The main interest of No. 8 is the decoration on the exterior. On the west wall a simple and effective pattern is produced by laying a couple of rows of brick tiles face outwards at intervals along the top of the wall, and below these, north of the door, a rectangular tablet was formed, for purely decorative purposes, by inserting 2 or 2½ rows of faced tiles into the wall. The top of the north wall was ornamented with a row of four arched niches (Plate 50, Fig. 2). Small engaged columns, without bases, carry imposts formed of a single brick, from which spring round arches decorated with three fillets in plaster. One of the niches is pierced by a narrow window. The vault construction is very similar to that of Ukhaiḍir. All the vaults oversail the walls by 4 centimetres. The lower part of the vault is composed of from five to nine courses of bricks laid horizontally, the upper of bricks laid vertically. Over the ovoid arch thus formed (it is always a course and a half thick) are carried the horizontal courses of the walls. I looked carefully for any trace of tubes between the parallel vaults, but found none; the masonry seems to be solid in every case. All the door arches, as far as can be determined in their ruined state, were round and sprang flush with the jambs. The fortress-like character of the khân of ‘Aṭshân, the plan of its gateway, and the details of its construction and decoration incline me to assign to it a date not far removed from that of Ukhaiḍir. The tower of Mudjḍah must stand in intimate connexion with the khân, for I can conceive of no reason for the erection of an isolated tower in the midst of a waterless desert, unless it were intended to serve some purpose on the caravan track from Kûfah to ‘Ain al-Tamr, of which the khân of ‘Aṭshan was the intermediate stage.[44] I would suggest that neither khân nor tower can be dated much later than the ninth century; both are valuable and interesting examples of early Mohammadan architecture of the age, or at least of the school, to which Ukhaiḍir itself belongs. CHAPTER III QAṢR-I-SHÎRÎN