roller-skating Recreation and sport in which the participants use roller skates (shoes with sets of wheels attached) to move about on special rinks or paved surfaces. The invention of roller skates is traditionally credited to the Belgian Joseph Merlin in the 1760s, but the first practical four- wheel skate was designed in 1863 by James Plimpton of Medford, Mass. Roller-skating speed events became popular in the early 20th century. Later, team competitions in “roller derbies” on banked tracks became a spectator sport. Other roller-skate contests, such as acrobatics and hockey, followed. In the late 20th century, roller skates gave way to in-line (Roll- erblade) skates, in which a single row of wheels is used in place of the standard rectangular configuration.
Rolle's theorem \Tolz\ Special case of the mean-value theorem of dif¬ ferential calculus. It states that if a continuous curve passes through the x-axis twice within a given interval and has a unique tangent line at every point of that interval, then somewhere between the two points of inter¬ ception it has a tangent parallel to the x-axis.
rolling In technology, the main method of forming molten metals, glass, or other substances into shapes that are small in cross-section in com¬ parison with their length, such as bars, sheets, rods, rails, and girders. Rolling is the most widely used method of shaping metals and is particu¬ larly important in the manufacture of steel. The process consists of pass¬ ing the metal between pairs of rollers revolving at the same speed but in opposite directions and spaced so that the distance between them is slightly less than the thickness of the metal.
Rolling Stones British musical group. Its original members were Mick Jagger (b. 1943), Keith Richards (b. 1943), Brian Jones (1944-69), Bill Wyman (b. 1936), and Charlie Watts (b. 1941). The band was formed in 1962 when Jagger, Richards, and Jones, who had been performing spo¬ radically in a blues band, recruited Wyman and formed their own group. Watts joined the band in 1963. Jagger was the lead vocalist, while Jones and Richards played guitars, Wyman played bass, and Watts played drums. The band’s name was adopted from a Muddy Waters song. By 1966 a series of outstanding songs had made the band second in popularity only to the Beatles. Jagger and Richards wrote most of its songs, which are marked by a driving backbeat, biting and satirical lyrics, and simple but expressive instrumental accompaniments. The group reached the height of its popularity with albums such as Beggar’s Banquet (1968) and Exile on Main Street (1972). Jones was succeeded by Mick Taylor (b. 1948) in 1969, who was replaced in turn by Ron Wood (b. 1947) in 1976. They continued to perform long after the other classic rock bands of the 1960s disbanded.
Rollins, Sonny orig. Theodore Walter Rollins (b. Sept. 7, 1930, New York, N.Y., U.S.) U.S. jazz saxophonist and composer. Rollins was inspired by Coleman Hawkins and Charlie Parker and performed with many musicians in the late 1940s, including Miles Davis. A member of the Clifford Brown-Max Roach quintet in 1955-57, he later formed his own groups. Rollins’s robust tone and technical dexterity are matched with athletic endurance in the service of the logical evolution of ideas in his solos.
Rollo (b. c. 860—d. c. 932) Scandinavian rover who founded the duchy of Normandy. After raiding Scotland, England, Flanders, and France on pirating expeditions, he took lands along the Seine River as his base (c. 911). He battled Charles III of France, who gave him, in return for Rol¬ lo’s promise to stop pillaging, the part of Neustria that came to be called Normandy.
Rolls-Royce PLC British manufacturer of aircraft engines and propul¬ sion and power systems and, for much of the 20th century, a maker of luxury automobiles. Charles S. Rolls, a pioneer motorist and aviator, and Henry Royce, an engineer and carmaker, incorporated Rolls-Royce Ltd. in 1906. The firm’s handsome, immaculately engineered cars included the Silver Ghost (introduced 1906 as “40/50 hp” model), a series of Phan¬ toms (1925), the Silver Dawn (1949), Silver Cloud (1955), Silver Shadow (1965), and Silver Seraph (1998). In 1931 Rolls-Royce acquired Bentley
Motors Ltd., another maker of fine cars. Rolls-Royce also developed a series of notable piston and jet aircraft engines, beginning with the Eagle (1914); eventually its turbine-engine operations accounted for the largest part of its sales. A fixed-price contract with Lockheed Aircraft (see Lock¬ heed Martin Corp.) to produce an engine for its L-1011 TriStar jetliner drove Rolls-Royce into bankruptcy in 1971. It was split into two compa¬ nies; its jet-engine division was taken over by the British government and later privatized as Rolls-Royce PLC, while its automobile operations were restructured into Rolls-Royce Motor Holdings Ltd. and privatized. The latter was acquired in 1980 by Vickers Ltd., which sold it to Volkswagen AG in 1998 as part of a novel agreement in which BMW AG would take over the manufacture of cars with the Rolls-Royce name in 2003, while Volkswagen retained the Bentley line.
Rolvaag Vrol-.vagV Ole (Edvart) (b. April 22, 1876, Donna Island, Helgeland, Nor.—d. Nov. 5, 1931, Northfield, Minn., U.S.) Norwegian- born U.S. novelist and educator. He immigrated to the U.S. in 1896 and spent most of his life at St. Olaf College (Northfield, Minn.), teaching Norwegian language and literature and the history of Norwegian immi¬ gration. His works, written in Norwegian, are noted for their realistic por¬ trayals of Norwegian settlers on the Dakota prairies and of the clash between transplanted and native cultures in the U.S. His best-known work is Giants in the Earth (1927), a translation of two of his novels.
ROM \'ram\ in full read-only memory Form of computer memory that does not lose its contents when the power supply is cut off and that is not rewritable once it is manufactured or written. It is generally employed for programs designed for repeated use without modification, such as the start-up procedures of a personal computer; the ROM is used for storing the program used in the control unit of the computer. See also CD-ROM, COMPACT DISC.
Rom or Gypsy plural Roma Any member of a people originating in northern India but now living worldwide, principally in Europe. Most speak Romany in addition to the local language. It is thought that Roma groups left India in successive migrations, reaching western Europe by the 15th century. In the 20th century they spread to North and South America and Australia. Because of their often nomadic and marginalized lives, population figures are largely guesswork; estimates in the early 21st century range from two to three million. They have often been persecuted and harassed; the Nazis killed about 400,000 Roma in extermination camps. How many Roma retain a nomadic lifestyle is unclear, but those that migrate do so at least seasonally along patterned routes that ignore national boundaries. They pursue occupations compatible with a nomadic life. In the past they were often livestock traders, tinkers, fortune-tellers, and entertainers; today they are often car mechanics, auto-body repair¬ men, and workers in traveling circuses and amusement parks. Confed¬ erations of 10-100 families elect chieftains for life, but their title is not heritable. Women are organized as a group within the confederation and represented by a senior woman. Modem Roma culture faces erosion from urban influences; integrated housing, economic independence, and inter¬ marriage with non-Roma have weakened Roma law.
Romains Vro-'maA, Jules orig. Louis-Henri-Jean Farigoule (b.
Aug. 26, 1885, Saint-Julien-Chapteuil, France—d. Aug. 14, 1972, Paris) French novelist, dramatist, and poet. A teacher of philosophy, Romains first became known as a poet and as founder (c. 1908-11), with Georges Chenneviere, of the literary movement Unanimisme, which combined belief in universal brotherhood with the psychological concept of group consciousness. His most popular work was the comedy Knock (1923), a satire on doctors. His masterpiece, Men of Good Will, 27 vol. (1932-46), is a vast novel cycle attempting to recreate the spirit of French society from 1908 to 1933 and exemplifying the Unanimiste interest in collec¬ tive life.