Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/310

294 Sweden and Zealand), the Great Belt (between Zealand and Fiinen), and the Little Belt (between Fiinen and Jutland). Each of these forms a distinct communication between the Baltic and the Cattegat, which is the open portion of the channel lying between the coast of Sweden and the eastern side of Jutland ; while the Cattegat opens freely into the Skager Rack, which is the continuation of sime open channel, between the southern end of Norway and the north-west coast of Jutland, into the North Sea. The length of the Baltic Sea, from Swinemiinde in the S. to Tornea in the N., is nearly 900 miles ; and its greatest width, between Karlscrona and Memel, exceeds 200 miles. Its &quot;whole area, including the Gulfs of Bothnia and Finland, is about 1GO,000 geographical square miles. It runs first in an easterly direction as far as Memel, a distance of 300 miles, and then northwards as far as lat. 59 21 N., a distance of 350 miles, at which point it separates into two great gulfs. One of these, the Gulf of Finland, runs nearly due E. ; the other, the Gulf of Bothnia, almost -N. The Gulf of Bothnia is 400 miles in length, with an extreme breadth of 120 miles, but where narrowest it does not exceed 40 miles. The archipelago of Aland lies at its entrance. The Gulf of Finland is 280 miles in length, with a mean breadth of GO or 70 miles. The depth of the Baltic rarely exceeds 100 fathoms being greatest between the island of Bornholm and the coast of Sweden, where it reaches 115 fathoms, and least in the neighbourhood of the mouths of large rivers, which bring down a great quantity of earthy matter, especially in tho spring, so that in many parts the bottom is being so r.ipidly raised by its deposit that the mouths of rivers formerly navigable are now inaccessible. This is especially the case in the northern part of the Gulf of Bothnia, above Quarken, where several tracts are now dry land which were once water ; and also in the neighbourhood of Tornea, where meadows now take the place of waters which were traversed in boats by the French Academicians, when they were measuring an arc of the meridian. Along the southern coast the shallowness of the harbours is a great obstacle to navigation, especially since they are closed by ice for nearly one-third of the year. On the western side it is not more than 15 fathoms deep ; and, in general, it is only from 8 to 10 fathoms. On the S. it nowhere exceeds 50 fathoms. The Gulf of Finland suddenly shallows from 50 or GO fathoms to 5, or even less. The average depth of the Gulf of Bothnia is not greater than that of the rest of the sea. Numerous rocky islands and reefs, many of them level with the water, render the navigation of this sea extremely dangerous. The shore of the Baltic is generally low. Along the southern coast it is for the most part sandy, with sand banks outside, and sand-hills and plains inland. Where streams come down, there are often fresh-water lakes termed kaffs, which are separated from the sea by narrow spits called nehrungs. Two of these haffs are of great extent ; one of them, termed the Frische Haff, lies between Danzig and Konigsberg, which last town is situated on the part of it most remote from the sea ; the other, termed the Kurische Haff, lies between Konigsberg and Memel, the latter town being situated on the channel connecting the haff with the sea. Near the entrance to the Gulf of Fin land the coast becomes rocky, and continues to be so for the most part around the gulfs both of Finland and Bothnia, except towards the head of each ; the rocks, however, are never high. The shores of the southern part of the Swedish peninsula are mostly high, but not rocky ; at Stockholm, however, there is an archipelago of rocky islands, on some of which the town is partly built.

Drainage Area.—The Baltic may be considered as the estuary of a great number of rivers, none of them individu ally of great size, but collectively draining a very large area, which is estimated at about 717,000 square miles, or nearly one-fifth of the entire area of Europe. This great drainage area is remarkable for the small proportion of its boundary that is formed by mountains or high table-lands, its greater part consisting of land of no considerable elevation, which slopes down very gradually to its coast-line, and of which a large proportion is covered by lakes. This is especially the character of the drainage area of the Neva, whose waters are immediately derived from the large shallow Lake Ladoga, which receives the contributions of numerous other lakes, Onega being the largest, though Lake Saima in Finland, with its irregular prolongations, is scarcely less extensive. The entire surface drained by the Neva is esti mated at about 100,000 square miles, or nearly twenty times that of the drainage area of the Thames. Through Lake Onega, the Nova is connected with the Dwina and the Volga by canals, through which small vessels can pass from the Baltic into either the White Sea or the Caspian. The Duna or South Dwina, which discharges itself into the Gulf of Riga, is another important river, draining an area of about 35,000 miles in West Russia, and having a length of 520 miles, of which 405 miles are navigable. The drainage area of the Nienien, which enters the Baltic at Memel, is conterminous with that of the Duna, and is of about the same extent ; this river is navigable for more than 400 miles from its outlet, and communicates with the Dnieper by a canal through which vessels can pass from the Baltic to the Black Sea. The Vistula, which receives the waters of the whole area of Russian and Prussian Poland, flowing past Warsaw into the Baltic at Dantzig, is a very large and important river, having a length of 520 miles, of which 430 are navigable, and a drainage area of 72,000 square miles. And the Oder, rising in the hill districts of Silesia, drains the extensive level areas of Brandenberg and Pomerania, and discharges into an estuary, that may be said to begin from Stettin, the water drawn from an area of 45,000 square miles. Numerous rivers discharge themselves into the Gulf of Bothnia, bringing down water from the mountain ranges of Sweden and Norway ; but their course is comparatively short and direct, with few tributaries, so that, individually, they do not attain any great size. The drainage of the more level southern portion of Sweden is for the most part collected by the great lakes Wener, Wetter, and Malar, of which the first pours its water into the North Sea, and the others into the Baltic. By means of a canal joining Lakes Weuer and Wetter vessels can pass directly from the Cattegat into the Baltic.

Climate.—It is not only, however, the extent of its drainage area, but the large proportion borne by the rain and snow which fall upon that area to the amount dissipated by evaporation from its surface, that goes to swell the aggre gate of fresh water poured into the basin of the Baltic ; for there is probably no inhabited region of the whole globe over which so large a quantity of snow falls, in proportion to its area, as it does in the countries round this basin. They receive, direct from the Atlantic, a vast amount of moisture brought by its west and south-west winds ; and even the winds which have already passed over the low plains of Jutland and Northern Germany will have parted with little of their moisture before reaching the Baltic provinces of Russia. When these vapour-laden west and south-west winds meet the cold dry east and north-east winds of Siberia, their moisture is precipitated, in summer as rain, and in winter as snow; and owing to the prevalence of a low atmospheric temperature through a large part of the year, the proportion lost by evaporation is extremely small as compared with what passes off from other inland seas. The large excess of the amount of fresh water dis- 