Porfirio Díaz
Díaz, Porfirio (1830–1915), Mexican general and president.
Díaz, Porfirio (1830–1915), Mexican general and president.
D'lndy, (Paul Marie Théodore) Vincent (1851–1931), French composer.
D'Oyly Carte, Richard (1844–1901), English impresario.
Diana, in Roman mythology, goddess of the moon and the hunt, later identified with the Greek goddess Artemis.
Diana Spencer, Princess of Wales (1961–97), British princess, married Prince Charles in 1981.
Diaphragm, in anatomy, dome-shaped, muscular partition separating the chest cavity from the abdominal cavity in humans and mammals.
Diarrhea, abnormally frequent evacuation of watery stools.
Diary, book containing a daily record of events and personal observations.
Dias or Diaz, Bartholemeu (d. 1500), Portuguese navigator and explorer who, in 1488, discovered the sea route around Africa past the Cape of Good Hope to India.
Diaspora See: Jews.
Diathermy, therapeutic use of high-frequency electric current to induce heat within deep tissues of the body that cannot be reached by surface heat.
Diatom, single-celled alga plant (class Bacillariophyceae) of fresh and salt water.
Dice (singular: die), two 6-sided cubes with sides numbered from 1 to 6.
Dick, Philip Kendrid (1928–82), U.S. science fiction author whose works illustrate his philosophical ideas and concentrate on the characters instead of action or technology.
Dickcissel (Spiza americana), small bird of the prairies of the central United States, named for its song.
Dickens, Charles (1812–70), English novelist.
Dickey, James Lafayette (1923– ), U.S. poet, novelist, and critic.
Dickinson, Anna Elizabeth (1842–1932), U.S. abolitionist and orator who spoke out for the rights of women and African-Americans.
Dickinson, Emily (1830–86), U.S. poet.
Dickinson, John (1732–1808), U.S. statesman.
Dictatorship, form of government in which one person holds absolute power and is not subject to the consent of the governed.
Dictionary, listing of the words of a language, usually in alphabetical order, with the meaning of each word, as well as information on pronunciation and etymology and examples of usage, with synonyms and antonyms. Foreign language dictionaries generally list only the translations of words without their definitions. Specialized or technical dictionaries define terms used in a particular field. The…
Diderot, Denis (1713–84), French encyclopedist, philosopher, and writer.
Didion, Joan (1934– ), U.S. writer concerned with the “atomization” of post-World War II society.
Didrikson, Babe See: Zaharias, Babe Didrikson.
Diefenbaker, John George (1895–1979), Canadian prime minister, 1957–63.
Diego Garcia, island in the Indian Ocean southwest of Sri Lanka.
Diem, Ngo Dinh See: Ngo Dinh Diem.
Diemaking See: Dies and diemaking.
Dien Bien Phu, military outpost in North Vietnam where in 1954 France was finally defeated in the Indochina War.
Dies and diemaking, tools and procedures for casting molds to shape metal in industrial processes.
Diesel engine, internal combustion engine patented in 1892 by the German engineer Rudolf Diesel (1858–1913).
Diesel, Rudolf (1858–1913), German engineer and developer of the oil-fueled internal-combustion engine that is named after him.
Diet, customary or specified kind of food and drink taken daily.
Dietitian, one who applies the principles of nutrition to the feeding of an individual or a group of individuals.
Dietrich of Bern See: Theodoric.
Dietrich, Marlene (Maria Magdalene von Losch; 1904–92), German-born U.S. actress and cabaret artist.
Diffraction, deviation and spreading of waves (such as electromagnetic radiation, sound or water waves) from a straight line, occurring when waves encounter an obstacle.
Diffusion, gradual mixing of different substances placed in mutual contact, due to the random thermal motion of their constituent particles.
Digestive system, organs in the body that play a major role in the digestion of food, including the mouth, esophagus, stomach, and bowels. The pancreas and liver secrete juices that assist in the digestive processes. The muscular activity of the digestive tract disturbs the daily existence of humans. Hunger and the desire to defecate may arise from awareness of the movement of a part of the tract.…
Digital computer See: Computer.
Digitalis, drug prepared from leaves of the foxglove plant (genus Digitalis).
Dik-dik, small African antelope (genus Madoqua), standing only 14 in (36 cm) high at the shoulder.
Dike, artificial embankment for controlling water flow.
Dill (Anethum graveolens), annual or biennial of the carrot family cultivated for its leaves and seeds, which are used as flavorings.
Dillinger, John (1903–34), U.S. gangster who terrorized the Midwest in 1933 after escaping from jail.
Dilthey, Wilhelm (1833–1911), German philosopher.
DiMaggio, Joseph Paul (1914– ), U.S. baseball player.
Dimethyl sulfoxide See: DMSO.
Dine, Jim (James Dine; 1935– ), U.S. artist.
Dinesen, Isak (Baroness Karen Blixen; 1885–1962), Danish author of romantic tales of mystery, such as Seven Gothic Tales (1934) and Winter's Tales (1942).
Dinka, plains tribe of southern Sudan, in Africa.
Dinkins, David (1927– ), first African-American mayor of New York City, elected 1990.
Dinoflagellate, single-celled organism that occurs in vast numbers in fresh and salt water.
Dinosaur (Greek, “terrible lizard”), extinct reptile that flourished between about 220 and 63 million years ago and then suddenly disappeared. Dinosaurs dominated the land life during most of this period and occurred in a wide variety of forms, some no bigger than a chicken and others weighing many tons. The dinosaurs arose in the Triassic Period (early Mesozoic Era) from a group of …
Dinwiddie, Robert (1693–1770), lieutenant governor of colonial Virginia (1751–58), who made alliances with Native American tribes to prevent French encroachment into western Pennsylvania and the Ohio Valley.
Diocletian (Gaius Aurelius Valerius Diocletianus; A.D. 245–313), Roman emperor A.D. 284–305.
Diode See: Electronics.
Diogenes (412?–323 B.C.), Greek philosopher.
Dionaea See: Venus's-flytrap.
Dionysius the Elder (430?–367 B.C.), Greek soldier who distinguished himself in battle against Carthage and thus got himself elected sovereign general of Syracuse (in 405 B.C.).
Dionysus, in Greek mythology, god of wine and fertility, generally thought of as a son of Zeus.
Diopside, mineral of the silicate family.
Dior, Christian (1905–57), French fashion designer.
Dioxin, toxic chemical produced in some chemical-manufacturing processes, contaminating various herbicides.
Diphtheria, acute contagious disease caused by Corynebacterium diphtheriae, characterized by the formation of a soft crust (pseudomembrane) that forms in the inflamed throat, and by tissue damage in the heart and nervous system, a result of poisons produced by the bacteria.
Diplodocus See: Dinosaur.
Diplomacy, conduct of negotiations and maintenance of relations in time of peace between sovereign states. A diplomatic mission is generally headed by an ambassador, supported by attachés, chargés d'affaires, and other officials specializing in economic, political, cultural, administrative, and military matters. An embassy building is considered to have extraterritoriality (to…
Dipper, small wrenlike bird (genus Cinclus) that dives under water.
Dirac, Paul Adrien Maurice (1902–84), English theoretical physicist.
Direct current See: Electric current.
Direct Selling Association, U.S. organization of some 150 companies that sell goods or services directly to the public.
Director See: Motion pictures; Theater.
Dirigible See: Airship.
Dirksen, Everett McKinley (1896–1969), U.S. legislator.
Disabled American Veterans, organization aimed at helping wounded war veterans, founded in 1920 by Judge Robert S.
Disarmament, procedure for abolishing, limiting, regulating, or reducing a nation's military forces or weapons arsenal. Widespread or universal disarmament has been a long-sought goal of many. After World War II, the existence of nuclear weapons and the split of the world into 2 hostile camps lent a new urgency to curbing the destructive power of nations. Several treaties (Nuclear Test Ban …
Disaster relief See: Civil defense; Coast Guard, U.S.; National Guard; Red Cross; Salvation Army.
Disciple See: Apostles.
Disciples of Christ (The Christian Church), now the International Convention of Christian Churches, U.S. religious body founded (1832) by followers of Alexander Campbell.
Discrimination, in science, perception of difference or of differential response, or ability to perceive slight differences.
Discus, disk thrown in athletic competition.
Disease, disturbance of normal body function in an organism. Disease is usually brought to a person's attention by symptoms of an abnormality of, or change in, body function: pain, headache, fever, cough, shortness of breath, dyspepsia, constipation, diarrhea, loss of blood, lumps, paralysis, or numbness, or loss of consciousness. Diagnosis is made on the basis of symptoms and from signs on…
Disinfectant, chemical substance or other agent, such as ultraviolet light, used to disinfect inanimate objects, with the aim of destroying or inhibiting the activity of disease-producing microorganisms.
Dislocation, movement of an organ, bone, or other body part away from its normal position, in particular the displacement of the bones of a joint.
Dismal Swamp, coastal region straddling the boundary of Virginia and North Carolina.
Disney, Walt (Walter Elias Disney; 1901–66), U.S. pioneer of animated film cartoons. Starting in the 1920s, the Disney studios in Hollywood created the cartoon characters Mickey Mouse, Pluto, Donald Duck, and Goofy. Disney produced the first full-length cartoon feature, Snow White and the Seven Dwarfs (1938), which was followed by Pinocchio (1940), Fantasia (1940), and Bambi (1942), among o…
Dispersion, optical phenomenon whereby a beam of white light is broken up into its component colors when it passes through a triangular glass prism.
Displaced person See: Refugee.
Disraeli, Benjamin, 1st earl of Beaconsfield (1804–81), British Conservative statesman, prime minister 1868 and 1874–80. Baptized a Christian, Disraeli was the first British prime minister of Jewish ancestry. A member of Parliament from 1837, he was chancellor of the exchequer 1852, 1858–59, and 1866–68. His influence was crucial in the passing of the 1867 Reform Bill, …
Dissection See: Anatomy.
Distant Early Warning line See: Dew line.
Distemper, term applied to several animal diseases, but particularly referring to a specific viral disease of dogs.
Distillation, method of separating the parts of mixtures of liquids or of separating liquids from solids.
Distilling, production of strong alcoholic drinks by distillation of the weak alcoholic liquors obtained in the fermentation of sugary substances with yeast.
District attorney, state or municipal official in charge of prosecuting criminal cases.
District of Columbia (D.C.) See: Washington, DC.
District court, federal court of original jurisdiction in the U.S. judicial system.
Disulfiram, sulphur-based drug used to treat alcoholism.
Dittersdorf, Karl Ditters von (1739–99), Austrian composer and violinist.
Diuretic, drug that increases urine production by the kidneys, removing excess sodium and water from the body.
Diverticulitis, disease of the intestine involving inflamation of diverticula, pouches or sacs that sometimes appear in the surface of the colon, causing it to bulge out in weak points.
Divide, line of high ground, such as a mountain ridge or chain of hills, that determines the direction of flow of streams and rivers.
Divination, any of various methods of foretelling the future by means of oracles, omens, or signs.
Divine, Father (George Baker; 1880?–1965), African-American religious leader.
Diving See: Swimming and diving.
Diving, deep-sea, descent by divers to the seabed, usually for extended periods, for purposes of exploration, recreation, or salvage. In 1715 John Lethbridge devised the forerunner of the armored suits used today in deepest waters. In 1802 William Forder devised a suit into which air is supplied by a pump. The diving suit today has a metal or fiberglass helmet with viewports and inhalation and exh…
Divining rod, forked stick used by diviners, or dowsers, to find buried objects or water.
Division, major combat unit of the U.S. armed forces.
Divorce, legal dissolution of a valid marriage, as distinguished from separation, in which the partners remain married but live apart, and annulment, in which the marriage is deemed to be invalid. In most cases, divorce leaves the partners free to remarry, sometimes after a set period. Divorce has existed in most cultures, but its availability and the grounds for it have varied widely. Christianit…
Dix, Dorothea Lynde (1802–87), U.S. social reformer and crusader for the humane and scientific treatment of mental illness.
Dix, Otto (1891–1969), German painter and leader of the “new objectivity” school of social realism.
Dixie, popular term for the southern states of the United States, particularly those that formed the Confederacy.
Dixiecrat Party, southern faction of the U.S.
Dizziness, sensations of whirling, giddiness, and vertigo caused by abnormal stimulation of receptors of balance or by rapid movements of the visual field, sometimes accompanied by nausea and nystagmus (rapid, jerky eye movements).
Djakarta See: Jakarta.
Djibouti (pop. 317,000), capital of the Republic of Djibouti.
Djibouti (official name, Republic of Djibouti), formerly French Somaliland, republic in northeastern Africa, situated where the coast of Africa approaches the Arabian peninsula, bounded by Ethiopia, Eritrea and Somalia. Its area is about 8,950 sq mi (23,200 km). The languages are Arabic and French. The official religion is Muslim. Most of the country is stony desert. The climate is hot. Rainfall i…
Djilas, Milovan (1911–95), Yugoslav communist leader and writer.
Dmitri (d. 1606), tsar of Russia.
DMSO, drug (dimethyl sulfoxide) proposed as an effective analgesic and anti- inflammatory agent in treating arthritis and bursitis.
DNA (deoxyribonucleic acid), informational molecules contained in the nucleus of every living cell that, along with ribonucleic acid (RNA), transmit all genetic information. The instructions of the nucleic acids are finally expressed by proteins, which form many of the structural and mechanical components of living systems and act as catalysts in the chemical activity of cells. The DNA molecule is…
Dnepr River, or Dnieper River, river in Russia, Byelarussia and Ukraine, about 1,400 mi (2,253 km) long, navigable for nearly its whole length.
Dnepropetrovsk (pop. c. 1,200,000), city in Ukraine, on the Dnepr River.
Dniester River, river in the former Soviet Union, about 875 mi (1,408 km) long.
Doberman pinscher, breed of dog originating in Germany.
Dobson fly See: Hellgrammite.
Dobzhansky, Theodosius (1900–75), U.S. biologist, famed for his study of the fruit fly, Drosophila.
Dock, large-leafed plant (genus Rumex), of the buckwheat family with clusters of small green flowers.
Doctor See: Medicine; Degree, academic.
Doctorow, E(dgar) L(aurence) (1931– ), U.S. novelist.
Dodder, parasitic plant (genus Cuscuta), that bears no leaves and gains all its nourishment from the host plant.
Dodecanese, group of about 20 Greek islands in the southeastern Aegean Sea off Turkey.
Dodge, family name of two early developers of the automobile.
Dodge City (pop. 21,129), city in southwest Kansas, on the Arkansas River, seat of Ford County.
Dodge, Mary Elizabeth Mapes (1831–1905), U.S. children's author who founded and edited the magazine St.
Dodgson, Charles Lutwidge See: Carroll, Lewis.
Dodo (Raphus cucullatus), extinct turkey-sized flightless bird with strong legs and a big bill, formerly found on the island of Mauritius.
Dodoma (pop. 85,000), capital of Tanzania, located in the central part of the country.
Doenitz, Karl (1891–1980), German admiral, head of the World War II U-boat service and later commander in chief of the German navy (1943–5).
Doesburg, Theo van (1883–1931), Dutch painter and author.
Dog, carnivorous mammal of the family Canidae.
Dog racing, spectator sport in which people gamble on dogs chasing a mechanical hare (or other lure) around a track which is generally .25 mi (.4 km) in diameter.
Dog Star See: Sirius.
Dogbane, plant (genus Apocynum), with clusters of small pinkish-white flowers and poisonous leaves and stems.
Dogfish, any of various small sharks of the family Squalidac.
Dogtooth violet (Erythronium dens-canis), also known as adder's tongue or trout lily, wildflower of eastern North America belonging to the lily family.
Dogwood, or cornel, name for any tree or shrub of the genus Cornus.
Doha (pop. 217,000), or Ad Dawhah, capital of the Middle Eastern state of Qatar.
Dohnanyi, Ernst von (1877–1960), Hungarian composer and pianist, conductor of the Budapest Philharmonic Orchestra (1919–44).
Doldrums, narrow belt of light, variable winds located between the trade winds near the equator.
Dole, Elizabeth Hanford (1936– ), U.S. politician; wife of politician Robert Dole.
Dole, Robert J. (1923– ), U.S. politician; husband of politician Elizabeth Dole.
Dole, Sanford Ballard (1844–1926), U.S. judge and leader of the Republic of Hawaii.
Dolin, Sir Anton (1904–83), English choreographer and dancer.
Doll, miniature representation of the human form, used as a toy or, in some societies, a sacred object.
Dollar, monetary unit originating in the 16th century as the German thaler, named after the Joachimsthal silver mines in Bohemia.
Dollar Decade See: Roaring Twenties.
Dollar diplomacy, U.S. foreign policy that attempts to protect the nation's political and financial interests through diplomacy.
Dollarfish See: Butterfish.
Dollinger, Johann Joseph Ignaz von (1799–1890), German Roman Catholic historian and theologian, excommunicated (1871) for rejecting the doctrine of papal infallibility.
Dolomite, calcium magnesium carbonate mineral; chemical formula CaMg(CO3)2.
Dolomites, mountain range in the eastern Alps, northeastern Italy.
Dolphin, Pacific spout fish (genus Coryphaena), of the family Coryphaenidae.
Dolphin, any of a family (Delphinidae) of small-toothed whales living in schools and feeding mainly on fish.
Domagk, Gerhard (1895–1964), German pharmacologist who discovered the antibacterial action of the dye prontosil red, which led to the discovery of other sulfa drugs.
Dome, in architecture, oval or hemispherical vault, used to roof a large space without interior supports.
Dome of the Rock See: Jerusalem.
Domenichino (Domenico Zampieri; 1581–1641), Italian Baroque painter noted for the landscape settings of his pictures.
Domesday Book, inventory of most of the land and property in England compiled by order of William the Conqueror (completed in 1086), giving the Norman overlords of the newly conquered country a basis for local control and taxation.
Domingo, Placido (1941– ), Spanish operatic tenor.
Dominic, Saint (11707–1221), Spanish-born founder of the Dominican order.
Dominica (official name, Commonwealth of Dominica), independent state, the largest island in the Windward Islands of the Lesser Antilles group, between Guadeloupe and Martinique.
Dominican Order, Roman Catholic religious order founded by Saint Dominic and confirmed by Pope Honorius III in 1216.
Dominican Republic, country in the Caribbean Sea, occupying the eastern two-thirds of the island of Hispaniola. (The western third is Haiti.) Land and climate. Parallel mountain chains cross the country from northwest to southeast. Between them are the Cibao and Vega Real lowlands, the country's main agricultural areas. The climate is subtropical, with lowland temperatures averaging 70…
Dominoes, game for 2 to 4 people, played with flat rectangular blocks usually made from wood, ivory, or bone.
Domitian (A.D. 51–96), Roman emperor (81–96), son of Vespasian and brother of Titus, whom he succeeded.
Domus Aurea See: Rome.
Don Juan, legendary libertine of Spain, often the subject of dramatic and literary works in which, after a dissolute life, he is led off to hell.
Don Quixote, classic novel by Spanish author Miguel de Cervantes.
Don River, river in the Soviet Union, about 1,220 mi (1,930 km) long.
Donatello (Donatello di Niccolo di Betto Bandi; c.1386–1466), Florentine sculptor, a major figure of the Italian Renaissance.
Donetsk (pop. c 1,100,000), large city in the Ukraine.
Donizetti, Gaetano (1797–1848), Italian opera composer.
Donjon See: Castle.
Donkey, herbivorous (plant-eating), hoofed mammal (Equus asinus), domesticated form of the wild ass.
Donleavy, J(ames) P(atrick) (1926– ), U.S. novelist and playwright.
Donne, John (1572–1631), English metaphysical poet and clergyman.
Donnelly, Ignatius (1831–1901), U.S. politician and writer.
Donner Pass, pass in the Sierra Nevada mountains of California, where a group of pioneers were trapped by snow during the winter of 1846–47.
Doodlebug See: Ant lion.
Dooley, Thomas Anthony (1927–61), U.S. physician, author, and a founder (1957) of Medico, an international medical aid organization for underdeveloped countries.
Doolittle, Hilda (1886–1961), U.S. poet who lived in Europe after 1911.
Doolittle, James Harold (1896– ), U.S. pilot and World War II air hero.
Doomsday Book See: Domesday Book.
Doppler effect, apparent change in frequency of waves of light or sound due to the motion of an observer relative to the source. If either source or observer is approaching the other, the waves are bunched together, like the folds of a squeezed accordion. The observer encounters more waves in a given period of time than would be the case if both observer and source were stationary, so the observed…
Doré, Gustave (1832–83), French engraver, illustrator, and painter.
Dorado See: Dolphin.
Dorians, people of ancient Greece.
Dorion, Marie (1790?–1850), Native American of the Iowa tribe, known for her bravery in the Astor Overland Expedition.
Dormancy See: Germination.
Dormouse, squirrel-like, nocturnal rodent of the family Gliridae that feeds on seeds, shoots, and small animals.
Dorr Rebellion, armed rebellion led by lawyer Thomas W.
Dos Passos, John (Roderigo) (1896–1970), U.S. novelist and writer of social history.
Dostoevsky, Fyodor Mikhaylovich (1821–81), Russian novelist. He spent several years in the army but resigned his commission in 1844 to devote himself to writing. His first novel, Poor Folk (1846), was well received. Arrested in 1849 as a member of a socialist circle, Dostoyevsky was condemned to be shot; however, the sentence was commuted in the execution yard to 4 years' hard labor …
Dou, Gerard (1613–75), Dutch painter.
Douala (pop. 852,700), largest city and major port of Cameroon, west central Africa, on the Wuori River, near the Gulf of Guinea.
Double jeopardy, prosecution of an individual twice for the same crime.
Double star See: Binary star.
Doubleday, Abner (1819–93), U.S.
Doughnut, small cake made of sweetened and flavored leavened dough, shaped as a “nut,” or ring, deep-fried in fat, and sprinkled lightly with sugar.
Doughty, Charles Montagu (1843–1926), English traveler and author.
Douglas See: Man, Isle of.
Douglas fir (Pseudotsuga menziesii), a cone-bearing pine tree valued for its lumber.
Douglas-Home, Alexander Frederick See: Home, Lord.
Douglas, Lloyd Cassel (1868–1951), Protestant minister and novelist.
Douglas, Stephen Arnold (1813–61), U.S. politician, Democratic representative (1843–47) and senator (1847–61) from Illinois, affectionately known as the “Little Giant.” He is remembered for his debates with Abraham Lincoln in the Illinois senatorial campaign of 1858, which brought Lincoln to national attention.
Douglas, William Orville (1898–1960), justice of the U.S.
Douglass, Frederick (Frederick Augustus Washington Bailey; 1817?–95), U.S. abolitionist, orator, and political activist who dedicated his life to the eradication of slavery and support for black rights. Born into slavery in Tuckahoe, Md., he was sent to work in Baltimore (1826), were he educated himself with the assistance of a slave master's wife. At the age of 20, he escaped and as…
Doukhobors, pacifist religious sect of Russian origin.
Doum palm, or doom palm, fruit-bearing tree of the palm family found in the Middle East and northern and central Africa.
Dove, name sometimes given to a small member of the pigeon family, for example, the rock dove (Columba livia).
Dove, Arthur Garfield (1880–1946), U.S. abstract painter.
Dover (pop. 32,800), seaport in Kent, England.
Dover (pop. 27,630), city, capital of Delaware and seat of Kent County, situated in central Delaware on the St.
Dover, Strait of, narrow passage separating southeastern England from northern France, connecting the English Channel with the North Sea.
Dow, Herbert Henry (1866–1930), pioneer in the U.S. chemistry industry.
Dow Jones Industrial Average, most frequently cited gauge of U.S. stock market performance.
Dowland, John (1563–1626), English composer and lutenist, best known for his songs and the collection of lute pieces Lachrimae (1604).
Down's syndrome, formerly called mongolism, chromosomal aberration resulting in mental retardation and physical abnormalities. In about 95% of cases of Down's syndrome, there is an extra chromosome 21, making 3 in all, hence its technical name trisomy 21. The overall incidence is about 1 in every 700 live births, but there is a marked variability depending on maternal age: In …
Dowser See: Divination.
Dowson, Ernest Christopher (1867–1900), English poet, one of the Decadents of the 1890s.
Doyle, Sir Arthur Conan (1859–1930), British writer, creator of the detective Sherlock Holmes, featured in many short stories and 4 novels.
Draco (fl. c.621 B.C.), lawgiver in Athens.
Dracula, novel (1897) by English writer Bram Stoker about a Transylvanian vampire count.
Draft, military, or conscription, system of raising armed forces by compulsory recruitment. The modern practice is more aptly described as selective service. Obligatory military service dates back to ancient times, but modern conscription began in the late 18th century when Napoleon I imposed universal conscription of able- bodied males. Peacetime conscription became standard practice in Europe in…
Dragon (Greek: drakon, “serpent”), legendary monster, usually represented as a firebreathing, winged serpent or lizard with crested head and large claws.
Dragonfly, insect of the order Odonata, indentifiable by its long, slender, abdomen, 2 pairs of transparent wings, each covered in a network of veins, and large compound eyes, which may contain 30,000 separate facets.
Drainage, removal of surplus water from land. Withot drainage, successful crop production and retention of soil fertility would be impossible. Wet lands are difficult to work with modern machinery, and most crops suffer from root injury if grown on water-logged ground. Undrained soils are structureless, with tightly packed subsoils full of stagnant water. Buildings and houses benefit from drainage…
Draisine See: Bicycle.
Drake, Edwin Laurentine See: Petroleum.
Drake, Sir Francis (1543–96), English admiral, the first English explorer to sail around the world (1577–80).
Dram See: Apothecaries' weight.
Drama See: Theater.
Dramamine, brand name of the drug dimenhydrinate, used to prevent motion sickness and to control the nausea and vomiting associated with certain illnesses.
Draughts See: Checkers.
Dravidian, member of a subgroup of the Hindu race, including some 100 million people of (mainly) southern India.
Drawbridge See: Bridge; Castle.
Drawing, pictorial representation by means of line on any surface. An artistic expression, drawing has developed in 3 main directions: as the independent, preparatory sketch for work in another medium; as the preliminary sketch eventually incorporated into another medium (for example, as the basic outline for a painting, fresco, or mural); and as an independently conceived and executed work. Littl…
Dreadnought, British battleship (built 1906) whose design became the model for warships of the first half of the 20th century.