I rode northwards from the ’Ashiḳ for exactly an hour to the ruins of Ḥuweiṣilât where there are traces of a wall set with towers. One tower alone stood to any height; it appeared to mark the north-west corner of a rectangular enclosure, in the centre of which was a mound covered with fragments of tiles, but the east side of the enclosing wall was so completely destroyed that I could not make out the line of it. One important point is to be noted: the wall and towers were not built of brick, but of pebbles set in concrete, exactly similar to the masonry of the Ḳâim tower, and I think it possible that both Ḳâim and Ḥuweiṣilât may belong to an age prior to the Abbâsid period. It must, however, be added that the gateway of the castle at Tekrît, which is undoubtedly Mohammadan, is built of the same materials. South of the ’Ashiḳ is the ruin known as Ḳubbet es Ṣlebîyeh (Fig. 149). It consists of a small square central chamber, octagonal upon the exterior, encompassed by an octagonal corridor (Fig. 150). The central chamber had been covered by a dome which was set on a simple bracket over the angles of the substructure (Fig. 151); the corridor had been barrel vaulted. Fragments of the transverse arches that helped to carry the vault are still in place. Ṣlebîyeh was built of sun-dried brick covered with plaster. When I went to the ’Ashiḳ for the second time I sent a guffah up the river to above Lekweir and dropped down-stream to the ruins of the castle, whence we floated down to the camp. On this most pleasant expedition I took occasion to examine Lekweir. It lies about an hour’s ride above Sâmarrâ, and unlike all the other ruins, it is in the low ground by the water’s edge. Its complete destruction is perhaps due to its having been at the mercy of the flooded river. Great blocks of fallen brickwork lie upon the bank and in the stream, while a massive brick wall forms a sort of quay. A large building must have adjoined this quay, for the ground is tossed into mounds for a considerable distance and the mounds are strewn with broken brick and with fragments of thin marble slabs, pink, green and greyish-white in colour. [Illustration: FIG. 152.--SÂMARRÂ, BEIT EL KHALÎFAH.] The only other edifice which has escaped complete destruction is the Beit el Khalîfah (the House of the Khalif) (Fig. 152).[136] It is a triple-vaulted hall standing above the Tigris (Fig. 153.)[137] The central hall was no doubt the audience chamber of the palace; it corresponds to the great hall at Ctesiphon. The two wings are divided into a small ante-chamber, covered with a semi-dome set on squinches (Fig. 154), and a larger room roofed with a barrel vault. The vaults are all slightly pointed and all are built on the [Illustration: FIG. 153.--SÂMARRÂ, BEIT EL KHALÎFAH.] [Illustration: FIG. 154.--SÂMARRÂ, BEIT EL KHALÎFAH, DETAIL OF VAULT OF SIDE CHAMBER.] [Illustration: FIG. 156.--SÂMARRÂ, BEIT EL KHALÎFAH, STUCCO DECORATION.]