The arch opening into the north aisle shows a curious device for preserving a different level on each of its sides. On the transept side we see the mouldings of an arch like, and on the same level as, its neighbours to the north. The western half of the whole thickness of the wall is, however, continued lower, exhibiting a plain surface to the east, but terminating on the aisle side, at the height of the eastern arches of the nave, in mouldings that we should have expected to find higher up. This lower level was necessary on account of the vaulting at this end of the aisle, of which traces still remain, but the whole arrangement was clumsy, and we cannot be surprised at not finding it repeated on the other side of the church. The next bay has on the triforium level a curious windowless recess, the mouldings of whose arch spring from two shafts on each side. There is another very similar recess opposite, but with only single side shafts. The two northern bays of the east wall are occupied by a wide and deep recess [3], the arched ceiling of which rises to within 3 or 4 feet of the clerestory level. The outside shafts, and those from which the central ribs of the ceiling used to spring, have all gone, though their caps remain. Within this great recess there is, on the spectator's right, a small one, with side shafts, containing a piscina. On the left, in the church's north wall, is a window, which rises to only half the height of the pointed arch, with side shafts, within which it is inclosed. It was at one time the general belief that this recess used to be the site of the parochial altar of St. Nicholas, which may possibly have stood here during the short time between the completion of the north transept and that of the new work at the east end of the nave, for a document published in the "Registrum Roffense" tells us that, after a dispute about a removal, the position before the pulpitum was assigned to it in 1322. Arrangements were then made to avoid any mutual disturbance of the services of the monks and the parishioners, and the new church for the latter was already talked of. The writer of the "History and Antiquities of Rochester,"[11] quotes a will that suggests a possibility that an altar of Jesu stood on this spot. [11] See note on p. 10. The transept end and its west wall have windows of the same form at the triforium level, and there is a similar resemblance in the blind arcades below, except for the doorway restored by Sir G. Scott, and surmounted by an obtuse arch. The arch to the east of this doorway was cleared of masonry in 1840. A large figure, in distemper, of St. Christopher bearing the Infant Christ was then uncovered, but only to fall away as the air was admitted to it. Miss Stevens, daughter of the dean, made as complete a copy of it as possible, as stone by stone was carefully removed to disclose only a small piece at a time, and her drawing, with a note by Mr. Spence, is preserved in the British Museum.