We come now to the central part of the eastern front.  Here, just below East Prussia, Russian Poland projects into German territory in a great salient, about 200 miles wide and 250 long, resembling a huge bite in shape.

This land is a monotonous, wind-swept plain, slightly undulating, its higher parts not even 500 feet above sea level.  To the northward and eastward it descends gradually into the still lower lands of East Prussia and White Russia, but in the south it lifts into the foothills of the Carpathian Mountains.

Gigantic armies are to move over this plateau, timbered in parts with oak, beech, and lime, and in some sections deeply cut by small rivers and streams forming fissures, some narrow and craggy, others broad and sloping with marshy bottoms.  Toward the south the soldiers must cross narrow ravines in all directions, often covered with wild, thick undergrowth.  The chief river is the Vistula, which enters by the southern boundary and flows first north, then northwest, skirting the plateau region at a height of 700 feet, finally making its exit near Thorn, thence on to the Baltic through East Prussia.  Its valley divides the hilly tracts into two parts:  Lublin heights in the east and the Sedomierz heights to the westward.  Picture in your mind the great armies approaching these ridges, the most notable of which is the Holy Cross Mountains, rising peaks almost 2,000 feet above sea level.

The fighting forces in the northeast, where the plain slopes gradually into the Suwalki Province, must pass over a country dotted with lakes and lagoons, which farther on take on the character of marshes, stagnant ponds, peat bogs, with small streams flowing lazily from one to the other.  Here and there are patches of stunted pine forests, with occasional stretches of fertile, cultivated soil.  Throughout this section many rivers flow along broad, level valleys, separating into various branches which form many islands and, during the rainy seasons, flood the surrounding country.

Farther west the armies pass through broad valleys or basins, once the beds of great lakes, whose rich, alluvial soil give forth abundant crops of cereals.  Here, too, flows the Niemen, 500 miles in length, watering a basin 40,000 square miles in area and separating Poland from Lithuania.  It advances northward in a great, winding pathway, between limestone hills covered with loam or amid forests, its banks rising to high eminences in places, past ruined castles built in the Middle Ages.  In the yellowish soil along its banks grow rich crops of oats, buckwheat, corn, and some rye.  Naturally such a section would be thickly populated, not only on account of the fertile soil, but because the Niemen, like the Vistula, is one of the country’s means of communication and transportation.  As many as 90,000 men earn their livelihoods in navigating the steamers and freight barges passing up and down this great waterway.  At Yurburg the Niemen enters East Prussia on its way to the Baltic.