pedigree Record of ancestry or purity of breed. Pedigrees of domes¬ ticated animals are maintained by governmental or private record asso¬ ciations or breed organizations in many countries. In human genetics, pedigree diagrams are used to trace the inheritance of a specific trait, abnormality, or disease. Standard symbols are used to represent males, females, mating (marriage), and offspring. The offspring symbols appear from left to right in the order of birth and are connected to the marriage line by a vertical line. Possession of the character under study is shown by a solid or blackened symbol, and absence is shown by an open or clear symbol.
pediment In Classical architecture, a triangular gable crowning a por¬ tico or facade. The pediment was the crowning feature of the Greek temple front. The pediment’s triangular wall surface, or tympanum, was often decorated with sculpture. The Romans adapted the pediment as a purely decorative form to finish doors, windows, and niches, sometimes using a
series of alternating triangular and segmentally curved pediments, a motif revived in the Italian High Renaissance. Baroque-era designers developed many varieties of broken, scrolled, and reverse-curved pediments.
pediment In geology, any relatively flat surface of bedrock (exposed or lightly covered with soil or gravel) that occurs at the base of a moun¬ tain or as a plain having no associated mountain. Pediments are most con¬ spicuous in basin-and-range-type desert areas throughout the world, but they also occur in humid areas. In the tropics, the surfaces tend to be cov¬ ered with soil and obscured by vegetation. Many tropical river towns are situated on pediments, which offer easier building sites than the steep hillsides above or the river marshes below.
pedology \pi-'da-b-je\ A branch of soil science focusing on the for¬ mation, morphology, and classification of soils as bodies within the natu¬ ral landscape. Pedology seeks to understand how the properties and distribution patterns of soils worldwide (collectively called the pedo- sphere) have developed along with broader landforms, biogeochemical environments, and habitats of living organisms. Through their understand¬ ing of the causes and magnitudes of soil variations, pedologists help to broaden knowledge of the surface of the Earth.
Pedrell \pa-'threl\, Felipe (b. Feb. 19, 1841, Tortosa, Spain—d. Aug. 19, 1922, Barcelona) Spanish musicologist and composer. He was largely self-taught as a musician. A scholarship for study in Rome exposed him to the great past of Spanish music preserved in archives there, and he set about reviving the tradition by bringing to light both folk and older art music and by promoting a national style of composition. His own works include operas and orchestral and choral works. He is regarded as the father of Spanish musical nationalism.
Pedro Vpa-dro, 'pa-drii\ I known as Dom Pedro (b. Oct. 12, 1798, Lisbon, Port.—d. Sept. 24, 1834, Lisbon) First emperor of Brazil (1822— 31) and, briefly, king of Portugal. The son of John VI of Portugal, he became regent of Brazil in 1821, but in 1822 he broke with Lisbon and declared Brazil’s independence. The former colony became a constitu¬ tional monarchy with Pedro its emperor. Strong opposition to his auto¬ cratic manner and impatience with parliamentary procedure induced him to abdicate in favour of his five-year-old son, Pedro II. When John VI died, Pedro I became Portugal’s King Pedro IV, but he quickly abdicated in favour of his daughter, the future Queen Maria II. See also Jose Bonifa¬ cio de Andrada e Silva.
Pedro II orig. Dom Pedro de Alcantara (b. Dec. 2, 1825, Rio de Janeiro, Braz.—d. Dec. 5, 1891, Paris, Fr.) Second and last emperor of Brazil (1831-89). He became emperor at age five when his father, Pedro I, abdicated. After a period of regency, he was crowned in 1841. His con¬ cern for his subjects, skill at arbitrating political disputes, and leadership in economic matters brought stability to the country. He led Brazil into the Paraguayan War, which brought Brazil prestige and territory. His support eroded primarily over the issue of the imperial prerogatives. Emancipation was proclaimed in 1888; in 1889 Pedro II was removed in a military coup, and a republic was established. See also Jose Bonifacio de Andrada e Silva.
Pee Dee River River, North and South Carolina, U.S. Rising as the Yadkin River in the Blue Ridge in northwestern North Carolina, it flows southeast into Winy ah Bay near Georgetown, S.C. It is 233 mi (375 km) long. The lower Pee Dee is navigable for 90 mi (145 km).
Peel, Sir Robert, 2nd Baronet
(b. Feb. 5, 1788, Bury, Lancashire, Eng.—d. July 2, 1850, London) Brit¬ ish prime minister (1834-35, 1841— 46) and principal founder of the Conservative Party. A member of Par¬ liament from 1809, Peel served as chief secretary for Ireland (1812-18) and resisted efforts to admit Catho¬ lics to Parliament. As home secretary (1822-27, 1828-30), he reorganized England’s criminal code. He estab¬ lished London’s first disciplined
Sir Robert Peel, detail of an oil painting by John Linnell, 1838; in the National Portrait Gallery, London.
COURTESY OF THE NATIONAL PORTRAIT GALLERY,
LONDON
© 2006 Encyclopaedia Britannica, Inc.
Peel River ► Pelagianism I 1465
police force, whose members were nicknamed after him “bobbies” or “peelers.” After a brief first term as prime minister, Peel led the newly formed Conservative Party to a strong victory in the 1841 elections and became prime minister again. He imposed an income tax, reorganized the Bank of England, and initiated reforms in Ireland. Favouring reduced tar¬ iffs on imports, he repealed the Corn Laws, which caused his government to fall, but he continued to support free-trade principles in Parliament. He was the chief architect of the mid-Victorian age of stability and prosper¬ ity that he did not live to see.
Peel River River, northwestern Canada. It rises in western Yukon Ter¬ ritory and flows east and then north into the Mackenzie River in the North¬ west Territories, near Fort McPherson, a fur-trading post. It is 425 mi (684 km) long. Its upper course through Peel Plateau is characterized by can¬ yons as deep as 1,000 ft (300 m). Its lower valley consists primarily of nature preserves and game sanctuaries.
peerage Body of peers or titled nobility in Britain. The five ranks, in descending order, are duke, marquess, earl (see count), viscount, and baron. Until 1999, peers were entitled to sit in the House of Lords and exempted from jury duty. Titles may be hereditary or granted for life.
Pegasus Vpe-go-sosV In Greek mythology, a winged horse. It sprang from the blood of Medusa as she was beheaded by Perseus. Bellerophon captured Pegasus and rode him in several of his exploits, including his fight with the Chimera, but when he tried to ride the winged horse to heaven he was unseated and killed, and Pegasus was placed in the sky as a constellation. The flight of Pegasus is often regarded as a symbol of poetic inspiration.
pegmatite Vpeg-mo-.tltV Almost any wholly crystalline igneous rock that is at least in part very coarse-grained, the major constituents of which include minerals typically found in ordinary igneous rocks (such as gran¬ ites) and in which extreme textural variations, especially in grain size, are characteristic. Usually found as irregular dikes, lenses, or veins, pegma¬ tite deposits occur in all parts of the world and are the chief source of commercial feldspar, sheet mica, and beryllium, tantalum-niobium, and lithium minerals.
Pei \'pa\, l(eoh) M(ing) (b. April 26, 1917, Canton, China) Chinese- born U.S. architect. He immigrated to the U.S. in 1935 and studied at the Massachusetts Institute of Technology and Harvard University. After working for the architectural firm of Webb & Knapp, he formed his own partnership in 1955. Early in his career he created the building for the National Center for Atmospheric Research, Boulder, Colo. (1968), which mimics the broken silhouettes of the surrounding peaks. His innovative East Building of the National Gallery of Art, Washington, D.C. (1978), was hailed as one of his finest achievements. Other works include Bos¬ ton’s John Hancock Tower (1973), Beijing’s Fragrant Hill Hotel (1982), and a controversial glass pyramid for a courtyard at the Louvre Museum, Paris (1989). Pei’s designs represent an elaboration on the rectangular forms and irregular silhouettes of the International Style but with a uniquely skillful arrangement of geometric shapes and a dramatic use of varied materials, spaces, and surfaces; in his Miho Museum of Art, Shiga, Japan (1997), for example, he achieved a harmony between the building, much of it underground, and its mountain environment. In 1983 Pei received the Pritzker Architecture Prize.