Thermometer Soundings in the High Atmosphere

Abstract

THE project, which was suggested by Le Verrier in 1874, of sending small balloons into the upper atmosphere with registering apparatus has been executed recently by M, Hermite, in Paris, with remarkable, success. No fewer than thirteen small balloons, constructed with paper and varnished with petroleum, were liberated during the last four months of 1892, and penetrated to an altitude of 9000 metres. A paper balloon of 60 cubic metres capacity was sent up on December 7, but exploded at a small distance from the earth. It was therefore resolved to build a balloon of 113 cubic metres capacity in goldbeaters' skin. The launching of this balloon took place on March 21 last, at Vaugirard, with the help of the Aerophytic Union of France, of which I have the honour to be the president. The balloon was filled with 113 cubic metres of coal-gas. Its weight with netting was about fourteen kilograms. It carried in a small basket a Richard registering apparatus for temperature and pressure, and about seven hundred postal-cards, to be liberated by the combustion of a cotton string specially prepared for the purpose. This part of the operation utterly failed. Although the fire was put to both extremities of the string, it was extinguished before all the cards had been sent down, and out of four hundred which were precipitated, no more than five or six were recovered. Thus, the hope of determining the path by dropping such objects from an immense height had proved futile. But the recovery of the balloon at 190 km. from Paris was very easy, and the registering apparatus was returned to its owner in excellent working order. The diagram, which had been traced on the revolving cylinder, has been submitted to a close inspection, of which the results have been published in the Comptes Rendus and L' Aerophile, a new periodical devoted to the study of aeronautics.