ENGINES FOR SOUTH AMERICA. 207 



finish. Mind, this is the 1st of October, and agreeable to pro- 

 mise the time is up. Mr. Uville wishes you to cast sixty carriage- 

 wheels for him, 11 inches in diameter from out to out, and to 

 weigh about 20 Ibs. ; cast them of strong iron, and of a strong 

 pattern, to take a 1 J-inch axle by 2J inches deep in the hole ; also 

 cast four plunger-pistons 11 inches dia- 

 meter to suit the 11-inch working barrels, 

 provided it should be used for the pur- 

 pose of a plunger. They must be in every 

 respect the same as the 14-inch plunger- 

 pistons, only 3 inches less in diameter. 



" Soon after the receipt of your next letter you may expect to 

 see us, as a vessel has been engaged to take all the boilers and 

 smith work on board to-morrow week for London. 



" 1 remain, Sir, 



" Your humble servant, 



"KicHARD TBEVITHICK. 



" MESSRS. HAZELDINE, RASTRICK, AND Co." 



Probably those cast-iron wheels were ordered with a 

 view to steam locomotion in the Cordilleras. An engine 

 is described in the invoice as having chimney, axles, 

 carriage-wheels, &c. 



[Rough draft]. 



"GENTLEMEN, "CAMBORNE, October llth, 1813. 



" On making the drawings of the engine with the winding 

 and crushing apparatus, when at work I find that if there is no 

 crank, but the sweep rod is connected to a pin in the arm of 

 the fly-wheel ; in that case the fly-wheel will cut off the engi- 

 neer from getting at the cock ; but if the sweep is connected 

 to a crank, then there will be sufficient room. The copy of 

 materials taken from your books and given to Mr. Uville does 

 not say in which way it was intended. I send you a sketch how 

 it will stand worked by a pin in the fly-wheel, and also if 

 worked by a crank over the cylinder, with the fly-wheel outside 

 the wood partition of the house. If you have cast all the parts 



