On the next day two principal engineers came to the duke, and said, if he would find them wood and workmen they would build for him four such high towers, as, when they were advanced to the walls of the castle, should overtop them. The duke commanded all the carpenters of the country to be sent for, and handsomely paid. These four towers were constructed, and placed on the decks of four large vessels; but they took a long time in making, and cost much money. Those ordered upon this attack embarked on board the vessels; and, when they were about half way over the river, the besieged let off four martinets, which they had newly constructed to defend themselves against these towers. These four martinets cast such large stones, and so very rapidly, that the men at arms in the towers were much hurt by them; and, having no means to shield themselves, they returned back as fast as they were able. But in their retreat one of the vessels foundered and sunk: the greater number of those that were on board were drowned, which was a great pity, as they were chiefly valiant knights who were eager to distinguish themselves. When the duke found that this scheme did not answer his expectations, he ordered them to disembark from the three remaining vessels. He was at a loss what plan to follow, by which he could gain the castle of Aiguillon; for he had vowed he would never quit the place until he was master of it and the garrison, unless the king his father ordered otherwise. The lords therefore advised him to send the Constable of France and the Earl of Tancarville to Paris, to inform King Philip of the state of the siege, and to know if the king wished the Duke of Normandy to continue before Aiguillon until he had through famine made himself master of it, since he could not gain it by force.