bait centres round each alternate court, which communicates with the two chambers on either side, and the intermediate court is merely a yard common to two baits. The bait of Ṭûbah is therefore the same as the typical bait of Qasṭal. The enclosing walls and the foundation of all other walls are of stone, the rest of the building is constructed of brick tiles. The western end of the palace, and most of the northern side were completed; the eastern and south-eastern parts were never carried above the foundations. The doorways are covered by brick and stone arches, but a stone or wood lintel was placed under the arch. Where the lintel is of stone its outer side is adorned with an interesting early Mohammadan pattern, which has affinities with the carving on the eastern end of the façade at Mshattâ. The stone lintels are not carried through to the inner side of the arch. The arches, which are round, are built of stone, as is the wall below them. The wooden lintels have rotted away or have been removed by the Arabs. They were laid in brick walls and covered by brick relieving arches composed of two rings of brick tiles. In the inner ring the bricks are set vertically, parallel to the main axis of the arch, with the broad side outwards; in the outer ring they are laid horizontally, at right angles to the main axis, with the narrow end outwards. It is the principle on which many of the smaller arches at Ukhaiḍir are constructed. The brick arches at Ṭûbah are a stilted, slightly pointed oval; that is to say that the transition from the ovoid to the pointed arch is illustrated here in much the same manner as at Ukhaiḍir. [Illustration: FIG. 29. Kharâneh, upper floor. (From _Qṣeir ‘Amra_, by kind permission of the Akad. der Wiss. in Vienna.)]