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, [Illustration: FIG. 372.--Jedburgh Abbey. View from North-West.] and a plain standard in the interior. These buttresses are projected on small corbels, and do not rise above the arches. It is thus evident that it was never intended that the central aisle of the nave should be vaulted, there being no suitable buttresses provided to resist the thrust of a vault. The side aisles, however, were vaulted, but the vaults are now demolished, only some fragments of the ribs being left, as shown in Fig. 372. As already mentioned, the west end of the nave (see Fig. 374), and especially the western doorway, are quite Norman in character. The west doorway (Fig. 375) is a noble specimen of its period. The ingoing [Illustration: FIG. 373.--Jedburgh Abbey. Clerestory Details.] is deeply recessed, and has contained five free nook shafts on each side, besides the door jamb, with intermediate shafts and elaborate enrichments. The caps are foliaged, and of late Norman character. In the arch there is an order over each shaft, and intermediate enrichments and mouldings. The ornaments consist of the chevron, both solid and under cut, and other greatly relieved enrichments and rosettes. The jambs of the doorway and the arch over it contain heads and other ornaments in panels, now much decayed. The doorpiece projects some feet, and on the north side of the projection a small round arch (see Fig. 374) can be traced. The doorpiece is surmounted by three little gablets. The central one [Illustration: FIG. 374.--Jedburgh Abbey. West End and part of North Side.] contains a trefoiled arch, and those at the sides seem to have contained a similar arch, but they are now much decayed. The west wall has flat buttresses of Norman character (see Fig. 374) at each side of the central aisle, and the upper portion of the wall has a central round-headed window, flanked on each side by three small pointed arch heads, the caps carrying which rested on long single free shafts, now gone. The central window has deep mouldings, but no enrichment. The west front has been finished with an octagonal turret at each side, as at Kelso Abbey, and the gable contains a central circular window, which has been filled with tracery at a late date. The west end walls of the aisles have each contained a circular headed window of Norman design, with a chevron ornament in the arch and a nook shaft at each side.