56 THE ADDRESSES, LECTURES, ETC., OF 



Laws was supplied in my opinion by James Watt when, just 100 

 years ago, he patented his invention of a hot working cylinder and 

 separate steam-engine condenser. After years of contest against 

 those adverse circumstances that beset every important innovation, 

 James Watt, with failing health and scanty means, was only 

 upheld in his struggle by the deep conviction of the ultimate 

 triumph of his cause. This conviction gave him confidence 

 to enlist the co-operation of, a second capitalist after the first 

 had failed him, and of asking for an extension of his declining 

 patent. 



Without this opportune help Watt could not have succeeded to 

 mature his invention. He would in all probability have relapsed 

 into the mere instrument maker, with broken health and broken 

 heart, and the introduction of the steam-engine would not only 

 have been retarded for a generation or two, but its final progress 

 would have been based probably upon the coarser conceptions of 

 Papin, Savory, and Newcomen. 



It can easily be shown that the perfect conception of the physi- 

 cal nature of steam, which dwelt, like a Heaven-born inspiration, 

 in Watt's mind, was neither understood by his contemporaries nor 

 by his followers up to very recent times, nor can it be gathered 

 from Watt's imperfect specification. James Watt was not satisfied 

 to exclude the condensing water from his working cylinder, and to 

 surround the same by non-conducting substances, but he placed 

 between the cylinder and the non-conducting envelope a source of 

 heat in the form of a steam-jacket, filled with steam at a pressure 

 somewhat superior to that of the working steam. His immediate 

 successors not only discarded the steam-jacket, and even condemned 

 it on the superficial plea that the jacket presented a larger and 

 hotter surface for loss by radiation than the cylinder, but expansive 

 working was actually rejected by some of them on the ground that 

 no practical advantage could be obtained by it. 



The modern engine, notwithstanding our perfected means of 

 construction, had in fact degenerated in many instances into a 

 virtual steam-meter, constructed apparently with a view of emptying 

 the boiler in the shortest possible space of time. 



It is only during the last twenty or thirty years that the subtile 

 action of saturated steam, in condensing upon the sides of the 

 cylinder when under pressure, and of evaporating when the 



