Morey's explosive Engine. 107 
when mixed with atmospheric ‘air, into the lower apartment of 
e preparing vessel; the proportion of each is not very ma- 
lamp at the inflaming valve. The piston being dor 
ascent would form a vacuum under it; this is preyented by 
vessel. ft then closes, and the vapour valve supplies the re- 
mainder of the cylinder, through the preparing vessel, with ex- 
plosive air, and just before the piston is up, say about } of 
an inch, the vapour valve closes at the same time that the in- 
it is instantly communicated te the charge in the cylinder; 
the explosion that ensues, drives out the air from within the 
cylinder, through the perforated arched plate and leather 
valve at bottom, which valve instantly collapses and prevents 
the return of the air. e steam, formed by the explosion 
and formation of the vacuum, is condensed, by keeping the 
lower part of the cylinder cool, by surrounding it with water, 
and suffering the vacuum to inject a small stream of cold wa- 
ter near the bottom—which also keeps the arched plate and 
leather valve cool. A vacuum under the-piston, instantly fol- 
lows the explosion, which descends by the pressure of the at- 
mosphere, and carries the crank with it, while the same pro- 
cess is repeated in the second cylinder, and the power is taken 
from the crank-shaft, or piston-rod, as in the steam-engine. 
When the temperature is low, smaller charges will produce 
the same effect, if a thin metallic plate of the same diameter 
of the piston, be introduced into the cy , called the 
charging pisten. It is fitted with a small rod, which moves 
through a stuffing-box in the main piston, so tight that the 
friction will support its weight. This charging-piston is pre- 
vented from rising higher than the vapour-pipe, by its end 
striking against a stationary point, in its ascent, forming 
a partition between the compound air in the cylinder, and the 
common atmospheric air, thereby preventing so great a mix- 
ture of atmospheric air in the cylinder, as to lessen the € 
of the explosion. “snes i 
When the temperature of the box is so high as to give off 
- 
teo great a proportion of vapour, the engine works better by 
