I camped, at about 19,500 feet, on the moraine-covered glacier opposite the junction of the northerly branch from Pks. 23,800 and 23,420. On the way up I followed the watercourse between the ice of the Main Rongbuk Glacier and the scree and conglomerate slopes to the East of it, as far as the mouth of the East Rongbuk stream (3 miles), which gave good though boulder-strewn going. Thence a short scramble up "cut-bank" on the right bank of the East Rongbuk stream to the shelf of an old lateral moraine of that glacier, and along the latter--excellent going--to near its snout. The stream is pretty big in the evening; but quite easy to cross--except for iced rocks--in the early morning: and from there I followed up a series of lateral moraines on the left bank, to my camp. It was not till I was coming down that I discovered that the moraine-covered glacier itself--here covered with shale instead of boulders and scree as in the case of the main glacier--gave comfortable walking. A little distance below my camp site, the moraine-covered snout gives place to pinnacled ice, divided into three sections by two broad, shaly medial moraines. Either of the latter would be very suitable for a camp, and would give an excellent route to our 21,500-foot camp below the Chang La. The latter might, I think, be reached by this route in three days from the base camp at the snout of the main glacier, camping the first night at 19,000 feet at the start of the medial moraine, the second at 20,000 feet on the medial moraine some 2 miles above the junction of the Northern and Southern branches of the East Rongbuk, and the third night on snow at 21,500 feet below the North Col. The better moraine to ascend would require reconnaissance; for the pinnacles between them are difficult and slow to cross. The valley sides are steep in the lower reaches of the glacier, but more shaly and gentle on both branches, above their junction.