Dictionary of National Biography, 1885-1900/Evans, Thomas Simpson
EVANS, THOMAS SIMPSON (1777–1818), mathematician, eldest son of the Rev. Lewis Evans (1755–1827) [q. v.], by his wife, Ann Norman, was baptised in August 1777. He was named after Thomas Simpson, the mathematician. In or about 1797 he appears to have taken charge of a private observatory at Blackheath belonging to William Larkins, formerly accountant-general to the East India Company at Bengal. After the death of Larkins, 24 April 1800 (Gent. Mag. vol. lxx. pt. i. p. 398), he was taken on as an assistant by Nevil Maskelyne [q. v.] at the Royal Observatory, Greenwich, but resigned the post in 1805. In that year, or perhaps in 1803, he was appointed mathematical master under his father at the Royal Military Academy, Woolwich. Here he continued until 1810, when he accepted the mastership of the mathematical school at New Charlton, near Woolwich, which office he vacated in 1813 to become master of the mathematics at Christ's Hospital, London. His attainments won for him the degree of LL.D. (from what university is not known) and the fellowship of the Linnean Society. He died 28 Oct. 1818, aged 41 (ib. vol. lxxxviii. pt. ii. p. 475). By his marriage in 1797 to Deborah, daughter of John Mascall of Ashford, Kent, he had five children: Thomas Simpson Evans (1798–1880), vicar of St. Leonard's, Shoreditch; Aspasia Evans (1799–1876), a spinster; Herbert Norman Evans, M.D. (1802–1877), a great book collector; Arthur Benoni Evans (d. 1838); and Lewis Evans (1815–1869), head-master of Sandbach Free Grammar School, Cheshire. Evans left a completed translation of Antonio Cagnoli's ‘Trigonometria piana e sferica,’ besides other translations from foreign scientific works and a vast collection of unfinished papers in several branches of philosophy. He also contributed some articles to the ‘Philosophical Magazine,’ among which may be mentioned ‘Problems on the Reduction of Angles’ (vol. xxviii.); ‘An Abridgment of the Life of Julien Le Roy, the Watchmaker, by his Son’ (vol. xxxi.); ‘A Short Account of Improvements gradually made in determining the Astronomic Refraction’ (vol. xxxvi.); ‘Historical Memoranda respecting Experiments intended to ascertain the Calorific Powers of the different Prismatic Rays’ (vol. xlv.); ‘On the Laws of Terrestrial Magnetism in different Latitudes’ (vol. xlix.). His library was considered one of the most valuable collections of mathematical and philosophical works in the kingdom.
[Information from John Evans, esq., F.R.S.; Royal Kalendars; Foster's Alumni Oxon. (1715–1886), sub voce.]