On the 30th of August I arrived at Yeumtong, a small summer cattle-station, on a flat by the Lachoong, 11,920 feet above the sea; the general features of which closely resemble those of the narrow Swiss valleys. The west flank is lofty and precipitous, with narrow gullies still retaining the winter's snow, at 12,500 feet; the east gradually slopes up to the two snowy domes seen from Lachoong; the bed of the valley is alternately a flat lake-bed, in which the river meanders at the rate of three and a half miles an hour, and sudden descents, cumbered with old moraines, over which it rushes in sheets of Loam. Silver-firs ascend nearly to 13,000 feet, where they are replaced by large junipers, sixty feet high: up the valley Chango Khang is seen, with a superb glacier descending to about 14,000 feet on its south flank. Enormous masses of rock were continually precipitated from the west side, close to the shed in which I had taken up my quarters, keeping my people in constant alarm, and causing a great commotion among the yaks, dogs, and ponies. On the opposite side of the river is a deep gorge; in which an immense glacier descends lower than any I have seen in Sikkim. I made several attempts to reach it by the gully of its discharging stream, but was always foiled by the rocks and dense jungle of pines, rhododendron, and dwarf holly. The snow-banks on the face of the dome-shaped mountain appearing favourable for ascertaining the position of the level of perpetual snow, I ascended to them on the 6th of September, and found the mean elevation along an even, continuous, and gradual slope, with a full south-west exposure, to be 15,985 feet by barometer, and 15,816 feet by boiling-point. These beds of snow, however broad and convex, cannot nevertheless be distinguished from glaciers: they occupy, it is true, mountain slopes, and do not fill hollows (like glaciers commonly so called), but they display the ribboned structure of ice, and being viscous fluids, descend at a rate and to a distance depending on the slope, and on the amount of annual accumulation behind. Their termination must therefore be far below that point at which all the snow that falls melts, which is the theoretical line of perpetual snow. Before returning I attempted to proceed northwards to the great glacier, hoping to descend by its lateral moraine, but a heavy snow-storm drove me down to Yeumtong.