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1 signalling wires
n (BrE)RAIL circuito de señalización m -
2 signalling
n (BrE)COMP&DP señalamiento m, señalización fSPACE, TELECOM señalización f, transmisión de señales fWATER TRANSP señalización f -
3 Preece, Sir William Henry
[br]b. 15 February 1834 Bryn Helen, Gwynedd, Walesd. 6 November 1913 Penrhos, Gwynedd, Wales[br]Welsh electrical engineer who greatly furthered the development and use of wireless telegraphy and the telephone in Britain, dominating British Post Office engineering during the last two decades of the nineteenth century.[br]After education at King's College, London, in 1852 Preece entered the office of Edwin Clark with the intention of becoming a civil engineer, but graduate studies at the Royal Institution under Faraday fired his enthusiasm for things electrical. His earliest work, as connected with telegraphy and in particular its application for securing the safe working of railways; in 1853 he obtained an appointment with the Electric and National Telegraph Company. In 1856 he became Superintendent of that company's southern district, but four years later he moved to telegraph work with the London and South West Railway. From 1858 to 1862 he was also Engineer to the Channel Islands Telegraph Company. When the various telegraph companies in Britain were transferred to the State in 1870, Preece became a Divisional Engineer in the General Post Office (GPO). Promotion followed in 1877, when he was appointed Chief Electrician to the Post Office. One of the first specimens of Bell's telephone was brought to England by Preece and exhibited at the British Association meeting in 1877. From 1892 to 1899 he served as Engineer-in-Chief to the Post Office. During this time he made a number of important contributions to telegraphy, including the use of water as part of telegraph circuits across the Solent (1882) and the Bristol Channel (1888). He also discovered the existence of inductive effects between parallel wires, and with Fleming showed that a current (thermionic) flowed between the hot filament and a cold conductor in an incandescent lamp.Preece was distinguished by his administrative ability, some scientific insight, considerable engineering intuition and immense energy. He held erroneous views about telephone transmission and, not accepting the work of Oliver Heaviside, made many errors when planning trunk circuits. Prior to the successful use of Hertzian waves for wireless communication Preece carried out experiments, often on a large scale, in attempts at wireless communication by inductive methods. These became of historic interest only when the work of Maxwell and Hertz was developed by Guglielmo Marconi. It is to Preece that credit should be given for encouraging Marconi in 1896 and collaborating with him in his early experimental work on radio telegraphy.While still employed by the Post Office, Preece contributed to the development of numerous early public electricity schemes, acting as Consultant and often supervising their construction. At Worcester he was responsible for Britain's largest nineteenth-century public hydro-electric station. He received a knighthood on his retirement in 1899, after which he continued his consulting practice in association with his two sons and Major Philip Cardew. Preece contributed some 136 papers and printed lectures to scientific journals, ninety-nine during the period 1877 to 1894.[br]Principal Honours and DistinctionsCB 1894. Knighted (KCB) 1899. FRS 1881. President, Society of Telegraph Engineers, 1880. President, Institution of Electrical Engineers 1880, 1893. President, Institution of Civil Engineers 1898–9. Chairman, Royal Society of Arts 1901–2.BibliographyPreece produced numerous papers on telegraphy and telephony that were presented as Royal Institution Lectures (see Royal Institution Library of Science, 1974) or as British Association reports.1862–3, "Railway telegraphs and the application of electricity to the signaling and working of trains", Proceedings of the ICE 22:167–93.Eleven editions of Telegraphy (with J.Sivewright), London, 1870, were published by 1895.1883, "Molecular radiation in incandescent lamps", Proceedings of the Physical Society 5: 283.1885. "Molecular shadows in incandescent lamps". Proceedings of the Physical Society 7: 178.1886. "Electric induction between wires and wires", British Association Report. 1889, with J.Maier, The Telephone.1894, "Electric signalling without wires", RSA Journal.1898, "Aetheric telegraphy", Proceedings of the Institution of Electrical Engineers.Further ReadingJ.J.Fahie, 1899, History of Wireless Telegraphy 1838–1899, Edinburgh: Blackwood. E.Hawkes, 1927, Pioneers of Wireless, London: Methuen.E.C.Baker, 1976, Sir William Preece, F.R.S. Victorian Engineer Extraordinary, London (a detailed biography with an appended list of his patents, principal lectures and publications).D.G.Tucker, 1981–2, "Sir William Preece (1834–1913)", Transactions of the Newcomen Society 53:119–36 (a critical review with a summary of his consultancies).GW / KFBiographical history of technology > Preece, Sir William Henry
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