CASPIAN SEA, an inland sea or great salt lake, the largest in the world, on the boundary between Europe and Asia, extending from lat. 36° 40' to 47° 20' n., and long. 46° 50' to 55° 10' east. Its length from n. to s. is about 700 m., and its average breadth about 200 miles. Its total area is estimated at 180,000 sq. miles. The coast-line is irregular, and on the e. side especially there are several bays and indenta tions of coast, the principal being those of Mertvoi, Nangushlak, Kenderlinsk, Kara bugos, and Balkan. From the W. the naphtha-impregnated peninsula of Apsheron stretches into the C. opposite the Balkan gulf; Mt. Caucasus also rises on its w. side. On the s. rises the lofty range of the Elburz mountains, between which, however, and the coast, on this side almost unbroken, extends a low fiat plain of from 15 to 20 m., in breadth. On the n., it is bordered by great steppes, and the country eastward is a vast plain. It is probable that at one time its waters, which are said to be still dimin ishing, covered great part of the adjacent steppes. Some singular changes appear to take place in the level of the Caspian. Various measurements have made its depth and elevation different. One Russian measurement made it 348 ft. below the level of the Black sea, another only 84 feet. The latter is confirmed by maj. Wood (The Shores of Lake Aral, 1876). It has no tides, but its navigation is dangerous because of violent storms, especially from the s.e., by which its waters are sometimes driven for many miles over the adjacent plains. The depth near the southern end, is about 600 ft., and in some places near the center it attains a depth of nearly 3,000 ft. ' • but near the coast
it is very shallow, seldom reaching a depth of more than 3 ft. at 100 yards from the shore, and in many places a depth of 12 ft. is not reached. within several miles of the beach. On the n.e. and e. it is especially shallow. It receives the waters of a num ber of large rivers, of which the greatest is the Volga. The Ural, the Terek, the Kur, and the Atrek also fall into it. The water of the C. S. is salt, but much less so than that of the ocean. Its northern parts are covered with ice during winter. It abounds in fish, and very valuable fisheries are carried on, especially for sturgeon and salmon. By a canal uniting the head-waters of the Volga with the rivers T'vertza and Schlina, the C. is united with the Baltic sea. The sea is now surrounded on three sides by Russian territory, the southern shore still remaining Persian. The Russians have a fleet stationed upon it, and the most of its commerce is in their hands. Steam packets have been established on it. The chief Russian town upon its shores is Astrakhan; less important are Derbend, Guriev, Baku, and Krosnoi-yar. Balfrush, Resi], and Astrabad are Persian towns. The practicability of making the Amu-Daria (see Oxus), now run ning into the sea of Aral, again an affluent of the C. S., has recently been much debated.
The C. S. was known to the Greeks and Romans. According to Strabo. it derived its name from the Caspii, a tribe inhabiting its western shores. The name Caspian was afterwards limited to the western portion of the lake—the eastern being designated the Ilyrcanian sea.