In his accurate (if for the general reader perhaps somewhat technical) pages on the interior, Street says: "The original scheme of the church is only to be seen now in the choir and its aisles. These are arranged in three gradations of height--the choir being upwards of a hundred feet, the aisle round it about sixty feet, and the outer aisle about thirty-five feet in height. The outer wall of the aisle is pierced with arches for the small chapels between the buttresses. The intermediate aisle has in its outer wall a triforium, formed by an arcade of cusped arches, and above this quite close to the point of the vault, a rose window in each bay. It is in this triforium that the first evidence of any knowledge on the part of the architect of Moorish architecture strikes the eye. The cusping of the arcade is not enclosed within an arch, and takes a distinctly horse-shoe outline, the lowest cusp near to the cap spreading inwards at the base. Now it would be impossible to imagine any circumstances which could afford better evidence of the foreign origin of the first design than this slight concession to the customs of the place in a slightly later portion of the works. An architect who came from France, bent on designing nothing but a French church, would be very likely, after a few years' residence in Toledo, somewhat to change in his views, and to attempt something in which the Moorish work, which he was in the habit of seeing, would have its influence. The detail of this triforium is, notwithstanding, all pure and good. The foliage of the capitals is partly conventional, and in part a stiff imitation of natural foliage, somewhat after the fashion of the work in the Chapter House at Southwell; the abaci are all square; there is a profusion of nail-head used in the labels; and well-carved heads are placed in each of the spandrels of the arcade. The circular windows above the triforium are filled in with cusping of various patterns. The main arches of the innermost arcade (between the choir and its aisle) are of course much higher than the others. The space above them is occupied by an arcaded triforium reaching to the springing of the main vault. This arcade consists of a series of trefoil-headed arches on detached shafts, with sculptured figures, more than life-size, standing in each division; in the spandrels above the arches are heads looking out from moulded circular openings, and above these again, small pointed arches are pierced, which have labels enriched with the nail-head ornament. The effect of the whole of this upper part of the design is unlike that of northern work, though the detail is all pure and good. The clerestory occupies the height of the vault and consists of a row of lancets (there are five in the widest bay, and three in each of the five bays of the apse) rising gradually to the centre, with a small circular opening above them. The vaulting-ribs in the central