Sang, Edward

(1805-1890), mathematician and civil engineer

by A. D. D. Craik

© Oxford University Press 2004 All rights reserved

Sang, Edward (1805-1890), mathematician and civil engineer, was born on 30 January 1805 at Kirkcaldy, the sixth of eleven children of Edward Sang (1771-1862), nurseryman and sometime provost of Kirkcaldy, and his wife, Jean Nicol (b. 1773) a sister of William Nicol (b. 1768) who invented the Nicol prism. He attended a subscription school founded by his father and others under a gifted headmaster, Edward Irving. At Edinburgh University during 1818 to 1824 he impressed professors William Wallace and John Leslie in mathematics and natural philosophy, despite periods of illness. Small for his age, he was first mocked by fellow students, then admired for his precocious talent.

Sang first worked in Edinburgh as surveyor, civil engineer, and mathematics teacher, and lectured on natural philosophy. During 1841 to 1843 he was professor of mechanical sciences at the nonconformist Manchester New College, then went to Constantinople to establish engineering schools, plan railways and an ironworks. He lectured (in Turkish) at the Imperial School, Muhendis-hana Berii and gained fame by predicting the solar eclipse of 1847, thereby dispelling superstition. He resigned against the sultan's wishes, returning to Edinburgh in 1854 to teach mathematics.

An active fellow of the Royal Scottish Society of Arts and the Royal Society of Edinburgh, Sang received awards from both and from the Institution of Civil Engineers, London (1879). He was a founder member and first official lecturer of the Faculty of Actuaries in Scotland, a corresponding member of the Royal Tunis Academy, an LLD of Edinburgh University, and an honorary member of the Franklin Institute, Philadelphia. In 1832 he married Isabella Elmslie (b. 1805?) and they had one son and four daughters.

Mainly in Edinburgh-based journals, Sang wrote extensively on mathematical, mechanical, optical, and actuarial topics including vibration of wires, a theory of toothed wheels, an improved lighthouse light, railways, bridges, manufacturing, and life insurance. He published actuarial, annuity, and astronomical tables, books on elementary and higher arithmetic, and much used tables of 7-place logarithms (1871). But his most remarkable achievement is his massive unpublished compilation of 28- and 15-place logarithmic, trigonometric, and astronomical tables, filling forty-seven manuscript volumes. Compiled over forty years, latterly with assistance from two daughters, Flora and Jane, these surpass in accuracy the (also unpublished) French Cadastre tables of 1801. They were given to the nation in 1907 by Anna and Flora Sang. Sang died at his home, 31 Mayfield Road, Edinburgh, on 23 December 1890.

A. D. D. CRAIK

Sources  
D. B. Peebles, 'Edward Sang', Proceedings of the Royal Society of Edinburgh, 21 (1895-7), xvii-xxxii [incl. list of writings]
NL Scot., Sang MS Acc. 10780 [89 vols. incl. items of tables, correspondence, etc. previously held by the Royal Society of Edinburgh]
C. G. Knott, 'Edward Sang and his logarithmic calculations', Napier tercentenary memorial volume, ed. C. G. Knott (1915), 261-8
A. R. Davidson, The history of the Faculty of Actuaries in Scotland, 1856-1956 (1956)
[C. G. Knott ?], 'Dr Edward Sang's logarithmic, trigonometrical, and astronomical tables', Proceedings of the Royal Society of Edinburgh, 28 (1907-8), 183-96
U. Edin. L., Edward Sang MSS, Gen. 310-349 [40 vols.]
W. Swan, 'Presidential address for 1882', Transactions of the Royal Scottish Society of Arts, 11 (1887), 1-7
C. D. Waterston, 'Notes on portraits in oils, busts and statuettes, the property of the Royal Society of Edinburgh, displayed in the rooms of the society', Year Book of the Royal Society of Edinburgh (1992-3), 83-117
microfiche index of old parish records, Scotland
Catalogue of scientific papers, 1800-1900, subject index, Royal Society, 1 (1908)
d. cert.
A. Craik, 'Edward Sang (1805-1890): calculator extraordinary', Newsletter of the British Society for the History of Mathematics (2002)
A. Craik, 'The logarithmic tables of Edward Sang and his daughters', Historia Mathematica (2003)

Archives  
NL Scot., corresp., mathematical notes and tables
NL Scot., corresp. and papers by and relating to him
U. Edin. L., papers |  NL Scot., corresp. with the Scottish Society of Arts

Likenesses  
A. R. Moffatt?, oils (after photograph), Royal Society of Edinburgh
photograph, NL Scot., Canon of Sines Part 1, Acc 10780 [frontispiece]
photograph, Royal Society of Edinburgh; repro. in Davidson, History of the Faculty of Advocates in Scotland, facing p. 28

Wealth at death  
£115 0s. 6d.: confirmation, 14 March 1891, CCI


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