H. N. Sporborg (1877-1965) an American by origin, was Chief Engineer and Senior Director of British Thomson-Houston (and became Chairman in 1944). From 1901 he was a design engineer there in traction engineering, from 1907 Chief Engineer, from 1907 to 1908 acting Works Manager. He became a Director in 1910 and Chairman in 1944 having been Chairman of the Manufacturing Committee from 1920 to 1922. He retired in 1945.

The British Thomson-Houston archives are held by the Bodleian Library as MSS Marconi 2921-2937 and the files relevant to the development of the Whittle engine are described by Michael Hughes in, 'British Thomson-Houston and Whittle gas turbine and jet engine records in the Marconi archives', Bodleian Library Record XX (2007) pp. 153-8. The company originated in the United States as the Thomson-Houston Electric Company when Elihu Thomson (1853-1937), an emigrant from England, Professor of Chemistry and Physics at Central High School Philadelphia, and his colleague there as Professor of Natural Philosophy, Edwin James Houston (1847-1914), who had been invited by Frederick H. Churchill of New Britain in 1880 to join him in forming the American Electric Company, decided in 1892, Churchill having died in 1881, to establish their own company, which evolved, in due course, into the General Electric Company (of New York). The British Thomson-Houston Company, having purchased the patents, was established in 1894 with offices at 38 Parliament Square, Westminster. Their early work was on the electrification of tramways and railways and on electricity meters. The Rugby works were built in 1900-02 and 1903 saw their first turbine contract. Early work also included electric textile mills and marine equipment and Mazda lamps. In terms of the present papers, significant developments were the enlargement of the turbine factory from 1913 to 1918 and the equipment in 1932 of P & O ships with turbo-electric machinery. In 1933 they acquired the Ladywood Iron Works at Lutterworth, where Power Jets was to be housed, and undertook a comprehensive investigation of gas turbine cycles with a view to jet propulsion. They were approached by Frank Whittle in 1936 and the first of his engines was tested in 1937. From 1939, apart from work with Power Jets, they were involved in armaments, radio valves, aircraft equipment and radar. Sir Frank Whittle (1907-1996), aeronautical engineer and inventor of the jet engine was born in Coventry on 1 June 1907 and in 1923 entered the apprentice wing of RAF College, Cranwell where he wrote a thesis on 'Future developments in aircraft design'. In 1939 he was attached to the Central Flying School at Wittering where he made the acquaintance of William Evelyn Patrick Johnson with whose help he filed a patent in 1930. British Thomson-Houston, Armstrong Siddleley and the Bristol Aeroplane, on being approached, showed no interest. In 1932 Whittle was posted to the RAF officers' engineering course at Henlow and in 1934 was sent by the Air Ministry to Cambridge to read Mechanical Sciences and was admitted at Peterhouse on the recommendation of Roy Lubbock. While studying for the tripos he was visited by Rolf Dudley Dudley-Williams, who had been a fellow cadet at Cranwell, and his partner James Collington Burdett Tinling, who thought that they might be able to find finance to fund Whittle's further work. Even before the resultant company, Power Jets, was formally established, the British Thomson-Houston Company had produced tentative assembly drawings early in March 1936, which Whittle revised by the end of the month, before returning to his work for the tripos. He achieved a First Class leading the Air Ministry to give permission for him to have another year in Cambridge on postgraduate work, after which he was placed on the RAF special duty list to enable him to continue with his work. For a futher account of his career and subsequent honours see G. B. R. Feilden in ODNB. Sir Frank Whittle’s papers, with a biographical introduction, are held by the Churchill Archives Centre, Cambridge as WHTL (96 archive boxes and 10 rolls ) with associated papers at WHTL AS (10 boxes). Other relevant papers there are those of Geoffrey J. Gollin (GOLN, 6 files) and of Sir William Hawthorne (HATN , 241 boxes, particularly HATN 2). Also at Chruchill are Exhibition material on the history and development of the Whittle Jet Propulsion Gas Turbine, 1963–73, at MISC 10 and a number of other related papers. See also for Power Jets: Frank Whittle, 'Jet: the story of a pioneer' (London, 1953); John Golley, in association with Sir Frank Whittle, 'Whittle: the true story', Airlife Publishing Ltd, 1987, new edition as 'Jet' by Datum Publishing Ltd, 2010; 'Commemorating the Reactionaries, 1946-2001, and the 60th anniversary first flight of the Whittle Gloster E29/39 aircraft, May 15th 2001', ed. Robert Dale, n.p. 1998; and for British Thomson-Houston: H. A. Price-Hughes (compiler), 'B.T.H., Reminiscences, sixty years of progress', (The British Thomson-Houston Co. Ltd., 1946); The British Thomson-Houston Co. Ltd., 'The Whittle Gas Turbine used in Jet Propulsion: Pioneer Development Work as carried out by the British Thomson-Houston Co.' (1946); David J. Wilson, 'The establishment and decline of British Thomson-Houston and Metropolitan Vickers (Associated Electrical Industries Ltd, August 2005); E. D. P. Symons, 'The photographic archives of the British Thomson-Houston Company' Institute of Electrical Engineers Proceedings, vol. 136, Pt A, no. 6 (November 1989) http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=35873>