WESTERN ASIATIC ARCHITECTURE. 43 B. Walls. — The Assyrians in tlie early period used stone only as a facing to their brick walls, forming a contrast with the solid marble work of the Greeks, and with the constructive use of stone and granite by the Egyptians. In Assyria, the massive walls, which were of cased brickwork, only remain, the columns being of wood having perished. In Persia, however, the walls which were thin have disappeared, leaving the massive stone or marble blocks forming the door and window openings, immense columns, and broad stairways which alone have survived the ravages of time. The slabs of alabaster with which the walls of the palaces were faced reveal much of the social history of the people, and many of the slabs are now in the British Museum (No. 13). c. Openings. — The lighting to the temples is conjectural, but it appears to have been effected by means of a " clerestory " (No. 12 b), somewhat similar to that in use in the Egyptian temples. It is believed that the Assyrian architects counted chiefly on the doorways, which were of great size, to give their buildings a sufficient supply of light and air, and openings may also have been formed in the upper parts of the walls. The use of the arch, both circular and pointed, was practised by the Assyrians, as is proved by the discoveries of Sir Henry Layardat Nimroud, and of M. Place at Khorsabad (No. 12F, g, h), where semi-circular arches spring from the backs of winged bulls with human heads. D. Roofs. — The roofing appears to have been effected by means of timber beams reaching from one column to the next, and resting on the backs of the " double-bull " capitals (No. 12 b). Some authorities consider that the halls of the palaces were covered with brick tunnel vaults, but in many cases the roof of con- siderable thickness was flat, formed of very tough but plastic clay and debris, and kept in condition by being occasionally rolled, as in modern eastern houses. Perrot and Chipiez, however, are of opinion that Assyrian builders made use of domes in addition to barrel vaults, because of the discovery of a bas-relief at Koyunjik in which groups of buildings roofed with spherical or elliptical domes are shown. Strabo (xvi. i. 5) also mentions expressly that all the houses of Babylon were vaulted. E. Columns. —These were primarily of wood, but in the later period at Persepolis, the Persians, on their return from Egypt, built them of the natural stone which had been wanting in Chaldaea. They were not so massive as in Egypt, where stone roofs had to be supported. The capitals were characteristic, being of the " double-bull," " double-unicorn," " double-horse " or " double-griffen " type (No. 13 A, c), and the Ionic scroll occurs in some examples. F. Mouldings. — As in the case of Egypt, in Western Asia
