part and carry round with the army,
and likewise the borer, and the scaling machine, by means of which one
can cross over to the wall on a level with the top of it, as well as the
destroyer called the raven, or by others the crane.

4. He also employed the ram mounted on wheels, an account of which he
left in his writings. As for the tower, he says that the smallest should
be not less than sixty cubits in height and seventeen in breadth, but
diminishing to one fifth less at the top; the uprights for the tower
being nine inches at the bottom and half a foot at the top. Such a
tower, he says, ought to be ten stories high, with windows in it on all
sides.

5. His larger tower, he adds, was one hundred and twenty cubits high and
twenty-three and one half cubits broad, diminishing like the other to
one fifth less; the uprights, one foot at the bottom and six digits at
the top. He made this large tower twenty stories high, each story having
a gallery round it, three cubits wide. He covered the towers with
rawhide to protect them from any kind of missile.

6. The tortoise of the battering ram was constructed in the same way. It
had, however, a base of thirty cubits square, and a height, excluding
the pediment, of thirteen cubits; the height of the pediment from its
bed to its top was seven cubits. Issuing up and above the middle of the
roof for not less than two cubits was a gable, and on this was reared a
small tower four stories high, in which, on the top floor, scorpiones
and catapults were set up, and on the lower floors a great quantity of
water was stored, to put out any fire that might be thrown on the
tortoise. Inside of this was set the machinery of the ram, termed in
Greek [Greek: kriodoche], in which was placed a roller, turned on a
lathe, and the ram, being set on top of this, produced its great
effects when swung to and fro by means of ropes. It was protected, like
the tower, with rawhide.

7. He explained the principles of the borer as follows: that the machine
itself resembled the tortoise, but that in the middle it had a pipe
lying between upright walls, like the pipe usually found in catapults
and ballistae, fifty cubits in length and one cubit in height, in which
a windlass was set transversely. On the right and left, at the end of
the pipe, were two blocks, by means of which the iron-pointed beam,
which lay in the pipe, was moved. There were numerous rollers enclosed
in the pipe itself under the beam, wh