The nave is 129 feet in length and 27½ feet in breadth in the central aisle, and measures about 57 feet in width internally over the aisles.
It is divided into nine bays, each of which (Fig. 368) comprises a main arch resting on clustered piers, a triforium with one round arch containing two pointed arches, and a clerestory forming a continuous arcade, with four pointed arches in each bay. The main clustered piers contain (Fig. 369) four principal shafts at the angles and four intermediate shafts between them. The former are brought to a point on the face, the latter are flatter. The caps are simple and of an ordinary transitional
[Illustration: FIG. 367.--Jedburgh Abbey. South Side of Choir and Crossing.]
[Illustration: FIG. 368.--Jedburgh Abbey. The Nave, looking West.]
form (Fig. 370), each with a square abacus. The bases are also simple and stand on a massive square plinth, a feature not uncommon in Norman work. The arches of the main arcade are somewhat acutely pointed, and the mouldings are bold, and resemble first pointed work. (See Fig. 369.)
[Illustration: FIG. 369.--Jedburgh Abbey. Details.]
In the triforium (Fig. 370) the principal arches are round, being an example of the round arch placed above the pointed arch. Each round arch is divided into two openings by smaller pointed arches, which contain first pointed mouldings (Fig. 371). The larger arches spring from clustered
[Illustration: FIG. 370.--Jedburgh Abbey. Details.]
shafts with bell caps and square abaci. The central pillars of the smaller arches vary in section. Those in the east part of the nave consist of four shafts united into one (being the same section as those of the clerestory of the choir), while those in the portion of the nave to the west of the centre are composed of two shafts. The shield between the smaller arches is perforated with a small circle. The simple constructional main arches of the triforium are seen on the exterior (Fig. 372), where also the corbels to carry the timbers of the roof of the triforium gallery are visible.
[Illustration: FIG. 371.--Jedburgh Abbey. Plan of one half Bay of Clerestory.]
The clerestory shafts are of trefoil section both on the exterior and interior (Fig. 373), and have foliaged caps of first pointed design. In the interior the caps have the angles of the abaci cut off so as to make them octagonal. The arches are all pointed, and contain first pointed mouldings. A corbel table supports the cornice on the exterior, and there are two small ornamental arches between every two corbels (Fig. 374). Over each main pier a small buttress is introduced in the exterior of the clerestory,