国立情報学研究所 - ディジタル・シルクロード・プロジェクト
『東洋文庫所蔵』貴重書デジタルアーカイブ

it is partly on the left, partly on the right side. Generally the river keeps to the
left or northern side where the mountains are steep; the southern hills are rounded
and afford excellent pasture grounds in summer. At a place called Nira, where the
road crosses the river, the rock consists of pegmatite and mica schist. Karcha-samba
is a bridge in ruins. Above this place the erosion terraces are in four stories, the
highest some fifty metres above the bottom of the valley.
The next section of the road, from Chomo-sumdo to Sha-oktsang, takes us over
the Chang-la-Pod-la. We have found the rise up the Mü-chu valley rather gradual,
although the ascent becomes somewhat steeper from stage to stage. But only close
to the crest of this water-parting range of Pabla does the slope become really steep. The
ascent from Chomo-sumdo to Chang-la-Pod-la or half a day's march, is more con-
siderable, 777 m, than the ascent the whole way up from Lingö, to Chomo-sumdo
or 725 m, eight days' journey. On the Chang-tang or northern side of the pass
we have four days' journey to reach a place where the altitude is about the same
as that of Chomo-sumdo, or 4 795 m. This gives an idea of the elevation and flat-
ness of the Chang-tang as compared with the southern side of the system, where the
running water has cut down the deep peripheric valleys.
From Chomo-sumdo to the pass the left or northern tributaries are: Yagelung
and Kemolung, Shalung, Tori and Kongmo, which comes from a pass not far N.E.
of Chang-la-Pod-la and in the same range; Tugelung is the last tributary, quite small
and with a flat, black mountain in its background. The right tributaries are: Shubru
with the high mountain Kaso in its upper part; near its mouth the solid rock con-
sists of marble. Pelung is a small valley; Tsak is a little larger and comes from
rocky mountains to the south.
The main valley up to the pass is full of gravel; the terraces become more
irregular and smaller. At a place called Chomo-taka there are hermits' grottos in
the very steep rocks of quartzitic mica schist. Near the junction with the Kongmo
the living rock consists of quartzitic sandstone. Finally the valley opens out and
the relative heights diminish. The pass has a height of 5 572 m., and forms a
large slightly rounded plateau. It is also called Chang-la-Pö-la, Pöd and Pö being
different pronunciations of the same word, meaning Tibet Proper, or southern Tibet,
inhabited by a settled population, in contrast to Chang-tang or the northern plains,
where only nomads live. Sometimes the pass is also called Chomo-la. The view
is limited; only to the east is a confusion of ridges and flat peaks seen, separated
from each other by innumerable small valleys.
On Chang-la-Pod-la we leave the system of Mü-chu. We have found it to
consist of a very deep cut main valley with two great tributaries, Bup-chu and Raga-
tsangpo, several moderate valleys and a great number of small tributaries. Combining
the first and second crossings, we get a fuller understanding of the topography of
the system, although every detail remains in darkness regarding the country between
my first crossing and the valley of Ta-nakpo-chu. The country west of the Mü-