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

125° E. Long. and 37° N. Lat., farther north than the sources of its tributaries, except
the Koas, and 6° above the confluence with the latter. Lassen therefore believes
that he does not mean the real, upper Indus but the Shayok, a view that cannot
possibly be correct. For even of Kashmir, Kaspeira, he had a rather vague idea,
as Dr. STEIN has shown. ¹

We now come to the most interesting question, namely, about the Tsangpo.
Lassen regards it as very likely that the greatest geographer of antiquity should
have known the Brahmaputra, and he positively affirms that Ptolemy calls this
river Bautisus. ² The feeders of Bautisus come from the Emodus, the Kasian and
the Ottorokorrhas mountains. Lassen identifies the Kasian mountains with the
ranges west of Kashgar, the Emodus with the ranges between Buthan and Tibet,
and Ottorokorrhas with the Tibetan Lo-kaha-ptra. It would take us too far to
follow Lassen's argument; be it sufficient to say that he finds an argument in the
very name as well, for the name Bautisus is derived from Bhota, the Indian name
of the Tibetans; therefore Bautisus must be identical with the upper Brahmaputra
or Tsangpo.

Amongst the very great number of authors who have tried to identify Ptole-
my's geography with our present knowledge of Central Asia, I will quote Richt-
hofen. He finds it easy to explain why Ptolemy places the origin of the Bautisus
on the Kasian mountains. ³ He agrees with Lassen in identifying the Bautisus with
the Yeru-tsangpo or upper Brahmaputra, and he finds it natural that the southern
branch should come from Emodus.

Both the situation and the name of the river are striking facts, and at first
sight one feels tempted to agree with Lassen and Richthofen. For my own
part I am, nevertheless, far from persuaded. On Plate III we find two source
branches which, after their junction, flow eastwards and empty themselves in a lake
without outlet. Near the lake is a town, Sera metropolis, and south of it, quite
close to the lake, is a range of mountains, Ottorocoras Mons, which is, it is true,
the immediate continuation of the Serici Montes, Emodii Montes, and Imaus Mons.
This orographical arrangement indeed seems to indicate the Tsangpo. But it is more
than doubtful whether Ptolemy with his long range of mountains meant one single
system, which, compared with our actual knowledge, should represent the Himalaya
system only. I believe his long range includes the whole mountainous land north
of India all the way up to Kwen-lun. The country south of the range is India, the
country north of it is the deserts and steppes of Central Asia.