ARCHITRAVE In classical architecture, the lowest division of the entablature resting immediately on the abacus of the capital. In Gothic buildings the ornamental mouldings round the openings of doors, windows, etc. ARCHIVOLT The under surface of the curve of an arch, from impost to impost. ASHLAR Shaped or squared stone used in building, as distinguished from that in the rough. ASTRAGAL A small semi-circular bead or moulding. BALL FLOWER An ornament resembling a ball in a circular flower with three enclosing petals. Dec. BASE The lower member of a column, pier, or wall. BASILICA A Roman law-court. Early Christian churches when built on the same lines were called by the same name. BILLET An ornament much used in Norman work and formed by cutting a moulding in notches, so that the remaining parts resembled wooden billets or pieces of stick. BLIND STOREY See Triforium. BOSSES Ornamental projections usually of foliage and placed at the intersection of the ribs of vaults, ceilings, etc. BRACES Timbers which brace or support the main rafters. Also called _struts_. BROACH A spire, generally octagonal and springing from the square top of the tower, without a parapet. (_See page 105_). BUTTRESS A projection from a wall, giving it additional strength. CANOPY In Gothic architecture an ornamental hood or projection over doors, windows, niches, tombs, etc., and rarely found except in the Dec. and Perp. styles. CAPITAL The head of a column or pilaster, found in a great variety of shapes. CATHEDRAL A church presided over by a Bishop. The principal church of a diocese. CHALICE The cup used for the wine at the celebration of the Eucharist. CHAMFER The surface formed by cutting away the rectangular edge of wood or stone work. CHANCEL The choir or eastern part of a church, appropriated to the use of those who officiate in the performance of the services. CHANTRY A chapel often containing a tomb of the founder, and in which masses were said. CHAPEL A small building attached to cathedrals and large churches. CHAPTER-HOUSE The room where the Dean and Prebendaries meet for the transaction of business. CHEVRON An ornament characteristic of the Norman period and divided into several equal portions chevron-wise or zig-zag.