The device presented here is a reproduction of the simple and rudimental carbon transmitter invented by the Englishman David Edward Hughes (1831-1900) who in 1877 had returned to Great Britain from the United States, where he had emigrated.
That device, which caused a sensation and surprise owing to its simplicity and efficacy, is the precursor of the carbon microphones used in the later development of telephone systems, the radio and radiotelephone systems.
The specimen on display in the museum is composed of two small rectangular wooden boards: one horizontal (17 x 8 cm) which is the base, and one vertical (12 x 8 cm) attached to the former and supporting the actual microphone.
This is composed of a small carbon cylinder pointed at both ends and placed vertically so as to touch two other sticks of carbon connected to two clamping screws on the wooden base.
The microphone which acts as a transmitter can thus be connected in series to a battery and to a Bell telephone acting as a receiver. ...continues