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570 I draft ► Drakensberg
Count Dracula in Tod Browning’s 1931 horror film version. Stoker had named the character for the notoriously cruel Vlad III Tepes (1431-76), a ruler of Walachia, whose epithet was Dracula (“Son of the Dragon”).V- lad was said to have put to death 20,000 men, women, and children by impaling them upright on stakes. The Dracula character became a stock figure in the horror repertoire, portrayed with varying degrees of sympa¬ thy and repulsion.
draft See bill of exchange draft See conscription
Draft Riot of 1863 Four days of violence in New York City to pro¬ test the inequities of American Civil War conscription. The law permitted draftees to buy their way out of army service for $300, a sum relatively few men could afford. When the drawing of names began on July 11, mobs of Irish and other foreign-born workers surged into the streets, burning draft headquarters and other buildings, and assaulting blacks, who they had feared would take their jobs. About 100 people (mostly rioters) died.
drafting Precise graphical representation of a structure, machine, or its component parts that communicates the intent of a technical design to the fabricator (or the prospective buyer) of the product. Drawings may present the various aspects of an object’s form, show the object projected in space, or explain how it is built. Drafting uses orthographic projection, in which the object is viewed along parallel lines that are perpendicular to the plane of the drawing. Orthographic drawings include top views (plans), flat front and side views (elevations), and cross-sectional views showing profile. Perspective drawing, which presents a realistic illusion of space, uses a horizon line and vanishing points to show how objects and spatial rela¬ tionships might appear to the eye, including diminution of size and con¬ vergence of parallel lines. Drafting was done with precision instruments (T square or parallel rule, triangle, mechanical pens and pencils) until computerization revolutionized production methods in architectural and engineering offices.
drafting See drawing
drag Force exerted by a fluid stream on any obstacle in its path or felt by an object moving through a fluid. Its magnitude and how it may be reduced are important to designers of moving vehicles, ships, suspension bridges, cooling towers, and other structures. Drag forces are convention¬ ally described by a drag coefficient, defined irrespective of the shape of the body. Dimensional analysis reveals that the drag coefficient depends on the Reynolds number; the precise dependence must be elucidated experi¬ mentally and can be used to predict the drag forces experienced by other bodies in other fluids at other velocities. Engineers use this principle of dynamic similarity when they apply results obtained with a model struc¬ ture to predict the behaviour of other structures. See also friction; stream¬ line.
drag racing Form of motor racing in which two contestants race side by side from a standing start over a straight quarter-mile strip of pave¬ ment. Winners go on to compete against others in their class until only one is left undefeated. There are three main classes of vehicle: (1) the Top Fuel Eliminator (called a “rail” or “slingshot”), a lightweight, long- chassied vehicle with wide rear tires that is fueled by a special mixture, such as methanol and nitromethane; (2) the “funny car,” a high- performance copy of a late-model production car that uses special fuel; and (3) the standard production car, a modified version of a gasoline- powered production car. The Top Fuel class is the fastest, followed by the funny car. Drag racing is most popular in the U.S.
dragon Legendary monster usually depicted as a huge, bat-winged, fire-breathing lizard or snake with a barbed tail. The dragon symbolized evil in the ancient Middle East, and the Egyptian god Apepi was the great serpent of the world of darkness. The Greeks and Romans sometimes rep¬ resented dragons as evil creatures and sometimes as beneficent powers acquainted with the secrets of the earth. In Christianity the dragon sym¬ bolized sin and paganism, and saints such as St. George were shown tri¬ umphing over it. Used as warlike emblems in many cultures, dragons were carved on the prows of Norse ships and depicted on royal ensigns in medieval England. In the Far East the dragon was a beneficent creature, wingless but regarded as a power of the air. In China it symbolized yang in the yin-yang of cosmology, and it served as the emblem of the royal family.
dragon worm See guinea worm
dragonfly Any member of the insect suborder Anisoptera (order Odo- nata), characterized by four large, membranous, many-veined wings, that, when at rest, are held horizon¬ tally rather than vertically (see dam- selfly). Dragonflies are agile and have bulging eyes that often occupy most of the head and a wingspan of about 6 in. (16 cm). The dragonfly is one of the fastest-flying and most preda¬ ceous insects; in 30 minutes it can eat its own weight in food. Dragonflies differ from most other insects by hav¬ ing the male copulatory organs at the front part of the abdomen rather than at the back end. Male and female often fly in tandem during sperm transfer.
dragoon In late 16th-century Europe, a mounted soldier who fought as a light cavalryman on attack and as a dismounted infantryman on defense. The term derived from his weapon, a short musket called the dragoon. Dragoons were organized in companies, and their officers bore infantry titles. By the 18th century, dragoon referred to members of certain cav¬ alry regiments. The term is still applied in the British Army to certain armoured reconnaissance units.
Drake, Sir Francis (b. c. 1540-43, Devonshire, Eng.—d. Jan. 28, 1596, at sea, off Puerto Bello, Pan.)
English admiral, the most renowned seaman of the Elizabethan Age.
Brought up by his wealthy Hawkins relatives (see John Hawkins) in Ply¬ mouth, Drake went to sea at about age 18. He gained a reputation as an outstanding navigator and became wealthy by raiding and plundering Spanish colonies. In 1577 he set sail with five ships, but ultimately only his flagship, the Golden Hind, made its way through the Strait of Magel¬ lan into the Pacific and up the coast of South and North America. He sailed at least as far north as what is now San Francisco, claiming the area for Elizabeth, and continued westward to the Philippines and around the Cape of Good Hope.
Having circumnavigated the globe, he returned to Plymouth, Eng., in 1580 laden with treasure, the first captain ever to sail his own ship around the world. In 1581 he was knighted. Appointed vice admiral (1588), he destroyed ships and supplies destined for the Spanish Armada and delayed the Spanish attack for a year. But he is not known to have played any part in the battle that eventually occurred. In his lifetime, his reputation at home was equivocal, yet his legend grew. On his last voyage he suc¬ cumbed to fever and was buried at sea.
Drake equation or Green Bank equation Equation claimed to yield the number of technically advanced civilizations capable of inter¬ stellar communication in the Milky Way Galaxy as a function of several factors conducive to evolution of intelligent life with technological capa¬ bilities. It was largely developed by Frank D. Drake (b. 1930) in 1961 at a SETI conference in Green Bank, W.Va. Of all the stars that form in the Galaxy, only some will give rise to life-supporting planets, and of those planets, only some will generate life capable of high technology and yet able to avoid technological destruction. Because the numbers for each factor are poorly known, the results generated vary from zero to millions.
Drake Passage Strait, connecting the Atlantic and Pacific oceans between Tierra del Fuego and the South Shetland Islands. Located about 100 mi (160 km) north of the Antarctic Peninsula, it is 600 mi (1,000 km) wide. In this area the climate changes from cool, humid, and subpolar to the frozen conditions of Antarctica. An important trade route in the 19th and early 20th centuries, its stormy seas and icy conditions made the rounding of Cape Horn a difficult journey.