364 WAIT. 



obscure, Smith's ' Harmonics.' This treatise, of which 

 only the first and less perfect edition was then pub- 

 lished, must have been read and understood by the 

 young engineer. While employed by Dr. Roebuck at 

 his Works, he made a guitar for his daughter, after- 

 wards Mrs. Stuart, which she still possesses, and 

 relates the sum given for it to have been five guineas. 



It only remains to add that all the reading and all 

 the speculations of Watt were strictly confined to hours 

 which did not interfere with his profession or his trade of 

 an instrument maker. The whole of the day was devoted 

 to his business, only subject to the interruption of the 

 discussions raised by those who frequented his workshop 

 in search of assistance and information. It was late 

 in the evening, or rather in the night, that he prose- 

 cuted with zeal and close attention his philosophical 

 studies ; for his principle through life was steadily kept 

 in view, and uniformly acted on, never to let anything 

 whatever interfere with business, the transaction of 

 which he regarded as a primary duty to be performed, 

 and entitled, as such, to take precedence of all other 

 pursuits. 



There chanced to be among the apparatus of the 

 Natural Philosophy class a model of Newcomen's 

 steam-engine, which, from some defect in the construc- 

 tion, never could be got to work well ; and Mr. Watt 

 was desired to examine and report to the Professor, 

 Mr. Anderson, successor of Dr. Dick, and better known 

 afterwards as having founded by his will the class in 

 which Dr. Birkbeck taught the working men, and 

 thus gave rise to Mechanics' Institutes. The construc- 

 tion of this \vorking model was found to be exceedingly 



