either the fortresses of Khorsabad and Nineveh were connected, and this circuit is actually given,--or Xenophon assumes that they once were in connection. We are hardly justified in excluding the first hypothesis. The lower part of the walls, so Xenophon tells us, was built of smoothed shell-stone;[407] the thickness was about 50 feet, and the height also 50 feet. On this substructure is raised the wall of bricks, which also is 50 feet thick, but 100 feet high. Hence these walls were standing 200 years after the fall of Nineveh; with the walls of Khorsabad, though broken by wide breaches, they were still to be traced through a circuit of 20 miles, and reached the astounding height of 150 feet, _i.e._ higher than Ctesias puts them. The remains of the walls of Khorsabad possess to this day a thickness of 45 feet, which agrees with Xenophon's measure; in the walls of Nineveh the substructure of well-hewn limestone can be traced, but the remains of the walls do not rise more than 46 feet above the present surface of the ground. If we are to venture on a supposition about the number of the inhabitants from the extent of the walls of Nineveh and Khorsabad--the total of the two cities, in which the royal palaces and temples occupied a considerable space, can hardly be put down at more than 300,000. Twenty good miles to the south of Nineveh lay the other residence of the kings of Asshur, Chalah, the city founded by Shalmanesar I. Chalah was naturally even stronger than Nineveh. On the west, as at Nineveh, the Tigris formed the protection; about seven and a half miles to the south the greater Zab emptied into the Tigris. The course of this from the north-east to the south-west formed on the east also an outer line of defence, which was made still more strong by the fact that a not inconsiderable tributary of the Zab, the Bumodus (Ghasr), which flows from north to south, empties into the Zab about ten miles to the east of Chalah, just before the latter unites with the Tigris. Above the mouth of the Zab, Assurnasirpal carried a canal from that river in a northern direction to Chalah (II. 312). The city itself formed, as has been already remarked, a regular square, the extent of which reached about half the circuit of Nineveh; the south-west corner of the city was occupied by the royal palace. Xenophon gives to the walls of this "large but desolated" city, which he calls Larissa, a circuit of two parasangs (seven miles, nearly). The walls also were of less dimensions here. Xenophon found the substructure of stones 20 feet high; the walls of burnt bricks on the substructure 100 feet high; the thickness of the walls was 25 feet.[408] Northward of Chalah, on the brook Shordere, which flows past on the south and east of Chalah, are heaps of ruins, extending as far as Keremles, and from this point again through the plain as far as the district of Khorsabad. It is possible that the line of these forts formed an outer system of defence for Nineveh and Chalah,