Greeley telegraph relay with key

Greeley telegraph relay with key

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Description
Telegraph relays amplified electrical signals in a telegraph line. Telegraph messages traveled as a series of electrical pulses through a wire from a transmitter to a receiver. Short pulses made a dot, slightly longer pulses a dash. The pulses faded in strength as they traveled through the wire, to the point where the incoming signal was too weak to directly operate a receiving sounder or register. A relay detected a weak signal and used a battery to strengthen the signal so that the receiver would operate.
Location
Currently not on view
Object Name
telegraph combination device
telegraph relay and key
telegraph relay
telegraph key
Other Terms
telegraph combination device; Telegraphy
date made
1883
maker
E. S. Greeley & Company
Physical Description
wood (part: material)
brass (part: material)
plastic (part: material)
steel (part: material)
Measurements
overall: 3 in x 12 3/4 in x 7 1/2 in; 7.62 cm x 32.385 cm x 19.05 cm
ID Number
EM.331828
accession number
294351
catalog number
331828
collector/donor number
100-031
Credit Line
from Western Union Corporation
See more items in
Work and Industry: Electricity
Communications
Data Source
National Museum of American History
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