The Sound of Distant Gun fire

Abstract

WITH reference to the letter of Father Schaffers in NATURE of March 10, it is certainly a fact that sounds from moderate distances are heard most plainly when there is a wind reversal at a moderate height and when the upper wind comes from the same direction as the sound. At this place the sound of firing off the east end of the Isle of Wight is heard best when a south wind is blowing over a light wind from some other quarter. As regards conditions when the sound of gun-fire from the Front was heard in this country, I do not altogether agree with what Father Schaffers writes. He says that soundwaves are bent upwards “when temperatures are diminishing and the strength of a head wind is increasing with altitude. The former is at its maximum efficiency in summer, when there is a steep gradient over the surface of the earth; the other is nearly always a characteristic of air-flows, since, as a rule, friction against the soil retards the lower strata”.