and excavated by the ice. Probably the large basins which I had crossed on my way from Kuti, and even the last one, facing our camp, were after all reservoirs formed by ancient moraines with alluvial deposits. [13] It must be remembered that at high elevations the exertion of walking eight miles would be equivalent to that of marching about twice the distance at much lower altitudes. [14] See Appendix. Letter by Dr. H. Wilson. CHAPTER XXIV Snow and troublesome _debris_--The doctor's sufferings--Kachi disabled--Further trials--A weird apparition--Delirium--All safe--The descent. THE Mangshan River rises from this glacier, but we left the glacier (17,800 feet) to the right, and, turning sharply northwards, began our ascent towards the pass. To gaze upon the incline before us was alone sufficient to deter one from attempting to climb it, had one a choice; in addition to this, the snow we struggled over was so soft and deep that we sank into it up to our waists. Occasionally the snow alternated with patches of loose _debris_ and rotten rock, on which we were no better off; in fact, the fatigue of progressing over them was simply overpowering. Having climbed up half-a-dozen steps among the loose cutting stones, we felt ourselves sliding back to almost our original point of departure, followed by a small avalanche of shifting material that only stopped when it got to the foot of the mountain. At 19,000 feet we were for a considerable distance on soft snow, covering an ice-field with deep crevasses and cracks in it. We had to feel our way with great caution, particularly as there was only the light of the moon to depend upon.