Flow of Smoke through a Hole in a Resonant Cavity

Abstract

F. W. Simpson¹ has described an experiment in which a resonant tube with a small hole in its end is excited in an outer atmosphere of smoke, and points out that smoke can be seen streaming in through the hole. This is the reverse of the effect originally noted by Prof. West², and was described by Lawson³. When West's experiment is performed with a glass tube, smoke can be observed streaming out and fresh air streaming in, apparently continuously.