eight pier angles, ribs in wood project
forward and carry a smaller octagon on which the lantern rests.
Internally the effect of this central octagon is of great beauty and
originality, and it is the only instance of such a feature in English
Gothic architecture. (See ARCHITECTURE, Plate VIII., fig. 82.)

[Illustration: FIG. 3.--Plan of Durham Cathedral.]

The earliest example of the chevet is probably to be found in the church
of St Martin at Tours; this was followed by others at Tournus,
Clermont-Ferrand, Auxerre, Chartres, Le Mans and other churches built
during the great church-building period of the 11th century. In the
still greater movement in the 12th century, when the episcopacy,
supported by the emancipated communes, undertook the erection of
cathedrals of greater dimensions and the reconstruction of others, in
some cases they utilized the old foundations, as in Chartres (fig. 5),
Coutances and Auxerre cathedrals, while in others (as at Le Mans) they
extended the eastern termination, much in the same way as in many of the
early examples in England, with this important difference, that when the
apsidal east end was given up (about the middle of the 12th century) in
favour of the square east end in England, the French, on the other hand,
developed it by doubling the choir aisles and adding to the number of
extra chapels; thus in Canterbury, Norwich and Gloucester, there were
only three apsidal chapels in the chevet, whereas in Noyon (1150),
Soissons (1190), Reims (1212), Tours, Seez, Bayeux (1230), Clermont
(1275), Senlis, Limoges, Albi and Narbonne cathedrals there were five;
in Amiens, Le Mans and Beauvais, there were seven apsidal chapels, and
in Chartres cathedral nine. Double aisles round the choir, of which
there are no examples in England, are found in the cathedrals of Paris,
Bourges and Le Mans; the cathedral of Sens (fig. 6) (1144-1168)
possesses one feature which is almost unique, viz. the coupled columns
of the alternate bays of nave and choir and of the apse; and these were
introduced into the chapel of the Trinity in Canterbury cathedral,
probably from the designs of William of Sens, by his successor William
the Englishman. The square east end found no favour in France--Laon,
Poiters and Dol being the only cathedral examples; and of the triapsal
arrangement, viz. with apses in the axes of the choir aisle and a
central apse, the only example is that of the cathedral of Autun. The
immense developmen