of the Bedouin tent. The same is true of the ger (or yurt), the traditional house of Mongolian herdspeople, still in use all year-round. Its self-supporting framed structure—a cylinder roofed with a dome—applies a dynamic arrangement, refined over centuries, of leather-lashed saplings, a roof ring, and tensioning bands. The covering, traditionally felt, is secured with ropes. The ger can be dismantled and carried by pack animals, although sometimes it is transported intact on a wagon.

Many Middle Eastern governments are attempting to impose a permanent sedentary lifestyle on the Bedouin, Modernization, if not altogether desirable, is probably inevitable. Trucks are displacing camels as the principal means of transportation; some camps have refrigerators and television sets powered by portable generators whose noise disturbs the quiet of the desert. Coffee is brewed for guests on gas stoves rather than the traditional hearth, and “off-the-hook” canvas tents are appearing among the “houses of hair.”

See also

Tension and suspension buildings

Further reading

Chatty, Dawn. 1986. From Camel to Truck: The Bedouin in the Modern World. New York: Vantage.

Crociani, Paola. 1994. Bedouin of the Sinai. Reading, UK: Garnet.

Hobbs, Joseph J. 1989. Bedouin Life in the Egyptian Wilderness. Austin: University of Texas Press.

Weir, Shelagh. 1976. The Bedouin: Aspects of the Material Culture of the Bedouin of Jordan. London: World of Islam.

Beijing-Hangzhou Canal

China

The Grand Canal (Chinese, Da Yunhe) in China is the world’s longest artificial waterway and the oldest canal still in existence. The 1,121-mile-long (1,794-kilometer) series of linked channels extends from Hangzhou on the southeast coast to the capital, Beijing, in the north. As an engineering achievement of the ancient Chinese, the canal compares with the more familiar Great Wall. It passes through twenty-four sophisticated locks and is crossed by sixty bridges. Most of China’s large rivers, including the Huai, the Huang Ho, the Wei, and the Yangtze flow from the west to the Pacific Ocean in the east, and the north-south Grand Canal provides a vital connector between their systems. That fact in itself presented a challenge to which the ancient builders were equal: the gradient of the canal was carefully designed and maintained by dredging to ensure that the seasonal flooding of the rivers did not inundate agricultural land along the artificial waterway. In places, dikes and levees provided further protection.

The Grand Canal—once known as the Grand Imperial Canal—had a simple reason for being. Successive emperors wanted to secure communication between the heavily populated politico-military centers of North China and the rice-producing regions of the south. This meant constructing a link that enabled the rapid deployment of troops and provided a faster, safer corridor for transporting grain and freight, free from the threat of the pirates who preyed on coastal shipping. During the Song dynasty (a.d. 960–1279), the annual grain traffic on the canal exceeded 340,000 tons (345,440 tonnes), carried by fleets of up to forty barges, lashed together up to four abreast and towed by water buffalo.

Suggested dates for the commencement of the canal vary from the fourth to the sixth century b.c. The 140-mile (225-kilometer) section traditionally known as the Shanyang Canal, from Qingjiang in northern Jiangsu to the Yangtze, probably was constructed sometime in that period and extended almost a thousand years later, during the Northern Qi dynasty (a.d. 550–576), when existing waterways were linked to form a single system. The second Sui emperor, Yang Di, launched an intensive building program between 605 and 610. He is said to have employed 6 million peasants constructing links between the Huang Ho and Yangtze Rivers. By thus joining the north and south of China, the canal allowed for the development of an integrated national economy and reestablished the power of the imperial civil service. Therefore, it is not surprising that it retained its importance during the Tang dynasty (618–907), when China was at the height of its power.

The canal was a key to trade expansion under the Tang and Song, and around 800 the center of political