Of the three drawings here given, the first gives the plan of the White Tower, London, at the second or chapel floor. The three well staircases are there seen, and the outer and cross walls. Here also is shown, in the south wall, the small mural staircase which ends at this level, and affords the only communication with the main floor of the chapel.
The next drawing shows a plan of the third or uppermost floor, at the level of the clerestory of the chapel. Here the outer wall is shown perforated all round by a mural gallery, which communicates with the three well staircases and with the chapel.
Finally follows a vertical section of the whole keep from east to west, in which is shown the chapel with its clerestory above and its two tiers of crypts below. These drawings, which more especially belong to the detailed description of the Tower of London which follows in its place, are here inserted as illustrating what is written of Norman rectangular keeps in general.
The kitchen, though a necessary appendage to a keep, is not often to be discovered. Probably the cooking was of a simple character, mostly carried on before an open fire, or by boiling, or broiling over a brazier. There is a kitchen in the forebuilding at Rochester, high up; and one 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 remains 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. Sometimes, 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 brétasche 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 Dover there is a very evident prison. At Carlisle, where the basement has recently been used as a prison, it probably was not one originally. Large as some of the keeps were, they were not calculated to be held against a long siege or a blockade, and all the spare room would then be needed for provisions and stores. The earlier keeps are very plain. The Tower has not even a moulding save in the chapel, and an exterior blocking over its main tier of windows. No doubt it has been much mutilated, but, had the ornaments been cut off, the courses of freestone that carried them would still be distinguishable from the ordinary rubble masonry. Some of the later keeps exhibit rather rich details, though usually marked by much simplicity, about the doors, windows, and fireplaces. Such is the case at Rochester, Hedingham, Dover and Newcastle, and specially at Castle Rising, one of the most highly ornamented of keeps. Bamburgh has a fine doorway early in the twelfth century; Ludlow and Guildford some arcades; Porchester some good windows. The exterior of Norwich is, or rather was, rudely panelled in tiers of arches. Goderich, otherwise very plain, has an exterior string of hatched or chevron work. In these keeps the arches are usually full-centred, but sometimes segmental, and where flat there is commonly above the lintel a relieving arch with a recessed tympanum, as at Chepstow. At Malling, though there are no mouldings, the first-floor window on one side is the centre of five deep plain full-centred niches in the exterior face, which cannot have been meant for use, and in another face, also outside, are five other niches, all unpierced. Occasionally false arches are turned in the walls, as though a door had been closed up, or the possibility of a new opening provided for. Such are seen at Dover, Norwich, and Guildford. They are thought, but scarcely on good grounds, to be intended to invite an attack where the wall is specially thick.
One or two keeps have buttresses of bold projection, greatly in contrast to the usual flat pilaster. This is so at Colchester and at Arques, where the exterior stair passes through one of them. At Arques also these buttresses are turned to account in the upper story, arches being thrown across from buttress to buttress, upon which are built chambers, and on one face a chapel, through the floor of which missiles could be dropped upon the assailants below. Arques, unfortunately, is built of chalk and flint with little or no original ashlar, and it is, in consequence, difficult to decide between what is original and what has been added.
Norman keeps differ in workmanship as in material. The White Tower, built in great haste, is of rubble, rudely coursed, with very open joints; but the plinth, quoins, and pilasters seem to have been of Kentish rag, dressed as ashlar, and also open jointed. Malling is an excellent example of very early Norman rubble, with open joints, and this may also be said of a part of the adjacent abbey church, and perhaps of the tower of the parish church. Guildford contains a good deal of herring-bone work; Chepstow and Penllyne a little. Colchester is partly built of old Roman materials, chiefly brick, and contains some herring-bone work. In the chalk districts flint was largely used, as at Bramber, Dover, Hastings, Canterbury, Thurnham, Berkhamsted, Bungay, and Walden. In the south, or near the sea, the ashlar is often in small blocks from Caen. Corfe is of excellent local ashlar, as is most of Kenilworth. Porchester is of chalk and flint rubble, faced with ashlar outside and partially inside. Hedingham is all ashlar, and altogether the finest keep in England. Bowes is a fine example of ashlar, in a local stone. Whatever Norman masonry may be in church towers, in keeps it is always sound, though often rough, and is very durable. Now and then chain courses of timber are inserted in the heart of the walls, to hold the work together till the mortar shall have set, and it has happened that the wall has been breached and the exposed timbers have been found to have rotted away, leaving cavities, as at Rochester, concerning the use of which much nonsense has been written.