III — Physical theories of dielectric behavior

IN THE session of the Harvard University insulation conference (see footnote) held under the auspices of the subcommittee on physics, a series of five papers bearing on present physical theories of dielectric behavior was presented. In the first of these, W. F. G. Swann drew a series of analogies amongst the accepted mathematical developments of the theories of steady currents in conducting media, electric induction in non-conducting media, and magnetic conduction in magnetic media. Formal expressions for the fundamental phenomena in these three fields are known to be quite similar. It was shown, however, that there are certain aspects imposed by the restriction to constancy of specific resistance, constancy of permeability, and similar factors, and also by the nature of the mathematical solutions, which raise some question as to the complete accuracy of many accepted relationships. Notably, it is shown that in the general case of simultaneous electric and magnetic fields, it is possible to have at a surface of separation between two media, physical conditions which are not consistent with the usual assumptions made in this case.