186 REPORTS ON THE STATE OF SCIENCE.—1914. 
taken during trial No. 72, together with the scales, are shown in 
figs. 5, 6, 7, 8. The following data relate to trial No. 72:— 
Mixture 6'88 air to 1 gas by volume. 
Jacket temperature 29°5. 
Temperature measured at crank-angle 200°; 77° C. 
Pressure measured from the diagram at 200° crank-angle; 147 
per square inch. 
Volume measured at this point, 0°38872 cubic feet. 
peter ee NB (NEE 10) | 
10 
aad = Ath 2073 eae 
" 10 
zi A+19 75 
10 
ot ee ALL 9: 75) 
Z A + 4-75 
475 aad 
Fira. 8. 
Speed 106 revolutions per minute. 
The gas constant for the charge is therefore = 0'01616. 
This constant may now be used to calculate the temperature at any 
point along the compression-curve, since at a point where the pressure 
is P and the volume V, the temperature is: 
eee 
01616" 
