Himalayan Journals, vol 2 by J. D. Hooker (android pdf ebook reader TXT) 📕

The Himalaya, north of Nepal, and thence eastward to the bend of the Yaru-Tsampu (or Tibetan Burrampooter) has for its geographical limits the plains of India to the south, and the bed of the Yaru to the

north. All between these limits is a mountain mass, to which Tibet

(though so often erroneously called a plain)* [The only true account of the general features of eastern Tibet is to be found in MM. Huc

and Gabet's travels. Their description agrees with Dr. Thomson's

account of western Tibet, and with my experience of the parts to the north of Sikkim, and the information I everywhere obtained.

The so-called plains are the flat floors of the valleys, and the

terraces on the margins of the rivers, which all flow between

stupendous mountains. The term "maidan," so often applied to Tibet by the natives, implies, not a plain like that of India, but simply an open, dry, treeless country, in contrast to the densely wooded wet

regions of the snowy Himalaya, south of Tibet.] forms no exception.

The waters from the north side of this chain flow into the Tsampu,

and those from the south side into the Burrampooter of Assam, and the Ganges. The line, however tortuous, dividing the heads of these

waters, is the watershed, and the only guide we have to the axis of the Himalaya. This has never been crossed by Europeans, except by

Captain Turner's embassy in 1798, and Captain Bogle's in 1779, both of which reached the Yaru river. In the account published by Captain Turner, the summit of the watershed is not rigorously defined, and

the boundary, of Tibet and Bhotan is sometimes erroneously taken for it; the boundary being at that point a southern spur of Chumulari.*

[Between Donkia and Chumulari lies a portion of Tibet (including the upper part of the course of the Machoo river) bounded on the east by Bhotan, and on the west by Sikkim (see chapter xxii). Turner, when

crossing the Simonang Pass, descended westwards into the valley of

the Machoo, and was still on the Indian watershed.] Eastwards from

the sources of the Tsampu, the watershed of the Himalaya seems to

follow a very winding course, and to be everywhere to the north of

the snowy peaks seen from the plains of India. It is by a line

through these snowy peaks that the axis of the Himalaya is

represented in all our maps; because they seem from the plains to be situated on an east and west ridge, instead of being placed on

subsidiary meridional ridges, as explained above. It is also across or along the subsidiary ridges that the boundary line between the

Tibetan provinces and those of Nepal, Sikkim, and Bhotan, is usually drawn; because the enormous accumulations of snow form a more

efficient natural barrier than the greater height of the less snowed central part of the chain beyond them.

Though, however, our maps draw the axis through the snowy peaks,

they also make the rivers to rise beyond the latter, on the northern slopes as it were, and to flow southwards through gaps in the axis.

Such a feature is only reconcilable with the hypothesis of the chain being double, as the Cordillera of Peru and Chili is said to be,

geographically, and which in a geological sense it no doubt is: but to the Cordillera the Himalaya offers no parallel. The results of

Dr. Thomson's study of the north-west Himalaya and Tibet, and

my own of the north-east extreme of Sikkim and Tibet, first gave

me an insight into the true structure of this chain. Donkia mountain is the culminant point of an immensely elevated mass of mountains, of greater mean height than a similarly extensive area around Kinchin

junga. It comprises Chumulari, and many other mountains much

above 20,000 feet, though none equalling Kinchinjunga, Junnoo, and

Kubra. The great lakes of Ramchoo and Cholamoo are placed on it; and the rivers rising on it flow in various directions; the Painomchoo

north-west into the Yaru; the Arun west to Nepal; the Teesta south-

west through Sikkim; the Machoo south, and the Pachoo south-east,

through Bhotan. All these rivers have their sources far beyond the

great snowed mountains, the Arun most conspicuously of all, flowing completely at the back or north of Kinchinjunga. Those that flow

southwards, break through no chain, nor do they meet any contraction as they pass the snowy parts of the mountains which bound the valleys in which they flow, but are bound by uniform ranges of lofty

mountains, which become more snowy as they approach the plains of

India. These valleys, however, gradually contract as they descend,

being less open in Sikkim and Nepal than in Tibet, though there

bounded by rugged mountains, which from being so bare of snow and of vegetation, do not give the same impression of height as the isolated sharper peaks which rise out of a dense forest, and on which the snow limit is 4,000 or 5,000 feet lower.

The fact of the bottom of the river valleys being flatter towards the watershed, is connected with that of their fall being less rapid at that part of their course; this is the consequence of the great

extent in breadth of the most elevated portion of the chain. If we

select the Teesta as an example, and measure its fall at three points of its course, we shall find the results very different. From its

principal source at Lake Cholamoo, it descends from 17,000 to 15,000

feet, with a fall of 60 feet to the mile; from 15,000 to 12,000 feet, the fall is 140 feet to the mile; in the third part of its course it descends from 12,000 to 5000 feet, with a fall of 160 feet to the

mile; and in the lower part the descent is from 5000 feet to the

plains of India at 300 feet, giving a fall of 50 feet to the mile.

There is, however, no marked limit to these divisions; its valley.

gradually contracts, and its course gradually becomes more rapid.

It is worthy of notice that the fall is at its maximum through that part of its valley of which the flanks are the most loaded with snow; where the old moraines are very conspicuous, and where the present

accumulations from landslips, etc., are the most extensive.* [It is not my intention to discuss here the geological bearings of this

curious question; but I may state that as the humidity of the climate of the middle region of the river-course tends to increase the fall in a given space, so I believe the dryness of the climate of the

loftier country has the opposite effect, by preserving those

accumulations which have raised the floors of the valleys and

rendered them level.]

With reference to Kinchinjunga, these facts are of importance, as

showing that mere elevation is in physical geography of secondary

importance. That lofty mountain rises from a spur of the great range of Donkia, and is quite removed from the watershed or axis of the

Himalaya, the rivers which drain its northern and southern flanks

alike flowing to the Ganges. Were the Himalaya to be depressed 18,000

feet, Kubra, Junnoo, Pundim, etc., would form a small cluster of

rocky islands 1000 to 7000 feet high, grouped near Kinchinjunga,

itself a cape 10,000 feet high, which would be connected by a low,

marrow neck, with an extensive and mountainous tract of land to its north-east; the latter being represented by Donkia. To the north of Kinchin a deep bay or inlet would occupy the present valley of the

Arun, and would be bounded on the north by the axis of the Himalaya, which would form a continuous tract of land beyond it. Since writing the above, I have seen Professor J. Forbes's beautiful work on the

glaciers of Norway: it fully justifies a comparison of the Himalaya to Norway, which has long been a familiar subject of theoretical

enquiry with Dr. Thomson and myself. The deep narrow valleys of

Sikkim admirably represent the Norwegian fiords; the lofty, rugged, snowy mountains, those more or less submerged islands of the

Norwegian coast; the broad rearward watershed, or axis of the chain, with its lakes, is the same in both, and the Yaru-tsampu occupies the relative position of the Baltic.

Along the whole chain of the Himalaya east of Kumaon there are, I

have no doubt, a succession of such lofty masses as Donkia, giving

off stupendous spurs such as that on which Kinchin forms so

conspicuous a feature. In support of this view we find every river

rising far beyond the snowy peaks, which are separated by

continuously unsnowed ranges placed between the great white masses

that these spurs present to the observer from the south.* [At vol. i.

chapter viii, I have particularly called attention to the fact, that west of Kinchinjunga there is no continuation of a snowy Himalaya, as it is commonly called. So between Donkia and Chumulari there is no

perpetual snow, and the valley of the Machoo is very broad, open, and comparatively flat.] From the Khasia mountains (south-east of Sikkim) many of these groups or spurs were seen by Dr. Thomson and myself, at various distances (80 to 210 miles); and these groups were between

the courses of the great rivers the Soobansiri, Monass, and Pachoo, all east of Sikkim. Other masses seen from the Gangetic valley

probably thus mark the relative positions of the Arun, Cosi, Gunduk, and Gogra rivers.

Another mass like that of Chumulari and Donkia, is that around the

Mansarowar lakes, so ably surveyed by the brothers Captains R. and H.

Strachey, which is evidently the centre of the Himalaya. From it the Gogra, Sutlej, Indus, and Yaru rivers all flow to the Indian side of Asia; and from it spring four chains, two of which are better known than the others. These are:--1. The eastern Himalaya, whose axis runs north of Nepal, Sikkim, and Bhotan, to the bend of the Yaru, the

valley of which it divides from the plains of India. 2. The

north-west Himalaya, which separates the valley of the Indus from the plains of India. Behind these, and probably parallel to them, lie two other chains. 3. The Kouenlun or Karakoram chain, dividing the Indus from the Yarkand river. 4. The chain north of the Yaru, of which

nothing is known. All the waters from the two first of these chains, flow into the Indian Ocean, as do those from the south faces of the third and fourth; those from the north side of the Kouenlun, and of the chain north of the Yaru, flow into the great valley of Lake Lhop, which may once have been continuous with the Amoor river.* [The

Chinese assert that Lake Lhop once drained into the Hoang-ho; the

statement is curious, and capable of confirmation when central Asia shall have been explored.]

For this view of the physical geography of the western Himalaya and central Asia, I am indebted to Dr. Thomson. It is more consonant with nature, and with what we know of the geography of the country and of the nature of mountain chains, than that of the illustrious Humboldt, who divides central Asia by four parallel chains, united by two

meridional ones; one at each extremity of the mountain district.

It follows in continuation and conclusion of our view that the

mountain mass of Pamir or Bolor, between the sources of the Oxus and those of the Yarkand river, may be regarded as a centre from which

spring the three greatest mountain systems of Asia. These are:--1. A great chain, which runs in a north-easterly direction as far as

Behring's Straits, separating all the rivers of Siberia from those

which flow into the Pacific Ocean. 2. The Hindoo Koosh, continued

through Persia, and Armenia into Taurus. And, 3. The Muztagh or

Karakorum, which probably extends due east