We must not forget to draw attention to the curious way in which the body of the fort is constructed. It is composed of crude bricks transfixed horizontally, and at rather narrow intervals, by pieces of wood. The situation of these beams may be easily recognized as they have decayed and left channels in the brickwork. That the holes with which the walls are pierced at regular distances (see Fig. 30) were thus caused, is beyond doubt, especially since a few fragments of wood which the centuries have spared have been found. These fragments have been recognized as having come from the _doum_ palm, which is very common in Upper Egypt, and commoner still in Nubia. We need not dwell upon the other fortress--that on the right bank. It may be seen in the distance in our restoration of Semneh. Being built upon rocks which were on all sides difficult of access, it did not require any very elaborate works. It was composed of an _enceinte_ inclosing an irregular square about 190 feet each way. It had but a few salient buttresses; there were only two on the north-east, towards the mountains, and one, a very bold one, on the south-west, commanding the river. There was no room for a wide ditch. But at a distance of thirteen feet from the walls there was a glacis similar to that at Semneh. It had the same casing of polished stone, but on account of the irregularities of the rock, the height of its crown varied considerably, and its slope was very steep, almost vertical. The trace of the counterscarp followed that of the _enceinte_, including the buttresses. Moreover, at its northern and southern angles it followed a line which roughly resembled the bastions of a modern fortification. Its structure was similar to that of Semneh. Lepsius does not hesitate to ascribe both these forts to Ousourtesen III., whose name appears upon all the neighbouring rocks, and who, with the deities of the south, was worshipped at Semneh.[45] They would thus date back, according to the chronology which is now generally adopted, to the twenty-seventh or twenty-eighth century B.C. In any case they cannot be later than the time of Thothmes III., who, in the course of the seventeenth century B.C. restored the temples which they inclose, and covered their walls with his effigies and royal cartouches. Even if we admit that these two castles are not older than the last-named epoch, we shall still have to give to Egypt the credit of possessing the oldest examples of military architecture, as well as the oldest temples and the oldest tombs. [45] LEPSIUS, _Briefe aus Ægypten_, p. 259.--See also MASPERO, _Histoire Ancienne_, pp. 111-113. CHAPTER II. METHODS OF CONSTRUCTION, THE ORDERS, SECONDARY FORMS. § 1. _An Analysis of Architectural Forms necessary._