The next morning the British advanced again to the attack. The skirmish of the night before had shown them that the Yankee flotilla was no mean adversary; and they now brought up re-inforcements, in the shape of the "Roebuck" forty-four, "Isis" thirty-two, "Pearl" thirty-two, and "Liverpool" twenty-eight. No sooner had the British squadron come within range than a heavy fire was opened upon the fort. The American flotilla was prompt to answer the challenge, and soon the action became general. Time and time again the Americans sent huge fire-ships, their well-tarred spars and rigging blazing fiercely, down among the enemy. But the skill and activity of the British sailors warded off this danger. Thereupon the Americans, seeing that they could not rely upon their fire-ships, changed their plan of action. Any one of the British vessels was more than a match for the largest American craft, so the Yankees saw they must rely upon force of numbers. Accordingly their larger vessels were each assigned to attack one of the enemy; while the swift-sailing galleys plied to and fro in the battle, lending aid where needed, and striking a blow wherever the opportunity offered itself. This course of action soon began to tell upon the British. All of their vessels began to show the effects of the American fire. The "Augusta" was in flames, owing to some pressed hay that had been packed upon her quarter having been set on fire. Despite the efforts of her crew, the flames spread rapidly. Seeing no chance to save the vessel, the crew abandoned her, and sought to gain the protection of other vessels of the British fleet. But the other ships, seeing the flames on the "Augusta" drawing closer and closer to the magazine, and knowing that her explosion in that narrow and crowded channel would work dreadful damage among them, determined to abandon the attack upon Fort Mifflin, and withdrew. The "Merlin," which was hard and fast aground, was fired, and the British fled. As they turned their ships' prows down the Delaware, the dull sullen roar of an explosion told that the "Augusta" had met her end. Soon after the "Merlin" blew up, and the defeat of the British was complete.