president's address. 5 







the ranges used in steam engines, and that, consequently, the greater 

 the steam pressure and the greater the range of expansion the greater 

 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. Having regard to the state of knowledge 

 at the time, his conclusions appear to have been the result of close 

 and patient reasoning by a mind endowed with extraordinary powers 

 of insight into physical questions, and wdth the faculty of drawing 

 sound practical conclusions from numerous experiments devised to 

 throw light on the subject under investigation. His resource, courage, 

 and devotion were extraordinaiy. 



In commencing his investigations on the steam engine he soon 

 discovered that there was a tremendous loss in the Newoomen engine, 

 which he thought might be remedied. 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 matters, he was not 

 satisfied; his intuition probably told him that there should be some 

 better solution of the problem, and doubtless he made many experi- 

 ments 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 formulated by Carnot, Joule, and Kelvin, 

 the separate condenser is the obvious means of constructing an 

 economical 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 that steam pressures were practically limited to a 

 few pounds above atmospheric pressure. The cylinders and pistons of 

 his engines were not constructed with the facility and accuracy to which 

 we are now accustomed, and chiefly for these reasons expansion ratios 

 of from two to threefold were the usual practice. Watt had given 

 to the world an engine which consumed from five to seven pounds of 

 coal per horse-power hour, or one-quarter of the fuel previously used 

 by any engine. With this consumption of fuel its field under the con- 

 ditions prevaihng at the time was practically unlimited. What need 

 was there, therefore, for commercial reasons, to endeavour still further 

 improve the engine at the risk of encountering fresh difficulties and 

 greater commercial embarrassments ? The course was rather for him 

 1919. 



