Nature has provided a substitute in the splendid waterways. In about the center of European Russia, rises the Valdai plateau to a height of 1,100 feet above the sea level. This is Russia's great watershed. Near it, in Lake Volgo, rises the largest river of Europe, "Mother Volga," as the Russian ballad singers love to call it. Its entire length is 2,336 miles, or nearly the length of the Missouri; it has a basin of 590,000 square miles. Owing to the slight slope of the land, the great river flows placidly in its bed, which is fortunate since its Waters are swollen by several large rivers, so that there are points where it is seventeen miles wide. The Kama, one of the tributaries of the Volga, is 1,266 miles long; the Oka, another confluent, has a length of 633 miles. At Kazan, the Volga is 4,953 feet wide, at Jaroslaf 2,106 feet, and at Samara, 2,446 feet. It empties into the Caspian Sea, with a delta of more than seventy branches. The fish caught in this river often grow to gigantic proportions; its sturgeons, lampreys, and salmon, are highly prized. Since time immemorial, the Volga has been a great highway of trade. Kostroma, Nishni Novgorod, Kazan, Simbirsk, Saratof, and Astrakhan, are the most populous cities on its banks. Other large rivers rise on the Valdai plateau. The Dnieper runs (p. 020) south, passing by Kief, and empties in the Black Sea, near Odessa. The Dwina runs northward, seeking the icy Arctic, which it enters by way of the White Sea near Archangel. The Duena takes a westerly course towards the Gulf of Riga where it empties near the city of that name. Of greater importance are the small streams which feed Lakes Ladoga and Onega, because they connect Central Russia with the Baltic Sea by means of the Neva. European Russia is usually divided into four zones or belts, from the character of the soil and the nature of its productions; their general direction is from southwest to northeast. In the north, as a screen against the Arctic blast, is the _poliessa_ or forest region, densely covered with lindens, birches, larches, and sycamores, with oaks on the southern fringe. These forests are invaluable to Russia where, in the absence of mountains, stone is scarce. The houses are built of wood, and fires are of common occurrence. Both lumber and fuel are supplied by these forests which originally extended to Novgorod, Moscow, and Jaroslaf. The increase in population together with the growing demand for lumber, have caused extensive clearings; but the area covered by the forests is so large, that the supply is well-nigh inexhaustible.