to the windlass, which is at the bottom
of the machine, and there be fastened. The windlass is now to be turned
by means of the handspikes, and it will raise the machine of itself
without danger. Thus, a machine of the larger kind will be set in
position, with its ropes in their places about it, and its stays
attached to the piles. Its blocks and traction ropes are arranged as
described above.

5. But if the loads of material for the work are still more colossal in
size and weight, we shall not entrust them to a windlass, but set in an
axle-tree, held by sockets as the windlass was, and carrying on its
centre a large drum, which some term a wheel, but the Greeks call it
[Greek: amphiesis] or [Greek: perithekion].

6. And the blocks in such machines are not arranged in the same, but in
a different manner; for the rows of sheaves in them are doubled, both at
the bottom and at the top. The traction rope is passed through a hole in
the lower block, in such a way that the two ends of the rope are of
equal length when it is stretched out, and both portions are held there
at the lower block by a cord which is passed round them and lashed so
that they cannot come out either to the right or the left. Then the ends
of the rope are brought up into the block at the top from the outside,
and passed down over its lower sheaves, and so return to the bottom, and
are passed from the inside to the sheaves in the lowest block, and then
are brought up on the right and left, and return to the top and round
the highest set of sheaves.

7. Passing over these from the outside, they are then carried to the
right and left of the drum on the axle-tree, and are tied there so as to
stay fast. Then another rope is wound round the drum and carried to a
capstan, and when that is turned, it turns the drum and the axle-tree,
the ropes get taut as they wind round regularly, and thus they raise the
loads smoothly and with no danger. But if a larger drum is placed either
in the middle or at one side, without any capstan, men can tread in it
and accomplish the work more expeditiously.

8. There is also another kind of machine, ingenious enough and easy to
use with speed, but only experts can work with it. It consists of a
single timber, which is set up and held in place by stays on four sides.
Two cheeks are nailed on below the stays, a block is fastened by ropes
above the cheeks, and a straight piece of wood about two feet long, six
digits wide, and f