Looking upwards the visitor will note the beauty of the vaulting and the bosses placed at the intersection of the ribs. These bosses at the east end of the choir chiefly represent a choir of angels playing on various kinds of musical instruments, and a figure of Our Lord in the attitude of blessing. All the roof was originally probably painted and decorated, but the existing colour and gilding is recent work, having been done by Clayton & Bell. At first sight the groining of the roof looks most complicated, but, if analysed and dotted down on paper, it will be seen to be in reality a simple geometrical pattern. The bosses will repay careful examination with a glass. Viewed from the door in the screen, the choir looks in very truth a piece of Perpendicular work, as the Norman substructure is then for the most part concealed. A closer examination, however, will prove that the Norman work is all there--that it has been veiled over with tracery from the floor level to the vaulting with open screen-work, fixed on to the Norman masonry, which was pared down to receive it. (_Vide_ page 52.) Professor Willis points out that "in all cathedrals ... a screen, about the height of the present altar-screen, separated the choir from the side-aisles and transepts; but in this cathedral the screen is carried to the roof, and the result is a beautiful, if not unique choir. This screen of tracery, which formed the sides, was, below the clerestory, merely plastered on to the Norman wall; or the original Norman columns had been chipped down till they harmonised with the general design." Professor Freeman, in writing of this casing work, said, "Paid for by the offerings at Edward II. shrine, ... to that abnormal worship the abbey of Gloucester owed its present form. I am half inclined to put it the other way, and to make it a new count in the articles of deposition against the unworthy king that this misguided devotion has cost us the minster of Serlo in its perfect form, and hinders us from studying the contrast which we should otherwise have been able to mark between its eastern and its western limb." [Illustration: CHOIR, LOOKING EAST.] [Illustration: PLAN OF TRIFORIUM OF THE CHOIR. From a Drawing by F. S. Waller, F.R.I.B.A.] We, however, have nothing to do with the question of the merits or demerits of Edward II. The beauty of the casing work compels our admiration. If we want to get an idea of what the choir would have been without the Perpendicular casing we must go to Norwich, and inspect the uncased work in the choir that is there, or else to Tewkesbury.[3] [Illustration: Plan of Feretory (High Altar) as laid bare when the new Reredos was erected in 1873. The site of the old Norman Piers could be as distinctly as in this sketch. From a Drawing by F. S. Waller, F.R.I.B.A.]