Oikell, a Sutherland stream, running 35 miles SSW. and E. by S. to the Dornoch Firth. Oil City, Pennsylvania, on the Alleghany River, 133 miles by rail N. by E. of Pittsburgh, is a great oil market, and contains, besides oil-refineries, engine and boiler factories, and a large cooperage. There were fearful inundations here in June 1S92. Pop. (1870) 2276 J (1900) 13,264.
Oil Rivers. See Niger.
Oise (Waz), a dep. in the north of France, separated from the English Channel by Seine-Inferieure; area, 2261 sq. m.; pop. (1881) 404,555; (1901) 405,642. The rivers are the Oise, a tributary of the Seine, 150 miles long, with its affluents the Aisne and Therain. The arron-dissements are those of Beauvais (the capital), Clermont, Compiegne, Senlis.
Oka, a navigable river of central Russia, the Volga's chief affluent from the south, rises in Orel, and flows 706 miles NE. to the Volga at Nijni-Novgorod. Towns on its banks are Orel, Bielev, Kaluga, Riazan, and Murom; affluents are the Moskwa, Kliasma, and Tzna.
Okavango. See Ngami.
Okeechobee, a lake of Florida (q.v.).
Okhotsk, Sea of, an inlet of the North Pacific Ocean, on the east coast of Siberia, nearly enclosed by Kamchatka and the Kuriles and Sag-halien. On its north shore, at the mouth of the Okhota, is the seaport of Okhotsk (pop. 300).
Old'bury, a busy manufacturing town of Wor- cestershire, 5 1/2 miles WNW. of Birmingham, stands in a rich mineral district, and has iron and steel works, factories for railway plant, edge-tools, chemicals, etc. Pop. (1851) 11,741; (1901) 25,191.
Old Sarum. See Sarum.
Olifant River, a forked stream of Cape Colony, rises in the mountains north-east of Capetown, and flows 150 miles NW. to the Atlantic. - Another stream of the same name rises in the Transvaal, and goes east to the Limpopo.
Olinda, a city of Brazil, 4 miles NE. of Per-nambuco. Pop. 8000.
Olives, Mount of, or Mount Olivet, a limestone ridge E. of Jerusalem, from which it is separated by the narrow Valley of Jehosaphat. The modern Jebel-al-Tor, it took its familiar name from a once magnificent grove of olive-trees on its western flank.