glass Solid material, typically a mix of inorganic compounds, usually transparent or translucent, hard, brittle, and impervious to the natural ele¬ ments (“vitreous properties”). It is made by cooling molten ingredients fast enough so no visible crystals form. A poor conductor of heat and electricity, glass takes on colours when certain metal oxides are included in the mix. Most glass breaks easily. Obsidian is a naturally occurring glass. Everyday glass (soda-lime or soda-lime-silica) is made of silica (silicon dioxide), soda (sodium carbonate), and limestone (calcium car¬ bonate), with magnesia (magnesium oxide) for sheet glass or alumina (aluminum oxide) for bottle glass. Fused silica is an excellent glass but expensive because of pure silica’s very high melting point. Borosilicate glass (e.g., Pyrex) is used for cookware and laboratory glassware because it expands very little when heated. Lead crystal is used for fine tableware. It has a heavy feel because of its lead oxide content and a sparkle due to its high refraction index. Even more specialized glasses include optical, photosensitive, metallic, and fibre-optic. Since glass has no sharp melting
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point, most types can be shaped while hot and plastic by many techniques, mostly blowing or molding. See also volcanic glass.
glass, architectural Glass used in structures. Glass was first used for windows in Roman imperial times. Lack of transparency and the diffi¬ culty encountered in making any but small panes eventually led to the introduction of stained-glass windows in the 12th century. Clear, colorless glass proved difficult to achieve until the Venetian manufacture of cris- tallo (see Venetian glass). Large sheets of glass first became practicable when the French introduced plate glass in the 17th century. Mechaniza¬ tion of glass forming did not occur until the late 19th century. The float- glass method currently in use, which eliminated the need for grinding and polishing, was introduced in the 1950s. Special glass products today include insulated (multipane) assemblies, laminated security glass (wired glass), and glass blocks and bricks (see masonry).
Glass, Carter (b. Jan. 4, 1858, Lynchburg, Va., U.S.—d. May 28, 1946, Washington, D.C.) U.S. politician. Largely self-educated, he pursued a successful career in journalism, eventually becoming proprietor of two Lynchburg newspapers. In the U.S. House of Representatives (1902-18), he sponsored legislation that established the Federal Reserve System. As secretary of the treasury (1918-20) he supported efforts by Pres. Wood- row Wilson to bring the U.S. into the League of Nations. Appointed, then elected, to the U.S. Senate (1920^46), he became a leader of the conser¬ vative Southern Democratic bloc. An expert on monetary policy, he coau¬ thored legislation that established the Federal Deposit Insurance Corp. (FDIC) in 1933. Though he supported Franklin Roosevelt for president in 1932, he soon became one of his sharpest critics.
glass, decorative See Amelung glass, Baccarat glass, Bohemian glass,
CAMEO GLASS, CUT GLASS, LUSTERED GLASS, STAINED GLASS, VENETIAN GLASS, WATER¬ FORD GLASS
Glass, Philip (b. Jan. 31, 1937, Baltimore, Md., U.S.) U.S. composer. He studied mathematics and philosophy at the University of Chicago and then studied composition at the Juilliard School and with Nadia Boulanger in Paris. His later studies with the Indian sitarist Ravi Shankar in 1966 and the tabla player Alla Rakha produced a radical shift in his compositional style. He became the leading exponent of musical “minimalism,” employ¬ ing insistently repeated notes and chords, subtly shifting timbres, and blocklike harmonic progressions without contrapuntal voice leading. He achieved fame suddenly with the opera Einstein on the Beach (1975) and went on to write more than 20 operas, including Satyagraha (1980), Akh- naten (1984), and The Voyage (1992). His other works include many film scores, such as Koyaanisqatsi (1983) and The Thin Blue Line (1988), and the recordings Glassworks (1981) and Songs from Liquid Days (1986). He collaborated with a wide range of writers, artists, and musicians, including Robert Wilson, Allen Ginsberg, Doris Lessing, David Bowie, and Paul Simon. Glass’s work appealed to fans of rock and popular music, and at the turn of the 21st century he was perhaps the world’s most famous living composer.
glass fiber See fiberglass
glaucoma \glau-'ko-m3, glo-'ko-moN Disease marked by increased pressure in the eye. A result of blockage of the flow of fluid (aqueous humour) at the outer edge of the iris, this pressure is transmitted to the optic nerve head and the retina. Chronic glaucoma can be treated with drugs that contract the pupil. Acute glaucoma may be intermittent. Per¬ manent relief requires surgery to provide an outlet for the fluid. Either type causes vision impairment or blindness if untreated.
glaucophane schist facies Vglo-ko-.fan-'shist-'fa-shezX One of the major divisions of the mineral facies classification of metamorphic rocks, encompassing rocks whose peculiar mineralogy suggests that they formed under conditions of high pressure and relatively low temperature (gener¬ ally less than about 662°F, or 350°C); such conditions are not typical of the normal geothermal gradient in the earth. The minerals that chiefly occur include soda amphibole (glaucophane), soda pyroxene (jadeite), garnet, lawsonite, and pumpellyite. Quartz, muscovite, chlorite, epidote, and plagioclase may also be present. Classic deposits occur in western California.
Glaucus Vglo-kssV Name of several figures in Greek mythology. One Glaucus was the young son of King Minos; he fell into a jar of honey and died, and the court seer restored him to life with a magic herb. Glaucus Pontius was a sea god; originally a fisherman and diver, he ate a magic plant and became divine. Glaucus, son of Sisyphus and father of Bellero-
phon, fed his horses human flesh and was tom to pieces by them. Another Glaucus was a grandson of Bellerophon, who assisted King Priam in the Trojan War.
Glazunov Vgla-zo-.nofX, Aleksandr (Konstantinovich) (b. Aug. 10, 1865, St. Petersburg, Russia—d. March 21, 1936, Paris, France) Rus¬ sian composer. A compositional prodigy, he achieved success with his Symphony No. 1 at age 16. He became a protege of the art patron M.P. Belyayev, who took him to western Europe; there he began to build an international reputation. He became director of the St. Petersburg Con¬ servatory in 1905. Though honoured by the government after the revo¬ lution, from 1928 he lived largely abroad. His music is generally conservative and Romantic. His works include the ballets Raymonda (1897) and The Seasons (1899); eight symphonies; concertos for piano (two), violin, and saxophone; and many orchestral tone poems and suites.
Gleason, Jackie orig. Herbert John Gleason (b. Feb. 26, 1916, Brooklyn, N.Y., U.S.—d. June 24, 1987, Fort Lauderdale, Fla.) U.S. comedian and actor. He performed in carnivals and nightclubs and later played minor roles in films and on the stage. He achieved success in the television comedy series Cavalcade of Stars (1950-52), The Jackie Glea¬ son Show (1952-59, 1961-70), and The Honeymooners (1955-56), which centred on his most beloved character, bus driver Ralph Kramden. He starred on Broadway in Take Me Along (1959, Tony Award) and received acclaim for his screen performances in The Hustler (1961), Requiem for a Heavyweight (1962), and Soldier in the Rain (1963). He later was fea¬ tured in Smokey and the Bandit (1977) and its sequels (1980, 1983).
Glendale City (pop., 2000: 218,812), south-central Arizona, U.S. Located in the Salt River valley, west of Phoenix, it was founded in 1892 and is an agricultural trading centre for fruits, vegetables, and cotton. Nearby this rapidly growing city is the American Graduate School of International Management, which trains employees of U.S. firms for work abroad.
Glendale City (pop., 2000: 194,973), southwestern California, U.S. Located north of Los Angeles, at the southeastern end of the San Fernando Valley, it was laid out in 1886. It was part of Rancho San Rafael (1784), the first Spanish land grant in California. Aircraft, optical instruments, and pharmaceuticals are among its manufactures. The city’s Forest Lawn Memorial Park is known for its elaborate statuary.