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.

The Nautilus then approached the African shore, where the depth of the sea was greater. There, between two waters clear as crystal, through the open panels we were allowed to contemplate the beautiful bushes of brilliant coral and large blocks of rock clothed with a splendid fur of green variety of sites and landscapes along these sandbanks and algæ and fuci. What an indescribable spectacle, and what variety of sites and landscapes along these sandbanks and volcanic islands which bound the Libyan coast! But where these shrubs appeared in all their beauty was on the eastern coast, which the Nautilus soon gained. It was on the coast of Tehama, for there not only did this display of zoophytes flourish beneath the level of the sea, but they also formed picturesque interlacings which unfolded themselves about sixty feet above the surface, more capricious but less highly coloured than those whose freshness was kept up by the vital power of the waters.

What charming hours I passed thus at the window of the saloon! What new specimens of submarine flora and fauna did I admire under the brightness of our electric lantern!

The 9th of February the Nautilus floated in the broadest part of the Red Sea, which is comprised between Souakin, on the west coast, and Komfidah, on the east coast, with a diameter of ninety miles.