On the north side of the nave is a single door, now called =the Dean's door=, of good Norman work. On each side are three shafts with cushion capitals slightly ornamented; and in the round arches above are different mouldings of the style. The windows to the aisle, ten in number, are very broad, of five lights each, under depressed arches. The tracery and mouldings indicate that these were substituted for the original windows towards the close of the thirteenth century. At the same time it would seem that the walls above, in the triforium range, were heightened, because the parapet at the top is of Early English work, although the three-light windows beneath it are Decorated, and were not inserted until the next century. At the foot of the triforium range is the original Norman arcade of round-headed arches: below the existing Decorated windows is now a blank space of wall, where at first was the Norman window, rising somewhat higher than the arcade. What the original arrangement was can be seen on the east side of the north transept. The Norman clerestory range has been altered only by having Perpendicular tracery put in the windows, and by the addition of a Decorated parapet. The original corbel-table was allowed to remain. [Illustration: The Dean's Door.] =The Lantern-tower= has on each face two large windows with transoms, of three lights. The tracery is that known as net-tracery. Between these windows is a blank window, if the term may be allowed; the tracery exists, but there never was a window; it is in four divisions; while between the windows and the corner turrets are similar traceries of two parts. The whole is surmounted by a parapet above a plain arcade. The corner turrets are octangular. As at present finished at the top there is undoubtedly an appearance of their being incomplete. The west side of the =North Transept= is a very excellent specimen of Norman work; and we find less change here than in any other part of the cathedral that belongs to the same period. The tracery of the windows is Perpendicular, but the windows themselves are otherwise unaltered: at the top of all is a Decorated parapet, which is here composed of a series of quatrefoils; and the parapet to the corner turrets is not Norman. As there is no aisle on the west side of this transept, there has been no alteration in the wall, as was the case with the nave aisles. The north end of the transept is similar; but the shallow buttresses between the windows rise to a greater height, and there is another arcade above the upper tier of windows, and a blank arch in the gable. The gable has crockets, and a cross at the apex. The lower Norman window in the aisle here is unlike any others on this side of the church, but there are four others like it on the south. The upper aisle window here is of three lights, with a large pointed trefoil above them instead of tracery.