[8] See Willis, p. x.: Introduction.

In the admirable plan and sections which Professor Willis prepared to
illustrate his work upon the history of the fabric it is possible to
see at once what work had been done during the different stages of
development. The work finished by the end of the thirteenth century
changed the earlier church of the eleventh and twelfth centuries in
its essential arrangements into the church we see to-day.

We have now briefly to review the changes produced in the plan of the
cathedral. There were those effected as an immediate consequence of
the fire, and others which were more the result of the continued
energy of the thirteenth-century builders. The most remarkable one was
that which converted the French chevet, or group of apses, into the
more familiar square, and characteristically English, eastern
termination. The apsidal chapels on the east side of each arm of the
transept had disappeared to make room for others of a different shape
and size. The other chapels at the east remained the same in number;
but towards the close of the thirteenth century the lady-chapel had
been lengthened, and the aisles of the choir, being continued
eastward, ended in small chapels to the north and south of the central
one. The other changes were those caused by the addition of chapels
off the south and north aisles of the nave. The addition of the south
and north porches, and the sacristy next to the south arm of the
transept, were the only other alterations, if we except the addition
of buttresses, which had been made in the original arrangement up to
the beginning of the fourteenth century.

[Illustration: THE CATHEDRAL FROM THE SOUTH-EAST, ABOUT 1836. _From
Winkles's Cathedral Churches_.]