Though King Robert had mustered a considerable force, probably as large as Edward's, he deemed it more prudent to despatch it on a raid into England than to launch it directly against the English entrenchments. He had, indeed, good reason to rely upon the skill and energy of the Steward. The five days' truce over, the English, on September 13, moved forward on wheels an immense sow, not only covering a mining party, but carrying scaffolds for throwing a storming party on the wall. By this time, John Crab, whom we have already met as a sea-captain or pirate, and whom the Count of Flanders presently assured Edward he would break on the wheel, if he could only get hold of him, had proved himself engineer enough to devise a 'crane,' which must have been of the nature of a catapult; and this engine he ran along the wall on wheels to encounter the sow. The first shot passed over the monster; the second just fell short; the third crashed through the main beam, and frightened the men out. 'Your sow has farrowed,' cried the Scots. Crab now lowered blazing faggots of combustible stuff upon the sow, and burnt it up. But presently another attempt was made from the harbour, and Crab's engine was hurried up to fight ships with top-castles full of men, and with fall-bridges ready at midmast. The first shot demolished the top gear of one of the ships, bringing down the men; and the other ships kept a safe distance. Meantime the general attack raged all along the wall. Sir Walter the Steward rode from point to point, supplying here and there men from his own bodyguard, till it was reduced from a hundred to a single man-at-arms. The severest pressure was at Mary Gate. The besiegers forced the advance barricade, burned the drawbridge, and fired the gate. Sir Walter drew reinforcements from the castle, which had not been attacked, threw open Mary Gate and sallied upon the foe, driving them back after a very hard struggle, and saving the gate. Night separated the combatants. Barbour tells how the women and children of the town had carried arrows to the men on the walls, and regards it as a miracle that not one of them was slain or wounded. But clearly the Steward could not sustain many days of such heavy fighting.