From the foregoing discussion of the entire school, it will be seen that the builders of Provence produced very little that was original in vault construction. It was not a school of progress, but rather one of conservative adherence to the Roman tradition of the province around which it centered. Its most progressive feature was, perhaps, the preference it displayed for the pointed tunnel vault,[49] and this may be explained by the fact that the vault in Provence generally carries directly the tiles of the roof and less masonry was necessary to carry a pointed vault up into a gable than would have been the case with one of semicircular section. One further preference, which shows the structural sense of the Provence builders, is that for transverse arches under the vaults, which not only make possible lighter masonry in the vaults themselves, but also lessen the centering necessary for their construction. VAULTS SIMILAR TO THOSE OF PROVENCE IN OTHER ROMANESQUE CHURCHES Such methods of vaulting as those just described are not confined to Provence. In Poitou, for example, there is a group of churches with half-tunnel vaults in their side aisles. Some of these, like Saint Eutrope at Saintes (Charente-Inférieure)[50] (eleventh century) and Aigues-Vives (Loir-et-Cher),[51] have corresponding half arches, others, like Parthenay-le-Vieux (Deux-Sèvres),[52] (cir. 1129) have full transverse arches beneath these vaults. Moreover, in Auvergne the triforium is regularly covered with a half tunnel vault buttressing the tunnel vault of the nave, and in a few instances, as at Culhat (Puy-de-Dôme),[53] the side aisles are in one story with similar vaulting. There are also many instances outside of Provence in which the aisles have full tunnel vaults. Between Auvergne and Bourgogne there is an example in the abbey church at Souvigny (Allier) (eleventh century) (Fig. 11), and such a system may quite possibly have been employed in the aisles of Cluny[54] and in those of the choir of Saint Benoît-sur-Loire (Loiret)[55] (second half of the eleventh century). Even in England it occurs in the Tower Chapel at London[56] (begun 1078), and is also found in Poitou at Melle (Deux-Sèvres), Saint Pierre[57] (early twelfth century), where the vaults are pointed, and at Lesterps (Charente),[58] where they are of semicircular section. The three-quarter tunnel vault also is not confined to Provence for it appears as far north as Saint Genou (Indre) in the eleventh century. The foregoing examples serve only to indicate that such systems as these which are inherently simple in construction came, very naturally, to be widely employed during the Romanesque era. Where they originated it is impossible to say, but the fact that they are so elementary in principle and often vary in some of their structural characteristics[59] may indicate that they were developed independently and contemporaneously in various localities. NAVES WITH TUNNEL VAULTS AND AISLES GROINED