Some of the bricks were made wedge-shaped, for use in the building of arches and vaults. The common bricks were sometimes used in the crude state, or unburnt, and burnt. Enamelled bricks were greatly used in Chaldea, but the clay of which they were made was softer and more friable. This was used purposely, so that the enamel would sink deeper into the soft material, and thereby make a more lasting surface protection. [Illustration: Fig. 169.—Babylonian Brick, 16 ins. square, 4 ins. thick. (P. & C.)] [Illustration: Fig. 170.—Brick from Erech. (P. & C.)] Assyria copied most of her art and sciences from her older sister in civilisation, and had the advantage over Chaldea in a good supply of building stone, that formed the substructural bed for the clay deposits. This was a sulphate of chalk known as alabaster, grey in colour, and easy to work. The great wall slabs used for the bas-reliefs and the winged bulls and other statuary, were carved out of this material; but the Assyrians used bricks for the main structure of their buildings, like the Chaldeans. Timber was scarce in Assyria, but was used very much in the palaces. It was brought from the mountains of Upper Mesopotamia, on the left bank of the Tigris, and, later, cedar and other woods were transported from the forests of Lebanon for the beams of the palaces and temples. All kinds of metals, burnished and unburnished, were used as decorative accessories, especially by the Chaldeans. [Illustration: Fig. 171.—One of the Gates of the Harumat, Dur-Sarginu. (M.)] The historians’ descriptions, the foundations that have been excavated, and the sculptured buildings on the bas-reliefs, are the materials, together with well-preserved fragments of architecture, which archæologists and architects have used to enable them to restore some of the wonderful temples and palaces of ancient Assyria (Fig. 172). [Illustration: Fig. 172.—Interior of a Temple, after Layard’s Restoration.] The bird’s-eye view of the palace of Dur-Sarginu will give a good idea of the typical Assyrian palaces (Fig. 174), and the triumphal gate with its man-headed winged bulls at the base and sides (Fig. 173), and also the other gate at Fig. 172, both with their crenallated battlements, serve to show the imposing character of these edifices. It will be noticed from the bird’s-eye view and the gateways that the general character of Assyrian architecture was rectangular in the highest degree. The arch and vaulted structures were known to the Assyrians, who used them to great advantage (Figs. 175 and 250), and much more so than the Egyptians, although the latter people occasionally employed them. [Illustration: Fig. 173.—Triumphal Gate at the entrance of the Palace. (M.)] The Chaldeans, as would naturally be expected, used the arch construction very much in their brick buildings, as it would be the only means of carrying roofs and upper floors, where stone and timber could not easily be obtained (Fig. 175).