PRECIPITATING CLOUDS.

Shannon News, 13 April 1923, Page 2

PRECIPITATING CLOUDS.

Bain can be had wherever it. may be « wanted, according to an announcement * made by experimenters in the Army Air. Service at Dayton, Ohio, says the New York correspondent of the London “ Times.” Under the direction 01 Professor Bancroft, of Cornell University, and a fellow scientist, Mr. Francis Warren, they have been making rain with sand electrically charged and dropped from aeroplanes into clouds. The results are described by observers as “ absolutely uncanny.”

The experiments have been made over ’a period of several months with the primary object of dissipating fogs over flying fields. An aeroplane, moif ing- 100 miles an hour 500 ft. over/the top of clouds, scattered with the propeller particles of sand charged with 10,000 volts, or about six ten-thou-sandths of an .electric static unit, per grain. The time, required t.o precipitate the moisture and destroy the clouds rarely exceeded 10 minutes.

The clouds varied from several t housand feet to several miles in length and breadth, and the thickness from 500 ft. .to 1500 ft., and the experiments were invariably successful, though in the case of very thin clouds the moisture disappeared by evaporation before. reaching the ground. According to Mr. Warren, the .electric charge diminishes the surface tension of the drops of moisture, and this facilitates coalescence and condensation.