Rivers and Lakes.— The main European watershed runs in a winding direction from southwest to northeast, at its northeastern ex tremity being of very slight elevation. From the Alps descend some of the largest of the European rivers, the Rhine, the Rhone and the Po, while the Danube, a still greater stream, rises in the Black Forest north of the Alps. The Volga, which enters the Caspian Sea, an inland sheet without outlet, is the longest of European rivers, having a direct length of nearly 1,700 miles, including windings of 2,400 miles. Into the Mediterranean flow the Ebro, the RhOne and the Po; into the Black Sea, the Danube, Dnieper Dniester and Don (through the Sea of Azov) ; into the Atlantic, the Guadil quivir, the Guadiana, the Tagus and Loire; into the English Channel, the Seine; into the North Sea, the Rhine, Elbe; into the Baltic, the Oder, the Vistula and the Duna; into the Arctic Ocean, the Dwina. The lakes of Europe may be divided into two groups, the southern and the northern. The former run along both sides of the Alps, and among them, on the north side, are the lakes of Geneva, Neuchatel, Thun, Lucerne, Zurich and Constance; on the south side, Lago Maggiore, and the lakes of Como, Lugano, Iseo and Garda. The northern lakes extend across Sweden from west to east, and on the east side of the Baltic a number of lakes, stretching in the same direction across Finland on the borders of Russia, mark the continuation of the line of depression. It is in Russia that the largest European lakes are found — Lakes Ladoga and Onega.
Geology.— The geological features of Europe are exceedingly varied. The older formations prevail in the northern part as compared with the southern half and the middle region. North of the latitude of Edin. burgh and Moscow there is very little of the surface of more recent origin than the strata of the upper Jura belonging to the Mesozoic Period, and there are vast tracts occupied either by eruptive rocks or one or other of the older sedimentary formations. Denmark and the por tions of Germany adjoining belong to the Creta ceous Period, as does also a large part of Russia between the Volga and the basin of the Dnieper. Middle and eastern Germany with Poland and the valley of the Dnieper present on the sur face Eocene formations of the Tertiary Period. The remainder of Europe is remarkable for the great diversity of its superficial structure, rocks and deposits belonging to all periods being found within it, and having for the most part no great superficial extent. Europe possesses abundant stores of those minerals which are of most importance to man, such as coal and iron, Great Britain being particularly favored in this respect. Coal and iron are also obtained in France, Belgium and Germany. Gold is found to an unimportant extent, and silver is widely spread in small quantities. The richest silver
ores are in Norway, Spain, the Erzgebirge and the Harz Mountains. Spain is also rich in quicksilver. Copper ores are abundant in the Ural Mountains, Thuringia, Cornwall and Spain. Tin ores are found in Cornwall, the Erzge birge and Brittany.
Climate.— Several circumstances concur to give Europe a climate peculiarly genial, such as its position almost wholly within the temperate zone, and the great extent of its maritime boundaries. Much benefit is also derived from the fact that its shores are exposed to the warm marine currents and warm winds from the southwest, which prevent the formation of ice on most of its northern shores. The eastern portion has a less favorable climate than the western. The extremes of temperature are greater, the summer being hotter and the winter colder, while the lines of equal mean temper ature decline south as we go east. The same advantages of mild and genial temperature which western has over eastern Europe, the continent collectively has over the rest of the Old World. The diminution of mean temper ature, as well as the intensity of the opposite seasons, increases as we go east. Peking, in lat. 40° N., has as severe a winter as Petrograd in lat. Botany,— With respect to the vegetable kingdom Europe may be divided into four zones. The first, or most northern, is that of fir and birch. The birch reaches almost to North Cape; the fir ceases a degree farther south. The culti vation of grain extends farther north than might be supposed. Barley ripens even under the 70th parallel of north latitude; wheat ceases at 64° in Norway to lat. 62° in Sweden. Within this zone the southern limit of which ex tends from lat. 64° in Norway to lat. 62° Russia, agriculture has little importance, its inhabitants being chiefly occupied with the care of reindeer or cattle, and in fishing. The next zone, which may be called that of the oak and beech, and cereal produce, extends from the limit above mentioned to the 48th parallel. The Alps, though beyond the limit, by reason of their ele vation belong to this zone, in the moister parts of which cattle husbandry has been brought to perfection. Next we find the zone of the chest nut and vine, occupying the space between the 48th parallel and the mountain chains of south ern Europe. Here the oak still flourishes, but the pine species become rarer. Rye, which char acterizes the preceding zone on the continent, gives way to wheat, and in the southern portion of it to maize also. The fourth zone, compre hending the southern peninsula, is that of the olive and evergreen woods. The orange, lemon and olive flourish in the southern portion of it, and rice is cultivated in a few spots in Italy and Spain.