Organic: primarily used of the structures of animals and plants; secondarily, of any organised, whole, composed of parts that perform definite functions; always in this book with an implication that the relation between the whole and its parts partakes of the nature of a living, as opposed to a mechanical, structure.
Oriel-window: See Bay-window.
Orientation: the construction of a temple or church on a main axis, regulated to the position of the sun or a star on some particular day or night; or to the points of the compass, usually an east and west axis.
Ovolo (lit. “egg-like”): a Classic convex moulding—a quarter-round in Roman architecture; in Hellenic, the curve of conic section known as hyperbolic.
[P]almette: See Anthemion.
Papier-maché: a tough plastic substance, formed of paper-pulp, mixed with glue, or of layers of paper, glued together; and modelled into ornamental forms.
Parapet: specifically, the portion of the wall of a building above the eaves of the roof. Generally, a retaining wall, or enclosing wall, e.g., the walls of a bridge, above the roadway.
Patio: the open, inner court of a Spanish or Spanish-American house.
Pavilion: specifically, a section of a building that projects from the plane of the main façade and has a distinct roof treatment.
Pediment: specifically, the triangular member surmounting the Portico of a Classic temple. It rests on the Entablature and terminates on each side in a raking Cornice, paralleling the slope of the roof. In Renaissance and later times, a triangular surface, framed by a horizontal and two sloping cornices, e.g., the embellishment surmounting windows and doors. The triangular space within the horizontal and raking cornices is called a Tympanum and is frequently decorated with sculptured figures or ornament. Tympanum is also used for the surface between a lintel and the curved cornice over it.