Physical geography. By Mary Somerville ...

CHIAP. XVIII. SIBERIAN RIVERS. 245
and Little Kern. The former rises at the junction of the Sayansk
range with the Baikalian mountains to the north-west of Lake Kassagol; the latter comes from the Egtag or Little Altai, in quite an
opposite direction, so that these two meet nearly at right angles, and
take the name of Yenessei; it then crosses the Sagaetses range in
cataracts and rapids, entering the plains of Siberia below the town
of Krasnojarsk. Below this many rivers join it, chiefly the Angara
from the Lake Baikal; but its greatest tributaries, the Upper and
Lower Tunguska, both large rivers from the Baikalian mountains,
join it lower down, the first to the south, the latter to the north of
the town of Yeniseisk, whence it runs north to the Icy Ocean, there
forming a large gulf, its length, measured along its bed, being 2500
miles.
The Oby rises in the Lake of Toleskoi, " the Lake of Gold," in
Great Tartary; all the streams of the Lesser Altai unite to swell it
and its great tributary the Irtish. The rivers which come from the
northern declivity of the mountains go to the Oby, those from the
western side to the Irtish, which springs from numerous streams on
the south-western declivity of the Little Altai, and run westward
into Lake Zaidzan, 200 miles in circumference. Issuing from thence,
it takes a westerly course to the plain on the north of Semipolatinsk.
In the plain it is joined by the Tobol, which crosses the steppe of
the Kirghiz Cossacks from the Ural Mountains, and soon unites with
the Oby; the joint stream then proceeds to the Arctic Ocean in 67~
N. lat. The Oby is 2000 miles long, and the basin of these two
rivers occupies a third part of Siberia.
Before the Oby leaves the mountains, at a distance of 1200 miles
from the Arctic Ocean, its surface has an absolute elevation of not
more than 400 feet, and the Irtish, at the same distance, is only 72
feet higher; both are consequently sluggish. When the snow melts,
they cover the country like seas; and as the inclination of the plains
in the middle and lower parts of their course is not sufficient to carry
off the water, those immense lakes and marshes are formed which
characterize this portion of Siberia.
The bed of the Oby is very deep, and there are no soundings at
its mouth; hence the largest vessels might ascend at least to its junction with the Irtish. Its many affluents also might admit ships, did
not the climate form an insurmountable obstacle the greater part of
the year. Indeed all Siberian rivers are frozen annually for many
months, and even the ocean along the Arctic coasts is rarely disencumbered from ice; therefore these vast rivers never can be important as navigable streams. They abound in fish and water-fowl, for
which the Siberian peasant braves the extremest severity of the
climate.
Local circumstances have. nowhere produced a greater difference
in the human race than in the basins of the great rivers north and
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