Selective Interruption of Molecular Oscillation

Abstract

In NATURE of July 22, 1922, vol. no, p. 112, correspondence occurred regarding the possibility of selectively interrupting haphazard molecular oscillation by means of special apparatus, narrower in certain specific directions than the mean free path of the gas in which it was immersed. In view of the fact that such methods have now been independently put forward by Mr. H. H. Platt in America (U.S.A. Patent, 1,414,895), the following aspect of the problem may be of interest, particularly since the possibility would appear to be rendered very much more clear by so regarding it. Fig. 1 represents a portion of a cone longer than that previously considered, its diameter, however, still being considerably less than the mean free path of the gas concerned, so that molecules of the latter may frequently cross from side to side without intermolecular interruption.