Mr. Corliss had already discarded the flanged boxes. He also first made this bearing in four parts. The wear in the horizontal direction, the direction of the thrust, could then be taken up. For this purpose he used two bolts behind the front side box only. I modified his construction by making the side boxes wider and taking up their wear by wedges behind both of them, thus preserving the alignment. One wedge could also be placed close to the crank. The dotted lines show the width of the side boxes and the location of the wedges. The shaft was made with a collar to hold the bearings in place, and was enlarged in its body. The substitution in place of the crank of the entire disk carrying a counterweight completed these changes. This was the fruit of my first lesson in high-speed engine designing, which had unconsciously been given to me by Mr. Sparks. The oil passage in the pin was added later, as will be described. I had another piece of good luck. I happened one day to see in the Novelty Iron Works the hubs being bored for the paddle-wheels of the new ship for the Collins line--the “Adriatic.” These were perhaps the largest castings ever made for such a purpose. I observed that they were bored out only half-way around. The opposite side of the hole had been cored to about half an inch greater radius, and three key-seats were cored in it, which needed only to be finished in the key-seating machine. The idea struck me that this would be an excellent way to bore fly-wheels and pulleys. As commonly bored, so that they could be put on the shaft comfortably they were bored too large, their contact with the shaft could then be only on a line opposite the key, and the periphery could not run perfectly true. I adopted the plan of first boring to the exact size of the shaft and then shifting the piece about an eighth of an inch, and boring out a slender crescent, the opposite points of which extended a little more than half-way around. The keyway was cut in the middle of this enlargement. The wheel could then be readily put on to the shaft, and when the key was driven up contact was made over nearly one half the surface and the periphery ran dead true. I remember seeing this feature much admired in London, and several times heard the remark, “I should think the key would throw it some.” To prevent fanning I made the fly-wheel and pulley with arms of oval cross-section. These have always been used by me. They have done even better than I expected. They are found to impart no motion to the air, however rapidly they may be run. [Illustration: Flanges on the Eccentric.] [Illustration: Flanges on the Strap.]