Page:Encyclopædia Britannica, Ninth Edition, v. 11.djvu/866

Rh 826 river-beds in a very few miles are found to be at an altitude of 9000 or 10,000 feet, indicating that the sudden increase to the height -of the mountains along this line is not con fined to the peaks alone, but consists of a general elevation of the whole surface. Having once crossed the line of great peaks, the inclination of the valleys again becomes much less, and they thus continue for some miles, those that are fed from the larger glaciers frequently emerging from the ice at a level no more than 12,000 feet above the sea in the western mountains, 1000 or 2000 feet higher on the east. Their The slope of the larger Himalayan rivers may be esti- slope. mated to range from 20 feet per mile near the plains to between 100 and 200 feet per mile where they approach the snowy mountains. In their passage through these the inclination increases to as much as 700 or 800 feet in the mile, but to the north it is again reduced to 1 50 or 200 feet. Like all Indian rivers, they vary greatly in volume at different seasons of the year, and among the higher mountains are liable to special fluctuations from the more or less rapid melting of the snow from which they are fed. In the summer their waters increase and decrease with the varying temperature of the day or power of the sun, and in the winter they contract to a small fraction of their summer volume as the permanent frosts set in. In the lower parts of their courses the rivers commonly present an alternation of sparkling rapids with long reaches of deep, clear, tranquil water, in which the action of the current is often hardly visible ; as we ascend, the rapids become by degrees more frequent and more impetuous, till in passing among the snowy mountains we find only the most furious torrents, pouring their turbid glacier waters over boulders of gigantic dimensions among which they are at times almost lost to view, and filling the valleys with their incessant roar. The valleys of Kashmir and Kathmandu, by their exceptionally large extent and comparatively level char- acter, offer such remarkable deviations from the normal characters of Himalayan valleys as to require some com ment. But the differences are after all rather in degree than in kind, and it would not be difficult to find somewhat similar areas, though on a much smaller scale of develop ment. In Kashmir, too, is found one of the very few lakes which occur in the Himalaya. The almost complete absence of such collections of water is among the circum stances which serve to give a special character to the scenery of the Himalaya, and to distinguish it from that of European mountains. On crossing the Indian watershed into Tibet, the general character of the country completely changes. The summit of the table-land, though deeply corrugated with valleys and mountains in detail, is in its general relief laid out horizontally at a mean height little inferior to that of the watershed itself. The valleys of central Tibet are commonly long, flat, and open, of no great breadth, perhaps 1 to 3 miles, with a bottom of alluvial soil laid out nearly horizontally, from which the mountains rise abruptly on either side. The plateau of Guge, immediately to the north of Kumaon, Kash ad Tabl la. n(1 l TIlMAEAYAN SlOPl- InJiin Turkish Water- Sh TIBETAN TAJJI.E-XA2STD KOB.THERN SLOPE Switzerland Italy Bernese Itennrue Scale of Miles FIG. 1. Sections of the Alps and of the Himalaya on the same scale. the average elevation of which is not less than 15,500 feet above the sea, and at the extremity of which lie the two lakes of Rakas-tal and Manasarowar, the waters of which are also nearly at that level, is a remarkable expansion of the ordinary Tibetan valley, and calls for special notice. It varies in breadth from 15 to 60 miles, and its extreme length is 120 miles, lying along the upper course of the Sutlej, which runs through it at the bottom of a stupendous ravine furrowed out of the alluvial matter of which the plateau is formed, to a depth of 2000 or 3000 feet. Into this run, across the western part of the plain, numerous other similar ravines in every gradation of size, often for miles together as even and straight as a railway cutting; and so extraordinary is their magnitude in some cases that, in his account of a journey across the plateau, Moorcroft, a traveller of great accuracy in general, describes these slopes as those of mountains. The main valleys are everywhere remarkable for their gentle slope, and in ths central parts of the table-land the inclination at length frequently becomes so small as to give rise to the accumulation of the drainage in lakes, invariably salt when there is no efflux, and as invariably fresh when there is. The upper Indus has a slope as little as 3 feet per mile. Further to the west, as it approaches its great bend to the south, the inclination becomes greater, aver aging about 24 feet per mile, and the width of its valley floor is reduced. It descends to a level of little above 4000 feet before it finally leaves Tibet. It may aid in conveying a clear conception of the Com- magnitude of these Himalayan masses, to compare them pans with the Swiss Alps, which will be familiar to many English of H readers. The above diagram represents on the same Jj * scale sections of the Alps and of the Himalaya, the curved line from which the latter are shown to rise repre senting the curvature of the earth. The Alps, measured across from the Lake of Thun to the plains of Lombardy, have a width of about 75 miles, the Tibeto-Himalayan mountains on a line drawn through Simla being about 400 miles across. To complete the comparison a few further explanations may be offered. The range that has* already been noticed as the Dhaola-dhdr, which rises from the Kangra dun, if measured in breadth from Kangra to the upper Ravi, and in length between that river and the Byas in Kullu, is about equal to the whole of the Bernese Alps comprised between Altdorf and Martigny in length, and laterally between lines drawn along the Rhone and Reuss on one side, and through the Lakes of Lucerne and Thun to the Lake of Geneva at Vevay on the other. The area covered. in both cases is rather less than 100 miles in length by 20 or 25 in breadth, the highest peaks being in the Alps the Finsteraarhorn, 14,100 feet, and in the Dhaola-dhar a point 17,100 feet above the sea. The prolongation of the Himalayan ridge just spoken of, which bounds Kashmir en the south, known as the Pir-panjal, would in like manner compare with the Pennine Alps and their continuation as far as St Gothard. Here the peak