This sleeve has cut upon it the right and left handed screws for
adjusting the cut-off valves; and it slides freely upon a central
spindle which has no longitudinal motion, but, projecting through the
upper end of the valve chest, can be turned at pleasure by means of a
bevel wheel and pinion. The rotation of the spindle is communicated to
the sleeve by means of two steel keys fixed in the body of the latter
and projecting inwardly so as to slide in corresponding longitudinal
grooves in the spindle.

Thus the point of cutting off is varied at will while the engine is
running, by means of the hand wheel on the horizontal axis of the bevel
pinion, and a small worm on the same axis turns the index, which points
out upon the dial the distance followed. These details are shown in
Figs. 3, 4, and 5; in further explanation of which it may be added that
Fig. 3 is a front view of the valve chest and its contents, the cover,
and also the balance plate for relieving the pressure on the back of the
main valve (in the arrangement of which there is nothing new), being
removed in order to show the valve stems, transverse yoke, sleeve, and
spindle above described. Fig. 4 is a longitudinal section, and Fig. 5 is
a transverse section, the right hand side showing the cylinder cut by a
plane through the middle of the exhaust port, the left hand side being a
section by a plane above, for the purpose of exhibiting more clearly the
manner in which the steam is admitted to the valve chest; the latter
having no pipes for this service, the steam enters below the valve, at
each end of the chest, just as it escapes in the center.

The second noteworthy feature consists in this: that the cut-off
eccentric is not keyed fast, as is customary when valve gear of this
kind is employed, but is loose upon the shaft, the angular position in