THE FIRST GROINED VAULTS
The first application of the system of intersecting vaults appears in
the great churches of Angers and Laval.
It is probable that the new methods propagated by the religious
architects of Aquitaine and neighbouring provinces had excited the
emulation of the Northern builders, more especially those of the
Ile-de-France. Evidences to this effect are to be found in certain
subordinate portions of their buildings at this period, such as side
aisles or apsidal chapels. Their timid arrangement seems, however,
reminiscent of the Roman system of ribbed vaulting, with a slightly
increased prominence of the ribs superadded, rather than of the
revolution that had been effected in church vaulting generally.
[Illustration: 9. PLAN OF A BAY IN THE NAVE OF ST. MAURICE AT ANGERS]
[Illustration: 10. TRANSVERSE SECTION OF THE NAVE OF ST. MAURICE AT
ANGERS]
But, if we except perhaps Laval, nowhere shall we find the new system
of vaulting upon intersecting arches more mightily demonstrated than
at Angers, the aisles of which measure 54 feet across. The grandeur
of the architectural composition, no less than the admirable technical
skill shown in the details, gives proof of the consummate mastery
arrived at by the builders of these noble structures so early as the
middle of the twelfth century. The plan of these churches resembles
that of Angoulême and Fontevrault. It is in no way allied to the
Northern buildings.
[Illustration: 11. PLAN OF A BAY OF THE NAVE IN THE CHURCH OF LA STE.
TRINITÉ AT LAVAL]
They are constructed with single aisles, like the cupola churches,
with a series of bays, square on plan; but the arrangement of the
vaults has been perfected by the logical use of intersecting arches in
the place of pendentives, the architects of the day having realised
by this time the progress we have explained and demonstrated in the
preceding chapter.
These vast aisles, vaulted on intersecting arches, are of course
allied to the cupolas; they recall their general outline, but the
arrangement of the vaulting is different. The intersecting ribs are
no longer merely decorative features; they have taken on all the
active functions of the _arc-doubleau_ and the formeret. Their union
constitutes an elastic ossature, the weight being concentrated upon
four points of support, which receive the impost of the arches, and
compose a stone skeleton, each unit of which has been cut and dressed
to fill the exact place it occupies in the whole.
[Illustration: 12. LONGITUDINAL SECTION OF TWO BAYS IN THE NAVE OF LA
STE. TRINITÉ AT LAVAL]
If we compare the sections (Figs. 13 and 14) of the churches of
Angoulême and Angers, we may clearly trace the filiation between these
buildings, the one dating from the first years of the twelfth century,
the other from some thirty or even forty years later. We shall also
note the advance made by the Angevin architects in the construction of
groined vaults in the place of domes with pendentives, a development
worked out by the more perfect and reasoned application of the same
architectural principle.
[Illustration: 13 AND 14. COMPARATIVE SECTIONS OF THE CHURCHES OF
ANGOULÊME AND ANGERS]
[Illustration: 15. VIEW IN PERSPECTIVE OF THE NAVE VAULT OF
ST. MAURICE AT ANGERS]
The Church of Laval, built simultaneously with that of Angers,
or only a few years later, shows a further advance, not merely in
the matter of form, but in the increased science and ingenuity of
combinations, and the methodical accuracy of the execution.
[Illustration: 16. PLAN OF A SUMMER OF THE NAVE VAULT OF LA STE.
TRINITÉ AT LAVAL]
[Illustration: 17. PLAN OF ONE OF THE PIERS OF THE NAVE OF LA STE.
TRINITÉ AT LAVAL]
The arches which compose the ossature of the vaults become independent
in their functions, as at Angers, immediately upon leaving the abacus,
an essential characteristic of the new system. The lateral points of
support are composed of piers proper and of clustered columns, crowned
by corbelled capitals, which, by prolonging them, mark the formerets,
the diagonal, and the transverse arches as they fall upon the abaci.
It is easy to see in this arrangement the origin of those clustered
shafts so generally and even excessively used in the thirteenth and
fourteenth centuries, the main object of which was to conceal as far
as possible the points of support.
These details, and the section (Fig. 12) showing the mode of
construction in the vaults, demonstrate sufficiently that at Laval, no
less than at Angers, a direct filiation exists between the dome upon
pendentives and the groined and ribbed vault.