air of the
+Gulf Stream which runs along our coast, and the adjoining waters and air
+over them. While on the south side of the belt of rains the _difference is
+actually against the theory_--and the same state of things is reversed in
+summer, when the sun is vertical at the north.
+
+From the log of an intelligent shipmaster, found in the wind and current
+charts of Lieutenant Maury, I abridge the following, which will illustrate
+this. Captain Young in February, found the N. E. trades at about 17° north
+latitude, with the water at 75° and air at 76°, trade-wind N. E.
+
+        At    12° 16' the water was 75°    the air 76° wind  N. E.
+   Feb. 22d.   9° 49'       "       76-1/2°   "    77°   "   N. E.
+    "   23d.   7° 13'       "       78°       "    78°   "   N. E.
+    "  24th.  no obs.       "       79-1/2°   "    79°   "   N. E.,
+                                                             E. S. E. rain.
+    "  25th.   3° 10'       "       81°       "    83°   "   E. S. E. rain.
+    "  26th.  no obs.       "       82°       "    82°   "   S. E. to
+                                                             E. S. E. hazy,
+                                                             rain & sqs.
+    "  27th.   2° 24'       "       82°       "    82°   "   calm,
+                                                             with rain.
+    "  28th.  no obs.       "       82°       "    82°   "   calm rain.
+  March 1st.   0° 29'       "       82°       "    82°   "   E. S. E.
+                                                             sqs. rain.
+    "    2d.   1° 27' S. L. "       82°       "    82°   "   S. E. sqs.
+                                                             rain.
+    "    3d.   2° 44'       "       82°       "    83°   "   S. E. &
+                                                             S. S. E.
+                                                             weather
+                                                             settled.
+    "   4th.   4° 17'       "       82°       "    83°   "   S. S. E. &
+                                                             S. E. fair
+                                                             weather.
+    "   5th.   6° 08'       "       82°       "    84°   "   S. E. fair
+                                                             wthr.
+    "   6th.   8° 08'       "       82°       "    84°   "   S. E. &
+                                                             E. S. E. fair
+                                                             weather.
+
+Here the air was seven degrees colder at the extreme limit of the N. E.
+trades than in the _center_ of the belt of rains, as it is, usually, in
+mid-winter, but not in summer. On the other hand, _after he left the
+region of calms and rains_, where the water and air stood with almost
+entire uniformity at 82°, on the 3d of March, and for three days
+thereafter, during which he was in the S. E. trades with fair weather,
+the water was the same as under the supposed vortex, _viz._, 82°, _and the
+air rose to 83° and 84°_! _This is demonstration._
+
+I also take from a letter of Lieutenant Walsh to Lieutenant Maury,
+relative to the cruise of the "Taney" the following, showing the warmth of
+the Gulf Stream compared with the adjacent ocean.
+
+     "We first crossed the Gulf Stream on the 31st of October; we struck
+     it in latitude 37° 22', longitude 71° 26' as indicated by the
+     temperature of the water, which was as follows:
+
+          8 A.M. water at surface 66°
+          9  "     "         "    73°
+         10  "     "         "    76°
+         11  "     "         "    77°
+
+     77° was the highest temperature found in crossing at this time.
+
+     Re-crossing it in May, in latitude 35° 30', longitude 72° 35', he
+     found the water as follows:
+
+          8 A.M. water at surface 71° 8'
+          9  "     "         "    73°
+         10  "     "         "    75° 5'
+         11  "     "         "    78° 5'
+         12  M.    "         "    78° 5'
+
+     79° being the highest temperature found."
+
+The average difference between the temperature of the water of the Gulf
+Stream and the adjoining ocean, at the line of division, is about ten
+degrees, increasing to more than twenty on approaching the coast, and
+within one hundred miles--a far greater difference than is ever found on
+the winter side of the inter-tropical rainy belt.
+
+It is not only not so, then, that the surface of the ocean is materially
+warmer under the belt of rains than the adjoining surface under the
+trades, especially on the summer side, but if it were so, the trades would
+not be created thereby, any more than upon the Gulf Stream. And the
+opposite is true of the land where the line of calms, and rains, and
+drought meet, all around the globe. The fact assumed is therefore untrue.
+The hottest surfaces, even at the rainless portion, where there is no
+vortex, no storm, and no wind but the continual uniform N. E. horizontal
+trade-wind, _never_ created, by reason of the heat alone, a mile of wind,
+a storm or shower.
+
+But, again, the belt of calms, where the air is supposed to rise and
+create a suction which draws the trades on either side a distance of from
+one thousand to two thousand miles, an average of three thousand miles in
+all, at least, is not itself, on an average, over five hundred miles in
+breadth from north to south. What a wonder of meteorology is here!
+
+With a breadth of five hundred miles, the rising of the atmosphere is
+supposed to be so rapid and of such immense volume that it draws the
+surface atmosphere, one thousand to fifteen hundred miles on one side and
+two thousand on the other, with a uniform steady velocity of twenty miles
+per hour. Is this vast suction found by the unlucky mariner who may be
+drawn within the vortex? _Not at all._ He finds no rapid suction there,
+but _horizontal currents_, not steady, indeed, like the trades, and
+sometimes calms _at the center_, but still the _currents are there_, and,
+_except near the center, there as squalls, showers, and baffling winds
+and as monsoons_.
+
+Again, is there at the mouth of this vortex, or as you approach it, an
+increased rapidity in the trade corresponding to the magnitude of its
+influence? Does the trade become a hurricane as it approaches the spot
+where it is to supply the place of that which has suddenly "expanded by
+heat, and been forced to rise, boil over, and run off at the top in turn?"
+Not at all. It blows gently, even up to the very line of the rainy belt,
+and becomes squally and baffling, falls gradually calm near the center, or
+changes to a monsoon.
+
+But, again, the belt of rains is so far from being a belt of calms
+strictly, that its monsoons in the Indian, Atlantic, and Pacific Oceans,
+at times, extend hundreds of miles out over the ocean. That of the
+Atlantic, triangular, with its base resting on Africa, according to
+Lieutenant Maury, extends sometimes almost to the coast of South America,
+a distance of one thousand miles, and thus under the supposed ascending
+vortex. Where is the great uprising suction during the prevalence of this
+extensive surface horizontal monsoon beneath it? Manifestly it does not
+exist. Nay, that monsoon is blowing from the warm current which sets up
+from the Cape of Good Hope toward the Caribbean Sea, and over the cold
+north polar current, which runs down between the continent and the Cape de
+Verdes. Equally untrue is the presumption that the air rises over heated
+portions of the earth elsewhere, and by reason of such heating.
+_Perpendicular currents of the atmosphere are rarely seen, never
+extensive, or attaining any considerable altitude._ I have watched for
+them thirty years. I have seen currents of air ascend, with their moisture
+condensing as they ascended, and unite with the under surface of a highly
+electrified cloud--the advance condensation of a thunder shower--but that
+cloud was moving horizontally at a distance of from one to two thousand
+feet above the surface of the earth, and did not rise. I have seen patches
+of scud rising from the surface during the intervals of a showery and
+highly electrified storm, toward, and uniting with, the clouds above, when
+very low, as I have seen them approach and unite horizontally; and
+doubtless there is a tendency upwards of the wind, created and attracted
+by the summer shower, as may be seen in the ascending dust before the
+rain, but I have never been able to detect an ascending current, except as
+induced and attracted by a cloud above moving horizontally, in the hottest
+day or dryest time. None of the clouds of our climate, even when the earth
+is heated and parched by a two months' unbroken drought, can be detected
+rising above the strata in which they form. I have watched the cumuli at
+such periods when they filled the air, and can assert that they never
+rise. The atmosphere moves, invariably, in horizontal strata, and the
+whole theory of ascending currents is fallacious.
+
+But let us look still further at the tropical currents. The true harmattan
+of north-western Africa (for the term is sometimes misapplied), hot and
+blistering, generated upon the sand of the desert--why does it blow from
+Sahara horizontally, on or over cooler surfaces, following the belt of
+rains as a N. E. trade? Why does it not ascend? The sirocco of north
+Sahara, the kamsin or chamsin of eastern Sahara, and the simoon of Arabia,
+which blow hot and suffocating from those deserts--why do they blow _from_
+heated surfaces and _horizontally over_ cooler ones? Why do they not
+ascend? Arabia is surrounded on three sides by seas and gulfs, from which
+evaporation is rapid. Her interior deserts are extensive and intensely
+hot--why are they rainless? Why do they not have a _vortex_, a _monsoon_,
+or even a _shower_? Because there is no such law or action as this theory
+supposes. Those winds blow horizontally in obedience to other laws, and
+under the control of other and more powerful agents. But further still,
+what heating and ascending process is it that makes the variable winds
+north of the tropics? that brings in the warm air and fog of the Gulf
+Stream upon our _snow-clad coast_, in mid-winter, to increase the January
+thaw? Nay, what heating process is it that disturbs the calms of the polar
+regions with fresh breezes and gales, sometimes of the force of 6, when
+the _sun does not shine_, the thermometer is from 20° to 40° below zero,
+the _earth and sea one frozen surface_, and the hardy explorer dressed in
+furs, barely lives in his cabin covered by an embankment of snow, and
+heated by a stove?
+
+Gentlemen, meteorologists, it will not do. The theory is unsound; the
+assumed facts do not exist. The whole universe has not an agent, organic
+or inorganic, which can play such absurd and inconsistent pranks in the
+face of its Creator, as your various and complicated theories assign to
+caloric.
+
+Away with the theory and all its incidental and complicated and mystified
+hypotheses, they rest like a pall upon the science;--away with the whole
+system, and let us seek some agent whose _power_ and _adaptation_
+correspond with the _extent_, and _simplicity_, and _magnificence_ of the
+phenomena, and, in some degree, with the _power_ and _wisdom of their
+Author_.
+
+
+
+
+CHAPTER V.
+
+
+One, and the principal end attained by the power of the agent, is the
+gathering of a volume of atmosphere from, or near, the _surface_ of the
+land and sea, so as to ensure its possession of all the moisture of
+evaporation which rises from the locality, and the highest degree of
+temperature, and from a space ranging from one to two thousand miles in
+width, in one hemisphere, and to carry it over into the other. Not over
+the top, or upon the top, of the whole mass of atmosphere situated in the
+opposite hemisphere--_out of reach of all influences from the earth_--but
+through it, and curving gradually down near to, and within influential
+distance of the surface of the earth, soon after it passes the outward
+limit of its fellow trade; and to continue the current onward, leaving
+portions of it and its heat and moisture on the way, but taking a
+considerable volume up and around the magnetic poles--it being impossible
+for the entire volume to be thus carried around the poles in consequence
+of the diminished circumference of the earth. To this end it is obvious it
+must possess _polarity_.
+
+Another end to be attained is to combine the moisture of evaporation with
+the air, so that the cold atmosphere through which, or the earth over
+which it passes, may not be _continually condensing its moisture_, and
+thereby _enveloping the earth in a perpetual mist_; but so that it may
+part with it at _intervals_, making _cloudy_ and _clear days_; and part
+with it in _portions_, so that a _regular_ and _necessary supply_ may be
+furnished to the _entire hemisphere_, even up to the geographical poles.
+Is there such an agent? There is, precisely and perfectly adapted to the
+ends to be attained, ever there and ever active, and that agent is
+_magnetism_.
+
+
+[Illustration: Fig. 12.]
+
+
+The earth is a magnet. It has its magnetic poles, and they are distinct
+from its geographical ones; and there are two in each hemisphere. They are
+situated from 17° to 19° distant from the geographical poles; and ours is
+not far from longitude 97° W. from Greenwich, and 71° north latitude.
+Navigators have gone north and north-west of it, and found its situation
+by the declination of the needle. From these poles, lines of magnetic
+intensity extend to the opposite and corresponding pole of the other
+hemisphere, and upon or near those lines the needle points north without
+variation; and toward these lines of no variation the needle every where,
+on either side declines. The foregoing diagram shows the situation of our
+magnetic pole and line of no variation, the dip of the needle by the
+arrows, and the magnetic equator.
+
+Recent discoveries have shown that the magnetic force is exerted in lines
+and currents; that such currents, as physical lines of force, surround
+magnets, and currents of electricity. Doubtless such lines of force exist
+around the earth and the magnetic poles. There are also _longitudinal_
+lines of force existing and active, between the poles, and extending from
+one side of the center to the other, occupying nearly one third of the
+magnet. If you take a large needle thoroughly magnetized, place it upon
+paper and drop filings of iron upon it, they will become arranged about it
+in circular and perpendicular, and also in _longitudinal lines_,
+conforming to the currents.
+
+
+[Illustration: Fig. 13.]
+
+
+This experiment is illustrated in all our books on natural philosophy.
+
+The foregoing diagram, copied from Olmstead's Philosophy, does not show as
+accurately as Faraday's projection of the lines upon a globe-magnet the
+comparative distance from the poles of the needle, at which the
+longitudinal currents commence and terminate, and _where the filings will
+not adhere_ to any considerable extent. The lines shown upon the needle
+should bear the same proportion to its length as the trade-winds bear to
+that of the earth, measured from pole to pole, and if the needle had a
+globular form they would so appear.
+
+These lines are made by currents arising from one side of the magnetic
+equator, and passing over to the other. Doubtless, just such currents
+rise, and pass over upon the earth.
+
+Magnetic and electric currents carry the air with them. This is well
+settled by experiment. _Oxygen_, too, is _magnetic_, and capable both of
+receiving and retaining polarity and of combining with, or attracting and
+retaining vapor, and of course the moisture of evaporation. Here then we
+have a power existing, capable of producing the result--precisely, and
+with evident wisdom adapted to its production--ever present and active;
+and no other known agent can.
+
+Is it not then the agent?
+
+Let us look a little further. This result is affected by the action of the
+sun: the trades with the central belts of rains travel north and south
+after it; so does the sun affect the magnetic currents every where, even
+the magnetic needle is daily affected by its action, as it increases the
+intensity of the terrestrial magnetic currents, and hence its well
+established diurnal oscillations.
+
+Again, along the eastern lines of the continents which skirt the great
+oceans on the west, run the northerly and southerly lines of no variation,
+and of greatest magnetic intensity. Here are the trade currents gathered
+into a volume, which curve and carry unusual fertility to South-eastern
+Asia, and North America, and in those great aerial gulf streams we find
+the _intense_ electric action which produces the typhoons of the former,
+and the hurricanes of the latter. It may still be said that these
+conditions and phenomena of the trade-wind region, are not produced by
+magnetism or magneto-electricity, _but the objector can point to no other
+adequate power_. That it must be heat, electricity, or magnetism, must be
+admitted. There is no other power known. Heat demonstrably can not produce
+them. Magnetism or electricity therefore must, and they are doubtless
+states or phases of the same power, producing in their different states or
+phases the different results. And even heat--atmospheric temperature, is
+often, if not always the result of their action. In the present state of
+science, it is enough for me that the _magnetic longitudinal currents are
+there_; that they are _lines of force_ and _adequate_; that _oxygen is
+magnetic_, and therefore the atmosphere must be affected by them--that so
+far as we can reason from analogy, they ought to produce the effect upon
+the atmosphere which we find produced, and until further light is thrown
+upon the subject I shall presume that they do. Every step we take
+hereafter in this investigation will confirm the presumption.
+
+There is one peculiarity to be more particularly noticed before we leave
+the trade-wind region, and we are now prepared to notice it.
+
+The belt of rains, formed by the currents of the two trades, threading
+their way through each other--how are they produced? Why should the place
+where the currents thus pass through each other be a place of almost daily
+precipitation? There is, in fact, no ascension, except that which the
+currents have in their line of ascent to attain the elevation which the
+magnetic law of the current requires.
+
+The trades have passed over an evaporating surface and are charged with
+moisture. This moisture they hold in magneto-electric combination.
+_Evaporation_ does not depend upon _temperature_. Ice and snow evaporate
+at all temperatures (Howard, vol. 1, p. 86). So the cold N. W. wind, full
+of positive electricity, will lap up, as it were, the pools from the
+earth, with astonishing quickness; and when this electricity is deranging
+the action of the machinery and material of the manufacturer, he allays it
+by a supply of moisture, with which the electricity can combine. Nor does
+the air lose its moisture when below the freezing point. In all parts of
+the atmosphere, as at the surface of the earth in winter, moisture is held
+in large quantities in the coldest and severest weather; and it is not
+till it moderates, and a perceptible _electric_ change takes place, that
+it is precipitated as rain or snow. Doubtless there is an exposure of
+considerable surfaces, of opposite currents, charged with opposite
+polarity, and a constant depolarization where their surfaces meet. May
+there not be a consequent dissolution of the electro-magnetic combination
+between the air and moisture, or the excitation of that electric action
+which attends or produces like rains every where? and hence the constant
+precipitation. This is rendered probable, by the fact that precipitation,
+at the meeting of the trades, takes place in level countries in the
+day-time, between 10 A. M. and sunset, in showers, with thunder and
+lightning, as with us in summer, although among the mountains the rain
+sometimes falls in the night also. The precipitation in the heat of the
+day is obviously induced by the action of the sun, although it is by no
+means certain that the friction of the opposing surfaces does not assist
+in the operation.
+
+I am well aware that the lines of magnetic force curve upward and carry
+the trades with them, and that, therefore, precipitation by condensation
+from the mere cold of the upper stratum of the atmosphere is possible.
+But, there are three reasons why I do not believe such to be the fact.
+
+1st. Precipitation takes place in the day time mainly, and in sudden,
+isolated, heavy showers and not in steady continuous rain. Nor is there
+condensation or continual mist at other hours of the day.
+
+2d. They occur at a time of day when the sun is affecting the magnetic
+currents most powerfully, _viz._, between ten o'clock A. M. and sunset,
+and mainly at the time of greatest heat.
+
+3d. The counter-trades _do not precipitate_ after they leave the rainy
+belt, although at a great elevation, until they reach the outward limits
+of the trades; and they _do precipitate again_, although they gradually
+descend _nearer the earth_, as soon as they become subject to the action
+of the currents of an opposite magnetism. Their precipitation is partial
+too, even then, and they carry a portion of their moisture through an
+atmosphere of the coldest temperature up to the geographical poles.
+
+A similar result attends the action of the sun in the extra-tropical
+regions. Cumuli commence forming in the counter-trade, or at the line
+between that and the surface current, at the same time of day that the
+diurnal motion of the magnetic needle commences, or the rain clouds form
+in the tropics; they continue to enlarge here as there, till about the
+same hour of the day that the _needle_ obtains its maximum diurnal
+variations; and when the influence of the sun upon the needle ceases, and
+it returns to its original status, the cumuli disappear. Hail storms too,
+it is said, always, or generally occur in the day time.
+
+In like manner the sea-breezes and other fair-weather surface winds, rise
+in the forenoon with the influence of the sun upon the magnetic currents
+and the needle, and die away at nightfall when the influence ceases.
+
+There are other electro-magnetic, or to speak more correctly,
+magneto-electric, effects of the sun's action equally illustrative, which
+tend to show that the precipitation at the passing of the trades, is the
+result of their action upon each other, aided by the sun, to which we
+shall allude when we come to speak of the causes and character of the
+surface winds of the extra-tropical regions.
+
+As, however, this takes place only, or mainly, where the threading
+surfaces meet, it is but partial, and the body of the respective polarized
+currents pursue their way unaffected, toward the opposite magnetic
+pole--and there for the present we leave them.
+
+Storms sometimes originate in these currents, when concentrated, as in the
+West Indies, the China Sea, the Bay of Bengal, and Indian Ocean, while
+passing through the rainy belt, and move with the current to the
+north-west if issuing on the north side of it, and to the south-west if
+issuing on the south side of it, until they respectively get beyond the
+extreme limits of the trades, and then they curve to the eastward,
+imbedded in and following their current. The peculiar extension of the
+land to the east on the northern portions of South America, prevents the
+gathering of an aerial gulf similar to the one which we have described to
+the north-west, entering upon our division of the continent over the Gulf
+of Mexico. It is otherwise in the Indian Ocean, and there the storms are
+found issuing from the rainy belt on the southern side, sweeping over the
+Mauritius and other islands of that ocean, and _often simultaneously_ with
+storms issuing on the north over the Bay of Bengal. Colonel Reid mentions
+instances and gives a diagram.[2]
+
+These storms in milder forms issue from the rain belt at other points, and
+may issue any where, but will always be found most extensive and most
+violent, that is to say, as hurricanes and typhoons, in the concentrated
+volumes of counter-trade on the western side of the great oceans, within a
+few hundred miles of the lines of magnetic intensity and no variation, and
+when they form in the rainy belt they are highly electric. Most
+frequently, however, as we shall see, they form in these currents after
+they have issued from the rainy belt, and after they have passed the
+extreme limits of the trades and become subject to the circular and
+perpendicular magnetic currents which exist north and south of the
+longitudinal ones, and which when seen upon the magnetic needle, attract
+the filings and cause them to adhere--although but slight attraction or
+adhesion takes place where the longitudinal currents exist.
+
+Such, then, are the atmospheric arrangements and phenomena of the
+trade-wind region, and the cause that produces them; such is the character
+and cause of the enlarged volume of counter-trade, which spreads out and
+blows over our country as permanently as the S. E. trades blow on the
+South Atlantic and South America, returning to us the rivers which had run
+from us to the sea.
+
+
+
+
+CHAPTER VI.
+
+
+Coming back now, to a consideration of the course and functions of the
+counter-trade after it leaves the northern limit of the surface-trades, we
+find it curves to the eastward and gradually assumes about an E. N. E.
+course, and becomes a W. S. W. current where it crosses the line of no
+variation, and continues on until it passes off over the Atlantic; and
+this course and curve is analogous to what may be found true of the
+counter-trades every where. It is best illustrated by the course of all
+the storms (in the American sense of the word, as distinguished from
+thunder showers and other brief rains), which have been traced north or
+south of the limits of the trades. It was found by Mr. Redfield in most of
+the storms investigated by him, which originated within, or north of the
+tropics.
+
+Doubtless it was the actual course of the others, and that the
+investigation was imperfect. All the great autumnal, winter, or spring
+storms which have traversed the whole or any considerable portion of the
+territory of the United States, east of New Mexico, which have been
+investigated by Professors Espy, Loomis, Redfield, or others, have been
+found to follow this course. A storm which passed over Madeira, appears
+from the investigations of Colonel Reid to have followed the same law of
+curvature.
+
+And so, doubtless, did another which he has described as passing over the
+Levant. The storms which supply the winter rains of California and Utah,
+reach them by this law of curvature and progress, after the northern
+limits of the trades have descended to the south with the sun, so that the
+counter-trades of the Pacific may descend to the surface and curve in upon
+them. But the absence of a concentration of the counter-trade, and its
+deficient action because of its passage over mountain ranges, and their
+location so near the northern limit of the trades that their storms can
+not expand and become extensive, as well as their weaker magnetic
+intensity, prevent their storms from becoming violent, and their supply of
+rain is not large and much of it falls in showers. The same is true of the
+Barbary States, of Syria, and Persia, and of Southern Europe; and indeed
+of all the countries of the globe which lie between the winter and summer
+extreme limits of the surface-trades, and without the limits of the two
+concentrated counter-trades. Enough appears in the writings of the
+meteorologists of Europe to show, that their long continued rains, which
+are analogous to our storms and are _preceded by the formation of the true
+cirrus of the counter-trade_, follow the same great law of curvature and
+progress; although the presence of the Gulf Stream with its mass of south
+polar waters on the western side of the British Islands, Denmark, and
+Norway supplies them with showers, and fogs, and cumuli from the west and
+north-west, and makes the mean of the surface winds of their storms
+somewhat variant from ours. A like law reversed prevails in the southern
+hemisphere. The storms of New Holland and the Indian Ocean, south of the
+limits of the trade, curve to the eastward and travel about south-east,
+their _south-west_ being a _clearing off wind_ as our _north-west_ is, and
+_precisely similar in all its other characteristics_, where the relation
+of magnetic intensity is the same.
+
+The storms of the Pacific on the S. W. coast of South America, in like
+manner travel to the S. E., flooding the western slopes of the mountain
+ranges with rain, and aggravated by the intensity of the magnetic currents
+at the extremity of the continent in a high latitude, meet the mariner in
+the face as he emerges from under the lee of the land and attempts to pass
+the Horn. It will ultimately be shown that the precipitation which takes
+place, as the storms and counter-trades pass north and east in the
+northern hemisphere and south and east in the southern hemisphere, is
+owing less to cold than increased magnetic intensity. And all this is the
+result of one great uniform law, existing every where, varying in its
+phenomena only in consequence of the difference in volume, and
+magneto-electric intensity of the portions of the counter-trade, as of the
+surface-trade at different places, and the different magnetic intensity of
+the local perpendicular and circular currents of the earth over which they
+pass, at different periods and at different points.
+
+Mr. Redfield and Lieutenant Maury have assumed that our S. W. current
+comes from the Pacific Ocean. Aside from the adverse evidence which the
+investigations of the former in relation to the course of the West Indian
+storms, and their curving over the continent, furnish to the contrary, and
+that which has herein before been stated in relation to the law of
+curvature, it is obvious they are mistaken, for another and conclusive
+reason.
+
+In order to reach us from the Pacific in a direction from S. W. to N. E.,
+it must pass the table lands and mountain ranges of Mexico and New Mexico,
+and it would supply them bountifully, even if it did not thereby leave us
+comparatively rainless and sterile. Every where currents passing from the
+ocean _over mountain ranges_ part with a large share of their moisture.
+Thus the counter-trade which curves over the Andes and over Peru, is
+deprived of its moisture and leaves the western coast rainless. So in
+degree of the counter-trade which curves over the Himalaya and Kuenlon
+Mountains, and from there passes over the Desert of Cobi, to the north and
+east--it is deprived by those elevated ranges of its moisture. So the
+mountains on the south-western coast of South America are drenched with
+rain, while Patagonia, which lies on the east of them is comparatively
+dry. And so of every other country similarly situated.
+
+Now the mountain ranges and table lands of Mexico are not thus supplied
+with moisture. For the space of four months in Southern and less in
+Northern Mexico, and in summer, and while the belt of the tropics is
+extended up over them, they have rain and in daily showers which _travel
+up from the south_, indicating the course of the counter-trade. (See
+Bartlett's Personal Narrative, vol. ii. p. 286.) At other seasons, and
+while we are bountifully supplied, they are dry. In short, there are no
+two portions of the earth that differ more widely in regard to their
+supply of moisture, and all their climatic characteristics and relations.
+It is therefore, according to all analogy, impossible that our
+counter-trade should come from the South Pacific across the continent and
+below 35°, and in this also those gentlemen are mistaken.
+
+Messrs. Espy and Redfield recognizing the existence of "a prevailing" S.
+W. current, but considering the surface-winds beneath it as the principal
+actors in producing the atmospherical conditions and changes, have
+attributed no office to that current, except that of giving direction and
+progression to our storms. This is their great mistake. It plays no such
+unimportant part in the philosophy of the weather, as we have already
+incidentally seen, and will proceed still further to consider.
+
+_All our storms originate in it._ This we may know from analogy.
+
+_Where there is no counter-trade, outside of the equatorial belt of rains,
+and within influential distance of the earth, there are neither storms nor
+rain._ So, when, as we have seen, the concentration of the volume of
+northern counter-trade in the West Indies, gathered by the hauling of the
+S. E. trades more from the east, as they approach the central belt,
+diminishing the volume of the counter-trade over the North Atlantic, the
+calms and drought of the horse-latitudes are found. And when the
+counter-trade is small in volume and weak in intensity, by reason of the
+fact that the surface-trades from the opposite hemisphere which constitute
+it, formed upon land where evaporation was small, as upon Southern Africa
+and New Holland, or formed where the magnetic intensity was weak, or
+passed over mountain ranges in their course, the annual supply of rain,
+the ranges of the barometer, and the alternations of atmospheres
+conditions are remarkably less.
+
+We have already seen where the rainless portions of the earth are, and why
+they are so; because those lying north of the northern limit of the
+equatorial rainy belt were yet too far south to be covered by the line of
+extra-tropical rains; or in other words, too far south to be uncovered by
+the surface N. E. trades and the longitudinal magnetic currents, and to be
+covered by the counter-trades in contact, or nearly so with the earth, and
+influenced by the perpendicular north polar magnetic currents. Thus we
+have seen that the rains of Southern Mexico were summer rains, due to the
+northern extension of the equatorial rainy belt; those of California were
+winter rains, due to the southern extension of the extra-tropical rains
+following the N. E. surface trades. We have also briefly alluded to the
+fact that either side of the equatorial rainy belt, evaporation is going
+on for months under a vertical sun, without precipitation--unless it be
+from an occasional brief storm of great intensity which originates in that
+belt at the line of it, and passing on in the counter-trade, reverses, for
+the time being, by its concentrated and powerful action, like a magnetic
+body introduced into the field of another magnet, the surface-trades. Mere
+evaporation then, does not produce the storm, or shower, or rain, where
+most active in the dry torrid zone. It may be said that those dry portions
+are, for the time being (as the rainless portions of the earth are
+continually), within the operation of the surface-trades, and that
+therefore the evaporated moisture is carried away by them toward the
+equatorial rainy belt. Precisely so; but why carried away? Why should it
+not condense, occasionally, at least, and drop the rain as it passes
+along, if a great supply of moisture from excessive evaporation could
+furnish rain. Perhaps it may still be said it is going from a cold to a
+warm section. This is not true, as we have shown.
+
+But, it may be said that the rainless regions at any rate receive no
+moisture, and therefore can not supply any by evaporation. This would not
+meet the case, as it would still be true that when the rainy belt has left
+a given spot, the dry weather sets in with excessive evaporation, and the
+north-east trades in summer, blowing from the countries lying north of the
+rainless regions, and which have been supplied during the interval by the
+extra-tropical rains, and are loaded with evaporation, are passing over
+the rainless regions on their way to enter the central belt. So blow the
+N. E. trades from the Mediterranean, and the Barbary States _over the
+Desert of Sahara_ and into the rainy belt south of it; but drop no
+moisture on their way, because exposed to no magnetic currents of an
+opposite polarity.
+
+But it is not true that all the rainless regions are without evaporation.
+Egypt is an exception. The annual freshets of the Nile saturate its
+central valley, and vast reservoirs of water are saved from it and let out
+over its surface, and it all evaporates, but produces no rain. And so are
+large quantities turned aside and scattered over the bottom lands of
+Northern Mexico, and other countries, during the dry season, and their
+evaporation furnishes no rain. Hygrometers and dew points are of no
+consequence there--nor are they of any, on either side of the rainy belt,
+where six perpendicular feet of moisture is evaporated in six months.
+
+Again we have alluded to a strip of coast on the Pacific west of the
+mountain ranges of South America, lying partly in Peru, partly in Bolivia,
+and partly in Northern Chili, which, although long and narrow, washed by
+the broad Pacific Ocean, is without rain. South America has no other
+_wholly_ rainless region, so far as is known. A part of this region would
+lie between the equatorial belt of rain, and the southern extra-tropical
+one, and never be covered by either; but the volume of N. E. trades from
+the Atlantic, although from the make of the land not concentrated to so
+great an extent as the volume of S. E. trade on the north, and therefore
+not so liable to hurricanes and other violent storms, is yet sufficiently
+so to carry the southern line of the equinoctial rainy belt down in winter
+to the summer line of extra-tropical rains, and give a supply of rain to
+all the continent--leaving no strictly rainless region south of the
+equatorial rainy belt and east of the Andes. Those mountains, however,
+present a barrier to its south-western progress which it doubtless passes
+to some extent, but deprived of its moisture, and unable to supply the
+rainless coast region of Peru, Bolivia, and Northern Chili. There is,
+therefore, a portion of this rainless line of coast which is within the
+region of extra-tropical rains, over which a portion of the N. E. trades
+of the Atlantic, as a counter-trade, should or do, curve, and where there
+should therefore be extra-tropical rains. It is washed by the Pacific, an
+evaporating surface, and westerly and south-west breezes are drawn in from
+that ocean over it. Why then is it rainless? The only reason which can be
+assigned why rain does not fall there is that the high mountain ranges of
+the Andes intercept and perhaps in part divert the counter-trade, and
+deprive that portion of it which passes them, of its moisture, by that
+reciprocal action of opposite polarities which takes place whenever and
+wherever the trade approaches so near the earth; and it curves over the
+narrow line of coast with the feeble condensation, and imperfect forms,
+and varied coloring which mark so peculiarly the rainless clouds of that
+region. (See Stewart's Journal of a Voyage to the Sandwich Islands, page
+72.)
+
+Again, it is estimated, and on reliable data, that twelve perpendicular
+feet of water are annually evaporated from the surface of the Red Sea,
+between Nubia on one side, and Arabia on the other; yet they are both
+rainless countries, except so far as the inter-tropical belt of rains
+extends up on to a small portion of them. The moisture of evaporation,
+floated up from a surface covered by the surface-trade is invariably so
+combined as to remain uncondensed till it has passed south into the
+equatorial rainy belt, and over to the opposite hemisphere, and been
+exposed to the currents of an opposite magnetism.
+
+Again, the N. E. trades extended up in summer over the Mediterranean Sea,
+an evaporating surface, blow over the Barbary States in June and July, but
+furnish no rain. And so of the S. E. or N. E. trades which blow over
+Brazil and other countries in the absence north or south of the tropical
+belt of rains.
+
+It is obvious from these facts--and more like them might be cited--that
+mere evaporation, however copious or long continued, does not make the
+storm or shower in the locality where it takes place, and _without the
+existence and influential agency_ of a counter-trade; and that _reciprocal
+action_, whatever it may be, that takes place _between it and the earth_.
+
+Again, our own experience is conclusive of this. We have no surface-trade
+north of 30°, and yet a long drought and great evaporation may follow a
+wet spring. Belts of droughts and frequent rains occur every year in
+different portions of the country side by side, and _the dividing line
+follows the course of the counter-trade_, and is sometimes distinctly
+marked for weeks. When a change occurs in the counter-trade, whether from
+causes existing there or the influence of terrestrial magnetism (in
+relation to which we shall inquire hereafter), showers form or storms come
+on: until it does they will not. Efforts at condensation will occasionally
+appear, but they will be feeble and ineffectual, and occasion a repetition
+of the axiom that "all signs fail in a drought." And we may know it from
+direct observation.
+
+The first indications of a storm, and of most if not all showers, are
+observable in the counter-trade. These indications, so far as they are
+visible, are of course to be looked for in the west; although the
+direction and character of the surface-winds are often indicative of these
+changes when not visible at the west as we shall see.
+
+The indications are those of condensation, and vary very much in different
+seasons of the year. It is not my purpose in this place to examine them
+particularly. They will be alluded to hereafter under the head of
+prognostics. Suffice it now to say, then, that whether it be the long
+threads or lines of cirrus which occur in the trade in the winter after a
+period of severe cold, following the interposition of a large volume of N.
+W. cold air and the elevation of the counter-trade; or the forms of cirrus
+which occur at other times and other seasons; or whether it be the
+ordinary bank at night-fall, or the evening condensation which makes the
+"circle" around the moon, or the morning cirro-stratus haze which
+gradually thickens, passes over and obscures the sun, all which may be
+followed by the easterly scud and winds: they are alike condensation in
+the trade, the advance or forming condensation of a storm or showers.
+
+The state of the weather, whether hot or cold, is extensively affected by
+this trade current. As we have already suggested, the mere presence of the
+sun in its summer solstice, or its absence in winter, is not an adequate
+cause of all the sudden and various changes to which we are subject. The
+state of the counter-trade, which is always over, or _within influential
+distance of us_, and sometimes probably in contact with us--the nature of
+the surface-winds which it is at any given time creating and attracting
+around us, and the electric condition of the surface-atmosphere _induced_
+by it, or by the immediate action of the earth's magnetism, produce those
+sudden changes which mark our climate. When no intervening surface-winds
+elevate it above us, and there is no storm or other condensation within
+influential distance, it induces the gentle balmy S. W. wind of
+spring--the cooling S. W. wind of summer--the peculiar Indian summer air
+of autumn, or the comparatively moderate, although cold, open weather of
+winter. If there be a partial tendency to condensation in it, the cumuli
+form under the magnetic influence excited by the sunbeams from ten to
+three o'clock in the day, and float gently away to the eastward,
+disappearing before night-fall. If the disposition to condensation is
+stronger, whether inherent or induced by an increased local activity of
+terrestrial magnetism, these cumuli will increase toward night-fall, or
+earlier, and terminate me showers; and if it is in a highly electrical
+state, the still oppressive sultriness which precedes the tornado, and
+that devastating scourge may appear. If this disposition to condensation
+becomes extensive, cirri form and run into cirro-stratus, or they extend,
+coalesce, and form stratus; the surface-wind will be attracted under them,
+the thermometer fall in summer or rise in winter, and a storm begin.
+Intense action and sudden cold may exist in and under this counter-trade
+over the southern portion of the country, while all is calm, warm, and
+balmy at the north. Heavy snow storms sometimes pass at the south when
+there are none at the north, and a corresponding state of the weather
+follows. If a large body of snow fall at the north, the winter is cold,
+regular, and "old fashioned;" if little snow falls at the north and more
+at the south, the winter at the north is open and broken. I have known the
+ice make several inches thick at Baltimore and Washington, when none could
+be obtained for the ice-houses on the Connecticut shore of Long Island
+Sound. In short, although heat and cold are mainly dependent upon the
+altitude of the sun, aided by the other arrangements we have alluded to,
+yet the counter-trade, and the reciprocal action which takes place between
+it and the earth, are most powerful agents, mitigating the rigors of
+winter, bringing about the changes from cold to warm weather which the
+sun is too far south to produce. And on the other hand, by this reciprocal
+action, producing the electrical phenomena, the gusts, the tornadoes, the
+hail storms, and the cool seasons of summer, and the period of intense
+cold in winter.
+
+_All our surface-winds, except the light, peculiar W. S. W. wind which is
+felt where the counter-trade is in contact with the earth, and which is a
+part of it, and perhaps the genuine N. W. wind which is very peculiar, are
+incidents of the trade, and are due to its conditions and attractions._ We
+have already said this was true of the easterly wind and scud of a
+storm--it is alike true of all. The storm winds east of the Alleghanies
+are usually, though not always, from the eastward. They are sometimes from
+the southward, as they doubtless are still more frequently in the interior
+of the continent.
+
+There is occasionally a southerly afternoon wind, followed by short rains
+in spring and fall, or a succession of showers in summer, which is rather
+a precedent wind than a storm wind; blowing toward and under an advance
+portion of the storm at the north, and hauling to the eastward when the
+rain sets in, or to the westward when the showers reach us.
+
+When there are no storms, or showers, or inducing electric action in the
+counter-trade, within influential distance to disturb the surface
+atmosphere, it is calm. If a storm approaches, or forms within inducing
+distance, the surface atmosphere is _affected_ and _attracted toward the
+storm_, from one or more points, and "blows," as we say, toward and under
+it. It commences blowing first nearest the storm, and extends as the
+storm travels, or becomes more intense and extends its inducing influence.
+I have repeatedly noticed this in traveling on steamboats and railroads
+running _toward_ or _from_, and in several instances _through_ a storm,
+and telegraphic notices and other investigations prove it. The point from
+which the surface atmosphere is attracted and blows, depends very much
+upon the position of the storm in relation to bodies of water and the
+point of observation, and its shape; and the force with which it may blow
+will depend much upon its intensity.
+
+Let us take an instance or two by way of illustration of all these points;
+and as I have given instances of summer in the introduction, we will take
+those of winter. It is January of an "old fashioned winter;" the snow is
+about three feet deep in Canada, about one foot in Southern New York, and
+a few inches in Philadelphia, and so extends west to the Alleghanies at
+least. For several days the sky has been clear, the thermometer rising in
+the day-time, in the vicinity of New York to about 25° Fahrenheit, falling
+at night to about 6°, with light airs from the N. W. during the middle and
+latter part of the day; the counter-trade and the barometer both running
+high; cold but pleasant, steady, winter weather. There is a warm
+south-east rain and thaw coming, as one or more such almost invariably
+occur in January. How coming? The sun is far south, and shines aslant, but
+through a pure and windless atmosphere; he has tried for several days to
+melt the snow from the roof; a few icicles are pendant from the eaves;
+but the body of the snow is still there. How can a thaw come? not from the
+sun, surely. No, indeed, not from the action of the sun directly, upon our
+country, nor from the Atlantic or the Gulf Stream which is off our coast.
+But a portion of the current of counter-trade is coming, heated by his
+rays and the warm water in the South Atlantic, in an intense
+magneto-electric state, capable of inducing an electro-thermal change in
+the surface atmosphere which it approaches, and of being reciprocally
+acted upon by the north polar terrestrial magnetism. It is now over
+Northern Texas and Western Louisiana, it will be here day after tomorrow.
+The day passes as the day previous had passed; the sleigh-bells jingle
+merrily in the evening; the moon shines clear all night; the storm is
+coming steadily on, but its influence has not reached us, and the morning
+and midday are like those which preceded it. As nightfall approaches,
+however, the thermometer does not fall as rapidly as on the day previous;
+the sun shines dimly and through lines of whitish cirrus cloud extending
+from the horizon at the west, appearing darker as the sun descends and
+shines more _horizontally_ through them--perhaps mainly in the N. W.--and
+which extend up and over toward the E. N. E. The air next the earth begins
+to feel raw; it is changing, not from warm to cold, but _electrically_
+from positive to negative; and dampening, from a tendency to condensation
+by induction, as we shall see--the same condensation which in warm
+weather may be seen on flagging stones, and walls, and vessels containing
+cold water. The advance cirrus condensation of the storm is over us and
+affecting us; the earth too is affecting the adjacent atmosphere by action
+extended from beneath the storm. Still there is no wind, although sounds
+seem to be heard a little more distinctly from the east, and so ends the
+day. Evening comes, and the moon wades in a smooth bank of cirro-stratus
+haze, with a very large circle around her; the cirrus bands of haze have
+coalesced and formed a thin stratus. The storm is coming steadily on, its
+condensation is seen to be thicker as it approaches, it is now raining
+from one hundred to one hundred and fifty miles to the west, but we do not
+know it.
+
+That it is about to storm all believe, for all are conscious of a change.
+The candle if extinguished will not relight as readily, if at all, on
+being blown; there is a crackling almost too faint for snow in the fire;
+the sun did not set clear; the old rheumatic joints complain, and the
+venerable corns ache.
+
+Morning comes, and the storm is on. The wind is blowing from the S. E.,
+the scud are running rapidly from the same quarter to the N. W., the
+thermometer continues rising, and it rains. The storm has reached us and
+the thaw has commenced. Gradually, as the densest portion of the storm
+cloud reaches us, it darkens; the scud are nearer the earth, and run with
+more rapidity; the rain falls more heavily and continuously, and by the
+middle of the day a thick fog has enveloped the earth; the wind is dying
+away, and the trade itself, with its southern tendency to fog, has settled
+near us; the barometer has fallen, the thermometer is up to fifty degrees,
+the water is running down the hills, the snow is saturated with water and
+is disappearing under the influence of the fog, the rain, and the warm
+air. Evening comes; the south-east wind and the rain have ceased; the rain
+clouds have passed off to the eastward; the fog has followed on and
+disappeared; there is a light trade air from the S. W.; the moon shines
+out, and a few patches of stratus, broken up into fragments and melting
+away, are following on in the trade: the storm is past.
+
+Hark! to the tones of Boreas as he bursts forth from the N. W., and
+rushing, whistling, howling, dashes on between the trade and the earth,
+following the storm. Now the barometer rises rapidly, the thermometer
+falls, and in an incredibly short time all is congealed, and cold and
+wintery as before. The cold N. W. wind has again interposed between the
+trade and the earth; the trade is elevated a mile or more above it and is
+entirely free from its influence and from condensation; the deep blue of a
+sky "as pure as the spirit that made it" is over us, and steady winter
+reigns again.
+
+It is obvious that there was nothing in the action of the sun upon our
+snow-clad country, to induce the thaw or the storm. It began, continued,
+approached, and passed off to the N. E. in the counter-trade. The S. E.
+wind which existed every where within its influence: in the interior
+States, Missouri, Illinois, Indiana, Ohio, Michigan, and in Canada, as
+well as upon the Atlantic coast, commencing in the former earlier than
+upon the last, was the result of its induction and attraction. Of the N.
+W. wind that followed we shall speak hereafter. If any one doubts whether
+this be a true sketch let him examine the investigation of a storm
+published by Professor Loomis, or observe for himself hereafter. If,
+however, the storm of Professor Loomis is referred to, it should be
+remembered that his notes show the occurrence of a slight distinct snow
+storm at the N. W. stations one day in advance of the principal storm. The
+latter appears first as rain at Fort Towson, on the nineteenth, moving
+north and curving to the east--its center passing near St. Louis, and
+south of Quebec, and the whole storm enlarging as it advanced.
+
+Take another instance. Since the thaw it has not been quite as cold as
+before; but the rain-soaked snow is hard and solid, the ground, where the
+snow was blown or worn off, icy and slippery--the thermometer falls during
+the night to about 12°, and rises to about 30°; the sun makes no
+impression upon the snow; the firmament is of the deepest blue, the
+borealis at night vivid. "O, for a storm of some kind, to mitigate the
+still severe cold;" for the thaw has made us more sensitive, and storm
+winds do blow warm in their season. But patience, it will come. Another
+day, or two, perhaps, pass: the sun rises as usual, the thermometer has
+the same range still. "Long cold snap," we exclaim; "how long will it
+last?"
+
+A change is coming, but this time it will snow. About an hour or two after
+sunrise the cirrus threads are discoverable again in the west, but now
+they are most numerous in the S. W. As the day passes on they thicken and
+advance toward the E. N. E., the sun begins to be obscured, the
+thermometer rises, and it slowly "_moderates_." There is a snow storm
+approaching from the S. W.
+
+But the thermometer rises slowly; it must get up to 26° or 28° before it
+can snow much. I have known in one instance, at Norwalk, a considerable
+fall of snow, although much mingled with hail, when the thermometer stood
+at 13° above zero, and one, a moderate fall, some two inches, with it at
+24°, but these were exceptions. The snow range of the thermometer on the
+parallel of 41° north latitude, and south of it, is from 26° to 30° above
+0°; when colder or warmer it may snow to whiten the ground, or perhaps
+barely cover it, but usually rains or hails. We have seen that in the
+polar regions, according to Dr. Kane, it is about zero, but the rise of
+the thermometer there, previous to the snow, was about the same as here,
+_i. e._, from 15° to 25°. This fact is instructive. Since the foregoing
+was written, and on the 7th of February, 1855, a snow-storm of
+considerable length set in, with the thermometer at 5°, and continued more
+than twenty-four hours, the thermometer gradually rising. The snow was
+very fine, like that described by Arctic voyagers as falling in extreme
+cold weather.
+
+As the dense and darker portions of the storm approach, and although the
+sun is obscured, and the ground frozen, it continues to moderate, and at
+evening, when the thermometer is up to 28°, and the dense portion of the
+storm has reached us, gently and in calmness the snow begins to fall.
+Perhaps a light air following the storm, or the presence of the trade near
+the earth, at first inclines the snow-flakes to the eastward. This is
+frequently so at the commencement of snow storms. Ere long, however, the
+wind rises from the N. E., and the snow is driven against the windows,
+rounded and hardened by the attrition of its flakes upon each other, in
+their descent through the eddying and opposite currents. The next day we
+rise to witness a heavy fall of snow, perhaps, and a continued driving N.
+E. storm, in full blast; the snow whirling and settling in drifts under
+the lee of every fence or building.
+
+Can it be, you ask, that this driving wind is but an _incident_ of the
+storm? the result of _attraction_, while the storm clouds are sailing
+quietly and undisturbed on in the counter-trade above, directly over the
+gale which is blowing below? It is even so. Nor has it "backed up," as it
+is termed by those who have ascertained that it has commenced snowing
+first, and cleared off first, at a point west of them. You saw, or might
+have seen, the cirro-stratus cloud passing to the E. N. E. in the
+afternoon, and until the snow-flakes filled the air, and the clouds became
+invisible. You may still see that the wind will die away before the storm
+breaks, and "come out" gently from the S. W., unless it should back into
+the northward and westward, and in either event you may see the last of
+the storm clouds, as you did see, or might have seen the first of them,
+pass to the eastward. Toward night the wind dies away, and the storm
+passes off abruptly, or the sky becomes clear in the N. W. Now you may see
+the smooth stratus storm cloud, continuous, or breaking up into fragments
+and passing off to the east, even at the edge which borders the clear sky
+in the west or north-west, to be followed that evening or the next day, by
+the north-west wind and its peculiar fair-weather scud.
+
+I have given these as instances illustrating the manner in which rain and
+snow storms originate the surface easterly winds in winter.
+
+But it must not be supposed that they commence with precisely the same
+appearances in every case in winter; much less in summer. There is very
+great diversity in this respect, in different seasons, and in different
+storms during the same season. A great many different and accurate
+descriptions might be given, if time and space would permit, which all
+would recognize as truthful. Very frequently in summer, and sometimes in
+winter, the wind will set in from the eastward, and blow fresh toward a
+storm, before the condensation in the trade, which forms the eastern and
+approaching edge of the storm, has assumed the form of a distinct cloud.
+Not unfrequently, when it is calm next the surface, a narrow stratum of
+easterly wind, a half a mile or a mile above the earth, may be seen with a
+continuous fog, condensing, but not in considerable patches like the
+usual scud, running with great rapidity toward the storm. Such a stream of
+fog blew with great rapidity for thirty-six hours toward the storm which
+inundated Virginia and Pennsylvania, in 1852, and carried away the Potomac
+bridge at Washington. Such a stream of fog was visible the evening before
+the great flood of 1854, which inundated Connecticut, and curried away so
+many railroad and other bridges. I have also seen such a stream of fog
+running at about the same height, when it was calm at the surface, from
+the S. W. toward a violent storm which formed over central New
+England--and from the north toward a heavy storm passing south of us. Such
+strata form, as far as I have been able to discover, the _middle current_
+of storms which are accompanied with very heavy falls of rain. These
+double currents are much more common than is supposed. East of the
+Alleghanies, short and heavy rain storms, which commence north-east,
+hauling to the south and lighting up about mid-day _after a very rainy
+forenoon_, frequently have a S. E. or S. S. E. middle current of this
+character, which involves the whole surface atmosphere when the storm has
+nearly passed, and the N. E. wind dies away, and the wind seems to haul to
+the S. S. E. and S.; so that it is rather the prevalence of a _different_
+and _coexisting current_, than a hauling of the _same wind_, which marks
+the period of lighting up in the south.
+
+Sometimes the easterly wind will set in and blow a day or two before the
+border of the storm reaches us. Sometimes the storm is passing, or will
+pass, in its lateral southern extension, south of us, and the
+condensation in the trade extends over us sufficiently dense to induce an
+easterly current beneath it, but not dense enough to drop rain, and then
+we have a dry north-easter. I can not, within the limits I have
+prescribed, allude to all the peculiarities attending the induction and
+attraction of an easterly wind, by the storm in the counter-trade. They
+are readily noticeable by the attentive and discriminating observer, and
+their existence and cause is all with which I have to do at present.
+
+Winds from the north, or any point from N. N. E. to N. N. W., are
+comparatively infrequent in the United States, east of the
+Alleghanies--though it is otherwise in the vicinity of the great lakes.
+
+Sometimes the wind "backs," as sailors term it, during a N. E. storm, from
+the N. E. through the N. N. E., N., and N. N. W. to N. W. When this takes
+place, it is toward the close of the storm. Occasionally, though very
+rarely, it continues to storm after the wind has passed the point of N. N.
+E., and until it gets N. W. I have known a few instances in the course of
+thirty years, and but a few. They are exceptions--rare exceptions. When
+the wind thus backs from the N. E. to the N. W. through the N., you may be
+very certain that the body of the storm, or at least the point of greatest
+intensity and greatest attraction, is at the time passing to the southward
+of you. This is most commonly the course of the wind when the storm
+extends far south and lasts several days, and does not extend north far,
+or if so, with much intensity, beyond the point of observation. The
+change of the wind is explained by the situation of the focus of intensity
+and attraction, to the south of the observer, and its passage by on that
+side.
+
+Probably in locations further north and (as I think I have observed) south
+of the lakes, it may be more frequent than upon the parallel of 44° east
+of the Alleghanies (which is as far north as I have observed), inasmuch as
+the further north the locality, the more likely storms and other
+disturbances in the counter-trade will be to pass to the southward of it.
+
+Between the N. E. and S. E. the wind may blow from any point, before and
+during storms, and in a clear day in the morning, as a light variable
+breeze, or, after mid-day, toward approaching showers. I have known it
+blow all day during a storm from due east; to change back and forth
+between south-east and north-east, and to blow for hours from any
+intermediate point--as different portions of the storm were of different
+intensity, and exerted a more or less powerful inducing influence; and
+doubtless this often takes place at sea. It depends upon the situation of
+the focus of attraction of the storm, its shape relative to the particular
+locality, and with reference to the atmosphere east of it, and peculiar
+local magnetic action; or, as is sometimes the case in low latitudes, is
+owing to the fact that the storm is made up of many imperfectly connected
+showers, which have different force, and induce changeable and baffling
+winds.
+
+The inducing and attracting influence of the approaching storm is exerted
+sooner, and with most force, upon the surface atmosphere, over bodies of
+water like the ocean and the lakes. Thus, the wind will set from the
+eastward toward an approaching storm out upon Long Island Sound, for hours
+before it is felt upon either shore; and when all is calm in the evening
+on land, and often before the moon forms a halo or circle in the milky
+condensation of the approaching storm, or any sign of condensation is
+visible, the breaking of the waves upon the shores may be heard. Doubtless
+this may be observed on the shores of the Atlantic at other points.
+
+This power of attracting the surface atmosphere from bodies of water like
+the ocean and the great lakes, will account for two apparent anomalies,
+mentioned by Mr. Blodget in a valuable and instructive article read to the
+Scientific Convention, in 1853, regarding the annual fall of rain over the
+United States.
+
+First--the influence of mountains in extracting the water from the
+atmospheric currents which pass over them, is well known and readily
+explainable. Mr. Blodget, however, found that the source of our rains,
+whatever it might be, when it reached the Alleghanies, was so far
+exhausted of its moisture that those mountains extracted less from it than
+fell to the westward, by some five to ten inches annually; and that the
+fall of rain upon them was less than upon the Atlantic slope eastward of
+them, to the ocean. This does not accord with observation elsewhere, but
+is easily explained. As the storm approaches the ocean, it attracts in
+under it the surface atmosphere of the ocean, loaded with vapor,
+condensing in the form of fog and scud, as it becomes subject to the
+increasing influence of the storm. Although the scud and fog would not of
+itself make rain, it aids materially in increasing the quantity of that
+which falls through it. The drops, by attraction and contact, enlarge
+themselves as they pass through, in the same manner as a drop of water
+will do in running down a pane of glass which is covered with moisture.
+The small drop which starts from the upper portion of a fifteen-inch pane,
+will sometimes more than double its size before it reaches the bottom. _It
+is by this power of attracting the surface atmosphere, which contains the
+moisture of evaporation, under it, and inducing condensation in it, that
+the moisture of evaporation which rarely rises very far in the atmosphere
+is made to fall again during storms and showers._ This attraction of a
+moist atmosphere from the ocean accounts for the excess of rain on the
+east of the Alleghanies, compared with its fall upon them. So the great
+valley of the Mississippi is comparatively level, and less of its water
+runs off than of that which falls upon the Alleghanies. There is,
+therefore, more moisture of evaporation in the atmosphere of the former to
+be thus precipitated and add to the annual supply of rain upon that
+valley, and it exceeds that which falls upon the Alleghanies. Those
+mountains, too, are elevated but about 1,500 feet above the table-lands at
+their base, and exert little influence on the counter-trade. If they, were
+6,000 or 8,000 feet high, a different state of things would exist.
+
+Second--Mr. Blodget found the quantity of rain which fell in Iowa, and to
+the south and west of the lake region, to be greater than fell over the
+lake region itself. This is doubtless in part owing to the same cause. The
+counter-trade, in a stormy state, attracts the surface atmosphere from the
+lake region, with its evaporated moisture, before it arrives over it, and
+therefore more rain falls S. W. of the lake region than upon it. This
+power of attracting the surface wind of the ocean in under it, produces
+the heavy gales which affect our coast, and which are rarely felt west of
+the Alleghanies to any considerable degree; and a storm coming from the W.
+S. W., extending a thousand miles or more from S. S. E. to N. N. W., may
+have the wind set in violently at S. E. on the _southern coast first_, and
+at later periods, successively, at points further north, and thus induce
+the belief that the storm traveled from south to north.
+
+Mr. Redfield finding that some of the gales which he investigated,
+particularly that of September 3d, 1821, did not extend far inland, and
+commenced at later periods regularly, at more northern points, concluded
+that the gale traveled along the line of the coast to the northward. In
+this, and in relation to the storm of 1821 (and perhaps some others), he
+has been deceived. My recollections of that storm are accurate and
+distinct. But I shall recur to this again when I come to speak of his
+theory.
+
+Toward storms, or belts of showers which would be storms if it were not
+summer and the tropical tendency to showers active in the trade, which
+pass mainly to the north of us, or commence north and pass over us,
+condensing south while progressing east, the wind may commence blowing
+before the body of the storm reaches us, from any point between south by
+west and south east, particularly in the summer season and in the
+afternoon. When the rain in a storm of this character sets in, in the
+night, it will sometimes haul into the S. E., if the focus of attraction
+be situated north of us, and so remain until just before the storm is to
+break.
+
+There are, however, a class of southerly summer winds which deserve more
+particular notice. For two or three months in the year--say from the
+middle of June to the 20th of August--storms on the eastern part of the
+continent, except in wet seasons, are rare, and most of our rain is
+derived from showers. During these periods belts of drought are frequent,
+sometimes in one locality, and sometimes in another, extending with
+considerable regularity from W. S. W. to E. N. E. in the course of the
+counter-trade, while rain falls in frequent and almost daily showers to
+the northward or southward of them. If the daily rains are at the north,
+over the belt of drought, S. S. W. and S. W. by S. winds blow, sometimes
+with cumuli or scud, during the middle of the day and afternoon, to
+underlie the showery counter-trade on the north of the line of drought.
+Thus, sometimes nearly every day for several days, the evaporated moisture
+of the dry belt will be carried over to increase the store of those who
+have a sufficient supply without. During the latter part of the afternoon
+the clouds in the west may look very much like a gathering shower, but the
+attractions of the counter-trade fifty or one or two hundred miles to the
+north, will absorb them all, and at nightfall the wind will haul to the S.
+W. on a line with the counter-trade, and die away.
+
+If there be a drought on any given line of latitude, and frequent showers
+or heavy rains at the south of it, although there may not be a like
+surface-wind, with cumuli and fog, blowing from the north toward it, yet a
+general, gentle set of the atmosphere, from the N. N. W., or N. W., or
+other northerly point, toward the belt of rains, some distance above the
+earth, will often be observable, with a barometer continually depressed,
+and perhaps a cool atmosphere.
+
+During set fair weather, when the attracting belt of rains is far north,
+on the north shore of Long Island Sound, the wind, like a sea breeze, will
+set in gently from about S. S. E. or S. by E. in the forenoon, blowing a
+gentle breeze through the day, and hauling to W. S. W. on a line with the
+trade at nightfall, and dying away. During a drought I have known this to
+happen for seventeen successive days. It is obvious to an attentive
+observer that this is the result of the influence of the sun in exciting
+the magnetic influence of the earth, and producing a state of the trade
+not unlike that which induces the formation of cumuli, and which attracts
+the surface atmosphere from the Sound in over the land: for the _tendency
+to cumulus condensation precedes the breeze_, and the breeze is often
+wanting in the hottest days where no such tendency to the formation of
+cumuli exists. The same is true of sea breezes elsewhere. They do not blow
+in upon some of the hottest surfaces. Where they do exist, they do not
+always blow, but are wanting during the hottest days; and careful
+observers have identified their appearance with the formation of cumuli,
+or other condensation, upon the hills inland. They are not, therefore, the
+result of ascending currents of heated air.
+
+The received theory regarding sea and land breezes is a mistaken one in
+another respect. There is no such thing as a land wind corresponding in
+force to, and the opposite of, the sea breeze--occasioned by the
+comparative warmth of the ocean. These breezes blow mainly within the
+trade-wind region. Of course they are either beneath the belt of rains or
+the adjoining trades. They are said to be, and doubtless are, most active
+and strongly marked on lines of coast, particularly the Malabar coast, and
+where the trade-winds are drawing usually from them. In the day-time, when
+the action of the sun increases the action of the magnetic currents upon
+the land, or there are _elevations inland_ which approach the
+counter-trade, and especially if it is elevated near the coast, as the
+Malabar coast is by the Ghauts, the attraction of this atmosphere over it
+_reverses the trade_, or inclines it in upon the land, and it blows in
+obliquely or perpendicularly, according to the relative trending of the
+coast and the direction of the surface-trade. Thus, where islands are
+situated within the range of the trades, the latter will be _reversed_
+during the day on the _leeward_ side, but continue to blow as land winds
+during the night. So they are sometimes deflected in upon the land on the
+sides, during the day, and in like manner return to their course in the
+night. So, too, the north-east trades of Northern Africa, are occasionally
+(though feebly where the coast is flat) deflected during the day-time, and
+blow in as N. W. winds. Upon the southern coast of Africa the S. E. trade
+is deflected, and blows in as a S. W. wind. Upon the south-western coast
+of North America, the N. E. trades are deflected in like manner, and so
+are the S. E. trades upon the western coast of South America. Where the
+coast mountain ranges are very elevated, as upon the western coast of the
+American continent, this attracting influence and consequent deflection
+extends to a considerable distance seaward, and hence the westerly winds
+of California, etc. It must be understood that we are now speaking of the
+winds which blow within the range and during the existence of the
+trade-winds or the presence of the dry belt--for the trades are not always
+perceptible on the land. Captain Fitzroy thus describes the sea breezes of
+the western coast of Peru, at 23° south latitude. "The tops of the hills
+on the coast of Peru are frequently covered with heavy clouds. The
+prevailing winds are from S. S. E. to S. W., seldom stronger than a fresh
+breeze, and often very slight. _Sometimes during the summer, for three or
+four successive days, there is not a breath of wind, the sky is
+beautifully clear, with a nearly vertical sun._ On the days that a sea
+breeze sets in, it generally commences about ten in the morning, then
+light and variable, but gradually increasing till one or two in the
+afternoon. From that time a steady breeze prevails till near sunset, when
+it begins to die away, and soon after the sun is down there is a calm.
+About eight or nine in the evening _light winds_ come off the land, and
+continue till sun-rise, when it again becomes calm until the sea breeze
+sets in as before."
+
+To illustrate this further, I take the following letter from Professor
+Espy's Philosophy of Storms:
+
+     CLINTON HOTEL, N. Y., Dec. 20, 1839.
+
+     TO PROFESSOR ESPY,
+
+     DEAR SIR,--Understanding you are desirous of collecting curious
+     meteorological facts, I take the liberty of communicating to you what
+     I saw in the month of December, 1815, at the Island of Owhyhee. I lay
+     at that island in the Cavrico Bay,[3] in which Captain Cook was
+     killed, three weeks, and every day during that time, very soon after
+     the sea breeze set in, say about nine o'clock, a cloud began to form
+     round the lofty conical mountain in that island, in the form of a
+     ring, as the wooden horizon surrounds the terrestrial artificial
+     globe, and it soon began to rain in torrents, and continued through
+     the day. In the evening the sea breeze died away and the rain ceased,
+     and the cloud soon disappeared, and it remained entirely clear till
+     after the sea breeze set in next morning. The land breeze prevailed
+     during the night, and was so cool as to render fires pleasant to the
+     natives, which I observed they constantly kindled in the evening. I
+     was particularly struck with the phenomena of the cloud surrounding
+     the mountain, when none was ever seen in any other part of the sky,
+     and none then till after the sea breeze set in, in the morning, which
+     it did with wonderful regularity. The mountain stood in bold relief,
+     and its top could always be seen from where the ship lay, above the
+     cloud, even when it was the densest and blackest, with the lightning
+     flashing and the thunder rolling, as it did every day. I passed up
+     through the cloud once, and I know, therefore, how violently it
+     rains, especially at the lower side of the cloud. This rain never
+     extends beyond the base of the mountain;[4] and all round the horizon
+     there is eternally a cloudless sky. The dews, however, are very
+     heavy, and there seems to be no suffering for want of rain. That this
+     state of things continues all the year, I have no doubt, from what an
+     American, by name Sears, who had spent four years there, told me; he
+     had seen no change in regard to the rain.
+
+     CALEB WILLIAMS.
+
+     Providence, R. I.
+
+Similar citations might be made to show that the sea breeze is induced by
+the same cause which forms the clouds over the land--that it is frequently
+wanting for three or four days under a vertical sun, and that the land
+breeze blows gently and not with corresponding force where there is no
+surface trade, or where it is deflected, not reversed.
+
+A succession of showers passing across the country to the north, within
+one hundred to one hundred and fifty miles, almost always produces a
+southerly wind to the southward of them. There is more that is peculiar
+about these belts of showers. Although they consist of large
+highly-electrified cumuli, there is a strong tendency to cirro-stratus
+condensation in the lower part of the trade over them; and it is that
+condensation rather than the cumuli, which attracts the surface atmosphere
+from the south. They would be storms, if the atmosphere had not a
+summer-tropical tendency to showers. There is, too, a tendency in these
+belts to extend to the south, and it is generally, as far as I have
+observed, the extension southerly of those belts, by the formation of new
+showers which terminate the "hot spells" or "heated terms" of mid-summer.
+The very oppressive and fatal one of the summer of 1853, was, in
+character, a type of all--although exceeding them in severity. The first
+three or four days were calm, hot, and smoky--an appearance which attends
+all similar periods more or less, refracting the red ray of the light, and
+giving the sun a peculiar dry-weather, red appearance. (This smoky haze is
+usually atmospheric, and occasionally seen even in March, although not
+unfrequently fires in the woods fill the air with actual smoke, and very
+much increase it, and when this is so, the odor of the smoke is often
+perceptible.) Then we began to have a fresh south-west by south breeze in
+the day-time, hauling to the south-west, and dying away at nightfall. The
+next day, the tendency to condensation and consequent belt of showers
+having extended further south and approached nearer to us, the S. S. W.
+wind blew _fresher_ toward it, and _did not die away at nightfall_. During
+the evening the reflection of the lightning playing upon the tops of the
+thunder clouds, just visible at the north (heat-lightning, it is termed,
+because supposed to be unaccompanied by thunder, but in reality lightning
+reflected from clouds at too great a distance for the thunder to be
+heard), and the continuance of the southerly wind after nightfall, gave
+sure evidence of the coming showers the next day, and an end of the
+excessive heat for that time. So ended both of those long-to-be-remembered
+"heated terms" of 1853.
+
+The same is probably true of the interior of the country every where.
+Lieutenant Maury, in the course of his investigations, and in order to
+ascertain the direction of the winds in the Mississippi valley during
+rain, addressed a number of gentlemen, and received their replies, which
+are published with his wind and current charts. Several answered, among
+other things, that, "whenever the lightning appears to linger at the north
+at eventide, rain almost invariably follows speedily; not so in the
+south." Thus it frequently is with us. If, during a hot, dry time, of a
+few days continuance, the lightning so lingers in the evening, and the
+wind continues to blow _fresh_ from the southward _after nightfall_,
+showers will generally follow within forty-eight hours, most commonly the
+next day, and a cool N. N. W. or N. W. wind with a favorable change ensue.
+Such, at least, has been the result of my observation for many years.
+
+Indeed this seems to be the general law in summer in the Mississippi
+valley, where the easterly winds are not so common as with us. To
+illustrate this further, I copy from a recent work by T. Bassnett,
+entitled the "Mechanical Theory of Storms," two short extracts, showing
+the manner in which belts of showers extend southerly, while progressing
+north-eastwardly, at Ottawa. The first occurred in August, 1853; the last,
+December, 1852. The first was a belt of showers; the latter would have
+been in August, but the lateness of the season changed its character
+somewhat, though not entirely, to a more regular rain, especially toward
+the close.
+
+     "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 fine 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 over head, 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.
+
+     "8th.--Clear all day; wind the same (S. W.); a hazy bank visible all
+     along on _southern horizon_.
+
+     "DECEMBER 21st, 1852.--Wind N. E., fine weather.
+
+     "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 cirro-cumulus, the
+     sun visible sometimes through the waves; wind around 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.
+
+     "23d.--Wind S. W., moderate, drizzly day; 10 P.M., wind west, and
+     getting clearer."
+
+It is obvious that the showers at the north passed east on the evening of
+the 6th of August; that new showers, taking the same course, originated in
+the north, but more southerly next day, with S. W. wind, and that they
+passed east, and others formed successively further south, which passed
+over the place of observation late in the afternoon, and that others
+formed south and passed east during the night and next day, visible in a
+bank on the southern horizon.
+
+Later or earlier in the spring and autumn, these brisk afternoon
+southerly winds continuing after nightfall, indicate moderate rains from a
+rainy belt extending in a similar manner, without the cumuli and thunder
+which attend those of mid-summer. I shall recur to this class of showers
+and storms when we come to their classification.
+
+Light surface winds from south-west to west are not often storm-winds, and
+are usually those which the trade near the earth draws after it. Sometimes
+the trade seems to draw the surface wind from the S. W. and W. S. W. with
+considerable rapidity, and some scud a little distance above the earth.
+When this is so, it will be found that a storm has passed to the north of
+us, or a belt of rains is passing north, which may or may not have
+sufficient southern extension to reach us. When there have been heavy
+storms at the south in the spring, especially if of snow, the S. W. wind
+which the trade draws after it, and which comes from the snowy or chilled
+surface, is exceedingly "raw"--that is, damp and chilly, although not
+thermometrically very cold. Probably every one has noticed these "_raw_"
+S. W. winds of spring.
+
+Usually, when storms and showers, which have not a southern lateral
+extension, pass off, the trade is very near the earth, and a light S. W.
+wind or calm follows for a longer or shorter period. Not unfrequently,
+however, our N. E. storms terminate with a S. W. wind, shifting suddenly,
+perhaps, just at the close of the storm, during what is sometimes called a
+"clearing-off-shower," or, more frequently, dying gradually away as a N.
+E. wind, and coming out gently from the S. W., following the retreating
+cloud of the storm. In such cases it is said to "clear off warm."
+
+With us the wind rarely blows from the west, except while slowly hauling
+from some southerly point to the N. W. It is probably otherwise east of
+the lakes and in some other localities to the north-west.
+
+Occasionally, and most frequently in March, a W. to W. N. W. wind follows
+storms, and blows with considerable severity, with large irregular,
+squally masses of scud, and sometimes a gale. Such was the character of
+the dry gale which crossed the country, particularly Northern New York, in
+March, 1854, doing great damage. These westerly winds are always
+accompanied by a continued depression of the barometer, and peculiar,
+foggy, scuddy, condensation, and should be distinguished with care from
+the regular and peculiar N. W. wind, as they may be, by the continued
+depression of the barometer, and the character of the scud. They are
+doubtless magnetic storms.
+
+The remaining surface wind, the N. W., the genuine Boreas of our climate,
+the invariable fair-weather wind, is one of great interest. It is unique
+and peculiar. It is not the left-hand wind of a rotary gale, and has no
+immediate connection with the storm. I have known it blow moderately,
+fifteen successive days in winter; rising about ten A.M., and dying away
+at nightfall. Occasionally, but very rarely indeed, a light wind exists
+from the N. W. during a storm, owing probably to a focus of intensity in
+relation to some surface the storm covers, like the focus which exhibits
+itself as a clearing-off shower near the close of a storm; but the real
+fair-weather Boreas is a different affair altogether. Let us observe with
+care its peculiarities; they are instructive.
+
+1st. It rarely blows with any considerable force beneath the trade while
+there are storm clouds, or any considerable condensation in it. It does
+not interfere with that reciprocal action which takes place between the
+trade and the earth, during approaching or existing storms. I have
+frequently seen it with its peculiar scud clouds in the N. W., waiting for
+the storm condensation of the trade to pass by, that full of positive
+electricity it might commence its sports; rushing and eddying along the
+surface, licking up the warm, south polar, electric rain, which stood in
+pools upon the ground, or rose in steamy vapor from the surface, and with
+its cool breath dry up the muddy roads as no degree of heat can dry them.
+
+The annexed figure (14) shows the appearance of the northern edge of a
+stratus storm cloud, passing off E. N. E. at the close of the storm, which
+was "_clearing off from the north-west_." It is from a daguerreotype view,
+looking W. N. W., taken at eight o'clock in the morning, in the fall of
+the year. Near the horizon maybe seen the N. W. scud, forming in the N. W.
+wind, which is about to follow the retreating edge of the storm cloud.
+
+Figure 15 is from a daguerreotype view, taken at eleven o'clock the same
+day, when the storm cloud had passed off and its edge remained visible
+only south of the zenith, and the north-east scud had risen up and covered
+the northern half of the sky, and the wind was blowing a gale from that
+quarter.
+
+
+[Illustration: Fig. 14.]
+
+
+Another view was taken about two P.M. of the same day, when the scud had a
+very dark, gloomy appearance--as _dark_ and _gloomy_ as those of a Mexican
+norther--too dark to represent by a cut.
+
+Not unfrequently in a moist summer season, after a day of showers or rain,
+which have had an extending formation or lateral extension from north to
+south, it will commence blowing in the morning, and encourage the
+hay-maker with the hope of fine weather. But often before noon, the milky
+stratus condensation above with cumuli below, will appear in the trade;
+the N. W. wind die away and variable airs from the east or south appear,
+to be followed toward night by an enlargement of the cumuli and showers.
+It rarely, if ever, blows fresh till the storm condensation of the trade
+has passed; or continues to blow after that condensation reappears. When
+it commences blowing after a storm, and the northern edge of the storm is
+not over us, we may frequently see the latter low down in the S. E.
+passing eastward.
+
+
+[Illustration: Fig. 15. NORTH VIEW.]
+
+
+2d. Its scud are peculiar. Every one, probably, has noticed them. They are
+distinct, more or less disconnected, irregular, with every form between
+those of the easterly scud, cumulus, and stratus, according to the season.
+If large, with _dark under surfaces_; forming _rapidly_ and as _rapidly
+dissolving_; rarely dropping any rain, sometimes dropping a flurry of
+snow, in November or March, oftener than at any other period; sailing away
+to the S. E., and casting a traveling shadow as they pass on over the
+surface of the earth. Their electricity, particularly when white, is
+probably always positive, as that of all whitish clouds is supposed to be.
+
+3d. _It is emphatically a surface wind._ The incident storm winds, the N.
+E. and S. E., frequently _commence blowing_ under the storm, toward its
+point of greatest intensity, _up near the line of cirro-stratus
+condensation_, evidenced by the running scud; or blow there with most
+rapidity, and so continue for hours before the whole surface atmosphere
+from thence to the earth becomes involved in the movement; and sometimes
+without being felt below at all. Not so with the N. W. wind; it _begins at
+the surface_ and blows there with more rapidity than above; it seems to be
+attracted by the earth; it interposes between the earth and the trade,
+wedging the trade up and occupying its place. It blows under at all
+seasons of the year, but most readily and strongly from a surface of snow
+whose electricity is always positive. Hence it blows most strongly and
+_continuously_ when snow has fallen at the north, and prevails during
+winter very much in proportion to the extent and continuance of the
+covering of snow which invests the earth in that direction. It follows
+after storms, and particularly warm rains, during the autumn, winter, and
+spring months, which have a lateral southern extension. Whether it is
+increased by the snow from the surface from which it blows, or is caused
+by the same magnetic action which causes the great fall of snow, is a
+question we shall consider hereafter.
+
+4th. It does not connect or mingle with the trade current in any way, or
+change or divert the course of that current; but interposes between it and
+the earth, elevating the trade in proportion to its own volume, above the
+influences of the earth (when the trade becomes free from condensation,
+and singularly, clear); and raising _proportionately_ the barometer. An
+experienced observer can frequently estimate, with considerable accuracy,
+the rise of the barometer, by measuring with his eye, (when the clouds
+will enable him to do so,) the depth of this interposed N. W. current. The
+barometer rarely rises after a storm, for twenty-four or forty-eight hours
+if the wind continues at any point from S. W. to W. N. W., but always
+rapidly as soon as the genuine N. W. current with any considerable depth
+interposes and elevates the trade.
+
+It will be obvious to every one, I think, certainly, if they will
+hereafter study the subject and observe for themselves, that the N. W.
+wind does not blow away the storm; and that it follows after it, blowing
+over the surface which is uncovered by the storm; rarely, if ever, with
+any force when the body of the storm passed south of us; and that it is a
+purely surface wind, seemingly attracted by the peculiar magneto-electric
+state in which the surface of the earth is left, compared with a snow-clad
+surface to the north, by a recent storm, or that peculiar state of the
+trade which is left by the action of the storm. It seems to follow that
+magnetic wave which, passing from north to south, acts in its course upon
+the counter-trade, producing the storm, or belt of showers, and giving
+them their southern lateral extension, and will well repay future
+telegraphic investigation. Its electricity is intensely positive--that of
+the earth by the action of the storm as intensely negative.
+
+5th. This N. W. wind occurs in all parts of the northern hemisphere, so
+far as we have data to determine, and its corresponding wind from the S.
+W. occurs in the southern hemisphere. It is identical with a class of the
+northers of the Gulf of Mexico, as a brief analysis of the character of
+the latter will show.
+
+1st. The fall and winter _norther_ is a dry wind without rain or falling
+weather--so is our N. W. wind.
+
+2d. It is preceded by a falling barometer; S. E. scud and rain at the
+point where it blows, or to the eastward of it. So is ours when it blows a
+gale in the fall and spring months, which bear the nearest resemblance in
+climatic character to the periods when the northers blow. With this
+distinction, however, that our precedent rains either pass over us or to
+the southward, the direction of storms being E. N. E.; their precedent
+storms passing over or to the eastward of them as they move more to the
+northward.
+
+3d. It is often preceded by a copious dew; so is ours--such dews often
+following light fall rains in our climate, and preceding N. W. wind.
+
+4th. The most peculiar characteristic, however, is that the barometer
+rises rapidly and invariably while the norther prevails, and very much in
+proportion to its violence. The same is true of our genuine N. W. wind,
+and is not true _of any other wind_ on this continent which I have
+observed or read of.
+
+5th. While they are thus alike in these respects, they are unlike in no
+respect.
+
+Mr. Redfield has traced them in _supposed_ connection with storms which
+continue from that vicinity across the United States to the E. N. E., and
+endeavored to connect them with those storms, as the left-hand winds of a
+rotary gale. Obviously, I think, they are identical with our N. W. winds
+which also _follow_, indeed, but _are distinct from the storms_.
+
+There are a class of northers in the Gulf of Mexico--the "Nortes del Muero
+Colorado"--sometimes occurring in the summer months, beginning at N. E.,
+veering about and settling at N. N. W., and as they decline hauling round
+by the west to the southward. These winds correspond precisely with the
+hurricane winds of the West Indies, and are doubtless the incident winds
+of a storm traveling thence to the N. N. W. precisely as our N. E. or E.
+N. E gales are incident storm winds to the N. E. storms of our latitude.
+
+In this connection we will look at the peculiarities of a West India
+hurricane.
+
+"It is not a little remarkable," says Mr. Espy, speaking of the storms and
+hurricanes of the West Indies, "that all these storms, and _all others
+which have been traced to the West Indies_, traveled N. W. almost at right
+angles to the direction of the trade-wind in those latitudes, but very
+nearly, if not exactly, in the direction of an upper current of the air
+known to exist there toward the N. W." Substantially the same facts have
+been repeated by Mr. Redfield, and demonstrated by his able
+investigations, both there and in the Eastern Pacific, and are confirmed
+by the observations of Edwards, Lawson, and others, while residents there.
+It is a matter of surprise that gentlemen like Messrs. Redfield and Espy,
+who have certainly displayed great ability in the investigations of
+meteorological phenomena, should fail to recognize a more intimate
+relation between this upper current and the storms they were
+investigating, and to detect the general laws which govern both. The
+storms and hurricanes of the West Indies are comparatively of small
+diameter, and have little advance condensation. When they pass on to the
+south-western portion of North America and curve to the N. E., as they
+frequently do, they enlarge in front and at the sides, and their advance
+condensation, which is not dense enough to drop rain, extends in some
+cases from one to three hundred miles; and the storm itself, by the time
+it reaches the Alleghanies, may extend one thousand to fifteen hundred
+miles, and perhaps in certain magnetic states of the surface, and
+occasionally, may cover the entire portion of the continent, from north to
+south. Such, probably, was very nearly the extension of the storm
+investigated by Professor Loomis. In the West Indies, however, at the
+commencement, they vary from twenty to one hundred miles, or possibly
+more, in width.
+
+First, they are preceded by a hot, sultry and oppressive atmosphere--_as
+are electric storms every where_--a peculiar electric state of the earth
+and adjacent air.
+
+Second, the black clouds and lightning which indicate the approaching
+hurricane are seen to the S., S. E., and E. S. E., according to the season
+of the year, as we see them at the westward. During the rainy season, and
+when the storm, as is usual at that period, is small, and the S. E. trade
+blows more eastwardly, the wind at the Windward Islands, possibly, may set
+in at the north, and back round by the east as it progresses. So Colonel
+Reid thinks it sometimes does, at Barbadoes. But when the belt of rains is
+south, and the hurricane comes from the south-east, and is larger and more
+violent in its action, and the north-east winds prevail, the first effect
+is an increase of these trades. Soon, however, the wind hauls to the north
+and north-west, in opposition to its course, bearing the same relation to
+it that our east and north-east winds bear to storms in the United States;
+and the wind hauls around during the passage of the storm to the west,
+south-west, and south-east, and at the latter point it clears off. Mr.
+Edwards in his History of Jamaica says--and as a resident, his authority
+should be decisive as to this Island--"_that all hurricanes begin from the
+north_, veer back to the W. N. W., W., and S. S. W., and when they get
+around to the S. E. the foul weather breaks up." Doubtless the same is
+true of the class of northers of which we are speaking on the Gulf of
+Mexico. _But with this class the barometer does not rise during the gale,
+and in proportion to its length and violence._ With the other class of N.
+W. winds--the northers of winter--it does.
+
+The following description of two winter northers, copied from Colonel
+Reid's valuable work, will illustrate what has been said. _Precisely such
+changes from S. E. rains to N. W. winds, with blue sky and detached dark
+clouds--fair-weather N. W. scud--occur every autumn in October and
+November_, and the falling of the thermometer and rising of the barometer,
+after rain, and a change of the wind, are perfectly characteristic.
+
+  ------------------------------------------------------------------------
+   1843.  |   Wind.    |Force.|Weather.| Bar.|Ther.|
+  ------------------------------------------------------------------------
+  Jan. 30.|            |      |        |     |     |
+  A.M. 4. |S. S. W.    |  2   |b. c.   |29.90|  77 |Off Tampico.
+  Noon.   |South.      |  5   |b. c. r.|29.86|  76 | {Lat. 23° 41' N.,
+  P.M. 8. |South.      |  6   |b. c. r.|29.84|  76 | {Long. 94° 50' W.
+  Jan. 31.|            |      |        |     |     |
+  A.M. 4. |S. Easterly.|  3   |b. c.   |29.90|  74 | {Between 6 and 10
+          |            |      |        |     |     | {A.M., wind was
+          |            |      |        |     |     | {variable.
+  Noon.   |N. by W.    |  9   |c. q. w.|29.96|  76 |Norther commenced at
+          |            |      |        |     |     |  10 A. M.
+  P.M. 8. |N. N. W.    |  9   |c.      |30.09|  73 |Lat. 22° 36' N.,
+          |            |      |        |     |     |  Long. 95° 48' W.
+  Feb. 1. |            |      |        |     |     |
+  A.M. 4. |N. N. W.    |  7   |c. g.   |30.29|  63 |Lat. 22° 9' N.,
+          |            |      |        |     |     |  Long. 94° 50' W.
+  Noon.   |Westerly.   |  6   |c.      |30.30|  67 |
+  P.M. 8. |Calm.       |  0   |c.      |30.26|  67 |
+  ------------------------------------------------------------------------
+  Feb. 14.|            |      |        |     |     |
+  A.M. 4. |S. E.       |  3   |b. c. r.|29.66|  73 |At Sacraficios.
+  Noon.   |S. W.       |  4   |b. c.   |29.62|     |Norther comc'd at 5.30
+          |            |      |        |     |     |  P.M.
+  P.M. 8. |N. W. by N. | 10   |c. q. u.|29.72|  65 |
+  Feb. 15.|            |      |        |     |     |
+  A.M. 4. |N. W. by N. | 10   |c. q. u.|30.10|  61 | {Gale moderated and
+          |            |      |        |     |     | {again freshened
+          |            |      |        |     |     | {about 8 A.M.
+  Noon.   |N. W. by N. | 10   |c. g. q.|30.19|  61 |
+  P.M. 8. |N. W.       |  4   |c. g.   |30.20|  65 |
+  Feb. 16.|            |      |        |     |     |
+  A.M. 4. |N. W.       |  3   |q.      |30.18|  62 |
+  P.M. 8. | N. N. W.   |  2   | c. g.  |30.21|  66 |
+  ------------------------------------------------------------------------
+
+  b. indicates blue sky--c. detached clouds--r. rain--v. visibility of
+  objects--q. squalls--w. wet dew--u. ugly threatening appearance--g.
+  gloomy weather.
+
+The exact counterpart of the first norther may be observed with us every
+fall. On the 30th January, with a rising thermometer and falling
+barometer, there was rain at midday. The night following was moist--the
+next day, about ten A.M., the wind came out N. W., with squalls and gloomy
+weather, a falling thermometer, and rising barometer.
+
+The norther of Feb. 14th differed from the other only in regard to the
+time of the day when it commenced; the order of events was the same. The
+rain fell in the night--it cleared off early in the day, and the norther
+followed in the afternoon. This also is frequently the case with us, as
+every one may observe.
+
+This brief notice of the surface winds of our climate would be incomplete
+without a description of those of the thunder-gust and tornado.
+
+The former is exceedingly simple. The showers, which are accompanied with
+much wind, form suddenly in hot weather, and have a considerable advance
+condensation (frequently with obvious lateral internal action), extending
+eastwardly from the line of smooth cloud from which the rain is falling,
+or rather where the falling rain obscures the inequalities of the cloud.
+_The gust is never felt until the advancing condensation has passed over
+us_, when it takes the place of the gentle easterly breeze which
+previously set toward the shower. _The gust ceases as soon as the cloud
+has passed._ It is obviously the result of the inducing and attracting
+influence of the cloud upon the atmosphere near the surface of the earth
+as it passes over it. Let the reader watch attentively this advance
+condensation, from its eastern edge to the line of smooth cloud and
+falling rain, and he will understand at a glance this internal action of
+gust-clouds. The whole phenomena are simple and intelligible. A cloud
+approaching from a westerly point, dark and irregular from its eastern
+edge to the line of falling rain, where it appears smooth and of a light
+color; wind from the east blowing gently toward it, till the condensation
+is over us; then the gust following the cloud; then the rain, and in a few
+minutes the cloud, and wind, and rain have passed on to the east, and
+"sunshine" returns.
+
+The tornado, as it is termed when it occurs upon land, "spout," if on the
+water, is sometimes of a different character, and as it undoubtedly had
+great influence in inducing the gyrating theory of Mr. Redfield, and the
+aspiratory theory of Mr. Espy, and has been cited by both in support of
+their respective theories, it deserves a more particular notice. There are
+several marked peculiarities attending it which determine its character.
+
+1st. It occurs during a _peculiarly sultry and electric_ state of the
+trade and surface atmosphere, and at a time when thunder showers are
+prevailing in and around the locality, and at every period of the year
+when such a state of the atmosphere exists. One recently occurred in
+Brandon, Ohio, in midwinter.
+
+2d. There is always a cloud above, but very near the earth, between which
+and the earth the tornado forms and rages. It is usually described as a
+black cloud, ranging about 1000 feet or less above the earth, often with
+a whitish shaped cone projecting from it, and forming a connection with
+the earth; at intervals rising and breaking the connection, and again
+descending and renewing it with devastating energy. Its width at the
+surface varies from forty to one hundred and eighty rods--the most usual
+width being from sixty to ninety rods. Sometimes when still wider, they
+have more the character of thunder-gusts, and are brightly luminous.
+
+3d. Two motions are usually visible, one ascending one near the earth and
+in the middle, and a gyratory one around the other. The latter is rarely
+felt, or its effects observed, near the earth. Occasionally, and at
+intervals, objects are thrown obliquely backward by it.
+
+4th. It is composed, at the surface of the earth, of _two lateral
+currents_, a northerly and southerly one, varying in direction, but
+normally at right angles in most cases, although not always, with its
+course of progression, extending from the extreme limits of its track to
+the axis; which currents are most distinctly defined toward the center,
+and upward. These currents prostrate trees, or elevate and remove every
+thing in their way which is detached and movable. There does not seem to
+be any current in advance of these lateral ones tending toward the
+tornado, save in rare and excepted cases, and then owing to the make of
+the ground or the irregular action of the currents; nor any following,
+except that made by the curving of the lateral currents toward the center
+of the spout as it moves on, and perhaps a tendency of the air to follow
+and supply the place of that which has been carried upward and forward,
+like that of water following the stern of a vessel. The south current is
+always the strongest, and often a little in advance of the other, and
+covers the greatest area. The proportion of the two currents to each other
+is much the same that the S. E. trades bear to the N. E. This excess in
+volume and strength of the southerly current will explain the
+irregularities in most cases, and the fact that objects are so often
+_taken up and carried from the south to the north side_, and so rarely
+from the north and carried south of the axis. These irregularities are
+such as attend all violent forces, and something can be found which will
+favor almost any theory; but the two lateral currents appear always to be
+the principal actors, except, perhaps, when it widens out and assumes more
+the character of a straightforward gust. See a collection by Professor
+Loomis, American Journal of Science, vol. xliii. p. 278.
+
+The following diagram is a section of the New Haven tornado, from
+Professor Olmstead's map accompanying his article in the "American Journal
+of Science and Art," vol. 37. p. 340.
+
+The manner in which the main currents flow is shown by their early and
+unresisted effect in a cornfield, as represented by the dotted lines. The
+direction in which the fragments of buildings were carried by the greater
+power of the southerly currents is shown also. And so is this irregular
+action, where a part of the southerly current broke through the northerly
+one, and prostrated two or three trees backward on the north side of the
+axis.
+
+
+[Illustration: Fig. 16.]
+
+
+5th. This cloud, and its spout, move generally with the course of the
+counter-trade in the locality--_i. e._, from some point between S. W. and
+W., to the eastward, but occasionally a little south of east, deflected by
+the magnetic wave beneath the belt of showers.
+
+6th. Several exceedingly instructive particulars have been observed and
+recorded.
+
+_a_. _No wind is felt outside of the track_, as those assert who have
+stood very near it, and its effects show.
+
+_b_. The track is often as distinctly marked, where it passed through a
+wood, as if the grubbers had been there with their axes to open a path for
+a rail-road. The branches of the trees, projecting within its limits, are
+found twisted and broken off, or stripped of their leaves, while not a
+leaf is disturbed at the distance of a foot or two on the opposite side of
+the tree, and outside of the track.
+
+_c_. As the spout passes over water, the latter seems to _boil up_ and
+_rise to meet it_, and _flow up_ its trunk in a _continued stream_.
+
+_d_. As it passes over the land, and over buildings, fences, and other
+movable things, they appear to _shoot up_, instantaneously, as it were,
+into the air, and into fragments. If buildings are not destroyed or
+removed, the doors may be burst open _on the leeward side_, and gable ends
+_snatched out_, and roofs taken off on the _same side_, while that portion
+of the building which is to the windward remains unaffected.
+
+_e_. Articles of clothing, and other light articles, have been carried out
+of buildings through open doors, or chimneys, or holes made in the roofs,
+and to a great distance, without _any opening_ being made for the air to
+_blow_ in.
+
+_f_. If there be a discharge of electricity up the spout from the earth,
+like that of lightning, the intense action ceases for a time or entirely.
+
+_g_. Vegetation in the track is often scorched and killed, and so of the
+leaves on one side of a tree, which is within the track, while those on
+the other side, and without the track remain unaffected. (Espy's
+Philosophy of Storms, 359, cited from Peltier.)
+
+_h_. The active agent whatever it is, has been known to _seize hold of a
+chain attached to a plow_ and _draw the plow about, turning the stiff sod
+for a considerable distance_. (See Loomis on the tornado at Stow, Ohio,
+American Journal of Science, vol. xxxiii. p. 368.)
+
+_i_. In passing over ponds, the spout has taken up all the water and fish,
+and scattered them in every direction, and to a great distance.
+
+_j_. The barometer falls very little during the passage of the spout. (See
+the Natchez hurricane of 1827, Espy page 337.) Not more than it
+_frequently_ does during gentle showers.
+
+_k_. Persons have been taken up, carried some distance, and if not
+projected against some object in the way, or some object against them,
+have usually been _set down gently and uninjured_.
+
+_l_. Buildings which stood upon posts, with a free passage for the air
+under them, although in the path of the tornado, escaped undisturbed.
+(Olmstead's account of the New Haven tornado, American Journal of Science,
+vol. xxxvii. p 340.)
+
+_m_. A chisel taken from a chest of tools, and stuck fast in the wall of
+the house. (Ibid.)
+
+_n_. Fowls have had all their feathers stripped from them in an instant
+and run about naked but uninjured.[5]
+
+_o_. Articles of furniture, etc., have been found torn in pieces by
+antagonistic forces.
+
+_p_. Frames taken from looking-glasses without breaking the glass. Nails
+drawn from the roofs of houses without disturbing the tiles.
+
+_q_. Hinges taken from doors--_mud taken from the bed of a stream_ (the
+water being first removed), and let down on a house covering it
+completely--a farmer taken up from his wagon and carried thirty rods, his
+horses carried an equal distance in another direction, _the harness
+stripped from them_, and the wagon carried off also, _one wheel not found
+at all_. (American Journal of Science, vol. xxxvii. p. 93.)
+
+Pieces of timber, boards, and clapboard, driven into the side of a hill,
+_as no force of powder could drive them, etc., etc._
+
+Now to my mind, these circumstances indicate clearly, that it is not wind,
+_i. e._, mere currents of air, which produces the effect, but that a
+_continuous current_ or _stream of electricity_ from the earth to the
+cloud exists, and carries with it from near the earth, such articles as
+are movable: That this stream collects from the _northerly_ and
+_southerly_ side upon the _magnetic meridian_, in _two currents_ with
+_polarity_, which meet in their passage up at the center; curving toward
+the center in the posterior part as the spout moves on, when acting in a
+normal manner, and making the "_law of curvature_" observed: That no
+conceivable movement of the air alone in such limited spaces could produce
+such effects; or if so, that no agent but electricity could so move the
+air: That the air in a building could not shoot the roof upward, and into
+fragments; much less could the air in a cellar by any conceivable force,
+be made to elevate _or shoot up_ the entire house, and its inmates, and
+contents--effects so totally unlike what takes place in gales,
+hurricanes, and typhoons: That elastic free air never did nor could take
+hold of the plow chain, and plow up the ground; or scorch and kill the
+vegetation; or twist the _limbs_ from one side of a tree, while the most
+delicate leaves on the other, and within two or three feet, remained
+unaffected and undisturbed; or pick the chickens: That even if the
+expansion of the air could produce these effects--if a sudden vacuum were
+produced--_nothing but currents of electricity could produce the sudden
+vacuum_, by removing the air above.
+
+It is well settled that atmospheric electricity can and does flow in
+currents with light, by experiments in relation to the brush discharge,
+etc. That it may do so without light or disruptive discharge, and in a
+stream, or as it is termed, by convection, with the force and effect seen
+in the tornado, is perfectly consistent with what we know of it--and it
+is, I think clearly evinced that such is the character of the phenomena,
+by the fact that a sudden powerful _disruptive_ discharge, _with light, up
+the spout_, produces an instantaneous partial or total suspension of its
+action; to be renewed as the cloud passes over _another_ and more highly
+charged _portion_ of the _earth's surface_. Peltier gives instances where
+the spout has been entirely and instantaneously destroyed by such a sudden
+and powerful discharge of electricity; marking the spot where it was so
+destroyed by a large hole in the earth, from which the discharge issued.
+And in fact these tornados are often steadily luminous, and so much so,
+when they occur in the night, as to enable persons to read without
+difficulty.
+
+The lateral inward and upward currents, are accompanied, after they meet
+and unite, or seem to unite, by gyratory or circular ones. How are they
+produced? This question can only be answered by analogy. No permanent
+impressions are left by the circular currents, except to a limited extent,
+and in occasional instances; and observation of them has been, and must
+necessarily be limited and uncertain. I have witnessed one or two on a
+moderate scale; but owing to the suddenness of their passage, and the
+confusion of the objects taken up, it was difficult to determine what the
+circular currents were. When the southerly current is much the strongest,
+it appears sometimes to cross the axis, and curve round the northerly one.
+Perhaps this may be all the curving that really takes place, except at the
+posterior part of the axis, for evidence of a curving on the south of the
+axis is rarely, if ever seen.
+
+Assuming, however, that the main currents unite and form one from the
+earth to the cloud, _induced_ circular currents would be in perfect
+keeping with the known laws of electricity. Such currents, and with
+magnetic properties, are always induced by powerful currents of voltaic
+electricity passing through wires. And doubtless _in all cases_ powerful
+currents of electricity _induce attendant circular currents_. This may
+account for the external gyration of the spout.
+
+Or it may be that the two lateral currents of air which attend the
+currents of electricity, do not unite; having opposite polarity, but pass
+by and around each other, in connection with the circular magnetic
+currents. Future observation and perhaps experimental research will
+determine this. But it may not be accomplished by the present generation;
+for the belief that tornados are mere whirlwinds, produced by the action
+of the sun in heating the land, is adhered to, notwithstanding they cross
+the intense magnetic area of Ohio in mid-winter, and seems to be
+ineradicable.
+
+The proportions of different winds vary in different localities. For the
+benefit of those who are curious, I copy a table from an able compilation
+by Professor Coffin, published by the Smithsonian Institute, showing the
+proportion of the winds at New Haven (the station nearest to me). It will
+be noticed that during the year the N. W. winds blow the greatest number
+of days; the S. W. next; the N. E. and S. E. less than either, and about
+equal. It may be observed that the two latter bear about the same
+proportion to the whole, that our number of cloudy and stormy days,
+averaging about ninety, bear to the whole number of days in the year.
+
+  +------------------------------------------------+
+  |Course.| 1804. | 1811. | 1812. | 1813. | Total. |
+  |------------------------------------------------|
+  | N.    |  143  |  105  |   90  |  111  |   449  |
+  | N. E. |   99  |  207  |  138  |  138  |   582  |
+  | E.    |   33  |   18  |   22  |   23  |    96  |
+  | S. E. |  131  |  108  |  135  |  110  |   484  |
+  | S.    |   58  |   69  |  113  |   80  |   320  |
+  | S. W. |  224  |  255  |  153  |  261  |   893  |
+  | W.    |   81  |   69  |  102  |   57  |   309  |
+  | N. W. |  329  |  264  |  345  |  315  |  1253  |
+  +------------------------------------------------+
+
+This work of Mr. Coffin has been brought to my notice since the foregoing
+pages were written. The facts embodied in it will be found to comport with
+what I have observed and stated. In relation to the proportionate number
+of days in the year during which the wind blows from the different points
+of the compass at the several stations it is very full and able.
+
+But it has cardinal defects. It does not show the _main currents_ of the
+atmosphere. It treats the surface-winds, which are incidental, as
+principals. The direction of the main currents is indeed shown frequently
+by the mean course of the surface winds, but not uniformly or
+intelligibly. Nor does it distinguish between the fair weather and storm
+winds; nor always between the trade winds during their northern transit,
+and the variable winds north of the trade-wind region. Hence, the
+deductions derived from it disclose no general system, and sustain no
+theory, although many very important facts appear. Some of these,
+Professor Coffin found it difficult to reconcile with received theories,
+or satisfactorily explain. For instance, he found the prevailing winds of
+the United States, in Louisiana and Texas, S. and S. E.; in western
+Arkansas, and Missouri, southerly, and in Iowa and Wisconsin, S. W.,
+forming a curve, and evidently connected together.
+
+Thus, alluding to the winds west of the Mississippi, and between the
+parallels of 36° and 60°, he says:
+
+     "On the American continent, west of the Mississippi, there appears to
+     be more diversity in the mean direction of the wind, yet here it is
+     westerly at sixteen stations out of twenty, from which observations
+     have been obtained. The most peculiar feature in this region, is the
+     _line_ of southerly winds on the western borders of Arkansas and
+     Missouri. It seems to form a connecting link between the winds of
+     this zone and the south-easterly ones that we find south of it; and,
+     in some degree, to favor an idea that has been advanced, that there
+     is a vast eddy, extending from the western shore of the Gulf of
+     Mexico, to the eastern shore of the Atlantic; that the easterly
+     trade-winds of the Atlantic Ocean, when they strike the American
+     continent, veer northwardly, and then N. E., and thus recross the
+     Atlantic, and follow down the coast of Portugal and Africa, till they
+     complete the circuit."
+
+This mean prevalence of the curving winds indicates the course of the
+western portion of the concentrated counter-trade, of which we have so
+fully spoken, and to which that portion owes its rains and fertility.
+Doubtless the curve would have been traced somewhat further west, if
+observations had been obtained from more westerly stations.
+
+The idea of an eddy, to which Professor Coffin alludes, is of course
+unsound; that of a counter-trade, most fully confirmed; the curve
+corresponding with that of the regular rains and fertility as they are
+known to exist.
+
+Professor Coffin is a believer in the generally-received theory of
+rarefaction, as the cause of all winds. His work is published by the
+Smithsonian Institution, and the theory is, so far forth, nationalized.
+But he found it very difficult to reconcile all the facts he obtained,
+with the theory, and, possessing a truth-loving mind, he frankly admits
+it. Alluding to the prevalence of N. E. winds off the coast of Africa in
+the summer months, as shown by certain numbered wind-roses, he says:
+
+     "Nos. 81, 83, 86, and 91, have caused me much perplexity. The arrows
+     for the warmer months evidently indicate a point of rarefaction
+     situated to the _south_ or _south-west_, and yet all the observations
+     from which they were computed were taken within a few hundred miles
+     of the African coast and desert of Sahara; a region, the annual range
+     of whose temperature must be exceedingly great. The only way in which
+     I can account for a fact so astonishing, is, by supposing the
+     deflecting forces at these numbers to be secondary to the influence
+     which we see so strongly marked in Nos. 88, 89, and 90. Let us, then,
+     first devote our attention to these."
+
+(We have not space for the map of Professor Coffin, nor is it necessary to
+insert it. The numbers 81, 83, 86, and 91, refer to respective portions of
+the Atlantic, west of Africa, North of the Cape de Verdes, of 5° of
+latitude each, where the N. E. trades are drawing off from the coast. The
+Nos. 88, 89, and 90 refer to like portions _below_ the Cape de Verde,
+where the S. W. monsoons are found under the rainy belt; and the
+explanation of the distinguished author is an attempt to account for the
+blowing of the trades _from_ Sahara, by supposing them connected with the
+monsoons further south, which seem to blow toward it.)
+
+     "The intense heat of the Great Desert rarefies the air exceedingly
+     from June to October, inclusive, and hence the arrows of unparalleled
+     length (Plate XII.)," (showing the monsoon winds below the Cape de
+     Verdes,) "pointing toward it during those months, the longest being
+     longer than that which represents the most uniform of the
+     trade-winds, in the ratio of 104 to 89. The influence of this
+     rarefaction is sufficient to curve the powerful current of the
+     trade-winds in the manner exhibited on Plate VII. Nos. 89 and 90, and
+     to produce the not less remarkable change in No. 88, holding the
+     current back and retarding it, so that its progressive motion in the
+     _three_ months of July, August, and September united, hardly exceeds
+     that during any _one_ of the colder months of the year. But while
+     this is so, the trades on the western side of the Atlantic are
+     pursuing nearly their regular track, being but slightly affected by
+     these influences. As a consequence, the latter must leave, as it
+     were, a partial vacuum behind them, which is filled by air flowing in
+     from the north-east and south-east. This will account for the seeming
+     anomaly of having a somewhat strong deflecting force directed toward
+     mid-ocean, in the hottest part of the year, as in the numbers above
+     referred to. _And yet it may be very naturally asked, Why does not
+     the air from these parts supply the Great Desert directly, instead of
+     taking a circuitous route to supply the region that supplies it? A
+     question which, I confess, it seems difficult to answer._"
+
+(The italicization in the foregoing extract is mine).
+
+Here the worthy professor finds a fact inconsistent with the theory of
+rarefaction--viz.: that the winds blow off shore, and toward mid-ocean,
+opposite Sahara, and he is "perplexed and astonished." The theory,
+however, must be maintained, and one of those modifying hypotheses which
+have made meteorology such a complicated piece of patch-work, must be
+invented; some "deflecting forces" found. There is the Great Desert,
+bordering upon the ocean, north of the Cape de Verde Islands, for a
+distance of six hundred miles, widening as it extends inland, whose
+temperature, as he says, "_must be exceedingly great_;" and doubtless is
+so, and yet the air, instead of blowing in upon it in a hurricane, is
+actually drawing off from it, and blowing towards the S. W., where the
+water and air do not rise above 84°. Well may he be "perplexed and
+astonished."
+
+Turning south, however, to the distance of five hundred miles or more, he
+finds the S. W. monsoon winds, which in those months blow under the belt
+of rains, toward the land, in the direction of, but at a great distance
+from, Sahara. It is an easy matter to suppose that they reach the Great
+Desert and supply its vortex of rarefaction, inasmuch as they blow in a
+direction toward it, and distance is no impediment to supposition.
+
+Then it is necessary to _suppose_ that the S. E. and N. E. trades, at the
+south-west, draw so strongly to the westward as to create a partial vacuum
+to the S. W. of Sahara, which is filled by the winds which draw off shore,
+and then we have the supply brought from the distance of five hundred
+miles or more, by an ascending vortex, which creates a vacuum, and the air
+near the vortex taken away in _another_ direction by a _partial_ vacuum;
+and so an ascending _vortex_, which creates a vacuum is supplied from a
+distance, and a _partial vacuum_ at a distance is supplied by the air near
+the perfect vacuum. Such an idea of a supply by a circuitous route, and
+secondary influence, is not very philosophical, to say the least, and
+Professor Coffin feels it; and to the question, Why is it so? which, he
+says, may very naturally be asked, he confesses there is no answer. And
+there would be none, even if his suppositions were based upon facts. But
+other questions might be asked equally difficult to be answered, viz.:
+
+1st. Is there any rarefaction which can draw the trades to the west, and
+in that particular locality, in opposition to the supposed vortex of
+Sahara, by creating a _partial vacuum_?
+
+2d. Are they in fact so drawn?
+
+3d. Do the S. W. winds, south of the Cape de Verdes, and _under the rainy
+belt_, which in the summer months extend up to these islands, _reach the
+desert at all_?
+
+These are pertinent questions, _and every one of them must be answered in
+the negative_. The hypothesis is without foundation, and Professor's
+Coffin's perplexity and astonishment must remain, until he abandons the
+theory of rarefaction entirely. The winds which so perplex him are nothing
+but the regular N. E. trades, made to originate on the coast and continent
+of Africa, in summer, by the northern transit of the whole machinery. They
+not only draw off from the desert coast, but they _blow over the desert
+itself_ on to the ocean, and into the rainy belt upon the land, as we have
+already seen, and the supposed vortex of rarefaction does not exist.
+
+That the monsoons do not reach the desert is demonstrated by the tables of
+Professor Coffin, and to set it at rest we will make the necessary
+extracts. Commencing with the region from the equator to 5° N., and from
+10° to 55° W. longitude, we have the observed winds in proportion, as
+follows, for July and August--the south-east trades prevailing, inasmuch
+as the belt of rains is at this season situated further north.
+
+LATITUDE 0° TO 5°, LONGITUDE FROM GREENWICH 10° TO 55°.
+
+  +-------------------------------------------------------+
+  | Course. | July. | August. | Course. | July. | August. |
+  |-------------------------------------------------------|
+  | North.  |    0  |     0   | S. S. W.|    54 |    111  |
+  | N. N. E.|    8  |     2   | S. W.   |     1 |     29  |
+  | N. E.   |    6  |     2   | W. S. W.|     6 |     19  |
+  | E. N. E.|   27  |    16   | West.   |     2 |      9  |
+  | East.   |   31  |    20   | W. N. W.|     1 |      6  |
+  | E. S. E.|  120  |    96   | N. W.   |     1 |      0  |
+  | S. E.   |  216  |   276   | N. N. W.|     0 |      2  |
+  | S. S. E.|  218  |   443   | Calm.   |     8 |      4  |
+  | South.  |   69  |   279   |---------------------------|
+  |         |       |         |  Total  |   768 |  1,314  |
+  +-------------------------------------------------------+
+
+Here, it is evident that the S. E. trades are the prevailing winds, but
+their course is variable.
+
+Ascending to the region between 5° and 10° north latitude, and 10° to 55°
+west longitude, the northern part of which at this season is covered by
+the rainy belt; we find the monsoon, the S., S. S. W., and S. W. winds,
+the prevailing ones in August, although the winds are variable, as usual
+under the rainy belt.
+
+  +-------------------------------------------------------+
+  | Course. | July. | August. | Course. | July. | August. |
+  |-------------------------------------------------------|
+  | North.  |   19  |     6   | S. S. W.|   188 |    368  |
+  | N. N. E.|   26  |    11   | S. W.   |    63 |     94  |
+  | N. E.   |  104  |    32   | W. S. W.|    73 |     93  |
+  | E. N. E.|   30  |    16   | West.   |    33 |     48  |
+  | East.   |   45  |    29   | W. N. W.|    30 |     18  |
+  | E. S. E.|   36  |    40   | N. W.   |    21 |      9  |
+  | S. E.   |   93  |    53   | N. N. W.|    17 |     13  |
+  | S. S. E.|  225  |   307   | Calm.   |   109 |     74  |
+  | South.  |  239  |   514   |---------|-------|---------|
+  |         |       |         |  Total  | 1,351 |  1,725  |
+  +-------------------------------------------------------+
+
+Ascending to the region of 10° to 15° north latitude, and 15° to 45° west
+longitude, we find the winds exceedingly variable, and the monsoons
+diminished remarkably. If Professor Coffin's theory was correct, they
+should increase as they approach the desert; but they in fact, diminish,
+and the N. E. trades are found at the north portion.
+
+  +-------------------------------------------------------+
+  | Course. | July. | August. | Course. | July. | August. |
+  |-------------------------------------------------------|
+  | North.  |   17  |    55   | S. S. W.|    30 |     71  |
+  | N. N. E.|   64  |    74   | S. W.   |    33 |     63  |
+  | N. E.   |   155 |   149   | W. S. W.|    19 |     43  |
+  | E. N. E.|    91 |    71   | West.   |    12 |     25  |
+  | East.   |    83 |    60   | W. N. W.|    17 |     21  |
+  | E. S. E.|    25 |    26   | N. W.   |    13 |     24  |
+  | S. E.   |    17 |    26   | N. N. W.|    24 |     56  |
+  | S. S. E.|    13 |    33   | Calm.   |    62 |     78  |
+  | South.  |     9 |    44   |---------|-------|---------|
+  |         |       |         |  Total  |   684 |    919  |
+  +-------------------------------------------------------+
+
+Ascending to the region between 15° and 20° north latitude, and 15° to 45°
+west longitude, we get north of the belt of rains _and lose the monsoons
+entirely although still below the desert_; and find the regular N. E.
+trades, with less variable winds than are found in almost any other part
+of the ocean.
+
+  +-------------------------------------------------------+
+  | Course. | July. | August. | Course. | July. | August. |
+  |-------------------------------------------------------|
+  | North.  |   39  |    20   | S. S. W.|     0 |      5  |
+  | N. N. E.|  210  |   185   | S. W.   |     0 |      5  |
+  | N. E.   |  112  |    87   | W. S. W.|     8 |      3  |
+  | E. N. E.|  114  |   104   | West.   |     0 |      1  |
+  | East.   |   20  |    36   | W. N. W.|     0 |      4  |
+  | E. S. E.|   21  |    17   | N. W.   |     3 |      4  |
+  | S. E.   |    0  |     2   | N. N. W.|     3 |     31  |
+  | S. S. E.|    2  |    11   | Calm    |    20 |      8  |
+  | South.  |    5  |     1   |---------|-------|---------|
+  |         |       |         |  Total, |   557 |    526  |
+  +-------------------------------------------------------+
+
+Ascending still further to the region between 20° and 25° north latitude,
+and 15° and 45° west longitude, which borders, in part, on the S. W.
+corner of the desert, and we have not, during the month of August, a
+single wind between S. S. E. and W. N. W., which blows in upon the land;
+and _only twelve instances out of three hundred and ninety-four in this
+hottest month in the year, and on the southern portion of the desert, when
+the wind blows on shore from any quarter_. This is demonstration. The
+monsoon winds are confined to the rainy belt; they do not reach the
+desert, nor does the desert attract the winds from the ocean, or
+reverse, hold back, or disturb the trades.
+
+  +-------------------------------------------------------+
+  | Course. | July. | August. | Course. | July. | August. |
+  |-------------------------------------------------------|
+  | North.  |   25  |    20   | S. S. W.|     3 |      0  |
+  | N. N. E.|  210  |   153   | S. W.   |     2 |      0  |
+  | N. E.   |  129  |    77   | W. S. W.|    13 |      0  |
+  | E. N. E.|  110  |    86   | West.   |     0 |      0  |
+  | East.   |    8  |    20   | W. N. W.|     0 |      3  |
+  | E. S. E.|    4  |    11   | N. W.   |     2 |      1  |
+  | S. E.   |    0  |     3   | N. N. W.|     5 |      8  |
+  | S. S. E.|    1  |     7   | Calm.   |     2 |      5  |
+  | South.  |    1  |     0   |---------|-------|---------|
+  |         |       |         |  Total, |   515 |    394  |
+  +-------------------------------------------------------+
+
+Ascending once more, to the region between the degrees of 25 and 30, north
+latitude, and 15 and 45, west longitude, we find it bounded east entirely
+on the center of the desert. Now here, certainly, there must be evidence
+of the truth of the rarefaction theory, if any where on the face of the
+earth. Yet here, in July and August, we find the trades as regular as any
+where, and not more variable winds than are found in the trades toward
+their northern limits every where, and in August, only forty out of four
+hundred and twenty-nine winds, blowing directly or indirectly on shore.
+
+  +-------------------------------------------------------+
+  | Course. | July. | August. | Course. | July. | August. |
+  |-------------------------------------------------------|
+  | North.  |   32  |    19   | S. S. W.|     9 |      6  |
+  | N. N. E.|  155  |   125   | S. W.   |     3 |      9  |
+  | N. E.   |  144  |    35   | W. S. W.|    13 |     14  |
+  | E. N. E.|  140  |    89   | West.   |    12 |      3  |
+  | East.   |   48  |    57   | W. N. W.|     7 |      7  |
+  | E. S. E.|   31  |    23   | N. W.   |    11 |      1  |
+  | S. E.   |    8  |     7   | N. N. W.|    36 |      6  |
+  | S. S. E.|    8  |    12   | Calm.   |    18 |     12  |
+  | South.  |    5  |     4   |---------|-------|---------|
+  |         |       |         |  Total, |   680 |    429  |
+  +-------------------------------------------------------+
+
+It would seem to be impossible for any man to believe in the theory of
+rarefaction, after an examination of these tables.
+
+Professor Coffin discovers other anomalies, for which he finds it
+difficult to account. Among these are the northerly tendency, in the
+afternoon, of the winds in Ohio, south of Lake Erie; the winds of
+south-western Asia, which, he says, "Are so irregular as to defy all
+attempts to reduce them to system;" particularizing the N. W. at
+Jerusalem, the westerly at Bagdad, the N. E. at Constantinople, the
+northerly at Trebizond, etc., etc. Jerusalem has the Mediterranean at the
+N. W., Bagdad has it at the west, Constantinople has the Black Sea at the
+N. E., Trebizond N. N. W. and N. E., and the counter-trade, as it passes
+over them, draws its storm-surface wind or sea-breeze, from the quarter
+where evaporation is greatest, and the atmosphere is most susceptible of
+electrical inductive influence. Precisely as it draws from the ocean and
+the eastward, east of the Alleghanies, from the lake region, west of the
+lakes, and from the northward, south of the lakes, and from the westward,
+east of them.
+
+This law of attraction will explain, too, the mean prevalence of easterly
+winds north of the parallel of 60°, at the stations named in his work.
+Great Bear Lake, Great Slave Lake, and Fort Enterprise, lie east of the
+Rocky Mountain range which interposes between them and the Pacific, and
+have Hudson's Bay and other large bodies of water on the east and north.
+Hence, easterly winds prevail at these places. At Norway House, on
+Nelson's River, near the north end of Lake Winnipeg, a large body of
+water, which stretches off to the south, we find the south wind the
+prevalent one, especially in December, when the northern and north-eastern
+waters are frozen up, and the N. E. largely present at all seasons of the
+year.
+
+At New Hernhut, in winter, when Davis' Straits are covered with floes, the
+prevailing wind is east, drawn from the warm, open sea east of Greenland,
+where the Gulf Stream is evaporating. But in June and July, when
+evaporation is going on over Davis' Straits and Baffin's Bay, the
+prevailing winds are west and south, and the east winds fall off.
+
+Other stations are equally instructive, but I must forbear.
+
+In relation, however, to the easterly zone of wind, of which Professor
+Coffin speaks, it should be added that the counter-trade, south of the
+magnetic pole, in high latitudes, pursues an easterly course, is near the
+earth, and attracts an opposite wind as it does on the east and north of
+the pole, in localities where the surface atmosphere is not peculiarly
+susceptible to its influence, and, therefore, the _winds are mainly
+opposite to its course_. Thus, at Melville Island, they are almost all
+westerly and north-westerly, for there the remnant of the counter-trade is
+passing west around the magnetic pole. These westerly and north-westerly
+winds are very light, and like the gentle easterly breeze which sets
+toward the cumulus clouds and summer showers.
+
+Since most of this work was written, I have procured, and read with great
+pleasure, Lieutenant Maury's "Geography of the Sea." It is a work of
+great interest, and should be in the hands of every one. The extent of
+ground covered, however, made it necessary for Lieutenant Maury to
+introduce much matter not derived from his own investigations. In doing
+this, he has taken received opinions, and has thereby introduced much
+heresy. The view he adopts in relation to the monsoons, although the
+popular one with philosophers, is of that character. He says (page 222):
+
+     "Monsoons are, for the most part, formed of trade-winds. When a
+     trade-wind is turned back, or diverted, by over-heated districts,
+     from its regular course at stated seasons of the year, it is regarded
+     as a monsoon. Thus, the African monsoons of the Atlantic, the
+     monsoons of the Gulf of Mexico, and the Central American monsoons of
+     the Pacific, are, for the most part, formed of the north-east
+     trade-winds, which are turned back to restore the equilibrium which
+     the over-heated plains of Africa, Utah, Texas, and New Mexico have
+     disturbed. When the monsoons prevail for five months at a time--for
+     it takes about a month for them to change and become settled--then
+     both they and the trade-winds, of which they are formed, are called
+     monsoons."
+
+Again (§ 476-7):
+
+     "The agents which produce monsoons reside on the land. These winds
+     are caused by the rarefaction of the air over large districts of
+     country situated on the polar edge, or near the polar edge, of the
+     trade-winds. Thus, the monsoons of the Indian Ocean are caused by the
+     intense heat which the rays of a cloudless sun produce, during the
+     summer time, upon the Desert of Cobi and the burning plains of
+     Central Asia. When the sun is north of the equator, the force of his
+     rays, beating down upon these wide and thirsty plains, is such as to
+     cause the vast superincumbent body of air to expand and ascend. There
+     is, consequently, a rush of air, especially from toward the equator,
+     to restore the equilibrium; and, in this case, the force which tends
+     to draw the north-east trade-winds back becomes greater than the
+     force which is acting to propel them forward. Consequently, they obey
+     the stronger power, turn back, and become the famous south-west
+     monsoons of the Indian Ocean, which blow from May to September
+     inclusive.
+
+     "Of course, the vast plains of Asia are not brought up to monsoon
+     heat _per saltum_, or in a day. They require time both to be heated
+     up to this point and to be cooled down again. Hence, there is a
+     conflict for a few weeks about the change of the monsoon, when
+     neither the trade wind nor the monsoon force has fairly lost or
+     gained the ascendency. This debatable period amounts to about a month
+     at each change. So that the monsoons of the Indian Ocean prevail
+     really for about five months each way, viz.: from May to September,
+     from the south-west, in obedience to the influence of the over-heated
+     plains, and from November to March inclusive from the north-east, in
+     obedience to the trade-wind force."
+
+What the "trade-wind force" is, Lieutenant Maury tells us in another
+paragraph, viz.: "Calorific action of the sun and diurnal rotation of the
+earth"--the received calorific theory. I have already shown, I think,
+conclusively, that there is no expansion and ascent in the supposed region
+of calms, which induces, or can induce, the trades; and that, in point of
+fact, the air on the land is cooler under the belt of rains. But as
+Lieutenant Maury, whose reputation is national, adopts the theory, I shall
+be pardoned for copying the following table, showing the difference of
+temperature at two cities of India, before, after, and while the belt of
+inter-tropical rains is over them. It will be seen that the temperature is
+actually less when the belt is there, viz., in July and August, than in
+April and May. _This should be conclusive upon that point._
+
+  +----------------------------------------------------+
+  |           |    Anjarakandy.    |     Calcutta.     |
+  |  Months.  |--------------------|-------------------|
+  |           |   Rain.  |  Temp.  |   Rain. |  Temp.  |
+  |-----------|----------|---------|---------|---------|
+  |           |    M. M. |         |    M. M.|         |
+  | January,  |    2,26  |  26°,5  |     0,0 |  18°,4  |
+  | February, |    2,26  |  27°,7  |   67,68 |  21°,5  |
+  | March,    |    6,77  |  28°,4  |   24,82 |  25°,6  |
+  | April,    |   29,33  |  29°,8  |  130,84 |  28°,5  |
+  | May,      |  175,96  |  28°,6  |   16,24 |  29°,7  |
+  | June,     |  794,05  |  26°,6  |  575,24 |  29°,3  |
+  | July,     |  807,59  |  25°,8  |  338,38 |  28,°1  |
+  | August,   |  572,98  |  26°,0  |  311,31 |  28°,3  |
+  | September,|  311,31  |  26°,4  |  254,91 |  28°,0  |
+  | October,  |  157,91  |  26°,8  |   42,86 |  27°,2  |
+  | November, |   65,42  |  26°,9  |   20,30 |  23°,0  |
+  | December, |   29,33  |  26°,5  |     0,0 |  19°,2  |
+  |-----------|----------|---------|---------|---------|
+  |     Year, | 2955,14  |  27°,2  | 1928,74 |  26°,4  |
+  +----------------------------------------------------+
+
+Anjarakandy is on the Malabar coast, between 12° and 13° north latitude.
+Calcutta in an angle of the Bay of Bengal, at 22° 30' north latitude. The
+former is in and near the focus of the monsoons, and has a temperature in
+July (when 18 inches of rain fall), about as low as in December.
+
+In the foregoing table from Kaemptz, the rain is in millimetres, about
+twenty-five of which make an inch, and the temperature is centigrade,
+which may be raised to Fahrenheit by adding four fifths of the quantity
+and also 32°--thus, if the height of the centigrade thermometer be 25°,
+add to this four fifths of 25°, which is 20°, and also 32°, the result is
+77°. Twenty-five centigrade is therefore equal to seventy-seven
+Fahrenheit.
+
+Lieutenant Maury is not, and should not be a theorist. He occupies the
+position, in some sort, of a national _investigator_, and, of course, of
+national _instructor_. Opinions which emanate from him, or which are
+endorsed by him, should be accurate. Sooner or later that which he has
+adopted in relation to the monsoons, and some others, must be abandoned.
+In addition to what has already been said, I wish to call his, and the
+reader's attention, to several other facts and considerations in relation
+to the monsoons, and particularly those of India.
+
+1st. The deserts of Cobi and Bucharia, which constitute the "burning
+plains" of _Central_ Asia, north-east of the Indian Ocean, lie between 38°
+and 45° of north latitude, and under the zone of extra-tropical rains.
+They are not wholly rainless. They partake of that saline character which
+affects so much of Asia and the western part of this continent. South of
+them, running nearly east and west, are the lofty ranges of the Himmalaya
+and Kuenlun Mountains, and the table lands of Thibet. To their saline
+character, in part, but mainly to the interposition of these mountain
+ranges, depriving the counter-trade of moisture, they owe their
+comparative sterility. _If bountifully supplied with rains, this salt
+would doubtless ere this have been washed to the ocean, as it has been
+from other countries, once as salt as they._ But they have some rain, and
+more or less vegetation, and are not intensely hot. They lie too far
+north, and are too elevated. Their temperature is not materially different
+from that of the western, and comparatively desert portions of our own
+country, and they are utterly incapable of creating a monsoon at the
+Indian Ocean, and especially from the long line of Malabar coast, where
+the south-west monsoons are found in most strength. The sterile portions
+of Utah, New Mexico, and Texas are alike incapable of such effect upon the
+atmosphere of Central America and Mexico. These monsoons commence in May,
+and prevail until October, and the temperature of the air where they blow
+ranges with considerable regularity between 76° at night, and 84° at
+mid-day, on the Malabar coast, and a trifle lower in Central America.
+
+     At Fort Fillmore, El Paso, New Mexico, in latitude 32°03, the mean
+     temperature for
+
+                     May        is     68°
+                     June       "      78°, 5'
+                     July       "      80°, 1'
+                     August     "      83°, 8'
+                     September  "      77°, 9'
+                                       -------
+     And for the whole period,         77°, 1'
+
+     At Santa Fé, New Mexico, the mean for
+                     May        is     66°, 9'
+                     June       "      72°, 5'
+                     July       "      75°, 3'
+                     August     "      72°, 9'
+                     September  "      62°, 3'
+                                       -------
+     And for the whole period,         69°, 3'
+
+     Mean of the two united,           73°, 2'
+
+The mean of Western Texas is about 2° higher than at Fort Fillmore, and of
+Utah not materially different; and the mean of _Central_ Asia between 38°
+and 45° does not materially vary from them.
+
+Now, it is perfectly evident that during May and September the temperature
+of Central Asia is far below that of the Indian Ocean and India, and never
+materially exceeds it. Central Asia is hot, "burning," if you please,
+compared with more elevated, fertile, or better watered territory _in the
+same latitude_, and so it has been characterized; but not so, compared
+with the Indian Ocean, or India, where the sun is vertical. During the
+greater part of the time, therefore, that the monsoons are in full blast,
+Utah, Texas, and New Mexico, and Cobi, and the burning plains of Asia, are
+from 5° to 10° colder than the temperature of the place where the monsoons
+are blowing. Would not such a fact be perfectly conclusive in any other
+science except theory-swathed meteorology?
+
+2d. The theory assumes that the heated air has an ascensive force, which
+causes it to rise and create a vacuum, and this vacuum, by its suction,
+draws in the adjoining air, which immediately ascends. The adjoining air,
+drawn away from its locality, leaves a vacuum, and that is filled by
+another rush from the S. W., and so on, till the Indian Ocean is reached,
+and the monsoons are accounted for.
+
+Now, look at the difficulties:
+
+The highest temperature that can be assumed for the air over Cobi, at any
+time, without disregarding facts and analogy, is 100°. What is the
+ascensive power of an area of atmosphere of 100°? For this we have no
+problem or formula, although problems and formulas abound in the science.
+Professor Espy relied on heated air only to give the storm a _start_. His
+main reliance was on the latent heat supposed to be given out during
+condensation, for his ascensive storm power. But over these "burning
+plains" there is, according to the theory, no storm or cloud, or
+condensation on which that supposed reliance for expansion can be placed.
+What, then, is the ascension force of air at 100°? _We ought to know, for
+we sometimes have it as high, or within two or three degrees as high, in
+all the eastern and middle States._
+
+The monsoons blow at from twenty to twenty-five miles an hour, and
+sometimes more. Is that the ascensive force of air at 100°? At 25 miles an
+hour it would be 2,200 feet; at 20 miles, 1,760 feet; and at 10 miles, 880
+feet per minute.
+
+Does any man believe that either current exists? Why, then, do we not have
+our hats taken off, or light objects carried up, or have a monsoon, or, at
+least, have the clouds running up, when we have such elevated
+temperatures. _Nothing of the kind occurs with us._ Our hottest days are
+comparatively still days; and I have seen the cumulus sailing gently to
+the east, horizontally, when the air was at 98°. Why should we be exempt?
+Is not our air the same and our heat the same?
+
+Again, suppose we grant that the ascensive force is equal to 20 or even 10
+miles an hour, will not the adjoining air hold back somewhat to avoid
+leaving behind an entire vacuum? or, will it all voluntarily rush in, and
+leave a new complete vacuum? and, if so, why the preference of vacuums by
+the air, and _when, where, and why_, should the _successive vacuums stop_?
+Nay, would not gravity fill the second vacuum from _above_, rather than
+from the south-west side? and will not the air incline to rush in, to some
+or all these successive vacuums, from some other side than south-west? or,
+have these deserts the power of selecting the quarter from which their
+vacuum shall be filled, and of delegating it to succeeding vacuums? Would
+it not incline to rush in from the east and west where there are no
+elevations, rather than from the S. W. and over the Kuenlun Mountains, the
+intervening ridges and valleys of Thibet, the lofty Himmalayas, the extent
+of India, and the Ghaut Mountains, from three to four thousand feet high,
+on its eastern coast? Would it not, at least, _leak in a little_, and
+lessen the force with which the vacuums would draw from the far-off Indian
+Ocean, so that the monsoon could not blow with equal force? or, if Cobi
+and its fellow deserts _must_ and _can_ draw from an _ocean_, why not from
+the head of the Arabian Sea, or Bay of Bengal, or the China Sea, which are
+nearer, or from the Japan Sea, which is still nearer, or the Yellow Sea,
+which is close by? Why draw only from under the central belt of rains?
+Nay, what shall be done with Professor Dove? In a recent article,
+republished in the American Journal of Science and Art, for January, 1855,
+he says: "A greatly diminished atmospheric pressure taking place in summer
+over the _whole continent_ of Asia must produce an influx from all
+surrounding parts; and thus we have west winds in Europe, north winds in
+the Icy Sea, east winds on the east coast of Asia, and south winds in
+India. _The monsoon itself becomes, as we see, in this point of view, only
+a secondary phenomena._" This looks very like _antagonism_. Who shall we
+believe?
+
+Again, suppose you get one atmosphere from the whole area, raised up by
+the supposed ascensive force, and at the rate of twenty-five, twenty, or
+even ten miles an hour, and a new volume drawn in from the south-west,
+and _over the mountains_: will it not take a _little time_ for _that_ to
+_heat up_? Does it heat so fast as to _keep up the ascensive force_
+without intermission, at twenty-five, or twenty, or ten miles the hour?
+What says Mr. Ericsson to this? Can he not arrange with a moderate lens,
+to move his engine with the rays of the summer sun? Nay, Lieutenant Maury
+says they can not heat up "_per saltum_, or in a day." But according to a
+reasonable calculation, they must heat up the air from 80°, or less, to
+100°, at the rate of 2,000 feet per minute. Heating 2,000 feet in depth,
+in the proportion of 20° per minute, night and day, for five months, is
+"_per saltum_" in a minute, and 1,440 "_saltums_" per day!
+
+And further still, the Indian Ocean, from which the monsoons are drawn to
+Cobi and Central Asia to the N. E., is during those months covered by the
+belt of calms and rains, as heretofore stated; and the S. E. trades
+blowing into it are attributed to the suction created by the ascent of
+heated air _there_. So, then, the monsoons are blowing away from under the
+rainy belt, from 500 to 1000 miles, to Cobi and the burning plains of
+Asia, while the ascensive force of that belt is such as to draw the S. E.
+trades toward the very spot, a distance of 1,200 or 1,500 miles, at 20
+miles an hour! What must the ascensive force over Cobi, etc., be, if, as a
+"stronger power," it can overcome an ascensive force over the Indian Ocean
+sufficient to draw the S. E. trades 1,500 miles, at 20 miles an hour; and,
+in addition to the force necessary to resist this central suction, not
+only stop or hold back the N. E. trade, but reverse it and draw it back,
+at 20 miles an hour, as a monsoon? Must it not be, at least, double that
+of the belt of calms, or the "great region of expansion," as Professor
+Dove calls it?
+
+Now, I am irresistibly tempted to ask whether a meteorological theory can
+be too absurd for credence, and whether it would not be as well to endow
+the deserts with ribs and lungs, and a proboscis long enough to reach the
+Indian Ocean, and the necessary power of inspiration and expiration? Such
+a theory would avoid all difficulties, conflict with no more analogies,
+and, in my judgment, be as much entitled to credit as the one to which
+meteorologists adhere.
+
+3d. North of the Malabar coast, in the north-west of India, lies an
+extensive desert. West of that is Beloochistan, with its rainless deserts.
+Further west are the rainless deserts of Arabia, and these three,
+including the Persian deserts further north, cover _as much surface_ as
+the deserts of Cobi and Bucharia--have the sun vertical in part, and
+nearly so over the entire surface--_are more intensely hot_, and lie
+within _one third of the distance_ which intervenes between that desert
+and the Indian Ocean off the Malabar coast, with _an open sea and_ no
+_mountains between_. Now, look at it. The north-west desert of India, and
+the rainless deserts of Beloochistan and Arabia _reverse no trade_ and
+_have no monsoon_, although the Arabian Sea heads right up among them.
+They do not attract one from the Indian Ocean off the Malabar coast,
+although not more than one third of the distance off, and without such
+mountains and table lands intervening as separate that coast from Cobi. It
+is said by Lieutenant Maury that the monsoons, "_obey the stronger
+force_." But which is the stronger force? Cobi, not _wholly_ rainless,
+lying north of 35°, under the zone of extra-tropical rains, with India and
+the Ghauts, the Himmalaya Mountains, the table lands of Thibet, and the
+Kuenlun Mountains between? or the deserts of India, Beloochistan, and
+Arabia, _wholly rainless_, and _intensely hot, near by_, and in _open
+view_. There can be but one answer to this question. Nothing in the way of
+desert barrenness, or elevated temperature, unless it be those of Sahara,
+can exceed the deserts about the head of the Arabian Sea and Persian Gulf.
+Certainly those of Cobi can not compare with them; yet the trades blow
+steadily over them, although more northerly there, as every where, near
+their northern limits, especially on land. Says Hopkins, in his
+atmospheric changes:
+
+     "If any one part of the broad expanse of the continent of Asia could
+     be heated so as to draw air from the Arabian Sea and the Indian Ocean
+     during the summer, it would be that part which lies between
+     Hindoostan and the Lake of Aral, including the region between the
+     Valley of the Oxus and Persia, and the land of this part, unlike
+     Hindoostan, is not screened from the sun by thick vapors. But what
+     says Burnes respecting the winds of this part? Why, that about the
+     latter end of June, though the thermometer was at 103° in the day,
+     'In this country a steady wind generally blows from the north.' And
+     on the 23d of August, after having passed the Oxus--'The heat of the
+     sand rose to 150°, and that of the atmosphere exceeded 100°, but the
+     wind blew steadily, nor do I believe that it would be possible to
+     traverse this tract in summer if it ceased to blow. The steady manner
+     in which it comes from one direction is remarkable in this inland
+     country.' Again--'The air itself was not disturbed but by the usual
+     north wind that blows steadily in this desert.' And he has many other
+     similar passages."
+
+Here there is a vast tract of country south of 35° which has a temperature
+often of 103°, and does not reverse the trade and create a monsoon. How
+utterly unphilosophical, then, to attribute the monsoons to Cobi because
+they "obey the stronger force!" or to attribute them to it at all.
+
+4th. The monsoons can not be _traced from_ the Malabar coast _to Cobi_.
+They do not exist on the south-west of Cobi and near it, where they should
+in greatest force, and there is no connection, in fact, shown between
+them. They do not often extend more than twenty-five miles inland, or to
+the east of the Ghauts. There are no corresponding intervening monsoons
+crossing India to the mountains--none over the mountains and table
+lands--none under the northern lee of the mountains--nor, in short, on the
+whole track, nor any S. W. winds except such as naturally belong to the
+action of the curving counter-trade.
+
+Finally, the investigations of Commodore Wilkes on Mauna Loa, a mountain
+upon Hawaii, more than 13,000 feet high, and the observations of Professor
+Wise and other aeronauts are sufficient to put this whole matter of heated
+lands and ascent of the atmosphere as the cause of winds, at rest.
+Commodore Wilkes was encamped for about _twenty days_ on Pendulum Peak, in
+December and January 1840. Although not up to the elevation of the
+counter-trade in that latitude, he was above the local clouds which form
+over the island during the day, where the sea breezes blow in with as
+great strength as any where. Indeed, he was on the top of the "lofty
+conical mountain" to which Caleb Williams alludes in the letter to
+Professor Espy I have quoted, and above the spot where Professor Espy
+assumed that the clouds were rising with such force as to induce the
+strong sea breezes of that island. During this time there were two
+snow-storms on Mauna Loa, and they had the wind from the S. W. during the
+storm, as might be expected, looking at the situation of the mountain on
+the western side of the island. These storms moved to the N. W., and were
+observed at the other islands in that direction as rain.
+
+The local clouds lay over the island every day, as they do over active
+volcanic islands which are very elevated, although it was the dry season.
+_Nothing like an ascent of the clouds or of the currents of air from the
+ocean was observed._ On the contrary, the clouds formed before the sea
+breezes set in, and the latter blew from the different sides of the island
+in under the clouds, and outward again, probably on the opposite side. The
+whole interior of the island is elevated, and its temperature low; and
+_there was no elevation of temperature on the high portions of the island
+over which the clouds formed, and toward which the winds blew, which could
+create an upward current_.
+
+     "During our stay on the summit, we took much pleasure and interest in
+     watching the various movements of the clouds; this day in particular,
+     they attracted our attention; the whole island beneath us was
+     covered with a dense white mass, in the center of which was the cloud
+     of the volcano rising like an immense dome. All was motionless until
+     the hour arrived when the sea-breeze set in from the different sides
+     of the island; a motion was then seen in the clouds, at the opposite
+     extremities, both of which seemed apparently moving toward the same
+     center, in undulations, until they became quite compact, and so
+     contracted in space as to enable us to see a well defined horizon; at
+     the same time there was a wind from the mountain, at right angles,
+     that was affecting the mass, and drawing it asunder in the opposite
+     direction. The play of these masses was at times in circular orbits,
+     as they became influenced alternately by the different forces, until
+     the whole was passing to and from the center in every direction,
+     assuming every variety of form, shape and motion.
+
+     "On other days clouds would approach us from the S. W. when we had a
+     strong N. E. trade-wind blowing, coming up with cumulus front,
+     reaching the height of about eight thousand feet, spreading
+     horizontally, and then dissipating. At times they would be seen lying
+     over the island in large horizontal sheets as white as the purest
+     snow, with a sky above of the deepest azure blue that fancy can
+     depict. I saw nothing in it approaching to blackness at any time."
+     (Exploring Expedition, vol iv. p. 155).
+
+Here, in the last paragraph, we have the whole truth disclosed. The N. E.
+trade was blowing on Mauna Loa, 13,000 feet above the sea, and the
+sea-breeze blew in on the _leeward side_, its moisture condensing over the
+volcanic island, but without rising _up the mountain_, or _through the
+surface-trade_, or _above 8,000 feet_.
+
+So, too, the celebrated aeronaut, Mr. Wise, in the course of more than a
+hundred ascensions, some during high wind, and others during rain storms,
+never met with an ascending current, except in a single instance, in the
+body of a hail-cloud, and then there were descending currents also, the
+usual intestine motion of hail-cloud with its opposite polarities.
+
+I copy a description of his passage through the clouds of a rain-storm,
+and his floating a long period above them; and there was no ascending
+current which disturbed their horizontal repose or progression. The double
+layer is not uncommon--condensation taking place at the connection of the
+upper and lower portions of the trades, with the surrounding atmosphere;
+or in the trade, and by _induction in the surface atmosphere_ at the same
+time. Such instances are frequently visible, and if his ascensions had
+been undertaken at other times in stormy weather he would have seen more
+of them.
+
+     "Before I passed the limits of the borough, a parachute, containing
+     an animal, was dropped, which descended fast and steady, and, just as
+     it reached the earth, my ærial ship entered a dense black body of
+     clouds. Ten minutes were consumed in penetrating this dismal ocean of
+     rainy vapor, occasionally meeting with great chasms, ravines, and
+     defiles, of different shades of light and darkness. When I emerged
+     from this ocean of clouds, a new and wonderfully magnificent scene
+     greeted my eyes. A faint sunshine shed its warmth and luster over the
+     surface of this vast cloud sea. The balloon rose more rapidly after
+     it got above it. Viewing it from an elevation above the surface, I
+     discovered it to present the same shape of the earth beneath,
+     developing mountains and valleys, corresponding to those on the
+     earth's surface. The profile of the cloud-surface was more depressed
+     than that on the earth, and, in the distance of the cloud-valley a
+     magnificent sight presented itself. Pyramids and castles, rocks and
+     reefs, icebergs and ships, towers and domes--every thing belonging to
+     the grand and magnificent could be seen in this distant harbor; the
+     half-obscured sun shedding his mellow light upon it, gave it a rich
+     and dazzling luster. They were really "castles in the air," formed of
+     the clouds. Casting my eyes upward, I was astonished in beholding
+     another cloud-stratum, far above the lower one; it was what is
+     commonly termed a "mackerel sky," the sun faintly shining through it.
+     The balloon seemed to be stationary; the clouds above and below
+     appeared to be quiescent; the air castles, in the distance, stood to
+     their places; silence reigned supreme; it was solemnly sublime.
+     Solitary and alone in a mansion of the skies, my very soul swelled
+     with emotion; I had no companion to pour out my feelings to. Great
+     God, what a scene of grandeur! Such were my thoughts; a reverence for
+     the works of nature, an admiration indescribable. The solemn
+     grandeur--the very stillness that surrounded me--seemed to make a
+     sound of praise.
+
+     "This was a scene such that I never beheld one before or after
+     exactly like it. Two perfect layers of clouds, one not a mile above
+     the earth; the other, about a mile higher; and, between the two, a
+     clear atmosphere, in the midst of which the balloon stood quietly in
+     space. It was, indeed, a strange sight--a meteorological fact, which
+     we cannot possibly see or make ourselves acquainted with, without
+     soaring above the surface of the earth." (History and Practice of
+     Aeronautics, p. 209).
+
+This is graphic. Perhaps in relation to the conformity of the upper
+surface of the inferior layer of clouds, to the irregularities of the
+earth's surface, he was misled during the enthusiasm of the moment. He is
+certainly mistaken as to the possibility of observing these double layers
+from the earth; I have seen them in hundreds of instances. But in relation
+to the _quiescence_ of the clouds for an hour, and _the entire absence of
+ascending currents_, he could not be mistaken.
+
+And now, in the absence of all direct proof to sustain the hypothesis,
+that the heating of the land produces ascending currents, and thereby the
+winds, and especially the monsoons, and in view of all the adverse
+evidence, I put it to Lieutenant Maury, and every sincere searcher after
+meteorological truth, whether the theory should not be abandoned.
+
+
+
+
+CHAPTER VII.
+
+
+The counter-trade of the northern hemisphere ranges at different heights
+in different latitudes, in the same latitude at different seasons, and
+also upon different days of the same season; and, like the line of
+perpetual snow, has its greatest elevation in the tropics, descending
+gradually to the surface of the ocean at the poles. At the northern limit
+of the N. E. trades, it does not, ordinarily, approach the earth
+sufficiently near for decided reciprocal action. Hence, at that point,
+storms do not often originate; the winds are lighter and more variable,
+and calms are more frequent than at any point, except at the meeting and
+elevation of the trades, or in the polar regions. Doubtless this state of
+things is increased by the feebler action of north polar magnetism, and
+the irregular action of the longitudinal magnetic currents, evinced by the
+irregular, and often, feeble action of the trades, near their extreme
+limits. They are not unfrequently wholly wanting, near the northern limit,
+for several days in succession, and calms and baffling winds are found in
+their place--another effect of the irregular action of terrestrial
+magnetism, consequent upon the ever-changing transit of central activity
+from south to north, and from north to south. Upon the islands, however,
+and continents, which have elevated mountain peaks and ridges, especially
+if of volcanic origin and activity, which approach more nearly the path of
+the counter-trade, a different state of things exists. There, showers and
+gusts are frequent. Thus, upon the Sandwich Island, Kauai, the most
+northern one, which is within the region of the N. E. trade during ten
+months of the year, and upon its volcanic peaks and elevated table-lands,
+and north-easterly from them, over the district of Waioli, rain falls in
+abundance during the year, while the coastlines upon other portions of the
+island can not be cultivated without irrigation. (See Wilkes' Exploring
+Expedition, vol. iv. pp. 61 and 71; and American Journal of Science and
+Art, for May, 1847).
+
+A like state of things, in degree, may be found upon the Canaries, and the
+more elevated of the West India Islands. The Cape de Verdes are an
+exception, and the Christian world are quite often called upon for
+contributions of provisions, to save the inhabitants of these islands from
+starvation. They lie at the northern limit of the equatorial belt, and for
+a period of two months only (July and August), are supplied with rain. If,
+from any cause, the belt does not move as far north as usual during any
+season, unbroken drought and famine are sure to overtake them. The islands
+contain some elevated peaks, and are of volcanic origin, but not of
+present volcanic activity, and the counter-trades as they issue from the
+equatorial belt at their highest elevation, are too far above them for
+reciprocal, influential action. If the islands could be placed 10° further
+north, we should hear no more of drought or famine from them, and their
+quantity of rain and fertility would be not only more permanent, but much
+increased. Superadded to this, is the fact, that at that point the belt of
+rains precipitates feebly because the S. E. trade originates upon the
+southern part of the continent of Africa, and the N. E. mainly, upon the
+desert and the Barbary States--and both are sparingly supplied with
+moisture.
+
+The same state of things is strikingly obvious upon continents wherever
+the mountains are sufficiently elevated, even within the trade-wind
+region. Thus, in South America, the Andean ranges are of great elevation,
+and spurs and table-lands extend from them a considerable distance to the
+eastward. There, the S. E. and N. E. trades of the Atlantic meet in very
+considerable volumes, and not only is the equatorial belt much wider than
+upon the Atlantic and Pacific, but the counter-trades are met upon the
+elevated peaks and mountain-ranges, and showers and storms on their
+eastern slopes and summits are frequent during the dry season--down even
+to the extra-tropical belt. I have already said that it was probable that
+the great elevation of the Andes diverted and turned south a portion of
+the N. E. counter-trade which would otherwise pass over the western coast
+of Peru.
+
+The report of Lieutenant Herndon, which has come to my notice since that
+was written, states facts which strongly corroborate that opinion. It
+seems that the trades and counter-trades actually _bank up_, in their
+passage to the westward, against those mountains, and the true elevation
+of their eastern slopes can not be barometrically ascertained. (See report
+of the Exploration of the Amazon, p. 261). Lieutenant Herndon says:
+
+     "I was surprised to find the temperature of boiling water at Egas to
+     be but 208° 2', the same within 2' of a degree that it was at a point
+     one day's journey below Tingo Maria, which village is several hundred
+     miles above the last rapids of the Huallaga river; at Santa Cruz, two
+     days above the mouth of the Huallaga, it was 211° 2'; at Nauta, three
+     hundred and five miles below this, it was 211° 3'; at Pebas, one
+     hundred and seventy miles below Nauta, 211° 1'. I was so much
+     surprised at these results that I had put the apparatus away,
+     thinking that its indications were valueless; but I was still more
+     surprised, upon making the experiment at Egas, to find that the
+     temperature of the boiling water had fallen 3° below what it was at
+     Santa Cruz, thus giving to Egas an altitude of fifteen hundred feet
+     above that village, which is situated more than a thousand miles up
+     stream of it. I continued my observations from Egas downward, and
+     found a regular increase in the temperature of the boiling water
+     until our arrival at Pará, where it was 211° 5'.
+
+     "From an after-investigation, I am led to believe that the cause of
+     this phenomenon arises from the fact that the trade-winds are dammed
+     up by the Andes, and that the atmosphere in those parts is, from this
+     cause, compressed, and, consequently, heavier than it is further from
+     the mountains, though over a less elevated portion of the earth. The
+     discovery of this fact has led me to place little reliance in the
+     indications of the barometer for elevation, at the eastern foot of
+     the Andes. It is reasonable, however, to suppose that this cause
+     would no longer operate at Egas, nearly one thousand miles below the
+     mouth of the Huallaga."
+
+The report of Lieutenant Gibbon, is also exceedingly instructive.
+Separating from Lieutenant Herndon at Tarma, upon the Andes, he pursued a
+southern course, along the eastern slopes of the chain from 11° 30'
+south, almost to 18° south, at Ohuro, making a journey of about 7° 30' of
+latitude.
+
+A considerable portion of this journey was over eastern and less elevated
+portions of the Andes; but little below, however, the line of perpetual
+snow. Here, during the dry season, he met with frequent showers and fogs
+from the eastward, but left them as he descended into the plains upon the
+table-land. There he found the dry season more distinctly marked; but
+occasional irregularities were found upon the table-lands, as every where
+upon corresponding elevations. The S. E. trades, however, were there
+obvious, during the dry season, notwithstanding the irregularities. The
+rainy season, from December to May, he spent at Cochabamba, and at its
+close he traveled north down the Madeira and its tributaries, to the
+Amazon. Although scarcely consistent with my prescribed limits, I can not
+forbear making a few extracts. Thus, when on the mountains, east of
+Huanvelica, in the N. E. counter-trade, he says:
+
+     "Our course is to the eastward. The snow-capped mountains are in
+     sight to the west. Temperature of a spring 48°; air 44°. Lightning
+     flashes all around us; as the wind whirls from _north-east_ to
+     south-west, rain and snow-flakes become hail, half the size of peas.
+     Thunder roars and echoes through the mountains; the mules hang their
+     heads, and travel slowly; the thinly-clad aboriginal walks shivering
+     as he drives the train ahead; the dark cumulus cloud seems to wrap
+     itself around us."
+
+Again, at the Bombam Post-house, in the focus of change from cirrus to
+cumulus, and stratus, and storm:
+
+     "The winds are very gentle, and curl the cirrus or hairy clouds in
+     most graceful shapes about the hoary-headed Andes, in rich and
+     delicate clusters; when the peak is concealed, all but the blue tinge
+     below the snow, we see a natural bridal vail. An _easterly wind_
+     lifts and turns them to dark, cumulus clouds, settled on the frosty
+     crown, like an old man's winter cap; the physiognomical expression is
+     that of anger. The change is accompanied by thunder, and seems to
+     command all around to clothe themselves for storms. The cold rain
+     comes down in _fine drops_ upon us; the day grows darker, and the
+     _clouds press close upon the earth_."
+
+During an excursion east of Cuzco--
+
+     "Turning from the river, we ascend a steep ridge of mountains--the
+     eastern range at last. A heavy mist _wafts upward as the winds drive
+     it against the side of the Andes_, so that our view is shortened to a
+     few hundred yards. We hope the curtain will rise that we may view the
+     productions of the tropical valley below; but the mist thickens, and
+     the day gets dark with heavy, heaped-up black clouds; a rain-storm
+     follows. The grasses are thrifty, and the top of the ridge covered
+     with a thick sod. By barometer, we stand eleven thousand one hundred
+     feet above the level of the sea."
+
+In May following, having spent the rainy season in Cochabamba, he travels
+north--
+
+     "Our route from Tarma to Oruro was south. We traveled ahead of the
+     sun. In December, when we arrived in Cochabamba, the sun had just
+     passed us. As soon as he did so, the rains descended heavily on this
+     side of the ridge; it was impossible to proceed. The roads were
+     flooded, the ravines impassable, and the arrieros put off their
+     journey until the dry season had commenced. After the sun passed the
+     zenith of Cochabamba, and had fairly moved the rain belt after him
+     toward the north, then we came out from under shelter, and are now
+     walking behind the rain belt in dry weather, while the inhabitants
+     are actively employed in tending their crops."
+
+So on the north of the equatorial belt, along the whole line of the Andes,
+up to the northern boundary of the desert valley of the Gila, rain falls
+on the high mountain-ranges, owing to the contiguity of the counter-trade
+and the diversion of showers to the north, along their eastern sides.
+
+During the survey of the boundary line between Mexico and California,
+etc., by the commission under Mr. Bartlett, it became necessary to find
+some spot where water and grass were abundant, for the head quarters of
+the commission. This was found, and _could only be found_, upon the
+Mimbres Mountains, at an old abandoned Spanish copper mine, 7,000 or 8,000
+feet above the level of the sea, surrounded with peaks of still greater
+height. These elevated ranges were within influential distance of the
+counter-trade, and here snow fell in the winter, from the extra-tropical
+belt, and rain, in showers, in summer, at the period of the most northerly
+extension of the tropical belt; when fifteen miles off, in the valley, it
+was unbroken drought. Mr. Bartlett thus describes it in his Personal
+Narrative:
+
+     "We reached this district on the 2d of May. Vegetation was then
+     forward, though there had been no rain. But it must be remembered
+     that during the winter there is snow, and hence a good deal of
+     moisture in the earth when the spring opens. The months of May and
+     June were moderately warm. On the third of July the first rain fell.
+     It then came in torrents, accompanied by hail, and lasted three or
+     four hours. Many of our adobe houses were deluged with water, and the
+     mountain-sides exhibited cataracts in every direction. The Arroyo,
+     which passes through the village, and which furnishes barely water
+     enough for our party and the animals, became so much swollen as to
+     render it difficult to cross; and, by the time it had received the
+     numerous mountain torrents, which fall into it within a mile from our
+     camp, it became impassable for wagons, or even mules. The dry gullies
+     became rapid streams, five or six feet deep, and sometimes fifty feet
+     or more across. On this day, a party, in coming to the copper mines,
+     from the plain below, _where there had been no rain_, found
+     themselves suddenly in a region overflowing with water, so that
+     their progress was arrested, and they were obliged to wait until the
+     flood had subsided. After this we had occasional showers, during the
+     months of July and August."
+
+The location of this mountain station is near the thirty-third degree of
+north latitude, while the northern limit of the equatorial belt, nowhere,
+except upon the mountain ranges and table-lands of Mexico, extends above
+25°.
+
+There, for the reason we have been considering, it does extend further
+north during July and August, in occasional showers, and in the vicinity
+of Mount Picacho, Mr. Bartlett met one of its mountain thunder-storms on
+the 13th of July, on his return south through Mexico, in latitude 32°, in
+the following year. (Personal Narrative, vol. ii. p. 285). These showers
+originated in strata of counter-trade, which had followed up along the
+eastern side of the mountains and not from strata which had crossed them
+and curved to the eastward, as is shown by the course of progression of
+the showers.
+
+Let us look, in this connection, at a fact or two of great interest,
+though not directly connected with the point in hand. The southern limit
+of the extra-tropical belt in winter, on the Pacific coast of North
+America, is in the vicinity of San Diego, at about 32°. In summer, that
+limit is carried up above Astoria, which is in latitude 46° 11'--about
+14°--yet New Mexico receives little if any rain in winter in the vicinity
+of Albuquerque, but does receive a limited supply of about seven inches in
+summer and autumn, five and a half inches of which falls in June, July,
+and August. Albuquerque is in latitude 35° 13', below the southern summer
+limit of the extra-tropical belt, and north of the northern limit of the
+equatorial belt. This anomaly is explained by the extension west over
+northern New Mexico, of the extreme western edge of our concentrated
+counter-trade, by reason of its issuing further west from the equatorial
+belt in its northern extension in the summer months. This western edge, in
+curving to the east, north-east of New Mexico, covers the north-western
+States, Iowa, Minnesota, Wisconsin, etc., and furnishes them that great
+excess of summer precipitation which is a peculiarity of their climate;
+and its absence further east in winter, and the very great elevation of
+the Rocky Mountains and other ranges over which their ordinary
+counter-trade of that season curves, account for the absence of much
+precipitation and snow there, or over the valley of the Rio Grande in New
+Mexico, in winter.
+
+We may now see, too, why the western coast and the Pacific region of the
+continent, below 45°, are so deficient in moisture. The S. E. trades,
+which arise from the western portion of the south Atlantic and the
+continent of South America, which, if it were not for the Andes chain, in
+their natural course, after passing the equatorial belt, would continue on
+to the north-west until they passed the limits of the N. E. trades, and
+curve in upon the western portion of our continent below 45°, and supply
+it bountifully with rain, are, in part, perhaps, diverted along the
+eastern side of those mountains to swell the volume of our counter-trade,
+and in part pass them, almost exhausted of their supply of moisture by
+their contiguous reciprocal action. Hence, too, the deficiency of
+precipitation at the base of the Andes, on the western side, and the
+peculiar and irregular character of the winds under the western lee of the
+Andean range. Baffling airs and bands of calms prevail on this portion of
+the Pacific, except where the mountains fall off, and then there is a
+westerly or south-westerly monsoon under the equatorial belt. Says
+Lieutenant Maury in his Charts, sixth edition, p. 731:
+
+     "The passage, under canvass, from Panama to California, as at present
+     made, is the most tedious, uncertain, and vexatious that is known to
+     navigators.
+
+     "My investigations have been carried far enough to show that at
+     certain seasons of the year a vessel bound from Panama to California,
+     must cross at least three, at some seasons four, such meetings of
+     winds or bands of calms, before she can enter the region of the N. E.
+     trades. Hence the tedious passage."
+
+Such will ever be the state of things on this continent and upon the
+eastern Pacific, so long as the S. E. counter-trades are compelled to pass
+over the mountain chain of South and Central America.
+
+Again, if we examine carefully the belt or zone of extra-tropical rains,
+we shall find that the focus of greatest precipitation is considerably
+north of its southern limit, and that, other things being equal, this
+focus travels north in summer, and gives to higher latitudes their needed
+summer rains. This is very apparent upon the north-western portion of our
+continent, as the following table will show:
+
+  +-----------------------------------------------------------
+  |                   | Lat.  |Jan.|Feb.|Mar.|Apr.|May.|June.|
+  |                   |-------|----|----|----|----|----|-----|
+  |San Diego, Cal.    |32° 41'| 0.3| 1.7| 1.1| 0.9| 0.5| 0.0 |
+  |San Francisco.     |37° 48'| 1.7| 0.5| 4.4| 2.1| 0.4| 0.0 |
+  |Cant., Far W., Cal.|39° 02'| 3.3| 0.6| 6.4| 2.2| 0.9| 0.0 |
+  |Astoria, Oregon.   |46° 11'|27.0|10.9| 6.1| 4.4| 5.9| 2.6 |
+  |Puget's S'd, Ore.  |47° 07'|11.8| 3.9| 4.7| 4.1| 0.8| 0.6 |
+  |Sitka, Russ. Am.   |57°  3'| 2.5| 9.6| 3.5| 3.3| 1.9| 5.9 |
+  +-----------------------------------------------------------
+
+                      ---------------------------------------+
+                      |July.|Aug.|Sept.|Oct.| Nov.|Dec.|Year.|
+                      |-----|----|-----|----|-----|----|-----|
+                      | 0.0 | 0.2| 0.0 | 0.1| 1.5 | 3.4|  9.6|
+                      | 0.0 | 0.0| 0.4 | 0.6| 3.0 | 5.5| 18.8|
+                      | 0.0 | 0.0| 0.3 | 0.1| 3.5 | 4.6| 21.9|
+                      | 0.0 | 2.3| 1.9 | 6.7|13.2 | 6.2| 87.2|
+                      | 0.5 | 1.3| 1.6 | 3.6| 5.9 | 6.1| 44.8|
+                      | 3.7 |10.1|14.8 |12.7| 7.4 | 4.2| 79.5|
+                      ---------------------------------------+
+
+  The figures are for inches and tenths of an inch of rain.
+
+Thus, it will be seen that in January, when the southern line is at San
+Diego, at the south line of California, the focus of precipitation is over
+Oregon; and that in August and September when the southern line is carried
+up and over Oregon, the focus has traveled north to Sitka, and that it is
+always at least 10° north of the southern line of the belt upon that
+coast. The increased quantities of rain which fall at the focus of
+precipitation there, from Oregon up, are doubtless much enhanced by the
+equatorial oceanic current which flows over opposite that part of the
+continent. A like effect, precisely, is produced in Europe. The quantity
+of rain which falls at Bergen, in Norway, being 87-61/100 inches per year,
+more than three times the average for that continent.
+
+The difference shown in the foregoing table, between Astoria and Puget's
+Sound, is owing to the fact that the latter lies in the interior and
+within the coast range of mountains, while Astoria is situated at the
+mouth of the Columbia River, with an open view of the ocean.
+
+A like comparative increase of precipitation in northern latitudes, in
+summer, is found every where varying according to the local influences
+which operate in the particular case. Thus,
+
+  ------------------------------------------------------------------------
+      There falls in               |Winter.|Spring.|Summer.|Aut'mn.| Year.
+  ---------------------------------|-------|-------|-------|-------|------
+  Burlington, Vt., lat. 44° 20'    |  5.7  |  7.3  | 11.4  |  9.8  | 33.9
+  Albany, N. Y.,   lat. 42° 39'    |  8.3  |  9.8  | 12.3  | 10.3  | 40.7
+  Minnesota, Iowa, lat. 41° 28'    |  7.3  | 12.3  | 17.4  | 11.7  | 48.8
+  St. Peters'g, Russ., lat. 59° 56'|  3.89 |  3.20 |  5.70 | 4.71  | 17.51
+  Pekin, China,    lat. 40°        |   .54 |  3.35 | 18.80 | 2.29  | 25.68
+  ------------------------------------------------------------------------
+
+Pekin lies in the northern part of China, and would have a much larger
+fall of rain from a concentrated counter-trade, but for the numerous
+mountain-ranges which intersect its path in winter, but over which it
+passes at a greater elevation during the summer--a peculiarity from which
+the eastern section of this country is most remarkably and happily free.
+
+Thus, it is obvious that the focus of precipitation in the zone of extra
+tropical rains, is some 8° to 12° north of its southern line, and travels
+with the whole machinery in its annual transit north and south.
+
+It is a question of some difficulty, perhaps, whether this focus is
+increased by the increase of magnetic action at this point, for both the
+line of descent of the counter-trade, and the focus of magnetic action,
+are carried up in a like manner, and for a like cause, and, in all
+probability, both concur in the result.
+
+There is exceeding wisdom in this provision for the gradual subsidence of
+the counter-trade, and gradual increase of magnetic intensity, and
+consequent gradual precipitation. On the European continent, and over
+western Asia, there are 50° of latitude to be supplied with moisture by
+this polar belt of rains. If the focus of precipitation was at its
+southern border, the counter-trade would be deprived of its moisture at
+that point, and little would reach the more northern portions of the globe
+which are to be supplied by it. But the movement of the whole machinery
+carries up the southern line from the south boundaries of the Barbary
+States on to the Mediterranean and portions of southern Europe, and the
+focus of precipitation and of near approach of the counter-trade to the
+earth, being situated far north of the southern line, is carried up
+correspondingly, while the combination of the moisture with the atmosphere
+by south polar magnetism and electricity, and the gradual descent of the
+counter-trade, enable it to resist, to some extent, the influence of north
+polar magnetism and cold, and thus retain portions of its moisture for
+distribution in the polar regions.
+
+_The elevation of the counter-trade above the earth varies in the same
+latitude with the variations in the phenomena of the weather._ An
+attentive observation of the clouds of our climate will soon satisfy any
+one of this, after he has become familiar with them, so as to distinguish
+with certainty the clouds of the trade. Its range, in this country, is
+from 3,000 feet, or less, to 12,000 feet above the earth, and its depth
+with us probably, from 6,000 to 8,000 feet. Gay-Lussac, in his scientific
+experimental balloon ascension, the first of _that character_ ever made,
+except an imperfect one just previous, by himself and Biot, found it at
+about 12,000 feet over Paris, and about 4,000 feet in depth. It is
+detected by the thermometer when much elevated.
+
+The atmosphere grows cool as it is ascended on mountains, or by balloons.
+The rate of cooling is ordinarily about 1° of Fahrenheit for every 300
+feet. If it were not for the equatorial current, this progressive decrease
+of temperature would doubtless be perfectly uniform. Of Gay-Lussac's
+ascension, on this point it was said:
+
+     "At forty minutes after 9 o'clock, on the morning of the 15th
+     September, 1804, the scientific voyager ascended, as before, from the
+     garden of the repository of models. The barometer then stood at 30.66
+     English inches, the thermometer at 82° Fahrenheit, and the hygrometer
+     at 57-1/2°. The sky was unclouded, but misty.
+
+     "During the whole of this gradual ascent, he noticed, at short
+     intervals, the state of the barometer, the thermometer, and the
+     hygrometer. Of these observations, amounting in all to twenty-one, he
+     has given a tabular view. We regret, however, that he has neglected
+     to mark the times at which they were made, since the results appear
+     to have been very materially modified by the progress of the day. It
+     would likewise have been desirable to have compared them with a
+     register, noted every half hour, at the Observatory. From the surface
+     of the earth to the height of 12,125 feet, the temperature of the
+     atmosphere decreased regularly, from 82° to 47° 3' by Fahrenheit's
+     scale; _but afterward it increased again, and reached to 53° 6' at
+     the altitude of 14,000 feet_; evidently owing to the influence of the
+     warm currents of air which, as the day advanced, rose continually
+     from the heated ground. From that point the temperature diminished,
+     with only slight deviations from a perfect regularity. At the height
+     of 18,636 feet the thermometer subsided to 32° 9', on the verge of
+     congelation; but it sunk to 14° 9' at the enormous altitude of 22,912
+     feet above Paris, or 23,040 feet above the level of the sea, the
+     utmost limit of the balloon's ascent."
+
+The high range of the barometer indicated a very considerable elevation
+of the trade at the time Gay-Lussac made his ascension. I am not aware
+that it has since been found at so great an elevation, in so high a
+latitude, though it is undoubtedly elevated by the interposition of a
+large volume of N. W. air, upon some occasions, to nearly the same
+altitude with us.
+
+In the extract in relation to the ascension of Gay-Lussac, we have another
+of the thousand hastily-adopted and absurd hypotheses connected with the
+caloric theory. It is obviously and utterly _impossible_ that in addition
+to the ordinary accumulation of heat at the surface of the earth "_as the
+day advanced_"--that is, _during the forenoon_, warm currents should
+ascend, unobserved by Gay-Lussac during an ascent of 12,000 feet--not
+_affecting in the least_ so large an intervening body of the atmosphere or
+his thermometer, and in such immense volumes as to increase the warmth of
+a stratum of 4,000 feet in depth, an average of 3° of Fahrenheit, and to
+the extent of 6° at the center.
+
+Very few balloon ascensions have been made with a view to scientific and
+accurate observation. But other aeronauts have met the counter-trade at
+different altitudes, and in both clear and stormy weather.
+
+Recently, in 1852, four ascensions were made in England, under the
+direction of the Kew Observatory Committee, of the British Association. I
+copy from the August number of the "London, Edinburg, and Dublin
+Magazine," for 1853, the following condensed amount of the result:
+
+     "The ascents took place on August 17th, August 26th, October 21st,
+     and November 10th, 1852, from the Vauxhall Gardens, with Mr. C.
+     Green's large balloon.
+
+     "The principal results of the observations may be briefly stated as
+     follows:
+
+     "Each of the four series of observations shows that the progress of
+     the temperature is not regular at all heights, but that at a certain
+     height (_varying on different days_) the regular diminution becomes
+     arrested, and for the space of about 2,000 feet the temperature
+     remains constant, or even increases by a small amount. It afterward
+     resumes its downward course, continuing, for the most part, to
+     diminish regularly throughout the remainder of the height observed.
+     There is thus, in the curves representing the progression of
+     temperature with height, an appearance of _dislocation_, always in
+     the same direction, but varying in amount from 7° to 12°.
+
+     "In the first two series, viz.: August 17th and 26th, this peculiar
+     interruption of the progress of temperature is strikingly coincident
+     with a _large_ and _rapid fall_ in the temperature of the
+     _dew-point_. The same is exhibited in a less marked manner on
+     November 10th. On October 21st a dense cloud existed at a height of
+     about 3,000 feet; the temperature decreased uniformly from the earth
+     up to the _lower_ surface of the cloud. When a slight rise commenced,
+     the rise continuing through the cloud, and to about 600 feet above
+     its upper surface, when the regular descending progression was
+     resumed. At a short distance above the cloud, the dew-point fell
+     considerably, but the rate of diminution of temperature does not
+     appear to have been affected in this instance in the same manner as
+     in the other series; the phenomenon so strikingly shown in the other
+     three cases being perhaps modified by the existence of moisture in a
+     _condensed_ or vesicular form.
+
+     "It would appear, on the whole, that about the principal plane of
+     condensation heat is developed in the atmosphere, which has the
+     effect of raising the temperature of the higher air above what it
+     would have been had the rate of decrease continued uniformly from the
+     earth upward."
+
+These gentlemen do not adopt the absurd explanation of the French
+philosophers; they account for the phenomenon by supposing heat to be
+_developed_ at that particular part of the atmosphere; but they are
+equally wide of the mark. They found the excess of heat there to the
+extent of 7° to 12°, and on days when there was no condensation, or other
+assignable cause for its _development_.
+
+The temperature of the counter-trade partakes, doubtless, of the
+temperature of the adjoining strata at its upper and lower portion, and
+has never been found much, if any, higher than 60° at the center. Nor
+could it be expected. The trade, in its upward curving course, within the
+tropics, attains a considerable altitude where the atmosphere is
+comparatively cold, and necessarily loses a portion of its heat there, and
+during its northern flow. Probably its central summer range, in the
+latitude of Paris, is not far from 55°, and with us 60°.
+
+The contrast between the trade and the surrounding atmosphere, in winter,
+is much more striking, and this has been observed particularly upon the
+Brocken of the Alps, and in the polar regions.
+
+"In all seasons the temperature is higher on the Brocken, on a serene,
+than on a cloudy day, and, in the month of January, _the serene days were
+warmer than at Berlin_." (Kämtz's Meteorology, by Walker, p. 217.--Note.)
+
+As the portion of the counter-trade, which does not become depolarized--in
+diminished volume--progresses toward the polar regions, it settles nearer
+the earth, and within the Arctic circle is found but little way above it.
+Thus, in December, 1821, Parry, at Winter Island, in latitude 66° 11',
+flew a kite, with a thermometer attached, to the height of 379 feet, and
+found that the temperature, instead of falling 1-1/4°, the usual ratio of
+decrease, rose 3/4 of a degree.
+
+The same thing was observed at Spitzbergen, in latitude 77° 30' north, and
+at Bosekop, latitude 69° 58', by a scientific commission, and by means of
+kites, confined balloons, and the ascent of elevations.
+
+     "In winter the temperature goes on increasing with the height, up to
+     a certain limit, which is variable, according to the different
+     atmospheric circumstances, the influence of which is not yet very
+     exactly known. The hour of the day appears to be indifferent, since
+     there exists no thermometric diurnal variation in the strata of the
+     surface. The mean of thirty-six experiments, made with kites, or with
+     captive balloons, at Bosekop, latitude 69° 58' north, has given a
+     mean rate of increase of 1° 6' for the first hundred meters.[6]
+     Beyond this limit, and even beyond the first 60 or 80 meters, the
+     temperature again becomes decreasing, at first very slowly, but
+     afterward the decrease is accelerated. The observations that have
+     been made on the flanks, or on the summits, of mountains, during the
+     same expeditions, entirely confirm these results. The cooling
+     influence of a soil, that radiates its own heat for several weeks,
+     without receiving any thing on the part of the sun, in compensation
+     of its losses, the influence of _counter-currents from above_, coming
+     from the west and the south-west, with a high temperature, account
+     for this anomaly, which, in winter, represents the normal state of
+     the most northern parts of the European continent." (Walker's Kämtz,
+     p. 515.--Note.)
+
+Mr. Walker is the only author, so far as I know, who has suspected the
+true cause of the phenomenon, viz.: "currents from above coming from the
+west and south-west, with a high temperature;" but the caloric theory
+"sticks like a burr," and he adheres also to the idea that a snow-clad
+surface, in the absence of the sun, can aid, by radiation, in warming the
+atmosphere for a distance of several hundred yards above it, increasing
+the warmth as the distance from the earth increases!
+
+This contrast between the counter-trade and the adjacent atmosphere, in
+winter, in latitudes as low as that of the Brocken, is probably heightened
+by the increased warmth of the former, at that season. The S. E. trades
+then form under a vertical sun, and the difference of temperature can not
+be less than from 6° to 8°. Not unfrequently in winter and spring the rain
+will fall with a temperature of 50° to 55°, when the atmosphere near the
+earth is 10° or 20° or more, below those points; and it is frozen to every
+object upon which it falls. The trade stratum, from which it descends, is
+not warmed by "radiation" or by ascending currents from a snow-clad
+surface, and during a cloudy day; nor by a "development of heat" at that
+particular altitude, but it has brought its heat from the South Atlantic,
+and imparts it to the rain which forms within it. There is every reason to
+believe that the counter-trade flows north in a regular descending plane,
+not materially differing from that of the line of perpetual snow. The
+descent of the latter is well ascertained to be from about 16,000 feet at
+the equator, to _the surface_ at the poles. The plane of the counter-trade
+is probably much the same, varying over different localities, from the
+varied action between it and the earth which we are considering; and
+probably both correspond with the increase of magnetic intensity.
+
+Lieutenant Maury, in an able and original article upon the circulation of
+the atmosphere, conceives the bands of comparative calms at the northern
+limits of the trades, which he appropriately terms the "_Calms of
+Cancer_," to be nodes in the circulation of the atmosphere, and that the
+upper or counter-trade here decends and becomes a surface wind from the S.
+W., as the N. E. trade is a surface wind; and that an upper current from
+the poles approaches and descends at the same node, to make the N. E.
+trade. But it is evident he adopted that conclusion too hastily, as he
+obviously did the conclusion that the calms of the horse latitudes were a
+type of all. We have seen that the latter are increased by a diversion of
+the counter-trade, and that they are avoided by making easting. So it may
+be observed that our upper current is a S. W. current, and no northerly
+upper current is visible, or exists over the country, however it may be in
+western Europe and the North Pacific, on the west of the magnetic poles,
+where cold, dry northerly and north-easterly winds are found. The origin
+and progress of storms withal demonstrates that no such node can exist.
+
+Two points have been made in relation to the course of the counter-trade
+in the tropics, and are relied upon to show its progress there to the N.
+E., which deserve consideration.
+
+In the first place, it is well known that "rain dust" falls in
+considerable quantities on the western coast of Africa, particularly about
+the Cape de Verde Islands, and also upon the Mediterranean and
+south-western Europe, where it is termed "sirocco dust."
+
+     "This dust," says Lieutenant Maury, "when subjected to microscopic
+     examination, is found to consist of infusoria and organisms, whose
+     _habitat_ (place of abode) is not Africa, but South America, and in
+     the S. E. trade-wind region of South America. Professor Ehrenberg has
+     examined specimens of sea dust, from the Cape de Verdes and the
+     regions thereabout, from Malta, Genoa, Lyons, and the Tyrol, and he
+     has found such a similarity among them as would not have been more
+     striking had these specimens been all taken from the same pile.
+
+     "South American forms he recognizes in all of them; indeed, they are
+     the prevailing form in every specimen he has examined.
+
+     "It may, I think, be now regarded as an established fact, that there
+     is a perpetual upper current of air from South America to north
+     Africa, and that the volume of air in these upper currents, which
+     flows to the northward, is nearly equal to the volume which flows to
+     the southward with the N. E. trade-winds, there can be no doubt,"
+     etc.
+
+Now, it is doubtless true that this dust is transported in a
+counter-trade, and that such dust is found in South America, and is taken
+up there by sand-spouts, like those of the ocean in form and action. Both
+Humboldt and Gibbon have graphically described them. Yet I do not think
+the point well taken. South-eastward of the Cape de Verdes, where the
+surface-trades--which, becoming counter-trades, pass over these islands,
+and, recurving, pass over the Mediterranean and south-western
+Europe--should originate, there is a vast extent of unexplored continent
+in the same latitude as the portion of South America where the dust is
+found; and the same dry seasons, and the same spouts, in all probability,
+exist in both. Until it be shown that such forms have no "_habitat_" in
+central and southern and unexplored Africa, upon the same latitudes as in
+South America, it may fairly be presumed that the dust is taken up there.
+Indeed, the _curve_ upon which this dust is found to fall, in the greatest
+quantities, is very remarkable, and corresponds remarkably with the _law
+of curvature_ of the counter-trade we have considered, and with the
+progress of a storm upon that coast, and over the Mediterranean,
+investigated by Colonel Reid. (See Reid, on Storms and Variable Winds, p.
+276.) This _curve clearly indicates the origin of the dust in South
+Africa_.
+
+The second point is, that ashes from the volcanos of Mexico and Central
+America have fallen to the north-east of the place where they were
+ejected. Mr. Redfield has grouped these instances of volcanic eruption
+usually cited, and I copy from him:
+
+     "We learn from Humboldt, that in the great eruption of Jorullo, a
+     volcano of southern Mexico, which is 2,100 feet above the sea, in
+     latitude 18° 45', longitude 161° 30', the roofs of the houses in
+     Queretaro, more than 150 miles north, 37° east from the volcano, were
+     covered with the volcanic dust. In January, 1845, an eruption took
+     place in the volcano of Cosiguina, on the Pacific coast of Central
+     America, in latitude 13° north, and having an elevation of 3,800
+     feet, the ashes from which fell on the island of Jamaica, distant 730
+     miles north, 60° east from the volcano. The elevated currents by
+     which volcanic ashes are thus transported are seldom or never of a
+     transient or fortuitous character; and these results, therefore,
+     afford us one of the best indications of their general course. Thus,
+     the progress of the higher portion of the trade-wind was marked by
+     the eruption of Tuxtla, latitude 18° 30', longitude 95°, which
+     covered the houses in Vera Cruz with ashes, at the distance of 80
+     miles north, 55° west, and also at Peroté, 160 miles north, 60° west.
+     The ashes from the volcano, at St. Vincent, which fell at Barbadoes,
+     and east of that island, in 1812, mark the course of a current from
+     the westward, which appears there at times, in the region of clouds,
+     and may, perhaps, be connected with the permanent winds on the
+     Pacific coast of Mexico."
+
+As to one of the instances cited in the foregoing paragraph, that of
+Tuxtla, it may be laid out of the case--the direction conforming
+substantially to the assumed course of the counter-trade at that point.
+St. Vincent lies W. N. W., or nearly so, of Barbadoes, and a N. W. or
+westerly surface-wind, prior to, and during storms, is common in the West
+Indies as the N. E. is here--both alike, blowing in opposition to the
+progressive course of the storm. There is nothing strange or peculiar,
+therefore, respecting that instance, or the existence of variable and
+especially S. W. currents, between the trades, with occasional partial
+condensation.
+
+The falling of the ashes from Cosiguina, upon Jamaica, has long and often
+been cited, as proof that in the West Indies the prevailing upper currents
+run from the S. W. But it has been ascertained that, _during the same
+eruption, ashes fell 700 miles to the westward, on the deck of the
+Conway_, a vessel then upon the Pacific Ocean. That case, therefore, does
+not prove the absence of the S. E. counter-trade at the time, but only the
+presence of another, and a different current above or below it--and it may
+have been either, and transient.
+
+So of the Jorullo instance. Investigation would probably have shown that
+ashes fell to the N. W., and that they were carried N. E. by a transient
+S. W. wind produced by the existence of a storm to the eastward, or one of
+those states of partial condensation of the counter-trade which often
+produce currents at greater distances without a storm. Not one of these
+cases disproves the existence of a S. E. counter-trade, and the invariable
+N. W. progression of the storms of those latitudes demonstrates it.
+
+Occasional anomalous currents, depending upon storm action at considerable
+distance, are found in our atmosphere, and doubtless are there also. Thus,
+although the N. W. wind is almost invariably a surface wind, I have, in a
+few instances, seen a N. W. set at a considerable elevation, converging
+toward a peculiarly stormy state of atmosphere far south of us, about the
+period of the spring equinox. And so in one or two instances I think I
+have seen light cirro-stratus clouds _above_ the counter-trade, when it
+ran very low, setting from the N. E., although the usual and almost
+invariable location of the N. E. wind is below the counter-trade and the
+stratus clouds of the storm. Aeronauts, too, have found these secondary
+currents beneath a serene and cloudless sky. Indeed, the S. E.
+counter-trade doubtless often induces a thin secondary current of S. W.
+wind between itself and the surface-trade, in the same manner that similar
+currents are induced with us, and every where.
+
+A question arises here of considerable interest, which, I confess, I can
+not answer to my own satisfaction. It is, whether there be, or not, _an
+eastern progression of the body of the atmosphere above the machinery of
+distribution_. I have thought there was, and that in set fair weather I
+had seen a peculiar kind of cirro-cumulus cloud, in patches, the small
+cumuli very distinct and rounded, moving due east, which indicated such a
+current. But I am not satisfied, from my own observation, that it is so,
+nor is it easy to determine the question. The moisture of evaporation
+rarely, if ever, ascends to any considerable elevation, and the upper
+strata must be very dry. Hence, condensation, if it takes place, is thin,
+and perhaps often undiscernable. Investigations upon mountains prove
+little, for the winds of the inferior strata rush up their sides and over
+them. It is an open question, and future observation may solve it. The
+prevailing opinion seems to be that there is. If the theory of Oersted, in
+relation to the circular currents of a magnet, be true, there should be
+such a progression produced by opposite secondary currents, unless,
+indeed, it be also true that those currents are inoperative at so great a
+distance, or their influence barely suffices to retain the attenuated
+atmosphere in its place. Perhaps the investigations of Ampère conflict
+with it. But it is worth while, I think, for philosophers to inquire
+whether the transverse position of the needle upon the wire is not the
+effect of the central _longitudinal_ currents, conforming to the circular
+currents of the wire, and whether it is not owing to the production of the
+same currents in a globe by the circular currents of Ampère, that the
+globe is magnetized, and the needles made to dip.
+
+
+
+
+CHAPTER VIII.
+
+
+It is exceedingly desirable, in a practical point of view, to understand
+the precise character of the reciprocal action which takes place between
+the earth and the counter-trade, and produces the varied phenomena which
+mark our climate. We have seen that the same laws, other things being
+equal, operate every where, and that analogies may be sought in the
+character of those phenomena elsewhere, under the same, or different,
+modifying circumstances. Looking, therefore, at the magneto-electric
+movable machinery as a whole, and its influence upon the atmospheric
+circulation and conditions, we find many facts which point to a primary
+action in the counter-trade, and others that point as significantly to a
+primary local-inducing-action in the earth. Let us briefly review those to
+which we have alluded, and advert to some others, and see what solution of
+the question they will justify:
+
+The belt of inter-tropical rains appears to be, in width, and amount of
+precipitation, and annual travel north and south, proportionate to the
+volume of trades which blow into it, the quantity of moisture they
+contain, and the elevation of the surface over which they meet.
+
+South America is the most thoroughly-watered country within the tropics,
+except, perhaps, portions of Hindoostan, Burmah, Siam, etc., on
+south-eastern Asia. The contrast between both, and Africa, as far as
+explored, and as shown by its rivers, is most obvious. The Amazon, alone,
+delivers more water to the ocean than all the rivers of Africa.
+
+Of the width of the belt of rains over Africa, in the interior, we know
+little. Its northern extension is less, by from 7° to 10°, than the same
+belt over South America, the West Indies, and Mexico. Probably its
+southern is also. Upon South America, the southern edge is carried down to
+Cochabamba, in latitude 18°, and probably to 25°, to the northern edge of
+the coast-desert of Peru, while it is rarely, if ever, found over the
+Atlantic below 7°, a difference of 12° to 20°. Over South America, too,
+the quantity of water which falls is also vastly in excess of that which
+falls upon the Atlantic. The main cause of these differences is obvious.
+The N. E. counter-trades which blow over Africa, originate on a surface
+which is rainless, as eastern Sahara, Egypt, Arabia, etc., or subject to a
+dry season by the northern ascent of the southern line of the
+extra-tropical belt, as the Barbary States, Syria, Persia, etc., and their
+supply of moisture is necessarily scanty. On the south, the S. E. trades
+originate, in part, upon the eastern portion of southern Africa, and, in
+part, upon the Indian Ocean, and from the latter source, and a portion of
+the Mediterranean, doubtless most of the water which falls upon Central
+Africa, is derived.
+
+The N. E. and S. E. trades which blow into the inter-tropical belt upon
+the eastern portion of the Atlantic, originate upon similar surfaces, and
+with like effect. Thus, the S. E. trades, in summer, are from the Southern
+portion of Africa, and the N. E., in part, from the Mediterranean; and, in
+winter, the N. E. from the deserts, Senegambia, Nigritia, etc., and the S.
+E., owing to the narrowing of the African continent, mainly from the South
+Atlantic and Indian Oceans. Going west, the belt widens, and its range
+increases until the Andes are reached; but under their lee, on the western
+side, a totally different state of things is found, and the belt of the
+coast becomes broken and irregular, as we have seen in the citation from
+Maury.
+
+The width, extension, and excessive precipitation of the belt, over South
+America, follow the same law. The South Atlantic widens out by the
+trending of the coast to the S. W., and furnishes a large area for the
+unobstructed formation and evaporative action of the S. E. trades. So the
+trending of the coast to the N. W., from 5° south to the northward, opens
+a large area for a like formation and action of the N. E. trades. No
+correspondingly favorable circumstances exist any where, except, perhaps,
+around Hindoostan, and there the fall of rain is very excessive in some
+places, as on the Kassaya hills, to the extent of 400 inches per annum. In
+addition to this, the magnetic line of no variation, and of greater
+intensity, which runs from our magnetic pole, obliquely, S. S. E., to its
+opposite and corresponding pole in the southern hemisphere, enters the
+Atlantic on the coast of North Carolina, and traverses it, and the eastern
+portion of South America, through the whole trade-wind region. The
+table-lands, and slopes, and high mountain peaks, meet the trades
+successively, as they go west, and the latter wrench from them, to an
+unusual extent, their moisture; depressing the line of perpetual snow, by
+an increase of quantity on the eastern sides, several thousand feet, as it
+is for a like cause depressed on the southern side of the Himmalayas. On
+the eastern slopes and tops of the Andes, as we have seen, and owing to
+their elevation, falls the moisture which, according to the working of the
+machinery, and the law of curvature, should bless the coast line of Peru
+and northern Chili, the eastern Pacific, northern Mexico, California,
+Utah, and New Mexico; and, while the Andes stand, the curse of comparative
+aridity must rest upon them all.
+
+Southern Chili, and western Patagonia are supplied by the N. E. trades,
+which originate in the West Indies, the Gulf of Mexico, and the Caribbean
+Sea, and the Pacific, off Central America, in the neighborhood of the Bay
+of Panama. But there, again, the same effect of elevation is seen. The
+mountain slopes of southern Chili and Patagonia are abundantly supplied,
+and their mountain ranges are drenched with rain, while eastern Patagonia
+and southern Buenos Ayres, under their lee, are comparatively dry. So the
+S. E. trades, which originate off the western coast of South America,
+curve in upon, and aided by the oceanic currents, supply, abundantly, the
+N. W. coast of this continent, north of California; and there, too, the
+coast, and its elevated ranges, receive, as we have seen, a very large
+proportionate supply of their moisture. Substantially, the same state of
+things, as far as circumstances permit, is reproduced upon Malaysia,
+Hindoostan, etc., and the interposition of arid New Holland upon the
+evaporating trade-surface may be distinctly traced upon south-western
+Asia. Deserts abound there; the Caspian Sea receives the drainage of a
+very large surface, without an outlet; their southern line of
+extra-tropical rains is carried up very far in summer, and their dry
+season is intensely hot. (See an article in the American Journal of
+Science, for July, 1846, by Azariah Smith.)
+
+Another fact in this connection is worthy of a moment's consideration. The
+magnetic equator, as sought by the dipping needle, is not coincident with
+the geographical one. Humboldt found it, on the Andes, at 7° 1' south, and
+it has been found still lower in the Atlantic. Over Africa it rises above
+the geographical equator, and descends again on the Indian Ocean. About
+midway the Pacific, it becomes coincident with the equator of the earth
+again. (See diagram, on page 83.) Perhaps it is not known, with certainty,
+why this is so. The south pole may be situated nearer the geographical
+pole than the north one--but this is not believed to be so, nor could it
+make the difference. The greatest southern depression of the magnetic
+equator is found where the lines of greatest intensity, and of no
+variation, are found; and at the more intense of these lines exists the
+greatest depression. From this, I think, it may be inferred that the
+needle is affected by the greater magnetic intensity of the northern
+hemisphere, to which it may yet appear the obliquity of the earth's axis
+is owing. However this may be, or whatever the cause, no marked effect is
+produced upon the trades. The S. E. trades, by reason of the greater
+extent of ocean-surface on which they originate, are every where the most
+extensive, regular, and forcible. The south polar waters, from which they
+rise, are every where trenching upon, and overriding, the north polar
+ones; and thus, by a most beneficent provision, the greater portion of the
+habitable surface is placed in the northern hemisphere, and the principal
+portion of the southern is left open to an extensive, active evaporative
+action, which supplies the northern habitable surface with a large excess
+of the needed moisture.
+
+The condensation, and consequent precipitation, which takes place at the
+passing of the trades, as we have already said, over the ocean and
+lowlands, takes place mainly in the day-time. Upon the table-lands and
+mountain-ranges, it often continues during the evening and night. The
+morning, and early part of the day, however, in tropical countries, are
+generally fair at all elevations.
+
+Storms also originate in the equatorial belt, and issuing forth in great
+volume and with great intensity of action, find their way up even within
+the Arctic circle. Those which pass over this continent, or the northern
+Atlantic, generally originate in the West Indies, some of them over the
+Caribbean Sea, some over the islands, and some over the open ocean to the
+east of them; and, nearly all the most violent, during the months of
+August, September, and October. It would seem most probable that the
+primary action in such cases was in the trades themselves, but it is by no
+means certain that such is the case. This is the class of storms of which
+Mr. Redfield has industriously investigated some twenty or more; Mr. Espy
+some, and Lieutenant Porter two. Their course, when very violent, is often
+more directly north than that of storms, however violent, which originate
+north of the calms of Cancer, owing, perhaps, to their greater
+paramagnetic character. This course I have myself observed, in several
+instances, about the period of the autumnal equinox--never, however, more
+southerly than from S. W. to N. E., on the parallel of 41°, except in
+three, and, perhaps, four, instances, when it has been S. W. by S. to N.
+E. by N. I know of no class of storms in relation to which the evidence of
+primary action in the counter-trade is stronger than in those of the class
+which originate on the ocean east of the Windward Islands. But it is not
+satisfactory as to them. Doubtless the conflict of polarities between the
+passing trades is sufficient to produce the showers and rains which are
+ordinarily found over the ocean and lowlands, in the equatorial belt; but
+it is doubtful whether it is sufficient to produce such extensive,
+long-continued, and violent action, as that which characterizes the
+hurricane autumnal gales.
+
+They occur, too, at the time when the whole machinery of distribution has
+reversed its course, and is rapidly pursuing its journey south. It is a
+period of great magnetic disturbance, over both land and sea; of more
+active gales and local-increased precipitation. At the Magnetic
+Observatory of Toronto, Canada West, these disturbances are carefully and
+systematically observed, and their maxima, or periods of greatest
+disturbance occur in April and September. (See Silliman's Journal, new
+series, vol. xvii. p. 145.)
+
+The tendency to volcanic action is not as great at the autumnal, as at the
+vernal equinox, for the reason that most of the volcanic action of the
+western hemisphere develops itself now upon South rather than North
+America. But both exist, and are active, and what are improperly termed
+equinoctial storms, and gales, and rains, are proverbial during, or just
+subsequent to, both periods with us--as they are when the same change,
+called the breaking up of the monsoons, takes place in the line of
+magnetic intensity, over southern and eastern Asia. A volume might be
+filled with extracts, showing, at least, most remarkable coincidences
+between violent volcanic action and great atmospheric disturbance. Perhaps
+the increased fall of rain at and after the equinoxes, in the northern
+hemisphere, and in certain localities subject to volcanic activity, is as
+strikingly illustrated by the register, kept by Mr. Johnson, on the
+volcanic Island of Kauai, one of the Hawaiian group, already alluded to,
+as in any other case, although it is by no means a singular one. The
+greatest fall of rain, in any month except April and October, was eight
+inches. In April, the fall was fourteen inches, in October, eighteen
+inches. Neither the equatorial, nor extra-tropical belt, were over the
+island during those months; but they were the N. E. trades, and the result
+was owing solely to the interposition of high volcanic mountains, _in a
+state of disturbance_, into, or near, the strata of the counter-trade. Mr.
+Dobson, in stating a theory to which we shall hereafter advert, advances
+the following proposition:
+
+"7. _Cyclones (hurricanes) begin in the immediate neighborhood of active
+volcanoes._ The Mauritius cyclones begin near Java; the West Indian, near
+the volcanic series of the Caribbean Islands; those of the Bay of Bengal,
+near the volcanic islands on its eastern shores; the typhoons of the China
+Sea, near the Philippine Islands, etc."
+
+The peculiar stormy state of the atmosphere, over the Gulf Stream, to
+which I have alluded, certainly affords no evidence of primary atmospheric
+action. It is a body of south polar water, pursuing its way under the
+guidance of magnetism--maintaining its polarity--arched somewhat like the
+roof of a house, by the outward pressure of a cold north polar current
+which it has met to the east of the Banks of Newfoundland, and forced to
+take an in-shore course to the southward, and the bodies of water which
+the rivers discharge, and a conflict with the north polar surface-winds
+which sweep over it, and fogs, and thunder, and rain, are a matter of
+course. Dr. Kane met a portion of this singular current in Baffin's Bay,
+north of 75°, which had preserved its characteristics and a considerable
+proportionate excess of heat, although it probably had been around
+Greenland, or found its way to the west, toward the magnetic pole, through
+some of its northern fiords or straits. (Grinnel Expedition, p. 120.)
+
+The investigations of Lieutenant Maury show, that when the Gulf Stream
+turns to the eastward, crossing the lines of declination at right angles,
+as the counter-trades also seem to do in the same latitude, it is _carried
+up, in summer, several degrees to the north_, and descends again in
+winter--thus demonstrating its connection with the shifting magnetic
+machinery which controls alike the ocean, the atmosphere, and the
+temperature of the earth.[7]
+
+There are other irregularities which deserve to be noticed, in this
+connection, although the analogical evidence they afford is far from being
+decisive.
+
+I have already said that it was within my own observation, that
+alternating lines of heat and cold, as well as rain and drought, existed
+frequently, without regard to latitude, following, to some extent, the
+course of the counter-trade. Such lines have been observed by others.
+
+Thus, Mr. Espy, after describing a snow-storm, which was followed by a
+very cold N. W. wind, of several days' continuance, says:
+
+     "This cold air covered the whole country, from Michigan to the
+     eastern coast of the United States, till the beginning of the great
+     storm of the 26th January; and, what is worthy of particular notice
+     is, that _the temperature began to increase first in the north and
+     north-west_. On the morning of the 25th, in the north-western parts
+     of Pennsylvania, and northern parts of New York, the _thermometer_
+     had already _risen in some places 30°_, and, in others, _above 40°_.
+     While in the S. E. corner of Pennsylvania, and in the S. E. corner of
+     New York it had not _begun to rise_. The _wind_ also began to change
+     from the _north-west_ to _south_ and _south-east_, _first_ in the
+     north-west parts of Pennsylvania and New York, some time before it
+     commenced in the south-east of those States; and, during the whole of
+     the 25th, the thermometer, in the north of New York, continued to
+     rise, though the wind was blowing from the southward, where the
+     thermometer was many degrees lower."
+
+Thus, too, Mr. Redfield (American Journal of Science, November, 1846, p.
+329):
+
+     "On the contrary, in times of the greatest depression of the
+     thermometer, in numerous instances, the cold period has been found to
+     have first taken effect in, or near, the tropical latitudes, and the
+     Gulf of Mexico, and has thence been propagated toward the eastern
+     portions of the United States, in a manner corresponding to the
+     observed progression of storms."
+
+This was because the cold N. W. wind which _followed_ storms began to
+follow them as the storms curved and passed to the N. E.
+
+They occur in Europe also. Says Kämtz:
+
+     "Such contrasts are not uncommon in Europe, and, in this respect, the
+     Alps form a remarkable limit; for they separate the climates of the
+     north of Europe from the Mediterranean climates, where the
+     distribution of rain is not the same as in the center of Europe.
+     Hence the differences between the climates of the north and south of
+     France. _If the winter is mild in the north_, the newspapers are
+     filled with the lamentations of the _Italians_ and _Provençals_ at
+     the _severity of the cold_."
+
+These facts seem to indicate a primary action in the counter-trade.
+Probably in connection with one class of storms they do, and with another
+do not. I shall endeavor to show the distinction when I come to the
+classification of storms.
+
+The difference of seasons in this country, and over the entire northern
+hemisphere, is often very great. In a remarkable work of a remarkable
+man--"A Brief History of Epidemic and Pestilential Diseases," by Noah
+Webster, published in 1799, 2 vols.--a history of the weather for about
+two centuries--1600 to 1799 inclusive, is given generally, and then in a
+tabular form. Those who think that every considerable extreme which occurs
+exceeds any thing before known, will do well to consult that work.
+Droughts are described, where "there was not a drop of rain for three or
+four months, and cattle were fed upon the leaves of the trees." Winters,
+so intensely cold that the thermometer fell to 20° below zero, at
+Brandywine; or so mild that there was little frost, and people upon
+Connecticut River plowed their fields, and the _peach trees blossomed in
+Pennsylvania in February_. These extremes generally existed in Europe and
+America at the same time, but occasionally they were opposite and
+alternate. Says Mr. Webster, in summing up the facts (vol. ii. p. 12): "It
+is to be observed that in some cases a severe winter extends to both
+hemispheres, sometimes to one only, and in a few cases to a part of a
+hemisphere only. Thus in 1607-8, 1683-4, 1762-3, 1766-7, 1779-80, 1783-4,
+the severity extended to both hemispheres. In 1640-41, 1739-40, and in
+other instances, the severe winter in Europe preceded, by one year, a
+similar winter in America. In a few instances, severe frost takes place in
+one hemisphere during a series of mild winters in the others; but this is
+less common. In general, the severity happens in both hemispheres at once,
+or in two winters, in immediate succession; and, as far as this evidence
+has yet appeared, this severity is closely attendant on volcanic
+discharges, with very few exceptions."
+
+It will be seen that Dr. Webster (LL.D. and not M.D., and therefore the
+remarkable character of the work) attributes great influence to
+earthquakes and volcanic action. Probably he is correct in this. The
+present active volcanic action of the western hemisphere is nearly all
+within the trade-wind region, from Mexico to Peru inclusive. The West
+India islands are of volcanic origin, and the influence of volcanic action
+is not confined to a concussion of the earth, or the eruption of mud and
+lava. Its connection with magnetic action, and disturbance, is
+unquestionable. But whether they operate to increase or diminish the
+trades, and the extent to which they induce violent electric action and
+storms within and without the tropics, is a question which further
+observation must determine. The ripples of the ocean, compared by
+Lieutenant Banvard to that of a "boiling cauldron, or such as is formed by
+water being forced from under the gate of a mill-pond," are met with in
+the vicinity of volcanic islands, where hurricanes and water-spouts
+originate, and have been observed to precede storms, and be connected with
+a falling barometer. But whether they are volcanic or magneto-electric,
+it is difficult to determine. Dr. Webster remarks, as the result of
+observation, during the 17th century, that earthquakes had a N. W. and S.
+E. progression in the United States, and especially in New England. In a
+recent article, Professor Dana has examined, with great ability, the
+general and remarkable trending of coast lines, groups of islands, and
+ranges of mountains, from N. E. to S. W. and from N. W. to S. E. (American
+Journal of Science, May, 1847.)
+
+The line of magnetic intensity, which connects our magnetic pole with its
+opposite, is now upon this continent nearly a N. W. and S. E. line, and
+the pole is fast traveling to the west. It may, and probably will yet, be
+established, that there is an intimate connection between the cause of
+volcanic action within the earth, to which the upheaval of the N. W. and
+S. E., and N. E. and S. W. ranges were due, and of magnetic action
+without, and between both, and the cause of _the S. E. extension_ of our
+summer storms and belts of showers and barometric _waves_, and the
+_peculiar N. W. wind_. Our limits do not permit us to pursue the subject.
+
+Much influence upon the weather has been attributed to the spots upon the
+sun. These spots are supposed to be breaks or openings in the luminous
+atmosphere or photosphere of the sun, through which its dark nucleus body
+is seen. Counselor Schwabe, of Dessau, has made them his study since 1826,
+and has arrived at some singular results. They seem to be numerous--in
+groups--and to appear periodically with minima and maxima of ten years.
+As the result of his observations, from 1826 to 1850, he gives us the
+following table and remarks:
+
+     +-----------------------------------------------+
+     | Year. | Groups. | Days showing |   Days of    |
+     |       |         |   no spots.  | Observation. |
+     |-------|---------|--------------|--------------|
+     | 1826  |   118   |       22     |     277      |
+     | 1827  |   161   |        2     |     273      |
+     | 1828  |   225   |        0     |     282      |
+     | 1829  |   199   |        0     |     244      |
+     | 1830  |   190   |        1     |     217      |
+     | 1831  |   149   |        3     |     239      |
+     | 1832  |    84   |       49     |     270      |
+     | 1833  |    33   |      139     |     267      |
+     | 1834  |    51   |      120     |     273      |
+     | 1835  |   173   |       18     |     244      |
+     | 1836  |   272   |        0     |     200      |
+     | 1837  |   333   |        0     |     168      |
+     | 1838  |   282   |        0     |     202      |
+     | 1839  |   162   |        0     |     205      |
+     | 1840  |   152   |        3     |     263      |
+     | 1841  |   102   |       15     |     283      |
+     | 1842  |    68   |       64     |     307      |
+     | 1843  |    34   |      149     |     312      |
+     | 1844  |    52   |      111     |     321      |
+     | 1845  |   114   |       29     |     332      |
+     | 1846  |   157   |        1     |     314      |
+     | 1847  |   257   |        0     |     276      |
+     | 1848  |   330   |        0     |     278      |
+     | 1849  |   238   |        0     |     285      |
+     | 1850  |   186   |        2     |     308      |
+     +-----------------------------------------------+
+
+     "I observed large spots, visible to the naked eye, in almost all the
+     years not characterized by the minimum; the largest appeared in 1828,
+     1829, 1831, 1836, 1837, 1838, 1839, 1847, 1848. I regard all spots,
+     whose diameter exceeds 50", as large, and it is only when of such a
+     size that they begin to be visible to even the keenest unaided sight.
+
+     "The spots are, undoubtedly, closely connected with the formation of
+     faculæ, for I have often observed faculæ, or narben, formed at the
+     same points from whence the spots had disappeared, while new solar
+     spots were also developed within the faculæ. Every spot is surrounded
+     by a more or less bright, luminous cloud. I do not think that the
+     spots exert any influence on the annual temperature. I register the
+     height of the barometer and thermometer three times in the course of
+     each day, but the annual mean numbers deduced from their observations
+     have not hitherto indicated any appreciable connection between the
+     temperature and the number of the spots. Nor, indeed, would any
+     importance be due to the apparent indication of such a connection in
+     individual cases, unless the results were found to correspond with
+     others derived from many different parts of the earth. If the solar
+     spots exert any slight influence on our atmosphere, my tables would,
+     perhaps, rather tend to show that the years which exhibit _a larger
+     number of spots_ had a _smaller number of fine days_ than those
+     exhibiting few spots."
+
+These observations _seem_ to show that the spots exert no influence upon
+the weather, and to be satisfactory. But, perhaps, they are not entirely
+so. No effect would, of course, be expected from day to day, and perhaps
+the annual mean may not be seriously disturbed, and yet the spots may
+seriously affect the seasons. Popular tradition has fixed upon certain
+periods, of 10, 20, and 40 years, for the return of winters of unusual
+severity; and the tables of Mr. Webster, and other facts, show that it is
+not wholly without foundation. If we, and those we have cited, are not
+mistaken in most of the views expressed, the natural effect of a partial
+interception or failure of the sun's rays, by or from the existence of the
+spots, would be to decrease the exciting power of the solar rays upon
+terrestrial magnetism, and, as a consequence, the volume of the trades and
+their amount of moisture. This would increase the _mean_ heat of the
+summer in the temperate zone--for the _less_ the volume of trade, the less
+precipitation and variable wind, and succeeding polar waves of cooler air,
+and the greater mean heat. On the other hand, the same cause, and the
+feebler heating power of the sun's rays, would make the winters more
+severe, both from an absence of a portion of heat, derived directly from
+the sun's rays, and a less mitigating influence, from the action of the
+trade, by reason of its decreased volume. So, too, the absence of spots,
+and a more powerful influence from the solar rays, may gradually carry
+the machinery further north in summer, and further south in winter, and
+thus make the _seasons extreme_ without seriously disturbing the mean of
+the year. And both these may occur in a more marked degree over our
+intense magnetic area than in Europe. I am satisfied that they do so
+occur. That the partial failure of the sun's rays limits the transit of
+the machinery, and the volume of the trades during the latter half of the
+decade, and extends the transit and increases the volume during the first
+half, producing an occasional severe summer drought and severe winter, in
+the warmest portion of the decade. And that the variations correspond with
+the difference in the character and number of the spots in different
+decades, and hence the longer and shorter periods.
+
+Turning to the tables of Dr. Webster, we find that a general tendency to
+extreme seasons does seem to exist from the 6th to the 10th year of every
+decade, and especially of every alternate decade. The periods of 1707-8,
+1728, 1737 and 1739, 1749-50, 1758-9, 1779-80, 1798-9, are those in which
+the tendency was seen most decided. These tables are very general. The
+thermometer was not perfected till about 1700, and did not get into
+general use before 1750. There were very few meteorological registers
+kept, or accessible to Dr. Webster. Hence he was obliged to resort to such
+other sources of information as were open to him, and such statements as
+he found are not always entirely reliable. The oldest inhabitant is apt to
+express himself very strongly respecting present extremes, and fail
+somewhat in his recollection of those which have past. Still his tables
+afford general and obvious evidence of the regularity of those periodic
+conditions.
+
+  +---------------------------------------------------------+
+  |A. D.|       Summer.           |       Winter.           |
+  |-----|-------------------------|-------------------------|
+  | 1701| hot and dry             | ....                    |
+  | 1702| hot and dry             | ....                    |
+  | 1703| ....                    | ....                    |
+  | 1704| dry Europe              | ....                    |
+  | 1705| ....                    | ....                    |
+  | 1706| hot, dry Europe         | ....                    |
+  | 1707| very hot                | ....                    |
+  | 1708| ....                    | very severe             |
+  | 1709| ....                    | ....                    |
+  | 1710| ....                    | ....                    |
+  | 1711| ....                    | cold Europe             |
+  | 1712| wet England             | ....                    |
+  | 1713| wet England             | mild                    |
+  | 1714| dry and hot             | ....                    |
+  | 1715| dry                     | ....                    |
+  | 1716| very dry                | severe                  |
+  | 1717| ....                    | severe                  |
+  | 1718| hot and wet             | ....                    |
+  | 1719| ....                    | cold America            |
+  | 1720| dry Europe              | ....                    |
+  | 1721| ....                    | ....                    |
+  | 1722| cold, wet               | ....                    |
+  | 1723| ....                    | cold                    |
+  | 1724| wet England             | ....                    |
+  | 1725| wet England             | ....                    |
+  | 1726| ....                    | ....                    |
+  | 1727| dry, hot Amer.          | ....                    |
+  | 1728| hot Amer.               | severe Europe           |
+  | 1729| ....                    | ....                    |
+  | 1730| ....                    | very cold Eng.          |
+  | 1731| ....                    | ....                    |
+  | 1732| ....                    | severe Amer.            |
+  | 1733| dry Eng.                | ....                    |
+  | 1734| ....                    | ....                    |
+  | 1735| wet                     | ....                    |
+  | 1736| wet                     | ....                    |
+  | 1737| ....                    | very severe Am.         |
+  | 1738| ....                    | ....                    |
+  | 1739| wet England             | very severe Eng.        |
+  | 1740| ....                    | very severe Am.         |
+  | 1741| ....                    | ....                    |
+  | 1742| ....                    | severe Syria            |
+  | 1743| hot                     | ....                    |
+  | 1744| ....                    | ....                    |
+  | 1745| ....                    | ....                    |
+  | 1746| ....                    | ....                    |
+  | 1747| hot and dry             | severe                  |
+  | 1748| dry                     | ....                    |
+  | 1749| very dry                | ....                    |
+  | 1750| very hot                | very severe             |
+  | 1751| wet England             | severe Amer.            |
+  | 1752| very hot Amer.          | ....                    |
+  | 1753| ....                    | severe                  |
+  | 1754| ....                    | mild Amer.              |
+  | 1755| ....                    | severe Europe           |
+  | 1756| ....                    | severe Syria            |
+  | 1757| ....                    | ....                    |
+  | 1758| hot                     | ....                    |
+  | 1759| ....                    | severe                  |
+  | 1760| ....                    | ....                    |
+  | 1761| very dry Amer.          | ....                    |
+  | 1762| very dry Amer.          | severe                  |
+  | 1763| ....                    | ....                    |
+  | 1764| hot Europe              | ....                    |
+  | 1765| hot Europe              | severe Europe           |
+  | 1766| hot and dry Eur.        | very severe             |
+  | 1767| ....                    | cold                    |
+  | 1768| hot                     | ....                    |
+  | 1769| hot                     | ....                    |
+  | 1770| wet England             | ....                    |
+  | 1771| wet Am. & Eng.          | cold Europe             |
+  | 1772| hot America             | Am., great snow         |
+  | 1773| ....                    | ....                    |
+  | 1774| ....                    | severe Europe           |
+  | 1775| ....                    | ....                    |
+  | 1776| hot                     | severe Europe           |
+  | 1777| ....                    | ....                    |
+  | 1778| hot                     | mild                    |
+  | 1779| hot Eng.                | very severe             |
+  | 1780| ....                    | ....                    |
+  | 1781| ....                    | ....                    |
+  | 1782| dry Amer.               | ....                    |
+  | 1783| hot                     | very severe             |
+  | 1784| hot                     | ....                    |
+  | 1785| dry Europe              | cold                    |
+  | 1786| cool                    | cold                    |
+  | 1787| cool                    | ....                    |
+  | 1788| rainy Amer.             | cold                    |
+  | 1789| cool spring, hot summer | severe Eur., mild Amer. |
+  | 1790| ....                    | ....                    |
+  | 1791| very hot Am.            | cold                    |
+  | 1792| ....                    | ....                    |
+  | 1793| hot, dry Am.            | mild Amer.              |
+  | 1794| ....                    | severe Europe           |
+  | 1795| Amer., hot, rainy       | ....                    |
+  | 1796| Autumn very Dry Am.     | cold Amer.              |
+  | 1797| cool Am.                | severe Amer.            |
+  | 1798| very hot      }         | { long & severe         |
+  | 1799| very dry Am.  }         | { Amer. & Eur.          |
+  +---------------------------------------------------------+
+
+Still more definite evidence is found in the meteorological tables of Dr.
+Holyoke and Dr. Hildreth, and an account, by Dr. Hildreth, of the seasons
+when the Ohio River was closed or obstructed by ice, found in Silliman's
+Journal, new series, vol. xiii. p. 238.
+
+Thus, we have, from the tables of Dr. Holyoke, the following annual means,
+from 1786 to 1825, inclusive. I have arranged them in periods of five
+years. It will be seen that there are three peculiarities observable.
+First, a marked difference between the first and second periods of the
+decade, corresponding, generally, with the presence or absence of the
+spots. Second, a difference in the mean of the decades which may well be
+supposed to correspond with the difference in the number or size of the
+spots since a like difference is observable in number and size, and the
+time when they reached their maxima and minima, in the table of Schwabe.
+And, third, there are occasional single cold years during the warm period,
+and these correspond with what the tables of Dr. Webster show for both the
+sixteenth and seventeenth centuries. In relation to this, it should be
+remembered that volcanic action is a frequent and powerful disturber of
+the regular action of terrestrial magnetism, and that the extremes, for
+that reason, are frequently meridional or local and alternating; and to
+that cause very great extremes, and marked exceptions, may be due,
+notwithstanding the spots upon the sun may exert an influence in producing
+hot summers and cold winters toward the close of each decade. Thus, to
+select an instance to illustrate this and explain an anomaly: The coldest
+season during the whole period, embraced in the following tables, is that
+of 1812. This occurs during the decrease of spots, and the warm half of
+the decade. Turning to the table of volcanic action, and of earthquakes,
+found in the Report of the British Association for 1854, we find that year
+was remarkable for earthquakes in the United States and South America. In
+December, 1811, earthquakes commenced in the valley of the Mississippi,
+Ohio, and Arkansas, felt also at places in Tennessee, Kentucky, Missouri,
+Indiana, Virginia, North and South Carolina, Georgia, and Florida, though
+not so severely east of the Alleghanies, _which continued until 1813_.
+About the same time they commenced in Caraccas, and, in March, 1812,
+became severe over the greater portion of the northern section of South
+America, and in the Atlantic. No such general and continued succession of
+earthquakes occurred during the other periods embraced in the tables, and
+the mean of the following five years was very low, embracing the memorable
+cold summer of 1816.
+
+  +---------------------------------------------------------------+
+  | Cold Period.  | Warm Period.  | Cold Period.  | Warm Period.  |
+  |---------------|---------------|---------------|---------------|
+  |1786    48°.53 |1791    48°.963|1796    48°.678|1801    50°.432|
+  |1787    47°.88 |1792    48°.44 |1797    48°.135|1802    50°.794|
+  |1788    47°.676|1793    50°.96 |1798    49°.471|1803    50°.24 |
+  |1789    47°.68 |1794    50°.768|1799    48°.291|1804    48°.328|
+  |1790    46°.53 |1795    50°.173|1800    49°.989|1805    50°.792|
+  |---------------|---------------|---------------|---------------|
+  |Mean of        |               |               |               |
+  |period  47°.659|Mean    49°.901|Mean    48°.910|Mean    50°.117|
+  |---------------|---------------|---------------|---------------|
+  |---------------|---------------|---------------|---------------|
+  |1806    47°.982|1811    50°.76 |1816    47°.113|1821    48°.15 |
+  |1807    48°.132|1812    45°.28 |1817    46°.277|1822    49°.81 |
+  |1808    49°.485|1813    47°.702|1818    48°.009|1823    47°.58 |
+  |1809    47°.92 |1814    48°.279|1819    50°.75 |1824    49°.25 |
+  |1810    49°.001|1815    47°.607|1820    48°.70 |1825    50°.99 |
+  |---------------|---------------|---------------|---------------|
+  |Mean    48°.505|Mean    47°.925|Mean    48°.169|Mean    49°.15 |
+  +---------------------------------------------------------------+
+
+The tables of Dr. Hildreth, from 1826 to 1854, inclusive, furnish,
+generally, evidence of a like character. There are, however, an anomaly or
+two which will be observed. From 1826 to 1830, the mean is high during
+the period when spots were at a maximum. But that maximum embraced a much
+less number of spots than the two succeeding ones. A contrast appears in
+the tables of Dr. Hildreth, during the early period, for Dr. Holyoke's
+register, for 1827, puts it _below the mean_, but Dr. Hildreth's one of
+the _highest of the half century_. In 1835 commenced a period when the
+spots were much more numerous, and from 1835 to 1838, inclusive, the
+seasons were correspondingly below the mean. From that period to 1844 a
+gradual and slightly irregular rise took place, excepting the year 1843,
+when another cold year intervened. The table of earthquakes, published by
+the British Association, closes with 1842, and I have not access to any
+others. The occurrence of such cold years, in the warm period, at
+intervals during the two centuries previous, and in 1812, and onward, and
+evidently owing to increased volcanic action beneath the western portion
+of the northern hemisphere, justifies the belief that the low temperature
+of 1843 was owing to the same cause. The following are the means from the
+tables of Dr. Hildreth:
+
+  +----------------------------------------------------------------+
+  |1826  54°.00|1831  50°.87|1836  50°.03|1841  52°.18|1846  53°.64|
+  |1827  54°.92|1832  52°.42|1837  51°.57|1842  52°.83|1847  52°.00|
+  |1828  55°.22|1833  54°.56|1838  50°.62|1843  50°.77|1848  52°.50|
+  |1829  52°.38|1834  52°.40|1839  52°.54|1844  53°.25|1849  52°.09|
+  |1830  54°.93|1835  50°.65|1840  52°.35|1845  52°.73|1850  51°.48|
+  |------------|------------|------------|------------|------------|
+  |Mean  54°.29|Mean  52°.18|Mean  51°.52|Mean  52°.35|Mean  52°.32|
+  +----------------------------------------------------------------+
+
+The observations of Dr. Holyoke were made at Salem, Massachusetts; those
+of Dr. Hildreth at Marietta, Ohio.
+
+The following, in relation to the freezing of the Ohio River, is evidence
+of a different kind, but shows the same general correspondence, and
+particularly _the mildness of the winters when there were few spots_, and
+their severity from 1836 to 1838, inclusive, when the spots were most
+numerous:
+
+  1829.--River open all winter--some floating ice.
+  1830.--River closed 27th January.
+  1831.--Floating ice--closed 23d January--opened 20th February.
+  1832.--Closed in December, which was a very cold month--opened January
+         8, and remained open all winter.
+  1833.--Open all winter.
+  1834.--Open all winter.
+  1835.--Closed January 6--opened the last of the month--cold.
+  1836.--Closed 28th January--opened 25th February.
+  1837.--Closed from 8th December to 8th February. Cold year.
+  1838.--Closed from 13th January to 13th March. Cold year.
+  1839.--Closed from 6th December to 13th January.
+  1840.--Closed 29th December--opened 15th January.
+  1841.--Closed 3d January--opened 8th do.
+  1842.--Open all winter.
+  1843.--Closed 28th November--opened 5th December--open all the rest of
+         the winter.
+  1844.--Open all winter.
+  1845.--Open all winter.
+  1846.--Closed 5th December--opened again a few days--closed again on the
+         26th. It is not stated how long it remained closed.
+  1847.--Open all winter.
+  1848.--Much floating ice, but not closed--heavy rains and floods.
+  1849.--Floating ice in January, but not closed.
+  1850.--Floating ice, but not closed.
+  1851.--Open all winter--a little ice.
+
+  (December in the above table, means December previous).
+
+This is more reliable as to the winter season than the tables of annual
+means--although the evidence they afford, making due allowance for the
+exceptions, is very striking.
+
+I shall return to this part of the subject again.
+
+But there is other evidence of the influence of these spots. Their
+connection with the irregular magnetic disturbance of the earth has been
+distinctly traced. Colonel Sabine, President of the British Association,
+in his opening address, September, 1852, after reviewing the recent
+discoveries in magnetism, says:--
+
+     "It is not a little remarkable that this periodical magnetic
+     variation is found to be identical in period, and in epochs of maxima
+     and minima, with the periodical variation in the frequency and
+     magnitude of the _solar spots_, which M. Schwabe has established by
+     twenty-six years of unremitting labor. From a cosmical connection of
+     this nature, supposing it to be finally established, it would follow
+     that the decennial period, which we measure by our magnetic
+     instrument, is, in fact, a solar period, manifested to us, also, by
+     the alternately increasing and decreasing frequency and magnitude of
+     observations on the surface of the solar disc. May we not have in
+     these phenomena the indication of a cycle, or period of _secular
+     change in the magnetism of the sun_, affecting visibly his gaseous
+     atmosphere or photosphere, and sensibly modifying the magnetic
+     influence which he exercises on the surface of our earth?"--American
+     Journal of Science, new series, vol. xiv. p. 438.
+
+I think it may fairly be inferred, that although these spots do not
+occasion the "cold spells" and "hot spells," and other transient
+peculiarities, they do materially affect the _mean_ temperature of the
+year, and exert an obvious influence when at their maxima; and there is a
+tendency to an increase of the heat and dryness of summer, and the
+severity of winter, at the periods named, in our excessive climate, and a
+well-established connection between the spots and magnetic disturbances
+and variations.
+
+Popular opinion has ever attributed to the moon a controlling effect upon
+the changes of the weather. If it be dry, a storm is expected _when the
+moon changes_; or if it be wet, dry weather. Such popular opinions are
+usually entitled to respect, and founded in truth. But every attempt to
+verify _this opinion_, by careful observation and registration, has
+failed. Weather-tables and lunar phases, compared for nearly one hundred
+years, show four hundred and ninety-one new or full moons attended by a
+change of the weather, and five hundred and nine without. The celebrated
+Olbers, after _fifty years of careful observation_ and comparison, decided
+against it. So did the more celebrated Arago, at a more recent
+date--summing up the result of his observations by saying--"Whatever the
+progress of the sciences, never will observers, who are trustworthy and
+careful of their reputation, venture to foretell the state of the
+weather." Still, the moon may influence the weather, though she may not
+effect changes at her syzygies or quadratures, and this subject should not
+be too summarily dismissed. That the moon can not effect changes at the
+periods named seems philosophically obvious. She changes, for the _whole
+earth_, within the period of twenty-four hours; yet, how varied the state
+of things on different portions of its surface. The equatorial belts of
+trades, and drought, and rains, cover from fifty to sixty degrees of its
+surface, and know nothing of lunar disturbance. The extra-tropical belt of
+rains and variable weather moves up in its season, uncovering 10°, or
+more, of latitude, and admitting the trades and a six months' drought over
+it, as in California, regardless of the moon. Under the zone of
+extra-tropical rains, even upon the eastern part of the continent of North
+America, "dry spells" and "wet spells" exist side by side; the focus of
+precipitation is now in one parallel, and now in another--_storms_ exist
+_here_ and _fair weather there_, on the same continent at the same time;
+and as the moon's rays in her northing pass round the northern hemisphere
+during the twenty-four hours, they, doubtless, pass from ten to thirty or
+more storms, of all characters and intensities, moving in opposition to
+her orbit--and as many larger intervening areas of fair weather, not one
+of which are indebted to her for their existence, or "take thought of her
+coming."
+
+The storm, which originates in the tropics, pursues its curving way now N.
+W., then N. E., and again north, to the Arctic circle, and, perhaps,
+around the magnetic pole, over gulf, and continent, and ocean, _occupying
+one third the time of a lunation, and two changes, perhaps, in its
+progress_, without any perceptible or conceivable influence from her. Yet
+every inhabitant of mother-earth, influenced by _coincidences remembered_,
+and uninfluenced by _exceptions forgotten_, looks up within his limited
+horizon, and devoutly expects from the agency of some phase of the moon, a
+change for the special benefit of his _dot_ upon the earth's surface. Upon
+how many of these countless dots is the moon at a particular phase, or
+relative distance from the sun, to change fair weather to foul, or foul to
+fair? Upon none. The storms keep on their way;--the wet spells, and the
+dry spells, the cold and the hot spells alternate in their time, and
+though the moon turns toward them in passing, her dark face, her half
+face, or her full orb (the gifts of the sun, which confer no power), they
+do not heed her. They are originated, and are continued, by a more potent
+agent. They are the work of an atmospheric mechanism, as _ceaseless_ in
+its operation as _time_, as _regular_ as the _seasons_, _as extensive as
+the globe_.
+
+Indeed, it seems as if it was expressly designed by the Creator that the
+moon should not interfere materially with this atmospheric machinery. She
+is the nearest orb; her influence would be controlling and continuous;
+would follow her monthly path from south to north, and with changes too
+violent, and intervals too long; and would interfere with the regular
+fundamental operation in the trade-wind region, where she is _vertical_.
+Aside from the attraction of gravitation, therefore, she seems to have
+been so created as to be incapable of exerting any influence. She is
+without an atmosphere; the rays which she reflects are polarized, and
+without chemical or magnetic power; and, if it be true that Melloni has
+recently detected heat in them, by the use of a lens three feet in
+diameter, which could not previously be effected, its quantity is
+exceedingly small, and incapable of influence. Doubtless, the attraction
+of her mass is felt upon the earth, as the tides attest; and upon the
+atmosphere as well as the ocean. But the atmosphere is comparatively
+_attenuated_, and exceedingly so at its upper surface. Her attraction,
+therefore, although felt, is not influential. She seemed, to Dr. Howard,
+to produce in her northing and southing, a lateral tide which the
+barometer disclosed, but owing to the attenuated character of the
+atmosphere, neither the sun nor moon create an easterly and westerly tide,
+that is observable, except with the most delicate instruments. Sabine is
+believed to have detected such a tide by the barometer, at St. Helena, of
+one four thousandth of an inch. But even this _infinitesimal influence_
+may prove an error upon further investigation. There is a diurnal
+variation of the barometer, but it is not the result of her attraction,
+for it is not later each day as are the tides, exists in the deepest mines
+as well as upon the surface, and is demonstrably connected with the
+_group_ of _diurnal_ changes produced by the action of the sun-light and
+heat upon the earth's magnetism.
+
+Can the lateral tide, if there be one, affect the weather? for in the
+present state of science it seems entirely certain that the moon can exert
+an influence in no other way.
+
+If the received idea of many, perhaps most, meteorologists, on which all
+wheel barometers are constructed, that a _high barometer_ necessarily
+produces _fair weather_, and a _low one foul_, were true, she certainly
+might do so. But that idea can not be sustained, and there is no known
+certain influence exerted by the moon upon the weather, in relation to
+which we have any reliable practical data.
+
+Humboldt appears to have adopted the impression of Sir W. Herschell, that
+the moon aids in the dispersion of the clouds. (Cosmos, vol. iv. p. 502.)
+But the tendency to such dispersion is always rapid during the latter part
+of the day and evening, when there is no storm approaching, and the full
+moon renders their dissolution visible, and attracts attention to them.
+The Greenwich observations, also, carefully examined by Professor Loomis,
+fail to confirm the impression of Herschell and Humboldt, and those
+eminent philosophers are doubtless in this mistaken.
+
+From this general and somewhat desultory view of the general facts, which
+bear analogically upon the question, no decisive inference can be drawn in
+relation to the seat of the primary influence which produces the
+atmospheric changes. The preponderance is in favor of the magnetic, or
+magneto-electric, action of the earth. We must come back to our own
+country and grapple with the question at home.
+
+
+
+
+CHAPTER IX.
+
+
+Before proceeding to do this, however, it may be well to look at some
+theories which have been advanced, and to a greater or less extent
+adopted, and at their bearing upon the question.
+
+The calorific theory is at present the prevailing one in Europe and in
+this country. Meteorologists there and here refer all atmospheric
+conditions and phenomena to the influence of heat. The principal
+applications of that theory have been considered. But within the last few
+years the elasticity and tension of the aqueous vapor of the atmosphere
+have received much attention, as exerting an auxiliary or modifying
+influence. Professor Dove, of Berlin, who ranks perhaps as the most
+distinguished meteorologist of that continent, attributes barometric
+variations to _lateral overflows_, and, in the upper regions, resulting
+from the elevation of the atmosphere by expansion; and in this view
+meteorologists of Europe seem generally to acquiesce. In an article sent
+to Colonel Sabine, and recently republished in the American Journal of
+Science, January, 1855, in thus attempting to account for the annual
+variation of barometric pressure, which occurs in Europe and Asia, and,
+indeed, over the entire hemisphere. He says:
+
+     "From the combined action or the variations of aqueous vapor, and of
+     the dry air, we derive immediately the periodical variations of the
+     whole atmospheric pressure. As the dry air and the aqueous vapor
+     mixed with it, press in common on the barometer, so that the up-borne
+     column of mercury consists of two parts, one borne by the dry air,
+     the other by the aqueous vapor, we may well understand that as with
+     increasing temperature the air expands, and by reason of its
+     augmented volume rises higher, and _its upper portion overflows
+     laterally_," etc.
+
+And in another place he says:
+
+     "From the magnitude of the variations in the northern hemisphere, and
+     the extent of the region over which it prevails, we must infer that
+     _at the time of diminished pressure a lateral overflow probably takes
+     place_," etc.
+
+Doubtless, the mean pressure of the atmosphere, in summer, in the northern
+hemisphere, is less than in winter, in some localities, and greater in
+others, and it differs in different countries of equal temperature. And
+this is all very intelligible. The mean of the pressure for the month is
+made up by _averaging_ all the _elevations_ and _depressions_. During a
+month, showing a very low mean, the barometer may, at times, attain its
+_highest altitude_, if the depressions below the mean are great or more
+frequent. The barometer is depressed during storms, and ranges high during
+_set fair_ weather. Ordinarily, therefore, the more stormy the season the
+more diminished the mean pressure; and it is a mistake to look to an
+overflow to account for the fact. The changes in the location of the
+atmospheric machinery, and consequent change in the amount and severity of
+falling weather, and the periodic frequency and character of storms, and
+consequent _periodic_ depressions and elevations of the barometer,
+explain the annual mean variations, as they do the other phenomena. But it
+is perfectly consistent with the calorific theory to attempt to account
+for these differences by another of those ever-necessary modifications,
+viz.: the different tension and elasticity of aqueous vapor in different
+countries of equal temperature; and then to _suppose_ an expansion of the
+whole body of the atmosphere and a lateral overflow from the place where
+the air is expanded, on to some other, where it is not; and thus _suppose_
+all necessary currents in the upper regions, setting hither and yon, by
+the force of gravity alone. And apparently he who is best at supposition
+becomes the most distinguished meteorologist. Perhaps I have already said
+all that I ought to be pardoned for saying, in relation to the utter
+absurdity of attributing all meteorological phenomena to the agency of
+heat; but when I find such views as those which that article contains,
+emanating from so distinguished a man, sanctioned by the President of the
+British Association, and copied into the leading journal of science in
+this country, I can not forbear a further and a somewhat critical
+examination of them. There is more error of supposition and less truth in
+it, than in any other article regarding the science, of equal length,
+which has fallen under my notice.
+
+What is the height of this expansion? The moisture of evaporation ascends,
+ordinarily, but a few thousand feet. The atmosphere grows regularly
+cooler, from the earth to the trade, and _the increased warmth that is
+felt at the surface extends but little way_. Currents of warm air do not
+ascend. The strata maintain, substantially, their relative positions; and
+this is a most beneficent provision. In northern latitudes of the
+temperate zone, all the warmth derived from a few hours' sunshine is
+needed at the surface; and, deplorable, indeed, would be our condition, if
+the atmosphere, as fast as warmed by the rays of the sun, were to hasten
+up, and the frigid strata descend in its place. The earth would not be
+habitable. All the warm air on its surface would be rising as soon as it
+became warmed, and the cold air above be descending, and enveloping us
+with the chilling strata which are ever floating within two or three miles
+above us. No. Infinite wisdom has ordered it otherwise. The laws of
+magnetism and of static-electric induction and attraction keep the strata
+in their places, and preserve to us the warmth which the solar rays afford
+or produce. The inhabitant of the valley, in a high northern latitude, in
+summer, can plant, and sow, and reap, at the base of the mountain whose
+summit penetrates the stratum of continual congelation, and up its sides,
+almost to the line of perpetual snow; and, as he looks upon the fruits of
+his labor, and up to the snow-clad peak that towers above him, can thank
+his Maker for placing a warm equatorial current, a perpetual barrier,
+between the fertility and warmth which surround him, and the cold
+destructive strata above; and thank Him for not creating such a state of
+things, as certain meteorologists insist we shall believe He has created.
+Again, where are the _upper regions_, from which the lateral overflow
+takes place? The atmosphere is differently estimated, at from thirty to
+forty-five miles, or more, in height. Whatever its height may be, it is
+exceedingly attenuated in its "upper regions."
+
+Gay-Lussac marked the barometer at 12-95/100 inches at the height of
+23,040 feet. Two thirds of the atmospheric density, then, is within five
+miles of the earth. Air, too, is _compressible_. Allowing for the latter
+and the attenuation, how many miles in vertical depth, of its "_upper
+regions_," must move from one portion to another, to depress the barometer
+two inches--its range sometimes in twenty-four hours--or even half an
+inch? Let the computation be made, and see how startling the proposition,
+how utterly impossible that the theory can be true.
+
+The distinguished Professor, in the paper referred to, introduces his
+theory of the formation of hurricanes, and we quote--
+
+     "If we suppose the upper portions of the air ascending over Asia and
+     Africa to flow off laterally, and if this takes place suddenly, it
+     will check the course of the upper or counter-current above the
+     trade-wind, and force it to break into the lower current.
+
+     "An east wind coming into a S. W. current must necessarily occasion a
+     rotatory movement, turning in the opposite direction to the hands of
+     a watch. A rotatory storm, moving from S. E. to N. W., in the lower
+     current or trade, would, in this view, be the result of the encounter
+     of two masses of air, impelled toward each other at many places in
+     succession, the further cause of the rotation (originating primarily
+     in this manner) being that described by me in detail in a memoir 'On
+     the Law of Storms,' translated in the 'Scientific Memoirs,' vol. iii.
+     art. 7. Thus, it happens that the West India hurricanes, and the
+     Chinese typhoons occur near the lateral confines on either side of
+     the great region of atmospheric expansion, the typhoons being
+     probably occasioned by the direct pressure of the air from the region
+     of the trade-winds over the Pacific, into the more expanded air of
+     the monsoon region, and being distinct from the storms appropriately
+     called by the Portuguese 'temporales,' which accompany the out-burst
+     of the monsoon when the direction of the wind is reversed."
+
+The analogy between this, and a theory of Mr. Redfield's, will be noticed
+further on. But I remark, in passing, that there is not a fact or
+inference in this paragraph which will bear examination.
+
+1. There is no such regular S. W. wind over the surface trade, as he
+supposes. Doubtless, there are, occasionally, secondary S. W. currents
+between the counter-trade and the surface one, with partial condensation,
+for much of both becomes depolarized by their reciprocal action and
+precipitation, and these induced S. W. currents are sometimes so strong as
+to usurp the place of the surface-trade, and become very violent in the
+latter part of hurricanes; but such is not the usual course of the upper
+currents of the West Indies, as the progress of storms there, and
+observation, prove.
+
+2. There can not be any _periods_ of extensive and _sudden_ expansion over
+Africa. If there is any place on the earth which has a more uniformly
+progressive temperature, either way, and is more free from _sudden_
+extremes, or which is more arid and destitute of aqueous vapor, and sudden
+aqueous expansions, than another, it is Africa. No such occasional sudden
+expansions are there possible.
+
+3. Winds do not, and can not, "_encounter_." They stratify upon each
+other. They are produced by the action of opposite electricity, and are
+_connected together_ in their origin and action. The atmosphere is never
+free from the regular and irregular currents, however invisible for the
+want of condensation. Aeronauts find them in the most serene days. They
+exist without encounter or tendency to rotation, every where, and at all
+times; even over the head of the distinguished Professor, whether he
+sleeps or is awake. We can all see them when there is condensation, and it
+is rarely the case that there is not some degree of it in some of them.
+
+4. That "Great region of expansion" is a chimera. It does not exist. It is
+a region of _lower temperature_, and of _condensation_, instead of
+_expansion_ of _aqueous vapor_. The trade does not rise in it, or the S.
+W. wind overflow from it. See the table cited page 165.
+
+5. The hurricanes do not originate _in the surface trades_, as he
+supposes. They originate in the belt of rains, the supposed "region of
+expansion," and issue out of it; or in the counter-trade, where volcanic
+elevations rise far into or above the surface trade.
+
+6. This hypothesis can not be sustained upon his own principles. The
+distance between Africa and the West India Islands, where most of the
+hurricanes originate, is from 2,500 to 3,000 miles. These gales are small
+when they commence, not ordinarily over one or two hundred miles in
+diameter, and often less. There are trades all the way over from Africa,
+and S. W. winds also, if they exist, as he supposes, in the West Indies.
+How can it happen that this lateral overflow should pass _without effect_,
+over 2,500 miles of S. W. wind and trade, and concentrating the overflow
+of a continent over one small and chosen spot of the West Indies, _pitch
+down_ there, and there only, and crowd the S. W. wind into the trade
+below? This is too much for sensible men to believe.
+
+What does Professor Dove mean by the term _impulsion_, as applied to the
+winds? How are they _impelled_? It is the fundamental idea of his
+calorific theory, that they are _drawn_ by the _suction_ caused by a
+_vacuum_, and the vacuum created by expansion and overflow above, in
+obedience to the law of gravity; that the S. E. trade is drawn to the
+great region of expansion, and the S. W. runs from it as an overflow. But
+if the S. W. is driven down into the plane and place of the
+surface-trades, how does it continue to be impelled, and why is it not
+then subject to the suction of the vacuum which draws the trade? Does that
+vacuum _select its air_, and so attract the trade, in preference to the
+depressed portion of the S. W. current, that the former runs around the
+latter to get to the vacuum, and the latter around the former to get away
+from it? And does the trade, when it has got around the S. W. current,
+instead of going to the vacuum, continue to gyrate, and the S. W. current,
+instead of pursuing its regular course, gyrate also about the trade, and
+both move off together, regardless of the vacuum of the great region of
+expansion, in a new direction to the N. W., in an independent,
+self-sustaining, cyclonic movement, increasing in power and extent,
+involving extended and increasing condensation, producing the most violent
+electrical phenomena, and thus continuing up, even to the Arctic circle?
+Yes, says Professor Dove. No, say all fact, all analogy, and his own
+principles.
+
+7. His theory relative to the typhoons is unintelligible. If they
+originate near the lateral confines of the great region of atmospheric
+expansion, they originate in the region of the trade-winds, for the two
+are identical. How the direct pressure of the air from the trade-wind over
+the Pacific, in the more expanded air of the monsoon region, can occasion
+a typhoon upon any principles, passes my comprehension. If, as Lieutenant
+Maury supposes, the monsoons are reversed trades, then the trade-wind and
+monsoon region are identical. If the monsoons are found in the belt of
+rains, then, the trades, upon Professor Dove's principles, pass into the
+monsoon region by attraction or suction, without pressure. Either way the
+theory is undeserving of consideration.
+
+A new theory has recently been started by Mr. Thomas Dobson, and, although
+it is (like all other efforts to get the _upper strata down_ to produce
+condensation, or those below _up_, that they may be condensed), without
+foundation, his collection of facts is brief and interesting. I copy his
+article from the London, Edinburgh, and Dublin Phil. Mag., for December,
+1853. It adds to the collection of facts in relation to the connection
+between volcanic action and storms for the seventeenth century, made by
+Dr. Webster:
+
+     The following appear to be the main facts which are available as a
+     basis for a theory which shall comprehend all the meteors in
+     question:
+
+     1st. The eruption of a submarine volcano has produced water-spouts.
+
+     "During these bursts the most vivid flashes of lightning continually
+     issued from the densest part of the volcano, and the volumes of smoke
+     rolled off in large masses of fleecy clouds, gradually expanding
+     themselves before the wind in a direction nearly horizontal, and
+     drawing up _a quantity of water-spouts_."--(Captain Tilland's
+     description of the upheaval of Sabrina Island in June, 1811, Phil.
+     Trans.)
+
+     With this significant fact may be compared the following analogous
+     ones:
+
+     "In the Aleutian Archipelago a new island was formed in 1795. It was
+     first observed _after a storm_, at a point in the sea from which a
+     column of smoke had been seen to rise."--(Lyell, Principles of
+     Geology.)
+
+     "Among the Aleutian Islands a new volcanic island appeared in the
+     midst of _a storm_, attended with flames and smoke. After the sea was
+     calm, a boat was sent from Unalaska with twenty Russian hunters, who
+     landed on this island on June 1st, 1814."--(Journal of Science, vol.
+     vii.)
+
+     "On July 24th, 1848, a submarine eruption broke out between the
+     mainland of Orkney and the island of Strousa. Amid thunder and
+     lightning, a very dense jet black cloud was seen to rise from the
+     sea, at a distance of five or six miles, which _traveled toward the
+     north-east_. On passing over Strousa, the wind from a slight air
+     became _a hurricane_, and a thick, well-defined belt of large
+     hailstones was left on the island. The barometer fell two
+     inches."--(Transactions Royal Society, Edinburg, vol. ix.)
+
+     2d. Hurricanes, whirlwinds, and hailstones accompany the paroxysms of
+     volcanos.
+
+     "1730. A great volcanic eruption at Lancerote Island, and _a storm_,
+     which was equally new and terrifying to the inhabitants, as they had
+     never known one in the country before."--(Lyell, Principles of
+     Geology, vol. ii.)
+
+     "1754. In the Philippine Islands a terrible volcanic eruption
+     destroyed the town of Taal and several villages. Darkness,
+     hurricanes, thunder, lightning, and earthquakes, alternated in
+     frightful succession."--(Edinburgh Philosophical Journal.)
+
+     "In 1805, 1811, 1813, and 1830, during eruptions of Etna, caravans in
+     the deserts of Africa perished by violent whirlwinds. In 1807, while
+     Vesuvius was in eruption, a whirlwind destroyed a caravan."--(Rev. W.
+     B. Clarke in Tasw. Journal.)
+
+     "1815, Java. A tremendous eruption of Tombow Mountain. Between nine
+     and ten P.M., ashes began to fall, and soon after _a violent
+     whirlwind_ took up into the air the largest trees, men, horses,
+     cattle, etc."--(Raffles' History of Java.)
+
+     "1817, Dec. Vesuvius in eruption. In the evening _a hail storm_,
+     accompanied with red sand."--(Journal of Science, vol. v.)
+
+     "1820, Banda. A frightful volcanic eruption, and in the evening an
+     earthquake and a violent hurricane."--(Annales de Chimie.)
+
+     "1822, Oct. Eruption of Vesuvius. Toward its close the volcanic
+     thunder-storm produced an exceedingly violent and abundant fall of
+     rain."--(Humboldt, Aspects of Nature.)
+
+     "1843, Jan. Etna in eruption. Violent hurricanes at Genoa, in the Bay
+     of Biscay, and in Great Britain.
+
+     "1843, Feb. Destructive earthquakes in the West Indies, a volcanic
+     eruption at Guadaloupe, followed by hurricanes in the Atlantic."
+
+     "1846, June 26. Volcano of White Island, New Zealand, in eruption.
+     Heavy squalls of wind and hail; it blew as hard as in a
+     typhoon."--(Commodore Hayes, R.N., in Naut. Mag., 1847.)
+
+     "1847, March 20. Volcanic eruption and earthquake in Java; and on the
+     21st of March, and 3d of April, violent hurricanes."--(Java Courant.)
+
+     "1851, Aug. 5. A frightful eruption of the long dormant volcano of
+     the Pelée Mountain, Martinique. Aug. 17. Hurricane at St. Thomas,
+     etc.; earthquake at Jamaica, etc.
+
+     "1852, April 14. Earthquake at Hawaii, and on the 15th a great
+     volcanic eruption. On the 18th _a gale of unusual violence_ lasted
+     thirty-six hours, and did great damage."--(The Polynesian, April 22,
+     1852.)
+
+     3d. In volcanic regions, earthquakes and hurricanes often occur
+     almost simultaneously, but in no certain order, and without any
+     volcanic eruption being observed.
+
+     In 1712, 1722, 1815, and 1851, earthquakes and hurricanes occurred
+     together at Jamaica; in 1762 at Carthagena; in 1780 at Barbadoes; in
+     1811 at Charleston; in 1847 at Tobago; in 1837 and 1848 at Antigua;
+     in 1819, an awful storm at Montreal, rain of a dark inky color, and a
+     slight earthquake. People conjectured that a volcano had broken out.
+     In 1766 the great Martinique hurricane, a _waterspout_ burst on Mount
+     Pelée and overwhelmed the place. Same night, an earthquake.
+
+     1843, Oct. 30. Manilla.--Twenty four hours' rain and two heavy
+     earthquakes. 10 P.M., a severe hurricane.
+
+     "1852, Sept. 16. Manilla--An earthquake destroyed a great part of the
+     city; many vessels wrecked by a great hurricane in the adjacent seas,
+     between the 18th and 26th of September."--(Singapore Times.)
+
+     "1731, Oct. Calcutta.--Furious hurricane and violent earthquake;
+     300,000 lives lost."
+
+     "1618, May 26. Bombay.--Hurricane and earthquakes; 2,000 lives
+     lost."--(Madras Lit. Tran., 1837.)
+
+     "1800. Ongole, India, and in 1815, at Ceylon, a hurricane and
+     earthquake shocks."--(Piddington.)
+
+     "1348. Cyprus.--An earthquake and a frightful hurricane."--(Hecker.)
+
+     "1819. Bagdad.--An earthquake and _a storm_--an event quite
+     unprecedented.
+
+     "1820, Dec. Zante.--Great earthquake and hurricane, with
+     manifestations of a submarine eruption."--(Edinburg Phil. Journal.)
+
+     "1831, Dec. Navigator's Islands.--Hurricane and
+     earthquakes."--(Williams' Missionary Enterprise.)
+
+     "1848, Oct., Nov. New Zealand.--Succession of earthquake shocks, and
+     several tempests.
+
+     "1836, Oct. At Valparaiso, a destructive tempest and severe
+     earthquakes."--(Nautical Magazine, 1848.)
+
+     When an earthquake of excessive intensity occurs, as at Lisbon, in
+     1755, the volcanic craters, which act as the safety-valves of the
+     regions in which they are placed, are supposed to be sealed up; and
+     it is a remarkable and highly-suggestive fact, that _no hurricane
+     follows such an earthquake_. The number of instances of the
+     concurrence of ordinary earthquakes and hurricanes might easily be
+     increased, but the preceding suffice to show the _generality_ of
+     their coincidence, both as _to time_ and place.
+
+     4th. The breaking of water-spouts on mountains sometimes accompanies
+     hurricanes.
+
+     In 1766, during the great Martinique hurricane, before cited.
+
+     "1826, Nov. At Teneriffe, enormous and most destructive water-spouts
+     fell on the culminating tops of the mountains, and a furious cyclone
+     raged around the island. The same occurred in 1812 and in
+     1837."--(Espy and Grey's Western Australia.)
+
+     "1829. Moray.--Floods and earthquakes, preceded by water-spouts and a
+     tremendous storm."--(Sir T. D. Lander.)
+
+     "1826, June. Hurricanes, accompanied by water-spouts and fall of
+     avalanches, in the White Mountains."--(Silliman's American Journal,
+     vol. xv.)
+
+     5th. The fall of an avalanche sometimes produces a hurricane.
+
+     "1819, Dec. A part (360,000,000 cubic feet) of the glacier fell from
+     the Weisshorn (9,000 feet). At the instant, when the snow and ice
+     struck the inferior mass of the glacier, the pastor of the village of
+     Randa, the sacristan, and some other persons, _observed a light_. A
+     frightful hurricane immediately succeeded."--(Edinburg Philosophical
+     Journal, 1820.)
+
+     6th. Water-spouts occur frequently near active volcanos.
+
+     This is well known with regard to the West Indies and the
+     Mediterranean. The following notices refer to the Malay Archipelago
+     and the Sandwich Islands:
+
+     "Water-spouts are often seen in the seas and straits adjacent to
+     Singapore. In Oct., 1841, I saw _six_ in action, attached to one
+     cloud. In August, 1838, one passed over the harbor and town of
+     Singapore, dismasting one ship, sinking another, and carrying off the
+     corner of the roof of a house, in its passage landward."--(Journal of
+     Indian Archipelago.)
+
+     "1809. An immense water-spout broke over the harbor of Honolulu. A
+     few years before, one broke on the north side of the island (Oahu),
+     washed away a number of houses, and drowned several
+     inhabitants."--(Jarves' History of Sandwich Islands.)
+
+     7th. Cyclones begin in the immediate neighborhood of active volcanos.
+
+     The Mauritius cyclones begin near Java; the West Indian, near the
+     volcanic series of the Caribbean Islands; those of the Bay of Bengal,
+     near the volcanic islands, on its eastern shores; the typhoons of the
+     China Sea, near the Philippine Islands, etc.
+
+     8th. Within the tropics, cyclones move toward the west; and, in
+     middle latitudes, cyclones and water-spouts move toward the N. E., in
+     the northern hemisphere, and toward the S. E. in the southern
+     hemisphere.
+
+     9th. In the northern hemisphere, cyclones rotate in a horizontal
+     plane, in the order N. W., S. E.; and in the southern hemisphere, in
+     the order N. E., S. W.
+
+     By applying the principles of electro-dynamics to the electricity of
+     the atmosphere, I shall endeavor to connect and explain the preceding
+     well-defined facts. The continuous observations of Quetelet, on the
+     electricity of the atmosphere, from 1844 to 1849 (Literary Journal,
+     February, 1850), show that it is always positive, and increases as
+     the temperature diminishes. It therefore increases rapidly with the
+     height above the earth's surface. We may, consequently, regard the
+     upper and colder regions of the atmosphere as an immense reservoir of
+     electric fluid enveloping the earth, which is insulated by the
+     intermediate spherical shell formed by the lower and denser
+     atmosphere. Now, whenever a vertical column of this atmosphere is
+     suddenly displaced, the surrounding aqueous vapor will be immediately
+     condensed and aggregated, and the cold rarefied air and moisture will
+     form a vertical conductor for the descent of the electrical fluid.
+     This descent will take place down a spiral, gyrating in the order N.
+     W., S. E., in the northern hemisphere, since the electric current is
+     under the same influence as that of the south pole of a magnet; and
+     in the order N. E., S. W., in the southern hemisphere. The air
+     exterior to the conducting cylinder will partake of the violent
+     revolving motion, and a tornado or cyclone will be produced.
+
+Upon the foregoing facts I shall comment in another place.
+
+Three theories have been advanced by meteorologists of this country, two
+of which profess to explain all the phenomena of the weather. Professor
+Espy attributed the production of storms and rain to an ascending column
+of air, rarefied by heat, and the rarefaction increased by the latent heat
+of vapor given out during condensation, and an inward tendency of the air,
+from all directions, toward the ascending vortex, constituting the
+prevailing winds. Thus, Professor Espy conceived, and to some extent
+proved, that the wind blew inward, from all sides, toward the center of a
+storm, either as a circle, or having a long central line, and he conceived
+that it ascended in the middle, and spread out above; and that clouds,
+rain, hail, and snow, were formed by condensation consequent upon the
+expansion and cooling of the atmosphere, as it attained an increased
+elevation.
+
+_This ascent_ was not, in fact, _proved_ by Professor Espy, _has not been
+found by others_, and _is not discoverable, according to my observations_.
+The theory was ingenious, founded on the theory of Dalton, that the vapor
+was maintained in the atmosphere by reason of a large quantity of latent
+heat, which was given out when condensation took place. This theory is
+also unsound. No such elevation of temperature is found in clouds or fogs
+when they form near the earth, however dense. Thus the two principal
+elements of Professor Espy's theory are found to be untrue, and the theory
+untenable. But it was sustained with great ability and research, and the
+distinguished theorist deserves much for the discovery and record of
+important facts in relation to the weather. Aside from its theoretical
+views, his book contains a great mass of valuable information, and will
+well repay the cost of purchase and perusal.
+
+Another theory, by Mr. Bassnett, is of recent date, founded on the
+influence of the moon, and the supposed creation of vortices in the ether
+above, whose influence extends to the earth, producing storms and other
+phenomena. No one can peruse his book without conceding to him great
+ability and scientific attainment; and if his theory was true, the periods
+of fair and foul weather could be calculated with great mathematical
+certainty. But it contains inherent and insuperable objections. I will
+only add that all herein before contained is in direct opposition to it.
+
+Mr. W. C. Redfield, of New York, as early as 1831, first advanced in this
+country the theory of gyration in storms, and investigated their lines of
+progress on our coast and continent. His theory is limited in its
+character, and does not profess, except indirectly, to explain all, or
+indeed any, of the other phenomena of the weather. As far as it goes,
+however, it is generally received in this country and Europe, and has
+been adopted by Reed, Piddington, and others, who have written on the law
+of storms. The position of Mr. Redfield is honorable to himself and his
+country. Science and navigation are much indebted to him for his industry
+in the collection of facts. Nevertheless, his theory is not in accordance
+with my observation, and I deem it unsound. Although expressed disbelief
+of the theory has been characterized as an "attack" upon its author, I
+propose, with that _respect_ which is due to him, but with that _freedom_
+and _independence_ which a search for _truth_ warrants, to examine it with
+some particularity. It is a part of the subject, and I can not avoid it.
+
+When the theory was first announced, I adopted it as probably true; and
+being then engaged in a different profession, which took me much into the
+open air by night and day, I watched with renewed care the clouds and
+currents for evidence to confirm it. I discovered none; on the contrary, I
+found much, very much, absolutely and utterly inconsistent with its truth.
+The substance only of these observations will be adduced.
+
+Mr. Redfield admits that the progression of our storms in the vicinity of
+New York, is from some point between S. S. W. and W. S. W., to some point
+between N. N. E. and E. N. E. According to my observation, except perhaps
+in occasional autumnal gales, they are not often, if ever, from S. of S.
+W., and the great majority of them, including, I believe, all N. E.
+storms, are between S. W. and W. S. W. Now, the card of Mr. Redfield,
+moving over any place from any point between S. W. and W. S. W., calls for
+a S. E. wind at its axis, an E. wind at its north front, and a S. wind at
+its south front, and does not call _for a N. E. wind on its front at all,
+except at the north extreme_, where it could _not continue for any
+considerable period_.
+
+
+[Illustration: Fig. 17.]
+
+
+In relation to this, I observe, 1st. _About one-half of our N. E. storms,
+including some of the most severe ones, not only set in N. E., but
+continue in that quarter without veering at all, during the entire period
+that the storm cloud is over us_; usually for twenty-four hours; not
+unfrequently for forty-eight hours, sometimes for seventy-two or more
+hours. This every one can observe for himself, and it can not, of course,
+be reconciled with his theory.
+
+2d. N. E. storms, whether they set in from that quarter in the
+commencement, or veer to it afterward, when they do "change" round, more
+frequently veer by the S. to the S. W. in clearing off, than back through
+the N. into the N. W. The former, in accordance with his theory, they can
+not do, as the reader can see by passing the left side of the card over
+his place of residence on the map from S. W. to N. E.
+
+3d. N. E. storms often pass off without hauling by S. or backing by N.,
+and with or without a clearing off shower, the _wind shifting and coming
+out suddenly at S. W._ This they could not do in accordance with his
+theory, as slipping the card will show.
+
+4th. From June to February it is _exceedingly uncommon_ for a N. E. storm
+to back into the N. W. They do so more frequently from February to May,
+especially about the time of the vernal equinox and after; and then,
+because the focus of precipitation and storm intensity of the extra
+tropical zone of rains is S. of 42° east of the Alleghanies. His theory
+requires them to back by N. into N. W. _in all cases, when they set in N.
+E._
+
+5th. When they do back from the N. E. into the N. W., it rarely indeed
+continues to storm after the wind leaves the point of N. E. by N., and
+generally, if it does continue stormy, _the wind is light_, and not a
+gale, how violent soever the gale from the eastward may have been.
+Usually, by the time the wind gets N. W., it has cleared off. This, Mr.
+Redfield, as we shall see, evades by embracing the N. W. fair wind as a
+part of the same gale. According to my observation, therefore, a _very
+large proportion_ of the _N. E. storms_, and they are a majority of the
+most violent ones of our climate east of the Alleghanies, do not
+_commence, continue_, or _veer_ in accordance with his theory, but the
+_reverse_; and so long as this is so, I can not receive his theory as
+true.
+
+6th. S. E. storms do not always, or indeed often, conform to the
+requirements of his card. When they set in violently at S. E., and
+continue so for hours without veering, the axis of the storm should be
+over us, and the wind should change _suddenly_ to N. W. This did not occur
+in the storm of Sept. 3, 1821, nor does it often, if ever, occur in the
+summer or early gales of the autumnal months. In the later storms of
+autumn, and as often in those which are very gentle as any, and in the
+winter months when S. E. gales are rare, it does sometimes so change after
+the storm cloud has passed. But in the winter months, as in the storm
+investigated by Professor Loomis, the storms are frequently long from S.
+E. to N. W., and the S. E. wind blows nearly in coincidence with its long
+axis, for a thousand or fifteen hundred miles, till the barometric minimum
+is passed, and the inducing and attracting force of this part of the storm
+cloud is spent, and then the N. W. wind follows; sometimes blowing in
+under the storm cloud, turning the rain to snow; but oftener following the
+storm within a few hours, or the next day. The storm of Professor Loomis,
+when over Texas, was not probably more than four or five hundred miles in
+length. As it curved more, and passed north and east, it extended
+laterally, its center traveling with most rapidity, and when it reached
+the eastern coast was about fifteen hundred miles long, and not more than
+six hundred broad. Along the eastern part of that storm, except when by
+its more rapid progress the front projected much further eastward over New
+England than its previously existing line, the S. E. winds blew. When it
+bulged out, so to speak, by reason of the increased progress of the
+center, the wind veered to the N. E. The center of the storm passed near
+St. Louis and south of Quebec, as the _fall of rain_, the _bulging_ of the
+_rapidly-moving center_, and the _line of subsequent cold_, attest. It is
+utterly impossible for any unbiased mind to look at the description of
+that storm, and attribute to it a rotary character. With all the data
+before him, Mr. Redfield himself has not attempted it directly.[8]
+
+The September storm of 1821 was more violent in character than any which
+have since occurred. My recollection of it is as distinct as if it
+occurred yesterday. Peculiar circumstances, not important in this
+connection, fixed my attention upon the weather during that day and night.
+There were cirro-stratus clouds passing all day, from about S. W. to N.
+E., thickening toward night with fresh S. S. W. wind and flocculent scud,
+such as I have since seen at the setting-in of S. E. autumnal gales. In
+the evening the wind (in the immediate neighborhood of Hartford, Ct.),
+veered to S. E., the cloud floated low, it became very dark, and the wind
+blew a most violent gale. The trees were falling about the house where I
+then resided, the windows were burst in, and I was up and observant. When
+the cloud passed off to the east, it was suddenly light, and almost calm.
+The western edge of the storm cloud was as perpendicular as a steep
+mountain side, and was enormously elevated, and very black. I have
+sometimes seen the western side of a summer thunder cloud, which had drawn
+a violent gust along beneath it, as elevated and perpendicular, but never
+a storm cloud. No cloud of that _depth_, or _intensity_ as exhibited by
+its peculiar blackness, ever floated or will float so near the earth,
+without inducing a devastating current beneath. After it had passed the
+ridges east of the Connecticut valley, its top could be seen for a long
+and unusual period over the elevated ranges.
+
+Now that storm was but an _intense portion_ of an extensive stratus-rain
+cloud. Such portions frequently exist, and Mr. Redfield admits the fact.
+Another like portion, in the same storm, passed over Norfolk, Virginia,
+and the adjacent section, where the wind was N. E., and veered round by N.
+W. to S. W. Baltimore, and some vessels at sea, were between the two
+intense portions of the storm, and were not affected by either. Its
+northern limit was bounded by a line, drawn from some point not far north
+of Trenton, New Jersey, north-eastward, and north of Worcester,
+Massachusetts. I was about forty miles south of its northern limit, and
+north of its center. During that day, and the next, there was wind from
+S. W. to S. E., inclusive, including the gale, and _from no other
+quarter_. It did not at any time veer to the W. or N. W. After the passage
+of the storm-cloud, the wind was very light. When this intense portion of
+the storm passed over the valley of the Connecticut, its longest axis was
+from S. S. E. to N. N. W., and the _wind was S. E. the whole length of
+it_. In its passage from the longitude of Trenton to Boston, there was N.
+W. wind at one point, and but one, and that was in the iron region, at the
+N. W. corner of Connecticut, at the northern limit of the intense cloud,
+and owing, doubtless, to some local cause. The direction of the wind in
+that storm was in accordance with what is generally true of our storms.
+The wind on the front of the storm depends upon its shape. If the storm is
+long in proportion to its width (and no other _violent_ autumnal or winter
+storm has been investigated, to my knowledge), the wind blows axially, or
+obliquely, on its front. Thus, if long from S. E. to N. W., the wind on
+its front will blow from the S. E. So, if the storm is long from S. W. to
+N. E., and has a south-eastern lateral extension, with an easterly
+progression, the wind will blow axially in the center, and obliquely at
+the edges. Instances might be multiplied, but I refer to one of recent
+date and striking character. All of us remember the drought of 1854. It
+ended in drenching rain on the 9th of September. This rain fell from a
+belt, half showery and half stormy in character, which had a S. E. lateral
+extension.
+
+The evening of the previous day there was some lightning visible at the
+north, and the usual S. S. W. afternoon wind _continued fresh after
+nightfall_. The next day we had a brisk wind from the same quarter, and,
+after noon, the clouds appeared to pile up in the far north, seeming very
+elevated. They continued to do so, extending southerly during the
+afternoon, _with a high wind from S. S. W._, the cumulus clouds moving E.
+N. E. At 5 P.M., gentlemen who left New York at 3 P.M., reported that a
+dispatch had been received from Albany, dated 1 P.M., stating that it was
+raining very heavily there. About 7 P.M., the belt reached us, and it
+rained heavily from that time till morning. Not far from 8 P.M., and
+during the heaviest rain, the wind shifted from the S. S. W. to N. E., and
+blew fresh and cold from that quarter during the night, and till the belt
+had passed south, and then from N. E. by N., cool, with heavy scud, during
+the forenoon, veering gradually to the N. N. E., and dying away. After the
+rain ceased, the northern edge of the belt was distinctly visible in the
+S. and S. E., its stratus-cloud moving E. N. E., and its scud to the
+westward.
+
+The front of that storm did not pass over us. It was long and narrow. The
+wind blew somewhat obliquely inward, along its southern border, to the
+eastward, and, in like manner, to the westward, on its northern border,
+but from the N. E. axially along its central portions.
+
+In the last instance, the wind changed from S. W. to N. E. This, too, is
+impossible, according to Mr. Redfield's theory. Similar instances, in
+summer, and early autumn, are not uncommon. But I shall recur to this in
+connection with the different _classes_ of storms.
+
+Again, the manner in which these S. E. winds co-exist with the N. E., and
+become the prevailing wind, toward the close of the storm, is instructive,
+and inconsistent with the theory of Mr. Redfield. In the West Indies, the
+first effect of the storm is to increase the N. E. trade; the wind then
+becomes baffling, but settles in the N. W. or N. N. W., _in direct
+opposition to the admitted progress of the storm_. At this point, or at S.
+W., it blows with most force. Sometimes it veers gradually, and sometimes
+falls calm, and comes out from the S. W., blowing violently. It ends by
+veering to the S. E., following gently the course of the storm. Thus, Mr.
+Edwards, in the third volume of his History of Jamaica, as herein before
+cited, "_all hurricanes begin from the north, veer back to W. N. W., W.,
+and S. S. W., and when they get round to S. E. the foul weather breaks
+up_."
+
+A short, sudden gale, resembling those of our summer thunder-showers, is
+sometimes met with from the S. E.; but the violent hurricanes of any
+considerable continuance are, in almost every case, as just stated.
+
+Now, there is, in our latitudes, an obvious law on the subject, and it is
+this:--If the storm is not disproportionately long, northerly and
+southerly, there is a general tendency to induce and attract a surface
+current, in opposition to the course of the storm on its front, and
+especially its north front. At the same time, there is a tendency to
+induce a lateral current on its side, particularly the southerly side, and
+sometimes its south front: that the latter current is, in the first part
+of the storm, above the former; in the middle and latter part, it becomes
+the prevailing current at the surface, and the wind changes accordingly,
+with or without a calm--that this lateral change sometimes takes place on
+either side, but usually occurs on the side where the water is warmest, or
+there is, for other and local reasons, a _greater susceptibility in the
+atmosphere to inductive and attractive influence_. Thus, our N. E. storms
+very frequently have a southerly current also, drawn from the ocean, south
+of us, which forms the middle current, and, in the middle and latter part
+of it, becomes the prevailing one. _I have seen more than a hundred such
+instances, clearly and distinctly marked._ Since I have been writing this
+chapter, January 29th, 1855, such an instance has occurred. On Sunday, the
+28th, the cirro-stratus were all day passing from the S. W. to N. E., and
+gradually thickening with light air from the E. N. E., in the afternoon.
+During the evening the wind set in _violently_ from the N. E., with a
+deluging rain. During the night, and after a brief calm, it changed
+suddenly to the southward, and blew in like manner. This morning the storm
+was gone, and with it, six inches of hard, frozen icy snow; the trade was
+clear, with the exception of here and there a broken, melting piece of
+stratus, but scud were still running from the southward, and the wind has
+been from the south, veering to S. W., all day, with sunshine. As I have
+before remarked, this middle current is always present, in this locality,
+in stratus storms, when there is a heavy fall of rain or snow, although,
+when the latter happens, the middle current is sometimes from the
+northward; if it be from the southward, it turns the snow first into very
+large flakes, and then to rain in our part of the storm.
+
+Doubtless, the same thing occurs every where. In the West Indies, and
+especially over the Leeward Islands, the middle current is most commonly
+from the stream of warm water which runs off to the westward into the
+Caribbean Sea; as the S. W. moonsoon is from the same current below the
+Cape de Verdes. The S. W. winds, which come from those south polar waters,
+in the West Indies, appear to be the most violent. But it may be on either
+or both sides.
+
+The hurricane cloud of the West Indies moves confessedly N. W. in most
+instances, and undoubtedly it does in all. There is an immutable law that
+requires it. The seeming exceptions are not such; they are but instances
+imperfectly investigated. Now, a circular storm moving N. W. can set in N.
+W. only on the left front, and _can not change to S. W. on that side of
+the axis_. Nor can the wind blow at the axis from N. W. at all. It should
+be N. E. in first half, and S. W. in last half. Strange as it may seem,
+the axis of a West India hurricane in conformity with Mr. Redfield's
+theory, and a N. W. progression, has never been found, with perhaps a
+single exception, in any one of which I have seen a description. On the
+west coast of Europe, the gale is commonly from the Atlantic, either
+following under the storm from the S. W., or blowing in diagonally from
+the W. or N. W.; the N. E. wind of western Europe being a cold, dry wind,
+which there is reason to believe has been around the Siberian pole and is
+returning, as the cold northerly winds of the North Pacific have around
+the North American magnetic pole. "If the N. E. winds always prevailed,"
+says Kämtz, speaking of Berlin, "even at a considerable height it would
+never rain." This was based on an observation of showers, and not fully
+reliable. But the dry and cool character of the N. E. wind of western
+Europe is unquestionable. The S. E. wind is also a storm wind, but owing
+to the character of the surface from which it is attracted, it is not as
+violent as the westerly winds are.
+
+Such, too, is the general course and character of the side wind in the
+southern hemisphere. There gales are less frequent, the magnetic intensity
+is less, the counter-trades are less; it is not in "the order of
+Providence" that as much rain shall fall there. Nevertheless, gales occur,
+although rarely, if ever, with equal violence. About New Holland, where
+storms are pursuing a S. E. course, they have the wind N. E.,
+corresponding to our S. E., veering from thence, _by the north_, to the
+westward, clearing off from S. W., with a rising barometer, as ours do
+from N. W.
+
+In the Bay of Bengal, the Indian Ocean, and the Arabian Sea, there is more
+irregularity.
+
+But the law of progress and lateral winds can be distinctly traced as
+_present_ and prevailing, notwithstanding the irregularities. Our limits
+do not permit an analysis. In the celebrated case of the Charles Heddle,
+there was much evidence to show that she was driven across the front of
+the storm by one lateral wind, and back by another. (Diagram of Colonel
+Reid, p. 206.)
+
+The waters of the Indian Ocean are hot and confined. Storms there are
+often composed of detached masses, move slower--sometimes not more than
+three or four miles an hour--and they curve over the ocean, where it is
+hotter than in any similar latitude. Yet, notwithstanding all
+peculiarities and irregularities, the law we have been considering is
+probably the _prevailing_ law there.
+
+No man knows better the existence of these different currents than Mr.
+Redfield. Doubtless it has escaped his attention that the upper of two,
+after the passage of a considerable proportion of the storm, becomes the
+lower, and causes a seeming change of the same wind.
+
+In a series of elaborate articles, substantially reviewing the whole
+subject, published in the American Journal of Science, for 1846, he says:
+
+     "In nearly all great storms which are accompanied with rain, there
+     appear two distinct classes of clouds, one of which, comprising the
+     storm scuds in the active portion of the gale, has already been
+     noticed. Above this is an extended stratum of stratus cloud, which is
+     found moving with the general or local current of the lower
+     atmosphere which overlies the storm. It covers not only the area of
+     rain, but often extends greatly beyond this limit, over a part of the
+     dry portion of the storm, partly in a broken or detached state. This
+     stratus cloud is often concealed from view by the nimbus, and scud
+     clouds in the rainy portion of the storm, but by careful
+     observations, may be sufficiently noticed to determine the general
+     uniformity of its specific course, and, approximately, its general
+     elevation.
+
+     "The more usual course of this extended cloud stratum, in the United
+     States, is from some point in the horizon between S. S. W. and W. S.
+     W. Its course and velocity do not appear influenced in any
+     perceptible degree by the activity or direction of the storm-wind
+     which prevails beneath it. On the posterior or dry side of the gale,
+     it often disappears before the arrival of the newly condensed cumuli
+     and cumulo-stratus which not unfrequently float in the colder winds,
+     on this side of the gale."
+
+     "The general height of the great stratus cloud which covers a storm,
+     in those parts of the United States which are near the Atlantic, can
+     not differ greatly from one mile; and perhaps is oftener below than
+     above this elevation. This estimate, which is founded on much
+     observation and comparison, appears to comprise, at the least, the
+     limit or thickness of the proper storm-wind, which constitutes the
+     revolving gale.
+
+     "It is not supposed, however, that this disk-like stratum of
+     revolving wind is of equal height or thickness throughout its extent,
+     nor that it always reaches near to the main canopy of stratus cloud.
+     It is probably higher in the more central portions of the gale than
+     near its borders, in the low latitudes, than in the higher, and may
+     thin out entirely at the extremes, except in those directions where
+     it coincides with an ordinary current. Moreover, in large portions of
+     its area, there may be, and often is, more than one storm-wind
+     overlying another, and severally pertaining to contiguous storms. In
+     the present case, we see, from the observations of Professor Snell
+     and Mr. Herrick, at Amherst, Massachusetts, and at Hamden, Maine (115
+     and 135 b.), that the true storm wind, at those places, was
+     super-imposed on another wind; and various facts and observations may
+     be adduced to show that brisk winds, of great horizontal extent, are
+     often limited, vertically to a very thin sheet or stratum."
+
+Much of the foregoing is graphically described, and unquestionably true.
+But it may well be asked how he, or others, distinguish which of two or
+more currents (for there are frequently three, and sometimes four
+visible), are the true currents of the storm, and which interlopers from
+another storm? Is the true one always the upper one, and why? If the
+upper one, why is the interloper at the surface noted and quoted to prove
+what a storm is? How does he know what proportions of the winds he has
+recorded to show the revolving motion of gales, were the true storm winds
+of the particular storm? or, that every one of them was not an interloping
+wind on which the true storm wind was superimposed?
+
+These inquiries are pertinent, for obviously, unless some rule for
+distinguishing between the currents is given, and there be evidence of
+direct observation to show that the surface wind, whose direction is
+noted, is the true wind of the storm, and that the _latter_ is not
+_superimposed_, no reliance can be placed upon logs, or newspaper
+accounts, or registers. There is another element besides direction, viz.:
+superimposition, a determination of which _is_ essential to _truth_. It
+will be difficult for Mr. Redfield to say that a determination of that
+element has been made, with certainty, in a single storm he has
+investigated; and in relation to the convergence of storms, and blending,
+and superimposition of their winds, I think he is mistaken.
+
+Mr. Redfield is right in saying (American Journal of Science, vol. ii.,
+new series, p. 321) that "too much reliance may be placed upon mere
+observations of the surface winds in meteorological inquiries," and yet
+_they_ only have thus far been regarded, and he has proved gyration in no
+other way. I have frequently, with a vane in sight, asked intelligent men
+how the wind was, and been amused and instructed by their inability to
+state it correctly. Mr. Redfield, in his inquiries, often found two
+reports of the weather at the _same time_, from the _same place_,
+materially different; and I have known, from my own observation,
+newspapers and meteorological registers to be several points out of the
+way; and this, because the vanes are influenced by local elevations, and
+change several points, and very often; because few know the exact points
+of the compass in their own localities, and because entire accuracy has
+not been deemed essential. For these reasons, newspaper and telegraphic
+reports are not always reliable; and therefore, and because, also,
+storm-winds are easterly and fair winds westerly, and the former veer from
+east around to west, on one or both sides in many cases, there are few
+storms which can not be represented as whirlwinds, by a proper _selection_
+of _reports_, a corresponding _location_ of the _center_, and an
+_extension_ of the lines of supposed gyration, so as to include the
+_preceding_ winds, the actual winds of the storm, and the _lateral_, and
+_succeeding_ fair weather ones.
+
+But, again, Mr. Redfield is right in saying there is, in such cases, "an
+extended stratum of stratus cloud," and it is always present. But why does
+he say this _covers the storm_? Is it distinct from it, and if so, what is
+it doing there? What power placed it there, and for what purpose? Has this
+extended stratum of cloud, which forms the canopy of a vast chamber--five
+hundred to one thousand miles in diameter, and less than two miles in
+vertical depth, while the earth forms the floor--any agency in producing
+the whirl that is supposed to be going on within it, and if so, what? Has
+the earth any agency, and if so, what? If neither the ceiling nor floor of
+the chamber have any agency in producing it, what does? Are we to consider
+the _storm-scud_ as possessing the power, and as waltzing around the
+aerial chamber, carrying the air with them in a hurricane-dance of
+devastation? _What, in short, is the power, and how is it exerted?_
+
+To these questions, Mr. Redfield's essays furnish no comprehensive answer.
+There is an intimation that the cause of storms will be, at some future
+day, developed. One attempt, and but one, has thus far been made, and that
+I quote entire:
+
+     "We have seen that the two Cuba storms, as well as the Mexican
+     northers, have appeared to come from the contiguous border of the
+     Pacific Ocean.
+
+     "Now, are there any peculiarities in the winds and aerial currents of
+     those regions, which may serve to induce or support a leftwise
+     rotation in extensive portions of the lower atmosphere, while moving
+     on, or near the earth's surface? I apprehend there are such
+     peculiarities, which have an extensive, constant, and powerful
+     influence. First, we find on the eastern portion of the Pacific, from
+     upper California to near the Bay of Panama, an almost constant
+     prevalence of north-westerly winds at the earth's surface. Next, we
+     have an equally constant wind from the southern and south-western
+     quarter, which, having swept the western coast of South America,
+     _extends across the equator to the vicinity of Panama_, thus meeting,
+     and commonly over-sliding the above-mentioned westerly winds, and
+     tending to a deflection or rotation of the same, from right to left.
+     As this influence may thus become extended to the Caribbean or
+     Honduras Sea, we have, next, the upper or S. E. trade of this sea,
+     which is here frequently a surface-wind, and must tend to aid and
+     quicken the gyrative movement, ascribed to the two previous winds;
+     and lastly we have the N. E. or lower trade, from the tropic, which,
+     coinciding with the northern front of the gyration, serves still
+     further to promote the revolving movement which may thus result from
+     the partial coalescence of these great winds of Central America, and
+     the contiguous seas.
+
+     "Thus, while a great storm is, in part, on the Pacific Ocean, its N.
+     E. wind may be felt in great force on that side of the continent,
+     through the great gorges or depressions near the bays of Papagayo or
+     Tehuantepec, as noticed by Humboldt, Captain Basil Hall, and others,
+     the elevations which there separate the two seas being but
+     inconsiderable; and, when the gyration is once perfected, the whole
+     mass will gradually assume the movement of the predominant current,
+     which is generally the higher one, and will move off with it,
+     integrally, as we see in the cases of the vortices, which are
+     successively found in particular portions of a stream, where subject
+     to disturbing influences."
+
+The analogy between this and the theory of Professor Dove, cited above,
+and prior, in point of time, is obvious. They are substantially alike in
+principle, with different locations. They differ also in this, Professor
+Dove appears to think something more than over-sliding necessary, and
+assigns the duty of crowding the upper current down in to the lower, to
+make an _encounter_, to a lateral overflow from Africa. Mr. Redfield seems
+to think there may be a tendency to deflection when they "over-slide" each
+other. They are both closet hypotheses, the poetry of meteorology, with
+something more than poetical license as to facts.
+
+In the first place, _no such concurring winds exist in the same locality
+at the same time_. When the inter-tropical belt of rains is over Central
+America and Southern Mexico, a S. W. monsoon blows in under it, but it
+usurps the place of all other surface winds; and, when the belt is absent,
+that portion of the eastern Pacific is most remarkably calm, or is covered
+by the N. E. trades. Secondly, the _trade-winds every where pursue their
+appointed course without "tendency to deflection" by the meeting, or
+"over-sliding," or "breaking in," or "encounter,"_ of other winds. The
+great laws of circulation do not admit of any such _confusion_. And,
+lastly, _no storm ever came over the eastern United States from that
+quarter_. The unchangeable laws of atmospheric circulation forbid it.
+Recent observations also have shown that the storms on the west coast of
+Central America, and the eastern Pacific, pursue a N. W. course, precisely
+as in the West Indies, and every where over the surface-trades of the
+northern hemisphere. Indeed _Mr. Redfield himself has recently
+investigated several of them, and admits their course to be
+north-westerly_. (See American Journal of Science, new series, vol. xviii.
+p. 181.)
+
+But, suppose the co-existence of the winds and the course of the storms
+admitted as claimed, let us seek for clearer views. What do these
+gentlemen mean? Do they intend to have us believe the air has inherent
+moving power, and that the "tendency" of which they speak is an attribute
+of the winds, and that when they thus meet, and "come into each other,"
+"encounter," or "over-slide," and become acquainted, they wheel into a
+waltz, and move off northward, "integrally," with unceasing circular
+movement, even until they arrive at the Arctic circle? Or is it a mere
+mechanical effect of meeting, "coming into each other," or "over-sliding?"
+If the latter, why a tendency to rotation from right to left? The
+trade-winds, at least, are _continuous, unbroken sheets_, and not
+disconnected portions which meet and blow past each other, and there is no
+warrant for placing them _side and side_, and attributing to them any
+such mechanical effect, and as little respecting the other winds. Outside
+of the fanciful hypothesis, there are no facts to show such a tendency one
+way rather than the other; and, in accordance with the known facts
+regarding stratification of the currents of air, no such "tendency" can
+exist.
+
+But what _power_ impels the winds, which thus meet at these points? If
+they be impelled, is it consistent with the action of this power that the
+_winds_ it has _created_ and _controls_, should thus assume an _opposite
+"tendency,"_ and whirl away to the north-eastward, regardless of the power
+that originated and controls them? What must this "_tendency_" be, which
+thus _occasionally_ not only diverts the winds from the _usually regular
+course_ given them by their originating power, but increases their action,
+from gentle, ordinary winds, to hurricanes? Nay, which gives them a new,
+resistless gyratory and electric energy, increasing as the new,
+independent, supposed cyclonic organization moves off, "_integrally_,"
+away from "the home of its many fathers," on a devastating journey towards
+the north pole?
+
+And, further, if all this were true as to the West Indies and Central
+America, what is to be said of the billions of other storms, originating
+on a thousand other portions of the earth's surface, and how are they to
+be accounted for, inasmuch as such other "meetings," "coming into each
+other," and "over-sliding," and "tendency to deflection," is not assumed
+to exist?
+
+These questions cannot be satisfactorily answered. The distinguished
+theorists are mistaken. The stratus-cloud does not over-lie or cover the
+storm. IT IS THE STORM. The winds beneath, whether surface or
+superimposed, are but its incidents, due to its static induction and
+attraction. Their _direction_ depends on the shape of the storm cloud, and
+its course of progression, and the susceptibility of the surface
+atmosphere in this direction or that, to its inductive and attractive
+influence. Their _force_ to its depth, its contiguity to the earth, and
+the intensity of its action; and the scud, are but patches of
+condensation, occasioned by the same inductive action which affects and
+attracts the surface current in which they form.
+
+Another objection to Mr. Redfield's theory of gyration is based upon the
+fact that in order to constitute his _storm_, to get the _gyration_, he
+has to include, at least, an equal amount, generally a great deal more, of
+_fair weather_. The N. W. wind, the "posterior, or dry side of the gale,"
+as he calls it (in the foregoing extract), is a _fair weather wind_. It is
+_necessary_, however, to complete the supposed _circle_, and it is
+_pressed into the service_. The practical answer given to the question,
+"_what are storms?_" is, they are cyclones, part storm, so called, and
+_part fair weather_; that is, the stratus-cloud, the scud, the easterly
+wind, and rain or snow of day before yesterday, were the _wet side_, or
+front part of the storm, and the sunshine, clear sky, and N. W. wind of
+yesterday, to-day, and, perhaps, to-morrow, are the posterior or dry side.
+When a storm clears off from the N. W. it is not _over_, it is, perhaps,
+_just begun_; and, inasmuch as it storms again, very soon after the wind
+changes back from the N. W. to the southward, in winter, our weather then
+is pretty much all _storms_.
+
+The statement of this claim seems so absurd that it may appear like
+injustice to make it. But gyration can not be made out without it, and it
+is evident in the extract quoted above; in the claim that the winter
+northers of the Mexican Gulf are parts of passing storms; and clearly and
+unequivocally advanced as a distinct proposition, as follows:
+
+"1. The body of the gale usually comprises an area of rain or foul
+weather, together with another, and, perhaps equal, or greater, area of
+fair or bright weather." (Am. Jour. of Science, vol. xlii. p. 114.)
+
+Now, in the first place, we must distinguish between a storm and fair
+weather, before we can tell what the former is, and it is difficult to
+assent to a theory which explains what a S. E. storm of _twelve hours'_
+continuance is, by including _two or three days of succeeding N. W. fair
+weather wind_, as a part of it. There is no proportionate relation as to
+_time_, nor any relation as to _qualities_, or the attending conditions of
+the atmosphere, nor any conceivable _connection_, except the hypothetical
+one of _gyration_, between the two winds.
+
+And, in the second place, it is true, and Mr. Redfield is well aware of
+the fact, that winds often blow for many days from the N. E., S. W., or N.
+W., without any preceding or succeeding winds to which they have any
+discoverable relation. If, therefore, truth would justify Mr. Redfield in
+including the fair weather wind, a difficulty would remain which his
+theory does not cover or explain.
+
+No American, except Mr. Redfield, has been able to discover satisfactory
+evidence of the gyration of storms, by actual careful observation, or a
+careful unbiased collation of the observation of others. Professor Coffin
+is reported to have read to the Scientific Association, at their Buffalo
+meeting, a paper, confirmatory, in part, but I have not been able to see
+it. The tracks of tornados have been searched as with candles. When they
+have been narrow, from forty to eighty rods, their action has been
+substantially similar, and, although, as we have herein before stated,
+some irregularities have been found which were consistent with
+gyration--for irregularities attend the violent action of all forces, and
+particularly the motion of electricity through the atmosphere, as every
+one who has seen the zig-zag course of a flash of lightning knows--yet the
+evidence of two lateral inward currents, or lines of force, has
+predominated over all others. In all cases, where the path is narrow,
+those lateral currents are the actors; they constitute the tornado; their
+_irregularities_ of action produce the exceptions; but the exceptions are
+neither numerous nor uniform, and do not prove either the theory of Mr.
+Espy or that of Mr. Redfield. The action is not that of moving air,
+merely, but of a power exceeding in force that of powder, which nothing
+but electricity or magnetism can exert. As the path widens, the wind
+becomes more like the straight-line gust which follows beneath the
+ordinary severe thunder-showers. His theory finds no substantial
+confirmation or support in the path of the tornado.
+
+Several storms were investigated by Professor Espy, some of them the same
+which Mr. Redfield had attempted to show were of a rotary character; one
+or two by the Franklin Institute of Philadelphia; one by Professor Loomis,
+already alluded to; and recently, two by Lieutenant Porter, from logs
+returned to the National Observatory. None of these investigations confirm
+the theory of Mr. Redfield. Indeed, Mr. Redfield himself has found it
+necessary to resort to suppositions of _modifying causes_ to explain the
+evident inconsistencies. It is assumed that the axis, or center,
+oscillates, and describes a series of circles; and thus, one class of
+difficulties is avoided. Again, it is assumed that simultaneous storms
+converge and blend upon the same field, and another class of difficulties
+are surmounted. And, again, inasmuch as it is notorious that violent gales
+are rarely if ever felt with equal violence around the area of a circle,
+but from one or two points only, it is assumed, that the storm winds
+ascend, superimpose, and descend again, when they return to the place of
+their first violent action, etc. The _simple truth_ requires no such
+resort to _modifying hypothesis_.
+
+Still, another objection is, that the changes in the barometer, which
+occur before, during, and after storms, do not sustain the claims of Mr.
+Redfield or the requirements of his theory.
+
+The barometer sometimes rises before storms. It generally commences
+falling about the time, or soon after the storm sets in, continues to fall
+during its progress, and rises again, sooner or later, afterward. This is
+the general rule.
+
+On this subject Mr. Redfield's claim is this:
+
+     "EFFECT OF THE GALE'S ROTATION ON THE BAROMETER.--The extraordinary
+     fall of the mercury in the barometer, which takes place in gales or
+     tempests, has attracted attention since the earliest use of this
+     instrument by meteorologists. But I am not aware that the principal
+     cause of this depression had ever been pointed out, previously to my
+     first publication in this journal, in April, 1831, when I took the
+     occasion to notice this result as being obviously due to the
+     _centrifugal force_ of the revolving motion found in the body of the
+     storm.
+
+     "Since that period, inquiries have been continued by meteorologists
+     in regard to the periodical and other fluctuations of the barometer,
+     and the relations of these fluctuations to temperature and aqueous
+     vapor. But these incidental causes of variation, in the atmospheric
+     pressure, prove to be of minor influence, and we are left to the
+     sufficient and only satisfactory solution of this marked phenomenon
+     which is found in the centrifugal force of rotation."
+
+The average pressure of the atmosphere, at the surface of the ocean, or in
+the interior of the country, allowing for elevation, is about equal to the
+weight of a column of quicksilver, thirty inches in height; hence the
+barometer is said to stand at about thirty inches at the level of the sea.
+
+This is sufficiently accurate for the northern hemisphere, north of the N.
+E. trades; but the average is somewhat lower in the trades and in the
+southern hemisphere. Thus, the average of sixteen months, during which the
+Grinnell expedition was absent, was 30.08/100.
+
+From a large number of logs examined by Lieutenant Maury, the mean
+elevation in the N. E. trades of the Atlantic was 29.97/100; the S. E.
+trades of the Atlantic, 29.93/100; off Cape Horn, 29.23/100; S. E. trades
+of the Pacific, 30.05/100; N. E. trades of the Pacific, 29.96/100. The
+height of the barometer off Cape Horn is not a fair index of the general
+elevation of the southern hemisphere, inasmuch as it stands lower there
+than at the coast of Patagonia and Chili, or at most, if not all, other
+stations in that hemisphere.
+
+As the barometer is constantly oscillating up and down (irrespective of
+its diurnal oscillation), it has no known fair weather standard. The point
+of 30 inches is taken only as it is a mean. I have known it to commence
+storming when the barometer was at 30.70, and not to fall before it
+cleared off, below 30.30. And I have known it to be below 30 for several
+days consecutively, with fair weather. In our climate there is no reliable
+fair weather standard for the barometer. It falls below 30 without
+storming; it rises far above, and storms without falling below. No
+reliance can be placed upon its elevation, except by comparison; but of
+that hereafter.
+
+The general rule, nevertheless, is, that it falls more or less during
+storms, whatever its height, and rises sooner or later, more or less,
+after they clear off.
+
+The difference between its highest and lowest points is called its range.
+The greatest range observed, and recorded, is about 3 inches--from about
+28 to 31--but this range is rare. The range, in the trade-wind region, is
+comparatively small; in this country it is greater than in Europe; and,
+generally, the range will be found greatest where the volume of
+counter-trade, and magnetic intensity, and the corresponding amount of
+precipitation, and extremes of heat and cold are greatest. One of the
+greatest ranges during one storm, or two successive portions of a storm,
+in this country, which I have seen recorded, occurred at Boston, in
+February, 1842. It was as follows--counting the hours as 24, and from
+midnight:
+
+  Feb. 15..10h..30.36.
+   "   16..13h..28.47 fall of 1.89 in 27 hours.
+   "   17..19h..30.39 rise of 1.92 in 30 hours.
+   "   18.. 2h..30.39 stationary       5 hours.
+   "   19.. 2h..29.46 fall of 0.93 in 24 hours.
+   "   20.. 2h..30.43 rise of 0.97 in 24 hours.
+    Amount of oscillation, 5.71 in 4 days, 11 hours.
+
+These ranges were owing to the alternation of S. E. storms, and N. W.
+winds.
+
+Taking the first range as a basis, and allowing the height of the
+atmosphere to be 1,100 feet for the first inch, we have nearly 2,000 feet
+displaced during one day, if we look for the displacement near the earth,
+or some 30 or 35 miles, if we soar aloft in the upper regions to look for
+the _lateral overflow_ of Professor Dove, and about the same quantity
+restored the next. This brings us to the inquiry, how was it done? It is
+perfectly idle to talk about _difference_ of _temperature_ or _tension_ of
+_vapor_, the _ascent_ of warm air, or _descent_ of cold in a case like
+this; or to say that they were occasioned by a lateral overflow of some
+thirty miles of its upper portion, first this way and then that, in such a
+brief space of time. The change is equal to nearly 1/15 of the weight of
+the whole atmosphere, and the cause, whatever it was, existed within two
+or three miles of the earth. Mr. Redfield's explanation I give in his own
+words, at length:
+
+     "One of the most important deductions which may be drawn from the
+     facts and explications which are now submitted, is an explanation of
+     the causes which produce the fall of the barometer on the approach of
+     a storm. This effect we ascribe to the centrifugal tendency or action
+     which pertains to all revolving or rotary movements, and which must
+     operate with great energy and effect upon so extensive a mass of
+     atmosphere as that which constitutes a storm. Let a cylindrical
+     vessel, of any considerable magnitude, be partially filled with
+     water, and let the rotative motion be communicated to the fluid, by
+     passing a rod repeatedly through its mass, in a circular course. In
+     conducting this experiment, we shall find that the surface of the
+     fluid immediately becomes depressed by the centrifugal action, except
+     on its exterior portions, where, owing merely to the resistance which
+     is opposed by the sides of the vessel, it will rise above its natural
+     level, the fluid exhibiting the character of a miniature vortex or
+     whirlpool. Let this experiment be carefully repeated, by passing the
+     propelling rod around the exterior of the fluid mass, in continued
+     contact with the sides of the vessel, thus producing the whole
+     rotative impulse, by an external force, analagous to that which we
+     suppose to influence the gyration of storms and hurricanes, and we
+     shall still find a corresponding result, beautifully modified,
+     however, by the quiescent properties of the fluid; for, instead of
+     the deep and rapid vortex before exhibited, we shall have a concave
+     depression of the surface, of great regularity: and, by the aid of a
+     few suspended particles, may discover the increased degree of
+     rotation, which becomes gradually imparted to the more central
+     portions of the revolving fluid. The last-mentioned result obviates
+     the objection, which, at the first view, might, perhaps, be
+     considered as opposed to our main conclusion, grounded on the
+     supposed equability of rotation, in both the interior and exterior
+     portions of the revolving body, like that which pertains to a wheel,
+     or other solid. It is most obvious, however, that all fluid masses
+     are, in their gyrations, subject to a different law, as is
+     exemplified in the foregoing experiment; and this difference, or
+     departure from the law of solids, is doubtless greater in aëriform
+     fluids than in those of a denser character.
+
+     "The whole experiment serves to demonstrate that such an active
+     gyration as we have ascribed to storms, and have proved, as we deem,
+     to appertain to some, at least, of the more violent class; must
+     necessarily expand and spread out, _by its centrifugal action, the
+     stratum of atmosphere subject to its influence, and which must,
+     consequently, become flattened or depressed by this lateral movement,
+     particularly toward the vortex or center of the storm_; lessening
+     thereby the weight of the incumbent fluid, and producing a consequent
+     fall of the mercury in the barometrical tube. This effect must
+     increase, till the gravity of the circumjacent atmosphere, superadded
+     to that of the storm itself, shall, by its counteracting effect, have
+     produced an equilibrium in the two forces. Should there be no
+     overlaying current in the higher regions, moving in a direction
+     different from that which contains the storm, the rotative effect
+     may, perhaps, be extended into the region of perpetual congelation,
+     till the medium becomes too rare to receive its influence. But
+     whatever may be the limit of this gyration, its effect must be to
+     _depress_ the _cold stratum_ of the upper atmosphere, particularly
+     toward the more central portions of the storm; and, by thus bringing
+     it in contact with the humid stratum of the surface, to produce a
+     permanent and continuous stratum of clouds, together with a copious
+     supply of rain, or a deposition of congelated vapor, according to the
+     state of the temperature prevailing in the lower region."
+
+The italics in the foregoing extract are mine; and, in relation to it, I
+observe:
+
+1st. There is no cylindrical vessel around storms, and _air will not thus
+resist air_. Confessedly, such resistance is necessary. Let any one watch
+his cigar smoke, and see how readily it moves on, with little momentum.
+Let any one try the experiment of creating a whirl in the _open air_, or
+in a room, or box of paper, or other material, which can be suddenly
+removed, with air colored by smoke. I am exceedingly mistaken if he does
+not find the presence of a "cylindrical vessel," absolutely essential to
+prevent the instantaneous tangential escape of the air.
+
+2d. Turn back to page 3 and look at the fall of the barometer in the polar
+regions (recorded in the extract from Dr. Kane), with _scarcely any
+wind_, and _as little variation_ in its _direction_, and see how utterly
+Mr. Redfield's theory fails to account for the phenomena.
+
+3d. If I understand Mr. Redfield correctly, he has abandoned the claim as
+originally made, that the wind moves in circles, expanding, and _spreading
+out_ by a "_lateral movement_," and now asserts that it blows spirally
+inward, and elevates the air in the center. I quote:
+
+     "VORTICAL INCLINATION OF THE STORM WIND.--By this is meant some
+     degree of involution from a true circular course. In the New England
+     storm above referred to, this convergence of the surface-winds
+     appeared equal to an average of about 6° from a circle. In the
+     present case, such indication seems more or less apparent in the
+     arrows on the storm figures of the several charts, where the
+     concentrical circle afford us means for a just comparison of the
+     general course of wind which is approximately shown by the several
+     observations.
+
+     "Perhaps we may estimate the average of the vorticose convergence, as
+     observed in the entire storm for three successive days, at from 5° to
+     10°--out of the 90° which would be requisite for a congeries of
+     _centripetal_ or center-blowing winds. This rough estimate of the
+     degree of involution is founded only on a bird's-eye view of the
+     plotted observations. But, however estimated, this involution seems
+     to afford a measure of the air and vapor which finds its way to a
+     _higher elevation_ by means of the vortical movement in the body of
+     the storm."
+
+If the elevation of the air at the borders of the storm, and depression in
+the middle, resulted from the outward tendency and "lateral movement" of
+the revolving air, and from the _centrifugal force_, as in the experiment
+with the water in a cylindrical vessel, as stated in the first paragraph
+quoted, an _involution_ of from 5° to 10° from the action of a
+_centripetal force_, must carry the air _inward_, and the _barometer
+should stand highest in the middle of the storm_. The change is fatal to
+his theory. The two are diametrically opposite in character and effect. In
+one, the superior strata would be brought down in the center by the
+_lateral pressure outward_; in the other, they would be elevated by the
+_involution_, which "affords a measure of the air and vapor which finds
+its way to a higher elevation," etc. It is perfectly obvious Mr. Redfield
+has refuted his own hypothesis.
+
+In doing this, he is met by the other difficulty alluded to, which he does
+not attempt to explain. This gathering of the air inward, spirally, by a
+centripetal force, if it took place, not only would not depress, but _must
+elevate the barometer in the center, above that of the adjoining
+atmosphere_.
+
+When he first attributed the depression of the barometer to a lateral
+movement and centrifugal force, he supposed the superior strata descended
+into the depression, and their frigidity occasioned the condensation, and
+cloud, and rain. How he now proposes to account for the formation of cloud
+and rain during storms, while the warm air of the inferior stratum finds
+its way to a higher elevation in the center of the storm, he does not
+inform us, and we must wait his time.
+
+     "I have," he says, "long held the proper inquiry to be, _what are
+     storms_? and not, _how are storms produced_? as has been well
+     expressed by another. It is only when the former of these inquiries
+     has been solved that we can enter advantageously upon the latter."
+
+The former does not seem to be yet solved, or the solution of the latter
+commenced. Mr. Redfield tells us (page 259, and onward), that there is an
+extended stratum of stratus-cloud, which overlies the storm, and that it
+does not differ greatly from one mile in height. We are not told how the
+air, which finds its way to a higher elevation during several days
+continuance of such a storm, _gets through the stratum_. If he is right it
+_must_ do so, and it would not answer to _suppose_ a very small opening or
+gentle current through it, to carry off all the air which works inward in
+a hurricane, during several days continuance. But he does not seem to
+recognize either the necessity or existence of any _vent_ at all; nor is
+there any; and this fact is open to the observation of every school-boy in
+the country; and it is equally open to his observation that _when and
+where the barometer is most depressed, the stratus storm-cloud is nearest
+the earth_. Colonel Reid has much to say about the "_storm's eye_," or
+"treacherous center" of a storm. A careful analysis of the instances where
+the "storm's eye" is noticed will show that the term is applied, in the
+northern hemisphere, to that lighting up in the W. or N. W., which is the
+commencement of the clearing-off process, and attended with a shift of
+wind to the fair-weather quarter: _i. e._, to W. or N. W. Just such an
+"eye" as is seen when the last of the storm cloud has passed so far to the
+east as to admit the rays of the sun under the western or north-western
+edge of it. The same kind of "storm's eye" is described in the southern
+hemisphere, except that the wind shifts to S. W. instead of N. W., that
+being the clearing-off wind there. No instance of a "_storm's eye_" in
+the center of the extended stratum of stratus-cloud, which overlies the
+storm, can be found recorded, to my knowledge; and it is obvious that
+Colonel Reid adopts the view of Mr. Redfield, that the westerly and N. W.
+_fair weather_ winds are a part of the storm. So long as these gentlemen
+hold to that opinion they will never solve the question, "_what are
+storms?_" or reach the other, "_how are storms produced?_"
+
+Notwithstanding, Mr. Redfield asserts, or adopts the assertion, that the
+inquiry should be, "What are storms?" not "How are storms produced?" that
+inquiry should be a _rational_ one, and should not violate all analogy, or
+call for an explanation which science can not _rationally_ furnish. Mr.
+Redfield does not seem to have formed any just conception of the
+_immeasurable power_ of a hurricane, _five hundred miles in diameter_; or
+of the nature of that _rod_ which the _Almighty must insert in it, to
+whirl it with such violent and long-continued force_; nor any just
+conception of the tendency of the whirling mass, in the absence of his
+"cylindrical vessel," to fly off, tangentially, into the surrounding air;
+or of the nature or power of the centripetal force necessary to hold the
+gyratory mass in its current, and gather it in involute spirals toward a
+center. Nor has any other man who has witnessed, or read of
+mountain-tossed waves; of the largest ships blown down and engulfed; of
+towns submerged, and vessels carried far inland, and left in cultivated
+fields, by the subsidence of the sea; of sturdy forests and strongly-built
+edifices prostrated; or listened to the howling of the tempest, and felt
+his own house rock beneath him, been able to conceive of any known form of
+calorific or mechanical, or other power, acting from a comparatively small
+center, which could hold such an immense irresistable mass of whirling air
+in a circle, and _gather it_ in toward the center in gradually contracting
+spirals. I confess that, to my mind, it seems little less than a mockery
+of our intelligence for Mr. Redfield, or Professor Dove, or any other man,
+how distinguished soever he may be, to tell us that all this is the result
+of a "tendency to left-wise rotation" of ordinary winds, "coming into each
+other," or "over-sliding," or "meeting," or "encountering," on this
+"front," or that, down in Central America, or in the West Indies, or the
+monsoon region; or to talk of "lateral overflows" from mere gravity; of
+the ascent of warm air, or the descent of cold strata; of the _resistance
+of adjacent passive air_, or other mere _atmospheric resistances_ in
+connection with such _awful manifestations of power_. Their explanations
+of these phenomena are not rational, nor can they be believed by any
+rational man, who will bestow upon them half an hour of _comprehensive,
+unbiased reflection_.
+
+Waiving many minor points of great force, for this notice of Mr.
+Redfield's theory is already too much extended for my limits, I am
+constrained to take issue with him on the fact, and to assert,
+unhesitatingly, that in a _majority of instances no such barometric curve
+exists_.
+
+Doubtless the depression beneath the storm is found, and exterior lateral
+elevations may also be had by _extending the line into the usual fair
+weather elevation on each side_, as Mr. Redfield is obliged to do, to get
+his supposed circle of winds at all. Doubtless, too, the seamen sailing
+out of a storm, on either _side_, and approaching fair weather, will have
+a rising barometer. But from _front to rear, on the line of progression_,
+in tropical storms, the curve does not exist on shore, in this latitude,
+oftener than in two, or possibly three, cases in ten; and then only upon a
+single state of facts--that is, when there is an interposition of N. W.
+wind; and this, at some seasons, rarely occurs. An elevation usually
+occurs before the storm, on its front, if it present an extensive easterly
+front, as one of these classes does, and a _depression is left_ after it
+has passed off, unless a considerable body of N. W. wind interposes, as
+heretofore stated. But when there is not such interposition of N. W. wind
+(for W., W. N. W., or even N. W. by W. will not suffice), there is not an
+immediate rise of the barometer corresponding in rapidity and extent with
+the fall, and frequently none during the first twenty-four hours of
+bright, fair weather. Let the reader, if he has access to a barometer,
+note this fact, for it is obvious and conclusive.
+
+Finally, there are other atmospheric conditions to which the barometric
+changes are obviously due:
+
+1st. The counter-trade is of a different _volume_, at different times,
+over the same locality, and hence a difference in the normal elevations of
+the barometer.
+
+2d. It is at a different _elevation_, at different times, over the same
+locality. It was so found by the investigations of the Kew Observatory
+Committee referred to; has been so found by other aeronauts, and may
+readily be seen by a careful, practiced observer.
+
+It is highest, with a high barometer, in serene weather, when a storm is
+not at hand; and can sometimes be plainly seen to ascend when a
+considerable volume of N. W. wind is blowing in beneath, and elevating,
+simultaneously, the trade and the barometer.
+
+Opportunities occur every year, when the northern edge of the dissolving
+stratus-cloud is attenuated, and the storm is clearing off in the N. W.,
+with wind from that quarter, and a rising barometer, when its gradual
+elevation may be observed to correspond with the _volume_ of that wind.
+
+3d. During storms, with a low barometer, the _trade_ and the _clouds run
+low_. This, too, is clearly observable, especially when the stratus-cloud
+passes off abruptly, very soon after the rain ceases. In such cases the
+barometer will remain depressed for a considerable time, unless another
+storm supervenes speedily, or the wind sets in from the N. W.
+
+4th. The _trade, in a stormy state, moves faster_ than when in a normal
+condition. This is observable during the partial breaks which frequently
+occur in storms, and at other times. It is also inferable from the more
+rapid progress of the more intense center, and other intense portions of
+storms, and the consequent greater depression of the barometer, under such
+centers or intense portions. (See the storm of Professor Loomis.) It is
+obvious, also, from the greater rapidity of progress attending the more
+intense and violent storms which all investigations discloses.
+
+These simple facts explain all the phenomena:
+
+1st. The trade stratum is a continuous unbroken sheet, and its descent
+must displace a portion of the surface atmosphere. A portion of it is
+impelled forward, aiding in the precedent elevation of the barometer, and
+a portion is attracted backward, into the space from which a like portion
+had been previously attracted by the passing storm cloud, forming the
+easterly wind.
+
+2d. The increased progress of the stormy portion of the counter-trade
+occasions an accumulation in front of the storm, and an elevation of the
+barometer, and tends also to increase the _depression_ under the spot from
+which it moves. The latter is, to some extent, counteracted by the thin
+sheets of surface wind which are drawn in under the stratus from the
+sides. That which is drawn from the front in successive portions, fills
+the space from which like portions had been drawn to the westward, and
+left behind in a passive state by the passing storm. Thus, the surface
+atmosphere of New England may pass under the entire width of a storm, as a
+gale; moving now in puffs with great violence, as it passes beneath
+irregular and intense portions of the cloud, and now moderately; and be
+left, in a passive state, in Kentucky, occupying the space from which the
+atmosphere had been previously drawn by the same storm, _in like manner_,
+on to northern Texas.
+
+3d. The nearer the stratus-cloud to the earth, the greater the
+displacement of surface atmosphere, the lower the barometer, and,
+ordinarily, the more violent the wind. First, because the same intensity,
+which, by attraction, brings the trade near the earth, acts with greater
+force upon the surface atmosphere; and, secondly, the storm winds, which
+are often most rapid beneath the clouds and above the earth, are likely to
+be felt with more violence at its surface, where the stratus cloud runs
+low, especially at sea.
+
+I desire to commend all these facts, in relation to the theory of Mr.
+Redfield, to the careful attention and observation of those who, although
+believers in the theory, are not wedded to it; and who have a sincere
+desire to understand the phenomena which are continually, and thus far,
+_mysteriously_, occurring within two or three miles of us, while our
+knowledge of the distant worlds around us--the science of astronomy--seems
+almost perfect.
+
+I will return to a further and a careful consideration of the nature of
+the reciprocal action between the earth and the counter-trade, and the
+facts bearing upon the question, in another chapter. It is obvious that
+received theories can not aid us materially in the inquiry.
+
+
+
+
+CHAPTER X.
+
+
+We are yet ignorant of the true nature of magnetism. We trace its lines,
+as in the diagrams, upon and around the magnet; but we can only do this
+with soft iron, or other substance, in which magnetic action may be
+induced. We know that these lines are currents, or lines of force, for
+that force produces sensible effects, and we measure it by the movements
+of the needle. We know that these lines may be _deflected_ by other
+magnetic bodies, and concentrated upon them. We know that the earth, and
+the smallest magnets, exhibit properties in common. The poles of the
+magnet are some distance from its extreme ends--so are those of the earth.
+The intensity increases, from the center, or near it, to the poles of the
+magnet, as shown by its attraction; and the same increase of magnetic
+intensity, from the magnetic equator to the magnetic poles, or near them,
+is traced upon the earth.
+
+We know that there are two lines, or rather _areas_, of greater intensity
+upon the globe. One extending from the American magnetic pole,
+south-eastwardly, to a corresponding pole in the southern hemisphere; and
+another, the Asiatic, extending from the Siberian pole to a corresponding
+southern one, in like manner. We know that, from those lines or areas,
+the intensity, east and west, on the same parallel of latitude, decreases
+each way, to about midway between them. Thus, calling the intensity where
+Humboldt found the magnetic equator over South America, in 7° 1' south
+latitude, 1, or unity--the least intensity known is, .706, found at the
+magnetic equator, over the South Atlantic, and at its most southern
+depression; and it increases to 1.4 in the West Indies, and to 2.0099 upon
+one or more points of the North American continent, south of the magnetic
+pole, and about the meridian of 92°. That it is 1.805, at Warren, Ohio, in
+latitude 41° 16', and longitude 72° 57', and decreases to 1.774 at New
+Haven, Connecticut, in latitude 41° 18'. That it is but 1.348 at Paris,
+nearly one third less than on the same latitude in some portions of this
+continent. That the line of equal intensity, or "_iso-dynamic_" line, of
+1-8/10, is a closed curve of an oval shape, extending somewhat below 40°,
+in the longitude of Cincinnati, and reaches off nearly to Bhering's
+Straits, on the west; rising in a similar manner, though not so abruptly,
+on the east; including the great northern lakes and a considerable part of
+Hudson's Bay. While the iso-dynamic lines of 1-85/100, and 1-875/1000, are
+smaller ovals, included within the former. Such, at least, is the present
+belief from such investigations as have been made. (See an article by
+Professor Loomis, American Journal of Science, new series, vol. iv. p.
+192.)
+
+Our subject demands a still closer examination of the elements of
+magnetism and its associated electricities, and their influence upon
+climate and the atmosphere with a view to the solution of the questions in
+hand, and we will pursue the inquiry in the present chapter.
+
+Waiving, for the present, any further notice of the fact that the
+counter-trades are concentrated over, and contiguous to, this area of
+intensity, for the purpose of examining the magnetic phenomena
+independently, and intending to return to a consideration of their
+connection with it, we observe:--That it is now well settled that the
+iso-geothermal lines, or lines of equal terrestrial heat, are coincident,
+or nearly so, with the lines of equal magnetic intensity. The points where
+the magnetic intensity is at a minimum, on the magnetic meridian, are the
+warmest points of that meridian, and those where it is most intense, the
+coldest.
+
+The magnetic elements of a place may be computed from its thermal ones.
+The laws producing or governing the distribution of one, have an intimate
+physical relation with those producing or governing the other. Professor
+Norton ably sums up a discussion of the subject (in the American Journal
+of Science for September, 1847), omitting the theoretic propositions, as
+follows:
+
+     "1. All the magnetic elements of any place on the earth may be
+     deduced from the thermal elements of the same; and all the great
+     features of the distribution of the earth's magnetism may be
+     theoretically derived from certain prominent features in the
+     distribution of its heat.
+
+     "2. Of the magnetic elements, the horizontal intensity is nearly
+     proportional to the mean temperature, as measured by Fahrenheit's
+     thermometer; the vertical intensity is nearly proportional to the
+     difference between the mean temperatures, at two points situated at
+     equal distances north and south of the place, in a direction
+     perpendicular to the iso-geothermal line; and, in general, the
+     direction of the needle is nearly at right angles to the
+     iso-geothermal line, while the precise course of the inflected line
+     to which it is perpendicular may be deduced from Brewster's formula
+     for the temperature, by differentiating and putting the differential
+     equal to zero.
+
+     "3. As a consequence, the laws of the terrestrial distribution of the
+     physical principles of magnetism and heat must be the same, or nearly
+     the same; and these principles themselves must have, toward one
+     another, the most intimate physical relations."
+
+The magnetic elements, of which Professor Norton speaks, are the
+declination, dip, and horizontal and vertical forces or intensities.
+
+I have said, that toward the areas of greatest magnetic intensity, the
+needle every where declines. So as intensity increases, from the magnetic
+equator toward the poles, the needle, when so suspended as to permit of
+the motion, _dips_, inclines downward, and the dip is greatest, on the
+same parallel, where intensity is greatest. To my mind, the magnetic
+elements are very intelligible. They are all attributable to attraction,
+and attraction is greatest where intensity is greatest. There is nothing
+in the earth or atmosphere to make the needle point northerly rather than
+in any other direction, except magnetic intensity. Thus, the greater
+intensity of magnetism near the northern and southern points of the globe,
+attracts the corresponding ends of the needle in those directions. And, as
+magnetism increases in quantity or intensity, and the poles are
+approached, the attraction increases, and the needle dips more and more,
+till the focus of intensity and attraction is reached, and then it becomes
+perpendicular. So magnetism is unequally diffused, meridionally, in or
+over the earth, and there are two equidistant areas where its quantity or
+intensity is greatest. These exert a lateral attraction upon the needle;
+it yields to this attraction, and hence its declination. If it is carried
+on to one area of intensity, and to the center of it, it will point to the
+northern focus of intensity or magnetic pole; and, if carried a trifle
+further west, it will yield to an eastern attraction, and point directly
+north. If carried still further west, its declination _east_ will
+increase. Thus its normal direction is to the pole, on the central focus
+of intensity, and when it points directly north it is west of the central
+line of intensity. And thus, it seems to me, all the magnetic elements may
+be resolved into the one element of attraction by excess of intensity or
+activity.
+
+This impression is strengthened by the fact that the needle moves to the
+east in the morning, when the solar rays increase magnetic activity in
+that direction, and west again, as their influence increases there.
+
+Now, these elements--the declination and horizontal and vertical
+forces--all these periodical, regular, and irregular variations of
+magnetic activity, are intimately connected with the variations of
+atmospheric condition:
+
+First, They show an increase of activity during certain hours of the day,
+corresponding to, and obviously connected with, the diurnal atmospheric
+changes.
+
+Second, They show an increase of activity during the northern transit of
+the atmospheric machinery--an _annual_ variation.
+
+Third, They show an increase in that activity during the latter portion of
+each decennial period, conforming to the occurrence of solar spots.
+
+And, fourth, _Irregular variations_ of activity, corresponding with the
+_irregular changes_ of atmospheric condition.
+
+We will examine these results, and in doing so, take those of the element
+of declination--one answering for all.
+
+The magnetic needle moves to the west in summer, from about 8 A.M. till
+about 2 P.M., and the extent of its progress, during that period,
+constitutes the magnitude of its daily variation. It is found that this
+variation differs in different months, and that it is normally greatest in
+the summer months, and least in the winter, in the ratio of about two to
+one. It is further found, that in different years the maximum activity
+occurs in different months, and that the years differ also, and there is a
+distinctly marked decennial period, corresponding most remarkably with the
+decennial maxima of recurring solar spots, as observed by Schwabe. Dr.
+Lamont, of Munich, gives us the following table of magnitude of
+declination there, for the ten years preceding 1851, which clearly
+exhibits this fact, and also the greater intensity during the northern
+transit of the atmospheric machinery. He says:
+
+     "The magnitude of the variations of declination have a period of ten
+     years. For five years there is a uniform increase, and during the
+     following five years a uniform decrease in the variations. With us
+     the magnetic declination is a minimum at about eight o'clock in the
+     morning, and is greatest at two o'clock in the afternoon. Subtracting
+     the declination at eight o'clock from that at two o'clock, we obtain
+     _the magnitude of the diurnal motion_. From the hourly observations,
+     conducted in this observatory since the month of August, 1840, we
+     ascertain the following to be the magnitude of the diurnal motion for
+     each month separately."
+
+  +-------------------------------------------------------------------+
+  |      | Jan. | Feb. | March.| April.| May.  | June. | July. | Aug. |
+  +-------------------------------------------------------------------|
+  | 1841 | 3.72 | 5.13 |  8.43 | 11.49 | 11.47 | 11.49 | 10.07 |  9.86|
+  | 1842 | 3.65 | 4.74 |  8.34 | 10.33 |  9.31 |  9.78 |  8.38 |  9.03|
+  | 1843 | 3.82 | 4.08 |  6.87 |  9.71 |  9.24 | 10.14 |  9.57 | 10.08|
+  | 1844 | 2.81 | 3.43 |  6.95 |  9.53 |  8.42 |  8.88 |  8.38 |  9.28|
+  | 1845 | 2.20 | 4.69 |  8.26 | 11.93 | 10.88 | 10.73 |  9.44 | 10.42|
+  | 1846 | 3.30 | 6.94 |  9.53 | 12.27 | 12.58 | 11.21 | 11.37 | 11.49|
+  | 1847 | 3.30 | 6.35 |  9.85 | 12.43 | 11.81 | 11.76 | 10.94 | 12.87|
+  | 1848 | 6.52 | 9.01 | 11.96 | 14.56 | 14.22 | 13.80 | 14.67 | 15.40|
+  | 1849 | 7.27 | 8.42 | 14.08 | 16.86 | 13.67 | 13.86 | 12.57 | 11.54|
+  | 1850 | 5.98 | 8.84 | 12.15 | 14.32 | 14.05 | 13.39 | 12.53 | 12.68|
+  +-------------------------------------------------------------------+
+         +----------------------------------------------------+
+         | Sept. |  Oct. | Nov. | Dec. | Autmn | Spring| Year.|
+         |       |       |      |      |& Wint.| & Sum.|      |
+         |----------------------------------------------------|
+         |  8.78 |  6.82 | 3.71 | 2.89 | 5.12  | 10.53 |  7.82|
+         |  7.72 |  7.05 | 3.86 | 2.81 | 5.07  |  9.09 |  7.03|
+         |  8.81 |  6.82 | 3.82 | 2.79 | 4.70  |  9.59 |  7.15|
+         |  8.23 |  6.54 | 3.94 | 2.98 | 4.44  |  8.79 |  6.61|
+         |  8.82 |  7.34 | 4.49 | 8.34 | 5.89  | 10.87 |  8.13|
+         | 10.39 |  7.82 | 5.66 | 3.22 | 6.08  | 11.25 |  8.81|
+         | 12.06 | 11.53 | 7.06 | 4.70 | 7.63  | 11.98 |  9.55|
+         | 14.00 | 10.30 | 5.78 | 3.53 | 7.85  | 14.44 | 11.05|
+         | 10.79 |  9.12 | 5.41 | 4.09 | 8.06  | 13.21 | 10.64|
+         | 12.64 |  9.04 | 6.20 | 3.45 | 7.61  | 13.27 | 10.44|
+         +----------------------------------------------------+
+
+The Philadelphia and Toronto observations disclose the same state of
+facts.
+
+Dr. Lamont, also, in his article, gives us the following table of the
+magnitude of the variations derived from observations at Gottingen:
+
+  +--------------------+
+  | Year.|Mean of Year.|
+  |--------------------|
+  | 1835 |    9.57     |
+  | 1836 |   12.34     |
+  | 1837 |   12.27     |
+  | 1838 |   12.79     |
+  | 1839 |   11.03     |
+  | 1840 |    9.91     |
+  | 1841 |    8.70     |
+  +--------------------+
+
+A comparison of these tables, and particularly the latter, with Schwabe's
+table of spots, is interesting. There is obviously a greater mean
+variation when the spots are most numerous. Comparing the two with the
+tables of Hildreth, in relation to the temperature, from 1830 to 1840,
+there is, to say the least, a most remarkable coincidence. And there are
+others equally remarkable.
+
+There are also irregularities of action disclosed by all, in different
+months of the different years, and of the same year, which are obviously
+connected with the difference of the seasons; and there are constantly
+occurring irregularities and disturbances which correspond with the, as
+constantly occurring, irregular atmospheric phenomena. A wide field is
+here opened for investigation and research. I have not time or opportunity
+to pursue it. Enough appears, so far as I have examined, to confirm the
+belief that magnetism is actively concerned in the production of the
+varied changes, as well as the normal conditions of the weather.
+
+In what manner does it act? An answer to this requires an extension of the
+inquiry. The lines of magnetic force are every instant passing upward from
+the earth, _around_ and _through_ us. Their connection with heat is
+unquestionable. They are intimately associated, also, with another equally
+obvious and intensely active agent--electricity. We speak of this as an
+independent, imponderable, elementary body, but how little we yet know of
+it. It is every where, in every thing, easily excited into action, and
+then traceable to a certain, but limited extent. It is set in motion, and
+becomes obvious to us, by the chemical action of the acids and metals of
+a galvanic apparatus. We separate it from the atmosphere by friction and
+excitation, upon non-conductors, as in the electric machine; by the
+cleavage of crystals and other exciting operations. We obtain it from
+magnets, by the magneto-electric machine, and from the lines of magnetic
+force which are ever passing into the atmosphere from the earth, by
+intersecting them with a movable iron wire, properly insulated. _From the
+current of magnetism which has passed through us from the earth,
+electricity may thus be separated and collected over our heads._ We set it
+in motion, and obtain it _by heating_ different metals in connection, or
+the same metal unequally; and from certain animals--like the torpedo and
+the gymnotus--whose organization is such as to enable them to evolve it.
+In all these cases, and they constitute an epitome of the principal
+methods by which we obtain it in a distinct form, it is made to flow in
+currents. When thus obtained, and imprisoned in non-conductors, it may be
+discharged, and with somewhat different effect, as it is discharged in a
+mass, disruptively, as it is called, as from the clouds in lightning, or
+permitted to flow convectively, in currents, along the wires of a galvanic
+apparatus, or in heated air, as from the earth to a cloud in the tornado.
+
+It is, moreover, capable of division into positive and negative, and when
+concentrated or disturbed in one body, it tends to create a similar
+disturbance or division in a contiguous mass. To this action of
+electricity, the term static induction is applied. Thus, a positively
+electrified body _induces_ a division of the electricity in a contiguous
+body, if both are insulated or surrounded by a non-conducting medium; the
+negative electricity of the contiguous body being attracted by, and
+tending to pass to, the positive of the adjoining body, and the positive
+being repelled to the opposite side. That, in its turn, if sufficiently
+powerful, tends to disturb the electricity of its neighbor, and attract
+away its negative electricity; or, if the body which contains it is free
+to move, to attract that. Thus, by the conflicting action of a positive
+atmosphere, and a negative earth, and perhaps counter-trade, influenced by
+magnetism and the solar rays, the currents and winds of the atmosphere are
+produced, the atmosphere moving with exceeding ease and rapidity.
+Electricity, excited into currents, or obtained and discharged in either
+of the methods enumerated, is identical in character, and produces certain
+well-known effects:
+
+1st. Physiological.--Shocking and convulsing the animal system; producing
+a peculiar sensation on the tongue, and a flash before the eyes, and in
+sufficient quantity destroying life.
+
+2d. Magnetic.--_Deflecting the needle_, and, by a suitable arrangement of
+wire into helices, _conferring magnetic power_, or constituting magnets.
+
+3d. Luminous.--Producing light--by a spark, as it does in natural
+phenomena--by the glow, the brush discharge, the ball of flame, the flash,
+or the chain of lightning, and probably the aurora.
+
+4th. Evolving heat.--Melting metallic substances by concentration, with a
+great intensity of heat--as the wire of the galvanic apparatus, and as is
+sometimes seen in the effects of lightning in fusing metals on persons
+stricken; and setting combustibles on fire.
+
+5th. Attraction and repulsion.--Attraction, when the currents flow
+parallel with each other, or are of opposite natures, and repelling when
+of like character.
+
+6th. Induction.--Inducing attendant circular or other secondary currents,
+such as may be seen in the atmosphere during its most violent displays of
+active energy.
+
+7th. Capable of being dissipated by heated air, or carried off by
+moisture, although isolated by dry air, of ordinary temperature, which is
+a bad conductor.
+
+Now, although magnetism can not be collected, imprisoned, or discharged,
+like electricity, or collected at all, but by its adherence to some
+substance capable of magnetization, it is obvious there is an intimate
+association, at least, between it and electricity. _They are never found
+alone._ All _electricity_ will _magnetize_. All _magnetism_ will evolve
+electricity. All _currents_ of _electricity_ have _encircling currents_ of
+_magnetism_, and all deflect the magnetic needle. All magnetic currents
+give out to intersecting wires, _currents of electricity_, and all magnets
+_induce_ them.
+
+Electricity, therefore, whether identical in substance with magnetism, but
+differing in form, or whether merely associated with it, as is variously
+believed, should be present with magnetism in greater quantity or
+intensity where magnetism is most intense, and active, and whenever
+present, should be active and influential. And so we find, from
+observation, the fact to be. No inconsiderable effort has been made by the
+advocates of the caloric and mechanical theories, to ignore the agency of
+electricity and of magnetism, in the production of the varied
+meteorological phenomena. But it will not do. The phenomena, grouped and
+analyzed, disclose a potential-controlling, magneto-electric agency, and
+meteorology will advance rapidly to perfection, as a simple, intelligible,
+and practical science, _as soon as that agency is admitted_.
+
+Electricity is always perceptibly present in storms and showers within the
+tropics. Most of the rain, from the tropical belt, falls from "thunder
+showers." So hurricanes and typhoons, and all tropical storms, are
+confessedly, and in proportion to their intensity, "_highly electric_."
+This excess of quantity or activity of electricity, exists in connection
+with the movable atmospheric machinery. When it moves up north in summer,
+and arrives at its highest point of northern transit, _storms_ are very
+_uncommon_, and the tropical forms of cloud and showers, with thunder and
+lightning, prevail. This is most obvious, if not most influential, where
+the magnetic intensity is greatest. Violent showers, and gusts, and
+tornadoes, are more frequent in this country than in Europe; and over the
+area of greatest intensity, as in Ohio, than at a distance on the extreme
+eastern or western coast. And the same is true over the intense magnetic
+area of Asia.
+
+Electricity, too, like magnetism, has its diurnal, and doubtless its
+annual and decennial variations, and also its irregular ones, and they are
+most obviously and intimately connected. Magnetism and electricity
+together, constitute the aurora. Its culmination is in the magnetic
+meridian--it affects the telegraph wires--is connected with the irregular
+disturbances which affect the magnetic needle, and does not exist in the
+limits of the trades, although occasionally seen from thence, when it
+passes south, and near them.
+
+The aurora sometimes extends south in waves, as do the magneto-electric,
+atmospheric, periodical changes of cold and heat, and storm, and sunshine.
+_The aurora is connected with the formation of cloud_, and with a smoky
+atmosphere, similar to that with which we are familiar in summer and
+autumn. Thus Humboldt (Cosmos, vol. i. pp. 191, 192).
+
+"This connection of the polar light with the most delicate cirrus clouds,
+deserves special attention, because it shows that the electro-magnetic
+evolution of light is a part of a meteorological process. Terrestrial
+magnetism here manifests its influence on the atmosphere, and on the
+condensation of aqueous vapor. The fleecy clouds seen in Iceland, by
+Thienemann, and which he considered to be the northern light, have been
+seen in recent times by Franklin and Richardson, near the American north
+pole, and by Admiral Wrangel on the Siberian coast of the Polar Sea. All
+remarked 'that the aurora flashed forth in the most vivid beams when
+masses of cirrus-strata were hovering in the upper regions of the air, and
+when these were so thin that their presence could only be recognized by
+the formation of a halo round the moon.' These clouds sometimes range
+themselves, even by day, in a similar manner to the beams of the aurora,
+and then disturb the course of the magnetic needle in the same manner as
+the latter. On the morning after every distinct nocturnal aurora, the same
+superimposed strata of clouds have still been observed that had previously
+been luminous. The apparently converging polar zones (streaks of clouds in
+the direction of the magnetic meridian), which constantly occupied my
+attention during my journeys on the elevated plateaux of Mexico, and in
+northern Asia, belong, probably, to the same group of diurnal phenomena."
+
+Mr. William Stevenson gives us (in the London, Edinburgh, and Dublin
+Philosophical Magazine for July, 1853) an interesting article on the
+connection between aurora and clouds. His observations on this most
+important branch of the subject trace a connection between the aurora and
+the formation of cloud, and open up, as he says, "a most interesting field
+for observation which promises to lead to very important results." Such
+observations point with great significance, to the primary influence of
+the magneto-electricity of the earth.
+
+To the difference in the magnetic intensity of the eastern portion of this
+continent, compared with Europe and our western coast, very much of the
+difference of climate, so far as temperature is involved, may be
+attributed. We have seen in what manner the iso-thermal lines surround
+these areas of intensity. So the most excessive climate--that is, the
+climate where the greatest extremes alternate, other things being equal,
+is upon or near the line or area of greatest magnetic intensity. I say
+other things being equal, because large bodies of water modify climates by
+equalizing the seasons--making the summers cooler and the winters warmer
+than the mean of the parallel.
+
+Thus, our great interior lakes modify the climate in relation to
+temperature in their vicinity. Their summers are cooler and their winters
+warmer; but westward of them the same line of equal summer temperature, or
+iso-thermal line, rises with considerable abruptness, and the winter, or
+iso-cheimal line of equal temperature, falls in a similar manner. Thus,
+the range of the thermometer, from the highest elevation to the lowest
+depression, for the year, is very great, while in the tropics the range is
+comparatively small. From observations made at the military posts of the
+United States, Dr. Forrey deduced summer and winter lines of equal
+temperature, starting from the vicinity of Boston and running west, which
+showed most remarkably the rise of the summer lines as intensity
+increased, and the fall of the winter lines in like manner.
+
+The influence of the lakes was also most obvious. The elevation of the
+earth increases, going west, to about 700 feet at the surface of the
+lakes, and to nearly 4,000 feet at the eastern base of the Rocky
+Mountains; and, although temperature does not decrease to as great a
+degree when the elevation above the level of the sea is _gradual_, yet
+some allowance should doubtless be made for that elevation on this line.
+When that allowance is made, the ascent of the summer line, to the north,
+over the area of greatest intensity, is strikingly apparent.
+
+Dr. Forrey also instituted a comparison between Fort Snelling, where the
+climate is as excessive, and the range of the thermometer as great, as in
+any portion of the continent in the same latitude, with Key West, and I
+copy his diagram. It is very instructive, showing the gradual mean rise of
+the temperature, from January to December, inclusive, while the cross
+lines show the _extremes of each month_.
+
+Perhaps the most interesting part of it, is the illustration of the
+monthly extremes, and the contrast between them, in the excessive climate
+of Fort Snelling, and the tropical one of Key West. Each is a type of the
+climate in which it is situated. The annual range and monthly extremes are
+small in tropical countries, and large in extra-tropical ones. The extreme
+range, or greatest elevation of heat, contrary to what is generally
+supposed, is greater at Fort Snelling than at Key West. But the climate of
+the latter is modified by the adjoining ocean.
+
+I copy, also, a table (p. 304), showing the range of the thermometer for
+the year, and the maxima and minima, during each month, at several other
+places in this country, and at London and Rome, for the purpose of showing
+the extent of the ranges compared with those places; and also, that these
+great changes in each month occur very uniformly all over the country,
+and may always be expected, and with considerable regularity. They are
+incident to our climate. I wish I could engrave the foregoing diagram, and
+the following table, upon the mind of every man, woman, and child in the
+country; and under it, in ever-visible letters, these words of precaution:
+CONFORM TO THE PECULIARITIES OF YOUR CLIMATE, AND CLOTHE YOURSELVES, AT
+ALL TIMES, IN ACCORDANCE WITH THE ALTERNATIONS OF THE WEATHER. If heeded,
+they would save thousands, every year, from premature death.
+
+
+[Illustration: Fig. 18.]
+
+
+The effect of this difference of magnetic intensity upon the climate of
+Europe is marked. There, the excessive summer heat, which our greater
+magnetic intensity and larger volume of counter trade give us, is unknown.
+Hence, while we can grow Indian corn (which requires the excessive summer
+heat) over all the Eastern States, up to 45°, and in some localities east
+of the lakes to 47° 30', and to 50° west of them, to the base of the Rocky
+Mountains, and notwithstanding the increase of elevation, they can not
+grow it except over a limited area, and with limited success. Nor can
+they, or the inhabitants of any other country except China, grow
+profitably the kind of cotton which is so successfully grown in the
+Southern States of the Union. Nor can China do so to a considerable
+extent, because of the mountainous character of the surface. To a level
+and remarkably watered country, greater magnetic and electric intensity,
+and a greater volume of counter-trade, we are, and ever shall remain,
+indebted, for an almost exclusive monopoly in the growth of two of the
+most important staple productions of the earth. On the other hand,
+although the same magnetic intensity, and its winter excess of positive
+electricity and cold, make our winters extreme, there are but few of the
+productions of temperate latitudes which we can not grow successfully, and
+they are comparatively unimportant.
+
+  A  Fort Vancouver, Oregon Territory
+  B  Fort Brady, outlet of Lake Sup.
+  C  Hancock Barracks, Houlton, Me.
+  D  Fort Armstrong, Rock Island, Ill.
+  E  West Point, New York
+  F  Washington, D. C.
+  G  Jefferson Barracks, near St. Louis
+  H  Fort King, interior of East Florid.
+  I  Environs of London
+  K  Rome, Italy
+
+                A    B    C    D    E    F    H    I    J    K
+
+  Lat.          45°  46°  46°  41°  41°  38°  38°  29°  51°  41°
+                37'  39'  10'  28'  22'  53'  28'  12'  31'  54'
+  Annual
+  Range.        78  110  118  106   91   84   89   78   67   62
+
+  Jan.  Min.    17  -21  -24  -10   -1   14   10   33   16   29
+        Max.    58   40   41   48   53   57   60   83   49   58
+  Feb.  Min.    32  -22  -11   -6    2   16   11   43   19   33
+        Max.    55   44   42   56   56   62   70   84   54   60
+  Mar.  Min.    32   -7   -1   13   16   28   31   39   24   37
+        Max.    60   51   54   70   72   70   76   87   60   65
+  Apr.  Min.    32   18   24   33   40   36   38   54   26   44
+        Max.    70   62   74   78   62   73   83   93   69   74
+  May.  Min.    32   32   81   44   47   50   45   64   33   52
+        Max.    75   79   83   84   72   85   88   97   78   80
+  June. Min.    45   41   38   57   57   59   59   73   39   60
+        Max.    95   86   90   89   79   92   95  105   80   88
+  July. Min.    40   39   45   62   64   64   50   73   41   64
+        Max.    95   84   90   95   86   94   96  102   83   91
+  Aug.  Min.    44   49   46   60   62   63   66   72   42   62
+        Max.    95   84   85   91   87   93   96  104   79   91
+  Sept. Min.    43   40   33   51   56   51   51   70   34   55
+        Max.    88   75   78   87   83   88   88   99   75   85
+  Oct.  Min.    50   27   24   82   42   33   38   41   30   46
+        Max.    66   70   72   73   69   77   80   91   68   77
+  Nov.  Min.    32   15    4   26   36   28   27   30   22   39
+        Max.    58   58   60   64   63   66   69   82   56   67
+  Dec.  Min.    32   -7   -4   15   20   17   14   36   20   31
+        Max.    55   42   53   62   56   61   64   79   53   60
+
+This excess of magnetic intensity and electricity not only gives a
+peculiar character to our vegetation, but also to our race, our animals,
+and every thing. He who supposes that the restless activity and energy of
+the people of the United States is the result of habit, or education, or
+any fortuitous circumstances alone, is mistaken. Let him watch the
+contrast in his own feelings during those occasional languid, damp, and
+sultry, although not thermometrically, hot days--which so much resemble
+the summer weather of England--with those days of bright, bracing, N. W.
+and S. W. air, so much more frequent here, and he will appreciate the
+difference. That term "bracing," so much in use, will express the effect
+of this peculiar weather. It "girds up the loins," both of body and mind.
+Men and animals can work with more ease, even in our peculiar extremes of
+heat, than they can in England, and fatten with less.
+
+A similar difference in degree is found between our climate and that of
+the Pacific portion of our country. Something is due to the difference in
+the volume and moisture of the counter-trades, and something to the
+contiguity of the Pacific Ocean; but to the difference in
+magneto-electric intensity, the contrast is mainly due. Corn and cotton
+will be grown, to some extent, in the valleys west of the meridian of
+105°, but never as successfully as east of it.
+
+The aurora is periodical, like all the other atmospheric phenomena, but
+its periodicity is not accurately ascertained. It is believed to have
+occurred much oftener during the second quarter of this century, than
+during the first. It is known, however, to occur most frequently in the
+spring and fall; and during those periods when the active and rapid
+transit of the atmospheric machinery produces the greatest degree of
+magnetic disturbance. This identifies it with terrestrial magnetism.
+Dalton gives us the following table of observations, arranged according to
+the months when they were seen.
+
+      Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.
+
+  (1)  18   18   26   32   21     5     2   21    23   36   38    9
+  (2)  21   18   23   13    3     2     1    3    35   22   22   21
+  (3)  21   27   22   12    1     5     7    9    34   50   26   15
+  (4)   5    6    4    8   10     7     6   14    14   17    5    6
+
+(1) contains those observed by him at Kendall; (2) are taken from another
+list; (3) is MARIAN'S list of those observed before 1732; and (4), those
+seen in the State of New York in 1828 and 1830.
+
+Mr. Stevenson's table of those observed by him at Dunse, from 1838 to
+1847, inclusive, is as follows:
+
+  Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.
+   32   20   18   18    3     0     2   14    43   34   30   23
+
+Observations in this country correspond substantially with the foregoing.
+They are, however, seen here in the summer months more frequently than in
+Europe. See an article by Mr. Herrick (American Journal of Science, vol.
+33. p. 297). In this, also, they conform to our greater magnetic intensity
+and more excessive climate.
+
+The auroras appear to follow the polar belts of condensation and
+precipitation. Dalton considers them indications of fair weather. They are
+often most brilliant just after a storm has passed, but their continuance
+is no indication that another will not follow within the usual period.
+
+The condensation with which the aurora is connected, is not, in my
+judgment, often in the counter-trade, or below it, but above, where feeble
+condensation has been seen by aeronauts when invisible at the surface of
+the earth. Neither the height of this condensation, not that of the
+aurora, have been satisfactorily ascertained. The aurora of April 7th,
+1847, was a favorable one for observation. It was carefully and
+attentively watched by Professor Olmsted, Mr. Herrick, Dr. Ellsworth, and
+others, and they are intelligent and skillful observers.[9] But the nature
+of the aurora forbids reliance on parallax, or measurements founded on the
+time when, any portion of the bow or arch rises in range of a particular
+star. The bow or arch moves southwardly, but the same rays or currents do
+not. The wave of magnetic _activity_ moves south, and each successive
+current, as it is reached by the _impulse_, becomes luminous. Hence the
+observers, when distant, do not see, at the same time, or at different
+times, the same rays. The phenomenon is unquestionably magneto-electric.
+Electricity becomes luminous in a vacuum, and De la Rive, by combining the
+electric currents with those of magnetism, produced all the peculiarities
+of the aurora. The magnetic currents, passing from the earth, have
+associated electric ones in connection, and these, in the upper attenuated
+atmosphere, become luminous. Whether, as De La Rive supposes, by combining
+with the positive electricity existing there, or because the associated
+electric currents are _then_ in excess, not being intercepted by
+atmospheric vapor and returned to the earth in rain, we can not know, nor
+is it very important we should.
+
+Having thus taken a general view of the nature of magnetism and its
+associated electricities, and their connection with the general and
+obvious peculiarities of climate, let us approach more nearly the varied
+atmospheric phenomena, resulting from variations of pressure, temperature,
+condensation, and wind, and give them a closer consideration. They all
+have regularity and periodicity--they all occur in degree, and in
+connection with magnetism and electricity, during the twenty-four hours of
+every serene and normal summer's day. Grouped together, in comparison with
+the changes in the activity and force of the magnetic elements, their
+connection is clearly discernible.
+
+The day may be said, with truth, to commence, in some portion of the
+summer, at 4 A.M. The atmospheric does at all seasons. At that hour the
+barometer is at its morning minimum. It has, as we have said, a
+perceptible diurnal variation of two maxima and two minima. Its periods of
+depression are at 4 A.M., and 4 P.M., and of elevation at 10 A.M., and 10
+P.M. The difference between the elevation and depression is considerable
+within the tropics, where Humboldt tells us the hour of the day can be
+known by the height of the barometer, and it decreases toward the poles.
+At 4 A.M. it is then at one of its minima, and rises till 10 o'clock.
+
+At, or about the same period, and sometimes when the barometer is falling,
+and previous thereto, there is a tendency to fog in localities subject to
+that condensation. This tendency is sometimes observed at the other
+barometric minimum, late in the afternoon or early in the evening, but
+less frequently. The tendency to fog condensation is greatest in this
+country about the morning minimum. It seems to be owing to the influence
+of the earth; it is confined to the surface atmosphere, and is apparently
+produced by the inductive agency of the negative electricity of the earth.
+It disappears, whether it be high or low fog, about the time when the
+barometer attains its morning maximum, or about 10 A.M.
+
+At about that period, when there has been fog, or earlier, when there has
+not, and sometimes as early as 8 A.M., there is a tendency to trade
+condensation--cirrus in mid-winter, and a cumulus in mid-summer, and,
+during the intermediate time, a tendency to cirro-stratus, partaking more
+or less of the character of one or the other, according to the season.
+
+Temperature, in summer, commences its diurnal elevation about 4 A.M.,
+also, and rises till about 2 P.M. From that time it falls with very little
+variation till 4 o'clock the next morning. It has but one maximum and one
+minimum in the twenty-four hours.
+
+As the morning barometric maximum approaches, and the heat increases the
+magnetic activity, condensation in the trade appears, or induced
+condensation in the upper portion of the surface atmosphere, that portion
+near the earth is affected and attracted--and the "wind rises," according
+to the locality, the season, and the activity of the condensation. The
+tendency to blow increases with the tendency to trade and cumulus
+condensation, and continues till toward night, when it gradually dies
+away, unless there be a storm approaching. As the heat increases, and
+stimulates magnetism into activity, the magnetic needle commences moving
+to the west, its regular diurnal variation, and continues to do so until
+about 2 P.M., when it commences returning to the east, and so continues to
+return until 10 P.M., when it moves west again until 2 A.M., and from
+thence to the east, till 8 A.M.
+
+Similar variations also take place in the horizontal force, as evinced by
+the action of the magnetometer needle, and in the vertical force, as shown
+by the oscillations. So that it is evident that there are two maxima, and
+two minima of magnetic activity every day, shown by all the methods by
+which we measure magnetic action and force--more than double at the acme
+of northern summer transit over that of winter, and proceeding _pari
+passu_, with the other daily phenomena--evincing the same irregular action
+which the other phenomena evince. Still another phenomenon, which has a
+daily change, is electric tension, or the increase or decrease in the
+tension of the positive or true atmospheric electricity.
+
+
+[Illustration: Fig. 19.]
+
+
+The following table shows the mean two hourly tensions for three years, at
+Kew, viz.:
+
+  Hours                   12 P.M.  2 A.M.  4 A.M.  6 A.M.  8 A.M.  10 A.M.
+  Number of observations   655     784     804     566     1,047   1,013
+  Tension                  22.6     20.1    20.5    34.2      68.2    88.1
+
+  Hours                   12 A.M.  2 P.M.  4 P.M.  6 P.M.  8 P.M.  10 P.M.
+  Number of observations   848     858     878     874     878     1,007
+  Tension                   75.4    71.5    69.1    84.8   102.4     104
+
+From this it will be seen that the tension of electricity is at a minimum
+at 4 A.M., also, that it rises till 10, falls till 4 P.M., but not as
+rapidly, rises till 10, falls again till 4 A.M., or the close of the
+meteorological day--having two maxima and minima, as have most of the
+phenomena thus far considered.
+
+In order to see what the connections between these ever-present, daily
+phenomena are, and their connection with other phenomena, and that we may
+understand their normal conditions, I will trace them approximately in a
+diagram (figure 17.)
+
+The foregoing diagram of the daily phenomena of a summer's day, when no
+disturbing causes are in operation, no storm existing within influential
+distance, and no unusual intensity or irregular action of any of the
+forces present, affords a basis for considering the various phenomena of
+the weather in all its changes and conditions.
+
+It is obvious that the other phenomena do not all depend upon temperature
+merely, if indeed any of them do.
+
+Temperature has but one maximum and minimum, and that is exceedingly
+regular, and does not correspond with any other.
+
+The barometer has two; electric tension, two; magnetic activity, two;
+condensation, two--one the formation of cloud, and the other the formation
+of fog and dew; wind, one--resembling temperature in that respect, but
+embracing a much less period.
+
+Fog forms at one barometric minimum, and cloud at another.
+
+Fog forms at one period of the magnetic variation, cloud at another.
+
+The formation of cloud corresponds with the greatest intensity of magnetic
+action, and its associate electricities. But the oscillations of the
+barometer do not correspond with either. And thus, then, we connect them:
+
+        CAUSE.        |        EFFECT.         | EFFECT.
+                      |                        |
+  Increase of magnetic|Decrease of pressure.   |Increase of primary
+  or magneto-electric |                        |condensation.
+  activity, as shown  |Of positive electric    |
+  by declination and  |tension.                |Of wind.
+  increase of         |                        |
+  horizontal and      |Of surface condensation,|Of electrical disturbance
+  vertical force.     |_i. e._, fog and dew.   |and phenomena in the
+                      |                        |trade and its vicinity.
+
+This connection is equally obvious if the order is reversed--thus;
+
+        CAUSE.        |        EFFECT.         | EFFECT.
+                      |                        |
+  Decrease of magnetic|Increase of pressure.   |Disappearance of primary
+  or magneto-electric |                        |condensation.
+  activity.           |Of tension of           |
+                      |atmospheric electricity.|Of wind, and
+                      |                        |
+                      |Of surface condensation,|Of electric disturbance
+                      |_i. e._, fog and dew.   |in the trade and its
+                      |                        |vicinity.
+
+If we examine still more particularly the different phenomena, we shall
+find the same relative action of the forces carried into all the
+atmospheric conditions, however violent.
+
+1. The barometer falls when horizontal magnetic force, and a tendency to
+cloud and wind, increase; and rises when they decrease. This corresponds
+with the character of the irregular barometric oscillation. Barometric
+depressions accompany clouds and winds, and are in proportion to them, and
+are all greatest where magnetic force is greatest. The barometer also
+rises as the magnetic energy decreases. Do the magnetic currents, passing
+upward with increased force, lift, elevate the atmosphere? How, then, are
+we to explain the increased range of the oscillations, as the center of
+atmospheric machinery is reached, where magnetism has least intensity, and
+the perpendicular currents are less, and attraction is less? Attraction is
+greatest where intensity is greatest, and there the barometer stands
+highest, and the diurnal range is least. Is it then the attraction of
+magnetism which produces the barometric oscillations? If so, how then can
+we explain the diurnal fall while magnetism is most active?
+
+Perhaps we have not yet arrived at such a knowledge of the nature of
+magnetism as is necessary to a correct answer of those questions. Faraday
+has taught us that the lines of magnetic force are close curves, passing
+into the atmosphere, and over to the opposite hemisphere, and returning
+through the earth, out on the opposite side in like manner, and back
+again, passing twice through the earth and twice through the atmosphere.
+All we know of this is what the iron filings indicate, and we do not know
+how much reliance to place upon the indications they give. But if Faraday
+is right, the sun will, twice each day, intersect and stimulate into
+increased activity the same closed magnetic curve--once when it is coming
+out of the earth, during our day, when its influence will be the most
+active, and once when it is returning on the opposite side of the earth;
+and a second, but feebler magnetic and electric maximum, may be occasioned
+by its action on the opposite and returning closed curve of the same
+current. However this may be, it is exceedingly difficult to conceive, of
+any adequate influence exerted by the tension of vapor.
+
+So the mid-day barometric minimum may be caused by the attraction of the
+earth, in a state of increased magnetic activity and intensity, upon the
+counter-trade, and its consequent approach or settling toward the earth.
+Observation, as I have already said, pointedly indicates such a state of
+things. So the increased magnetic activity, with or by its associate
+electricity, acts upon the electricity of the counter-trade, condensation
+takes place, the electricity is disturbed in the surface-atmosphere, by
+induction, and its tension is changed. Opposite electrical conditions are
+induced in the surface strata, and attraction takes place. The air moves
+easily, and thus the attractions originate the winds. Secondary currents
+are induced, as in all other cases of electric activity, and winds, in
+_different strata_ and directions, occur, with or without cumulus, or scud
+condensation, according to their activity, and the proportion of moisture
+of evaporation they may contain.
+
+I am well aware that the various received theories of meteorology
+attribute condensation to the action of cold, mingling of colder strata,
+etc. But I think that view will have to be abandoned.
+
+It assumes that moisture is evaporated and held in the atmosphere by
+latent heat, which is given out during condensation, and actually warms
+the surrounding atmosphere. Thus, the Kew Committee undertook to explain
+the development of greater heat, at the elevation where they, in fact,
+found the counter-trade. But how unphilosophical to suppose a portion of
+the air or vapor contained in it, can give out to another adjoining
+portion _more heat than is necessary to produce an equilibrium_. This can,
+indeed, be done by experiment--_but the experiment is made with currents
+of electricity_. How unphilosophical, too, to talk of latent heat in
+connection with evaporation, _at the lowest temperature known_.
+Meteorologists must revise their opinions on the subject of condensation.
+This latent heat has never been actually met with; on the contrary, the
+most sudden and complete condensations of the vapor of the atmosphere are
+attended by as sudden and extraordinary productions of cold, and
+consequent hail, and the connection between condensation and electricity
+is shown by too many facts to permit the old theory to stand.
+
+_Fog never forms with the thermometer below 32°._ It is mainly a _summer
+condensation_, especially high fog. It has been attributed to the cooling
+effect of an atmosphere colder than the earth, but it often occurs when
+the earth is the coldest, and when the vapor, as it rises, is colder than
+the air, and could not give out heat to a warmer medium. (See American
+Journal of Science, vol. xliv. p. 40.) Again, it is not mere condensation,
+but a formation of globules or vesicles, hollow, and the air expanded in
+them, by means of which they float like a soap bubble which contains the
+warm air of the breath. Is not every vesicle a model shower, positively
+electrified on the outside, negatively in the center, or the reverse,
+according to the strata, with the air expanded in the middle by the excess
+of heat which negative electricity detains? Look at them, as they attach
+themselves to the slender nap of the cloth you wear, when passing through
+them, and see how many of them it would require to form a large drop of
+rain. The clouds are of a similar vesicular character, and rain does not
+fall till the vesicles unite to form drops. Sudden and extreme cold is
+indeed produced in the hail-storm, when, above, below, and around it, the
+temperature is unaffected. Testu, Wise, and other aeronauts, have so found
+it, and the hail tells us it is so. But it is idle to say it results from
+radiation. All the phenomena of the sudden, violent hail-storms are
+electric in an extraordinary degree. The electricity is disturbed and
+separated--the associated heat continues with the negative, and leaves the
+positive portion of the cloud, and a corresponding reduction of
+temperature results. So Masson found in his eudiometrical analytical
+experiments the _negative_ wire would heat to fusion, while the positive
+was cold. (See London, Edinburgh, and Dublin Journal of Science for
+December, 1853.) This disturbed electricity is diffused over the vesicles.
+Listen to the thousand _crackling_ sounds which initiate the clap of
+thunder, and may be heard when the lightning strikes near you; produced by
+the gathering of the lightning from as many points of the cloud where it
+was diffused, to unite in one current and produce the "clap" or
+"peal"--and to the "pouring" of the rain, which follows the union of the
+vesicles, after the excess of repelling electricity is discharged.
+
+No _change_ of temperature is observed when fogs form, except the ordinary
+change between night and day; and it seems perfectly obvious, in looking
+at all the phenomena, that fogs form at a temperature of 70° or 75°, in
+consequence of the electric influence of the earth upon the adjoining
+surface-atmosphere; and, when formed, they withstand the most intense
+action of a summer sun, till the time of day arrives for the barometric
+and electric tension to fall, condensation to take place in the
+counter-trade above, and wind to be induced. Who that has noticed the
+almost blistering force of the solar rays, as they break through a section
+of high fog, about 10 A.M., can forget them.
+
+Fogs form near the earth, during the night, when the atmosphere above is
+loaded with moisture many degrees colder, and yet remains free from
+condensation. On the other hand, during the heat of the day, and of the
+hottest days, the heavy rains condense above--nay, they frequently fall at
+a temperature of 75° to 80°, in the tropics, and of 50° to 55° in
+mid-winter here.
+
+Thus far, an adherence to the opinion that condensation was simply a
+cooling process; the driving out of its latent heat, not merely to another
+body to make an equilibrium, but "_getting rid of it_" by positive active
+radiation, or in some other way, so as to cool off and condense, has
+involved the formation and classification of clouds in obscurity. Hopkins
+(Atmospheric Changes, p. 331) laments this, but fettered by a false and
+imperfect theory, in relation to the tension of vapor, he falls into a
+similar error.
+
+Now, there are, as we have seen, peculiar, distinctly-marked varieties of
+cloud, connected with peculiar and distinctly-marked conditions of the
+atmosphere, _irrespective of temperature_. None of the theories advanced,
+account, or profess to account for the differences in either. No
+modification of the calorific theory will account for them. They differ in
+shape, in color, in tendency to precipitation, in line of progress, and in
+electrical character. The explanation of this is found in the fact, that
+they form in distinct and different strata, partake of the positive
+electric character of the one, or the negative of the other; or are
+secondary, induced by the action of a primary condensation in a different
+stratum. There is not any mingling of the different strata, as has been
+supposed; and many other facts than those to which we have alluded, show
+that the formation of cloud is a magneto-electric process.
+
+The observations of Reid show that every violent shower cloud has the
+electricities disturbed, and portions of it are positive, and others
+negative. Howard gives us the following _résumé_ of Reid's observations:
+
+     "From an attentive examination of Reid's observations I have been
+     able to deduce the following general results:
+
+     "1. _The positive electricity, common to fair weather, often yields
+     to a negative state before rain._
+
+     "2. _In general, the rain that first falls, after a depression of the
+     barometer, is_ NEGATIVE.
+
+     "3. _Above forty cases of rain, in one hundred, give negative_
+     electricity; although the state of the atmosphere is positive, before
+     and afterward.
+
+     "4. _Positive rain, in a positive atmosphere, occurs more rarely_:
+     perhaps fifteen times in one hundred.
+
+     "5. _Snow and hail, unmixed with rain, are positive, almost without
+     exception._
+
+     "6. _Nearly forty cases of rain, in one hundred, affected the
+     apparatus with both kinds_ of electricity; sometimes with an
+     interval, in which no rain fell; and so, that a positive shower was
+     succeeded by a negative; and, _vice versâ_; at others, the two kinds
+     alternately took place during the same shower; and, it should seem,
+     _with a space of non-electric rain between them_."
+
+Howard attributes, with great apparent probability, the successive
+differences in the electrical character of the rain, to the passage of
+different portions of the cloud, having different polarity, over the place
+of observation. So _positive hail_, and _negative rain_ fall in _parallel
+bands_ from the same cloud. Many such instances are on record. It should
+be remembered that he is describing the phenomena in the showery climate
+of England.
+
+But the most decisive, perhaps, as well as practically important evidence
+of the influence of magnetism, or magneto-electricity, in meteorological
+phenomena, is derived from the action of storms. My observation has been
+limited, for my life has been, and must be, a practical one. But, subject
+to future, and I hope speedy corroboration, or correction, by extensive
+systematic observation, I think I may venture to divide all storms into
+four kinds:
+
+1. Those which come to us from the tropics, and constitute the class
+investigated by Mr. Redfield. That these are of a magneto-electric
+character is evident. They originate near the line of magnetic intensity,
+over, or in the vicinity of, the volcanic islands of the tropics; are
+largely accompanied by electrical phenomena; extend laterally as they
+progress north; induce and create a change of temperature in advance of
+them, and do not abate until they pass off over the Atlantic to the E. or
+N. E., and perhaps not until they reach the Arctic circle. Their extensive
+and continued action is not owing to any mere _mechanical agency_ of the
+adjoining passive air, or other supposed currents, originated, no man can
+tell how, but they concentrate upon themselves the local magnetic currents
+as they pass over and intersect them, and, by their inductive action upon
+the surface-atmosphere, in different directions, attract it under them,
+and within their more active influence. Here the action of the magnetic
+currents is probably the primary cause, but the power of the storm to
+concentrate upon itself the new magnetic currents which it intersects as
+it enters each new, successive field, enables them to maintain and extend
+their action.
+
+The following diagram illustrates the course and gradual enlargement of a
+mid-autumn tropical storm, which induces a S. E. wind in front, and
+occasions a thaw.
+
+
+[Illustration: Fig. 20.]
+
+
+2. Another class originate at the N. W., and extend gradually south
+easterly on the magnetic meridian. These are most frequent in summer,
+forming belts of showers, but occur, I believe, at all seasons of the
+year. They seem to be produced by magnetic waves passing south, and are
+followed in autumn and winter, and sometimes in summer, by the peculiar N.
+W. wind and scud, and a term of cooler weather.
+
+Thus, it is believed that many, perhaps all of the alternating terms of
+heat and cold, are dependent on magnetic waves passing over the country in
+a similar manner, with a greater or less belt of condensation between
+them, and depending on peculiar magnetic action traveling in the same
+way. The S. E. extension of showers and storms, and the cooler changes of
+temperature which immediately follow them; with light N. W. wind in
+mid-summer, and with it fresher at earlier and later periods, in the form
+of northers blowing violently, according to the season, are intimately
+connected, and indicate such waves. The indication is strengthened also by
+the frequent progress of auroras in like manner, occurring usually after
+the belt of condensation has passed, and frequently following it. The
+clouds and currents of the atmosphere, so far as I have been able to
+discover, show no permanent current from the pole to the atmospheric
+equator, compensating for the counter-trade; and that compensation is
+furnished by the periodical but frequent atmospheric waves, connected with
+the periodical changes of storm, and cloud, and sunshine, which gradually
+extend from north to south, in or near the magnetic meridian. Perhaps such
+compensating currents are found west of the magnetic poles, as we have
+suggested, and make the N. E. and northerly dry winds of Western Europe
+and the Pacific; but, in the present state of our knowledge, it is
+impossible to say that they are. If it be so, the compensation they
+furnish must be small; for the volume of counter-trade which is not
+depolarized before it reaches the Arctic circle, and which passes round
+the magnetic pole, must be very small. A majority of our periodical
+changes, during the northern transit, and I believe at all seasons, are of
+this character; and, I have reason to believe, from observation, in one
+or two cases, that where belts of rains and showers begin, over _any
+locality_ in the United States, they may assume this character. I have
+been in Saratoga when an easterly storm commenced _south of that place_;
+the condensation and mackerel sky being visible at the south, and no cloud
+formation or rain occurring there at the time, and have traced it
+afterward as a belt which had a lateral extension south-eastward. Leaving
+that place immediately after a belt had passed south, I have overtaken it
+by railroad, and run into it again before arriving at New York; and
+witnessed its subsequent extension south-eastwardly, out over the
+Atlantic. I have witnessed the approach of such a belt in the spring, at
+Sandusky, upon Lake Erie, and its passage over to the S. E., followed by
+the N. W. wind, as Mr. Bassnett describes them at Ottawa, and run under
+the attenuated edge of the same belt, on the same day, on the way to
+Pittsburg, leaving the N. W. wind behind, but finding it present again
+with clear sky on the following morning. I have seen hundreds of them
+approach from the north, and pass to S. E., out over the Atlantic;
+followed by the N. W. wind in spring and autumn. This class of storms pass
+off toward, and doubtless over the track, of our European steamers and
+packets. I know this, for I witness it nearly every month in the year. It
+is not a matter of speculation, but of actual, long-continued observation.
+Probably, as one approaches the Gulf Stream, and when over it, its induced
+winds may be more violent. It is time our navigators understood this; and
+that all the gales of the North Atlantic, certainly, are not rotary; and
+do not approach from the S. W. in the same manner as the class
+investigated by Mr. Redfield do. Where a fresh southerly or south-westerly
+wind is followed by any considerable cirro-stratus or stratus-condensation,
+it is usually of this character.
+
+The following diagram exhibits the peculiarities of this class of storms.
+It is intended to represent the same storm or belt of showers, on _two
+successive_ days, and, of course, its usual rate of southerly extension:
+
+
+[Illustration: Fig. 21.]
+
+
+This class of storms, or belts of showers, present the following
+succession of phenomena in summer:
+
+1. Still warm weather, one or more days.
+
+2. Fresh southerly wind, one or more days; if more than one, dying away at
+the S. W., at night-fall, but continuing into the evening of the day
+before the belt of condensation arrives.
+
+3. Belt of condensation, with or without rain or showers, with the
+easterly wind blowing axially, if the condensation is heavy and the belt
+wide; westerly if the condensation is feeble or the belt narrow--the
+clouds moving about E. N. E.
+
+4. Cooler air, light N. W. in summer, heavy N. W. in autumn, winter, and
+spring.
+
+And, the next period--
+
+5. Still warm weather or light airs.
+
+6. Southerly wind, fresh.
+
+7. Belt of condensation.
+
+8. Cool northerly wind.
+
+And so on, successively, unless broken in upon by some other class.
+
+Sometimes these periods are exceedingly regular, at other times the other
+classes prevail. I have much reason to believe that this is the _normal,
+periodic_ provision for condensation of our portion of the northern
+hemisphere, and probably of every other where rain falls regularly in the
+summer season, and that the other classes are exceptions, as the
+hurricanes are exceptions to the normal condition of the weather every
+where. Perhaps in some seasons, during the northern transit, the
+exceptions may equal the rule, but I do not now remember such a season. In
+other years nearly all the storms are of this character. Thus, Dr.
+Hildreth (in Silliman's Journal for 1827), speaking of the year 1826, in a
+note to his register of that year, says: "There have been, this year, an
+unusual number of winds from N. or N. W. Nearly every rain the past summer
+has been followed with winds from the northward, when, in many previous
+summers, the wind continued to the southward after rain." The immediate
+occurrence of northerly wind after the passage of the belt of
+condensation, is a peculiar feature of this class of storms.
+
+As this also will be new, and is of great practical interest, I shall be
+pardoned for referring to other evidence. Bermuda is in latitude 32°
+north. In the summer season they are within the range of the Calms of
+Cancer, as Lieutenant Maury terms them, and not subject to storms. From
+November to May, inclusive, they have successions of revolving wind.
+Colonel Reid gave them much attention, and studied them barometrically:
+that is, he studied the changes of the wind during the successive periodic
+depressions. He found them revolving like ours, and hence inferred the
+truth of the gyratory theory in relation to all winds. But it is perfectly
+evident the same polar belts which pass over us reach them during the
+southern transit. The precedent southerly wind, the _central
+condensation_, the appearance of lightning, and the rotation of the wind
+by both the east and west, but most frequently by west, are the same. In
+his chapter on observations at the Bermudas, he gives us many examples.
+Probably the existence of the Gulf Stream to the west and north has a
+modifying influence upon them, and their action becomes less intense in
+that latitude, but they are very similar. I copy a record of the weather,
+for a month, which may be found on pages 252, 253, and 254, and a portion
+of his remarks:
+
+     "The month of December, 1839, presents a continual succession of
+     revolving winds passing over the Bermudas, with scarcely an
+     irregularity, as regards the fall and rise of the barometer
+     accompanying the veering of the wind. One, however, occurred on the
+     10th and 11th. The S. W. wind abated, and changed to W. N. W., with
+     the barometer still falling. But in the column of remarks it is noted
+     that there was lightning seen in the N. and N. W., from 7 P.M.,
+     during the night. This irregularity may, therefore, have been
+     occasioned by a gale passing over the banks of Newfoundland,
+     influencing the direction of the wind at Bermuda.
+
+"REVOLVING WINDS.
+
+  +-----------------------------------------------------------------+
+  | Date.  |  Hour.  |Direction of| Wind's | Weather.  |  Bar.|Ther.|
+  |        |         |    Wind.   | Force. |           |      |     |
+  |--------|---------|------------|--------|-----------|------|-----|
+  | 1839.  |         |            |        |           |      |     |
+  |Nov. 30 |Midnight.| S. S. E.   |    1   |b. c.      | 30·06| 65  |
+  |Dec.  1 |  Noon.  | S. S. W.   |    3   |b. c.      | 30·07| 71  |
+  |      2 |    "    | S. W.      |    5   |g. m. q.   | 29·86| 70  |
+  |      3 |    "    | S. S. W.   |    3   |g. c.      | 29·76|  "  |
+  |      4 |    "    | S. W.      |    6   |g. m. r.   | 29·62| 68  |
+  |      5 |    "    | W. N. W.   |    5   |p. q.      | 29·56|  "  |
+  |      6 |    "    | N. W.      |    6   |p. q.      |*29·55|  "  |
+  |      7 |    "    | N. N. W.   |    5   |b. c.      | 29·78| 70  |
+  |      " |Midnight.| N. N. W.   |    3   |b. c.      | 29·89| 68  |
+  |      8 |  Noon.  | W. N. W.   |    2   |b. c.      | 29·82| 71  |
+  |      9 |    "    | S. S. W.   |    5   |p. q.      | 29·84| 70  |
+  |     10 |    "    | S. W.      |    2   |b. c.      | 29·96|  "  |
+  |     11 |    "    | W. N. W.   |    6   |b. c. m.   |*29·88| 68  |
+  |     12 |    "    | S. S. W.   |    "   |b. v.      | 29·99| 69  |
+  |     13 |    "    | N. N. by W.|    "   |b. v.      | 30·01| 66  |
+  |     14 |    "    | N. N. W.   |    5   |b. c. v.   | 30·06| 64  |
+  |      " |Midnight.| N. W.      |    2   |b. c. p.   | 30·05| 63  |
+  |     15 |  Noon.  | S. W. by S.|    6   |g. m. r.   | 29·72| 65  |
+  |      " | P.M. 2  | S. S. W.   |    7   |m. q. r.   | 29·92| 64  |
+  |      " |  "   4  | S. S. W.   |    "   |g. m. q. r.| 29·55|  "  |
+  |      " |  "   6  | W. S. W.   |    "   |q. w.      |*29·53|  "  |
+  |      " |  "   8  | N. W.      |    6   |b. c. q.   | 29·54|  "  |
+  |      " |  "  10  | N. N. W.   |    "   |b. c.      | 29·55|  "  |
+  |     16 |  Noon.  | N. W.      |    7   |b. c. m.   | 29·53| 62  |
+  |     17 |    "    | N. W. by N.|    "   |p. q.      | 29·67| 60  |
+  |     18 |    "    | N. W.      |    6   |c. q.      | 29·86|  "  |
+  |     19 |    "    | N. W. by N.|    7   |m. q. r.   |*29·73| 59  |
+  |     20 |    "    | N. N. W.   |    "   |p. q. c.   | 29·89| 58  |
+  |     21 |    "    | N. W. by N.|    6   |c. q.      | 29·96| 56  |
+  |      " |Midnight.| S. W.      |    1   |b. c.      | 29·95| 55  |
+  |     22 |  Dawn.  | ----       |    0   |           |      |     |
+  |      " |  Noon.  | S. S. W.   |    5   |g. m.      | 29·83| 56  |
+  |      " | P.M. 4  | S.         |    7   |g. m.      | 29·79|  "  |
+  |      " |  "   6  | S. S. E.   |    "   |g. m. r.   | 29·61|  "  |
+  |      " |  "   8  | S. S. E.   |    "   |w. r.      | 29·52|  "  |
+  |      " |  "  10  | S. E.      |    "   |m. w. r.   | 29·48|  "  |
+  |     23 |  Noon.  | S. W.      |    6   |b. c. m.   |*29·44| 57  |
+  |     24 |    "    | W. N. W.   |    "   |b. m.      | 29·71| 59  |
+  |     25 |    "    | W. N. W.   |    5   |b. c.      | 29·88| 56  |
+  |     26 |    "    | N.         |    3   |c.         | 30·09| 62  |
+  |     27 |    "    | S. E.      |    5   |c. q. r.   | 30·07| 61  |
+  |     28 |    "    | S. W.      |    6   |c. q.      | 29·88| 66  |
+  |      " |Midnight.| S. S. W.   |    "   |b. c.      | 29·76| 65  |
+  |     29 | Noon.   | S. W.      |    7   |c. b.      |*29·48| 64  |
+  |     30 |    "    | W. N. W.   |    6   |b. c. q.   | 29·83| 55  |
+  |     31 |    "    | N. W.      |    5   |b. c.      | 30·12| 58  |
+  +-----------------------------------------------------------------+
+
+     "_Remark printed in the Register._
+
+     "The changes of the wind during the December gales have been nearly
+     the same in all: _i. e._, commencing with a southerly wind at first,
+     the wind has veered by the west, toward the north-west, sometimes
+     ending as far round as N. N. W."
+
+These extracts show the passage of several successive belts, each with the
+phenomena in regular order.
+
+The first commences with blue sky and detached clouds, barometer up,
+thermometer down to 65°, and nearly calm, on the 30th of November.
+
+Dec. 1 (at noon). Wind freshens from S. S. W.; thermometer rises;
+barometer still up.
+
+Dec. 2. Barometer has fallen; thermometer up; wind increasing from S. W.,
+with gloomy, squally appearance.
+
+Dec. 3. Wind S. S. W.; barometer slowly falling; thermometer slightly.
+
+Dec. 4. Wind fresh; S. W.; condensation and rain has reached them, and it
+carries barometer and thermometer down.
+
+Dec. 5. Wind shifting by the west, and squally.
+
+Dec. 6. Winds gets N. W.; blows fresh; barometer at its minimum, probably
+at the time of the change of wind, although the register does not show the
+precise time.
+
+Dec. 7. Wind N. N. W.; blue sky and detached clouds (N. W. scud), cleared
+off; barometer elevated by the N. W. wind, from 29.55 to 29.78. Midnight:
+blue sky; detached clouds (N. W. scud probably); barometer up to 29.89;
+thermometer fallen, from the cooler character of the northerly wind.
+
+Dec. 8. Wind having lulled as a northerly wind has got round to S. W.
+again; thermometer up; barometer falling, and another belt approaching,
+and so on.
+
+The first and last part of December show each two regular occurrences of
+substantially the same phenomena. The middle is somewhat more irregular.
+
+There were five distinctly-marked periods, and one squally, long-continued
+period, with a slight tendency to condensation, and a slight fall of
+barometer and rain on the 19th (N. W. squall probably), but not sufficient
+to reverse the wind to the south. In Colonel Reid's opinion there were
+five revolving gales which passed over Bermuda during the month. In my
+opinion, there were five perfect polar waves of condensation, and one
+imperfect one, with as many successive southerly winds preceding the
+condensation, with or without rain in the center, followed by as many cold
+N. W. or N. N. W. winds, with squalls, in the rear, about five days apart.
+(See the * in the barometric column.)
+
+_We are at issue._ Let the question be determined by _actual observation_,
+and not by _speculation_. It is of fundamental and exceeding importance to
+the science.
+
+Now, let us take a month in summer, from the observations of Mr. Bassnett,
+at Ottawa. Here the climate differs somewhat from that east of the
+Alleghanies; the magnetic intensity is greater, and the action more
+violent and irregular. That part of the country, it should be remembered,
+has a greater fall of rain in summer, for reasons we have stated, and
+those periodic revolutions are more frequent.
+
+     "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): 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.
+
+     "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 wreaths, 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.
+
+     "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
+     clearer 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, etc.--all
+     this time there is a bright sky in the south visible through the rain
+     15° high; 7 P.M., clearing (S. W. mod.).
+
+     "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.
+
+     "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 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.
+
+     "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.
+
+     "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
+     Cassiopeia, traveling _westward_ 1-1/2° per minute. This moves to the
+     other side of the pole, but not more inclined toward 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
+     downward 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.
+
+     "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, above 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 scud, 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)."
+
+The letters in a parenthesis signify the direction of the wind.
+
+During this month there were three distinctly marked periods of belts of
+showers, preceded by "fresh" or "strong" south wind, and followed by the
+N. W. There was a period when a belt of less intense stratus, without much
+wind, occurred (28th, 29th, and 30th of June). This was followed by a
+distinct belt of showers and _fresh_ S. wind, on the 2d of July, and by
+the N. W. wind and clear weather, on the 3d.
+
+During the rest of July it was more irregular, with the exception of the
+7th, 8th, and 9th, when another belt and revolution occurred.
+
+Now, these periods, when distinctly marked, exhibit the same succession of
+phenomena--viz., elevation of temperature, fresh southerly wind, belt of
+condensation, cumulus or stratus with cirrus running east, but extending
+south, followed by N. W. wind, and clear, cold air. Can any one believe
+they were successive rotary gales?
+
+I wish, in this connection, to make a suggestion to Lieutenant Maury and
+others. The descriptions of M. Bassnett, although not perfect, are very
+intelligible. He describes things as they were, and as they should be
+described. He distinguishes the clouds, and the scud, and other
+appearances.
+
+But Colonel Reid's descriptions are unmeaning and unintelligible. G.
+M.--Gloomy, misty! Gloomy from what? fog, or stratus, or a stratum of
+scud, or what? We can not know. Again, C. The table tells us this stands
+for detached clouds. But of what kind? Cumulus, broken stratus, patches of
+cirro-cumulus or cirro-stratus, or scud? All these, and indeed every kind
+of cloud or fog formation, except low fog, may exist in detached portions.
+
+These abbreviations will not answer; they do not describe the weather. The
+clouds must be studied and described. There is no difficulty in doing it.
+Sailors will learn them very soon after their teachers have; and those who
+teach them should see to it that the logs contain terms of description
+which convey the meaning which may, and ought to be, conveyed. The use of
+these indefinite terms can not be continued without culpability.
+
+Again, the observations of seamen off our coast are in accordance with the
+progress of this class of storms on land, and prove that they continue S.
+E. over the Atlantic, abating in action as they approach the tropics.
+There is abundant evidence of this in the work of Colonel Reid, and the
+charts of Lieutenant Maury, but I can not devote further space to them.
+
+The third class form in the counter-trade, over some portion of the
+country, from excessive volume or action of the counter-trade, or local
+magnetic activity, without coming from the tropics or being connected with
+a regular polar wave of magnetic disturbance.
+
+The following diagram exhibits their form, progress, and accompanying
+induced winds.
+
+
+[Illustration: Fig. 22.]
+
+
+The gentle rains of spring, particularly April, and the moderate and
+frequent snow-storms of winter, are often of this character; and so are
+the heavy rains, which commence at the morning barometric minimum, rain
+heavily through the forenoon, and light up near mid-day in the south,
+followed by gentle, warm, S. W. winds. This class are more frequent in
+some years than others--probably the early years of the decade, while
+polar storms are, during the later ones. It is this class which have
+_violent_ easterly winds _in front_, and on the _south side_, with two or
+more currents, and which Mr. Redfield has also supposed to be cyclones.
+
+The fourth class are isolated showers, occurring over particular
+localities, or belts of drought and showers alternating; sometimes a
+general disposition to cloudy and showery weather for a longer or shorter
+interval over the whole country; at others, limited to particular
+localities in the course of the trade. Such a period occurred during the
+wheat harvest of 1855. This class I attribute to a general increased
+magnetic action, but it may be induced by an increased volume, or greater
+south polar magnetic intensity of the counter-trade, exciting and
+concentrating the regular currents of the field, and increasing their
+activity and energy. These also often work off south gradually, and are
+followed by a cold N. W. air for a day or two; showing a tendency, in the
+excited magnetism, to pass as a wave toward the tropics.
+
+The following diagram will give some idea of this class:
+
+
+[Illustration: Fig. 23.]
+
+
+There are sometimes very obvious local tendencies to precipitation over
+portions adjoining an area affected with drought, as there are other
+magnetic irregularities over particular areas.
+
+All these classes of storms are variant in intensity. Sometimes the
+general or local cloud-formation is weak, and does not produce
+precipitation at all; so of that which extends southerly. Probably the
+tropical storm are always sufficiently dense and active to precipitate.
+Their action is often violent over particular localities, and hence the
+more frequent occurrence of the tornado over the more intense area of
+Ohio, and other portions of the west. All violent local storms are
+doubtless owing to local magneto-electric activity.
+
+
+
+
+CHAPTER XI.
+
+
+The reader who has attentively perused and considered the facts stated,
+and the principles deduced, in the preceding pages, and is ready to make a
+practical application of them by careful observation, will have little
+difficulty in understanding the varied atmospheric conditions; and will
+soon be able to form a correct judgment of the immediate future of the
+weather, so far as his limited horizon will permit.
+
+But there are other facts and considerations, not specifically alluded to,
+which will materially aid him in his observations; and there is a degree
+of philosophical truth in the proverbs and signs, which ancient popular
+observation accumulated, and poetry and tradition have preserved, that
+meteorologists have been slow to discover or admit, but which will be
+obvious upon examination, and commend them to his attention.
+
+The classical reader is doubtless familiar with that part of the first
+Georgic of Virgil, which contains a description of the signs indicative of
+atmospheric changes. Much of it is beautifully poetic, and, if read in the
+light of a correct philosophy, is equally truthful.
+
+I copy from a creditable translation, found in the first volume of
+Howard's "Climate of London":
+
+  "All that the genial year successive brings,
+  Showers, and the reign of heat, and freezing gales,
+  Appointed signs foreshow; the Sire of all
+  Decreed what signs the southern blast should bring,
+  Decreed the omens of the varying moon:
+  That hinds, observant of the approaching storm,
+  Might tend their herds more near the sheltering stall."
+
+
+  PROGNOSTICS.--_1st. Of Wind._
+
+  "When storms are brooding--in the leeward gulf
+  Dash the swell'd waves; the mighty mountains pour
+  A harsh, dull murmur; far along the beach
+  Rolls the deep rushing roar; the whispering grove
+  Betrays the gathering elemental strife.
+  Scarce will the billows spare the curved keel;
+  For swift from open sea the cormorants sweep,
+  With clamorous croak; the ocean-dwelling coot
+  Sports on the sand; the hern her marshy haunts
+  Deserting, soars the lofty clouds above;
+  And oft, when gales impend, the gliding star
+  Nightly descends athwart the spangled gloom,
+  And leaves its fire-wake glowing white behind.
+  Light chaff and leaflets flitting fill the air,
+  And sportive feathers circle on the lake."
+
+
+  _2d. Of Rain._
+
+  "But when grim Boreas thunders; when the East
+  And black-winged West, roll out the sonorous peal,
+  The teeming dikes o'erflow the wide champaign,
+  And seamen furl their dripping sails. The shower,
+  Forsooth, ne'er took the traveler unawares!
+  The soaring cranes descried it in the vale,
+  And shunn'd its coming; heifers gazed aloft,
+  With nostrils wide, drinking the fragrant gale;
+  Skimm'd the sagacious swallow round the lake,
+  And croaking frogs renew'd their old complaint.
+    Oft, too, the ant, from secret chambers, bears
+  Her eggs--a cherished treasure--o'er the sand,
+  Along the narrow track her steps have worn.
+  High vaults the thirsty bow; in wide array
+  The clamorous rooks from every pasture rise
+  With serried wings. The varied sea-fowl tribes,
+  And those that in Cäyster's meadows seek,
+  Amid the marshy pools, their skulking prey,
+  Fling the cool plenteous shower upon their wings,
+  Crouch to the coming wave, sail on its crest,
+  And idly wash their purity of plume.
+  The audacious crow, with loud voice, hails the rain
+  A lonesome wanderer on the thirsty sand.
+  Maidens that nightly toil the tangled fleece,
+  Divine the coming tempest; in the lamp
+  Crackles the oil; the gathering wick grows dim."
+
+
+  _3d. Of Fair Weather._
+
+  "Nor less, by sure prognostics, mayest thou learn
+  (When rain prevails), in prospect to behold
+  Warm suns, and cloudless heavens, around thee smile.
+    Brightly the stars shine forth; Cynthia no more
+  Glimmers obnoxious to her brother's rays;
+  Nor fleecy clouds float lightly through the sky.
+  The chosen birds of Thetis, halcyons, now
+  Spread not their pinions on the sun-bright shore;
+  Nor swine the bands unloose, and toss the straw.
+  The clouds, descending, settle on the plain;
+  While owls forget to chant their evening song,
+  But watch the sunset from the topmost ridge.
+  The merlin swims the liquid sky, sublime,
+  While for the purple lock the lark atones:
+  Where she, with light wing, cleaves the yielding air,
+  Her shrieking fell pursuer follows fierce--
+  The dreaded merlin; where the merlin soars,
+  _Her_ fugitive swift pinion cleaves the air.
+  And now, from throat compressed, the rook emits,
+  Treble or fourfold, his clear, piercing cry;
+  While oft amid their high and leafy roosts,
+  Bursts the responsive note from all the clan,
+  Thrill'd with unwonted rapture--oh! 'tis sweet,
+  When bright'ning hours allow, to seek again
+  Their tiny offspring, and their dulcet homes.
+    Yet deem I not, that heaven on them bestows
+  Foresight, or mind above their lowly fate;
+  But rather when the changeful climate veers,
+  Obsequious to the humor of the sky;
+  When the damp South condenses what was rare,
+  The dense relaxing--or the stringent North
+  Rolls back the genial showers, and rules in turn,
+  The varying impulse fluctuates in their breast:
+  Hence the full concert in the sprightly mead--
+  The bounding flock--the rook's exulting cry."
+
+
+  _4th. The Moon's Aspects, etc._
+
+  "Mark with attentive eye, the rapid sun--
+  The varying moon that rolls its monthly round;
+  So shalt thou count, not vainly, on the morn;
+  So the bland aspect of the tranquil night
+  Will ne'er beguile thee with insidious calm.
+    When Luna first her scatter'd fires recalls,
+  If with blunt horns she holds the dusky air,
+  Seamen and swains predict th' abundant shower.
+  If rosy blushes tinge her maiden cheek,
+  Wind will arise: the golden Phoebe still
+  Glows with the wind. If (mark the ominous hour!)
+  The clear fourth night her lucid disk define,
+  That day, and all that thence successive spring,
+  E'en to the finished month, are calm and dry;
+  And grateful mariners redeem their vows
+  To Glaucus, Inöus, or the Nereid nymph."
+
+
+  _5th. The Sun's Aspects, etc._
+
+  "The sun, too, rising, and at that still hour,
+  When sinks his tranquil beauty in the main,
+  Will give thee tokens; certain tokens all,
+  Both those that morning brings, and balmy eve.
+  When cloudy storms deform the rising orb,
+  Or streaks of vapor in the midst bisect,
+  Beware of showers, for then the blasting South
+  (Foe to the groves, to harvests, and the flock),
+  Urges, with turbid pressure, from above.
+  But when, beneath the dawn, red-fingered rays
+  Through the dense band of clouds diverging, break,
+  When springs Aurora, pale, from saffron couch,
+  Ill does the leaf defend the mellowing grape;
+  Leaps on the noisy roof the plenteous hail,
+  Fearfully crackling. Nor forget to note,
+  When Sol departs, his mighty day-task done,
+  How varied hues oft wander on his brow;
+  Azure betokens rain: the fiery tint
+  Is Eurus's herald; if the ruddy blaze
+  Be dimm'd with spots, then all will wildly rage
+  With squalls and driving showers: on that fell night,
+  None shall persuade me on the deep to urge
+  My perilous course, or quit the sheltering pier.
+  But if, when day returns, or when retires,
+  Bright is the orb, then fear no coming rain:
+  Clear northern airs will fan the quiv'ring grove.
+  Lastly, the sun will teach th' observant eye
+  What vesper's hour shall bring; what clearing wind
+  Shall waft the clouds slow floating--what the South
+  Broods in his humid breast. Who dare belie
+  The constant sun?"
+
+I copy also the following from Howard:
+
+  "Dr. Jenner's signs of rain--an excuse for not accepting the
+  invitation of a friend to make a _country_ excursion.
+
+  "The hollow winds begin to blow,
+  The clouds look black, the glass is low,
+  The soot falls down, the spaniels sleep,
+  And spiders from their cobwebs creep.
+  Last night the sun went pale to bed,
+  The moon in halos hid her head,
+  The boding shepherd heaves a sigh,
+  For see! a rainbow spans the sky.
+  The walls are damp, the ditches smell;
+  Closed is the pink-eyed pimpernel.
+  Hark! how the chairs and tables crack;
+  Old Betty's joints are on the rack.
+  Loud quack the ducks, the peacocks cry;
+  The distant hills are looking nigh.
+  How restless are the snorting swine!--
+  The busy flies disturb the kine.
+  Low o'er the grass the swallow wings;
+  The cricket, too, how loud it sings!
+  Puss, on the hearth, with velvet paws,
+  Sits smoothing o'er her whisker'd jaws.
+  Through the clear stream the fishes rise
+  And nimbly catch the incautious flies;
+  The sheep were seen, at early light,
+  Cropping the meads with eager bite.
+  Though _June_, the air is cold and chill;
+  The mellow blackbird's voice is still;
+  The glow-worms, numerous and bright,
+  Illumed the dewy dell last night;
+  At dusk the squalid toad was seen,
+  Hopping, crawling, o'er the green.
+  The frog has lost his yellow vest,
+  And in a dingy suit is dress'd.
+  The leech, disturbed, is newly risen
+  Quite to the summit of his prison.
+  The whirling wind the dust obey
+  And in the rapid eddy plays.
+  My dog, so altered in his taste,
+  Quits mutton-bones, on grass to feast;
+  And see yon rooks, how odd their flight!
+  They imitate the gliding kite:
+  Or seem precipitate to fall,
+  As if they felt the piercing ball.
+  'Twill surely rain; I see, with sorrow,
+  Our jaunt must be put off to-morrow."
+
+Howard attributes the foregoing to Jenner; but Hone, in his "Every-Day
+Book," attributes it to Darwin, and gives it, with several couplets, not
+found in that attributed to Jenner. These I add from Hone, as follows:
+
+  "Her corns with shooting pains torment her--
+  And to her bed untimely send her."
+
+That couplet is included by Hone with what is said of Aunt Betty.
+
+  "The smoke from chimneys right ascends,
+  Then spreading back to earth it bends.
+  The wind unsteady veers around;
+  Or, settling in the south is found."
+
+Those are as philosophically accurate and valuable as any.
+
+  "The tender colts on back do lie;
+  Nor heed the traveler passing by.
+  In fiery red the sun doth rise,
+  Then wades through clouds to mount the skies."
+
+The first of those couplets is untrue. It is doubtless alluded to as one
+of the acts of the animal creation, indicating sleepiness and inaction,
+which precede storms; but colts do not lie on the back. The other couplet
+is both true and important. This collection entire, whether written by
+Darwin or Jenner, contains most of the signs which have been preserved,
+and which are of much practical importance in our climate.
+
+It is unquestionably true that "appointed signs foreshow the weather," to
+a great extent, every where, but with more certainty in the climate in
+which Virgil wrote than in our variable and excessive one. "Showers" and
+"freezing gales" we can, perhaps, as well understand; but the "_reign of
+heat_," by which he probably meant the dry period, when the southern edge
+of the extra-tropical belt of rains is carried up to the north of them, we
+do not experience. Something like it we did indeed have, during the
+excessive northern transit, in the summer of 1854; but it was an
+exception, not the rule.
+
+Some of the most important of those signs from Virgil and Jenner I propose
+to allude to in detail; but it is necessary to look; in the first place,
+to the character of the season and the month.
+
+We have seen that the years differ during different periods of the same
+decade. That they incline to be hot and irregular during the early part of
+it, and cool, regular, and productive during the latter portion--subject,
+however, to occasional exceptions. The latter half of the third decade of
+this century (1826 to 1830, inclusive) was comparatively warm; and, in the
+latitude of 41°, was very unhealthy, and so continued during the early
+part of the next, over the hemisphere, embracing the _cholera seasons_.
+The spots upon the sun were much less numerous than usual, during the
+latter half of the third decade. Thus the spots from
+
+     1826 to 1830, inclusive, were  873
+     1836 to 1840      "       "   1201
+     1846 to 1850      "       "   1168
+
+     and the size of those from 1836 to 1840 exceeded those of the other
+     years.
+
+The attentive observer will very soon be satisfied that the seasons have a
+character; and those of every year differ in a greater or less degree from
+those of other years in the same decade, and those of one decade not
+unfrequently from those of some other. _Periodicity_ is stamped upon all
+of them, and upon all resulting consequences. Like seasons come round,
+and, like productiveness or unproductiveness, healthy or epidemic
+diatheses, attend them. We have seen that, in relation to mean
+temperature, there are such periodical diversities, but they are more
+strongly marked in the character of storms, and other successions of
+phenomena. "_All signs fail in a drouth_," for then all attempts at
+condensation are partial, imperfect, and ineffectual. "_It rains very
+easy_," it is said, at other times, and so it seems to do, and with
+comparatively little condensation. In the one case, no great reliance can
+be placed upon indications which are entirely reliable in the other. So
+"_all our storms clear off cold_," or, "_all our storms clear off warm_,"
+are equally common expressions--as the _prevailing classes_ of storms give
+a _character_ to the _seasons_. It "_rains every Sunday now_," is
+sometimes said, and is often peculiarly true--the storm waves having just
+then a weekly or semi-weekly period, and one falls upon Sunday for several
+successive weeks; and when it is so, _that_ coincidence is sure to be
+noticed and commented upon, and the other perhaps disregarded.
+
+If the seasons depended upon the northward and southward journey of the
+sun alone, entire regularity might be expected--for we have no reason to
+believe that magnetism and electricity contain, within themselves,
+inherently, any tendency to irregularity, or periodicity; and, the sun
+being constant in his _periods_, would be constant in his _influence_. But
+he is inconstant and variable in his influence, and it is apparently
+traceable to the existence of spots; but I am not quite sure that it is
+occasioned by the _observable_ spots alone. Grant that the intensity and
+power of his rays differ on the same day, in different years, and that
+difference may be attributable in part to causes which our telescopes can
+not discover.
+
+But the differences in the seasons do not depend on the variability of the
+sun's influence alone. This appears from the frequent meridional and
+latitudinal diversities and contrasts, to which allusion has been made.
+The sun can not be supposed to exert a _less_ influence on a middle, than
+a more northern latitude; nor on one series of meridians, than another.
+There must, therefore, be another local and powerful disturbing cause,
+varying the magnetic and electric activity and influence upon the trades,
+as well in their incipiency as in their circuits, and thus controlling the
+atmospheric conditions locally and in _the opposite hemispheres_. That
+other disturbing cause is _volcanic action_. We can conceive of none
+other, and we can detect and trace the influence of that to a considerable
+extent. Unfortunately we know, and can practically know, comparatively
+little of it. It has been busy with the earth since the creation, and will
+continue to be so till, possibly, by a collision, it shall burst into
+asteroids--its molten interior flowing out in seeming combustion--each
+fragment retaining its magnetic polarities entire, and continuing on in an
+independent orbit in the heavens, an asteroid, or meteorite.
+
+While, therefore, the agency of magnetism in itself may be regular, and
+the transit of the sun is regular, and "seed-time and harvest shall not
+cease," yet the sun is not regular in his influence, and the magnetic
+agency is disturbed by another and irregular power. And, although we can
+trace the influence of both upon the seasons, we can not measure that
+influence, and from it reliably foretell the weather. The discoveries of
+Swabe, and future ones, relative to solar irregularities, will assist us,
+but, till we understand better, and to some extent anticipate, the
+changes of volcanic action, we shall not be able to understand or foresee
+all the differences in the seasons. That time may come; for progress is
+yet to be read in the front of meteorology, and simultaneous practical
+observations made and interchanged at every important point on the globe.
+Nevertheless, the seasons have a character--often a regular one--one class
+of storms prevailing over all others--one series of phenomena occurring to
+the exclusion of others--and we must regard it if we would arrive at
+intelligent estimates of their future condition.
+
+The most difficult part to understand are the meridional contrasts. Last
+year we had one of the worst drouths which has occurred since the
+settlement of the country. But while all the eastern portion of the United
+States was dry, New Mexico was unusually wet; and the North-western
+States, on the same curving line of the counter-trade, were not affected
+by the drouth.
+
+Extract from a letter written by Governor Merriweather, to Mr. Bennett, in
+answer to a circular, published in the "New York Herald," and dated
+
+     "SANTA FE, NEW MEXICO, Oct. 25th, 1854.
+
+     "More rain has fallen during the last six months, within this
+     territory, than ever was known to have fallen in the same length of
+     time, in this usually dry climate. Generally, little or no crops have
+     been produced without irrigation; but this season some good crops
+     have been produced without any artificial watering."
+
+We have seen that there was an apparent connection between the remarkable
+volcanic action, exerted beneath the western continents during the second
+decade of this century, and the remarkable coldness of that decade. And
+it is easy to see that the comparative absence of volcanic action from
+immediately beneath the Old World, and its presence in great excess
+beneath the New, may disturb the regular action of terrestrial magnetism
+above it in the earth's-crust here, and affect seasons, diatheses, and
+health unfavorably; while from its absence they may be favorably affected
+there. I have some general views in relation to this, but they are
+necessarily speculative, for the data are few, and I reserve them.
+
+I am, however, induced to believe that the transit of the atmospheric
+machinery is greater over some portions of the northern hemisphere, in
+some seasons, than others. The most natural explanation of the unusual
+contrast between the drouth of the Eastern States, and the wet of the
+Territories, during the last summer, is, that the concentrated
+counter-trade was carried west, by some irregular magnetic action in the
+South Atlantic or West Indies. But there was much evidence that the
+northern extension of the atmospheric machinery was greater than usual.
+The transit began _early_--it was evidently _rapid_; the rains of May fell
+in April, and the spring was wet; _summer set in earlier_--all the
+appearances then were unusually tropical--the polar belts of condensation
+descended upon us, but they were feeble, as they doubtless become, when
+they reach the tropics, and did not precipitate; the summer continued full
+twenty days later--no rain falling till about the 10th of September. The
+season throughout was excessive, but otherwise regular. Spring came
+earlier; summer commenced earlier and continued longer; autumn held off
+later, and cold weather, when it came, was uniform and severe. This season
+the transit has seemed to be less than for several years.[10] The spring
+was backward; the summer cool, but exceedingly regular; the autumn thus
+far without extremes, and the whole year healthy and productive. It is the
+normal period of the decade, between the irregular heat of the first part,
+and the irregular cold of the last; and it has been normal in character,
+and conformed beautifully to its location. If the transit of 1854 was
+further north than the mean, as it seemed to be over this country, that of
+itself would convey the showers which follow up in the western portion of
+the concentrated trade, on the east of the mountains of Mexico, and cause
+them to precipitate further north, over New Mexico, and thus, rather than
+from a diverted trade, they may have derived their unusual supply of
+moisture during the summer of 1854. On this subject I can but conjecture,
+and leave to future observation a discovery of the truth.
+
+Enough appears, however, to show the importance of taking the location of
+the year in the decade, and even the character of the decade itself, into
+the account.
+
+But whatever the remote cause of the difference in the seasons, the
+character of the seasons is directly influenced by the character of
+storms, or periodic changes. Sometimes the tropical storms are most
+numerous; at others the polar waves; and at others the irregular local
+storms, or general tendency to showers. The seasons when the polar waves
+are most prevalent, are the most regular, healthy, and productive. Those
+where the tropical tendency is greatest, are irregular; and so are those
+where the other classes predominate. These differences in the character of
+the storms, are but the varying forms in which magnetic action develops
+itself. I have said that there was a decided tendency to cirrus without
+cumulus, in mid-winter, and cumulus without cirro-stratus or stratus, in
+midsummer, and during the intermediate time an intermediate tendency. But
+there is a difference between spring and autumn. Dry westerly (not N. W.)
+gales prevail in March, and N. E. storms in April and May, but violent S.
+E. gales are not as common. On the other hand, the dry westerly gales of
+March are comparatively unknown in autumn, and the violent, tropical,
+south-easters are then common.
+
+Snow-storms occur during the northern transit, not unfrequently in April
+and May; but they do not occur so near the acme of the northern transit on
+its return; nor until it approaches very near its southern limit. The
+quiet, warm, and genial air of April, is reproduced in the Indian summer
+of autumn, but they present widely different appearances. Those, and many
+other peculiarities of the seasons, deserve the attentive consideration of
+every one who would become familiar with the weather and its prognostics.
+
+These irregularities in the character of the seasons have doubtless always
+existed, and always been the objects of popular observation. There are
+some very old proverbs which show this. I copy a few of the many, which
+may be found in Foster's collection. Mr. Graham Hutchison does not seem to
+think any of those ancient proverbs worthy of notice. But he misjudges.
+They are the result of popular observation, and many of them accord with
+the true philosophy of the weather.
+
+_Irregular_ seasons are unhealthy, and unreliable for productiveness. When
+the southern transit was late, or limited, and the autumn ran into winter,
+our ancestors feared the consequences in both particulars, and expressed
+their fears, and hopes also, in proverbs. Thus,
+
+  "A green winter
+  Makes a fat churchyard."
+
+There is very great truth in this proverb. Again,
+
+  "If the grass grows green in Janiveer,
+  It will grow the worse for it all the year."
+
+This is emphatically true, for the season which commences irregularly will
+be likely to continue to be irregular in other respects.
+
+Another of the same tenor:
+
+  "If Janiveer Calends be summerly gay,
+  It will be winterly weather till Calends of May."
+
+Janiveer is an alteration of the French name for January, and the proverb
+is very old.
+
+So March should be normally dry and windy.
+
+This, too, they understood, and hence the strong proverb:
+
+  "A bushel of March _dust_
+  Is worth a king's ransom."
+
+And another:
+
+            "March hack ham,
+  Come in like a lion, go out like a lamb."
+
+So April and May should be cool and moist. It is their normal condition in
+regular, healthy, and productive seasons. The grass and grain require such
+conditions; and the spring rains are needed to supply the excessive summer
+evaporation. This, too, they well understood. And hence the proverbs:
+
+  "A cold April the barn will fill."
+
+  "A cool May, and a windy,
+  Makes a full barn and a findy."
+
+And--
+
+  "April and May are the keys of the year."
+
+This was not very favorable, to be sure, for corn; but their consolation
+was found, as we find it, in the truth of another proverb:
+
+  "Look at your corn in May, and you'll come sorrowing away;
+  Look again in June, and you'll come singing in another tune."
+
+This difference in the character of the seasons occasioned the adoption of
+a great variety of "Almanac days;" and they are still very much regarded.
+Candlemas-day (2d of February) was one of them.
+
+Says Hone, in his "Every-Day Book":
+
+     "Bishop Hall, in a sermon, on Candlemas-day, remarks, that 'it has
+     been (I say not how true) an old note, that hath been wont to be set
+     on this day, that if it be clear and sunshiny, it portends hard
+     weather to come; if cloudy and lowering, a mild and gentle season
+     ensuing.'"
+
+To the same effect is one of Ray's proverbs:
+
+  "The hind had as lief see
+  His wife on her bier,
+  As that Candlemas-day
+  Should be pleasant and clear."
+
+St. Paul's day, or the 25th of January, was another great "Almanac day,"
+and so the verse:
+
+  "If Saint Paul's day be fair and clear,
+  It does betide a happy year;
+  But if it chance to snow or rain,
+  Then will be dear all kinds of grain.
+  If clouds or mists do dark the sky,
+  Great store of birds and beasts shall die;
+  And if the winds do fly aloft,
+  Then war shall vex the kingdom oft."
+
+St. Swithin's day was another of these "Almanac days." Gay said truly,
+
+  "Let no such vulgar tales debase thy mind;
+  Nor Paul, nor Swithin, rule the clouds or wind."
+
+Yet "_Almanac days_" are still in vogue to a considerable extent--such as
+the _three first days_ of the year, old style--the first three of the
+season--the last of the season--different days of the month--of the
+lunation, etc., etc. And some still look to the breastbone of a goose, in
+the fall, to judge, by its whiteness, whether there is to be much snow
+during the Winter, etc.
+
+These _Almanac days should all be abandoned_; they have no foundation in
+philosophy or truth. There is one proverb, however, in relation to
+Candlemas-day, which the "oldest inhabitant" will remember, and which it
+may be well to retain. It has a practical application for the farmer, and
+in relation to the length of the winter:
+
+  "Just half of your wood and half of your hay
+  Should be remaining on Candlemas-day."
+
+The months, too, have a character which must be remembered and regarded.
+
+_January_ is the coldest month of the year, in most localities. The
+atmospheric machinery reaches its extreme southern transit, for the
+season, during the month--usually about the middle. It remains stationary
+a while--usually till after the 10th of February. One or more thaws,
+resulting from tropical storms, occur during the month, in normal winters,
+but they are of brief duration. Boreas follows close upon the retreating
+storm with his icy breath. There is a remarkable uniformity in the
+progress of the depression of temperature, to the extreme attained in this
+month, over the entire hemisphere. It differs in degree according to
+latitude and magnetic intensity; but it progresses to that degree,
+whatever it may be, with as great uniformity in a southern as northern
+latitude. The table, copied from Dr. Forrey, discloses the fact, and so
+does the following one, taken from Mr. Blodget's valuable paper, published
+in the Patent Office Report for 1853:
+
+
+TABLE SHOWING THE MEAN TEMPERATURE FOR EACH MONTH AT SEVERAL PLACES, VIZ.:
+
+  +---------------------------------------------------------------------+
+  |                   |  Lat. | Jan. | Feb. |March.|April.| May. |June. |
+  |-------------------|-------|------|------|------|------|------|------|
+  |Quebec, Canada E.  |46° 49'|  9.9 | 12.8 | 24.4 | 38.7 | 52.9 | 63.7 |
+  |New York, N. Y.    |40° 42'| 30.2 | 30.8 | 38.5 | 49.1 | 59.6 | 69.1 |
+  |Albany, N. Y.      |42° 39'| 24.5 | 24.3 | 34.8 | 47.7 | 59.8 | 68.0 |
+  |Rochester, N. Y.   |42° 45'| 26.1 | 25.8 | 33.0 | 45.8 | 56.2 | 64.5 |
+  |Baltimore, Md.     |39° 17'| 33.1 | 34.3 | 42.4 | 53.0 | 63.2 | 71.6 |
+  |Savannah, Ga.      |32° 05'| 52.6 | 54.7 | 60.0 | 68.4 | 74.8 | 79.4 |
+  |Key West, Fla.     |24° 33'| 70.0 | 70.7 | 73.8 | 76.3 | 80.2 | 82.1 |
+  |Mobile, Ala.       |30° 40'| 51.3 | 53.7 | 59.4 | 67.1 | 74.1 | 77.8 |
+  |New Orleans, La.   |30° 00'| 54.8 | 54.5 | 61.5 | 67.6 | 74.0 | 78.6 |
+  |Marietta, Ohio     |39° 25'| 32.2 | 34.1 | 42.6 | 53.0 | 61.8 | 69.2 |
+  |San Antonio, Tex.  |29° 25'| 52.7 | 57.9 | 65.5 | 69.7 | 76.4 | 80.5 |
+  |San Francisco, Cal.|37° 48'| 50.1 | 51.0 | 53.8 | 57.7 | 55.9 | 58.8 |
+  +---------------------------------------------------------------------+
+
+                      +-----------------------------------------+
+                      |July. | Aug. | Sept.| Oct. | Nov. | Dec. |
+                      |------|------|------|------|------|------|
+                      | 66.8 | 65.5 | 56.2 | 44.1 | 31.5 | 17.3 |
+                      | 74.9 | 73.3 | 65.9 | 54.3 | 43.5 | 33.9 |
+                      | 72.2 | 70.3 | 61.4 | 49.2 | 39.4 | 28.3 |
+                      | 69.7 | 67.8 | 60.1 | 47.7 | 38.2 | 28.8 |
+                      | 76.6 | 74.5 | 67.7 | 55.8 | 45.0 | 37.8 |
+                      | 81.3 | 80.6 | 76.9 | 67.2 | 58.3 | 52.2 |
+                      | 83.3 | 83.5 | 82.5 | 79.1 | 75.6 | 72.8 |
+                      | 79.8 | 79.4 | 76.1 | 65.7 | 57.0 | 52.8 |
+                      | 80.4 | 79.6 | 77.1 | 69.1 | 57.5 | 56.2 |
+                      | 72.7 | 70.9 | 63.5 | 51.8 | 42.6 | 34.7 |
+                      | 82.3 | 83.3 | 79.9 | 72.2 | 62.2 | 52.1 |
+                      | 57.9 | 62.2 | 61.6 | 61.9 | 56.2 | 50.0 |
+                      +-----------------------------------------+
+
+Snows during this month are much heavier, and more frequent, in some
+localities than others. The reasons why this is so have been stated. The
+mountainous portions of the country receive the heaviest falls. They
+affect condensation somewhat, and according to their elevation. They
+intercept the flakes before they melt, and retain them longer without
+change. The thaws, or tropical storms, also sometimes have a current of
+cold air, with snow setting under them on their northern and north-western
+border. Such was the case with that investigated by Professor Loomis.
+January is without other marked peculiarities. It shows, of course, those
+extremes of temperature found, to a greater or less degree, in all the
+months, and differs, as the others differ, in different seasons. Normally,
+in temperate latitudes, it is a healthy month. The digestive organs have
+recovered from that tendency to bilious diseases which characterizes the
+summer extreme northern transit, and the tendency to diseases of the
+respiratory organs, which characterizes the southern extreme and the
+commencement of its return, is not often developed till February.
+February, in its normal condition until after the 10th, and about the
+middle, is much like January. Often the first ten days of February are the
+coldest of the season. The average of the month is a trifle higher, in
+most localities, as the tables show. This results from the increasing
+warmth of the latter part of the month. There are localities, however,
+where the entire month is as cold as January. Such (as will appear from
+Blodget's table) are Albany and Rochester, in the State of New York, and
+New Orleans, in Louisiana. At most places the difference is slight, either
+way. South of the latitude of 40° heavy snows are more likely to occur in
+the last half of January and first half of February than earlier. About
+the middle of the month we may expect thaws of more permanence in normal
+seasons. They are followed, as in January, by N. W. wind and cold weather,
+but it is not usually as severe. Many years since, an observing old man
+said to me, "_Winter's back breaks about the middle of February_." And I
+have observed that there is usually a yielding of the extreme weather
+about that period. Here, again, it is interesting and instructive to look
+at the tables, and see how regularly and uniformly the temperature rises
+in all latitudes, at the same time; as early and as rapidly at Quebec as
+at New Orleans or San Antonio; and subsequently rises with greatest
+rapidity where the descent was greatest. The elevation of temperature does
+not progress northwardly, a wave of heat accompanying the sun, but is a
+magneto-electric change, commencing about the same time over the whole
+country, and indeed over the hemisphere.
+
+March is a peculiar month--the month of what is termed, and aptly termed,
+"unsettled weather." It, may "come in like a lion," or be variable at the
+outset. The northern transit is fairly started, and is progressing
+rapidly, and there is great magnetic irritability. A reference to the
+table of Dr. Lamont will show that the declination has increased with
+great rapidity. Normally, the early part is like the latter part of
+February, and the latter part approaches the milder but still changeable
+weather of April. Its distinguishing feature is violent westerly wind. Not
+the regular N. W. only--although that is prevalent--but a peculiar
+westerly wind, ranging from W. by N. to N. W. by W., often blowing with
+hurricane violence. This wind was alluded to on page 130. With the change
+and active transit to the north, in February and in March, comes the
+tendency to diseases of the respiratory organs--pneumonias and lung
+fevers--and this is the most dangerous period of the year for aged people.
+
+April is a milder and more agreeable month. During some period of it, in
+normal seasons, and at other times in March, there is a warm, quiet,
+genial, "lamb-"like _spell_, exceedingly favorable for oat seeding. When
+it comes, advantage should be taken of it, for long heavy N. E. storms are
+liable to occur, and frequently with snow. On the latitude of 41° heavy
+snow-storms are not uncommon in April. Within the last fifteen years two
+such have occurred after the 10th of the month. April, as we have seen,
+should be cool and moist. If dry, the early crops are endangered by a
+spring drouth; if very wet, there is danger of an extreme northern
+transit, and an early summer drouth. It is emphatically true that
+
+  "April and May are the keys of the year."
+
+Its distinguishing peculiar feature is the gentle, _warm_, _trade_
+rains--"_April showers_"--which, in the absence of great magnetic
+irritability, that current drops upon us. There is great _mean_ magnetic
+activity, but it is not so _irregularly excessive_ as in March.
+
+May, in our climate, should be, and normally is, a wet month, and a cool
+one, considering the altitude of the sun. The atmospheric machinery which
+the sun moves is, however, ordinarily about six weeks behind it--the
+latter reaching the tropic the 20th of June, and the former its farthest
+northern extension about six weeks later. Hence it is not a cause for
+alarm if May be wet and cool. The great staples, wheat, grass, and oats,
+are benefited; and corn, according to the proverb, will not be seriously
+retarded. The movable belt of excessive magneto-electric action, with its
+tropical electric rains, so exciting to vegetation, and its periods or
+terms of excessive heat, is on its way north, and sure to arrive in
+season, and remain long enough to mature the corn. There have been but two
+seasons in this century when corn did not mature in the latitude of 41°.
+One during the cold decade, and the cold part of it, between 1815 and
+1820; and the other, during the cold half of the fourth decade, between
+1835 and 1840.
+
+The distinguishing feature, if there be one, of May, is its long, and, for
+the season, cool storms. These have, in different localities, different
+names. In pastoral sections we hear of the "_sheep storms_"--those which
+effect the sheep severely when newly shorn--killing them or reducing them
+in flesh by their coldness and severity.
+
+In relation to this too early shearing, there is an old English proverb,
+in "Forster's Collection," viz.:
+
+  "Shear your sheep in May,
+  And you will shear them all away."
+
+So there are others called "_Quaker storms_," which occur about the time
+when that estimable sect hold their yearly meeting. And there are other
+names given in different localities to these long spring storms. But they
+are all _mere coincidences_--equinoctial and all.
+
+Notwithstanding the storms, however, the temperature rises at a mean. The
+declination is often as great as in mid-summer. The earth is growing
+warmer by the increase of magneto-electric action, whatever the state of
+the atmosphere. The yellow, sickly blade of corn is extending its roots
+and preparing to "_jump_" when the atmosphere becomes hot, as it is sure
+to do, when the machinery attains a sufficient altitude, how backward
+soever it may seem to be. The farmer need not mourn over its backwardness,
+unless the season is a very extraordinary one, like those of 1816 and
+1836. The storms ensure his hay, wheat, and oat crops; the warming earth
+is at work with the roots of his corn, and is filling with water, and
+preparing for the hot and rapidly-evaporating suns of mid-summer. The
+earth would grow warmer if every day was cloudy.
+
+By the middle of June the atmospheric machinery approaches its northern
+acme, the summer sets in, and not unfrequently, as extremely hot days
+occur during the latter part of the month, as at any period of the
+summer. But the heat is not so continuous, or great, at a mean.
+
+From the middle of June to the latter part of August is summer in our
+climate, and during that period from one to three or four terms of extreme
+heat occur, continuing from one to five or six days, and possibly more,
+terminating finally in a belt of showers overlaid with more or less
+cirro-stratus condensation in the trade, and controlled by the S. E. polar
+wave of magnetism, and followed by a cool but gentle northerly wind.
+During these "heated terms," a general showery disposition sometimes,
+though rarely, appears, with isolated showers, which bring no mitigation
+of the heat. Not until a southern extension of them appears, followed by a
+N. W. air, does the term change, so far as I have observed.
+
+By the 20th of August, in the latitude of 42°, an evident change of
+transit is observable, by one who watches closely, although the range of
+the thermometer in the day-time may not disclose it. A greater tendency to
+cirrus-formation is visible. The nights grow cooler in proportion to the
+days. The swallows are departing, or have departed; the blackbirds, too,
+and the boblinks, with their winter jackets on, _their plumage all changed
+to the same colors_, are flocking for the same purpose, and hurrying away.
+The pigeons begin to appear in flocks from the north, and the first of the
+blue-winged teal and black duck are seen straggling down the rivers. At
+this season, and nearly coincident with the change, the peculiar annual
+catarrhs return. These are colds (so called) which at some period of the
+person's life were taken about or soon after the period of change, and
+have returned every year, at, or near the same period. They soon become
+_habitual_, and no care or precaution will prevent them. I know one
+gentleman who has had this annual cold in August for twenty-seven years,
+with entire regularity; and another who has had it nineteen years; and
+many others for shorter periods. I never knew one which had recurred for
+two or three years that could be afterward prevented, or broken up. _Very
+instructive are these annual catarrhs_ to those who think health worth
+preserving, and in relation to the change of transit.
+
+_The change is felt over the entire hemisphere._ Between the 20th of
+August and the 10th of September hurricanes originate in the tropics and
+pursue their curving and recurving way up over us; or long "north-easters"
+commence in the interior and pass off to E. N. E. on to the Atlantic,
+followed now in a more marked degree by the peculiar N. W. wind, so common
+over the entire Continent in autumn and winter.
+
+By the 10th of September the pigeons may be seen in flocks in the morning,
+and just prior to the setting in of a brisk N. W. wind, hurrying away
+southward with a sagacity that we scarcely appreciate, to avoid the
+anticipated rigors of winter, and to be followed soon by all the migratory
+feathered tribes that remain.
+
+The nights grow cooler, although the sun shines hot in the day-time, and
+woe to the person, unless with an iron constitution, who disregards the
+change, and exposes himself or herself without additional protection, to
+its influence. Nature has taken care of those who depend upon her, or upon
+instinct, for protection. The feathers of birds and water-fowl are full;
+the hair and the fur are grown. Beasts and birds have been preparing for
+the change, and are ready when it begins. They know that the earth is
+changing. The shifting machinery is fast carrying south that excess of
+negative electricity which has so much to do with giving it its summer
+heat. They feel its absence, even during the day, and the contrast between
+that and the positively electrified northern atmosphere, which now follows
+every retreating wave of condensation.
+
+The musk-rat builds, of long grass and weeds, his floating nest in the
+pond, that he may have a place to retire to, when the rain fills it up and
+drives him from his burrow in its banks.
+
+But man, with all his intellect, is too heedless of the change. Additional
+clothing is now as necessary to him as to animals, but it is burdensome to
+him in the day time, and therefore he will not wear it, how much soever it
+would add to his comfort and safety during the night. He stands with his
+thin summer soles upon the changed ground, or sits in a current, or in the
+night air, less protected than the animals, and dysentery or fever sends
+him to his long home. He has _intelligence_, but he lacks _instinct_. He
+has time for the changes of dress which fashion may require, but none for
+those which atmospherical changes demand. _Fashion_ has attention in
+_advance_; _death_ none till _at the door_.
+
+Now the southern line of the extra-tropical belt of rains descends upon
+those who, living between the areas of magnetic intensity, have a dry
+season; and the focus of precipitation in that belt descends every where.
+"_Winter no come till swamps full_," the Indians told our fathers, and
+there is truth in the remark; although like other general truths
+respecting the weather, it is not always so in our climate. Rains fall
+during the autumnal months, as during the spring months, and while the
+transit of the machinery is active and the evaporation is less. And the
+magnetic comparative rest, and the seed time and equable "spell" of April
+is reproduced in the Indian summer of autumn.
+
+The machinery gradually and irresistibly descends, and with an excess of
+polar positive electricity, comes snow; Boreas controls, and winter sets
+in, reaching its maximum of cold in January again.
+
+Remembering, then, the differences in the normal conditions of the seasons
+and months, and the different characters that the winds, and storms, and
+clouds, and other phenomena bear in them respectively, let us now look at
+the signs of foul or fair weather not herein before fully stated, upon
+which practical reliance may be placed.
+
+In the first place, we must look to the forming condensation. There are
+many days when the atmosphere is without visible clouds, but few when it
+is entirely without condensation. Such days are seen during the dry season
+in the trade-wind region; and with us, in mid-summer drouths, which
+partake of this tropical character; and when, at any season, but
+particularly in winter, the N. W. wind in large volume has elevated the
+trade very high. Condensation is not necessarily in form of visible cloud.
+It may be of that smoky character which sometimes attends mid-summer
+drouths, giving the sun a blood-red appearance; or it may be like that
+change from deep azure to a "lighter hue," obscuring the vision, which
+Humboldt describes as preceding the arrival of the inter-tropical belt of
+rains. Gay-Lussac, and other aeronauts, have seen a thin cloud stratum at
+the height of 20,000 to 30,000 feet, not visible at the earth, although
+some degree of mistiness and obscurity were observed. At that elevation
+the clouds are thin, and always white and positive. Some degree of
+turbidness is frequent; it may occur, as we have stated, with N. W. wind,
+but, if it does, the wind soon changes round to the southward.
+
+This turbidness or mistiness, where it exists, and indicates rain, does
+not disappear toward night, as it should do if but the daily cloudiness
+which results from ordinary diurnal magnetic activity, but becomes more
+obvious at nightfall; and, when hardly visible at mid-day, or during the
+afternoon, may then be observed, obscuring in a degree, the sun's rays;
+and, later in the evening, forming a circle round the moon. Thus Jenner--
+
+  "Last night the sun went _pale to_ bed,
+  The moon in _halos_ hid her head."
+
+And so, too, Virgil--
+
+  "The sun, too, rising, and at that still hour,
+  When sinks his tranquil beauty in the main,
+  Will give thee tokens; certain tokens all,
+  Both those that morning brings, and balmy eve.
+
+       *       *       *       *       *
+
+  When Sol departs, his mighty day-task done,
+  How varied hues oft wander on his brow.
+
+       *       *       *       *       *
+
+                    If the ruddy blaze
+  Be _dimm'd_ with _spots_, then all will wildly rage
+  With squalls and driving showers: on that fell night
+  None shall persuade me on the deep to urge
+  My perilous course, or quit the sheltering pier.
+  But if, when day returns, or when retires,
+  _Bright_ is the orb, then fear no coming rain:
+  Clear northern airs will fan the quiv'ring grove.
+  Lastly, the sun will teach th' observant eye
+  What vesper's hour shall bring; what clearing wind
+  Shall waft the clouds slow floating--what the South
+  Broods in his humid breast. Who dare belie
+  The constant sun?"
+
+More frequently this kind of condensation is sufficiently dense at
+night-fall to take shape, and show a bank when the sun shines horizontally
+through a mass of it. I am now speaking of _storm_ condensation, or that
+which indicates the approach of a storm. Thunder clouds at nightfall,
+dark, dense, and isolated, are, of course, to be distinguished. Those,
+every one understands to indicate a shower, and immediate succeeding fair
+weather.
+
+The halos do not, in cases of incipient storm condensation, always appear.
+The moon may not be present: though, in her absence, I have seen them in
+the light of the primary planets; or she may be in the eastern portion of
+the heavens. When this is so, and the condensation forms slowly, there may
+be less appearance of it, after the sun disappears, than before, although
+a storm is approaching, and sure to be on by the middle of next day, and
+perhaps with great violence. When the failure of the light no longer
+reveals the denser condensation in the west, the stars may shine, as did
+the sun, dimly but visibly, through the partial and invisible
+condensation; and one who did not notice the bank in the west, at
+nightfall and before dark, may be deceived by the seeming clearness of the
+evening. Thus Virgil--
+
+  "Mark, with attentive eye, the rapid sun--
+  The varying moon that rolls its monthly round;
+  So shalt thou count, not vainly, on the morn;
+  _So the bland aspect of the tranquil night
+  Will ne'er beguile thee with insidious calm_."
+
+All early condensation and indications derived from it, must be looked for
+in the west. From that quarter all storms come. These indications at
+nightfall are of a varied character. They may consist of primary
+condensation in the trade, or of secondary condensation, scud running
+north toward a storm, the condensation of which has not yet visibly
+reached us, but which will extend south and pass over us. It may be a
+heavy bank, or consist of narrow cirrus bands. Cirro-stratus cloud banks,
+in the S. W., in the fall and winter, of a foggy and uniform character,
+are indicative of snow. The body of the storm will pass south of us, and a
+portion over us, the wind be north of east, and the snow will not be
+likely to turn to rain before it reaches the earth, by reason of a
+southern middle current.
+
+Banks in the N. W. indicate rain at all seasons. The storm is north of us,
+working southerly, and such storms rain on the southern border--in winter
+even--because they have the wind on that border from south of east. It
+may, indeed, snow, but if so, probably in large flakes, soon turning to
+rain. There are other appearances at nightfall which deserve
+consideration. A red sun, with smoky air, is indicative of continued dry
+weather, a frequent appearance in dry terms, lasting three or four days,
+at least, from the commencement. So is a red appearance of the sky, when
+there are no clouds, indicative of a fair day following. On this subject
+we have an allusion to the weather, by our Saviour while on earth, which,
+like all such allusions found in the Bible, is of remarkable philosophical
+accuracy. It is found in Matthew, chapter xvi., verses 2 and 3: "He
+answered and said unto them, When it is evening ye say, It will be fair
+weather, for the sky is red. And in the morning, It will be foul weather
+to-day, for the sky is red and lowering. O, ye hypocrites, ye _can
+discern_ the face of the sky," etc.
+
+Another allusion to the weather, though not applicable to this point, I
+will refer to in passing. It is found in Luke, chapter xii., verses 54 and
+55: "And he said also to the people, When ye see a cloud rise out of the
+west straightway ye say, There cometh a shower; and so it is. And when ye
+see the south wind blow, ye say, There will be heat; and it cometh to
+pass."
+
+This is all very true, and might have been cited to show the universality
+of the phenomena. But to return.
+
+We have an old English proverb alluding to the same phenomena, of great
+value and truth, viz.:
+
+  "An evening red and a morning gray
+  Are sure signs of a fair day;
+  Be the evening gray and the morning red,
+  Put on your hat or you'll wet your head."
+
+The sky is red if there be no condensation at the west to obscure the rays
+of the sun; if there be, it is gray, or there is a bank or cloud, and it
+is obscured. So if there be no condensation over, or to the east of us, in
+the morning, to reflect the rays of the sun, the sky is gray; if there be
+such condensation, the sun is reflected from it, and the sky is red. Such
+morning condensation is indicative of foul weather. It is, as we have
+said, the eastern edge of an approaching storm, on, or under which, the
+sun shines and illumines it. Thus, at night, it shines through a portion
+at the west, which is situate between the sun and us, making the sky gray:
+but shines on, or under, a portion in the morning, east of us, but not far
+enough east to obscure the horizon, and the rays of the rising sun are
+reflected from it. In either case the red or gray appearance results from
+the relative situation of the sun and the eastern edge of an approaching
+storm.
+
+The following couplet of Darwin is an apt description of the morning
+appearance:
+
+  "In fiery red the sun doth rise,
+  Then wades through clouds to mount the skies."
+
+The sun is often reflected in vivid colors, from the under surface of
+clouds, at sunset. This is an indication of fair weather. It is evident
+the sun shines through a _clear atmosphere beyond the cloud_, or his rays
+would not reach and illume the lower surface of the cirro-stratus with
+such distinctness. He "_sets clear_," as is said; the clouds are passing
+off, and there are none beyond. It is this appearance, in different forms,
+when there happen to be patches of broken, melting cirro-stratus above the
+horizon, which makes the beautiful sunsets that attract attention. So the
+sun is reflected, in beautiful colors sometimes, from the cumulus clouds
+which have passed over to the east. The most beautiful and variegated I
+have ever seen, were reflected from that imperfect cumulus condensation
+which takes place occasionally during long drouths--doubtless resembling
+that which is seen over Peru, hereinbefore alluded to, as described by
+Stewart.
+
+It is not, then, the presence of cloud condensation at the west, at
+nightfall, which alone indicates foul weather; but such condensation,
+whatever its form, as evinces that it is not the _dissolving_ cloud of the
+day, but the eastern, approaching portion of a _still denser portion
+beyond, through, or under which, the sun can not shine clearly, but which
+wholly or partially obscures it_. _Remembering this philosophy of the
+matter_, the observer will soon be able to detect the various forms of
+condensation which originate or exhibit themselves at nightfall, and
+whether they indicate an approaching storm or not, without a more explicit
+specification of them. It is an important hour for observation; "Let not
+the sun go down" without attention.
+
+When the condensation is obvious, but thin, at nightfall, it may not, as I
+have said, be discernible in the evening. But there are methods by which
+the incipient storm condensation may be detected. The number of the stars
+visible, and the _distinctness_ with which they may be seen, indicate the
+absence or presence of condensation and its density. Virgil, alluding to
+the indications of fair weather, says:
+
+  "_Brightly_ the stars shine forth; Cynthia no more
+  _Glimmers_ obnoxious to her brother's rays;
+  Nor fleecy clouds float lightly through the sky."
+
+The brightness of the stars and the clear appearance of the moon show the
+absence of condensation and the _dissolution_ of the fleecy clouds at the
+close of the day is, as we have seen, always a fair-weather indication.
+
+There is much true philosophy in the allusions of Virgil to the moon.
+Thus--
+
+  "When Luna first her scatter'd fires recalls,
+  If with _blunt horns_ she holds the _dusky_ air,
+  Seamen and swains predict th' abundant shower."
+
+The horns, or angles of the moon will, of course, appear distinct and
+sharp or indistinct and blunt, in proportion to the amount of
+condensation in the atmosphere which impedes the passage of the light. For
+the same reason, when the moon is new, her entire disk is visible when the
+atmosphere is very clear, by reason, as is supposed, of light reflected
+from the earth to the moon and back to us. This double reflection can only
+take place when the atmosphere is very clear. Hence, Virgil alludes to it,
+and correctly, as an indication of continued fair weather:
+
+                  "If (mark the ominous hour!)
+  The clear fourth night her lucid disk define,
+  That day, and all that thence successive spring,
+  E'en to the finished month, are calm and dry."
+
+Probably Virgil alluded to a month of the summer trade-wind drouth which
+reaches up on Southern Italy. But that appearance of the moon is
+occasionally seen here, and the indication is, in degree, philosophically
+true.
+
+It is somewhat more difficult to determine what will be the result of the
+condensation seen at the west in the morning, and which is not so far
+east, or of such a character, as to reflect the rays of the sun; for,
+although always suspicious, it is sometimes of a foggy character, and
+disappears between eight and nine o'clock. If it increases in density
+after ten o'clock, or is of a dense cirro-stratus character, rain may
+generally be expected. If of a decided _cirro-cumulus_ character, it is
+certain to disappear. Cirro-cumulus is seen in small patches, with small,
+distinct, and rounded masses, in summer, in the morning, and sometime,
+during the day, after high fog has disappeared, and at other times, and is
+always, when of that _distinct_ character, a fair weather indication. I
+have seen it thus when the wind was blowing from the N. E., and the scud
+running toward a storm passing near, but to the south of us, when those
+who relied upon the existence of the wind and scud as evidences that we
+were to have the desired rain, were deceived. Thus, the couplet from an
+old almanac:
+
+  "If _woolly fleeces_ strew the heavenly way,
+  Be sure no rain disturb the summer day."
+
+When this morning condensation is not high fog, and is dense and passing
+east with a wavy appearance, it is very certain to rain. Jenner says:
+
+  "The boding shepherd heaves a sigh,
+  _For see, a rainbow spans the sky_."
+
+An old almanac had the following verse:
+
+  "A rainbow in the morning
+  Is the shepherd's warning;
+  A rainbow at night
+  Is the shepherd's delight."
+
+So the proverb was originally made; but as our ancestors were not
+shepherds, and had a horror of ocean storms, it was commonly quoted, in
+this country, in the following form:
+
+  "A rainbow in the morning,
+  The sailors take warning," etc.
+
+Rainbows are not reflected from _clouds_, but falling rain, and a morning
+rainbow at the west is, of course, evidence that it is _actually raining
+there_, and will, in all probability, pass over us. "Thunder in the
+morning, rain before night," is a common saying, and a true one. There is
+a belt of showers, or showery period approaching, of unusual
+intensity--for thunder showers in the morning are rare. The afternoon is
+their most common period, and they are very apt to appear then, when the
+morning is showery.
+
+Of the different forms of cirrus and cirro-stratus, which appear during
+the day, and indicate approaching storms, or of cumulus indicative of
+showers, it is difficult to give an intelligible description without very
+many illustrations. I have many daguerreotype views, taken at different
+seasons of the year, and at a time when different forms of cirrus and
+cirro-stratus condensation, indicative of storms, exhibited themselves.
+They differ, as I have said, and it must be remembered, very much at
+_different seasons_ of the year, and in _different years_, and their
+delicate shades are taken with difficulty by the artist, and reproduced
+with difficulty, and only at considerable expense, by the engraver; and I
+have omitted them. The time will come when a knowledge of their language
+will be sought for and read--when the "countenance of the sky" will be an
+object of intelligent interest to all whose business may be affected by
+the weather, or who love to learn of nature. But it is not yet. This is
+the age of theory and speculation. The time of actual, practical,
+connected observation and prognostication, which may justify expensive
+illustration, is yet to arrive.
+
+The reader will find in the general plates representations of several
+kinds of cirri. They are delicate, always white, more or less fibrous, and
+form in the upper part of the trade or the adjoining atmosphere above it.
+Their character and elevation should be studied, and the observer should
+be careful to distinguish which is the most elevated. Not unfrequently it
+may seem, to a hasty observer, that the cirrus is below the cirro-stratus
+or forming stratus. But the genuine cirrus never is. It forms near, and
+above, the point of congelation, and is often composed of crystals of ice
+or snow. If they fall, they melt and evaporate, when there is no storm,
+before reaching the earth. Aeronauts have met with them and their crystals
+when there was no fall of moisture at the surface of the earth; and the
+angles of reflection exhibited by halos and other optical phenomena which
+form in them, enable us to detect their crystallization and the form of
+it.
+
+They are produced by electric changes which condense the vapor, and the
+coldness of the air at that elevation freezes it at the _instant of its
+condensation_.
+
+Congelation is crystallization, and all crystallization is electric, or
+magneto-electric. The snow-flakes differ in form and size according to the
+suddenness of the condensation, the amount of moisture condensed, the
+polarity of the strata through which they pass, and their consequent
+attraction and adhesion to each other.
+
+The connection of electricity with these formations of cirri has
+frequently been admitted, and it is perfectly obvious that the long
+fibrous bands, shooting from horizon to horizon, could not be formed by
+commingling of currents any more than the perfectly isolated, distinct,
+enlarging-outward cumulus hail-storm, could be so formed. Cirri form at
+the line of meeting, between the trade and the upper atmosphere, and in
+one or the other, or both, very much according to the season, and the
+suddenness with which storms are produced. These often _induce_ a layer of
+cirro-stratus or stratus at the lower line of the counter-trade, and in
+the surface-atmosphere, which precipitates; and this operation is clearly
+discernible, and very frequently, before gentle rains. Condensation in the
+whole body of the trade is usually in the form of turbidness or mistiness,
+a bank or incipient stratus, without cirri.
+
+It seems matter of astonishment that water should float so far condensed,
+in strata where the air is so much lighter, without being precipitated.
+But electric attraction and repulsion between the different strata and the
+vesicles, explain it.
+
+In mid-winter, the cirrus forms are prevalent and most distinct. After
+severe cold weather, when a storm approaches, the cirri form in long,
+narrow threads, parallel to each other, extending from about W. S. W. to
+E. N. E., gradually thickening and forming, or inducing, cirro-stratus and
+stratus, and dropping snow. This form is called the _linear_-cirrus. The
+tufted, and other fibrous forms, are seen in patches also, in great
+distinctness, during these mid-winter days, when the wind gets around to
+the southward, and the weather is pleasant. Such days are called
+"_weather-breeders_," and their _offspring_ the patches of cirrus, which
+are to extend and compose, or induce the storm, and indeed are an advance
+part of it, are then never absent. A clear, moderate day, in a normal
+winter, with wind from any southern point, however light, between the 1st
+of January and the middle of February, without these patches of cirrus, is
+very uncommon. Watch and see whether they tend to cirro-stratus, or
+whether the wind gets around to the N. W. at nightfall, and they
+disappear. If the former, a storm may be expected; if the latter, fair
+weather.
+
+Thus there are three peculiarities attending the forming cirrus of
+mid-winter (1st of January to 10th of February): long, fibrous, parallel
+bands in the morning (linear cirrus), gradually coalescing as the day
+advances, after severe cold; the comoid, curled, or tufted cirrus, in
+curling bunches, called "_mares'-tails_," and the _transverse_, when the
+fibers are in bands or threads, which are not parallel, but cross each
+other at angles, more or less acute. The two former varieties are
+represented on Figure 5, page 26, indicated by one bird, but the last form
+is a very prevalent one in our atmosphere.
+
+Various names have been given to different forms of _cirro-stratus_. Those
+represented in Figure 5, page 26, are the "_cymoid_" on the right, the
+"_mottled_" on the left, below the cirro-cumulus; and the "_linear_"
+below that. The form known as the "_mackerel sky_" is not represented
+there. It consists of regular forms, resembling the _waves_ on the surface
+of the water when the wind blows a gentle breeze. But the _wavy_ form, and
+of all sizes, is very frequently assumed by cirro-stratus, which is
+rapidly condensing, and turning to stratus. In the "mackerel sky,"
+strictly so called, the waves are small, parallel, nearly distinct and
+equi-distant, and resembling the appearance of a school of mackerel,
+swimming in the same direction, one above another. All _wavy_ forms of
+cirro-stratus indicate a disposition to increased condensation and rain.
+When the waves are very large and dense, and cross obliquely, or unite at
+one end, rain is very certain to fall soon, if the line of progress of the
+condensation is over the observer, and the clouds are seen in the western
+or N. W. quarter of the sky.
+
+But there are few forms which are not occasionally seen when no rain or
+snow falls. The intensity of the electric action which produces them may
+not be sufficient to effect precipitation, or they may be the attendant,
+attenuated _lateral_ condensation, which frequently "thins out" a
+considerable distance from the dense, precipitating portions of the storm.
+
+If that denser portion is north of us, the probabilities of rain are
+greater, for there is always a probability that the storm may be of the
+character which is extended south, by a polar wave. The observer must
+watch the formation of cirri, and the different forms of cirro-stratus and
+stratus, and become familiar with their appearance. It is not a difficult
+task. With the aid of a few general directions he will soon be familiar
+with them:
+
+1. Get a correct idea of the different characters of the primary clouds.
+The true fibrous _cirrus_--the different forms of _cirro-stratus_--the
+smooth, uniform _stratus_--the _cirro-cumulus_, which is nothing but a
+cirro-stratus, separated into _distinct masses_ by the repulsion of static
+electricity--and the _cumulus_, too distinct ever to be mistaken. There is
+no difficulty, except with the varied forms of cirro-stratus. It is
+useless to attempt to give, or the observer to rely on, names for these
+numerous forms, without as numerous illustrations. Those in use are rarely
+applied correctly. I have never met with ten persons who applied even the
+term "mackerel sky" to the same precise form of cirro-stratus. In relation
+to all of them it is to be observed that polar belts of condensation, and
+local appearances of considerable extent, are often too feeble in action
+to precipitate, even when the mackerel form is present; and all may be the
+lateral attendants of passing storms. Therefore,
+
+2. Satisfy yourself whether the cirrus or cirro-stratus increases in
+density and tends to the formation, or induction, of stratus; and whether
+it is isolated, or an extension of the condensation of a storm, and if the
+latter, _where that storm is_. The time will come when an intelligent use
+of the telegraph will do this for you.
+
+3. Look also to the character of the wind, if there be any. On this
+subject I have perhaps said all that is necessary in the preceding pages.
+Next to condensation, the direction and character of the wind is the most
+valuable prognostic. Indeed it often tells us that a storm is approaching,
+and the quarter from which it will come, and its character, before the
+condensation is visible.
+
+4. See if there is any _secondary_ condensation or scud. These are
+sometimes seen running toward a storm, when there are not distinct clouds
+visible in the western horizon, at nightfall, or in the evening, as in the
+instance stated in the introduction, and sometimes from the north-east, as
+in cases heretofore so often stated. But the easterly scud do not often
+form in winter, until after the cirrus has passed into the form of
+cirro-stratus, or has induced the latter forms in the inferior portion of
+the trade, or the surface atmosphere.
+
+The inductive effect of the primary condensation, therefore, is not
+always, and especially in winter, sufficient to create the easterly
+current and scud, and it is often the case that the easterly wind is not
+felt, or the scud seen, in snow-storms, until the snow has begun to fall,
+and the first snow will fall with a S. W. air, as I have heretofore
+stated. But when the condensation has so far advanced toward stratus that
+the easterly wind and scud are obvious, there is little or no doubt that
+rain or snow will fall speedily. The occasional occurrence of easterly
+wind and scud, without rain, however--dry north-easters, as I have termed
+them--in connection with storms passing south of us, or condensation too
+feeble to precipitate, should be remembered. The long, dry,
+north-easterly winds of spring have been attributed to the icebergs, but
+they are overlaid by feeble stratus or cirro-stratus condensation, or are
+the result of attraction, by a more southern precipitation. The observer
+must be careful to distinguish between the various forms of N. W. scud and
+cirro-stratus, which they sometimes resemble. This he may do _from the
+direction in which they move_. Cirro-stratus always moves from some point
+between S. S. W. and W. S. W. to some point between N. N. E. and E. N. E.
+The various forms of N. W. scud move to the S. E. The March, foggy scud,
+from between W. and N. W., rarely have any cirro-stratus above them, but
+rather a peculiar turbid condensation.
+
+The character of the primary condensation, the direction and force of the
+wind, and the direction of the secondary condensation or scud, must be the
+main reliance of the observer. But I must reiterate that they all differ
+in different kinds of storms, in different seasons of the same year, and
+the same seasons of different years; and the observer must be careful to
+make due allowance for those differences.
+
+There are, however, divers other secondary signs, which, although not
+alone to be relied upon, will aid the observer, if carefully studied, when
+the character of the clouds, and the pressure of easterly or southerly
+wind and scud, are not decisive. Of these, a large class are electrical.
+
+The smoke descends the adjoining chimney-flues, or outside of the chimney,
+toward the ground.
+
+Thus, Darwin, as quoted by Hone:
+
+  "The smoke from chimneys right ascends,
+  Then, _spreading_, back to earth it bends."
+
+Smoke is electrified _positively_, by the act of combustion; the earth and
+the adjacent atmosphere, when storms are gathering or approaching, is
+_negative_. Hence the smoke spreads, and is attracted downward by an
+opposite electricity. On the other hand, it is interesting to see, at
+other times, and when the difference in temperature is not material, but
+the whole atmosphere is positive, with what rapidity and compactness the
+smoke will ascend in a _straight and elevated column_ from the chimney,
+repelled by a similar electricity. I am aware it is generally supposed the
+smoke descends because the _air is lighter_. But it is a mistake. I have
+seen it descend when the barometer was at 30°.60, or .60 above the mean.
+
+There is, too, a draught downward in chimneys, in such cases when there is
+no smoke or fire in any of its flues. Thus Jenner says: "The soot falls
+down;" whether he meant by this that there was an actual fall of soot
+other than what is occasioned by the rain falling in through the chimney
+top, and disturbing the soot, as sometimes happens, I do not know. It
+occurs rarely, and is of very little practical importance. But every
+housewife knows that chimneys, which have been used in winter, and are
+full of soot, _smell_ before storms. The odor results from a downward
+draught and the dampness of the air. So the smoke from one flue will
+descend another, into some unused room, on such occasions. Another class
+of these electrical signs are felt by those who are suffering from chronic
+diseases, which have affected the nerves and made them sensitive. Thus
+Jenner:
+
+  "Old Betty's joints are on the rack."
+
+And Hone adds:
+
+  "Her corns with shooting pains torment her,
+  And to her bed untimely send her."
+
+But Old Betty's rheumatism or corns are not alone in this. Those whose
+bones have been broken feel it. All invalids feel it. And, indeed, all
+observing healthy persons may, and do, although all are not distinctly
+conscious of it. It is common for such to say, I feel sleepy, or I feel
+dull, or, It _feels_ like snow, or _feels_ like rain, and thus from their
+own feelings to be able to predict, not only falling weather, but its
+_character_, whether snow or rain, at a time when either may occur
+consistently with appearances.
+
+This change is a change from the positive electricity which is so
+congenial to the active--"bracing" is the usual term--to negative and
+damp--for this change is accompanied by condensation, as I believe all
+changes from positive to negative are. Certain it is, if the atmosphere is
+highly charged with negative electricity, condensation takes place; if
+with positive, evaporation. Perhaps it is a change of the associated
+electricity which accompanies magnetism, and not of the free atmospheric
+electricity alone. Hence another phenomenon alluded to by Jenner:
+
+  "The walls are damp, the ditches smell."
+
+There are localities where this dampness is very obvious. The celebrated
+William Cobbett, many years since, when a farmer on Long Island, observed
+and published the fact that the stones grew damp before a storm. I know of
+flagging stones that usually grow damp two or three hours before rain,
+especially in spring and fall, and every step taken upon them is made
+visible by a corresponding increase of condensation.
+
+The reverse of this takes place just before the close of storms. Flagging
+stones, and walls under cover, will frequently become dry before the rain
+ceases. The negative electricity becomes less as the positive prevails,
+although the clouds above are still dropping rain.
+
+In the comparatively moist, showery climate of England, these changes from
+positive to negative alternate rapidly between successive showers; but
+observations of electric phenomena, or of clouds, in that climate, are
+not, without qualification, safe guides for us.
+
+So "the ditches smell," particularly in the evening before a rain, when
+the immediate surface-atmosphere is charged with negative electricity, and
+the _condensing moisture_ prevents the diffusion of the odors. For the
+same reason the candle will not relight, and there is crackling in the
+ashes or lamp. Thus, again, Virgil:
+
+  "Maidens that nightly toil the tangled fleece
+  Divine the coming tempest; in the lamp
+  _Crackles_ the oil, the gathering wick grows dim."
+
+Virgil did not live in our cold climate, and knew nothing of the crackling
+in the fire, or in the ashes or coals which remain after the wood is
+consumed. The lamp exhibits it on a smaller scale, and perhaps he had
+noticed it when in company with the maidens. But it is sometimes
+noticeable even in the lamp or candle with us. A small particle of
+moisture will produce it, in a marked degree, at any time.
+
+In winter, when the air is highly positive and cold, the candle can be
+blown out, and by another puff of the breath relighted, with ease. But
+when the electricity before a storm becomes negative, and partial
+condensation takes place, this can not be done. This partial condensation
+before storms and showers shows itself upon vessels containing cold-water,
+in summer. It seems to be the received opinion, that the condensation is
+evidence of a greater _quantity_ of moisture in the atmosphere. But this,
+too, is a mistake, and hence the little reliance to be placed on
+hygrometers.
+
+This partial condensation is sometimes visible. When the sun shines
+clearly, at the east or west, through a _small opening_ in the clouds, the
+condensing vapor is shown by the streaks of sunlight, just as the fine
+particles of dust are seen in a dark room, when a few rays of sunlight are
+admitted through a small aperture. This phenomenon is often observed, and
+it is said of it--"It's a going to rain; _the sun is drawing water_."
+
+Virgil alludes to this as seen in the east in the morning, thus:
+
+  "But when beneath the dawn _red-fingered rays_
+  Through the dense band of clouds _diverging_ break,
+
+       *       *       *       *       *
+
+  Ill does the leaf defend the mellowing grape;
+  Leaps on the noisy roof the plenteous hail,
+  Fearfully crackling."
+
+It is well ascertained that storm-clouds of great intensity have polarity
+in the different portions, and that in the less intense magneto-electrical
+climate of England isolated showers are often of this character--the
+polarity existing in rings. Showers are doubtless thus found with us. Mr.
+Wise got into one of them; see his description (Theory and Practice of
+Aeronautics page 240).
+
+I have, in another place, alluded to the upward attraction of the dust
+beneath the advance condensation of a shower. Jenner alludes to it in the
+following lines:
+
+  "The whirling winds the _dust_ obeys,
+  And in the rapid eddy plays."
+
+So Virgil:
+
+  "Light chaff and leaflets, _flitting, fill the air_,
+  And sportive feathers circle on the lake."
+
+All these are electrical.
+
+In England, where the action of such isolated clouds is less intense, the
+different electricities in different portions of the cloud, whose opposite
+and changing action produce all the phenomena, the condensation, the cold
+and congelation, the currents, etc., have been accurately ascertained. We
+can not get into the situation occupied by Mr. Wise. But every man may
+observe these _intestine motions_ occasionally, in the advance
+condensation of an isolated thunder-shower, in front of, but near the
+smooth line of falling rain. They are more lateral than upward or
+downward, and are often exceedingly rapid in movement.
+
+I have said that hail has often been found to fall from particular and
+well-defined portions of a cloud, and rain from the other portions, the
+hail being positive, and rain negative. An instance of very striking
+character may be found in Espy's Philosophy of Storms (Introduction, page
+xx.) Doubtless in all cases thunder-showers, which are isolated and
+distinct, have opposite electricity in different portions, to whose active
+agency all the phenomena are owing. And the return of electricity to the
+earth in the rain explains the greater fertilizing effect of the latter
+compared With all artificial watering. He was a true philosopher who
+attempted to stimulate vegetation by electricity.
+
+Sounds may sometimes aid the observer in doubtful cases in foretelling the
+weather. The roar of the surf, or breaking of the waves on the shore, when
+great bodies of water are disturbed by a precedent storm-wind, often heard
+before the wind is perceived on the land, I have already alluded to. And
+thus Virgil:
+
+  "When storms are brooding--in the _leeward gulf_
+  Dash the swelled waves; the mighty mountains pour
+  A harsh, dull murmur; far along the beach
+  Rolls the deep rushing roar."
+
+The moaning or whistling of the wind all have noticed. It is not uncommon
+to hear the expression, "The wind sounds like rain." Jenner says:
+
+  "The _hollow_ winds begin to blow."
+
+And Virgil:
+
+  "The _whispering_ grove
+  Betrays the gathering elemental strife."
+
+This whispering is the motion of the leaves; and they are often stirred by
+a peculiar motion which is not that of wind. Sometimes every leaf upon a
+tree may be seen _vibrating_ with an _upward and downward_ motion, when
+there is not wind enough to stir a twig. This interesting phenomenon is
+electrical. Trees, and all vegetables, confessedly discharge electricity,
+and such discharges move the leaves, when very active.
+
+With us, sounds can be heard more distinctly from the east or south,
+before storms, according to the character of the coming wind. Howard
+mentions an instance when he heard carriages five miles off. Steamboat
+paddles, rail-road cars, and other sounds, are often heard a great
+distance. The distance at which the now common steam-whistle is heard, and
+the direction, is not an unimportant auxiliary indication of the weather.
+Howard attributes these peculiar phenomena to the "_sounding board_," made
+by the _stratum of cloud_; but sounds may be heard from the north-west,
+when there is no condensation, and the wind is from that quarter, and also
+from the east when it is not cloudy; and in a level country the village
+bells often tell the direction of the current of air just over our heads
+when we do not feel it at the surface. The wind is undoubtedly moving in a
+rapid, and perhaps invisible current, not far above us. If from the east
+or south, it betokens rain; if from the western quarter, fair weather.
+
+The conduct of the different animals furnish a considerable portion of the
+signs alluded to by Virgil and Jenner, and are never unimportant auxiliary
+evidence of the approaching changes, whether from dry to wet, or wet to
+dry.
+
+The observer will find, in the conduct of our birds and animals,
+especially those which are not domestic, ample evidence of the truth of
+the descriptions of Virgil. He denies the animals and birds foresight, but
+he does not seem to have observed that the swallow leaves for the south as
+soon as the _autumnal_ change begins to be felt, and in August; nor the
+evident sagacity of other _migratory_ birds. They do not act from the
+"_varying impulse_" produced by an actual state of things, but a knowledge
+or apprehension of those which are to come. This is nothing more or less
+than foresight. So foresight tends to prudence and skill, and they
+exercise both, and with reference to the future. The goldfinch does not
+build her nest in the hole of the tree, or in the crotch of the limb; but
+_hangs it_ with _exquisite skill_ on the slender _waving, outward branch_,
+where no animal, or larger bird, or any depredator, can be sustained. She
+is not more timid than others; why does she invariably thus build? What
+makes her "_impulses_" differ from those of other birds, and always in the
+_same manner_?
+
+Jenner, too, has grouped, in admirably descriptive language, many of the
+peculiarities exhibited by animals and birds before approaching storms,
+some of which exhibit foresight, and others not.
+
+Perhaps the rooster, who keeps ceaseless watch over his harem, is the most
+reliable weather-watcher we have. In my earlier days, when it was the
+practice to keep valuable birds of the kind much longer than it now is,
+and they had opportunity to become _experienced_, it was interesting to
+observe how closely they watched the weather. I well remember a venerable
+chanticleer, who, perched on the tree among his hens, would always
+foretell the coming storm of the morrow, by sounding forth _in the
+evening_, and _often_, his defiant note. Such note in the evening was
+invariable evidence of foul weather. And during the night, their earlier
+and more frequent crowing is often indicative of it. It is, however, in
+the earlier part of the day, in doubtful cases, that no inconsiderable
+reliance may be placed on their sagacity. Often, when a storm is gathering
+in the forenoon, they will announce it by an almost incessant crowing. The
+habits of an _experienced_, old-fashioned bird, of this kind, will well
+repay attention; but I can not answer for the Shanghai and other _fancy
+breeds_.
+
+Jenner says:
+
+  "The leech disturbed, is newly risen
+  Quite to the summit of his prison."
+
+Few have had, or will have, opportunities to observe this, but it is
+strikingly true. It is difficult to conceive how mere condensation, from
+an increase of vapor in the atmosphere, should be foreseen by the leech in
+his watery prison. It is obvious, I think, there is an electric change
+which reaches him, as it does the whole animal creation, the once broken
+bones, and the joints of Aunt Betty. Thus much of the philosophy of signs.
+
+_The barometer_ is a useful instrument, in connection with observations of
+the other phenomena. It is especially useful to the sailor, as its
+indications relative to the winds are much the most certain. But it is
+not, _alone_, to be relied upon. This is well settled, although the
+reasons for it have not been understood. Why it should rise sometimes
+before storms, in opposition to the general rule--or fall at others
+without rain--or rise occasionally during the heaviest gales, has been a
+mystery, and impaired the confidence in its accuracy and usefulness even
+of the class of philosophers of whom Sir George Harvey spoke, in the
+sentence quoted in the introduction. But, as I have already intimated, it
+is all very intelligible.
+
+I have said that the barometer has no fair weather standard--the mean of
+30 inches at the level of the sea being an _average_ of the _fair weather_
+elevations and the _foul weather_ depressions. Its fair weather position,
+it would seem, must be above the mean, therefore, and as much above as its
+foul weather depressions are below. But this is not precisely true. Its
+extreme fair weather range is 31 inches, and it rarely reaches that; while
+its lowest storm range is down to 28, and is the most often reached of
+the two. My barometer stands about 40 feet above ordinary high-water mark.
+It is not a "wheel," but an open, "scale" barometer, and a perfectly good
+one. Its most reliable fair weather standard is about 30-30/100 inches. It
+is its _most common summer, set fair position_, but that position is often
+at other and different elevations, at other periods of the year, during
+fair weather. The reader must observe for his own locality, and satisfy
+himself what the most common set fair position for the barometer is, at
+the different periods of the year, where he resides. When he has
+ascertained this, he may apply the following principles to illustrate its
+exceptional action, and in judging of the future of the weather:
+
+1st. _As to its rise before storms._--Supposing it to have been
+stationary, at or about a set fair position, _for the period_, and for one
+or two or more days, a very _gradual_ and _moderate_ rise is an indication
+of continued fair weather; and a _sudden_ and _considerable rise_ is
+indicative of a storm. If the sudden and considerable rise occurs in the
+latter part of spring, summer, or early autumn, it indicates a storm of
+the _first_ or _third classes_ described in Chapter X., if in winter, a
+storm of the _first class_ only. If the elevation is _very_ sudden and
+considerable, the storm will probably be _severe_. The philosophy of this,
+according to my present apprehension of it, is, that these storms present
+an _extended easterly front_--_settle very near the earth_--and _have a
+rapid progress_--thus accumulating the atmosphere somewhat, in advance of
+them.
+
+2d. _As to its fall before storms without previous rise._--This is always
+very regular before the second class of storms, or polar belts of showers
+and storms. It is very fairly exemplified in the table from Reid, on page
+329. The barometer, so far as I have opportunity to observe, does not rise
+from a stationary position on the approach of this class of storms. At the
+commencement of heated, summer, dry terms, my barometer has most
+frequently ranged at about 30.30, and gradually, but slowly, fallen below
+30 inches before the belt of showers arrived, and the term closed. The
+fourth rule of Dalton (Meteorology, page 183) indicates a similar law in
+England. It is as follows:
+
+     "In summer, after a long continuance of fair weather, with the
+     barometer high, it generally falls gradually, and for one, two, or
+     more days, before there is much appearance of rain. If the fall be
+     sudden and great for the season, it will probably be followed by
+     thunder."
+
+3d. _It falls frequently and considerably without rain._--This is owing to
+the fact that _all_ regular, periodic efforts at condensation do not
+result in rain. The second, third, and fourth classes of storms described,
+may not (as we have said) _be sufficiently active to precipitate_,
+although the _series of phenomena_ (including the fall of the barometer)
+may be, in other respects, perfect. Such an instance may be found in
+Reid's table, on page 329, and on the 11th of the month. But the fall in
+such cases is not as great, unless the wind be violent.
+
+4th. _It rises during considerable gales._--But these are of the kind so
+often alluded to--viz., the N. W., in the northern hemisphere, and the S.
+W., in the southern; and the _philosophy_ of it has been explained, and is
+observable.
+
+With these explanations, the reader will be able to understand, and
+practically apply, the barometric changes, in connection with the other
+phenomena, in forming an opinion of the weather.
+
+_The thermometer_ is also an auxiliary. It _rises_, during the winter half
+of the year, in the _advance portion of the storm_, and falls when it
+passes off again; and the reverse is true, as we have seen, when its range
+is very high in summer. It is, therefore, to some extent, a useful
+auxiliary, although of minor importance.
+
+_The hygrometer_ is of less importance still. It is not in general use as
+a practical guide to the changes of the weather, and does not deserve to
+be.
+
+A question, which has been much mooted, deserves a passing notice in this
+connection--viz., whether our climate has gradually become ameliorated and
+milder on the eastern part of our continent, since its settlement. I have
+not space left for its discussion. Humboldt (Aspects of Nature, page 103)
+is of opinion that there has been no material change. He says:
+
+     "The statements so frequently advanced, although unsupported by
+     measurements, that since the first European settlements in New
+     England, Pennsylvania, and Virginia, the destruction of many forests
+     on both sides of the Alleghanys, has rendered the climate more
+     equable--making the winters milder and the summers cooler--are now
+     generally discredited. No series of thermometric observations worthy
+     of confidence extend further back, in the United States, than
+     seventy-eight years. We find, from the Philadelphia observations,
+     that from 1771 to 1824, the mean annual heat has hardly risen 2°.7
+     Fahrenheit--an increase that may fairly be ascribed to the extension
+     of the town, its greater population, and to the numerous
+     steam-engines. This annual increase of temperature may also be owing
+     to accident, for in the same period I find that there was an increase
+     of the mean winter temperature of 2° Fahrenheit; but, with this
+     exception, the seasons had all become somewhat warmer. Thirty-three
+     years' observation, at Salem, in Massachusetts, show scarcely any
+     difference, the mean of each one oscillating within 1° of Fahrenheit,
+     about the mean of the whole number; and the winters of Salem, instead
+     of having been rendered more mild, as conjectured, from the
+     eradication of the forests, have become colder, by 4° Fahrenheit,
+     during the last thirty-three years."
+
+The facts hereinbefore stated show that there is nothing like a _regular_
+amelioration; that the seasons differ during the same decade, and
+different decades. The cold decade, from 1811 to 1820, has not been
+reproduced. But it may be, and we know not how soon. Since that period
+there has certainly been a change--for even the cold period from 1835 to
+1840 did not equal that from 1815 to 1820, nor indeed those of 1775 to
+1780 or 1795 to 1800. But as these variations, so far as we are enabled to
+judge, depend upon the varying influence of the sun's rays, and of
+volcanic action, it is impossible to say that equally cold periods will
+not return, during the latter half of this century.
+
+If the influence of the sun was constant, and volcanic action regular, two
+causes would tend to modify the seasons:
+
+1st. The exposure of the surface to a more effective action of the solar
+rays, by a removal of the forests, and by drainage. That such action would
+be more effective upon a surface thus uncovered and drained, can not be
+doubted.
+
+2d. _The movement of the area of magnetic intensity, and the magnetic
+pole, to the west._--There is such a movement, and its progress can be
+measured by the increase of declination on the east of it, and its
+decrease on the west. And the effect of it on climate is unquestionable.
+In all probability it has had an influence upon ours; and a removal of
+that area and pole still further west--60° or 80°--would change the
+location of the concentrated trade, and the Gulf Stream, and restore to
+Greenland the fertility she once had, and which the Faroe Islands now
+enjoy. And, on the other hand, its removal as far east of its present
+position would again depopulate Greenland, and render it again
+inaccessible. But I can not pursue this subject.
+
+Finally, assistance may be derived from the occasional, although
+imperfect, accounts of the state of the weather elsewhere, which the
+newspapers afford. I have been much indebted to the Associated Press of
+New York for intelligence contained in their telegraphic reports.
+Occasionally they have been very full and instructive.
+
+On this point, however, there is less of reality in the present than of
+hope in the future. The time must come when the collection and
+dissemination of meteorological truth, will be deemed an object of
+national importance, and national duty. Population is increasing, by
+immigration and propagation, in a rapidly progressive ratio. There has
+been great danger that it would outrun agricultural production. A short
+crop this year would have been disastrous to our prosperity--and the
+danger was imminent. Every description of business, and every financial
+circle, felt that fever of anxiety it was so well calculated to induce.
+The importance of extended agricultural production, and the dependence of
+all classes upon its success, are now in a greater measure appreciated;
+and none can fail to see the value of a correct understanding of the
+weather to the agriculturist, how short-sighted soever they may be, in
+relation to its direct influence upon their own prosperity and happiness.
+
+Our country is, physically, a most favored one. The facts disclosed or
+alluded to in this volume show that it is without a parallel on the face
+of the globe; and our facilities for meteorological observation, and the
+ascertainment and practical application of meteorological truth, are
+equally pre-eminent. The great extent and unbroken surface of the eastern
+portion of the continent; its excessive supply of magnetism and
+atmospheric currents, and the consequent marked character of the
+phenomena; the existence and prospective increase of telegraph lines over
+most of its surface; the homogeneous and energetic character of a
+population united, upon so large a surface, under one government; the
+freedom of that government from debt, and the excess of its revenue; the
+possession of a National Observatory, with a competent philosopher at its
+head; and a national institution, liberally endowed, and adapted to the
+collection and diffusion of practical and scientific intelligence, give
+us an opportunity and a capacity for connected observation and
+investigation, and an ability to profit by it, that no other nation can
+boast.
+
+We have, too, a just national pride. Our exploring ships have penetrated
+and made discoveries in both hemispheres, and our travelers have visited
+successfully every clime; and thus our national interests, and
+obligations, and pride, demand an organization, practical and permanent,
+in relation to this subject, and the time will come when we shall have it.
+
+When that time comes--when the present _limited horizon_ of each of us is
+_practically extended over the entire country_--and when the actual state
+of the weather over every part of it is known, at the same time, to the
+inhabitants of every other, and every where _read in the light of a
+correct philosophy_, prognostication will be comparatively simple and
+certain; and A PROGRESS will have been made, productive of an amount of
+pecuniary, intellectual, and social benefit to the people, which can not
+be overestimated. May it come before the shadows of the night of death
+have gathered around us, that we may have a more perfect view of that
+atmospheric machinery which distinguishes our planet from others, and is,
+with such infinite wisdom, adapted to make it a fit habitation for man!
+
+
+THE END.
+
+
+
+
+APPENDIX.
+
+
+Since this work was completed I have received a very valuable publication,
+entitled, the "Army Meteorological Register." It is a compilation of the
+observations made by the officers of the medical department of the army,
+at the military Posts of the United States, from 1843 to 1854 inclusive,
+prepared under the supervision of the Surgeon-general, and published by
+direction of the Secretary of War. To this, there is appended a report or
+general review of the prominent features of American climatology, so far
+as the basis afforded by the published observation of the army medical
+Bureau would warrant positive deduction, by Mr. Lorin Blodget, a
+distinguished meteorologist, accompanied by temperature and rain charts,
+for each of the four seasons;--exhibiting the various local differences
+and peculiarities relative to temperature and precipitation in each.
+
+These local differences and peculiarities and contrasts are deduced and
+delineated by Mr. Blodget with much ability. He was fettered, however, by
+the prevailing calorific theories, and the unfortunate practice of
+grouping the phenomena into means for the seasons, Spring, Summer, Autumn,
+and Winter, which grouping is arbitrary, and comparatively uninstructive.
+Hence, he failed to discover what the tables and summaries most clearly
+disclose--the principles and system unfolded in the foregoing work.
+
+But the summaries of this register contain observations made at posts in
+Western and Southwestern Texas, in Kansas and Nebraska, and in New Mexico
+and California, where there has been a dearth of such observations
+hitherto, and enable me to demonstrate, more conclusively, and I think so
+that none can fail to understand it, the truth of the philosophy I have
+endeavored to exhibit.
+
+To do this, I will take a _year_,--divide it into two seasons, the periods
+of northern and southern transit, the only natural and correct
+division--and note the phenomena in each, as each progresses.
+
+And I will take the year 1854, because that is the last year for which the
+record of observation is complete; because it had marked peculiarities
+which are remembered; and because I have alluded to those peculiarities,
+and those allusions should be confirmed or disproved by the record. Unless
+I mistake exceedingly, the confirmation will be found signal and
+convincing.
+
+I have assumed, pp. 187, 351, that the transits were greater in some
+seasons than others; that the drought of 1854 was owing to an extreme
+northern transit, or to an extension west of the concentrated
+counter-trade, or both, leaving us less supplied with moisture than
+usual.
+
+In point of fact, it appears from these observations that it resulted from
+_both_ causes, operating _connectedly_; and the annals of Science rarely
+furnish a more striking instance of analogical inference proved true by
+subsequent investigation.
+
+Commencing then with the commencement of the northern transit about the
+1st of February, we are enabled to trace the then location of our
+concentrated trade, and its subsequent progress to the north till August,
+and its influence upon temperature and precipitation. And we can also
+trace the situation during the same period, of the intervening drought,
+and the inter-tropical belt of rains, and the extension of the latter
+north over Florida and the cotton-planting States.
+
+On the 1st of February, 1854, our counter-trade was somewhat more
+concentrated on its extreme winter curve, over the Southern States, than
+usual. Its line of excess reached up from Fort Brooke, on the peninsula of
+Florida, to the northwest, a little east of Pensacola on the gulf, cutting
+Mount Vernon Arsenal north of Pensacola, and extending thence
+north-westwardly on to Eastern Louisiana, and curving thence and passing
+N. E. or E. N. E., to the Atlantic, about the waters of the Chesapeake
+Bay. It thinned out to the west over New Orleans and Baton Rouge,
+supplying them moderately, but did not extend to the forts of Texas on the
+west, nor the posts in the Indian Territory at the N. W. It was east of
+Fort Towson, which is the south-eastern one. It did not reach St. Louis on
+the north, nor extend north of the Ohio River, as will appear from the
+tables hereinafter given. The following cut shows substantially its
+situation on the 1st of February.
+
+
+[Illustration]
+
+
+Now, during the month of January, we find the following state of things.
+_Under_ this concentrated trade, the temperature was above the mean, even
+if Forts Monroe and McHenry on the Atlantic are included; but Mr. Blodget
+discredits their returns, and some others which do not conform to general
+results. On the west and north of its curving line, both precipitation and
+temperature were below the mean.
+
+Under the counter trade, we have the following stations, with their actual
+and mean temperature. I have inserted the temperature for several
+subsequent months, to show a depression in April.
+
+
+TABLE I.
+
+  -------------------------------------------------------------------------
+                  |  LAT. |  LON. |  JAN. |  FEB. |  MAR. | APRIL.| MAY.  |
+  ------------------------------------------------------------------------|
+  Fort Moultrie   | 32.45 | 79.51 | 50.83 | 53.09 | 62.72 | 62.76 | 73.35 |
+   Mean of 28 yrs.|       |       | 50.36 | 52.41 | 58.68 | 65.44 | 73.42 |
+  Fort Pierce     | 27.30 | 80.20 | 67.91 | 67.33 | 73.01 | 71.10 | 78.41 |
+   Mean of 5 yrs. |       |       | 62.75 | 64.42 | 69.77 | 73.63 | 76.92 |
+  Fort Meade      | 28.01 | 82.00 | 63.75 | 63.33 | 70.64 | 68.10 | 76.31 |
+   Mean of 3 yrs. |       |       | 58.40 | 63.23 | 69.02 | 69.89 | 76.69 |
+  Fort Brooke     | 28.00 | 82.28 | 62.94 | 62.36 | 70.06 | 70.07 | 77.49 |
+   Mean of 25 yrs.|       |       | 61.53 | 63.54 | 67.72 | 71.82 | 76.64 |
+  Fort Myers      | 26.38 | 82.00 | 67.56 | 67.39 | 73.74 | 71.07 | 79.13 |
+   Mean of 4 yrs. |       |       | 63.39 | 67.98 | 72.19 | 73.86 | 80.13 |
+  Key West        | 24.32 | 81.48 | 71.75 | 71.95 | 76.56 | 73.89 | 80.84 |
+   Mean of 14 yrs.|       |       | 66.68 | 68.88 | 72.88 | 75.38 | 79.10 |
+  Fort Barrancas  | 30.18 | 87.27 | 54.71 | 54.56 | 64.98 | 62.93 | 75.40 |
+   Mean of 17 yrs.|       |       | 53.61 | 55.58 | 61.80 | 68.51 | 75.45 |
+  Mt. Vernon Ars'l| 31.12 | 88.02 | 51.52 | 53.18 | 65.24 | 62.30 | 74.64 |
+   Mean of 14 yrs.|       |       | 50.44 | 53.69 | 60.26 | 66.87 | 73.92 |
+  Baton Rouge     | 30.26 | 91.18 | 53.43 | 56.48 | 66.24 | 64.63 | 75.10 |
+   Mean of 24 yrs.|       |       | 53.47 | 55.02 | 61.93 | 69.30 | 75.60 |
+  -------------------------------------------------------------------------
+
+                                   -------------
+                                   JUNE. | JULY.
+                                   -------------
+                                   78.55 | 82.06
+                                   79.01 | 81.72
+                                   82.09 | 84.16
+                                   79.02 | 82.50
+                                   79.10 | 80.17
+                                   78.24 | 79.76
+                                   80.51 | 81.08
+                                   79.46 | 80.72
+                                   82.35 | 81.91
+                                   81.25 | 82.87
+                                   83.34 | 83.30
+                                   81.63 | 83.00
+                                   81.00 | 84.55
+                                   80.80 | 82.26
+                                   79.17 | 78.90
+                                   78.03 | 78.62
+                                   80.61 | 80.09
+                                   80.56 | 81.81
+                                   -------------
+
+It will be seen that the temperature was above the mean in January at
+every post except Baton Rouge, and there it was at the mean. We shall see
+hereafter that Baton Rouge was near its western line.
+
+Under this trade during this month, and at the same posts, the fall of
+rain was as follows, compared with the mean:--
+
+
+TABLE II.
+
+  --------------------------------------------------------------
+                   |   JANUARY.   |   FEBR'Y.    |    MARCH.   |
+  --------------------------------------------------------------
+                   | 1854. | Mean.| 1854. | Mean.| 1854.| Mean.|
+  --------------------------------------------------------------
+  Key West.        |  1.77 | 2.86 |  2.55 | 1.38 | 0.51 | 4.21 |
+  Fort Myers.      |  1.15 | 3.90 |  4.70 | 2.16 | 0.20 | 4.60 |
+   "  Brooke.      |  3.88 | 2.20 |  6.89 | 3.01 | 2.44 | 3.37 |
+   "  Mead.        |  1.30 | 1.07 |  2.21 | 1.01 | 1.85 | 1.64 |
+   "  Pierce.      |  3.55 | 4.45 |  3.40 | 2.72 | 1.05 | 3.01 |
+   "  Barrancas.   |  3.45 | 3.87 |  5.55 | 4.95 | 7.21 | 5.87 |
+  Mt. Vernon Ars'l | 11.01 | 6.80 | 12.83 | 6.04 | 6.22 | 4.59 |
+  Baton Rouge.     |  2.85 | 5.26 |  5.50 | 4.91 | 6.15 | 4.68 |
+  Fort Moultrie.   |  3.80 | 2.39 |  2.84 | 2.33 | 0.25 | 4.06 |
+  --------------------------------------------------------------
+
+                   -------------------------------------------
+                   |    APRIL.   |     MAY.     | JUNE.| JULY.
+                   | 1854.| Mean.| 1854. | Mean.|      |
+                   -------------------------------------------
+                   | 2.99 | 1.55 |  3.14 | 2.58 | 4.54 |  3.45
+                   | 2.75 | 3.14 |  5.65 | 3.33 | 6.75 |  9.70
+                   | 8.82 | 1.95 |  6.21 | 3.24 | 9.44 | 15.53
+                   | 3.19 | 1.78 | 10.51 | 5.34 | 7.24 |  8.55
+                   | 7.00 | 3.85 |  5.70 | 4.27 | 6.63 |  4.97
+                   | 0.50 | 2.94 |  3.47 | 4.05 | 3.39 |  5.43
+                   | 1.96 | 4.21 |  4.45 | 4.62 | 6.72 |  6.13
+                   | 3.58 | 5.22 |  8.05 | 5.18 | 4.00 |  6.55
+                   | 2.20 | 1.75 |  3.70 | 4.08 | 4.20 |  5.69
+                   -------------------------------------------
+
+It will be observed that in February the counter-trade and extra-tropical
+belt had moved up from Key West, and a drought, which sometimes intervenes
+between the concentrated counter-trade and the inter-tropical belt,
+appeared there in February and March. In April, the inter-tropical belt
+appeared at that point, and went on increasing till September. As the
+counter-trade commenced moving north in February, an increased
+precipitation above the mean commenced at all the more southern stations
+under the concentrated-trade--an earnest of that irregularity which
+followed, and marked the season as the most excessive of the century.
+
+In March, the intervening drought appeared at the other posts on the
+peninsula, and also at Fort Moultrie, followed _much more closely than
+usual_, by the inter-tropical belt of rains. In April, the drought
+appeared at Fort Barrancas and Mount Vernon Arsenal (the wave of
+precipitation having moved to the west), and slightly in comparison at
+Baton Rouge.
+
+If now we look at the condition of things, _west_ and _north_ of the
+curving line of concentrated trade, from Fort Brown, at the mouth of the
+Rio Grande, in South-western Texas, through that State, the Indian
+Territory, Arkansas, Missouri, Kentucky, and Northern Pennsylvania, to the
+Atlantic, we find the thermometer every where in January below the mean.
+The following table will show this, and the precipitation for that month
+and February:--
+
+
+TABLE III.
+
+  ------------------------------------------------------------------------
+                         |    JANUARY.   |   FEBRUARY.   |    MARCH.     |
+                         |-----------------------------------------------|
+                         | 1854. | Mean. | 1854. | Mean. | 1854. | Mean. |
+  -----------------------------------------------------------------------|
+  _Western Texas._       |       |       |       |       |       |       |
+  Fort Brown             | 59.34 | 60.41 | 62.45 | 63.63 | 71.87 | 68.95 |
+   "   Ewell             | 50.47 | 52.92 | 58.12 | 57.61 | 70.34 | 67.00 |
+   "   Inge              | 47.24 | 49.46 | 56.04 | 55.39 | 67.54 | 62.63 |
+                         |       |       |       |       |       |       |
+  _Indian Territory._    |       |       |       |       |       |       |
+  Fort Towson.           | 36.32 | 43.14 | 49.29 | 45.97 | 59.55 | 53.40 |
+  Forts Gibson, Washita, |       |       |       |       |       |       |
+    and Arbuckle, in much|       |       |       |       |       |       |
+    the same proportions.|       |       |       |       |       |       |
+                         |       |       |       |       |       |       |
+  _Arkansas._            |       |       |       |       |       |       |
+  Fort Smith.            | 33.92 | 40.18 | 47.01 | 43.89 | 57.01 | 51.58 |
+                         |       |       |       |       |       |       |
+  _Missouri._            |       |       |       |       |       |       |
+  St. Louis Arsenal.     | 25.47 | 31.44 | 36.66 | 33.43 | 46.10 | 42.30 |
+                         |       |       |       |       |       |       |
+  _Kentucky._            |       |       |       |       |       |       |
+  Newport Barracks.      | 31.75 | 34.04 | 39.60 | 36.94 | 46.74 | 45.46 |
+                         |       |       |       |       |       |       |
+  _Pennsylvania._        |       |       |       |       |       |       |
+  Allegheny Arsenal.     | 29.08 | 29.25 | 33.49 | 31.16 | 40.36 | 39.02 |
+                         |       |       |       |       |       |       |
+  _Delaware._            |       |       |       |       |       |       |
+  Fort Delaware          | 32.38 | 33.67 | 34.56 | 35.84 | 43.18 | 42.90 |
+                         |       |       |       |       |       |       |
+  _New York Harbor._     |       |       |       |       |       |       |
+  Fort Columbus.         | 28.71 | 30.18 | 28.17 | 30.44 | 36.17 | 38.28 |
+  ------------------------------------------------------------------------
+
+                         --------------------------------------
+                         | Rain in January. | Rain in February.
+                         --------------------------------------
+                         |       0.45       |       1.50
+                         |       0.22       |       2.86
+                         |       0.20       |       2.15
+                         |                  |
+                         |       1.01       |       2.00
+                         |                  |
+                         |       1.37       |       2.05
+                         |                  |
+                         |       0.65       |       2.40
+                         |                  |
+                         |       3.20       |       5.30
+                         |                  |
+                         |       2.23       |       2.33
+                         |                  |
+                         |       2.30       |       5.45
+                         |                  |
+                         |       2.60       |       4.00
+                         --------------------------------------
+
+We find, also, from this and table first, that every where, except at Fort
+Brown, and upon the Atlantic coast, the temperature had risen above the
+mean in February.
+
+The situation of the belt which supplied the western coast in winter, and
+its excess of precipitation, are also represented upon the cut. The
+intervening area was not without counter-trade and precipitation--the
+latter, of course, greatest over the area of intensity--but they were
+_comparatively_ less, as the tables will show.
+
+The following cut and table show the situation of the concentrated
+counter-trade in March.
+
+
+[Illustration]
+
+
+TABLE IV.
+
+  ------------------------------------------------------------------------
+                               | JAN.|FEBR.| MAR.| APR.| MAY.|JUNE.|JULY.
+  ------------------------------------------------------------------------
+  Fort Barrancas, Pensacola Bay| 3.45| 5.55| 7.21| 0.50| 3.47| 3.39| 5.43
+          Mean.                | 3.87| 4.95| 5.87| 2.94| 4.05| 4.66| 6.80
+  Baton Rouge, Louisiana       | 2.85| 5.50| 6.15| 3.58| 8.05| 4.00| 6.55
+          Mean.                | 5.26| 4.91| 4.68| 5.22| 5.18| 5.52| 7.42
+  Fort Towson, Indian Territory| 1.01| 2.00| 5.10| 2.22|Recr'd stops here.
+          Mean.                | 3.13| 2.97| 4.38| 5.33|     |     |
+  Fort Gibson, Indian Territory| 0.30| 1.43| 7.83| 3.16| 7.67| 2.80| 0.21
+          Mean.                | 1.33| 2.26| 2.54| 4.19| 4.65| 4.30| 2.75
+  Fort Smith, Arkansas         | 1.37| 2.05| 7.05| 6.55| 6.25| 2.26| 1.02
+          Mean.                | 1.96| 2.17| 2.92| 5.10| 4.46| 4.74| 3.82
+  St. Louis Arsenal            | 0.65| 2.40| 7.10| 4.30| 4.65| 2.20| 1.70
+          Mean.                | 1.93| 3.37| 3.82| 4.16| 4.88| 6.94| 0.04
+  Newport Barracks, Kentucky   | 3.20| 5.30| 8.10| 2.10|     |     |
+          (No Mean given.)     |     |     |     |     |     |     |
+  ------------------------------------------------------------------------
+
+We see from this table that its focus had extended west in Florida over
+Fort Barrancas, and over Baton Rouge in Louisiana; N. W. to Forts Towson
+and Gibson in the Indian Territory, and Smith in Arkansas; north to St.
+Louis Arsenal at St. Louis, and to Newport barracks in Kentucky; but it
+was spread over a larger surface east of the mountains. Its greatest
+progress for the month, was a west and north-west progress.
+
+In April, we find it had progressed rapidly west and north-west, and its
+position is shown by the following cut and table.
+
+
+[Illustration]
+
+
+TABLE V.
+
+  ------------------------------------------------------------------------
+                                | JAN.|FEBR.| MAR.| APR.| MAY.|JUNE.|JULY.
+  ------------------------------------------------------------------------
+  Fort Riley, Kansas.           | 0.00| 0.94| 1.86| 4.55| 4.35| 1.10| 0.00
+  Fort Leavenworth, Kansas.     | 0.04| 1.78| 1.33| 3.35| 5.55| 4.50| 0.18
+          Mean                  | 0.72| 1.01| 1.61| 2.74| 3.62| 5.80| 3.15
+  Alleghany Arsenal, Pittsburgh | 2.23| 2.33| 2.82| 4.21| 2.24| 2.06| 1.45
+          Mean                  | 2.18| 2.17| 2.70| 3.10| 3.58| 3.56| 2.97
+  Fort Columbus, New York Harbor| 2.60| 4.00| 0.70| 8.80| 7.70| 2.20| 1.90
+          Mean                  | 2.78| 2.92| 3.44| 3.33| 4.78| 3.46| 3.17
+  Fort Independence, Boston     | 2.50| 3.36| 2.55| 5.40| 4.28| 2.00|
+  West Point.                   | 3.52| 5.04| 2.81|10.53| 2.00| 1.62|
+          Mean                  | 3.50| 3.44| 3.71| 4.55| 6.18| 4.79|
+    ----------------------------------------------------------------------
+
+We see, too, that both east and west of the mountains, its focus of
+precipitation was one month in advance of the mean. At all the stations
+where the greatest fall was in March, it should have been in April, and
+the fall at those points was greatly in excess of the usual quantity. And
+the same was true of stations reached in April. The concentrated trade,
+instead of spreading out, and precipitating over the whole south-eastern
+portion of the continent (its normal condition), was gathered into a wave
+of greater volume, resulting in greater precipitation, and was rapidly
+hastening its curve to the west over Texas, and to the north-west over the
+Indian Territory, and northward on its usual curve to the north and east
+of them.
+
+The observations for April disclose another singular and instructive
+condition. The temperature, that had every where been above the mean in
+March, fell below it in April under the concentrated trade. And snow fell
+on three days in some localities, and four in others.
+
+Along the Ohio River, it fell to the depth of 8 to 10 inches on the 17th,
+and east of the mountains to a greater depth on the 18th, one day later.
+It fell to the depth of 4 inches at Marietta on the 29th also. Dr.
+Hilldreth, American Journal of Science for March, 1855, says:--
+
+"It is a singular fact that the deepest snow, 8 inches, fell on the 17th
+of April, and at the head waters about Pittsburg over a foot. Also, on the
+29th of the month, at Marietta, 4 inches, a very rare occurrence." This
+depression of the temperature was quite general, but the fall of snow was
+local. The latter was north of a line drawn from Fort Laramie, at the base
+of the Rocky Mountains, in an E. S. E. direction--north of Forts Kearney
+and Leavenworth, and of St. Louis, but south of Newport barracks in
+Kentucky, and from thence to the Atlantic. Snow fell at every station
+north of this line, at no station south of it. The depression of
+temperature, however, was experienced over the continent, east of the
+Rocky Mountains, under, and south of, the belt of precipitation. Now what
+occasioned this general depression of temperature, and local fall of snow?
+It will not do to say, as perhaps some calorific theorist may be inclined
+to say, because the concentrated trade had been carried up where it was
+cold, a month too soon; or that the sun had heated the land in advance of
+it, and drawn it up.
+
+For, 1st, it might be asked how, if it was warm enough to draw it up,
+could it be cold enough to make it snow; or, 2d, how happened it to start,
+when, as we have seen, it was warmer than the mean under it, and colder
+than the mean to the north and west of it, when it commenced its journey?
+
+But again, it snowed at posts north of the line, while the thermometer
+remained above the mean; and the thermometer fell below the mean down to
+Fort Brown in south-western Texas, and at Key West in the southern part of
+Florida; and what is more remarkable still, at Key West, Fort Barrancas,
+and every other south-eastern station, except Forts Brooke and Moultrie,
+it not only fell below the _mean_ of the month, but _below the actual
+temperature of March_. (See Table I.) At Forts Brooke and Moultrie it did
+not rise above that temperature. West of the Rocky Mountains the
+depression was not felt; nor at stations north, or north-west of the belt
+of precipitation.
+
+It is obvious, the calorific theory can furnish no rational explanation of
+this matter; for the reason that, whatever the cause, it operated not
+only under, but south, and far south of the belt of precipitation. It
+could not have been spots upon the sun, or other general cause, for then
+it would have operated in New Mexico and California, and at the
+north-western stations. It operated most intensely in Florida and the
+South-Eastern States, which approach most nearly the volcanic areas of
+South America and the West Indies. I believe it to have been occasioned by
+volcanic action affecting the local magnetism of our intense area; but it
+is a most important development, and should be thoroughly investigated. We
+may find in it the key to the mysterious, but unquestionable, influence of
+volcanic upon magnetic action; and I hope the distinguished
+surgeon-general will cause the records of that month to be published "in
+extenso."
+
+In May and June, the trade became more concentrated, a perfectly developed
+belt from the Rio Grande to the Lakes and British possessions, and
+doubtless to the Atlantic, with every where a central focus of excessive
+precipitation, gathering to itself in one vast wave the current that
+should have been spread out over the whole country; and leaving every
+where on its eastern and southern borders, down to the northern edge of
+the inter-tropical belt of rains--(which extended up to lines drawn from
+Baton Rouge to Charleston)--a _perfectly well developed_ and _defined
+drought_. That drought will long be remembered. The following cuts show,
+approximately, the location of the belt of precipitation and drought for
+those months, and the table which follows will show their correctness.
+
+The tables also show that this wave was occasionally a double, or divided
+one--evinced by an intervening _partial_ precipitation. Tables IV., V.,
+and VI., also show the commencement of the drought at the several
+stations, as the wave moved to the west and north.
+
+
+[Illustration: MAY.]
+
+
+[Illustration]
+
+
+TABLE VI.
+
+                     JAN.  FEBR. MAR.  APR.  MAY.  JUNE.  JULY. AUG.  SEPT.
+  Fort Brown         0.45  1.50  1.15  0.05  4.10   7.65  4.25  5.00  11.31
+          Mean       1.61  2.25  1.20  0.56  2.21   4.55  1.95  2.76   6.73
+  Ringgold Barracks  0.70  1.69  0.22  0.00  2.83  10.98  4.06  1.58   3.02
+          Mean       1.24  1.18  0.72  1.08  2.09   3.47  3.18  1.50   3.22
+  Fort Merrill       0.11  1.99  0.05  1.16  7.66   4.70  5.44  3.13   5.01
+          Mean       0.23  2.09  0.09  1.62  3.43   4.10  6.13  3.40   4.60
+  Fort Duncan        0.05  0.69  1.50  0.00  2.53   6.83  0.83  0.90   4.81
+          Mean       0.26  1.27  1.34  0.71  1.50   5.63  3.35  0.93   3.28
+  Fort Inge          0.20  2.15  3.00  0.75  3.88   2.09  0.97  1.67   4.80
+          Mean       0.64  2.21  1.79  1.26  3.01   5.38  3.66  2.02   2.21
+  Fort McKavet       0.01  0.77  2.10  0.28  3.72   0.15  2.91  0.04   3.86
+   " Belknap         0.11  1.10  1.42  1.75  4.97   8.33  0.00  0.75   1.53
+   " Massachusetts,
+      Northern New
+       Mexico                                3.93   0.24  2.14  2.61   1.53
+  Fort Kearney       0.23  1.33  1.87  2.56  4.15   5.40  3.51  1.18   4.60
+          Mean       0.50  0.48  1.55  2.68  6.57   4.36  5.07  2.62   1.83
+  Fort Laramie       0.18  0.40  0.80  3.98  4.46   3.67  3.26  1.27   1.60
+          Mean       0.27  0.71  1.37  1.93  5.39   2.95  1.83  0.92   1.33
+  Fort Ridgley       1.20  0.01  1.18  2.83  6.84   2.70  2.49  2.28   2.58
+  " Snelling         0.72  0.03  1.03  2.51  4.30   3.31  3.92  1.75   6.55
+          Mean       0.73  0.52  1.30  2.14  3.17   3.63  4.11  3.18   3.32
+  Fort Ripley        0.67  0.03  0.79  0.97  4.34   3.68  0.62  1.69   4.40
+          Mean       0.86  0.37  1.80  1.42  3.09   5.15  5.20  2.27   4.92
+  Fort Mackinac      2.59  1.23  1.56  1.04  2.65   6.35  5.67  4.26   3.22
+          Mean       1.25  0.82  1.14  1.21  2.32   2.81  3.20  2.87   2.97
+  Fort Brady         2.49  1.18  1.34  2.14  3.61   1.23  3.21  3.86   3.18
+          Mean       1.84  1.13  1.37  1.83  2.24   2.83  3.73  3.39   4.33
+  Fort Niagara       1.63  2.52  1.87  2.25  3.90   1.71  4.08  1.52   2.61
+          Mean       2.25  1.89  2.12  2.20  2.55   3.28  3.49  3.04   3.95
+
+But the belt of trade continued its progress to the west and north, and
+during the months of July and August the drought extended in both
+directions, reaching, in August, from Mississippi, Alabama, Georgia, and
+South Carolina, to the Lakes, and from the Rocky Mountains to the
+Atlantic. Its position is shown by the following cut, and the position of
+the belt of precipitation by the following table.
+
+[Illustration]
+
+  TABLE VII.
+
+  _Situation of the focus of Precipitation in July and August._
+
+  -----------------------------------------------------------
+                           | JUNE.| JULY.| AUG. | SEPT.| OCT.
+  -----------------------------------------------------------
+  _New Mexico._            |      |      |      |      |
+                           |      |      |      |      |
+  Fort Thorne              | 0.08 | 2.23 | 6.01 | 3.50 | 0.00
+  Albuquerque              | 0.28 | 2.50 | 1.19 | 2.67 | 1.37
+  Santa Fe                 | 0.32 | 4.11 | 3.86 | 4.06 | 2.50
+  Fort Defiance            | 1.24 | 3.94 | 5.24 | 3.47 | 0.62
+   "   Yuma                | 0.00 | 0.01 | 2.37 | 0.17 | 0.30
+  San Diego                | 0.02 | 0.07 | 1.35 | 0.13 | 0.01
+  Fort Snelling, Minnesota | 3.31 | 3.92 | 1.75 | 6.35 | 1.23
+   "   Brady               | 1.23 | 3.21 | 3.86 | 3.18 | 3.40
+   "   Mackinac            | 6.35 | 5.67 | 4.26 | 3.22 | 2.28
+  -----------------------------------------------------------
+
+I have not space for all the comment which this exposition is calculated
+to induce. The reader will not only find in it an explanation of the
+extraordinary character of the summer of 1854, but will see from the
+_means_, that it was but an _excessive development_ of an ANNUAL
+PHENOMENON,--THE PROGRESS OF A CONCENTRATED COUNTER-TRADE.
+
+It is not necessary to follow with particularity the return transit. It
+required no great degree of sagacity to predict, at the time, that the
+drought would continue in the vicinity of New York till about the 10th of
+September. The return of the belt to that latitude, was not to be expected
+before that time, and the drought continued, in fact, until the 9th of
+September.
+
+Its return progress was slow, and it was every where behind time. The
+autumn was warm, and so, indeed, were December and January, west of the
+area of magnetic intensity, although upon, and east of it, there was a
+depression in December. The retreating but lingering edge of
+counter-trade, with its excess of snow for the season, caught the Iron
+Horse, with its train and passengers, upon the prairies of the west, and
+laid its embargoing hands upon them. Few, if any, can have forgotten the
+thrilling accounts which reached us from that section, of the sufferings
+endured by those who were thus embargoed for days and nights, far from the
+comfortable habitations of their fellow men.
+
+But the return transit, though slow, was extreme, and February and March
+were exceedingly cold for the season. The transit to the north, again, did
+not commence as early as usual, and the spring was backward, and the
+summer cool. Both were without irregularity, and the season was
+productive. The following table exhibits the temperature on a line of
+posts, running north and south at the west, during the winter months of
+1855, and will illustrate what has been said.
+
+TABLE VIII.
+
+  ---------------------------------------------------
+  1855.           |JANUARY |FEBRUARY.| MARCH.| APRIL.
+  ---------------------------------------------------
+  Key West        | 67.18  |  65.94  | 70.28 | 75.09
+          Mean    | 66.58  |  68.88  | 72.88 | 75.38
+  Fort Snelling   | 17.09  |  12.62  | 25.30 | 49.86
+          Mean    | 13.76  |  17.57  | 31.41 | 46.34
+  Fort Kearney    | 23.55  |  25.69  | 32.86 | 54.39
+          Mean    | 21.14  |  26.11  | 34.50 | 47.13
+  Fort Laramie    | 35.85  |  29.01  | 36.41 | 52.94
+          Mean    | 31.03  |  32.60  | 36.81 | 47.60
+  Fort Arbuckle   | 41.94  |  39.86  | 49.09 | 67.43
+          Mean    | 39.10  |  43.69  | 53.22 | 61.85
+  Fort Belknap    | 45.92  |  44.49  | 53.09 | 70.00
+          Mean    | 42.80  |  47.47  | 56.90 | 65.79
+  Fort Chadbourne | 48.89  |  45.87  | 56.68 | 68.51
+          Mean    | 44.29  |  46.75  | 58.01 | 65.52
+  Fort McKavitt   | 46.74  |  44.51  | 53.66 | 67.05
+          Mean    | 44.75  |  46.87  | 57.39 | 66.25
+  Fort Merrill    | 54.51  |  54.65  | 61.82 | 74.50
+          Mean    | 54.82  |  57.20  | 68.66 | 73.27
+  Fort Brown      | 60.23  |  61.60  | 66.24 | 74.98
+          Mean    | 60.41  |  63.63  | 68.95 | 75.05
+  Fort Inge       | 52.21  |  50.63  | 61.22 | 74.48
+          Mean    | 49.46  |  55.39  | 62.63 | 68.02
+  ---------------------------------------------------
+
+The return transit to the south for this winter, 1855-6, has been an
+extreme one. It is too early yet (Feb. 18th) to write its history, but the
+extreme southern transit is as obvious as the unusual severity of the
+cold. The rains which usually fall upon the Southern States are
+precipitated further south upon the West Indies, and threaten a
+deterioration of their sugar crop. The snow, and cold winds, and ice, of
+the middle latitudes, are felt even in Florida. Our sheet of
+counter-trade has been exceedingly thin, and the barometer has ranged, in
+fair weather, much below the mean. Occasional, and for a part of the time,
+_weekly_ periods of an increase of its volume, with a corresponding
+elevation of the barometer, and a consequent moderation of the intense
+cold, and a storm, have occurred. But those periods have been few and
+brief. No regular thaw has yet occurred. From the 26th of December to this
+date, at Norwalk, there have been but two periods when the wind has blown
+from the south-west with sufficient force to stir the limbs of the trees.
+There has been no wind from south of that point, or east of north-east;
+and even our storm-winds, with one exception, have been north of
+north-east--owing to the situation of the focus of precipitation far to
+the south of us--and there is reason to fear that a cold summer like those
+of 1816 and 1836 may follow. If this extreme transit is owing to defect in
+the influence of the sun, from spots, or other causes, such will probably
+be the result. If from volcanic action at the south, the influence of that
+action may cease, and a rapid return transit, and an ordinary season, may
+follow. Believing in the laws of periodicity in relation to the weather
+and disease, I planted an early kind of corn (the Dutton), in 1836, and
+had a crop when few around me succeeded. We must watch this return
+transit, with hope, indeed, but not without fear, and be wise in time.
+
+There is a mass of other evidence in these summaries which shows the truth
+of what I have written. There is not a deduction of Mr. Blodget which it
+will not explain. The ascent of the summer lines of temperature to the
+west is explained by the diminution of magnetic intensity. Their descent
+in winter by the location and attractions of the concentrated trade. The
+excess of precipitation in Alabama and Mississippi by the succession of
+summer and winter belts. That of the interior of the Atlantic slope in
+summer, by the showers which fall upon the elevations; and of the coast,
+by the easterly storms and their attraction of the surface atmosphere of
+the ocean, at other seasons. But I cannot further particularize. Even the
+influence of the spots is clearly demonstrated by the observations at
+_interior stations_, which were unaffected by contiguous oceans or
+elevations. At Forts Washita, Gibson, Scott, Smith, and others, the years
+1847 and 1848 were below the mean. All that evidence, and those
+deductions, however, I must pass by for want of space, and take leave of
+the subject.
+
+
+
+
+Footnotes:
+
+[1] See the diagram for summer at page 55.
+
+[2] Law of Storms, p. 42.
+
+[3] Kearakakua Bay (called Cavrico above), is on the S. W. side of the
+island, and the trade was reversed during the day by the cloud
+condensation inland.
+
+[4] Lieutenant Wilkes spent twenty days upon the top of this or an
+adjoining mountain, and his observations there will be alluded to in
+another connection.
+
+[5] All attempts to produce this result by the sudden exhaustion of air
+about the chickens in receivers, or shooting them from cannons, have
+failed, and no patent for a chicken-picker has been applied for.
+
+[6] A meter is 1 yard, and .0936 of a yard.
+
+[7] See his map, accompanying the Geography of the Sea.
+
+[8] See Am. Jour. of Science, New Series, Vol. 18. p. 187.
+
+[9] Their estimate was 100 to 120 miles.
+
+[10] Since the text was in type, and, as might have been anticipated, we
+have intelligence confirmatory of this, from the Cape De Verde Islands.
+The inter-tropical belt of rains has not moved as far north as the
+northern islands--they have had no rain--and the people are in a starving
+condition.
+
+
+
+
+Transcriber's Notes:
+
+Passages in italics are indicated by _italics_.
+
+Punctuation has been corrected without note.
+
+The following misprints have been corrected:
+  "appearnces" corrected to "appearances" (page 44)
+  "Faroday's" corrected to "Faraday's" (page 84)
+  "gentleman" corrected to "gentlemen" (page 96)
+  "two" corrected to "too" (page 105)
+  "surise" corrected to "sunrise" (page 111)
+  "acion" corrected to "action" (page 164)
+  "Stanta corrected to "Santa" (page 167)
+  "Augugst" corrected to "August" (page 167)
+  "baloon's" corrected to "balloon's" (page 192)
+  "mannner" corrected to "manner" (page 214)
+  "1198" corrected to "1798" (page 221)
+  "sevententh" corrected to "seventeenth" (page 240)
+  "maner" corrected to "manner" (page 254)
+  "particulary" corrected to "particularly" (page 256)
+  "are are" corrected to "are" (page 288)
+  "iso-theral" corrected to "iso-thermal" (page 299)
+  "the the" corrected to "the" (page 360)
+  "phenonema" corrected to "phenomena" (page 403)
+  "calorifice" corrected to "calorific" (page 409)
+
+Other than the corrections listed above, inconsistencies in spelling and
+hyphenation have been retained from the original.
+
+Tables throughout this text version have been adjusted for readability.
+
+
+
+
+
+
+End of the Project Gutenberg EBook of The Philosophy of the Weather, by 
+Thomas Belden Butler
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