The military engines in use in attacking or defending castles, or other fortified places, were the _Loup de Guerre_, or war-wolf, a frame formed of heavy beams, with spikes, and made to fall on the assailants in the manner of a portcullis--the _Scorpion_, a large stationary cross-bow of steel, which discharged darts of an uncommon size, and the _Balista_, _Catapulta_, and _Trebuchet_, which were engines of great power in throwing large stones, which were often heated to a high temperature. The _Bricolle_ threw large square-headed darts, called _Carreaux_, or _Quarrels_. This engine was used by the Flemings in fortifying their factory at Berwick, called the “Red Hall.” The _Espringal_ threw darts with brass plates, instead of feathers, to make their flight steady. The _Berfrarium_, an engine also called _Belfredus_, was made of wood, covered with skins to defend it from fire, and was formed like a tower, and of a height to overlook the walls. It consisted of several stories, and was rolled on wheels towards the object of attack, and filled with archers and spearmen; the latter, under cover of the former, either rushed upon the walls, or fought hand to hand with the besieged. The name was afterwards given to high towers erected in cities, for the purpose of alarming by bells. Hence the origin of the term “Belfrey.” The most expert in the manufacture of these engines of destruction was a monk of Durham. This man supplied the greatest portion of the artillery required for the defence of Berwick. Respecting the state of the Arts, it would be difficult to give any thing like a circumstantial detail. That various useful mechanical professions were known and prosecuted, there is abundance of evidence to prove; but to what degree of perfection they were brought, is not so clear. That the compass was familiar to the mariners of Scotland at an early age, appears from the manner in which Barbour expresses himself, in the description of Bruce and his companions, who, in crossing from Arran to Carrick in the night-time, steered by the light of a fire upon the shore. “For thai na _nedill_ had, na _stane_, Bot rowyt always in till ane, Steerand all tyme apon the fyr.” _Buke Feyrd_, 1. 23-25. According to Wyntown, great attention was paid to agriculture by Alexander III., who fixed that well-known measurement of land called “Ox-gang.” The passage is worth extracting.