For example, Varillas[38] writes that ‘at his ineffectual siege of Carolstein in 1422, Coribut caused the bodies of his soldiers whom the besieged had killed to be thrown into the town in addition to 2,000 cartloads of manure. A great number of the defenders fell victims to the fever which resulted from the stench, and the remainder were only saved from death by the skill of a rich apothecary who circulated in Carolstein remedies against the poison which infected the town.’ [38] French historian, born 1624, died 1696. Froissart tells us that at the siege of Auberoche, an emissary who came to treat for terms was seized and shot back into the town. This author writes: ‘To make it more serious, they took the varlet and hung the letters round his neck and instantly placed him in the sling of an engine and then shot him back again into Auberoche. The varlet arrived dead before the knights who were there and who were much astonished and discomfited when they saw him arrive.’ Another historian explains that to shoot a man from the sling of an engine he must first be tied up with ropes, so as to form a round bundle like a sack of grain. The engine with which such fiendish deeds were achieved was the trebuchet. [Page 40] A catapult was not powerful enough to project the body of a man. This difficulty was overcome by cutting off the head of any unfortunate emissary for peace, if the terms he brought were scornfully rejected. His letter of supplication from the besieged was then nailed to his skull, and his head was sent flying through space to fall inside the town as a ghastly form of messenger conveying a refusal to parley. As it was always an object to the besiegers of a town to start a conflagration if they could, Greek fire was used for the purpose. The flame of this fearfully destructive liquid, the composition of which is doubtful, could not be quenched by water. It was placed in round earthenware vessels that broke on falling, and which were shot from catapults; as the roofs of ancient and mediæval dwelling-houses were usually thatched, it of course dealt destruction when it encountered such combustible material. The successful attack or defence of a fortified town often depended on which of the armies engaged had the more powerful balistas, catapults or trebuchets, as one engine of superior range could work destruction unimpeded if it happened that a rival of similar power was not available to check its depredations.