(Encyclopedia) solenoidsolenoidsōˈlənoidˌ [key], device made of a long wire that has been wound many times into a tightly packed coil; it has the shape of a long cylinder. If current is sent through…
(Encyclopedia) Quidor, JohnQuidor, Johnkĭdôrˈ [key], 1801–81, American painter, b. Tappan, N.Y., studied with J. W. Jarvis. Little appreciated in his own time, he was subsequently accorded a place…
(Encyclopedia) hardening, in metallurgy, treatment of metals to increase their resistance to penetration. A metal is harder when it has small grains, which result when the metal is cooled rapidly.…
(Encyclopedia) meteor shower, increase in the number of meteors observed in a particular part of the sky. The trails of the meteors of a meteor shower all appear to be traceable back to a single…
(Encyclopedia) Mount Wilson Observatory, astronomical observatory located in California on Mt. Wilson, near Pasadena. Mt. Wilson Observatory was founded in 1904 by George E. Hale. Its equipment…
(Encyclopedia) parity or space parity, in physics, quantity that refers to the relationship between an object or process and the image that it can produce in a mirror. For example, any right-handed…
(Encyclopedia) social contract, agreement or covenant by which men are said to have abandoned the “state of nature” to form the society in which they now live. The theory of such a contract, first…
(Encyclopedia) supply and demand, in classical economics, factors that are said to determine price, by correlating the amount of a given commodity producers hope to sell at a certain price (supply),…
(Encyclopedia) urinalysisurinalysisy&oobreve;rˌənălˈĭsĭs [key], clinical examination of urine for the purpose of medical diagnosis. Urine is initially examined for such characteristics as color,…
(Encyclopedia) creosotecreosotekrēˈəsōt [key], volatile, heavy, oily liquid obtained by the distillation of coal tar or wood tar. Creosote derived from beechwood tar has been used medicinally as an…
