394 JAMES WATT. 



of condensing steam in a vessel separate from the cylin- 

 der in which the mechanical action goes on was in 

 1765. Two years elapsed without his scarcely making 

 an effort to apply it on a large scale. His friends at last 

 put him in communication with Dr. Roebuck, founder of 

 the large works at Carron, still celebrated at the present 

 day. The engineer and the man of projects enter into 

 partnership ; Watt cedes two thirds of his patent to him. 

 An engine is constructed on the new principles : it con- 

 firms all the expectations of theory ; its success is com- 

 plete. But in the interim, Dr. Roebuck's affairs receive 

 various checks. Watt's invention would undoubtedly 

 have restored them : it would have sufficed to borrow 

 money ; but our associate felt more inclined to give up 

 his discovery and change his business. In 1767, while 

 Smeaton was carrying on some triangulations and level- 

 lings between the two rivers of the Forth and the Clyde, 

 forerunners of the gigantic works of which that part of 

 Scotland was to be the theatre, we find Watt occupied 

 with similar operations along a rival line crossing the 

 Lomond passage. Later, he draws the plan of a canal 

 that was to bring coals from Monkland to Glasgow, and 

 superintends the execution of it. Several projects of a 

 similar nature, and, among others, that of a navigable 

 canal across the Isthmus of Crinan, which Mr. Rennie 

 afterwards finished ; some deep studies on certain im- 

 provements in the ports of Ayr, Glasgow, and Greenock ; 

 the construction of the Hamilton and Rutherglen bridges ; 

 surveys of the ground through which the celebrated Cale- 

 donian Canal was to pass, occupied our associate up to 

 the end of 1773. Without wishing at all to diminish the 

 merit of these enterprises, I may be permitted to say that 

 their interest and importance was chiefly local, and to 



