Page:Dictionary of National Biography, Second Supplement, volume 1.djvu/380

 CHRYSTAL, GEORGE (1851–1911), mathematician, born at Mill of Kingoodie in the parish of Bourtie near Old Meldrum, Aberdeenshire, on 8 March 1851, was the son of William Chrystal, first a grain merchant and afterwards a farmer and landed proprietor, by his wife Margaret, daughter of James Burr of Mains of Glack, Aberdeenshire. After education at Aberdeen grammar school and university (1867) he proceeded in 1872 to Peterhouse, Cambridge. There he won the member's prize for an English essay in 1873, and graduated B.A. in 1875 as second wrangler and Smith's prizeman, proceeding M.A. in 1878. He was elected to a fellowship of Corpus Christi College in 1875, and was appointed a lecturer there; in later life he was made an honorary fellow. While an undergraduate at Cambridge, Chrystal not only read mathematics but studied experimental physics under Prof. Clerk-Maxwell [q. v.], and at Maxwell's suggestion engaged in a series of investigations for verifying 'Ohm's law' respecting the relation between the current and the electromotive force in a wire. To the report of these experiments which Clerk Maxwell presented to the British Association at Glasgow in 1876 Chrystal added a brief account of another series of experiments which he had undertaken on the deflection of a galvanometer (published in Philos. Mag. 1876; cf. and, Life of J. C. Maxwell, 1882, p. 365).

In 1877 Chrystal left Cambridge to become professor of mathematics at St. Andrews university, and two years later he was elected to the chair of mathematics at Edinburgh (Nov. 1879). There he greatly stimulated interest in mathematics in the university through the clearness and conciseness of his expositions of mathematical theory. At the same time he actively interested himself in the general academic organisation. Elected dean of the faculty of arts in 1891, he rendered valuable service in reorganising the arts curriculum. He was also first chairman of the provincial committee for the training of teachers, and for many years served on a committee appointed by the war office to advise the army council on the education of officers. In addition to his professorial duties, Chrystal pursued experimental researches which he had begun at Cambridge, working in the laboratory of his colleague, Peter Guthrie Tait [q. v. Suppl. II], and he took an active part in the affairs of the Royal Society of Edinburgh. He was elected a fellow of the society in 1880 and became vice-president in 1887, at the early age of thirty-six. He served in this capacity for two terms of six years, and in 1901, on Professor Tait's death, he was chosen general secretary. He was largely instrumental in the movement which led to the transfer of the society's premises from the Mound to George Street. To the society's 'Transactions' (xxix. 609 seq.) he contributed in 1880 the result of his inquiries into the differential telephone, for which he was awarded the society's Keith prize. Photography was another of Chrystal's interests, and his photographic studies produced an account of the properties of lenses and doublets (Trans. Edin. Math. Soc. 1895, vol. xiv.).

During his later years he was engaged in investigating theories on the oscillations in lakes, and invented instruments and obtained results which shed a new light on the whole set of phenomena. These are embodied in his papers 'On the Hydrodynamical Theory of Seiches,' with a bibliographical sketch (Trans. Roy. Soc. Edin. 1905, xli. 599 seq.; cf. Proc. Roy. Soc. Edin. xxv. 328 and 637); 'Calculation of the Periods and Nodes of Lochs Earn and Treig, from the Bathymetric Data of the Scottish Lake Survey' (Trans, xli. 823 seq.; 'An Investigation of the Seiches of Loch Earn' (ibid. xlv. 362 seq., 1907-8); and 'Seiches arid other Oscillations of Lake Surfaces, observed by the Scottish Lake Survey' (in Bathymetrical Survey of the Scottish Freshwater Lochs, edit, by Murray and Pullar, Edinburgh, 1910, i. 29 seq.). For these researches he was awarded a royal medal by the Royal Society of London in 1911. He read a paper on the subject before the Royal Institution in London on 17 May 1907. He was made hon. LL.D. of Aberdeen University in March 1887 and of Glasgow in Oct. 1911.

Chrystal wrote many articles for the 9th edition of the 'Encyclopedia Britannica,' the chief being those on 'Electricity' and 'Magnetism' (1883), which compress into a small compass a very complete account of those sciences at that date. His 'Algebra, an Elementary Textbook for the Higher Classes of Secondary Schools' (Edinburgh, 2 pts. 1886-9), became a standard book, and was notable for the lucidity of its reasoning. The first part reached a fifth edition in 1904, and a second edition of part ii. was published in 1900. He also published 'Introduction to Algebra' (1898; 3rd edit. 1902) and 'Non-Euclidean Geometry' (in Proc. Roy. Soc. Edin. 1880). 