Britannica Concise 2005

trench warfare Warfare in which the opposing sides attack, counter¬ attack, and defend from sets of trenches dug into the ground. It was developed by Sebastien Le Prestre de Vauban in the 17th century for laying siege to fortresses. Its defensive use was first institutionalized as a tactic during the American Civil War. It reached its highest development in World War I. Little used in World War II, it reappeared in the Iran-Iraq War in the 1980s. A typical construction consisted of two to four parallel trenches, each dug in a zigzag, protected by sandbags, and floored with wooden planks. The parallel trenches were connected by a series of com¬ munication trenches dug roughly perpendicular to them. The first row was fronted by barbed wire and contained machine-gun emplacements; the rear trenches housed most of the troops. Increased use of tanks marked the end of trench warfare, since tanks were invulnerable to the machine- gun and rifle fire used by entrenched soldiers.

Trent, Council of (1545-63) 19th ecumenical council of the Roman Catholic church, which made sweeping reforms and laid down dogma clarifying nearly all doctrines contested by the Protestants. Convened by Pope Paul III at Trento in northern Italy, it served to revitalize Roman Catholicism in many parts of Europe. In its first period (1545—47) it accepted the Nicene Creed as the basis of Catholic faith, fixed the canon of the Old and New Testaments, set the number of sacraments at seven, and defined the nature and consequences of original sin; it also ruled against Martin Luther’s doctrine of justification by faith. In its second period (1551-52) it confirmed the doctrine of transubstantiation and issued decrees on episcopal jurisdiction and clerical discipline. In the final period (1562-63) it defined the mass as a true sacrifice and issued statements on several other doctrinal issues. By the end of the 16th century, many of the abuses that had motivated the Protestant Reformation had disappeared, and the church had reclaimed many of its European followers.

Trent, River River, central England. It rises in Staffordshire and flows northeast 168 mi (270 km) to unite with the River Ouse west of Hull to form the River Humber. It is navigable by barge for over half its length.

Trent Canal Canal, southeastern Ontario, Canada. Linking Lake Huron with Lake Ontario, the canal extends from the southeastern shore of Georgian Bay up the Severn River to Lake Simcoe, connects several lakes of the Kawartha Lake region to Rice Lake, and passes down the Trent River to the Bay of Quinte and Lake Ontario. Its 242-mi (389-km) main course consists of 33 mi (53 km) of man-made channels and 42 locks. Construction began in 1833. The waterway once served a busy lumber trade; it is now a popular tourist attraction.

Trentino-Alto Adige Vtren-'te-no-.al-to-'a-de-jaX/orm^r/y (until 1947) Venezia Tridentina Autonomous region (pop., 2001 prelim.: 937,107), northeastern Italy. Its capital is Trento. A mountainous area cov¬ ering 5,258 sq mi (13,618 sq km), Trentino-Alto Adige has some of the

© 2006 Encyclopaedia Britannica, Inc.

Trento ► trial by ordeal I 1935

highest peaks in Europe, cut through by passes into Switzerland and Aus¬ tria. Historically it included the medieval ecclesiastical principalities of Trento and Bressanone. Austria annexed it in 1815. It was the scene of much fighting during World War I, and it was ceded to Italy at the end of the war. The population is a mix of German speakers in the north and Italian speakers in the south; the regional parliament alternates German¬ speaking and Italian-speaking chairmen. The region grows grain and grapes, raises cattle, and mines zinc, lead, and other minerals. Tourism is a major industry.

Trento English Trent ancient Tridentum City (pop., 2001 prelim.: 104,844), capital of Trentino-Alto Adige region, on the Adige River in northern Italy. Reportedly founded by the Raetians c. 4th century bc, it later became a Roman colony on the road to the Brenner Pass in the Alps. In the Christian era Trento came under the Ostrogoths, Lombards, and Franks. It was the site of the Council of Trent (1545-63). It came under the Napoleonic kingdom of Italy in the early 19th century and passed to Austria in 1814 and to Italy in 1918. An agricultural market centre, it also has some light industry.

Trenton City (pop., 2000: 85,403), capital of New Jersey, U.S. It lies at the head of navigation on the Delaware River. Settled c. 1679 by English Quakers, it was incorporated in 1745. On Dec. 25, 1776, George Wash¬ ington led his army across the ice-choked Delaware River to attack Hes¬ sian troops quartered at Trenton (see battles of Trenton and Princeton). It served as temporary capital of the U.S. in 1784 and 1799 and was made the state capital in 1790. The completion of a canal and railroad line in the 1830s spurred Trenton’s industrial development, and it remains an industrial city.

Trenton and Princeton, Battles of (1776-77) Engagements won by the Continental Army in the American Revolution. Defeats in New York forced the army under George Washington to retreat through New Jersey into Pennsylvania. On Dec. 25, 1776, Washington led a force of 6,000 troops across the ice-filled Delaware River to surprise the 1,400-man British-Hessian force at Trenton, N.J., and captured 900 troops. A British force of 7,000 troops under Charles Cornwallis arrived to force the Ameri¬ can army into retreat. At night Washington led his men around the Brit¬ ish to defeat an outpost at Princeton, causing Cornwallis to retreat to New Brunswick and enabling Washington to lead his troops into winter quar¬ ters near Morristown. The victories restored American morale and renewed confidence in Washington.

trespass In law, unlawful entry onto land. Trespass was formerly defined as wrongful conduct causing injury or loss; today it is generally confined to issues involving real property (see real and personal property). Once a trespass is proved, the trespasser is usually held liable for any damages resulting, regardless of whether the trespasser was negligent or the damage was foreseeable. Criminal trespass, trespass to property that is forbidden by statute, is punishable as a crime.

Trevelyan Uri-'vel-yonX, G(eorge) M(acauley) (b. Feb. 16, 1876, Welcombe, Warwickshire, Eng.—d. July 21, 1962, Cambridge, Cam¬ bridgeshire) English historian. He is known for books accessible to gen¬ eral readers that often show an appreciation of the Whig tradition in English thought and reflect a keen interest in the Anglo-Saxon element in the English constitution. They include three on Giuseppe Garibaldi (1907, 1909, 1911), England in the Age of Wycliffe (1899), British History in the Nineteenth Century (1782-1901) (1922), History of England (1926), and The Seven Years of William IV (1952).

Trevino Uro-'ve-noV Lee (Buck) (b. Dec. 1, 1939, near Dallas, Tex., U.S.) U.S. golfer. Of Mexican American descent, Trevino received a grade-school education, served in the U.S. Marine Corps, and worked as an odd-job man and assistant professional at golf courses in his native Texas. In 1967 he unexpectedly came in fifth in the U.S. Open, then won it the next year. In 1971 Trevino became the first player to win the U.S., British, and Canadian Open championships in a single year. He won the British Open in 1972 and the U.S. PGA Championship in 1974. He then underwent several back surgeries but returned to win the PGA again in

Trevithick Vtrev-o-.thikX, Richard (b. April 13, 1771, Illogan, Corn¬ wall, Eng.—d. April 22, 1833, Dartford, Kent) British inventor of the first steam locomotive. With little formal education, in 1790 he became an engineer for several ore mines in Cornwall. In 1797 his experiments with high-pressure steam led him to develop a small, light engine to replace

the large, low-pressure mine engines then used for hoisting ore. In 1801 he built the first steam carriage, which he later drove in London. In 1803 he built the first steam railway locomo¬ tive for an ironworks in Wales. He abandoned his locomotive projects in 1808 because the iron rails were too fragile to carry their weight. He adapted his engine to produce the first steam dredger in 1806. In 1816 he traveled to South America to deliver engines to Peruvian silver mines, hoping to become wealthy, but returned to England in 1827 pen¬ niless.

Trevor, William orig. William Trevor Cox (b. May 24, 1928,

Mitchelstown, County Cork, Ire.)

Irish writer. Educated at Trinity Col¬ lege, Dublin, he worked as a teacher, sculptor, and advertising copywriter before moving to England to write fiction full-time. His works, noted for their exquisite characterizations and finely tuned irony, focus largely on the psychology of eccentrics and outcasts. Trevor’s second novel. The Old Boys (1964), tells the story of an “old boys” committee whose aging members plot against each other. His later novels include Felicia’s Jour¬ ney (1994) and Death in Summer (1998). He is perhaps best known for his acclaimed collections of wry and often macabre short stories.

Triad Term used variously for secret societies in Qing-dynasty China (and sometimes earlier), for modern Chinese crime gangs, and for crime gangs of other Asian nationals operating in their own countries or abroad. A secret society with the name Triad started operat¬ ing in the early 19th century in southern China, where it took root and spread. In the 1850s Triad rebellions threatened Shanghai and Xiamen (Amoy) and contributed to the revolution of 1911. Chinese secret soci¬ eties have in common the swearing of an oath to join, strict rules, a fam¬ ily relationship among members, the duty of mutual help, a hierarchy of functions, and hereditary membership within families.

triage Vtre-.azh, tre-'azh\ Division of patients for priority of care, usu¬ ally into three categories: those who will not survive even with treatment; those who will survive without treatment; and those whose survival depends on treatment. If triage is applied, the treatment of patients requir¬ ing it is not delayed by useless or unnecessary treatment of those in the other groups. Triage originated in military medicine, when limited resources faced many wounded soldiers. It is used in civilian settings dur¬ ing disasters or epidemics and in emergency rooms. Triage decisions are made after relatively quick examination; patients in lower-priority groups should be reexamined periodically.

trial In law, a judicial examination of issues of fact or law for the pur¬ pose of determining the rights of the parties involved. Attorneys for the plaintiff and the defendant make opening statements to a judge or jury, then the attorney for the plaintiff makes his case by calling witnesses, whom the defense attorney may cross-examine. Unless the case is then dismissed for lack of sufficient evidence, the defense attorney next takes a turn calling witnesses, whom the plaintiff’s attorney cross-examines. Both sides make closing arguments. In a trial before a jury, the judge instructs the jury on the applicable laws, and the jury retires to reach a verdict. If the defendant is found guilty, the judge then hands down a sen¬ tence.

trial by ordeal See ordeal

Richard Trevithick, detail of an oil painting by John Linnell, 1816; in the Science Museum, London.

COURTESY OF THE SCIENCE MUSEUM, LONDON, THE WOODCROFT BEQUEST

William Trevor, 1982.

MARK GERSON

© 2006 Encyclopaedia Britannica, Inc.

1936 I triangle ► trichinosis

triangle Geometric figure with three sides and three angles. Each two sides meet at a point called a vertex, and the three angles sum to 180°. A triangle with one 90° (right) angle is a right triangle. A triangle with all sides (and thus all angles) equal is equilateral, one with two sides equal is isosceles, and one with no two sides equal is scalene. Triangles are par¬ ticularly useful in surveying, astronomy, and navigation. Two observation points (sight lines) form a triangle with a reference object serving as one vertex and the observation points as the other two. Knowing the angles of the sight lines and the distance between the observation points allows the calculation of the lengths of the other sides using the methods of TRIGONOMETRY.

Triangle Shirtwaist Co. fire (March 25, 1911) Industrial disaster that led to the enactment of many safety and labour laws. The fire, which started in the garment factory on the eighth floor of the Asch Building in New York City, resulted in the deaths of 146 people, mostly young immi¬ grant women. Fire truck ladders, then able to reach only six stories, were of little help. The sweatshop had few fire escapes, and its doors were locked to prevent theft, forcing panicked workers to leap from upper-floor windows. Public outcry also led to new fire codes and child-labour laws and greater influence for the International Ladies' Garment Workers Union.

Trianon \,tre-3-'n6n\, Treaty of (June 4, 1920) Treaty at the end of World War I between Hungary and the Allied Powers, signed at the Tri¬ anon Palace at Versailles, France. By its terms, Hungary lost two-thirds of its former territory, which was divided among Czechoslovakia, Aus¬ tria, the future Yugoslavia, and Romania. Hungary’s armed forces were restricted to 35,000 lightly armed men, to be used only to maintain inter¬ nal order.

Triassic \trl-'a-sik\ Period Interval of geologic time, c. 248-206 mil¬ lion years ago, that marks the beginning of the Mesozoic Era. Many new vertebrates emerged during the Triassic, heralding the major changes that were to occur in both terrestrial and marine life forms during the Meso¬ zoic Era. The seas became inhabited by large marine reptiles. On land, ancestral forms of various modern amphibians arose, as did reptiles such as turtles and crocodilians. By the Late Triassic, archosaurs were becom¬ ing more and more dominant, and the first true mammals, small shrew¬ like omnivores, evolved. Seed ferns dominated the flora of southern Gondwana, and gymnosperms, including conifers, cycads, and ginkgos, were common throughout much of Pangea.

triathlon Endurance contest involving swimming, cycling, and running. Triathlons originated in California in the 1970s and became an Olympic event in 2000. Olympic and world championship triathlons consist of a 1.5-km open water swim, a 40-km bicycle ride, and a 10-km run. The sport’s most famous event, the Ironman triathlon, is held annually in Hawaii and consists of a 3.8-km (2.4-mi) swim, a 180-km (112-mi) bicycle ride, and a 42.2-km (26.2-mi) marathon run.

tribe Any of a variety of social units, including some defined by unilineal descent and some defined by ethnic origin. Cultural anthropologists now usually apply the term to a unit of social organization that is culturally homogeneous and consists of multiple kinship groups—such as the family, lineage, or can —that prohibit marriages within themselves but endorse or require marriages with persons of the other kinship groups. (See exogamy and endogamy.) Most tribes are organized as unitary political entities, within which people share a common language and culture. Some tribes are spread across large territories, and individual members may never meet or know all of the others. Some are small groups, confined to a limited terri¬ tory, sometimes a single small island, within which everyone knows every¬ one else very well. What unites societies of such diverse scales as being “tribal” is their own internal sense of “being a single people,” but— anthropologists would add—a people that lacks the equipment of citizen¬ ship, a constitution, or a formalized legal system that would define them as a nation-state. Throughout most of the history of modem cultural anthro¬ pology, the terms tribe and primitive were usually linked; however, in recent years primitive has been avoided by most anthropologists because it appears to carry with it an unintended judgment of the moral or techno¬ logical development of a people. See also ethnic group.

tribe (Greek, phylai; Roman, tribus ) In ancient Greece and Rome, any of a group of political and demographic subdivisions of the population. In Greece the groups divided into tribes were distinct by location, dialect, and tradition, and they included the Ionians, Dorians, Achaeans, and Aeto- lians. In Attica, Cleisthenes replaced the 4 Ionian tribes with 10 new tribes, each of which was named after a local hero; these came to develop politi¬

cal and civic functions, including the election of magistrates. The demes developed out of the tribal system. In Rome the tribes formed the 3 (later 4, and still later 35) original divisions of Roman citizens. These were the basis of military levies, property tax, census taking, and voting units in political assemblies.

tribology \tri-'ba-lo-je\ Study of the interactions of sliding surfaces. It includes three subjects: friction, wear, and lubrication. Many manifesta¬ tions of tribology are beneficial and make modem life possible. Many others are serious nuisances, and careful design is necessary to overcome problems caused by excessive friction or wear. Friction uses up, or wastes, a substantial amount of the energy generated by humans; in addition, a great deal of productive capacity is devoted to replacing objects that have worn out.

tribune In ancient Rome, any of various military and civil officials. Military tribunes were originally infantry commanders. In the early repub¬ lic there were six to a legion; some were appointed by consuls or mili¬ tary commanders, others elected by the people. During the Roman empire (from 27 bc), the emperor nominated military tribunes, the office of which was considered preliminary to a senatorial or equestrian career (see eques ). Of the civil tribunes, the most important were the tribunes of the plebs (see plebeian), who were elected in the plebeian assembly. By 450 bc there were 10 plebeian tribunes, who were elected annually with the right to intervene in cases of unjust acts of consuls or magistrates by saying “Veto” (meaning “I forbid it”). The office became powerful; its powers were cur¬ tailed by Sul A but restored by Pompey. Under the empire the powers of the plebeian tribunes passed to the emperor.

tricarboxylic \ I trI- I kar-bak-'sil-ik\ acid cycle or Krebs cycle or citric-acia cycle Last stage of the chemical processes by which living cells obtain energy from foodstuffs. Described by Hans Adolf Krebs in 1937, the reactions of the cycle have been shown in animals, plants, microorganisms, and fungi, and it is thus a feature of cell chemistry shared by all types of life. It is a complex series of reactions beginning and end¬ ing with the compound oxaloacetate. In addition to re-forming oxaloac- etate, the cycle produces carbon dioxide and the energy-rich compound ATP. The enzymes that catalyze each step are located in mitochondria in animals, in chloropasts in plants, and in the cell membrane in microor¬ ganisms. The hydrogen atoms and electrons that are removed from inter¬ mediate compounds formed during the cycle are channeled ultimately to oxygen in animal cells or to carbon dioxide in plant cells.

Triceratops \tn-'ser-3-,taps\ genus of large, plant-eating ornithischian dinosaurs of the Late Cretaceous Epoch (99-65 million years ago). Tricer¬ atops had a very long skull (some more than 6 ft [1.8 mj long); a large bony frill about the neck; a relatively short, pointed horn on the nose; a beaklike mouth; and two pointed horns, more than 3.3 ft (1 m) long, above the eyes. Adults weighed 4-5 tons (3.6^4.5 metric tons) and grew up to 30 ft (9 m) long. The limbs were very stout, and the hind limbs were more massive than the forelimbs.

trichina Uri-'kI-noX Species ( Trichinella spiralis) of parasitic nematode, found worldwide, that causes the dis¬ ease trichinosis. Trichinae (or trichi¬ nas), 0.06-0.2 in. (1.5-4 mm) long, mate in the host’s small intestine.

Fertilized females penetrate the intestinal wall and release larvae, which the blood carries throughout the body. The larvae grow, mature, and become encysted within muscle tissue. The digestive juices of an ani¬ mal that eats the muscle tissue break down the cyst, liberating the larvae for further development; the worms mature, and the cycle begins again.

trichinosis \ 1 tri-ko- , no-s3s\ Disorder caused by the roundworm trichina, commonly acquired from undercooked infested pork. Larval worms invade the small intestine, maturing within a week. Fertilized females deposit new larvae, which are carried by the blood, notably to the muscles (most often the diaphragm, eyes, throat, and tongue), where they encap¬ sulate and may remain alive for years. Though trichinosis usually even¬ tually subsides, it may be fatal if the heart and brain are involved. Few infected persons have sufficient parasites to produce symptoms (includ¬ ing diarrhea, nausea, and fever, followed by pain, stiffness, and swelling

Trichina encysted in muscle

RUSS KINNE-PHOTO RESEARCHERS/EB INC.

© 2006 Encyclopaedia Britannica, Inc.

trichomonad > Trimble I 1937

of various muscular structures). Anti-inflammatory drugs can relieve symptoms; thiabendazole may effectively destroy parasites in the intes¬ tine. There is no practical way to detect trichinous pork; the surest safe¬ guard remains thorough cooking.

trichomonad \ I tri-k3-'mo- l nad\ Any protozoan of the zooflagellate order Trichomonadida. Trichomonads have three to six flagella, and they may have one or multiple nuclei. Most inhabit the digestive systems of animals. Three species occur in humans: T. hominis in the intestine, T. vaginalis in the vagina, and T. buccalis in the mouth.

trickster tale In oral traditions worldwide, a story of deceit, magic, and violence perpetrated by a mythical animal-human (trickster). The trickster-hero is both creator god and innocent fool, evil destroyer and childlike prankster. Coyote, the trickster of tales from American Indian peoples in California and the Southwest, is one of the most widely known. In the Pacific Northwest, the trickster is Raven. Many African peoples also have tales about tricksters (hare, spider, tortoise, etc.), which slaves brought to the New World. Tales involving the trickster Brer Rabbit were given literary form by Joel Chandler Harris.

Trident missile U.S.-made SUBMARINE-Iaunched ballistic missile. The most advanced Trident missiles, deployed by the U.S. Navy since 1990 and by the Royal Navy since 1994, are more accurate than most land- based ballistic missiles. Their extended range (up to 7,000 mi [11,300 km]) allows the submarines that carry them to patrol almost anywhere, making detection extremely difficult. Each missile is capable of carrying more than 10 multiple independently targeted reentry vehicles (see MIRV), though arms-control considerations limit the actual number to as few as three.

Trieste \tre-'es-ta, tre-'est\ in full Free Territory of Trieste Former region, western Istria, southern Europe, surrounding and including the city of Trieste. It was occupied by Yugoslavia in 1945. The UN established it as a free territory in 1947. It was divided for administrative purposes into two zones: Zone A in the north, including the city, was under the British and Americans; Zone B in the south was under the Yugoslavs. In 1954 most of the northern zone was incorporated into Italy; the southern zone went to Yugoslavia.

Trieste ancient Tergeste Seaport city (pop., 2001 prelim.: 209,520), capital of Friuli-Venezia Giulia region, northeastern Italy. It lies at the head of the Adriatic Sea on the Gulf of Trieste. It was under Roman control from the 2nd century bc until the collapse of the empire; then it was under episcopal rule (948-1202). It placed itself in 1382 under Habsburg pro¬ tection and later became the prosperous main port of the Austro- Hungarian Empire. After World War I Trieste was ceded to Italy. Occupied by Germany in World War II and seized by Yugoslavia in 1945, it became the centre of the Free Territory of Trieste in 1947. Returned to Italy in 1954, it became the regional capital in 1963.

triggerfish Any of about 30 species (family Balistidae) of shallow- water marine fishes, found world¬ wide in tropical seas. Triggerfishes are deep-bodied, usually colourful fishes with large scales, high-set eyes, and three dorsal-fin spines, which they use for protection. When a triggerfish is threatened, it darts into a coral crevice and erects its large and strong first spine, which it locks in place with the second (the “trigger”); when the trigger is later withdrawn, the first snaps back down. Though generally considered edible, some cause food poisoning. The largest grow 2 ft (60 cm) long.

triglyceride \trl- , gli-s3-,rid\ Any of an important class of naturally occurring lipids, esters in which three molecules of fatty acids are linked to glycerol. The three fatty acids may be all the same kind or different kinds. The types of triglycerides in animals vary with the species and the fats in their food. In mammals they are stored in adipose tissue until needed and then broken down to the glycerol and fatty acids. Many vegetable triglycerides (oils) are liquid at room temperature, unlike those of ani¬ mals, and tend to contain a greater variety of fatty acids. In alkali, trig¬ lycerides break down to form glycerol and three molecules of soap (saponification).

trigonometric function X.tri-go-no-'me-trikV In mathematics, one of six functions (sine, cosine, tangent, cotangent, secant, and cosecant) that represent ratios of sides of right triangles. They are also known as the circular functions, since their values can be defined as ratios of the x and y coordinates (see coordinate system) of points on a circle of radius 1 that correspond to angles in standard positions. Such values have been tabu¬ lated and programmed into scientific calculators and computers. This allows trigonometry to be easily applied to surveying, engineering, and navigation problems in which one of a right triangle’s acute angles and the length of a side are known and the lengths of the other sides are to be found. The fundamental trigonometric identity is sin 2 0 + cos 2 0 = 1, in which 0 is an angle. Certain intrinsic qualities of the trigonometric func¬ tions make them useful in mathematical analysis. In particular, their deriva¬ tives form patterns useful for solving differential equations.

trigonometry Mathematical discipline dealing with the relationships between the sides and angles of triangles. Literally, it means triangle mea¬ surement, though its applications extend far beyond geometry. It emerged as a rigorous discipline in the 15th century, when the demand for accu¬ rate surveying techniques and navigational methods led to its use for the “solution” of right triangles, or the calculation of the lengths of two sides of a right triangle given one of its acute angles and the length of one side. The solution can be found by using ratios in the form of the trigonomet¬ ric functions.

Trilling, Lionel (b. July 4, 1905, New York, N.Y., U.S.—d. Nov. 5, 1975, New York, N.Y.) U.S. literary critic and teacher. He taught at Columbia University from 1931 until his death. His collections of liter¬ ary essays include The Liberal Imagination (1950), Beyond Culture (1965), Sincerity and Authenticity (1972), and Mind in the Modern World (1972). He was one of the best-known American literary critics of his time. His wife was the critic and writer Diana Trilling (1905-96).

trillium Vtri-le-omV Any of about 25 species of spring-flowering peren¬ nial herbaceous plants that make up the genus Trillium in the uly family, native to North America and Asia. Whorls of oval leaves, flower parts, and fruits are arranged in groups of three. Each solitary white, greenish- white, yellow, pink, or purple flower is borne on a short stalk that arises from the whorl of leaves. Many species are cultivated in wildflower gar¬ dens. Wild trillium (also called wake-robin or birthroot) is a protected species.

trilobite Vtrl-lo-.bltX Any of a group of ovate arthropods (subphylum Trilobita) that came to dominate the seas c. 540 million years ago and became extinct c. 245 million years ago. Trilobites had a chitinous exoskeleton and three body lobes: a raised middle lobe with a lower lobe on each side. The head, thorax, and tail were segmented; each segment bore two appendages. The forward- most appendages were sense and feeding organs. Most species had two compound eyes, though some were eyeless. Some were predators, others were scavengers, and still oth¬ ers probably ate plankton. Paradox- ides harlani, found near Boston, grew to 18 in. (45 cm) long and may have weighed 10 lbs (4.5 kg). Other species were small.

Trimble, David orig. William David Trimble (b. Oct. 15, 1944, Belfast, N.Ire.) Former first minister of Northern Ireland and corecipient with John Hume of the Nobel Prize for Peace in 1998. Trimble was elected to the British Parliament in 1990 and became leader of the Ulster Union¬ ist Party (UUP) in 1995. He represented the UUP in multiparty peace talks beginning in September 1997. These talks, which included members of Sinn Fein, the political wing of the Irish Republican Army (IRA), culminated in the Good Friday Agreement of April 1998, which aimed to restore self- government in Northern Ireland. Defying opposition from hard-line unionists, he signed the agreement and successfully campaigned for its acceptance in referenda in Northern Ireland and in Ireland. In subsequent elections to the new Northern Ireland Assembly, he was elected first min¬ ister. He resigned as first minister in 2001, following a conflict with the IRA over decommissioning (disarmament), though he returned to gov¬ ernment later that year after decommissioning commenced; the post of

Triggerfish (Batistes conspicillus).

DOUGLAS FAULKNER

Trilobite

LESLIE JACKMAN-NATURAL HISTORY PHOTOGRAPHIC AGENCY

© 2006 Encyclopaedia Britannica, Inc.

1938 I trimurti ► Triple Entente

first minister was suspended the following year. In 2005 he lost his seat in the British Parliament and subsequently resigned as leader of the UUP.

trimurti \tri-'mur-te\ In Hinduism, the triad of the three great gods: Brahma, Vishnu, and Shiva. Scholars consider the trimurti doctrine an attempt to reconcile different monotheistic approaches with one another and with the philosophic doctrine of ultimate reality. In trimurti symbol¬ ism, the three gods are collapsed into a single form with three faces. Each god is in charge of an aspect of creation, with Brahma as creator, Vishnu as preserver, and Shiva as destroyer; however, some sects ascribe all aspects of creation to their deity of choice. Though sometimes called the Hindu Trinity, trimurti has little similarity to the Holy Trinity of Chris¬ tianity.

Trinidad and Tobago \ , tri-n3-,dad...t3- , ba-go\ officially Republic of Trinidad and Tobago Island country, West Indies. The islands of Trinidad and Tobago—the two southernmost links in the Antilles island

CARIBBEAN

SEA

Charlotteville^;

TOBAGO 0 G«

Plymouth.^ T ^, boroug|l cCjd Scarborough

Galera Point

ATLANTIC OCEAN

VENEZUELA

© 2002 Encyclopaedia Britannica, Inc.

chain—lie northeast of Venezuela and northwest of Guyana. Area: 1,980 sq mi (5,128 sq km). Population (2005 est.):

1,298,000. Capital: Port of Spain. The people are mainly of South Asian or Afri¬ can ancestry. Language: English (official). Religions: Christianity (Prot¬ estant, Roman Catholic), Hinduism, Islam. Currency: Trinidad and Tobago dollar. The islands are mostly flat or rolling, with narrow belts of mountainous highlands and luxuriant rain forests. The Caroni Swamp, an important bird sanctuary on Trinidad, supports flamingo, egret, and scar¬ let ibis populations. The country has large reserves of petroleum and natural gas, as well as one of the world’s largest supplies of natural asphalt. Other industries include agriculture, fishing, and tourism. Chief crops include sugarcane, citrus fruits, cocoa, and coffee. It is a republic with two legislative houses; its chief of state is the president, and the head of government is the prime minister. When Christopher Columbus visited Trinidad in 1498, it was inhabited mostly by Arawak Indians, though there were probably some Carib speakers as well; Caribs inhabited Tobago. The islands were settled by the Spanish in the 16th century. In the 17th—18th centuries African slaves were imported for plantation labour to replace the original Indian population, which had been decimated by the impact of slavery and diseases introduced by the Europeans. Trinidad was sur¬ rendered to the British in 1797. The British attempted to settle Tobago in 1721, but the French captured the island in 1781 and transformed it into a sugar-producing colony. The British acquired it in 1802. After slavery ended in the islands (1834-38), immigrants from India were brought in to work the plantations. Trinidad and Tobago were administratively com¬ bined in 1889. Granted limited self-government in 1925, the islands became an independent state within the Commonwealth in 1962 and a

republic in 1976. There occurred some political unrest and in 1990 a failed Muslim-fundamentalist coup against the government.

Trinity, Holy In Christian doctrine, the unity of the Father, Son, and Holy Spirit as one God in three persons. The word Trinity does not appear in the Bible. It is a doctrine formulated in the early church to interpret the way God revealed himself, first to Israel, then in Jesus as Saviour, and finally as Holy Spirit, preserver of the church. The doctrine of the Trinity developed in the early centuries of the church and was explicitly stated at the Council of Nicaea in 325.

Trinity College See University of Dublin

Trintignant \tra n -ten-'ya n \, Jean-Louis (b. Dec. 11, 1930, Piolenc, France) French film actor. After leaving law school to study acting, he made his stage debut in 1951 and his film debut in 1956. He won favour¬ able notice in And God Created Woman (1956) and gained international fame for his role as a race-car driver in A Man and a Woman (1966). Known for his reserved but intense screen persona, he conveyed the psy¬ chic conflicts of repressed characters in My Night at Maud’s (1969), Z (1969), and, most strikingly, The Conformist (1970), among many other films. He worked sparingly in the 1980s and ’90s because of poor health, but his role in Three Colours: Red won him acclaim.

trio sonata Principal chamber music genre of the Baroque era. Despite its name, it requires four performers: two melody instruments and con- tinuo (usually a keyboard instrument and a bass instrument). It arose early in the 17th century as an instrumental version of the Italian vocal-duet ensemble. The two upper instruments, usually violins, generally wove their melodic, quasi-vocal lines high above the accompanying parts. Two standard forms emerged after 1750: the sonata da chiesa, or church sonata, standardized as a four-movement form (in slow-fast-slow-fast order); and the suiTE-like sonata da camera, or chamber sonata. By 1770 the genre had been abandoned in favour of the solo sonata.

Tripitaka Uri-'pi-to-koN Pali Tipitaka Collective term for the three major divisions of the Pali canon, the canon of Theravada Buddhism. (The term means “Triple Basket.”) It consists of the Abhidhamma Pitaka, the Sutta Pitaka, and the Vinaya Pitaka, which were transmitted orally by the sangha until they were committed to writing about 500 years after the Buddha’s death. The texts appeared in two languages, Sanskrit and Pali, the Pali version being the better preserved. Sanskrit versions were trans¬ lated into Tibetan, Chinese, and other languages.

Triple Alliance (1882) Secret agreement between Germany, Austria- Hungary, and Italy. It provided that Germany and Austria-Hungary would support Italy if it was attacked by France, that Italy would similarly assist Germany, and that Italy would remain neutral if Austria-Hungary was attacked by Russia. The alliance advanced Otto von Bismarck’s efforts to isolate France. Conflicts between Italy and Austria-Hungary over their interests in the Balkans led Italy to reach an understanding of neutrality with France in 1902, which effectively nullified Italy’s pledge to the mem¬ bers of the Triple Alliance, though the alliance was renewed in 1907 and 1912. See also Austro-German Alliance.

Triple Alliance, War of the or Paraguayan War (1864/65-70) Bloodiest conflict in Latin American history, fought between Paraguay and the allied countries of Argentina, Brazil, and Uruguay. The Para¬ guayan dictator Francisco Solano Lopez (1827-70), objecting to Brazil’s interference in the politics of neighbouring Uruguay, declared war on Brazil in 1864. The next year Argentina organized the Triple Alliance with Brazil and Uruguay. After three years of fighting, the allies annihilated the Paraguayan forces, but Solano Lopez carried on a guerrilla war until he was killed. Paraguay was devastated by the war; its population was reduced by half, and territory covering some 55,000 sq mi (140,000 sq km) was annexed by Brazil and Argentina.

Triple Crown In U.S. horse racing, an unofficial championship attrib¬ uted to a Thoroughbred horse that in a single season wins the Kentucky Derby, the Preakness Stakes, and the Belmont Stakes. First won in 1919 by Sir Barton, it has since been won 10 times, most recently by Secretariat (1973), Seattle Slew (1977), and Affirmed (1978).

Triple Entente \an-'tant\ (1907) Association between Britain, France, and Russia. It developed from the Franco-Russian Alliance of 1894, the Anglo-French Entente Cordiale of 1904, and the Anglo-Russian Entente of 1907. Formed to settle mutual colonial disputes, the alignment became the nucleus of the Allied Powers in World War I.

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triple jump ► Triton I 1939

triple jump or hop, step, and jump Track-and-field distance jump. It incorporates three distinct, continuous movements: a hop, in which the athlete takes off and lands on the same foot; a step, in which he lands on the other foot; and a jump, in which the athlete lands in any manner, usu¬ ally with both feet together. It has been a modern Olympic event since the first games in 1896.

Tripoli Vtri-p9-le\ Arabic Tarabulus al-Sham Uo-'ra-bo-los- al-'sham\ Seaport city (pop., 1998 est.: 160,000), northwestern Lebanon. Founded c. 700 bc, it became the capital of a federation of three Phoeni¬ cian city-states: Sidon, Tyre, and Arvad. It was controlled by the Seleuc- ids and Romans and taken by the Muslims in the mid-7th century ad. Besieged and partially destroyed by crusaders in the early 12th century, it was rebuilt by the later Crusaders (see Crusades). It was occupied by the Egyptians in the 1830s, the British in 1918, and the British and Free French in 1941. It became part of the Republic of Lebanon in 1946. It has sometimes been a centre of Christian-Muslim conflict during Lebanon’s history. It was also the scene of a siege in 1983 by Palestine Liberation Organization (PLO) rebels against PLO leader Yasir ‘Arafat. It is a major port, a commercial and industrial centre, and a popular beach resort. At the terminus of an oil pipeline from Iraq, it is an important oil storage and refining centre.

Tripoli Arabic Tarabulus al-Gharb Uo-'ra-bo-los-al-'gartA City (pop. 2003 est.: city, 1,150,000; urban agglom., 2,006,000), capital of Libya. Located on the Mediterranean Sea, it is the country’s largest city and chief seaport. Founded by the Phoenicians c. 7th century bc, it was known as Oea in ancient times and was one of the three cities of the region of Tripolitania. It was controlled by the Romans from the 1st century bc and later by the Byzantines. It was taken by the Arabs in 645. Conquered by the Ottoman Empire in 1551, it was made an Ottoman colonial capital. It was under Italy’s control (1911—43), after which it was occupied by the British until Libya’s independence in 1951. U.S. warplanes bombed tar¬ gets within the city in 1983 in response to Libya’s alleged support of ter¬ rorist activity. Historical structures include numerous mosques and a Roman triumphal arch. In 1973 Al-Fateh University replaced the former University of Libya.

Tripolis \'tri-p3-l3s\ City (pop., 2001: 28,976), southern Greece, the commercial centre of the central Peloponnese. It was founded in the 14th century ad as Drobolitza to replace the ancient cities of Pallantium, Tegea, and Mantinea. Rebuilt in 1770, it became the seat of the local Ottoman pasha. The city prospered until 1828, when it was destroyed in the War of Greek Independence. It was rebuilt after 1834.

Tripolitan \tri-'pa-lo-t 3 n\ War (1801-05) Conflict between the U.S. and Tripoli. The U.S. refused to continue paying tribute to the rulers of the North African Barbary Coast states, which had bought immunity from pirate attacks in the Mediterranean. The pasha of Tripoli demanded greater tribute and then declared war on the U.S. (1801). A U.S. naval squadron was sent to Tripolitan waters and fought several skirmishes, including a raid by Stephen Decatur. A U.S. naval blockade and an overland expedi¬ tion from Egypt ended the war with a peace treaty favourable to the U.S.

Tripolitania \tri-,pa-l9-'ta-ne-9\ Historical region, North Africa. It is now part of northwestern Libya. Colonized by the Phoenicians in the 7th century bc, it was named for its three chief cities— Leptis Magna, Oea (Tri¬ poli), and Sabrata. It comprised the eastern part of Carthaginian territory by the 3rd century bc and came under Numidian chieftains in the mid- 2nd century bc. After the Numidian War (46 bc), it was attached to the Roman province of Africa Nova (see Roman Africa). It fell under the Islamic caliphate in the 7th century ad and was ruled by successive Arab and Berber dynasties before becoming part of the Ottoman Empire in 1551. The region gained its independence in 1711. As part of the Barbary Coast, corsairs operating from there plundered shipping in the Mediter¬ ranean Sea, leading to the Tripolitan War with the U.S. (1801-05). It came under Ottoman administration again in 1835. The Italians acquired the region in 1912, and it was the scene of fierce fighting between British and German forces during the North Africa campaigns (1940^-3) of World War II. In 1951, with the provinces of Cyrenaica and Fezzan, it formed the independent kingdom of Libya; the provinces were dissolved in 1963.

Trippe, Juan T(erry) (b. June 27,1899, Seabright, N.J., U.S.—d. April 3, 1981, New York, N.Y.) U.S. airline founder. He served as a pilot in World War I. After graduating from Yale University in 1922, he promptly established an air taxi service using government-surplus aircraft. He next formed Colonial Air Transport, which began the first airmail route

between New York City and Boston. In 1927 he founded Pan American World Airways. Under him the company introduced the first round-the- world air service (1947) and the first commercial jets (1955). He retired in 1968.

Tripura Vtri-p9-r9\ State (pop., 2001 prelim.: 3,191,168), northeastern India. It is bordered on three sides by Bangladesh and by Mizoram state; it has an area of 4,049 sq mi (10,486 sq km), and its capital is Agartala. It was an independent Hindu kingdom for more than 1,000 years before it became part of the Mughal Empire in the 17th century. After 1808 it was under the influence of the British government. Tripura became a union territory in 1956 and acquired full status as a state in 1972. The main economic activity is agriculture, with rice and jute the major crops.

trireme \'tri-,rem\ Oar-powered warship. Light, fast, and maneuverable, it was the principal naval vessel with which Persia, Phoenicia, and the Greek city-states vied for mastery of the Mediterranean from the Battle of Salamis (480 bc) through the end of the Peloponnesian War (404). The Athenian trireme was about 120 ft (37 m) long, and was rowed by 170 oarsmen seated in three tiers along each side; it could reach speeds of more than 7 knots (8 mph, or 13 kph). Square-rigged sails were used when the ship was not engaged in battle. Armed with a bronze-clad ram, it car¬ ried spearmen and bowmen to attack enemy crews. By the late 4th cen¬ tury bc, armed deck soldiers had become so important in naval warfare that it was superseded by heavier ships. See also galley.

Tristan and Isolde Lovers in a medieval romance based on Celtic legend. The hero Tristan goes to Ireland to ask the hand of the princess Isolde for his uncle, King Mark of Cornwall. On their return the two mis¬ takenly drink a love potion prepared for the king and fall deeply in love. After many adventures, they make peace with Mark, who marries Isolde. The distraught Tristan goes to Brittany, where he marries another noble Isolde. When he is wounded by a poisoned arrow, he sends for the first Isolde. His jealous wife tells him his true love has refused to come; he dies just before she arrives, and she dies in his arms. The original poem has not survived, but it exists in many later versions and even became part of Arthurian legend. Gottfried von Strassburg’s 13th-century version, considered the masterpiece of medieval German poetry, was the basis for Richard Wagner’s opera Tristan und Isolde (first performed in 1865).

Tristano, Lennie orig. Leonard Joseph Tristano (b. March 19, 1919, Chicago, Ill., U.S.—d. Nov. 18, 1978, New York, N.Y.) U.S. jazz pianist. Blind from childhood, Tristano performed and taught in New York City from the 1940s. His recordings featured players who had studied with him, including saxophonists Lee Konitz (b. 1927) and Wame Marsh (1927-87). Although resistant to classification, Tristano’s music displayed a rigour and virtuosity appropriate to bebop while its aesthetic foreshad¬ owed much of cool jazz.

triticale \,tri-t9-'ka-le\ Wheat-rye hybrid that has a high yield and rich protein content. The first cross was reported in 1875, the first fertile cross in 1888. The name triticale first appeared in scientific literature in 1935 and is attributed to Erich Tschermak von Seysenegg. In favourable envi¬ ronmental conditions its yield equals that of wheat; under poor conditions its yield exceeds that of wheat. Its flour is not very suitable for bread¬ making but can be blended with wheat flour. Major producers are Rus¬ sia, the U.S., and Australia.

tritium Vtri-te-am, 'tri-she-9m\ Isotope of hydrogen, chemical symbol written as 3 H or T, with atomic number 1 but ATOMIC weight approximately 3. Its nucleus contains one proton and two neutrons. Tritium is radioactive (see radioactivity), with a half-life of 12.32 years. Its occurrence in natural water in an amount 10 -18 that of ordinary hydrogen is believed to be due to the action of cosmic rays. Some tritium is used in self-luminous materials (e.g., for watch dials) and as a radioactive tracer in chemical and biochemi¬ cal studies. Nuclear fusion of deuterium and tritium at high temperatures releases enormous amounts of energy. Such reactions have been used in nuclear weapons and experimental power reactors. See also heavy water.

Triton \'tr!-t 3 n\ In Greek mythology, a merman and a demigod of the sea. He was the son of Poseidon and Amphitrite. According to Hesiod, Triton lived in a golden palace in the depths of the sea. He was represented as human down to the waist, which tapered into a fish tail, and he had a spiral conch shell that he blew to calm or raise the waves. Some tradi¬ tions held that there were many Tritons.

Triton \'tri-t 3 n\ Largest of Neptune’s moons. Its diameter is about 1,680 mi (2,700 km), nearly 80% that of Earth’s Moon. Unique among the large

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1940 I triumph ► trompe I'oeil

moons of the solar system, Triton moves in a retrograde orbit, opposite the direction of Neptune’s rotation. Its orbital period of 5.9 Earth days is the same as its rotation period; as a result it always keeps the same face toward Neptune. It has a very thin atmosphere of nitrogen and methane and a sur¬ face temperature of -390 °F (-235 °C). Its surface is covered with enor¬ mous expanses of ice sculpted with fissures, puckers, and ridge-crossed depressions. Geyser-like plumes observed by the Voyager 2 spacecraft may be gas venting through fissures when the surface is warmed by sunlight. Triton appears to have formed elsewhere in the solar system and to have been gravitationally captured by Neptune in the planet’s early history.

triumph Ancient Roman ritual procession honouring a general who had won a major battle and killed at least 5,000 of the enemy. Senators and magistrates were followed by sacrificial animals, captured loot, and cap¬ tives in chains. The general, in a purple-and-gold tunic, rode in a chariot, holding a laurel branch in his right hand and an ivory sceptre in his left, while a slave held a golden crown over his head. Lastly came the soldiers, who sang songs. Under the empire only the emperor and members of his family celebrated triumphs.

triumphal arch Monumental structure, originating in Rome, pierced by at least one arched passageway and erected to honour an important person or commemorate a significant event. It usually spanned a street or roadway and was built astride the line of march of a victorious army dur¬ ing its triumphal procession. Most were built during the empire period. The basic form consisted of two piers connected by an arch and crowned by a superstructure, or attic, that served as a base for statues and bore inscriptions. The large central arch could also be flanked by two smaller arches. The Roman triumphal arch had a facade of marble columns, and the archway and sides were adorned with relief sculpture. Among those built since the Renaissance is the Arc de Triomphe in Paris.

triumvirate \tri-'9m-vir-9t\ In ancient Rome, usually a board of three officials who assisted higher magistrates in judicial functions, oversaw festival banquets, or ran the mint. The First Triumvirate (60 bc) of Pompey, Julius Caesar, and Crassus was an informal group of three strong leaders with no sanctioned powers. The Second Triumvirate (43 bc), consisting of Mark Antony, Lepidus, and Octavian (later Augustus) —formally tresviri rei publicae constituendae (“triumvirate for organizing the state”)—held absolute dictatorial power.

Troas Vtro-,as\ or the Troad Ancient region surrounding the city of Troy. It consisted mainly of the northwestern projection of Anatolia into the Aegean Sea. It extended from the Gulf of Edremit to the Sea of Mar¬ mara and the Dardanelles and from the Ida mountain range to the Aegean. St. Paul visited the region on his missionary journeys.

Trobriand Islands Vtro-bre-,and\ or Kiriwina Islands

\,kir-9-'we-n9\ Group of small coral islands, Solomon Sea, South Pacific Ocean, Papua New Guinea. The islands are low-lying with coral reefs. The group has a total land area of about 170 sq mi (440 sq km). The largest, Kiriwina, is an atoll 30 mi (48 km) long and 3-10 mi (5-16 km) wide, covered largely with swamp; it served as an air and naval base for the Allies in 1943. Anthropologist Bronislaw Malinowski conducted research among the Trobriand islanders 1915-18.

Trobriander Any of the Melanesian people of the Kiriwina (Trobriand) Islands, lying off eastern New Guinea. Their subsistence is based on yams and other vegetables, domesticated pigs, and fish. Trobrianders are noted for their elaborate intertribal trading system, the kula, by which red shell necklaces are traded between permanent trading partners in a clockwise direction around a ring of islands; white shell bracelets are traded coun¬ terclockwise. Among the Trobrianders, wealth is extremely important as a sign of power. They were the subject of highly influential studies by BRONistAW Malinowski.

Troilus and Cressida \'tr6i-l9s...'kre-si-d9\ Lovers in medieval romance, based on characters from Greek mythology. In the Iliad, Troilus, son of Priam and Hecuba, is dead before the Trojan War starts. In non- Homeric legends he was said to have been killed during the war by Achil¬ les. He was first turned into a romantic figure in the Middle Ages, when he was portrayed as an innocent young lover betrayed by the faithless Cressida, who abandoned him for the Greek warrior Diomedes. The first version of the story was written by the 12th-century trouvere Benoit de Sainte-Maure in the poem “Roman de Troie.” More famous versions include Giovanni Boccaccio’s “II Filostrato,” Geoffrey Chaucer’s “Troilus and Criseyde,” and William Shakespeare’s drama Troilus and Cressida.

Trojan asteroids Two groups of asteroids named for heroes of Greece and Troy in Homer’s Iliad. These objects revolve around the Sun at the Lagrangian points (see Joseph-Louis Lagrange) in Jupiter’s orbit. Achil¬ les, the first, was discovered in 1906. About 650 are known, but their actual number is estimated in the thousands. The term Trojan also applies to objects occupying the corresponding Lagrangian points in the orbits of other planets. Two such asteroids were discovered in Mars’s orbit in the 1990s.

Trojan War Mostly legendary conflict between the Greeks and the people of Troy in western Asia Minor. It was dated by later Greeks to the 12th or 13th century bc. It is celebrated in Homer’s Iliad and Odyssey, in Greek tragedy, and in Roman literature. In Homer’s account the Trojan prince Paris ran off with the beautiful Helen, wife of Meneaus of Sparta, whose brother Agamemnon then led a Greek expedition to retrieve her. The war lasted 10 years; its participants included Hector, Achilles, Priam, Odysseus, and Ajax. Its end resulted from a ruse: The Greeks built a large wooden horse in which a raiding party hid. When the Greeks pretended to leave, the Trojans brought the horse into the walled city and the Greeks swarmed out, opening the gates to their comrades and sacking Troy, kill¬ ing the men and enslaving the women. The extent of the legend’s actual historical content is not known; excavations have revealed human habi¬ tation from 3000 bc to ad 1200, and there is evidence of violent destruc¬ tion about 1250 bc.

trolley car See streetcar

Trollope Vtra-tapV Anthony (b. April 24, 1815, London, Eng.—d. Dec. 6, 1882, London) English nov¬ elist. He worked for the post office in England and Ireland from 1834 to 1867. Beginning in 1844 he pro¬ duced 47 novels, writing mainly before breakfast at a fixed rate of 1,000 words an hour. His best-loved and most famous works are the six interconnected Barsetshire novels, including Barchester Towers (1857) and The Last Chronicle of Barset (1867). Depicting the social scene in an imaginary English county, they abound in memorable characters and atmosphere. The Palliser novels, dealing with political issues and fea¬ turing the character Plantagenet Pal¬ liser, include the sharply satirical The Eustace Diamonds (1872). Other works, such as He Knew He Was Right (1869), show great psycho¬ logical penetration. The Way We Live Now (1875), with its ironic view of the Victorian upper classes, is especially highly regarded.

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

© 2006 Encyclopaedia Britannica, Inc.

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.

© MERRIAM-WEBSTER INC.

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.

troubadour Vtrii-bo-.dor, ‘trii-bo-.dmA One of a class of lyric poets and poet-musicians, often of knightly rank, that flourished from the 11th through the 13th century, chiefly in Provence and other regions of south¬ ern France, northern Spain, and northern Italy. They wrote in the langue d’oc of southern France (see Languedoc) and cultivated a lyric poetry intricate in metre and rhyme and usually of a romantic amatory strain reflecting the ideals of courtly love. Favoured at courts, troubadours had great freedom of speech and were charged with creating around the court ladies an aura of pleasant cultivation. Their poetry, often set to music, was to influence all later European lyrical poetry. See also trouvere.

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1942 I Troubles ► trullo

Troubles, Time of (1606-13) Period of political crisis in Russia. After the death of Fyodor I and the end of the Rurik dynasty (1598), the boyars opposed the rule of Boris Godunov and after his death placed the noble¬ man Vasily Shuysky (1552-1612) on the throne in 1606. Shuysky’s rule was weakened by revolts, challenges by the second False Dmitry, and the invasion of Russia by the Polish king Sigismund III Vasa in 1609-10. The Russians finally rallied against the Polish invaders and succeeded in oust¬ ing them from their control of Moscow in 1612. A new representative assembly met in 1613 and elected Michael Romanov as tsar, commencing the 300-year reign of the Romanov dynasty.

trout Any of several prized game and food fishes of the family Salmo- nidae, native to the Northern Hemisphere but widely introduced else¬ where. Though most species inhabit cool fresh waters, a few (called sea trout; e.g., cutthroat trout) migrate to the sea between spawnings. Some weakfish are also called sea trout. The genus Oncorhynchus includes salmon and several trout species; Salvelinus contains trout species regarded as chars. Trout species vary greatly in anatomy, colour, and hab¬ its. Most live among submerged objects or in riffles and deep pools, eat¬ ing insects, small fishes and their eggs, and crustaceans. See also brook trout; brown trout; lake trout; rainbow trout.

trouvere \tru-'ver\ One of a school of poets that flourished in northern France from the 11th to the 14th century. Trouveres were the counterparts in the language of northern France (the langue d’oil ) to the Provencal troubadour. Of either aristocratic or humble origins, they were originally connected with feudal courts but later found middle-class patrons. Noted for such forms as the chanson de geste, their works are generally narra¬ tives; their basic subject was courtly love. Trouveres pleased their audi¬ ences by combining stylized themes and traditional metrical forms rather than by originality of expression. The lyrics were intended to be sung, by the poet alone or accompanied by a hired musician.

Trowbridge \'tro-,brij\ Town (pop., 1995 est.: 30,000), county seat of Wiltshire, southern England. Trowbridge has some notable buildings, including St. James’s parish church, which dates from the 14th century. George Crabbe was rector there toward the end of his life. The town is famous for its fine woolen cloth.

Troy or Ilium Ancient city in Troas, northwestern Anatolia. It holds an enduring place in both literature and archaeology. In literature, it is well known as the location of the Trojan War. The archaeological site, a huge mound at modern Hisarhk, Tur., on the Menderes (Scamander) River, was first excavated by archaeologist Heinrich Schliemann (1870-90). It consists of nine major layers dating from the early Bronze Age to Roman times (c. 3000 Bc-4th century ad). In Greek legend, the city was besieged by the Greeks for 10 years and finally destroyed. Its story is told in Homer’s Iliad and Odyssey and in Virgil’s Aeneid. Whether the site is the actual city of these works is still debated, but the archaeological evidence indi¬ cates that a city (Troy Vila) was destroyed at that location c. 1260—40 bc and likely was the Homeric Troy. The ruins were designated a UNESCO World Heritage site in 1998.

Trubetskoy \,tru-byit-'sk6i\, Nikolay (Sergeyevich) (b. April 16, 1890, Moscow, Russia—d. June 25, 1938, Vienna, Austria) Russian lin¬ guist. Born into a family of scholars, he held professorships in Russia and (from 1922) at the University of Vienna. One of the founders of the Pra¬ gue school of linguistics, he was noted as the author of the school’s most important work on phonology, Principles of Phonology (1939). Influenced by Ferdinand de Saussure, Trubetskoy redefined the phoneme functionally as the smallest distinctive unit within the structure of a language. He died of a heart attack after being persecuted by the Nazis for criticizing racist theory.

Truce of God Measure by the medieval Roman Catholic Church to suspend warfare on certain days of the week and for certain church fes¬ tivals and Lent. It was instituted in France as early as 1027, and else¬ where in Europe (excluding England) during the next several decades. The popes later took its direction into their own hands, and the first decree of the Council of Clermont (1095) proclaimed a weekly truce for all Christendom, with an oath of adherence to be taken by all men over age 12. The truce was most powerful in the 12th century but was never entirely effective.

Trucial States See United Arab Emirates

truck or lorry Motor vehicle designed to carry freight or heavy articles. The first truck was built in Germany in 1896 by Gottlieb Daimler. By the

1920s trucks had become a major means of freight transport. Gasoline engines for trucks were common until the 1940s, when diesel engines gen¬ erally replaced them. Trucks may be either straight (all axles attached to the frame) or articulated (two or more frames connected by couplings); large articulated trucks consist of a towing tractor and a connected semi¬ trailer. Air brakes were added to trucks in 1918 and four-wheel brakes in 1925; later improvements included power steering.

Trudeau, Pierre (Elliott) (b. Oct. 18, 1919, Montreal, Que., Can.—d. Sept. 28, 2000, Montreal) Prime minister of Canada (1968-79, 1980-84). He practiced law before being elected to the Canadian House of Com¬ mons (1966-84). He was minister of justice (1967-68) in Lester Pearson’s administration. He became leader of the Liberal Party and prime minis¬ ter in 1968. A determined antiseparatist, he advocated a strong federal government and took a determined stand against separatist terrorists. After nine months out of office, he returned in 1980 to initiate reforms that called for the constitutional “patriation,” or transfer, of the amending authority from the British Parliament to Canada. To this end, he effected passage of the Canada Act, which precipitated Canada’s official indepen¬ dence from Britain. His term saw the adoption of official bilingualism. He spent his final years in office seeking greater economic independence for Canada, forming better trade relations between industrialized democra¬ cies and developing countries, and urging further international disarma¬ ment talks. He resigned as leader of the Liberal Party and retired from politics in 1984, by which time he was the longest-serving leader of any Western democracy.

Truffaut \tnE-'fb,\ English \tru-'fo\, Francois (b. Feb. 6, 1932, Paris, France—d. Oct. 21, 1984, Neuilly-sur-Seine, near Paris) French film director and critic. As a film critic for the avant-garde Cahiers du Cinema, he advocated the auteur theory and helped establish the New Wave move¬ ment. His first feature film was the semi-autobiographical The 400 Blows (1959), a portrait of a delinquent boy, that won him international acclaim. Influenced by Jean Renoir and Alfred Hitchcock, he made varied and admired movies such as Shoot the Piano Player (1960), Jules and Jim (1961), Fahrenheit 451 (1966), Stolen Kisses (1968), The Wild Child (1969), Day for Night (1973, Academy Award), The Story of Adele H. (1975), and The Last Metro (1980). His films record life’s grayness and flatness with a sense of resignation quite distinct from platitude or petu¬ lant nihilism.

truffle Edible, underground fungus in the genus Tuber (class Asco- mycetes, division Mycota), prized as a food delicacy since antiquity.

Native mainly to temperate regions, truffles flourish in open woodlands on calcium-rich soil. The different species range from pea-sized to orange-sized. Truffles usually are associated with tree roots and are found up to about 1 ft (30 cm) below the soil surface. Experienced gather¬ ers occasionally detect mature truffles by scent or by the morning and evening presence of hovering columns of small yellow flies, but more often with the help of trained pigs or dogs. The truffle is important in French cookery, and truffle gathering is an important industry in France. Truffles are among the most highly valued foods in the world. False truffles (genus Rhizopogon ) form small, underground, potato-like struc¬ tures under coniferous trees in parts of North America.

Trujillo \tru-'he-y6\ (Molina), Rafael (Leonidas) (b. Oct. 24,1891, San Cristobal, Dom.Rep.—d. May 30, 1961, Ciudad Trujillo, near San Cristobal) Dictator of the Dominican Republic (1930-61). He entered the army in 1918 and rose through the ranks to become a general in 1927. In 1930 he seized power from Pres. Horacio Vasquez, and from then until his assassination he remained in absolute control of the country. Though he introduced a degree of economic modernization, its benefits were dis¬ tributed inequitably, government corruption was rife, and Dominicans suffered the loss of civil and political liberties under his regime.

trullo Circular stone building roofed with a conical construction of dry stone masonry, unique to the region of Puglia in southeastern Italy and especially to the town of Alberobello, where trulli are used as dwellings. Trulli were built by piling circular courses of gray stone to a pinnacle on

in the genus Tuber (class Asco-

English truffle (Tuber aestivum).

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Truman ► trust company I 1943

a whitewashed cylindrical wall. No mortar was used; the stones were held in place by gravity and pressure against one another.

Truman, Harry S. (b. May 8, 1884, Lamar, Mo., U.S.—d. Dec. 26, 1972, Kansas City, Mo.) 33rd president of the U.S. (1945-53). He worked at various jobs before serving with distinction in World War I. He became a partner in a Kansas City haberdashery; when the business failed, he entered Democratic Party politics with the help of Thomas Pendergast. He was elected county judge (1922-24), and he later became presiding judge of the county court (1926-34). His reputation for honesty and good man¬ agement gained him bipartisan support. In the U.S. Senate (1935-45), he led a committee that exposed fraud in defense production. In 1944 he was chosen to replace the incumbent Henry Wallace as the Democratic Party vice presidential nominee, and he won election with Pres. Franklin D. Roosevelt. After only 82 days as vice president, he became president on Roosevelt’s death (April 1945). He quickly made final arrangements for the San Francisco charter-writing meeting of the UN, helped arrange Ger¬ many’s unconditional surrender on May 8, which ended World War II in Europe, and in July attended the Potsdam Conference. The Pacific war ended officially on September 2, after he ordered atomic bombs dropped on Hiroshima and Nagasaki; his justification was a report that 500,000 U.S. troops would be lost in a conventional invasion of Japan. He announced what would become known as the Truman Doctrine, which entailed aid for Greece and Turkey (1947); established the Central Intelligence Agency; and pressed for passage of the Marshall Plan to aid the economic recovery of western Europe. In the 1948 presidential election he defeated Thomas Dewey despite widespread expectation of his own defeat. On July 26, 1948, Truman issued an executive order banning segregation in the armed forces. He initiated a foreign policy of containment to restrict the Soviet Union’s sphere of influence, pursued his Point Four Program, and initi¬ ated the Berlin airlift (see Berlin blockade and airlift) and the NATO pact of 1949. He sent troops under Gen. Douglas MacArthur to fight in the Korean War. Problems of pursuing the war occupied his administration until he retired. Though he was often criticized during his presidency, his reputation grew steadily in later years.

Truman Doctrine Pronouncement by Pres. Harry Truman. On March 12, 1947, he called for immediate economic and military aid to Greece, which was threatened by a communist insurrection, and to Turkey, which was under pressure from Soviet expansion in the Mediterranean. Engaged in the Cold War with the Soviet Union, the U.S. sought to protect those countries from falling under Soviet influence after Britain announced that it could no longer give them aid. In response to Truman’s message, Con¬ gress appropriated $400 million in aid.

Trumbull, John (b. June 6, 1756, Lebanon, Conn.—d. Nov. 10, 1843, New York, N.Y., U.S.) U.S. painter, architect, and author. The son of Gov. Jonathan Trumbull (1710-85), he served as an aide to George Washing¬ ton during the American Revolution and later as secretary to John Jay in London. In 1784 he studied painting in London with Benjamin West, and with West’s encouragement he began the celebrated series of historical paintings and engravings he would work on throughout his life. In 1817 he was commissioned by Congress to paint the four large pictures that decorate the Capitol rotunda (completed 1826); most of the figures in the often-reproduced Declaration of Independence were painted from life.

Trump, Donald J(ohn) (b. 1946, New York, N.Y., U.S.) U.S. real- estate developer. He joined his father’s Trump Organization (1968) and expanded its holdings of rental housing. By the 1990s Trump’s business empire encompassed a number of high-rises (including the Empire State Building), hotels, and condominiums, including Trump Tower; more than 25,000 rental and co-op apartment units in Queens and Brooklyn; and several hotel-casino complexes in the nearby gambling centre of Atlantic City, N.J. An economic slump in the late 1980s forced him to cede par¬ tial control of his properties to creditors, but his fortunes rebounded in the 1990s, and he embarked on a vast building project on New York’s West Side. His political ambitions and enjoyment of publicity combined to keep him in the public eye.

trumpet Brass instrument with tubing twice-folded in an elongated shape. (In its broad sense, trumpet may refer to any lip-vibrated instru¬ ment.) The modern trumpet has a mostly cylindrical bore, three valves, and a cup-shaped mouthpiece, and it is usually a B-flat or C instrument. The trumpet had taken its basic modem shape, with its ovoid loop, by c. 1500. In the 17th—18th centuries it employed crooks (removable lengths of tubing) to enable playing in different keys. The valved trumpet was

developed in the 1820s. The trumpet has been associated with ceremo¬ nial and military uses since the 16th century. It joined the standard orches¬ tra by c. 1700, though it was only selectively used, usually with the timpani. Its brilliant sound has since made it indispensable in a wide vari¬ ety of ensembles. See also cornet; flugelhorn.

trumpeter swan Black-billed species (Cygnus cygnus buccinator) of swan, named for its far-carrying, low-pitched call. About 6 ft (1.8 m) long, with a 10-ft (3-m) wingspan, it is the largest swan, though it weighs less than the mute swan. Once threatened with extinction (fewer than 100 were counted in the U.S. in 1935), it has made a strong comeback; though still listed as vulnerable, its population in western Canada and the northwest¬ ern U.S. now exceeds 5,000.

Truong Chinh Uru-'oq-'chinV orig. Dang Xuan Khu (b. Feb. 9, 1907, Ha Nam Ninh province, Viet.—d. Sept. 30, 1988, Hanoi) Vietnam¬ ese statesman, writer, and communist intellectual. He was an anticolo¬ nialist activist as a youth, joining Ho Chi Minh in 1928. He became a teacher and joined the Indochinese Communist Party, becoming its secretary-general in 1941. With Vo Nguyen Giap he developed the strat¬ egy that led to a Vietnamese victory over the Japanese occupation forces in 1945. With Le Duan (1908-86) and Pham Van Dong (1906-2000) he ruled North Vietnam after Ho’s death in 1969.

Truro City (pop., 1995 est.: 25,000), county seat of Cornwall, south¬ western England. It is located on the River Truro at the head of Falmouth Harbor. Industries include food processing and light engineering.

truss In building construction, a structural frame usually fabricated from pieces of metal or timber to form a series of triangles lying in a single plane. The linear members are subject only to compression or tension. The horizontal pieces forming the top and bottom of the truss are called the chords, and the sloping and vertical pieces connecting the chords are collectively called the web. Unlike a vault, the truss exerts no thrust but only downward pressure; supporting walls require no buttressing or extra thickening. Trusses have been used extensively in roofing and bridges. Wood trusses were probably first used in primitive dwellings c. 2500 bc. Wood was replaced by iron, which in turn was succeeded by steel.

A truss's outer members are called the chords, its interior members are called the web members, and each triangular section is called a panel. A pitched truss (top) has inclined top chords; a flat truss (bottom) has parallel top and bottom chords.

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trust In law, a relationship between parties in which one, the trustee or fiduciary, has the power to manage property, and the other, the beneficiary, has the privilege of receiving the benefits from that property. Trusts are used in a variety of contexts, most notably in family settlements and in charitable gifts. The traditional requirements of a trust are a named ben¬ eficiary and trustee, an identified property (constituting the principal of the trust), and delivery of the property to the trustee with the intent to create a trust. Trusts are often created for the sake of advantageous tax treatment (including exemption). A charitable trust, unlike most trusts, does not require definite beneficiaries and may exist in perpetuity. See also TRUST COMPANY.

trust company Company, often a commercial bank, acting as trustee for individuals and businesses and providing related financial or estate¬ planning services. Trust services for individuals commonly include the administration of estates, living trusts (trusts that become effective dur¬ ing the lifetimes of their makers, or settlors), and testamentary trusts (trusts originating in a will). Services for businesses include the admin-

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1944 I trust fund ► tsunami

istration of corporate bond indentures and corporate pension funds. Trust companies may also serve as corporate stock registrars and as paying agents for the distribution of dividends.

trust fund Property (e.g, money or securities) held in a trust; that is, property held legally by one party (the legal owner) for the benefit of another party (the equitable owner). The legal owner, or trustee, has the right of possession and the right of use of the property, but must exercise those rights to the benefit of the equitable owner, or beneficiary. In Anglo- American law, trust funds are set up principally for family settlements and for charitable giving. In the commercial sector, trust funds are often set up to provide for employee pensions and profit-sharing programs.

truth In philosophy, the property of statements, thoughts, or propositions that are said, in ordinary discourse, to agree with the facts or to state what is the case. At least four major types of truth theory have been proposed: correspondence theories (see realism), coherence theories (see coherentism, idealism), pragmatic theories (see pragmatism), and deflationary theories. The latter group encompasses a wide variety of views, including the redundancy theory, the disquotation theory, and the prosentential theory.

Truth, Sojourner orig. Isabella Van Wagener (b. c. 1797, Ulster county, N.Y., U.S.—d. Nov. 26,

1883, Battle Creek, Mich.) U.S. evangelist and social reformer. The daughter of slaves, she spent her childhood as an abused chattel of several masters. After being freed in about 1827, she worked as a domes¬ tic in New York City (1829^13) and began preaching on street comers with the evangelical missionary Eli¬ jah Pierson. Adopting the name Sojourner Truth, she left New York to obey a “call” to travel and preach.

Adding abolitionism and women’s rights to her religious messages, she traveled in the Midwest, where her magnetism drew large crowds. At the start of the American Civil War she gathered supplies for black volunteer regiments. In 1864 she went to Washington, D.C., where she helped integrate streetcars and was received at the White House by Pres. Abraham Lincoln. After the war she worked for the freedmen’s relief organization and encouraged migration to Kan¬ sas and Missouri.

TRW Inc. U.S manufacturer of advanced equipment and systems for industry and government. Founded in 1901 as a maker of cap screws, it was incorporated in 1916 as the Steel Products Co. The name was changed to Thompson Products, Inc., in 1926, then to Thompson Ramo Woold¬ ridge Inc. after a merger in 1958, and to TRW Inc. in 1965. Through its various divisions and subsidiaries, TRW designed and manufactured a wide range of automotive parts, electronic systems for military aircraft, and spacecraft. Its information systems and services segments maintain databases for screening credit histories. In 2002 defense contractor Northrop Grumman acquired TRW for its aerospace division.

tryptophan Vtrip-to-.fanX One of the essential amino acids. It is a het¬ erocyclic compound that is found in small amounts in most proteins. It plays an important role in the growth and development of infants and in the biosynthesis of serotonin and niacin (thus, deficiency of niacin or tryp¬ tophan can cause pellagra). Its occurrence in milk has been suggested as the reason that drinking milk before bedtime helps people sleep. It is used in medicine and nutrition research, in enriched foods, and as a dietary supplement.

Ts'ai-shen See Caishen Ts'ao Chan See Cao Zhan

Ts'ao Ts'ao See Cao Cao

tsar or czar Vzar, ‘(t)sar\ Byzantine or Russian emperor. The title, derived from caesar, was used in the Middle Ages to refer to a supreme ruler, particularly the Byzantine emperor. With the fall of the Byzantine Empire in 1453, the Russian monarch became the only remaining Ortho¬

dox monarch, and the Russian Orthodox clergy considered him a possible new supreme head of Orthodox Christianity. Ivan IV (the Terrible) was the first to be crowned tsar, in 1547. Though theoretically wielding absolute power, he and his successors were limited by the power of the Orthodox church, the Boyar Council, and the successive legal codes of 1497, 1550, and 1649. In 1721 Peter I changed his title to “Emperor of All Russia,” but he and his successors continued to be popularly called tsars.

Tsaritsyn See Volgograd

Tsavo Vtsa-,vo\ National Park Park, southeastern Kenya, east of Mount Kilimanjaro. Established in 1948, it covers 8,036 sq mi (20,812 sq km) and is Kenya’s largest national park. It comprises semiarid plains covered by dormant vegetation (which blooms after a light rain) and aca¬ cia and baobab trees. Wildlife includes elephants, lions, rhinoceroses, hippopotamuses, hartebeests, and hundreds of bird species. Poaching and brush fires are constant problems.

Tschermak von Seysenegg Vcher-.mak-fon-'zI-zo-.nekV Erich (b. Nov. 15, 1871, Vienna, Austria—d. Oct. 11, 1962, Vienna) Austrian bota¬ nist. He was one of the codiscoverers of Gregor Mendel’s classic papers on heredity and the garden pea. Before running across Mendel’s papers he had conducted his own breeding experiments with the garden pea, but he found that Mendel’s work duplicated and in some ways surpassed his own. In the same year that he reported his findings (1900), Hugo de Vries and Carl Erich Correns also reported their discovery of Mendel’s papers. See also William Bateson.

Tselinograd See Astana Tseng Kuo-fan See Zeng Guofan

tsetse fly Vtset-se, 'tse-tse\ Any of about 21 species (genus Glossina, family Muscidae) of African bloodsucking dipterans that are robust, sparsely bristled, and usually larger than a housefly. They have stiff, pierc¬ ing mouthparts. Only two species commonly transmit the protozoan para¬ sites (trypanosomes) that cause human sleeping sickness: G. palpalis, found primarily in dense streamside vegetation, and G. morsitans , found in more open woodlands. The female requires a sufficient blood meal to produce viable larvae, but both sexes suck blood almost daily.

Tshombe Ychom-baX, Moise (-Kapenda) (b. Nov. 10, 1919, Musumba, Belgian Congo—d. June 29, 1969, Algiers, Alg.) President of the secessionist African state of Katanga (1960-63) and premier of the united Congo Republic (1964-65). After losing national elections to Patrice Lumumba in 1960, Tshombe declared his Katanga province inde¬ pendent. When the UN intervened in 1963, he was forced into exile; he returned the following year as premier in Joseph Kasavubu’s government but was dismissed in 1965. See also Mobutu Sese Seko.

Tsimshian Vchim-she-9n\ One of the peoples of the Northwest Coast Indians living in the Skeena and Nass river area in west-central British Columbia, Can., and southern Alaska, U.S. The Tsimshian dialects belong to the family of Penutian languages. The traditional economy was based on fishing, with some hunting in winter. Large winter houses, made of wood and often carved and painted, symbolized family wealth. Descent was traced through the maternal line. Lineages functioned largely inde¬ pendently, but all participated in major ceremonies and in warfare. Vari¬ ous important events were marked by a potlatch. At the turn of the 21st century the Tsimshian numbered in the thousands.

Tsinan See Jinan Tsinghai See Qinghai Tso chuan See Zuo zhuan

Ts'u-hsi See Cixi

Tsugaru \tsu-'gar-u\ Strait Strait, northwestern Pacific Ocean. It extends from the Sea of Japan (East Sea) to the open ocean between the islands of Honshu and Hokkaido, Japan. It is 15—25 mi (24^10 km) wide. The Seikan Tunnel linking Aomori and Hakodate cities runs beneath the strait. Completed in 1988, it is the longest railway tunnel in the world; 14.5 mi (23.3 km) of its 33.5 mi (53.9 km) length lie under the strait.

tsunami \tsu-'na-me\ or seismic sea wave or tidal wave Cata¬ strophic ocean wave, usually caused by a submarine earthquake. Under¬ water or coastal landslides or volcanic eruptions also may cause tsunamis. The term tsunami is Japanese for “harbour wave.” The term tidal wave is a misnomer, because the wave has no connection with the tides. Perhaps

Sojourner Truth.

COURTESY OF THE BURTON HISTORICAL COLLECTION, DETROIT PUBLIC LIBRARY

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Tsvet > Tubman I 1945

the most destructive tsunami ever occurred in 2004 in the Indian Ocean, after an earthquake struck the seafloor off the Indonesian island of Sumatra. More than 200,000 people were killed in Indonesia, Thailand, India, Sri Lanka and other countries as far away as Somalia on the Horn of Africa.

Tsvet \'tsvet\, Mikhail (Semyonovich) Tsvet also spelled Tsvett or Tswett (b. May 14, 1872, Asti, Italy—d. June 26, 1919, Voronezh, Russian S.F.S.R.) Italian-born Russian botanist and chemist. He is cred¬ ited with the discovery (in 1903) and application of chromatography. In 1910 he described how he extracted plant pigments with ether and alcohol and percolated the solution through columns of calcium carbonate or powdered sugar; the different pigments appeared as separate coloured bands. Tsvet discovered several new chlorophylls and coined the words chromatography and carotenoid. His work was not discovered by main¬ stream Western scientists for nearly 30 years.

Tsvetayeva \tsv y i-'ta-y3-v9\, Marina (Ivanovna) (b. Oct. 8, 1892, Moscow, Russia—d. Aug. 31, 1941, Yelabuga) Russian poet. After spend¬ ing most of her youth in Moscow, she began studies at the Sorbonne in Paris at age 16. She published her first poetry collection in 1910. Her verses on the Russian Revolution glorify the anti-Bolshevik resistance, of which her husband was a part. She lived abroad from 1922 to 1939, mostly in Paris, writing varied works including poetry that increasingly reflected nostalgia for her homeland. Many of her best and most typical poetic qualities are displayed in the long verse fairy tale Tsar-devitsa (1922; “Tsar-Maiden”). Separated from her husband and daughter and isolated from friends after the evacuation of Moscow, she committed suicide. Though little known outside Russia, she is considered one of the finest 20th-century poets in Russian.

Tswana Vtswa-noV Westerly division of the Sotho peoples of South Africa and Botswana. The Tswana, numbering 4.1 million, live in a grass¬ land environment in which they raise livestock and grow com and sor¬ ghum. There is a seasonal migration of Tswana men, many of whom work in the mining and industrial centres of South Africa.

Tu Fu See Du Fu t'u-ti See tudi

Tuamotu X.tu-o-'mo-tiA Archipelago Group of about 80 islands (pop., 1996: 14,283), French Polynesia. The archipelago comprises 75 atolls, one raised coral atoll (Makatea), and innumerable coral reefs, roughly dispersed northwest-southeast as a double chain for over 900 miles (1,450 km). Europeans visited the islands in the 16th—17th centu¬ ries. France occupied them in 1844 and annexed them in 1880 as a Tahi¬ tian dependency. They now form, with the Gambier Islands, an administrative division of French Polynesia. In 1947 Thor Heyerdahl’s Kon-Tiki expedition ended on Raroia—one of Tuamotu’s many reefs. France has used some uninhabited atolls in the archipelago for nuclear testing.

Tuareg Vtwa-,reg\ A member of a nomadic Berber-speaking people of the southwestern Sahara in Africa. Their feudal, matrilineal culture divides society into nobles, clergy, vassals, artisans, and labourers (once slaves). Northern Tuareg live mainly in true desert; southern Tuareg live in steppe and savanna. They have traditionally engaged in herding, agri¬ culture, convoying caravans across their territories, and raiding neigh¬ bouring tribes. They combine many pre-Islamic rituals and customs with Sunnite Muslim beliefs. Droughts in the 1970s and ’80s reduced their numbers and eroded their traditional way of life.

tuatara \ l tii-9- , ta-ra\ Either of two species ( Sphenodon punctatus and S. guntheir) of lizardlike, nocturnal reptiles of the order Rhynchocephalia, found on certain islets of New Zealand. Up to 2 ft. (60 cm) long and weighing over 2 lbs (1 kg), tuataras have two pairs of well-developed limbs, a scaly crest down the neck and back, a third eyelid that closes horizontally, and a pineal eye between the two normal eyes. A bony arch behind the eyes distinguishes tuataras from lizards. They eats insects, other small animals, and birds’ eggs. In spring, they lay 8-15 eggs away from their burrow. Tuataras may live about 100 years.

Tuatha De Danann \ , tu-9-h3- , d y a- , da-n3n\ In Celtic mythology, a race inhabiting Ireland before the arrival of the Milesians, the ancestors of the modern Irish. Skilled in magic, they were banished from heaven because of their knowledge and descended on Ireland in a cloud of mist. They were thought to have disappeared into the hills when overcome by the

Milesians. They were regarded as actual people by native historians up to the 17th century. Representative of the Celtic pantheon, they have become associated in popular legend with the numerous fairies still said to inhabit the Irish landscape.

tuba Deep-pitched valved brass instrument with a widely expanding coni¬ cal bore. Tubas vary in size and pitch. The tubing is coiled in an oblong shape, and the bell points upward or forward. Patented in Berlin in 1835, the tuba displaced the ophicleide to become the foundation of the brass section in the orchestra and in military and brass bands. See also eupho¬ nium, SOUSAPHONE.

Tubb, Ernest (Dale) (b. Feb. 9, 1914, Crisp, Texas, U.S.—d. Sept. 6, 1984, Nashville, Tenn.) U.S. country music singer and songwriter. His first musical influence was the yodeling of Jimmie Rodgers. He became one of the earliest exponents of honky-tonk with hits such as “I’m Walking the Floor over You” (1941). He joined the Grand Ole Opry in 1942, and he became one of the first musicians to record in Nashville. He was a pio¬ neer of the electric guitar in the early 1950s. His Nashville radio program, Midnight Jamboree (from 1947), helped launch many stars, including the Everly Brothers and Elvis Presley. In 1947 he starred in the first country music show at Carnegie Hall.

tube worm Any of numerous species of sedentary, solitary or colonial, marine worms that spend their entire life in a tube made from special secretions or from sand grains glued together. Found worldwide, tube worms range from less than an inch (25 mm) to more than 20 ft (6 m) long. The bottom of the tube is attached to the seafloor; the mouth and tentacles are at the upper, open end. The worm breathes through gills, the tentacles, or the body wall. The tentacles, variously arranged, are used to filter-feed aquatic plants and animals. Tube worms occur in the annelid class Polychaeta and in the phyla Phoronida and Pogonophora. Many, mostly unnamed, forms live in deep-ocean vent communities.

tuber Short, thickened, mostly underground stem that constitutes the resting stage of certain seed plants. It is often an organ of food storage, reproduction, or both. It bears minute scale leaves, each with a bud that has the potential for developing into a new plant. The common potato is a typical tuber; the much-reduced leaves and associated buds form its “eyes.” The term is also used imprecisely but widely for fleshy roots or rhizomes that resemble tubers (e.g., the “tuber” of the dahlia, actually a tuberous root).

tuberculosis Uu-.bor-kyo-'lo-sosV (TB ) formerly consumption Bac¬ terial disease caused by some species of mycobacterium (tubercle bacillus). Mentioned in ancient Egyptian records and by Hippocrates, it has occurred throughout history worldwide. In the 18th—19th centuries it reached near¬ epidemic proportions in the rapidly industrializing and urbanizing West¬ ern world, where it was the leading cause of death until the early 20th century. TB resurged in the 1980s, spreading from AIDS patients to oth¬ ers, especially in prisons, homeless shelters, and hospitals, since enclosed settings promote spread. It occurs worldwide and is still a major cause of death in many countries. The body isolates the bacilli by forming tiny tubercles (nodules) around them. This often arrests TB’s progress and no symptoms occur, but if the disease is not treated, it may become active— and contagious—later in life, most often when the immunity of the infected individual is suppressed (e.g., AIDS, after organ transplant). The original tubercle breaks down, releasing still viable bacilli into the blood¬ stream to cause a new infection, which starts with loss of energy and weight and persistent cough. Health deteriorates, with increasing cough and possibly pleurisy (see thoracic cavity) and spitting up blood. Grow¬ ing tubercle masses may destroy so much lung tissue that respiration can¬ not supply the body with enough oxygen. Other organs can be affected, with complications including meningitis. A vaccine with weakened bacte¬ ria has helped control infection, but preventing exposure by recognizing and treating active TB early is more effective. Because many strains are resistant to drugs, treatment requires at least two drugs to which the patient’s strain is sensitive and at least six months; inadequate treatment lets resistant bacilli multiply. The acute disease caused by multidrug- resistant strains is very hard to cure and usually fatal.

Tubman, Harriet orig. Arminta Ross (b. c. 1820, Dorchester county, Md., U.S.—d. March 10, 1913, Auburn, N.Y.) U.S. abolitionist. Born into slavery, she escaped to the North by the Underground Railroad in 1849. She made frequent trips into the South to lead over 300 slaves to freedom, despite large rewards offered for her arrest. Known as the “Moses of her people,” she was admired by abolitionists such as John

© 2006 Encyclopaedia Britannica, Inc.

1946 I Tubman ► Tukhachevsky

Brown, who called her General Tubman. In the American Civil War, she served as a nurse, laundress, and spy for Union forces in South Carolina. She later settled in Auburn, N.Y., and was eventually granted a federal pension for her war work.

Tubman, William V(acanarat) S(hadrach) (b. Nov. 29, 1895, Harper, Liberia—d. July 23, 1971, London, Eng.) President of Liberia (1944-71). Tubman educated himself in law before entering public ser¬ vice, eventually ascending to the Supreme Court (1937-44). As president, Tubman enacted suffrage and property rights for women, authorized par¬ ticipation in government by all ethnic groups, and established a nation¬ wide public-school system.

Tuchman Vtok-monV Barbara orig. Barbara Wertheim (b. Jan. 30, 1912, New York, N.Y., U.S.—d.

Feb. 6, 1989, Greenwich, Conn.)

U.S. historian. She wrote for The Nation and other publications before beginning to write most of the books that made her a leading popular his¬ torian. Marked by a masterly literary style and a powerful grasp of com¬ plex issues, they include The Zim- mermann Telegram (1958); The Guns of August (1962, Pulitzer Prize), on the first month of World War I; Stilwell and the American Experience in China, 1911-45 (1970, Pulitzer Prize), a study of the China-U.S. relationship; and A Dis¬ tant Mirror (1978), concerning 14th- century France.

Tucson Vtu-,san\ City (pop., 2000:

486,699), southeastern Arizona, U.S.

It lies along the Santa Cruz River on a hilly plain of the Sonoran Desert rimmed by mountains. In 1700 the Spanish founded several missions nearby, and in 1776 the small walled pueblo of Tucson was made a Span¬ ish presidio (fort). It remained the province’s military headquarters under Mexican rule. The U.S. acquired the territory through the Gadsden Pur¬ chase (signed in 1853). Tucson was the territorial capital from 1867 to 1877. It grew with the arrival of the railroad in 1880 and the discovery of silver at nearby Tombstone and copper at Bisbee. Its dry, sunny climate and desert locale have made it a popular tourist and health resort and retirement community. It is the seat of the University of Arizona (1885).

Tucuna or Ticuna or Tikuna \t3-'ku-nos\ South American Indian people living in Brazil, Peru, and Colombia. Traditional Tucunas live in the rainforest of the northwestern Amazon basin, cultivating cassava and com (maize), raising chickens, and hunting and gathering in the forest. They make baskets, pottery, and bark cloth and trade animal hides and handmade canoes for money and manufactured goods. They were once skilled hunters with blowguns, spears, and snares, but depletion of ani¬ mal populations has altered old hunting patterns.

Tudjman \'tuj-man\, Franjo (b. May 14, 1922, Veliko Trgovisce, King¬ dom of Serbs, Croats, and Slovenes—d. Dec. 10, 1999, Zagreb, Cro.) Croatian politician and president of Croatia (1990-99). He served with the partisans under Marshal Tito in World War II. He taught political science and history at the University of Zagreb (1963-67) and later wrote numer¬ ous books on history and politics. He was expelled from the Yugoslav Communist Party in 1967 for his nationalist writings, and he was impris¬ oned in 1972 and 1981. In 1989 Tudjman founded the Croatian Democratic Union, which won Croatia’s first free parliamentary elections in 1990. Named president, he pressed for the creation of a homogenous Croatian state. When Serbian areas of Eastern and Western Slavonia and the Krajina revolted, they were occupied by the Yugoslav army. Beginning in 1995, Tudjman reasserted control over these areas and established virtual control over portions of Bosnia and Herzegovina with majority Croatian popula¬ tions. His authoritarian style, along with his refusal to cooperate with the International Criminal Tribunal for the Former Yugoslavia, led to the inter¬ national isolation of Croatia, and his excesses in the Bosnian conflict and his autocratic rule earned Tudjman a reputation for brutality.

Tudor, Antony orig. William Cook (b. April 4, 1908, London, Eng.—d. April 20, 1987, New York, N.Y., U.S.) British-born U.S. dancer,

teacher, and choreographer. In 1927 he joined Marie Rambert’s company, where he choreographed and danced such works as The Planets (1934) and The Lilac Garden (1936). In 1940 he moved to New York City, join¬ ing the new Ballet Theatre (later American Ballet Theatre), for which he created many of his signature psychological ballets, including Pillar of Fire (1942) and Shadow of the Wind (1948). In these works he sought to convey emotional conflict and aspects of character and motivation. In 1974 he became associate director of American Ballet Theatre.

Tudor, Henry See Henry VII (England)

Tudor, house of English royal dynasty that gave five sovereigns to England (1485-1603). The Tudors originated in the 13th century, but the dynasty’s fortunes were established by Owen Tudor (c. 1400-61), a Welsh adventurer who took service with Henry V and married Henry’s widow, Catherine of Valois (1401-37). Owen and Catherine’s son Edmund Tudor (c. 1430-56) was created earl of Richmond and married Lady Margaret Beaufort (1443-1509), a descendant of John of Gaunt of the house of Lancaster. Their son Henry Tudor claimed the English throne as Henry VII in 1485 and cemented his claim with his marriage to Elizabeth of the house of York, daughter of Edward IV. The Tudor rose symbolized the union between the red rose of the Lancastrians and the white rose of the Yorkists. The Tudor dynasty continued in the 16th century with the reigns of Henry VIII and his children Edward VI, Mary I, and Elizabeth I. In 1603 the dynasty was succeeded by the house of Stuart.

Tudor, Margaret See Margaret Tudor

Tudor, Mary See Mary I

Tudor style Architectural style in England (1485-1558) that made lav¬ ish use of half-timbering (see timber framing), as well as oriels, gables, decorative brickwork, and rich plasterwork. Exposed diagonal bracing usually occurs at building corners, with the second story often sporting a picturesque overhang; this cantilevered construction partially counterbal¬ ances the load carried by the spanning portions of the beams.

tuff Relatively soft, porous rock that is usually formed by the compac¬ tion and cementation of volcanic ash or dust. Tuff may vary greatly not only in texture but also in chemical and mineralogical composition. In some eruptions, foaming magma wells to the surface as an emulsion of hot gases and incandescent particles; the shredded pumice-like material spreads swiftly, even over gentle slopes, as a glowing avalanche (nuee ardente) that may move many miles at speeds of 100 mph (160 kph).

Tugela River \tu-'ga-b\ Principal river, KwaZulu-Natal province, South Africa. It rises in the Mont-aux-Sources plateau and hurtles 3,110 ft (948 m) down a series of waterfalls to cut through Tugela Gorge. It ends its 312-mi (502-km) course at the Indian Ocean. It was the scene of battles in the South African War in 1899-1900. Historically, the Tugela marked the southern boundary of Zululand.

Tug well, Rexford G(uy) (b. July 10, 1891, Sinclairville, N.Y., U.S.—d. July 21, 1979, Santa Barbara, Calif.) U.S. economist. He joined the economics faculty of Columbia University in 1920, and in 1932 he became a member of the Brain Trust that advised Franklin D. Roosevelt. Appointed undersecretary of agriculture, he helped formulate farm policy and other New Deal economic reforms (1933-36). He chaired the New York City Planning Commission (1938-41), served as governor of Puerto Rico (1941^-6), and taught at the University of Chicago (1946-57).

Tuileries Palace Vtwe-b-,rez\ French royal residence, adjacent to the Louvre in Paris, destroyed by arson in 1871. The original palace, com¬ missioned by Catherine de Medicis, was begun in 1564 by Philibert Delorme (c. 1515-1570); the next 200 years saw numerous additions and alter¬ ations by Jean Bullant (15207-1578), Jacques du Cerceau (c. 1520-1585), Louis Le Vau (1612-1670), and others. The Tuileries Gardens have changed little since Andre Le Notre redesigned them in 1664. His design extended the central walkway beyond the gardens and out into the coun¬ tryside to the hilltop west of the palace, where the Arc de Triomphe now stands.

Tukhachevsky \,tuk-9-'chef-ske\, Mikhayl (Nikolayevich) (b.

Feb. 16, 1893, near Slednevo, Russia—d. June 11, 1937) Soviet Red Army officer. In the Russian Civil War, he commanded the recapture of Siberia from Aleksandr Kolchak and led the Cossack forces against Anton Deni¬ kin (1920). He thereafter played a leading role in military reform; from 1931 he directed the rearmament of the Soviet Union. He served as Soviet chief of staff (1925-28) and later as deputy commissar for defense (1931—

Barbara Tuchman.

©JERRY BAUER

© 2006 Encyclopaedia Britannica, Inc.

Tukulor ► tungsten I 1947

37); he was made a marshal of the Soviet Union in 1935. A victim of the purge trials in 1937, he was tried and executed with other top Red Army commanders. In 1988 he was cleared judicially and rehabilitated by offi¬ cial decree.

Tukulor \,tu-ku-'lsr\ Muslim people of Senegal and western Mali. Because of extended contacts with the Fulani, the Tukulor speak a dialect of Fula, an Atlantic language of the Niger-Congo family. In the 10th— 18th centuries they were dominated by a succession of non-Tukulor groups in the kingdom of Tekrur. About 1850 they established an empire and conquered the Bambara kingdoms of Kaarta and Segu and extended their empire to Timbuktu before it was destroyed by the French in 1890. Today the Tukulor raise livestock, fish, and cultivate millet and sorghum.

Tula Ancient city in Mexico, the capital of the Toltecs, which flourished in the 10th— 12th centuries. Its exact location is uncertain; the archaeo¬ logical site now designated Tula, near the town of that name in Hidalgo state, has been the choice of historians, but other scholars identify Tula with what is now usually called Teotihuacan. The Tula site suggests a city that had a population in the tens of thousands. The major civic centre con¬ sists of a plaza bordered by a five-stepped pyramid, two other pyramids, and two ball courts. Tula’s art and architecture are strikingly similar to those of the Aztec capital, Tenochtitlan, and its artistic themes suggest that the Aztecs’ concept of themselves as warrior-priests of the sun god was borrowed directly from Tula.

tulip Any of almost 4,000 varieties of about 100 species of cultivated bulbous herbaceous plants making up the genus Tulipa in the lily family, native to Eurasia. Among the most popular of all garden flowers, the tulip produces two or three thick, bluish-green leaves clustered at the base of the plant. The usually solitary inverted bell-shaped flowers have three petals and three sepals. Colors range from white through yellows and reds to brown and deep purple to almost black. Streaked blossoms get their streaks from a harmless virus infection that causes the color to disappear in patterns, letting white or yellow show through.

tulip tree or tulip poplar or yellow poplar Lofty North Ameri¬ can ornamental and timber tree ( Liriodendron tulipifera) of the magnolia family, not related to true poplars. It occurs in mixed hardwood stands in eastern North America. It is taller than all other eastern broad-leaved trees (up to 197 ft, or 60 m), and its trunk often has a diameter greater than 7 ft (2 m). Long-stemmed, bright-green leaves have two to four side lobes and blunted tips. Yellowish-green tuliplike flowers have six petals, orange at their bases, and three bright-green sepals. Other characteristics include conelike clusters of winged fruits; aromatic, purplish-brown twigs; stun¬ ning golden-yellow autumn leaves; winter buds resembling a duck’s bill; and resistance to pests and diseases. The wood is used to manufacture furniture parts, plywood panels, paper, boxes, and crates.

Tull, Jethro (b. 1674, Basildon, Berkshire, Eng.—d. Feb. 21, 1741, Prosperous Farm, near Hungerford, Berkshire) British agronomist and inventor. He was educated at Oxford. Around 1701 he perfected a horse- drawn seed drill that economically sowed the seeds in neat rows, and later a horse-drawn hoe. He stressed the use of manure and the importance of breaking up the soil into small particles. Tull’s methods, though initially attacked, were eventually adopted by many large landowners, and they helped form the basis of modern agriculture.

Tulsa City (pop., 2000: 393,049), northeastern Oklahoma, U.S. On the Arkansas River, Tulsa originated in 1836 as a settlement of Creek Indian immigrants; white settlement began in 1882 after the arrival of the railway. The discovery of oil nearby in the early 20th century launched an oil and gas boom, and phenomenal growth followed. Many major oil companies now have plants and offices in the city. It is the head of navigation for the Arkansas River Navigation System, a waterway that stretches 440 mi (708 km) to the junction of the Arkansas and Mississippi rivers. The commercial and financial centre of a rich agricultural area, it is the seat of the University of Tulsa (1894) and Oral Roberts University (1965).

tumbleweed Plant that breaks away from its roots and is driven about by the wind as a light rolling mass, scattering seeds as it goes. Examples include pigweed (. Amaranth retroflexus, a widespread weed in the west¬ ern U.S.) and other amaranths, tumbling mustard, Russian thistle, the steppe plant Colutea arborea, and the grass Spinifex of Indonesian shores and Australian steppes.

Tumen Vtu-'monV River River, eastern Asia. It forms the northeastern frontier of North Korea with China and Russia. It originates on Mount

Paektu, North Korea’s highest mountain, and flows generally north and northeast before turning southeast to enter the Sea of Japan (East Sea). It is 324 mi (521 km) long but navigable for only 53 mi (85 km). Many historic battle sites lie along its banks.

tumour or neoplasm Mass of abnormal tissue that arises from nor¬ mal cells, has no useful function, and tends to grow. Cell abnormalities may include increased size or number or loss of characteristics that dif¬ ferentiate their tissue of origin. Cells in malignant tumours (see cancer) have a distorted size, shape, and/or structure. Less differentiated cells tend to grow faster. Malignant tumours invade tissues locally and spread (metastasize) in blood or lymph: the stronger the tendency to metastasize, the more malignant the tumour. Tumours may not cause pain until they press on or invade nerves. Both benign and malignant tumours can press on nearby structures, block vessels, or produce excess hormones, all of which can cause death. Benign tumours remain as a solid mass that can be removed by surgery if accessible; they can consist of various tissues and may become malignant; malignant tumours, though they may remain quiescent for a time, never become benign.

tuna Any of seven species (genus Thunnus, family Scombridae) of com¬ mercially valuable food fishes. Species range from the 80-lb (36-kg) alba- core to the bluefin tuna ( T. thynnus), which grows to 14 ft (4.3 m) long and weighs up to 1,800 lbs (800 kg). Tunas have a slender, streamlined body and a forked or crescent-shaped tail. They are unique among fishes in having a vascular system modified to maintain a body temperature above the water temperature. Though slow swimmers, they migrate long distances over all the world’s oceans. They eat fishes, squid, shellfish, and plankton.

tundra Treeless, level or rolling ground above the taiga in polar regions (Arctic tundra) or on high mountains (alpine tundra), characterized by bare ground and rock or by such vegetation as mosses, lichens, small herbs, and low shrubs. Animal species are limited by harsh environmen¬ tal conditions. In the Arctic tundra they include lemmings, the Arctic fox, the Arctic wolf, caribou, reindeer, and musk-oxen. In the alpine tundra many animals, including mountain sheep and wildcats, descend to warmer zones during winter. The climate of alpine tundra is more moderate and has a higher amount of rainfall than does Arctic tundra. The freezing cli¬ mate of the Arctic produces a layer of permanently frozen soil (perma¬ frost). An overlying layer of soil alternates between freezing and thawing with seasonal temperature variations. Alpine tundras have a freeze-thaw layer but no permafrost. Because Arctic tundras receive extremely long periods of daylight and darkness (lasting between one and four months), biological rhythms tend to be adjusted more to variations in temperature than to variations in sunlight. Arctic tundra covers about one-tenth of the earth’s surface. Alpine tundras begin above the timberline of spruce and firs. Because of the small number of plant and animal species and the fragility of the food chains in tundra regions, natural or mechanical dam¬ age to any element of the habitat affects the whole ecosystem.

tuned circuit Electrically conducting pathway containing both induc¬ tance and capacitance elements. When these elements are connected in series, the circuit presents low electrical impedance to alternating current of the same frequency as the resonance frequency of the circuit and high impedance to current of other frequencies. The circuit’s resonance fre¬ quency is determined by the values of inductance and capacitance. When the circuit elements are connected in parallel, the impedance is high at the resonance frequency and low at other frequencies. With their ability to pass only certain frequencies, tuned circuits are important in, for example, radio and television receivers.

Tung Ch'i-ch'ang See Dong Qichang Tung Chung-shu See Dong Zhongshu Tung-lin Academy See Dongun Academy Tung-Pei See Manchuria Tung-ting Hu See Dongting Hu

tungsten or wolfram Vwul-fromX Metallic chemical element, one of the transition elements, chemical symbol W, atomic number 74. Excep¬ tionally strong, white to grayish, and brittle, it has the highest melting point (6,170 °F [3,410 °C]), greatest high-temperature strength, and low¬ est thermal expansion coefficient of any metal. Its chief uses are in steels to increase hardness and strength and in lightbulb filaments (see incandes¬ cent lamp). It is also used in electrical contacts, rocket nozzles, chemical

© 2006 Encyclopaedia Britannica, Inc.

1948 I tungsten-halogen lamp ► Tunney

apparatus, high-speed rotors, and solar-energy devices. Tungsten is rela¬ tively inert, but compounds (in which it has various valences) are known. The most important, tungsten carbide, noted for its hardness, is used to increase the wear-resistance of cast iron and of tools’ cutting edges.

tungsten-halogen lamp See halogen lamp Tungusic languages See Manchu-Tungus languages

Tunguska event \tuq-'gu-sk3\ (June 30, 1908) Enormous aerial explo¬ sion that flattened about 500,000 ac (2,000 sq km) of pine forest near the Stony Tunguska River in central Siberia. Its energy is estimated to have been equivalent to that of about 15 megatons of TNT. Uncertain evidence suggests that a meteoroid (see meteor) 150-300 ft (45-90 m) in diameter or, less likely, a comet disintegrated in the atmosphere high above Earth’s surface, creating a fireball and blast wave but no crater. Eyewitnesses spoke of a fireball lighting the horizon, initially visible from about 500 mi (800 km) away, followed by trembling ground and hot winds strong enough to throw people down and shake buildings. The object’s vapor¬ ization scattered dust high into the atmosphere, causing abnormally bright nighttime skies in Siberia and Europe for some time afterward.

tunicate Vtu-ni-kotV Any of some 2,000 species (chordate subphylum Tunicata, or Urochordata) of small marine invertebrates that are abundant worldwide. Tunicates are either sessile (permanently attached), free- swimming, or planktonic (floating). The name tunicate derives from a secreted protective covering (the tunic) containing cellulose. Floating spe¬ cies often form colonies that may be 13 ft (4 m) long. Some free- swimming species are too small to see. Adults filter feed on microorganisms. Sessile forms growing on ships’ hulls may be a nuisance, but some species are pharmaceutically useful. See also sea squirt.

tuning and temperament In music, the adjustment of one sound source, such as a voice or string, to produce a desired pitch in relation to a given pitch, and the modification of that tuning to lessen dissonance. Tuning assures a good sound for a given pair of tones; temperament com¬ promises the tuning to assure a good sound for any and all pairs of tones. Two vibrating strings sound best together if the ratio between their lengths can be expressed by two small whole numbers. If two strings vibrate in a ratio of 2:1, the vibrations will always coincide and so reinforce each other. But if they vibrate in a ratio of 197:100 (very close to 2:1), they will cancel each other out three times per second, creating audible “beats.” These beats are what make something sound “out of tune.” Since a tone produced by one ratio will not necessarily agree with the same tone cre¬ ated by repeatedly applying another ratio, either some intervals must be mistuned to allow for the perfect tuning of others or all intervals must be slightly mistuned. Before 1700, several systems were used based on the former compromise, including “just intonation”; since then, the compro¬ mise known as “equal temperament,” in which the ratios represented by each pair of adjacent notes are identical, has prevailed.

Tunis Vtu-nosV City (pop., 2004: 728,453), capital of Tunisia. It is situated on Tunis Lake, an inlet of the Gulf of Tunis; its port, La Goulette (Halq al-Wadl), is 6 mi (10 km) to the northeast. Founded by Libyans, it was later a small town under Carthage; it became important after the Muslim conquest in the 7th century ad. It was a religious centre during the Aghla- bid dynasty (9th century) and reached its greatest prosperity under the Hafsid dynasty (13th century). The Spanish and Ottomans controlled it during the 16th century, and it was occupied by the Germans in 1942. It was made the national capital when Tunisia gained independence from France in 1956. It produces textiles, carpets, and olive oil and has met¬ allurgical industries. Tourism is also important. The city’s historic centre was designated a UNESCO World Heritage site in 1979.

Tunisia \tii-'ne-zh9\ officially Tunisian Republic Country, North Africa. Area: 63,170 sq mi (163,610 sq km). Population (2005 est.): 10,038,000. Capital: Tunis. The population is of Arab and Berber (Amazigh) ancestry. Languages: Arabic (official), French. Religion: Islam (official; predominantly Sunni). Currency: Tunisian dinar. Tunisia com¬ prises a coastal region, mountains, an extensive hilly steppe, a marshy area with shallow salt lakes, and a tract of the Sahara. The Majardah is its longest (about 290 mi [460 km]) and only perennial river. Tunisia con¬ tains some of the largest phosphate and natural gas reserves in Africa, as well as substantial oil reserves. Major economic activities are services, agriculture, light industries, and the production and export of petroleum and phosphates. Tourism, focusing on Tunisia’s beaches and Roman ruins, is also important. Tunisia is a republic with one legislative house; its chief

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