Botucatu, city, central São Paulo estado (state), Brazil. It lies near the Pardo River in the Serra de Botucatu at 2,549 feet (777 metres) above sea level. It was given town status in 1855 and was made the seat of a municipality in 1876. Crops grown in the region (including corn [maize], sugarcane,

Geral Mountains, mountain escarpment of the southern and eastern reaches of the Paraná Plateau. It constitutes the principal mountain relief of interior southern Brazil. Stretching east-west across northern Rio Grande do Sul state to the great escarpment in Santa Catarina state, it then turns and

botulinum toxin, poisonous protein made by Clostridium botulinum and several closely related species of bacteria that causes botulism, a condition characterized by neurotoxicity, primarily muscle paralysis. Botulinum toxin also has therapeutic and cosmetic applications. Botulinum toxin was

botulinum toxin, poisonous protein made by Clostridium botulinum and several closely related species of bacteria that causes botulism, a condition characterized by neurotoxicity, primarily muscle paralysis. Botulinum toxin also has therapeutic and cosmetic applications. Botulinum toxin was

Botox, trade name of a drug based on the toxin produced by the bacterium Clostridium botulinum that causes severe food poisoning (botulism). When locally injected in small amounts, Botox blocks the release of the neurotransmitter acetylcholine, interfering with a muscle’s ability to contract. It is

botulinum toxin, poisonous protein made by Clostridium botulinum and several closely related species of bacteria that causes botulism, a condition characterized by neurotoxicity, primarily muscle paralysis. Botulinum toxin also has therapeutic and cosmetic applications. Botulinum toxin was

botulism, paralytic syndrome caused by poisoning by botulinum toxin, a substance produced by Clostridium botulinum bacteria. Botulism results most frequently from the eating of improperly sterilized home-canned foods containing the toxin. Poisoning also may result from wound infection. C. botulinum

Mikhail Moiseyevich Botvinnik was a Soviet chess master who held the world championship three times (1948–57, 1958–60, and 1961–63). (Read Garry Kasparov’s Britannica essay on chess & Deep Blue.) At the age of 14, less than two years after he had learned the moves of chess, Botvinnik defeated the

Middle Atlas: …metres), with the highest being Mount Bou Nasser (Bou Naceur; 10,958 feet [3,340 metres]). Covered by cedar forests, the mountains form a fishing, hunting, and skiing area.

Middle Atlas: …metres), with the highest being Mount Bou Nasser (Bou Naceur; 10,958 feet [3,340 metres]). Covered by cedar forests, the mountains form a fishing, hunting, and skiing area.

Bou Saâda, town, north-central Algeria. It is located between el-Hodna Depression (a salt lake) and the peaks of the Saharan Atlas Mountains. Although north of the Sahara, Bou Saâda is a true oasis, spread along the left bank of the Bou Saâda Wadi and standing in pleasant contrast to the nearby

Bouaké, city, central Côte d’Ivoire (Ivory Coast). It lies on the road and railroad from Abidjan (the national capital) to Ouagadougou, Burkina Faso (formerly Upper Volta). Bouaké was established as a French military post in 1899; it became an autonomous municipality in 1969. The city is the

Mohamed Bouazizi was a Tunisian street vendor whose self-immolation after being harassed by municipal officials catalyzed the Jasmine Revolution in Tunisia and helped inspire a wider pro-democracy protest movement in the Middle East and North Africa known as the Arab Spring. Bouazizi’s early life

Mohamed Bouazizi was a Tunisian street vendor whose self-immolation after being harassed by municipal officials catalyzed the Jasmine Revolution in Tunisia and helped inspire a wider pro-democracy protest movement in the Middle East and North Africa known as the Arab Spring. Bouazizi’s early life

Luxembourg: …a rocky promontory called the Bock (Bouc) forms a natural defensive position where the Romans and later the Franks built a fort, around which the medieval town developed. The purchase of this castle in 963 ce by Siegfried, count of Ardennes, marked the beginning of Luxembourg as an independent entity.…

Lucien Bouchard is a Canadian politician who was a founder and leader of the Bloc Québécois (1990–96) in the federal House of Commons, and who later served as premier of Quebec (1996–2001). Bouchard received a degree in social sciences (1960) and a degree in law (1963) from Laval University in

rubber: The rise of synthetic rubber: The Frenchman Georges Bouchardat, with the aid of hydrogen chloride gas and prolonged distillation, converted isoprene to a rubberlike substance in 1875, and in 1882 another Briton, W.A. Tilden, produced isoprene by the destructive distillation of turpentine. Tilden also assigned isoprene the structural formula CH2=C(CH3)―CH=CH2.

Edmé Bouchardon was a French sculptor who was a precursor of Neoclassicism. His statues are characterized by a skillful combination of classical Roman techniques and contemporary motifs. Bouchardon studied with Guillaume Coustou and in 1722 won the Prix de Rome. For the next 10 years he lived in

Jacques Boucher de Perthes was a French archaeologist and writer who was one of the first to develop the idea that prehistory could be measured on the basis of periods of geologic time. From 1825 Boucher de Perthes was director of the customhouse at Abbeville, near the mouth of the Somme River, and

Klaus Barbie was a Nazi leader, head of the Gestapo in Lyon from 1942 to 1944, who was held responsible for the death of some 4,000 persons and the deportation of some 7,500 others. Barbie was a member of the Hitler Youth and in 1935 joined the Sicherheitsdienst (SD; “Security Service”), a special

Jacques Boucher de Perthes was a French archaeologist and writer who was one of the first to develop the idea that prehistory could be measured on the basis of periods of geologic time. From 1825 Boucher de Perthes was director of the customhouse at Abbeville, near the mouth of the Somme River, and

Anthony Boucher was an American author, editor, and critic in the mystery and science fiction genres who in 1949 cofounded The Magazine of Fantasy & Science Fiction, a major science fiction periodical. He was one of the premier critics of mystery; for his reviews he won three Edgar Allan Poe Awards

non-fungible token: NFT history and milestones: …and performs under the name Grimes, sold 10 digital images from a portfolio of her artwork for a reported $5.8 million in 2021, and, in the same year, Jack Dorsey, the founder of Twitter, sold an NFT of his first tweet, from March 2006, at auction for $2.9 million. That…

François Boucher was a painter, engraver, and designer whose works are regarded as the perfect expression of French taste in the Rococo period. Trained by his father, a lace designer, Boucher won the Prix de Rome in 1723. He was influenced by the works of Giovanni Battista Tiepolo, Peter Paul

Clara Hughes: Early career: Inspired by Gaétan Boucher’s success in the 1984 Olympic Winter Games in Sarajevo and by the 1988 Olympic Winter Games in Calgary, Hughes took up speed skating at 16 and won a junior national title in the 3,000 metres. She skated competitively for two years and started…

Joan Bocher was an English Anabaptist burned at the stake for heresy during the reign of the Protestant Edward VI. Bocher first came to notice about 1540, during the reign of Henry VIII, when she began distributing among ladies of the court William Tyndale’s forbidden translation of the New

Jonathan Boucher was an English clergyman who won fame as a loyalist in America. In 1759 Boucher went to Virginia as a private tutor. After a visit to London in 1762 for his ordination, he became rector of Annapolis, Maryland, and tutored George Washington’s stepson, thus becoming a family friend.

Auguste-Gaspard-Louis, Baron Desnoyers was a French engraver, one of the most eminent line engravers of his time. Desnoyers studied engraving and drawing and, after visiting Italy, entered the studio of Pierre-Alexandre Tardieu in 1800. His fame was established in 1805 by an engraving after

Provence–Alpes–Côte d’Azur: Alpes-de-Haute-Provence, Var, Bouches-du-Rhône, and Vaucluse. Provence–Alpes–Côte d’Azur is bounded by the régions of Occitanie to the west and Auvergne-Rhône-Alpes to the north. Other boundaries include Italy to the east and the Mediterranean Sea to the south. The région is nearly coextensive with the historic region of

Edward Alexander Bouchet was a renowned physicist and the first African American to earn a Ph.D. in the United States, as well as the sixth person to earn a doctorate in physics from an American university, which he received from Yale University in 1876. Bouchet’s father was brought by a young

French literature: Language and learning in 16th-century Europe: Octovien de Saint-Gellais, Jean Marot, Jean Bouchet, and Jean Lemaire de Belges), better known for their commitment to formal play, rhyme games, and allegorizing, in the medieval tradition. Writing inspired by the medieval tradition continued to be produced well into the 16th century. Old and New Testaments of the Christian…

textile: Drawlooms: In 1725 Basile Bouchon added to the mechanical drawboy a mechanism that selected the cords to be drawn to form the pattern. Selection was controlled by a roll of paper, perforated according to the pattern, which passed around a cylinder. The cylinder was pushed toward the selecting…

Dion Boucicault was an Irish-American playwright and actor, a major influence on the form and content of American drama. Educated in England, Boucicault began acting in 1837 and in 1840 submitted his first play to Mme Vestris at Covent Garden; it was rejected. His second play, London Assurance

Jean II le Meingre Boucicaut was a marshal of France, a French soldier, and a champion of the ideals of chivalry. (Read Sir Walter Scott’s 1824 Britannica essay on chivalry.) He was the son of Jean I le Meingre (d. 1368), also called Boucicaut and likewise a marshal of France. After the younger

yarn: …to produce special effects, include bouclé, characterized by projecting loops; nub yarn, with enlarged places, or nubs, produced by twisting one end of a yarn around another many times at one point; and chenille, a soft, lofty yarn with pile protruding on all sides. Textured yarns are synthetic filament yarns…

Mali: Plant and animal life: Boucle du Baoulé National Park along the Baoulé River in the west and the Ansongo-Ménaka Animal Reserve and Douentza (Gourma) Elephant Reserve in the east are major wildlife sanctuaries.

Maryse Condé was a Guadeloupian author of epic historical fiction, much of it based in Africa. Condé wrote her first novel at the age of 11. In the politically turbulent years between 1960 and 1968, she taught in Guinea, Ghana, and Senegal. She studied at the Sorbonne in Paris (M.A., Ph.D., 1975).

Driss Chraïbi: Les Boucs (1955; The Butts) shifted the author’s accusatory finger from a paternalistic Islamic formalism to the oppressed condition of many North Africans living in France. Then, leaving aside the directness of polemic, Chraïbi turned to more allegorical political expression in L’Âne (1956; “The Donkey”) and La Foule…

Baldwin I was the first ruler of Flanders. A daring warrior under Charles II the Bald of France, he fell in love with the king’s daughter Judith, the youthful widow of two English kings, married her (862), and fled with his bride to Lorraine. Charles, though at first angry, was at last conciliated,

Baldwin II was the second ruler of Flanders, who, from his stronghold at Bruges, maintained, as his father Baldwin I before him, a vigorous defense of his lands against the incursions of the Norsemen. On his mother’s side a descendant of Charlemagne, he strengthened the dynastic importance of his

Baudouin I was the king of the Belgians from 1951 to 1993, who helped restore confidence in the monarchy after the stormy reign of King Leopold III. The son of Leopold III and Queen Astrid, Baudouin shared his father’s internment by the Germans during World War II and his postwar exile in

Baldwin IV was the count of Flanders (988–1035) who greatly expanded the Flemish dominions. He fought successfully both against the Capetian king of France, Robert II, and the Holy Roman emperor Henry II. Henry found himself obliged to grant to Baldwin IV in fief Valenciennes, the burgraveship of

William I: New alliances of William I: In 1049 William negotiated with Baldwin V of Flanders for the hand of his daughter, Matilda. Baldwin, an imperial vassal with a distinguished lineage, was in rebellion against the emperor, Henry III, and was in desperate need of allies. At the Council of Reims in October 1049, the emperor’s cousin,…

Muhammad Boudiaf was an Algerian political leader who was a founder of the revolutionary National Liberation Front (FLN) that led the Algerian war of independence (1954–62), and, after a 27-year exile, the president of Algeria (1992). Boudiaf fought in the French army in World War II, but by 1950

Boudicca was an ancient British queen who in 60 ce led a revolt against Roman rule. Boudicca’s husband, Prasutagus, was king of the Iceni (in what is now Norfolk) as a client under Roman suzerainty. When Prasutagus died in 60 with no male heir, he left his private wealth to his two daughters and to

Boudicca was an ancient British queen who in 60 ce led a revolt against Roman rule. Boudicca’s husband, Prasutagus, was king of the Iceni (in what is now Norfolk) as a client under Roman suzerainty. When Prasutagus died in 60 with no male heir, he left his private wealth to his two daughters and to

boudinage, (from French boudin, “sausage”), cylinderlike structures making up a layer of deformed rock. Seen in cross section, the cylinders, or boudins, are generally barrel-shaped but may be lenslike or rectangular. They commonly lie adjacent to each other and are joined by short necks to give

Eugène Boudin was one of the first French landscape painters to paint in the open air, directly from nature. His many beach scenes directly link the carefully observed naturalism of the early 19th century and the brilliant light and fluid brushwork of late 19th-century Impressionism. Encouraged at

boudinage, (from French boudin, “sausage”), cylinderlike structures making up a layer of deformed rock. Seen in cross section, the cylinders, or boudins, are generally barrel-shaped but may be lenslike or rectangular. They commonly lie adjacent to each other and are joined by short necks to give

Elias Boudinot was an American lawyer and public official who was involved in the American Revolution. Boudinot became a lawyer and attorney-at-law in 1760. He was a leader in his profession, and, though he was a conservative Whig, he supported the American Revolution. He became a member of the

Rachid Boudjedra is a prolific and revolutionary Algerian writer whose first novel, La Répudiation (1969; The Repudiation), gained notoriety because of its explicit language and frontal assault on Muslim traditionalism in contemporary Algeria. Because of that work, Boudjedra was hailed as the

Lou Boudreau was an American professional baseball player and manager who led the Cleveland Indians to the 1948 World Series championship. Boudreau was a two-sport star in high school, and he went on to captain both the baseball and basketball teams at the University of Illinois before being signed

Lou Boudreau was an American professional baseball player and manager who led the Cleveland Indians to the 1948 World Series championship. Boudreau was a two-sport star in high school, and he went on to captain both the baseball and basketball teams at the University of Illinois before being signed

Ami Boué was an Austrian geological pioneer who fostered international cooperation in geological research. While studying medicine in Edinburgh, Boué became interested in geology through the influence of the noted Scottish geologist Robert Jameson. Boué studied the volcanic rocks in various parts

Buea, town located in southwestern Cameroon. It is situated at an elevation of 3,000 feet (900 metres) above sea level and is located on the southeast slope of Mount Cameroon. Buea was the capital of German Kamerun from 1902 to 1916. Several historic sites of the early mission and colonial periods

Boufarik, town, northern Algeria, in the centre of the irrigated Mitidja plain. Founded by Governor Bertrand Clauzel in 1836 on malarial swampland, the settlement successfully adopted intensive cultivation methods. Built on a rectangular plan with long, straight, shaded streets, the town is bounded

Louis-François, duke de Boufflers was a leading French general in the wars of King Louis XIV. Born into an ancient Picard family, he entered the French army in 1662 and distinguished himself as a commander of the royal dragoons during the Dutch War (1672–78). Boufflers became a marshal of France in

Stanislas-Jean, chevalier de Boufflers was a French writer, soldier, and academician remembered chiefly for his picaresque romance, Aline, reine de Golconde (“Aline, Queen of Golconde”). His mother, the Marquise de Boufflers, became the mistress of Stanisław Leszczyński, king Stanisław I of Poland

Giovanni Battista Pergolesi: There it led to la guerre des bouffons (“the war of the buffoons”), with musical forgers vying to produce spurious works of Pergolesi, leaving some uncertainty about the authenticity of works attributed to him. Some of the works credited to Pergolesi by Igor Stravinsky in arrangements he made for…

Giovanni Battista Pergolesi: There it led to la guerre des bouffons (“the war of the buffoons”), with musical forgers vying to produce spurious works of Pergolesi, leaving some uncertainty about the authenticity of works attributed to him. Some of the works credited to Pergolesi by Igor Stravinsky in arrangements he made for…

Bougainville Island, easternmost island of Papua New Guinea, in the Solomon Sea, southwestern Pacific. With Buka Island and several island groups, it forms the autonomous region of Bougainville. Geographically, Bougainville is the largest of the Solomon Islands, located near the northern end of

Louis-Antoine de Bougainville was a French navigator who explored areas of the South Pacific as leader of the French naval force that first sailed around the world (1766–69). His widely read account, Voyage autour du monde (1771; A Voyage Round the World, 1772), helped popularize a belief in the

bougainvillea, (genus Bougainvillea), genus of about 18 species of shrubs, vines, or small trees, belonging to the four-o’clock family (Nyctaginaceae), native to South America. Many species are thorny. Only the woody vines have attained wide popularity; several species have produced very showy

bougainvillea, (genus Bougainvillea), genus of about 18 species of shrubs, vines, or small trees, belonging to the four-o’clock family (Nyctaginaceae), native to South America. Many species are thorny. Only the woody vines have attained wide popularity; several species have produced very showy

bougainvillea: glabra, from Brazil, is called paperflower; the bracts are purple or magenta to lighter tints in certain varieties. The stem of B. glabra may be 20 to 30 metres (about 60 to 100 feet) long in warm climates, and the plant is in flower throughout most of the year. The…

bougainvillea: The stem of B. spectabilis is covered with many short hairs, and the flowers are relatively short-lived. The combination of bract plus inconspicuous flower itself resembles a flower with conspicuous petals. B. peruviana, from Colombia to Peru, has rose to magenta bracts. B. × buttiana, a probable hybrid…

reproductive behaviour: Protective adaptations: The eggs of the jellyfish Bougainvillia, for example, contain stinging cells on the surface that deter predators. Many female butterflies deposit their eggs on plants that contain poisonous compounds, which the larvae incorporate into their bodies, making them distasteful. When disturbed many insect larvae, especially those that are camouflaged, give…

floral decoration: 18th century: …were referred to as “bough pots.” The best known English illustrations of Georgian flower arrangements are those designed by the Flemish artist Peter Casteels for a nursery catalog called The Twelve Months of Flowers (1730). Since the flowers in each bouquet are numbered and keyed to a list at…

Archie Mayo: Films of the 1930s: Mayo then made Bought! (1931), a drama starring Constance Bennett—then Hollywood’s highest-paid actress—as a woman who aspires to be wealthy until discovering the shallowness of many in high society. In 1932 he directed Mae West in her film debut, Night After Night. The romantic drama featured one of…

Harry Blackstone, Sr. was an American magician who entertained audiences at the turn of the 20th century and into the 1950s. Nicknamed the Great Blackstone, he was noted for performing the dancing handkerchief, the vanishing birdcage, and the floating light bulb (see magic). (Read Harry Houdini’s

Rutland Boughton was a composer of operas, and the principal English advocate of the theories of music drama expounded by Richard Wagner. Boughton studied at the Royal College of Music in 1900 but was otherwise self-taught. He had the idea of writing a series of music dramas based on Arthurian

Bejaïa, town, Mediterranean Sea port, northeastern Algeria. The town lies at the mouth of the Wadi Soummam. Sheltered by Mount Gouraya (2,165 feet [660 metres]) and Cape Carbon, it receives an annual average rainfall of 40 inches (1,000 mm) and is surrounded by a fertile plain. The older town,

gravity: Gravimetric surveys and geophysics: This is commonly called the Bouguer correction factor.

colorimetry: …which is also known as Lambert’s law, relates the amount of light absorbed and the distance it travels through an absorbing medium; and Beer’s law relates light absorption and the concentration of the absorbing substance. The two laws may be combined and expressed by the equation log I0/I = kcd,…

Pierre Bouguer was a versatile French scientist best remembered as one of the founders of photometry, the measurement of light intensities. Bouguer was a prodigy trained by his father, Jean Bouguer, in hydrography and mathematics. Upon his father’s death, Pierre—at age 15—succeeded the elder

William-Adolphe Bouguereau was a French painter, a dominant figure in his nation’s academic painting during the second half of the 19th century. Bouguereau entered the École des Beaux-Arts in 1846 and was awarded the Prix de Rome in 1850. Upon his return to France from four years’ study in Italy,

Third Cinema: …Third Cinema was Algerian filmmaker Abderrahmane Bouguermouh’s La Colline oubliée (1997; The Forgotten Hillside), which was shot in the Berber language and treated the traditional ways of its mountain-dwelling characters with ambivalence.

T4 Program: Karl Brandt and Chancellery chief Philipp Bouhler were “charged with responsibility for expanding the authority of physicians…so that patients considered incurable, according to the best available human judgment of their state of health, can be granted a mercy killing.”

bouillabaisse, complex fish soup originating on the Mediterranean coast of France, one of the glories of Provençal cuisine. Recipes for bouillabaisse abound, but the Marseilles formulation is generally acknowledged as being the most authentic; it contains, besides fish and shellfish, olive oil,

Jean-Baptiste Bouillaud was a French physician and medical researcher who was the first to establish clinically that the centre of speech is located in the anterior lobes of the brain. He was also the first to differentiate between loss of speech resulting from the inability to create word forms

Bouillon, ancient town in Wallonia Region, southeastern Belgium, lying on the Semois River in the Ardennes. It was long known for the ducal title connected with it. Bouillon in the 11th century was held by the counts of Ardennes, whom the German kings invested with the dukedom of Lower Lorraine.

Bouira, town, north-central Algeria. Bouira is situated southwest of the Great Kabylie mountain region, near the watershed of the Isser and Soummam wadis and 58 miles (93 km) southeast of Algiers. Bouira (Arabic: “The Small Wells”) is a market centre for a low-yield olive- and cereal-producing

Cape Bojador, extension of the West African coast into the Atlantic Ocean, now part of Western Sahara. Located on a dangerous reef-lined stretch of the coast, its Arabic name, Abū Khaṭar, means “the father of danger.” Early European navigators called it “the point of no return” until it was first

Blaise Compaoré: Jean-Baptiste Lingani and Capt. Henri Zongo—helped organize the coup and the resulting regime, and all held positions of leadership in the country. Compaoré served as minister of state at the presidency (1983–87), essentially making him second in command in the regime, and also as minister…

Houari Boumedienne was an army officer who became president of Algeria in July 1965 following a coup d’etat. Boukharouba’s service to Algeria began in the 1950s, during his country’s struggle for independence from France, when, after studying at al-Azhar University in Cairo, he joined the rebel

boule, deliberative council in ancient Greece. It probably derived from an advisory body of nobles, as reflected in the Homeric poems. A boule existed in virtually every constitutional city-state and is recorded from the end of the 6th century bce at Corinth, Argos, Athens, Chios, and Cyrene. It

Blida, town, northern Algeria. It lies on the southern edge of the Mitidja plain at the base of the Tell Atlas Mountains and is about 30 miles (48 km) southwest of Algiers. French in character, the town is surrounded by orchards, trades in oranges and flour, and has light manufacturing. The Wadi

Henri de Boulainvilliers, count de Saint-Saire was a French historian and political writer who set forth a broad cultural conception of philosophical history that influenced intellectual developments in the 18th century. He was among the first modern historians to claim that historical studies can

restaurant: …believed to have been one A. Boulanger, a soup vendor, who opened his business in Paris in 1765. The sign above his door advertised restoratives, or restaurants, referring to the soups and broths available within. The institution took its name from that sign, and restaurant now denotes a public eating…

Georges Boulanger was a French general, minister of war, and political figure who led a brief but influential authoritarian movement that threatened to topple the Third Republic in the 1880s. A graduate of the Saint-Cyr Military Academy, he entered the army in 1856 and saw service in Italy,

Georges Boulanger was a French general, minister of war, and political figure who led a brief but influential authoritarian movement that threatened to topple the Third Republic in the 1880s. A graduate of the Saint-Cyr Military Academy, he entered the army in 1856 and saw service in Italy,

Nadia Boulanger was a conductor, organist, and one of the most influential teachers of musical composition of the 20th century. Boulanger’s family had been associated for two generations with the Paris Conservatory, where her father and first instructor, Ernest Boulanger, was a teacher of voice.

harbours and sea works: Breakwater design: …an outer covering of larger boulders, or armouring, to protect it from removal by the sea. The design of this outer armouring has fostered considerable ingenuity. The larger the blocks, the less likely they are to be disturbed, but the greater the cost of placing them in position and of…

Boulder, city, seat (1861) of Boulder county, north-central Colorado, U.S., on Boulder Creek, at the base of the Flatiron Range of the Rocky Mountains, at an elevation of 5,354 feet (1,632 metres), 30 miles (48 km) northwest of Denver. Settled by miners in 1858, it was organized in 1859 and named

Kalgoorlie-Boulder: …of the neighbouring towns of Boulder and Kalgoorlie in 1989, it is the principal settlement of the East Coolgardie goldfield, on the western fringe of the Nullarbor Plain and the Great Victoria Desert.

Colorado River: Economic development: …1928, when Congress passed the Boulder Canyon Project Act. The act authorized the construction of Boulder (now Hoover) Dam, a multipurpose water-storage project that was a major engineering feat of its time; since its completion in 1936, the dam and Lake Mead, which it created with its impounded waters, have…

Boulder City, city, Clark county, southeastern Nevada, U.S., overlooking Lake Mead, which is impounded by the Hoover Dam. Lying above the deep, narrow Black and Boulder canyons of the Colorado River on the Nevada-Arizona border, it was established in 1931 by the federal government as a residential

till, in geology, unsorted material deposited directly by glacial ice and showing no stratification. Till is sometimes called boulder clay because it is composed of clay, boulders of intermediate sizes, or a mixture of these. The rock fragments are usually angular and sharp rather than rounded,

Hoover Dam, dam in Black Canyon on the Colorado River, at the Arizona-Nevada border, U.S. Constructed between 1930 and 1936, it is the highest concrete arch-gravity dam in the United States. It impounds Lake Mead, which extends for 115 miles (185 km) upstream and is one of the largest artificial

Natalia Grossman: …of the leading competitors in bouldering. A standout from an early age, Grossman won her first world championship in 2021 at age 20. She also has excelled in lead climbing and competes in combined and speed events.