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61 Heaviside, Oliver
[br]b. 18 May 1850 London, Englandd. 2 February 1925 Torquay, Devon, England[br]English physicist who correctly predicted the existence of the ionosphere and its ability to reflect radio waves.[br]Brought up in poor, almost Dickensian, circumstances, at the age of 13 years Heaviside, a nephew by marriage of Sir Charles Wheatstone, went to Camden House Grammar School. There he won a medal for science, but he was forced to leave because his parents could not afford the fees. After a year of private study, he began his working life in Newcastle in 1870 as a telegraph operator for an Anglo-Dutch cable company, but he had to give up after only four years because of increasing deafness. He therefore proceeded to spend his time studying theoretical aspects of electrical transmission and communication, and moved to Devon with his parents in 1889. Because the operation of many electrical circuits involves transient phenomena, he found it necessary to develop what he called operational calculus (which was essentially a form of the Laplace transform calculus) in order to determine the response to sudden voltage and current changes. In 1893 he suggested that the distortion that occurred on long-distance telephone lines could be reduced by adding loading coils at regular intervals, thus creating a matched-transmission line. Between 1893 and 1912 he produced a series of writings on electromagnetic theory, in one of which, anticipating a conclusion of Einstein's special theory of relativity, he put forward the idea that the mass of an electric charge increases with its velocity. When it was found that despite the curvature of the earth it was possible to communicate over very great distances using radio signals in the so-called "short" wavebands, Heaviside suggested the presence of a conducting layer in the ionosphere that reflected the waves back to earth. Since a similar suggestion had been made almost at the same time by Arthur Kennelly of Harvard, this layer became known as the Kennelly-Heaviside layer.[br]Principal Honours and DistinctionsFRS 1891. Institution of Electrical Engineers Faraday Medal 1924. Honorary PhD Gottingen. Honorary Member of the American Association for the Advancement of Science.Bibliography1872. "A method for comparing electro-motive forces", English Mechanic (July).1873. Philosophical Magazine (February) (a paper on the use of the Wheatstone Bridge). 1889, Electromagnetic Waves.1892, Electrical Papers.1893–1912, Electromagnetic Theory.Further ReadingI.Catt (ed.), 1987, Oliver Heaviside, The Man, St Albans: CAM Publishing.P.J.Nahin, 1988, Oliver Heaviside, Sage in Solitude: The Life and Works of an Electrical Genius of the Victorian Age, Institute of Electrical and Electronics Engineers, New York.J.B.Hunt, The Maxwellians, Ithaca: Cornell University Press.See also: Appleton, Sir Edward VictorKF -
62 Smith, J.
SUBJECT AREA: Textiles[br]fl. 1830s Scotland[br]Scottish inventor of the first endless chain of flats for carding.[br]Carding by hand required a pair of hand cards. The lump of tangled fibres was teased out by pulling one card across the other to even out the fibres and transfer them onto one of the cards from which they could be rolled up into a rollag or slubbing. When Arkwright began to use cylinder cards, the fibres were teased out as they passed from one cylinder to the next. In order to obtain a greater carding area, he soon introduced smaller cylinders and placed strips of flat card above the periphery of the main cylinder. These became clogged with short fibres and dirt, so they had to be lifted off and cleaned or "stripped" at intervals. The first to invent a self-stripping card was Archibald Buchanan, at the Catrine mills in Ayrshire, with his patent in 1823. In his arrangement each flat was turned upside down and stripped by a rotary brush. This was improved by Smith in 1834 and patented in the same year. Smith fixed the flats on an endless chain so that they travelled around the periphery of the top of the main cylinder. Just after the point where they left the cylinder, Smith placed a rotary brush and a comb to clear the brush. In this way each flat in turn was properly and regularly cleaned.Smith was an able mechanic and Managing Partner of the Deanston mills in Scotland. He visited Manchester, where he was warmly received on the introduction of his machine there at about the same time as he patented it in Scotland. The carding engine he designed was complex, for he arranged a double feed to obtain greater production. While this part of his patent was not developed, his chain or endless flats became the basis used in later cotton carding engines. He took out at least half a dozen other patents for textile machinery. These included two in 1834, the first for a self-acting mule and the second with J.C. Dyer for improvements to winding on to spools. There were further spinning patents in 1839 and 1844 and more for preparatory machinery including carding in 1841 and 1842. He was also interested in agriculture and invented a subsoil plough and other useful things.[br]Bibliography1834, British patent no. 6,560 (self-stripping card). 1834, British patent no. 656 (self-acting mule). 1839, British patent no. 8,054.1841, British patent no. 8,796 (carding machine). 1842, British patent no. 9,313 (carding machine).1844, British patent no. 10,080.Further ReadingE.Leigh, 1875, The Science of Modern Cotton Spinning Manchester (provides a good account of Smith's carding engine).W.English, 1969, The Textile Industry, London (covers the development of the carding engine).RLH
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