Robinet. See [No. 1026].

Two- or three-cylinder engines, with slide valves operated either by eccentrics as in the steam engine, or by the oscillation of the cylinder. The slide valves have no lap or lead; there is no cushioning except what is given by an air vessel on the supply pipe. Three-cylinder engines are usually made single acting with rams. See [No. 1743].

[1741]. Single cylinder engines. These must have the slide or other distributing valve reversed by pistons A, A, operated by the pressure of the supply water. This is usually done by an auxiliary valve B, reversed by the main piston rod C. This valve admits the pressure water to the pistons A, A, which reverse the main slide valve. See [No. 1506]. See [note] below.

[1742]. Mode of working an underground pumping engine by water cylinders above ground, connected to those below by pipes A, A. B is the suction, C the delivery.

[1743]. One, two, or three cylinder water engine. The ports are in the segmental base of the cylinder, have no lap, and are opened and closed by the oscillation of the cylinder.

[1744]. Circular oscillating cylinder, in a case which opens and closes its ports by its own oscillation.

In lieu of the weighted lever valve gear for single cylinder water pressure engines, the engine may be arranged to compress a spring during the stroke, which at the end of the stroke shall be released, and by its expansion reverse the valve.


Section 94.—WASHING.

[1745]. Cylindrical revolving screen washer, for roots, &c.