8. When one considers the character of the land along the upper course of the Tigris, where the Assyrians dwelt, one cannot help wondering why they went on building mounds and using nothing but bricks in their constructions. There is no reason for it in the nature of the country. The cities of Assyria--NINEVEH (Koyunjik), KALAH (Nimrud), ARBELA, DUR-SHARRUKIN (Khorsabad) were built in the midst of a hilly region abounding in many varieties of stone, from soft limestone to hard basalt; some of them actually stood on rocky ground, their moats being in part cut through the rock. Had they wanted stone of better quality, they had only to get it from the Zagros range of mountains, which skirts all Assyria to the East, separating it from Media. Yet they never availed themselves of these resources, which must have led to great improvements in their architecture, and almost entirely reserved the use of stone for ornamental purposes. This would tend to show, at all events, that the Assyrians were not distinguished for inventive genius. They had wandered northward from the lowlands, where they had dwelt for centuries as a portion of the Chaldean nation. When they separated from it and went off to found cities for themselves, they took with them certain arts and tricks of handicraft learned in the old home, and never thought of making any change in them. It does not even seem to have occurred to them that by selecting a natural rocky elevation for their buildings they would avoid the necessity of an artificial platform and save vast amount of labor and time. [Illustration: 13.--RAFT BUOYED BY INFLATED SKINS. (ANCIENT.) (Kaulen.)] [Illustration: 14.--RAFT BUOYED BY INFLATED SKINS. (MODERN.) (Kaulen.)]