The Philosophy of the Weather Part 26

"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 lat.i.tude and magnetic intensity; but it progresses to that degree, whatever it may be, with as great uniformity in a southern as northern lat.i.tude. 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 lat.i.tudes, 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 lat.i.tude 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 lat.i.tudes, 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 lat.i.tude 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 alt.i.tude 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, gra.s.s, and oats, are benefited; and corn, according to the proverb, will not be seriously r.e.t.a.r.ded. 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 lat.i.tude 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 alt.i.tude, 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 lat.i.tude 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 pa.s.s 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 antic.i.p.ated 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 const.i.tution, 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 gra.s.s 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 ma.s.s 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--