lathe work; in fact the whole of the work may be done on a very ordinary
foot lathe. The engine is necessarily single-acting, but it is effective
nevertheless, being about 1-20 H. P., with suitable steam supply. It is
of sufficient size to run a foot lathe, scroll saw, or two or three
sewing machines.

The cylinder and piston are made from mandrel drawn brass tubing, which
may be purchased in any desired quantity in New York city. The fittings
are mostly of brass, that being an easy metal to work.

The principal dimensions of the engine are as follows:

Cylinder.--Internal diameter, 11/2 in.; thickness, 1/8 in.;
length, 3-3/8 in.

Piston.--External diameter, 11/2 in.; thickness, 3-32 in.; length,
33/4 in.

Length of stroke. 2 in.

Crank pin.--Diameter, 1/4 in.; length of bearing surface, 1/2 in.

Connecting rod.--Diameter, 5/16 in.; length between centers, 51/2
in.

Shaft.--Diameter, 5/8 in.; diameter of bearings, 1/2 in.; length. 6
in.; distance from bed to center of shaft, 11/2 in.

Flywheel.--Diameter, 8 in.; weight, 10 lb.

Valve.--Diameter of chamber, 9-16 in.; length, 11/4 in.; width of
valve face working over supply port, 3/32 in.; width of space under
valve, 3/8 in.; length of the same, 1 in.; distance from center of
valve spindle to center of eccentric rod pin, 3/4 in.

Ports, supply--Width, 1/16 inch.; length, 1 in. Exhaust.--Width,
1/8 in.; length, 1 in.; space between ports, 5-16 in.

Pipes.--Steam supply, 1/4 in.; exhaust, 3/8 in.

Eccentric.--Stroke, 3/4 in.; diameter, 1-5/16 in. length of
eccentric rod between centers, 8-3/8 in.

Cut off, 5/8

Thickness of base plate, 1/4 in.

Wooden base, 61/4 in x 8 in.: 2-3/8 in. thick.

Thickness of plate supporting cylinder, 3/8 in.

Total height of engine, 131/4 in.

Distance from base plate to under side of cylinder head. 91/4 in.

Diameter of vertical posts, 9-16 in.; distance apart, 31/2 in.;
length between shoulders 61/4 in.

Base plate fastened to base with 1/4 in. bolts.

The connecting rod, eccentric rod, crank pin, and shaft, are of
steel. The eccentric-strap and flywheel are cast iron, and the other
portions of the engine are of brass. The screw threads are all
chased, and the flange, a, and head of the piston, F, in addition to
being screwed, are further secured by soft solder.

Fig. 1 shows the engine in perspective. Fig 2 is a side elevation,
with parts broken away. Fig. 3 is a vertical transverse section.
Fig. 4 is a par