Lualaba V.lu-a-'la-biA River River, central Africa. It is the headstream of the Congo River, and its 1,100-mi (1,800-km) course lies entirely within the Democratic Republic of the Congo. It is harnessed in places for hydro¬ electric power.
Luan \lu-'wan\ River River, Hebei province, northeastern China. It rises in eastern Inner Mongolia and flows north, then curves to the southeast. It passes through the Great Wall and divides into a number of smaller rivers, discharging into the Bo Hai (Gulf of Chihli) after a course of 545 mi (877 km). The river is navigable below Chengde.
Luanda \lu-'an-d3\ or Loanda \lo-'an-d3\ City (pop., 1999 est.: 2,555,000), capital of Angola. Situated on the Atlantic coast, it is Ango¬ la’s largest city and its second busiest seaport. Founded in 1576 by Paulo Dias de Novais, it became the administrative centre for the colony of
Angola in 1627. It was a major out¬ let for slave traffic to Brazil until the 19th century. It is a commercial and industrial area, with oil-refining capacity. It is the seat of the Univer¬ sity of Luanda; the old fortress of Sao Miguel lies beyond the port. It was damaged during the persistent Angolan civil war that ended in
Luang Pradist Manudharm
See Pridi Phanomyong
Luba or Baluba Cluster of some 5.6 million Bantu-speaking peoples who share a common political his¬ tory surrounding the Luba-Lunda states. They are savanna and forest dwellers who hunt and gather, engage in agriculture, and keep live¬ stock; they also fish intensively in the Congo and its tributaries. They have associations for hunting, magic, and medicine and a well-developed oral tradition that includes epic cycles. Two groups are noted as wood-carvers.
Luba-Lunda states Vlii-bo- 'liin-doV Complex of states that flour¬ ished in Central Africa in the 16th— 19th centuries. In the late 15th century a small group of ivory hunt-
Female Luba ancestral statue of carved wood; in the Musee de I'Homme, Paris.
COURTESY OF THE MUSEE DE L'HOMME, PARIS
© 2006 Encyclopaedia Britannica, Inc.
Lubbock ► Luce I 1145
ers founded a state around which a number of satellites proliferated, spreading by the 17th century into the southern Congo Basin and what are now western Angola, and Zambia. The northeastern portion was inhab¬ ited by the Luba; the southwestern portion by the Lunda. These groups traded slaves and ivory to the Portuguese for cloth and other goods. In the 18th century migrants founded Kazembe farther southeast; it flour¬ ished until late in the 19th century, when it was colonized by the British.
Lubbock Vb-bakA City (pop., 2000: 199,564), northwestern Texas, U.S. Located south of Amarillo, it was named for Tom S. Lubbock, a signer of the Texas declaration of independence. Formed in 1890 from Old Lub¬ bock and Monterey, it developed as a ranching centre and was incorpo¬ rated in 1909. A tornado in 1970 caused widespread damage. It is one of the nation’s leading cotton markets and the centre of a diversified agri¬ cultural and industrial region. It is the seat of Texas Tech University
(1923).
Lubeck Vlui-.bekX City (population 2002 est.: 213,486), northern Ger¬ many. Founded on the site of a Slavic settlement in 1143, it developed as a trading post. It became a free city in 1226 and the seat of the Hanseatic League in 1358. It declined after the 16th century, and its trade was ruined during the Napoleonic Wars. It revived after the Elbe-Liibeck canal was built in 1900. Its status as a self-governing entity ended in 1937, when the Nazis made it part of the Prussian province of Schleswig-Holstein. It is one of Germany’s largest Baltic ports. Historic sites include a 12th- century cathedral and several Gothic churches.
Lubitsch Vlu-bich\, Ernst (b. Jan. 28, 1892, Berlin, Ger.—d. Nov. 30, 1947, Hollywood, Calif., U.S.) German-U.S. film director. He acted with Max Reinhardt’s German stage company (1911-14) and in short film com¬ edies, then turned to directing costume dramas that were the first German films shown abroad, including Passion (1919), Deception (1920), and The Loves of Pharaoh (1921), as well as comedies such as The Doll (1919) and The Oyster Princess (1919). He moved to Hollywood in 1923 and developed a style of sophisticated wit and unerring narrative timing —the famous “Lubitsch touch”—in successful comedies such as The Marriage Circle (1924), The Love Parade (1929), Trouble in Paradise (1932), Ninotchka (1939), The Shop Around the Corner (1940), To Be or Not to Be (1942), and Heaven Can Wait (1943).
Lublin \'lu-blin\ City (pop., 2000 est.: 355,803), eastern Poland, situated on the Bystrzyca River. Founded as a stronghold in the late 9th century, the settlement received town rights in 1317. In 1795 it passed to Austria and in 1815 to Russia. In 1918 the first independent temporary Polish government was proclaimed in Lublin. In World War II the Nazi concen¬ tration camp Majdanek was established in one of its suburbs. After the war Lublin served briefly as the seat of the national government. It is now an industrial and cultural centre for southeastern Poland.
lubrication Introduction of any of various substances between sliding surfaces to reduce wear and friction. Lubricants may secondarily control corrosion, regulate temperature, electrically insulate, remove contami¬ nants, or damp shock. Prehistoric peoples used mud and reeds to lubri¬ cate sledges, timbers, or rocks. Animal fat lubricated the axles of the first wagons and continued in wide use until crude oil became the chief source of lubricants. Crude oil has been the basis of products designed for the specific lubricating needs of automobiles, aircraft, locomotives, turbojets, and all other power machinery. There are three basic varieties of lubri¬ cation: fluid-film (in which a fluid film completely separates sliding sur¬ faces), boundary (in which the friction between surfaces is determined by the properties of the surfaces and properties of the lubricant other than viscosity), and solid (used when liquid lubricants lack adequate resistance to load or temperature extremes). The principal lubricants are liquid, oily materials (petroleum-based or synthetic, and including greases); solids (such as graphite, molybdenum disulfide, soft metals, waxes, and plas¬ tics); and gases.
Lubumbashi V.lii-biim-'ba-sh e\ formerly (until 1966) Elisabethville City (pop., 1994 est.: 851,381), Democratic Republic of the Congo. It was established by Belgian colonists in 1910 near the border with Zambia and grew to become the centre of one of the world’s largest copper mining and smelting operations. It was the centre of Katanga province’s seces¬ sion movement in the early 1960s.
Luca da Cortona See Luca Signorelli
Lucas, George (b. May 14, 1944, Modesto, Calif., U.S.) Film direc¬ tor and producer. He studied filmmaking at the University of Southern
California. His first feature film, THX 1138 (1971), was followed by the surprise success American Graffiti (1973). He wrote and directed the immensely popular science-fiction movie Star Wars (1977), which made innovative use of computerized special effects. He formed the production company Lucasfilms (1978) and its special-effects division Industrial Light and Magic and produced the Star Wars sequels —The Empire Strikes Back (1980) and The Return of the Jedi (1993)—as well as Steven Spiel¬ berg’s Raiders of the Lost Ark (1981) and its sequels. He returned to directing with the first Star Wars prequel, The Phantom Menace (1999), which was followed by the other prequels Attack of the Clones (2002) and Revenge of the Sith (2005).