THE problem of the elimination of the interference caused to broadcast reception by electrical machines and apparatus is of widespread interest and is being studied in many countries. A Conference has been held in Paris recently under the auspices of the Electrotechnical Commission, at which representatives of various international electrical and broadcasting organisations were present. A brief report of the results of this Conference is given in World Radio of July 13. It was agreed that no protection need be considered at the present time for the case of a wanted signal strength of less than 1 millivolt per metre, and that the interference should be considered relative to a signal carrier wave of this intensity, modulated to a mean depth of 20 per cent. Under these conditions it was considered desirable, if reception free from interference is to be obtained, that the level of the interference field should be 40 db. below that of the wanted signal. At the present time, it would appear to be difficult and premature to fix a definite, practical value applicable to electrical installations, until further experimental data on this aspect of the problem have been obtained.