LE 1-1/2" = 1 FOOT. (Page 299.)]

Figure 321 represents a side elevation of the cylinder, and Figure 322
an end view of the same, the expansion support being for the purpose of
permitting the cylinder to expand and contract under variations of
temperature without acting to bend the bed-plate, while at the same time
the cylinder is supported at both ends. The cylinder and cylinder covers
are jacketted with live steam in the steam-spaces shown.

[Illustration: Fig. 323--100 H.P. ENGINE--OUTSIDE VIEW OF CYLINDER AND
STEAM-CHEST. (Page 301.)]

[Illustration: Fig. 324--SECTIONAL VIEW OF CYLINDER AND VALVES--SCALE
1-1/2 INCHES = 1 FOOT. (Page 301.)]

[Illustration: Fig. 325--PLAN OF CUT-OFF DEVICE. (Page 301.)]

[Illustration: Fig. 326--WORKING DRAWING OF 100 H.P. ENGINE--DETAILS OF
MAIN VALVE MOTION--SCALE 3" = 1 FOOT. (Page 301.)]

[Illustration: Fig. 328--100 H.P. HORIZONTAL STEAM-ENGINE--CROSS HEAD.
(Page 301.)]

[Illustration: Fig. 329.
Fig. 329 _a_. Working Drawings of 100 H.P. Steam Engine--Eccentric and
Eccentric Strap--Scale: 3" = 1 Foot. (Page 301.)]

[Illustration: Fig. 330--100 H.P. HORIZONTAL STEAM-ENGINE--CONNECTING
ROD. (Page 303.)]

A view of the steam-chest side of the cylinder is given in Figure 323,
and a horizontal cross section of the cylinder, the steam-chest and the
valves, is shown in Figure 324. The main valves are connected by a right
and left hand screw, to enable their adjustment, as are also the cut-off
valves.

Figures 325 and 326 show the cam wrist plate and the cut-off mechanism.
The cam wrist plate, which is of course vibrated by the eccentric rod,
has an inclined groove, whose walls are protected from wear by steel
shoes. In this groove is a steel roller upon a pin attached to the bell
crank operating the main valve stem. The operation of the groove is to
accelerate the motion imparted from the eccentric to the valve at one
part of the latter's travel, and retard it at another, the accelerated
portion being during the opening of the port for steam admission, and
during its closure for cutting off, which enables the employment of a
smaller steam-port than would otherwise be the case.

The shaft for the cam plate is carried in a bearing at one end, and fits
in a socket at the other, the socket and bearing being upon a base plate
that is bolted to the bed-plate of the engine; a side view of the
construction being shown in Figure 327.

Figure 328 represents the cross-head, whose wr