ces at each stage of our journey through the art
history of antiquity, but we may at once state the general law that our
studies and comparisons will bring to light. The arch was soonest
discovered and most invariably employed by those builders who found
themselves condemned, by the geological formation of their country, to the
employment of the smallest units.

The Chaldaeans were among those builders, and they made frequent use of the
arch. They built no long arcades with piers or columns for supports, like
those of the Romans, and that simply because such structures would have
been contrary to the general principles of their architecture. They made no
use, as we have already explained, of those isolated supports whose
employment resulted in the hypostyle halls of Egypt and Persia, in the
naves of Greek temples and Latin basilicas. The want of stone put any such
arrangement out of the question. We have, then, no reason to believe that
their arches ever rested upon piers or upon the solid parts of walls freely
pierced for the admission of light. The type from which the modern east has
evolved so many fine mosques and churches was unknown in Chaldaea. In every
building of which we possess either the remains or the figured
representation the archivolts rest upon thick and solid walls.

Under these conditions the vault was supreme in certain parts of the
building. Its use was there so constant as to have almost the character of
an unvarying law. Every palace was pierced in its substructure by drains
that carried the rain water and the general waste from the large population
by which it was inhabited down into the neighbouring river, and nearly all
these drains were vaulted. And it must not be supposed that the architect
deliberately hid his vaults and arches, or that he only used them in those
parts of his buildings where they were concealed and lost in their
surroundings; they occur, also, upon the most careful and elaborate
facades. The gates of cities, of palaces and temples, of most buildings, in
fact, that have any monumental character, are crowned by an arch, the curve
of which is accentuated by a brilliantly coloured soffit. This arch is
continued as a barrel vault for the whole length of the passage leading
into the interior, and these passages are sometimes very long. Vaults would
also, in all probability, have been found over those narrow chambers that
are so numerous in Assyrian palaces were it not for the unive