ending away all his cavalry
by night, before the fortifications should be completed by the Romans.
He charges them when departing "that each of them should go to his
respective state, and press for the war all who were old enough to bear
arms; he states his own Merits, and conjures them to consider his
safety, and not surrender him, who had deserved so well of the general
freedom, to the enemy for torture; he points out to them that, if they
should be remiss, eighty thousand chosen men would perish with him;
that, upon making a calculation, he had barely corn for thirty days, but
could hold out a little longer by economy." After giving these
instructions he silently dismisses the cavalry in the second watch, [on
that side] where our works were not completed; he orders all the corn to
be brought to himself; he ordains capital punishment to such as should
not obey; he distributes among them, man by man, the cattle, great
quantities of which had been driven there by the Mandubii; he began to
measure out the corn sparingly, and by little and little; he receives
into the town all the forces which he had posted in front of it. In this
manner he prepares to await the succours from Gaul, and carry on the
war.

LXXII.--Caesar, on learning these proceedings from the deserters and
captives, adopted the following system of fortification; he dug a trench
twenty feet deep, with perpendicular sides, in such a manner that the
base of this trench should extend so far as the edges were apart at the
top. He raised all his other works at a distance of four hundred feet
from that ditch; [he did] that with this intention, lest (since he
necessarily embraced so extensive an area, and the whole works could not
be easily surrounded by a line of soldiers) a large number of the enemy
should suddenly, or by night, sally against the fortifications; or lest
they should by day cast weapons against our men while occupied with the
works. Having left this interval, he drew two trenches fifteen feet
broad, and of the same depth; the innermost of them, being in low and
level ground, he filled with water conveyed from the river. Behind these
he raised a rampart and wall twelve feet high: to this he added a
parapet and battlements, with large stakes cut like stags' horns,
projecting from the junction of the parapet and battlements, to prevent
the enemy from scaling it, and surrounded the entire work with turrets,
which were eighty feet distant from one anot