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ammonia

(Encyclopedia)ammonia, chemical compound, NH3, colorless gas that is about one half as dense as air at ordinary temperatures and pressures. It has a characteristic pungent, penetrating odor. Ammonia forms a minute ...

standpipe

(Encyclopedia)standpipe, tank or pipe for holding water in an elevated position to create pressure in a water supply system. For a tall building, where the pressure from the mains at street level is insufficient to...

Buys Ballot, Christoph Heinrich Diedrich

(Encyclopedia)Buys Ballot, Christoph Heinrich Diedrich krĭsˈtôf hīnˈrĭkh dēdˈrĭkh boisˈ bälōˈ [key], 1817–90, Dutch meteorologist. Director of the Dutch Royal Meteorological Institute after 1854, he ...

excretion

(Encyclopedia)excretion, process of eliminating from an organism waste products of metabolism and other materials that are of no use. It is an essential process in all forms of life. In one-celled organisms wastes ...

sky

(Encyclopedia)sky, apparent dome over the earth, background of the clouds, sun, moon, and stars. The blue color of the clear daytime sky results from the selective scattering of light rays by the minute particles o...

slate

(Encyclopedia)slate, fine-grained rock formed when sedimentary rocks such as shale are metamorphosed by great pressure. Slate splits into perfectly cleaved, broad thin layers; this characteristically regular and pl...

Venus, in astronomy

(Encyclopedia)Venus, in astronomy, 2d planet from the sun; it is often called the evening star or morning star and is brighter than any object in the sky except the sun and the moon. Because its orbit lies between ...

edema

(Encyclopedia)edema ĭdēˈmə [key], abnormal accumulation of fluid in the body tissues or in the body cavities causing swelling or distention of the affected parts. Edema of the ankles and lower legs (in ambulato...

wind

(Encyclopedia)wind, flow of air relative to the earth's surface. A wind is named according to the point of the compass from which it blows, e.g., a wind blowing from the north is a north wind. The diurnal, or dai...

monsoon

(Encyclopedia)monsoon mŏnso͞on [key] [Arab., mausium=season], wind that changes direction with change of season, notably in India and SE Asia. To a lesser degree, monsoonal winds also develop in portions of all o...