It is observable here, its the first place, that the houses have no windows, and are, therefore, probably lighted from the roof; next, that the roofs are very curious, since, although flat in some instances, they consist more often either of hemispherical domes, such as are still so common in the East, or of steep and high cones, such as are but seldom seen anywhere.  Mr. Layard finds a parallel for these last in certain villages of Northern Syria, where all the houses have conical roofs, built of mud, which present a very singular appearance. [PLATE LVI., Fig. 2.] Both the domes and the cones of the Assyrian example have evidently an opening at the top, which may have admitted as much light into the houses as was thought necessary.  The doors are of two kinds, square at the top, and arched; they are placed commonly towards the sides of the houses.  The houses themselves seem to stand separate, though in close juxtaposition.

[Illustration:  PLATE 56]

The only other buildings of the Assyrians which appear to require some notice are the fortified enceintes of their towns.  The simplest of these consisted of a single battlemented wall, carried in lines nearly or quite straight along the four sides of the place, pierced with gates, and guarded at the angles, at the gates, and at intervals along the curtain with projecting towers, raised not very much higher than the walls, and (apparently) square in shape. [PLATE LVII., Fig 1.] In the sculptures we sometimes find the battlemented wall repeated twice or thrice in lines placed one above the other, the intention being to represent the defence of a city by two or three walls, such as we have seen existed on one side of Nineveh.

[Illustration:  PLATE 57]

The walls were often, if not always, guarded by moats.  Internally they were, in every case, constructed of crude brick; while externally it was common to face them with hewn stone, either from top to bottom, or at any rate to a certain height.  At Khorsabad the stone revetement of one portion at least of the wall was complete; at Nimrud (Calah) and at Nineveh itself, it was partial, being carried at the former of those places only to the height of twenty feet.  The masonry at Khorsabad was of three kinds.  That of the palace mound, which formed a portion of the outer defence, was composed entirely of blocks of stone, square-hewn and of great size, the length of the blocks varying from two to three yards, while the width was one yard, and the height from five to six feet. [PLATE LVII., Fig.2.] The masonry was laid somewhat curiously.  The blocks (A A) were placed alternately long-wise and end-wise against the crude brick (B), so as not merely to lie against it, but to penetrate it with their ends in many places. [PLATE LVII, Fig. 2.] Care was also taken to make the angles especially strong, as will be seen by the accompanying section.