Ogee

An ogee (oʊˈdʒiː ˈoʊdʒiː) is the name given to objects, elements, and curves—often seen in architecture and building trades—that have been variously described as serpentine-, extended S-, or sigmoid-shaped. Ogees consist of a "double curve", the combination of two semicircular curves or arcs that, as a result of a point of inflection from concave to convex or vice versa, have ends of the overall curve that point in opposite directions (and have tangents that are approximately parallel). First seen in textiles in the 12th century, the use of ogee elements—in particular, in the design of arches—has been said to characterise various Gothic and Gothic Revival architectural styles. The shape has many such uses in architecture from those periods to the present day, including in the ogee arch in these architectural styles, where two ogees oriented as mirror images compose the sides of the arch, and in decorative molding designs, where single ogees are common profiles (see opening image). The term is also used in marine construction. The word was sometimes abbreviated as o-g as early as the 18th century, and in millwork trades associated with building construction, ogee is still sometimes written similarly (e.g., as O.G.). 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. First seen in textiles in the 1100s CE, the use of ogee elements, and in particular in the design of arches, has been said to characterise Venetian Gothic and Gothic Revival architectural styles. Ogee windows and arches were introduced to European cities from the Middle East, probably via Venetian Gothic architecture. In particular, the ogee characterises Gothic architecture, especially in late Gothic decorative elements of the 14th and 15th century—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.