[556]. Differential governing device. The motive power drives A which winds up the large weight; the small weight tending to run down, drives the fan regulator, and the two weights are so adjusted that when the proper speed is attained, both weights are stationary; any change of speed causes them to run up or down, so actuating the regulation by the bell crank lever and rod.
[557]. Varying differential regulator. The upper rod A is connected to the regulator valve or other device, and it is capable of receiving motion from either the piston, which acts against a spring, or from the rod B attached to some positive reciprocating part, so that the nett movement of A is due to the difference of motion of B and the piston C.
Differential Worm Gear, [No. 1559].
Section 32.—ENGINES (TYPES OF).
The following sketches are type drawings of the most important forms of Steam Engines in use, and are intended to afford a choice of outline arrangements from which in any scheme under consideration a selection may be made as a basis, without reference to details.
VERTICAL ENGINES.
[558]. Overhead cylinder engine.
[559]. Overhead crank engine,
[560]. Overhead crank engine, cylinder oscillating.