all. The sequence is, of course, interrupted by the oriel window
in the central bay on the south; and the narrower openings in the apse
only admit of a twofold division. There are said to have been originally
windows at the back of the triforium-gallery, as at Durham,
Peterborough, and other Norman churches of the same period; but the
mutilation and rebuilding in the external walls have greatly destroyed
the original work.

#Prior Bolton's Window# was probably inserted about 1530, when the device
of a "bolt in tun" was officially authorized for Bolton's arms, on his
own choice, as presenting his name in the emblematical form then in
vogue. The window is an "oriel" in the Perpendicular style, separated
vertically by mullions into three lights in front, with one at each end
of the projection, and horizontally by transoms into an upper and lower
tier, the former having a trefoil heading to each division. There is a
sloping hipped roof to the window, and a broad moulded corbel below it.
The well-known rebus is boldly displayed upon the central of the five
square panels (all sculptured) which adorn the face of this picturesque
chamber (_oriolum_), probably built as a convenient private pew for the
Prior, from which he could survey the whole of the choir and the
Founder's tomb. The Tudor doorway, which now opens into the choir vestry
at the eastern end of the south wall, has the Bolton rebus in the
spandrels of the arch.[3]

#The Clerestory.#--In his reconstruction here Sir Aston Webb has followed
the precedent of the Perpendicular work introduced in the fifteenth
century, which, fortunately, had not been seriously injured in the upper
part of the side walls. He has accordingly adopted that style in the
apse, where the clerestory arcade is entirely new. It displays a series
of five windows of two lights each, with traceried headings, and slender
columns on the inner and outer plane, sufficient to uphold the arcading
without intercepting the light--none too abundant in any part of the
church, though it is entirely destitute of stained glass at the present
day.

The walls of the triforium and clerestory are perforated longitudinally
to form a continuous passage on each side of the choir--interrupted,
however, by the interposition of masonry at the junction of the lateral
walls with the apse.

The passage along the clerestory is formed by a succession of
"shouldered arches," as they are commonly called, though each merely
c