Hall, James (b. Sept. 12, 1811, Hingham, Mass., U.S.—d. Aug. 7, 1898, Bethlehem, N.H.) U.S. geologist and paleontologist. He made extensive explorations in the St. Lawrence valley while teaching at Rens¬ selaer Polytechnic Institute (1832-36). In 1836 he was appointed state geologist for the Geological Survey of New York; his studies culminated in the massive Geology of New York (part 4, 1843), a classic in U.S. geol¬ ogy that introduced the geosynclinal theory of mountain building. He was state geologist of Iowa (1855—58) and of Wisconsin (1857-60). He served as director of New York State’s Museum of Natural History (1871-98). His major later work was the huge Paleontology of New York (13 vol.,
1847-94).
Hall, Sir Peter (Reginald Frederick) (b. Nov. 22, 1930, Bury Saint Edmonds, Suffolk, Eng.) British theatre, opera, and film director. After producing and acting in plays at Cambridge University, he entered the professional theatre. At London’s Arts Theatre (1955-56) he staged Lon¬ don premieres of important continental plays. Especially renowned for his Shakespearean productions, he was managing director of the Royal Shakespeare Co. (1962-68) and continued to direct plays for it long after¬ ward. He succeeded Laurence Olivier as managing director of London’s National Theatre (1973-88). He formed his own theatrical production company in 1988 and also directed operas and several films.
Hall, Radclyffe orig. Marguerite Radclyffe-Hall (b. Aug. 12, 1880, Bournemouth, Hampshire, Eng.—d. Oct. 7, 1943, London) English writer. Born to a wealthy family and educated at King’s College, London, Hall began her literary career by writing verses, which eventually were collected into five volumes. She won prizes for her novel Adam ’s Breed (1926), a plea for animal rights. She was condemned for writing openly and sympathetically about lesbianism in The Well of Loneliness (1928), one of the first lesbian novels in English. It was judged obscene and banned in Britain; the ban was overturned on appeal after Hall’s death. Most of her five other novels express her strong Christian beliefs.
hall church Type of church with side aisles approximately equal in height to the nave, unlike the typical basilica. The interior is lit by large aisle windows instead of a clerestory, with chapels sometimes arranged alongside the nave. Hall churches originated in Germany and were char¬ acteristic of the Late Gothic period there. Special features of German hall churches include lofty nave arcades and immense roofs. St. Elizabeth in Marburg (c. 1257-83) is an archetypal example.
Hall effect Development of a transverse electric field in a solid material carrying an electric current and placed in a magnetic field perpendicular to the current. Discovered in 1879 by Edwin H. Hall (1855-1938), the Hall
The Old Town Clock on Citadel Hill, Halifax, Nova Scotia
JOHN DE VISSER
© 2006 Encyclopaedia Britannica, Inc.
830 I Hallaj ► Halmahera
field results from the force exerted by the magnetic field on the moving particles of the current. The Hall effect can be used to measure certain properties of current carriers as well as to detect the presence of a cur¬ rent on a magnetic field.
Hallaj \ka-'laj\, al- (b. c. 858, Tur, Iran—d. March 26, 922, Baghdad, Iraq) Muslim teacher of Sufism. Brought up in the Iraqi city of Wasit, he was drawn to asceticism at an early age and studied with a series of Sufi teachers. From c. 895 he traveled extensively as a teacher and preacher, making three pilgrimages to Mecca and gathering a large following. These travels and his popularity alienated his Sufi masters, and his demands for reform earned him the enmity of non-Sufi Muslims. Accused of foment¬ ing rebellion and claiming to be divine, he was arrested, imprisoned (c. 911-922), and eventually crucified and tortured to death.
Halle \'ha-l3\ (an der Saale) City (pop., 2002 est.: 243,045), east- central Germany. Lying on the Saale River, Halle’s location was the site of settlements that centred around the local salt deposits and flourished c. 1000-400 bc. Halle and its valuable saltworks were granted to the arch¬ bishopric of Magdeburg in ad 968. It was a member of the Hanseatic League (1281-1478). The capital of Halle district in East Germany (1952— 90), it is an important rail junction and a principal commercial and indus¬ trial centre. It was the birthplace of George Frideric Handel and the site of the Martin Luther University of Halle-Wittenberg, founded in 1694.
Halleck Vhal-okV, Henry W(ager) (b. Jan. 16, 1815, Westernville, N.Y., U.S.—d. Jan. 9, 1872, Louisville, Ky.) Union officer during the American Civil War. A graduate of West Point, he was commissioned in the engineers and sent on a tour of military facilities in Europe (1844), after which he wrote a textbook on war (1846) that became widely used. In 1861 he became supreme commander of Union forces in the western theatre and hurriedly organized large volunteer armies, though the mili¬ tary successes of the following spring were largely due to subordinate generals such as Ulysses S. Grant and John Pope. In 1862 he was appointed general in chief of Union forces, but subsequent reverses in Virginia and conflict with his subordinates and with the secretary of war Edwin M. Stanton resulted in his replacement by Grant in 1864.
Halley Vha-le, 'ha-le\/ Edmond (b. Nov. 8, 1656, Haggerston, Shore¬ ditch, near London—d. Jan. 14,
1742, Greenwich, near London)
English astronomer and mathemati¬ cian. He studied at the University of Oxford. In 1676 he set sail for the South Atlantic with the intention of compiling an accurate catalog of the stars of the Southern Hemisphere.
His star catalogue (1678) recorded the position of 341 stars. In 1684 he met Isaac Newton at Cambridge, which led to his prominent role (with Robert Hooke and Christopher Wren) in the development of Newton's law of gravitation. Halley edited New¬ ton’s Philosophiae Naturalis Prin- cipia Mathematica, bringing it to print in 1687. He produced the first meteorological chart (1686, showing the distribution of prevailing winds in the world’s oceans) and magnetic charts of the Atlantic and Pacific (1701). In astronomy, he described the parabolic orbits of 24 comets observed in the years 1337-1698. He showed that three of these were so similar that they must have been the same comet, and he accurately pre¬ dicted its return in 1758 (see Halley's Comet).
Halley's Comet First comet whose return was predicted, proving that at least some comets are members of the solar system. Edmond Halley showed in 1705 that comets seen in 1531, 1607, and 1682 were really one comet, and he predicted its return in 1758. Later calculations identified it with the large, bright comet seen during the Norman Conquest (and depicted in the Bayeux Tapestry) and with other comet sightings at inter¬ vals of about 76 years, the first in 240 bc. The only easily seen comet that returns in a single lifetime, it approached Earth twice in the 20th century (1910, 1985-86). Its nucleus is roughly 9 mi (15 km) across.
hallmark Symbol stamped on an item of silver or gold to indicate that it conforms to legal standards of purity. Hallmarking in Britain dates from 1300; no gold or silver could be sold until tested for purity and struck with the king’s mark. A maker’s mark was introduced in 1363; at first a symbol, such as a fish or key, it came to include or be replaced by ini¬ tials. A “hallmark” was a mark made at Goldsmith’s Hall, London. In the U.S., no hallmarks were initially required. In the late 18th and early 19th century, local regulations were established in New York, Boston, Balti¬ more, and elsewhere; makers’ marks appeared and the words “coin” and “sterling” were stamped on silver objects. In 1906 the use of the words came under federal regulation. Hallmarks on gold, similar to those on sil¬ ver, are also subject to federal regulation.