“The radical changes that have taken place since the nave was built by Bishop Eborard (1121-45) consist of the insertion in the aisles of later ‘Decorated’ traceried windows in place of the original Norman ones, and of the superimposition, before referred to, at triforium level, of a whole range of ‘Perpendicular’ windows over the old Norman work, which were blocked up at this period. The battlementing, too, over the clerestory to the nave is later work, to correspond with battlementing over the triforium windows. It will be noticed that the two bays next the transept in the triforium are higher than the others, in order to throw additional light into the choir. “Also on this same south side, in the seventh and eighth bays from the west end, two very late windows occur, inserted in the Norman arcading under the original triforium windows; these were inserted by Bishop Nykke to light the chapel he built in two bays of the south aisle of the nave. “The curious raking of the lead rolls to the nave roof is noticeable; the mediæval builders did this with a view of counteracting the ‘crawl’ of the lead.”--(C. H. B. Q.) Norwich Cathedral is famous for its magnificent interior. A noble view is obtained on entering, for the great =Nave= reaches 200 feet to the choir-screen; and if the organ on the latter were removed, the view would be longer, for the extreme length of the Cathedral is 407 feet. The perspective is splendid, as it is, and very largely is it so because of the lierne vault of Perpendicular days, which relieves the severity of the Norman work below. The nave consists of seven double bays (fourteen compartments) from the west end to the transepts. The main piers are, of course, large, and the arcade arches are ornamented with the billet. The triforium arches are decorated with a chevron or zigzag. Over it is the typical Norman clerestory and above all spreads the handsome lierne vault (Perpendicular). This splendid vault (72 feet), built by Bishop Lyhart (1446-1472), after the Norman roof had been destroyed by fire in 1463, is of great value to the student. There are 328 carved bosses at the intersection of the ribs, the subjects of which are taken from Biblical history. “The vault is of Perpendicular design, and known as _lierne_; such vaults may be distinguished by the fact that between the main ribs, springing from the vaulting shafts, are placed cross ribs forming a pattern, as it were, and bracing the main ribs, but not in any great measure structural. This vault at Norwich may be taken as typical of the last legitimate development of the stone roof; it was the precursor of the later fan-vaulting, such as we find in Henry VII.’s chapel at Westminster, where legitimate construction was replaced by ostentatious ingenuity and the accumulation of needless ornament and detail.