Above the windows the eaves of the original roofs remain, supported on a corbel-table which is carried round the apsidal chamber at the corner and round the eastern apse. At the south side of the latter the builders have left a narrow recess which extends from the ground nearly to the top of the crypt. The apse displays in the lower storey a round-headed unglazed window like those along the south wall, and in the upper storey a small round-headed light at the south side and a larger window in the middle, of the same size as that below, but not so deeply splayed, and with the head rudely trefoiled. On either side of these central windows, a shaft, made in short joints, runs up the apse from base to eaves. The string between the two storeys is carried round these shafts, and their circular bases overhang the plinth and rest on small blocks, while the capitals are square-topped, as in Archbishop Roger's work. From the roof of this apse and of the apsidal chamber at the corner, and from the eaves that project along the south wall, it would seem that the whole structure was roofed with stone at a steep inclination. Where its wall joins the transept the stone-work seems to be of the same date on both sides of the corner, so that there may have been an original buttress or wall extending southwards from this point. The third storey is now the Cathedral library, but was originally the =Lady-chapel=, and was commonly called the Lady-loft. Such a position for a Lady-chapel--at the south side of the choir, and in an upper storey--is extremely unusual.[46] Authorities have differed widely as to its date. Some have assigned it to about 1482; but the Lady-loft is clearly mentioned in the Treasurers' Rolls in 1470, and its architecture, which is Decorated rather than Perpendicular, would be in favour of ascribing it to the middle of the previous century, were it not for a certain coarseness of execution which makes a suspension of judgment advisable.[47] To support this additional storey, the two western buttresses were carried up, diminishing both in projection and in width, to within a few feet of the upper string-course. The huge buttress at the corner was very possibly added later, to counteract a settlement which is evident to anyone so standing as to bring the shafts on the apse in line with the corner of the choir, and which was doubtless due to the weight of the Lady-loft. This buttress is of the same height as the others, but is broader, and has as many as seven stages, the fourth of which is crowned by a truncated hip roof and pierced with a slit to light the apsidal chamber within, from whose sloping top the upper stages spring. Traces of some external means of access to this apsidal chamber from below may be seen at the west side. Except one small lancet adjoining this buttress, the windows of the Lady-loft are square-headed, with mullions branching out into intersecting arches whose cusps spring from the soffit independently of