| | land itself, the relative altitudes of which are everywhere approximately the same. Yet we know too little about these two ranges to institute any general or definite comparisons between them. From what we do know about them, we may infer that the Arka-tagh possesses the more accentuated relief, a larger number of rocky peaks that still set denudation at defiance, and more extensive snow-fields and glaciers. The circumstance that the known passes of the Arka-tagh are lower than the pass which we have now reached may be of course purely fortuitous; for it would not be difficult to find in the former range passes which in all probability exceed an altitude of 5462 m., while on the other hand the Nameless range possibly possesses other passes which lie considerably lower than the figure just given. That a much greater quantity of snow should lie upon the peripheral ranges than upon the central ranges is self-evident. These last are screened from precipitation by the Himalayas and several other ranges to the north of them. The snow lies thicker upon even the Arka-tagh, owing to the fact that it is not screened by any other ranges to the north, even though it has, lying stretched out at its foot on that side, the arid lowlands of Central Asia. From our experiences of the days which I am now about to describe it will be seen that the country south of this lofty central range is visited by a more copious precipitation than the region to the north of it, though something also must be attributed to the fact' that the rainy season was then approaching the maximum period of its incidence. We also observed that the country south of this same range is rather richer in vegetation than the region north of it, although at the same time the grass for several days southwards was distinguished by the usual niggardliness of Tibet. The faunal life too was rather greater on the same side of the range as compared with the country to the north of it. Still the wild yaks decreased rapidly in numbers as we approached the grazing-grounds of the Tibetan nomads; indeed it may be said that as a rule the wild yak occurs in greatest numbers on the loftiest swelling of the plateau, namely between the Arka-tagh and the great Nameless range. The prospect southwards from the pass was not particularly encouraging. One might have expected to find there, as usual, one of the immense, broad, level latitudinal valleys which separate the mountain-ranges of Tibet. But instead of such, our eyes were met by a chaos of relatively small, low, rounded crests, including the spurs and ramifications of the main range. It soon turned out that we still had a good distance to travel, indeed not less than eleven days, before we reached relatively low regions, that is to say regions possessing the same altitude above sea-level as the summit of Mont Blanc! Immediately south of the pass stretches a highland basin, which lies in general 500 m. higher than the top of the highest mountain in Europe. Our descent from the pass was very gentle, but we soon obtained a clue to the apparently confused relief relations by striking a brook, which showed us the most convenient way down between the ramifications of the range. This stream grew very rapidly bigger in proportion as it was joined by tributaries from both glacier areas. The country here was absolutely barren. 'The strenuous exertions which the caravan had just undergone rendered it imperative that we should halt as soon as ever we possibly could. Accordingly no sooner did the first blades of |
IIIFカラー高解像度
