pipe vine: see birthwort.

pipe tree: see lilac; saxifrage.

pipe smoking. The habit of smoking various substances probably arose independently in different parts of the world. Herodotus in the 5th cent. B.C. describes the Scythians as inhaling the fumes of burning leaves until they were intoxicated. The leaves may have been marijuana, which was smoked in Africa and Asia long before the diffusion of tobacco from America in the 16th cent. Among the Native Americans, pipe smoking was practiced long before the arrival of Europeans. The peace pipe, or calumet, was smoked in ceremonies to signify a covenant between tribes. The use of tobacco and pipes spread around the world rapidly. In Asia, opium, which up to that time had only been eaten, was first smoked in the 17th cent. The hookah of Persia and the narghile of India, both of which filter smoke through water, may have evolved independently from the marijuana-smoking practices among aboriginal groups of S Africa and of central Asia. Everywhere, pipes have acquired particular national characteristics and have blossomed into many shapes, fashioned from many materials, including brier, stone, clay, wood, porcelain, meerschaum, and corncobs.

pipe rolls, ancient records of the crown revenue and expenditures of England, so called, probably, because of the pipelike form of the rolled parchments on which these records were kept. The oldest extant pipe roll dates from the 31st year of the reign of Henry I (1130), and from 1156 they are almost completely intact. The earliest of these records have been published and are an invaluable source for social and administrative history. The pipe rolls were not completely abandoned for modern accounting methods until 1833.

pipe, hollow structure, usually cylindrical, for conducting materials. It is used primarily to convey liquids, gases, or solids suspended in a liquid, e.g., a slurry. It is also used as a conduit for electric wires.

The earliest pipes were probably made of bamboo, used by the Chinese to carry water c.5000 B.C. The Egyptians made the first metal pipe of copper c.3000 B.C. Until cast iron became relatively cheap in the 18th cent. most pipes were made of bored stone or wood, clay, lead, and, occasionally, copper or bronze. Modern materials include cast iron, wrought iron, steel, copper, brass, lead, concrete, wood, glass, and plastic. Welded steel pipe is made by bending strips of steel into the form of a tube and welding the longitudinal seam either by electric resistance, by fusion welding, or by heating the tube and pressing the edges together. Seamless pipe is made from a solid length of metal pierced lengthwise by a mandrel with a rounded nose.

Steel pipe, introduced in the early 20th cent., is widely used for conducting substances at extremely high pressures and temperatures. Cast-iron pipes, which came into common use in the 1840s, resist corrosion better than steel pipes and are therefore frequently used underground. Clay and concrete pipes usually carry sewage, and concrete pipes are also used to carry irrigation water at low pressures; for moderate pressures, the concrete is reinforced with steel or mixed with asbestos. Seamless copper and brass pipes are used for plumbing and boilers. Because of its softness and resistance to corrosion, lead is used for flexible connections and for plumbing that does not carry drinking water. The chemical and food industries use glass pipes. During World War II manufacturers developed plastic pipe to replace metals that were in short supply. Today PVC pipe is widely used to carry waste water as well as certain corrosive liquids.

A pipeline carries water, gas, petroleum, and many other fluids long distances. In laying an oil pipeline, 40-ft (12-m) sections of seamless steel pipe are electrically welded together while held over a trench. Before being lowered into place the pipe is coated with a protective paint and wrapped with a substance composed of treated asbestos felt and fiberglass. Pumping stations located 50 to 75 mi (80-120 km) apart boost the dwindling pressure back up to as much as 1,500 lb per sq. in. The piping must be kept clean, either by applying a negative electrical charge to the pipe or by regular use of a "pig," or scrubbing ball, inserted at one end and carried along by the current. An oil pipeline 6 in (15 cm) to 24 in (60 cm) in diameter will move its contents at about 3 to 6 mi (5-10 km) per hr.

Water has been moved since ancient times in pipelines called aqueducts. The first natural-gas and petroleum pipelines in the United States were built during the 19th cent. Today in many parts of the world pipelines are an extremely important means of transporting diverse fluids. The Trans-Arabian Pipeline, which carries oil from the Persian Gulf to the Mediterranean, is over 1,000 mi (1,600 km) long. There are more than 180,000 mi (288,000 km) of pipeline in the United States alone.

peace pipe: see calumet.

Pipe Spring National Monument: see National Parks and Monuments (table).

Organ Pipe Cactus National Monument: see National Parks and Monuments (table).

Indian pipe, common name for the genus Monotropa and for the family Monotropaceae, low flowering plants of north temperate zones. They are chlorophylless saprophytes with a funguslike appearance. Each stem has scalelike leaves and, with its nodding flower, resembles a pipe. The plant's waxy white or yellowish-white color has given rise to such names as corpse plant and ghost flower. The related snow plant (Sarcodes sanguinea) of the Sierra Nevadas is a bright red species that shoots up and blooms as soon as the snow melts. Indian pipes, snow plants, and related saprophytes are classed by most botanists as a separate family, the Monotropaceae; by others they are included in the family Ericaceae (heath family). Both families are classified in the Magnoliophyta, class Magnoliopsida, order Ericales.

Dutchman's-pipe: see birthwort.

Climbing vine (Aristolochia durior), also called pipe vine, of the birthwort family (Aristolochiaceae), native to central and eastern North America. It bears heart-shaped or kidney-shaped leaves and yellowish-brown or purplish-brown tubular flowers resembling a curved pipe. Exhibiting rapid growth, Dutchman's-pipe is often planted as a screen or an ornamental on porches and arbors.

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Keyboard instrument in which pressurized air produces notes by means of a series of tuned pipes. The simplest organs consist of a single rank of pipes, each corresponding to a single key. They are arranged over a wind chest connected to the keys by a set of valves and fed with a supply of air by electrically or mechanically activated bellows. By pulling out knobs, called stops, the player engages new ranks of pipes. Two distinct types of pipes are used: flue pipes (both open and stopped) produce sound by directing air against the edge of an opening in the pipe, whereas reed pipes sound by means of a thin metal tongue inside the pipe that vibrates against a fixed projection next to it. A large organ may have five or more banked keyboards, or manuals, each of which controls a distinctive group of pipes. Most organs also have pedalboards played with the feet. A large organ's pipes may vary in length from about 1 in. to 32 ft (2.5 cm to 10 m), resulting in a huge nine-octave range. The earliest organ (circa 250 BC) was the Greek hydraulis, in which the wind was regulated by water pressure. The bellows-fed organ appeared about the 7th century AD. The organ became firmly associated with the church by the 10th century. As organs became widespread, different regions pursued different modes of construction and sought different tonal ideals. The Baroque German organ is ideally suited to polyphony, while the French taste for variety of timbres eventuated in Aristide Cavaillé-Coll's vast “orchestral” organs. Seealso harmonium.

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National monument, southwestern Arizona, U.S., at the Mexican border. It was established in 1937. With an area of 330,689 acres (133,929 hectares), it preserves segments of the mountainous Sonoran Desert and is named for the organ-pipe cactus. Wildlife includes Gila monsters, antelope, coyotes, and a variety of birds.

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(born Jan. 1, 1879, London, Eng.—died June 7, 1970, Coventry, Warwickshire) British writer. Forster was born into an upper-middle-class family. He attended the University of Cambridge and from roughly 1907 was a member of the informal Bloomsbury group. His early works include Where Angels Fear to Tread (1905), The Longest Journey (1907), A Room with a View (1908), and his first major success, Howards End (1910), novels that show his acute observation of middle-class life and its values. After periods in India and Alexandria, he wrote his finest novel, A Passage to India (1924), examining the failure of human understanding between ethnic and social groups under British rule. Maurice, a novel with a homosexual theme written in 1913, appeared posthumously. Aspects of the Novel (1927) is a classic discussion of aesthetics and the creative process. Awarded an honorary fellowship in 1946 at Cambridge, he lived there until his death.

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Nongreen herbaceous plant (Monotropa uniflora) that is saprophytic (living on the remains of dead plants). Clusters grow in moist, shady, wooded areas of North America and Asia. The entire plant is white or grayish, occasionally pink, and turns black as it dries out. A single odourless, cup-shaped flower droops from the tip of a stalk 6–10 in. (15–25 cm) tall. The leaves, which lack chlorophyll and do not perform photosynthesis, are small scales. The name reflects the resemblance of this plant to a miniature Indian peace pipe with its stem stuck in the ground.

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