67. — The 3rd parallel being completed, and sup-
plied with a proper number of troops, the besieger
has much less to fear from the sallies : for, if they
should venture (o advance from the covert-way op-
posite the parallel, they would be exposed to a very
destructive fire from this last; whilst, if in order to
turn the parallel, they should advance upon its flanks,
the guards of the trenches who are posted there
would instantly be joined by the troops left for this
purpose at the outward ends of the extreme demi-
parallels, and at the ends of the 2nd parallel. New
batteries a fpl. 4, Jig. 21), the disposition and im-
portant objects of which will be hereafter explained,
may also be safely constructed under the protection
of the 3rd parallel. In short, this parallel facili-
tates the means to the besieger of storming the

* Supposing that the fire of the place being not very brisk, the
besieger has been able to employ the flying-sap occasionally in
the course of the 10th night, the 3rd parallel may of course be
completed sooner than abovesaid.
