cable car See streetcar
cable modem Modem used to convert analog data signals to digital form and vise versa, for transmission or receipt over cable television lines, especially for connecting to the Internet. A cable modem modulates and demodulates signals like a telephone modem, but is a much more complex device. Data can be transferred over cable lines much more quickly than over traditional phone lines. Transmission rates are typically around 1.5 megabits per second. Faster transmission is actually possible, but speed is usually restricted by the cable company’s (typically slower) connection to the Internet. Cable Internet access is regarded as a replacement for slower dial-up and ISDN services, and is competitive with other broadband modes of delivery (e.g., DSL connections). See also broadband technology.
Cable News Network See CNN
cable structure Form of long-span structure that is subject to tension and uses suspension cables for support. Highly efficient, cable structures
© 2006 Encyclopaedia Britannica, Inc.
cable television ► cactus I 307
include the suspension bridge, the cable-stayed roof, and the bicycle- wheel roof. The graceful curve of the huge main cables of a suspension bridge is almost a catenary, the shape assumed by any string or cable sus¬ pended freely between two points. The cable-stayed roof is supported from above by steel cables radiating downward from masts that rise above roof level. The bicycle-wheel roof involves two layers of tension cables radiating from an inner tension ring and an outer compression ring, which in turn is supported by columns.
cable television System that distributes television signals by means of coaxial or fibre-optic cables. Cable television systems originated in the U.S. in the early 1950s to improve reception in remote and hilly areas, where broadcast signals were weak. In the 1960s they were introduced in large metropolitan areas where reception is sometimes degraded by reflection of signals from tall buildings. Since the mid-1970s there has been a pro¬ liferation of cable systems that offer special services and which generally charge a monthly fee. Besides providing high-quality signals, some sys¬ tems can deliver hundreds of channels. Another feature increasingly offered by cable operators is two-way, interactive communication by which viewers can, for example, participate in public-opinion polls as well as connect to the Internet. Cable operators are also involved in the devel¬ opment of video compression, digital transmission, and high-definition tele¬ vision.
Cabot, George (b. Jan. 16, 1752, Salem, Mass.—d. April 18, 1823, Boston, Mass., U.S.) U.S. Federalist Party leader. After studying at Har¬ vard University, he went to sea; he became a shipowner and successful merchant, retiring from business in 1794. Elected to the U.S. Senate (1791-96), he supported the fiscal policies of Alexander Hamilton. In 1793 he was appointed a director of the Bank of the United States. A member of the Federalist Essex Junto, he presided at the Hartford Convention in 1814.
Cabot, John orig. Giovanni Caboto (b. c. 1450, Genoa?—d. c. 1499) Italian navigator and explorer. In the 1470s he became a skilled navigator in travels to the eastern Mediterranean for a Venetian mercan¬ tile firm. In the 1490s he moved to Bristol, Eng., and, with support from city merchants, he led an expedition in 1497 to find trade routes to Asia. After landing somewhere in North America, possibly southern Labrador or Cape Breton Island, he took possession of the land for Henry VII and conducted explorations along the coastline. On a second expedition in 1498, he may have reached America but probably was lost at sea. His two voyages for England helped lay the groundwork for the later British claim to Canada. Sebastian Cabot was his son.
Cabot, Sebastian (b. c. 1476, Bristol, Gloucestershire, Eng., or Venice—d. 1557, London) English navigator, explorer, and cartographer. The son of John Cabot, he served at various times both the English and Spanish crowns. In 1525 he took charge of a Spanish expedition, aban¬ doning the original goal of developing trade with the Orient and instead embarking on a fruitless expedition to South America. Later he served in England as governor of the Merchant Adventurers, organizing an expe¬ dition to search for a northeast passage from Europe to the Orient.
Cabral \k9-'bral\, Amilcar (b. 1921, Bafata, Portuguese Guinea—d. Jan. 20, 1973, Conakry, Guinea) Guinean nationalist politician. In 1956 he founded the Partido Africano da Independence da Guine e Cabo Verde, which in 1962 began a war of liberation against Portuguese forces. By the late 1960s Cabral controlled much of Portuguese Guinea. He was assas¬ sinated in 1973. His half-brother, Luis de Almeida Cabral, became the first president of independent Guinea-Bissau in 1974.
Cabral, Pedro Alvares (b. 1467/68, Belmonte, Port.—d. 1520, San- tarem?) Portuguese navigator credited with the discovery of Brazil. A nobleman, Cabral long enjoyed the favour of Manuel I of Portugal, who in 1500 sent him and 13 ships on the second Portuguese voyage to India, following the route taken by Vasco da Gama, to strengthen commercial ties and further Portugal’s conquests. Cabral sailed southwest on a route that took him close to lands that had previously been sighted and claimed by the Portuguese. On April 22, 1500, he landed on the coast of what is now Brazil and formally took possession of the country for Portugal. The rest of his journey to India and back was beset by misfortune; only four ships returned to Portugal.
Cabrillo \k3-'bri-lo\, Juan Rodriguez (d. Jan. 3, 1543?, off the coast of northern California) Explorer in the service of Spain and discoverer of California. Little is known of his early life, though he may have been born in Portugal. In 1520 he accompanied Spanish explorers to Mexico.
He was one of the conquerors of present-day Guatemala, where he may have served as governor. In 1542 he left Mexico and sailed along the California coast, entering San Diego and Monterey bays. He landed on several islands off the coast; he apparently died of complications from a broken leg suffered on one such landing.
Cabrini, Saint Frances Xavier known as Mother Cabrini (b.
July 15, 1850, Sant’Angelo Lodigiano, Lombardy, Austria—d. Dec. 22, 1917, Chicago, Ill., U.S.; canonized July 7, 1946; feast day December 22) Italian-born U.S. missionary, the first U.S. citizen to be canonized by the Roman Catholic church. She was determined from childhood to become a missionary, and she took her vows in 1877. She founded the Mission¬ ary Sisters of the Sacred Heart in 1880, and in 1889 Pope Leo XIII sent her to the U.S. to work among Italian immigrants. She lived in New York City and Chicago but traveled in the Americas and Europe to found 67 houses of her order.
cacao \k9-'kau\ Tropical New World tree ( Theobroma cacao) of the chocolate family (Sterculiaceae, or Byttneriaceae). Its seeds, after fer¬ mentation and roasting, yield cocoa and chocolate. Cocoa butter is extracted from the seed. The tree is grown throughout the wet lowland tropics, often in the shade of taller trees. Its thick trunk supports a canopy of large, leathery, oblong leaves. The small, foul-smelling, pinkish flow¬ ers are borne directly on the branches and trunk; they are followed by the fruit, or pods, each yielding 20^10 seeds, or cocoa beans.
Caccini \kat-'che-ne\, Giulio or Giulio Romano (b. c. 1550, Rome, Papal States—buried Dec. 10, 1618, Florence) Italian composer and singer. He accompanied his patron, Cosimo I, to Florence in the 1570s; there he became associated with the Camerata, an academy that dedicated much attention to producing a revival of ancient Greek drama. His Euridice (1600), embodying the Camerata’s ideals, was the first opera to be published and was one of the first two surviving operas; the other, also titled Euridice, is largely by Jacopo Peri (1561-1633), whose lost Dafne (1598) was the first opera of all. Caccini’s Le nuove musiche (1602), a collection of songs with basso continuo, was of landmark importance in establishing the new monodic style.