FORSYTH, ANDREW RUSSELL (1858— ), Scot tish mathematician, was born at Glasgow, on June 18, 1858. He studied at Liverpool and Trinity college, Cambridge, and has held the following posts : professor of mathematics, University college, Liverpool (1882-83) ; lecturer in mathematics, Trinity college, Cambridge ; Sadlerian professor at Cambridge (1895, 191o) and professor of mathematics, Imperial college of science and technology, London (1913-23). Since 1923 Forsyth has held the post of Emeritus professor at the Imperial college, London. His work covers a wide field in pure mathematics and his treatises contain much that is original, show creative ability and at the same time establish his reputation as a teacher. Forsyth is the author of a number of papers on differential equations, on the theory of functions and on the differential invariants of space. His Treatise on the Theory of Functions (1893, etc.) deals with the theories of Riemann, Cauchy and Weierstrass and by means of this work and his other writings on the theory of functions, Forsyth has stimulated interest in the works of Klein, Poincare, Weierstrass and other foreign mathematicians. He has also writ ten exhaustively on the subject of differential equations and most of his work on this subject is contained in A Treatise on Differ ential Equations (1885, etc.) and Theory of Differential Equa tions (4 vols. 189o-1906). Forsyth edited volumes viii. to xiii. and the supplementary volume of Cayley's Collected Mathe matical Papers and was the editor of the Quarterly Journal of Mathematics from 1884 to 1895. He is a member of many learned societies and was awarded the Royal medal of the Royal Society in Some of his works are Lectures Introductory to the Theory of Functions of two Complex Variables (1914) ; Lectures on Differ ential Geometry (1912, etc.) ; Calculus of Variations (1927).