crenellated parapet in order to protect those who walked along it. Nor was it only from the angles of the yard that the chemin de ronde could be approached. It was accessible from the top story of the palace and also by means of stairs which were situated on either side of the east, south and west gates. None of these gates are well preserved and in no case have the stairs escaped ruin, but the mark of the stair can be seen clearly on the inner face of the wall (Plate 9, Fig. 1). The three gateways are all alike (section _g-h_, Plate 5, Fig. 2). They are flanked on the exterior by segments of towers (Plate 9, Fig. 2). The outer archway, which contained the door, has in every case been blocked up by the Beduin; it is therefore impossible to tell its exact depth, though its width, 2·10 metres, can be determined. I omitted to note the portcullis of which the authors of _Ocheïdir_ found traces outside the door.[15] An inner arched niche, 1·45 metres long by 2·50 metres wide, is visible from the interior, together with a portion of the chamber into which it led. This chamber was 6·30 metres long by 3·10 metres wide, and was covered by a pointed barrel vault oversailing the face of the walls. Over the doorway on the inside, there is an arched niche which communicated with the arch of the outer gate by a rectangular funnel. It is impossible to imagine what can have been the purpose of this funnel, which connected the bottom of the niche with the top of the arch, unless it were meant to receive the bolt of the door, but I do not think that even this explanation will hold. The authors of _Ocheïdir_ observed a similar communication between every niche placed over a doorway and the arch below it. The construction is made clear in their admirable drawing (_Ocheïdir_, Fig. 19). They offer no conclusion as to its purpose, but since it occurs in archways which show no sign of having contained a door, the idea that it was meant to provide space for a bolt cannot be maintained. The inner wall of the gate-house, which has in every case fallen, projected into the palace yard 3·50 metres from the face of the inner pilasters of the enclosing wall. Besides the vaulted passage or chamber in the centre, it comprised the above-mentioned staircases. I detected traces of a door between the gate-room and the staircase on either side. The stair wound once round the rectangular newel post and reached a chamber on the first floor, above the gate-room. The doors of communication between the stair and this chamber are not preserved. The chamber is unusually low, 3·30 metres from the floor to the top of the vault. It is provided with a large window, 2·50 metres high, in the outer wall, opening on to the desert. The stair turned once more round the newel post and led into the chemin de ronde, with which the upper chamber of the gate-house communicated by doorways. The vaulting construction of the south gateway, which is the best preserved (Plate 9, Fig. 1), shows that the