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In

(Encyclopedia)In, symbol for the element indium. ...

amalgam

(Encyclopedia)amalgam əmălˈgəm [key], alloy containing mercury. The alloy may be liquid or solid, depending on the proportion of mercury, although all naturally occurring amalgams, i.e., those of gold and silve...

perturbation

(Encyclopedia)perturbation pŭrˌtərbāˈshən [key], in astronomy and physics, small force or other influence that modifies the otherwise simple motion of some object. The term is also used for the effect produce...

mercurous chloride

(Encyclopedia)mercurous chloride, mercury (I) chloride, or calomel, chemical compound, Hg2Cl2, a white crystalline powder, very slightly soluble in water. It was once used medicinally as a purgative, cathartic, li...

barometer

(Encyclopedia)CE5 Aneroid barometer barometer bərŏmˈətər [key], instrument for measuring atmospheric pressure. It was invented in 1643 by the Italian scientist Evangelista Torricelli, who used a column...

National Radio Astronomy Observatory

(Encyclopedia)National Radio Astronomy Observatory (NRAO), federal observatory for radio astronomy, founded in 1956 and operated under contract with the National Science Foundation by Associated Universities, Inc.,...

Nuffield Radio Astronomy Laboratories

(Encyclopedia)Nuffield Radio Astronomy Laboratories: see Jodrell Bank Observatory. ...

quicksilver

(Encyclopedia)quicksilver: see mercury.

Hg

(Encyclopedia)Hg, symbol for the element mercury. ...

thermostat

(Encyclopedia)thermostat, automatic device that regulates temperature in an enclosed area by controlling heating or refrigerating systems. It is commonly connected to one of these systems, turning it on or off in o...