A journey might be made to the Palisades of the Hudson to observe how that river broke through the great lava intrusion and kept its course to the Atlantic. A pilgrimage to the great lava beds of Washington and Oregon, which cover tens of thousands of square miles to a depth, in some places, of 4,000 feet, would reveal how the Snake River has held to its ancient course in spite of all the efforts of the lava flows to drive it into the camp of some pirate river. In Alaska one might see how Old Vulcan himself threw a huge heatwelded dam across the doughty Yukon at the confluence of the Pelly and note how the gallant river tore down this formidable barrier in its effort to free itself from the lake that held it captive. So, too, we might turn to those mighty avalanches of stone which have ruthlessly flowed down the sides of thousands of mountains and across the paths of rivers, only to be pushed aside by waters that would not accept captivity. Lost rivers and sinking creeks that dot the map of America might also be followed into the ground and watched as they excavate, with silent hands, stupendous caverns in solid limestone and build up magnificent interiors, fit abodes even for Old Pluto himself. Scores of Beaver Dams in the United States could tell us how even busy little animals have played the rôle of Tom Thumb pirates, attacking Lilliputian rivers and imprisoning them in Toyland lakes. MAN AS A PIRATE AGAINST RIVERS Man himself has some piracies against rivers and creeks to answer for. The Chagres might tell how it was led around at his will and forced to carry the ships of the Seven Seas across the narrow backbone of the Western Hemisphere. Strawberry and Gunnison rivers might tell their story of being compelled to abandon their own valleys and to pass through tunnels. in mountains in order that Western deserts might become lands flowing with milk and honey. Even the Tiber and Goose Creek, which once flowed respectively at the base of Capitol Hill and across Pennsylvania Avenue in Washington, D. C., but which are both only a memory now, might tell of man's mastery over many waters. But our wanderings must end. As we bid farewell to our river friends, let us remember that piracy is not their principal activity, but that, as the sculptors of the world's landscapes, the makers of the world's Edens, the forerunners of every civilization, they have made the geography of every continent what it is and have prepared the earth as a habitation for all things that live. Members of the National Geographic Society are again reminded that The Society employs no agents or canvassers to solicit subscriptions to its Magazine or collect the dues of its members. Many individuals have been defrauded recently by unauthorized agents and bogus solicitors. Remittances should be made payable and sent directly to the National Geographic Society at its headquarters in Washington, D. C. GEOGRAPHIC ADMINISTRATION BUILDINGS SIXTEENTH AND M STREETS NORTHWEST, WASHINGTON, D. C. GILBERT GROSVENOR, President HENRY WHITE, Vice-President O. P. AUSTIN, Secretary GEO. W. HUTCHISON, Associate Secretary EDWIN P. GROSVENOR, General Counsel ORGANIZED FOR "THE INCREASE AND DIFFUSION OF GEOGRAPHIC KNOWLEDGE" TO carry out the purposes for which it was founded thirty-eight years ago, the National Geographic Society publishes this Magazine. All receipts are invested in the Magazine itself or expended directly to promote geographic knowledge. use, ARTICLES and photographs are desired. For material which the Magazine can generous remuneration is made. Contributions should be accompanied by an addressed return envelope and postage. IMMEDIATELY after the terrific eruption of the world's largest crater, Mt. Katmai, in Alaska, a National Geographic Society expedition was sent to make observations of this remarkable phenomenon. Four expeditions have followed and the extraordinary scientific data resulting given to the world. In this vicinity an eighth wonder of the world was discovered and explored-"The Valley of Ten Thousand Smokes," a vast area of steaming, spouting fissures. As a result of The Society's discoveries this area has been created a National Monument by proc. lamation of the President of the United States. AT an expense of over $50,000 The Society sent a notable series of expeditions into Peru to investigate the traces of the Inca race. Their discoveries form a large share of our knowledge of a civilization waning when Pizarro first set foot in Peru. THE Society also had the honor of subscribing a substantial sum to the expedition of Admiral Peary, who discovered the North Pole. NOT long ago The Society granted $25,000, and in addition $75.000 was given by individual members to the Government when the congressional appropriation for the purpose was insufficient, and the finest of the giant sequoia trees of California were thereby saved for the American people. THE Society is conducting extensive explorations and excavations in northwestern New Mexico, which was one of the most densely populated areas in North America before Columbus came, a region where prehistoric peoples lived in vast communal dwellings and whose customs, ceremonies, and name have been engulfed in an oblivion. THE Society also is maintaining expeditions in the unknown area adjacent to the San Juan River in southeastern Utah, and in Yunnan, Kweichow, and Kansu, China-all regions virgin to scientific study. Copyright, 1926, by National Geographic Society, Washington, D. C., in the United States and Great Britain. All rights reserved. Entered at the Post Office at Washington, D. C., as Second-Class Mail Matter. Acceptance for mailing at special rate of postage provided for in Sec. 1103, Act of October 3, 1917, authorized July 1, 1918. THE COPYRIGHT. 1926. BY NATIONAL GEOGRAPHIC SOCIETY. WASHINGTON D. C. IN THE UNITED STATES AND GREAT BRITAIN THROUGH THE GREAT RIVER TRENCHES OF ASIA National Geographic Society Explorer Follows the Yangtze, Mekong, and Salwin Through Mighty Gorges, Some of Whose Canyon Walls Tower to a Height of More Than Two Miles BY JOSEPH F. Rock LEADER OF THE NATIONAL GEOGRAPHIC SOCIETY'S YUNNAN PROVINCE EXPEDITION, AUTHOR OF W With Illustrations from Photographs by the Author HERE in all the world is to be found scenery comparable to that which awaits the explorer and photographer in northwestern Yünnan Province, China, and in the mountain fastnesses of Tsarüng, in southeastern Tibet? Few have been privileged to climb the towering ranges separating the mightiest streams of China, if not of Asia. The whole region, so geologists tell us, was once one vast, high plateau, now intersected and eroded by some of the longest rivers in the world. These rivers changed this high plateau not merely into a land of lofty mountains, but of deep valleys with gloomy shadows and forbidding gorges never trodden by human foot. In these trenches the Salwin, Mekong, and Yangtze, cutting through mountain ranges 20,000 feet in height, make their way to the oceans. These three rivers, flowing parallel, north to south, for some distance in western China and southeastern Tibet, at one place come within 48 miles of each other, as the crow flies, and yet their mouths are separated by thousands of miles (see map, page 134). It was this region which I wanted to bring home to America in pictures when I led the National Geographic Society's Yunnan Province Expedition.* THE FIRST PHOTOGRAPHS EVER MADE OF MANY SCENES No white man had previously had a glimpse of many of the scenes here photographed, for the few explorers who have penetrated these terrifying fastnesses have done so when the snow-crowned peaks were hidden from view by the enveloping monsoon clouds of summer. All three of these rivers have their * See "The National Geographic Society's Yünnan Province Expedition," by Gilbert Grosvenor, LL. D., in the NATIONAL GEOGRAPHIC MAGAZINE for April, 1925. WHERE THE GREAT RIVER TRENCHES OF ASIA RUN PARALLEL In Yunnan Province, China, the Yangtze, the Mekong, the Salwin, and the eastern branch of the Irrawaddy flow south for a considerable distance; then each takes its separate way, the Yangtze to enter the Pacific near Shanghai; the Mekong to enter the South China Sea, and the Salwin and Irrawaddy the Indian Ocean (see pages 133-136). origin in the high plateau land of Tibet, but their ultimate sources are still unknown. The Salwin, which flows for a long distance through Tibet proper, enters Yünnan south of Tibet. In its southward course it becomes part of the BurmoSiamese border and finally enters the Indian Ocean at Moulmein, made famous by one of Kipling's poems. The Mekong parallels the Salwin to about the 20th degree of latitude; then turns westward, forming the border of three countries-Burma, Siam, and IndoChina-and finally enters the tropical South China Sea near Saigon. The Yangtze, the mightiest and longest of them all, is also the least consistent. It flows parallel to the Mekong to a point near Shiku, and thence makes a sharp curve, turning directly north; describes a huge loop which adds hundreds of miles. to the length of the river; returns to the south, then turns to the east, becoming in part a boundary for the provinces of Yünnan and Szechwan, and at length bends to the northeast and enters the Pacific Ocean near Shanghai. Of these rivers, the Salwin is the least known; it is navigable for only a short distance above its mouth. The Yangtze, on the other hand, is navigable for a distance of some 1,500 miles, to Chungking, and thence by small boats as far as Suifu. Beyond that rowboats ply as far as Machang, in eastern Yünnan. In the north, near Batang, it is navigable by skin boats or coracles, but only for short distances. Extensive stretches of this river, which is more than 3,000 miles long, are unknown and parts of its course appear on accurate maps as dotted lines. Much has been written about the Yangtze gorges in the vicinity of Ichang, so |