Description

This transmitter consists of a rectangular wooden box with a concave bowl-shaped mouthpiece centered on the front panel. The mouthpiece ends in a circular opening through which the instruments diaphragm is visible. There is a metal keyhole to the right of the mouthpiece. There are two binding posts on the top of the instrument, and three binding posts on the bottom. There is a metal hook on one side of the box which was used to hang the telephone receiver. Serial number 422499.

This type of transmitter was developed by the American inventor Francis Blake, Jr., who developed a carbon microphone that could convert sound into electrical signals that could ten be transmitted over a long distance. Blake sold his invention to the Bell Telephone Company, and also took on a job at Bell Telephone to continue work on his transmitter. Along with Emile Berliner, the two perfected a transmitter that allowed Bell to manufacture a commercially viable telephone system. This type of transmitter was used on virtually every Bell telephone throughout the 1880s.

Type

inscription

Location

front of wooden box

Method

engraved

Text

Property of the American Bell Telephone Co., Manufactured under patents of Bell Berliner, Edison, Blake // Blake Transmitter 422499 Edison Carbon Telephone