National Institute of Informatics - Digital Silk Road Project
Digital Archive of Toyo Bunko Rare Books

had the dimensions: breadth = 2.0 m., depth = 0.215 m., velocity = 0.823 m., volume
= 0.354 cub. m; No. II: breadth = 7.6 m., depth = 0.37 m., velocity = 1.04 m., vol-
ume = 2.92 cub. m; No. III: breadth = 3.9 m., depth = 0.22 m., velocity = 0.15 m.,
volume = 0.129 cub. m. Between No. II and No. III the Chema-yundung, including
the six upper branches of the Maryum-chu, had the following dimensions: breadth =
29.8 m., depth = 0.525 m., velocity = 0.976 m., and volume = 15.26; to this the vol-
umes of the separately measured No. I and No. II have to be added, which gives
the whole volume at 18.53 cub. m. The first measurement, which gave 9.97 cub. m.,
was made at 11 o'clock, the second, of 18.53, at 4.30 p. m. This gives an idea of
the very considerable swelling of the rivers towards evening. But as the same is the
case with the Kubi-tsangpo the proportion will always be about the same.
The remaining Maryum-chu branches are situated just west of Umboo. They
had the following dimensions: — No. IV: breadth = 11.0 m., depth = 0.15 m., velocity
= 0.65 m., volume = 1.07 cub. m.; No. V: breadth = 9.8 m., depth = 0.34 m., velocity
= 1.39 m., volume = 4.6 cub. m.; No. VI: breadth = 4.0 m., depth = 0.16 m., velocity
= 0.047 m., volume = 0.028 cub. m.; No. VII: breadth = 6.8 m., depth = 0.14 m.,
velocity = 0.64 m., volume = 0.609 cub. m.; No. VIII: breadth = 12.0 m., depth =
0.19 m., velocity = 0.92 m., volume = 2.09 cub. m.; No. IX: breadth = 6.0 m., depth
= 0.43 m., velocity = 1.06 m., volume = 2.73 cub. m.
All the Maryum-chu branches thus carried 14.53 cub.m. together, though, as
shown above, this value cannot be compared with the results from Shamsang.
From Umboo the road takes us W.S.W. and west to Camp 198 at Tok-
jonsung on the Chema-yundung, where the height is 4,732 m. (15,521 feet). Just
west of Umboo there are several beds, which, in the rainy season, become inundated
by the Maryum-chu, but were now perfectly dry. It is pretty certain, however, that
by far the greatest part of this water comes from the sum-la or three passes of
the Transhimalaya, which were known to the Chinese, but are still unknown to us,
— and not from Maryum-la.
Continuing westwards we leave the valley of Rachen on our right, from which
the Maryum-chu comes down. A little rocky promontory here consists of graywacke
sandstone. A little isolated rock on the right bank of the Chema-yundung, called
Punti-pakto-naya, consists of the same kind of rock. At this point the river, divided
into four branches, is crossed, and the road then follows along the right-side erosion
terrace which is 2 to 3 m. high, rounded and old. Between the foot of this older
terrace and the edge of the present one, is level steppe, with good grass. From the
left, that is to say from the mountain ridge between the Maryum-chu and Chema, two
tributary valleys join the latter, the first called Lanta-ji. To the N.N.W. a dominat-
ing peak with some snow, is called Rachen-sagre. At Tok-jonsung, where nomads
dwelt in three black tents, the Chema is slow and deep, but not far from that place
it forms small rapids. The hard S. W. wind carried much sand and dust through
the valley.