Columbia Encyclopedia

(Encyclopedia) water power, mechanical energy derived from falling or flowing water, e.g., rivers, streams, and the overflow of dams. The wooden water wheel, long utilized for driving machinery in flour mills and fa...

(Encyclopedia) Grand Canyon, great gorge of the Colorado River, one of the natural wonders of the world; c.1 mi (1.6 km) deep, from 4 to 18 mi (6.4–29 km) wide, and 217 mi (349 km) long, NW Ariz. The canyon shows ...

(Encyclopedia) cesium sēˈzēəm [key] [Lat.,=bluish gray], a metallic chemical element; symbol Cs; at. no. 55; at. wt. 132.90545; m.p. 28.4℃; b.p. 669.3℃; sp. gr. 1.873 at 20℃; valence +1. Cesium is a ductil...

(Encyclopedia) fountain, natural or artificially conveyed flow of water. In ancient Greece columnar shrines were built over springs and dedicated to deities or nymphs. In ancient Rome fountains fed by the great aque...

(Encyclopedia) Transcaucasia trănzˌkôkāˈzhə, –shə, trănsˌ– [key], transitional region between Europe and Asia, extending from the Greater Caucasus to the Turkish and Iranian borders, between the Black a...

(Encyclopedia) Gordimer, Nadine nādēnˈ gôrˈdəmər [key], 1923–2014, South African writer, b. Springs. A member of the African National Congress, Gordimer fought apartheid in her political life and in her wri...

(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) Pliocene epoch plīˈəsēn [key], fifth epoch of the Cenozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table), from 5.1 to 2 million years ago. By the beginning of the P...

(Encyclopedia) Northern Territory, territory (2016 pop. 228,833), 520,280 sq mi (1,347,525 sq km), N central Australia. It is bounded on the N by the Timor Sea, the Arafura Sea, and the Gulf of Carpentaria. Darwin i...

(Encyclopedia) Cambrian period [Lat. Cambria=Wales], first period of the Paleozoic geologic era (see Geologic Timescale, tablegeologic timescale, table) extending from approximately 570 to 505 million years ago. It ...