"Mr. J. Rawlings, Strood, Kent."
"Camborne, 28th August, 1813.
"Dear Trevithick,
"Camborne, 28th August, 1813.
"Messrs. Hazeldine, Rastrick, and Co.,
"Gentlemen,—Lord Dedunstanville's engine thrashed yesterday 1500 sheaves in 90 minutes with 40 lbs. of coal.
"Rd. Trevithick."
The first steam thrashing engine was worked by a labouring man for eighteen months, without needing repair, or even attention beyond three or four minutes each hour to put on a little coal.
Necessary stoppages for various purposes caused a day's work to be no more than the engine could perform in half a day. No additional feed-water was required during an ordinary day's work to thrash 1500 sheaves of wheat with 168 lbs. of coal, while on a special occasion that quantity was thrashed in an hour and a half, consuming only 40 lbs. of coal. Three horses during three days were required to do the same amount of work. A farmer sold his horses used in thrashing for more money than his engine cost, which did twice as much work at a reduced expenditure, and also saved the feed of the horses.
Such an engine could be delivered in London for 100 guineas, while a portable engine on wheels with a differently constructed boiler, requiring no mason work, would cost 160 guineas.