WATT, JAMES. Of all the great men whose names are indissolubly connected with the history of the steam-engine, James Watt undoubtedly takes the lead. Watt was born at Greenock in 1730; and in his 16th year he was apprenticed to an instrument maker • in Glasgow. At the end of three years he re moved to London, in 1755, and placed himself with a mathematical Instrument maker ; but in little more than twelve months the state of his health compelled him to return to Scotland.
Shortly after his return from London, Watt established himself as an instrument maker within the precincts of Glasgow University. In 1763 Professor John Anderson, who then occupied the chair of natural philosophy in the university, having requested him to examine and repair a small model of New comen's steam-engine, which could never be made to work satisfactorily, his sagacity led' him to discover and remove the defects of this model; and he also discovered the im. perfections of the machine itself, and was led to investigate those properties of steam upon which its action depended. The character of • Watt's improvements is briefly noticed in the article STEAN-ENGINE: He next opened a shop in the Salt Market, Glasgow, where he continued to make improvements in the steam-engine; and where, in addition to his employment as a mathematical instrument maker, he devoted much time to the practice of land-surveying. He afterwards adopted the profession of a civil engineer. In 1768 he found in Dr. John Roebuck an individual capable of appreciating the value of his im provements in the steam-engine, and suffi ciently enterprising to support him in further experiments. The assistance of this gentle, man enabled him to set up an engine, for which he obtained a patent, Jan. 5, 1709. Matthew Boulton, of Soho near Birmingham, purchased Roebuck's share ; and in 1774 Boulton and Watt entered into partnership.
At the latter end of 1774 Watt completed at Soho his fourth model engine, which was exhibited to a deputation from the Cornish miners, and to other persons competent to judge of its performances, which were deemed highly satisfactory. Perfect however as was
the action of the improved machine, the patentees knew that much remained to be done to bring it into extensive operation; and they succeeded in obtaining an extension of the patent till the year 1800. Of the spirited manner in which 13oulton conducted the mercantile department of the great ad venture some idea may be formed from the fact, that upwards of 47,000/, was spent before the patentees began to receive any return; but at length their remuneration began to pour in, and in no scanty stream. They were, however, put to great expense by legal proceedings against infringements of their patent, and in defence of the patent itself.
At a social meeting of scientific men, a suggestion was thrown out which led Watt to the invention of the useful little machine known its the Gapping Press, for which he obtained a patent. Towards the latter end of 1780, on a visit to Delis, undertaken at the instance of the French government for the purpose of suggesting improvements on the Machine de Marly, Watt became acquainted with Berthollet, whose method of bleaching with chlorine he brought to this country, and introduced, with certain improvements of his own, in the bleach-works of Mr. Macgrigor, near Glasgow, whose daughter he had married in 1776.
Concerning Watt's share in the discovery of the composition of water, an investigation in which be, Cavendish, and Lavoisier, were engaged about the same time, we must refer those who aro curious to Arago's Life ox! 'Eloge' of Watt, and to the 'Historical Ac count of the Discovery of the* Composition of Water,' by Lord Brougham.
One of the last of the projects to which Watt devoted his attention after his retire ment from business was a machine for copy, ing sculpture, with which he proceeded so far as to execute several specimens.