The Bay of Naples, painted and sung forever, but never adequately, must consent to be here described as essentially a parallelogram, with an opening towards the southwest. The northeast side of this, with Naples in the right-hand corner, looking seaward and Castellamare in the left-hand corner, at a distance of some fourteen miles, is a vast rich plain, fringed on the shore with towns, and covered with white houses and gardens. Out of this rises the isolated bulk of Vesuvius. This growing mountain is manufactured exactly like an ant-hill. The northwest side of the bay, keeping a general westerly direction, is very uneven, with headlands, deep bays, and outlying islands. First comes the promontory of Posilipo, pierced by two tunnels, partly natural and partly Greek and Roman work, above the entrance of one of which is the tomb of Virgil, let us believe; then a beautiful bay, the shore of which is incrusted with classic ruins. On this bay stands Pozzuoli, the ancient Puteoli where St. Paul landed one May day, and doubtless walked up this paved road, which leads direct to Rome. At the entrance, near the head of Posilipo, is the volcanic island of "shining Nisida," to which Brutus retired after the assassination of Caesar, and where he bade Portia good-by before he departed for Greece and Philippi: the favorite villa of Cicero, where he wrote many of his letters to Atticus, looked on it. Baiae, epitome of the luxury and profligacy, of the splendor and crime of the most sensual years of the Roman empire, spread there its temples, palaces, and pleasure-gardens, which crowded the low slopes, and extended over the water; and yonder is Cape Misenum, which sheltered the great fleets of Rome. This region, which is still shaky from fires bubbling under the thin crust, through which here and there the sulphurous vapor breaks out, is one of the most sacred in the ancient world. Here are the Lucrine Lake, the Elysian Fields, the cave of the Cumean Sibyl, and the Lake Avernus. This entrance to the infernal regions was frozen over the day I saw it; so that the profane prophecy of skating on the bottomless pit might have been realized. The islands of Procida and Ischia continue and complete this side of the bay, which is about twenty miles long as the boat sails.