RAINFALL AND GUNFIRE.

New Zealand Herald, Volume LVI, Issue 17145, 26 April 1919, Page 2 (Supplement)

RAINFALL AND GUNFIRE.

PREVALENT THEORY REJECTED. Now that the cannonades in France ant! Flanders have ceased, it is possible to discuss the prevalent theory that heavy gunfire produces abnormal rainfalls. The directors of the British and French Meteorological Departments are not among thoso who believe in the gun-fire theory. The latter went very thoroughly into the available data, and declared that the guns at the front had about as muoh effect on rainfall " as a sprat would have in trying to bar the month of the Thames"; while Sir Napier Shaw gives it as his considered opinion that the firing of heavy guns has ! no effect whatever in inducing either ! clouds or rain from them. The natural forces which operate to produce even a 'slight shower, he pointed out, are so j gigantic that the enerev of the biggest bombardment is infinitesimal by comparison. The heat liberated as the result lof a rainfall of only one-tenth of an inch I (over one square mile, he says, is equal j to 10,000,000 horse-power for a period of I thirty minutes. In many civilised countries subject to drought attempts have frequently been made to manufacture rain by means of •heavy and continuous explosions, both on the earth and by moans of balloons filled with explosives in the air; hut thoy have nearly always ended in failure. j To sum up, there is no evidenco that meteorologists would accept in support of 'tho theory that gunfire, howevo; heavy, lis a factor in producing precipitation or lin the formation of cWida; while Uiero 'have been friods during peace times when I rain has fallen as profusely as it has during the late war.