12-inch gramophone record of lecture 'Forty Years of BBC Engineering' by Sir Harold Bishop (December 1st, 1970) 12-inch gramophone record of lecture 'Forty Years of BBC Engineering' by Sir Harold Bishop December 1st 1970
Two 12-inch gramophone records of lecture 'The Early days of Broadcasting' by Capt. P.P. Eckersley, with ensuing discussion (February 16th 1960) Two 12-inch gramophone records of lecture 'The Early days of Broadcasting' by Capt. P.P. Eckersley February 16th 1960