Flame-proof Telegraph Key

Flame-proof Telegraph Key

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Description (Brief)
Telegraph keys are electrical on-off switches used to send messages in Morse code and can spark when the circuit opens. Flame-proof telegraph keys, like this one made by L. S. Brach Company, were designed to contain the spark within a sealed chamber. These keys were necessary on early aircraft and in confined spaces such as aboard ships and submarines where the spark might ignite flammable gasses.
Currently not on view
Object Name
telegraph key
Other Terms
telegraph key; Radio
date made
L. S. Brach Manufacturing Co.
Physical Description
black (base color)
bakelite (overall material)
metal (overall material)
rubber (overall material)
overall: 2 1/2 in x 3 3/4 in x 7 1/2 in; 6.35 cm x 9.525 cm x 19.05 cm
ID Number
catalog number
accession number
collector/donor number
Credit Line
from the United States Bureau of Standards, Dept. of Commerce
See more items in
Work and Industry: Electricity
Telegraph Keys
Data Source
National Museum of American History
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