With light breezes, we came, on the following day, in sight of the island of Ustica. Sea-gulls (_Thalassidroma pelagica_) enlivened the scene, as they, from time to time, flew after the garbage thrown from the ship, or sought for sea-nettles and other small inhabitants of the sea's surface. These birds much resemble our land swallows, and their movements are so graceful, that one cannot but admire them, especially when they lightly touch the agitated water with their little webbed feet, and directly, as if repelled, withdraw. The muscular power of these feathered creatures is truly wonderful; they follow the ship for entire days continually on the wing, ever on the watch to snatch at the little food which the sea seems but scantily to supply to them. [Illustration: "PALINURUS".] Whilst we were passing down the Mediterranean, a great deal of time was employed in drawing up regulations, and in digesting all those instructions which had reached the Commander of the Expedition from all sides, and by which we were to be guided in our future proceedings. The scientific gentlemen were the first who received certain rules for their guidance; for, life on board a ship, and especially of a man-of-war, is so entirely different from that on shore,--the etiquette and usages practised appear, to those unused to the sea, so vexatious and annoying, that it was absolutely necessary to inform them of the regulations which are essential in order to keep so singular an organization as that of a ship at sea in working order. Erelong every one perceived, that the matutinal annoyance of holystoning the decks, the daily cleaning of everything on board, &c., are measures of importance, which contribute materially to the preservation of the health of the crew, and that a strict observance of discipline is absolutely necessary to exercise their powers, and thus to fit them for all eventualities. For the better accommodation of the naturalists, a place on the lower gun-deck was fitted up for those operations which, on account of the limited space and noxious exhalations, could not well be performed in the cabins. We had a large quantity of alcohol on board, destined for the preservation of interesting objects of natural history. In order to prevent any calamity by fire arising therefrom, the whole quantity was put in a large iron tank placed in the hold, and covered over with sand. It will, however, be seen in the sequel, that even this precaution proved insufficient to protect the ship from the ignition of this highly-combustible substance.