THE WATT AND THE TREVITHK'K EXdlXKS. 141 



the head man over the engines, made a trial between Trevi- 

 thick's hio-h-pressiire puffer whim and Watt's low-pressure con- 

 denser. When Captain Trevithick heard of it, he wrote down 

 from London that he would bet Glanville 50Z. that his high- 

 pressure puffer should beat Watt's low-pressure condenser. Then 

 he came down from London and found that the piston of his 

 engine was half an inch smaller in diameter than the cylinder. 

 When a new piston was put in, she beat Boulton and Watt all 

 to nothing. Persons were chosen to make a three or four 

 weeks' trial, and when it was over, ' a little pit was found with 

 coal buried in it, that Glanville meant to use in the Watt 

 engine.' " 1 



Pooly, Smith, and others, say that Trevithick's 

 Dolcoath puffer had the outer case of the boiler of cast 

 iron, the fire-tube of wrought iron, the cylinder hori- 

 zontal, and fixed in the boiler. Captain Joseph Yivian 

 saw Trevithick's whim in Stray Park Mine about 1800 

 or 1801, and a similar one was erected in Dolcoath, and 

 after a year or two a Boulton and Watt low-pressure 

 whim was put up to beat it. The trial was in favour 

 of the Watt engine, but everybody said the agents were 

 told beforehand which way the report ought to go ; so 

 the engine that puffed the steam up the chimney was 

 beaten. 



Trevithick, who was busily engaged in Manchester 

 at that time, the early part of 1805, when informed ot 

 what was going on in Cornwall, wrote : 



" I fear that engine at Dolcoath will be a bad one. I never 

 knew anything about its being built until you wrote to me 

 about Penberthy Crofts engine, when you mentioned it. I 

 then requested Captain A. Vivian to inform me the particulars 

 about it, and I find that it will not be a good job. I wish it 

 never was begun." 2 



1 Recollections of Henry Clark, living at Redruth in 1869. 



2 See Trevithick's letter, January 10th, 1805, vol. i., p. 324. 



