THE ROYAL ARTILLERY INSTITUTION. 
441 
howitzers fired with charges of 3 - 3 -th and ^h of the weight of their 
projectiles respectively, the 24-pr. gun with a charge of -/^rd, and the 
68 -pr. carronade with one of -gyth and ^-th. A practicable breach 
14 ft. in width was made by their fire, and the buttresses were much 
injured. 
On the 6 th August the firing recommenced from eight 68 -pr. car- 
ronades at 500 yds., two 8 -inch iron howitzers and four 10 -inch 
howitzers at 400 yds. Fifty rounds per piece were fired in two hours, 
when the breach was examined and found to be complete in every 
respect, and the buttresses to be in a ruinous state. 
There is no rifled piece in existence, which fires with a small charge 
with accuracy, capable of dropping its shell at such an angle from a 
range so short as 500 yds.; but the Russian 12-prs. (321b. common 
shell) could attain this angle at ranges of from 1120 to 1266 yds.; and 
the same might be effected by their larger pieces from greater ranges. 
This case—that of a wall covered by a counterguard at a distance of 
only 31 ft.—is an extreme one; no instance of CarnoFs system, as far 
as I am aware, having been actually constructed. The distance between 
the wall to be breached and the covering mass in ordinary fortifications 
is usually very much greater than 31 ft. 
At the siege of Strasburg by the Prussians in 1870, a breach was 
made in one of the bastions of the enceinte from a battery of four short 
B.L. 24-pr. guns,* firing common shells weighing 61 lbs., inclusive of 
a bursting charge of 4*4 lbs.; the range was about 900yds., and the 
escarp breached was invisible from the battery. An eye-witness who 
examined the breach after the siege, describes the wall as fairly down, 
but the earth of the rampart and parapet so far intact that a good deal 
had yet to be done to render the breach practicable. 
As this system of breaching is, I believe, practically unknown in 
England, some description of the method by which this result is 
attained may be of service. 
The Russian “ Handbook for Artillery Officers,” published in 1870, 
and Prelnds “ Schiesskunst,” Berlin, 1867, give full details of this 
system. From these sources I purpose to describe it. 
The problem resolves itself into this:—At what angle and with 
what charge must a certain piece be fired from a given distance, so 
as to send its shell just clear of the covering work which intercepts the 
view—whether glacis, counterguard, or counterscarp—and to strike 
the escarp wall at the proper height above the bottom of the ditch 
with the maximum velocity ? 
As the range, the height of the covering work, and its distance from 
the escarp, as well as the height of that escarp, may all vary, it is 
* This piece had just bedn introduced into the Prussian service for the above purpose. It is a 
howitzer to all intents and purposes, and worthy of imitation. The following are some of the 
details of the piece:—Calibre, 5 , 866 // ; length of piece, 14-4 calibres; length of bore rifled, 58 , 7 // ; 
number of grooves, 24; pitch of rifling, ^; weight of piece, 29 cwt., or 53 times the weight of its 
projectile; maximum charge, 3*3 lbs.; load-ratio (powder to projectile), length of shell, 14 , 2 // ; 
weight of shell, 61 "07 lbs.; weight of bursting charge, 4*4 lbs. See “Artilleristisches Taschenbuch,” 
Witte, Berlin, 1870. 
