SINOPE (8), a seaport of Turkey in Asia, situated on a narrow isthmus connecting with the mainland the rocky headland of Cape Sinope which projects into the Black Sea, 350 m.  NE. of Constantinople; possesses two fine harbours, naval arsenal, Byzantine ruins, etc.; an ancient Greek town, the birthplace of Diogenes, and capital of Mithridates; it was captured by the Turks in 1461, who themselves in 1853 suffered a disastrous naval defeat in the Bay of Sinope at the hands of the Russians.

SION, capital of the Swiss canton of Valais, on the Rhine, 42 m.  E. of Lausanne; is a mediaeval town, with an old Gothic cathedral, and in the neighbourhood ruined castles.

SIOUT or ASIOOT (32), capital of Upper Egypt; commands a fine view near the Nile, 200 m.  S. of Cairo; has a few imposing mosques and a government palace; is a caravan station, and noted for its red and black pottery; occupies the site of the ancient city of Lycopolis.

SIOUX or DAKOTA INDIANS, a North American Indian tribe, once spread over the territory lying between Lake Winnipeg (N.) and the Arkansas River (S.), but now confined chiefly to South Dakota and Nebraska.  Failure on the part of the United States Government to observe certain treaty conditions led to a great uprising of the Sioux in 1862, which was only put down at a great cost of blood and treasure; conflicts also took place in 1876 and 1890, the Indians finding in their chief, Sitting Bull, a determined and skilful leader.

SIRDAR, a name given to a native chief in India.

SIREN, an instrument for measuring the number of aerial vibrations per second, and thereby the pitch of a given note.

SIRENS, in the Greek mythology a class of nymphs who were fabled to lure the passing sailor to his ruin by the fascination of their music; Ulysses, when he passed the beach where they were sitting, had his ears stuffed with wax and himself lashed to the mast till he was at a safe distance from the influence of their charm.  Orpheus, however, as he passed them in the Argonautic expedition so surpassed their music by his melodious notes, that in very shame they flung themselves into the sea and were changed into boulders.

SIRIUS or THE DOG-STAR, the brightest star in the heavens, one of the stars of the Southern constellation of Canis Major; is calculated to have a bulk three times that of the sun, and to give 70 times as much light.  See DOG-DAYS.

SIRKAR, a name used in India to designate the government.

SIROCCO.  See SIMOOM.

SISMONDI, JEAN CHARLES LEONARD SIMONDE DE, celebrated Swiss historian, born at Geneva; son of a Protestant clergyman of Italian descent; the family fortune was lost in the troublous days of the French Revolution, and exile in England and Italy followed, but in 1800 Sismondi returned to Geneva, and having received a municipal appointment gave himself to literary pursuits; the works which have established his reputation are his great histories of “The Italian Republics in the Middle Ages,” “European Literature,” and “A.  History of the French”; wrote also on political economy (1773-1842).