and 4·02 m. × 2·03 m.); in both cases the dome is very shallow and the rectangular substructure is adapted to the oval by means of wooden beams laid across the angles. Everywhere wooden beams were used in conjunction with brick, and it is to be borne in mind that though the country round Raḳḳah is now entirely devoid of trees, all the Arab geographers speak of the well-wooded gardens and groves of fruit-trees that surrounded the town. In the tower-like building and in the Baghdâd gate bands of wood were laid in the face of the wall, but the wood has perished, leaving the space it occupied to tell of its former presence, as in the eastern minaret. The cusp motive can be seen in the blind arcade on the exterior of the Baghdâd gate (Fig. 43). In the interior there is a bay to the south which appears to have been covered by a barrel vault, and may have been balanced by a similar bay to the north of the doorway, for the blind arcade on the outside of the gatehouse breaks off abruptly at the northern end and must certainly have been carried further (Fig. 44). This would allow for a northern bay corresponding to the bay that still appears south of the door. The vaulting of the gate has fallen, but from the indications that are left it appears certain that while the south bay was covered by a barrel vault the central space was occupied by a groin (Fig. 45).[50] [Illustration: FIG. 45.--RAḲḲAH, BAGHDÂD GATE, RECONSTRUCTED.] The whole of the two areas of ruin are strewn with potsherds of the Mohammadan period, and over the greater part of the walled city the ground is honeycombed with irregular holes and trenches, the excavations of peasants in search of the now celebrated Raḳḳah ware. A few years ago their labours were rewarded by a large find of unbroken pieces, many of which made their way through the hands of Aleppo dealers to Europe, and though such a stroke of good fortune is rare, perfect specimens are occasionally unearthed, and I saw a considerable number, together with one or two fragments of exquisite glass embossed with gold, during the two days I spent at Raḳḳah. In some instances the original factories and kilns have been brought to light, and it is not unusual to see bowls or jars which have been spoilt in the baking and thrown away by the potter. No exhaustive study of Raḳḳah ware has as yet been made, though it is of the utmost importance in the history of the arts of Islâm. The fabrication of it must have reached a high state of perfection during the twelfth and thirteenth centuries, to which period the pieces which have been preserved are usually assigned.