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

water springs at a lower level than the surface of the lake and probably fed by its
water. Ryder, however, regards the lakes as entirely cut off from the Satlej, the
sources of which must be sought for north or south of the dry Satlej bed west of
the lake region; or else the Manasarovar and Rakas-tal no longer belong to the
Satlej system, a view that is, superficially, correct, but genetically and scientifically wrong.

Ryder gives a good photograph of the entrance to the channel from the Ma-
nasarovar side.¹ Having fixed the Kailas at 21,800 feet and the Gurla-mandata or
Mémo at over 25,000, he went on to Menzé or Misar, which was reached on De-
cember 5th. This speed, necessitated by the advanced season and so as not to
be shut up in Tibet by snow on the Himalayan passes, was too quick to allow the
travellers to make any detailed investigations beyond the survey work. Jerko-la was
found to be 16,200 feet high, Gartok 15,100, Ayi-la 18,700 and Totling 12,200.
He calls this part the most cut-up country he had ever seen. At Shipki, 9,300 feet,
they were able to cross the Satlej on the ice. Shipki-la was 15,400 feet. They
reached Simla on January 11th 1905.

Ryder sums up the results of his expedition in the following words:²
»The area we surveyed with the plane-table comes to about 40,000 square miles. We
surveyed the Tsangpo from Shigatse to its source, surveyed the Mansarowar lake region, and
settled the doubtful points connected with it, which have been the subject of much discussion;
we completed the survey of the Sutlej river from its source to where it enters British terri-
tory, and surveyed the source of the Gartok branch of the Indus. The triangulation was in-
valuable for correcting the plane-table work and fixing many heights.»

As will be shown later on, the expedition cannot be said to have surveyed
the Tsangpo to its very source, as it went north of the source region and surveyed
to the source of the Maryum-chu, which is a tributary. Neither was the hydrograph-
ical problem of the lakes definitely solved, which could be done only by wandering
round the lakes and measuring all their affluents as well as the depth of the lakes
themselves. Only by help of all historical data and detailed exact measurements on
physico-geographical objects can a problem of this character be solved. And only
in connection with all these data can the question of the situation of the genetic,
real source and of the actual, temporary source of the Satlej be answered. For such
observations Ryder's and Rawling's expedition had no time and no opportunity. And
still their programme was fulfilled in the most brilliant way and from a mathematical
point of view their expedition was the most important ever undertaken in Tibet.
Ryder's map is classic, and all cartographical work hereafter carried out in southern
Tibet will have to refer to it, start from it, and be built up on the strong and solid
basis given by Ryder and his comrades.

To Ryder's narrative Captain C. G. RAWLING adds some interesting information,
although he only saw the lakes from some distance, but visited the Satlej bed west