High Rates of Ascent of Pilot-Balloons

Abstract

ABNORMAL rates of ascent shown by pilot-balloons have in recent years aroused considerable interest amongst aerologists. These digressions were mostly ascribed to the occurrence of vertical air-currents, but three years ago Wenger (Annalen der Hydrographie, 1917, Hamburg) suggested¹ that, for the greater part, the observations did not permit of such an explanation. He advanced the theory that these abnormal rates were chiefly caused by increased turbulence of the air, and he stated, making use of the Lindenberg material, that the rates observed depended on different conditions, of the air, as wind, friction, etc., which, no doubt, must have a notable influence on its turbulence.