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. This British “thumb key” was designed for use on underwater telegraph cables. Typical telegraph keys turn the current on and off in the line. This double-current key keeps the battery on the line and reverses the direction of the current flow when the operator presses down on the lever. Setting the small lever to “receive” sends the current to a separate relay instead of through the main section of the key.
Currently not on view
Physical Description
brass (overall material)
metal (overall material)
plastic (overall material)
wood (overall material)
overall: 3 3/4 in x 4 3/4 in x 8 1/4 in; 9.525 cm x 12.065 cm x 20.955 cm
ID Number
accession number
collector/donor number
catalog number
Credit Line
from Western Union Corporation
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Work and Industry: Electricity
Telegraph Keys
Data Source
National Museum of American History


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