DEFENCE OP PLACES^ 161

are also to be supplied with a greater numb.er of
pieces of ordnance, as independently of those
placed in such other parts of the fortifications as
admit of them, some should be established in the
dry ditches; the latter being so directed that the
shotj &c. after passing over the parapet of the
works in front, will bear upon the enemy's tren-
ches ; indeed, the besieged troops have no other
means of enfilading with their artillery the tren-
ches which form the crowning of the covert-way.
Secondly, the same system also requires that
the 1st parallel, which other systems allow to be
placed at the distance of 600 yards from the most
advanced saliants of the covert-way (33.) should
not be further than that distance from the sali-
ants of the lower bastions and ravelins, or even
from the capital works behind them ; the reason
is that by being nearer to these works, which it
is materially important for the besieger to enfilade,
his 1st batteries will be able to keep up a more
effectual ricochet fire against them ; whilst the
requisite length of the 1st parallel will likewise
be smaller.
Thirdly, the besieger should very accurately
determine the prolongations of all the faces to be
enfiladed, and erect ricochet batteries not only
against the works belonging to the front of attack,
but also against the collateral ravelins ; such of
these batteries as are intended to enfilade the



162 ON THE ATTACK AND

terrepleins of the capital works, should consist
of guns; and those directed against the dry
ditches, covert-way, and the coffers in front of
the re-entering places of arms, are to contain
howitzers, or mortars mounted upon carriages
which allow them to be used for ricochet firing.
