Telegraph Key
Telegraph Key
Usage conditions apply
- 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
- Object Name
- telegraph key
- cable key
- submarine telegraph key
- date made
- ca 1880
- Physical Description
- brass (overall material)
- metal (overall material)
- plastic (overall material)
- Measurements
- overall: 5 3/4 in x 4 1/4 in x 6 in; 14.605 cm x 10.795 cm x 15.24 cm
- ID Number
- EM.331461
- accession number
- 294351
- catalog number
- 331461
- collector/donor number
- 03-38
- Credit Line
- from Western Union Corporation
- See more items in
- Work and Industry: Electricity
- Communications
- Telegraph Keys
- Data Source
- National Museum of American History
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