ETYM Old Eng. halle, hal, AS. heal, heall; akin to Dutch hal, OS. and Old High Germ. halla, German halle, Icel. höll, and prob. from a root meaning, to hide, conceal, cover. Related to Hell, Helmet.
(Homonym: haul).
1. A large building for meetings or entertainment.
2. A large building used by a college or university for teaching or research.
3. A large room for gatherings or entertainment.

(1863-1914) US chemist who developed a process for the commercial production of aluminum 1886. A similar process was independently but simultaneously developed in France by Paul Héroult.
He found that when mixed with cryolite (sodium aluminum fluoride), the melting point of aluminum was lowered and electrolysis became commercially viable. It had previously been as costly as gold.
By 1890, Hall was in charge of the Aluminum Company of the US and aluminum utensils began to spread throughout the world.
Hall was born in Ohio and educated at Oberlin. He invented the aluminum process at 22 and, after initial difficulties, formed the Pittsburgh Reduction Company (later to become the Aluminum Company of America) and became a multimillionaire.

(1904-1982) English mathematician who specialized in the study of group theory.
Hall was born in London and studied at Cambridge, where he spent his whole career. He was professor of pure mathematics 1953–67.
In 1928 Hall began a study of prime power groups. From this work he developed his 1933 theory of regular groups. An investigation of the conditions under which finite groups are soluble led him in 1937 to postulate a general structure theory for finite soluble groups. In 1954, he published an examination of finitely generated soluble groups in which he demonstrated that they could be divided into two classes of unequal size. At the end of the 1950s Hall turned to the subject of simple groups, and later also examined non-strictly-simple groups.

(Reginald Frederick) (1930-) English theater, opera, and film director. He was director of the Royal Shakespeare Theatre in Stratford-upon-Avon 1960–68 and developed the Royal Shakespeare Company 1968–73 until appointed director of the National Theatre 1973–88, succeeding Laurence Olivier. He founded the Peter Hall Company 1988.
Hall’s stage productions include Beckett’s Waiting for Godot 1955, The Wars of the Roses 1963, Pinter’s The Homecoming stage 1967 and film 1973, The Oresteia 1981, and Orpheus Descending 1988. He has directed operas at Covent Garden, Bayreuth, and New York, and in 1984 was appointed artistic director of opera at Glyndebourne, with productions of Carmen 1985 and Albert Herring 1985–86.

(1901-1994) Australian film and TV director and producer, a pioneer of feature film production in Australia, with 19 credits to his name between 1932 and 1946. While the films he made for Cinesound were often artless, they represented Australia’s chief demonstration of an indigenous production base until the “new wave” of the 1970s.
Under Hall’s leadership Cinesound became in its modest way an impressive production power. From 1932 he directed a succession of films for the company—homespun comedies such as Dad and Dave Come to Town 1936, which introduced Peter Finch to the screen, and rural dramas like Orphan of the Wilderness 1936. His last feature was Smithy 1946. Hall was also the moving spirit behind the Cinesound newsreel. In 1956, he took on the running of Australia’s first television station, Channel Nine.

(1761-1832) Scottish geologist, one of the founders of experimental geology. He provided evidence in support of the theories of Scottish naturalist James Hutton regarding the formation of the Earth's crust.
Hall was born in Berwickshire (Borders region) and spent much of the 1780s traveling in Europe. He undertook extensive geological observations in the Alps and studying Mount Etna in Sicily. He was also won over to the new chemistry of Antoine Lavoisier.
Hall set out to prove his friend Hutton’s “Plutonist” geological theories (the view that heat rather than water was the chief rock-building agent and shaper of the Earth’s crust). By means of furnace experiments, he showed with fair success that Hutton had been correct to maintain that igneous rocks would generate crystalline structures if cooled very slowly. Hall also demonstrated that there was a degree of interconvertibility between basaltine and granitic rocks; and that, even though subjected to immense heat, limestone would not decompose if sustained under suitable pressure.

US astronomer who discovered the two Martian satellites, Deimos and Phobos, 1877. He determined the orbits of satellites of other planets and of double stars, the rotation of Saturn, and the mass of Mars.
Hall was born in Goshen, Connecticut. Apprenticed to a carpenter at 16, he later enrolled at the Central College in McGrawville, New York. In 1856, he took a job at the Harvard College Observatory in Cambridge, Massachusetts, and turned out to be an expert computer of orbits. Hall became assistant astronomer at the US Naval Observatory in Washington, DC 1862, and within a year of his arrival he was made professor.
In 1875 Hall was given responsibility for a 66-cm/26-in telescope, the largest refractor in the world at the time. He noticed a white spot on Saturn which he used as a marker to ascertain the planet's rotational period. In 1884, he showed that the position of the elliptical orbit of Saturn's moon, Hyperion, was retrograding by about 20ş per year.
Hall also investigated stellar parallaxes and the position of the stars in the Pleiades cluster.