Complete YourMENTORLIBRARYSUBSCRIPTIONS ALWAYS BEGINWITH THE CURRENT ISSUEThe following numbers of The Mentor Course,already issued, will be sent postpaid at therate of fifteen cents each.SerialNo.1. Beautiful Children in Art2. Makers of American Poetry3. Washington, the Capital4. Beautiful Women in Art5. Romantic Ireland6. Masters of Music7. Natural Wonders of America8. Pictures We Love to Live With9. The Conquest of the Peaks10. Scotland, the Land of Song and Scenery11. Cherubs in Art12. Statues With a Story13. Story of America in Pictures: The Discoverers14. London15. The Story of Panama16. American Birds of Beauty17. Dutch Masterpieces18. Paris, the Incomparable19. Flowers of Decoration20. Makers of American Humor21. American Sea Painters22. Story of America in Pictures: The Explorers23. Sporting Vacations24. Switzerland: The Land of Scenic Splendors25. American Novelists26. American Landscape Painters27. Venice, the Island City28. The Wife in Art29. Great American Inventors30. Furniture and Its Makers31. Spain and Gibraltar32. Historic Spots of America33. Beautiful Buildings of the World34. Game Birds of America35. Story of America in Pictures: The Contest for North America36. Famous American Sculptors37. The Conquest of the Poles38. Napoleon39. The Mediterranean40. Angels in Art41. Famous Composers42. Egypt, the Land of Mystery43. Story of America in Pictures: The Revolution44. Famous English Poets45. Makers of American Art46. The Ruins of Rome47. Makers of Modern Opera48. Durer and Holbein49. Vienna, the Queen City50. Ancient Athens51. The Barbizon Painters52. Abraham Lincoln53. George Washington54. Mexico55. Famous American Women Painters56. The Conquest of the Air57. Court Painters of France58. Holland59. Our Feathered Friends60. Glacier National Park61. Michelangelo62. American Colonial Furniture63. American Wild Flowers64. Gothic Architecture65. The Story of the Rhine66. Shakespeare67. American Mural Painters68. Celebrated Animal Characters69. Japan70. The Story of the French Revolution71. Rugs and Rug Making72. Alaska73. Charles Dickens74. Grecian Masterpieces75. Fathers of the Constitution76. Masters of the Piano77. American Historic Homes78. Beauty Spots of India79. Etchers and Etching80. Oliver Cromwell81. China82. Favorite Trees83. Yellowstone National Park84. Famous Women Writers of England85. Painters of Western Life86. China and Pottery of Our Forefathers87. The Story of The American Railroad88. Butterflies89. The Philippines90. Great Galleries of the World: The Louvre91. William M. Thackeray92. Grand Canyon of Arizona93. Architecture in American Country Homes94. The Story of The Danube95. Animals in Art96. The Holy Land97. John Milton98. Joan Of Arc99. Furniture of the Revolutionary Period100. The Ring of the Nibelung101. The Golden Age of Greece102. Chinese Rugs103. The War of 1812104. Great Galleries of the World: The National Gallery, London105. Masters of the Violin106. American Pioneer Prose Writers107. Old Silver108. Shakespeare's Country109. Historic Gardens of New EnglandNUMBERS TO FOLLOWJuly 15. AMERICAN POETS OF THE SOIL.By Burges Johnson, Associate Professor of Literature, Vassar College.August 1. ARGENTINA.By E. M. Newman, Lecturer and Traveler.
SUBSCRIPTIONS ALWAYS BEGINWITH THE CURRENT ISSUEThe following numbers of The Mentor Course,already issued, will be sent postpaid at therate of fifteen cents each.
SerialNo.
1. Beautiful Children in Art2. Makers of American Poetry3. Washington, the Capital4. Beautiful Women in Art5. Romantic Ireland6. Masters of Music7. Natural Wonders of America8. Pictures We Love to Live With9. The Conquest of the Peaks10. Scotland, the Land of Song and Scenery11. Cherubs in Art12. Statues With a Story13. Story of America in Pictures: The Discoverers14. London15. The Story of Panama16. American Birds of Beauty17. Dutch Masterpieces18. Paris, the Incomparable19. Flowers of Decoration20. Makers of American Humor21. American Sea Painters22. Story of America in Pictures: The Explorers23. Sporting Vacations24. Switzerland: The Land of Scenic Splendors25. American Novelists26. American Landscape Painters27. Venice, the Island City28. The Wife in Art29. Great American Inventors30. Furniture and Its Makers31. Spain and Gibraltar32. Historic Spots of America33. Beautiful Buildings of the World34. Game Birds of America35. Story of America in Pictures: The Contest for North America36. Famous American Sculptors37. The Conquest of the Poles38. Napoleon39. The Mediterranean40. Angels in Art41. Famous Composers42. Egypt, the Land of Mystery43. Story of America in Pictures: The Revolution44. Famous English Poets45. Makers of American Art46. The Ruins of Rome47. Makers of Modern Opera48. Durer and Holbein49. Vienna, the Queen City50. Ancient Athens51. The Barbizon Painters52. Abraham Lincoln53. George Washington54. Mexico55. Famous American Women Painters56. The Conquest of the Air57. Court Painters of France58. Holland59. Our Feathered Friends60. Glacier National Park61. Michelangelo62. American Colonial Furniture63. American Wild Flowers64. Gothic Architecture65. The Story of the Rhine66. Shakespeare67. American Mural Painters68. Celebrated Animal Characters69. Japan70. The Story of the French Revolution71. Rugs and Rug Making72. Alaska73. Charles Dickens74. Grecian Masterpieces75. Fathers of the Constitution76. Masters of the Piano77. American Historic Homes78. Beauty Spots of India79. Etchers and Etching80. Oliver Cromwell81. China82. Favorite Trees83. Yellowstone National Park84. Famous Women Writers of England85. Painters of Western Life86. China and Pottery of Our Forefathers87. The Story of The American Railroad88. Butterflies89. The Philippines90. Great Galleries of the World: The Louvre91. William M. Thackeray92. Grand Canyon of Arizona93. Architecture in American Country Homes94. The Story of The Danube95. Animals in Art96. The Holy Land97. John Milton98. Joan Of Arc99. Furniture of the Revolutionary Period100. The Ring of the Nibelung101. The Golden Age of Greece102. Chinese Rugs103. The War of 1812104. Great Galleries of the World: The National Gallery, London105. Masters of the Violin106. American Pioneer Prose Writers107. Old Silver108. Shakespeare's Country109. Historic Gardens of New England
NUMBERS TO FOLLOW
July 15. AMERICAN POETS OF THE SOIL.By Burges Johnson, Associate Professor of Literature, Vassar College.
August 1. ARGENTINA.By E. M. Newman, Lecturer and Traveler.
Central Office of the United States Weather BureauCENTRAL OFFICE OF THE UNITED STATES WEATHER BUREAU, WASHINGTON, D. C.
P
OSTED up in public offices, in hotel corridors, and other conspicuous places in our cities, the official weather map is a familiar sight. Even more familiar is the official weather forecast, displayed, as a rule, on the first page of the daily newspaper, and sent broadcast over the country on the little brown cards which one may see in the village postoffice as well as in the city drug-store. When a great storm sweeps over land or sea, detailed official reports concerning its progress and characteristics are published in the daily press. When a lawsuit involves a dispute as to the temperature or the state of the sky on a certain day, the official weather records are consulted.
How much do you know about the branch of the national government that is charged with the duty of keeping watch of the weather—recording its vagaries as they occur, and also predicting them, as far as is humanly possible?
Besides its office in Washington, where more than two hundred persons are constantly employed, the Weather Bureau has about two hundred stations, manned by professional meteorologists and observers. One of these will be found in almost every large city, while some are in towns of very modest importance. A regular Weather Bureau station is well worth a visit. The instrumental equipment of these stations is almost superhuman in the accuracy with which it sets down on paper the chronicle of weather happenings from day to day and from moment to moment. Little less marvelous is the system by means of which weather information—past, present and future—is disseminated from these official foci. The postoffice, the telephone, the telegraph (wire and wireless) are all pressed into service to the fullest extent—especially in giving timely notice of approaching storms and other destructive forms of weather. These agencies are supplemented by visible and audible signals, in the shape of flags, lanterns, railway whistles and so forth.
Contrary to popular belief, the Weather Bureau does not exist primarily for the purpose of telling the public (with a considerable margin of uncertainty) whether it will be advisable, on the morrow, to carry an umbrella or wear an overcoat. The important work of the Bureau is twofold. It consists, first, in the prediction of those atmospheric visitations, such as storms, floods, and cold waves, which endanger life and property on a large scale; and, second, in the maintenance of the records that form the basis of climatic statistics. In both these directions the Bureau splendidly justifies its existence.
Our national weather service was founded in 1870, and for twenty years was maintained by the Signal Corps of the Army. In 1890 it was established on the present basis, as the Weather Bureau of the Department of Agriculture.
Most civilized countries possess official services for the observation and prediction of weather, though no other is organized on quite so grandiose a scale as ours. The British Meteorological Office, the Prussian Meteorological Institute, the Central Meteorological Bureau of France, and the Central Physical Observatory of Petrograd are among the leading institutions of this character in the Old World. Admirable weather services also exist in India, Japan, Australia, Canada, Argentina and elsewhere.
PREPARED BY THE EDITORIAL STAFF OF THE MENTOR ASSOCIATIONILLUSTRATION FOR THE MENTOR, VOL. 4, No. 10, SERIAL No. 110COPYRIGHT, 1916, BY THE MENTOR ASSOCIATION, INC.
A Simple Weather StationA SIMPLE WEATHER STATION
T
HE history of meteorological instruments dates back at least as far as the fourth century before the Christian era, when the depth of rainfall was measured in India by some form of gauge. We again hear of rain-gauges being used in Palestine in the first century of the present era. Thermometers with fixed scales were used in Italy in the seventeenth century, and the great Galileo, born in Pisa in 1564, took part in perfecting these instruments. Wind-vanes were known to the ancients. The earliest one of which we have any record surmounted the famous Tower of the Winds at Athens. In the Middle Ages the weathercock became the usual adornment of church steeples. The barometer was invented by Torricelli in 1643.
Most meteorological instruments, however, are of quite recent origin, and this is true especially of these types of apparatus that make automatic records, thus replacing, to a large extent, the human observer.
Our picture on the other side of this sheet shows the instruments used by the "co-operative" observers of the Weather Bureau. These observers, of whom there are about 4,500, well distributed over the country, serve the government without pay, and their painstaking observations have alone made possible a detailed survey of our climate. In the picture we see, on the right, an ordinary rain-gauge, and, on the left, a thermometer-screen containing two thermometers; viz., a maximum thermometer, for recording the highest temperature of the day, and a minimum thermometer, for recording the lowest. The screen, which is of wood, painted white, serves to shield the instruments from the rays of the sun, while permitting free ventilation. Under these conditions the thermometers show the temperature of theair; whereas when exposed to direct sunlight a thermometer shows the temperature acquired by the instrument itself, and this may differ materially from the air temperature.
In contrast to this simple equipment, we find at a regular meteorological station, or observatory, an impressive collection of apparatus for observing and recording nearly all the elements of weather. The pressure of the air is measured by the mercurial barometer, and registered continuously by the barograph; the temperature of the air is automatically recorded by the thermograph. Other self-registering instruments maintain continuous records of the force and direction of the wind, the amount and duration of rainfall, the duration of sunshine, the humidity of the air, etc. There are also instruments for measuring evaporation, the height and movement of clouds, the intensity of solar radiation, the elements of atmospheric electricity, and various other phenomena of the atmosphere.
PREPARED BY THE EDITORIAL STAFF OF THE MENTOR ASSOCIATIONILLUSTRATION FOR THE MENTOR, VOL. 4, No. 10, SERIAL No. 110COPYRIGHT, 1916, BY THE MENTOR ASSOCIATION, INC.
Cumulus CloudA MAJESTIC CUMULUS CLOUD
T
HE International Cloud Classification, now generally used by meteorologists, is an amplification of one introduced by an ingenious English Quaker, Luke Howard, in the year 1803. Howard distinguished seven types of cloud, to which he gave the Latin namescirrus,cumulus,stratus,cirro-cumulus,cirro-stratus,cumulo-stratus, andnimbus. In passing, it may be of interest to note that, a few years after Howard's classification was published, an attempt was made by one Thomas Forster to introduce "popular" equivalents of these terms. Forster proposed to call cirrus "curlcloud," cumulus "stackencloud," stratus "fallcloud," etc. In other words, he assumed that because Howard's names were Latin in form they were unsuitable for use by the layman, and therefore needed to be supplemented by English names—although the proposed substitutes were, on the whole, somewhat longer and more difficult to pronounce than the originals! A parallel undertaking would be an attempt to discourage the public from calling the wind-flower "anemone," or virgin's bower "clematis." Forster's superfluous names have never taken root in our language.
The highest clouds—cirrus and cirro-stratus—are feathery in appearance, and consist of minute crystals of ice. Their altitude above sea-level averages about five miles, but is frequently much greater than this. All other clouds are composed of little drops of water—not hollow vesicles of water, as was once supposed. Neither crystals nor drops actually "float" in the air. They are constantly falling with respect to the air around them, though, as the air itself often has an upward movement, the cloud particles are not always falling with reference to the earth. In any case, their rate of fall depends upon their size, and in the case of the smaller particles is very slow. Under some conditions the particles evaporate before reaching the earth, while under others they maintain a solid or liquid form and constitute rain or snow. A fog is a cloud lying at the earth's surface.
Rainfall is one of the most important elements of climate, chiefly because of its effects upon vegetation. It is measured in terms of the depth of water that would lie on the ground if none of it ran off, soaked in, or evaporated; and this is, in practice, determined by collecting the rain, as it falls, in a suitable receiver, or rain-gauge. Usually the gauge is so shaped as to magnify the actual depth of rainfall, in order to facilitate measurement. Snow is measured in two ways; first, as snow, and, second, in terms of its "water equivalent." The latter measurement is commonly effected by melting the snow and pouring it into the rain-gauge, where it is measured as rain. By this expedient we are enabled to combine measurements of rain and snow, in order to get the total "precipitation" of a place during a given period.
Nature is notoriously partial in her distribution of this valuable element over the earth. A region having an average annual rainfall of less than ten inches is normally a desert, though irrigation or "dry-farming" methods may enable its inhabitants to practice agriculture.
The heaviest average annual rainfall in the United States (not including Alaska) is about 136 inches, in Tillamook County, Oregon. The rainiest meteorological station in the world is Cherrapunji, India, with an average of about 426 inches per annum.[B]
[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 encyclopædias and other reference books.
[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 encyclopædias and other reference books.
PREPARED BY THE EDITORIAL STAFF OF THE MENTOR ASSOCIATIONILLUSTRATION FOR THE MENTOR, VOL. 4, No. 10, SERIAL No. 110COPYRIGHT, 1916, BY THE MENTOR ASSOCIATION, INC.
Monte RosaTHE OBSERVATORY ON MONTE ROSA
T
HE expression used in our title 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 circumpolar zones. Public attention has all too rarely been called to the heroism and self-sacrifice of the men who constitute the staffs of these lonely outposts.
The institution 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 altitudes and various other researches, and is open to thesavantsof 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.
PREPARED BY THE EDITORIAL STAFF OF THE MENTOR ASSOCIATIONILLUSTRATION FOR THE MENTOR, VOL. 4, No. 10, SERIAL No. 110COPYRIGHT, 1916, BY THE MENTOR ASSOCIATION, INC.
Meteorological KiteLAUNCHING A METEOROLOGICAL KITE
M
ETEOROLOGISTS 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 principal 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 altitude.
Captive balloons are sometimes used for similar investigations. When, however, it is desired to attain great altitudes 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 sparsely 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 Godhavn, Greenland, by a Danish exploring expedition reached the unprecedented altitude of more than 24 miles.
PREPARED BY THE EDITORIAL STAFF OF THE MENTOR ASSOCIATIONILLUSTRATION FOR THE MENTOR, VOL. 4, No. 10, SERIAL No. 110COPYRIGHT, 1916, BY THE MENTOR ASSOCIATION, INC.
Snow and IceTHE EFFECTS OF SNOW AND ICE—THE CAMPUS, PRINCETON UNIVERSITY
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 aperennial 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.
PREPARED BY THE EDITORIAL STAFF OF THE MENTOR ASSOCIATIONILLUSTRATION FOR THE MENTOR, VOL. 4, No. 10, SERIAL No. 110COPYRIGHT, 1916, BY THE MENTOR ASSOCIATION, INC.