COMPOUND PIER, an architectural term for a pier (q.v.) or column (q.v.) consisting of a number of vertical members or mouldings clustered around or attached to a central mass. It developed in Roman architecture to allow a single pier to support several arches. In the Romanesque and Gothic periods the idea was worked out in a more complicated way in order to furnish support, or the appearance of support, not only for cross, diag onal and wall ribs, but often to carry the main elements of the arch mouldings. In some cases in the late Gothic work of France and Germany, the mouldings of a compound pier are the identical mouldings of the arch or ribs carried down to the ground without a capital. Compound piers are usually built of continuous layers of stone, but occasionally, in English work, the clustering shafts are independent and sometimes of a different material.