This building is a hexagon on plan (Fig. 1424), measuring 29 feet in
internal diameter, and stands about 3 feet from the south wall of the
church, against which the angle buttresses have impinged.
On each of the three sides facing towards the south there is a window,
now built up, each of which has a very flat four-centred arch, and
contains three cusped lights (Fig. 1425), divided by two mullions. The
section of the jambs and mullions is shown in Fig. 1426. The roof is
vaulted (Fig. 1427) with ribs springing from a central pier, which has a
filleted roll towards each angle (Fig. 1428).
[Illustration: FIG. 1429.--Restalrig Collegiate Church.