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level

(Encyclopedia)level: see spirit level.

sea level

(Encyclopedia)sea level, the level of the sea, which serves as the datum used for measurement of land elevations and ocean depths. Theoretically, one would expect sea level to be a fixed and permanent horizontal su...

spirit level

(Encyclopedia)spirit level, tool for determining whether a surface is horizontal. It consists essentially of a slightly bent transparent tube that is held in a frame. The tube contains some alcohol, ether, or simil...

lock, canal

(Encyclopedia)lock, canal, stretch of water enclosed by gates, one at each end, built into a canal or river for the purpose of raising or lowering a vessel from one water level to another. A lock may also be built ...

Mangyshlak Peninsula

(Encyclopedia)Mangyshlak Peninsula mən-gĭshläkˈ [key], W Kazakhstan, extending into the NE Caspian Sea. Except for the Kara-Tau range, the peninsula is below sea level; Batyr Sink is c.430 ft (130 m) below sea ...

evaporimeter

(Encyclopedia)evaporimeter ĭvăpˌərĭmˈətər [key], instrument that measures the rate of evaporation of water into the atmosphere, sometimes called an atmometer. Evaporimeters are of two types, those that meas...

siphon

(Encyclopedia)siphon sīˈfən, –fŏn [key], tube or other enclosed conduit through which a liquid is lifted over an elevation and then emptied at a lower level. The movement of the liquid is driven primarily by ...

biodiesel

(Encyclopedia)biodiesel, fuel made from natural, renewable sources, such as new and used vegetable oils and animal fats, for use in a diesel engine. Biodiesel has physical properties very similar to petroleum-deriv...

river

(Encyclopedia)river, stream of water larger than a brook or creek. Land surfaces are never perfectly flat, and as a result the runoff after precipitation tends to flow downward by the shortest and steepest course i...

Gatún Lake

(Encyclopedia)Gatún Lake gäto͞onˈ [key], artificial lake, 163 sq mi (422 sq km), Colón Prov., Panama, formed by the impounding of the Chagres River. Gatún Dam (completed 1912), 11⁄2 mi (2.4 km) long and 115...