BUTTRESS

(Fr. aboutir, to lie out.) In Architecture, a ma of brickwork or masonry, built to resist the horizontal thrust of another ma . Buttre es are much used 11 Gothic architecture, to resist the thrust of the vaulting which covers the naves and aisles of cathedrals. When open they are called flying buttre es. BUTTS, Short ridge* of different lengths, which nece arily occur in the angle of a field when the direction of the ridges is not parallel to one of the sides. [s. 191]