The lunette filling
the western dome arch had doubtless a similar window arrangement, though
at present it has only one window.

[Illustration: PLATE XXI.
(1) S. IRENE. INTERIOR, LOOKING NORTH-WEST.
(2) S. IRENE. DOOR AT THE EAST END OF THE NORTH AISLE.
_To face page 98._]

The eastern ends of the side galleries have been formed into separate
chambers since the Turkish occupation. Of the additions beyond the
original east wall of the church, that to the north was connected with
the gallery by a tall wide arch, while that to the south was divided off
from the gallery with only a small door as a means of communication. The
southern addition was divided into two chambers as on the ground floor.

The walls above gallery level and the large vaulting surfaces of the
building are now covered with plaster, but a close examination proves
that if any mosaic or marble revetment ever existed above gallery level,
none of it, excepting the mosaic in the apse, remains.

Looking next at the exterior of the building, it is to be observed that
the ground on the north, south, and east has been raised as much as
fifteen feet. In many places the walls have undergone Turkish repair.
The apse shows three sides. The drum of the dome is pierced by twenty
semicircular-headed windows (of which only five are now open), and as
their arches and the dome spring at about the same level the heads of
the windows impinge upon the dome's surface. Two low shoulders cover the
eastern pendentives. The plan of the drum is peculiar. From the
shoulders, just mentioned, to the windows, it is a square with rounded
corners, one side of the square being joined with and buried in the drum
of the western dome vault; but upon reaching the base of the windows it
becomes an accurate circle in plan, and at the springing of the window
arches is set back, leaving a portion of the piers to appear as
buttresses. The upper portion of the drum is carried well up above the
springing of the dome, leaving a large mass of material properly
disposed so as to take the thrusts produced.

The careful examination of the building by Mr. George has proved that
the fabric is not the work of one age, but consists of parts constructed
at different periods. For the full evidence on the subject we must await
the forthcoming monograph on the church. Here, only the main results of
Mr. George's survey can be presented.

Up to the level of the springing of the aisle vaults, the wal