Petroleum

a natural rock oil found in great abundance in various parts of the earth's crust. The most reasonable theory of its origin is that it has resulted from the slow decay of animals and plants that were imbedded in the mud out of which petroleum-bearing rocks were made by pressure and heat; that is to say, petroleum consists essentially of fats and oils once contained in animals and plants. This theory does not seem unreasonable when we recall the vast amount of fat yielded by the blubber of a whale or of oil in the form of turpentine yielded by a Georgia pine. The same result might be obtained from millions of small organisms. The use of petroleum is older than that of coal. No petroleum is found in the earliest rocks, such as granites. It is found usually in sandstone. Petroleum in the United States was first discovered at Titusville, Pennsylvania, in 1858, and has since been found in almost every state of the union. Our great petroleum fields, however, lie in Pennsylvania, New York, Ohio, West Virginia, Colorado, Illinois, Kansas, Oklahoma, Louisiana, Texas, and California. Paying wells are discovered in new localities each year. The total area of oil fields of the United States is about equal to that of Massachusetts. Mexico, Canada, Japan, and New Zealand have important oil fields, but, outside of the United States, the Russian fields about the Caspian Sea are by far the most important. The United States produces sixty-seven per cent; Russia, twentysix per cent, and all other countries seven per cent. The total annual yield is over 250,000,000 barrels.

Petroleum is obtained by driving wells until a supply of oil is obtained. Sometimes the oil rises to the surface, but usually it requires to be pumped like water. Under modern management the crude petroleum is conveyed from tanks through underground passages to refineries. Pipes lead from the oil fields of Pennsylvania to Baltimore, New York, Philadelphia, Pittsburg, and Cleveland. A pipe runs from Kokomo, Indiana, to Chicago. The Kansas-Oklahoma field is piped clear to New York harbor. Pipe systems of corresponding magnitude have been laid in other oil-producing districts. A pipe line costing $4,000,000 leads from Baku to the port of Batoum on the Black Sea. The petroleum supply of the United States is in the hands, practically, of the Standard Oil Company, which aims to control the pipe mains. This company is willing, usually, to lay a branch pipe to any productive well in its region, and to accept the crude oil of the local producer at a price fixed by the purchaser. The company controls 25,000 miles of pipe lines.

Crude petroleum is distilled in refineries. It yields quite a variety of products, as natural gas, gasoline, naphtha, benzine, paraffin, and vaseline; chiefly, however, kerosene or illuminating oil. A very great number of lubricating and healing preparations are made at the refineries and byfactories. The crude petroleum output for the United States during 1908 was:

Total . . . . . 184,734,678

The world production for 1907 was:

Total . . . . . 262,212,000

See Trust; Oil; Baku