Chester telegraph relay

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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.
This relay was made by the firm of Charles T. and John N. Chester, two brothers who successfully partnered in New York City. Charles (1826-1880) founded the firm and provided the expert telegraphy knowledge while John (1820-1871) kept the books and managed the business operations. Donated to the Smithsonian in 1905, the relay is in poor condition and the lever arm or tensioning arm may not be original to the piece. The oddly-shaped hammer head does not seem to be correct for the contacts on the arm.
Currently not on view
date made
ca 1860
Chester, Charles T.
Physical Description
marble (overall material)
brass (overall material)
steel (overall material)
plastic (overall material)
silk (overall material)
overall: 3 in x 8 5/8 in x 5 5/8 in; 7.62 cm x 21.9075 cm x 14.2875 cm
ID Number
catalog number
accession number
Credit Line
from William A. Glassford
See more items in
Work and Industry: Electricity
Telegraph Relays & Repeaters
Data Source
National Museum of American History


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