The Audibility of Thunder

Abstract

FROM reading a recent letter in NATURE (October 16) discussing the distance that thunder can be heard, I am induced to send you the following observation:—On the evening of February 26, 1912, when camped on North Chincha Island (off the west coast of South America), a brilliant display of lightning in the distant high interior to the east attracted our attention. The cloud-stratum from which the storm evidently issued lay far behind the clear coastal zone and the lower foothills, but hid from my camp the upper regions of the Cordillera. Both I and a Peruvian friend heard quite clearly the low distant peals of thunder. As I had been told that thunder was an almost, if not a quite, unknown phenomenon on the coast—this was the first thunderstorm, indeed, that my companion, a man of more than forty years of age, had experienced—I purposely made a record, during the best part of an hour, of the intervals elapsing between the flashes and the peals, and from my journal I find the average to have been 320 seconds.