Page:Medieval Military Architecture in England (volume 1).djvu/156

 140 Mediceval Military Architecture in England. amined, and the only trace of its keep is a fragment of a drain. Montacute, where the hill is wholly natural, has also been cleared of masonry. But by far the larger number of these mounds are either wholly artificial, or of a mixed character. In plan and dimensions these keeps are roughly governed by the figure of the mound on which they stand. Most are polygons of ten or twelve sides, not always equal. Some are circular, others polygonal outside and circular within. Others, are slightly oval, others more complex in plan. York, for example, approaches to a quatrefoil, 64 feet by 45 feet, and this seems to have been the plan of the long-since destroyed keep of Warwick. Their diameter is rarely less than 30 feet, and seldom exceeds 100 feet. The wall was usually 8 feet to 10 feet thick, and, as a security against settlement, was generally placed 2 feet to 3 feet within the edge of the mound. Sometimes, as at Lincoln and Tickhill, the walls were strengthened by flat Norman pilas- ters, but more commonly they were of plain rubble with plinths and angle quoins of ashlar. Cardiff, though without a plinth, has angle quoins, and probably dates from early in the twelfth century. The walls of these keeps were 20 feet to 25 feet high to the rampart walk, which was reached by open interior staircases either of wood or stone. Traces of the latter were visible a few years ago at Cardiff. Such a shell is well suited to be placed upon made ground, which would not have supported a solid mass. At Cardiff, where a heavy tower was long afterwards added, it slipped and fell. The interior of the larger keeps was an open court, around which were placed the buildings — sometimes mere sheds — against the ring wall. Where the keep was large and the castle important, these buildings were permanent, though even in the greater keeps, such as York, timber was Jargely used. Windsor, before the alterations, contained an open court, as still does the keep of Ledes Castle, Vv'hich is peculiar in standing upon a small island, completely occupied by it. The present round tower at Windsor, though modern, is built upon the lines of the Edwardian tower, which again was built upon those of a late Norman keep, the foundations of which were laid open by Wyattvillc, and found to rest upon an arti- ficial mound. Durham keep is said to have been originally open, but to have been closed to accommodate the bishops, who were forced, by the disturbed state of the country, to reside within it. The keep at York, known as Clifford's tower, is rather Early English than Norman, and probably succeeded a timber structure. It much resembles some of the French keeps built by Philip Augustus. It has a well in the court,