corate those portions of the walls that were not faced with
sculptured slabs.

[Illustration: FIG. 37.--THE ROCK-CUT TOMB OF DARIUS.]

The superior lightness and elegance of the Persepolitan ruins to those
of an earlier epoch will not fail to be noticed, but there is still a
certain amount of barbaric clumsiness discernible, and it is not till
we come to Greek architecture that we see how an innate genius for art
and beauty, such as was possessed by that people, could cull from
previous styles everything capable of being used with effect, and
discard or prune off all the unnecessary exuberances of those styles
which offend a critically artistic taste.

ANALYSIS OF BUILDINGS.

_Plan._

The floor-space of a great Assyrian or Medo-Persian building was laid
out on a plan quite distinct from that of an Egyptian temple; for the
rooms are almost always grouped round quadrangles. The buildings are
also placed on terraces, and no doubt would secure external as well as
internal effects, to which the imposing flights of stairs provided
would largely contribute. We find in Assyrian palaces, halls
comparatively narrow in proportion to their great length, but still so
wide that the roofing of them must have been a serious business, and
we find them arranged side by side, often three deep. In the Persian
buildings, halls nearly square on plan, and filled by a multitude of
columns, occur frequently. In the plan of detached buildings like the
Birs-i-Nimrud, we are reminded of the pyramids of Egypt, which no
doubt suggested the idea of pyramidal monuments to all subsequent
building peoples.

_Walls._

The magnificently worked granite and stones of Egypt give place to
brick for the material of the walls, with the result that a far larger
space could be covered with buildings by a given number of men in a
given time, but of course the structures were far more liable to
decay. Accordingly, sturdy as their walls are, we find them at the
present day reduced to mere shapeless mounds, but of prodigious
extent.

_Roofs._

We can only judge of the roofs by inference, and it has already been
stated that a difference of opinion exists respecting them. It appears
most probable that a large proportion of the buildings must have been
roofed by throwing timber beams from wall to wall and forming a thick
platform of earth on them, and must have been lighted by some sort of
clerestory. At any rate the stone roofs of the Egyptians s