PHYSICS OF THE EIGHTEENTH CENTURY. 



supplied to the force-pump M to feed the boiler. The comparison of 

 Fig. 146 with Fig. 147, in conjunction with the remarks made above, 

 will, it is hoped, enable the intelligent reader to clearly perceive the 

 principles by which Watt converted the mere draining-pump of New- 

 comen into the steam-engine. 



FIG. 147. WATT'S ENGINE. 



The story of successful inventions and continued prosperity which 

 marked Watt's career from the period (1774) when he became con- 

 nected with Boulton in the gigantic manufacturing establishments at 

 Soho near Birmingham, has been told too often to require recapitula- 

 tion here. Watt retained his intellectual faculties to the last. In the 

 last months of his life he was occupied in devising a machine for 

 copying statuary with mathematical precision. Some examples of 



