"I have been waiting your answer to my last, and especially that part respecting the West India engine, as there is a large field there for engines of this kind. I have received an order for a thrashing engine for Lord de Dunstanville of Tehidy, and as I wish those thrashing engines to be known through the country, I intend to take one of the engines ordered for Padstow and send it to Tehidy; one of the Padstow farmers can wait until you make another for him; therefore I would thank you to send the first finished by ship from Bristol for Portreath or Hayle. Send a drum with everything complete, of which you are a better judge than I; probably about 3 feet in diameter and 3-1/2 feet long will be sufficient. There must be a fly-wheel, with a notch to carry the rope, and also a small notch wheel on the drum-axle. I think 6-1/2 feet diameter for the fly and 9-1/2 inches diameter for the small wheel, will give speed enough to the drum. Mind to cast a lump or screw on a balance of about 1 cwt. on one side of the wheel. There must be two stands on the boiler, and a crank-axle or otherwise a crank-pin in the fly-wheel, whichever you please; with a shaft 3 feet long with a carriage. The engine to stand in a room under the turn-about, 7-1/2 feet high, 7 feet wide, and 17 feet long. The fly-wheel will stand across the narrow way of the room. The rope will go up through the floor and the drum be shifted by a screw, horizontally on the barn floor, so as to tighten the rope. I shall put down the top of the boiler level with the surface, with an arched way to the fire and ash-pit underground to prevent the chance of fire, which the farmers are very much afraid of. [Footnote 12: See rough draft, Trevithick's letter, 7th December, 1812, chap. xvii.] "I send you a sketch showing how it is to stand. I do not bind you to the size of the drum or wheels, only the room that the fly-wheel works in is but 7 feet wide. Put the engine and drum for Lord de Dunstanville out of hand neat and well, as it will be well paid for, and make the stands, &c., in your own way." This description of Lord Dedunstanville's thrashing machine illustrates the drawing of that supplied to Sir Charles Hawkins. [Rough draft.] "MR. RASTRICK, "CAMBORNE, _January 26th, 1813_.