To begin with the north side. The arch in the first bay has been built up, probably to strengthen the tower, and by the twelfth-century builders themselves, for the abacus-moulding of the capital is continued across the blocking wall. In the latter the fifteenth-century builders have made a small pointed doorway, which is now blocked but apparently once gave access from the top of the screen to a staircase in the north aisle. This and the two next bays bear in all three stages a general resemblance to the east side of the north transept. The columns, however, are clusters of eight cylindrical shafts, and stand upon circular plinths, the base proper following, of course, the form of the pillar. The capitals, as usual, are compound and composed of plain inverted bells, and have square tops with the abacus hollowed and grooved. The arches differ from those in the transept only in that the large moulding under the soffit is 'keeled,' and that the mouldings which flank it are simple ridges. In the triforium the cusps visible in the glazed sub-arches belong to some tracery which has been applied to the back at a later period. [Illustration: THE GREAT EAST WINDOW.] The treatment of the vaulting-shafts is very remarkable; indeed, nothing is more instructive than the variety shown in the treatment of this feature throughout Archbishop Roger's church, the different parts of which are suggestive of nothing so much as of a series of architectural experiments. Here, upon the capital of each column, rests a sort of compound rectangular plinth, from which project three corbels, hollowed underneath and having little blocks beneath their overhanging edge. From this plinth and corbels springs a cluster of no less than five shafts, which, by their united width, conceal the springing of the upper order of the main arches. They are banded at the string-course below the triforium, and end at the sill of the clearstorey in a compound capital, of which the three central members are square, and the others round. Upon this capital, apparently, stand the two adjoining shafts that carry the thickening of the wall above the clearstorey, and here (but hidden by the vaulting) stands also the original roof-shaft, and these three are 'detached.' Thus the arrangement is in principle similar to that adopted in the north transept, while at the same time the clustered shafts are even more disproportionate here than there to the slight burden they have to carry; indeed the effect is that of five shafts diminishing to one. The vaulting hides a feature which is not found in the transept, namely, a little lancet arch whose apex comes exactly behind the roof-shaft in each bay. [Illustration: BAY OF ARCHBISHOP ROGER'S CHOIR (WITHOUT THE VAULTING). (From a drawing by Sir G. G. Scott, by permission of the Archaeological Institute.)] [Illustration: DECORATED CAPITAL IN CHOIR.]