The Hood-moulding, resting on small and elegant heads or bosses, is an almost invariable accompaniment of arches of every description.
The Vaulting-shaft sometimes rises from the floor in front of the principal Pier,—but more usually from a corbel-shaft, resting on a large ornamental corbel, placed immediately over the pier; it consists generally of a triple cluster of small elegant shafts, with hollows between them.
The Triforium-arch generally covers two smaller arches; but occasionally, a pair of principal Triforium-arches cover two pair of subordinate arches, which are sometimes plain, and sometimes trefoiled; the spandrel wall above them being ornamented with foliage, or a sunk trefoil, and sometimes pierced through with a quatrefoil or other opening. Sometimes, indeed, one large primary arch covers two secondary arches, which again contain two small tertiary arches; thus fully developing the principle of subordination in this part of the building.
The principal Triforium-piers generally exhibit a row of light shafts on the face of a solid pier, carrying arch-mouldings of three orders, and separated sometimes by a line of dog-tooth moulding, or stiff foliage.
The secondary piers are usually single, double, or triple detached shafts, carrying the smaller arches.
Where the Triforium contains three orders of piers, the tertiary pier consists of a single shaft only, carrying the third order of arch-mouldings.
The Vaulting-shaft usually terminates in an elegant capital, just below the Clerestory-string, the mouldings of which form in that case the impost mouldings of the capital. The Arcade generally corresponds with the windows, and consists either of a row of continuous arches, of equal height, or, as is commonly the case, of three tall arches carried on a triple shaft, of which the centre one is the loftiest: the mouldings and ornaments being similar to those of the rest of the building.
The Vaulting is generally simple, and acute, and usually of the quadripartite or sexpartite form.
The Aisle-arcade consists generally of a series of plain, or trefoil-headed arches on single shafts, carrying the usual mouldings and ornaments.