The air which issued from these funnel-shaped apertures was very sensibly warm, and had a strongly sulphurous odour. Unfortunately, we had not anticipated the necessity for observing the temperature, which was not by any means oppressive, and was only remarkable in contrast with the extreme cold of the external air.
In the neighbourhood of the sulphur-pits, the hot springs along the course of the stream were very numerous, evolving much gas. A little higher they ceased altogether, and the upper part of the plain was without any springs, as was evident from the quantity of ice by which it was covered. For more than a mile it was a dead level, and very swampy; but afterwards the valley became gently sloping and gravelly, the little stream being often hidden under the pebbles. Large boulders of the same granite which we had observed the day before, were scattered over the surface. The vegetation in this valley was extremely scanty, a few scattered tufts of _Dama_, and some shrubby _Artemisiæ_, were occasionally seen, but the herbaceous vegetation had been almost entirely destroyed by the intense morning frosts, which had for some time been of daily occurrence. On the latter part of the day's journey the rock on the mountain-side changed from mica-slate to gneiss, of which very lofty scarped cliffs rose abruptly on the right hand. We encamped on a level spot, after ten miles of almost imperceptible ascent.
Next morning we continued to ascend the valley, which was now very rugged, from masses of boulders, which were heaped one on another to a very great thickness. The stream had cut for itself a narrow channel, nearly a hundred feet in depth, the walls of which were entirely composed of huge incoherent masses of rock, all more or less angular. A walk of three miles brought us to the crest of the pass, which was nearly level and grassy for about a mile; its elevation was about 16,500 feet. The pass (Pulokanka La) is a very deep depression in the axis of the chain, which runs parallel to the left bank of the Indus, separating the waters tributary to that river from those which join the Zanskar river, some of the feeders of the latter springing from the valleys on the western slopes of these mountains. The hills right and left of the pass rise very boldly into rugged masses, contrasting strongly with the level plain which constitutes the pass, in which the watershed is scarcely perceptible.