Telegraph Sounder and Speaking Telephone

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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. Inventor Amos Dolbear, known for his early experiments in telephony, made this patent model of a combination device that worked both as a telegraph sounder and a telephone receiver.
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Work and Industry: Electricity
Telegraph Sounders
ID Number
catalog number
accession number
patent number
Dolbear, Amos E.
Physical Description
wood (overall material)
metal (overall material)
rubber (overall material)
cloth (overall material)
overall: 4 1/4 in x 4 1/2 in x 4 1/4 in; 10.795 cm x 11.43 cm x 10.795 cm
National Museum of American History
Object Name
patent model
telegraph receiver
telegraph sounder