Neither did any greater degree of chivalry display itself in the matter of the modes and weapons of warfare. Although reason can urge no valid objection against the means of destruction resorted to by hostile forces, whether poisoned arrows, explosive bullets, or dynamite, yet certain things have been generally excluded from the category of fair military practices, as for example the poisoning of an enemy’s water. But the warriors of the fourteenth century, even if they stand acquitted of poisoning rivers and wells, had no scruples about poisoning the air: which perhaps is nearly equivalent. The great engines they called Sows or Muttons, like that one, 120 feet wide and 40 feet long, from which Philip von Artefeld and the men of Ghent cast heavy stones, beams of wood, or bars of hot copper into Oudenarde, must have made life inside such a place unpleasant enough; but worse things could be injected than copper bars or missiles of wood. The Duke of Normandy, besieging the English garrison at Thin-l’Evêque, had dead horses and other carrion flung into the castle, to poison the garrison by the smell; and since the air was hot as in midsummer, it is small wonder that the dictates of reason soon triumphed over the spirit of resistance. And at the siege of Grave the chivalry of Brabant made a similar use of carrion to empoison the garrison into a surrender. Even in weapons different degrees of barbarity are clearly discernible, according as they are intended to effect a disabling wound, or a wound that will cause needless laceration and pain by the difficulty of their removal. A barbed arrow or spear betokens of course the latter object, and it is worth visiting the multi-barbed weapons in Kensington Museum from different parts of the world, to learn to what lengths military ingenuity may go in this direction. The spear heads of the Crusaders were barbed;[54] and so were the arrows used at Crecy and elsewhere, as may be seen on reference to the manuscript pictures, the object being to make it impossible to extract them without laceration of the flesh. The sarbacane or long hollow tube was in use for shooting poisoned arrows at the enemy;[55] and pictures remain of the vials of combustibles that were often attached to the end of arrows and lances.[56]