Columbia Encyclopedia

Search results

339 results found

Pre-Raphaelites

(Encyclopedia)Pre-Raphaelites prēˌ-răfˈēəlītsˌ [key], brotherhood of English painters and poets formed in 1848 in protest against what they saw as the low standards and decadence of British art. The princip...

beach

(Encyclopedia)beach, a gently sloping zone where deposits of unconsolidated sediments are subject to wave action at the shore of an ocean or lake. Most of the sediment making up a beach is supplied by rivers or by ...

smoke

(Encyclopedia)smoke, visible gaseous product of incomplete combustion. Smoke varies with its source, but it usually comprises hot gas and suspended particles of carbon and tarry substances, or soot. To reduce the a...

ultraviolet radiation

(Encyclopedia)ultraviolet radiation, invisible electromagnetic radiation between visible violet light and X rays; it ranges in wavelength from about 400 to 4 nanometers and in frequency from about 1015 to 1017 hert...

Bangkok

(Encyclopedia)Bangkok băngˈkŏkˌ [key], Thai Krung Thep, city (2021 est. pop. 10,539,000), capital of Th...

Michigan, Lake

(Encyclopedia)Michigan, Lake, 22,178 sq mi (57,441 sq km), 307 mi (494 km) long and 30 to 120 mi (48–193 km) wide, bordered by Mich., Ind., Ill., and Wis.; third largest of the Great Lakes and the only one entire...

atomic clock

(Encyclopedia)atomic clock, electric or electronic timekeeping device that is controlled by atomic or molecular oscillations. A timekeeping device must contain or be connected to some apparatus that oscillates at a...

madder

(Encyclopedia)CE5 Bluet, Houstonia caerulea, a member of the madder family madder, common name for the Rubiaceae, a family of chiefly tropical and subtropical trees, shrubs, and herbs, especially abundant in N ...

concrete

(Encyclopedia)concrete, structural masonry material made by mixing broken stone or gravel with sand, cement, and water and allowing the mixture to harden into a solid mass. The cement is the chemically active eleme...

chemical industry

(Encyclopedia)chemical industry, the business of using chemical reactions to turn raw materials, such as coal, oil, and salt, into a variety of products. During the 19th and 20th cent. technological advances in the...