Dictionary of National Biography, 1885-1900/Riddle, Edward
RIDDLE, EDWARD (1788–1854), mathematician and astronomer, son of John Riddell, an agricultural labourer, was born at Troughend in Northumberland, where he received his early education. He afterwards attended a school at Otterburn on Reedwater, about two miles from Troughend, and there his enthusiasm for science was stimulated by a local scientific celebrity, James Thompson. While he was still a boy, Riddle opened a school of his own at Otterburn. In 1807 he removed to Whitburn in Durham, and in 1810 began contributing to the ‘Ladies' Diary,’ winning in 1814 and 1819 the prizes given by the editor, Dr. Hutton. It was through the latter that, in September 1814, Riddle was appointed master of the Trinity House School, Newcastle-on-Tyne. While here he made an extensive series of observations to ascertain the longitude of the school and the trustworthiness of certain lunar observations. In September 1821, again through Dr. Hutton, he was appointed master of the upper mathematical school, Royal Naval Hospital, Greenwich, where he remained till September 1851. His abilities as a nautical educator were highly appreciated by the admiralty. After his retirement his bust in marble was publicly presented to him by a large number of friends (Illustrated London News, 29 May 1852).
Riddle was elected a fellow of the Royal Astronomical Society, to whose ‘Transactions’ he contributed several valuable papers, and from 1825 to 1851 was an active member of the council. He died from paralysis at Greenwich on 31 March 1854. His son John (1816–1862) was headmaster of Greenwich Hospital schools, and examiner in navigation to the science and art department.
Riddle's most valuable work was a ‘Treatise on Navigation and Nautical Astronomy,’ 1824; 4th edit. 1842; 8th edit. 1864, forming a complete course of mathematics for sailors, and combining practice and theory in just proportion, which was not usually done at that time in books of this class; the tables of logarithms were issued separately in 1841 and 1851. He re-edited Hutton's ‘Mathematical Recreations,’ 1840, 1854. He also published some sixteen papers on astronomical subjects, of which eight are in the ‘Philosophical Magazine,’ 1818–22, 1826, 1828, five in ‘Memoirs of the Royal Astronomical Society,’ 1829, 1830, 1833, 1840, 1842, and three in ‘Monthly Notices of the Royal Astronomical Society,’ 1833–9, 1845–7 (see Roy. Soc. Cat. Scientific Papers). The most important are those on chronometers (in which the author shows how to find the rates without the help of a transit instrument) (cf. Phil. Mag. 1818; Mem. Royal Astronomical Soc. 1829); ‘On the Present State of Nautical Astronomy’ (Phil. Mag. 1821, and published separately); ‘On a Simplification of Ivory's Solution of the Doublealtitude Problem’ (Phil. Mag. 1822); and ‘On the Longitude of Madras’ (Mem. Royal Astronomical Soc. 1842), a paper containing valuable formulæ and remarks.
[Ridlon's Hist. of the Ancient Ryedales … comprising the Biography of the Families of Riddell, &c., 1884, pp. 150–2; Mem. Roy. Astron. Soc. xxi. 176, xxiv. 200; Gent. Mag. 1854, i. 661.]