AND STJIM-'ACK CnXDKXSKK. 333 



This machine will be ready before your return to Cornwall, and 

 I intend to prove it effectually before I go to Holland. 



" The Holland engine lifted on the trial, when they came 

 down to see it, 7200 gallons of water a minute 10 feet high 

 with 1 bushel of coal an hour; exceedingly good duty for a 

 small engine of 24-inch cylinder, being 34,560,000 of duty. 



"On the 17th August the trial comes on between the two 

 companies about the quays. They are as desperate as possible 

 on both sides, and castings and every other article are thrown 

 down to 30 per cent, below cost price ; iron pumps for 6s. 6d. 

 per cwt., and coal sold to the mines for 37s. 3d. per wey, when 

 48s. per wey on board ship was paid for it. Several thousands 

 lost per year by each party. This never can last long. If you 

 can think of any improvement I shall be very glad to hear in 

 time, before it may be too late to adopt it. At all events, if it 

 is not too much trouble to write, I shall be very glad to hear 

 from you. What effect do you think the water will have in 

 heating the steam on its passage to the top of the water from 

 the false bottom of the boiler ? 



" I have a cistern of cold water, with a proper condenser in it, 

 connected between the bottom of the boiler-case and the force- 

 pump to the bottom of the boiler, therefore I can partially 

 condense by cold water sides, or by cold air sides just as I 

 please, by rising or sinking the water in the cistern. 



" The boiler is made very strong to try different temperatures, 

 and an additional length to the water-pump makes all very 

 suitable for a great number of experiments, and if there is any 

 good in the thing I will bring it out. 



" I shall have indicators at different places to prove what 

 advantages can be gained. I hope to have the pleasure of your 

 company during those experiments, which I think will throw 

 more light on this subject than ever has yet been done. Some 

 trials since 1 last wrote to you make me very confident that 

 much good will arise from these experiments, but to what 

 extent is uncertain. 



" I remain, Sir, 



"Your most obedient servant, 



" KlCHARD TliEVITHICK." 



