e
very superior kiln-baked article. The former, however, was only applied
to platforms, and to the interior of palace mounds and of very thick
walls, and was never made by the later people the sole material of a
building. In every case there was at least a revetement of kiln-dried
brick, while the grander buildings were wholly constructed of it. The
baked bricks used were of several different qualities, and (within
rather narrow limits) of different sizes. The finest quality of brick
was yellow, approaching to our Stourbridge or fire-brick; another very
hard kind was blue, approaching to black; the commoner and coarser
sorts were pink or red, and these were sometimes, though rarely, but
half-baked, in which case they were weak and friable. The shape was
always square; and the dimensions varied between twelve and fourteen
inches for the length and breadth, and between three and four inches
for the thickness. [PLATE XVII., Fig. 1.] At the corners of buildings,
half-bricks were used in the alternate rows, since otherwise the
joinings must have been all one exactly over another. The bricks were
always made with a mold, and were commonly stamped on one face with
an inscription. They were, of course, ordinarily laid horizontally.
Sometimes, however, there was a departure from this practice. Rows of
bricks were placed vertically, separated from one another by single
horizontal layers. This arrangement seems to have been regarded as
conducing to strength, since it occurs only where there is an evident
intention of supporting a weak construction by the use of special
architectural expedients.

[Illustration: PLATE XVII.]

The Babylonian builders made use of three different kinds of cement. The
most indifferent was crude clay, or mud, which was mixed with chopped
straw, to give it greater tenacity, and was applied in layers of
extraordinary thickness. This was (it is probable) employed only where
it was requisite that the face of the building should have a certain
color. A cement superior to clay, but not of any very high value, unless
as a preventive against damp, was bitumen, which was very generally used
in basements and in other structures exposed to the action of water.
Mortar, however, or lime cement was far more commonly employed than
either of the others, and was of very excellent quality, equal indeed to
the best Roman material.

There can be no doubt that the general effect of the more ambitious
efforts of the B