The steam inlet is a gasoline pipe connection such as used on
automobiles.

The valve-operating cams, F, are made of the metal ends of an old
typewriter platen, one being finished to shape and then firmly
fastened face to face to the other, and used as a pattern in
filing the other to shape. Attachment to the shaft, N, is by means
of setscrews which pass through the sleeves.

The main bearings, M, on the supports, O, and the crank-end
bearings of the connecting rods, K, are split and held in position
by machine screws with provision for taking them up when worn.

The exhausting of spent steam is accomplished by means of slots,
I, sawed into the fronts of the cylinders at about 1/8 in. above
the lowest position of the piston's top at the end of the stroke,
at which position of the piston the valve rod drops into the
cutout portion of the cam and allows the valve to seat.

All the work on this engine, save turning the pistons, which was
done in a machine shop for a small sum, and making the flywheel,
this being taken from an old dismantled model, was accomplished
with a hacksaw, bench drill, carborundum wheel, files, taps and
dies. The base, Q, is made of a heavy piece of brass.

The action is smooth and the speed high. Steam is supplied by a
sheet brass boiler of about 3 pt. capacity, heated with a Bunsen
burner.
--Contributed by Harry F. Lowe, Washington, D. C.