190 Medic^val Military Architecture. the north front. The upper story has been vaulted in six bays, three on each side, duly groined and ribbed, as is shown by the springers. The material and the workmanship, no less than the section of the ribs, show this to be a late addition, probably of the sixteenth century. The supposed two upper floors were very possibly intended for one floor of state, with two tiers of windows and a chapel above. The chapel seems to have had a barrel round-headed vault, pro- bably groined. The accounts show this eastern side to have been the royal chamber in the fourteenth century. The fireplaces seem to be confined to the upper floors. As now seen, they are of the date of the vaulting. In the south-west angle of the keep, very near the wall, is the well, of which the pipe was continued at least to the first floor, as in the additions at Richmond. It is about 6 feet diameter, lined with ashlar, and in 1768 was choked up at 254 feet deep, or about the level of the river ; a depth now reduced to 30 or 40 feet. Outside, between the buttresses, are traces of walls, as though the spaces between them had been turned to account below as well as above ; but these walls are thin, and do not seem original. M. Deville cites the public records for the existence in 13 18 of four turrets on the keep, roofed with lead. M. Le Due, in his Dictionary, Art. " Donjon," gives a great variety of very curious detail connected with this keep, detail unknown to M. Deville, and for which there should be some authority other than the traces actually existing, which are very unsatisfactory. The keep is built of large chalk flints grouted copiously in mortar, and cased outside with ashlar, now mostly stripped off" and removed. Within, the flints are occasionally laid herring-bone fashion. The ashlar was a calcareous tufa, known in the country, and formed by the trickling of calcareous springs over moss and similar vegetation. It was much used in the earlier French castles. The later ashlar of the vaulting ribs and inserted door-cases seems to be a fine hard lime- stone, approaching Caen stone in appearance, and perhaps actually that material. Where the ashlar is wanting, the putlog holes are seen, placed with exceeding regularity. The joints of the original ashlar are large, those of the later fine. The new and old ashlar can readily be distinguished ; but one flint wall is very much like another. The inner ward, in length about 160 yards, and in its greatest breadth about 70 yards, is a natural chalk platform, revetted all round by a wall about 8 feet thick, which on the east side is reduced to a parapet, but on the west rises about 20 feet higher, pro- bably its original height. In 1708 this court contained the apart- ments of the governor and the staff of the garrison, a well, and a chapel. These were probably of the sixteenth century or later, and have now entirely disappeared. The enceinte wall, which girdles this inner ward, deserves attention, as most of it is of early date. Setting aside the four northern
