Columbia Encyclopedia

Search results

500 results found

backswimmer

(Encyclopedia)backswimmer, common name for water bugs of the cosmopolitan family Notonectidae, so named because they swim upside down, usually near the surface of the water. They have oval bodies and long, oarlike ...

Kara Kum

(Encyclopedia)Kara Kum kärˌə ko͝omˈ [key], two deserts, one in Kazakhstan and one in Turkmenistan. The Caspian Kara Kum or Garagum, the larger desert (c.115,000 sq mi/297,900 sq km), is W of the Amu Darya Rive...

surface tension

(Encyclopedia)surface tension, tendency of liquids to reduce their exposed surface to the smallest possible area. A drop of water, for example, tends to assume the shape of a sphere. The phenomenon is attributed to...

photosynthesis

(Encyclopedia)photosynthesis fōˌtōsĭnˈthəsĭs [key], process in which green plants, algae, and cyanobacteria utilize the energy of sunlight to manufacture carbohydrates from carbon dioxide and water in the pr...

heating

(Encyclopedia)CE5 Typical warm-air heating system heating, means of making a building comfortably warm relative to a colder outside temperature. Old, primitive methods of heating a building or a room within it ...

sponge

(Encyclopedia)sponge, common name for members of the aquatic animal phylum Porifera, and for the dried, processed skeletons of certain species used to hold water. Over 4,500 living species are known; they are found...

Delaware River Basin Compact

(Encyclopedia)Delaware River Basin Compact dĕlˈəwâr, –wər [key], providing for the utilization and development of the water resources of the Delaware River basin. In 1961 the federal government and the state...

divining rod

(Encyclopedia)divining rod or dowser, stick used in searching for underground water or minerals. This form of divination is still in common use in many parts of the world. The instrument is typically a forked twig....

dry farming

(Encyclopedia)dry farming, farming system adopted in areas having an annual rainfall of approximately 15 to 20 in. (38.1–50.8 cm)—with much of the rainfall in the spring and early summer—where irrigation is i...

hygiene

(Encyclopedia)hygiene, science of preserving and promoting the health of both the individual and the community. It has many aspects: personal hygiene (proper living habits, cleanliness of body and clothing, healthf...