r 
400 W. A. Norton on Ericsson’s Caloric Engine. 
that which is expelled from the supply cylinder into the receiver. 
If we suppose the pressure in receiver to be 8 lbs. above the 
atmospheric pressure, and that the leakage and clearance, at this 
pressure amounts to 4, then # of the air furnished by the supply 
cylinder will enter the working cylinder, and its elastic force, 
for the 3 stroke, would be reduced to 114 lbs. (? of 15 ibs.), by 
the expansion, if the temperature remained unchanged, but the 
480° of additional heat will augment this to 224 Ibs., or 15 Ibs. 
+ 74lbs. Now 8 lbs. above the atmosphere, is the actual work- 
ing pressure of the engines, we may conclude therefore, that 
if the working temperature is 480° above the atmospheric tem- 
perature or a little less, the waste from leakage and clearance, 
during the double stroke, must amount to nearly 4. The actual 
working temperature is undoubtedly less than this, but how much 
Ihave not been able to ascertain with certainty. The actual 
leakage is therefore less than 4, but its exact amount cannot at 
present be determined. According to the newspaper accounts 
the working temperature, on the trial trip, was about 450°, or 
418° above the temperature of the air (taken at 32°). This 
would make the waste, from leakage and clearance, about }. It 
‘undoubtedly lies between 4 and }. 
Working at a given temperature, and with a given cut off, the 
leakage will determine the working pressure. To show this, 
suppose the elevation of temperature to be 480°, and the leakage 
4 at a pressure of 8 lbs., shown by the receiver-guage; then at 
12 Ibs. pressure the leakage, if we disregard the clearance which 
is comparatively small, would be 2ths, and the elastic force of 
the air in the working cylinder would be reduced from 73 lbs. to 
3% lbs. If the communications remained the same, so great a 
gine would be nearly in its permanent working condition. shit 
~ From this cause, (viz., the leakage,) mainly, as it would seem, 
the expected pressure of 12 |bs. has not been obtained in t 
power of the caloric engine. Suppose that the constant nr 
in the receiver is 15 lbs. +15 Ibs. . On this supposition air W 
the end of the stroke ata little above this. At 
: ° pressure a little a - ; 
end of the 4 stroke of the supply piston the body of air which 
