PEDIMENT.--The triangular or segmental space formed by the carrying up of a cornice over a door or window or in a gable, &c. PEEL or PELE.--A fortified tower or stronghold forming a dwelling; a term principally applied to the fortified houses of the North. PIER.--A pillar or column; also sometimes a flat buttress. PILASTER.--A square pillar or column attached to a wall, usually of slight projection. PITCH (of a Roof).--The slope. PORTCULLIS.--A strong grating of timber which slid up and down in a groove, to protect the entrance of a castle or fortified house. PRINCIPAL (Rafter).--A massive framing of wood which spans a building from wall to wall and carries the purlins. PURLIN.--A stout piece of timber resting on the principals and carrying the common rafters. QUATREFOIL (in Tracery).--A form composed of four segments of circles. QUOINS.--The external angles of a building; also the stones which form the angles. RESPOND.--A half-column attached to a wall. RIBS (Stone).--Narrow projecting stones which form the framework of vaulting. SASH-WINDOW.--A window in two halves, one over the other, which slide up and down. SCANTLING.--The dimensions of a piece of timber in breadth and thickness. SCREENS.--The entrance passage formed at the end of a hall by the screen. SHAFT.--A small column. SOLAR.--The retiring or private room of the lord in early houses. SPAN.--The width between the supports of an arch or roof. SPANDREL.--The space between an arch and the horizontal feature above it. SQUINCH.--An arch carried across the internal angle of a tower or building. STOREY.--A horizontal division of a building containing rooms at one level. STRING (of a Staircase).--The inclined piece of wood which carries the steps. STRING-COURSE.--A narrow projecting horizontal line of stone or brickwork. TRACERY.--The ornamental stonework of a Gothic window formed by ramifications of the mullions; also decorations of a corresponding character applied to panels, &c. TRANSOME.--The horizontal cross-bar of a casement window (as distinguished from a sash window). TRIFORIUM.--An upper storey over the aisle of a church, with arches opening into the nave or choir. TYMPANUM.--The space enclosed between the flat head of a door or window and the surmounting arch. UNDERCROFT.--A vaulted chamber underground. VAULTING.--An arched roof or ceiling of stone or brick. WINDERS (of a Staircase).--The steps sometimes formed where a staircase changes direction; they are wide against the wall and are narrowed almost to a point against the newel or string. A Brief List of Books recommended for the Study of The History of English Domestic Architecture.