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

information I can now supply refers to the depth of the lake, an interesting subject of enquiry,
and one which has, I believe, never been investigated with reference to this or any other of the
Himalayan Lakes. A portable India rubber boat, which I had procured from England in the
hope of ultimately floating it on Lake Lob, was the means which enabled Captain Biddulph
and myself to make a section across the bottom of the lake. We arranged to halt a day for
the purpose at Lukong.

The soundings were taken by Captain Biddulph with a fishing line, which I had carefully
measured and marked before starting. We fortunately had a quiet day, and owing to the
entire absence of wind and current there was not the slightest difficulty in getting these
soundings most accurately.

Starting from the sandy shore at the west end of the lake we made for the island,
lying about two miles off and situate nearly equidistant from the two sides of the lake. At 100
yards from the shore (N.B.—The horizontal distances are only rough estimations) the depth
was 55 feet, the bank sinking gradually; 150 yards further on, the depth was 93 feet, and 200
yards further 112 feet; at 550 yards more, depth 130 feet, the maximum depth reached between
shore and island. As we approached the latter the water grew rapidly shallow. At a distance
of 400 yards from it, there was only 50 feet of water, and at 250 yards only 14 feet, from this
point a shelving sandy bottom stretched up to the island, which consisted of a mass of rocks,
about 150 yards in length and considerably less in breadth, of irregular shape, and extending in a
direction parallel to that of the lake, viz., from north-west to south-east. It was composed mostly
of calcareous tuffa, and in no place rose to more than four feet above the surface of the lake.
The rock was very brittle and jagged, and in many places was covered with masses of shells, of
which I brought away specimens: these shells appeared to me to have become only recently
untenanted, but they were pronounced by Dr. Stoliczka to be many centuries old and to be
fresh-water specimens. The island or rather islands (a short distance from the main rock in
a south-east direction is a long sandbank rising only a few inches above the water) are
submerged during heavy storms, for we found many fragments of wood, weeds, and even
cattle dung, which had evidently been washed ashore from the mainland. Although the
water was beautifully clear we looked in vain for fish, and with the exception of a species of
bug, of which myriads were swimming about, we failed to see any animal or signs of life
of any description. This is the more curious, as in a small stream which flows into the
lake near Lukong there is an abundance of fish. The temperature of the water, which was
decidedly brackish, was 55° F.; its color, a very pure blue where deep, and green where shallow.

From the island I pulled to the north shore of the lake, which lying under precipi-
tous cliffs I expected to find much deeper. The water deepened out gradually to 107 feet at
300 yards from the island, and at about half way across, say half a mile from shore, there was a
depth of 136 feet; at 250 yards from the mainshore we found 142 feet; at 100 yards, 114 feet;
at 50 yards, 95 feet; at 30 yards, 80 feet; at 20 yards, 50 feet; at 10 yards, 12 feet. The boat,
12 feet long, was very well adapted for work of the kind, and in the absence of wind I was,
without violent exertion, able to pull it along, carrying one passenger, at the rate of nearly, if
not quite, four miles an hour, and this at an elevation of 14,000 feet above the sea. In fact
the exertion required was considerably less than would be needed for walking at the same pace.
The banks of the lake, which is about forty miles in length, showed evident signs of the water
having formerly stood at a much higher level than it does at present: and there can be little
doubt but that the valley along which the road passes from Tankse up to the lake, was, at no
very distant period, its main outlet; for although there is now a low pass, about two miles
from the head of the lake, yet it is not much more than 100 feet above the present level of the
water, and is moreover chiefly formed by detritus washed down from two side ravines, and of
very recent formation.

With reference to my short excursion up the Kárákásh in search of a new road, I
left Sugét on the morning of the 17th October, and was accompanied as far as Balakehi (9 miles)
by Drs. Bellew and Stoliczka, who were paying a visit to the jade mines. After leaving them
I marched on for two and a half hours to Gúlbáshem, where I met Captain Biddulph on his way
down the Kárákásh to Sháhidúla. My syce (groom) and guide, the only man in our united camps
at Sugét, who professed to know of the existence of the road I was now searching for, had led