A Direct Production of Iron and Its Development on Territory of Czech Lands

Jiří Merta

Archeologia technica, vol. 23 (2012)
Pages: 3–20
Language: Czech
Type of article: scientific article
DOI: n/a

Abstract:
In area of east Anatolia, already associated with the beginnings of processing of copper ores, the iron production called as a direct method of producing malleable iron bloom started at the end of the third millennium BC. From that area the knowledge of the iron production spread to the Mediterranean and the adjacent city-states of the Near East. From that period any specific type of iron reduction furnace is not known, it was probably a hearth with a gradually emerging shaft. Near the coast of the Mediterranean Sea there was gradually built a number of important iron production centers (Western Crete, Southern Greece, and Elba). To the Central Europe the knowledge of iron production got through the Balkans and from the 6th century BC the Hallstatt bloomeries processed local ores. The expansion of the iron production occurred in the community of Celtic tribes which used the shaft furnaces with a recessed hearth, the scheme of which was taken over later by Germanic tribes and they used it for more than five centuries. Another type of furnaces was an apparatus with a cupola inner space capable of producing very tangible blooms (up to 50 kg). In Western Europe we know the shaft furnaces with a height of up to 2,5 m which were also used by Romans (Les Martys), like furnaces from the Alpine area (Magdalensberg). From the period of the Middle Ages several workshops are known to be scattered on the territory of Europe, in which the production of a raw iron took place independently. Those were furnaces with stone brickwork and the inner diameter of a shaft about 1 m and height about 3 m. In the Czech lands the development of Celtic recessed furnaces known from the production area northwest of Prague led through independently standing shaft furnaces of Germanic tribes (Boskovice furrow), to the Slavic iron smelters using underground furnaces of Želechovice type and embanked furnaces with a thin breast part built in batteries (period of the Great Moravia – northern Morava river area, Moravian Karst). Since the beginning of the new millennium, the freestanding shaft furnace was used. The documentation of development of ferrous metallurgy in the Czech lands from 12th to 13th century, the period of formation of urban agglomerations is very low. Nevertheless, this period brings a number of fundamental changes associated with an increased consumption of iron gradually covered by implemented iron mills equipped with water wheels. The waterwheel was probably used first to drive the expanding bellows allowing magnification of the furnace and increasing of its production. In Alpine countries in the modern era the iron furnaces were up to 5 meters high and they produced iron bloom weighing up to 1000 kg. That – for Czech lands – new type of furnace was used since the mid-16th to the gradualintroduction of the blast furnace producing an indirect way pourable raw iron with higher carbon content (about 2–4 %). The blast furnace developed out of Czech territory and its use came from the Saxon side of Erzbegirge (Krušné hory) at the end of 16th century. In some areas of Europe, however, the bowl furnaces were used. In area of Scandinavia the shaft furnaces were replaced, in the western Mediterranean their development and use continued until the end of the 18th century (Corsican forge, Catalan forge).