138 WATT. 



determined him to commence his career as a mathematical instru- 

 ment maker. For this purpose he set out for Glasgow in 1754, but 

 owing to the limited resources of the town at that period, he finally 

 decided on going to London, where, after great difficulty, he was 

 apprenticed for a twelvemonth to an instrument maker in Finch 

 Lane. At the end of his apprenticeship Watt, having become en- 

 feebled from over attention to work, repaired to Greenock to recruit 

 his health, and ultimately returned to Glasgow, where he was estab- 

 lished by the authorities, within the precincts of the college as 

 mathematical instrument maker to the University. In process of 

 time Watt's shop became a favourite resort for professors as well as 

 students, and he counted among his visitors Professor Simson, Drs. 

 Black, Dick, and Moor;* but his most intimate friend, and the one 

 most closely connected with his after life, was John Robison, a 

 student at Glasgow, afterwards Professor of Natural Philosophy at 

 Edinburgh University, to whom the honour is due of having first 

 directed Watt's attention to the steam-engine. The event which 

 actually led to the commencement of his invaluable discoveries on 

 this subject, was the entrusting to him the repair of a small model 

 of Newcomen's engine, which the college possessed. In his endea- 

 vours to put this engine into working order, Watt was led to in- 

 vestigate thoroughly the properties of steam upon which its action 

 depended ; and ultimately in the spring of 1765, after many trials 

 and untiring perseverance, he arrived at the great and simple idea 

 of a separate condenser, into which the steam expanded ; thereby 

 preventing that wasteful expenditure of heat, which was the neces- 

 sary result of the old plan of condensing the steam in the working 

 cylinder, by admitting a jet of cold water directly under the piston. 

 In addition to this Watt surrounded the cylinder with a second 

 casing to be filled with the surplus steam, for the purpose of pre- 

 venting radiation of heat, and closed in the top (which in Newco- 

 men's engine had been left open for the sake of the pressure of the 

 atmosphere upon the piston) by putting a cover on, with a hole and 

 stuffing box for the piston rod to slide through ; a plan which en- 

 abled steam pressure to be used in place of atmospheric. Newcomen's 



* During his residence at Glasgow, a Mason's Lodge were desirous of pos- 

 sessing an organ, and Watt was asked to build it. He was totally destitute of a 

 musical ear, and could not distinguish one note from the other, but he neverthe- 

 less accepted the offer ; for having studied the philosophical theory of music, he 

 found that science would be a substitute for want of ear. He commenced by 

 building a small one for Dr. Black, and then proceeded to the large one, in the 

 building of which he devised a number of novel expedients, such as indicators 

 and regulators of the strength of the blast, with various contrivances for im- 

 proving the efficiency of the stops. The qualities of this organ when finished 

 are said to have elicited the surprise and admiration of musicians. During 

 this period of his life Watt used likewise to construct and repair guitars, flutes, 

 and violins, and had the same success as with his organ. Quarterly Revieie, 

 October, 1858. 



