WATT, JAMES (1736-1819). A British me chanical engineer, famous for his improvements on the steam engine, which were so important and fundamental as often to lead to his being styled its inventor. He was born at Greenock, Scotland, the son of a carpenter and merchant, who also at times held such town offices as treas urer and chief magistrate. His early education was obtained at the town schools, which, how ever• he was unable to attend regularly on ac count of ill health. At the same time lie was learning the use of wood and metal working t sots and constructing ingenious models and original pieces of mechanism. He early evinced a taste for mathematics and a fondness for read ing which he maintained throughout his life. \Then eighteen years old Watt went to Glasgow to learn the trade of an instrument-maker, but after a short time proceeded to London, where he followed this calling for a year. In 1756 he re turned to Glasgow, but experienced difficulty in starting in business on his own account, owing to the opposition of workers in the same trade. He became connected with the university, however, as an instrument-maker, and remained until 1760, when he became established independently, work ing also at times as a civil engineer. While at the university he became acquainted with the various professors and students and received from them instruction and suggestions. As early as 1759 he turned his attention to the construc tion of a steam carriage, and in 1704 he was called upon to repair the model of the Neweomen engine in the cabinet of the university. Studying this machine thoroughly, he soon realized its de and lack of efficiency, and determined that the losses of heat in the cylinder could be cor rected, and the imperfect method of condensing the steam could be improved. Accordingly lie contrived an independent condenser where the steam was exhausted and condensed after doing its work on the piston, instead of being con densed by a jet of cold water in the cylinder. as was done in the Newcomen engine. To develop the invention Watt secured the financial co operation of Dr. John Roebuck, the founder of the Carron Iron Works, and in 1765 constructed a small engine, which was operated with some success. Watt was in the meanwhile spending all of his resources, but at the same time mak ing considerable progress in engine-building, until financial misfortunes deprived him of the co operation of Dr. Roebuck. At this time (1767), fortunately, an enterprising manufacturer, Mat thew Bonito') (q.v.), joined with Watt and their names were subsequently associated in the manu facture and improvement of steam engines that resulted from the partnership. In 1774 a steam engine was completed which was noteworthy in that it embodied the essential features of the modern steam engine. So much time had been spent in the development of the engine that in 1775 an act to prolong the life of W'att's original patent until 1800 was passed by Parliament, and during this interval other• valuable patents were acquired and many engines were manufactured and disposed of to mines and collieries. Next to
the external condensation principle the most im portant features were: The making of the engine double-acting by the addition of valves, instead of having the steam act only on one side of the piston, which was then returned to its original position by a counterweight ; and the use of steam expansively. With the double-acting engine by the use of a ily-wheel it was possible to have continuous rotary motion through the medium of a crank, which, while claimed as an invention of Watt, was actually patented by one Pickard. a former employee of his, and disposed of to a Mr. Washbrongh of Bristol. To meet this de ficiency Watt contrived various devices, of which the 'sun and planet' gear wheels were the most successful, for changing the reciprocating into rotary motion. The application of the centrif ugal governor to the steam engine, the inven tion of the water gauge, and the mercury steam gauge, are but a few of the many improvements contributed by Watt to the steam engine. With his many improvements and additions to the steam engine it was somewhat singular• that Watt did not employ steam at high pressures, as was suggested by Tree it hick and others, and which was the next important step in the development of the steam engine. The invention of the steam hammer naturally resulted from his work on the steam engine. but the copying press, a spiral oar or screw propeller. the discovery of the com position of water. a machine for reproducing sculpt tire, and numerous physical instruments and methods show the diversity of his researches and the breadth of his talents.
Retiring from active business in 1800, he turtwd over to his two sons his interest in the large and remunerative business which had been built up at Soho by Boulton's effort. lle died at Heathfield. in Staffordshire, on August 25. 1819. lle was elected a fellow of the Royal Society of Edinburgh in 1784; a fellow of the Royal So ciety of London in 1785: and in 18n8 a corre sponding member. and afterwards a foreign mem ber of the institute of France. The University of Glasgow conferred on him the degree of 1,1,1). in 1806. A statue, the funds for which had been raised by public suhseription, was erected at Birmingham, %Odle a national monument was placed in Westminster Abbey. on which an ap propriate inscription written by Lord Berryham was inscribed.
BIBLIOGRAPHY. Smiles. ',ices of Bannon and Bibliography. Smiles. ',ices of Bannon and Watt (London. 1865) ; Muirhead. Origin and Progress of the Mechanical Inrentimns of dames Watt (London, 1854) ; id., Lifc of Watt (ib., 1858) : Thurston, The Growth of tin' En gine (New York, 1879).