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. One knob is missing from this specimen.
Currently not on view
date made
ca 1890
Western Electric
Physical Description
brass (overall material)
metal (overall material)
plastic (overall material)
overall: 2 1/4 in x 2 3/4 in x 5 3/8 in; 5.715 cm x 6.985 cm x 13.6525 cm
ID Number
accession number
collector/donor number
catalog number
Credit Line
from Western Union Corporation
See more items in
Work and Industry: Electricity
Telegraph Keys
Data Source
National Museum of American History


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