The method followed in the combination of these countless apartments is, as M. Place has said, “almost naïve in its simplicity.”[33] The plan is divided into as many separate parallelograms as there were departments to be accommodated; these rectangles are so arranged that they touch each other either at an angle or by the length of a side, but they never penetrate one into the other, and they never command one another. They are contiguous, or nearly so, but always independent. Thus the palace contains three main divisions, the seraglio, the harem, and the khan. Each of these is a rectangle, and each lies upon one side of the great common square marked A on our plan. The same principle holds good in the minor subdivisions. These consist of smaller rectangles, also opening upon uncovered courts, and without any lateral communication with each other. Examine the plan and you will see the system carried out as rigidly in the seraglio as in the harem. Thus the various sections of the palace are at once isolated and close together, so that their occupants could live their lives and perform their duties in the most perfect independence. The methodical spirit by which these combinations were governed was all the more necessary in a building where no superposition of one story upon another was possible. The whole palace was one vast ground floor. To arrange on one level more than thirty courtyards and more than two hundred halls and chambers, to provide convenient means of access from one to the other, to keep accessory parts in due subordination, to give each room its most fitting place in the whole--such was the problem put before the Assyrian constructor. Profiting by a long experience he solved it with the utmost judgment, and proved himself to be wanting neither in forethought, skill, nor inventive power. § 3. _Other Palaces of Mesopotamia._ The type of palace we have studied at Khorsabad, is, like the staged towers, a development from Chaldæan structures whose leading lines were established many centuries before the princes of Calah and Nineveh began to raise their sumptuous houses. The sites of the ancient cities of Lower Chaldæa inclose buildings that seem to date from a very remote epoch, buildings in which we may recognize the first sketch, as it were, for the magnificent dwellings of Sargon and Sennacherib.