OIL CAKE 12 OKEECHOBEE LAKE (1882), "Countess Sarah" (1883), "Lise Fleuron" (1884), "The Great Maalpit" (1885), "Will" (1888), "In Deep Abyss." Died 1918. OIL CAKE, the marc or refuse after dH is pressed from flax, rape, mustard, cotton, or hemp seed; or from cocoanut pulp. Used for cattle feed or manure. OIL CITY, a city in Venango co.. Pa. ; at the junction of Oil creek and the Alle- gheny river and on the Erie, the Lake Shore and Michigan Southern, and Penn- sylvania railroads; about 70 miles N. of Pittsburgh. It received its name from the extensive petroleum oil wells and oil industries located here. The city has a public hospital, public library, electric street railroads, electric lights, high school, daily and weekly newspapers, and National, State, and private banks. Be- sides large oil refineries, it has pipe works, iron foundries, engine and boiler works, wagon works, etc. Pop. (1910) 15,657; (1920) 21,274. OILCLOTH, a tarpaulin; painted can- vas for floor covering. Figures or pat- terns in oil colors are printed on one side by means of wooden blocks. A separate block is used for each color. OIL GAS, in chemistry, a gas of high illuminating power, obtained by dropping oil on substances heated to redness and collecting the gaseous product. OIL OF VITRIOL, the common name of strong sulphuric acid. OIL PIPE LINES, a system of con- nected pipes used for the purpose of transporting oil — usually petroleum — from the fields to the refinery or selling point. The first successful pipe line was laid in 1865 by Samuel von Syckle, of Titus- ville, Pennsylvania, who placed in suc- cessful operation a line four miles in length. Although General S. D. Earns suggested a gravity line from Burning Springs to the Ohio River at Parkers- burg, West Virginia, in 1860, it was never constructed, and in 1862 a line of about three miles was laid by J. S. Hutchinson, but was unsuccessful be- cause of the excessive leakage. The success of this early line soon led to the construction of many others, in the face of much opposition, and actual inter- ference, on the part of those people who made their livelihood by the transporta- tion of oil in wagons. The tendency to locate the refineries at the seaboard soon developed, and these refineries were soon connected with their oil fields by pipe lines. A pipe line from Olean, New York to Bayonne, New Jer- Voi. VII — cyc sey, was constructed in 1897. Standard Oil subsidiaries soon built a net work of lines reaching from the wells to the coast or to Great Lake cities. It is estimated that there are now about one hundred thousand miles of pipe lines and feeders in the United States, as the western fields also have extensive pipe line systems. Pipe lines have also been constructed in Russia and Mexico, in Burma, Roumania, and in the Dutch East Indies. The oil is kept in motion either by gravity or, as is more frequently the case, by high pressure compound pumps. In some parts of the country where the viscosity of the oil is very high, refilling is used to facilitate the forcing of the oil through the pipe. OINTMENT, a soft, unctuous sub- stance used for smearing or anointing; an unguent. OISE, a department of France; sepa- rated from the English Channel by Seine-Inf erieure ; area, 2,272 square miles; pop. about 435,000. The principal rivers are the Oise, a tributary of the Seine, 150 miles in length, with the Aisne and Therain, affluents of the Oise. The soil is in general fertile, and agriculture advanced. The products are the usual grain crops, with an immense quantity of vegetables, which are sent to the markets of the metropolis. Before the World War there were extensive iron manufactures; porcelain, paper, chemi- cals, beet-root sugar, woolens, cottons, and lace (at Chantilly) were also made. Capital, Beauvais. During the World War (1914-1918) the Department was devastated by the German armies and repeatedly fought over by the opposing forces. OKA, an important navigable river of central Russia, the principle aflSuent of the Volga from the S., rises in the government of Orel, and flows in a gen- erally N. E. direction, and joins the Volga at Nijni-Novgorod, after a course of 706 miles. Its basin comprises the richest and most fertile region of Russia. The principal towns on its banks are Orel, Bielev, Kaluga, Riazan, and Muron; the most important affluents are the rivers Moscow, Kliasma, and Tzna. During spring the Oka is navigable from Orel to the Volga; but in summer the navigation is obstructed by sandbanks. OKEECHOBEE LAKE, a large shal- low lake in Southern Florida; about 40 miles in length by 25 in breadth, and with a maximum depth of 12 feet. Its waters are discharged through the Ever- glades, but there is no appreciable outlei 1
