The Philosophy of the Weather Part 25

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 lat.i.tude 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 cla.s.ses_ 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 lat.i.tudinal 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 lat.i.tude; 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 a.s.sist us, but, till we understand better, and to some extent antic.i.p.ate, 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 cla.s.s 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 cla.s.ses 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 c.u.mulus, in mid-winter, and c.u.mulus 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 gra.s.s 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 gra.s.s 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 suns.h.i.+ny, 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: