the other was that, although they were interlinked and covered large areas of Britain, the canals were never conceived as an integrated system. The canals for the most part were built piecemeal for local traffic using traditional regional vessels that often varied in size. Because there was no standard canal lock, a fragmented, inefficient transport system resulted. They gradually went out of use as commercial thoroughfares.

World War II witnessed a temporary revival. Following years of neglect and war damage, the canals were soon regarded as derelict. They were nationalized under the aegis of British Waterways in 1947 and over the next couple of decades their leisure and recreation value began to be recognized. The Inland Waterways Association was formed to “rescue” them, and volunteer restoration projects continue. Millions of pounds are being spent on maintenance projects, and there are now more craft using British canals than at the height of their commercial success.

See also

Hydraulic boat lifts

Further reading

Boughey, Joseph. 1994. Hadfield’s British Canals. Stroud, UK: Alan Sutton.

Chrimes, Mike, ed. 1997. The Civil Engineering of Canals and Railways before 1850. Aldershot, UK: Ashgate.

Paget-Tomlinson, E. W. 1993. The Illustrated History of Canal and River Navigations. Sheffield, UK: Sheffield Academic Press.

Cappadocia: underground cities

Turkey

Cappadocia, a region of central Anatolia in Turkey, lies within the triangle of Nevsehir, Aksaray, and Kayseri. It is bounded by the now dormant Mount Erciyes in the east and Mount Hasandag in the south. Prehistoric eruptions of these volcanoes blanketed a wide area with a 1,500-foot (450-meter) layer of ash and detritus. The hardening tufa was carved by nature into thousands of distinctive pyramidal rock formations known as “fairy chimneys,” within which generations of settlers have created astounding subterranean cities. Guesses at the total number vary from 30 to 200. Carved from the living rock to a depth of at least twenty stories, and each able to house tens of thousands of people, the underground cities result from 3,000 years of continual adaptation and extension. Derinkuyu and Kaymakli, described below, are only two of such architectural feats in the region.

Who were these intrepid constructors, who built downward instead of upward, and whose houses were framed with shafts and corridors rather than columns and beams? Over millennia Cappadocia has been occupied in turn by invading Lycians, Phrygians, Persians, Greeks, Romans, Arabs, Byzantines, and Seljuk and Ottoman Turks. The indigenous Hittites were probably first to build underground. In the fourteenth century b.c., retreating from Phrygian invaders, they made excavations, normally of no more than two levels. The next major wave of building was not until the fourth century a.d. Always strategically vital, fertile Cappadocia became a Roman province in a.d. 17, and its towns flourished under stable Roman rule. Within about 200 years it became a center of eastern Christianity and when the persecution reached its final peak around a.d. 305, the Christians withdrew to the mountain fastnesses, building secure subterranean places in which to live and worship. The peril passed with the Edict of Toleration (a.d. 313) but reemerged for different reasons under the excesses of iconoclasm (726–843), as well as the incursions of Arabs. The Christian response to renewed threats was to build rock-cut churches and monasteries, often adapting and extending much older underground houses. The Göreme Valley abounds with well-hidden churches and monastic buildings—the number has been estimated at 600 to 3,000—carved out of the soft tufa. Most were built in the tenth century. The Seljuk Turks defeated the Byzantine army at the Battle of Manzikert (a.d. 1071) and then spread over Anatolia. They were followed in the fourteenth century by the Muslim Ottoman Turks. None of these changes put the Christian communities of Anatolia under threat, but by then rock-hewn architecture had become an established cultural expression.

At the beginning of the twentieth century, a Jesuit named Guillaume de Jerphanion began a long study