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

country but itself and its feeders, which occupy the largest of the Himalayan valleys between the Tambur in East Nepal, and the Machoo in Western Bhotan.

An immense spur, sixty miles long, stretches south from Kinchin to

the plains of India; it is called Singalelah, and separates Sikkim

from East Nepal; the waters from its west flank flow into the Tambur, and those from the east into the Great Rungeet, a feeder of the

Teesta. Between these two latter rivers is a second spur from

Kinchinjunga, terminating in Tendong.

The eastern boundary of Sikkim, separating it from Bhotan, is formed for the greater part by the Chola range, which stretches south from the immense mountain of Donkia, 23,176 feet high, situated fifty

miles E.N.E. of Kinchinjunga: where the frontier approaches the

plains of India, the boundary line follows the course of the Teesta, and of the Rinkpo, one of its feeders, flowing from the Chola range.

This range is much more lofty than that of Singalelah, and the

drainage from its eastern flank is into the Machoo river, the upper part of whose course is in Tibet, and the lower in Bhotan.

The Donkia mountain, though 4000 feet lower than Kinchin, is the

culminant point of a much more extensive and elevated mountain mass.

It throws off an immense spur from its north-west face, which runs

west, and then south-west, to Kinchin, forming the watershed of all the remote sources of the Teesta. This spur has a mean elevation of 18,000 to 19,000 feet, and several of its peaks (of which Chomiomo is one) rise much higher. The northern boundary of Sikkim is not drawn along this, but runs due west from Donkia, following a shorter, but stupendous spur, called Kinchinjhow; whence it crosses the Teesta to Chomiomo, and is continued onwards to Kinchinjunga.

Though the great spur connecting Donkia with Kinchin is in Tibet, and bounds the waters that flow directly south into the Teesta, it is far from the true Himalayan axis, for the rivers that rise on its

northern slope do not run into the valley of the Tsampu, or Tibetan Burrampooter, but into the Arun of Nepal, which rises to the north of Donkia, and flows south-west for many miles in Tibet, before entering Nepal and flowing south to the Ganges.

Sikkim, thus circumscribed, consists of a mass of mountainous spurs, forest-clad up to 12,000 feet; there are no flat valleys or plains in the whole country, no lakes or precipices of any consequence below

that elevation, and few or no bare slopes, though the latter are

uniformly steep. The aspect of Sikkim can only be understood by a

reference to its climate and vegetation, and I shall therefore take these together, and endeavour, by connecting these phenomena, to give an intelligible view of the main features of the whole country.*

[This I did with reference especially to the cultivation of

Rhododendrons, in a paper which the Horticultural Society of London did me the honour of printing. Quarterly Journ. of Hort. Soc., vol.

vii., p. 82.]

The greater part of the country between Sikkim and the sea is a dead level, occupied by the delta of the Ganges and Burrampooter, above

which the slope is so gradual to the base of the mountains, that the surface of the plain from which the Himalayas immediately rise is

only 300 feet above the sea. The most obvious effect of this position is, that the prevailing southerly wind reaches the first range of

hills, loaded with vapour. The same current, when deflected easterly to Bhotan, or westerly to Nepal and the north-west Himalaya, is

intercepted and drained of much moisture, by the Khasia and Garrow

mountains (south of Assam and the Burrampooter) in the former case, and the Rajmahal hills (south of the Ganges) in the latter. Sikkim is hence the dampest region of the whole Himalaya.

Viewed from a distance on the plains of India, Sikkim presents the

appearance--common to all mountainous countries--of consecutive

parallel ridges, running east and west: these are all wooded, and

backed by a beautiful range of snowy peaks, with occasional breaks in the foremost ranges, through which the rivers debouch. Any view of

the Himalaya, especially at a sufficient distance for the remote

snowy peaks to be seen overtopping the outer ridges, is, however,

rare, from the constant deposition of vapours over the forest-clad

ranges during the greater part of the year, and the haziness of the dry atmosphere of the plains in the winter months. At the end of the rains, when the south-east monsoon has ceased to blow with constancy, views are obtained, sometimes from a distance of nearly two hundred miles. From the plains, the highest peaks subtend so small an angle, that they appear like white specks very low on the horizon, tipping the black lower and outer wooded ranges, which always rise out of a belt of haze, and from the density, probably, of the lower strata of atmosphere, are never seen to rest on the visible horizon.

The remarkable lowness on the horizon of the whole stupendous mass is always a disappointing feature to the new comer, who expects to see dazzling peaks towering in the air. Approaching nearer, the snowy

mountains sink behind the wooded ones, long before the latter have

assumed gigantic proportions; and when they do so, they appear a

sombre, lurid grey-green mass of vegetation, with no brightness or

variation of colour. There is no break in this forest caused by rock, precipices, or cultivation; some spurs project nearer, and some

valleys appear to retire further into the heart of the foremost great chain that shuts out all the country beyond.

From Dorjiling the appearance of parallel ridges is found to be

deceptive, and due to the inosculating spurs of long tortuous ranges that ran north and south throughout the whole length of Sikkim,

dividing deep wooded valleys, which form the beds of large rivers.

The snowy peaks here look like a long east and west range of

mountains, at an average distance of thirty or forty miles.

Advancing into the country, this appearance proves equally deceptive, and the snowy range is resolved into isolated peaks, situated on the meridional ridges; their snow-clad spurs, projecting east and west, cross one another, and being uniformly white, appear to connect the peaks into one grand unbroken range. The rivers, instead of having

their origin in the snowy mountains, rise far beyond them; many of

their sources are upwards of one hundred miles in a straight line

from the plains, in a very curious country, loftier by far in mean

elevation than the meridional ridges which run south from it, yet

comparatively bare of snow. This rearward part of the mountain region is Tibet, where all the Sikkim, Nepal, and Bhotan rivers rise as

small streams, increasing in size as they receive the drainage from the snowed parts of the ridges that bound them in their courses.

Their banks, between 8000 and 14,000 feet, are generally clothed with rhododendrons, sometimes to the almost total exclusion of other woody vegetation, especially near the snowy mountains--a cool temperature and great humidity being the most favourable conditions for the

luxuriant growth of this genus.

The source of this humidity is the southerly or sea wind which blows steadily from May till October in Sikkim, and prevails throughout the rest of the year, if not as the monsoon properly so called, as a

current from the moist atmosphere above the Gangetic delta.

This rushes north to the rarefied regions of Sikkim, up the great

valleys, and does not appear materially disturbed by the north-

west wind, which blows during the afternoons of the winter months

over the plains, and along the flanks of the outer range, and is a

dry surface current, due to the diurnal heating of the soil. When it is considered that this wind, after passing lofty mountains on the

outer range, has to traverse eighty or one hundred miles of alps

before it has watered all the forest region, it will be evident that its moisture must be expended before it reaches Tibet.

Let the figures in the accompanying woodcut, the one on the true

scale, the other with the heights exaggerated, represent two of these long meridional ridges, from the watershed to the plains of India,

following in this instance the course of the Teesta river, from its source at 19,000 feet to where it debouches from the Himalaya at 300.

The lower rugged outline represents one meridional ridge, with all

its most prominent peaks (whether exactly or not on the line of

section); the upper represents the parallel ridge of Singalelah

(D.E.P.), of greater mean elevation, further west, introduced to show the maximum elevation of the Sikkim mountains, Kinchinjunga (28,178

feet), being represented on it. A deep valley is interposed between these two ridges, with a feeder of the Teesta in it (the Great

Rungeet), which runs south from Kinchin, and turning west enters the Teesta at R. The position of the bed of the Teesta river is indicated by a dotted line from its source at T to the plains at S; of

Dorjiling, on the north flank of the outer range, by d; of the

first point where perpetual snow is met with, by P; and of the first indications of a Tibetan climate, by C.

Illustration--SECTION OF THE SIKKIM HIMALAYA ALONG THE COURSE OF THE

TEESTA RIVER.

A warm current of Air, loaded with vapour, will deposit the bulk of its moisture on the ridge of Sinchul, which rises above Dorjiling

(d), and is 8,500 feet high. Passing on, little will be

precipitated on e whose elevation is the same as that of Sinchul; but much at f (11,000 feet), where the current, being further

cooled, has less capacity for holding vapour, and is further

exhausted. When it ascends to P (15,000 feet) it is sufficiently

cooled to deposit snow in the winter and spring months, more of which falling than can be melted during the summer, it becomes perennial.

At the top of ginchin very little falls, and it is doubtful if the

southerly current ever reaches that prodigiously elevated isolated

summit. The amount of surface above 20,000 feet is, however, too

limited and broken into isolated peaks to drain the already nearly, exhausted current, whose condensed vapours roll along in fog beyond the parallel of Kinchin, are dissipated during the day over the arid mountains of Tibet, and deposited at night on the cooled surface of the earth.

Other phenomena of no less importance than the distribution of

vapour, and more or less depending on it, are the duration and amount of solar and terrestrial radiation. Towards D the sun is rarely seen during the rainy season, as well from the constant presence of nimbi aloft, as from fog on the surface of the ground. An absence of both light and heat is the result south of the parallel of Kinchin; and at C low fogs prevail at the same season, but do not intercept either

the same amount of light or heat; whilst at T there is much sunshine and bright light. During the night, again, there is no terrestrial

radiation between S and P; the rain either continues to pour--in some months with increased violence--or the saturated atmosphere is

condensed into a thick white mist, which hangs over the redundant

vegetation. A bright starlight night is almost unknown in the summer months at 6000 to 10,000 feet, but is frequent in December and

January, and at intervals between October and May, when, however,

vegetation is little affected by the cold of nocturnal radiation.

In the regions north of Kinchin, starlight