132 
CAPTAIN NOBLE AND ME. E. A. ABEL ON EIEED GUNPOWDEE. 
Table XIX. — Giving the temperature, in degrees Centigrade, and in terms of the density, 
of the products when expanded, with production of work, in the bore of a gun 
supposed impervious to heat. 
Mean density 
of products of 
combustion. 
Number of 
volumes of 
expansion. 
Temperature. 
Degrees 
Centigrade. 
Mean density 
of products 
of combustion. 
Number of 
volumes of 
expansion. 
Temperature. 
Degrees 
Centigrade. 
1-00 
1-0000 
2231° 
•50 
2 0000 
2019 
•95 
1-0526 
2209 
•45 
2-2222 
1996 
•90 
1-1111 
2188 
•40 
2-5000 
1971 
•85 
1-1765 
2167 
•35 
2-8571 
1943 
•80 
1-2500 
2146 
•30 
3-3333 
1914 
•75 
1-3333 
2126 
•25 
4-0000 
1881 
•70 
1-4286 
2105 
•20 
5 0000 
1843 
•65 
1-5385 
2084 
•15 
6-6667 
1796 
•60 
1-6667 
2063 
•10 
10-0000 
1734 
•55 
1-8182 
2041 
•05 
20-0000 
1637 
X. WOEK EPPECTED BY GUNPOWDEE. 
The theoretic work which a charge of gunpowder is capable of effecting during the 
expansion to any volume v is, as we have said, represented by the area between the 
curve B, Plate 24, the ordinates corresponding to v and v 0 , and the axis of abscissae. 
In mathematical language it is expressed by the definite integral 
j ' . dv. (32) 
Replacing in this equation the value of jp derived from equation (30), we have for the 
work done by the powder in expanding from v 0 to v, 
The values of all the constants in this equation have already been given ; but for our 
present purpose it is convenient to determine the work which 1 gramme of powder is 
capable of performing for different degrees of expansion. Assuming, then, that a 
gramme of powdei is of the gravimetric density of unity (that is, that it occupies a 
volume of 1 cub. centim.), we have v 0 =l i an d expressing the initial pressures 4T5 tons 
(6320 atmospheres) in grammes per square centimetre, we have ^ 0 =6,532,450 grammes 
per square centimetre. 
We have calculated W from (34) for various values of v up to and inclusive of v=20. 
The results are embodied in the following Table, and are expressed both in kilogramme- 
metres per kilogramme and foot-tons per lb. of powder. 
