Hamilton telegraph repeater patent model

Telegraph repeaters 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, limiting the distance a message could travel. Repeaters remedied that problem by detecting a weak signal and using a local power source to re-energize and re-transmit the signal down the line.
This model was submitted to the U.S. Patent Office by inventor William Hamilton of Albany, New York, along with his patent application. On 12 September 1865, he received patent #49875 for his "Improvement in Telegraphic Repeaters." Hamilton's idea was to improve automatic repeaters that could switch between lines without the aid of an operator. He modified the two sounders by lengthening the lever arms so they could activate a new switch and circuit design. The cylinders represent batteries that may be of the Grove type. Hamilton used real relays and sounders made by A. S. Chubbuck of Utica, NY, on his model.
Currently not on view
Object Name
telegraph relay
telegraph repeater
date made
A. S. Chubbuck
Hamilton, William H.
Physical Description
wood (overall material)
brass (overall material)
copper (overall material)
paper (overall material)
cloth (overall material)
plastic (overall material)
steel (overall material)
silver (overall material)
overall: 3 1/2 in x 11 7/8 in x 7 3/4 in; 8.89 cm x 30.1625 cm x 19.685 cm
ID Number
catalog number
accession number
patent number
Telegraph Relays & Repeaters
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Work and Industry: Electricity
Telegraph Relays & Repeaters
Data Source
National Museum of American History, Kenneth E. Behring Center
Additional Media

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