Drogo de Hauteville was a Norman count of Apulia (1046–51), half brother of the conqueror Robert Guiscard. He led the Norman conquest of southern Italy after the death of his older brother William Iron Arm, whom he succeeded as count of Apulia. Arriving in Italy about 1035 with William and his

Drohobych, city, western Ukraine. Known from the 11th and 12th centuries for its salt, it was a small trade and administrative centre until the 19th century, when it expanded with the development of nearby deposits of ozokerite, petroleum, and natural gas. Potassium and magnesium also have been

Drohobych, city, western Ukraine. Known from the 11th and 12th centuries for its salt, it was a small trade and administrative centre until the 19th century, when it expanded with the development of nearby deposits of ozokerite, petroleum, and natural gas. Potassium and magnesium also have been

Drogheda, urban district and seaport on the southern border of County Louth, Ireland. Drogheda lies along the River Boyne about 4 miles (6.5 km) from its mouth. Drogheda was a stronghold and trading post of the Norsemen in the 8th–11th century and of the Anglo-Normans in the 12th century. Two towns

Bandon, town, County Cork, Ireland, 17 miles (27 km) southwest of Cork. Founded in 1608 by Richard Boyle, later 1st earl of Cork, Bandon was initially populated by English and Scottish settlers. Parts of the original town wall remain; the ruins of a 15th-century castle are nearby. Kilbrogan Church

Banbridge, town and former district (1973–2015) within the former County Down, now part of Armagh City, Banbridge and Craigavon district, southeastern Northern Ireland. Located on the River Bann, the town of Banbridge came into existence following the building of a stone bridge across the river in

Loys Bourgeois: …Droict Chemin de musique (1550; The Direct Road to Music) in which he proposed an adaptation of traditional solmization.

Dromore, town, Armagh City, Banbridge and Craigavon district, southeastern Northern Ireland, lying on the River Lagan just southwest of Belfast. A bishopric developed from an abbey reputedly founded there by St. Colman about 600. The town and cathedral were destroyed in an insurrection (1641). The

inheritance: Modern tendencies: …of the fente and the droit de retour. Under the former, the estate is divided equally between the paternal and the maternal lines (and under the refente between the various lines of grandparents). Under the droit de retour, assets that were received as a gift by an intestate who dies…

Emmerich de Vattel: …a Swiss jurist who, in Le Droit des gens (1758; “The Law of Nations”), applied a theory of natural law to international relations. His treatise was especially influential in the United States because his principles of liberty and equality coincided with the ideals expressed in the Declaration of Independence. In…

Declaration of the Rights of Man and of the Citizen, one of the basic charters of human liberties, containing the principles that inspired the French Revolution. Its 17 articles, adopted between August 20 and August 26, 1789, by France’s National Assembly, served as the preamble to the Constitution

Droitwich, town (parish), Wychavon district, administrative and historic county of Worcestershire, west-central England. The older portion of the town lies along the River Salwarpe, a tributary of the River Severn; the modern portion lies on higher ground. Droitwich is famous for the salt obtained

droll, short comic scene or farce adapted from an existing play or created by actors, performed in England during the period of the Civil Wars and the Commonwealth (1642–60) while the London theatres were closed down by the Puritans. Because stage plays were prohibited at this time, actors

Droll Stories, collection of short stories by Honoré de Balzac, published in three sets of 10 stories each, in 1832, 1833, and 1837, as Contes drolatiques. Rabelaisian in theme, the stories are written with great vitality in a pastiche of 16th-century language. The tales are fully as lively as the

droll, short comic scene or farce adapted from an existing play or created by actors, performed in England during the period of the Civil Wars and the Commonwealth (1642–60) while the London theatres were closed down by the Puritans. Because stage plays were prohibited at this time, actors

droll, short comic scene or farce adapted from an existing play or created by actors, performed in England during the period of the Civil Wars and the Commonwealth (1642–60) while the London theatres were closed down by the Puritans. Because stage plays were prohibited at this time, actors

dromaeosaur, (family Dromaeosauridae), any of a group of small to medium-sized carnivorous dinosaurs that flourished in Asia and North America during the Cretaceous Period (145.5 million to 65.5 million years ago). Agile, lightly built, and fast-running, these theropods were among the most

dromaeosaur, (family Dromaeosauridae), any of a group of small to medium-sized carnivorous dinosaurs that flourished in Asia and North America during the Cretaceous Period (145.5 million to 65.5 million years ago). Agile, lightly built, and fast-running, these theropods were among the most

dromaeosaur: Dromaeosaurus and Velociraptor both reached a length of about 1.8 metres. There is debate as to whether Microraptor, the smallest and most birdlike dinosaur known, is a dromaeosaur or a troodontid. Only about the size of a crow, Microraptor appears to have possessed feathers. The…

emu: The Kangaroo Island emu (D. baudinianus), found only on Kangaroo Island in South Australia, was likely hunted to extinction prior to 1827.

emu: The King Island emu (D. minor), a species found only on King Island in the Bass Strait, was last seen in the wild in 1802, and the last captive specimens died in 1822. The Kangaroo Island emu (D. baudinianus), found only on Kangaroo Island in South…

emu, (Dromaius novaehollandiae), flightless bird of Australia that is the second largest living bird: the emu is more than 1.5 metres (5 feet) tall and may weigh more than 45 kg (100 pounds). The emu is the sole living member of the family Dromaiidae (or Dromiceiidae) of the order Casuariiformes,

crab plover, (species Dromas ardeola), long-legged, black and white bird of Indian Ocean coasts, related to plovers and allied species of shorebirds. It comprises the family Dromadidae (order Charadriiformes). Crab plovers are tame, noisy birds about 40 cm (16 inches) long. They flock on beaches

Rhône-Alpes: Savoie, Isère, Drôme, and Ardèche. In 2016 the Rhône-Alpes région was joined with the région of Auvergne to form the new administrative entity of Auvergne-Rhône-Alpes.

dromedary, Arabian (one-humped) riding camel (Camelus dromedarius), a swift domestic species not found in the wild. Although wild dromedaries are extinct, the importation of dromedaries to Australia in the 19th century resulted in the establishment of a feral population that continues to live in

dinosaur: Clues to dinosaurian metabolism: Gallimimus, and Dromiceiomimus, had long hind legs and must have been very fleet. The dromaeosaurs, such as Deinonychus, Velociraptor, and Dromaeosaurus, also were obligatory bipeds. They killed prey with talons on their feet, and one can argue that it must have taken

emu, (Dromaius novaehollandiae), flightless bird of Australia that is the second largest living bird: the emu is more than 1.5 metres (5 feet) tall and may weigh more than 45 kg (100 pounds). The emu is the sole living member of the family Dromaiidae (or Dromiceiidae) of the order Casuariiformes,

monito del monte, (Dromiciops gliroides), a small opossum representing an ancient group related to Australian dasyurid marsupials. It is the only surviving species of the order Microbiotheria (family Microbiotheriidae) and differs from other living American opossums by having uncrowded lower

Albania: The Illyrians: …type of warship called the liburnian.

Dromore, town, Armagh City, Banbridge and Craigavon district, southeastern Northern Ireland, lying on the River Lagan just southwest of Belfast. A bishopric developed from an abbey reputedly founded there by St. Colman about 600. The town and cathedral were destroyed in an insurrection (1641). The

Dromore: The 8th- or 9th-century Cross of Dromore, formerly in the marketplace, was restored and reerected beside the Lagan Bridge in 1887. Pop. (2001) 4,959; (2011) 6,011.

Aegean civilizations: The Shaft Grave Period on the mainland (c. 1600–1450): …parts: a narrow entranceway, or dromos, often lined with fieldstones and later with cut stones; a deep doorway, or stomion, covered over with one to three lintel blocks; and a circular chamber with a high vaulted or corbeled roof, the thalamos. When the facades are finely dressed with cut stones…

A Dream Play, fantasy play in 14 scenes by August Strindberg, published in Swedish as Ett drömspel in 1902 and first produced in 1907. Presented as a dream, this fluid tableau of human foibles is a poignant lament that humans are to be pitied. As the play opens, the daughter of the Vedic god Indra

beekeeping: Honeybees: …to 1,000 male bees, or drones. The female of most species of bees is equipped with a venomous sting.

unmanned aerial vehicle (UAV), military aircraft that is guided autonomously, by remote control, or both and that carries sensors, target designators, offensive ordnance, or electronic transmitters designed to interfere with or destroy enemy targets. Unencumbered by crew, life-support systems, and

drone, in music, a sustained tone, usually rather low in pitch, providing a sonorous foundation for a melody or melodies sounding at a higher pitch level. The term also describes an instrumental string or pipe sustaining such a tone—e.g., the drone strings of a hurdy-gurdy or the three drone pipes

Drones, War, and Peace: …witnessing the future as unmanned drones fly over every 15 minutes, loaded with laser-guided bombs. Those controlling the drones are half a world away, watching on computer screens, untouched by grief as their missiles detonate inside communities of flesh and blood. In the next phase similar drones will be autonomous,…

didjeridu, wind instrument in the form of a straight wooden trumpet. The instrument is made from a hollow tree branch, traditionally eucalyptus wood or ironwood, and is about 1.5 metres (5 feet) long. Decorated ceremonial varieties, however, may be two or three times longer. Modern instruments may

ARCHIVED TOPIC: This topic was archived on March 31, 2025, and will no longer be updated. Unmanned aerial vehicles (UAVs), otherwise known as drones, are remotely controlled aircraft that may be armed with missiles and bombs for attack missions. Since the World Trade Center attacks on Sept. 11,

I have spent much of my life creating art for peace in the face of war. As an artist, filmmaker, and photojournalist, I have witnessed more than three decades of wars from the front line, in Nicaragua, Cambodia, the Philippines, Somalia, Western Sahara, Palestine, South Africa, Northern Ireland,

drongo, any of approximately 26 species of Old World woodland birds constituting the family Dicruridae (order Passeriformes). Drongos frequently attack much larger birds (e.g., hawks and crows) that might hurt their eggs or young; innocuous birds (such as doves and orioles) nest near drongos to

Edwin Drood, fictional character, the alleged victim in the unfinished novel The Mystery of Edwin Drood (1870) by Charles

proportional representation: Single transferable vote: …developed a quota (the so-called Droop quota) to determine the number of votes a candidate needed to capture to win election under STV. The quota is calculated by dividing the total number of valid votes cast by the number of seats to be filled plus one, and one is then…

baking: The sponge-and-dough method: …for this process, called the drop or break, depends on such variables as temperature, type of flour, amount of yeast, absorption, and amount of malt, which are frequently adjusted to produce a drop in about three to five hours.

baseball: The pitching repertoire: The fundamental, or regulation, curve is a swerving pitch that breaks away from the straight line, to the left (the catcher’s right) if thrown by a right-handed pitcher, to the right if by a left-hander. Some pitchers also employ a curving ball that breaks in the opposite way from…

drop cut, method of faceting gemstones into a pear shape suitable for pendants, earrings, and other jewelry. A pendeloque, a shape credited to Louis de Berquem in the 15th century, is a pear-shaped modification of the round brilliant cut used for diamonds. A briolette is an elongated pear-shaped

Rik Mayall: Career and personal life: …of the dark romantic comedy Drop Dead Fred opposite actress Phoebe Cates. The film was not a critical success, but over the years it has remained popular as a fan favourite and cult classic. Mayall returned to a seemingly more comfortable fit in British television comedy, working again with Edmondson…

Del Shannon: Drop Down and Get Me (1982), a strong album and a modest chart success, was produced by Tom Petty and featured his band, the Heartbreakers.

drop forging, Process of shaping metal and increasing its strength. In most forging, an upper die is forced against a heated workpiece positioned on a stationary lower die. If the upper die or hammer is dropped, the process is known as drop forging. To increase the force of the blow, power is

keel: A “centreboard”—also called a drop keel, or sliding keel—is a retractable keel midships that may be lowered to increase lateral resistance and prevent sideslip. A “skeg” is an aftward extension of the keel intended to keep the boat moving straight and to protect the propeller and rudder from underwater…

materials testing: Specific heat: …is generally measured by the drop method, which involves adding a known mass of the material at a known elevated temperature to a known mass of water at a known low temperature and determining the equilibrium temperature of the mixture that results. Specific heat is then computed by measuring the…

tennis: Strategy and technique: The drop shot, which is often hit from the same motion as a drive, attempts to get the ball just over the net with underspin so that it barely bounces, either catching an opponent flat-footed in the backcourt where he cannot reach the ball or forcing…

spindle and whorl, Earliest device for spinning fibres into thread or yarn. The spinster lets the spindle fall to draw out the fibres while the whorl keeps it rotating to apply the necessary twist. The spindle and whorl was replaced by the spinning

Guy Ben-Ner: … (2009), and the “live film” Drop the Monkey (2009), which he made with no external editing, rehearsals, or other conventional elements of film for Performa 2009, the third biennial of visual art performance in New York City.

liquid: Surface tension: …shape of a volume of liquid is one that has a minimum area—i.e., a sphere. In the Earth’s field this shape is found only for small drops, for which the gravitational forces, since they are proportional to the volume, are negligible compared with surface forces, which are proportional to the…

James Gandolfini: …relationship, and the crime drama The Drop (2014), in which he played a corrupt bar owner, were released posthumously.

drop-leaf table, table with one or two hinged leaves supported by articulated legs, arms, or brackets. An early 17th-century form is the gateleg table, which was followed by two later English forms—the Pembroke table and its more elongated version, the sofa table, which dates from about the 1790s.

roller coaster: Coney Island amusement park: …high-speed coaster, Drop-the-Dip (later called Rough Riders). These increased levels of danger, however, brought improvements in safety, such as the introduction of lap bars, which kept passengers seated. Prior to lap bars, riders simply held on to seat handles during inversions while being pressed into their seats by the g-forces…

Yiddish literature: Yiddish women writers: Celia Dropkin lived in Warsaw and Kiev before immigrating to the United States in 1912. She began writing poetry in Russian. She was associated with both Di Yunge and the Introspectivists, and, in the words of critic Kathryn Hellerstein, “her poems of sex, love, and…

industrial glass: Phase separation: …of phase separation exist, the nucleated droplet and the spinodal; the microstructures produced by these two mechanisms, as revealed by electron microscopy, are shown in Figure 4. In Figure 4A the interface between the droplets and the matrix is sharp, owing to a sharp change in composition. With time the…

cave: Doline karst: The latter, known as cover collapse sinks and cover subsidence sinks, occur where soils are thick and can be washed into the subsurface by the process of soil piping. Soil loss begins at the bedrock interface. An arched void forms, which migrates upward through the soil until finally the…

Claes Oldenburg: …century, installing various sculptures, including Dropped Cone (2001), which was placed atop a shopping mall in Cologne, Germany. Their final collaboration, Tumbling Tacks, was unveiled on the grounds of the Kistefos Museum, Jevnaker, Norway, in 2009, several months after van Bruggen died from breast cancer. In 2011 Oldenburg created his…

rugby: Scoring: …it through the uprights (“drop-goal”). In 1892 a try was worth three points, and drop-goals were worth four points. Penalty goals were introduced in 1894. By 1900 a try counted three points, a goal converting a try added two more points, and a penalty or drop-goal from the field…

baseball: Getting on base: …of reaching base is the dropped third strike. If, with two men out or with first base unoccupied regardless of how many are out, the batter swings and misses the ball for his third strike or the umpire calls the third strike and if the catcher does not catch the…

Sir John Tenniel: …famous cartoon was probably “Dropping the Pilot” (1890), on the subject of Bismarck’s resignation. Tenniel was knighted in 1893 and retired from Punch in 1901. He illustrated many books; his drawings for Alice’s Adventures in Wonderland and Through the Looking-Glass are remarkably subtle and clever and are extremely well-suited…

dropshipping, an e-commerce business model in which the vendor does not hold the product inventory but serves as an intermediary between the buyers and a third-party supplier. The dropshipping model became possible with the growth of online content and social media, which allow the vendor to reach

Cyrus Adler: …became the first president of Dropsie College for Hebrew and Cognate Learning, in Philadelphia. There Adler published and edited the Jewish Quarterly Review, which had been previously printed in England. With Schechter, in 1913, he created the United Synagogue of America, a laymen’s organization that remains the chief organ of…

tropical cyclone: Use of satellites and aircraft: …and an instrument called a dropsonde is released through the bottom of the aircraft to measure the temperature, humidity, atmospheric pressure, and wind speed. In many cases, the naming of a tropical storm, or its upgrade from tropical storm to tropical cyclone, is based on aircraft observations.

varved deposit: These clasts are called dropstones and were introduced vertically through the water column into the lake area, where only fine-grained sediments normally accumulate, by ice rafting and melting. This phenomenon of disrupted varvites constitutes the strongest evidence of past glacial activity in a region.

anasarca, a severe, generalized form of edema

sundew, (genus Drosera), genus of approximately 152 carnivorous plant species in the family Droseraceae. Sundews are widely distributed in tropical and temperate regions, especially in Australia, and are common in bogs and fens with sandy acidic soil. Carnivory does not provide sundews with energy

sundew: Major species: The Cape sundew (D. capensis), native to the Cape region of South Africa, features long narrow leaves with red-tipped glands and is commonly sold as a novelty plant. Two species (D. katangensis and D. insolita) native to the Democratic Republic of the Congo are listed as…

sundew: Major species: katangensis and D. insolita) native to the Democratic Republic of the Congo are listed as critically endangered on the IUCN Red List of Threatened Species.

sundew: Major species: Two species (D. katangensis and D. insolita) native to the Democratic Republic of the Congo are listed as critically endangered on the IUCN Red List of Threatened Species.

sundew: Major species: …and west European sundew, the roundleaf sundew (Drosera rotundifolia), has small white or pinkish flowers 1.25 cm (0.5 inch) across or less and bears round flat leaves with purplish hairs on a long fuzzy stalk. The Cape sundew (D. capensis), native to the Cape region of South Africa, features long…

Droseraceae, sundew plant family, consisting of three genera and some 155 species of carnivorous plants in the order Caryophyllales. With the exception of the aquatic genus Aldrovanda, the members of Droseraceae typically grow in bogs and fens with poor soil conditions. The largest genus, Drosera,

Jules Hoffmann: …for regulating a gene called drosomycin, which encodes an antifungal peptide. Hoffmann found that mutations in molecules in the signaling pathway, known as the Toll (from the German word meaning “amazing” or “great”) signaling pathway, resulted in reduced survival of Drosophila following fungal infection. The discovery was crucial because it…

vinegar fly, (genus Drosophila), any member of a genus in the small fruit fly family, Drosophilidae (order Diptera). Drosophila species number about 1,500. Some species, particularly D. melanogaster, are used extensively in laboratory and field experiments on genetics and evolution because they are

Drosophila, genus of flies commonly known as vinegar flies but also misleadingly called fruit flies. See vinegar

evolution: Ethological (behavioral) isolation: The vinegar flies Drosophila serrata, D. birchii, and D. dominicana are three sibling species (that is, species nearly indistinguishable morphologically) that are endemic in Australia and on the islands of New Guinea and New Britain. In many areas these three species occupy the same territory, but no hybrids are known…

evolution: Ethological (behavioral) isolation: birchii, and D. dominicana are three sibling species (that is, species nearly indistinguishable morphologically) that are endemic in Australia and on the islands of New Guinea and New Britain. In many areas these three species occupy the same territory, but no hybrids are known to occur in…

evolution: Geographic speciation: willistoni and D. equinoxialis, each consist of groups of populations in the first stage of speciation and are identified as different subspecies. Two D. willistoni subspecies live in continental South America—D. willistoni quechua lives west of the Andes and D. willistoni willistoni east of the Andes. They…

Calvin Blackman Bridges: …experiments using the fruit fly, Drosophila melanogaster, which showed that heritable variations in the insect could be traced to observable changes in its chromosomes. These experiments led to the construction of “gene maps” and proved the chromosome theory of heredity. Bridges, with Morgan and Alfred Henry Sturtevant, published these results…

evolution: Geographic speciation: …species of the group is D. paulistorum, a species that includes groups of populations well into the second stage of geographic speciation. Six such groups have been identified as semispecies, or incipient species, two or three of which are sympatric in many localities. Male hybrids between individuals of the different…

Theodosius Dobzhansky: …populations of the vinegar fly Drosophila pseudoobscura, he found extensive genetic variability. Furthermore, about 1940 evidence accumulated that in a given local population some genes would regularly change in frequency with the seasons of the year. For example, a certain gene might appear in 40 percent of all individuals in…

evolution: Ethological (behavioral) isolation: The vinegar flies Drosophila serrata, D. birchii, and D. dominicana are three sibling species (that is, species nearly indistinguishable morphologically) that are endemic in Australia and on the islands of New Guinea and New Britain. In many areas these three species occupy the same territory, but no hybrids…

evolution: Geographic speciation: …related species of New World Drosophila flies that have been extensively studied by evolutionists for several decades. Two of these sibling species, D. willistoni and D. equinoxialis, each consist of groups of populations in the first stage of speciation and are identified as different subspecies. Two D. willistoni subspecies live…

fruit fly: …flies, and those of the Drosophilidae as small fruit flies or vinegar flies. (See vinegar fly.)

carnivorous plant: Major families: …placed within its own family, Drosophyllaceae (order Caryophyllales), of which it is the only species.

carnivorous plant: Major families: Once classified within Droseraceae, the Portuguese sundew (Drosophyllum lusitanicum) is now placed within its own family, Drosophyllaceae (order Caryophyllales), of which it is the only species.

Aernout Drost was a Dutch writer whose historical novels were the first important works of the 19th-century Romantic movement in the Netherlands. His passion for history influenced many of his contemporaries and successors. Drost’s first novel, Hermingard van de Eikenterpen (1832; “Hermingard of

Annette, Freiin von Droste-Hülshoff was a poet and prose writer, among the most important poets of 19th-century Germany and the author of a novella considered a forerunner of 19th-century realistic fiction. Born into a family of Roman Catholic aristocracy, she was educated by tutors and lived most

drott-kvaett, a medieval Scandinavian verse form used in skaldic poetry. Drott-kvaett consists of stanzas of eight regular lines, each of which has three stresses and ends with a trochee. The form exhibits a complex pattern of internal and terminal rhyme, alliteration, and especially alternation of

Carl Jonas Love Almqvist: …rewritten and published 1839) and Drottningens juvelsmycke (1834; “The Queen’s Diamond Ornament”), a historical novel whose heroine, the mysterious, hermaphroditic Tintomara, is Almqvist’s most fascinating character and a central symbol in his creative writings. Det går an (1838; Sara Videbeck, 1919) is a brilliant, realistic story pleading for the emancipation…

Nicodemus Tessin, the Elder: …in Sweden, the palace at Drottningholm (1662–86), was commissioned by the dowager queen Hedvig Eleonora. It shows French Baroque influences in its plan, gardens, and interior, but it also has Italian Classical elements and is capped by the peculiarly Nordic sateri roof. Tessin’s other principal works are the cathedral at…

Lake Mälaren: The island of Drottningholm (Queen’s Island) has a 17th-century palace that is a royal summer residence with a fine park and formal gardens. The château of Skokloster, south of Uppsala, on the northern arm of Lake Mälaren, has a remarkable collection of trophies, including an armoury, from the…

Drottningholm Palace, Royal palace, near Stockholm. It was designed by Nicodemus Tessin (1615–81) and built 1662–86. It shows French Baroque influences in its plan, gardens, and interior, but it also has Italian Classical elements and is capped by a Nordic sateri roof. A theatre attached to it was

Drottningholm Theatre, 18th-century court theatre of the Royal Palace of Drottningholm, near Stockholm, Swed. It is preserved with its original sets and stage machinery as a theatrical museum. Built in the 1760s by the architect Carl Fredrik Adelcrantz, it was the home of several French and Swedish

Drottningholm Theatre, 18th-century court theatre of the Royal Palace of Drottningholm, near Stockholm, Swed. It is preserved with its original sets and stage machinery as a theatrical museum. Built in the 1760s by the architect Carl Fredrik Adelcrantz, it was the home of several French and Swedish

Jean-Germain Drouais was a historical painter who was one of the leading early Neoclassicists in France. Drouais’s father, François-Hubert Drouais (1727–75), and his grandfather, Hubert Drouais (1699–1767), were well-known portrait painters. Jean studied first under his father, then under N.-G.