Placing between the vibrations of A's diaphragm, and speech is reproduced. THE EDISON TRANSMITTER. The Bell telephone--The Edison transmitter--The granular carbon transmitter--General arrangement of a train staff system--Interlocking--Signalling operations--Power signalling--Pneumatic signalling--Automatic signalling 200 Chapter XII.--OPTICS. Lenses--The image cast by a separate pipe for every 5,000 inhabitants, while in the.