therefrom had not care been taken to put the chamber in communication
with a reservoir of ten times greater capacity, and which is formed by
the interior of the frame. This brings about an almost constant
counter-pressure.

The type of motor under consideration, which we represent in the
accompanying plate, is possessed of remarkable simplicity. The number
of parts is reduced to the extremest limits; it works at high speed
without perceptible wear; it does not require those frequent repairs
that many other cheap engines do; and the expansion of the steam is
utilized without occasioning violent shocks in the parts which
transmit motion. Finally, the plainness of the whole apparatus is
perfectly in accordance with the uses for which it was devised.

[Illustration: FARCOT'S IMPROVED WOOLF COMPOUND ENGINE.]

_Details of Construction._--Figs. 1 and 2 represent the motor in
vertical section made in the direction of two planes at right angles.
Figs. 3 and 4 are horizontal sections made respectively in the
direction of the lines 1-2 and 3-4.

The frame, which is of cast iron and entirely hollow, consists of two
uprights, B, connected at their upper part by a sort of cap, B¹, which
is cast in a piece with the two cylinders, C and _c_. The whole rests
upon a base, B², which is itself bolted to the masonry foundation.

Each of the uprights is provided internally with projecting pieces for
receiving the guides between which slides the cross-head, _g_, of the
piston rod. The slides terminate in two lubricating cups designed for
oiling the surfaces submitted to friction.