Vibroplex Telegraph Key

Vibroplex Telegraph Key

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Description (Brief)
Telegraph keys are electrical on-off switches used to send messages in Morse code. Horace G. Martin patented a practical semi-automatic telegraph key in 1903 and his company dominated the market for these devices. Keys like Martin's "Vibroplex" automatically produced rapid Morse codes dots by using a weighted pendulum to quickly make and break contact in the electrical circuit. The operator would make the dashes manually, but could send much faster than with an ordinary key.
Stamped on label: "Trade The Vibroplex Mark / Pat. June 30.03 / Aug.9.04 / Jan.22.07 / Others Pending / Horace G. Martin / New York - U.S.A." and "11875". Faded decorative painted marks on base. A semi-automatic key with switch, two binding posts.
Currently not on view
Object Name
semi-automatic key
telegraph key
Other Terms
date made
ca 1908
Martin, Horace G.
Physical Description
slate (overall material)
metal (overall material)
plastic (overall material)
overall: 2 1/2 in x 3 1/2 in x 8 in; 6.35 cm x 8.89 cm x 20.32 cm
ID Number
catalog number
accession number
Credit Line
from Franklin Wingard
See more items in
Work and Industry: Electricity
Telegraph Keys
Data Source
National Museum of American History
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