THE WATT AND THE TREV1THICK ENGINES. 153 



years afterwards, in 1806, a steam-cylinder burst in 

 Wales, therefore Mr. Williams, a large shareholder in 

 Dolcoath, objected to the use of high-pressure expansive 

 steam in their large Watt pumping engine, and desired 

 their engineer, Mr. Sims, to make a competitive trial 

 after his own fashion. At Condurrow Mine one of 

 Trevithick's engines was to be ordered if the Foxes and 

 Williamses did not object ; and so it was that Trevi- 

 thick's high-pressure steam-boiler was not ordered, and 

 the Watt vacuum engine was for a longer time to 

 receive no increase of power. 



"Some of Captain Dick's early boilers had flattish or oval 

 fire-tubes. In 1820 I repaired an old one in Wheal Clowance 

 Mine in Gwinear. The flat top had come down a little ; we put 

 in a line of bolts, fastening the top of the tube to the outer 

 casing. 



"About 1818 I saw in Carsize Mine in Gwinear a pumping 

 engine that Captain Dick had put up. The boiler was a cylinder 

 of cast iron, with a wroiight-iron tube going through its length 

 in which the fire was placed. The steam-cylinder was vertical, 

 fixed in the boiler. She had an air-pump and worked with a 

 four-way cock. The steam was about 100 Ibs. to the inch." 1 



"About 1820 I removed one of Captain Trevithick's early 

 high-pressure whim-engines from Creuver and Wheal Abraham, 

 and put it as a pumping engine in Wheal Kitty, where it con- 

 tinued at work for about fifteen years. The boiler was of cast 

 iron, in two lengths bolted together, about 6 feet in diameter 

 and 10 feet long. At one end a piece was bolted, into which 

 the cylinder was fixed, so that it had the steam and water 

 around it. There was an internal wrought-iron tube that turned 

 back again to the fire-door end, where the wrought-iron chimney 

 was fixed ; the fire-grate end of the tube was about 2 feet 

 (3 inches in diameter, and tapered down to about 1 foot 6 inches 

 at the chimney end. It was a puffer, working 60 Ibs. of steam 



1 Ban field's recollections in 1869. 



