KUEN-LUN, or KOUEN-LUN, the name given to the mountains between western Tibet and the plains of eastern Turkestan; it is derived from the Chinese geographers, and is probably a corruption of some Turkish or Tibetan word; it appears to be unknown locally. The name hav-ing been adopted, chiefly on the initiative of Humboldt, before any correct geographical knowledge had been obtained of the region to which it was applied, it has been used with inconvenient want of precision, and this has encouraged erroneous conceptions. Little precise informa-tion is yet available on the subject, but there is no reason to doubt that, within the limits to which actual exploration has gone, the mountains designated as Kuen-lun form the northern border of the high lands of Tibet, descending to the central Asian plain, just as those commonly spoken of under the name of Himalaya constitute the broad moun-tainous slope which descends to the lower levels of India.
Nothing can be said with confidence of the northern border of Tibet east of 82° E. long., but from this point westward, to about the 75th meridian, it consists of a series of mountain ranges on a scale of magnitude quite analogous to that of the higher ranges of the Himalaya, and beyond the last-named meridian merges into the Thian-Shan moun-tains. A line of demarcation between the summit of the Tibetan plateau and its northern flank can, in the present condition of our knowledge, only be fixed in an arbitrary manner, and it may for convenience be regarded as follow-ing the watershed line from which the streams flow north-ward to the plain of eastern Turkestan. Using the name Kuen-lun in the sense thus explained, the zone it includes will be seen to abut at its north-western extremity on the series of elevated plateaus known under the name of Pamir, which extend over a distance of nearly 200 miles to a little beyond 39° N. lat. Here the width of the zone is about 100 miles. To the eastward it becomes broader, and on the 79th meridian is nearly 150 miles across. In this region the chief ranges appear to be laid out, generally, in a north-west and south-east direction, like those of western Tibet, with transverse ridges at irregular intervals. The transverse direction would seem to predominate in the outer portion of the zone nearest to the plain of Turkestan, but the geographical details are too little known to permit us to say more on this point. Of the longitudinal ranges two are of conspicuous magnitude, running approximately parallel to one another about 60 or 70 miles apart; the more northern or outer may be spoken of as the main Kuen-lun ; the other, which separates the waters of the Indus, which run off to the south-west, from those of the streams which pass down to the plains of Khotan, Yarkand, and Kashgar, constitutes the watershed before referred to, and has been called the Muztagh or Karakorum range from two of the best known passes across it. The latter of these great lines of elevation, from which the Kuen-lun slope of the Tibetan plateau may be said to commence, is of very considerable altitude throughout, its summits rising more than 28,000 feet above sea-level, and few of the passes falling below 18,000 or even 19,000 feet over a length of some 400 miles. Its flanks are covered with enormous glaciers, some of them being continuous for distances of 60 or 70 miles. The main Kuen-lun is not much inferior in magnitude, one of its peaks rising above 25,000 feet, while the points between that elevation and 20,000 feet are numerous. The passes lie between 18,000 feet on the east and 13,000 feet on the west. The valleys between these ranges vary in elevation from about 15,000 feet to 10,000 feet, the drainage in some cases collecting in small lakes, in others forming streams which, after flowing for some distance parallel to the separating ridges, suddenly change their direction and run off to the north-east through deep transverse lines of rupture, in a manner analogous to that observed on the border of the Himalayan mountain slope.
The whole of the region is described as remarkable for its general barren character. The mountain sides are naked and the valleys for the most part narrow and steep. There is a complete absence of forest, and trees of any sort are only found at the lower levels bordering on the northern plain,walnuts, poplars, and willows alone being mentioned, besides a few fruit trees. The vegetation is scanty and botanically poor, brushwood being found along some of the rivers, and pastures in the bottoms of the deep valleys among the higher ranges. Among the shrubs are species common in Tibet, such as tamarisk, juniper, astragalus, willow, rose, barberry, and clematis. The animal life also appears to be mainly that found in the neighbouring parts of Tibet.
Some facts of interest relating to the geological structure of these mountains may be gathered from the fragmentary reports of Dr Stoliczka, the accomplished geologist who so prematurely died from the results of exposure in these inhospitable regions. The summit of the Karakorum Pass is of Triassic age, and cretaceous beds are found in some of the ranges on the north of the Kuen-lun main range, associated with Palteozoic deposits supposed to be Carboni-ferous and Silurian. For the greater portion of the year the climate is very rigorous. The extremes of temperature are great, and the rainfall little.
The population is small. The fixed settlements are confined to the outer valleys ; few villages or hamlets are found above 6000 feet of altitude, and hardly any over 8000 feet. The upper valleys are occupied by a nomadic population, wholly pastoral in their habits.
The tract may be regarded as appertaining politically to the sove-reigns for the time being of the principalities lying in the plain below it. But from the nature of the case any recognized authority hardly extends beyond the permanently inhabited region. (R. S.)
For information as to the geographical details which have been collected reference may be made to the map published in the Royal Geog. Soc. Journal, vol. xlviii., accompanying Captain Trotter's ac-count of the results of Sir T. D. Forsyth's mission to Kashghar.