THE BEGINNINGS OF ROMANESQUE VAULTING overrated by M. Puig y Cadafalch, and the so-called crypt of St. Wipert at Quedlinburg in Saxony of c. 930). Nowthe vaulting of the wider naves of major churches was mastered, and—as always hap- pens when an innovation is the full expression of the spirit of an age —mastered independently by several ingenious architects in several centres of building activity at about the. same time. Burgundy re- mained faithful to massive tunnel-vaults. The earliest that can be dated seem to belong to about 1065; those at Cluny, when this mightiest monastery of Europe was rebuilt, about noo, had the widest span anywhere. Speyer, the imperial cathedral on the Rhine, received her first cross-vaults in the eighties. And then there is Durham, A good deal of controversy still remains about dates of early vaults (especially concerning S. Ambrogio in Milan, whose rib-vaults some count amongst the pioneer works, while others date them about the second and third quarters of the I2th century). The new powerful initiative of the late nth century however is beyond doubt. Now the most remarkable fact about the vaults of Durham is that rib-vaults as against ribless cross-vaults are accepted as one of the leit- motivs of the Gothic style. Their structural advantages, just like those of pointed arches and buttresses, lie in. the fact that they concentrate thrusts along specially chosen lines and leave the masonry between stretched out lie the canvas of a tent from post to post. Thus great saving in stone and in solid timber centering could be achieved. Hence the Gothic style appears to most people as a constructional affair ex- clusively. Durham proves this materialistic theory to be wrong. The ribs here are not built up independently, the filling masonry is not lighter. The motif is there, but its constructional application has not yet been discovered. Thereason of theDurham builders for introduc- ing so telling a feature must have been the very fact that it is so telling, that it represents the ultimate fulfilment of that tendency towards ar- ticulation which had driven Romanesque architects forward for over a hundred years. Now the bay has become a unity not only by the two-dimensional means of lines of demarcation along the walls, but by the three-dimensional means of those diagonal arches set across. Where the two arches meet, where later architects inserted their bosses, there each unified bay has its centre. "We move along through the cathedral, not driven towards the altar without halt as in Early Christian churches but stepping from spatial compartment to spatial compartment in a new measured rhythm. 21