Our country and its resources; . n seventy-five times as attenuated as the bestvacuum obtainable with an ordi-nary mechanical air pump. At 300miles above the earth it is computedto be about one-two-millionth asdense as at sea-level. (>zone, whichoccurs transiently and in smallamounts in the lower atmosphere, isbelieved to be permanently presentand abundant at high levels, whereit is formed from oxygen, probablyunder the influence of ultra-violet The past twenty years have wit-nessed a remarkable development ofupper-air research, or aerology. Up to a height of about four miles theatmosphere
Our country and its resources; . n seventy-five times as attenuated as the bestvacuum obtainable with an ordi-nary mechanical air pump. At 300miles above the earth it is computedto be about one-two-millionth asdense as at sea-level. (>zone, whichoccurs transiently and in smallamounts in the lower atmosphere, isbelieved to be permanently presentand abundant at high levels, whereit is formed from oxygen, probablyunder the influence of ultra-violet The past twenty years have wit-nessed a remarkable development ofupper-air research, or aerology. Up to a height of about four miles theatmosphere has been extensively ex-plored by means of self -registeringmeteorological instruments (mete-orographs) attached to kites—not ofthe schoolboy pattern, but box orcellular kites, the string of whichConsists of several miles of steelwire, wound around the drum of apower-driven winch. Captive bal-loons have also been utilized to someextent. For attaining great alti-tudes, however, free balloons mustbe used. The so-called sounding-. SOUNDING THE UPPER AIRLeft: Launching a pair of Bounding balloons, with self-registering meteorological instru-ments attached. Dpper right: Balloon meteorograph and the protective cage in which it issenl aloft. Lower right: Weather Bureau party making upper air observations. lighl from the sun and of auroraldischarges. The existence in the at-mosphere of a gas unknown to chemists and lighter than hydrogen hasbeen maintained in some quarters(especially by Dr. Alfred Wegener). and it has been named geocoroni-um, or zodiacon. I f present al all,it is presumably the chief constituentof the atmosphere in t he upper levels. balloon, which carries a meteoro-graph, bursts far above the the attached instruments arecarried gently down by a parachute,or an auxiliary balloon. Sounding-balloons rise to various heights upto -!i> miles. Small balloons sent upwithout a meteorograph for the sake of observing thedrift of the air at various l
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1917
