BALTIC SEA, an enclosure of the North Sea with which it is connected by the Skager rack and Kattegat. It washes the coasts of Denmark, Germany, Courland, Livonia and other parts of Russia and of Sweden, and ex tends to lat. 65° 30' N. It is nearly 930 miles long, from 50 to 425 broad, and its superficial extent, together with the contents of the gulfs of Bothnia and Finland, amounts to 160,000 square miles. Its generally small breadth; its depth, amounting on an average to from 40 to i 50 fathoms, but in many places hardly half so much; its shallowness toward the Prussian shores, and the rugged nature of the Swedish coasts, where deepest water is sounded (1,542 feet south of Stockholm); but above all, the sudden and frequent changes of the wind, ac companied by violent storms (especially from the east), render this sea dangerous for navi gators, although its waves are less powerful than those of the North Sea. A chain of islands separates the southern part from the northern, or the Gulf of Bothnia. In the north east the Gulf of Finland stretches eastward and separates the province of Finland from Esthonia. A third gulf is that of Riga or Livonia. The Kurisches Haff and the Frisches Haff are inlets or lagoons on the Prussian coast. The water of the Baltic is colder and clearer than that of the ocean; it contains a smaller proportion of salt, and ice obstructs the navigation three or four months in the year. The ebb and flow of the tide are inconsiderable, as is the case in other inland seas, the difference between high-water and low-water mark being only about a foot; yet the water rises and falls from time to time, probably owing to the vary ing rainfall and evaporation. In stormy weather amber is often found on the coasts of Prussia and Courland, which the waves wash upon the shore. It forms the drainage basis
for a great part of northern Europe. Among rivers that empty into it are the Neva, Dwina, Oder, Vistula, Niemen and a number of Swedish rivers. Between the Kattegat and Baltic are the large Danish islands Zealand and Funen; others in the sea itself are Samsoe, Moen, Bornholm, Langeland, Laaland, which belong to Denmark; the Swedish islands — Gottland and Oeland (besides Hveen in the sound, with the ruins of Oranienburg, the ob servatory built by Tycho Brahe) ; Riigen, be longing to Prussia; the Aland Islands at the entrance of the Gulf of Bothnia, and Dagoe, tom gether with Oesel, on the coast of Livonia, all of which belong to Russia. The Sound, the Great and the Little Belt lead from the Katte gat into the Baltic. The Baltic and North Sea are now connected by the great ship canal con structed between Brunsbiittel, near the mouth of the Elbe, to Holtenan, near Kid, a distance of 61 miles, and opened in 1895. The canal is a work of the German government, and is in tended for the use of war-vessels as well as trading-ships, many of which, bound to or from Baltic ports, are able to effect a saving on the voyage of over 500 miles by means of this waterway. The chief seaports of the Baltic are Petrograd, Kronstadt, Riga, Revel, Narva, Libau, Helsingfors, in Russia; Stockholm, Gefle, Karlskrona, Malmo, in Sweden; Memel, Konigsberg, Danzig, Stettin, Lubeck and Kiel, in Germany; Copenhagen, in Denmark. Dur ing the great international European War, the Baltic Sea was an active field of naval and mili tary operations. See WAR, EUROPEAN.