he aisles of later
"Decorated" traceried windows in place of the original Norman ones, and
of the superimposition, before referred to, at triforium level of a
whole range of "Perpendicular" windows over the old Norman work, which
were blocked up at this period. The pristine aspect, then, of this
elevation of the nave would have shown a sloping roof over the aisles
where now the later addition occurs. The battlementing, too, over the
clerestory to the nave is later work, to correspond with battlementing
over the triforium windows. It will be noticed that the two bays next
the transept in the triforium are higher than the others, in order to
throw additional light into the choir.

Also on this same south side, in the seventh and eighth bays from the
west end, two very late windows occur, inserted in the Norman arcading
under the original triforium windows; these were inserted by Bishop
Nykke to light the chapel he built in two bays of the south aisle of the
nave.

The curious raking of the lead rolls to the nave roof is noticeable; the
mediaeval builders did this with a view of counteracting the "crawl" of
the lead. Lead, under the variations of temperature of the atmosphere,
expands and contracts considerably; and from its own weight, and the
steepness of the roofs, the contraction takes place in a downward
direction, and starts the joints, letting in the weather. This raking of
the vertical rolls was a device whereby the old builders in some measure
got over their difficulty by inducing a fixed expansion and contraction.

[Illustration: The Clerestory and Triforium of Choir (South Side).]

#The South Transept# projects boldly forward from under the tower;
without aisles, its ridge and parapet correspond in height to those of
the nave; this narrowness, with the tower and spire showing over
behind, gives it an appearance of height, as approached from the lower
close. This effect of height is emphasised by the partition of the
design in its width, by flat Norman buttresses, with shafts in the
angles, and by the flat faces of the flanking turrets. The work,
however, is without interest, from the fact that, though the _ensemble_
in some measure has been retained, the whole of the exterior face of the
stonework was re-cased by Salvin, 1830-40, during which period various
restorations were effected. Before these alterations, the Norman
flanking turrets finished with a "Perpendicular" battlementing, enriched
with shields an