Sounding Balloons
free, unmanned balloons sent up with selfrecord the conditions of the atmosphere at various heights. Upon reaching the height intended, the common form of minished atmospheric pressure and a parachute is provided for the return of the recording instruments to the earth.
A sounding balloon sent up in Java in the recording instruments to the earth. temperature on record, 113 degrees below zero, Fahrenheit. zero, Fahrenheit. temperature on record, 113 degrees below ous objects found in the heavens next to number of hundreds of thousands. The largest to be seen is the great nebula in has shown the spiral form and has furhas shown the spiral form and has further revealed "knots" or gathering condensations in the arms of the spirals suggestive of new stars in process of formation. It has also been shown by spectrum analysis that the nebula is composed of non-gaseous matter. These discoveries, together with the finding of spiral nebulæ in such vast numbers in the heavens as to indicate the existence of some universal law governing their formation, has led to the proposal of the spiral or planetesimal hypothesis of the solar system. (See PLANETESIMAL HYPOTHESIS.) covered condition in the stellar universe in accordance with which the stars of covered condition in the stellar universe