Telegraph Key

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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.
Currently not on view
date made
ca 1870
Charles Williams, Jr.
Physical Description
wood (overall material)
rubber (overall material)
ivory (overall material)
brass (overall material)
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
catalog number
accession number
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Work and Industry: Electricity
Telegraph Keys
Data Source
National Museum of American History