Experimental microphone in sound box, 1878-1890

PART OF:
Experimental wood-charcoal microphones, 1878-1890
Made:
1878-1890 in England
maker:
David Edward Hughes

Experimental microphone in sound box, consisting of two small blocks of wood-charcoal pressed upon each other by a spring, probably made by David Hughes, England, 1878-1890.

The development of the microphone owes much to David Edward Hughes (1831-1901). Building on the work of Willoughby Smith and Sir William Thomson, Hughes attempted to detect changes in the resistance of wire with sound. He discovered that these changes occurred only when his stretched test wire broke and when he touched the ends together. He found that light but constant pressure was the only essential and that pieces of carbon in light contact worked best. Hughes did not patent his discoveries, meaning that subsequent inventors were able to make use of them without giving Hughes the credit.

Details

Category:
Telecommunications
Object Number:
1922-142/2
Materials:
wood (unidentified), brass (copper, zinc alloy), wax, paper (fibre product) and carbon
Measurements:
overall: 50 mm x 100 mm x 100 mm, .04 kg
type:
microphone
credit:
Executors of the late Anna C. Hughes