ball-and-socket joint, in engineering, mechanical connection used between parts that must be allowed some relative angular motion in nearly all directions. As the name implies, the joint consists essentially of a spherical knob at the end of a shaft, with the knob fitting securely into a mating socket. Like other mechanical joints, a ball-and-socket joint must have some provision for lubrication and is normally provided with a seal to prevent loss of the lubricant. Joints of this type are commonly used in mounting the front wheels of automobiles, allowing these wheels movement sufficient for steering. In this application they are usually called ball joints.

ball joint: see ball-and-socket joint.

ball bearing: see bearing.

Ball, Thomas, 1819-1911, American sculptor, b. Charlestown, Mass.; son of a house and sign painter. Thomas Ball was also a singer of reputation, the first in the United States to sing the title role in Mendelssohn's Elijah. Although he lived many years in Florence, Ball's work remained distinctly American. He made portrait busts of many distinguished people. Among his works are the mounted figure of Washington in the Boston Public Gardens and a statue of Daniel Webster in Central Park, New York. His autobiography, My Three Score Years and Ten, appeared in 1890.

Ball, Lucille, 1911-89, American actress and producer, b. Celoron, N.Y. At first promoted by Hollywood as another glamorous movie star, Ball was often cast as a spunky sidekick in second features. In 1951, as one of the first movie stars to headline a television series, she scored a spectacular success with the comedy I Love Lucy, costarring her first husband, Desi Arnaz. For six seasons she was the most popular female star of the small screen, which was an ideal showcase for her comic energy, flair for slapstick, and gift for vocal mimicry. She went on to star in two subsequent but less successful sitcoms, the last of which ended in 1974. Ball also headed Desilu Productions (1962-67) and Lucille Ball Productions (1967-89). Her films include Stage Door (1937) and Mame (1974).

Ball, John, d. 1381, English priest and social reformer. He was one of the instigators of the Peasant's Revolt of 1381 (see under Tyler, Wat). He was an itinerant for many years, acting independently of the influence of John Wyclif and advocating ecclesiastical poverty and social equality. Excommunicated in 1376, he was in prison at Maidstone when the rebels released him in 1381. After the dispersal of the rebels, Ball was captured at Coventry. He was taken to St. Albans, where he was hanged, drawn, and quartered. He is perhaps best remembered for giving currency to the couplet "When Adam delved and Eve span/Who was then the gentleman?" William Morris wrote one of his works on utopian socialism under the title The Dream of John Ball.

Ball, George Wildman, 1909-94, American lawyer and diplomat, b. Des Moines, Iowa. Admitted to the bar in 1934, he served (1942-44) as counsel in the Lend Lease Administration and the Foreign Economic Administration. An expert on economic foreign policy, Ball became (1961) Undersecretary of State for Economic Affairs and then served (1961-66) as Undersecretary of State. During that period he played a major role in formulating U.S. foreign aid and foreign trade policy and was the chief architect of the Trade Agreements Act of 1962. A persistent critic of U.S. military involvement in Vietnam, Ball left the State Department to become (1966-68) chairman of Lehman Brothers, a major investment banking firm. After briefly serving (1968) as U.S. representative to the United Nations, he returned to Lehman Brothers as a senior partner. Ball is the author of The Discipline of Power (1968).

Ball State University, at Muncie, Ind.; coeducational; founded 1918 as a state institution. In 1929 it became Ball State Teachers College and in 1965 achieved university status.

Game resembling baseball but played on a smaller diamond with a larger ball (12 in. [30.5 cm] in circumference), which is pitched underhand. Since the first standard set of rules was published in the 1920s, the game has been popular as an amateur sport in the U.S., and since the 1960s it has grown considerably in popularity outside of North America. In U.S. high schools and colleges it is a popular women's sport; a women's softball competition was added to the Olympic Games in 1996.

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One of the two types of rolling, or antifriction, bearings (the other is the roller bearing). Its function is to connect two machine members that move relative to one another so that the frictional resistance to motion is minimal. In many applications, one of the members is a rotating shaft and the other a fixed housing. Each ball bearing has three main parts: two grooved, ringlike races and a number of balls. The balls fill the space between the two races and roll with negligible friction in the grooves. The balls may be loosely restrained and separated by means of a retainer or cage.

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(born Aug. 6, 1911, Celoron, near Jamestown, N.Y., U.S.—died April 26, 1989, Los Angeles, Calif.) U.S. actress and television star. She performed in films from 1933 and starred in a comedy radio series from 1947. With her bandleader husband, Desi Arnaz, she created the very successful television comedy series I Love Lucy (1951–57) and later the Lucy-Desi Comedy Hour (1957–60). After their divorce in 1960, Ball appeared in The Lucy Show (1962–68) and Here's Lucy (1968–74). With her red hair and rasping voice and a comic persona alternately brassy and feminine, she was the preeminent female star of the early decades of television.

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(born Aug. 6, 1911, Celoron, near Jamestown, N.Y., U.S.—died April 26, 1989, Los Angeles, Calif.) U.S. actress and television star. She performed in films from 1933 and starred in a comedy radio series from 1947. With her bandleader husband, Desi Arnaz, she created the very successful television comedy series I Love Lucy (1951–57) and later the Lucy-Desi Comedy Hour (1957–60). After their divorce in 1960, Ball appeared in The Lucy Show (1962–68) and Here's Lucy (1968–74). With her red hair and rasping voice and a comic persona alternately brassy and feminine, she was the preeminent female star of the early decades of television.

Learn more about Ball, Lucille (Désirée) with a free trial on Britannica.com.