calcium-rich amphibole mineral that is monoclinic in crystal structure. Hornblende's generalized chemical formula is (Ca,Na)2(Mg,Fe,Al)5(Al,Si)8O22 (OH)2. The four end-members and the cation content of their respective compositions are as follows: hornblende, Ca2(Mg4Al) (Si7Al); tschermakite, Ca2(Mg3Al2)(Si6Al2); edenite, NaCa2(Mg)5(Si7Al); pargasite, NaCa2 (Mg4Al)(Si6Al2). Extensive solid solution occurs, and each end-member has iron-rich equivalents; ... [7 Related Articles]
(from the article "metamorphic rock") A generally deeper level of contact metamorphism at pressures of a few kilobars is represented by the hornblende-hornfels facies. Hydrated phases become stable, and the transition to regional metamorphism becomes apparent. Because of the generally greater depth, this type of aureole is often superposed on a metamorphism at more normal ...
(from the article "amphibolite") a rock composed largely or dominantly of minerals of the amphibole group. The term has been applied to rocks of either igneous or metamorphic origin. In igneous rocks, the term hornblendite is more common and restrictive; hornblende is the most common amphibole and is typical of such rocks. Hornblendite is ...
(from the article "Forester, C.S.") British historical novelist and journalist, best known as the creator of the British naval officer Horatio Hornblower, whose rise from midshipman to admiral and peer during the Napoleonic Wars is told in a series of 12 novels, beginning with The Happy Return (1937; U.S. title Beat to Quarters).
form of children's primer common in both England and America from the late 16th to the late 18th century. A sheet containing the letters of the alphabet was mounted on a wooden frame and protected with thin, transparent plates of horn. The frame was shaped like a table-tennis paddle, had ...
(from the article "lake") ...support the growth of bottom-attached plants, these may accelerate the extinction of a lake. In several European countries, steps are being taken to restore lakes threatened by choking plant growth. Lake Hornborgasjon, Sweden, long prized as a national wildlife refuge, became the subject of an investigation in 1967. Lake Trummen, ...
(from the article "Classification and Examples of Some Musical Instruments") ...material, craftsmanship, and exuberant imagination that produced an endless variety of stringed instruments. In the West the most widely accepted system of classification is that developed by Hornbostel and Sachs, a method based on the type of material that is set into vibration to produce the original sound. Thus, stringed ...
(from the article "typography") The third great English private press, the Ashendene, was conducted by C.H. St. John Hornby, a partner in the English booksellers W.H. Smith and Son. Hornby in 1900 met Emery Walker and Sydney Cockerell (Morris' secretary at the Kelmscott Press), who encouraged and instructed him and helped in devising two ...
pair of volcanic islands (Futuna and Alofi) forming the southwestern part of the French overseas collectivity of Wallis and Futuna, in the west-central Pacific Ocean. Futuna (not to be confused with its namesake in Vanuatu, which is said to have been settled from Futuna) is the site of Mount Singavi ...
stadtholder of Gelderland and Zutphen, admiral of the Netherlands, and member of the council of state of the Netherlands (1561-65), who sought to preserve the traditional rights and privileges of the Netherlands and to end the Spanish Inquisition. [2 Related Articles]
American mezzo-soprano noted for the seamless quality and exceptional range and flexibility of her voice, especially in coloratura roles by Gioacchino Rossini and George Frideric Handel. She was also instrumental in reviving interest in their lesser-known operas.
(from the article "Leptodactylidae") Horned frogs (Ceratophrys) are frog-eating South American forms that typically have a projecting flap, or "horn," of skin above each eye. They have wide heads and mouths and range in length from about 2.5 cm (1 inch) in the small species to more than 15 cm (6 ...
(from the article "Wicca") ...occult community and founded a new movement based on a reverence of nature, the practice of magic, and the worship of a female deity (the Goddess) and numerous associated deities (such as the Horned God). He also borrowed liberally from Western witchcraft traditions. Following the 1951 repeal of England's archaic ...
(from the article "lark") family name Alaudidae, any of about 75 species of a songbird family (order Passeriformes). Larks occur throughout the continental Old World; only the horned, or shore, lark (Eremophila alpestris) is native to the New World. The bill is quite variable: it may be small and narrowly conical or long ...
any of 17 species of owls with hornlike tufts of feathers on the head. The name refers especially to the great horned owl (B. virginianus) of the Americas. The great horned owl ranges from Arctic tree limits to eastern South America but is absent from the Amazon Rainforest. It is ... [1 Related Articles]
any of approximately 25 species of plants that constitute the genus Glaucium of the poppy family (Papaveraceae). All species are weedy garden plants native to Eurasia. The yellow horned poppy (G. flavum) is native to sea beaches of Great Britain and southern Europe and has become established in the eastern ...
(from the article "screamer") The horned screamer (Anhima cornuta), of northern South America, has a slender, forward-curving, calcified spike on its forehead. The crested screamer, or chaja (a name that comes from its cry; Chauna torquata), of open country in east-central South America, and the black-necked screamer (C. chavaria), of Colombia and Venezuela, have...
(genus Phrynosoma), any of about 14 species of lizards belonging to the family Iguanidae that are usually characterized by daggerlike head spines, or horns; a flattened oval body, pointed fringe scales along the sides of the body, and a short tail are typical features. The lizards range in length from ... [1 Related Articles]
(from the article "Cerastes") genus of venomous, desert-dwelling snakes of the viper family, Viperidae. There are two species, the horned viper (C. cerastes), which usually has a spinelike scale above each eye, and the common, or Sahara, sand viper (C. vipera), which lacks these scales. Both species are small (seldom more than 60 cm ...
the first modern European to make the dangerous crossing of the northeastern Sahara. His journal, later published, contained a substantial amount of information on the then-unknown terrain and inhabitants of the central Sudan.
(from the article "Horner, William George") mathematician whose name is attached to Horner's method, a means of continuous approximation to determine the solutions of algebraic equations of any degree.Islamic mathematicsmathematicsIslamic mathematics to the 15th century...decimal fractions as a means of approximating irrational quantities. In
(from the article "eye, human") ...the outer corner of the eye, the lateral canthus, to form a band of fibres called the lateral palpebral raphe. Additional parts of the orbicularis have been given separate names-namely, Horner's muscle and the muscle of Riolan; they come into close relation with the lacrimal apparatus and assist in drainage ...
(from the article "ptosis") ...diseases (such as muscular dystrophy or myasthenia gravis) or damage to the oculomotor nerve from diabetes, hypertension, atherosclerosis, trauma, or direct compression. In a disorder called Horner syndrome, a slight ptosis occurs in association with a smaller pupil and decreased sweat production on the affected side.
(from the article "1949: Other Winners") ...for BattlegroundCinematography, Black-and-White: Paul C. Vogel for BattlegroundCinematography, Color: Winton Hoch for She Wore a Yellow RibbonArt Direction, Black-and-White: Harry Horner and John Meehan for The HeiressArt Direction, Color: Cedric Gibbons and Paul Groesse for Little WomenMusic Score...Oscar for best art direction, 1961
(from the article "dinosaur") ...and nest builder. These eggs were at first attributed to Protoceratops, but they are now known to have been those of Oviraptor. In 1978 John R. Horner and his field crews from Princeton University discovered dinosaur nests in western Montana. A few other finds, ...
Canadian ice hockey player (b. May 28, 1909, Lynden, Ont.-d. April 27, 2005, Toronto, Ont.), had a reputation as the toughest and most intimidating player of his era. As a defenseman for the Toronto Maple Leafs (1928-40), he accrued 1,264 penalty minutes, leading the National Hockey League in that category ...
mathematician whose name is attached to Horner's method, a means of continuous approximation to determine the solutions of algebraic equations of any degree.
(from the article "Representative venomous animals that inflict a sting") ...with formidable stings. Some Vespula species are called yellow jackets owing to the black and yellow bands on their abdomen. Other species of both Vespula and Vespa are called hornets, which are mostly black, with yellowish markings on the face, thorax, and the tip of the abdomen.
German-born American psychoanalyst who, departing from some of the basic principles of Sigmund Freud, suggested an environmental and social basis for the personality and its disorders. [1 Related Articles]
(from the article "metamorphic rock") The hornfels are formed by contact metamorphism and typically show little sign of the action of directed pressure. They are fine-grained rocks in which crystals display little orientation.
a major division of metamorphic rocks (rocks that form by contact metamorphism in the inner parts of the contact zone around igneous intrusions). All of the rocks called hornfels-a hard, fine-grained, flinty rock-are created when heat and fluids from the igneous intrusion alter the surrounding rock, changing its original mineralogy ... [1 Related Articles]
lake, Sogn og Fjordane fylke (county), western Norway. Occupying the trough of a glacial valley, the long and narrow lake has a length of about 16 miles (25 km) and a maximum width of 3 miles (5 km). In the west it tapers to a sharp point and drains westward ...
(from the article "1958: Other Winners") ...Alan Jay Lerner for GigiCinematography, Black-and-White: Sam Leavitt for The Defiant OnesCinematography, Color: Joseph Ruttenberg for GigiArt Direction: Preston Ames and William A. Horning for GigiMusic Score of a Dramatic or Comedy Picture: Dimitri Tiomkin for The Old Man and the SeaScoring of a Musical Picture: Andre Previn for...Oscar for ...
(from the article "Sports and Games") Indianapolis Speedway staged the 90th Indianapolis 500 as part of the Indy Racing League (IRL) series. Team Penske's veteran driver Sam Hornish, Jr., nipped Marco Andretti of Andretti Green Racing (AGR) by 15 feet in the final straight to win by 0.0635 second. Marco's father, Michael Andretti, who had come ...
(from the article "hornpipe") Hornpipe refers also to several dances that Renaissance courtiers believed were once performed to the rustic instrument. At times it meant a jig, a reel, or a country dance. As an Irish, Scottish, or English solo dance, the hornpipe is in 44 time and is related to the jig and ...
name of a wind instrument and of several dances supposedly performed to it. The instrument is a single-reed pipe with a cowhorn bell (sometimes two parallel pipes with a common bell) and is often converted into a bagpipe. Known since antiquity, it is today played in Basque Spain (where it ... [1 Related Articles]
American professional baseball player, generally considered the game's greatest right-handed hitter. His major league career batting average of .358 is second only to Ty Cobb's .367. [2 Related Articles]
(from the article "Zingiberales") In the genus Hornstedtia (family Zingiberaceae), the inflorescences are wholly just above ground level, with firm empty outer bracts forming a spindle-shaped structure out of the top of which the flowers emerge, one or two at a time. In one Malaysian species of Hornstedtia, however, the whole rhizome is raised ...
any of about 85 species of solitary (nonsocial), primitive wasps (order Hymenoptera), classified in five different genera, that are moderately large, some reaching 3.75 cm (about 1.5 inches) in length. The cylindrical body is usually brown, blue, or black, often with yellow spots or bands. The abdomen is connected broadly ...
(from the article "hawk moth") The leaf-feeding larva generally has a smooth body with a characteristic dorsal caudal horn, hence the common name hornworm. Two economically destructive North American species, the tobacco, or southern, hornworm (Manduca sexta) and the tomato, or northern, hornworm (M. quinquemaculata), attack tomato, tobacco, and ...
(from the article "Ceratophyllales") hornwort order of flowering plants, consisting of just one family (Ceratophyllaceae) with one cosmopolitan genus (Ceratophyllum) that contains about six species.
any member of 6-7 genera, containing about 300 species of creeping annual or perennial plants of the class Anthocerotopsida. In some classification systems, hornworts have been grouped as horned liverworts in the subclass Anthocerotidae (class Hepaticae), class Anthocerotopsida, order Anthocerotales, or entirely separated from the bryophytes in the division Anthocerotophyta. ... [5 Related Articles]
(from the article "cnidarian") Long axial polyps bear lateral polyps. Skeleton of spicules fused with a horny material. Tropical.Sea fans and sea whips. Colonies commonly arborescent with axial skeleton of gorgonin and/or calcareous spicules. Polyps rarely dimorphic. Tropical and...prehistory and taxonomycnidarianEvolution...there were two ...
(from the article "scale") Horny scutes, or corneoscutes, derived from the upper, or epidermal, skin layer, appear in reptiles and on the legs of birds. In crocodilians and some lizards, bony dermal scales (osteoderms) underlie the external scales. Bird feathers are developmentally modified epidermal scales. Modified epidermal tissue, mostly made up of keratin, forms ...
any sponge of the orders Dictyoceratida and Dendroceratida (class Demospongiae). It has a skeleton consisting exclusively of fibrous organic components. Most other sponges, by contrast, have siliceous or calcareous elements as well as organic materials in their skeletal tissue. Collagen, the main organic component of horny sponges, may appear as ...
(from the article "chub") ...at the base of the dorsal fin, it grows to about 30 cm (1 foot). It is also called the horned dace, for the hornlike projections that develop on the head of the male during the breeding season. The hornyhead chub is blue-backed with greenish sides and a light belly. ...
