BETWEEN the desert plain of the Punjab, fertilized only by such irrigation as is allowed by the volume of water of the great “Five Rivers’ which cross it and give it its name, and the vast stretches of sandy desert, burnt and and, which fall away towards Central Asia, rises a gigantic bastion of mountains, the greatest on Earth. They are not always real mountains, however: the vast extent of this mighty mass thrown up from the Earth’s surface consists rather of plateaux than of mountains—an immense altar, rising almost everywhere to more than 16,000 feet, wide and open, as though stretching towards heaven, from the Pamirs to Tibet, the real roof of the world. But the plateau rises at its outer edges, as though to emphasize the contrast with the wide lowlands which lie at its feet. It rises, along its northern edge, in the range of Kunlun; even higher, along its southern edge, in the range of the Himalaya, so that the latter, for a great part of its extent, forms not so much a real chain of mountains, as merely the highest point of the southern flank, deeply broken with valleys, of the immense Tibetan plateaux. About half-way along the southern edge of the Tibetan plateaux opens out the wide mirror of the sacred Lake Manasarowar, where storms are not unknown, and round which long processions of faithful Buddhists, intoning the short but eternal prayer of their faith, accomplish their pilgrimages. From here the Brahmaputra towards the East, the Indus towards the West, run close and parallel to the outer edge of the great zone of plateaux—at first calm and slow-moving through elevated, wide, rolling plains, then steadily more and more swollen and impetuous as their course plunges more deeply into the mass of mountains, cutting valleys of rough, wild grandeur. It is only here that the Himalaya no 2longer forms the outer edge of the plateaux, but becomes a majestic chain of mountains, embracing in their wide semicircle the whole of India, with its seething humanity and boiling passions. Where, towards the West, the chain of mountains is bounded by the deep channel of the Indus, beyond this river another gigantic range lifts its crests and peaks, rough-hewn from rock and ice: this is the Karakoram, which, as it were, forms a link between the Tibetan plateaux and those of the Pamirs. It is the upper valley of the Indus, with all its tributaries, shut in between the opposing flanks of the Himalaya and the Karakoram, which constitutes Western Tibet. Farther to the East open out suddenly the immense stretches of Great Tibet, naked and desolate, uninhabited for whole months of travelling, until one reaches the region where villages and little towns are assembled round Lhasa, the sacred, forbidden city.