96 Ward’s Steam Engine. 
in Hornblewer’s valve : the moveable plate is attached to 
the cylinder, and is turned by it; while the other plate, 
being attached to the centre-piece, remains stationary. 
The steam-tube, after passing from the boiler along the cen- 
tre-piece, arrives at the cocks, and enters one of these sec- 
torial apertures, from the back, in the plate attached to the 
centre-piece. In like manner, the eduction-tube extends 
from the bottom of the opposite aperture in the same plate, 
ibrough the centre-piece, to the condenser ;—or, if the en- 
gine be made without a condenser, the tube terminates in 
the open air, and the steam escapes. A tube extends from 
the bottom of each aperture, in the plate attached to the 
cylinder, to each end of the cylinder, and there enters its 
cavity. The revolution of the cylinder and the moveable 
plate attached to it, brings the aperture belonging to each 
end of the cylinder, alternately to the aperture in the station- 
ary plate, pou wi ich the steam qnters 5 while, at the 
same time, t ‘e belongin - other end of the 
cunt! is ‘passing the aperture belonging to the eduction- 
The: ‘often end of the piston-rod is attached to a cross- 
piece, which is supported by gudgeons, moveable in boxes 
in the arms of the water-wheel. From the middle of this 
cross-piece, and perpendicular to it, proceed two wings, one 
on each side, from the ends of which two rods extend, play- 
ing through steps on the sides of the cylinder. These rods 
are necessary in order aerntely to overcome the inertia, 
and resist the momentum, 0 the cylinder, encountered i in 
conmesignee of the rey of its motion, 
operation of this engine is as follows =the steam, 
by means of the piston, alternately aeating and pressing 
upon the cross-piece, which works in the arms of the water- 
se forces the wheel around, at the same time that the 
cylinder itself is carried round, by reason of its connexion 
with the See ee the reaction being sustained by the 
gudgeons of the cy niece resting on the centre-piece ces. 
_. Asthe cylinder revolves ona different centre from that of 
radii of its an motion vary from the 
a 
eel, the radii of its ) ry f 
of the wheel, coinciding with Seri in two opposite 
; wee which is at the moment the engine is Se 
ai oints. If the revolution of weve be supposed 
