Bolshoi Ballet \b6l-'shoi\ Leading ballet company of Russia, noted for elaborate productions of 19th-century classical ballets. The company was formed in 1776 and took the name of its home, Moscow’s Bolshoi The¬ atre, in 1825. Its influential choreographers included Marius Petipa, Carlo Blasis, and Aleksandr Gorsky. Yuri Grigorovich was artistic director from 1964 to 1995. Its many successful tours have introduced its outstanding
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dancers, including Yekaterina Geltzer, Vasily Tikhomirov, Galina Ulanova, and Maya Plisetskaya, to audiences worldwide.
bolt Mechanical fastener, usually used with a nut, for connecting two or more parts. Bolted joints can be readily disassembled and reassembled; hence bolts or screw fasteners are used more than other types of mechanical fastener. A bolt consists of a head and a cylindrical body with screw threads along a portion of its length. Nuts have internal (or female) threads to match those of the bolt. Washers are often used to prevent loosening and crushing.
bolt action Type of breech mechanism that was key to developing an effective repeating rifle. It combines the firing pin, a spring, and an extrac¬ tor, all housed in or attached to the bolt. A projecting handle with a round knob moves the bolt back and forth. As the bolt is thrust forward, it pushes a cartridge into the chamber and cocks the piece. The trigger releases the spring-driven firing pin inside the bolt. After firing, the extractor on the head of the bolt removes the spent cartridge and ejects it. The bolt then moves a new cartridge from the magazine.
Bolton, Guy (Reginald) (b. Nov. 23, 1884, Broxboume, Hertford¬ shire, Eng.—d. Sept. 5, 1979, London) British-born U.S. playwright and librettist. The son of American parents, Bolton studied architecture before he began writing plays. His first play appeared on Broadway in 1911, but it was not until he began contributing to Broadway musicals that his fame spread. In collaboration with P.G. Wodehouse and others, he wrote doz¬ ens of scripts scored by composers such as Jerome Kern {Oh, Boy!, 1917), George Gershwin {Lady, Be Good!, 1924; Girl Crazy, 1930), and Cole Porter {Anything Goes, 1934).
Boltzmann \'bolts-,man\, Ludwig (Eduard) (b. Feb. 20, 1844, Vienna, Austria—d. Sept. 5, 1906, Duino, Italy) Austrian physicist. He obtained his doctorate from the University of Vienna and thereafter taught at several German and Austrian universities. He was one of the first Euro¬ pean scientists to recognize the importance of James Clerk Maxwell’s elec¬ tromagnetic theory. He explained the second law of thermodynamics by applying the laws of mechanics and the theory of probability to the motions of atoms, and he is remembered as the developer of statistical mechanics. His work was widely attacked and misunderstood; subject to depression after 1900, he eventually committed suicide. Shortly after his death, his conclusions were finally supported by discoveries in atomic physics and by recognition that phenomena such as Brownian motion could be explained only by statistical mechanics.
Boltzmann constant Ratio of the universal gas constant (see gas laws) to Avogadro's number. It has a value of 1.380662 x 10 -23 joules per kelvin. Named after Ludwig Boltzmann, it is a fundamental constant of physics, occurring in nearly every statistical formulation of both classi¬ cal and quantum physics.
bomb In volcanology, any unconsolidated volcanic material that has a diameter greater than 1.25 in. (32 mm). Bombs form from clots of wholly or partly liquid lava ejected during a volcanic explosion; they solidify and become rounded during flight. The final shape is determined by the ini¬ tial size, viscosity, and flight velocity of the magma.
Bombay See Mumbai
bomber Military aircraft designed to drop bombs on surface targets. Aerial bombardment can be traced to the Italo-Turkish War (1911), in which an Italian pilot dropped grenades on two Turkish targets. In World War I Zeppelins and large two- to four-engined biplanes were used as stra¬ tegic bombers. In the 1930s small dive bombers were developed; they caused great destruction and panic in the Spanish Civil War and early in World War II. The latter conflict saw further development of heavy stra¬ tegic bombers, which were used to destroy targets in the enemy’s home territory; meanwhile, smaller fighter-bombers supported ground troops on the battlefield. After the war, jet-propelled long-range bombers carrying nuclear bombs were important to Cold War strategy, and they also dropped conventional bombs during the Vietnam War, the Persian Gulf War, and the Afghan conflicts. Efforts to evade increasingly sophisticated electronic early-warning systems have culminated in the development of U.S. stealth bombers, but cheaper and smaller jet fighter-bombers, equipped with elec¬ tronic sensors and guided “smart” bombs, have proved effective in con¬ flicts ranging from the Balkans to the Middle East.
Bombon, Lake See Lake Taal
Bomu River \'bo-mu\ River, central Africa. Flowing west, it forms the boundary between northern Congo and southern Central African Repub¬
lic (where it is called the Mbomou). It flows in a wide 500-mi (800-km) curve through savannas to join the Uele River and form the Ubangi.
Bon Vpce n \ Indigenous religion of Tibet. It was originally concerned with magical propitiation of demonic forces, and its practices included blood sacrifices. It later developed a cult of divine kingship (with kings regarded as manifestations of the sky divinity), reformulated in Tibetan Buddhism as the reincarnation of LAMAS. Bon’s order of oracular priests had their coun¬ terpart in Buddhist soothsayers, and its gods of air, earth, and underworld in the lesser Tibetan Buddhist deities. Though its religious supremacy ended in the 8th century, Bon survives in many aspects of Tibetan Bud¬ dhism and as a living religion on Tibet’s northern and eastern frontiers.
Bon \'bon\ Popular annual festival in Japan, usually observed July 13-15, in honor of the spirits of deceased family members and of all the dead. As at the New Year festival, the dead are believed to return to their birth¬ places. Memorial stones are cleaned, dances performed, and paper lan¬ terns and fires are lit to welcome the dead and to bid them farewell when their visit ends.
Bon, Gustave Le See Gustave Le Bon
Bon Marche \bo n -mar-'sha\ French "Good Buy" Paris department store. It was founded as a small shop in the early 19th century, and by c. 1865 it had become the world’s first true department store. Its 1876 build¬ ing was designed by Alexandre-Gustave Eiffel (1832-1923). It is unrelated to the Bon Marche chain of department stores in the northwestern U.S.
Bona Dea \,bo-n9-'da-3\ In Roman religion, the deity of fruitfulness, both in the earth and in women. The dedication day of her temple on the Aventine was May 1. Her temple was cared for and attended only by women, though inscriptions show that there was a public side to her wor¬ ship in which men could participate.
Bonaparte, (Marie-Annonciade-) Caroline (b. March 25, 1782, Ajaccio, Corsica—d. May 18, 1839, Florence) Queen of Naples (1808— 15). The youngest sister of Napoleon, she married Joachim Murat in 1800. Her ambitious nature was partially responsible for her husband’s becom¬ ing king of Naples, among other achievements. Her relations with Napo¬ leon became strained as she associated herself with Murat’s shifting allegiances in 1814-15, which led to his execution. Caroline then took refuge in Trieste and became countess de Lipona.
Bonaparte, Jerome (b. Nov. 15, 1784, Ajaccio, Corsica—d. June 24, 1860, Villegenis, France) French nobleman. He was the youngest brother of Napoleon, from whom he became estranged after marrying a U.S. resi¬ dent (1803) without Napoleon’s consent; he later allowed his marriage to be annulled. Napoleon then married Jerome to Princess Catherine of Wurttemberg and made him king of Westphalia (1807-13). He served in the Russian campaign of 1812 and at the Battle of Waterloo. After Napo¬ leon’s fall, he lived in Florence; after the rise of his nephew, Napoleon III, he returned to France to become a marshal of France and president of the Senate.