trombone Brass instrument with an extendable slide with which the length of its tubing can be increased. It has a mostly cylindrical bore and a cup-shaped mouthpiece. The slide performs the same function as the valves in other brass instruments. Valve trombones, both with and with¬ out slides, were developed in the early 19th century; they provide increased agility but diminished tone quality. The trombone exists in sev¬ eral sizes; the tenor trombone in B-flat is the standard instrument, but the bass trombone is also used orchestrally. The trombone (long known as the sackbut) developed in the 15th century and has changed little over 400 years. By the 16th century it had been adopted by town, court, church, and military bands; it was employed in early opera orchestras, but it only began to be used in the symphony orchestra c. 1800. In the 20th century it became important in dance and jazz bands.
trompe I'oeil \tro n p-Toei,\ English \,tr6mp-T9i\ French "deceive the eye" Style of representation in which a painted object is intended to deceive the viewer into believing it is the object itself. First employed by the ancient Greeks, trompe I’oeil was also popular with Roman muralists. Since the early Renaissance, European painters have used trompe I’oeil to create false frames from which the contents of still lifes or portraits seemed to spill and to paint windowlike images that appeared to be actual openings in a wall or ceiling.
Anthony Trollope, oil painting by S. Laurence, 1865; in the National Por¬ trait Gallery, London.
COURTESY OF THE NATIONAL PORTRAIT GALLERY, LONDON
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Trondheim ► troubadour I 1941
Trondheim \ , tron- 1 ham\ City (pop., 2000: 148,859), central Norway. It is located on Trondheim Fjord, an inlet of the Norwegian Sea that extends 80 mi (130 km) inland. Trondheim was founded by King Olaf I Tryggva- son in 997, and it prospered as a trade centre until the Hanseatic League made Bergen its chief port. The city declined until the late 19th century, when it was linked by rail to Oslo. Norway’s third largest city, it is a major Norwegian land and sea transport link and a manufacturing centre.
Tropic of Cancer Parallel of latitude approximately 23°27' north of the terrestrial Equator. It is the northern boundary of the tropics and marks the northernmost latitude at which the Sun can be seen directly overhead at noon.
Tropic of Capricorn Parallel of latitude approximately 23°27' south of the terrestrial Equator. It is the southern boundary of the tropics and marks the southernmost latitude at which the Sun can be seen directly overhead at noon.
tropical cyclone Severe atmospheric disturbance in tropical oceans. Tropical cyclones have very low atmospheric pressures in the calm, clear centre (the eye) of a circular structure of rain, cloud, and very high winds. In the Atlantic and Caribbean they are called hurricanes; in the Pacific they are known as typhoons. Because of the Earth’s rotation, tropical cyclones rotate clockwise in the Southern Hemisphere and counterclock¬ wise in the Northern. They may be 50-500 mi (80-800 km) in diameter, and sustained winds in excess of 100 mph (160 kph) are common. In the eye, however, the winds drop abruptly to light breezes or even complete calm. The lowest sea-level pressures on Earth occur in or near the eye.
descending dry air high-level winds
Cross section of a tropical cyclone. A cyclone derives its power from the warm air and water found at tropical latitudes. Its winds rotate around the low-pressure cen¬ tre, or "eye," where relative calm prevails. Wind and rain are usually most severe in or near the eyewall.
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tropical fish Any of various small fishes of tropical origin often kept in aquariums. They are interesting for their behaviour or showiness or both. Popular varieties include the angelfish, guppy, kissing gourami, sea horse, Siamese fighting fish, and tetra.
tropical medicine Science of diseases seen primarily in tropical or subtropical climates. It arose in the 19th century when European colonial doctors encountered infectious diseases unknown in Europe. The discov¬ ery that many tropical diseases (e.g., malaria, yellow fever) were spread by mosquitoes led to discovery of other vectors’ roles (see sleeping sickness, plague, typhus) and to efforts to destroy vector breeding grounds (e.g., by draining swamps). Later, antibiotics came to play an increasingly impor¬ tant role. Research institutes and national and international commissions were organized to control common tropical illnesses, at least in areas with Europeans. As colonies became independent, their governments took over most of these efforts, with help from the World Health Organization and the former colonizing countries.
troposphere Vtro-po-.sfuA Lowest region of the atmosphere, bounded by the Earth below and the stratosphere above, with the upper boundary
being about 6-8 mi (10-13 km) above the Earth’s surface. The tropo¬ sphere is marked by decreasing temperature with height, which distin¬ guishes it from the stratosphere. Most clouds and weather systems occur in the troposphere.
Troppau Vtro-.pauV Congress of (1820) Meeting of the Holy Alli¬ ance powers held at Troppau in Silesia (modern Opava, Czech Rep.). Attended by representatives of Austria, Russia, and Prussia and by observ¬ ers from Britain and France, the alliance signed a declaration of intention (the Troppau protocol) to take collective action against revolution. The congress agreed that states having undergone revolutions would be excluded from the European alliance. They invited the king of the Two Sicilies to meet at the Congress of Laibach to discuss intervention against the revolution in Naples. Britain and France did not accept the protocol, demonstrating the division between the eastern and western members of the alliance and seriously weakening it.
Trotsky, Leon orig. Lev Davidovich Bronshtein (b. Nov. 7,1879, Yanovka, Ukraine, Russian Empire—d. Aug. 20, 1940,
Coyoacan, Mex., near Mexico City)
Russian communist leader. Born to Russian Jewish farmers, he joined an underground socialist group and was exiled to Siberia in 1898 for his revo¬ lutionary activities. He escaped in 1902 with a forged passport using the name Trotsky. He fled to London, where he met Vladimir Lenin. In 1903, when the Russian Social-Democratic Workers' Party split, Trotsky became a Menshevik, allying himself with Lenin’s opponents. He returned to St. Petersburg to help lead the Russian Revolution of 1 905. Arrested and again exiled to Siberia, he wrote Results and Prospects, setting forth his theory of “permanent revolution.” He escaped to Vienna in 1907, worked as a journalist in the Balkan Wars (1912-13), and moved around Europe and the U.S. until the Russian Revolution of 1917 brought him back to St. Petersburg (then Petrograd), where he became a Bolshevik and was elected leader of the workers’ soviet. He played a major role in the overthrow of the provisional government and the establishment of Lenin’s communist regime. As commissar of war (1918-24), Trotsky rebuilt and brilliantly commanded the Red Army during the Russian Civil War. Although favoured by Lenin to succeed him, Trotsky lost support after Lenin’s death (1924) and was forced out of power by Joseph Stalin. After a campaign of denun¬ ciation, he was expelled from the Politburo (1926) and Central Commit¬ tee (1927), then banished from Russia (1929). He lived in Turkey and France, where he wrote his memoirs and a history of the revolution. Under Soviet pressure, he was forced to move around Europe and eventually found asylum in 1936 in Mexico, where, falsely accused in the purge tri¬ als as the chief conspirator against Stalin, he was murdered in 1940 by a Spanish communist.
Trotskyism Marxist ideology based on the theory of permanent revo¬ lution first expounded by Leon Trotsky. Trotsky believed that because all national economic development was affected by the laws of the world market, a revolution depended on revolutions in other countries for per¬ manent success, a position that put him at odds with Joseph Stalin’s “socialism in one country.” After Trotsky’s exile in 1929, Trotskyists continued to attack the Soviet bureaucracy as “Bonapartist” (based on the dictatorship of one man). In the 1930s Trotskyists advocated a united front with trade unions against fascism. After Trotsky’s murder (1940), Trotsky¬ ism became a generic term for various revolutionary doctrines that opposed the Soviet form of communism. See also Leninism, Marxism, Stalin¬ ism.