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A semaphore telegraph, optical telegraph, shutter telegraph chain, Chappe telegraph, or Napoleonic semaphore is a system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Information is encoded by the position of the mechanical elements; it is read when the shutter is in a fixed position. The system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth century.〔(Chapter 2: Semaphore Signalling ) ISBN 978-0-86341-327-8 ''Communications: an international history of the formative years'' R. W. Burns, 2004〕〔(Telegraph ) Vol 10, ''Encyclopaedia Britannica'', 6th Edition, 1824 pp. 645–651〕〔(Telegraph ), Volume 17 of ''The Edinburgh Encyclopaedia'', pp. 664–667, 1832 David Brewster, ed.〕 They were much faster than post riders for bringing a message over long distances, and also cheaper in their long-term operating costs, once constructed. Semaphore lines were a precursor of the electrical telegraph which would replace them half a century later. The electrical telegraph would in turn be cheaper, faster, and more private. The distance that an optical telegraph can bridge is limited by geography and weather; thus, in practical use, most optical telegraphs used lines of relay stations to bridge longer distances. This also prevented the optical telegraph from crossing long expanses of water, unless a convenient island could be used for a relay station. Modern derivatives of the semaphore system include flag semaphore (a flag relay system) and the heliograph (optical telegraphy using mirror-directed sunlight reflections). ==Etymology== The word ''semaphore'' was coined in 1801 by the French inventor of the semaphore line itself, Claude Chappe.〔''Groundbreaking Scientific Experiments, Inventions & Discoveries of the 18th Century'', Jonathan Shectman, p. 172〕 He composed it from the Greek elements σῆμα (sêma, "sign") and φωρος (phoros, "bearer").〔''Oxford English Dictionary''〕 Chappe also coined the word ''telegraph''. The word ''semaphoric'' was first printed in English in 1808: "The newly constructed Semaphoric telegraphs", referring to the destruction of telegraphs in France.〔''500 Years of New Words'', Bill Sherk〕 The word ''semaphore'' was first printed in English in 1816: "The improved Semaphore has been erected on the top of the Admiralty", referring to the installation of a simpler telegraph invented by Sir Home Popham. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「semaphore line」の詳細全文を読む スポンサード リンク
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