STRATUS
Courtesy of Richard F. Warren
Stratus is merely lifted fog in a horizontal form, the lowest of all, and the simplest as regards structure. It means neither rain nor snow and the apparent clearness of the blue above it would indicate clear weather to come. But through the break in the stratus near the horizon shows a cloud of firmer texture, which is less reassuring. Stratus over the land in winter takes the appearance of long bolsters of gray through which a pale blue sky shines. Such clouds may blanket the sky for days without causing a drop of rain. If they show a tendency to glaze over expect snow or rain, but not in large quantities.
The fascination that a thunderstorm has formany people is explained partially by the fact that one sees the whole process from beginning to end. The officials of the Weather Bureau have this privilege as regards cyclones. It is their business and pleasure to watch the setting up of these vast storms, to follow them on their journey. It is small wonder then that they find the spectacle fascinating.
THE TORNADO
The birds, the flowers, and the tornadoes are all busiest in spring. And the tornadoes probably make the largest impression.
A tornado is merely a whirl of air, caused, as are all the other whirls, by a striking difference in temperature in adjacent areas. A tornado is a local and restricted example of the same thing that a cyclone is. But a tornado rarely crosses more than a single state; a cyclone strides continents. A tornado lasts, in one place, about a minute; a cyclone affects the weather for three days. A tornado never survives the night; a cyclone plods on for a week. And yet if you are betting on destruction put your money on the tornado. What it lacks in the realms of space and time it makes up in intensity. Its sting is fatal.
Tornadoes occur chiefly in the spring becausethe temperature changes are greatest then and it is from these that the tornado sucks its nourishment. Over the plains, for example, a limited area is abnormally heated by a local cause. Abnormal cold comes in contact with the abnormal heat. The great difference in pressure results in a spiral as it did in the cyclone, only in a very small spiral, and once begun its energy is self-aggravating. The whole thing moves off toward the northeast attended by the black cloud of its condensation. From the black cloud a funnel like an elephant’s trunk sways back and forth, now touching the ground and now escaping it. The black cloud has been in the southwest for some time probably before it has commenced to move. The day has been very oppressive. The sun rose rather coppery, in all likelihood. As the black cloud with the swaying funnel nears a roaring is heard. Darkness falls. The roar increases.... Instantly it is over.
Now that you’ve been through a tornado you know how it feels,—almost. After the funnel passes hail falls, lightning flashes through the lessening murk. Heavy rain succeeds, and if you’re alive you go out and rescue the perishing.
The wind velocity in the path of a tornado is enormous,—anything up to 500 miles anhour,—but no instruments have been devised to withstand the strain. Varying pressures are responsible for the destruction. As the funnel passes over a house where the normal air pressure is about 2,000 pounds to the square foot it removes 1,500 pounds for an instant. Naturally the outside walls cannot withstand this enormous inside out pressure and the house explodes like a projectile. Only under such conditions could the vagaries of matter,—straws piercing logs and chickens bereft of every feather—be perhaps not explained but pardoned.
Stories of any degree of incredibility crop up after each tornado, often with accompanying photographs as proof. People are plastered with mud, pianos are deposited in neighboring lots, babies are hung up unhurt by their clothes in tree-tops, and often one person is killed and another nearby escapes unhurt, Bible-fashion.
Tornadoes may form almost anywhere, but they are never found on the immediate Pacific coast. They are most common in the Mississippi Valley, are rather common in the Gulf States, and have occurred throughout most of the East at one time or another.
Since there is no way of stopping them the next best thing is to know the conditions thatmake for their formation. If the Weather Bureau predicts a cold wave for sections of the country where the weather is already abnormally warm the line of meeting will probably produce a tornado somewhere. The officials, however, advise you not to worry until you see the intensely black cloud in the southwest trailing its funnel. See where this funnel is tending and run the other way. All tornadoes progress from the southwest to the northeast. Bad as they are, this makes them far less terrifying than if they whipped back and forth over a town or chased you around the pasture. If you happen to be in the house, take to the cellar, the southwest corner of it. If you can’t escape lie face down to the ground.
The only tornado that I have ever witnessed was an undeveloped one in England, and a bit lethargic compared to those of the Prairie States. But even this blew an entire train off the track. It had all the other appurtenances of a tornado, the hail, the twisted trees, the narrow southwest to northeast path. The fact that the houses had only corners of their roofs blown off showed that as a tornado it was distinctly second-grade and without power to explode.
England, shortly after, was raided by threewater-spouts. These phenomena are caused by precisely the same conditions as are the tornadoes. They form over the sea, and the funnel is composed of water. They take considerable bodies of water up into the skies and torrential rains result over adjacent districts. If I remember correctly, two of the English water-spouts broke against the cliffs and the other, moving inland in modified form, gave Gloucester a nine-inch rain. Ships have been known to fire cannon at these spouts. If one hit a boat directly damage might be caused, but they have little of the destructive force of the tornado.
As our country builds up the destruction from this most powerful of all phenomena is likely to increase. Bureau warnings over phones may result in the saving of some lives; cellars will undoubtedly be built in the principal zones. But the problem is an interesting one, for unlike the waterspout, cannon cannot be employed to shatter an emptiness that stalks the more malignantly the emptier it is.
THE HURRICANE
The tropical hurricane is undoubtedly nature’s mightiest exhibit. The hurricane is the cyclone par excellence. It does not differ from our ordinary weekly cyclone in the essentials ofwind rotation or pressures or rainfall; but it does differ in place of birth, in its course, and chiefly in its intensity.
The genuine hurricane is a West Indian production. It is generally cradled in those islands south and east of Jamaica and Cuba. It is nursed by the trade-winds. The first notice of its birth is an alteration in these winds, which are among the most regular observances on our planet. An extensive formation of cirrus clouds spreads over the sky and the barometer, which has been stationary for some days, edges off and begins a long and gradual fall. Great rollers are noticed for a day or two before the winds rise. A hurricane moves slowly.
This tropical organization is superior in depth to our shallow, disc-like, continental cyclone which is one and rarely over two miles thick. The hurricane rears its head three, four, and even five miles high. Instead, too, of dissipating its force over thousands of miles at once it is only a few hundred miles in diameter. Its center moves methodically along at the not very impressive speed of fifteen miles an hour, while our cyclones hurry along at thirty. But the hurricane is thorough. The wind about its center reaches a velocity of 120 miles an hour. This velocity has never yet been attained on thesurface of the earth by our trans-continental cyclone.
Our cyclone always has an eastward trend; the hurricane has a parabolic course. It begins by moving west on the trades, drifting and dealing destruction to the banana and sugar plantations of Jamaica. It enters the Gulf of Mexico, and since it is then pretty much out of the influence of the trades it curves to the right and begins to act like any other storm by heading directly for the St. Lawrence. If it passes out through the Florida straits it never reaches the St. Lawrence but speeds up the coast and out to sea, usually at Hatteras to follow the shipping routes across the North Atlantic.
But if it has become so involved in the Gulf of Mexico that it cannot escape to sea again, it comes up through the Gulf States and on toward New England. Fortunately as it goes inland its intensity diminishes because it has not so much energy-giving moisture to draw from. Also its sphere of action widens, its embrace is less mighty, its characteristics more those of an ordinary continental cyclone. It manages, however, to deliver gales of 80 miles an hour along the coastal plain, increasing to 100 at the exposed places such as Hatteras and Block Island.
The intensest hours of a hurricane are those when its course is changing from westward to eastward. Enormous rainfalls accompany these storms, amounting to six inches in some instances. Since one inch of rain amounts to 100 tons per acre, and 64,000 tons to a square mile one can imagine the great amount of evaporation that has taken place to so saturate the air as to drench vast territories to such an extent.
While scarcely a year goes by without one of these West Indian hurricanes distinguishing itself on our shores the one that visited Galveston in 1904 eclipsed all. It chose to turn in the vicinity of the city. The gale increased to over 100 miles an hour and the wind gauge then blew away. The waters of the Bay were heaped up and three thousand lives were lost in the flood and wreck of flying houses. This peculiar storm did not turn northeast at once but ascended the Mississippi, turning at the Lakes and proceeding down the St. Lawrence after having spent a week in our country.
The listless doldrums have sent us 121 of these storms in the last generation. June has seen 8, July 5, August 28, September 40, and October 40.
Sea-yarners have seized upon the hurricane to energize many a flagging chapter, and particularlyhave they emphasized the eye of the storm. The eye is that vortex where contending winds neutralize each other into a calm, where the sun shines out through the scud, where the waves, relieved of the great pressure, leap upward in wild disorder. Then the center passes and the wind flings itself upon the unlucky bark from the opposite quarter. Its first onslaught is always represented as being the fiercest of the whole storm and gradually lessening as the center drives farther away. This is true in the same way that the first attack of the thunderstorm is usually the fiercest, both being when the pressure begins to rise. This savage change to the northwest is naturally the hardest of all for the ships to bear as they must steady at once against the severest blast instead of gradually bracing for its culmination. In no department of meteorology has fiction adhered so closely to the facts as in the sea-rover accounts of the hurricane.
But in real life there is very little excuse for the vessel to be caught anywhere near the disastrous center of the storm. Indeed, for generations sea-captains have known how to escape the deadly eye. By watching the barometer and noticing in which direction the wind is working round they can tell the course to a nicetyand estimate its speed. Then the wise ones run the other way for even theOlympicsandImperatorsof the sea are cowed by the might of the West Indian.
The typhoons of the West Pacific are similar manifestations.
The hurricane moves off from its birthplace so slowly that our Weather Bureau has an opportunity to size it up, to chart its probable course, and to warn shipping interests. The ship-owners, as a class, appreciate the service of the Bureau and obey its warnings. Vessels with cargoes of a total value of $30,000,000 were known to have been detained in port on the Atlantic coast by the Bureau’s warnings of a single hurricane. Now that a much vaster commerce will steam through these dangerous waters toward the Panama Canal the warnings will assume an even greater importance.
The best description of a hurricane that it has been my fortune to read is in a story entitled “Chita,” one of the remarkable fictions of Lafcadio Hearn. As truthfully as a scientist and with great beauty of style he has pictured the long days of burning sun, the foreboding calm, the thickening haze, the ominous increasing swell of the ocean, a breathless night with the lightning glowing from between pilingtowers of cloud, the startling suddenness of the wind’s attack, its fury, the hissing rain, the shrill crescendo of the gale.
CLOUDBURST
It is the American tendency to exaggerate. We call every snowstorm a blizzard, every breeze a gale, every shower a cloudburst. In our generous vocabulary it never rains but it pours. Consequently if we, in the East, ever had a real blizzard or a real cloudburst we should be at a considerable loss to find words for an unprofane description. I do not know how they manage out West where these things occur.
A genuine cloudburst must be an amazing spectacle. It is caused by a furious updraft of wind keeping a rainstorm in suspense until so much water has accumulated that it has to let go all at once and the accumulation descends like a wet blanket.
This phenomenon is staged in the mountains; most often in the Rockies where melting snow and desert-hot ravines provide the necessary extremes of temperature. Wind blowing up a mountain-side can maintain considerable force,—so much that a man cannot possibly walk against it. Black thunder clouds brew on thepeaks. Suddenly the collapse, and the person who tells the story afterward finds himself struggling in a torrent that a minute before had been a dry gulch. The moral of the story seems to be that if you are camping in the mountains and there is a strong upstream wind blowing and the clouds darken about the hill-tops and the thunder mumbles then don’t make your bed in the creek-bottom lands. The high water marks of former freshets, but not of cloudbursts, show on the side of the stream.
Even in the less impulsive East a couple of inches of rain make a surprising rise in a little creek.
THE HALO
The halo is a luminous circle around the moon or the sun. It is caused by the refraction of light passing through moisture, which at the usual height is in the form of ice-crystals. The halo when complete consists of two large circles whose diameters are constant, 45 and 92 degrees. Then there are often other arches in contact. At each point of contact occurs a parhelion which is a mock sun of brilliant colors and called a sun-dog. Since the sun-dog is brighter than the other parts of the halo it sometimes appears when the rest of the halo cannotbe seen. Sun-dogs hunt in pairs or fours. If the halo is colored the red is on the inside. When the colors are caused by diffraction instead of refraction, the red is on the outside of the prismatic ring and the halo is called a corona.
Having now satisfied the demands of science all that can be forgotten except that the halo around either sun or moon means excess moisture in the atmosphere. The wide halos are seen in the high cirrus clouds 25, 36, 48 hours in advance of a cyclone. At first the ring is very wide and faint with several stars in it. If the storm is advancing rapidly the halo brightens and narrows and the stars fade. This is proof to show that the proverb stating that the number of stars inside the ring is a forecast of the number of days of storm is sheer nonsense. For presently the ring closes and the stars disappear which would show according to the proverb that the storm had changed its mind and would cut down the number of days from several to none.
The moon grows paler. The light that it casts upon the earth is eerie at this stage. Within a few hours the cocoon of mist is completely woven about the moon. The circle has closed. Snow or rain begins within a few hours after the moon has entirely disappeared. If itdoes not so begin it shows that the process of increasing humidity is a very slow one and the storm center is probably passing far to one side of the observer. Also if the snow begins before the light of the moon is entirely suppressed the disturbance is a shallow one and the storm will be light.
When the halo is actually a corona (red outside) the approach of the storm can be gauged by the rapidity with which the circle grows smaller. For a decrease in diameter denotes that the size of the moisture drops is increasing and therefore the storm is approaching. As a matter of fact the corona will have disappeared long before the time for rain. Still it is useful to know that if the corona increases in size the conditions are clearing. With the halo the reverse holds. For when the clouds are very high the halo looks small, and high clouds imply swifter winds and a greater distance from the storm center.
The Zuñi Indians who have an eye for the picturesque as well as for the truth state the chief fact about haloes happily: “When the sun is in his house it will rain soon.” Another saying of theirs anent cumulus clouds holds for our country as well as for theirs: “When the clouds rise in terraces of white, soon will thecountry of the corn-priests be pierced with the arrows of rain.”
There are many little observations which the man who has kept the corner of his eye open may profit by and yet which are rather difficult to express in type. Who could describe an egg for instance whose springtide of youth was far behind and yet was not quite ready for the discard! In nature it is the fleeting moment of transition, the half-tones of the border that are so hard to catch, so difficult to portray, and yet so very important not to miss if one is to become sure. There follow some of the baldest and most communicable half-facts about the weather that should be used oftener to bolster up some opinion gleaned from more positive sources than to mould one in their own strength.
Moisture in the atmosphere helps sight to a certain extent. For when the air is full of moisture its temperature tends to become equalized, obliterating irregularities which would otherwise reflect the vibrations producing sight and sound. So if one hears better or sees better on a certain day it augurs a moister atmosphere,—an auxiliary sign if there is a view that you are fond of looking at many times a day. In the city, alas, clearer vision on one day than another means merely that less coal is being used. Butin camp there is very often a perceptible difference in one’s seeing ability even on days that could all be classed as clear.
Another thing that the haunter of the woods may notice is that his smelling capacity is increased before a storm. The increase of humidity which precedes a rain buoys up odors and depresses smoke. Even in dry weather if you will stroll by a marsh you will notice how rank the vegetation smells and how the smells float in layers in the air strata of different humidity. One’s sense of smell is a very slender thread on which to hang a storm, however.
Fires burn more briskly in dry air than in moist, but to tell the difference (if you can’t feel it) you must be very sure that your wood is as dry on one day as on another.
Before a rain many plants close their flowers or shift their leaves. The dandelion, pimpernel, red clover, silver maple are good examples of this, but they would not be of much use in the North Woods. The closing, too, takes place only a few hours before rain and is merely confirmation of the signals rendered more adequately by clouds and winds.
Bugs and flies are particularly annoying before a storm and it is surprising that the spider should not take advantage of this to get a meal.But spiders are cautious and they never spin a web on the grass, at least on the day that brings a storm. The insects do not fly so high on these weather-breeding days and consequently the birds that feed on them fly lower. The chimney swifts are a particularly good guide to the different altitudes at which insects fly.
The stars are on a par with bugs as weather guides, although there are many proverbs that grant them much. One circumstance should not be neglected, however, and that is that wind mixes air and when air is well mixed atmospheric inequalities are less disturbing to vision. Hence when one can see the stars and the moon well wind currents are oftenest the cause. Even if it is not blowing on earth these wind currents may yet be blowing above to reach the earth later. In this way cold waves arrive. There is an old proverb about this condition, applying it to the moon, “Sharp horns do threaten windy weather.”
But the stars are of second rate importance because they are so soon obscured. If you can’t see them it is cloudy, but you do not know what kind of cloud it is. If only the brightest show, a veil of cirrus is arriving. A dark sky with only a few dim stars is an omen of storms. If the stars twinkle it is because the varyingcurrents of the upper air are in juxtaposition. If they twinkle while the northwest wind is on it is a sign of colder weather,—not because they are twinkling but because of the northwest wind.
In the days when almanacs were the sole guides to the weather a man with a sense of humor, Butler by name, got out one and dedicated it to “Torpid Liver and Inflammatory Rheumatism, the Most Insistent Weather Prophets Known to Suffering Mortals.” Rheumatism is following the almanac to the scrap heap, and it would be harder for a camper to guess what a torpid liver was like than to forecast the weather, yet for the majority of “suffering mortals” there is still much truth in the amiable observation of Mr. Butler,
“As old sinners have old pointsO’ the compass in their bones and joints.”
THE BAROMETER
Whateverthe foregoing chapters may imply as to the whole world going camping the fact is that the woods are still, unfortunately, for the few. The woodsman must yield gracefully to the suburbanite,—in numbers.
But the weather is for everybody. To be sure the sunrise that talks so confidentially to the hunter of the coming day does not exist for the commuter. But the coming day does, even though the things it means are essentially different. To the hunter with his seasoned clothes and well-earned health a rain is only of concern in so much as it affects the business of the day; personally it is of small moment. But to the commuter what does the weather mean? Dollars and cents, of course. His business goes on, but to his person one unexpected shower == the cost of pressing a suit; one thorough soaking == one doctor’s bill. For you cannot expectthe man to throw off a chill who can quiet his conscience on the matter of daily exercise by watering the geraniums and reading the newspaper.
Weather wisdom is necessary for the hunter; for the commuter it pays.
The hunter had to rely on local weather signs. The commuter can go him one better by investing $10 (how finance will creep in!) in a little aneroid barometer. The local weather signs were good for twelve hours at the longest. The barometer is a faithful instrument that adds another twelve hours to a man’s knowledge. Half a day, or even a day before any local sign of changing wind or growing cloud appears the barometer is on the job. It will register in Philadelphia the news of a disturbance approaching the Mississippi. So sensitive is it that it is the slave to every wave of the great air ocean.
The barometer gauges for the eye the amount of atmosphere that is piled above one. If the amount is normal and at sea-level the instrument will measure 30.00 inches. This air pressure is equivalent to a column of water 30 feet high. As this would make unwieldy prognosticators the scientists use mercury instead, which requires a column less than three feet long. And forgeneral purposes this is supplanted by the handy little aneroid (which means “without fluid”). This is so fixed that the pressure of the air influences the upper surface of a vacuum chamber, balanced perfectly between this pressure and a main spring. This action is transmitted to an index hand moving across the dial marked into fractions of inches after the manner of the recognized standard, the mercurial barometer.
When the warm moist light air of a cyclone invades a locality the pressure is partially removed, the vacuum chamber is not pressed so hard and the dial hand or the mercury subsides. When the cold, dry, heavy air of the anticyclone lumbers in more pressure is applied and the mercury, or the dial hand, climbs. So a falling barometer means a storm, a rising one fair weather.
That is a generality that glitters. If that were all there was to it weather officials would have a sinecure. But each cyclone varies in size, intensity, and rate of progress. Some do not advance for days. Therefore there has grown up a pretty large body of information as each storm has had to be watched and the barometric movements recorded. The most important variations follow:
Remembering that 30.00 inches is sea-levelnormal, if the barometer is steady at 30.10 or 30.20 the weather will remain fair as long as the steadiness continues, and on the turn, if the fall proceeds slowly with the wind from a westerly direction fair to partly cloudy weather with slowly rising temperature will follow for two days.
If the barometer rises rapidly from 30.10 the fall will be equally rapid and rain or snow may be expected within a couple of days. Since the depressions of the atmosphere tend to a certain regularity about the center of the storm it follows that the reactions will follow the actions in similar manner,—a long rise portending a long fall and a variable glass meaning unsettled conditions.
The barometer does not rise with wind from an easterly direction unless a shift is imminent. In winter the air is so much colder over the land than over the sea that the air brought in by an easterly wind is soon condensed. Consequently with winds from the south or southeast, even if the barometer is 30.20 or 30.10 and falling slowly rain usually arrives (and rain of course is meant to include snow whenever the mercury is below the freezing point) within 24 hours. If the fall is rapid there may be precipitationwithin 12 hours, and the wind will rapidly increase and the temperature rise.
If the wind is from the east or northeast and the barometer 30.10 or above and falling slowly it means rain within 24 hours in winter. In summer if the wind is light rain may not fall for a day or so. If the fall is rapid in winter rain with increasing winds will often set in when the barometer begins its fall and the wind gets to a point a little east of north.
If the barometer is 30.00 or below and falling slowly with northeast to southeast winds the storm will continue 24 to 48 hours. If the barometer falls rapidly the wind will be high with rain and the change to rising barometer with clearing and colder will probably come within 20 to 30 hours.
If the barometer is below 30.00 but rising slowly the clear weather will last several days.
If the barometer is 29.80 or below and falling rapidly with winds south of east a severe storm is at hand to be followed within 24 hours by clearing and colder. Under the same conditions but with northeast winds there will occur heavy snow followed by a cold wave.
If these promises do not always bear fruit it is because they will have been interrupted by anunseen shifting of the atmospheric weights. But the barometer will record them. A rapid rise may be checked in ascent and the instrument may fluctuate like a stock-ticker. Its tale is of very unsettled weather conditions and consequently no particular brand of weather will last for very long at a time.
A sudden rise of the barometer may bring its gale of wind as well as a sudden fall. But the tendency will be toward clearing and much colder.
A fall of the barometer on a west wind is not common. It means rain. A rise on a south wind means fair. A low barometer and a cold south wind mean a change to west with squalls for a while. On the other hand, a high barometer with warmer weather means a shift of the wind to southerly quarters and an imminent fall.
If the barometer rises fast and the temperature does, too, look for another storm. This is often noticed in summer.
There is a slight daily oscillation of the mercury, which, if other things are steady, registers highest at 10A. M.and 10P. M.and lowest at 4A. M.and 4P. M.
If this data confuses bear in mind the simple ordinary progress of the barometer in the usual storm: First, it will stand steady for a day orso at any point between 30.10 and 30.50. Then the glass will begin (for most storms) to fall gradually. As the center nears the fall hastens. After the lowest point has been reached a slight rise will be followed by another slight fall and then the final long rise will commence. The rain begins and ceases at different stages for different storms, depending upon the wind’s velocity and direction.
For every 900 feet of altitude the height of the mercury is about one inch less. Do not complain that your barometer is inaccurate if you are living up in the mountains and your readings are not the same as the weather reports which are reduced to sea level. All the figures given in this chapter are for sea level and if your house is 1900 feet above you must move the copper hand of your aneroid 1.95 inches from the pressure hand. If the pressure hand would read 28.05 the adjustable copper hand would read 30.00 which is the sea level reading.
One good thing to remember is that a barometer falls lower for high winds than for heavy rain. A fall of two- or three-tenths of an inch in four hours brings a gale. In the ordinary gale the wind blows hardest when the barometer begins its rise from a very low point.
In summer a suddenly falling barometerforetells a thunderstorm, and if the corresponding rise does not at once take place the unsettled conditions will continue with probably another thunderstorm. If you see the thunderstorm first, that is, if the barometer is not affected by the approaching black cloud you may be sure that the storm will amount to nothing.
The man in the fields or along the shore has many natural barometers in animal life. But these natural barometers only corroborate; they do not foretell, at least very long before. Some are useful at times and among these the birds are foremost. The observant Zuñis have incorporated this in one of their pretty proverbs, “When chimney swallows circle and call they speak of rain.” As a matter of fact the swallows are circling most of the time after insects. If they are flying high it is because the bugs are flying high and that is because there is no danger of rain. As the rain nears the air gets moister, the bugs and the birds fly lower.
Whether they do this because their instinct is to avoid a wetting or because the lighter atmosphere of a cyclone makes flying more difficult, particularly at altitudes, I do not know. For weather purposes it is enough to watch their comparative levels. Wild geese are excellentsigns, I am told, but it would be a dry country that waits for a sight of them for its rain.
Bees localize before a storm and will not swarm. Flies crowd upon the screens of houses when humidity is high, possibly because the appetizing odors from within are buoyed afar by the heavy air. Cuckoos seek the higher ground in fair weather and disappear into bottom lands before a rain. Although they are called rain-crows they are heard in all weathers.
Smoke is as good an evidence of barometric pressure as anything except the instrument itself. On clear, still days it will mount; on humid days without wind it will cling to the hill. There is that difference. But it takes skill and many comparisons to gauge its angles in the wind. It becomes a test in observation and finally rewards one by becoming an excellent sign not only of air texture but of the direction of its currents.
No reference to barometers would be complete without mentioning spiders. They show a most delicate apprehension of changing conditions. If the day is to be fine and without wind they will run out long threads and be rather active. If the rain is nearing they strengthen their webs, shorten the filaments and sit dully inthe center. Fresh webs on the lawn insure a clear day. But for the commuter, whose time is money, there is little leisure to consider the spider.
As a natural result of the variation in altitude affecting the barometer the words which are printed on the face become entirely useless. In some places it would be impossible for the needle to point higher than “Very Stormy.” Even at sea level a sudden fall to “Fair” would cause a rain, much to the indignation of the person who thought that he had purchased a self-registering weather prophet. Disregard the words but watch the needle and you will never be surprised at what the weather is doing next.
THE SEASONS
Toogreat emphasis cannot be laid upon the futility, at present, of trying to forecast the weather for more than a very few days in advance. Long range efforts are not made by the Bureau because with its present limited knowledge of the factors that control seasons and with the present limited facilities for collecting data the process of looking into next month has not been perfected, and the attempt to investigate next winter’s weather proves scientifically impossible.
As usual, fakers step in where science fears to tread. With goose-bones (not their own) and hickory nuts they prophesy with all their might. And if their prophecies come true, as sometimes they must, there is wide rejoicing in the newspapers and the cause of science is set back by just so much. But science cannot be thwarted in the end and every year new discoveries are made, new speculations proved true or forever false, and some time, doubtless, theweather will be predicted from year to year with the same 85% accuracy with which the 36 hour forecast is now made. Experimenting is worth the little that it costs, too, for to know when the summer is to be dry or wet, hot or cold will be a boon to everybody and to the farmer most of all.
One conclusion has already been reached by officials in the Weather Bureau and scientists generally. It has been decided by long search through creditable records, painstaking comparisons of averages coupled with the most accurate investigations for half a century, that, on the basis of ten years, our seasons do not change. That is, counting the decade as a unit, our weather keeps to the same level of efficiency through the centuries.
This statement comes always as a blow. It always provokes argument and citations of grandmother’s blizzards. There is a great and universal hesitation in believing that our weather is as good to-day as it used to be. The good old times when there was a general debauch of snow and you could skate all winter on anything but the Atlantic Ocean certainly appear no more. As a matter of fact there has been a change, but it has been in our memories. In grandmother’s youth the trains,—if they had trains then,—doubtless were stalled by a big snow for thenthey did not have rotary plows. In father’s day they may have had an unbroken winter of sleighing. We couldn’t now; sleighs are extinct. But in our time, in fact every year, some record is being broken and the records go back a respectable length of time.
For example in Philadelphia the most accurate records made by standard instruments have been kept for 43 years. During this time the highest wind velocity was recorded in 1878 (75 miles an hour). The greatest rainfall in 24 hours occurred in 1898 (5.89 inches). The lowest temperature was registered in 1899 (6 degrees below zero); the highest in 1901 (103 degrees). The greatest number of thunderstorms for any one year took place in 1905 when we had 51. As late as 1909 the heaviest snowfall ever recorded at this station, amounting to 21 inches, occurred. And just a few weeks ago (April 3rd, 1915) it snowed 19 inches in half as many hours. All these items do not indicate a climate decreasing in virility very swiftly.
But there is more evidence yet that Philadelphia is experiencing the same varieties of weather in about the same proportions. Diaries of observant men running back to 1700 show that almost any kind of memory could be founded on fact, that the same violent changesin temperature, the same deep snows and unseasonable seasons that we endure to-day were noticed then. To quote:
“The whole winter of 1780 was intensely cold. The Delaware was closed from the 1st of December to the 14th of March. The ice was from two to three feet thick.” We despaired of ever living up to this until three years ago when the same thing happened and sleighs crossed the river a little above the city. And despite the new ice-boats!
“The winter of 1779 was very mild, particularly the month of February when trees were in blossom.”
“On the 31st of December, 1764, the Delaware was frozen completely over in one night, and the weather continued cold until the 28th of March with snow about two and a half feet deep.”
“The winter of 1756 was very mild. The first snow was as late as the 18th of March.”
And so it goes. 1750 was mild; 1742 “one of the coldest since the settlement of the country”; 1741 was intensely cold, 1725 mild, 1714 very mild after the 15th of January, 1697 long, stormy and severely cold. The upshot of it all is that February violets and April snowswere just as well known to General Washington as they are to us.
NIMBUS
Courtesy of Richard F. Warren
Nimbus is any cloud from which rain is falling, and the important thing to know is how to judge from the formless thing how much longer it is to rain. The wind is the surest guide. In this picture the nimbus cloud is only that at the end of the cape. All the rest is torn stratus and cumulus, which needs to condense a little further before it becomes nimbus. This will likely happen because the cloud at the left is very dark. The broken appearance denotes some wind. Rain does not fall from a mottled sky nor yet a streaky one; the nimbus is uniform in appearance. In summer a break in the nimbus will show a veil of cirro-stratus above. Just nimbus by itself will not support much of a storm. In winter if the nimbus is particularly seamless snow is about to fall.
But though all facts point to the fact that the climate does not change in a decade or a generation or a dozen generations, there is some comfort for those who are not satisfied in knowing that it doesn’t stay the same forever. During the carboniferous times the poles were as warm as the tropics and when the Ice Age came on it was very chilly everywhere. If one might only live an eon or two he might then well complain of the changing climate.
Climate, however, is one thing, weather another. The climate is the sum total of the weather. Climate is as enduring as our Constitution, the weather is as changeable as our city governments. No matter how proud a scientist may be of the lasting qualities of the climate, he has to admit that our weather, taken day by day or even year by year, is versatile in the extreme. And the question he has set himself to solve is how to explain the variations of the seasonable weather. He wants to find out why all winters are not alike, and why no two successive springs are the same. Then he will be on firm ground at last and able to make scientific forecasts for the ensuing year.
The obvious thing was to find out as accurately as possible what had happened and science’s keenest eye was focused on records in the hope of discovering fixed periods of warmth or wetness, cycles of cold and drought. So far no cycles have been discovered that are beyond dispute. Nothing has been found that cannot be contradicted successfully. This is discouraging.
One of the most frequent starting places for investigators is the spots on the sun. They found that periods of three, eight, eleven, and thirty-five years should bear some resemblance; 1901 was eagerly looked forward to. They wanted it to correspond with the remarkably cool summer of 1867. When it started off in July with a temperature of 103 degrees, the highest ever recorded in Philadelphia, they concluded that the sunspots were fooling them. A connection between sunspots and weather has not been established, therefore, although they are now known to affect the electrical condition of the earth’s atmosphere. Longer periods of observation will permit comparisons that may yet define concurrent cycles of sunspots and weather.
A definite weather cycle has not yet been discovered, but one step in the way has been clearedup. We now are pretty sure of one cause for unusual single seasons of heat and cold.
There exist in winter great bodies of cold, dry air heaped up over Canada and Siberia, which are formed by the greater rapidity of radiation over land surfaces than over water. These mounds of cold air build up during December, January, and February and form great so-called permanent areas of high barometer. It is on the skirts of the Canadian high that the smaller highs form which sweep over our country, giving us our cold waves. Also in winter permanent lows form over the North Pacific and North Atlantic where warm currents afford continuous supplies of warm moist air. From the great Aleutian (Pacific) low spring most of the cyclones which swing down below the border of the Canadian high, make their turn somewhere in the Mississippi Valley, and then head for the Icelandic low.
It can be seen that if the Canadian high is a little stronger than usual and spreads a little farther south, then the northern half of our country will come more directly under its influence and we will experience an unusually severe winter. As the storms are pushed south and as the cold air pours into the northern quadrantsthe snow line is pushed south too. Hence all abnormally snowy winters are caused by a strengthening of the permanent Canadian high which may be central anywhere north of our Dakota or Montana borders.
Conversely, if this high is weaker than usual the cyclones can cross the country on a line farther north, there will be less snow, and the cold waves that follow will be less severe or even non-existent.
In summer the reverse occurs. Great oceanic highs are built up over the South Atlantic and South Pacific and a permanent low occupies the center of our continent. The character of the season is determined by the strength and position of these areas. The eastern states are affected especially by the slow movements of the South Atlantic low. The puzzle is why should these areas change their power and position, and if they must change why don’t they do it regularly? The puzzle will undoubtedly be solved. These great centers of action will be plotted against and observed from every vantage point by a thousand observers. A fascinating field for scientific speculation opens.
At present our Government exchanges daily observations with stations in Siberia, Canada, and the West Indies. The great storm-breeder,the Aleutian Low, is watched from Alaskan shores. In the Atlantic the Bureau needs stationary ships to record the growth and decline of the High over the Azores. Knowledge of the wind circulation from this would inform us whether our storms were to be shunted farther north and pushed somewhat inland. A storm which is pushed to the left of its normal track increases tremendously in intensity. Whereas a cyclone that limps slackly to the right of its normal line loses intensity at once. It misses coil. In this respect storms seem to resemble rattlesnakes.
The energy of the Azores High influences the number and destructiveness of the West Indian hurricanes: the larger the area is the closer do the hurricanes hug our shores and the more destruction do they accomplish.
The very sureness that the general average of the seasons is to be the same enables us to guess pretty accurately for individual purposes as to the kind of season coming next. A guess, let me add, is not a forecast. It is a gamble and disapproved of by the Bureau, but until they supply us with a basis for judgment we will have to go on guessing, for human curiosity is as near to perpetual motion as the weather is to the lacking fourth dimension.
One of these guesses is that if the winter has been a warm one the summer will be cool, for the very good reason that the yearly average does depart so slightly from the fixture. Unfortunately one hot summer does not mean that the following summer will be cool. Certain sequences of the seasons have been observed often enough to have been gathered into proverbs. Everybody agrees that “A late spring never deceives.” “A year of snow, Fruit will grow.” “A green winter makes a full churchyard.”
Of the many hundreds of proverbs relating to the seasons a few are sage, some outworn, and many sheer nonsense. Nearly all refer to the obvious fact that one kind of season is followed by another rather unlike it, not much telling what. And there, unsatisfactorily enough, they leave one. But much is to be hoped for from the scientific explorations now in progress. And until they are heard from few of us will realize how many seasonable seasons we really enjoy.
THE WEATHER BUREAU
Atthe cost of a cent and a half a year apiece we Americans are supplied with detailed information in advance about the weather. And the information is correct for more than four-fifths of the time. If stock brokers never missed oftener, what reputations would accrue!
Cheapness, accuracy, and a certain modesty are the three qualities that distinguish the out-givings of the Bureau from the old-fashioned predictions of the weather which used to appear in almanacs. Almanacs have probably kept appearing ever since the art of printing first allowed unscrupulous persons to juggle with words. They cost fifty cents and their predictions were based on nothing but the strength of their author’s imagination. Of course, it was impossible for him to guess wrong more than half the time so that when he announced in January that July would be hot with thunderstormshe was often right. This gave him prestige, but aided his clients little.
The Weather Bureau was in about the same position in regard to the quack predictions of the almanacs as was the honest doctor of the last decade who could only prescribe good food and fresh air and moderate exercise for the patient who much preferred the expensive allurements of the medicinal cure-all as advertised. In humility the Bureau said that as things stood it could not forecast with accuracy for more than 48 hours, and its honesty brought it into disregard.
But, although the Weather Bureau,—like the Christian Church and other things that have had to combat superstition at every step—has grown slowly it has grown surely and its work is being recognized more widely and relied upon more understandingly every month. It was an American scientist who discovered the rotary motion of cyclones and their progressive character, but due to the conservative nature of our Government three other nations had established weather services before we had. In 1870 the War Department was authorized to start a system of observations that would permit of a rough sort of forecasting. The forecasts proved of so much value to shippers and sailorsthat the work was handed over to the Department of Agriculture and enlarged (1891). To-day every part of our country contributes to the knowledge of existing weather conditions.
At 8A. M.observations are made at hundreds of stations and wired to the Central Office at Washington. The Chief there, knowing these conditions, is enabled to locate a storm, to gauge its rate of speed, to learn its course, and to measure its intensity. He can dictate storm warnings and be sure that within an hour every sailing master will have a copy. He can detect a cold wave at its entrance into our territory and know that within an hour every shipper, every truckster (who has signified that he wishes to be informed) will have the facts that will save him money.
At 8P. M.the same stations telegraph the changed conditions, and if any very violent disturbance is in progress an observation is made at noon. Besides the Washington distributing station there are 1700 others from which warnings are sent by telegraph, telephone, or mail. There are 100,000 addresses on the mailing list and 5,000,000 telephone subscribers can get them within an hour. The newspapers reach many millions. And all this at a cost of 1½ cents a year. If we, in a fit of generosity,should pay 2 cents, or even 2½ the Government would be enabled to work out many of the larger problems awaiting only a larger appropriation to be attacked.
The people’s investment of $1,600,000 a year is a good investment. In one year the Service saves a great many hundred per cent. A few known savings are worth giving; $3,500,000 worth of protection was made possible from one exceptionally severe cold wave; the California citrus growers estimated that one warning saved $14,000,000 worth of fruit; $30,000,000 of shipping (and cargoes) was known to have been detained in port just on account of one hurricane warning, and there are many warnings of gales every year. Uncalculated savings have been effected among the growers of tobacco, sugar, cranberries, truck. The railway and transportation companies save, through use of the forecasts, in shipments of bananas, oysters, fish, and eggs. Farmers, manufacturers, raisin driers, photographers, insurance companies, and about a hundred and fifty other occupations increase their profits by a systematic study of the forecasts.
The people who live along the rivers often owe their lives and frequently much of their property to telephone warnings of approachingfloods. The flood stages in all the principal rivers and streams have been calculated and losses are reduced by 75 per cent. by accurate predictions as to when the crest of the flood may be expected and how high it will reach. A hundred uses of river forecasts, even when flood stages are not expected are given in the booklet, “The Weather Bureau” which you can have from Washington for the asking, like many another of their publications.
Yet, with all the good it does, the man on the street still regards the Bureau as an uninteresting, undependable exhibit in the upper corner of the newspaper,—if he regards it at all. It is his child, however, who is instructing him. For his child is being taught in the public school all about it and he takes his teaching home and becomes the teacher. The child is father of the (old) man in lots of instances.
The most impressive thing about the whole output of the Bureau to the child is its Map. The Bureau issues a map every day which is posted in post-offices and railroad stations and in schools, too, if they ask for it. And every day this map shows in all its gripping details the way our storms are sidling across the continent or rushing up our coasts. It prints the word low where the stormy area of low barometer is.About the low run continuous black lines numbered 29.7, 29.8, 29.9, etc., which show where in the country the pressures are the same.
As the numbers run up to 30.0, 30.1, 30.2 they begin to circle about the word High which denotes where the pressure is highest. Little circles will be observed on the map. Some are clear, indicating clear weather; others are half clear, half black, indicating partly cloudy conditions; others are all black, showing clouds; others have R. or S. inside them, telling where it is raining. The numbers under the circles show how much it has rained or snowed and the numbers under the other numbers are the velocities of the winds. The arrows through the circles fly with the wind. A little zig-zag locates each thunderstorm and the shaded portions show over what portions of the country it has rained during the last 24 hours. As an intelligent puzzle picture the map is unequaled and no wonder the child likes it.
With this map you can tell at a glance what the weather is doing to your uncle in Tacoma and to your cousin in Missouri. With two successive maps you can find out about how fast the storms are traveling, in what direction, and how low the temperatures are under their influence,and so estimate for yourself the weather for the next three days.
Besides the invaluable daily weather map the Bureau issues many other maps that present the phenomena of the week, the month, and the season in graphic form. Masters of vessels are now coöperating with the government to provide observations at sea, and both on our northwest and southeast coasts such information is very valuable. In the west several hundreds of stations are maintained in the mountains for the purpose of obtaining the depth and content of the great snowfalls there. Estimates can then be given out as to the amount of water to be available for irrigating purposes. In addition to the 220 stations of the first class there are 4200 coöperative stations at which observations are made and mailed to 44 centers for distribution.
Special local data help to establish the relations between climate and forestry, agriculture, water resources, and allied subjects. Many bulletins are compiled by experts in their respective lines and these are for free distribution. A study of forest cover is being made in Colorado and the effects of denudation on the flow of streams will soon be scientifically established.As soon as practicable the Bureau hopes to extend its period of forecasting. Weekly forecasts have been tried in a general way with success, but long-range forecasting depends upon so many relationships of the air that present knowledge and facilities do not warrant its adoption.
A CHAPTER OF EXPLOSIONS
Inthe good old times when a man was born, spent his life, and died in the same village the weather proverb was fashioned. Generations had watched the clouds gather under certain circumstances and scatter under certain others and they naturally drew conclusions. These conclusions crystallized until they resembled nuggets of golden weather wisdom. Some were even used as charms. And all contained a deal of truth so long as they were only meant to refer to the country in which they had originated.
But nowadays when the very idea of remaining in the same place for very long at a time is obnoxious the weather proverb suffers. It suffers chiefly by transportation. The weather in County Cork is so very different from the weather that makes Chicago famous that the same weather lore does not fit. Yet it is often applied. The old truths, treasured in picturesque phrase and jingle, were brought over theocean unchanged and made to do duty,—a case of new wine in old bottles again, for a gentle old Irish proverb splits up the back when it tries to accommodate itself to a week of our reckless but magnificent weather.
Fairy stories are jewels to be cherished. And it is a careless and unimaginative race that perpetuates no legends. Even old saws are quaint and should be preserved: “See a pin and pick it up, all the day you’ll have good luck.” Let that sort of thing go on because it adds richness to our conversation. But if a thousand men, after having picked up their morning pins, sat around waiting for the ensuing luck the progress of scientific business management would be halted. And precisely that way is the knowledge of ordinary weather facts halted,—a full-grown superstition sits in the path. Instead of relying upon their eyes the majority of people rely upon a bit of doggerel. For example, millions of people firmly believe that the ground-hog is a key to the weather. They say that if the ground-hog does not see his shadow on the 2nd of February that winter is over!
This is the sort of thing that obscures the findings of science not to mention common-sense. Few of these people have ever seen a ground-hog.Few of the rest have ever studied its habits. The ant, the mouse, the fly, the rat, and the mosquito have far more influence upon our lives than the ground-hog has and the most ambitious animal cannot expect to influence atmospheric pressure, which is responsible for our weather. Yet as often as the 2nd of February comes around the hopes of many are either dashed or raised according to the actions of this creature. As a matter of fact, whether February 2nd is clear or cloudy can have no influence on the rest of the winter.
Almost all the other proverbs have a basis of reason. But this puts its believers in the wrong either way. If they say that it is the actions of the animal that they rely upon they depend upon a characteristic thoroughly and surely disproved. No animal, although it may sense a change in the weather a few hours in advance, is able to feel it for three days ahead to say nothing of six weeks. If these people say, on the other hand, that a cloudy February 2nd means an immediate and complete let up of winter, or that a clear February 2nd means a certain continuance of cold weather for six weeks, they have only to trouble themselves to look at the files of the nearest Weather Bureau for the last forty years. They will find no connection. The trouble isthat they will not look, but keep on repeating the bit of nonsense and believing in it, although the strength of their convictions probably does not reduce their coal-bills.
The same people are fond of saying that the first three days of December show what the winter will be like. That is, if the 1st is fair so will December be; if the 2nd is cold so will January be; and if it snows on the 3rd, so will it snow in February. If all three should be clear and warm certainly a remarkable winter would follow! No rain, no snow, no cold! You see how absurd this superstition is.
“A dry moon lies on its back!” After the ground-hog the moon is supposed to have the most influence on our seasons. The Government and many scientists connected with no governments have made careful, exhaustive and conclusive investigations. No relation between the moon and our weather has been discovered except as she causes our tides and they affect atmospheric pressure in an infinitesimal degree. We would still have just as much and just as variable weather if there were no moon. The weather changes with the changing moon, and it does not change as the moon changes, and the chances are about even that the times of change will coincide. So there is, therefore, absolutelyno foundation for the dozens of proverbs that yoke the changes of the moon with the changes of our weather. Neither in science nor in observation has any sequence been deduced.
So the moon may lie on its back or on its side or stand on its head and the weather will remain dry if no low pressure areas cross the country, and it can lie on its back for days and the country be drowned out if they do. There are enough pretty things to say about the moon, anyway, and will be more all the time for, to commit a paraphrase: Science is stranger than superstition.
“It will rain for forty days straight if it rains on St. Swithin’s Day,” which, I might as well say for the benefit of those who don’t know their saints, falls on July 15th every year. It would be interesting to know how many people in a hundred really believe this, or really believe all the other things that are attributed to the saints,—quite a few, probably. Luckily for St. Swithin July and August are wet months, with often several days of showers or thunderstorms in succession. But never once in Philadelphia has it rained for forty days, one right after another, although half the July 15ths have been rained on. This proverb is one of those that had better never been transplanted from itsnative Ireland where rain for 40 days would excite scarcely a curse.
“Long and loud singing of robins denotes rain.” It does not. Oftener than not it denotes the time of day. Just watch the robins and listen to them and see what they do before a storm, during it, after it, and then you will see how little the songs of birds can be depended upon to supplant the barometer.
“If March comes in like a lion it will go out like a lamb,” and the other way round. I have seen March come in like a lion and go out like a lion, come in like a lion and go out like a lamb, come in like a lamb and go out like a lion, and come in like a lamb and go out like a Noah’s ark. But I never have seen March do anything dependable. It is quite impossible to tell how March is going out on March 27th, and absolutely impossible to tell on March 1st.
But there is this much observation expressed in the proverb, that March is so changeable that, if it comes in cold, windy, unsettled, there is not so much chance for such weather still to be going on at the end of the month, and still less in England where the proverb came from. This is a harmless proverb unless it should lead people to actually count upon a pleasant spring just because March had an unpleasant inception.Misfortunes rarely come singly, even on the weather calendar.
“When squirrels are scarce in autumn the winter will be severe.” Aside from the scientific truth that the animals cannot know in advance about the seasons there is little evidence on either side to base a contention. Nobody has made a squirrel census; nobody, probably, has found out whether they increase in numbers for six years and then die off in great quantities as do the rabbits in the north country on the seventh; nobody has connected their apparent numbers year after year with the actual severities of the winters. And so nobody has a right to promulgate the report (except as a bit of nonsense like April Fool) that the ensuing winter is going to be a record breaker because the squirrels have disappeared. It would be far truer to say that “When squirrels are scarce in autumn the hunters have been busy,” and let it go at that.
There are a lot of proverbs in this connection about goose bones and hickory nuts and wild geese, which sound plausible but are never proved. If the birds have all the sense credited to them it is strange that some allow themselves to be caught by an early snowstorm in the fall and decimated. Also it is not uncommon forearly migrations in the spring to arrive in the north to be slain by the thousand by a belated blizzard. It is granted that animals and birds, having a far greater sensitiveness than man, occasionally sense a catastrophe some hours before it is evidenced by any visual signs, but seasonal wisdom has not been proved in any one instance and disproved in many. None of the proverbs relating to the animals and birds are to be depended upon. They deceive, much to the regret of all the meteorologists who would welcome any genuine clue to nature of the coming season. Any farmer would be only too glad to keep a menagerie of squirrels and wild geese and toads if only he might be assured by them of the coming seasonal conditions.
The proverbs given indicate the range, possibly, but certainly not the full absurdity of the old weather sayings. There are many other proverbs that contain at least a half truth.
“Enough blue sky to make a Dutchman’s breeches indicates clearing,” is one that is true if the wind has changed to the west. If the wind still blows from an easterly quarter blue sky for a Dutchman’s whole wardrobe would not insure clear weather. All sayings must be tested many times before they are believed implicitly.
“There is always a thaw in January,” isabout as true a generalization as can be made about things for which generalizations are never strictly in place. Even in Canada the severity of the winter is often broken by a spell of warmer weather with a rain, perhaps, in the dead of winter. In the United States a winter without some break in each of the months would be a most unusual occurrence. So that it is quite reasonable to expect the “January thaw” any time from Christmas until the middle of February.
“A late spring never deceives,” unless it is so very late, like the phenomenal spring of 1907, that the jump is made, perforce, into summer. That is a cruel deception. What is meant of course is that if the freezing weather continues consistently, well past the average, the likelihood of frost-damage to fruit is slight. There is nothing much worse than for the blossoms to be forced by a period of warm weather early, for there is only a slim chance that it will continue past the danger limit. It is surprising how late frost may occur,—the last date for killing frost in Pennsylvania is about May 10th on theaverage, which makes it possible till June.
“The first robins indicate the approach of spring.” But certainly not its arrival.
“If the moon rises clear expect fairweather.” Right; because if it is summer even the eastern horizon would show the humidity necessary enough to cause a thunderstorm, and in winter the cirrus clouds give several hours’ warning. But, again, the wind is the chief factor to be considered.
Proverbs, representing variations of the truth, could be given about every manifestation of the skies as well as about things that were never manifest except in the imagination, for every country has contributed to the volume of weather-lore. But, unfortunately, neither age nor amount of repetition are as good as the truth and they should be discarded if they are false. The way to discard is not to repeat.
The man who desires weather-wisdom should seek it with his eyes. His comparison will be that which he sees with that which he has seen, and he will soon form all the weather axioms he needs for himself. The local Bureau or the Bureau at Washington will answer all his inquiries, cheerfully, promptly, and free of charge. Of course there are things that the Bureau wants to know itself. It is very curious about the higher strata of air. Small balloons have carried very light instruments to an altitude of fifteen miles and brought considerable knowledge to earth,but each bit makes more knowledge imperative.