420 THE HISTORY OF MEDIEVAL EUROPE building. The general features of this cruciform plan were to be retained in the later Gothic style. A feature found more in Romanesque than in Gothic cathedrals was the raising of the level of the floor of the choir considerably above that of the rest of the building so as to give room for a crypt underneath. As a rule Romanesque builders made their churches loftier as well as larger than previous ones. This increased height Other new both of nave and aisles made necessary larger and features stronger supporting columns between the nave and the aisles. Often they became several feet in diameter and sometimes massive piers were substituted for columns or were alternated with them to give increased support. The round arches which connected the rows of piers or columns were now broader and higher in order to harmonize with their more massive supports. Above these arches opening into the aisles no longer appeared the horizontal strip of mosaic of the Ravenna basilicas, but a second series of archways opening or appearing to open into galleries above the aisles. Above this tri- forium, as it came to be called, and beneath the roof were the windows of the clear-story. Most Romanesque churches, espe- cially when first built, had light, flat roofs of wooden tim- bers over their lofty naves. The lower and narrower aisles were more usually vaulted with round arches or barrel vaults, cathedral since their outer walls could be
