The cathedral of Santiago is constructed of sparkling grey granite; that of St. Sernin is of brick and mortar. Not only the cathedral, but practically the whole town of Santiago, is built, like Aberdeen, of granite, that material being exceedingly abundant in Galicia. Travellers used in former times to complain of the sombre look of the houses on that account. But now almost every dwelling is well whitewashed, and presents, with its green shutters, quite a cheerful appearance. And the grey cathedral itself lights up beautifully under the golden rays of the afternoon sun. Many a time have I seen its sparkling stones resembling rather burnished bronze than sombre grey granite. Lopez Ferreiro points out that one of the singularities of the cathedral of Santiago is the length of its transept, which is almost as long as the body of the edifice. And well I remember how, on entering for the first time, I for a moment mistook the wide and lofty transept for the central nave. In the whole of Europe there are only five other cathedrals which share this peculiarity--Pisa, Salisbury, Conques, St. Sernin of Toulouse, and St. Petronius of Bologna. Ferreiro firmly believes that the cathedral of St. Sernin is a copy of that of Santiago. This writer has also drawn attention to the ingenious and original form of the buttresses[131] which surround the body of the cathedral. They are all joined together and strengthened by arches; they thus form, as it were, one great buttress. There seem to be only two other examples of this--that of Poictiers and that of Celles (Belgium). It is not known who were the respective architects of the cathedrals of St. Sernin and Santiago, so that when French writers claim for their country the honour of having produced both these works of art, they have no real foundation to go upon. Still one cannot deny that they have an appearance of great probability on their side, especially when we find that Dalmatius, the bishop of Compostela under whose guidance so much of the work was carried on, had himself issued from the cloisters of Cluny.[132] It was the monks of Cluny who designed the beautiful porch (_narthex_) of the church of Vézelay which is permeated with the Greco-Roman art of Syria. In 1150 they constructed the capitular chapel of the same edifice, of which the sculpture is so remarkably Byzantine, and, as we shall see, there is a strong Byzantine element in the design and sculpture of the Cathedral of Santiago. But then Byzantine influence made itself felt in Spain as far back as the first century of the Christian Era, through commercial intercourse with the Mediterranean. In the eighth century, too, Spain was filled with Byzantine Christians fleeing from the Iconoclast persecution.[133]