Even this was insufficient. The eastern bays of the nave, where the stalls were placed, and where, most of all, light was needed, were the darkest of all, being obstructed by the stalls and by the cloister roof. So in the exterior of the two easternmost bays of the nave the Perpendicular triforium windows and the Norman clerestory windows were thrown into one, to give as much light as possible to the stalls below. For the same reason large Perpendicular windows were inserted in the transepts. Several of these, however, have recently been replaced by Norman windows: “genuine Perpendicular by sham Norman.” In the middle of the south aisle of the nave Bishop Nix (1501-1536) built himself a gorgeous chantry, to light which he inserted two large windows, high up so as to clear the cloister roof. Large square-headed windows were inserted in the triforium of the presbytery also; and an enormous Perpendicular window was inserted in the west front, still further to light the nave. These measures were fairly successful in nave and transept; but, fortunately for us, less successful than in the presbytery. [Illustration: SOUTH-EAST APSE.] Now we come to the measures taken to make the building fireproof. These took the form of costly stone vaults, and they seem to have been undertaken by the monks most reluctantly. All the high vaults are the direct outcome of some great fire, and but for the fire they would not have been undertaken. There were conflagrations in 1170 and 1271, and in the fearful riots of 1272 the cathedral was set on fire by the citizens. Still, when the presbytery was repaired in 1362, it seems to have been roofed again in wood. In 1463 the wooden spire was struck by lightning, and set fire to the roofs both of nave and presbytery. At last the monks had to bestir themselves. To secure the spire against fire they rebuilt it in stone instead of wood; and, to make the nave and presbytery fireproof, they made up their minds to vault both in stone. Between 1463 and 1472 Bishop Lyhart put up over the nave the present magnificent lierne vault, and at his death bequeathed two thousand marks to his successor to continue the work. Bishop Goldwell vaulted the presbytery between 1472 and 1499. It seems to have been very difficult to get the funds for this costly work. Bishop Goldwell, however, was a personal friend of the Pope, who had consecrated him with his own hands; and he had not much difficulty in persuading the Pope to grant a perpetual indulgence in the terms that “all who came to the cathedral on Trinity Sunday and Lady Day, and made an offering towards the fabric, should be entitled to an indulgence of twelve years and forty days.” The transepts had still wooden roofs. It required another fire—in 1509—in which these roofs were consumed, to compel the monks to complete the vaulting of the cathedral. This was done in the time of Bishop Nix. At the end of four hundred years Norwich cathedral was at length fireproof.