Telegraphy
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Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semap
Replica of a Chappe telegraph on the Litermont near Nalbach, Germany
A section of the Great Wall of China built during the Ming dynasty (1368–1644)
19th-century demonstration of the semaphore
A site in Hammersmith London (UK) where Sir Francis Ronalds constructed the first electric telegraph in 1816
Electrical telegraph
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Electrical telegraphy is point-to-point distance communicating via sending electric signals over wire, a system primarily used from the 1840s until the late 20th century. It was the first electrical t
Telegraphy
…Chappe in the late 18th century. The system was used extensively in France, and European nations occupied by France, during the Napoleonic era. The electric telegraph started to replace the optical telegraph in the mid-19th century. It was first taken up in Britain in the form of the Cooke and Wheatstone telegraph…
Cooke and Wheatstone's five-needle telegraph from 1837
Morse telegraph
Hughes telegraph, an early (1855) teleprinter built by Siemens and Halske
Sömmering's electric telegraph in 1809