M. Aragd's Memoir of James IVatt. 311 



their complexity and the noise they made in workingj and which well 

 exemplified the proverb, " heaucoup de bruit, peu de besogne." In 1786-87, 

 Mr Watt and Mr Boulton proceeded to Paris at the instance of the French 

 Government, to suggest improvements on this machine, which were not 

 carried into effect in consequence of financial difficulties, and the dismissal 

 of the ministry. Since then, a steam-engine has been erected by the 

 French to do part of the work ; and two of the wheels, with their appa- 

 ratus, are all that remain of this cumbersome machinery. 



" Adam Smith, Black,* and Robert Simson," (p. 228.) Dr Dick, the pro- 

 fessor of Natural Philosophy, might also, with propriety, have been in- 

 cluded in this number. Mr Watt and Mr Robison were alwa5'S accus- 

 tomed to speak of him as a most able man. He was also Mr Watt's 

 strenuous friend ; and it was through his recommendation that he went to 

 Mr Morgan. 



" He made out the scale of temperament," (p. 230.) See the article Tem- 

 perament in the Encyclopeedia Britannica, which is given in Brewster's 

 edition of Robison's Mechanical Philosophy, vol. iv. p. 412. 



" Another and a still more important change introduced by Captain Sa- 

 very, will more appropriately find a place in the remarks we shall presently 

 devote to the labours of Papin and Newcomen." — (p. 242.) 



We do not find, however, that farther mention is made under the heads 

 referred to, of any other improvements by Savery. But the fact is, that 

 Savery's engine consisted of two distinct principles ; raising water by the 

 condensation of steam, and likewise by the expansive power of steam. The 

 steam from the detached boiler was let into a vessel called a receiver, and 

 having driven out the air, was condensed by the affusion of cold water, 

 and a partial vacuum formed. A communication being then opened with 

 a suction-pipe, 24 feet in height, the lower end of which was placed in a 

 cistern or reservoir of water, that water was forced upwards, hy the pres- 

 sure of the atmosphere, into the receiver. When nearly filled, the com- 

 munication with the suction-pipe was shut off, and the steam readmitted 

 into the receiver, and by its expansive power, forced the water contained 

 in it up an ascending, or as he called it, a force pipe. This second ope- 

 ration is similar to that indicated by Solomon de Caus and by the Mar- 

 quis of Worcester, but which, as far as is certainly known, Savery was 

 the first to practise. The prior operation, that of raising the water into 

 a vacuum formed by the condensation of steam, we believe to have been 

 original with Savery. For although Papin described in the Acta Erudi- 

 torum of Leipzig for 1690, the condensation of steam in a cylinder hav- 

 ing a piston, it was a different application of the principle ; and it is not 

 likely that Savery knew of it when he invented his engine in 1696, or 



* An interesting letter by Watt, containing an account of hia connection with 

 Dr Black and Professor Robison, as well as remarlta on the origin of his im- 

 provements upon ihe Steam-Engine, will be found in the Edinburgli Philosophi- 

 cal Journal, vol. ii. p. 1. — Editok. 



