Between the river Indus and the plains of north-west India is interposed a mountain tract which has a breadth of about 150 miles in linear distance. This tract is everywhere (with one exception) extremely rugged and mountainous, nor is it at all an easy task to convey an idea of the extreme complication of the ramifications of the numerous ranges of which it consists. No wide plain (Kashmir alone excepted) is interposed between these ranges, so that the only feasible mode of division which appears to be applicable to them is afforded by the course of the different rivers which traverse them in various directions. If these be taken as a guide, the mountains will be found to resolve themselves into two great systems connected to the eastward, but otherwise independent of, though nearly parallel to, one another.
From the sources of the west branch of the Chenab or Chandrabhaga river, a range of very great elevation runs in a north-west direction as far as Kashmir, and, after reaching the north-east corner of that valley, assumes a more westerly direction so as to encircle the whole of its north side, bending at the same time gradually towards the south. This chain forms the line of separation between the waters of the Indus and those of the Chenab and Jelam. To the eastward of the Baralacha Pass it ramifies to a considerable extent, its different branches including between them several depressions quite unconnected with the general drainage of the country, and surrounded on all sides by ranges of hills which prevent any exit of their waters. The principal of these depressions is that of lake Chumoreri; another is occupied by the little salt lake first visited by Trebeck, and called by him Thogji[30].
SALT LAKES.
All these depressions, though at present unconnected with any of the river systems, have evidently at some former period been so. Chumoreri, as I am informed by Major Cunningham, is even now very slightly saline, though scarcely perceptibly so to the taste. It has evidently had an outlet at its southern extremity, where it is only separated from the valley of the Parang river by a very low range of hills which was crossed in 1846 by Mr. Agnew, and more recently by Captain H. Strachey. The outlet of the little salt lake of Thogji has evidently been near its north end, and its waters, previous to the change in the state of the country which interrupted their exit, in all probability flowed into that tributary of the Zanskar river which runs to the eastward of the Lachalang pass, and which is marked in the map accompanying Moorcroft's Travels as the Sumghiel. Major Cunningham, who travelled in 1846 by the same route as that previously followed by Moorcroft, informs me that no obstacle intervenes to prevent the waters of the lake taking that direction in case of their being raised in the lake itself to a height of two or three hundred feet above their present level.
If we consider the basins of these two lakes to be referable to the systems of drainage to which they appear to have formerly belonged, though now separated from them by accidental alterations of level, the course of the mountain chain which I am endeavouring to trace must be considered to run between the two. This is in fact the position of the loftiest part of the chain, which, skirting the north and east sides of Chumoreri, is thence continued in a south-east direction, forming that lofty but little-known range which separates the valley of the Sutlej from that of the Indus. This chain was crossed by Moorcroft on his visit to Garu, and appears to extend uninterruptedly as far as Kailas to the north of lake Manasarawar.
The mountain chain which lies to the south of the river Sutlej may also be considered to have its origin in the lofty country adjoining the lakes, but a little to the south and east of them. This chain, which separates the valley of the Sutlej from that of the Ganges and its tributaries (including the Jumna), sinks at last into the plains of India a little to the south of the town of Nahan.
CIS-SUTLEJ HIMALAYA.
The course of this chain has been admirably described by Captain Herbert in his Geological Report of the Himalaya[31], a paper which contains exceedingly accurate general views of the mountains between the Sutlej and Jumna. He was quite unacquainted with the details of the mountains north of the former river, and therefore could not form any idea of their arrangement. Captain Herbert calls the chain south of the Sutlej the Indo-Gangetic chain, a very inappropriate name, for which, however, it is difficult to substitute a better. Perhaps the name of Cis-Sutlej Himalaya, though not exactly classical, is the best that can be devised, and if so, the chain which, commencing in Kailas, separates the waters of the Sutlej from those of the Indus, may not improperly be designated the Trans-Sutlej Himalaya[32].
To these two great chains the whole of the mountains between the Indus and the plains may be referred. Both are of very great elevation, in the eastern half of their course more especially, but that north of the Sutlej is much less covered with snow than the other. This is owing to the moisture-bringing winds, which are entirely derived from the Indian side, being stopped by the chain to the south; and in fact, as soon as the elevation of the latter is so far diminished that it ceases to be covered with perpetual snow, the more northerly chain, without any increase of elevation, becomes much more snowy, so as to merit the appellation of great snowy range, a term which, more to the eastward, is applied to the mountains south of the Sutlej. As several of the principal ramifications of the northern chain attain an elevation not at all inferior to that of the axis from which they are derived, they produce a similar effect upon the climate of the ranges to the north of them, being themselves covered with vast masses of snow, while the mountains which they shelter are in a great measure bare.
KOUENLUN.