96 
COMPOSITION AND STRENGTH OE A SIEGE TRAIN 
at a range of 1600 yards, as a minimum; it should fulfil the same 
general conditions as the corresponding gun of the first position, its 
power being a maximum for that weight which moderate ease of 
draught allows, namely, 37i cwts.* *, for, as the besieger approaches the 
fortress and gets further from his park, the difficulties of bringing 
guns into battery increase. 
Where enfilade fire, for dismounting, is possible, which will be the 
exception, it can be continued by the pieces of the first position, allotted 
to that purpose, moved into the second position, if necessary, to complete 
their work, and therefore there is no need to make special provision 
for this purpose in the latter position. 
With regard to Description n. we may assume that breaches will, as 
a rule, in future be made from a distance by curved fire,f the besieger 
not only thus avoiding much difficulty of transport and the execution 
of “ crowning” works, but because “they demoralise the garrison, 
facilitate attack de vive force, augment the difficulties of guarding and 
enfeeble the action of the artillery in this way, that the besieged loses 
or must retire the pieces which are behind the falling parapet. 
The practicability of this manner of breaching, under certain 
conditions has been demonstrated at the siege of Strasburg in the 
Franco-German war of 1870, and by experiments since carried out in 
Germany ;|| but the profile and width of ditch in modern fortresses will 
render the conditions usually much more unfavourable than in the 
instances quoted, necessitating an angle of fall of about 26° to reach the 
middle of the escarp (see Plate i. fig. 1) which, with the final velocity 
necessary for breaching, will be difficult to obtain. We cannot, however, 
even under the most unfavourable conditions, consider breaching by 
If guns in the future are mounted in the last-mentioned manner, they would have to be 
reached from the second position by curved fire, in which case medium howitzers would 
take the place of medium guns for the purpose. 
In England there have been no experiments in dismounting fire to the results of which 
we can refer. 
* See p. 109. 
f “We take it for granted that, as a rule, crowning batteries are unnecessary, and that 
curved fire, corrected, if necessary, by observation, from the crowning, will do all that is 
required.”—Kraft, on Sieges. 
£ La fortification deduite de son histoire, par le General Tripier. 
|| At Strasburg, in breaching the right face of Lunette 53, with the 15 c.m. short gun, the 
range was 853 yds., the angle of descent 7° 7\' and the angle of fire with the wall 55 Q ; 
the latter being of red sandstone about 4|' thick at top and ' at bottom. 
At the experiments of Graudenz, 1873, the 12 c.m. gun rendered a capioner of brick 
quite untenable, the walls of which were 4 ^! thick at the upper storey and 1 at the lower, 
from a range of 1487 yds. In a wall of granite boulders, of considerable size, and 16*4' in 
thickness at the top, including buttresses, the short 15 c.m. gun made a practicable breach 
at a range of 1148 yds., with angle of descent 7°, and horizontal angle of impact 57|° ; 
and the short 21 c.m. gun at a range of 1170 yds., with angle of descent of 6 Q 37iand 
horizontal angle of impact about 57i°. From the results of these experiments it is stated 
that, “ the practicability of demolition at angles of descent up to 15° may be accepted,” and 
“ that generally the conditions should be so arranged as to secure 25 to 30 per cent, of 
masonry hits, with a final velocity of 525 to 591 feet.”—Prussian Fortress and Siege 
Artillery, fourth part, by Major H. Muller.—We may remark that these conclusions only 
hold good for the particular guns then under trial, for the limiting angle of descent to 
effect a given demolition, without undue expenditure of ammunition, varies with the 
accuracy of the gun used and its power. No experiments have been made in England on 
this point to the results of which we can refer. 
