The subject of puzzles in vaulting suggests a notice of that of the choir at Lincoln, where the architect (De Noyes) seems to have put himself out of the way to make an easy matter difficult; for, instead of groining his oblong bays in the usual way, he has made each cell strike obliquely to points dividing the central ridge of the bay into three equal parts (Fig. 375); so that neither the cells nor the diagonal ribs from either side ever meet one another, but each cell is met by an intermediate or an oblique transverse rib from the opposite side. Professor Willis, in his peripatetic lecture there in 1848, called the architect “a crazy Frenchman,” it being then thought that he had been brought over by Bishop Hugh of Burgundy; but it has since been discovered that he was a member of a Norman family long settled in Lincolnshire; and the beauty of his work is such that we may well excuse this freak of eccentricity, and wish that this form of craziness was more prevalent amongst ourselves! A curious effect is produced by carrying vaulting out accurately in a circular aisle or corridor, where it gives the diagonal ribs a twisted line, bending them out of the vertical plane. This is well seen in the apsidal aisle in the Cathedral at Bourges, both in the church itself and the crypt. I will only notice two or three more varieties of this stage of vaulting, and those of a miscellaneous character. The Chapter-house at Lichfield is an elongated octagon (Fig. 376), one of its sides on either hand being double the length of the others, and divided into two bays. The vaulting is a curious elongation of that of the regular octagonal chapter-house: a cell on either hand being interpolated, and the ribs all converging obliquely to the central pillar. [Illustration: Fig. 376. Chapter-house, Lichfield.] [Illustration: Fig. 377. Kitchen of the Monastery, Durham.] At Caudebec, in Normandy, we have, though of much later date, a hexagon vaulted much as our own chapter-houses, but with a pendant substituted for the central pillar, and ingeniously suspended by a long stone from a constructional vault above. At Durham, in the octagonal kitchen of the monastery, we have a curious piece of vaulting planned with a view to a central ventilating lantern (Fig. 377). The ribs run from every corner at right angles to the side of the octagon, and consequently meet the third angle from that from which they set out, and their intersections leave an octagonal opening equal in diameter to one side of the original octagon in the centre, and this is strong enough to support the required lantern or louvre.