Columbia Encyclopedia

(Encyclopedia) petroleum, oily, flammable liquid that occurs naturally in deposits, usually beneath the surface of the earth; it is also called crude oil. It consists principally of a mixture of hydrocarbons, with t...

(Encyclopedia) Charleston. 1 City (2020 pop. 17,286), seat of Coles co., E Ill.; inc. 1835. Charleston is an industrial, rail, and trade center located in an ...

(Encyclopedia) influenza or flu, acute, highly contagious disease caused by a RNA virus (family Orthomyxoviridae); formerly known as the grippe. There are three types of the virus, designated A, B, and C, but only t...

(Encyclopedia) tunnel, underground passage usually made without removing the overlying rock or soil. Although tunnels are approximately horizontal, they must be built with sufficient gradient for proper drainage. Tu...

(Encyclopedia) salmon sămˈən [key], member of the Salmonidae, a family of marine fish that spawn in freshwater, including the salmons, the trouts, and the chars (subfamily Salmoninae), the whitefish and the cisco...

(Encyclopedia) Sinn Féin shĭn fān [key] [Irish,=we, ourselves], Irish nationalist movement. It had its roots in the Irish cultural revival at the end of the 19th cent. and the growing nationalist disenchantment w...

(Encyclopedia) Reconstruction, 1865–77, in U.S. history, the period of readjustment following the Civil War. At the end of the Civil War, the defeated South was a ruined land. The physical destruction wrought by t...

(Encyclopedia) Reagan, Ronald Wilson rāˈgən [key], 1911–2004, 40th president of the United States (1981–89), b. Tampico, Ill. In 1932, after graduation from Eureka College, he became a radio announcer and spo...

(Encyclopedia)  CE5 Plate tectonics: Map of the world showing major plates and plate boundaries CE5 Plate tectonics: Schematic model of the oceanic crust, showing the three types of plate boundaries plate tect...

(Encyclopedia) radio astronomy, study of celestial bodies by means of the electromagnetic radio frequency waves they emit and absorb naturally. Radio waves also come from outside the Milky Way. These extragalact...