At the north-west corner of the cloister is the doorway through which Becket passed to the north-west transept, with his murderers in pursuit of him. Near here is a hole in the wall, the Buttery hatch. In the fifteenth century the south walk of the cloister was divided into “studies” for the monks by wooden partitions (at Gloucester they are of stone), and its windows were glazed. From the cloister we pass to the _West Front_, and commence the tour of the exterior. The south-west tower (with the Deans’ chapel) was completed by Prior Goldstone (1449-1468); the copy of it was put up in 1834: “it was an eyesore that the two towers did not match.” Very bad modern statues adorn the niches. Later still (1517) is _Christ Church Gateway_, through which one first approaches the cathedral, with doors inserted in 1662. Originally it had two turrets. Outside it is a monument to the dramatist Marlowe. [Illustration: NAVE.] On the south side is seen the porch; the nave, a beautiful design; and the charming pinnacle of the south-west transept. East of the Warrior’s chapel is the projecting end of Stephen Langton’s tomb. East of this, the two lower rows of windows are those of Conrad’s choir; the upper row that of William of Sens. The middle windows in the S.E. transept were the clerestory windows of Conrad; the windows above them are those of William of Sens. The three upper stages of the tower on the south of this transept are late Norman work; one of the prettiest bits in Canterbury. Farther east we have French design, pure and simple; here, for the first time in English architecture, the flying-buttresses are openly displayed; notice how flat and plain they are; it had not yet occurred to architects to make them decorative. The grand sweep of apse and ambulatory seems to send one straight back to France. Then comes the broken, rocky outline of the _corona_—the great puzzle of Canterbury. North-east of the corona are two groups of ruined Norman pillars and arches discoloured by fire; once they were continuous, forming one very long building, the _Monks’ Infirmary_, of which the west end was originally an open dormitory, open to the roof, and the east end, separated off by a screen, the Chapel; which has a late Geometrical window. A mediæval infirmary of this type is still in use at Chichester. The Canterbury infirmary had a north transept, called the Table Hall or Refectory (now part of the house of the Archdeacon of Maidstone), in which the inmates dined. On the north side of Trinity chapel is seen the _Chantry of Henry IV._; then _St. Andrew’s Tower_ and the barred _Treasury_; the lower part of the latter is late Norman work, largely rebuilt. The south alley of the _Infirmary Cloister_ was built about 1236. Along this one passes to the _Baptistery_, which was originally nothing but a mediæval water-tower; late Norman below, Perpendicular above. Returning towards the Infirmary, we turn to the north up the east alley of the Infirmary Cloister, now