annexed ground-plan. [PLATE XXXVII., Fig. 3.] It seems to have consisted
of three gateways, whereof the inner and outer were ornamented with
colossal human-headed hulls and other figures, while the central one was
merely panelled with slabs of alabaster. Between the gateways were two
large chambers, 70 feet long by 23 feet wide, which were thus capable of
containing a considerable body of soldiers. The chambers and gateways
are supposed to have been arched over, like the castles' gates on the
bas-reliefs. The gates themselves have wholly disappeared: but the
debris which filled both the chambers and the passages contained so much
charcoal that it is thought they must have been made, not of bronze,
like the gates of Babylon, but of wood. The ground within the gate-way
was paved with large slabs of limestone, still bearing the marks of
chariot wheels.

The castellated rampart which thus surrounded and guarded Nineveh did
not constitute by any means its sole defence. Outside the stone basement
wall lay on every side a water barrier, consisting on the west and south
of natural river courses; on the north and east, of artificial channels
into which water was conducted from the Khosr-su. The northern and
eastern walls were skirted along their whole length by a broad and deep
moat, into which the Khosr-su was made to flow by occupying its natural
bed with a strong dam carried across it in the line of the eastern wall,
and at the point where the stream now enters the enclosure. On meeting
this obstruction, of which there are still some remains, the waters
divided, and while part flowed to the south-east, and reached the Tigris
by the ravine immediately to the south of the city, which is a natural
water-course, part turned at an acute angle to the north-west, and,
washing the remainder of the eastern and the whole of the northern wall,
gained the Tigris at the north-west angle of the city, where a second
dam kept it at a sufficient height. Moreover, on the eastern face, which