Of the early mosques the most important are those of Omar and Abd-el-Malek at Jerusalem and of Wallid at Damascus. The mosque of Omar was but a simple vaulted chamber, oriented in order to enable the faithful to turn in the direction of Mecca while praying. That of Abd-el-Malek, called the Aksah, adjoins it and is an extensive structure. It is chiefly remarkable for its general resemblance to the basilica in its division into aisles. The columns forming these carry pointed arches, built over connecting beams. It is not improbable that this design was inspired by the order of the church of the Dome of the Rock, adjoining it, built by Constantine, where the columns support circular arches, over a continuous entablature. Wallid, Caliph of Damascus, erected a mosque on the site of the old church of St. John the Baptist, and employed labour and material in its construction furnished by Justinian, Emperor of Byzance. The mosques of Cairo resemble each other in a great degree. They have usually a first court, giving access to apartments for the accommodation of strangers, with baths, and stables for their camels, connected with a second and larger quadrangular court, having a fountain in the centre and porticos on three sides. The fourth side, facing the entrance, has a series of aisles roofed in and forming the sanctuary, with recesses in the rear wall, where the prayers are offered. Reading-desks, provided with copies of the Koran, and hanging lamps form the chief furniture. The minarets, one or more of which are usually erected at the angles of the building, are special features. These tall, graceful towers, from whose summits a crier calls the people to prayers five times daily, serve a purpose similar to that of the belfries and campaniles of Europe. The diameter of most of them is small in proportion to the height, giving them a slender and beautiful aspect, very distinct from another class of towers, of which the Giralda at Seville is the best known, which were conceived in the same spirit of massiveness in which the campanile in the square before St. Mark’s in Venice was built. They are ascended by spiral staircases placed either within or without, and have projecting balconies at various stages. The building materials employed by the Arabs were chiefly stone of different colours, combined in bands and patterns, and brick covered with stucco. Enamelled tiles and multicoloured marbles were used both externally and internally, while within, carved wood, gilding, painting, and plaster were lavishly employed. Of the forms of decoration, the chief were elaborate gold inscriptions in Arabic characters, floral and geometric designs in interlaced patterns of the most intricate combinations, coloured with all the profusion suggested by the Oriental love of brilliancy and with the exquisite harmony which we see in Persian and Indian fabrics.