William the Norman found no castles to resist him. He resolved that any one who came after him should complain of no such omission. England proper immediately bristled with strongholds. They were afterwards extended to Wales and Ireland; and it is perhaps the most remarkable episode in the history of Norman fortification, as indicative of the systematic zeal with which the system was conducted, that during the brief tenure of Scotland, the opportunity was taken for dispersing throughout the country Edwardian castles. The earliest Norman form was the vast square keep, such as Bamborough New Castle, or the Tower of London. The value of projecting angles seems soon to have been felt, but it does not appear that the noble flanking round towers, which make a perfect Norman fortress, were devised until the days of the Edwards. The central strength then consisted of a square work, with a round tower at each angle. When the work was very large, demi-towers might project here and there from its face. This was the leading principle of modern fortification—the protection of the face. It is understood that no plain wall-plate, however strong, can be defended from an enemy ready to sacrifice a sufficient number of men to batter it open and rush in by the breach. The object, then, is by outworks to keep the assailants at a distance. The flanking towers accomplished this for the Norman fortress, and the work of a siege was not in those days utterly unlike what it now is in general character, though the less destructive character of the weapons on either side made it a much closer affair. There is room for considerable classification, and even for abundant technical nomenclature, among the besieging engines used before the invention of gunpowder. The term mangona, or mangonel, was generally applicable to ballistic engines, moved by springs, or quick descending weights. The trebuchet, the matafunda, the ribaudequin, and the petrary, were special machines for discharging what the Americans call rocks. There were the robinet, the espringal, and the bricole, which discharged huge iron bolts and other miscellaneous mischievous articles. The oddest of all names to find among these wicked and destructive agents is conveyed in a sentence by Grose, who says that “Beugles, or bibles, were also engines for throwing large stones, as we learn from an ancient poem;” and he quotes as his authority the Romance of Claris, in the Royal library of Paris (No. 7534). “Et pierres grans, et les perrieres, Fit les bibles qui sont trop fieres, Gétent trop manuement.”