FLYING BUTTRESS

In Gothic Architecture, a but tre in the form of an arch, springing from a solid ma of masonry, and abutting against the springing of another arch which rises from the upper points of abutment of the first. It is seen in most of our cathedrals, and its office is to act as a counterpoise against the vaulting of the nave. If flying buttre es were, built solid from the ground, it is obvious that they would interfere with the vista along the aisles of the church; hence the project of continuing a resistance by means of arches. Their stability depends on the resistance afforded by the weight of the vertical buttre from whence they spring. See the diagram, art. Gothic Architecture AFTER THR 12TH CtENTURY. [s. 476]