CAPTIVE MOLECULES 



THE COMING OF JAMES WATT 



The Newcomen engine had low working efficiency as 

 compared with the modern engine; nevertheless, some 

 of these engines are still used in a few collieries where 

 waste coal is available, the pressure enabling the steam 

 to be generated in boilers unsafe for other purposes. 

 The great importance of the Newcomen engine, how- 

 ever, is historical ; for it was while engaged in repairing 

 a model of one of these engines that James Watt was 

 led to invent his plan of condensing the steam, not in the 

 working cylinder itself, but in a separate vessel, 

 the principle upon which such vast improvements in the 

 steam engine were to depend. 



It is impossible to overestimate the importance of the 

 work which Watt accomplished in developing the steam 

 engine. Fully to appreciate it, we must understand 

 that up to this time the steam engine had a very limited 

 sphere of usefulness. The Newcomen engine repre- 

 sented the most developed form, as we have seen; and 

 this, like the others that it had so largely superseded, 

 was employed solely for the pumping of water. In 

 the main, its use was confined to mines, which were 

 often rendered unworkable because of flooding. We 

 have already seen that a considerable number of en- 

 gines were in use, yet their power in the aggregate 

 added but a trifle to man's working efficiency, and the 

 work that they did accomplish was done is a most 

 uneconomical manner. Indeed the amount of fuel re- 

 quired was so great as to prohibit their use in many 

 mines, which would have been valuable could a cheaper 



[93] 



