The walls of the eastern part of the cloister are not over 2 feet 6 inches in thickness (which would be very unusual in Norman work), and they have been strengthened by interior piers when the present flat barrel arch was erected over the chapter house. This probably took place when the upper part of this portion of the building was raised a story in height, possibly in order to form the library on the upper floor. It is evident, from an examination of the junction of the walls on the exterior, that the upper floor of this part of the building was added at a late period. Both vestibule and chapter house appear to have had a stone seat running along the walls, and the whole may possibly have formed the place of assembly of the monks. Probably, like the chapter house at St. Andrews, the western portion, or vestibule, was the original chapter house, and the inner division was added at a later period.
From the chapter house a passage is visible in the upper part of the east wall of the north transept. In order to admit of this, the wall of the transept (as above pointed out) has required to be made of great thickness, and this explains the depth of the two recesses under it in the transept previously referred to. As already mentioned, there was an upper floor over the chapter house and the adjoining portions of the east range of the cloister buildings. Part of this upper floor is believed to have been the library—the literary treasures of which were famous—and part would, no doubt, be the dormitory of the monks.
It seems not improbable that the passage in the transept wall may have led from the library or dormitory to the chapel in the upper aisle of the choir over the sacristy, and the use of that chapel would thus be explained. The chapel, as already mentioned, is a structure of late erection, as is apparent from the imitation dog-tooth running round the straight-sided arch of the east window (see Fig. [1002]). The passage in the transept wall may be much older, but was possibly utilised in connection with the late reconstruction of the monastery, as above suggested.
To the north of the chapter house are two chambers of good size, over which an upper story has extended, as the remains of the windows show.
The north side of the cloister has been occupied by the refectory, a building 63 feet long by 20 feet wide. It is situated on the first or upper floor, and is of late work; but seems to occupy the position of a previous refectory, which formerly stood on the site, and of which some portions of the walls remain. The first refectory appears to have been on the ground floor, as the remains of what must have been a handsome doorway in the south wall near the west end of this range prove. This doorway has had three orders of mouldings with shafts and caps, about 7 feet high, apparently of thirteenth century work, of which some fragments remain, partly built into the adjoining angle structure. The latter is evidently a late erection, as it encloses part of the west jamb of the above doorway. The pier of the diagonal arch of the cloister walk at the east end of the refectory also encroaches on the door beside it. At a somewhat late period the refectory has been raised to the upper floor, and an entrance made to it by a wide staircase at the east end (which would also probably form the day staircase to the dormitory). The ground floor is low, and has loopholes for windows. It has apparently been used for cellars or storages. There is a wide pointed doorway leading into it at the north-west angle (see Fig. [997]). The north elevation of the structure is fairly preserved.
The buttresses seem to be reconstructions on the lines of the original ones, but the windows, both in the north elevation and towards the cloister, are of later date.
The eastern range of buildings is continued northwards beyond the refectory by a chamber 33 feet long by 12 feet 6 inches wide, which seems to have been connected on the upper floor with a lavatory and latrine. The latter has a built channel, evidently intended, from the low aperture at each end, for the passage of a stream of water, which could be easily led into it from the neighbouring burn. To the west of this stand the walls, 3 feet high, of a nearly detached edifice, with a separate outer doorway, which may perhaps have been an infirmary. To the north-east, the low walls are observable of a detached structure 58 feet 9 inches long by 21 feet 6 inches wide. The only wall opening traceable is the doorway, which has been of simple design. This is supposed by some to have been the kitchen, but it seems doubtful. There is no appearance of a fireplace.
A small detached chapel, 38 feet in length by 20 feet 9 inches in width over the walls, lies to the north-east of the chapter house. It has had a doorway in the north wall, a small centre window in the east wall, and a similar window in each of the side walls near the east end. The windows are trefoil headed and cusped, and appear to be late. The doorway had two orders, with a bead on each. The orientation of this building is different from that of the cathedral.
Adjoining the south-west angle of the cloister, and built out from it, is a small enclosure containing stone coffins (see Fig. [994]). Immediately beyond this are the remains of another enclosure, connected with a Celtic cross (called St. Martin’s) near the west end of the cathedral (see Fig. [995]). The inner of these chambers, which encloses the stone coffins, is called “St. Columba’s Tomb.” Dr. Skene is of opinion that it is actually the structure which contained the body of St. Columba, the coffin of that Saint being placed on the right or south side, and that of St. Blathmac (a martyr who died in defending the abbey against the Northmen in 825) being placed on the left or north side. This view is, however, controverted by Sir Henry Dryden in a MS. of 1879, deposited in the Antiquarian Museum in Edinburgh.
There is also a well in the same locality as the above enclosures.