A name applied to the mechanism employed for telegraphing purposes prior to the discovery of the electric telegraph; invented in 1767 by Richard Edgeworth, but first extensively used by the French in 1794, and afterwards adopted by the Admiralty in England; consisted at first of six shutters set in two rotating circular frames, which, by opening and shutting in various ways, were capable of conveying sixty-three distinct signals; these were raised on the tops of wooden towers erected on hills; later a different form was adopted consisting of a mast and two arms worked by winches. The speed at which messages could be transmitted was very great; thus a message could be sent from London to Portsmouth and an answer be received all within 45 seconds. The railway signal now in use is a form of semaphore.
The Nuttall Encyclopædia: Being a Concise and Comprehensive Dictionary of General Knowledge[1] is a late 19th-century encyclopedia, edited by Rev. James Wood, first published in London in 1900 by Frederick Warne & Co Ltd.
WikipediaEditions were recorded for 1920, 1930, 1938 and 1956 and was still being sold in 1966. Editors included G. Elgie Christ and A. L. Hayden for 1930, Lawrence Hawkins Dawson for 1938 and C. M. Prior for 1956.[2]
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