Telegraph Sounder
Telegraph Sounder
Usage conditions apply
- 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. The date for US Patent #165156 is stamped on this sounder. That patent was issued to Patrick B. Delany of Jersey City, NJ., on 6 July 1875 for an "Improvement in Automatic Telegraphs." Delany's patent was intended to address the issue of induced currents in a telegraph line that created "false records or signals" by activating the sounder during the pauses between dots and dashes. This became a problem with the adoption of automatic sending devices that could transmit messages faster than human operators.
- Location
- Currently not on view
- Object Name
- telegraph receiver
- telegraph sounder
- date made
- ca 1875
- Physical Description
- wood (overall material)
- brass (overall material)
- rubber (overall material)
- nickle (overall material)
- Measurements
- overall: 3 3/4 in x 3 in x 5 5/8 in; 9.525 cm x 7.62 cm x 14.2875 cm
- ID Number
- EM.332364
- accession number
- 294351
- catalog number
- 332364
- Credit Line
- from Western Union Corporation
- See more items in
- Work and Industry: Electricity
- Communications
- Telegraph Sounders
- Data Source
- National Museum of American History
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