Chester telegraph relay

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 includes a marble base and was made by Charles T. Chester of New York City. The electromagnet coils are fixed but the steel core can be moved to adjust the strength of the magnetic field.
date made
ca 1860
Chester, Charles T.
Physical Description
brass (overall material)
marble (overall material)
fabric (overall material)
copper (overall material)
overall: 3 1/2 in x 8 3/8 in x 5 3/8 in; 8.89 cm x 21.2725 cm x 13.6525 cm
ID Number
catalog number
accession number
serial number
Credit Line
from Janet Lewis
See more items in
Work and Industry: Electricity
Telegraph Relays & Repeaters
Data Source
National Museum of American History


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