TIIK WATT AND THE TKKVITHICK ENGINKS. 171 



made, did sixteen millions. These trials in 1792 and 

 1798 enable us to compare the Newcomer), the Horn- 

 blower, and the Watt engines ; shortly after which Tre- 

 vithick tried higher steam in one or more of those 

 same engines from his globular boiler. 1 



" SIR CH. HAWKINS, " CAMBOBSE, March 10th, 1812. 



" Sir, This day I shall attend the account at Wheat 

 Prosper Mine, in Gvvythian, to contract with the adventurers 

 for erecting a steam-engine on my improved plan, for drawing 

 the water 50 fathoms under the adit. I called on Wheal 

 Liberty adventurers at St. Agnes last week, and found that 

 several of them had given up their shares rather than put in a 

 new engine, and the remainder of them very sick. 



"I told them that I would fork the water with the present 

 engine, and draw instead of 40 gallons each stroke, 47 fathoms 

 deep (which she did), 85 gallons per stroke, 65 fathoms deep, 

 by altering the engine on the same principle as I have done 

 with the Dolcoath great engine, and several more that are now 

 altering. The expense of altering the engine, and forking the 

 water to bottom, and proving the mine, will not exceed 10007. 



" All the adventurers are very anxious to again resume their 

 shares and make the trial, on condition that I will undertake 

 the completion of the job at a certain sum, but not. otherwise. 



" I am certain, from what Dolcoath engine is doing, that I 

 can far exceed the power above stated, and perform the duty 

 with one-half the coal the engine consumed before, and would 

 not hesitate a moment to engage the job on the terms they 

 propose, but I have not money sufficient to carry it into execu- 

 tion, as I must lay out a large sum in erecting the engine on 

 the Gwythian Mine, and unless I can be assisted with 500/., 

 shall not be able to undertake the job. 



" If you think it worth your notice to encourage this under- 

 taking by lending me the above sum for six months, I will pay 

 you interest for it, and before drawing any part of it from you 

 would get materials in the mine that should amount to above 



1 Sec vol. ii. p. 11!. 



