faces on emery cloth supported by an old looking-glass.

[Illustration: FIG. 68.-Wall-piece for steam chest, with gland and valve
rod in position.]

Two perfectly flat plates of 1/8-inch brass are cut to the size given in
Fig. 59, or a little longer both ways, to allow for working down to the
same area as the wall-piece. This operation should be carried out after
soldering the three pieces together. File and rub the sides until no
projections are visible. Then drill twelve 3/32-inch holes right through
the three parts. After separating them, the holes in the walls and what
will be the cover must be enlarged to an easy fit for 1/8-inch bolts, and
the valve plate tapped.

Now drill 3/16-inch holes centrally through the ends of the walls for the
valve rod. If the first hole is drilled accurately, the second hole should
be made without removing the drill, as this will ensure the two holes being
in line. If, however, luck is against you, enlarge the holes and get the
rod into its correct position by screwing and soldering small drilled
plates to the outside of the chest. Also drill and tap a hole for the
lubricator. The attachment of the gland (Fig. 54, G2) is similar to that of
the cylinder gland, and therefore need not be detailed.

The Valve Plate (Fig. 59).--Three ports must be cut in this--a central
one, 7/8 by 3/32 inch, for the exhaust; and two inlets, 7/8 by 3/32 inch,
1/8 inch away from the exhaust. These are easily opened out if a series of
holes be drilled along their axes.

[Illustration: FIG. 69.--Valve plate.]

The Steam Ways.--The formation of the steam ways between valve plate and
cylinder is the most ticklish bit of work to be done on the engine as it
entails the making of a number of solder joints close together.

[Illustration: FIG. 60.--Piece for steam ways.]

We begin by cutting out of 1/20-inch sheet brass a piece shaped as in Fig.
60. Parallel to the long edges, and 3/8 inch away, scribe bending lines.
Join these by lines 5/8 inch from the short edges, and join these again by
lines 1/4 inch from the bending lines. Cuts must now be made along the
lines shown double in Fig. 60. Bend parts CC down and parts BB upwards, so
that they are at right angles to parts AA. The positions of these parts,
when the piece is applied to the cylinder, are shown in Fig. 62.

[Illustration: FIG. 61.--Valve plate and steam ways in section.]

One must now make the bridge pieces (Fig. 61, a, a) to separate the inlet