RENNIE, John, Scottish civil engineer: b. Phantassie, Haddingtonshire, 7 June 1761; d. London, 4 Oct. 1821. At an early age he showed an interest in mechanics and frequented the shop of the millwright Andrew Mickle, inventor of the threshing machine. Later he spent three years at the Edinburgh University, and in 1784, having already established a business of his own, he visited James Watt at Soho, Stafford shire, and by Bonlton and Watt was engaged to take charge of the work of the Albion Flour Mills, Blackfriars, London. Rennie designed all the machinery, using iron instead of wood for the shafting and framing. In London his reputation rapidly increased until he was ranked foremost among the civil engineers of Great Britain. Among his public works may be men tioned Ramsgate Harbor; Waterloo and South wark Bridges, across the Thames, and the design of London Bridge, the structure being completed after his death; the breakwater at Plymouth, and several similar structures, where submarine masonry was carried to great per fection. He superintended likewise the execu
tion of the Grand Western Canal, from the mouth of the Exe to Taunton; the Polbrook Canal, Cornwall; the Aberdeen Canal, uniting the Don and the Dee; that between Arundel and Portsmouth, and, his chief work in connec tion with inland navigation, the Kennet and Avon Canal, between Bath and Newbury, the London Docks, the East and West India Docks, the Prince's Dock at Liverpool, and those of Dublin, Greenock and Leith were also designed by him. In prosecuting his works he made use of the diving-bell which he greatly improved and the steam-dredging machine, apparently without the knowledge that in its invention he had been anticipated by Sir Samuel Bentham.