GREAT WINDS

Dominion, Volume 22, Issue 75, 21 December 1928, Page 7

GREAT WINDS

ROTATORY ORIGIN

All storms of wind are in their origin rotatory. They revolve round a centre because they are really whirlwinds, says a writer in the Loudon “Spectator.” The centre, or axis, of the storm may not move forward more than ten miles an hour. Twenty miles an hour is quite a high rate of progress. Yet the velocity of tlie wind round tlie continually expanding circumference may be of full-gale force (say, 60 miles an hour), or of the force of a hurricane, typhoon, or tornado, and reach 130 or more miles an hour. North of the equator the storm' revolves against the hands of the clock, and south of the equator in the contrary direction. It was in 1848 that Mr. Piddiugton suggested that the rotatory movement of storms should be signified in the single word “cyclone,” which would cover all the various names for storms. How well his suggestion has succeeded maybe seen from the daily’ weather forecasts, which make us familiar with cyclonic and anti-cyclonic conditions. It was only in modern times that the circular movement of storms became so well understood that seamen learned how to escape from the deadly centre. In the old days a seaman who ran before the storm believed that he was escaping from it, though he may only have been edging gradually into the centre. And if he arrived there he almost certainly did not return to tell the tale. The wind does not blow accurately round the centre, hut lias a spiral inward movement. There is much legend about the centre of the storm, but it is, no doubt, legend based on fact; there is, it is said, a patch of uncanny calm surrounded by squalls from every point of the compass, and the sea at that point is forced'up into a kind of pyramid by tlie outside pressure. The typhoon of the East Indies and the China seas, the tornado, and the simoom, are all different names for much tlie same thing.