# Dictionary of National Biography, 1885-1900/Towson, John Thomas

​TOWSON, JOHN THOMAS (1804–1881), scientific writer, son of John Gay Towson and his wife, Elizabeth Thomas, was born at Fore Street, Devonport, on 8 April 1804, and educated at Stoke classical school. He followed his father's trade of a chronometer and watch maker. When the daguerreotype process was introduced in 1839 he and Robert Hunt (1807–1887) [q. v.] devoted considerable attention to it, and in the ‘Philosophical Magazine’ for November 1839 he published a paper ‘On the Proper Focus for the Daguerrotype,’ in which he demonstrated the fact that the luminous and chemical rays did not focus at the same distance from the object (cf. Harrison, History of Photography, 1888, p. 42). Towson was also the first to devise the means of taking a photographic picture on glass and of using the reflecting camera; and, with his colleague Hunt, produced highly sensitive photographic papers, for the sale of which they appointed agents in London and elsewhere. About 1846 he turned his attention to navigation, and gave lessons in that subject to young men in the naval yard. His investigations led to the suggestion that the quickest route across the Atlantic would be by sailing on the great circle. Sir John Herschel drew the attention of the admiralty to Towson's discovery, and that department subsequently published Towson's ‘Tables for facilitating the Practice of Great Circle Sailing,’ and his ‘Tables for the Reduction of Ex-Meridian Altitudes’ (1849), the copyrights of which works he presented to the admiralty. In 1850 he removed to Liverpool on being appointed scientific examiner of masters and mates in that port, which post he held until 1873, when he retired, still holding an appointment as chief examiner in compasses. In 1853 he brought before the Liverpool Literary and Philosophical Society the subject of the deviation of the compass on board iron ships, and in 1854 he aided Dr. William Scoresby (1789–1857) [q. v.] in directing the attention of the British Association to the matter. The result of the discussion was the formation of the Liverpool compass committee, and three reports were subsequently presented to both houses of parliament, these being in the main the result of Towson's labours. In recognition of his services to navigation he was on 9 Jan. 1857 presented by the shipowners of Liverpool with a dock bond for 1,000l. and an additional gratuity of more than 100l. In 1863 he was instructed by the board of trade to prepare a manual which was afterwards published under the title of ‘Practical Information on the Deviation of the Compass, for the Use of Masters and Mates of Iron Ships.’ In 1870 he prepared a syllabus, adopted by the board of trade, for examinations in compass deviations. Towson died at his residence, Upper Parliament Street, Liverpool, on 3 Jan. 1881. He married Margaret Braddon on 19 Nov. 1840 at Stoke-Damerel church, Devonport.
Besides the papers mentioned he wrote ‘A Lecture to the Officers, Seamen, and Apprentices of Mercantile Marine,’ 1854, and twelve or more communications to the Historic Society of Lancashire and Cheshire (vols. ix–xxvi.), the Liverpool Literary and Philosophical Society (vols. vii–viii.), the Liverpool Polytechnic Society (1872), and the British Association (1859); the subjects including (1) ‘The Goldfields of Australia,’ (2) ‘History of Photography,’ (3) ‘Icebergs in the Southern Ocean,’ (4) ‘Mythology of Aerostation,’ (5) ‘Solar Eclipse of 15 March 1858,’ (6) ‘Visit to the Tomb of Theodora Paleologus.’
C. W. S.