REGULATION OF STEAM.

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to work in any other grade than full gear; but should it be desirablethe lifting lever can be made longer, and so arranged as to travelmerely a portion of the circle, keeping the lifting link nearly verticalthroughout. Thus the Suspension of the link in this manner isbetter calculated for working expansively; but it must be borne inmind that when the slide-valve works for any length of time in anintermediate position it is apt to wear a hollow on the cylinder face.Instead of the two rods for the slide-valve, as in the previous ex-ample, with the return eccentric rod System retained, one valve rodhas been substituted, placed above the main shaft of the engine. Theaction cannot be so good as with two rods, owing to the eccentricrods working at a considerable angle, the proper position being inas nearly a straight line as possible with the valve rods. When sofitted for direct action the valve rod is guided with a suitable cross-head, placed at the side of the rod. This works in cast-iron guides,bolted to the valve-casing; the link is suspended similar to the

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Fig. 59-—Link Motion and Starting Gear for Marine Engines.

locomotive arrangements, thus working expansively by the link.The plan may be adopted for small engines, but undoubtedly forlarge power there should be a separate valve for working expansively.The brackets for taking the reversing lever are placed on the mainframing, the starting wheel is on its edge or at an inclination; theshaft for carrying it is supported at both ends, and is fitted with a