THE ROYAL ARTILLERY' INSTITUTION. 
229 
NOTES ON CURYED EIRE. 
SUBMIIIED BY * 
COLONEL S. E. GORDON, C.B. 
In a paper published in a late number of these “Proceedings,” 
Captain Clarke, R.A., has called attention to the employment of curved 
fire by the Prussians at the siege of Strasburg, and shows that they 
successfully breached a hidden escarp at a range of 910 yds. with their 
6 -in. B.L.R. gun, with a charge of powder ¥ V h the weight of the pro¬ 
jectile fired, which was 60 lbs. 
In 1863, General Lefroy, F.R.S., published in Vol. III. of these 
“ Proceedings,” a paper “ On Breaching Unseen Defences,” which may 
be referred to with great advantage in reading the operations of the 
besiegers of Strasburg. He there proves that our 64-pr. B.L. gun, with 
a charge of powder *y h , projects its shell with sufficient velocity to give 
a vis viva which will breach masonry at 900 yds. 
From the result of a few rounds fired at the request of the writer at 
Shoeburyness, from a 64-pr. B.L. gun, with a charge of 4 V 11 the shell's 
weight, a range of 900 yds. was obtained with an elevation of 15°; 
while in the Prussian account the range of 910 yds. is stated to have 
been obtained, with a proportionate charge, with only 7^° elevation. 
It may be assumed that the 64-pr. B.L. gun has disappeared from our 
siege train, and therefore it is not practically material whether the 
Prussian 60-pr. has such a far flatter trajectory than our 64-pr. with 
these small charges or not. Still, if there is not a mistake in the 
elevation given, it would be a subject of interesting enquiry; because 
the flatter trajectory shows a greater initial velocity, and consequently 
more penetrative power. 
The ranges obtained with charges of 4 V 11 , -ro th , and of the 
projectile's weight, from the guns which until a recent period formed 
our siege train, are given below. They are computed from the results 
of five rounds fired at each of the elevations of 10 °, 12 °, and 15°. 
