At half-past two, signal was made to begin the attack, and the bombs and gunboats opened a heavy fire upon the town, to which the batteries replied. In a short time the walls of the seven-gun battery were nearly demolished. The small vessels kept their stations steadily under an annoying fire. Suddenly on board one of the prize gunboats was seen a burst of flame followed by a terrific crash; a hot shot had passed through the magazine and exploded it. The young commander of the gunboat, Lieutenant Caldwell, and Dorsey, one of the midshipmen who stood with him on the quarter-deck, with all the seamen near them, were killed, and the stern of the boat was blown to atoms. In the bow was the gun's crew under Midshipman Robert Spence. The crew had just loaded the gun, and for a moment stood paralyzed, as the boat was sinking fast. "All right, boys!" sung out Spence as he coolly pointed the gun. "We'll give them one more, any way. Fire!" _Crack!_ went the gun. "Now, then, three rousing cheers for the flag! Hip, hip, hurrah!" The gallant tars gave three cheers, and the boat sank from under them. Spence, who could not swim, seized an oar as he plunged into the water, and so kept himself up until help came to him from one of the boats near by. In this way were rescued all whom the explosion had left alive. The eight remaining gunboats, which though here and there cut up were not disabled, continued the action until late in the afternoon, when the freshening wind warned the squadron to retire. During the engagement a strange sail had been seen to the northward, and the "Argus" was sent in chase. It proved to be the frigate "John Adams," Captain Chauncey,--the first ship of the new squadron that was coming out from the United States. Unfortunately she had left her gun-carriages to be brought out by the other ships, so that she could not be used for active operations. Still more unfortunately it turned out that the authorities at Washington, who were somewhat given to red-tape, had thought it necessary to send an officer in command of the squadron of reinforcement who was higher in rank than Preble, and who would therefore upon his arrival replace the latter in the command. It was a cruel blow to the commodore to be cast aside after having done so much where others had accomplished little; and in his private journal, written with his own hand in the solitude of his cabin, and meant only for his own eye, we find these words:-- "How much my feelings are lacerated by this supersedure at the moment of victory cannot be described, and can be felt only by an officer placed in my mortifying situation."