150 
SHOUT NOTES ON PltOFESSIONAL SUBJECTS. 
(F.) Projectiles fitted with Crusher Gauges . 
The Committee have commenced experiments with projectiles fitted, in the centre 
of their bases, with crusher gauges, in order to ascertain whether the compression 
of a copper cylinder thus placed would indicate with sufficient exactness the pres¬ 
sure in the powder-chamber,. as shown by the crusher gauges in the gun, so as to 
be taken as a criterion of the pressures exerted by various charges. If this mode 
of measuring pressure should prove feasible, it would furnish a convenient test 
applicable to any large gun without further fittings or arrangements. The following 
tables show the results hitherto obtained with crushers in the projectiles i— 
Muzzle 
Pressure by crusher gauge at 
velocity. 
A. 
JB. 
C. 
Base of 
projectile. 
10-inch gun, 641b. pellet... 
C 851b. pebble... 
12-inch gun| 671b>E L G | 
f.s. 
1392 
1380 
1380 
1287 
1163 
1152 
tons. 
217 
29-0 
21-8 
19-1 
23-7 
tons. 
21-4 
21-7 
19-3 
18-2 
17-9 
15-8 
tons. 
24-6 
22-8 
23-4 
tons. 
22-0 
22-0 
18 5 
15*0 
21-9 
16-0 
The position of 
C plug in the 
gun corresponds 
with that of the 
base of the shot. 
The next table shows the results in 7-inch, 9-inch, and 12-inch guns, which 
were not fitted with crusher plugs; the projectiles however were provided with 
them in the base. 
Pebble powder. 
Muzzle 
Projectile 
velocity. 
crusher. 
f.s. 
tons. 
1235 
16-6 
12-inch gun. 
1362 | 
11*6 
14-8 
( 
11-2 
9-inch gun . 
1420 1 
10-3 
l 
10-9 
1525 | 
10-6 
10-4 
7-inch gun . 
12-inch gun. 
9-inch gun . 
7-inch gun . 
H.L.G. powder. 
Muzzle 
velocity. 
f.s. 
1161 
1317 £ 
1312 
1381 | 
1338 
1435 | 
Projectile 
crusher. 
tons. 
21-0 
17- 2 
16*0 
14-8 
18- 7 
19- 6 
21-1 
20- 5 
157 
17-0 
(G.) Miscellaneous Experiments . 
Shells filled with picric powder have been fired from the 40-pr. B.L. and 7-inch 
M.L. rifled gun, to ascertain whether the material is so sensitive as to explode by 
the shock of the discharge. No such explosion having occurred in twenty rounds, 
further experiments will be made with the view of testing its destructive effect 
under the conditions of ordinary use. 
Mr. Punshon’s gun-cotton, and Mr. Hahn’s powder, were fired from a Martini- 
Henry rifle, and the results compared with those of service gunpowder cartridges 
