are, for the most part, intelligently designed, and consist of square members grouped with reference to the transverse ribs of the vaults and to the ground-story archivolts, accompanied by engaged shafts to support the sub-orders, where such occur, and sometimes to support the diagonal vaulting ribs. These piers frequently exhibit the peculiarity of coupled engaged shafts to carry a single rib or arch order. The main ribs and archivolts are of plain square section; and are usually, though not always, of two orders. The clerestory is low with heavy walls pierced by small and usually round-arched windows. The triforium space is narrow and without openings. These features appear in the old Cathedral of Salamanca, the Cathedral of Tudela, the Abbey Church of Veruela, the Cathedral of Lérida, and many others.
At the same time another and smaller class of buildings were erected with barrel vaults, strengthened by projecting transverse ribs over their central aisles, and with open triforium galleries. Examples of this class are the Cathedral of Santiago and the Church of S. Isidore at Leon.
It will be seen that these two classes of buildings exhibit characteristics that belong to various localities on the French side of the Pyrenees. The dome on pendentives over the crossing is characteristic of the style of Auvergne and its neighbourhood, as in the Churches of St. Stephen of Nevers, and Notre-Dame du Port at Clermont-Ferrand, as well as of the great Romanesque churches of the Rhine. The barrel vault with transverse ribs is also a feature of the style to which the Church of Notre-Dame du Port belongs. The quadripartite vaults in nearly square compartments are conspicuous in the early twelfth century architecture of Burgundy, though the rib systems with which, in Spain, these vaults are furnished belong to the style of the Ile-de-France. The composition of the pier, the absence of triforium openings, and the square arch section are, like the square compartment, chiefly Burgundian, while the coupled vaulting shafts are from Poitou, as may be seen at Fontevrault.
It thus appears that the early Christian architecture of Spain was by no means of local growth, but that it was almost wholly the result of influences derived from Gaul. And such influences may be naturally accounted for by the incoming at this period of the Cistercian order, bringing
