rack and pinion Mechanical device consisting of a bar of rectangu¬ lar cross section (the rack), having teeth on one side that mesh with teeth on a small gear (the pinion). If the pinion rotates about a fixed axis, the rack will move in a straight path. Some automobile steering mechanisms have rack-and-pinion drives that use this principle. If the rack is fixed and the pinion is carried in bearings on a table guided on tracks parallel to the rack, rotation of the pinion shaft will move the table parallel to the rack. On machine tools, this principle is used to obtain rapid movements of worktables.
racketeering See organized crime
rackets Game for two or four players with ball and racket on a four- walled court. Rackets is played with a hard ball in a relatively large court (approximately 9x18 m), unlike the related games of squash and rac- quetball. As in these other games, the object of rackets is to bounce, or rebound, the ball off the front and other walls in such a way as to defeat an opponent’s attempt to reach and return it. It appears to have developed in England in the early 19th century.
Rackham, Arthur (b. Sept. 19, 1867, London, Eng.—d. Sept. 6, 1939, Limpsfield, Surrey) British artist and illustrator. While a staff artist for a
North American raccoon (Procyon lotor).
LEONARD LEE RUE III
Racer [Coluber constrictor)
© 1971 Z. LESZCZYNSKI—ANIMALS ANIMALS
© 2006 Encyclopaedia Britannica, Inc.
1582 I racquetball ► radical
London newspaper, he also began illustrating books. He became skillful using the new halftone process, and his highly detailed drawings revealed a unique imagination. He achieved renown with a 1900 edition of Grimm’s Fairy Tales, and his illustrations for Rip Van Winkle (1905) brought him recognition in America as well. Altogether he illustrated more than 60 books, including classics of children’s literature as well as works by William Shakespeare, Charles Dickens, John Milton, Richard Wagner, and Edgar Allan Poe.
racquetball Game similar to handball but played with racquets. The game is played on a four-walled court with a short-handled racket and a ball larger than that used in handball. It was invented in 1950 by Joseph G. Sobek (1918-98), who was unhappy with the indoor racquet sports then available. By the late 1990s there were 8.5 million racquetball play¬ ers in 91 countries.
radar System that uses electromagnetic echoes to detect and locate objects. It can also measure precisely the distance (range) to an object and the speed at which the object is moving toward or away from the observ¬ ing unit. Radar (the name is derived from radio detecting and ranging) originated in the experimental work of Heinrich Hertz in the late 1880s. During World War II British and U.S. researchers developed a high- powered microwave radar system for military use. Radar is used today in identification and monitoring of artificial satellites in Earth orbit, as a navigational aid for airplanes and marine vessels, for air traffic control around major airports, for monitoring local weather systems, and for spot¬ ting “speeders.”
radar astronomy See radio and radar astronomy
Radcliffe, Ann orig. Ann Ward (b. July 9, 1764, London, Eng.—d. Feb. 7, 1823, London) English gothic novelist. Brought up in a well-to-do family, in 1787 she married a journalist who encouraged her literary pur¬ suits. Her first two novels were published anonymously. She achieved fame with her third novel. The Romance of the Forest (1791). With her fourth, The Mysteries of Udolpho (1794), she became the most popular novelist in England. The Italian (1797), which displays rare psychologi¬ cal insight, reveals her full powers. In her tales, scenes of terror and sus¬ pense are infused with an aura of romantic sensibility. See also gothic novel.
Radcliffe-Brown, A(lfred) R(eginald) (b. Jan. 17, 1881, Birming¬ ham, Warwick, Eng.—d. Oct. 24, 1955, London) British social anthro¬ pologist. He taught at the universities of Cape Town, Sydney, Chicago, and Oxford. In his version of functionalism, he viewed the component parts of society (e.g., the kinship system, the legal system) as having an indis¬ pensable function for one another, the continued existence of one com¬ ponent being dependent on that of the other, and he developed a systematic framework of concepts relating to the social structures of small-scale societies. He had a profound impact on British and American
W social anthropology. Among his major works are The Andaman Islanders
(1922) and Structure and Function in Primitive Society (1952).
M Radek Vra-dyik\, Karl (Bernhardovich) orig. Karl Sobelsohn
(b. 1885, Lemberg, Galicia, Austria-Hungary—d. 1939?) Russian com-
wm munist politician. He took part in the Russian Revolution of 1905, then
wrote for leftist newspapers in Poland and Germany (1906-14). After meeting Vladimir Lenin in 1915, he helped reorganize the German Com¬ munist Party in 1918. He returned to Russia in 1919 and rose to leader¬ ship in the Comintern but was ousted in 1924 for his support of Leon Trotsky. After recanting in 1929, he became a fervent Stalinist and edito¬ rial board member of Izvestiya (1931-36). Despite his conversion, he was arrested and tried in the purge trials and sentenced to 10 years in prison, where he died.
Radetzky \ra-'det-ske\, Joseph, Count (b. Nov. 2, 1766, Trebnice, Bohemia—d. Jan. 5, 1858, Milan) Austrian army officer. He fought with distinction against the French in the Napoleonic Wars. As army chief of staff, he attempted to modernize the Austrian army. As commander in chief of the Austrian army in northern Italy (1831-57), he suppressed the revolt in the Austrian-ruled provinces of Lombardy and Venetia in 1848. He served as governor-general of these provinces (1849-57). His status among conservatives as a national hero inspired Johann Strauss the Elder to compose the Radetzky March.
Radha \'ra-da\ In Hindu mythology, mistress of the god Krishna when he lived among the cowherds of Vrndavana. Though Radha was the wife of another cowherd, she was the most beloved of Krishna’s consorts and