ts E 1 and K
could not show dark through the port D. They might, of course, be shown
by dotted outlines, but they would not appear to such advantage, and on
this account it is permissible where artistic effect is sought, the
object being to subserve the shading to making the mechanism and its
operation clearly and readily understood.

[Illustration: Fig. 306.]

Figure 307 affords another excellent example for shading. It consists of
an independent condenser, whose steam-cylinder and valve mechanism is
the same as that described with reference to Figures 305 and 306.

[Illustration: Fig. 307. (Page 288.)]

[Illustration: Fig. 308. (Page 289.)]

[Illustration: Fig. 309. (Page 289.)]

[Illustration: Fig. 310--SECTION OF CYLINDER AND STEAM CHEST. (Page
289.)]

CHAPTER XV.

_EXAMPLES IN ENGINE WORK._

In the figures from 308 to 328 inclusive are given three examples in
engine work, all these drawings being from _The American Machinist_.
Figures 308 to 314 represent drawings of an automatic high speed engine
designed and made by Professor John E. and William A. Sweet, of
Syracuse, New York. Figure 308 is a side and 309 an end view of the
engine. Upon a bed-plate is bolted two straight frames, between which,
at their upper ends, the cylinder is secured by bolts. The guides for
the cross-head are bolted to the frame, which enables them to be readily
removed to be replaned when necessary. The hand wheel and rod to the
right are to operate the stop-cock for turning on and off the steam to
the steam-chest.

The objects of the design are as follows: Figure 310 is a vertical
section of the cylinder through the valve face, also showing the valve
in section, and it will be seen that the lower steam passage enters the
cylinder its full depth below the inside bottom, and that the whole
inside bottom surface of the cylinder slopes or inclines towards the
entrance of this passage. The object of this is to overcome the
difficulty experienced from the accumulation of water in the cylinder,
which, in the vertical engine, is usually a source of considerable
annoyance and frequently the cause of accident.

Any water that may be present in the bottom finds its way by gravity to
the port steam entrance, and is forced out by and with the exhaust steam
at or before the commencement of the return stroke.

To assist in the escape of water from the top of the cylinder, the
piston is made quite crowning at that end, the effect