Before bidding good-by to England, I must tell the luck I had in endeavoring to introduce Mr. Allen’s double-opening slide valve, shown in the general view of my London exhibit, now in common use the world over. No locomotive engineer would even look at it. Finally I got an order from Mr. Thomas Aveling for one of these valves with single eccentric valve-gear, to be tried on one of his road locomotives or traction engines. Mr. Aveling is known to fame as the inventor of the road locomotive and steam road roller. He once told me how he came to make this invention. He was a maker of portable engines in Rochester, which was the center of a wheat-growing district. These engines were employed universally to drive threshing machines. Horses were used to draw both the machine and the engine from farm to farm. The idea occurred to him that this was almost as foolish as was the practice of the Spanish muleteers, in putting the goods they transported on one side of the animal and employing a bag of stones on the other side to balance them. Why not make the engine capable of moving itself and drawing the threshing machine, and dispense with the horses altogether? So he applied himself to the job and did it. Then it was found that the self-propelling threshing-machine engines could draw a great many other things besides threshing machines, and the business grew to large proportions. Mr. Aveling made an engine with valve and valve-gear from my drawings, and I took a ride with him on it from Rochester to London, the engine drawing two trucks loaded with the two halves of a fly-wheel. The performance was entirely satisfactory. He said the engine was handled more easily than any other he ever made, and it maintained its speed in going up hill in a manner to astonish him, which was accounted for by the double valve opening. The little engine ran very rapidly, about 300 revolutions per minute, being geared down to a slow motion of the machine, about 4 miles travel per hour. With a single opening for admission it had admitted only a partial pressure of the steam, but the double opening valve admitted very nearly the whole pressure and made a sharp cut-off, all which I showed by the indicator. He told me that he was then filling a large order for traction engines for Australia, and this valve and valve-gear were the very thing for them. I went back to Manchester happy in the satisfaction of having accomplished one thing in the engine line at any rate.