The Vizier, Almanzor, removed the eastern wall of the Mosque and extended the building in order to add eight new naves. These naves had the same number of arches as those already standing, and they were intersected at right angles with lesser naves, thirty-five in number. At this period a lack of space necessitated a narrowing of some of the arches, and the curves were made more pointed. Every conceivable ornamentation was introduced in the beautifying of these arches. The _foseyfasa_, or enamel-work of the Moors, is seen in its brilliant examples in the Mosque. This enamel, called _foseyfasa_ by the Arabs, is composed of crushed glass and small pebbles baked together with gorgeous colours, and sometimes containing an admixture of gold and silver. It was used at Damascus, in the great Mosque, and at Constantinople. According to Gayangos, this mosaic enamel was set in its place by Greek mechanics imported by Abd-er-Rahman. This work is finely exampled upon the entrance to the sanctuary, and throughout the Mosque there are specimens of this wondrous art of embellishment. The principal nave of the Mezquita has huge arches on stone columns, with finely carved capitals, and a large number of minor arches in the Estilo del Califato. Most of these columns were made from the stone of Spanish quarries. They are of jasper, marble, and other stone, and number nearly nine hundred. Narrow avenues run transversely through the grand aisles. We are lost in them; these passages appear interminable, and their ribbon decorations bewilder the eyes. We approach the sacred mih-rab, the receptacle of the Koran, the holiest of holies of the temple. The façade is exceedingly beautiful, in the later style of decoration, and the arcades of the vestibule of the sanctuary have fine triple arches and interlacing curves of exquisite design. The dome is cone-shaped. The door is in the Estilo del Califato, dazzling in the wealth of its colouring, marvellous in the grace and symmetry of its main arch, trefoil arches, and delicate frets. The mih-rab is seven-sided, with a cupola of extraordinary richness of hue, and details of the greatest interest. One is baffled in attempting to describe this sanctuary. The technical terms of architecture do not convey a conception of its beauty to the lay mind. In the days of its glory, the mih-rab was illuminated by an enormous lamp and huge candles. El-Makkari, the Arab, says that the great lantern had nearly fifteen hundred lights, and that the total number of lights was over ten thousand. The enamels shone with their brilliant hues in the rays of these lamp-lights and candles until the eye could scarcely rest upon the walls and the cupola. Here the khalifs came in pomp to worship, and to scan reverently the pages of the costly Koran.