Capital (architecture)

In architecture the capital (from the Latin caput, or "head") or chapiter forms the topmost member of a column (or a pilaster). It mediates between the column and the load thrusting down upon it, broadening the area of the column's supporting surface. The capital, projecting on each side as it rises to support the abacus, joins the usually square abacus and the usually circular shaft of the column. The capital may be convex, as in the Doric order; concave, as in the inverted bell of the Corinthian order; or scrolling out, as in the Ionic order. These form the three principal types on which all capitals are based. The Composite order (illustration, right), established in the 16th century on a hint from the Arch of Titus, adds Ionic volutes to Corinthian acanthus leaves.

From the highly visible position it occupies in all colonnaded monumental buildings, the capital is often selected for ornamentation; and is often the clearest indicator of the architectural order. The treatment of its detail may be an indication of the building's date.

The two earliest Egyptian capitals of importance are those based on the lotus and papyrus plants respectively, and these, with the palm tree capital, were the chief types employed by the Egyptians, until under the Ptolemies in the 3rd to 1st centuries BC, various other river plants were also employed, and the conventional lotus capital went through various modifications.

Some kind of volute capital is shown in the Assyrian bas-reliefs, but no Assyrian capital has ever been found; the enriched bases exhibited in the British Museum were initially misinterpreted as capitals.

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