====+==================================+=========+======== | 51 ft. 24-inch Donb Belt 692 | 352.91 | | 2 lbs. Rivets 80 | 1.60 | | 1 „ Cement | 1.00 | | 1 Side Lacing | 5.00 | | Cartage | .50 | | 1 Cask | 1.25 | | Insurance | 4.15 | 366.52 | Collection 2¹⁄₂% | | 9.16 | | +--------- | | | 375.68 I put this belt on quite loose. The bottom side was the tight one, and the upper side hung in a loop nearly three feet deep. This exhibited the uniform running of the engine in a striking manner. As is well known, variations of speed produce waves in such a loop, the height of which waves indicates the amount of these variations. This belt hung motionless. The most careful observations on the loop did not indicate that it was running at all. The engine had no fly-wheel; the belt drum, 10 feet in diameter, served this purpose also. This showed the value in this respect of high speed, 150 turns per minute. This _absolute_ uniformity of motion surprised me, I knew nothing about the equalizing action of the reciprocating parts of the engine, to which this remarkable result was largely due. I was then absorbed in balancing, which was as far as I had advanced, and in this case, as previously in the governor, I “had builded better than I knew.” The accompanying diagrams are from a duplicate of the Pooley engine built at the same time for a Mr. Adams, a paper-maker in the north of England. This engine was directly connected to the line of shaft. I was called home from Paris to go to Mr. Adams’ mill and start that engine. Mr. Adams’ mill was not yet connected, and I was obliged to return to Paris after taking friction diagrams, of which the following are examples. [Illustration: ATMOSPHERE SCALE, 16 LBS. TO 1 INCH ATMOSPHERE SCALE, 16 LBS. TO 1 INCH Diagrams from Engine Built for Mr. Adams.] CHAPTER XIII The French Exposition of 1867. Final Break with Mr. Whitworth.