Let us now pass ahead of the armies into the southern section of the eastern front. Here we have to consider only Austrian Poland, Galicia and Bukowina, for here there is much less swaying back and forth, the Russians maintaining their lines much more steadily than farther north. This section is an undulating terrace which slopes down to the Vistula and the Dniester; behind rise the Carpathian ranges, forming the natural frontier between the broad, fertile plains of Hungary and Russia. Here the population is quite dense, there being 240 inhabitants to the square mile. Nearly half of the total area is in farm lands, about one-fourth woodland, and the rest mostly meadow and pasture, less than a quarter of one per cent being lake or swamp. Rich crops of barley, oats, rye, wheat, and corn are grown here, while the mineral resources include coal, salt, and petroleum, the latter especially being important in modern warfare on account of the great quantities of fuel necessary for motor carriages. Here, in Galicia, we shall witness the conquests of the important city of Lemberg--with its 160,000 population--fourth in size of all Austrian cities, only Vienna, Prague, and Triest being larger. Further in toward the mountains we shall see the storming of the strongly fortified city of Przemysl (pronounced Prshemisel), also important as the junction of the network of railroads that the Austrians had built throughout the country, including several lines passing over the Carpathians into Hungary. And farther west still we shall look upon the invasion of the old Polish city of Cracow, also strongly fortified. This section is especially rich in industries, mines, and agriculture. Here, too, are staged many of the battles of the rivers--parallel with the mountain ranges flows the Dniester in a southeasterly direction, into which, flowing down from the north and running parallel with each other, empty the Gnila Lipa, the Zlota Lipa, and the Stripa, all of which figure prominently in the war movements, for each of these is crossed several times by both armies engaged at bloody costs. As will be noted by reading the chapters on the fighting on the eastern front, here, as in East Prussia, the Russians make a determined advance and actually succeed in conquering this territory from the Austrians. At one time we find them even in possession of all except one of the chief passes in the Carpathians and threatening to overrun the plains of Hungary. To hold Russian Poland it was necessary that they should have a firm grip of East Prussia and Austrian Poland, thus protecting the flanks of their center. Had they been able to hold their grip, then they could have straightened out their entire line from north to south, and Warsaw would have been safe. But we shall see both their extremities driven back; therefore Warsaw was in danger, in spite of its fortifications.