double fosse of great depth, defended by a strong wall, originally
afforded almost equal protection on the opposite side.

The circular keep is of extraordinary strength; and in its construction
it differs wholly from any of our English dungeon-towers.--It may be
described as a cylinder, placed upon a truncated cone. The massy
perpendicular buttresses, which are ranged round the upper wall, from
which they project considerably, lose themselves at their bases in the
cone from which they arise. The building, therefore, appears to be
divided into two stories. The wall of the second story is upwards of
twelve feet in thickness. The base of the conical portion is perhaps
twice as thick.--It seldom happens that the military buildings of the
middle ages have such a _talus_ or slope, on the exterior face, agreeing
with the principles of modern fortification, and it is difficult to
guess why the architect of Château Gaillard thought fit to vary from the
established model of his age. The masonry is regular and good. The
pointed windows are evidently insertions of a period long subsequent to
the original erection.

The inner, ballium is surrounded by a high circular wall, which consists
of an uninterrupted line of bastions, some semi-circular and others
square.--The whole of this part of the castle remains nearly perfect.
There are also traces of extensive foundations in various, directions,
and of great out-works. Château Gaillard was in fact a citadel,
supported by numerous smaller fortresses, all of them communicating with
the strong central hold, and disposed so as to secure every defensible
post in the neighborhood. The wall of the outer ballium, which was built
of a compact white and grey stone, is in most places standing, though in
ruins. The original facing only remains in those parts which are too
elevated to admit of its being removed with ease.--Beneath the castle,