ENGINEERING BEFORE AND AFTER WAR 35 



will be the work obtained from a given amount of steam. 

 Secondly, as may now seem to us obvious, that steam 

 from its expansive force will rush into a vacuum. Hav- 

 ing regard to the state of knowledge at the time, his con- 

 clusions appear to have been the result of close and pa- 

 tient reasoning by a mind endowed with extraordinary 

 powers of insight into physical questions, and with the 

 faculty of drawing sound practical conclusions from 

 numerous experiments devised to throw light on the sub- 

 ject under investigation. His resource, courage and de- 

 votion were extraordinary. 



In commencing his investigations on the steam engine 

 he soon discovered that there was a tremendous loss in 

 the Newcomen engine, which he thought might be reme- 

 died. This was the loss caused by condensation of the 

 steam on the cold metal walls of the cylinder. He first 

 commenced by lining the walls with wood, a material of 

 low thermal conductivity. Though this improved mat- 

 ters, he was not satisfied; his intuition probably told 

 him that there should be some better solution of the prob- 

 lem, and doubtless he made many experiments before he 

 realised that the true solution lay in a condenser separate 

 from the cylinder of the engine. It is easy after discovery 

 to say, "How obvious and how simple," but many of us 

 here know how difficult is any step of advance when 

 shrouded by unknown surroundings, and we can well 

 appreciate the courage and the amount of investigation 

 necessary before James Watt thought himself justified in 

 trying the separate condenser. But to us now, and to the 

 youngest student who knows the laws of steam as for- 

 mulated by Carnot, Joule, and Kelvin, the separate con- 

 denser is the obvious means of constructing an economi- 

 cal condensing engine. 



Watt's experiments led him to a clear view of the great 

 importance of securing as much expansion as possible in 

 his engines. The materials and appliances for boiler and 

 machine construction were at that time so undeveloped 



