152 EXCAVATIONS ON SITE OE MAUSOLEUM.

The interval between the two walls was 12'. The
occurrence of these pierced walls proves that this
branch of the gallery must have served as an aque-
duct.

It is to be presumed that the object of this double
barrier was to binder too sudden a rush of water
from the hill.

The remains of a similar barrier were to be traced
at the commencement of branch D in the Vakuf
field.

It has been shown that branch C is continued by
rubble walls across the foot of the southern stair,
and that this continuation must have been made
subsequently to the cutting of the stair itself, and
reasons have been given why the rubble wall of the
gallery at its point of intersection with the southern
terrace wall must be anterior in date to the ashlar-
work of the terrace wall itself, the latter being,
as is presumed, of the date of the Mausoleum.

Prom these facts, and from the correspondence
in direction of branch C with the lines of the stair,
and of the two chambers of the south side, it would
seem that this gallery at some time or other served
as a passage between them, as well as for the con-
veyance of water, which must have been conducted
in a narrow channel in the centre of its floor. The
fact that this branch must have been so completely
interrupted by the basement of the Mausoleum at the
south-west corner of the quadrangle, would rather
lead us to suppose that branch D was substituted for
it as an aqueduct, either at the time of the building
of the Mausoleum or on some earlier occasion.