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continent to be for some time severely oppressed with a sultry atmosphere, invariably experiencing a corresponding degree of vivid lightning and loud thunder, while a different division shall remain comparatively cool, and much exempt from those phenomena.* But it must not be forgotten, that in proportion as the heat is diminished, in that proportion do we always find the absence of thunder and lightning. This fact is indeed familiar to every person capable of observation.
Arguments are not necessary to show the constant efforts of nature to keep up a general equilibrium in her movements. This is visible every where ; and so long as the vital principle of heat shall continue to be profusely spread upon the earth, and so long as its resistless energy is felt through nature's depths,' so long will the whole phenomena of thunder-showers, hail storms, hurricanes, and furious winds, with all their inseparable concomitants, be the undeviating and natural consequence. The vivifying effects which immediately spring out of these convulsive movements of the elements, sufficiently point out the cause, while they demonstrate their efficacy and usefulness.
A high degree of heat is seldom known to prevail for several successive days in any section of country, without being succeeded by a fierce tempest. One cannot exist, without the certainty of producing the other. This operation will be as constant and as durable as the existence of those laws to which, under the present system of things, the whole are subject; for cause and effect must remain unchangeable.
Here, however, it may be proper to remark, that notwithstanding the intense heat of the summer of 1825, which exceeded in degree and duration any thing that we have an account of, perhaps no season ever passed off in which, not only at this place, but for an extended district contiguous to it, there were fewer thunder-showers, or so small a display of the electric property. But it will be remembered, that in other parts of this state, and in various parts of the United States, tempests of a most terrific nature were experienced. From the numerous accounts detailed in the gazettes, we are authorized to believe, that so much destruction was never before produced in one season from the same cause. Whole districts of country were swept by tremendous winds ; vegetation of every kind prostrated and cut to pieces by the most extraordinary quantities of hail, some of which was of enormous size; and many people and animals were killed by the lightning.
To show the rapid operation of the elements upon each other, I would simply refer to a metal or glass vessel filled with cold water in a sultry day. It will be perceived, that in a few minutes the whole surface of the vessel will be covered with water; and the ordinary term which people make use of to express their idea of it, is sweating.
* It will doubtless be recollected by many, that during a part of the summer of 1824, the heat in the southern portion of the United States was felt to a degree never before known, which was attended by very terrific thunder and lightning. Buring the prevalence of these phenomena in that direction, it cannot be forgotten that in some of the northern and middle states, the season was unusually cool, and marked with inconsi. derable electrical displays.
But it is well known to be occasioned solely by the powerful influence which a mass of cold water, and metal or glass of equal coldness, have on a very sultry and humid atmosphere; the warm air rushing strongly into the colder and denser element, which it continues to do until the water in the vessel becomes of the same temperature as the circumambient air itself. By this operation, the moisture soon accumulates to such a degree as to form large drops, which fall from the sides of the vessel.
The same effect, though the operation be reversed, may often be seen in winter, when the cold is severe.
The windows of a room without shutters, in which a fire has been kept up through the day, will be found the next morning to be completely coated with ice. This is produced by a cold atmosphere acting on a warm one, after the fire is extinguished, but the warmth retained. The external moisture which lodges on the glass, but which cannot enter the room, soon becomes completely congealed.
Of the immense quantities of vapor that are exhaled into the atmosphere, and which are sometimes so abundant as to skirt the whole heavens, always floating in or near the cold regions, large portions must necessarily be drawn to those sections of the country that are overcharged with heat; and hence the very common occurrence of thunder-showers in the afternoon. Such frequently is its overbearing ascendancy during the day, that some time before sun-down we perceive clouds rising in the north-west, which, by means of the wind being drawn from that direction, it being the quarter from whence proceed the coldest currents of air,) soon multiply and spread, until they gather sufficient strength to produce in their course all their usual and interesting characteristics. The infinite inequalities in the surface of the ground, connected with the causes before mentioned, must give rise to the constant succession of these operations, in numberless portions of the country, and to the great diversity in their character. Some showers afford bountiful supplies of water, and copious emissions of the electric property; while others are limited in their effects in both of these particulars.
The heat in any district must be supposed to multiply, until its influence shall become so predominant as to be felt in those cold regions that are nearest to it. Action and rëaction quickly succeed a consequence which I presume must immediately follow and the effects must always be proportioned to the force and peculiarities of the combined causes. Currents of cold air will often set strongly in that direction ; sometimes rushing with extreme impetuosity. This cannot take place, without carrying along with them large bodies of vapor, which are speedily condensed to such a degree as to form heavy, dark, and extended clouds; and this condensation must beget showers of rain in proportion to their depth, surface, and compactness. If they rise to an unusual height in the atmosphere, it appears to me the cold is communicated through them in the like degree to the earth; for that they serve as a medium through which heat and cold are equalized, is a conclusion that I believe will not be disputed. The inference therefore seems reasonable, that vapor must be very much condensed, and extend to a great height, before it reaches those
extreme cold regions which are sufficient to congeal the water, and occasion it to fall in masses of ice.
Mr. Volney, in his view of the United States, suggests the probability of occasional vertical currents ; but if my memory serves me, he barely makes the suggestion, without proceeding to trace their general influence or agency. Had he pursued the theory, he would beyond all doubt have established it not only to his own, but to the satisfaction of every reader. It has often struck me as matter of surprise, that so little has been said on this subject; and the more so, as it appears to me a position as important as it is undeniable. That almost all the great changes which are so frequently felt in our atmosphere, are brought about through this medium, I believe to be capable of sufficient demonstration. The usual serenity of the air consequent on these changes, is itself a pretty clear evidence of it. Strong horizontal currents, of great extent, could only bring with them the impure exhalations of boundless forests, extensive morasses, and great inland seas. These could neither produce a serene atmosphere, nor could they yield that portion of health and comfort which are required by nature in her complicated and infinitely varied concerns. Such movements would not only be contrary to every principle of that wise and rational economy, which is one of the most prominent features in all her multifarious works, but they would be attended with such wide-spread ruin, as in a great measure to counteract all those kind and beneficent intentions which, under all circumstances, and in all seasons, are so striking and manifest, even to a superficial observer.
I have the fullest faith in a constant succession of these operations; and am persuaded, that to this cause more than to any other, nay, infinitely more than to all others, is to be ascribed the coolness, freshness, and serenity, so commonly experienced after a thunder-storm. It is difficult to conceive from what other quarter such delightful changes should come, or how and by what other means effects so extraordinary should so soon be brought about. The common fact that these currents, in the great majority of cases, come from the north-west, furnishes no argument that they proceed from remote cold regions in that quarter; because nothing is more common than the occurrence of a thunder-storm, not only in the maritime districts, but frequently very far in the interior, attended with furious winds that sweep over the face of the country, producing much devastation, while another district, not very far to the north or north-west of it, shall experience a calm and serene atmosphere. If any man will be at the trouble to make suitable inquiries, he will find this to be an almost every day occurrence in the summer season. And the operation of these causes thus explained, presents itself to my mind as not less correct and simple in theory, than it is obviously beneficial and delightful in its results. Hence I conclude, that there can be little doubt or hesitation entertained that it is one of the permanent laws in our system, and that to the operation of this law are we constantly indebted for nameless enjoyments and benefits. The circumstance that currents of air at such times set strongly from the north-west, is an objection of very little weight against the prevalence of vertical currents ; for as the maritime districts are univer. sally found to be hotter than those in the interior, it would seem to follow, as a fair consequence, that these currents, owing to the influ. ence of such a cause, would take that direction, even before they reached the ground.
From every view that can be taken of the subject, it seems reasonable to suppose, that a flood of accumulated heat, covering a measureless area of land and water, must have an inconceivably strong influence on cold air and vapor that are placed near it : it must of necessity produce a high degree of excitement and agitation amongst them; and action will be succeeded by rëaction, until their complete approximation ; when those fierce but salutary concussions take place, which are so often observed in the summer months. All the superabundance of heat which has been poured upon the earth, and which is either aggregated in bodies or otherwise, (for that the heat is constantly aggregating in small globes or volumes, I am fully convinced,) rushes into the clouds, with a rapidity proportioned to their coldness, weight, and magnitude, and bursts from them in successive and splendid streams, as they are carried along by the force of the winds through the atmosphere ; thus fulfilling a most important and wise provision in nature, the effects of which are infinitely beneficial. The earth is at once relieved from the overwhelming and wasting influence of an agent that at times becomes almost insupportable to every grade of animated nature, while vegetation every where withers and sinks beneath its consuming power.
In addition to the arguments already advanced in support of my theory, there is one prominent fact to which I would advert, and which may be seen by any one, whenever a thunder-shower is at such a distance that it can be contemplated with safety and composure. In almost every instance, the lightning bursts immediately on the surface of the cloud, and the streams of fire continue to spread themselves on its surface, until their whole force is spent. If there are instances, (and such may occasionally be observed,) where the lightning seems to shoot from the body of the cloud, I am still persuaded that the effect is only apparent, not real. It doubtless explodes on a more distant part of the cloud, while the eye is deceived by the light shining through the vapor. It must be recollected that very frequently a small portion of the surface of a cloud only is seen. This I deem a sufficient answer to any objection that might be suggested to the remark.
I have not unfrequently observed, while contemplating the lightning playing on the bosom of a distant cloud, that streams of electricity would ascend from the lower part of the cloud, almost in a right line, for some distance before they separated into diverging lines. During the summer of 1824, I beheld an interesting occurrence of this kind. A heavy cloud, which apparently hung over the southern shore of Long Island, was suspended a few degrees above the horizon. A stream of electricity shot up from the lower skirt of the cloud, and ascended in a right line eight or ten degrees. Hence it appears to me that no other judgment can be formed from these plain indications, than that electricity is drawn solely from the surface of the earth, and that it is no other than the great mass of redundant heat which collects together in low grounds, being attracted
into the body of dense vapor, and that it explodes the moment they come in contact. Any other conclusion adduced from these facts, I should certainly conceive to be erroneous. My full persuasion therefore is, that this is the natural and true operation of the elements. It agrees with those simple movements which are known to characterize nature wherever they are understood; that this operation too is as wise and useful as it is sublime and beautiful ; and, in my judgment, the electric property neither is nor can be produced from any other possible source.
The utility of these movements has been already explained :* and the indispensable necessity there would seem to be for such operations during the oppressive and sultry season of the year, with numerous other circumstances, all combine to show, that the economy of nature actually requires such an agency; that without it her benign intentions would in a great measure be frustrated, and the grandeur and majesty of her works deprived of much of their imposing and interesting scenery, as well as of some of their noblest and most useful purposes.
THEORY OF WEST AND NORTH-WEST WINDS.
I PROCEED to offer a few
remarks by way of a Theory of West and North-West Winds. These are the most generally prevailing winds that we have, and ordinarily they are much the fiercest. That these winds originate from a quarter totally different from what has been the general supposition, is sufficiently clear to my understanding; and that they do not come from the distant western or north-western regions, is susceptible of abundant proof.
It is a fact not sufficiently adverted to, or perhaps not generally known, that west of the mountains the prevalence of boisterous winds is extremely rare. A residence of several years in the state of Ohio enables me to speak confidently on this subject. Boisterous winds are of unusual occurrence in that country; and furious gales from the north-west are almost unknown, after getting beyond the great dividing ridges. It is beyond all question true, that in most cases during the prevalence of those strong winds in the Atlantic states, the atmosphere in the great Ohio valley, and between that and the lakes, and even onward west to the Mississippi, remains unmoved. The currents of air in that quarter generally move in a different direction. The prevailing wind there is known to come from the south-west ;t though north-east winds are not unfrequent. Both are almost always comparatively gentle ; and this is not only the common character of the winds in that country, but it may be easily ascertained, that such is the usual state of the atmosphere in that region, during the movements of the fiercest western gales on the Atlantic coast, and east of the mountains.
Then how and by what means are those boisterous and piercing winds engendered, and from what region do they proceed? This leads me to the purpose which was before me, and on which I propose to offer my opinions.
* Article on Electricity.
# Drake's View.