THE ROYAL ARTILLERY INSTITUTION. 
493 
of the French form, slightly modified in size but not in principle; the 
oblique inclined plane forming the driving side of the groove is at 110° 
to the radius. The projectiles weigh 9 lbs. They are three in number. 
(1) Shrapnel, containing 63 bullets of 18 and 34 to the lb. (2) Common 
shell, containing 7J oz. of powder. (3) Case shot, containing 113 
one-ounce hardened lead bullets. A segment shell of the same weight 
is to form part of the equipment, as soon as a trustworthy concussion- 
fuze can be produced. This matter is left in such good hands, that 
there can be no doubt we shall shortly be in possession of a projectile 
for long ranges which can be fired as readily as case shot. 
The charge of powder is 1 lb. 12 oz.; the nature of the powder 
being as yet undecided. /The initial velocity with F.L.G. powder is 
1381 feet per second, and with a special powder made at Waltham 
Abbey, it is within one or two feet of 1400 feet per second. 
The accuracy and uniformity of shooting of this gun is, I think, 
remarkable. This short table will give you a fair notion of it:— 
Elevation. 
Mean 
range. 
Mean 
difference 
of range. 
Mean 
reduced 
deflection. 
degs. 
yds. 
yds. 
yds. 
2 
1176 
14-2 
0*5 
3 
1552 
17*1 
0-9 
7 
2665 
18-9 
0*8 
This means that at 3° of elevation, if you were to fire 100 rounds, 
50 shells would be found to have fallen 17 yards short of or beyond 
the mean range of 1552 yards, and T %ths of a yard in width right or left 
of the line of fire.* 
As to rapidity of firing, 50 rounds have been fired in 7 minutes; and 
as to rapidity combined with accuracy, 50 rounds were fired in 13 minutes, 
making 27 hits in a 9 feet target at 1000 yards. Further, 140 rounds 
were fired from one gun without stopping, at the rate of 3 rounds a 
minute—that is, continually for three-quarters of an hour. The metal 
became so hot as to boil water. 
The shrapnel shell, fired at a column of troops, represented by 
targets 54 feet wide by 9 feet high, in four ranks 20 yards apart, 
made 48 hits through 2" boards at 1200 yards, 40 through at 1600 yards* 
and 10 through at 2000 yards. The case shot, fired at two rows of the 
same targets, 50 yards apart, at 300 yards, gave 6'5 hits through 
2" boards; 11*9 lodged, and 3*3 strtick, in total 21*7 hits per round.f 
The sighting of the gun is central, and both muzzle and breech-sights 
are completely protected against injury. The plate carrying the notch 
in the breech-sight is capable of lateral deflection. This refinement 
* This interpretation is not mathematically accurate, but quite near enough for all practical 
purposes. 
f An improved pattern case shot, fired on 20th May, 1870, gave 42’5 hits through 2" boards, 
13‘3 lodged, 15 ; 2 struck, in total 71 hits per round. 
