Page:The castellated and domestic architecture of Scotland from the twelfth to the eighteenth century (1887) - Volume 1.djvu/41

 NORMAN SHELL KEEPS 21 INTRODUCTION corbelled out from the interior of the wall, and running round the sides of the apartments, led to the upper floors. The roof was probably flat, and had a parapet with crenelations, which was only destroyed some years ago when the tower was struck by lightning. The openings for light are small and narrow longitudinal slits in the masonry, without splay or ornament, and they have no internal bay, but are mere oblong holes passing through the walls. This tower was built in the twelfth century. The design of these southern towers was probably derived from that of similar Roman buildings, just as the northern keeps of the Normans may be another descendant from the same original. It will be afterwards pointed out how the same simple form continued for several centuries to be the ordinary plan of castles and houses in Scotland. It would thus appear that in all places, and at all times, the simple square tower seems to have been adopted as the most natural form in which to build a tower of defence. Besides these Rectangular Keeps the Normans erected another kind of stronghold, called the Shell Keep. For several centuries before the Norman Conquest (as already mentioned) the castles of Northern Gaul and England consisted of earthworks with ditches and palisades, the buildings within these strongholds, like all the domestic buildings of the Saxons and Norsemen, generally being of wood. A large number of these fortresses existed and were occupied at the time of the Conquest. They were generally well situated for defence, and, like the early establishments of the Roman Gauls above described, they comprised an extensive enceinte, within which was a lofty mound or motte, with its ditch, having the chiefs house built with wood on the top. It now (eleventh century) became the fashion with the Normans to substi- tute stone for wood in their castles, and, finding that a solid square keep could not safely be erected on the mottes of forced earth, they built a wall round the top of the mound and placed their dwellings as lean-to's against the interior of this wall, leaving a courtyard in the centre. These Shell Keeps are polygonal or curved in form to suit the ground. As a rule, the Shell Keeps are always on an old mound, natural or artificial, while the Rectangular Keeps are on new sites without mounds, and the two forms of keep rarely occur together. The Shell Keep, like the Rectangular Keep, is generally situated on the enceinte, and has its own ditch and drawbridge, and a steep flight of steps leading up the mound to the door. Of the Shell Keep, the Castle of Gisors, near Vernon, in the north of France, may be taken as an illustration. It has the lofty artificial mound or motte, situated in the centre of a large enceinte surrounded with lofty