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  • Mach cone (physics)
    ...or changes of pressure. At supersonic speeds, however, the pressure field is confined to a region extending mostly to the rear and extending from the craft in a restricted widening cone (called a Mach cone). As the aircraft proceeds, the trailing parabolic edge of that cone of disturbance intercepts the Earth, producing on Earth a sound of a sharp bang or boom. When such an aircraft flies at......
  • Mach, Ernst (Austrian physicist)
    Austrian physicist and philosopher who established important principles of optics, mechanics, and wave dynamics and who supported the view that all knowledge is a conceptual organization of the data of sensory experience (or observation)....
  • Mach number (physics)
    in fluid mechanics, ratio of the velocity of a fluid to the velocity of sound in that fluid, named after Ernst Mach (1838–1916), an Austrian physicist and philosopher. In the case of an object moving through a fluid, such as an aircraft in flight, the Mach number is equal to the velocity of the object relative to the fluid divided by the velocity of so...
  • Mach-pelah, Cave of (cave, West Bank)
    ...or “Tetrapolis”), possibly referring to four confederated settlements in the area in biblical times or to the fact that the city is built on four hills. At Hebron Abraham purchased the Cave of Machpelah (Hebrew: Meʿarat ha-Makhpelah) as a burial place for his wife, Sarah, from Ephron the Hittite (Genesis 23); this became a family sepulchre. According to tradition, Abraham,....
  • Macha (Celtic war goddess)
    in Celtic religion, one of three war goddesses; it is also a collective name for the three, who were also referred to as the three Morrígan. As an individual, Macha was known by a great variety of names, including Dana and Badb (“Crow,” or “Raven”). She was the great earth mother, or female principle, and a great slaughterer of men, as was another of the trinity...
  • Mácha, Karel Hynek (Czech poet)
    literary artist who is considered the greatest poet of Czech Romanticism....
  • Machabees (priestly Jewish family)
    priestly family of Jews who organized a successful rebellion against the Seleucid ruler Antiochus IV and reconsecrated the defiled Temple of Jerusalem....
  • Machabees, The Books of the (biblical literature)
    four books, none of which is in the Hebrew Bible but all of which appear in some manuscripts of the Septuagint. The first two books only are part of canonical scripture in the Septuagint and the Vulgate (hence are canonical to Roman Catholicism and Eastern Orthodoxy) and are included in the Protestant Apocrypha....
  • MacHack VI (computer)
    Computers began to compete against humans in the late 1960s. In February 1967 MacHack VI, a program written by Richard Greenblatt, an MIT undergraduate, drew one game and lost four in a U.S. Chess Federation tournament. Its results improved markedly, from a performance equivalent to a USCF rating of 1243 to reach 1640 by April 1967, about the average for a USCF member. The first American......
  • Machačkala (Russia)
    port and capital of Dagestan republic, southwestern Russia. The city is situated along the western shore of the Caspian Sea, at the northern end of a narrow coastal plain. Founded as the Petrovskoye fortress in 1844, it became Petrovsk Port in 1857 and was renamed in 1921 after the Dagestani revolutionary Makhach. Present-day Makhachkala is a seaport linking the North Caucasus, Transcaucasus, and ...
  • machada (musical instrument)
    (Hawaiian: “flea”), small guitar derived from the machada, or machete, a four-stringed guitar introduced into Hawaii by the Portuguese in the 1870s. It is seldom more than 24 inches (60 cm) long....
  • Machado, Antonio (Spanish author)
    outstanding Spanish poet and playwright of Spain’s Generation of ’98....
  • Machado, Bernardino Luís (president of Portugal)
    Brazilian-born political leader who was twice president of Portugal (1915–17, 1925–26)....
  • Machado de Assis, Joaquim Maria (Brazilian author)
    Brazilian poet, novelist, and short-story writer, a classic master of Brazilian and world literature, whose art is rooted in the traditions of European culture and transcends the influence of Brazilian literary schools....
  • Machado de Castro, Joachim (Portuguese sculptor)
    Sculpture found rich expression in the magnificent tombs of the 12th and 13th centuries, and late 18th-century Baroque wood sculptures, of which the crèches of Joachim Machado de Castro are the finest, also are outstanding. The Classical and Romantic traditions of Italy and France influenced Machado de Castro in the late 18th century and António Soares dos Reis a century later. A......
  • Machado, Manuel (Spanish author)
    Spanish poet and playwright, brother of Antonio Machado. The son of an Andalusian folklorist, he is best known for his popular poetry inspired by traditional folklore, as in Cante hondo (1912; “Singing from the Depths”). He collaborated with his brother on several verse plays, including Desdichas de fortuna o Julianillo Valcárcel (1...
  • Machado y Morales, Gerardo (Cuban dictator)
    hero in the Cuban War of Independence (1895–98) who was later elected president by an overwhelming majority, only to become one of Cuba’s most powerful dictators....
  • Machado y Ruiz, Antonio (Spanish author)
    outstanding Spanish poet and playwright of Spain’s Generation of ’98....
  • Machado y Ruiz, Manuel (Spanish author)
    Spanish poet and playwright, brother of Antonio Machado. The son of an Andalusian folklorist, he is best known for his popular poetry inspired by traditional folklore, as in Cante hondo (1912; “Singing from the Depths”). He collaborated with his brother on several verse plays, including Desdichas de fortuna o Julianillo Valcárcel (1...
  • Machaerium (plant genus)
    The name jacaranda is also applied to several tree species of the genus Machaerium of the pea family (Fabaceae), from which some of the commercial rosewoods are obtained. Jacaranda cabinet wood is a rosewood from the tree species Dalbergia nigra, also of the pea family....
  • Machaire Fíolta (district, Northern Ireland, United Kingdom)
    Magherafelt district is bounded by the River Bann and Lough (lake) Neagh on the east and by the Sperrin Mountains on the west. It borders the districts of Antrim and Ballymena to the east; Coleraine to the north; Limavady, Strabane, and Omagh to the west; and Cookstown to the south. Gently rolling lowlands in the east rise gradually westward to elevations of more than 1,800 feet (550 metres)......
  • Machaire Fíolta (Northern Ireland, United Kingdom)
    town, seat, and district (established 1973), formerly within County Londonderry, central Northern Ireland. Magherafelt town was originally an English-company (Plantation of Ulster) town and is now the marketing centre and administrative seat of the district; Maghera town, 9 miles (14 km) to the northwest, was the birthplace of Charles Thomson (1730–1824...
  • Machairondontinae (subfamily of mammals)
    any of the extinct catlike carnivores belonging either to the extinct family Nimravidae or the subfamily Machairodontinae of the cat family (Felidae). Named for the pair of elongated, bladelike canine teeth in their upper jaw, they are often called sabre-toothed tigers or sabre-toothed lions, although the modern l...
  • Machala (Ecuador)
    city, southwestern Ecuador, in the Pacific coastal lowlands 2 mi (3 km) from the Gulf of Guayaquil. A commercial centre for the surrounding agricultural region, the city trades in bananas, cacao, coffee, and hides. Industrial development is slight, but a technical university was established in 1969. Puerto Bolívar, 4 mi southwest, is the outport of Machala and handles muc...
  • Mach’ang (Chinese pottery)
    ...in the provinces of Honan and Kansu. Perhaps the best known of these wares is a series of large urns of red polished pottery with geometric decoration found in the Pan-shan cemetery and at Mach’ang, both in Kansu Province. These were made by hand, the latest specimens with perhaps some assistance from a slow wheel, and are at least as early as 2000 bc....
  • Machang culture (anthropology)
    ...ease, were the most prominent. Related designs involving sawtooth lines, gourd-shaped panels, spirals, and zoomorphic stick figures were painted on pots of the Banshan (mid-3rd millennium) and Machang (last half of 3rd millennium) cultures. Some two-thirds of the pots found in the Machang burial area at Liuwan in Qinghai, for example, were painted. In the North China Plain, Dahe culture......
  • Machanganaland (historical region, South Africa)
    former nonindependent Bantustan, northeastern Transvaal, South Africa, designated for the Shangaan and Tsonga people. It was made up of four detached portions of low veld, two of which adjoined Kruger National Park. The Tsonga people, the traditional inhabitants of the area, were joined by 19th-century Shangaan migrants from what is now Moza...
  • Machatý, Gustav (Czech director)
    Czech motion-picture director whose films became world-famous for treating mature subjects in a stylishly erotic manner....
  • Machaut, Guillaume de (French poet and musician)
    French poet and musician, greatly admired by contemporaries as a master of French versification and regarded as one of the leading French composers of the Ars Nova musical style of the 14th century. It is on his shorter poems and his musical compositions that his reputation rests. He was the last great poet in France to think of the lyric and its musical setting as a single enti...
  • Machel, Samora (president of Mozambique)
    Mozambican politician, who was the first president of independent Mozambique (1975–86)....
  • Machen, Arthur (Welsh writer)
    Welsh novelist and essayist, a forerunner of 20th-century Gothic science fiction....
  • Machen, John Gresham (American theologian)
    American Presbyterian theologian and fundamentalist leader....
  • Machendra Jatra (Hindu festival)
    Festivals in Kathmandu include, in spring, the Shivaratri and the Machendra Jatra with its procession bearing the image of the god Machendra; in late summer, the Gai Jatra (festival of the cow); and, in early autumn, the Indra Jatra, during which the goddess Devi, represented by a young girl, is carried in procession. Pop. (2001) 671,846....
  • machete (musical instrument)
    (Hawaiian: “flea”), small guitar derived from the machada, or machete, a four-stringed guitar introduced into Hawaii by the Portuguese in the 1870s. It is seldom more than 24 inches (60 cm) long....
  • Machias (Maine, United States)
    town, seat (1790) of Washington county, eastern Maine, U.S., near the mouth of the Machias River, at the head of Machias Bay, 84 miles (135 km) east-southeast of Bangor. It was the site of an English trading post (1633) that was quickly destroyed by the French. For many years its sheltered coastal location was a haven for Atlantic privateers, including Rhodes the Pirate and Samu...
  • Machiavelli, Bernardo (Italian lawyer)
    From the 13th century onward, Machiavelli’s family was wealthy and prominent, holding on occasion Florence’s most important offices. His father, Bernardo, a doctor of laws, was nevertheless among the family’s poorest members. Barred from public office in Florence as an insolvent debtor, Bernardo lived frugally, administering his small landed property near the city and suppleme...
  • Machiavelli, Niccolò (Italian statesman and writer)
    Italian Renaissance political philosopher and statesman, secretary of the Florentine republic, whose most famous work, The Prince (Il Principe), brought him a reputation as an atheist and an immoral cynic....
  • Machiavellians, Defenders of Freedom, The (work by Burnham)
    ...(1941) he propounded a theory of bureaucratic revolution: the rulers of the new society, the class with power and privilege, will be the bureaucratic managers of “super states.” In The Machiavellians, Defenders of Freedom (1943), he reinterprets Machiavelli and cites Mosca as a modern Machiavellian. Following Pareto’s idea of the “circulation of elites,...
  • Machiavellism; the Doctrine of Raison d’État and Its Place in Modern History (work by Meinecke)
    ...he optimistically traced Germany’s emergence from the cosmopolitanism of the 18th century to the nationalism of the 19th. His Idee der Staatsräson in der neueren Geschichte (1924; Machiavellism; the Doctrine of Raison d’État and Its Place in Modern History) has been read as both a handbook and a condemnation of power politics. In it he questioned the va...
  • machicolation (military technology)
    ...moats from being crossed. The gateway was often protected by a barbican—a walled outwork in front of the gate—and the passage through the gateway was defended by portcullises, doors, and machicolations. Portcullises were generally made of oak, were plated and shod with iron, and were moved up and down in stone grooves, clearing or blocking the passage. Machicolations were of two.....
  • Machida (Japan)
    city, Tokyo to (metropolis), Honshu, Japan, on the border of Kanagawa Prefecture (ken). Situated on the southern slopes of the Tama Hills, the city was formed by the amalgamation of Hara-Machida and three neighbouring villages in 1958. During the Meiji era (1868–1912) Hara-Machida was a market for goods (mostly silk) destined for the port of Yokohama. In 190...
  • Machigonne (Maine, United States)
    city, seat (1760) of Cumberland county, southwestern Maine, U.S. The state’s largest city, it is the hub of a metropolitan statistical area that includes the cities of South Portland and Westbrook and the towns of Falmouth, Cape Elizabeth, Cumberland, Freeport, Gorham, Scarborough, Windham, and Yarmouth and, in York county, the town of Old Orchard Beach. The city is built...
  • Machilipatnam (India)
    city, eastern Andhra Pradesh state, southern India. Masulipatam was the first British trading settlement (1611) on the Bay of Bengal. From 1686 to 1759 the city was held by the French and Dutch, until it was finally ceded to the British, who captured the city and fort from the French in 1759. The ruined fort is still a point of interest. The city received its present name in 1949....
  • Machimoi (Egyptian army)
    ...Amon and thus became heiress to the position of God’s Wife. Essential to the settling of internal conflicts was the Saite dynasty’s superior army, composed of Libyan soldiers, whom the Greeks called Machimoi (“Warriors”), and Greek and Carian mercenaries, who formed part of the great emigration from the Aegean in the 7th and 6th centuries bc. Greek pira...
  • Machin, John (English mathematician)
    English mathematician, notable for studies in finding the area of a circle. In 1706 he was the first to compute the value of the constant π to 100 decimal places. Machin’s formula for π was adapted by others, including Euler, to extend his result. Machin was professor of astronomy at Gresham College, London (1713–51). He worked extensively on the luna...
  • machina (stage device)
    The permanent facade was also used to hide the stage properties and the machinery. Evidence for the use of the so-called flying machine, the mēchanē (Latin machina), in the 5th century is given in the comedies of Aristophanes; a character in his play Peace ascends to heaven on a dung beetle and appeals to the scene shifter not to let him fall. The......
  • machine
    device, having a unique purpose, that augments or replaces human or animal effort for the accomplishment of physical tasks. This broad category encompasses such simple devices as the lever, wedge, wheel and axle, pulley, and screw (the five so-called simple machines) as well as such complex mechanical s...
  • machine art
    French painter who was deeply influenced by modern industrial technology and Cubism. He developed “machine art,” a style characterized by monumental mechanistic forms rendered in bold colours....
  • machine carbine (weapon)
    lightweight automatic small-arms weapon chambered for relatively low-energy pistol cartridges and fired from the hip or shoulder. Most types utilize simple blowback actions. Using cartridges of such calibres as .45 inch or 9 mm, they usually have box-type magazines that hold from 10 to 50 cartridges, or occasionally drums holding more rounds. A short-range weapon, the submachine gun is rarely eff...
  • machine code (computing)
    the numeric codes for the operations that a particular computer can execute directly. The codes are strings of 0s and 1s, or binary digits (“bits”), which are frequently converted both from and to hexadecimal (base 16) for human viewing and modification. Machine language instructions typically use some bits to represent operations, such as additi...
  • machine display (ergonomics)
    ...The simplest model of a man-machine unit consists of an individual operator working with a single machine. In any machine system, the human operator first has to sense what is referred to as a machine display, a signal that tells him something about the condition or the functioning of the machine. A display may be the position of a pointer on a dial, a light flashing on a control panel,......
  • machine finish
    ...only slightly beaten in stock preparation. The sheet is lightly calendered (pressed between rollers) to provide a degree of surface smoothness while preserving the antique or eggshell appearance. Machine finish has a medium-smooth surface obtained for this finish from a calender stack at the dry end of the machine. Machine finish book is a relatively inexpensive general utility paper. It is......
  • machine gun (weapon)
    automatic weapon of small calibre that is capable of rapid, sustained fire. Most machine guns are belt-fed weapons that fire from 500 to 1,000 rounds per minute and will continue to fire as long as the trigger is held back or until the supply of ammunition is exhausted. The machine gun was developed in the late 19th century and has profoundly altered the character of modern warfare....
  • machine indexing (information retrieval)
    The subject analysis of electronic text is accomplished by means of machine indexing, using one of two approaches: the assignment of subject descriptors from an unlimited vocabulary (free indexing) or their assignment from a list of authorized descriptors (controlled indexing). A collection of authorized descriptors is called an authority list or, if it also displays various relationships among......
  • “Machine infernale, La” (work by Cocteau)
    ...seem today less private and more universal because they have appeared in other works. Also in the early 1930s Cocteau wrote what is usually thought to be his greatest play, La Machine infernale, a treatment of the Oedipus theme that is very much his own. In these two works he moved into closer contact with the great myths of humanity....
  • machine language (computing)
    the numeric codes for the operations that a particular computer can execute directly. The codes are strings of 0s and 1s, or binary digits (“bits”), which are frequently converted both from and to hexadecimal (base 16) for human viewing and modification. Machine language instructions typically use some bits to represent operations, such as additi...
  • machine learning (artificial intelligence)
    There are a number of different forms of learning as applied to artificial intelligence. The simplest is learning by trial and error. For example, a simple computer program for solving mate-in-one chess problems might try moves at random until mate is found. The program might then store the solution with the position so that the next time the computer encountered the same position it would......
  • machine pistol (weapon)
    lightweight automatic small-arms weapon chambered for relatively low-energy pistol cartridges and fired from the hip or shoulder. Most types utilize simple blowback actions. Using cartridges of such calibres as .45 inch or 9 mm, they usually have box-type magazines that hold from 10 to 50 cartridges, or occasionally drums holding more rounds. A short-range weapon, the submachine gun is rarely eff...
  • machine, political
    in U.S. politics, a party organization, headed by a single boss or small autocratic group, that commands enough votes to maintain political and administrative control of a city, county, or state....
  • machine programming (technology)
    The programmed instructions determine the set of actions that is to be accomplished automatically by the system. The program specifies what the automated system should do and how its various components must function in order to accomplish the desired result. The content of the program varies considerably from one system to the next. In relatively simple systems, the program consists of a......
  • machine screw
    ...device was used to turn them. Slotted, roundheaded screws were used in the 16th century, but few screw-and-nut-fastened clocks are in evidence earlier than the 17th century. Metal screws were called machine, or machinery, screws since they were made of metal and mated with threaded holes....
  • machine shop
    The successful introduction of interchangeable parts and the development of machine tools, both in the 19th century, brought the modern machine shop into being. Then, as now, the independent machine shop was called a job shop, which meant that it had no product of its own but served large industrial facilities by fabricating tooling, machines, and machinepart replacements. Eventually, some......
  • Machine Stops, The (story by Forster)
    E.M. Forster’s much-anthologized story The Machine Stops (1909) was written as a counterblast to Wellsian technical optimism. The story depicts a soulless push-button, heavily networked world. The sudden collapse of Forster’s dystopia supplies motive force to the plot—a scheme so common in science fiction that it is known as the “house-of-car...
  • machine tool
    any stationary power-driven machine that is used to shape or form parts made of metal or other materials. The shaping is accomplished in four general ways: (1) by cutting excess material in the form of chips from the part; (2) by shearing the material; (3) by squeezing metallic parts to the desired shape; and (4) by applying electricity, ultrasound, or corrosive chemicals to the material. The four...
  • machine translation (linguistics)
    ...Theoretically more interesting, though much more difficult, is the automatic grammatical analysis of texts by computer. Considerable progress was made in this area by research groups working on machine translation and information retrieval in the United States, Great Britain, the Soviet Union, France, and a few other countries in the decade between the mid-1950s and the mid-1960s. But much......
  • machine vision
    ...devices that can be used as components in automatic feedback control systems. These devices include highly sensitive electromechanical probes, scanning laser beams, electrical field techniques, and machine vision. Some of these sensor systems require computer technology for their implementation. Machine vision, for example, requires the processing of enormous amounts of data that can be......
  • Machine-Readable Cataloging (library science)
    ...wishing to participate, and the Bibliographic Services Division and its predecessor, the British National Bibliography, cooperated closely with the U.S. Library of Congress in the Project for Machine-Readable Cataloging (MARC), which provides on-line access to the catalogs of the current acquisitions of the British Library Reference Division and the Library of Congress....
  • Machine-Readable Cataloging Project (library science)
    ...a file at any point and then to be transmitted to a central data file from which other libraries can obtain details by means of telecommunications links. The process is demonstrated by the revised Machine-Readable Cataloging Project, known since its revision in 1968 as MARC II. Library users find no difficulty in consulting such on-line catalogs, and many prefer them to the more cumbersome, if....
  • machine-tractor station (Soviet institution)
    in the Soviet Union, state-owned institution that rented heavy agricultural machinery (e.g., tractors and combines) to a group of neighbouring kolkhozy (collective farms) and supplied skilled personnel to operate and repair the equipment. The stations, which became widespread and prominent during the collectivization drive in the early 1930s, were instr...
  • machinery
    device, having a unique purpose, that augments or replaces human or animal effort for the accomplishment of physical tasks. This broad category encompasses such simple devices as the lever, wedge, wheel and axle, pulley, and screw (the five so-called simple machines) as well as such complex mechanical s...
  • Machinery Hall (building, Philadelphia, Pennsylvania, United States)
    Unquestionably the focal point of the exposition was Machinery Hall, where viewers marveled at the working models of steam engines and dynamos and celebrated the advent of the United States as an internationally important industrial power. Although some critics were offended by the ornate and grandiose symptoms of the “Gilded Age” and by the wild confusion of architectural styles......
  • Machinery Hall (building, Tokyo, Japan)
    Horiguchi graduated in 1920 from the University of Tokyo, where he also received a Ph.D. in architecture in 1944. The Machinery Hall, which he designed for the Tokyo Peace Exhibition of 1922, was among the important works of the Secessionist group of young architects, who rebelled against the tradition of formalism in Japan. Shortly thereafter, Horiguchi went to Europe for two years, visiting......
  • machinery insurance
    Special casualty forms are issued to cover the hazards of sudden explosions from equipment such as steam boilers, compressors, electric motors, flywheels, air tanks, furnaces, and engines. Boiler and machinery insurance has several distinctive features. A substantial portion of the premium collected is used for inspection services rather than loss protection. Second, the boiler policy provides......
  • machinery screw
    ...device was used to turn them. Slotted, roundheaded screws were used in the 16th century, but few screw-and-nut-fastened clocks are in evidence earlier than the 17th century. Metal screws were called machine, or machinery, screws since they were made of metal and mated with threaded holes....
  • Machines à peindre (works by Tinguely)
    ...moved or spun at varying speeds. Further innovations on Tinguely’s part in the mid- and late 1950s led to a series of sculptures entitled “Machines à peindre” (“Painting Machines”); these robotlike machines continuously painted pictures of abstract patterns to the accompaniment of self-produced sounds and noxious odours. The 8-foot-long “painting...
  • Machines, Gallery of (building, Paris, France)
    ...an engineer who had done outstanding work in the Paris Exposition of 1878 and in steel structures such as the trussed parabolic arches in the viaduct at Garabit, France (1880–84). In the Palais des Machines (at the 1889 exhibition) by Ferdinand Dutert and Victor Contamin, a series of three-hinged trussed arches sprang from small points across a huge space, 385 feet (117 metres) long......
  • Machines, Palais des (building, Paris, France)
    ...an engineer who had done outstanding work in the Paris Exposition of 1878 and in steel structures such as the trussed parabolic arches in the viaduct at Garabit, France (1880–84). In the Palais des Machines (at the 1889 exhibition) by Ferdinand Dutert and Victor Contamin, a series of three-hinged trussed arches sprang from small points across a huge space, 385 feet (117 metres) long......
  • machining (technology)
    Rigid thermoplastics and thermosets can be machined by conventional processes such as drilling, sawing, turning on a lathe, sanding, and other operations. Glass-reinforced thermosets are machined into gears, pulleys, and other shapes, especially when the number of parts does not justify construction of a metal mold. Various forms can be stamped out (die-cut) from sheets of thermoplastics and......
  • machining centre (machine tool)
    A further development in the automation of machine tools is the “machining centre,” usually a vertical milling machine fitted with automatic tool-changing facilities and capable of several axes of control. The tools, of which there can be more than 100, are generally housed in a rotary magazine and may be changed by commands from the machine tool program. Thus, different faces of a.....
  • Machito (Cuban musician)
    ...notably to Mexico. However, New York City became the forge for its transformation into salsa, beginning in the 1940s with the contributions of the orchestra led by Cuban émigré Machito (Frank Grillo), which blended Afro-Cuban styles with jazz and big band approaches. Another Cuban émigré, Celia Cruz, became the reigning diva of Afro-Cuban dance music in the......
  • Machkund Lake (lake, India)
    ...avoid encroachments by the Chambal River. It was the capital of the former princely state of Dholpur, which became part of the state of Rājasthān in 1949. Several temples surround nearby Machkund Lake, on the shores of which annual religious fairs are held. An agricultural distribution centre, Dholpur is connected by Grand Trunk Road with Āgra and Delhi to the north and wit...
  • Machkund River (river, India)
    river, Andhra Pradesh state, southern India. The river rises as the Machkund in the Eastern Ghāts in northeastern Andhra Pradesh. Leaving the Machkund reservoir, it flows (as the Sileru) parallel to the mountain ranges at an elevation of 2,000–3,000 feet (600–900 m) in a northeast-to-southwest direction to empty into the Sābari River, opposite Konta, in Madhya Pradesh s...
  • Machlina (Belgium)
    municipality, Antwerp province, north-central Belgium. It lies along the Dijle River, a few miles north-northeast of Brussels. St. Rumoldus (Rombold) was said to have come there in 756. In the Middle Ages it was called Machlina (Mechlinia) and belonged to the prince-bishops of Liège (915–1333) and the counts of Flanders (1333–69). It passed to the Burgundians (1369), an...
  • Machmeter (instrument)
    ...differences and temperature give the true airspeed, which is used to calculate the aircraft’s position. In faster aircraft, indicators that measure airspeed relative to the speed of sound, called Machmeters, are used....
  • Machpelah, Cave of (cave, West Bank)
    ...or “Tetrapolis”), possibly referring to four confederated settlements in the area in biblical times or to the fact that the city is built on four hills. At Hebron Abraham purchased the Cave of Machpelah (Hebrew: Meʿarat ha-Makhpelah) as a burial place for his wife, Sarah, from Ephron the Hittite (Genesis 23); this became a family sepulchre. According to tradition, Abraham,....
  • Machramion (ancient city, Turkey)
    ancient Greek city of the Troad, located on the coast of what is now northwestern Turkey, with the island of Lesbos lying about 7 miles (11 km) offshore to the south. Founded by Aeolic colonists from Methymna in Lesbos in the 1st millennium bc, the city was constructed on the terraced slopes, partly natural and partly artificial, of an isolated cone of trachyte that rises steeply mor...
  • Machray, Robert (Scottish archbishop)
    Scottish-born archbishop of Rupert’s Land in northern and western Canada....
  • Mach’s bands (physics)
    ...he continued to identify himself as a physicist and to conduct physical research throughout his career. During the 1860s he discovered the physiological phenomenon that has come to be called Mach’s bands, the tendency of the human eye to see bright or dark bands near the boundaries between areas of sharply differing illumination....
  • Mach’s construction (mechanics)
    The diagrams in Figure 8 show a well-known construction attributed to the Austrian physicist Ernst Mach that explains the origin of the shock front accompanying a supersonic projectile. The circular arcs in this figure represent cross sections through spherical disturbances that are spreading with speed Vs from centres (S′, S″, etc.), which mark the position of......
  • Mach’s principle (astronomy)
    in cosmology, hypothesis that the inertial forces experienced by a body in nonuniform motion are determined by the quantity and distribution of matter in the universe. It was so called by Albert Einstein after the 19th-century Austrian physicist and philosopher Ernst Mach. Einstein found the hypothesis helpful in formulating his theory of general relativity...
  • Machu Picchu (ancient city, Peru)
    site of ancient Inca ruins located about 50 miles (80 km) northwest of Cuzco, Peru, in the Cordillera de Vilcabamba of the Andes Mountains. It is perched above the Urubamba River valley in a narrow saddle between two sharp peaks—Machu Picchu (“Old Peak”) and Huayna...
  • Machuca, Pedro de (Spanish architect)
    ...removed. Charles V, who ruled in Spain as Charles I (1516–56), rebuilt portions in the Renaissance style and destroyed part of the Alhambra in order to build an Italianate palace designed by Pedro de Machuca in 1526. In 1812 some of the towers were blown up by the French during the War of Independence, and in 1821 an earthquake caused further damage to the structure. Restoration of the.....
  • Machund River (river, India)
    river, Andhra Pradesh state, southern India. The river rises as the Machkund in the Eastern Ghāts in northeastern Andhra Pradesh. Leaving the Machkund reservoir, it flows (as the Sileru) parallel to the mountain ranges at an elevation of 2,000–3,000 feet (600–900 m) in a northeast-to-southwest direction to empty into the Sābari River, opposite Konta, in Madhya Pradesh s...
  • Machupicchu (ancient city, Peru)
    site of ancient Inca ruins located about 50 miles (80 km) northwest of Cuzco, Peru, in the Cordillera de Vilcabamba of the Andes Mountains. It is perched above the Urubamba River valley in a narrow saddle between two sharp peaks—Machu Picchu (“Old Peak”) and Huayna...
  • Machupijchu (ancient city, Peru)
    site of ancient Inca ruins located about 50 miles (80 km) northwest of Cuzco, Peru, in the Cordillera de Vilcabamba of the Andes Mountains. It is perched above the Urubamba River valley in a narrow saddle between two sharp peaks—Machu Picchu (“Old Peak”) and Huayna...
  • machzor (Judaism)
    originally a Jewish prayer book arranged according to liturgical chronology and used throughout the entire year. Though cantors (hazzanim) still use such a book, mahzor has come to mean the festival prayer book, as distinguished from the siddur, the prayer book used on the ordinary sabbath and on weekdays....
  • machzorim (Judaism)
    originally a Jewish prayer book arranged according to liturgical chronology and used throughout the entire year. Though cantors (hazzanim) still use such a book, mahzor has come to mean the festival prayer book, as distinguished from the siddur, the prayer book used on the ordinary sabbath and on weekdays....
  • machzors (Judaism)
    originally a Jewish prayer book arranged according to liturgical chronology and used throughout the entire year. Though cantors (hazzanim) still use such a book, mahzor has come to mean the festival prayer book, as distinguished from the siddur, the prayer book used on the ordinary sabbath and on weekdays....
  • Macià, Francesc (Catalan politician)
    Catalan leader and founder of the nationalist party Estat Català (1922), who played a major role in achieving an autonomous status for Catalonia....
  • Macias Nguema Biyogo (island and province, Equatorial Guinea)
    island in the Bight of Biafra (Gulf of Guinea), lying about 60 miles (100 km) off the coast of southern Nigeria and 100 miles (160 km) northwest of continental Equatorial Guinea, western Africa. The island was named after the first president of the country in 1973, but Bioko became the local official name after he was deposed in 1979. Volcanic in origin, it is parallelogram-shaped with a north...
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