Dial telegraph. 19th-century artwork of a dial telegraph. The dial (top) is turned to generate and transmit the telegraph signal for the letter select

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Dial telegraph. 19th-century artwork of a dial telegraph. The dial (top) is turned to generate and transmit the telegraph signal for the letter selected. Several electric telegraph systems were developed from the 1830s and 1840s onwards. This artwork is from 'History, Theory, and Practice of the Electric Telegraph' (1860) by US telegraph engineer George Bartlett Prescott (1830-1894).

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Size: 3706px × 4746px
Photo credit: © KING'S COLLEGE LONDON/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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