Telegraph Key

Description (Brief)
Telegraph keys are electrical switches used to send coded messages that travel as a series of electrical pulses through a wire. Due to special difficulties in sending pulses through long underwater cables, so-called double-current keys were used. Instead of the short dots and long dashes of land-line telegraphs, submarine telegraphs sent positive pulses and negative pulses that made the receiver move right or left. The operator pressed one lever on the key to send a positive pulse and another to send a negative pulse. The code consisted of the sequence of left and right movements recorded on a paper tape.
Location
Currently not on view
date made
ca 1870
maker
Charles Williams, Jr.
Physical Description
wood (overall material)
rubber (overall material)
ivory (overall material)
brass (overall material)
Measurements
overall: 3 1/2 in x 7 in x 8 3/4 in; 8.89 cm x 17.78 cm x 22.225 cm
ID Number
EM*181671
catalog number
181671
accession number
32985
See more items in
Work and Industry: Electricity
Communications
Telegraph Keys
Data Source
National Museum of American History, Kenneth E. Behring Center

Comments

Add a comment about this object