Ogee

An ogee (/oʊˈdʒiː/ /ˈoʊdʒiː/) is a curve shaped somewhat like the letter S, consisting of two arcs that curve in opposite senses, so that the ends are parallel, or roughly so. It is a kind of sigmoid curve. An ogee (/oʊˈdʒiː/ /ˈoʊdʒiː/) is a curve shaped somewhat like the letter S, consisting of two arcs that curve in opposite senses, so that the ends are parallel, or roughly so. It is a kind of sigmoid curve. The shape has many uses in architecture, where two such curves make up an ogee arch, and where single ogees are very common in mouldings. It is also used in mathematics and fluid mechanics, as well as in marine construction and in plastic surgery. Ogee is also written O.G. This long-standing variant may have originated from a mis-hearing of the spoken word ogee as an abbreviation. Nevertheless, the quasi-abbreviation is often seen in print within the millwork trade. In architecture, the principal use of the term is to describe an arch composed of two ogees, mirrored left-to-right and meeting at an apex. The ogee shape is one of the characteristics of the Gothic style of architecture, especially decorative elements in the 14th and 15th century late Gothic styles called Flamboyant in France and Decorated in England. In these the usual pointed lancet arch with a single curve to each side is supplemented by ogee arches, especially in windows. Ogee windows and arches were introduced to European cities from the Middle East, probably via Venetian Gothic architecture. Ogee arches were a feature of English Gothic architecture in the later thirteenth century. A building's surface detailing (indoors or out) may have a moulding with an ogee-shaped profile, consisting (going from low to high) of a concave arc flowing into a convex arc, with vertical ends; if the lower curve is convex and higher one concave, this is known as a Roman ogee, although frequently the terms are used as if they are interchangeable and for a variety of other shapes. Alternative names for such a true Roman ogee moulding include cyma reversa and talon. The ogee curve is an analogue of a 'cyma curve', the difference being that a cyma, or 'cyma recta', has horizontal rather than vertical ends. The cyma reversa form occurs in antiquity. For example, in ancient Persia, the Tomb of Cyrus featured the cyma reversa. The cyma reversa is also evident in ancient Greek architecture, and takes its name from the cymatium. The ogee and Roman ogee profiles are used in decorative moulding, often framed between mouldings with a square section. As such it is part of the standard classical decorative vocabulary, adopted from architrave and cornice mouldings of the Ionic order and Corinthian order. An ogee is also often used in the 'crown moulding' frequently found at the top of a piece of case furniture, or for capping a baseboard or plinth, or where a wall meets the ceiling. An ogee moulding may be run in plaster or wood, or cut in stone or brickwork.