boring machine Machine tool for producing smooth and accurate holes in a workpiece by enlarging existing holes with a cutting tool, which may bear a single tip of steel,
Lucrezia Borgia, detail from the fresco the "Dispute of St. Catherine, " by Pintu- ricchio, 1492-94; in the Vatican.
AUNARI/ART RESOURCE, NEW YORK
Gutzon Borglum.
COURTESY OF THE LIBRARY OF CONGRESS, WASHINGTON, D.C.
cemented carbide, or diamond or may be a small grinding wheel. The hole’s diameter is controlled by adjusting the boring head. Bored holes are more accurate in roundness, concentricity, and parallelism than drilled holes. Boring machines used in toolmaking shops have a vertical spindle and a work-holding table that moves horizontally in two perpendicular directions so that holes can be accurately spaced. In mass-production plants, boring machines with multiple spindles are common. See also drill; drill press; lathe.
Boris I orig. Mikhail (d. May 2, 907, Preslave, Bulg.) Khan of Bul¬ garia (852-89). He resolved to use Christianity to unite his ethnically divided country, and an unsuccessful war with the Byzantines led to his baptism in the Orthodox faith (864). Boris’s attempt to enforce mass bap¬ tism set off a pagan rebellion, which he quelled, and he helped establish the Bulgarian church. He sponsored missionaries to foster Slavic learn¬ ing and the use of the Old Church Slavic language. He abdicated in 889 to become a monk but returned to drive his reactionary son Vladimir from the throne. After installing another son, Simeon I, as khan, Boris went back to his monastery. He was later made an Orthodox saint.
Boris Godunov See Boris Godunov
Borlaug Vb6r-,l6g\, Norman (Ernest) (b. March 25, 1914, Cresco, Iowa, U.S.) U.S. agricultural scientist and plant pathologist. He earned his Ph.D. at the University of Minnesota. As a researcher with the Rock¬ efeller Foundation in Mexico (1944-60), he developed strains of grain that tripled Mexican wheat production. Later his dwarf wheats raised har¬ vests in Pakistan and India by 60%, ending the food shortages that had plagued the subcontinent in the 1960s. For helping lay the groundwork of the Green Revolution, he was awarded the Nobel Prize for Peace in 1970. Afterward he worked on improving crop yields in Africa and taught at Texas A&M University.
Bormann Vbor-.manX, Martin (b. June 17, 1900, Halberstadt, German Empire—d. May 1945, Berlin, Ger.) German Nazi leader. He joined the Nazi party in 1925 and served as Rudolf Hess’s chief of staff (1933^-1). He was appointed head of the party chancellery in 1941 and became one of Adolf Hitler’s closest lieutenants. A shadowy but extremely powerful presence, Bormann controlled all legislation, party promotions and appointments, and the personal access of others to Hitler. He disappeared shortly after Hitler’s death. Though some reports allege that he escaped to South America, German authorities officially declared him dead after exhuming his presumed remains.
Born, Max (b. Dec. 11, 1882, Breslau, Ger.—d. Jan. 5, 1970, Gottin¬ gen, W.Ger.) German physicist. He taught theoretical physics at the Uni¬ versity of Gottingen from 1921 to 1933, when he fled to Britain. There he taught principally at the Univer¬ sity of Edinburgh (1936-53). In 1921 he gave a very precise defini¬ tion of quantity of heat, the most sat¬ isfactory mathematical statement of the first law of thermodynamics. In 1926 he collaborated with his stu¬ dent Werner Heisenberg to develop the mathematical formulation that would adequately describe Heisen¬ berg’s first laws of a new quantum theory. He later showed, in the work for which he is perhaps best known, that the solution of the Schrodinger equation has a statistical meaning of Max Born physical significance. His later work concerned the scattering of atomic particles and calculations dealing
with the electronic structures of molecules. In 1954 he shared a Nobel Prize for Physics with Walther Bothe (1891-1957).
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Borneo Island, Malay Archipelago. Bounded by the South China Sea, the Sulu and Celebes seas, the Makassar Strait, and the Java Sea, it is the third largest island in the world, measuring 290,320 sq mi (751,929 sq km). The northern part includes the Malaysian states of Sabah and Sarawak and the sultanate of Brunei; the southern section forms part of Indonesia. Borneo is mountainous and largely covered in dense rainforest; its high¬ est point is Mount Kinabalu, at 13,455 ft (4,101 m). Much of it is drained
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Bornholm ► borzoi I 253
by navigable rivers, including the Rajang, which are the principal life¬ lines of trade and commerce. It is mentioned in Ptolemy’s Guide to Geog¬ raphy (c. ad 150); Roman trade beads give evidence of an earlier civilization. Brahman and Buddhist images in the Gupta style indicate the influence of Indians who apparently arrived in the 5th century. With the arrival of Islam in the 16th century, various Muslim kingdoms were founded, some of which owed allegiance to Java. Around the same time, the Portuguese, followed by the Spanish, set up trading stations. In the early 17th century the Dutch broke the Portuguese-Spanish monopoly, but they in turn had to deal with newly established British interests. After World War II, Sarawak and North Borneo (later Sabah) became British crown colonies. Strong nationalist sentiment emerged in Dutch Borneo, and sovereignty passed to Indonesia in 1949. The British relinquished Sabah and Sarawak to the Malaysian federation in 1963, while Brunei became independent in 1984.
Bornholm Island (pop., 2001: 44,126), Denmark. Lying in the Baltic Sea south of Sweden, it has an area of 227 sq mi (588 sq km). Its seat is at Rpnne. Once a Viking stronghold, it was seized by the Hanseatic League in 1510. Until 1660 it was held for varying periods by Sweden and Den¬ mark, but it has since been Danish. It is now a popular tourist resort.
bornite Common copper-ore mineral, copper and iron sulfide (Cu 5 FeS 4 ). Typical occurrences are found in Mount Lyell, Tasmania; Chile; Peru; and Butte, Mont. Bornite may form isometric crystals but occurs most commonly as irregular masses. Under appropriate geologic conditions, it alters to chalcocite and other copper minerals.
Bornu Historical region, northeastern Nigeria. Prominent physical fea¬ tures include a vast plain, a volcanic plateau, and swamps south of Lake Chad. Now inhabited chiefly by the Kanuri people, it constituted a Mus¬ lim kingdom from about the 11th century. Together with Kanem it later formed an empire (see Kanem-Bornu), which reached the height of its power c. 1570-1600. In 1902 it became part of Nigeria, which was then under British rule. The region is largely contained in Nigeria’s present- day state of Borno.
Borobudur N.bo-ro-bii-'durV Buddhist monument in central Java, built c. 778-850 under the Shailendra dynasty. Constructed with about 2 million cu ft (57,000 cu m) of gray volcanic stone, it resembles a stepped pyramid. Its base and first five ter¬ races are square; the highest three ter¬ races are circular. Reliefs on its terrace walls represent the ascending stages of enlightenment. The simple and spacious upper circular terraces carry 72 bell-shaped stupas, each con¬ taining a statue of the Buddha.
Borodin \,b6r-9-'den\, Aleksandr (Porfiryevich) (b. Nov. 12, 1833, St. Petersburg, Russia—d. Feb. 27, 1887, St. Petersburg) Russian composer. From 1862 he took lessons from Mily Balakirev; fired by nation¬ alist sentiment, the two men became the core of the group of Russian composers known as The Five. A professor of chemistry for much of his life, he left a small compositional output, which includes the orchestral suite In the Steppes of Central Asia (1880), two string quartets, and three symphonies, the second of which has remained highly popular. His opera Prince Igor —which contains the often-heard “Polovtsian Dances”—was left unfinished after 18 years of intermittent work.