Laval
The first improvements in defence, designed to meet an improved attack, consisted in the protection of the ramparts. Behind the outer parapet of the wall was the rampart-walk, a level path along the top of the wall, which was sometimes protected by a parapet in the rear. From an early date in stone fortification, it was customary to break the upper portion of the parapet at intervals by openings called crenellations, through which it was possible for an archer to command a limited part of the field at right angles to the wall.[95] The crenellations, however, were narrow compared with the unbroken parapets between them, and, even in advanced examples of fortification like the ramparts of Aigues-Mortes ([77]) and Carcassonne ([78]), these unbroken pieces are still very broad, although they are pierced by arrow-slits. Even allowing for an arrow-slit between each crenellation, the foot of the wall could not be commanded from behind the parapet. In time of siege, then, it became customary to supply the walls with projecting wooden galleries, known as hoardings or brattices (hourds, bretèches), which could be entered through the crenellations. The joists of the flooring passed through holes at the foot of the parapet, and were often common to the outer gallery and an inner gallery (coursière) covering the rampart-walk. Both galleries had a common roof.[96] In the floor of the outer gallery, between the joists, were holes, through which missiles could be directed upon the besiegers at the foot of the wall; while slits in the outer face were still available for straight firing. The defenders of the ramparts were thus able to work under shelter, with some command both of the field and the foot of the wall. The defensive advantages of this scheme are obvious; but the galleries were also liable, although the usual precautions for their covering were taken, to destruction by fire, whether from arrows tipped with burning tow, or the more formidable red-hot stones flung by catapults. In any case, the catapults were a serious menace to their solidity.
Coucy; parapet of donjon
The donjon and the towers of the enceinte were also bratticed at the rampart-level.[97] Indications of this practice are common in military architecture abroad. The cylindrical donjon of Laval ([80]), a work of the twelfth century, is covered with hoarding which is supposed to be contemporary with the tower. The stone corbels which carried the hoarding of the great thirteenth-century tower of Coucy remain; and a row of plain arches pierced in the tall parapet show how the gallery was entered from the roof ([81]). The somewhat earlier round tower at Rouen was restored by Viollet-le-Duc on the lines of Coucy, with a conical roof and hoarding. The inner wall at Carcassonne and the curtain of Loches, among other examples, keep the holes in which the joists of the hoarding were fixed; and the walls of Nuremberg are still covered with inner galleries or coursières. The practice of supplementing stone walls with timber defences lasted till a late period; but, even before the end of the twelfth century, corbelled-out parapets with machicolations appeared in isolated instances. In subsequent chapters we shall see how military masons and engineers applied their architectural skill to meet the problems which siege-engines of greater strength and tactics more finished than those of the past forced upon them. We have now to deal with earlier efforts, which we have to some degree anticipated.