Buchanan was educated at Edinburgh University, where he was a favourite pupil of Sir John Leslie. About 1812 he began business as a land surveyor, but his strong scientific bent soon led him to devote himself to the profession of a civil engineer. In this capacity he was engaged in several public works of importance, in construction of harbours an bridges, and made a considerable local reputatlon. In 1822, on the invitation of the directors of the School of Arts, he delivered a course of lectures on mechanical philosophy in the Freemasons' Hall, remarkable for the original and striking experiments. Buchanan afterwards gave one or two courses of lectures on natural philosophy, but his increasing business as an engineer interfered with ang further educational work. In 1827 he drew up a report on the South Esk estuary at Montrose in relation to a question then in dispute concerning salmon fishing. This report attracted the attention and gained the marked commendation of Lord-justice-clerk Hope, then solicitor-general, who afterwards, as long as he remained at the bar, always gave the advice in any case involving scientific evidence to ‘secure Buchanan.' Subsequently in allthe important salmon-fishing questions which arose, and which embraced nearly every estuary in Scotland, Buchanan’s services were enlisted, the point be` generally to determine where the river ended and the sea began. VVhen the tunnel of the Edinburgh and Granton railway was bein constructed under the new town, and the adjacent bujldings were considered in imminent danger, Buchanan was commissioned by the sheriff of Edinburgh to supervise the works on behalf of the city. In 1848 he began the work of erecting the huge chimney, nearly 400 feet in height, of the Edinburgh Gasworks, and carried cut an exhaustive series of experiments to assure its stability. He communicated an account of this work in detail in two papers read before the Royal Scottish Society of Arts. Buchanan was the author of several scientific treatises. He published a ‘Report on the Theo and Application of Leshe's Photometer’ (Edinburgh, 1824, 8vo). He communicated a series of papers in 1851 to the ‘Courant’ newspaper upon pendulum experiments relating to the earth's rotation, and was a constant contributor to the ‘Transactions of the Royal Scottish Society of Arts.' He also contributed the article on ‘furnaces’ to the eighth edition of the ‘Encyclopædia Britannica.' He was a fellow of the Royal Society of Edinburgh, and was elected president of the Royal Scottish Society of Arts for the session 1847–8. He died of lung disease on 30 Oct. 1852. David Buchanan (1779–1848) [q. v.] and William Buchanan (1781–1863) [q. v.] were Buchanan’s elder brothers.
[Scotsman, November 1852; Courant, 19 June 1851; Proceedings Roy. Scot. Soc. of Arts.]
BUCHANAN, JAMES, D.D., LL.D. (1804–1870), preacher and theological writer, was born in 1804 at Paisley, and studied at the university of Glasgow. In 1827 he was ordained minister of Roslin, near Edinburgh, and in 1828 he was translated to the large and important charge of North Leith. In this charge he attained great fame as a preacher, being remarkable or a clear, vigorous, and flowing style, a graceful manner, a vein of thrilling tendemess, broken from time to time by passionate egpeals, all in the most pronounced evangelic strain. Most of his parochial duties being discharged by assistants, he read and wrote much in his study. While at North Leith he wrote: 1. ‘Comfort in Affliction,' a series of meditations, of which between 20,000 and 30,000 copies were issued. 2. ‘Improvement of Affliction.’ 3. ‘The Office and Work of the Holy Spirit,' In 1840 Buchanan was translated to the High Church (St. Giles’), Edinburgh, and in 1813, after the disruption, he became first minister of St. Stephen‘s Free Church. In 1815 he was appointed professor of apologetics in the New College (Free church), Edinburgh, and in 1847, on the death of Dr. Chalmers, he was transferred to the chair of systematic theology, continuing there till his resignation in 1868. During this time he published: 4. ‘On the Tracts for the Times.’ 5. ‘Faith in God and Modern Atheism compared,’ 2 vols. 8vo, 1855. 6. ‘Analogy: considered as a Guide to Truth, and applied as an Aid to Faith,’ 2nd edit. 1867. 7. ‘The Doctrine of Justification,’ being the Cunningham Lectures for 1866. In 1844 the degree of D.D. was conferred on him by Princeton College, New Jersey, and some time after that of LL.D. by the university of Glasgow. Though not eminent for his powers of original thought, Buchanan had a remarkable faculty of collecting what was valuable in the researches and arguments of others, and presenting it in clear form and lucid language. His work on ‘Faith in God’ is a very valuable summary of facts and reasonings applicable to the state of the apologetic question, both in natural and revealed religion, some thirty years ago. The book on ‘Analogy’ follows so far the lines of Butler, but makes much wider application of the principle than Butler's purpose required. Owing to delicate