Fig. 45. The Harris Corliss Engine
The standard Harris Corliss engine shown in [Fig. 45], is typical of its class. It is provided with the girder type of frame, and with an outboard bearing mounted upon a stone foundation. The valve gear is of the regular Corliss type, driven by a single eccentric and wrist-plate. The dash pots are mounted on cast-iron plates set in the floor at the side of the engine, where they may be easily inspected. The governor is similar in construction to the one already described, and shown in [Fig. 27]. The four engines so far described are simple engines, the expansion taking place in a single cylinder. [Figs. 46] to [48] show three different types of the compound engine.
Fig. 46. The Skinner Tandem Engine
The engine shown in [Fig. 46] is of a type known as the tandem compound. In this design the cylinders are in line, the low-pressure cylinder in front of the high-pressure, as shown. There is only one piston rod, the high-pressure and low-pressure pistons being mounted on the same rod. The general appearance of an engine of this design is the same as a simple engine, except for the addition of the high-pressure cylinder. The governor is of the shaft type and operates by changing the cut-off in the high-pressure cylinder. The cut-off in the low pressure cylinder is adjusted by hand to divide the load equally between the two cylinders for the normal load which the engine is to carry.
Fig. 47. American Ball Duplex Compound Engine