than 1800 toises, or 11,500 English feet. The supposition of its forming the wall of a very high table-land is exceedingly erroneous. The plains in the neighbourhood of lake Dzaisang, on the southern side of the chain, and near its western extremity, are elevated only 1600 feet above the level of the sea, and the steppes round lake Balkash have a still less considerable elevation.

On our common maps two systems of mountains are laid down under the name of Altai-the Great and Little Altai-but the Russians and the inhabitants of the country are acquainted with no such distinction. Arrowsmith, who has been followed by most of our modern geographers, gave the name of Great Altai to an imaginary chain which he represented as a continuation of the Thian-chan, stretching from the east of Khamil (Hami) and Bar-koul to the north-east, towards the sources of the Ienisei, and lake Kossogol. If the name of Great Altai is to be preserved, it ought, in Humboldt's opinion, to be given to a chain of high mountains which range in a direction exactly at right angles with that assigned to it by Arrowsmith, that is to say, from north-west to south-east, between the right bank of the Upper Irtyche and the Ieke-Aral-Noor (lake of the Steppe), near Gobdo-Khoto.

From the meridian of Oust Kamenogorsk, the Altai system is prolonged towards the west, under the parallel of 49° or 50°, by a chain of hills and low mountains stretching over an extent of 160 geographical leagues. This prolongation has great geognostical interest, as it appears to have been upraised through a fissure, which forms the line of separation between the affluents of the Sarasou to the south, and the Irtyche to the north, and follows the same direction through 16 degrees of longitude. On our ordinary maps a continuous chain of mountains is usually represented under the name of Alghydin-chamo, connecting the Altai with the southern extremity of the Ourals. But no such chain exists. The actual range of low hills is neither continuous, nor does it extend to the Ourals, but terminates abruptly under the meridian of Svermogovloskoi, about 10 degrees to the east of the latter chain. Isolated hillocks of five or six hundred feet, and groups of little mountains, rising boldly to the height of a thousand or twelve hundred feet, deceive the traveller not accustomed to estimate the irregularities of ground, and, when viewed from a distance, give that appearance of continuity which has led geographers into the error we have here alluded to.

At the point where this range of low hills terminates, there commences a very remarkable region of little lakes, comprising the groups of Balek-koul and Koum-koul, which seems to indicate, at a remote era, the existence of a great mass of water in the interior of Siberia, communicating with the lakes Aksakal and

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Aral. It extends to the north-east, between the rivers Tobol and Ichim, and may be traced eastward beyond Omsk through the steppe of Baraba, thence to Sourgout beyond the Ob, through the country of the Ostiaks of Berezov, and even to the marshy coasts of the Frozen Sea. The geognostic appearances of this tract render it highly probable that it has formerly been entirely covered by a mass of water, of which the Caspian and lake Aral are the most considerable remaining portions. The Chinese also preserve a tradition of the existence of a salt lake in the interior of Siberia, which traversed the course of the Ienisei; and Humboldt observed that, at present, through the effects of cultivation, the dry land is constantly gaining on the marshes and lakes of the steppe of Baraba. The salt plain which surrounds the oasis of Hami, is expressively called by the Chinese the Dried up Sea, (Han-hai).

The second great chain of mountains, called in Chinese Thianchan, and in Turki Tengri-tugh, (both appellations signifying the Celestial Mountains,) runs from west to east, nearly along the 42d parallel of north latitude. The culminating point of the chain is probably to be found in the mass of mountains celebrated under the name of Bokhda-Oola (Holy Mountain), situated about 88 degrees to the east of the meridian of Paris. Pallas gives the name of Bokhda to the whole chain, and Arrowsmith confers the same name on a portion of his imaginary Great Altai. From Bokhda-Oola, the Thian-chan stretches eastward towards Bar-koul, beyond which its elevation suddenly falls to the level of the elevated desert of Gobi, but after an interruption of about 10 degrees of longitude, another chain appears, that of the Gadjar or In-chan, which follows the same direction from west to east, and which Humboldt regards as a prolongation of the Thian-chan. About four degrees to the west of Pekin, the In-chan is connected with the Ta-hang-chan, or snowy mountain, and to the north of this city with the mountains of Mongolia, which extend even to the northern frontier of the peninsula of the Corea. In a westerly direction the Thian-chan is prolonged to the neighbourhood of Samarkand. A part of the chain, to the north of Kashgar, is celebrated in the Memoirs of Baber under the denomination of the Mouz-tagh; to the west of this it assumes the name of Asferah and Ak-tagh.

The third great system of parallel mountains is the Kuenlun, which runs nearly along the 35th parallel of latitude. A part of this range, under the meridian of about 72 degrees east from Paris, is called the Thsoung-ling, or Blue Mountains, and forms the southern extremity of the Bolor, or Belut-tagh, a transverse chain which follows the direction of the meridian through nearly ten degrees of latitude. From the Bolor the chain of the

Kuen-lun extends in an easterly direction towards the sources of the Hoang-ho, and it penetrates even into the Chen-si, a province of China. That part of Asia, however, which it traverses, is very little known, and we have as yet no observations, either of the mean height of the chain, or of its principal summits. Between the Kuen-lun and Thian-chan, and between the 90th and 100th degree of east longitude, there are two ranges of mountains running in the same direction, the Nanchan, or Khilian-chan, a little to the north of lake Khoukhounor, and the Tangout, which forms the northern boundary of the desert of Gobi.

The last and best known of the four great chains is the Himalaya. The general direction of this system is from north-west to south-east; it is consequently inclined at a considerable angle to the Kuen-lun, with which it unites between Kashmir and Fyzabad. Following this range, to the east we find it forming the northern boundary of the English territory in Hindostan, of the kingdoms of Assam and Ava, and penetrating to the Chinese province of Yun-nan. It then takes a direction to the north-east, and advances in a series of snowy peaks to the eastern ocean, opposite the island of Formosa, which indeed may be regarded as the termination of the chain. The mountains of this island are covered with snow during a great part of the year, indicating in that latitude an elevation exceeding 12,000 feet. To the west of the Bolor, the united chains of the Himalaya and Kuen-lun form the range of the Hindoo-kho, which Humboldt regards as a continuation of the Kuen-lun, though it is generally considered as a prolongation of the Himalaya. After following the direction of the parallel through five or six degrees, this range inclines to the north-west, and, passing between the plateau of Iran and the Caspian, is at length lost in the province of Adzerbaidjan, about 45 degrees to the east of Paris. If, therefore, we regard the Hindoo-kho as a continuation of the Himalaya, the last will form a continuous system, extending from the west of Persia to the eastern sea, or through 73 degrees of longitude. Some of the summits of this stupendous range are known to have a greater elevation than any other points on the surface of the earth. Djavahir, on the western side of the country of Nepaul, attains the altitude of 4026 toises, or 25,746 feet; while Dhawalaghiri, on the eastern side of the same country, rises to the enormous height of 4390 toises, or 28,096 feet above the level of the sea.

Between the first and second systems the country is enclosed on the eastern side by the Khing-khan-oola, a range which stretches between the Altai and the Thian-chan, in the direction of north-north-east, beyond the meridian of Pekin. On the western side, towards Tchoui, Sarasou, and the lower Sihoun, it

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is entirely open. Exactly the reverse of this is the case with the country between the Thiau-chan and Kuen-lun, which is the eastern side, but strikingly enclosed on the west by the transverse chain of the Bolor. This chain strikes off from the Kuenlun at right angles, and, following the direction of the meridian, pierces through the Thian-chan to the north-west of Kashgar, and extends to the Alatau, another chain running from west to east between the lakes Balkash and Issikoul. The intermediate space between the Kuen-lun and the Himalaya, comprehendiug Thibet and Katchi, is covered with mountains so closely grouped together as to form an almost continuous plateau or table land. Its general elevation is great, but, as might be anticipated, very unequal. The mildness of the winters and the cultivation of the vine in the gardens of H'lassa in Eastern Thibet, under the parallel of 29° 40', indicate, as Humboldt remarks, the existence of deep valleys and circular depressions.

We have considered it necessary to enter into the above details, at the risk of being thought tedious, for two reasons: first, because it would be difficult to trace, on any of our common maps, the parallelism which Humboldt has signalized; and second, because the subject has an interest altogether independant of the question of geographical position. It is an opinion now entertained, almost universally, by the most distinguished geologists, that the great mountain chains have been upraised from the bowels of the earth subsequently to the stratification and consolidation of the exterior crust. Now if we admit this theory, it will follow as a natural consequence, that the melted matter extruded by a force acting from below would carry along with it the consolidated strata, which would thus obtain an inclined position, and form a covering to the flanks of the new mountain. The nature of the strata which cover the sides of a mountain chain will therefore indicate the state of the surface at the epoch when the elevation took place; and hence, since geologists are able to assign certain relations, in respect of age or priority of formation, among the different stratifications, we are enabled, by the same means, to determine the relative ages of the mountains. But it is extremely remarkable that those chains which are covered by strata, or sedimental deposits, belonging to the same era of formation, are generally found to range in a direction parallel to the same great circle of the sphere; and this relation between the direction of the mountain chains and the nature of their covering has been found to hold good in so many instances, that some geologists of distinguished name do not hesitate to rank it among the principles of their science, and to regard the parallelism of different chains as a distinctive character of syn

chronous elevation. According to this theory, which was first broached by Elie de Beaumont, and which Humboldt thinks the phenomena of the Asiatic continent tend to support, the four great parallel chains of Central Asia must have had a contemporaneous formation, while the transverse ranges of the Oural, the Bolor, the Ghauts of Malabar, and the Khing-khan, have been elevated at a subsequent and probably a very different epoch. In the present state of geological knowledge, the hypothesis of Beaumont cannot be admitted to rest on firm or tenable grounds; yet it cannot be disputed that even in the position of the different mountain-chains, and without any reference to the materials of which they are constituted, we have abundant evidence that the earth has only attained its present form through a succession of revolutions caused by the action of internal forces.

Though Asia undoubtedly presents a greater mass of elevated land than any of the other quarters of the world, Africa not excepted, yet all the facts that bear on the subject concur in proving that the notions prevalent respecting its general elevation have been greatly exaggerated. A large portion of the interior of the continent, however, still remains unexplored by European travellers; and even in regard to those parts where it is easy of access, there is a great want of good barometrical observations. On this head we have to regret that numberless opportunities of acquiring authentic information have been lost to science through the ignorance or indifference of our own countrymen. The routes from Hindostan to Europe are travelled annually by English officers, generally men of active habits, and sufficiently eager to distinguish themselves by scientific pursuits; but from being unaccustomed to the use of philosophical instruments, it unfortunately happens, most frequently, that when they are thrown into situations favourable for making observations, they are either unprovided with the means, or incapable of turning them to any good account. From this general charge there are indeed some splendid exceptions; but it cannot be denied, that in many cases the activity and talents of our travellers are expended in collecting useless details respecting the manners of barbarian hordes, or in loose descriptions of the appearance and aspect of the different countries through which they pass. It is but seldom that they are aware of the importance of measuring the height of a mountain or the elevation of a plain, and still more seldom that they can perform the operation with any tolerable degree of accuracy; hence it happens that the most important information,—that which regards the physical condition, the climate, and the natural history of a country,-is often entirely overlooked. May we not