2. The mountain system of the Thian-schan, or Celestial Mountains, the Tengri-tagh of the Turks (Tukiu) and of the kindred race of the Hiongnu, is eight times as long, in an east and west direction, as the Pyrenees. Beyond,—i. e. west of its intersection with the transverse or north and south chain of the Bolor and Kosuyrt, the Thian-schan bears the names of Asferah and Aktagh, is rich in metals, and has open fissures, which emit hot vapours, luminous at night, and which are used for obtaining sal-ammoniac. (Asie Centrale, T. ii. p. 18–20.) East of the transverse Bolor and Kosyurt chain, there follow successively in the Thian-schan,—the Kashgar Pass (Kaschgar-dawan); the Glacier Pass of Djeparle, which leads to Kutch and Aksu in the Tarim basin; the volcano of Pe-schan, which sent forth fire and streams of lava at least as late as the middle of the seventh century; the great snow-covered massive elevation Bogdo-Oola; the Sol-fatara of Urumsti, which furnishes sulphur and sal-ammoniac (nao-scha), and is situated in a coal district; the still active volcano of Turfan (or volcano of Ho-tscheu or Bischbalik), almost midway between the meridians of Turfan (Kune-Turpan), and of Pidjan. The volcanic eruptions of the Thian-schan chain, recorded by Chinese historians, reach as far back as the year 89, A.D., when the Hiongnu of the sources of the Irtysh were pursued by the Chinese army as far as Kutch and Kharaschar (Klaproth, Tableau hist. de l’Asie, p. 108). The Chinese General, Teu-hian, surmounted the Thian-schan, and saw “the Fire Mountains which send out masses of molten rock that flow for many Li.”
The great distance from the sea of the volcanoes of the interior of Asia is a remarkable and solitary phenomenon. Abel Rémusat, in a letter to Cordier (Annales des Mines, T. v. 1820, p. 137), first directed the attention of geologists to this fact. The distance, for example, in the case of the volcano of Pe-schan, to the north, or to the Icy Sea at the mouth of the Obi, is 1528 geographical miles; to the south, or to the mouths of the Indus and the Ganges, 1512 geographical miles; to the west, 1360 geographical miles to the Caspian in the Gulf of Karaboghaz; and to the east, 1020 geographical miles to the shores of the sea of Aral. The active volcanoes of the New World were previously supposed to offer the most remarkable instances of such phenomena at a great distance from the sea; their distance, however, is only 132 geographical miles in the case of the volcano of Popocatepetl in Mexico, and only 92, 104, and 156 geographical miles in those of the South American volcanoes Sangai, Tolima, and de la Fragua, respectively. I exclude from these statements all extinct volcanoes, and all trachytic mountains which have no permanent connection with the interior of the earth. (Asie Centrale, T. ii. p. 16–55, 69–77, and 341–356.) East of the volcano of Turfan, and of the fertile Oasis of Hami rich in fine fruit, the chain of the Thian-schan gives place to the great elevated tract of Gobi which follows a S.W. and N.E. direction. This interruption of the mountain chain, caused by the transverse intersection of the Gobi, continues for more than 9½ degrees of longitude; but beyond it the mountains recommence in the somewhat more southerly chain of the In-schan, or the Silver Mountains, running (north of the Pe-tscheli) from west to east almost to the shores of the Pacific near Pekin, and forming a continuation of the Thian-schan. As I have viewed the In-schan as an easterly prolongation (beyond the interruption of the Gobi) of the cleft above which the Thian-schan stands, so one might possibly view the Caucasus as a westerly prolongation of the same, beyond the great basin of the Aral and Caspian Seas or the depression of Turan. The mean parallel of latitude or axis of elevation of the Thian-schan oscillates between 40⅔° and 43° N. lat.; that of the Caucasus, according to the map of the Russian Etat-Major (running rather E.S.E. and W.N.W.), is between 41° and 44° N. lat. (Baron von Meyendorff, in the Bulletin de la Societé géologique de France, T. ix. 1837–1838, p. 230.) Of the four parallel chains which traverse Asia from east to west, the Thian-schan is the only one in which no summits have yet had their elevation above the sea determined by measurement.
3. The mountain system of the Kuen-lün (Kurkun or Kulkun), if we include in it the Hindu-Coosh and its western prolongation in the Persian Elbourz and Demavend, is, next to the American Cordillera of the Andes, the longest line of elevation on the surface of our planet. Where the north-and-south chain of Bolor intersects the Kuen-lün at right angles, the latter takes the name of the Thsung-ling (Onion Mountains), which is also given to a part of the Bolor at the eastern angle of intersection. The Kuen-lün, forming the northern boundary of Thibet, runs very regularly in an east and west direction, in the latitude of 36°. In the meridian of H’lassa an interruption takes place from the great mountain knot which surrounds the alpine lake of Khuku-noor, the Sing-so-hai, or Starry Sea, so celebrated in the mythical geography of the Chinese. The somewhat more northerly chains of Nan-schan and Kilian-schan may almost be regarded as an easterly prolongation of the Thian-schan. They extend to the Chinese wall near Liang-tscheu. West of the intersection of the Bolor and Kuen-lün (the Thsung-ling) I think I have been the first to shew (Asie Centrale, T. i. p. 23, and 118–159; T. ii. p. 431–434 and 465) that the corresponding direction of the axes of the Kuen-lün and the Hindu-Coosh (both being east and west, whereas the Himalaya is south-east and north-west) makes it reasonable to regard the Hindu-Coosh as a continuation, not of the Himalaya, but of the Kuen-lün. From the Taurus in Lycia to Kafiristan, through an extent of 45 degrees of longitude, this chain follows the parallel of Rhodes, or the diaphragm of Dicearchus. The grand geognostical view of Eratosthenes (Strabo, Lib. ii. p. 68; Lib. xi. p. 490 and 511; and Lib. xv. p. 689), which is farther developed by Marinus of Tyre, and Ptolemy, and according to which “the continuation of the Taurus in Lycia extends across the whole of Asia to India, in one and the same direction,” appears to have been partly founded on statements which reached the Persians and Indians from the Punjaub. “The Brahmins affirm,” says Cosmas Indicopleustes, in his Christian Topography, (Mountfauçon, Collectio nova Patrum, T. ii. p. 137) “that a line drawn from Tzinitza (Thinæ) across Persia and Romania, exactly cuts the middle of the inhabited earth.” It is deserving of notice that Eratosthenes had so early remarked that this longest axis of elevation in the Old Continent, in the parallels of 35½° and 36°, points directly through the basin (or depression) of the Mediterranean to the Pillars of Hercules. (Compare Asie Centrale, T. i. p. 23 and 122–138; T. ii. p. 430–434, with Kosmos, Bd. ii. S. 222 and 438, p. 188, and note 292, Engl. ed.) The easternmost part of the Hindu-Coosh is the Paropanisus of the ancients, the Indian Caucasus of the companions of Alexander. The now generally used term of Hindu-Coosh, belongs, as may be seen from the Travels of the Arab Ibn Batuta (English version, p. 97), to a single mountain pass on which many Indian slaves often perished from cold. The Kuen-lün, like the Thian-schan, shews igneous outbreaks or eruptions at many hundred miles from the sea. Flames, visible at a great distance, issue from a cavity in the Schin-khieu Mountain. (Asie Centrale, T. ii. p. 427 and 483, where I have followed the text of Yuen-thong-ki, translated by my friend Stanislas Julien.) The highest summit measured in the Hindu-Coosh, north-west of Jellalabad, is 3164 toises above the sea (20132 English feet); to the west, towards Herat, the chain sinks to 400 toises (2558 English feet), until, north of Teheran, it rises again to a height of 2295 toises (14675 English feet) in the volcano of Demavend.
4. The mountain system of the Himalaya. The normal direction of this system is east and west when followed from 81° to 97° E. long. from Greenwich, or through more than fifteen degrees of longitude from the colossal Dhawalagiri (4390 toises, 28071 English feet) to the breaking through of the long-problematical Dzangbo-tschu river (the Irawaddy, according to Dalrymple and Klaproth), and to the chains running north and south which cover the whole of Western China, and in the provinces of Sse-tschuan, Hu-kuang, and Kuang-si form the great mountain group of the sources of the Kiang. The next highest culminating point to the Dhawalagiri, of this east and west part of the Himalaya, is not, as has been hitherto supposed, the eastern peak of the Schamalari, but the Kinchinjinga. This mountain is situated in the meridian of Sikhim, between Bootan and Nepaul, and between the Schamalari (3750? toises, 23980 English feet) and the Dhawalagiri: its height is 4406 toises, or 26438 Parisian, or 28174 English feet. It was first measured accurately by trigonometrical operations in the present year, and as the account of this measurement received by me from India says decidedly, “that a new determination of the Dhawalagiri leaves to the latter the first rank among all the snow-capped mountains of the Himalaya,” the height of the Dhawalagiri must necessarily be greater than that of 4390 toises, or 26340 Parisian, 28071 English feet, hitherto ascribed to it. (Letter of the accomplished botanist of Sir James Ross’s Antarctic Expedition, Dr. Joseph Hooker, written from Dorjiling, July 25, 1848.) The turning point in the direction of the axis of the Himalaya range is not far from the Dhawalagiri, in 79° E. long. from Paris (81° 22′ Greenwich). From thence to the westward the Himalaya no longer runs east and west, but from SE. to NW., connecting itself, as a great cross vein, between Mozuffer-abad and Gilgit south of Kafiristan, with a part of the Hindu-Coosh. Such a bend or change in the direction or strike of the axis of elevation of the Himalaya (from E-W. to SE-NW.), doubtless points, as in the western part of our European Alps, to a difference in the age or epoch of elevation. The course of the Upper Indus, from the sacred lakes Manasa and Ravana-hrada (at an elevation of 2345 toises, 14995 English feet) in the vicinity of which the great river rises, to Iskardo and to the plateau of Deo-tsuh, (at an elevation of 2032 toises, 12993 English feet) measured by Vigne, follows in the Thibetian highlands the same north-westerly direction as the Himalaya. Here is the summit of the Djawahir, long since well measured and known to be 4027 toises (25750 English feet) in elevation, and the valley of Kashmeer, where at an elevation of only 836 toises, (5346 English feet), the Wulur Lake freezes every winter, and, from the perpetual calm, no wave ever curls its surface.
Having thus described the four great mountain systems of Asia, which in their normal geognostic character are chains coinciding with parallels of latitude, I have next to speak of the series of elevations coinciding nearly with meridians, (or more precisely, having a SSE.-NNW. direction), which, from Cape Comorin opposite to the Island of Ceylon to the Icy Sea, alternate between the meridians of 66° and 77° E. long. from Greenwich. To this system, of which the alternations remind us of faults in veins, belong the Ghauts, the Soliman chain, the Paralasa, the Bolor, and the Ural. The interruptions of the series of elevations are so arranged that, beside their alternate position in respect to longitude, each new chain begins in a degree of latitude to which the preceding chain had not quite reached. The importance which the Greeks (although probably not before the second century) attached to these chains induced Agathodemon and Ptolemy (Tab. vii. and viii.) to represent to themselves the Bolor, under the name of Imaus, as an axis of elevation extending as far as 62° N. lat. into the low basin of the Lower Irtisch and the Obi. (Asie Centrale, T. i. p. 138, 154, and 198; T. ii. p. 367.)
As the perpendicular elevation of mountain summits above the level of the sea (unimportant as in the eyes of the geologist the circumstance of the greater or lesser corrugation of the crust of the earth may be), is still, like all that is difficult of attainment, an object of popular curiosity, the following historical notice of the gradual progress of hypsometric knowledge may here find a suitable place. When I returned to Europe in 1804 after a four years’ absence, not a single Asiatic snowy summit either in the Himalaya, the Hindu-Coosh, or the Caucasus, had been measured with any exactness; and I could not therefore compare my determinations of the height of perpetual snow in the Cordilleras of Quito, or the mountains of Mexico, with any corresponding determinations in the East. The important journey of Turner, Davis, and Saunders, to the highlands of Thibet, does indeed belong to the year 1783, but Colebrooke justly remarks, that the elevation given by Turner to the Schamalari (lat. 28° 57′, long. 89° 30′, a little to the north of Tassisudan) rests on foundations as slight as those of the so-called measurements of the heights seen from Patna and the Kafiristan by Colonel Crawford and Lieutenant Macartney. (Compare Turner, in the Asiatic Researches, vol. xii. p. 234, with Elphinstone’s Account of the Kingdom of Caubul, 1815, p. 95, and Francis Hamilton, Account of Nepal, 1819, p. 92.) The excellent observations and writings of Webb, Hodgson, Herbert, and the brothers Gerard, have thrown great and certain light on the elevation of the colossal summits of the Himalaya; yet, in 1808, the hypsometric knowledge of this great Indian chain was still so uncertain that Webb wrote to Colebrooke: “The height of the Himalaya still remains a problem. I find, indeed, that the summits visible from the high plain of Rohilcund are 21000 English feet above that plain, but we do not know the absolute height above the sea.”
It was not until the beginning of the year 1820 that it began to be reported in Europe, that not only were there in the Himalaya, summits much higher than those of the Cordilleras, but also that Webb had seen in the Pass of Niti, and Moorcroft in the Thibetian plateau of Daba and the Sacred Lakes, fine pastures and flourishing fields of corn, at altitudes far exceeding the height of Mont Blanc. These accounts were received in England with much incredulity, and were met by doubts respecting the influence of refraction. I have shown the groundlessness of these doubts in two memoirs (Sur les Montagnes de l’Inde), printed in the Annales de Chimie et de Physique. The Tyrolese jesuit, P. Tiefenthaler, who in 1766 penetrated into the provinces of Kemaun and Nepal, had already divined the importance of the Dhawalagiri. We read on his map, “Montes Albi, qui Indis Dolaghir, nive obsiti.” Captain Webb always uses the same name. Until the measurements of the Djawahir (lat. 30° 22′, long. 79° 58′, altitude 4027 toises, or 25750 English feet) and of the Dhawalagiri (lat. 28° 40′, long. 83° 21′, altitude 4390? toises, 28072 English feet) were made known in Europe, the Chimborazo (3350 toises, or 21421 English feet), according to my trigonometric measurement, (Recueil d’Observations astronomiques, T. i. p. 73) was still everywhere regarded as the highest summit on the surface of the earth. The Himalaya now appeared, according as the comparison was made with the Djawahir or the Dhawalagiri, 676 toises (4323 English feet), or 1040 toises (6650 English feet), higher than the Chimborazo. Pentland’s South American travels, in the years 1827 and 1838, fixed attention (Annuaire du Bureau des Longitudes, 1830, p. 320 and 323) on two snowy summits of Upper Peru, east of the Lake of Titicaca, which were supposed to surpass the height of the Chimborazo respectively by 598 and 403 toises, (3824 and 2577 English feet.) I have remarked above, pp. [53]–[54], that the latest calculation of the measurements of the Sorata and Illimani shews this view to be incorrect. The Dhawalagiri (on the declivity of which, in the valley of the Ghandaki, the Salagrana Ammonites, so celebrated among the Brahmins as symbols of one of the incarnations of Vishnu, are collected) therefore still shews a difference between the culminating points of the Old and the New Continents of more than 6200 Parisian, or 6608 English feet.
The question has been raised, whether there may not exist behind the southernmost more or less perfectly measured chain, other still greater elevations. Colonel George Lloyd, who in 1840 edited the important observations of Captain Alexander Gerard and his brother, entertains an opinion that in the part of the Himalaya which he calls somewhat vaguely “the Tartaric chain,” (meaning therefore in north Thibet towards the Kuen-lün, and perhaps in Kailasa of the sacred lakes, or beyond Leh) there are summits of from 29000 to 30000 English feet,—one or two thousand feet higher therefore than the Dhawalagiri. (Lloyd and Gerard, Tour in the Himalaya, 1840, vol. i. p. 143 and 312; Asie Centrale, T. iii. p. 324.) So long as actual measurements are wanting, one cannot decide respecting such possibilities; as the indication, from which the natives of Quito, long before the arrival of Bouguer and La Condamine, recognised the superior altitude of the Chimborazo (namely, from the portion of its height above the region of perpetual snow being greater than in any of the other mountains), might prove very deceptive in the temperate zone of Thibet, where radiation is so active in the table-land, and where the lower limit of perpetual snow does not form a regular line at an equal elevation, as it does in the tropics. The greatest elevation above the level of the sea ever attained by human beings on the declivity of the Himalaya, is 3035 toises, or 18210 Parisian, or 19409 English feet, reached by Captain Gerard, with seven barometers, on the mountain of Tarhigang, a little to the north-west of Schipke. (Colebrooke, in the Transactions of the Geological Society, vol. vi. p. 411.) This happens to be exactly the same height as that reached by myself on the 23rd of June, 1802, and thirty years later by my friend Boussingault, on the 16th of December, 1831, on the declivity of the Chimborazo. The unattained summit of the Tarhigang is, however, 197 toises, or 1260 English feet, higher than that of the Chimborazo.
The passes across the Himalaya, leading from Hindostan into Chinese Tartary, or rather into Western Thibet, more particularly between the rivers of Buspa and Schipke or Langzing Khampa, are from 2400 to 2900 toises, or 15346 to 18544 English feet. In the chain of the Andes I found the pass of Assuay, between Quito and Cuenca on the Ladera de Cadlud, having a similar elevation, being 2428 toises, or 15526 English feet, high. A great part of the mountain plains of the interior of Asia would be buried throughout the year in perpetual snow and ice, if it were not, that by the great radiation of heat from the Thibetian plateau, by the constant serenity of the sky, by the rarity of the formation of snow in the dry atmosphere, and by the powerful solar heat peculiar to the eastern continental climate, the limit of perpetual snow is wonderfully raised on the northern slope of the Himalaya,—perhaps to 2600 toises, or 16625 English feet above the level of the sea. Fields of barley (Hordeum hexastichon) are seen in Kunawur up to 2300 toises, or 14707 English feet; and another variety of barley called Ooa, and allied to Hordeum cœleste, even much higher. Wheat succeeds extremely well in the Thibetian highlands up to 1880 toises, or 12022 English feet. On the northern declivity of the Himalaya, Captain Gerard found the upper limit of the higher birch woods ascend to 2200 toises, 14068 English feet; and small bushes which serve the inhabitants for fuel to warm their huts, attain, in the latitude of 30¾° and 31° of north latitude, a height of 2650 toises (16945 English feet), or almost 200 toises (1279 English feet) higher than the limit of perpetual snow under the equator. From the data hitherto collected it would follow, that we may take the lower limit of perpetual snow on the northern side of the Himalaya, on the average, and in round numbers, at 2600 toises, or about 16600 English feet; whilst on the southern declivity of the Himalaya the snow-line sinks to 2030 toises, or about 13000 English feet.
But for this remarkable distribution of temperature in the upper strata of the atmosphere, the mountain plain of Western Thibet would be uninhabitable to the millions who dwell there. (Compare my Examination of the Limit of Perpetual Snow on the two declivities of the Himalaya, in the Asie Centrale, T. ii. p. 435–437; T. iii. p. 281–326, and in Kosmos, Engl. ed. vol. i. note 403; S. 483 of the original.)