[Fig. 183]. One of the many forms of rotary engine. A is a cylinder having the shaft B pass centrally through it. The piston C is simply an eccentric fast on the shaft, and working in contact with the cylinder at one point. The induction and eduction of steam take place as indicated by arrows, and the pressure of the steam on one side of the piston produces its rotation and that of the shaft. The sliding abutment D, between the induction and eduction ports, moves out of the way of the piston to let it pass.
Figs. 181, 182, 183. For drawing curves. Rotary engine
[Fig. 184]. Another form of rotary engine, in which there are two stationary abutments D, D, within the cylinder; and the two pistons A, A, in order to enable them to pass the abutments, are made to slide radially in grooves in the hub C of the main shaft B. The steam acts on both pistons at once, to produce the rotation of the hub and shaft. The induction and eduction are indicated by arrows.
[Fig. 185]. Jonval turbine. The shutes are arranged on the outside of a drum, radial to a common centre, and stationary within the trunk or casing b. The wheel c is made in nearly the same way; the buckets exceed in number those of the shutes, and are set at a slight tangent instead of radially, and the curve generally used is that of the cycloid or parabola.
[Fig. 186]. A method of obtaining a reciprocating motion from a continuous fall of water, by means of a valve in the bottom of the bucket which opens by striking the ground, and thereby emptying the bucket, which is caused to rise again by the action of a counterweight on the other side of the pulley over which it is suspended.
Figs. 184, 185, 186. Different forms of water movements