At Gloucester and at Tewkesbury many of the stones bear on their faces the interesting devices incised by the Norman masons. These marks are in many cases the same, but there are some found at Gloucester which are not found at Tewkesbury, and _vice versâ_. One small point may be noticed which may perhaps interest a few, viz., that the same workman set out and worked at the first few courses of the stone work of the staircases, and then was followed by others, possibly less intelligent, but capable of following the indicated plan. A monk named Alfred was the "Master of the Work," and it would be interesting to know if the stones marked A are marked with his mark. [Illustration: _Photo. A.H. Hughes._ THE NAVE, FROM THE WEST END.] The nave here was being built in all probability while the great Flambard was busy with Durham (1105-1130), and very soon after he had finished his labours at Twynham or Christchurch, Hants. Gloucester is generally assigned to Serlo, 1089 to 1100, and Norwich was begun in 1096. [Illustration: MASONS' MARKS.] Above the arches of the nave are small double round-headed openings into a very narrow triforium walk, which is vaulted, as at Gloucester, with a quadrantal arch. There is another peculiarity, too, here, in that the vaulting of the roof springs from corbels which rest directly on the capitals of the piers. As a result of this the roof looks low and heavy. The triforium openings, which are divided by small shafts, similar in character to those in the tower chamber, are 5 feet 6 inches high and 4 feet 10 inches wide. The passage is 26 inches wide and 6-½ to 7 feet high. The two western bays of the triforium are not alike. On the north the openings correspond to those in the other bays, and are not contracted to correspond with the narrowed arch below; whereas on the south side they are so contracted. By this means the square angle of the western pier was continued to the roof. On the north side the western pier ends abruptly at the capital of the respond. The clerestory windows are partly concealed by the vaulting. Of course the original windows were much smaller, and were removed and the space enlarged when the re-roofing was done in the fourteenth century. =The Roof.=--Originally, no doubt, as at Peterborough, where it remains, the inner roof was a flat panelled ceiling of wood, supported by a moulded framing. Whether the wooden roof decayed or was destroyed by fire, it was found necessary in the early part of the fourteenth century to re-roof the nave, and the present vaulting was then constructed. Beautiful though it is architecturally, it has the effect of dwarfing the nave, as it springs directly from the tops of the piers in the nave. In character it is a simple pointed vaulting, and the ribs at their many points of intersection are lavishly decorated with bosses.