195 
Steam Engine. 
ployed for opening the valves, and there is no hand gear. 
The steam and exhaustion valves are on the same hori- 
zontal plane ; those which are vertical to each other are not 
like those hitherto used, both exposed to the steam or 
both to a vacuum ; but by a simple contrivance in the 
construction of the nozzles, the one is exposed to the steam 
while the other has a communication with the condens- 
ing vessel. From what has been said it may easily be 
perceived, if the two valves be connected together by a 
straight rod, that wi;en this rod is lifted, the pressure is 
given to the piston, and the machine is put into motion ; 
and if the other two valves be connected in the same man- 
ner and lifted at an appointed time, the engine is kept in 
motion. The outside appearance of these nozzles may 
be seen at Fig. \.c Cy ( Plate II. ^ The rods which come 
out of the bottom of the nozzles are kept tight by verti- 
cal stuffing-boxes, the whole of which is hid in the draw- 
ing by the frame. 
The next is a new contrivance for producing a rotative 
motion from a reciprocating one, which not only simpli- 
lies the machine very much, but exceeds the power of 
the common crank by nearly one-third, in consequence 
of its acting always perpendicular to the radius of the 
wheel, which is done by a rock and wheel, as represented b}; 
Fig. 2 and 3 ; and as this plan of connection distributes 
the power uniformly, of course a much lighter fly-wliecl 
is required, which diminislies friction, 
Explanation of the Pla te. 
Fig. 1. is a representation of the engine : one of the 
corner columns AA, which supports the frame, serves 
likewise for an eduction-pipe and condeiising-vessel ; the 
air-pump E is joined to the condensing 'v^essef by the pipe 
D; e is the piston rod, and though it works out at the^ 
bottom of the cylinder, it is as easily kept tiglit as it' it 
worked out at the top ; h is a similar rod which keeps the 
