EXPLANATION OF THE PLATES. 
343 
water to the condenser is regulated by a cock, moved by the handle c on the 
spindle d. 
The governor g (see art. 550.) is kept in motion by bands from the crank shaft, 
and opens or closes the throttle valve in the steam pipe C by means of a lever h h. 
See Plate vm. Fig. 1. 
The proportion of the parts for a double engine of this kind may be ascertained 
by art. 414—423. It ought to be made to work expansively, but in this case it 
has not been done: the saving resulting from causing the engine to work ex 
pansively, will be in the ratio of about 10 to 7 to do the same work, (art. 422.) 
See Table in. art. 664. 
PLATE XV. 
As an example of a portable condensing engine for impelling machinery, I have 
taken that of Mr. Maudslay, where the beam is omitted, and the crank connected 
directly with the piston rod. Fig. 1. is a front elevation of an engine ; Fig. 2. 
a longitudinal section; and Fig. 3. an end view. The cylinder B is supported by 
a cast iron frame A, and C is the piston, with the rod D, connected to a cross head 
at E, and guided by the wheel F, which keeps the piston rod in a vertical direction, 
by moving in the frame G ; the side rods H H connect the cross head E with the 
double crank I I, which turns in the plummer blocks or bearings J J, one on 
each side of the frame, and to which the % wheel shaft K, carrying a fly wheel M, 
is connected by a coupling box, or clutch L, at the end next the engine. 
Two eccentric wheels N N, on the crank shaft K, give motion to the levers 0 
and T, by means of the connecting rods P P. The lever O, supported by the 
bearing Q, works the cold water pump S, by the rod R; while the beam T, 
working on the centre V, works the air pump X by the slings v, and the hot 
water pump Y; which by the feed pipe Z supplies the boiler with hot water. On 
the cross rail (a) the guide is fixed to confine the air pump rod to a vertical motion; 
the condenser b surrounds the air pump, and is again surrounded by one of the 
cold water cisterns c ; the two cisterns are connected by a pipe d: the steam from 
the cylinder passes to the condenser through the eduction pipe e, and the cold 
water for injection is admitted to the condenser by the cock f. The air and con 
densed steam ascends through the foot valve g in the bottom into the air pump.