In the same cupboard may be observed, scarcely above the floor, a wide stone ledge with a bold moulding worked along the front. If the floor can ever have been lower than it is now, this ledge may have been used as a bench. In itself, it is of course the set-off on which the piers of the arcading stand. Now it will be remembered that the portion of Archbishop Roger's wall-base visible from the graveyard (between the choir and the apse) has at the top a wide set-off or slope. This ledge in the vestry, then, seems to be level with the base of that slope, where moreover there is a moulding similar to that found here; also the front of the ledge here seems to be flush with Archbishop Roger's masonry there. If, then, the work there is his,[113] the above considerations afford some reason surely for the belief that this set-off on which the piers of the arcading stand, and perhaps also the uppermost courses of the wall beneath it, are Archbishop Roger's work. Nor is it improbable that this set-off once had a slope, of which that above-mentioned was the continuation, and out of which the buttresses (_i.e._, the arcade piers) rose after the manner of those on the other side of the choir--in fact, that Archbishop Roger intended to make this wall the exterior of his church by demolishing the crypt, vestry, and Chapter-house; and that it was only after some such idea had been conceived and abandoned, that the arches were thrown across from buttress to buttress, the vaulting constructed against them, this ledge formed (by cutting away the slope of the set-off), and the stone benches carried along the wall of the Chapter-house. The arch above the ledge has been mutilated to make way for a modern spiral staircase of wood leading to the Library. Half-way up this staircase there remain upon the wall and upon the buttress (if it may now be so called) portions of a string-course which may be taken perhaps as additional evidence for the theory that Archbishop Roger at first intended to demolish the vestry and Chapter-house.[114] It does not, however, match the external string on the other side of the choir, but resembles the internal string in the choir-aisles. The single window in the south wall is round-headed internally, and is partially splayed on one side and not at all on the other: indeed the wall here appears to have undergone some alteration. In this room this wall is of the same thickness with the corresponding wall of the crypt, which is not the case in the Chapter-house. East of the above window a square-headed doorway opens into the apsidal chamber enclosed by the corner buttress. This curious little chamber was probably a sacristy or treasury. It has a recess in the west side, and seems to have communicated directly with the graveyard. In the roof is a slab which has a small cross graven upon it, and which may have formed part of an altar.