CAPTAIN NOBLE AND MR. F. A. ABEL ON FIRED GUNPOWDER. 
129 
Therefore 
and 
L p~ L u 
1_(V 0 \C V +PK 
t 0 VJ ’ 
Cp+fi A. 
»o \W 
or, since v' 0 =v 0 (l — a), v'=v — ctv 0 , 
P. 
Po 
C p +j3A 
C„+/3,V 
(28) 
(29) 
(30) 
and equation (30) gives the true relation connecting^ and v when the gaseous products 
expand in the bore of a gun with production of work. 
The values of the constants in this equation we have already determined ; they are 
as follow :—C„= -1782, C p = -2353, ^=41-477, X=-4090, /3=1-3148. 
The results of equation (30) are given in Table XVIII.; and, as before, for comparison 
we give similar values of p both as derived from experiments with heavy ordnance and 
on the supposition of expansion without performance of work. 
Table XVIII.— Giving, in terms of the density, the tensions actually found to exist in 
the bores of guns with pebble and E. L. G. powders ; giving, further, (1) the tensions 
calculated from equation (30), (2) the tensions which would exist were the gases 
suffered to expand without production of work. 
Mean density 
of products of 
combustion. 
Tension observed 
in bores of guns. 
Pebble powder. 
Tension observed 
in bores of guns. 
B. L. Gr. powder. 
Tension calculated 
from formula (30). 
Tension observed 
when the gases 
expand without 
production of work. 
Tons per 
sq. inch. 
Atmo- 
spheres. 
Tons per 
sq. inch. 
Atmo- 
spheres. 
Tons per 
sq. inch. 
Atmo- 
spheres. 
Tons per 
sq. inch. 
Atmo- 
spheres. 
1-00 
41-48 
6316 
41-48 
6316 
•95 
36-30 
5528 
36-65 
5581 
•90 
20*35 
3099 
27-33 
4162 
31-84 
4848 
32-46 
4943 
•85 
18-63 
2837 
24-63 
3751 
27*95 
4256 
28-78 
4383 
•80 
17-01 
2590 
22-01 
3352 
24-56 
3740 
25-53 
3888 
•75 
15-48 
2357 
19-50 
2969 
21-56 
3283 
22-63 
3446 
•70 
14-03 
2136 
17*16 
2613 
18-89 
2877 
•20-02 
3049 
•65 
12-65 
1926 
15-05 
2292 
16-51 
2514 
17-68 
2692 
•60 
11-33 
1725 
13-21 
2011 
14-38 
2190 
15-55 
2368 
•55 
10-07 
1533 
11-61 
1768 
12-46 
1897 
13-62 
2074 
•50 
8-87 
1351 
10-18 
1550 
10-72 
1632 
11-85 
1804 
•45 
7-73 ,| 
1177 
8-87 
1351 
9-15 
1393 
10-23 
1558 I 
•40 
6-65 
1013 
7-65 
1165 
7-71 
1174 
8-73 
1329 
•35 
5-63 
857 
6-49 
988 
6-40 
975 
7-35 
1119 
•30 
4-67 
711 
5-39 
821 
5-21 
793 
6-07 
924 
•25 
3-77 
574 
4-34 
661 
4-11 
626 
4-88 
743 
•20 
2-93 
446 
3-33 
507 
3-11 
474 
3-77 
574 
•15 
2-15 
327 
2-35 
358 
2-20 
335 
2-73 
416 
•10 
1-37 
209 
1-76 
268 
s 
MDCCCLXXV. 
