As you approach the Isthmus of Suez--which will soon be annihilated, so to speak, by M. de Lesseps' great ship-canal--the desert resumes the character which we have seen it bear in Persia and Central Arabia. The rocks, much rarer and less lofty, gradually give place to mountains of sand. Salt lakes and fields of salt re-appear. Near the shores of the Mediterranean lies a pool of salt, still known by that name of Lake Baudouin (Baldwin), which the Crusaders imposed upon it. There the salt forms a firm and tenacious crust, on which the camel safely plants its foot. Sometimes the iron hoof of a horse breaks through, but beneath this first frail stratum it meets with another of astonishing hardness. "You might think yourself," says a traveller, "on the Mer de Glace of Mont Blanc. Our camel-drivers collected some large pieces from the surface. Nothing can be more brilliant or more transparent than these crystals. It is by tasting them only that you can distinguish them from rock crystal. As we advance, the impression grows overpowering. A plain of dazzling whiteness surrounds us, and is prolonged far beyond our ken. Dimly on the left may be perceived, like an indigo-coloured ribbon, the line of the distant sea. The sky itself appears jet black. The reverberation of sound is unendurable." Still further, between Suez and Cairo, the same traveller speaks admiringly of a natural amphitheatre, enclosed between two mountain-spurs, and strewn with _débris_ of rock, and especially with petrified wood. It might be compared to a forest-clearing which the woodmen had just quitted. The splinters are quite fresh, the cloven fragments still expose the notches made by the axe. Great trees, divided into beams, resemble long serpents which have been slain by blows from a hatchet. The division is so clear that each gash reveals the concentric tissues perfectly preserved by this mineral embalming, this natural silification. Similar petrifactions may be seen in abundance on the plateaux of the Makattam, and the amphitheatre now described is not far from the hill, visited by every tourist, which has received the name of the Petrified Forest. Thus it appears that the Land Deserts, despite the proverbial monotony of their aspect, do not fail to offer to the artist as well as the savant, the philosopher no less than the historian, objects worthy of patient study. Everywhere the handiwork of God and the evidences of Almighty design awaken the admiration of the thoughtful. Whether the picture be sombre or beautiful, grand or appalling, we see that it was conceived and filled up by superhuman power. But we are now in Egypt, on the threshold of the world's vast deserts. Egypt, kept alive by the fertilizing and genial Nile, is but an island in the great ocean of sand which encircles it, and which, far more truly than the Red Sea or the Mediterranean, isolates it from the rest of the globe. CHAPTER III. THE NUBIAN DESERT--THE GREAT SAHARA--DESERTS OF AFRICA.