Telegraph Resonator

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Description (Brief)
Telegraph sounders convert electrical pulses into audible sounds and are used to receive Morse code messages. The message travels as a series of electrical pulses through a wire. Short pulses make a dot, slightly longer pulses make a dash. The sequence of dots and dashes represent letters and numbers. The pulses energize the sounder’s electromagnets which move a lever-arm. The arm makes a loud “click” when it strikes a crossbar and the operator translates the pattern of sounds into the original language. A resonator like this was used to amplify the sound, making it easier for an operator to hear his or her own sounder when working in a room filled with these devices. This unit is mounted on a folding stand for the operator's convenience.
Currently not on view
Physical Description
cast iron (overall material)
aluminum (overall material)
wood (overall material)
overall: 13 in x 4 in x 10 in; 33.02 cm x 10.16 cm x 25.4 cm
ID Number
catalog number
accession number
Credit Line
from Foote Pierson & Co.
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Work and Industry: Electricity
Telegraph Sounders
Data Source
National Museum of American History


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