66 A History of Art in Ciiald^ea and Assyria. tions of each other. Our Figs. 50 in the first volume, 24 and 25 in this, show severally the present condition, the plan and the restored elevation of & porte simple. 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 10 SO 00 40 50 '" Fig. 24. — Plan of one of the ordinary gates at Khorsabad ; from Place. 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