ich they are placed.

Two kinds of cement are used in the early structures. One is a coarse
clay or mud, which is sometimes mixed with chopped straw; the other is
bitumen. This last is of an excellent quality, and the bricks which it
unites adhere often so firmly together that they can with difficulty be
separated. As a gen eral rule, in the early buildings, the crude brick
is laid in mud, while the bitumen is used to cement together the burnt
bricks.

[Illustration: PLATE 8]

These general remarks will receive their best illustration from a
detailed description of the principal early edifices which recent
researches in Lower Mesopotamia have revealed to us. These are for the
most part temples; but in one or two cases the edifice explored is
thought to have been a residence, so that the domestic architecture of
the period may be regarded as known to us, at least in some degree. The
temples most carefully examined hitherto are those at Warka, Mugheir, and
Abu-Shahrein, the first of which was explored by Mr. Loftus in 1854, the
second by Mr. Taylor in the same year, and the third by the same
traveller in 1855. The Warka ruin is called by the natives Bowariyeh,
which signifies "reed mats," in allusion to a peculiarity, already
noticed, in its construction. [PLATE VIII., Fig. 1.] It is at once the
most central and the loftiest ruin in the place. At first sight it
appears to have been a cone or pyramid; but further examination proves
that it was in reality a tower, 200 feet square at the base, built in two
stories, the lower story being composed entirely of sun-dried bricks laid
in mud, and protected at intervals of four or five feet by layers of
reeds, while the upper one was composed of the same material, faced with
burnt brick. Of the upper stage very little remains; and this little is
of a later date than the inferior story, which bears marks of a very high
antiquity. The sundried bricks whereof the lower story is composed are
"rudely moulded of very incoherent earth, mixed with fragments of pottery
and fresh-water shells," and vary in size and shape, being sometimes
square, seven inches each way; sometimes oblong, nine inches by seven,
and from three to three and a half inches thick. The whole present
height of the building is estimated at 100 feet above the level of the
plain. Its summit, except where some slight remains of the second story
constitute an interruption, is "perfectly flat," and probably cont