CHARACTERISTICS AND DISTRIBUTION OF LAKES 599 
accumulated there in a past epoch, and ultimately found its wayjto 
the ocean in a north-westerly direction as the rivers Yenisei, Selenga, 
Vitim, etc., formed first a succession of large lakes along the inner 
base of the range bordering the plateaus, traces of which are still 
seen in Kosso-gol and Lakes Shaksha and Bahunt. The overflowing 
streams from these lakes cut their way through the range and formed 
another series of lakes on the outer side. These in turn overflowed, 
and the waters subsequently found their way to the sea. 
Lake Telezkoie (or Altyn Kol) was surveyed in the summer of River Obi. 
1901 by an expedition under Ignatov.^ The lake lies in a narrow 
valley at an elevation of 1700 feet above the sea, has a length of 48 
miles, with a breadth of 33 miles, the widest part being in the south, 
and covers an area of about 880 square miles. The main portion of 
the lake runs north and south, the Chulishman River entering at the 
southern end, while the Biya, which makes its exit at the north-west 
end, joins the Katun to form the Obi. Tectonic causes have evidently 
contributed to the origin of the lake. The result of 2500 soundings 
is to show that it is shallow in its northern section, but reaches 
a depth of about 1017 feet in the south. There are two deep basins, 
separated by a submerged ridge, over which the depth is 870 feet. In 
the middle of June 1901, the surface temperature was 39° Fahr. 
(3° -9 C), and the temperature of the lower layers 374° Fahr. (3°-l C), 
while the temperature of the inflowing streams was 48° to 57° Fahr. 
(8° '9 to 13° '9 C). About the middle of July the surface temperature 
was 531° to 61° Fahr. (12° to 16°-1 C). The shallow portion freezes 
over in November ; the deep southern portion is rarely frozen over — 
perhaps once in seven years. 
Zaisan Lake. — The great tributary of the Obi, the Irtish, gathers 
its head streams in the Zaisan Lake, 80 square miles in area, Iving 
at an elevation of 1350 feet in a valley of the Altai. 
Lake Baikal. — The largest lake of this system is Lake Baikal, a River Yenisei, 
deep, long trough in the crystalline mountains, drained by the Angara, 
a tributary of the Yenisei. Different authorities give varving figures 
for the dimensions of the lake, but those of Schokalsky ^ are given 
here as representing the most recent survey. The length is over 370 
miles, the breadth over 50 miles, and the area is about 11,580 square 
miles ; the altitude of the surface is 1588 feet above sea-level, and the 
bottom of the lake is 3825 feet below sea-level, the maximum depth 
being 5413 feet — said to be the greatest depth in any lake. The 
1 See Globus, Bd. Ixxxi. p. 34, 1902. 
2 Schokalsky and Schmidt, Exploratiojis scientifiques des Mers et des Eaux douces 
de V Empire russe (Section Scient., Exp. Maritime Intern., Bordeaux, 1907). 
