t--all these belong
to one immense Alpine belt bordering that of the plateaus. These
have long been known to Russian colonists, who, seeking to escape
religious persecutions and exactions by the state, early penetrated
into and rapidly pushed their small settlements up the better valleys
of these tracts, and continued to spread everywhere as long as
they found no obstacles in the shape of a former population or in
unfavourable climatic conditions.

As for the flat-lands which extend from the Alpine hill-foots to
the shores of the Arctic Ocean, and assume the character either of
dry deserts in the Aral-Caspian depression, or of low table-lands
in central Russia and eastern Siberia, of lake-regions in north-west
Russia and Finland, or of marshy prairies in western Siberia, and of
_tundras_ in the north,--their monotonous surfaces are diversified
by only a few, and these for the most part low, hilly tracts.

As to the picturesque Bureya mountains on the Amur, the forest-clothed
Sikhota-alin on the Pacific, and the volcanic chains of Kamchatka,
they belong to quite another orographical world; they are the
border-ridges of the terraces by which the great plateau-belt descends
to the depths of the Pacific Ocean. It is owing to these leading
orographical features--divined by Carl Ritter, but only within
the present day revealed by geographical research--that so many
of the great rivers of the old continent are comprised within the
limits of the Russian empire. Taking rise on the plateau-belt, or
in its Alpine outskirts, they flow first, like the upper Rhone
and Rhine, along high longitudinal valleys formerly filled up with
great lakes; next they find their way through the rocky walls;
and finally they enter the lowlands, where they become navigable,
and, describing great curves to avoid here and there the minor
plateaus and hilly tracts, they bring into water-communication
with one another places thousands of miles apart. The double
river-systems of the Volga and Kama, the Obi and Irtish, the Angara
and Yenisei, the Lena and Vitim on the Arctic slope, the Amur and
Sungari on the Pacific slope, are instances. They were the true
channels of Russian colonization.

A broad depression--the Aral-Caspian desert--has arisen where the
plateau-belt has reached its greatest height and suddenly changes
its direction from a north-western into a north-eastern one; this
desert is now filled only to a small extent by the salt waters of
t