In quitting this sea we sighted Muscat for an instant, one of the most important towns of the country of Oman. I admired its strange aspect, surrounded by black rocks upon which its white houses and forts stood in relief. I saw the rounded domes of its mosques, the elegant points of its minarets, its fresh and verdant terraces. But it was only a vision! The _Nautilus_ soon sank under the waves of that part of the sea. We passed along the Arabian coast of Mahrah and Hadramaut, for a distance of six miles, its undulating line of mountains being occasionally relieved by some ancient ruin. The 5th of February we at last entered the Gulf of Aden, a perfect funnel introduced into the neck of Bab-el-mandeb, through which the Indian waters entered the Red Sea. The 6th of February, the _Nautilus_ floated in sight of Aden, perched upon a promontory which a narrow isthmus joins to the mainland, a kind of inaccessible Gibraltar, the fortifications of which were rebuilt by the English after taking possession in 1839. I caught a glimpse of the octagon minarets of this town, which was at one time the richest commercial magazine on the coast. I certainly thought that Captain Nemo, arrived at this point, would back out again; but I was mistaken, for he did no such thing, much to my surprise. The next day, the 7th of February, we entered the Straits of Bab-el-mandeb, the name of which, in the Arab tongue, means The Gate of Tears. To twenty miles in breadth, it is only thirty-two in length. And for the _Nautilus_, starting at full speed, the crossing was scarcely the work of an hour. But I saw nothing, not even the Island of Perim, with which the British Government has fortified the position of Aden. There were too many English or French steamers of the line of Suez to Bombay, Calcutta to Melbourne, and from Bourbon to the Mauritius, furrowing this narrow passage, for the _Nautilus_ to venture to show itself. So it remained prudently below. At last about noon, we were in the waters of the Red Sea. I would not even seek to understand the caprice which had decided Captain Nemo upon entering the gulf. But I quite approved of the _Nautilus_ entering it. Its speed was lessened: sometimes it kept on the surface, sometimes it dived to avoid a vessel, and thus I was able to observe the upper and lower parts of this curious sea. The 8th of February, from the first dawn of day, Mocha came in sight, now a ruined town, whose walls would fall at a gunshot, yet which shelters here and there some verdant date-trees; once an important city, containing six public markets, and twenty-six mosques, and whose walls, defended by fourteen forts, formed a girdle of two miles in circumference.