S I S I R 95 it possesses the finest natural harbour save one in the Black Sea, defective communication with the interior, and the consequent rivalry of Ineboli (since about 1848), have prevented Sinope taking its natural position as a great commercial centre. But between 1882 and 1885 roads have been constructed which give direct access southward to Csesarea and even to Tarsus, near the south coast. The town still bears the stamp of its former importance. On the isthmus stands a huge but for the most part ruined castle, originally Byzantine and afterwards strengthened by the Seljuk sultans ; and the old town is surrounded by Byzantine walls. Of early Roman or Greek antiquities there is little trace ; but the ancient local coinage furnishes a very beautiful and interesting series of types (see M. J. P. Six's paper in The Numismatic Chronicle, 1885). The population has not greatly changed since 1868, when it was found to be 9668 inhabitants, of whom 7299 were Mohammedans and 2369 Greeks and others. Sinope (SJJ/COTTTJ), whose origin was mythically assigned by its own ancient inhabitants to Autolycus, a companion of Hercules, was colonized by the Milesians, and ultimately became the most Nourishing Greek settlement on the coast of the Euxine. In the 5th century B.C. it received a colony of Athenians; and by the 4th it had extended its authority over a considerable tract of country and become itself the mother of several colonies Cerasus (Kerasun), Trapezus (Trebizond), Cotyora, &c. Its fleet was practically dominant in the Euxiue, except towards the west, where it shared the field with Byzantium. When in 220 B.C. Sinope was for the first time attacked by the king of Pontus, the assistance of the Rhodians enabled it to maintain its independence. But where Mithradates IV. failed Pharnaces succeeded ; and the city, taken by surprise in 183 B.C., became the capital of the Pontian monarchy. Under Mithradates.the Great, who was born in Sinope, it had just been raised to the highest degree of prosperity, with fine buildings, naval arsenals, and well-built harbours, when the Romans under Lucullus and Pompey effected the subjugation of Poiitus. In 64 B.C. the body of the murdered Mithradates was brought home to the royal mausoleum. Under Julius Caesar the city received a Roman colony. In the Middle Ages it became subject to Trebizond, and in 1470 it passed into the hands of the Turks. In November 1853 the Russian vice-admiral Nakhimoff destroyed here a division of the Turkish fleet and reduced a good part of the town to ashes. SIOUX CITY, a city of the United States, the capital of Woodbury county, Iowa, lies 156 miles north-west of Des Moines, on the sloping banks of the Missouri river. It. is a great railway centre (Chicago, Milwaukee, and St Paul Railway, Sioux City and Pacific Railway, &c.), has an extensive trade, and contains an opera house, foundry and machine shops, pork-packing factories, and mills. The population of the city (which was laid out in 1854 and incorporated in 1857) was 3401 in 1870 and 7366 in 1880 (township 7845). SIPHANTO, SIPHENO, or SIPHNO (ancient Greek S^os), an island of the Greek Archipelago, in the nomarchy of the Cyclades, 30 miles south-west of Syra. It has an area of 28 square miles, and the population in 1879 was 5762. A ridge of limestone hills whose principal sum- mits, Mount Elias and St Simeon, are crowned by old Byzantine churches runs through the island ; for about 2 miles along the western slope stretches a series of villages, each white-washed house with its own garden and orchard. Apollonia, one of the five (so called because built on the site of a temple to Apollo), is the modern capital ; formerly this rank belonged to Kastro (also called Seraglio), an "old-world Italian town" with mediaeval castle and fortifications, and an old town-hall bearing date 1365. Inscriptions found on the spot show that Kastro stands on the site of the ancient city of Siphnos ; and Mr Bent identifies the other ancient town of Minoa (see Stephanos) with the place on the coast where a Hellenic white marble tower is distinguished as the Pharos or lighthouse and another as the tower of St John. Churches and convents of Byzantine architecture are scattered about the island. One building of this class is especially interesting the school of the Holy Tomb or school of Siphnos, founded by Greek refugees from Byzantium at the time of the iconoclastic persecutions, and afterwards a great centre of intellectual culture for the Hellenic world. The endowments of the school are now made over to the gymnasium of Syra. In ancient times Siphnos was famous for its gold and silver mines, the site of which is still easily recognized by the excavations and refuse-heaps. A French company has started mining operations at Karnara. As in antiquity so now the potters of the island are known throughout the Archipelago. The wealth of the ancient Siphniotes was shown by their treasury at Delphi, where they deposited the tenth of their gold and silver ; but, says the legend, they once sent Apollo a gilded and not a golden bull, and he in his anger flooded their mines. That the mines were invaded by the sea is still evident ; and by Strabo's time the inhabitants of the island were noted for their poverty. During the Venetian period it was ruled first by the Da Corogna family and after 1456 by the Gazzadiui, who were expelled by the Turks in 1617. SIPHON", or SYPHON, an instrument usually in the form of a bent tube for conveying liquid over the edge of a vessel and delivering it at a lower level, or in a position of less hydrostatic pressure. The principle on which it acts (see HYDROMECHANICS) may be understood from the accompanying diagram. ABC is a tube filled with liquid, the shorter limb dipping under the _B_ B* surface of the liquid in jar a, the longer in jar b. The pressure in the tube at A is atmospheric pressure minus that of the vertical column AB', while that at C is atmospheric pressure minus that of the column CB". When CB" is longer than AB' the pressure at C is of course less than that at A, and a current flows in the direction ABC through the siphon. When E~^ ~ - AB' = B"C, that is, when the liquid stands at the same level, pressure is equal in the two limbs, and the current ceases. The siphon has practically a certain minimum diameter for each liquid, as capillarity prevents a - fluid from flowing out of tubes of very small bore unless under the influence of electricity, heat, or great pressure. The instrument is largely employed for chemical work, both in the laboratory and in manufacturing processes ; it is formed of glass, india-rubber, lead, or other substance, according to the purpose for which it is intended. The simple siphon (see fig.) is used by filling it with the liquid to be decanted, closing the longer limb with the finger and plunging the shorter into the liquid, and it must be filled for each time of using. Innumerable forms have been devised adapted for all purposes, and provided with arrangements for filling the tube, or for keeping it full and starting it into action automatically when required. The former purpose is usually effected by blowing into the vessel through a second opening in the stopper through which the siphon passes, or by means of a sucking or blowing tube attached to the longer limb, or by pouring in liquid through a flexible tube attached at the bend. The second plan is frequently realized by having a stop- cock on the longer limb and a valve opening upwards on the shorter, or by having both limbs of equal length and each standing in a cup, in which case when the level changes in either cup the siphon tends to equalize it by conveying liquid from the higher to the lower. Many other forms are in constant use in the arts, and the siphon is also employed in some of its modifications in surgery, in engineering, and in other sciences. SIR ACH IDES. See JESUS, THE SON OF SIRACH. SIRAJGANJ, a town in the district of Pabna, Bengal,
