th century. Of the stained
glass, that in the last window on the south side is of some merit. The
capitals of the Decorated vaulting-shafts are better executed in this
aisle than in the other. Here, as there, the Decorated vaulting begins
in the middle of the fourth bay, where the fillet is again found upon
the two eastern groins only. At the south-east corner of this aisle are
the remains of a piscina--a fragment of a basin resting on a
shaft--which probably belonged to one of the many chantries. The
staircase at this corner affords the best access to the turret cell
described in the last chapter, and to the attic over the choir, where
the framing of the roof is a very remarkable specimen of modern joinery.

On account of the alterations that have taken place at different periods
in the part of the Cathedral south of the choir, it will be well to
examine the crypt under the Chapter-house before examining either the
latter itself or the Library.

=The Norman Crypt.=--A round-headed doorway in the west wall of the
Chapter-house admits to a staircase which, roofed with a sloping
barrel-vault and descending southwards, turns eastwards, under another
round arch, into the crypt. The age of this staircase is uncertain, but
its west wall is of course the east wall of Archbishop Roger's transept,
and its barrel-vault is under his buttresses which will be seen in the
Library. The crypt is divided by a cross-wall with a round arch in it
into two portions, each having the vaulting supported on pillars along
the middle; but half of the first and third bays of the western portion
has been walled up in modern times for burial-vaults. The width of the
crypt is about 18 feet and the total length about 68 feet.

[Illustration: THE NORMAN CRYPT.]

This part of the church was assigned by Walbran to Thomas of Bayeux
(1070-1100), and by Sir Gilbert Scott to Thurstan (1114-1141); but it is
quite possible that both these Archbishops, if not Oda or Oswald before
them, may have had a share in its construction. Much of the work at any
rate belongs to a Norman church which preceded that of Archbishop Roger.

In the vaulting (which by-the-way has had to be propped at some period
by two rude pointed limestone arches at the west end) the chamfered
groin-ribs seem to have been added later for strength, probably when the
storey above was remodelled; but the vaulting itself, with its square
pillars, its plain round arches from pillar to pillar an