Glancing up at the superstructure and vaulting, there is a great consciousness of light and joy,--a feeling that it would have been well-nigh perfect, if the choir and its rejas could only have remained in their old proper place east of the crossing, instead of sadlycongesting a nave magnificent in length and size. The brightness is due, partly to the stone itself, almost white when first quarried from Ontoria, and partly to the uncolored glass in the greater portion of the clerestory. Here and there the masonry has the mellow tones of meerschaum, shaded with pinkish and lava-gray tints, but the effect is rather that of ancient marble than of limestone. The interior, compared to Toledo, is a bride beside a nun. Granting the loss of original simplicity and a rather distressing mixture of two styles, the combination has been handled with a skill and genius peculiarly Spanish and therefore picturesque. The austerity of the French prototype has been replaced by joyousness and regal splendor. If we examine carefully the older portions of the interior structure and carving as well as the traces of parts that have disappeared, we feel how very French it is, and undoubtedly erected without assistance from Moorish hands. The vaulting is like some of the French, very rounded, especially in the side aisles. It is all plain excepting under the dome and the vaults immediately abutting, where additional ribs were evidently added at a later time. The vaulting ribs of the main arches start unusually low down, almost on a level with the top of the triforium windows, giving the church relatively a much lower effect than Leon or the French Rheims or Amiens. Both triforium and clerestory are very fine, especially in the nave, where, although they have undergone alterations, these are less radical than in the Capilla Mayor. The triforium, which is early thirteenth-century work, is strikingly singular. Its narrow gallery is covered by a continuous barrel vault parallel to the nave. Six slender columns divide its seven arches, while above them are trefoil and quatrefoil penetrations contained within a segmental arch, broken by carved heads. The fine old shafts, separating the trefoiled or quatrefoiled arcade, are hidden by crocketed pinnacles and a traceried balcony. The triforium east of the crossing has only four arches, with much later traceried work above. The charming old simplicity is of course lost wherever gaudy carving has been added, but the oldest portions belong decidedly to the early Gothic work of northern France. Above rises the clerestory in its early vigor, with comparatively small windows, consisting of two arches and a rose.