l important features. First,
the spindle sleeve is integral with the governor yoke, and the whole
rotates about a vertical stationary spindle, so that two motions are
encountered--a rotary motion and an up and down motion, according to the
position taken by the governor. This spiral motion almost entirely
eliminates the effect of friction of rest, and thereby enhances the
sensitiveness of the governor. Second, the governor weights move outward
on a parallel motion opposed directly by spring thrust, thus relieving
the fulcrum entirely of spring thrust. Third, the lay shaft driving the
governor oil pump and reciprocator is located underneath the main
turbine shaft, so that the rotor may be readily removed without in the
least disturbing the governor adjustment.

The Valve-Gear

The valve-gear is shown in section in Fig. 51, the main admission being
shown at V{1} at the right, and the secondary V{2} at the left of the
steam inlet. The pilot valve F receives a constant reciprocating motion
from the eccentric upon the layshaft of the turbine through the lever F
(Fig. 50). These reciprocations run from 150 to 180 per minute. The
space beneath the piston C is in communication with the large steam
chest, where exists the initial pressure through the port A; the
admission of steam to the piston C being controlled by a needle valve
B. The pilot valve connects the port E, leading from the space beneath
the piston to an exhaust port I.

[Illustration: FIG. 51]

When the pilot valve is closed, the pressures can accumulate beneath the
piston C and raise the main admission valve from its seat. When the
pilot valve opens, the pressure beneath the piston is relieved and it is
seated by the helical spring above. If the fulcrum E (Fig. 50) of the
lever F were fixed the admission would be of an equal and fixed
duration. But if the governor raises the fulcrum E, the pilot valve F
(Fig. 51) will be lowered, changing the relations of the openings with
the working edges of the ports.

The seating of the main admission valve is cushioned by the dashpot, the
piston of which is shown in section at G (Fig. 51). The valve may be
opened by hand by means of the lever K, to see if it is perfectly free.

The secondary valve is somewhat different in its action. Steam is
admitted to both sides of its actuating piston through the needle valves
M M, and the chamber from which this steam is taken is connected with
the under side of the main admissi