I consented to the change in Philadelphia because this arrangement involved too much waste room, but the change was not satisfactory after all. I had become possessed with the idea that the engine running at high speed needed 50 per cent. more room for exhausting than for admission. This was not the case. I have always regretted that I did not retain this design, and content myself with reducing the exhaust area. The lightness of the piston in this view will be observed. This was a special design for adapting the engine to be run at 200 revolutions, giving 1200 feet piston travel per minute. The stuffing-box was a freak which was abandoned. The next figures show the valve-stem guides, rocking-levers, coupling-rods and gab, which latter when thrown over unhooks the link-rod, as is done on steamboat engines. The following figures show the construction of the main bearing with adjustments on opposite sides, by which the shaft is kept in exact line, and shows also the solid support of the shaft quite out to the hub of the crank. This view contains one error. The cap is not made a binder. I relied on the strength of the thick continuous web of the bed under the boxes in addition to the depth of the bed. But we once had a bed break right here under enormous strain, and since then the caps have been made binders. It will be observed that the wedges are drawn upward to tighten the boxes. It is not necessary to explain why. [Illustration: Main Bearing.] [Illustration: Eccentric and Crosshead Pin Lubricator.] [Illustration: Front View of Wiper Section on the Line a-b Center Line of Shaft Crank-pin Lubricator.] The above left-hand cut shows the automatic lubricator of the eccentric and the cross-head pin. The stud _A_, on the eccentric strap and on the strap of the connecting-rod, carries a curved blade, _a_, which at the beginning of each forward stroke rises to take the drop of oil from the stem of the sight-feed lubricator. This is set on an arm fixed on the cap of the main-bearing and on a bridge between the upper guide-bars. The drop is made sure to come to this central point by a wire _B_ filling the brass tube, grooved on opposite sides and terminating in a point. The automatic lubrication of the crank-pin presented a still more serious problem. It was solved by the construction shown, in the right hand view, which will be understood without further description. It will be seen that here the oil tube is inclined, and the drop follows it to a point on its lower side. Both these lubricators proved absolutely reliable. The last one is equally applicable on double-crank engines.