Baltic Sea is the great inland sea, bordered by Denmark, Germany, Russia, Finland and Sweden. It is nearly 900 miles long, from 100 to 200 miles broad, and 40 to 140 fathoms deep, and has an area, including the Gulfs of Finland and Bothnia, of 184,496 square miles, over 12,000 square miles being occupied by islands. The great number of islands, the sudden changes of wind and the violent storms make navigation very dangerous. The main gulfs are those of Bothnia, Finland and Riga. About 250 rivers flow into it, which makes the sea much more nearly fresh water than other bodies of salt water. For this reason it freezes easily, so that navigation is interfered with from three to five months in the year. The chief rivers are the Oder, Vistula, Niemen, Düna, Narva and Neva. The shipping-trade is large, the exports of the countries around the Baltic being timber, hides, tallow and grain. The Eider and Gotha Canals connect the Baltic and the North Sea. A larger canal for ships from the mouth of the Elbe to Kiel Bay was begun in 1887 and completed in 1895. It cuts the base of the peninsula of Jutland through Schleswig-Holstein. It is about sixty miles long and saves a dangerous voyage of about 600 miles. Another projected canal is a Russian enterprise, which is designed to connect the Gulf of Riga with southern Russia at Kherson, north of the Crimea. It will utilize the water ways of the Düna and the Dnieper. The most important harbors on the Baltic are Copenhagen, Kiel, Lübeck, Stralsund, Stettin, Dantzic, Königsberg, Memel, Riga, Narva, Kronstadt, Sveaborg, Stockholm and Karlskrona. A noticeable feature of the Baltic is the slow vertical movement of its coasts downward in the south of Sweden and an upward movement farther north. Its area is said to be gradually decreasing. The Germans call it the East Sea. The Baltic is connected with the Cattegat and the North Sea by the Sound and the Great and Little Belts.