"Occasionally these icebergs approach each other so as to conceal the land entirely, and we only perceive two walls of threatening ice, whose sonorous echoes send back the word of command of the officers. The corvette which followed the _Astrolabe_ appeared so small, and its masts so slender, that the ship's crew were seized with terror. For nearly an hour we only saw vertical walls of ice." Ultimately they reached a vast basin, formed on one side by the chain of floating islands which they had traversed, and on the other by high land rising three and four thousand feet, rugged and undulating on the surface, but clothed over all with an icy mantle, which was rendered dazzlingly imposing in its whiteness by the rays of the sun. The officers could only advance by the ship's boats through a labyrinth of icebergs up to a little islet lying opposite to the coast. They touched the land at this islet; the French flag was planted, possession was taken of the new continent, and, in proof of possession, some portions of rock were torn from the scarped and denuded cliffs. These rocks are composed of quartzite and gneiss. The southern continent, therefore, belongs to the primitive formation, while the northern region belongs in great part to the transition, or coal formation. According to the map of Adelia's Land, traced by D'Urville over an extent of thirty leagues of country, the region is one of death and desolation, without any trace of vegetation. A little more to the north, the French navigator had a vague vision on the white lines of the horizon of another land, which he named _Côte Clarie_, or Coast Clear, the existence of which was soon confirmed by the American expedition under Commodore Wilkes. This officer has explored the southern land on a larger scale than any other navigator, but he suffered himself to be led into error by the dense fogs of the region, and has laid down coast lines on his map where Sir James Boss subsequently found only open sea--an error which has very unjustly thrown discredit on the whole expedition.