in the old wall, and carted away the earth from the bottom of the
mound. To prevent this, the Peloponnesians filled up the space thus
caused with heavy masses of clay, rammed tightly into baskets of
osier, which made a solid structure, much harder to remove than the
loose earth. Then the Plataeans had recourse to another device:
marking carefully the position of the mound, they ran a mine from the
city under it, and as fast as the earth fell in, they carried it away.
This continued for a long time, for the Peloponnesians, who saw their
mound rising no higher, for all their labour, but rather growing less,
did not guess the cause, but went on heaping up materials, which were
swallowed up as fast as they were brought.

Still the Plataeans feared that in spite of these counterworks they
would at length be overpowered by numbers, unless they contrived some
better means of defence. So they left off building the wall of bricks
and timber, and beginning at either end of it, they built a crescent-
shaped wall, curving inwards towards the city. Thus the
Peloponnesians, if they succeeded in carrying the first wall, would
find themselves confronted by a second line of defence, and would have
all their work to do over again, besides being exposed to a cross-
fire.

While the Plataeans were thus vigorously defending themselves, and
before the mound was completed, the Peloponnesians brought siege-
engines to bear on the wall, one of which greatly alarmed the besieged
garrison, by severely shaking their wall of timber and bricks. But
this new mode of attack was frustrated, like the rest, by the
ingenuity of the Plataeans, who dropped nooses over the ends of the
battering-rams, and drew them up just before the moment of impact.
Moreover they suspended heavy beams of wood at intervals along the