The great court is surrounded by arcades of pointed arches, that have a slight tendency to turn inwards at the base, and are built as piers of plastered brick; it is said to be the first mosque built on piers, instead of the usual round columns. The Saracens did not make columns themselves, but took them from the ruins of Roman buildings, or even from existing Christian churches, and as often as not used the capitals turned upside down as bases. The Saracens have a form of capital of Moorish design which harmonizes with their architecture; it has a slightly tapering, smooth, long neck, a heavy projecting head, and is well covered with characteristic foliated work (Fig. 351). In the mosque of Ibn-Tūlūn there are only two columns; these are placed at the niche or mihrab. Three sides of this mosque have two rows of arches, and the fourth—the side towards Mecca—which is the _liwān_ or sanctuary, has five. The architect of this mosque was a Coptic Christian, who received £5,000 and a costly dress of honour as his fee. The total cost of the building was £60,000 (_Lane-Poole_). Around the arches and the windows, which were placed high up between the arches, are bands of palmated ornament. These borders, according to Mr. Stanley Lane-Poole, are the earliest examples of geometrical design and scroll-work that afterwards became so characteristic of Saracenic ornament. They were made in plaster or stucco-work by hand, while the plaster was wet, and not cast in moulds, which was the case of later Moorish plaster ornament. [Illustration: Fig. 350.—Arcades in the Mosque of Ibn-Tūlūn. (L.-P.)] The arcades were roofed over with sycamore planks resting on heavy beams, and the whole structure was crowned with crenellations or embattlements. One of the back walls of the arcades is pierced with grilles of stone, of beautiful tracery design. The Arabian or Saracen arches are of three kinds—the Ogee, the Horseshoe, and the Pointed (Fig. 352, _a_, _b_, _c_). [Illustration: Fig. 351.—Moorish Capital.] A peculiar arrangement of cusped inter-arching, combined with the horseshoe arch, is seen in the _maksura_, or space in front of the mihrab, of the mosque of Cordova, built A.D. 786 (Fig. 353). This arrangement of cusping, though characteristically Moorish, is anything but beautiful. The Mosque of Cordova was begun by the Caliph Abd-al-Rahman in the year before he died, and was continued by his son Hisham, and his grandson El-Hakim. It is one of the great congregational mosques, and occupied a space of ground 580 feet by 435 feet. [Illustration: Fig. 352.—Arches; _a_, ogee; _b_, horseshoe; _c_, pointed.]