hrough the port from the cylinder side shows that the port is again fully
exposed. Insert and mark the bar again. The distance between the marks
gives you the "travel" required.

Order of Assembly.--The following list of operations in their order may
assist the beginner:

Make the bed.

Cut out cylinder barrel, piston, and valve tube.

Bevel off the ends of the last inside to allow the valve to enter easily.

Make the valve.

Bore the steam ports, and solder valve tube and cylinder together.

Solder holding-down wing, W, to cylinder.

Finish off the piston.

Solder the bearings in their standards.

Prepare shaft, crank disc, crank pin, and piston rod.

Fix the cylinder to the bed, in which a slot must be cut for the wing and
holding-down bolt.

Attach the piston rod to the piston, and insert piston in cylinder.

Bore hole for shaft in centre of crank disc, and another, 9/16 inch away
(centre to centre), for crank pin.

Solder in crank pin squarely to disc.

Pass shaft through bearings and slip on the crank disc.

Pass front end of piston rod over the crank pin.

Lay bearing standard on bed squarely to the centre line of the cylinder,
turn crank fully back, and move the standard about till the back end of the
piston clears the back end of the cylinder by about 1/32 inch.

Get standard quite square, and adjust sideways till connecting rod is in
line with axis of cylinder.

Mark off and screw down the standard.

Make the eccentric, eccentric rod, and strap. Slip eccentric on shaft.

Put valve in position and draw it forward till the port is exposed.

Turn the eccentric forward, and mark the rod opposite centre of valve pin.

Bore hole for pin, and insert pin.

Hold the crank shaft firmly, and revolve eccentric till the port just
begins to open on its forward stroke. Rotate crank disc on shaft till the
crank pin is full forward.

Solder eccentric and disc to shaft.

Solder steam pipe to cylinder, and a brass disc to the rear end of the
cylinder.

Fit a fly wheel of metal or wood. This must be fairly heavy, as it has to
overcome all friction during the return or exhaust stroke.

Action of Engine.--During the forward motion of the piston the valve is
pushed back by the eccentric until the steam port is fully opened, and is
then drawn forward, covering the port. At the end of the power stroke the
port has begun to open to the air, to allow the steam to escape throughout
the exhaust stroke