condenser Device for reducing a gas or vapour to a liquid. Condens¬ ers are used in power plants to condense exhaust steam from turbines and in refrigeration plants to condense refrigerant vapours, such as ammonia and Freons. The petroleum and chemical industries use condensers for hydrocarbons and other chemical vapours. In distillation, a condenser transforms vapour to liquid. All condensers work by removing heat from
the gas or vapour. In some, the gas passes through a long tube of heat- conductive metal, such as copper (usually arranged in a coil or other compact shape), and heat escapes into the surrounding air. Large indus¬ trial condensers use water or some other liquid to remove the heat. The term condenser also refers to a device attached to carding machines in textile factories to collect fibres into roving for spinning machines.
Condillac \ko n -de-'yak\, Etienne Bonnot de (b. Sept. 30, 1715, Grenoble, France—d. Aug. 2/3, 1780, Flux) French philosopher, psy¬ chologist, and economist. He was ordained a priest in 1740. In his Essay on the Origin of Human Knowledge (1746), he systematically discussed the empiricism of John Locke. In Treatise on Sensations (1754), he ques¬ tioned Locke’s doctrine that intuitive knowledge is available directly through the senses. In his works Logic (1780) and The Language of Cal¬ culation (1798), he emphasized the importance of language in logical rea¬ soning and stressed the need for a scientifically designed language. His economic views, presented in Commerce and Government (1776), were based on the notion that value depends on utility rather than labour. The need for something useful, he argued, gives rise to value, while prices result from the exchange of valued items.
conditioning Process in which the frequency or predictability of a behavioral response is increased through reinforcement (i.e., a stimulus or a reward for the desired response). Classical, or respondent, condition¬ ing, which involves stimulus substitution, is based on the work of Ivan Pavlov, who conditioned dogs by ringing a bell each time the aroma of food was presented. Eventually the dogs salivated when the bell rang, even if no food odour was present; salivation was thus the conditioned response. In instrumental, or operant, conditioning, a spontaneous (oper¬ ant) behaviour is either rewarded (reinforced) or punished. When rewarded, a behaviour increases in frequency; when punished, it decreases. Operant conditioning was studied in detail by B.F. Skinner.
condominium In modern property law, individual ownership of one dwelling unit within a multidwelling building. Unit owners have undi¬ vided ownership interest in the land and those portions of the building shared in common. This type of ownership has been present in Europe since the end of the Middle Ages; in the U.S. it dates to the latter half of the 19th century and has been popular in crowded urban areas. An alter¬ native to the condominium is the cooperative, in which residents own a share of a corporation, with each share entitling the owner to reside in a particular unit in the building.
condor Either of two species of large New World vultures. Two of the largest flying birds, each is about 4 ft (1.2 m) long. Both feed on dead animals. The Andean condor ( Vultur gryphus ), which ranges from the Pacific coast of South America to the high Andes Mountains, has slightly longer wings (10 ft [3 m]) and is black with a white ruff and bare pinkish head and neck. The California condor ( Gymnogyps californianus) is nearly black, with white wing linings, a bare yellow head, and a red neck. It hovered on the brink of extinction in the 1980s, and every California condor was captured. Careful nurturing has since led to the release of more than 200 condors into the wild.
Condorcet \k6 n -d6r-'se\, Marie-Jean-Antoine-Nicolas de Car- itat, marquis de (b. Sept. 17, 1743, Ribemont, France—found dead March 29, 1794, Bourg-la-Reine) French mathematician, statesman, and revolutionary. He showed early promise as a mathematician and was a protege of Jean Le Rond d'Alembert. In 1777 he became secretary of the Academy of Sciences. In sympathy with the French Revolution, he was elected to represent Paris in the Legislative Assembly (1791-92), where he called for a republic. His opposition to the arrest of the moderate Girondins led to his being outlawed (1792). While in hiding he wrote his famous Sketch for a Historical Picture of the Progress of the Human Mind, in which he advanced the idea of the continuous progress of the human race to an ultimate perfection. He was captured and subsequently found dead in prison.
conducting Art of leading a group of musical performers. Simple coor¬ dination of a group does not always require a conductor (members of a Renaissance choir kept together by one tapping another on the shoulder, for example, and musicians in a recording studio listen to a “click track” on headphones). Before c. 1800, the first violinist usually gave the few necessary signals with his bow; the keyboard player might also lead the orchestra, using his hands and head. In the 19th century the larger size of ensembles and growing complexity of music, including its varying tem¬ pos and heightened expressiveness, made it necessary for a person to
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448 I conduction ► Confucianism
coordinate and interpret the music for the group. The first conductors, including Felix Mendelssohn, Hector Berlioz, and Richard Wagner, were composers themselves. By the end of the 19th century, conducting had become a specialty and the great conductors had become celebrities in their own right.
conduction See thermal conduction
conductor Any of various substances that allow the flow of electric cur¬ rent or thermal energy. A conductor is a poor insulator because it has a low resistance to such flow. Electrical conductors are used to conduct electric current, as in the metal wires of an electric circuit. Electrical conductors are usually metallic. Thermal conductors allow thermal energy to flow because they do not absorb radiant heat; they include materials such as metal and glass.
cone or strobilus \stro-'bI-l9s, 'stro-b9-bs\ In botany, a mass of scales or bracts, usually ovate, containing the reproductive organs of certain non-flowering plants. A distinguishing feature of pines and other conifers, the cone is roughly analogous to the flower of other plants. Cones (stro- bili) are also found on club mosses and horsetails.
conef lower Any of three genera ( Echinacea , Ratibida, and Rudbeckia). They are weedy plants in the composite family, native to North America. Some species in each genus have reflexed ray flowers. The purple- flowered perennials E. angustifolia and E. purpurea are often cultivated as border plants; they have strong-smelling black roots and hairy stems. These two species, along with E. pallida, are used to prepare an herbal cold and flu remedy called echinacea. Ratibida species have yellow ray flowers and brownish disk flowers. Prairie coneflowers {Ratibida colum- naris and R. pinnata ) are grown in wildflower gardens. Rudbeckia spe¬ cies have yellow ray flowers and brown or black disk flowers. Black-eyed Susan {Rudbeckia hirta ), thimble-flower {R. bicolor ), and cutleaf cone- flower {R. laciniata) are grown as border plants.
Conestoga wagon Horse-drawn covered freight wagon. It originated in the 18th century in the Conestoga Creek region of Pennsylvania. It had a flat body and low sides; with its floor curved up at each end to prevent freight from shifting, it was well suited for travel over early American roads. It became famous as later adapted by westward-traveling pioneers for hauling their possessions; with its tall white canvas top, it resembled a sailing ship from a distance, which earned it the name “prairie schooner.”
coney See cony
Coney Island Amusement area, southern Brooklyn, N.Y., U.S. It was an island in the Atlantic Ocean until its creek silted up and it became part of Long Island. The first pavilion and bathhouse were erected in 1844, and it gained popularity with the coming of the subway in 1920. It has a 3.5-mi (5.6-km) boardwalk and an amusement park known for its roller coaster (the Cyclone). It is also the site of the New York Aquarium.