48 
MINUTES OF PROCEEDINGS OF 
(a) Curved defensive fire; in which guns placed in low-lying case¬ 
mates, or otherwise protected, fire over a covering rampart in their 
front at a fixed point in the open, and 
(b) Curved dismounting fire ; which is employed when a dismounting 
battery has to strike an object, firing over a protecting mass close to 
its own front. 
In all these cases, in order that a satisfactory effect may be pro¬ 
duced, it is most important that the object be struck with the greatest 
possible force. This will only be the case when the projectile just 
clears the top of the covering mass. Consequently, in curved fire, the 
path of the trajectory must be made to pass, not only through the 
muzzle of the gun and the object to be struck, but also through a 
third point—namely, the highest point of the crest to be fired over- 
In enfilading a rampart by means of curved fire, the flatter the 
path of the projectiles, and the greater their final velocity, the better 
will be the effect produced. With a low final velocity and a high 
angle of descent (over 22°) most of the shells lodge, and have there¬ 
fore no effect at all on materiel placed on the terreplein, unless they 
happen to strike it directly, and very little on the troops on duty, since 
the greater part of the splinters remain in the ground. 
In bombarding a vertical object capable of resistance (such as 
masonry) by means of curved breaching and demolition fire, the 
employment of the largest allowable charge of powder is, however, 
much more important; because, with small charges, the final velocity, 
and consequently the depth of penetration of the projectile, is too 
small, and the bursting effect is thereby lessened. Moreover, at a 
given range, the vertical spread is considerably greater with small than 
with large charges. 
In the case of vertical objects capable of resistance, not only the 
angle of descent but also the angle of impact (measured horizontally) 
is of importance. Elongated projectiles fired from rifled guns against 
strong scarp walls easily glance off if the angle of impact is less than 
60°. It is only when the same place is repeatedly struck, and that 
with a sufficient final velocity, that the projectiles penetrate at a smaller 
angle of impact—say down to about 80°. 
The limits within which penetration is possible, and the depth of the 
penetration, depend, not only on the resulting final velocity (in other 
words on the charge employed), but also on the nature of the object 
fired at. 
In the experiments at Silberberg in 1869—when the short 15c.m. 
gun was fired against very strong masonry in an oblique direction, the 
line of fire meeting the scarp at an angle of 57^° with a final velocity 
of about 176 m —the depth of penetration proved too slight to allow 
the bursting effect of the shells to be appreciated.* 
At Strasburg, in 1870, the line of fire of Battery No. 8—which 
was armed with short 15 c.m. guns—made an angle of 55° with the 
* Witte. Artillerie-Lelire. Ill Theil, pag. 189, 
