At the crossing of the nave and transept, we have the typical, small Spanish octagonal dome,--in this instance covering possibly what was in the original mosque a central octagonal court. It is a construction rising some hundred and seventy feet above the level of the eye, admitting light below its spring into what in the French Gothic edifices would usually be the gloomiest portions of the building. The side aisles differ slightly in width, the two lateral ones being filled with various chapels. There are nine bays, separated by thirty-six clustered pillars, some of them perfect towers in their huge and massive strength. Their detail and outline are excellent, all of the greatest simplicity and restraint. The delicate engaged shafts which surround the huge supports of fifteen feet diameter terminate below the vaulting ribs in delicately interlaced palm-leaf caps. Nothing is confused or intricate. Sixty-eight compartments spring from the various piers with a loftiness reminding one of Cologne. The groining differs very much. The greater portion is admirably plain, of simple quadripartite design; other parts are fanciful and elaborate, recalling florid German prototypes. The five central vaults forming the cross under the dome alone have elaborate fan-vaulting; the geometrical design is as excellent as its detail. The richness given this central and most correct portion of the great roofing is all the more effective by contrast with the plain, unelaborated groins of the surrounding vaults. The petals of the flower, the very holy of holies, between the choir and the Capilla Mayor, before the high altar, are what is most beautiful and enriched. The lighting is very unusual, and better than either Leon or Toledo. Ninety-three windows are filled with the most glorious glass. There are two clerestories to light the body of the church, one in the walls of the second side aisle, admitting light above the roofs of the chapels, the second in the nave. Added to this come the huge lights of the five rose windows. In Seville, as in Toledo and many of the other great Spanish cathedrals, the general view of the interior is blocked, and the majesticeffectiveness of the columnar rows marred, by the placing of the great choir in the centre of the edifice.