The Black Forest in south-west Germany embraces the biggest centre of clock making in the world. The industry began because of the need for local farmers to adopt some indoor occupation during the hard winters. Many took up woodcarving and, according to tradition, a wooden-wheeled clock imported from Bohemia gave them the idea of producing wooden clocks. By the early 18th century certain men had found clock production more to their taste than farming. The earliest clocks had wooden wheels and frames, and were controlled by a wooden foliot balance. The driving weight was a stone, and the clocks only ran about twelve hours. The 18th century saw the addition of striking work, mechanism to operate a cuckoo, 'cowtail' pendulums, and later, anchor excapements with longer pendulums. After brass casting had been introduced into the area about 1780 brass wheels were used instead of wood, although wooden frames and arbours were retained. The making of organ clocks became a separate industry, and production was helped by various mechanical improvements in tools. Production increased until about 1850, when American competition drove the old Black Forest wall clock off the market. The American clock was factory-produced with an all-metal movement and did not have exposed weights and chains. By the end of the 19th century the Black Forest had gone to factory methods. The two world wars had a serious effect on the Black Forest industry: many factories went over to military production, and overseas markets were lost. The area is now chiefly known for alarm and travelling clocks, but the cuckoo clock and the 400-day clock are still firm favorites.