Flying Butte

Although fully fledged flying buttresses only developed in the gothic period, their precursors can be found in Byzantine architecture and in some Romanesque buildings, such as Durham Cathedral, where quadrant arches were used to carry the lateral thrust of the stone vault over the aisles. However these arches were hidden under the gallery roof and only transmitted the forces to the massive outer walls. By the 1160's, architects in the \xcele-de-France were employing similar systems but with longer and finer arches running from the outer surface of the clerestory wall, over the roof of the side aisles (and hence visible from the outside) to meet a heavy vertical buttress rising above the level of the outer wall.[2] The main advantage of such systems is that the outer walls no longer need to be heavy and massive enough to resist the lateral thrusts of the vault. Instead the wall surface could be reduced (allowing larger windows filled with stained glass), with the vertical mass concentrat