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Telegraph Sounder and Relay
Telegraph Sounder and Relay
The Smithsonian catalogs Telegraph Sounder and Relay as telegraph relay in its Communication, telegraph records.
WHY IT’S INTERESTING
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 “cl