After arranging the difficulty with Morocco, Preble made a formal declaration of the blockade of Tripoli, before which town he believed that the Philadelphia and Vixen were then cruising; though, unknown to him, the latter had been temporarily detached, and the Philadelphia was in possession of the enemy. From this time until the succeeding spring, the Nautilus was employed in convoying, or in carrying orders necessary to the preparations that were making for the coming season; but in March she formed a part of the blockading force in front of Tripoli. In consequence of the captivity of Capt. Bainbridge, Lieut. Com. Stewart was the officer second in rank in the squadron, and he was consequently kept much upon the coast in command, while Preble was carrying on the negotiations by means of which he obtained the gunboats and other supplies necessary to the attacks he contemplated. In March, 1804, while the Siren and Nautilus were alone maintaining the blockade, the two vessels had been driven to the eastward of their port by a gale, and early in the morning, while returning, they made a warlike looking brig lying to off the place, with which she was evidently in communication. Signal was made to the Nautilus to stand close in, and watch the gunboats, while the Siren ran alongside of the stranger, who was captured for a violation of the blockade. The prize proved to be a privateer called the Transfer, with an English commission. She carried 16 guns and 80 men, and hailed from Malta, but, in fact, belonged to the Bashaw of Tripoli; her papers having been obtained through the Tripolitan consul in Malta, who was a native of that island. This vessel was appraised, equipped by the squadron, and used in the war, having had her name changed to the Scourge. Owing to certain scruples of Mr. Jefferson on the subject of blockades, the vessel was not condemned until the war of 1812, nor were the captors paid their prize money until Somers had been dead nearly eleven years. Between the time of the capture of the Transfer and the month of July, the Nautilus was much employed by the commodore, going below and visiting different ports in Sicily. On the 20th of that month, Somers sailed from Malta, in company with the Constitution, the Enterprise, two bomb ketches and six gunboats that had been obtained from the Neapolitans, bound off Tripoli. On the arrival of the commodore, his whole force was collected, and that series of short but brilliant operations commenced, which has rendered the service of this season so remarkable in the history of the American navy.