THE ROYAL ARTILLERY INSTITUTION. 
485 
for 1400 feet velocity; this load, with fuzes, cartridge-bags, &c., will 
amount to 8 cwt.; the loaded limber, with its entrenching tools, and so 
forth, will thus weigh about 14 cwt .; deducting this weight from 30 cwt., 
the lowest limit of the total weight above laid down, will leave us only 
16 cwt. for the gun and carriage. 
Let us next compare the initial velocity of recoil of such a gun on 
its carriage, firing a 9 lb. projectile at a rate of 1400 feet per second, with 
that of the 12-pr. breech-loading gun of the service. An easy calcu¬ 
lation gives the former at 7 feet per second, and the latter 6’2 feet per 
second.* 
The recoil with the 12-pr. breech-loading gun at 6‘2 feet per second 
is lively, and I think should not be much exceeded for both convenience 
in service and endurance of the carriage. 16 cwt. is then too light for 
a velocity of 1400 feet with a 9 lb. projectile. 
Taking, then, 6*2 feet per second as about the highest admissible 
limit, we can determine the weight of the gun and carriage which will 
project a 9 lb. projectile with a velocity of 1400 feet. Calculation gives 
us 18 cwt.f 
This weight, added to that of the loaded limber, 14 cwt., will give a 
total of 32 cwt. 
If, then, you wish to have a gun with which errors in estimation of 
the distance are of less importance than with your present guns; if you 
want a gun which shall give you a more grazing fire than your present 
guns, approaching closely or being equal in this respect to the fire of 
the old smooth-bore guns up to 800 yards, and beyond that range much 
better—if, I say, you want these advantages, you must increase the 
velocity of your projectiles as much as possible; and this, With a velocity 
of 1400 feet involves a weight of gun and carriage of 18 cwt., and a total 
weight behind the gun-team of 32 cwt. 
Cannot some of the weight of the limber be got rid of? 
After a good deal of consideration and inquiry, I am reluctantly 
compelled to believe that no very great diminution is feasible, without 
injury to the efficiency of the system. 
7. We have, then, 18 cwt. for the Weight of the gun and carriage. 
What is to be the weight of the gun itself? It must be mainly 
decided by the weight of the carriage. If the latter can be brought 
down to 10 cwt., and yet have adequate strength, the gun may be 
* 9-pr. M.Li:—• 
12-pr. B.L. 
t S. CWt. f. S. lbs. 
do x 16 x 112 = 1400 x 9 
x — 7 feet per second; 
do x 20| x H2 - 1239 x 11-75 
x — 6-2 feet per second. 
1239 f. s. was the velocity of the 12-pr. B.L. with the slack pressed powder.—Vide te Handbook 
for Eield Service/’ 1867, p. 322. 
f. s. cwt. f; s. lbs; 
f 6-2 x x x 112 = 1400 * 9 
cwt. 
x = 18-1 
