CHAPTER III

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.

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.

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.

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.

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.

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.