Columbia Encyclopedia

Search results

500 results found

air mass

(Encyclopedia)air mass, large body of air within the earth's atmosphere in which temperature and humidity, although varying at different heights, remain similar throughout the body at any one height. Air masses for...

Aïr Massif

(Encyclopedia)Aïr Massif or Aïr Mountains, Africa: see Sahara. ...

air navigation

(Encyclopedia)air navigation, science and technology of determining the position of an aircraft with respect to the surface of the earth and accurately maintaining a desired course (see navigation). Basic to air ...

air plant

(Encyclopedia)air plant: see epiphyte.

air pollution

(Encyclopedia)air pollution, contamination of the air by noxious gases and minute particles of solid and liquid matter (particulates) in concentrations that endanger health. The major sources of air pollution are t...

Wake Island

(Encyclopedia)Wake Island, atoll with three islets (Wake, Wilkes, and Peale), 3 sq mi (7.8 sq km), central Pacific, between Hawaii and Guam. It is a U.S. military base and scientific research center under the juris...

Whittle, Sir Frank

(Encyclopedia)Whittle, Sir Frank, 1907–96, English aeronautical engineer. Whittle was one of the first persons to associate the gas turbine with jet propulsion. Previously the gas turbine had been regarded as a m...

Johnston Atoll

(Encyclopedia)Johnston Atoll, atoll, 2.8 sq mi (7.25 sq km), central Pacific, c.700 nautical mi (1,300 km) SW of Honolulu, central Pacific, an uninc. territory of the United States. It consists of four islands and ...

Prince of Wales Island, United States

(Encyclopedia)Prince of Wales Island, 2,231 sq mi (5,778 sq km), off SE Alaska; largest island of the Alexander Archipelago. The island is heavily forested, but has little arable land, no source of freshwater, and ...

Kootenai, river, Canada and the United States

(Encyclopedia)Kootenai ko͞oˈtĭnā [key], river, 407 mi (655 km) long, rising in the Rocky Mts., SE British Columbia, Canada. It flows S into NW Montana, NW through N Idaho, then N into Canada. There it flows thr...