The besieger is then to proceed to the crowning



99 ON THE ATTACK AND

of the covert-way ; and, in order to begin it, two
of the four brigades of sappers employed for con-
stracting the double-saps r should turn to their
right, and theothers to their left, so as to form four
BfRgle-aaps, two of which, namely those inward,
are to meet opposite the saliant, whilst the others
follow a direction parallel to the branches.
8Q<-^The I9th day and 20th night may enable
the besieger to crown a large portion of the covert-
way in front of the ravelin ; but the proximity of
the re-entering places of arms, besides the action
of the ravelins, will render it scarcely possible f(Mr
him to extend during that time his lodgments op-
posite the bastions, further than the prolonga-
tion of the magistral line of the faces of these
works. In constructing the traverses g which
are to secure these lodgments and those in front
of the ravelin, the sappers should cautiously avoid
placing any of them in those parts of the lodg-
ments where they would interfere with the situa-
tions for the guns of the eounter^batteries and
breaching batteries that the besieger is subse-
quently to erect, as will hereafter be more par-
ticularly explained. The epaulments h require
such a length, and sueh a height, as will allow
them to secure the lodgments from the fire of the
collateral works.
