MATERIALS. 121 In Assyria long chains of hills traversed the plain and stretched here and there as far as the borders of the two rivers, besides which the last buttresses of the mountains of Kurdistan came very near the left bank of the Tigris, These hills all contained limestone. Two sorts were found : one fine, hard, close grained, and a little shelly, the other softer and more friable. For the decoration of his monumental doorways and the lining of his richest apartments, the architect chose and committed to the sculptor those fine slabs of gypseous alabaster of which so many examples are to be seen in the Louvre and British Museum. In the plains gypsum serves as a base or foundation for the wide banks of clay that spread over the country, and are much less thick than in the south of Chaldaea. Alabaster is there to be met with in great quantities, often but little below the surface of the soil. 1 It is a sulphate of chalk, gray in colour, soft and yet susceptible of polish. But it has many defects ; it breaks easily and deteriorates rapidly on exposure to the air. The Assyrians, however, did not fear to use it in great masses, as wit- ness the bulls in the Louvre and British Museum. Before removal these carved man-headed animals weighed some thirty-five tons, and some of those remaining at Khorsabad and Kouyundjik are still larger. In Assyria as in Chaldsea the dark and hard volcanic rocks have only been found in a few isolated fragments. They were used by the statuary and ornamentist rather than by the architect, and we cannot say for certain where they got them. We know, however, that basalt and other rocks of that kind were found in the upper valleys of the streams that flowed into the two great rivers. 2 The Assyrian architect had therefore only to stretch out his hand to win stone of a sufficiently varied nature from the soil of his own country or the flanks of its mountains. It was, of course, mediocre in quality but it had powers of resistance that fitted it for use in certain positions. At the first glance it is difficult to understand why so little use was made of it. But 1 BOTTA, Monuments de Ninive, vol. v. p. 3. 2 In the valley of the Khabour, the chief affluent of the Euphrates, LAYARD found volcanoes whose activity seemed only to have been extinguished at a very recent epoch. Long streams of lava projected from their sides into the plain. Discoveries, P- 37- R
