Cupola

A small cylindrical or polygonal structure on the top of a dome.

Curtain Wall

A thin wall supported independent of the wall below, every one or two stories, by the structural steel or concrete frame of the building.

Cyma

One form of a moulding. See Plate 75.

Cymatium

The name given to a cyma moulding when it is used as a crowning moulding.

Dentils

Rectangular supporting blocks beneath the cornice of an entablature. See Plate 66.

Diaper

An over-all decorative pattern.

Die

The plane center member of a pedestal. When continuous it is called a Podium. See Plate 62.

Dividers

An instrument for stepping off equal divisions. See Plate 3.

Dormer

A structure projecting from a sloping roof, usually to accommodate a window. See Plates 24 and 25.

Drain

A means of carrying off waste water. See also House Drain.

Drip Mould

A moulding designed to prevent rain water from running down the face of a wall; used also to protect the bottom of doors, windows, etc., from leakage.

Echinus

The half-round moulded part of a column capital directly below the abacus.

Elevations

Drawings of the walls of a building, usually made as though the observer were looking straight at the wall. See page 7 and Plate 2.

Escutcheon Plate

The protective metal plate at a keyhole. Sometimes merely an ornamental plate around an opening.

Extrados

The name applied to the upper or outside curving line of an arch.

Face Brick

Usually a special brick used for "facing" a wall.

Fenestration

The distribution or arrangement of windows in a wall.

Finial

The ornamental termination of a pinnacle, consisting of leaf forms, etc.

Flange

The upper and lower cross parts of a steel I beam or channel. A projecting rib.

Flashing

The sheet metal work to prevent leakage over windows, doors, etc., and around chimneys and at other roof details.

Floor Plan

The horizontal section through a building showing size and location of rooms, also doors, windows, etc., in the walls.

Footing

The spread portion at the bottom of a basement wall or column to prevent settlement.

Freestone

A soft, easily worked variety of sandstone.

Fresco

Painting on fresh plaster before it has dried. Commonly, though incorrectly, used for any painting on plaster.

Frieze

That part of a classic entablature between the cornice and the architrave. See Plate 63.

Furring

The leveling up or building out of a part of a wall or ceiling by wood strips, etc.

Gable

The triangular portion of an end wall formed by the sloping roof.

Gable Roof

One sloping up from two walls only.

Gain

The mortise or notch cut out of a timber to receive the end of a beam.

Gambrel Roof

A roof having two different slopes such as the house of Plate 24.

Gargoyle

A projecting ornamental water spout to throw the roof water clear of the walls below.

Girder

A large horizontal structural member, usually heavier than a beam and used to support the ends of joists and beams, or to carry walls over openings.

Girt

The heavy horizontal timber carrying the second floor joist in a braced frame building. See Plate 46.

Grade

The level of the ground around a building.

Grille

A protective metal screen, sometimes highly ornamented.

Groined Vaulting

A ceiling formed by several intersecting cylindrical vaults.

Ground

Strips of wood the thickness of the plaster of a wall, secured to the framing. They aid the plasterer and afterward serve as nailing strips for securing the wood finish.

Grout

A thin mortar for filling up spaces difficult of access or where the heavier mortar would not penetrate.

Guttae

The drops used for enriching the Greek Doric Order of Plate 64 and the Mutular Doric of Plate 65. They are cylindrical in the first and conical in the second example.

Gutter

A trough or depression for carrying off water.

Halving

A method of splicing the ends of two timbers by cutting half of each away and overlapping these parts. The joint is thus the same size as the timbers.

Hanging Stile

The vertical part of a door or casement window to which the hinge is fastened.

Hatching

The shading of an imaginary cut surface by a series of parallel lines. See Plate 21.

Head Room

The vertical clearance on a stairway or in a room. See Plate 59.

Hearth

The vitreous portion of a floor in front of a fireplace. See also Back Hearth and Plate 61.

Heel

The end of a rafter that rests on the wall plate.

Herring-Bone

The name given to masonry work when laid up in a zig-zag pattern. It is usually found in brick work.

Hip-Roof

One sloping up from all walls of the building.

Hood

The small roof over a doorway, supported by brackets or consoles.

House Drain

The horizontal piping beneath the basement floor of a building, which carries off the discharge from all soil and waste lines to a point outside the building.