e north side. In the thirteenth century, the aisles were lengthened
eastwards, to flank the western part of the chancel. The builders moved
back the eastern responds of the old arcades to the points from which
the lengthened arcades were to start. They set themselves, however, a
difficult problem when they reserved a space at the end of the north
aisle for a sacristy, and set the respond on the west side of this
narrow bay. Their north aisle thus consisted of five bays and a very
narrow eastern bay for the sacristy. On the south side no space
corresponding to the sacristy was marked out, although the eastern
respond was placed in a line with the east side of the opening of the
sacristy. The number of bays on the south side had to be five, as there
was no room for six. The result is that the pillars of the arcades,
with the exception of those of the two bays furthest west, which were
left unaltered, are not opposite each other. In the meantime, the old
transeptal chapel was left standing between a south aisle and a short
south chapel of the chancel. About 1300, the aisle and chapel seem to
have been widened to the full length of the transeptal chapel, and thus
a broad south aisle was formed. In this plan, the chancel proper
projects for some distance east of the aisles; but, for ritual purposes,
the eastern part of the nave, corresponding to the eastern bay of the
north aisle and the sacristy bay beyond, forms, and has formed since the
twelfth century, a western extension of the chancel.

Sec. 68. The addition of aisles to chancels was an even more gradual
process than the addition of aisles to naves; and, as a rule, the aisles
were at first mere chapels. Chancel aisles or chapels of twelfth century
date are not very common in smaller churches. But a plan like that at
Melbourne, where the apsidal chapels east of the transepts flank the
chancel very closely, leads naturally to the provision of chapels
communicating directly with the chancel. The logical consequence of such
a plan is seen at Oundle, at the close of the twelfth century, where
rectangular chapels were built along the north and south walls of the
western part of the chancel. The walls were pierced with broad, low
arches, and arches were built between the chapels and the transepts. The
chapels, in this instance, are at the back of the quire stalls; and a
long projecting piece of aisleless chancel was left beyond them, to
which, in the fifteenth century, a large