optics: Historical background: In 1957 the Italian physicist Vasco Ronchi went the other way and defined an image as any recognizable nonuniformity in the light distribution over a surface such as a screen or film; the sharper the image, the greater the degree of nonuniformity. Today, the concept of an image often departs…

Ronda, town, Málaga provincia (province), in the Andalusia comunidad autónoma (autonomous community), southern Spain. It lies in the Ronda Mountains west of Málaga city. The town is situated on two hills divided by a deep ravine (El Tajo de Ronda) containing the Grande River, which is an affluent

Riccardo Bacchelli: …on the Roman literary periodical La Ronda, he attempted to discredit contemporary avant-garde writers by holding up as models the Renaissance masters and such fine 19th-century writers as Giacomo Leopardi and Alessandro Manzoni. Somewhat later he was drama critic for the Milanese review La fiera letteraria.

Rondane, mountain range in Oppland and Hedmark fylker (counties), south-central Norway. For the most part dry, the range has several small glaciers around its highest peaks, which average 7,000 feet (2,100 metre); Rondeslottet, at 7,146 feet (2,178 metre), is the highest point. Most of the area is

Rondane National Park, park in south-central Norway established as a nature preserve in December 1962 by royal decree; by a law of 1970 the area became a national park. The park covers an area of 221 square miles (572 square km), with a range of elevation of from 3,000 to 7,000 feet (900 to 2,100

Rondane National Park, park in south-central Norway established as a nature preserve in December 1962 by royal decree; by a law of 1970 the area became a national park. The park covers an area of 221 square miles (572 square km), with a range of elevation of from 3,000 to 7,000 feet (900 to 2,100

African architecture: Savanna kraals and compounds: … tend toward a consistent form—the rondavel, or cylindrical, single-cell house with a conical thatched roof. This type is prevalent throughout Southern Africa. Variants in the region include a low plinth or curb supporting a domed roof (some Swazi and Zulu), flattened domes or low-pitched cones on head-height cylinders, and high,…

La campanella, final movement of the Violin Concerto No. 2 in B Minor, Op. 7, by Italian composer and violinist Niccolò Paganini, renowned for its intricate and technically demanding solo passages and for the bell-like effects featured in both the solo and orchestral parts. The movement derives its

rondeau, one of several formes fixes (“fixed forms”) in French lyric poetry and song of the 14th and 15th centuries. The full form of a rondeau consists of four stanzas. The first and last are identical; the second half of the second stanza is a short refrain, which has as its text the first half

rondel, a fixed poetic form that runs on two rhymes. It is a variant of the rondeau. The rondel often consists of 14 lines of 8 or 10 syllables divided into three stanzas (two quatrains and a sextet), with the first two lines of the first stanza serving as the refrain of the second and third

Guillaume Rondelet was a French naturalist and physician who contributed substantially to zoology by his descriptions of marine animals, primarily of the Mediterranean Sea. Rondelet’s book, Libri de Piscibus Marinis (1554–55; “Book of Marine Fish”), contains detailed descriptions of nearly 250

rondel, a fixed poetic form that runs on two rhymes. It is a variant of the rondeau. The rondel often consists of 14 lines of 8 or 10 syllables divided into three stanzas (two quatrains and a sextet), with the first two lines of the first stanza serving as the refrain of the second and third

Giacomo Puccini: Mature work and fame: …Monte-Carlo in Monaco, Puccini’s opera La rondine was first performed and then was quickly forgotten.

rondo, in music, an instrumental form characterized by the initial statement and subsequent restatement of a particular melody or section, the various statements of which are separated by contrasting material. Although any piece built upon this basic plan of alternation or digression and return may

bush baby: Even smaller is the Rondo bush baby (P. rondoensis), first described in 1997, which weighs just 60 grams and is restricted to a few coastal forests in southeastern Tanzania.

Cândido Rondon was a Brazilian explorer and protector of indigenous people. As a young soldier, he was assigned to extend telegraph lines into the Brazilian backlands. In 1913–14 he and U.S. Pres. Theodore Roosevelt headed an expedition that explored a tributary of the Madeira River. In both these

Cândido Rondon was a Brazilian explorer and protector of indigenous people. As a young soldier, he was assigned to extend telegraph lines into the Brazilian backlands. In 1913–14 he and U.S. Pres. Theodore Roosevelt headed an expedition that explored a tributary of the Madeira River. In both these

Rondônia, estado (state), west-central Brazil, bordering Bolivia to the south and west, Amazonas state to the north, and Mato Grosso state on the east. Formerly a part of Amazonas, it was established in 1943 as Guaporé territory, which was renamed in 1956 after Marshal Cândido Mariano da Silva

the Ronettes, American girl group whose single “Be My Baby” (1963) was one of the defining songs of the girl-group era. The Ronettes were formed in 1959 by sisters Ronnie Bennett (byname of Veronica Bennett, later Ronnie Spector; b. August 10, 1943, New York City, New York, U.S.—d. January 12,

Canadian literature: Contemporary trends: Jean-Pierre Ronfard, one of the founders of the Nouveau Théâtre Expérimental, created a defining moment in Quebec theatre with La Vie et mort du roi boiteux (1981; “The Life and Death of the Lame King”), a six-play cycle whose performance in 1982 lasted more than…

Lepchā, people of eastern Nepal, western Bhutan, Sikkim state, and the Darjeeling district of West Bengal in India. They number about 46,000 (11,000 in India; 25,000 in Sikkim; and 10,000 in Bhutan). They are thought to be the earliest inhabitants of Sikkim, but have adopted many elements of the

Mount Everest: Drainage and climate: In Tibet the Rong River originates from the Pumori and Rongbuk glaciers and the Kama River from the Kangshung Glacier: both flow into the Arun River, which cuts through the Himalayas into Nepal. The Rong, Dudh Kosi, and Kama river valleys form, respectively, the northern, southern, and eastern…

Rong Yiren was a Chinese businessman and politician. He was the founder (in 1979) and president of China International Trust and Investment Corporation (CITIC), China’s largest investment company at the time, and later (1993–98) was vice president of China. Rong was educated at a British-run

Yuan Shikai was a Chinese army leader and reformist minister in the twilight of the Qing dynasty (until 1911) and then the first president of the Republic of China (1912–16). Yuan was from a landed military family of Xiangcheng in Henan province. In his youth he showed a propensity for

Rengao language, language of the North Bahnaric subbranch of Bahnaric, a branch of the Mon-Khmer family (itself a part of the Austroasiatic languages. Rengao is spoken by some 15,000 individuals in south-central

Lac la Ronge, lake, central Saskatchewan, Canada; it drains northeastward through the Rapid River into the Churchill River. Island-studded, it is 36 miles (58 km) long, has an area of 546 square miles (1,414 square km), and is noted for its trout, northern pike, and pickerel (walleye). It has been

Ronglu was an official and general during the last years of the Qing dynasty who organized and led one of the first brigades of Chinese troops that used Western firearms and drill. He achieved high office as a favourite of the powerful empress dowager Cixi, and he ensured that the army remained

Easter Island: Traditional culture: …covered with incised signs (called rongo-rongo) placed in boustrophedon (a method of writing in which the lines run alternately from right to left and from left to right) were copied from earlier specimens merely for ritual purposes; their proper reading was forgotten, and—despite many claims—modern attempts at deciphering them have…

Astrid Lindgren: …and in Ronja Rövardotter (1981; Ronia, the Robber’s Daughter), she let the undaunted Ronja and her friend Birk experience both the dangers and hardship and the beauty and mystique of an animated forest. Once again, the author created a source of relief and mutual empowerment for her young characters and…

John Frankenheimer: Later work: Ronin (1998), Frankenheimer’s next theatrical release, however, was an assured thriller, with Robert De Niro giving one of his most intense latter-day performances as a former CIA agent hired to steal a briefcase. The film was a modest hit, but less effective was Reindeer Games…

rōnin, any of the masterless samurai warrior aristocrats of the late Muromachi (1138–1573) and Tokugawa (1603–1867) periods who were often vagrant and disruptive and sometimes actively rebellious. By the 12th century the term rōnin began to be used for samurai who, as a result of either losses in

Astrid Lindgren: …and in Ronja Rövardotter (1981; Ronia, the Robber’s Daughter), she let the undaunted Ronja and her friend Birk experience both the dangers and hardship and the beauty and mystique of an animated forest. Once again, the author created a source of relief and mutual empowerment for her young characters and…

Antarctica: National rivalries and claims: Ronne Antarctic Research Expedition (RARE) in 1947–48 to the old U.S. Antarctic Service East Base camp on Marguerite Bay, the peninsula protagonists—British, Argentine, and Chilean—became concerned that the United States might restore its claims.

Ronne Ice Shelf, large body of floating ice, lying at the head of the Weddell Sea, which is itself an indentation in the Atlantic coastline of Antarctica. More than 500 feet (150 metres) thick and extending inland for more than 520 miles (840 km), it lies immediately west of Filchner Ice Shelf,

Finn Ronne: Edith Ronne and a scientist, Jenny Darlington, traveled with the Ronne Expedition, becoming the first women researchers to take part in a polar exploration. Ronne won many honours, among them three Congressional Gold Medals. His books include Antarctic Conquest (1949) and Antarctica, My Destiny (1979).

Finn Ronne was a Norwegian-born American explorer and writer who visited Antarctica nine times, discovering and charting vast areas of the 4,000,000-square-mile (10,400,000-square-kilometre) continent. On his expeditions Ronne traveled an estimated 3,600 miles (5,800 km) by ski and dogsled. He

the Ronettes, American girl group whose single “Be My Baby” (1963) was one of the defining songs of the girl-group era. The Ronettes were formed in 1959 by sisters Ronnie Bennett (byname of Veronica Bennett, later Ronnie Spector; b. August 10, 1943, New York City, New York, U.S.—d. January 12,

Toini Gustafsson is a Swedish skiing champion who competed in two Olympics, winning two gold and two silver medals in Nordic competition. Small in stature, Gustafsson compensated for her short stride length with unusually powerful strokes that provided her more stamina at the end of races. A

athletics: Long-distance running: Henry Rono (Kenya), one of the most successful at the steeplechase, also held world records at 3,000, 5,000, and 10,000 meters.

canals and inland waterways: Inclined planes: …been constructed in Europe, at Ronquières, Belgium, for 1,350-ton vessels; at Saint-Louis-Arzviller, France, for 300-ton vessels; and at Krasnoyarsk, Russia, for 1,500-ton vessels. At Ronquières and Krasnoyarsk, vessels are carried longitudinally up relatively gentle inclines with gradients of 1 in 21 and 1 in 12, respectively, while at Arzviller the…

perciform: Annotated classification: Family Bathymasteridae (ronquils) Resemble Opistognathidae, but jaws not so large; no spines in dorsal or anal fins; pelvic fins slightly ahead of pectorals; about 7 species; bottom-dwelling; coasts of North Pacific Ocean. Family Cryptacanthodidae (wrymouths) Pelvic fins absent, mouth oblique. Marine, northern Atlantic and Pacific. 1 genus…

Pierre de Ronsard was a poet, chief among the French Renaissance group of poets known as La Pléiade. Ronsard was a younger son of a noble family of the county of Vendôme. He entered the service of the royal family as a page in 1536 and accompanied Princess Madeleine to Edinburgh after her marriage

Bruno Mars: Doo-Wops & Hooligans, Unorthodox Jukebox, and Uptown Funk: …a collaboration with British producer Mark Ronson that recalled 1980s funk and R&B. The song, which appears on Ronson’s album Uptown Special (2015), became a major worldwide hit and won the Grammy for record of the year.

David Bowie: …to good use, including guitarists Mick Ronson and Carlos Alomar and ace nouveau-funk producer Nile Rodgers for “Let’s Dance” (1983), when he needed a hit. As music, Low and its sequels, “Heroes” (1977) and Lodger (1979), would prove to be Bowie’s most influential and lasting, serving as a blueprint for…

Journey to the Center of the Earth: Cast:

Linda Ronstadt is an American singer, with a pure, expressive soprano voice and eclectic artistic tastes, whose performances called attention to a number of new songwriters and helped establish country rock music. After winning attention with a folk-oriented trio, the Stone Poneys, in California in

Linda Ronstadt is an American singer, with a pure, expressive soprano voice and eclectic artistic tastes, whose performances called attention to a number of new songwriters and helped establish country rock music. After winning attention with a folk-oriented trio, the Stone Poneys, in California in

X-ray, electromagnetic radiation of extremely short wavelength and high frequency, with wavelengths ranging from about 10−8 to 10−12 metre and corresponding frequencies from about 1016 to 1020 hertz (Hz). X-rays are commonly produced by accelerating (or decelerating) charged particles; examples

Wilhelm Conrad Röntgen was a physicist who received the first Nobel Prize for Physics, in 1901, for his discovery of X-rays, which heralded the age of modern physics and revolutionized diagnostic medicine. Röntgen studied at the Polytechnic in Zürich and then was professor of physics at the

ROSAT, X-ray astronomy satellite launched on June 1, 1990, as part of a cooperative program involving Germany, the United States, and the United Kingdom. ROSAT had two parallel grazing-incidence telescopes. One of them, the X-ray telescope, bore many similarities to the equipment of the earlier

rod: The rood also was a British linear unit, containing 660 feet (201.2 metres).

rod: …also akin to the Dutch rood which referred to a land area of 40 square rods, equal to one-quarter acre, or 10,890 square feet (1,012 square metres). It also denoted just one square rod, or 272.25 square feet (25.29 square metres). The rood also was a British linear unit, containing…

rood screen: …chancel and known as the rood beam. Later a rood screen was added, rising from the floor to this beam; the rood loft, above the screen, was also added. Upon this loft, or gallery, were displayed the rood and the two statues (of the Virgin Mary and St. John) that…

loft: In churches the rood loft is a display gallery above the rood screen, and a choir or organ loft is a gallery reserved for church singers and musicians. In theatres a loft is the area above and behind the proscenium.

rood screen, in Western architecture, element of a Christian church of the Middle Ages or early Renaissance that separated the choir or chancel (the area around the altar) from the nave (the area set apart for the laity). The rood screen was erected in association with the rood, which in Old

rood screen: The rood stairs, either built into the stone wall of the chancel or housed in a freestanding turret, rose from the church floor to the loft.

Roodepoort, city, Gauteng province, South Africa. It lies immediately west of Johannesburg in the Witwatersrand. The first discovery of gold in the Witwatersrand in 1884, which soon thereafter proved unprofitable, occurred within the present city boundaries. Two years later, the Roodepoort

roof, covering of the top of a building, serving to protect against rain, snow, sunlight, wind, and extremes of temperature. Roofs have been constructed in a wide variety of forms—flat, pitched, vaulted, domed, or in combinations—as dictated by technical, economic, or aesthetic considerations. The

Andy Goldsworthy: Permanent artworks: …created a major installation called Roof (2004–05) for the National Gallery of Art in Washington, D.C., which consists of nine hollow domes (27 feet [8.3 metres] in diameter), each with a hole at the top made of stacked slabs of slate rock. The installation is in a ground-level gallery that…

rock bolt, in tunneling and underground mining, steel rod inserted in a hole drilled into the roof or walls of a rock formation to provide support to the roof or sides of the cavity. Rock bolt reinforcement can be used in any excavation geometry, is simple and quick to apply, and is relatively

construction: Primitive building: the Stone Age: The usual roofing material was thatch: dried grasses or reeds tied together in small bundles, which in turn were tied in an overlapping pattern to the light wooden poles that spanned between the rafters. Horizontal thatched roofs leak rain badly, but, if they are placed at the…

construction: Primitive building: the Stone Age: The usual roofing material was thatch: dried grasses or reeds tied together in small bundles, which in turn were tied in an overlapping pattern to the light wooden poles that spanned between the rafters. Horizontal thatched roofs leak rain badly, but, if they are placed at the…

gardening: Roof gardens: The modern tendency in architecture for flat roofs has made possible the development of attractive roof gardens in urban areas above private houses and commercial buildings. These gardens follow the same principles as others except that the depth of soil is less, to…

roof pendant, downward extension of the surrounding rock that protrudes into the upper surface of an igneous intrusive body. The intrusions that most commonly contain roof pendants are relatively shallow stocks or batholiths; the roof pendants occur as isolated pieces of the surrounding rock within

human nervous system: Midbrain: The roof plate of the midbrain is formed by two paired rounded swellings, the superior and inferior colliculi. The superior colliculus receives input from the retina and the visual cortex and participates in a variety of visual reflexes, particularly the tracking of objects in the contralateral…

rat: …the Norway rat), and the house rat, R. rattus (also called the black rat, ship rat, or roof rat), live virtually everywhere that human populations have settled; the house rat is predominant in warmer climates, and the brown rat dominates in temperate regions, especially urban areas. Most likely originating in…

Inoue Yasushi: …notably Tempyō no iraka (1957; The Roof Tile of Tempyō), which depicts the drama of 8th-century Japanese monks traveling to China and bringing back Buddhist texts and other artifacts to Japan.

flunitrazepam, benzodiazepine drug known for its sedative, hypnotic, and anxiolytic (antianxiety) properties and for its illicit use, most notably as a so-called date rape drug. Flunitrazepam is sold under various trade names, including Rohypnol. Because of its high potential for misuse and its

tile: Roof tiles of some Greek temples were made of marble; in ancient Rome, of bronze. Stone slabs used for roofing in parts of England are called tiles. Many rough forms of terra-cotta are called tiles when used structurally. The steel forms for casting certain types…

rook, (Corvus frugilegus), the most abundant Eurasian bird of the crow family Corvidae (q.v.). It resembles the carrion crow in size (45 cm [18 inches]) and in black coloration, but the adult rook usually has shaggy thigh feathers and has bare white skin at the base of its sharp bill. The species

chess: Rook: Each player has two rooks (formerly also known as castles), which begin the game on the corner squares a1 and h1 for White, a8 and h8 for Black. A rook can move vertically or horizontally to any unobstructed square along the file or rank…

Gibraltar: History: …War of the Spanish Succession, Sir George Rooke captured Gibraltar for the British, and Spain formally ceded it to Britain under the terms of the Treaty of Utrecht in 1713. The Spanish nevertheless made several attempts to retake Gibraltar from Britain, most notably in a protracted but unsuccessful military siege…

Daniel Burnham: Burnham & Root: …notable early works are the Rookery (completed 1886), the second Rand McNally Building (completed 1890, demolished 1911), the Monadnock Building (completed 1891), and the Masonic Temple (completed 1892). Finished a year after William Le Baron Jenney’s Home Insurance Building (completed 1885), which was the first building to use structural steel…

baseball: Awards: Begun in 1947, the Rookie of the Year award is given to the best new player in each league. A rookie is defined as a player who meets at least one of the following three criteria: fewer than 130 at bats, fewer than 50 innings pitched, or fewer than…

Charlie Sheen: Acting stardom in the 1980s and ’90s: …film), and the crime drama The Rookie (opposite Clint Eastwood, the film’s director). Sheen showed his gift for comedy in the popular Top Gun parody film Hot Shots! (1991) and its Rambo-inspired sequel, Hot Shots! Part Deux (1993). Yet he continued to do action films, such as Beyond the Law…

Brian Cox: Career: …Quaid) in the sports drama The Rookie (2002). Cox played the villainous colonel William Stryker in the superhero film X2: X-Men United in 2003, and he portrayed the wealthy father-in-law of a former professional tennis player in director Woody Allen’s psychological thriller Match Point (2005). Cox’s career continued to gain…

Aleksey Kondratyevich Savrasov: …such popular Russian paintings as The Rooks Have Returned (1871).

Dick Turpin: Harrison Ainsworth, in his romance Rookwood (1834), gave a spirited account of a ride by Dick Turpin on his mare, Black Bess, from London to York, but the incident is pure fiction.

pottery: The United States: …a result of its work, Rookwood Pottery was established in 1880 by Maria Longworth Storer. Rookwood wares show a distinct Japanese influence and have excellent red and yellowish brown glazes.

A24: Films: …book of the same name, Room (2015), directed by Lenny Abrahamson and starring Brie Larson and Jacob Tremblay, earned accolades for its portrayal of the unbreakable bond between a parent and child forced to endure intolerable conditions and earned Larson an Oscar for best actress in a leading role.

Brie Larson: …was based on a 2010 novel by Emma Donoghue.

mining: Underground mining: …of extracting ore are called stopes or rooms. There are two steps involved in stoping. The first is development—that is, preparing the ore blocks for mining—and the second is production, or stoping, itself. Ore development is generally much more expensive on a per-ton basis than stoping, so that every effort…

James L. Brooks: …of the groundbreaking TV comedy Room 222 (1969–74), which centred on the travails of an African American high-school teacher. Brooks then cocreated and produced the hit sitcom The Mary Tyler Moore Show (1970–77) and its spin-offs Rhoda (1974–78) and Lou Grant (1977–82). Brooks’s next success as writer and producer, the…

John Braine: …so-called Angry Young Men, whose Room at the Top (1957; film 1959) typifies the concerns of a generation of post-World War II British writers.

Simone Signoret: …a jilted older woman in Room at the Top (1958), which won her numerous awards, including the British and American Academy Awards. After that success she appeared in a few Hollywood films but preferred working in France. In her later films, such as Le Chat (1971; The Cat) and La…

Olafur Eliasson: In Room for One Colour (1997), he flooded a room with saturated yellow light, causing all other colours to be perceived as black. Conversely, in 360° Room for All Colours (2002), a circular space changed colours almost imperceptibly.

Norman Taurog: Martin and Lewis films of Norman Taurog: …the pleasant Warner Brothers comedy Room for One More (1952), with Cary Grant and Betsy Drake (who were married in real life) as the adoptive parents of several underprivileged orphans. Taurog then returned to Paramount for a second stint. First up was a pair of the studio’s enormously popular Dean…

John Mayer: …which released the full-length album Room for Squares (2001). Columbia Records repackaged the album with additional material for a much higher-profile national release later in 2001. The songs “No Such Thing” and “Your Body Is a Wonderland” both became hits, and the latter earned Mayer a Grammy Award for best…

Edward Hopper: …by the Railroad (1925) and Room in Brooklyn (1932) show still, anonymous figures and stern geometric forms within snapshot-like compositions that create an inescapable sense of loneliness. This isolation of his subjects was heightened by Hopper’s characteristic use of light to insulate persons and objects in space, whether in the…

Kate Grenville: The fictional memoir A Room Made of Leaves (2020) chronicles the life of Elizabeth Macarthur, who was married to John Macarthur, founder the Australian wool industry in the 1800s. Grenville also wrote such nonfiction books as Searching for the Secret River (2006) and One Life: My Mother’s Story…

Pedro Almodóvar: All About My Mother and Talk to Her: …made his first English-language film, The Room Next Door. The drama, based on a novel by Sigrid Nunez, focuses on a dying woman (Tilda Swinton) who reconnects with an old friend (Julianne Moore).

A Room of One’s Own, essay by English writer Virginia Woolf, published in 1929. The work was based on two lectures given by the author in 1928 at Newnham College and Girton College, the first two colleges for women at the University of Cambridge. Woolf addressed the status of women, and women

the Strokes: …release of the new wave-inspired Room on Fire, the Strokes phenomenon had already peaked, but the band retained a large following. Featuring another crop of infectious but coolly delivered rock songs—including “12:51,” which cracked the top 10 of the British pop singles chart—the album was considered by critics to be…

William A. Seiter: …directed the Marx Brothers in Room Service. Based on a Broadway farce, it was the only film in which the script was not written specifically for the popular comedy team, and the results were mixed. The colonial-era drama Allegheny Uprising (1939) was a box-office disappointment, despite the presence of John…

Reba McEntire: Acting and later music: …including So Good Together (1999), Room to Breathe (2003), Reba: Duets (2007), and Love Somebody (2015). In 2017 she released Sing It Now: Songs of Faith & Hope, which later won a Grammy for best roots gospel album. The following year she was named a Kennedy Center honoree. Her 33rd…

John Bolton: The Room Where It Happened was published soon after the ruling, and it offered a highly critical account of Trump’s presidency. Bolton alleged that Trump had engaged in numerous illegal acts, notably offering political favours to foreign countries in exchange for assistance with his reelection.

Merchant and Ivory: …by three Forster adaptations—Maurice (1987), A Room with a View (1986), and Howards End (1992)—all of which won awards. For the latter two films, Ivory received Academy Award nominations for best director, and both were nominated for best picture. By the time The Remains of the Day was released in…

A Room with a View, novel by E.M. Forster, published in 1908. Forster’s keen observation of character and of British life informed the work, which reflected the author’s criticism of restrictive conventional British society. While on vacation in Italy, affluent young Lucy Honeychurch becomes

Harold Pinter: The Room (first produced 1957) and The Dumb Waiter (first produced 1959), his first two plays, are one-act dramas that established the mood of comic menace that was to figure largely in his later works. His first full-length play, The Birthday Party (first produced 1958;…

mining: Room-and-pillar mining: The most common mining system is room-and-pillar. In this system a series of parallel drifts are driven, with connections made between these drifts at regular intervals. When the distance between connecting drifts is the same as that between the parallel drifts, then a…