he north and south
ends, and an apsidal choir with four chevet chapels. In St Front de
Perigueux (1150), based on St Mark's at Venice, the plan consists of
nave, transept and choir, all of equal dimensions, each of them, as well
as the crossing, vaulted over with a dome, while originally there was a
simple apsidal choir.

[Illustration: FIG. 6.--Plan of Sens Cathedral.]

[Illustration: FIG. 7.--Plan of Angouleme Cathedral.]

Returning now to the great cathedrals in the north of France, we give an
illustration (fig. 8) of Amiens cathedral (from Viollet le Duc's
_Dictionnaire raisonne_) which shows the disposition of a cathedral,
with its nave-arches, triforium, clerestory windows and vault, the
flying buttresses which were required to carry the thrust of the vault
to the outer buttresses which flanked the aisle walls, and the lofty
pinnacles which surmounted them. In this case there was no triforium
gallery, owing to the greater height given to the aisles. In Notre Dame
at Paris the triforium was nearly as high as the aisles; in large towns
this feature gave increased accommodation for the congregation,
especially on the occasion of great fetes, and it is found in Noyon,
Laon, Senlis and Soissons cathedrals, built in the latter part of the
12th century; later it was omitted, and a narrow passage in the
thickness of the wall only represented the triforium; at a still later
period the aisles were covered with a stone pavement of slight fall so
as to allow of loftier clerestory windows.

[Illustration: FIG. 8.--Perspective of Amiens Cathedral.]

The cathedrals in Spain follow on the same lines as those in France. The
cathedral of Santiago de Compostela is virtually a copy of St Sernin at
Toulouse, consisting of nave and aisles, transepts and aisles, and a
choir with chevet of five chapels; at Leon there is a chevet with five
apsidal chapels, and at Toledo an east end with double aisles round the
apse with originally seven small apsidal chapels, two of them rebuilt at
a very late period. At Leon, Barcelona and Toledo the processional
passage round the apse with apsidal chapels recalls the French
disposition, there being a double aisle around the latter, but in Leon
and Toledo cathedrals the east end is masked externally by other
buildings, so that the beauty of the chevet is entirely lost. At Avila
and Salamanca (old cathedral) the triapsal arrangement is adopted, and
the same is found in the German cathedrals, with one