Columbia Encyclopedia

(Encyclopedia) sediment, mineral or organic particles that are deposited by the action of wind, water, or glacial ice. These sediments can eventually form sedimentary rocks (see rock). Sediments form sedimentary ...

(Encyclopedia) Embargo Act of 1807, passed Dec. 22, 1807, by the U.S. Congress in answer to the British orders in council restricting neutral shipping and to Napoleon's restrictive Continental System. The U.S. merch...

(Encyclopedia) Dead Sea, salt lake, c.390 sq mi (1,010 sq km), extending c.45 mi (70 km) in the Jordan trough of the Great Rift Valley between the Ghor on the north and Wadi Arabah on the south, on the border betwee...

(Encyclopedia) shark, member of a group of almost exclusively marine and predaceous fishes. There are about 250 species of sharks, ranging from the 2-ft (60-cm) pygmy shark to 50-ft (15-m) giants. They are found in ...

(Encyclopedia) Germanic religion, pre-Christian religious practices among the tribes of Western Europe, Germany, and Scandinavia. The main sources for our knowledge are the Germania of Tacitus and the Elder Edda and...

(Encyclopedia) minnow, common name for the Cyprinidae, a large family of freshwater fish which includes the carp (Cyprinus carpio), and of which there are some 2,400 species. Minnows have soft-rayed fins and teeth i...

(Encyclopedia) boat, small, open nautical vessel propelled by sail, oar, pole, paddle, or motor. The use of the term boat for larger vessels, although common, is somewhat improper, but the line between boats and shi...

(Encyclopedia) sodium, a metallic chemical element; symbol Na [Lat. natrium]; at. no. 11; at. wt. 22.98977; m.p. 97.81℃; b.p. 892.9℃; sp. gr. 0.971 at 20℃; valence +1. Sodium is a soft, silver-white metal. Ext...

(Encyclopedia) water bug, name for a large number of water-living bugs, comprising several families of the order Hemiptera (true bugs). All have jointed, sharp, sucking beaks, breathe air, and undergo gradual metamo...

(Encyclopedia) Wilder, Thornton Niven, 1897–1975, American playwright and novelist, b. Madison, Wis., grad. Yale (B.A., 1920), Princeton (M.A., 1925). He received most of his early education in China, where his fa...