Thomas Simpson, an English mathematician, born in Market-Bosworth, Leicestershire, Aug. 20, 1710, died there, May 14, 1761. He was a weaver, and while young married a widow 50 years of age, having two children, both older than himself; but the family lived in harmony, and Simpson employed his evenings in study, especially of mathematics, and in keeping a school. In 1733 he went to Derby, and in 1735 or 1736 to London, where he soon established himself as a teacher of mathematics, while employing his leisure hours in researches into the higher branches of science. In 1743 he was appointed professor of mathematics in the royal military academy at Woolwich, a post which he filled until the beginning of 1761, when with impaired mental faculties and disordered health he retired to his native town. In 1746 he was elected a fellow of the royal society. He published works on fluxions, the laws of chance, annuities and reversions, algebra, geometry, trigonometry, logarithms, etc.; but his most valuable publication was a volume of "Miscellaneous Tracts" (1754), consisting of four papers on pure mathematics and four on physical astronomy.