398 ALONG THE CENTRAL LAKES.
regarded as a special range parallel with and east of the Surla Range. It may be a ramification from the latter. But the most likely hypothesis is that there is only one broad range, and that the Bongba-yeke simply is the eastern front of the Surla Range. The Bongba -yeke should, therefore, be regarded as a portion of the Surla. Such questions as this can only be solved by detailed exploration.
On Tune 13th, our march goes W. S. W. for Do.' km. to Camp CCCCXX VIII, Shaktik, where the altitude is 5,202 m., or 105 m. below the previous camp, being a rate of 1: 96. From this camp Pan. 520A and B, Tab. 98, was sketched, giving a good view of the range of Bongba-yeke-gangri, or simply Yeke-gangri, to the N. N. W., N. W. and west with snowfields and small glaciers. To the N. E. are moderate hills standing east of Peru-Ise. The old beach-lines are partly visible, the highest being 108 m. above the lake. Pan. 519, Tab. 98, is taken from the same place. It shows to the S. S. E. well - developed beach - lines, and to the S. W. and W. S. W., the southern continuation of the Surla Range.
The next day we travelled 8.9 km. W. S. W. , crossing the plain south of the lake and gradually ascending into the broad mouth of the valley of Surla to Camp CCCCXXIX, where the hight was 5,215 m. The ascent is, therefore, only 13 m. and the rate 1 : 685. Pan. 521 and 5 2 2 A and B, Tab. 98, together form an uninterrupted view of the whole horizon. It begins with the comparatively low mountains situated between the Kaj5la and Surla Ranges. To the S. 10° E. is Men-la, a pass on the continental water-parting. To the S. S. W., S. W., west, N. W., and to N. I I° E. is again the Yeke-gangri or northern Surla Range. To the N. 35° E. is a pass called Tsalam-la.
On Tune I6th, our road proceeds W. N. W. for 14.6 km. up the Surla valley to Camp CCCCXXX, Surle -u, with an altitude of 5,525 m., an ascent of 310 m. and a rate of 1:47.
The high pass, Surla-kemi-la, which is a water-parting between the Poru-tso and Shove-Ise, was crossed on Tune 17//i. The direction is N. W. and north. From Camp CCCCXXX we had 3.7 km. to the pass, 5.832 m. high, a rise of 307 m. and a rate of 1 : 12. The descent to Camp CCCCXXXI, Dung-lung, at 5,443 m., was 9.4 km., a fall of 389 m. at a rate of 1:24, or only half as steep. From a point a little to the south of the pass the panorama p. 358, Vol. III, was made in watercolours. It shows some of the glaciers of the Surla Range. The pass is also simply called Sur-la.
On Tune ISM, we continued down 14.6 km. N. W. to Camp CCCCXXXII, Pedangelm, at an altitude of 5,069 m. , a descent of 374 m. at a rate of 1 :39. From a point 4 km. S. 54° E. of Camp CCCCXXXII, Pan. 523, Tab. 98, was drawn, showing portions of the Surla Range to the N. N. E. and N. E. Pan. 524, Tab. 99, is its immediate continuation. To the W. S. W., west and W. N. W. it shows portions of
IIIFカラー高解像度
