106 
COMPOSITION AND STRENGTH OF A SIEGE TRAIN 
is sufficient. We may assume § of tlie medium guns to be employed 
in tbis manner; tlie total amount of ammunition required for both 
natures of guns is then* ;—• 
Common shell: — Heavy guns , 68948. Medium guns , 58080. 
■fShrapnell shell :— ,, 3628. „ 12960. 
Case shot: — ,, 280. ,, 720. 
Breaching batteries fire as quickly as they can with precision during 
daylight and during night keep up only sufficient fire to prevent the 
beseiged doing anything towards the repair of the damage done. The 
amount of ammunition requisite for the pieces of these batteries is better 
based directly upon that quantity required to form a practicable breach, 
than indirectly upon the time it may occupy to do so. This quantity 
will necessarily vary not only with the nature of the revetment and 
the gun employed, but upon the circumstances of range, &c., under 
which the latter is used. 
From the experience of the siege of Strasburg and from the results 
of the German experiments on breaching, already mentioned,{ we may 
assume that per yard of breach, under favourable conditions || for curved 
fire, heavy ordnance must expend 35 rounds and medium 80, to make 
the breach practicable. Adding 50 per cent, to these figures, as a 
margin to meet less favourable conditions, or those which, as already 
stated, will generally rule; and shrapnel, at the rate of 48 rounds per 
night (12 hours) for each heavy piece for two nights, and for each 
medium piece for three nights, with an addition of 50 per cent, for 
keeping the breach clear after completion until the assault; we get the 
following ammunition as necessary for the pieces (12 heavy, 8 medium 
howitzers) making breaches in the faces of the encient 33 yards wide 
and in the flanks of the ravelins 22 yards, namely :—• 
Common shell:—Heavy howitzer , 3464. Medium howitzers , 5280. 
Shrapnell shell: — ,, 1728. „ 1728. 
For demolition of casemated works a somewhat less proportion of 
ammunition than for breaching will suffice; allowing 35 rounds for 
heavy howitzers (8) and 80 for medium, (26) per yard, for f of the length 
of the work to be demolished and 20 per cent, additional, gives us the 
ammunition required for this purpose to be :— 
Common shell:—Heavy howitzer , 2520. Medium howitzer , 12960. 
* Should works of the future be armour plated, the heavy guns, employed then for 
breaching or demolition, will require special projectiles for the purpose. 
j- The proportion of shrapnel to common shell for tho medium gun is thus 1 to 4‘48 
(in the heavy 1 to 19,) In tho heavy unit of the English siege train the laid down pro¬ 
portion for the 64 pr. and 40 pr. is 1 to 2'26, this however seems large. 
% Note p. 96 and note p. 97. 
|| The masonry fired at in the Graudentz experiments was very strong but the angle of 
descent less than what in practice we may generally expect it to be. 
