Columbia Encyclopedia

Search results

500 results found

airfoil

(Encyclopedia)airfoil, surface designed to develop a desired force by reaction with a fluid, especially air, that is flowing across the surface. For example, the fixed wing surfaces of an airplane produce lift, whi...

ferret

(Encyclopedia)ferret, name for a domesticated polecat, Mustela putorius, common in the Old World. It has been used for centuries to hunt rats, mice, and rabbits. Domestic ferrets are found in many color types inclu...

depreciation

(Encyclopedia)depreciation, in accounting, reduction in the value of fixed or capital assets, as by use, damage, weathering, or obsolescence. It can be estimated according to a number of methods. In the straight-li...

indulgence

(Encyclopedia)indulgence, in the Roman Catholic Church, the pardon of temporal punishment due for sin. It is to be distinguished from absolution and the forgiveness of guilt. The church grants indulgences out of th...

ruthenium

(Encyclopedia)ruthenium ro͞othēˈnēəm [key], metallic chemical element; symbol Ru; at. no. 44; at. wt. 101.07; m.p. about 2,310℃; b.p. about 3,900℃; sp. gr. 12.41 at 20℃; valence commonly +2, +3, +4, +6, ...

alpaca

(Encyclopedia)alpaca ălpăkˈə [key], partially domesticated South American mammal, Lama pacos, of the camel family. Genetic studies show that it is a descendant of the vicuña. Although the flesh is sometimes us...

Boutwell, George Sewall

(Encyclopedia)Boutwell, George Sewall so͞oˈəl boutˈwəl, –wĕl [key], 1818–1905, American politician, b. Brookline, Mass. He served seven terms in the Massachusetts legislature between 1842 and 1851, was el...

nitric acid

(Encyclopedia)nitric acid, chemical compound, HNO3, colorless, highly corrosive, poisonous liquid that gives off choking red or yellow fumes in moist air. It is miscible with water in all proportions. It forms an a...

Snowden, Philip Snowden, 1st Viscount

(Encyclopedia)Snowden, Philip Snowden, 1st Viscount snōˈdən [key], 1864–1937, British statesman. Born to poverty, he was a civil service clerk until crippled by a spinal ailment. Resigning in 1893, he began to...

aldehyde

(Encyclopedia)CE5 Aldehydes aldehyde ălˈdəhīd [key] [alcohol + New Lat. dehydrogenatus=dehydrogenated], any of a class of organic compounds that contain the carbonyl group, >C=-->O, and in which t...