K>S Messrs J. and C. Carmichael on a New Method of 
it are horizontal, and, of course, all the valves will be shut 
But the momentum of the paddle (or fly) wheel carries on the 
motion, and immediately the two valves that were formerly shut, 
viz. the upper steam- valve and lower eduction-valve, are opened, 
and the steam presses down the piston with a force equal to the 
difference between its own elasticity and the elasticity of the un- 
eondensed vapours below the piston. Thus the engines will 
Continue to go, and the paddle-wheel to turn in the direction of 
the dart. 
But that we may endeavour to explain to you the method 
of stopping or reversing the motion of the paddle-wheel, all 
that is necessary is to shut all the valves ; and this is effected by 
disengaging the eccentric rod from the spanner of the rocking 
shaft, and the valves all shut of their own accord, by the weight 
of the valves, lifter rods, &c., and the engine will stand : and to 
set the engine agoing, either the one way or the other, is to 
lower the eccentric rod, to take hold of the double ended span- 
ner on the end of the rocking shaft, as represented on the sketch, 
and then the paddle-wheel will move in the direction of the dart, 
or lift the eccentric rod to the top of the spanner on the rocking 
shaft, and then the paddle wheel will move in the opposite di- 
rection. The use of the sector formed appendages T, on the 
end of the eccentric rod, is to conduct the pins on the ends of 
the double ended spanner into the notches adapted for them on 
each side of the eccentric rod ; The form of which is better 
seen detached, at Fig. 8. 
The hand-gearing, for starting or stopping the engines, is si- 
tuated upon the deck of the boat, and all concentrated upon the 
top of a small table in view, and in hearing of the man at the 
helm, or the master, who directs both, when coming to the 
quay. 
1, a double ended handle, which is upon the upright shaft % 
on the lower end of which is a bevel wheel 8, working into ano- 
ther wheel 4 ; this wheel is on a lying shaft, which extends from 
the one engine to the other, and carries on each end of it a spur- 
pinion 5, which pinion works into the rack 6. There is a simi- 
lar rack connected with the eccentric rod of the other engine, 
into which the other spur-pinion w^orks, so that, by turning the 
handle 1, both engines can be started, stopped, or reversed, with 
