Mathematician, engineer and actuary. Born Kirkcaldy, son of Edward Sang, nurseryman and Provost of the town, and his wife Jean Nicol (b.1773) sister of William Nicol (1768 - 1851) who invented the Nicol prism. Sang was educated in Kirkcaldy and at the University of Edinburgh where his talent impressed his professors, William Wallace (1768 - 1843) and Sir John Leslie (1766 - 1832). He lectured at the University, and also worked in the City as a surveyor and civil engineer. He then moved to a chair at Manchester and Istanbul (Turkey), where he built engineering schools and railways. While teaching in Turkish, he became famous for predicting the solar eclipse of 1847, effectively countering the superstitions in that country at the time. Returning to Edinburgh in 1854, Sang gained a reputation as a prodigious author of scientific and engineering articles, together with mathematical, actuarial and astronomical tables. He became a founder member of the Faculty of Actuaries in Scotland.