The Thermionic Valve of Professor J. H. Fleming—a Piece of Apparatus Capable of Amplifying Sound,with a Demonstration to show the Possibilities of Applying the Thermionic Valve to Aid the Deaf
Free accessMeeting reportFirst published online May, 1922
The Thermionic Valve of Professor J. H. Fleming—a Piece of Apparatus Capable of Amplifying Sound,with a Demonstration to show the Possibilities of Applying the Thermionic Valve to Aid the Deaf