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Show high speed against a head wind meets only with increasing resistance, but when the wind favors, the winged air-man air-man spurns the slow fellow creeping on wheels below. With accelerated speed he passes over mountain an5 sea, and If need be, vaults over clouds. If the aviator Is not content with this speed, he has only to climb to upper levels where the flow of air increases to 30 and even 40 meters per second, and in this stream he would move along with a speed relative rela-tive to the earth of 200 milen per hour. These are not extreme values. In a stiff northwester, which the writer experienced in a flight a considerable time ago, the wind blew for 72 consecutive con-secutive hours 7,563,000 meters, which i3 nearly 30 meters per sscond. ThT3 is equivalent to going 4,700 miles in three days, or twice the distance 'rom Labrador to England. The highest speed of the wind for any single hour was 164,000 meters (102 mil.?s). For a period of about 15 minutes .he rate was about 137 miles per hour, or swifter than the average person can ordinarily comprehend. SOME FACTS ABOUT NAVIGAHONJN THE AIR (By Lieut Elmer E. Adams, U. S. A., A. S.) Editor "Steam Shovel and Dredge": It is admitted without controversy that the nearer we are to the danger line the most fascinating Is the thrill of satisfaction which we experience, hence for the moment the - reader-should reader-should eliminate from his mind the frequent references that are made to the picturesque stunts which so often result in fatalities, as these have no place in actual science of air navigation naviga-tion and ought not be considered even as typical of flying activities now becoming be-coming so general in many portions of the world and which seem to attract at-tract so much attention from the reading public. In a recent flight which nearly touched the altitude record the writer found trade winds moving with a registered velocity of 200 miles an hour. This height, it should be understood, under-stood, was far above the clouds. The physics and chemistry of the atmosphere atmos-phere at great heights are fairly well understood, yet the geography of the air remains an unsurveyed and almost al-most an unknown pathway, but this needed information is gradually being supplied by aerial flights. It is conceded that there are well-marked well-marked areas, levels and zones in what might be termed an ' inverted bowl, and though not visible to us, there are mighty currents of air rushing rush-ing on for miles of space, pressing vertically as well as horizontally. Likewise, there are. vast calm areas, stagnant pools, choppy seas and regions re-gions of 'great violence. The air navigator is just learning that there are numerous layers in the atmosphere, all of which must be patiently pa-tiently studied and explored before airships may travel with greater safety. safe-ty. In flying, men will use the lower strata designated as the cloud levels. Above the clouds are unknown heights which it will be necessary to explore and chart. This is not practical to do by airplanes or dirigibles, sounding sound-ing balloons of the aerographer being required for the task. It might be stated in passing that there can be no geography of the air, for there are no continents, oceans or visible geographical features in this "inverted bowl" called the "sky." We look clear through the atmosphere up into the heavens, and, except for pass-' pass-' ing clouds, we know that there is nothing to be seen. If the density of the atmosphere remained constant it could all be compressed com-pressed into a layer about five miles thick. If this were the case, the highest mountain peaks would stand out in space, piercing the so-called homogeneous atmosphere. But the density decreases with elevation, and when the aviator reaches an altitude of 10,000 meters he is in a medium .which is only about one-third as dense as at the ground. Above this level there are never any clouds. The greatest discovery thus far made in exploring the air is that the atmosphere consists of two thick layers, the lower extending from sea level up to 10,000 meters, in which there is a steady fall of temperature and elevation. This is known as the treposphere. Above this there is no full and up to 20,000 meters, a slight rise. The upper layer is called the stratosphere. In this day of high-powered airplanes air-planes it is possible to rise from the ground to the bottom of the stratosphere, strato-sphere, about six miles, in one hour, but if we wish to explore somewhat higher, say 20 miles, we must install light Instruments on a sounding balloon. bal-loon. The pilot who forces his way at |
