Black Sea (anc. Pontus Euxinus, the hospitable sea), an inland sea between Asia and Europe, enclosed N. and E. by Russia and S. and W. by Turkey, and connected N. E. with the sea of Azov through the strait of Yenikale, and S. W. with the Mediterranean through the Bosporus, the sea of Marmora, and the Dardanelles. It lies between lon. 27° 25' and 41° 50' E., and lat. 40° 50' and 46° 45' N. Its extreme length is 700 m. from E. to W., its extreme breadth nearly 400 m. on the 31st meridian. It has a coast line of more than 2,000 m., and a superficial area of about 180,000 sq. m. It receives from Europe the waters of the Danube, Dniester, Bog, and Dnieper, and through the sea of Azov those of the Don, and from Asia the waters of the Kizil Irmak (Halys) and Sa-karia, besides smaller rivers, and drains a territory in Europe and Asia of scarcely less than 1,000,000 sq. m. There are geological indications that the Black sea was at one time much larger than it is now, having no outlet to the Mediterranean, flooding a considerable part of southern Russia, and reaching even to the Caspian and Aral seas, with which it formed one body. Natural features probably assisted in suggesting the name of Black, which is given it in all modern European languages.

The ancient name, Euxine, is supposed to have been a euphemistic modification .of a former appellation, Pontus Axenus, meaning inhospitable sea. The prevalent wind is from the N. E.; it comes laden with moisture from a wide swampy territory, and frequently veils the sea in darkness by fogs and rain. Owing, too, to the confined extent of the water, a strong wind quickly lashes it into a tempest, and gives to the whole sea something of the appearance of a whirlpool. These brief but troublesome tempests are especially frequent during the winter. The difficulties which the atmosphere offers to the navigation of the Black sea are compensated by the character of the sea itself. Both its shores and its interior parts are remarkably free from rocks, sand bunks, or shallows, and ships may always lie to or ride at anchor with very little danger. There is but one island in the whole sea, Serpent isle, 30 m. from the mouth of the Danube, once a sacred place, with a temple, but unoccupied for centuries, till of late years it was made a station for English and French vessels. There is now a lighthouse upon it.

The principal peninsulas are on the north, among them the Crimea. The depth of the sea increases regularly according to the distance from the shore; and in its central parts no bottom is reached even by a line of 160 fathoms. There is no observable ebb and flow of its waters, but its large accessions from the rivers occasion strong currents, which all set, with more or less directness, toward the Bosporus. When these currents are also helped by the winds, the waters are sent through the straits with such violence that vessels are sometimes detained for months outside, unable to enter against them. An English surveying ship recently confirmed the conclusion of Prof. Carpenter that these currents are only superficial, and discovered at the depth of 20 fathoms an undercurrent running with prodigious force into the Black Sea. To test the strength of this undercurrent, a special apparatus was constructed and attached to the ship's boats, when the boats were in many places driving along against the upper current with greater velocity than that of the steam launch of the ship. Its climate has wide extremes, but is generally colder than would be inferred from its latitude, owing to the prevalence of north winds. Its fisheries are unimportant.

The specific gravity of its water is 1.142. It contains less salt than the ocean, and freezes easily. Odessa is the most im-portant commercial port on its coast, and Varna is the chief Turkish fortress; besides which, the principal harbors are Sebastopol, Sinope, and Trebizond, and on the estuaries of the Bog and Dnieper, respectively, Nikolavev and Kher- son. - The shores of the Black sea are known both in fable and history. Colchis, the goal of the Argonautic expedition, was on its east; the Cimmerian region was upon its north; and on all its sides the Persian, Byzantine, Turkish, and Russian powers have acted the events of their history. From the time of Constantine till the 15th century it was the centre of the transplanted Roman world; and till the Cape of Good Hope was discovered and sailed round, it was a passageway of the Genoese and other European trade with the Indies. The Turks for a time excluded the ships of all other nations from it, and at one time Russia sought to make it a closed sea under its own military command; but since the peace of Paris, which terminated the Crimean war, it has been open to the commerce of all nations, and the equal exclusion of all ships of war established by the neutrality clause of that treaty was abrogated at the close of 1870.

Opening of the Black Sea from the Bosporus.

Opening of the Black Sea from the Bosporus.