THE ROYAL ARTILLERY INSTITUTION. 
371 
Table 
SHEWING- THE INITIAL VELOCITY, THE VELOCITY OF ROTATION, THE DRIFT AND TIME OF 
FLIG-HT OF COMMON SHELLS FIRED WITH LOW-ANGLE CHARGES FROM THE 3-pr, MOUN¬ 
TAIN RIFLED GUN. 
Charge of powder, and 
weight of projectile, 
Range. 
Drift. 
Time of 
flight. 
Remarks. 
The charge of powder 
weighs7*4 oz.; the common 
shell weighs 4*289 “lbs; 
ratio ys 1 .^ 
yds. 
415 
830 
1659 
2489 
ft. 
-0 
7*8 
99*5 
326*6 
sec. 
1*5 
4 
9 
16*5 
The initial velocity is 777*6 ft. 
per second; the velocity of rota¬ 
tion is 123*4ft. per second; 
the number of revolutions of 
the common shell in the 1st 
second is 152. 
The trajectories of shrapnel shells fired from rifled guns are similar to 
those of common shells up to the moment when the former burst by means 
of the time fuze and powder charge at a suitable height and certain distance 
from the object fired at. The initial and rotating velocities depend on the 
same conditions as have been mentioned with regard to common shell. At 
the point of the trajectory when the explosion of the bursting charge takes 
place, the shrapnel shell is shattered into a certain number of splinters ; 
the splinters, and the leaden balls contained in the cavity of the shell 
proceed on in diverging paths, until they reach the object fired at or strike 
the ground. The perpendicular height of the exploding shell above the 
ground is termed the height of hurst; and the horizontal interval between 
the point on the ground directly below the burst and the object to be fired 
at is called the interval of hurst. 
The velocity with which the pieces of the shell or leaden balls begin their 
separate paths immediately after the bursting of the projectile is nearly the 
same as the velocity of the shrapnel shell the moment before bursting. 
From observations made at experimental practice we are entitled to 
conclude, that, in comparison with spherical shrapnel shells, the velocity of 
rotation at the moment of bursting of elongated shrapnel shells gives rise 
to a rather greater spread of the splinters of the shell and the leaden balls. 
Shrapnel shells have a rather smaller initial velocity than common shells, 
because the former weigh more than the latter, while the charge is the 
same. The drift of shrapnel shells differs from that of common shells in 
such a slight degree that it may be taken as identical. 
Case shot from rifled guns, as from smooth-bores, are broken up in the 
bore by the shock of the explosion of the charge; the zinc shot are driven 
forward, each in a diverging curve, until they reach the object fired at or 
strike the ground; in the latter case, when the ground is firm and even, 
they continue their path of flight with several ricochets. The grooves have 
no influence over the trajectories of the case shot balls. 
In general the main differences between the trajectories of elongated and 
spherical projectiles are as follows :— 
(l) As the low-angle charge of powder of rifled guns amounts to between Jth 
and ith of the weight of the projectile with field guns and between -^th and -^th 
with mountain guns; while with smooth-bores the ratio lies between -^rd and ith 
(the common shell and round shot being taken at their normal weight); the initial 
velocities of the elongated projectiles are less than those of spherical projectiles. 
