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1868 __ Automatic transmitter
Charles Wheatstone (1802-1875)
Comment : Wheatstone's next great invention was the automatic transmitter, in which the signals of the message are first punched out on a strip of paper, which is then passed through the sending-key, and controls the signal currents. By substituting a mechanism for the hand in sending the message, he was able to telegraph about 100 words a minute, or five times the ordinary rate. In the Postal Telegraph service this apparatus is employed for sending Press telegrams, and it has recently been so much improved, that messages are now sent from London to Bristol at a speed of 600 words a minute, and even of 400 words a minute between London and Aberdeen. On the night of April 8, 1886, when Mr. Gladstone introduced his Bill for Home Rule in Ireland, no fewer than 1,500,000 words were despatched from the central station at St. Martin's-le-Grand by 100 Wheatstone transmitters. Were Mr. Gladstone himself to speak for a whole week, night and day, and with his usual facility, he could hardly surpass this achievement. The plan of sending messages by a running strip of paper which actuates the key was originally patented by Bain in 1846; but Wheatstone, aided by Mr. Augustus Stroh, an accomplished mechanician, and an able experimenter, was the first to bring the idea into successful operation. [...] Wheatstone was knighted in 1868, after his completion of the automatic telegraph. (John Munro)Wheatstone developed his perforator, automatic transmitter, and recorder. He used three keys, a row for holes down the center of the tape for spaces, holes on the other side of the tape for dashes. The motor-driven transmitter sent the plus and minus signals as contacts penetrated through the perforations. The recorder brought a pin in contact with the moving tape for long or shorts periods of time. That system was used from 1883 to 1901 on some truck circuits, duplexed eighty to 150 words a minute in each direction. (George P. Oslin)
Source : Munro, John (1891), “Heroes of the Telegraph”, Published by BiblioBazaar, 2008, Chapter 2, pp. 32-33, and Published by Icon Group International Inc (Webster’s French Thesaurus Edition), p. 24.
Source : Oslin, George P. (1999), “The Story of Telecommunications”, Mercer University Press, p. 298.
Urls : http://www.worldwideschool.org/library/books/tech/engineering/HeroesoftheTelegraph/chap2.html (last visited )

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