The Mentor: The Weather Part 5

[B] This is the latest official record. There are several rain-gauges at Cherrapunji, and the average amount of rain collected by any one of them varies considerably with the length of the record. Hence the widely divergent values of the rainfall at this famous station published in encyclopaedias and other reference books.

[Ill.u.s.tration: THE OBSERVATORY ON MONTE ROSA]

THE OUTPOSTS OF METEOROLOGY

Monograph Number Four in The Mentor Reading Course

The expression used in our t.i.tle seems a fitting one to apply to a number of meteorological observatories and stations maintained for the benefit of science in regions remote from the comforts and conveniences of civilization. Some are on the summits of lofty mountains, the ascent of which is laborious and even perilous. Others are situated in the bleak wildernesses of the circ.u.mpolar zones. Public attention has all too rarely been called to the heroism and self-sacrifice of the men who const.i.tute the staffs of these lonely outposts.

The inst.i.tution shown in our gravure--officially known, in honor of the Dowager Queen of Italy, as the Regina Margherita Observatory--crowns the summit of Monte Rosa, on the northern Italian frontier, and is 14,960 feet above sea-level. It is devoted not only to meteorological investigations, but to studies of the physiological effects of great alt.i.tudes and various other researches, and is open to the _savants_ of all nationalities who are courageous enough to scale the second highest summit of the Alps. It is habitable for only about two months; viz., from the middle of July to the middle of September. Each year a temporary telephone line is constructed connecting the observatory with the plains of Italy. This is the highest telephone line in the world, and its installation is an arduous undertaking. A permanent line is impossible, on account of the shifting of the glaciers and snowfields on which the poles must be erected.

There is also a meteorological observatory on Mont Blanc, but it is not at the summit and is not quite so high as that on Monte Rosa. The solar observatory which once stood at the very top of Mont Blanc no longer exists. The United States Signal Service (now the Weather Bureau) formerly maintained observatories on Pike's Peak (14,134 feet) and Mount Washington (6,280 feet). The loftiest of meteorological stations was, however, that formerly operated by Harvard College Observatory on the summit of El Misti, Peru (19,200 feet).

For a number of years the United States Weather Bureau maintained a large and important observatory at Mount Weather, at the crest of the Blue Ridge, near Bluemont, Virginia. In the Old World one of the most famous of mountain meteorological observatories was that which stood on Ben Nevis (4,406), the highest summit in the British Isles. This was closed in 1904.

If the conditions of life at these high-level stations are such as to repel any but the ardent lover of science, the same is true in even greater measure of those endured by the little band of meteorologists who man the observatory maintained by the government of Argentina at Laurie Island, in the South Orkneys, on the verge of the Antarctic.

Every year a party of four is sent out from Buenos Aires to spend a year of exile in this inhospitable spot, which is generally ice-bound, and has not even wireless communication with the rest of the world. This station has been in operation since 1904. The staff, which is changed each year, has embraced men of several nationalities--Scotch, American and others.

Far within the Arctic Circle two meteorological observatories are maintained in Spitsbergen; but these are, at least, connected with the world by radiotelegraphy.

If the hopes of explorer Peary are accomplished, an observatory will, one of these days, be established at the South Pole.

[Ill.u.s.tration: LAUNCHING A METEOROLOGICAL KITE]

THE AIR ABOVE US

Monograph Number Five in The Mentor Reading Course

Meteorologists are not content to limit their investigations to the stratum of air lying close to the earth's surface. Even before the demands of the aeronaut for information concerning the structure and phenomena of the atmosphere far overhead became pressing, many efforts had been made to secure such information, in view of its important bearing upon many scientific problems. As long ago as the year 1784 a balloonist, equipped with various meteorological instruments, made an ascent from London and brought back an interesting series of observations, which were communicated to the Royal Society. For more than a century the manned balloon was the princ.i.p.al means of sounding the upper atmosphere.

Nowadays, as a rule, the meteorologist, instead of going aloft in person, sends up a kite or a balloon to which are attached automatically registering instruments. When the aerial vehicle returns to earth its record shows in detail the conditions encountered during the journey.

Everybody remembers how Franklin brought lightning from the clouds; but it is a far cry from the simple apparatus that served Franklin's purpose to the "box kite" of modern meteorology. Science has perfected the kite almost beyond recognition. It has been shorn of that crucial feature of the schoolboy article, the tail. Even the kite "string" has become several miles of steel piano wire, wound around the drum of a power-driven winch, with elaborate apparatus for recording the force of the pull, and the angles of azimuth and alt.i.tude.

Captive balloons are sometimes used for similar investigations. When, however, it is desired to attain great alt.i.tudes the meteorologist has recourse to the so-called "sounding-balloon," which is not tethered to the earth. This is usually made of india-rubber, and when launched is inflated to less than its full capacity. As it rises to regions of diminished air pressure it gradually expands, and finally bursts at an elevation approximately determined in advance. A linen cap, serving as a parachute, or sometimes an auxiliary balloon which does not burst, serves to waft the apparatus, with its delicate self-registering instruments, gently to the ground. This commonly happens many miles--sometimes two hundred or more--from the place of ascent. Attached to the apparatus is a ticket offering the finder a reward for its return, and giving instructions as to packing and shipping. Sooner or later it usually comes back; though often months after it falls. Indeed, the large percentage of records recovered, even in spa.r.s.ely settled countries, is not the least remarkable feature of this novel method of research. The instruments attached to sounding-balloons register the temperature of the air, the barometric pressure, and sometimes the humidity.

By means of the sounding-balloon the air is explored to heights of twenty miles and more! The records obtained by means of these balloons have, within the past fifteen years, completely revolutionized our ideas concerning the upper atmosphere.

Still another device employed by meteorologists is the pilot-balloon.

This is also a free balloon, but carries no meteorological instruments.

Its motion in the air is followed by means of a theodolite, and it serves to show the speed and direction of the wind at different levels.

During the winter of 1912-13 a pilot-balloon sent up from G.o.dhavn, Greenland, by a Danish exploring expedition reached the unprecedented alt.i.tude of more than 24 miles.

[Ill.u.s.tration: THE EFFECTS OF SNOW AND ICE--THE CAMPUS, PRINCETON UNIVERSITY]

OUR WINTERS

Monograph Number Six in The Mentor Reading Course

In the year 1781 Thomas Jefferson wrote in his "Notes on Virginia": "A change of climate is taking place very sensibly. *** Snows are less frequent and less deep. They do not often lie below the mountains more than one, two or three days, and very rarely a week. The snows are remembered to have been formerly frequent, deep, and of long continuance. The elderly inform me that the earth used to be covered with snow about three months in every year."

Probably long before the white man came to America the patriarchs of the Indian tribes regaled the young men and maidens gathered about the campfire with reminiscences of the deep snows that prevailed in a previous generation.

In short the "old-fashioned winter" is a _perennial myth_, perpetuated by a familiar process of self-delusion! The occasional periods of abundant snow make a more lasting impression upon our minds than the long intervals in which this element was scarce or lacking. The resulting misconception is promptly dissipated when we consult the weather records, which, in some parts of the country, extend back more than a century, and prove that there has been no actual change in the climate within the period they embrace.

Of course the erroneous idea is, in some cases, due to the fact that one's childhood was spent in a part of the country in which the snowfall is normally heavier than in that where one has recently lived. The average yearly snowfall over the New England States, New York, and the borders of the Great Lakes is from 50 to 100 inches, and upward. Over the North Central States it is much less. In the Southern tier of States and along almost the whole of our Pacific coast snow is a rarity. The heaviest snowfall in this country probably occurs in the high Sierra Nevada of California, near the border of Nevada. In some places in these mountains more than 40 feet of snow falls in an average winter, while more than 65 feet has been recorded in extreme cases. Here it is a common occurrence for one-story houses to be buried, to the eaves, or above. The Southern Pacific Railway, which intersects this region, has built 32 miles of snowsheds, at a cost of $42,000 a mile over single track and $65,000 a mile over double track. In an average year $150,000 is spent on these sheds in upkeep and renewals. Flat-roofed houses are unknown in this vicinity; all roofs are gabled at a sharp angle to shed the snow.

A picturesque feature of our American winters is the "ice storm," so enthusiastically described by Mark Twain:

"... When a leafless tree is clothed with ice from the bottom to the top--ice that is as bright and clear as crystal; when every bough and twig is strung with ice-beads, frozen dew-drops, and the whole tree sparkles cold and white, like the Shah of Persia's diamond plume."

Such is the artist's view of the phenomenon; but, alas! these same ice storms cause endless inconvenience and heavy expense every winter to the electrical industries, by breaking wires.