Perhaps the weakest point in the cathedral is the modern glass. There is much that shows careful work and thought, but there has been no systematic controlling spirit at work to suggest, to guide, or to check. The chief blots, too, are the so-called memorial windows, and the reason is not hard to find. It is well put by Mr Ruskin, who, in his "Seven Lamps of Architecture," says: "The peculiar manner of selfish and impious ostentation, provoked by the glassmakers for a stimulus to trade, of putting up painted windows to be records of private affection, instead of universal religion, is one of the worst, because most plausible and proud, hypocrisies of our day." Just imagine the difference in the south aisle, for instance, if there had been a scheme carefully planned beforehand for the windows, instead of the threefold, but haphazard, process of a window offered, a window accepted, a window put up, and no questions asked as to designer or artist. Imagine what the effect might, or would, have been, had the windows, as a set, been designed by Burne-Jones and executed by William Morris, or by other competent artists. Now, unfortunately, these two great artists are dead, and Gloucester has not a single specimen of their work. The #Nave# as it is (174 feet by 34 1/4 feet long, 67 feet 7 inches high) is quite unique, and differs considerably from other Norman naves, such as are to be found in the cathedrals at Ely, Norwich, or Peterborough, and in the neighbouring abbey churches at Tewkesbury, and Great Malvern. The unique features here are the great height of the massive circular columns, fourteen in number, and the consequently dwarfed triforium or gallery running over the main arches. There are traces to be seen of the original Norman clerestory under the Perpendicular windows, and, judging from this, the height of the clerestory, as originally constructed, must have been but little less than that of the piers in the nave. This Norman clerestory was altered at the same time that the roof of the nave was vaulted--viz. in 1242, in the time of Henry Foliot. This work was done by the monks themselves, who thought, as Professor Willis suggests, that they could do it better than common workmen. Their work is made of a light and porous kind of stone, treated with plaster on the under-side, and it was rendered necessary by the previous roof, which was of wood, having been destroyed by fire in 1190. Of this fire the piers certainly show the traces to this day, all having become reddened and slightly calcined. To make the new clerestory the whole of the original Norman work over the arcade of the triforium was removed, with the exception of the jambs of the side-lights (which extended beyond the arches of the triforium) and the wall between them.