ore powerful people at the
south, the Russians chose to advance eastward along higher latitudes
toward the Pacific. But within a few years after the Muscovite empire
had acquired central and northern Siberia, there were loud complaints
that the tribes on the south were making raids on them, robbing them of
their property and carrying their people into slavery. So, from time to
time, Cossack forces were sent to chastise the offenders; and in many
instances they were punished and their territories were annexed to
Siberia.

In these raids the Turkomans were the most active. During the forty
years previous to 1878 it is estimated that eighty thousand Russian
subjects and two hundred thousand Persians were made captives and sold
into slavery. In 1873 the Russians captured Khiva and liberated thirty
thousand Persian slaves.

Notwithstanding these lessons, some of the Turkoman tribes still went on
marauding expeditions, robbing, killing, and enslaving their neighbors.
So, in 1878, another strong force of the Cossacks was sent against the
pillaging tribes, who were made to release all slaves and abolish
slavery. Little by little all Turkistan became Russian territory.
Bokhara and Khiva alone keep their old forms of government, but they are
practically Russian states and pay Russia annually a stipulated tribute.

It is thought that once upon a time Siberia had a much larger population
than it has now and the peoples who lived there dwelt farther north. The
first colonists lived in the stone age and were contemporaneous with the
mammoth, whose remains are found scattered all over the northern part of
Siberia and the adjacent islands.

In the interior these remains are found imbedded in thick strata of pure
blue ice, which is covered by the river gravels of streams that do not
now exist. So thick are these layers of ice that they may be likened to
the rocks found in lower latitudes. Several of these animals have been
found imbedded in the ice in an almost perfect state of preservation,
and quantities of their tusks are obtained annually along the northern
rivers where the spring freshets have worn away the banks of the
streams.

Whenever the ivory-tusk hunter sees the end of a tusk sticking out of
the river bank, he is soon able to remove it from its resting place with
pick and shovel. Great quantities of this fossil ivory are also obtained
from the islands to the north of the mainland.

As in arctic America, the ground of