Early field telephone. Historical artwork of a 19th century field telephone. Telephone technology was developed by Alexander Graham Bell by 1876. It r

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Early field telephone. Historical artwork of a 19th century field telephone. Telephone technology was developed by Alexander Graham Bell by 1876. It revolutionised communications, allowing the direct transmission of voices. It eventually replaced the telegraph, and the use of batteries (centre left) allowed a portable version to be used in the field (usually during a war) if it could be connected by wire to a telephone or telegraphy network. An incoming call triggers the ringing of the bells (lower left), and the headset (upper centre) is used to talk and listen to the caller. From La Telegraphie Historique (Alexis Belloc, 1888).

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Size: 3057px × 3672px
Photo credit: © SHEILA TERRY/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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