But while the smaller vessels of the Mediterranean squadron were enforcing the blockade before Tripoli, Commodore Preble, with the flag-ship and the larger vessels, was at Malta preparing for a vigorous attack upon the city of the Bashaw itself. He had added to the fleet he had brought with him from the United States two bomb-vessels and six gunboats. He had also added somewhat to the armament of the "Constitution," and now proposed to try the effect upon Tripoli of a vigorous bombardment. By the 21st of July, the commodore was able to leave Malta with his fleet, fully prepared for active hostilities. Tripoli was then defended by heavy batteries mounting a hundred and fifteen guns. In the harbor were moored nineteen gunboats, two galleys, two schooners, and a brig. The available force under the command of the Bashaw numbered not less than twenty-five thousand men. It was no pygmy undertaking upon which the Americans had embarked. On the 31st of August, 1804, the first attack was made; and though only a bombardment of the town had been contemplated, there followed one of the most desperate hand-to-hand naval battles recorded in history. It was a sultry midsummer day, and the white walls of the city of Tripoli glared under the fierce rays of a tropical sun. A light breeze stirred the surface of the water, and made life on the ships bearable. Before this breeze the American squadron ran down towards the town. All preparations had been made for a spirited bombardment; and as the Americans drew near the shore, they saw that the Tripolitans had suspected the attack, and had made ready for it.