Semi-automatic Telegraph Key

Description (Brief)
Telegraph keys are electrical on-off switches used to send messages in Morse code. A semi-automatic telegraph key like this one allows an operator to send land-line and wireless telegraph messages at a much faster rate than with an ordinary key. The key automatically produces rapid morse code dots by using a weighted pendulum to quickly make and break contact in the electrical circuit. The operator still makes the dashes manually. This key was used by Postal Telegraph operator Bryant W. Fields in the early 1910s.
Currently not on view
Object Name
semi-automatic key
sending key
telegraph key
Physical Description
iron (overall material)
metal (overall material)
plastic (overall material)
cloth (overall material)
overall: 3 in x 2 1/2 in x 7 1/2 in; 7.62 cm x 6.35 cm x 19.05 cm
ID Number
accession number
catalog number
collector/donor number
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Work and Industry: Electricity
Telegraph Keys
Data Source
National Museum of American History, Kenneth E. Behring Center


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