Himalayan Journals, vol 2, J. D. Hooker [small books to read txt] 📗

moraine backed by an existing glacier

that I examined with care: I doubt its being so high as the moraine of the Allalein glacier below the Mat-maark sea in the Sachs valley (Valais, Switzerland); but it is impossible to compare such objects from memory: the Donkia one was much the most uniform in height.] and crosses the valley from N.N.E. to S.S.W. From the summit, which rises above the level of the glacier, and from which I assume its present retirement, a most striking scene opened. The ice filling an immense basin, several miles broad and long, formed a low dome,* [This

convexity of the ice is particularly alluded to by Forbes ("Travels in the Alps," p.386), as the "renflement" of Rendu and "surface

bombee" of Agassiz, and is attributed to the effects of hydrostatic pressure tending to press the lower layers of ice upwards to the

surface. My own impression at the time was, that the convexity of the surface of the Donkia glacier was due to a subjacent mountain spur

running south from Donkia itself. I know, however, far too little of the topography of this glacier to advance such a conjecture with any confidence. In this case, as in all similar ones, broad expanses

being covered to an enormous depth with ice, the surface of the

latter must in some degree be modified by the ridges and valleys it conceals. The typical "surface bombee," which is conspicuous in the Himalaya glaciers, I was wont (in my ignorance of the mechanical laws of glaciers) to attribute to the more rapid melting of the edges of the glacier by the radiated heat of its lateral moraines and of the flanks of the valley that it occupies.] with Forked Donkia on the

west, and a serried range of rusty-red scarped mountains, 20,000 feet high on the north and east, separating large tributary glaciers.

Other still loftier tops of Donkia appeared behind these, upwards of 22,000 feet high, but I could not recognise the true summit (23,176

feet). The surface was very rugged, and so deeply honey-combed that the foot often sank from six to eight inches in crisp wet ice.

I proceeded a mile on it, with much more difficulty than on any Swiss glacier: this was owing to the elevation, and the corrosion of the

surface into pits and pools of water; the crevasses being but few and distant. I saw no dirt-bands on looking down upon it from a point I attained under the red cliff of Forked Donkia, at an elevation of

18,307 feet by barometer, and 18,597 by boiling-point. The weather

was very cold, the thermometer fell from 41 degrees to 34 degrees,

and it snowed heavily after 3 p.m.

The strike of all the rocks (gneiss with granite veins) seemed to be north-east, and dip north-west 30 degrees. Such also were the strike and dip on another spur from Donkia, north of this, which I ascended to 19,000 feet, on the 26th of September: it abutted on the scarped precipices, 3000 feet high, of that mountain. I had been attracted to the spot by its bright orange-red colour, which I found to be caused by peroxide of iron. The highly crystalline nature of the rocks, at these great elevations, is due to the action of veins of fine-grained granite, which sometimes alter the gneiss to such an extent that it appears as if fused into a fine granite, with distinct crystals of

quartz and felspar; the most quartzy layers are then roughly

crystallized into prisms, or their particles are aggregated into

spheres composed of concentric layers of radiating crystals, as is

often seen in agates. The rearrangement of the mineral constituents by heat goes on here just as in trap, cavities filled with crystals being formed in rocks exposed to great heat and pressure. Where mica abounds, it becomes black and metallic; and the aluminous matter is crystallised in the form of garnets.

Illustration--SUMMIT OF FORKED DONKIA, AND "GOA" ANTELOPES.

At these great heights the weather was never fine for more than an

hour at a time, and a driving sleet followed by thick snow drove me down on both these occasions. Another time I ascended a third spur

from this great mountain, and was overtaken by a heavy gale and

thunderstorm, the latter is a rare phenomenon: it blew down my tripod and instruments which I had thought securely Propped with stones, and the thermometers were broken, but fortunately not the barometer.

On picking up the latter, which lay with its top down the hill, a

large bubble of air appeared, which I passed up and down the tube,

and then allowed to escape; when I heard a rattling of broken glass in the cistern. Having another barometer* [This barometer (one of

Newman's portable instruments) I have now at Kew: it was compared

with the Royal Society's standard before leaving England; and varied according to comparisons made with the Calcutta standard 0.012 during its travels; on leaving Calcutta its error was 0; and on arriving in England, by the standard of the Royal Society, +.004. I have given in the Appendix some remarks on the use of these barometers, which

(though they have obvious defects), are less liable to derangement, far more portable, and stand much heavier shocks than those of any

other construction with which I am familiar.] at my tent, I hastened to ascertain by comparison whether the instrument which had travelled with me from England, and taken so many thousand observations, was

seriously damaged: to my delight an error of 0.020 was all I could

detect at Momay and all other lower stations. On my return to

Dorjiling in December, I took it to pieces, and found the lower part of the bulb of the attached thermometer broken off, and floating on the mercury. Having quite expected this, I always checked the

observations of the attached thermometer by another, but--how, it is not easy to say--the broken one invariably gave a correct

temperature.

Illustration--VIEW FROM AN ELEVATION OF 18,000 FEET OF THE EAST TOP

OF KINCHINJHOW, AND OF TIBET, OVER THE RIDGE THAT CONNECTS IT WITH

DONKIA. WILD SHEEP (OVIS AMMON) IN THE FOREGROUND.

The Kinchinjhow spurs are not accessible to so great an elevation as those of Donkia, but they afford finer views over Tibet, across the ridge connecting Kinchinjow with Donkia.

Broad summits here, as on the opposite side of the valley, are quite bare of snow at 18,000 feet, though where they project as sloping

hog-backed spurs from the parent mountain, the snows of the latter

roll down on them and form glacial caps, the reverse of glaciers in valleys, but which overflow, as it were, on all sides of the slopes, and are ribboned* [The convexity of the curves, however, seems to be upwards. Such reversed glaciers, ending abruptly on broad stony

shoulders quite free of snow, should on no account be taken as

indicating the lower limit of perpetual snow.] and crevassed.

On the 18th of September I ascended the range which divides the

Lachen from the Lachoong valley, to the Sebolah pass, a very sharp

ridge of gneiss, striking north-west and dipping north-east, which

runs south from Kinchinjhow to Chango-khang. A yak-track led across the Kinchinjhow glacier, along the bank of the lake, and thence

westward up a very steep spur, on which was much glacial ice and

snow, but few plants above 16,000 feet. At nearly 17,000 feet I

passed two small lakes, on the banks of one of which I found bees, a May-fly (Ephemera) and gnat; the two latter bred on stones in the water, which (the day being fine) had a temperature of 53 degrees,

while that of the large lake at the glacier, 1000 feet lower, was

only 39 degrees.

The view from the summit commands the whole castellated front of

Kinchinjhow, the sweep of the Donkia cliffs to the east,

Chango-khang's blunt cone of ribbed snow* [This ridging or furrowing of steep snow-beds is explained at vol. i, chapter x.] over head,

while to the west, across the grassy Palung dunes rise Chomiomo, the Thlonok mountains, and Kinchinjunga in the distance.* [The latter

bore 241 degrees 30 minutes; it was distant about thirty-four miles, and subtended an angle of 3 degrees 2 minutes 30 seconds. The rocks on its north flanks were all black, while those forming the upper

10,000 feet of the south face were white: hence, the top is probably granite, overlaid by the gneiss on the north.] The Palung plains, now yellow with withered grass, were the most curious part of the view: hemmed in by this range which rises 2000 feet above them, and by the Lachen hills on the east, they appeared a dead level, from which

Kinchinjhow reared its head, like an island from the ocean.* [It is impossible to contemplate the abrupt flanks of all these lofty

mountains, without contrasting them with the sloping outlines that

prevail in the southern parts of Sikkim. All such precipices are, I have no doubt, the results of sea action; and all posterior influence of sub-aerial action, aqueous or glacial, tends to wear these

precipices into slopes, to fill up valleys and to level mountains. Of all such influences heavy rain-falls and a luxuriant vegetation are probably the most active; and these features are characteristic of

the lower valleys of Sikkim, which are consequently exposed to very different conditions of wear and tear from those which prevail on

these loftier rearward ranges.] The black tents of the Tibetans were still there, but the flocks were gone. The broad fosse-like valley of the Chachoo was at my feet, with the river winding along its bottom, and its flanks dotted with black juniper bushes.

The temperature at this elevation, between 1 and 3 p.m., varied from 38 degrees to 59 degrees; the mean being 46.5 degrees, with the

dew-point 34.6 degrees. The height I made 17,585 feet by barometer, and 17,517 by boiling-point. I tried the pulses of eight, persons

after two hours' rest; they varied from 80 to 112, my own being 104.

As usual at these heights, all the party were suffering from

giddiness and headaches.

Throughout September various parties passed my tent at Momay,

generally Lamas or traders: the former, wrapped in blankets, wearing scarlet and gilt mitres, usually rode grunting yaks, which were

sometimes led by a slave-boy or a mahogany-faced nun, with a broad

yellow sheep-skin cap with flaps over her ears, short petticoats, and striped boots. The domestic utensils, pots, pans, and bamboos of

butter, tea-churn, bellows, stools, books, and sacred implements,

usually hung rattling on all sides of his holiness, and a sumpter yak carried the tents and mats for sleeping. On several occasions large parties of traders, with thirty or forty yaks* [About 600 loaded yaks are said to cross the Donkia pass annually.] laden with planks,

passed, and occasionally a shepherd with Tibet sheep, goats, and

ponies. I questioned many of these travellers about the courses of

the Tibetan rivers; they all agreed* [One lad only, declared that the Kambajong river flowed north-west to Dobtah and Sarrh, and thence

turned north to the Yaru; but all Campbell's itineraries, as well as mine, make the Dobtah lake drain into the Chomachoo, north of

Wallanchoon; which latter river the Nepalese also affirm flows into Nepal, as the Arun. The Lachen and Lachoong Phipuns both insisted on this, naming to me the principal towns on the way south-west from

Kambajong along the river to Tingri Maidan, via Tashirukpa Chait, which is north of Wallanchoon pass.] in stating the Kambajong or

Chomachoo liver, north of the Lachen, to be the Arun of Nepal, and

that it rose near the Ramchoo lake (of Turner's route). The lake

itself discharges either into the Arun, or into the Painomchoo

(flowing to the Yaru); but this point I could never satisfactorily

ascertain.

The weather at Momay, during September, was generally bad after 11