134 MedicEval Military Architecture in England, at the first-floor level in a mural chamber, at Castle Rising and at Norwich. The kitchen when it was in a distinct chamber was at the level of the hall, or even above it. The defences of the outer doorway in a Norman keep were usually one or two stout doors of oak, strengthened with iron, and held close by one or two bars, also of oak, which ran back into deep holes in the wall about four inches square. The herse or portcullis, though used in other parts of castles, was rare in the keep. It is a very old method of defence, formed of stone in the Great Pyramid, and the groove for which re- mains in the city gate of Pompeii. When employed, as in the keeps of Scarborough, Hedingham, and Rochester, it was a single grate, probably of oak spiked and plated with iron, and it was worked from a mural chamber over the archway. Some- times, from the narrow dimensions of the groove, the grate seems to have been wholly of iron. It was worked by chains or cords wrapped round a cylinder or windlass, such as is still in use in the main gate-house of the Tower. Norman keeps very seldom retain their original parapets or turrets. The parapet was about two feet thick and five feet high. It was either plain or had broad merlons and narrow embrasures. Usually it was a mere continuation of the wall, without corbels or any contrivance to widen the rampart walls, which were of sufficient thickness for the walk. At Rochester, holes are seen at the base of the parapet for beams to carry a bretascJie or external gallery, but these probably are not original. The angle turrets are usually mere places of arms, the rampart walks passing through them. Sometimes they have an upper floor reached by a stone stair or a movable ladder. Much has been said of Norman dungeons, oubliettes, and subterranean vaults, damp and wretched, appliances of Norman tyranny. So far as these keeps are concerned in the matter, they never contain underground chambers of any kind. The basement floor is usually at the ground level, or at most two feet or three feet below it. Where the keep is built on rising ground it may happen that a chamber, the door of which is at the ground level, may have one wall half buried beneath the soil, but there is nothing beyond this. Prisoners of the common sort were not shut up in the keep, space there was too valuable. The basement could scarce have been used as a prison where it contained the castle well, and the mural chambers usually are barred inside. The rooms under the vestibule, and some of the lower vaults at Dover, and the crypts of the Tower of London, and at Colchester, probably were used as prisons. In the upper gallery at
