130 THE WATT AND THE TREVITHICK ENGINES. 



In 1804 an 8-inch cylinder high-pressure puffer- 

 engine, with steam of 48 Ibs. to the inch, worked a large 

 hammer as well as a 28-inch cylinder atmospheric engine, 

 and more economically than a Watt low-pressure steam 

 vacuum engine with an 18-inch cylinder, which was 

 five times as large as the little high-pressure. In con- 

 sequence of this superiority those who came to witness 

 the trial ordered several more of Trevithick's engines, 

 one of which with a 15-inch cylinder and 6-feet stroke 

 was to be at work in a few weeks. 



Watt wrote to Mr. Homfray " that he could not make 

 any of his experiments in strong steam answer the 

 purpose," and Trevithick declared Watt never could 

 have tried any experiments with high steam. 



Dixon refused to pay patent right because the words 

 of Mr. Watt's specification, " in cases where cold water 

 cannot be had in plenty, the engines may be wrought 

 by the force of steam only, by discharging the steam 

 into the open air after it has done its office," " are 

 enough to indemnify him." Eminent counsel were of 

 opinion that " the words in Watt's specification will 

 have no weight whatever." 



Marratt and Gribbs were inclined to rest on the 

 difference in the construction of the two kinds of 

 engines, while Erskine boldly said that the principle 

 was different, and he cared little for the kind of con- 

 struction. 



The admission by Watt that he could do nothing 

 with high steam after an experience of thirty years 

 from the date of his patent, shows how difficult the 

 work was to those who had to find the way ; yet Trevi- 

 thick had several at work within a few months of his 

 first mental sight of a steam-engine without condensing 

 water, fitful glimpses of which passed and repassed 



