[Illustration: FIG. 24.--Plan of one of the ordinary gates at Khorsabad; from Place.] The entrance was covered by an advanced work, standing out some eighty-three feet into the plain. Each angle of this sort of barbican was protected by a low tower, about forty feet wide. Through the centre of the curtain uniting these towers there is a first vaulted passage, leading to a large courtyard (A in Fig. 24), beyond which are the space (B) between the great flanking towers of the gate proper and the long vaulted passage (C--G) which gives access to the town. This passage is not a uniform tunnel. The mass through which it runs is 290 feet thick, and in two places it is crossed at right angles by transepts wider than itself (D and F). The tunnel ends in a kind of open vestibule interposed between the inner face of the wall and the commencement of the street. All these courts, passages and transepts are paved with large limestone slabs except the small chamber that opens from one end of the outer transept (I). This small apartment was not a thoroughfare, but it has been thought that signs of a staircase leading either to upper rooms or to the battlements could be traced in it. We have seen that the Egyptian pylons had such staircases and upper chambers.[87] It would be curious to find the arrangement repeated here, but we cannot certainly say that it was so. On the other hand the situation of the doors by which the entrance into the city was barred is very clearly marked. At the point where the passage C opens into the transept D the sockets in which the metal feet of the door pivots were set, are still in place.[88] [Illustration: FIG. 25.--Restoration in perspective of one of the ordinary gates of Khorsabad; from Place.] The state doorways are distinguished from their more humble companions, in the first place by a flight of eleven brick-built steps which have to be mounted before the court A can be reached from the outside; in the ordinary gateways a gentle inclination of the whole pavement of the court makes such steps unnecessary. A second difference is of more importance. At the entrance to the passage marked C on our plan the state doorways have a pair of winged bulls whose foreparts stand out a little from the wall while their backs support the arch. The latter is decorated with the semicircle of enamelled bricks of which we have already spoken at length in our chapter upon decoration (Vol. I., Figs. 123 and 124, and below, Fig. 26). Behind the bulls there are two winged genii facing each other across the passage and about thirteen feet high (Fig. 27). [Illustration: FIG. 26.--State gateway at Khorsabad. Elevation; from Place.]