“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: