to the usual height of
turrets, which was effected in the following manner.

IX.-When the turret was raised to the height for flooring, they laid it
on the walls in such a manner that the ends of the joists were covered
by the outer face of the wall, that nothing should project to which the
enemy's fire might adhere. They, moreover, built over the joists with
small bricks as high as the protection of the plutei and vineae
permitted them; and on that place they laid two beams across, angle-ways,
at a small distance from the outer walls, to support the rafters
which were to cover the turret, and on the beams they laid joists across
in a direct line, and on these they fastened down planks. These joists
they made somewhat longer, to project beyond the outside of the wall,
that they might serve to hang a curtain on them to defend and repel all
blows whilst they were building the walls between that and the next
floor, and the floor of this story they faced with bricks and mortar,
that the enemy's fire might do them no damage; and on this they spread
mattresses, lest the weapons thrown from engines should break through
the flooring, or stones from catapults should batter the brickwork.
They, moreover, made three mats of cable ropes, each of them the length
of the turret walls, and four feet broad, and, hanging them round the
turret on the three sides which faced the enemy, fastened them to the
projecting joists. For this was the only sort of defence which, they had
learned by experience in other places, could not be pierced by darts or
engines. But when that part of the turret which was completed was
protected and secured against every attempt of the enemy, they removed
the plutei to other works. They began to suspend gradually, and raise by
screws from the first-floor, the entire roof of the turret, and then
they elevated it as high as the length of the mats allowed. Hid and
secured within these coverings, they built up the walls with bricks, and
again, by another turn of the screw, cleared a place for themselves to
proceed with the building; and, when they thought it time to lay another
floor, they laid the ends of the beams, covered in by the outer bricks
in like manner as in the first story, and from that story they again
raised the uppermost floor and the mat-work. In this manner, securely
and without a blow or danger, they raised it six stories high, and in
laying the materials left loop-holes in such places as they thoug