se,
something like the back of a half-submerged submarine, which seems to
cross the country, where the land becomes more solid. The armies must
move, instead of through marshes, along innumerable small lakes, most of
the lakes being long and narrow and running north and south, with a
fairly thick growth of timber among them, mostly pine and spruce and
fir. In character this section is rather similar to parts of Minnesota.
There are two cities to be conquered in this drier region, Dvinsk, and,
further south, Vilna, once the chief city or capital of the Lithuanians.
We shall see the Russians thrust back from Koenigsberg, and the heavy
fighting shifted over to this section; yet even here, where the huge
guns of the Germans could find footing, the terrain was not suited to
trench warfare, and every arrival of reenforcements on either side would
swing the lines back or forth.

In studying the military movements in a country of this character,
special attention must be paid to the railway lines. Railways, and more
especially those running parallel to the fronts, are absolutely
necessary to success. In looking, therefore, for a key to the object of
any particular movement, the first step must be a close study of this
railroad situation.

We find from Riga to the fortress of Rovno there is a continuous line of
railroad, running generally north and south and passing through Dvinsk,
Vilna, Lida, Rovno, and thence down through Poland to Lemberg. Every
effort of the Russian armies in the succeeding chapters will be made to
keep to the westward of and parallel to this line, and for a very good
reason.

Feeding into this great north and south artery are the branch lines from
Petrograd to Dvinsk; from Moscow to the junction at Baranovitschi; from
Kiev to Sarny. Aside from these three important branch lines, there are
a few other single-track off-shoots, but from a military point of view
they are of no importance.

This line was the main objective (short of capturing Riga itself) of the
German operations. This line proves especially vital to the Russians,
for nowhere east of it is there another such line which could be used
for the same purpose.

If, in the campaigns to be described, this railroad falls into Russian
hands, it gives every facility for strengthening or reenforcing any part
of the Russian front where German pressure becomes excessive. It is, in
addition, a solution to the difficult problem of transportation of
supp