Oman', the most eastern portion of Arabia, a strip of maritime territory, extending between the Strait of Ormuz and Ras-el-Had, and bounded on the SW. by the deserts of the interior. At a distance of from 20 to 45 miles inland a chain of mountains runs parallel to the coast, reaching 6000 feet in Jebel Akhdar. There are some richly fertile tracts in this region, which is under the rule of the sultan of Muscat.


Omdurman (Om-door'man), a town of the eastern Soudan, on the Nile, opposite Khartoum (q.v.), which, as the headquarters of Mahdism, for a time it superseded.


Omsk, chief town of the Siberian province of Akmolinsk, at the Om's confluence with the Irtish, 1800 miles E. of Moscow, with a military academy, Greek and R. C. cathedrals, museum, governor's palace, etc. Pop. 44,721.


One'ga, a seaport in the north of Russia, at the Onega's mouth in the White Sea, 87 miles SW. of Archangel. Pop. 2547.


Onega, Lake, in the north of Russia (after Ladoga, to which it sends off the Swir south-westward, the largest lake in Europe), is 146 miles long, 50 in greatest breadth, 3764 sq. m. in area, and 1000 feet deep. The northern end is studded with islands and deeply indented with bays. The shores in other parts are flat. Icebound generally for five months, the lake is the scene of busy traffic at other seasons. Fish abound. Surveys were completed in 1890 for a canal to connect Lake Onega with the White Sea, and to be 145 miles long, 10 feet deep, and 63 wide, mostly along natural water-ways.


Oneglia (O-nel'ya), a town on the Gulf of Genoa, 3 miles NE. of Porto Maurizio by rail. Pop. 8286.


Oneida (Onl'da), a manufacturing post-village of New York, on the Oneida Creek, 58 miles SE. of Oswego; pop. 6383. Four miles S. was the Oneida Community, long the headquarters of the Perfectionists.


Ongar, or Chipping-Ongar, a town of Essex, 6 miles E. by N. of Epping, and 23 1/4 NE. of London. It has memories of the Taylor family. Pop. of parish, 970.


Oodeypore. See Udaipur.


Oojein. See Ujjain.


Ookiep (O-keep), a copper-mining station in the north-west of Cape Colony, 90 miles SE. of Port Nolloth by rail.


Oori. See Limpopo.


Oosterhout, a Dutch town in North Brabant, 6 miles NE. of Breda. Pop. 11,911.


Ootacamund', or Utakamand, the chief town in the Neilgherry Hills, the principal sanatorium of the Madras Presidency. It stands on a hill-girt plateau, 7228 feet above the sea, 350 miles WSW. of Madras city, and 24 from the nearest railway station on the Madras line. There are a public library (1859), the Lawrence Asylum (1858) for the children of British soldiers, and botanic gardens. The mean annual temperature is 58° F. The first house was built in 1821. Pop. 15,335.


Ophir, the region to which Solomon's ships traded, has been identified with the east coast of Africa near Sofala, the south of Arabia, and the west coast of India, as well as other less likely countries (see Zimbabye). The name has been given to a mountain of Sumatra, near the equator (9600 feet); and to one 45 miles NE. of the town of Malacca (5700 feet).