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Plano-convex ingots are lumps of metal, with a flat or slightly concave top and a convex base. Although they are sometimes referred to as bun ingots, this is misleading as it implies the opposite orientation.〔Weisgerber, G. and Yule, P (2003) ‘Al Aqir near Bahla–an Early Bronze Age Dam Site with Plano Convex Ingots’ in Arabian Archaeology and Epigraphy 14 p.48〕 They are most often made of copper although plano-convex ingots of other materials such as copper alloy, lead and tin are also known.〔Bass, G.F. (1967) Cape Gelidonya: A Bronze Age Shipwreck US: American Philosophical Society, Maddin, R. & Merkel, J. (1990) ‘Metallographic and statistical analyses’ in Lo Schiavo, F Maddin, R Merkel, J. Muhly, J. D. & Stech, T (eds) Metallographic and statistical analyses of copper ingots from Sardinia P.42-199. Ozieri: Il Torchietto Tylecote, R.F. (1987) The Early History of Metallurgy in Europe. London: Longman, p.204 Pulak, C (1998) ‘The Uluburun Ship: An Overview’ IJNA 27 (3) p199 Waschmann, S. (2009) Seagoing Ships and Seamanship in the Bronze Age Levant (2nd Ed) US: Texas A&M University Press〕 Plano convex ingots are found across a wide chronological and geographical range with the first examples known from the Near East during the 3rd and 2nd Millennia BC.〔Piggott, V.C. (1999) ‘The development of metal production on the Iranian Plateau: An Archaeometallurgical Perspective’ in The Archaeometallurgy of the Asian Old World :MASCA Research Papers, Weisgerber, G. and Yule, P (2003) ‘Al Aqir near Bahla–an Early Bronze Age Dam Site with Plano Convex Ingots’ in Arabian Archaeology and Epigraphy 14 p.48〕 By the end of the Bronze Age they were found throughout Europe〔Tylecote, R.F. (1987) The Early History of Metallurgy in Europe. London: Longman, p.194-209, Janzon, G.O. (1988) ‘Early Nonferrous Metallurgy in Sweden’ In Maddin, R. (ed) The Beginning of the Use of Metals and Alloys US: MIT Press p.104-17,〕 and in Western and South Asia 〔Rothenberg 1990, chapter 5, Piggott, V.C. (1999) ‘The development of metal production on the Iranian Plateau: An Archaeometallurgical Perspective’ in The Archaeometallurgy of the Asian Old World :MASCA Research Papers, Weisgerber, G. and Yule, P (2003) ‘Al Aqir near Bahla–an Early Bronze Age Dam Site with Plano Convex Ingots’ in Arabian Archaeology and Epigraphy 14〕 and similar ingot forms continue in use during later Roman and Medieval periods ==Manufacture of Bun Ingots== Traditionally bun ingots have been seen as a primary product of smelting, forming at the base of a furnace beneath a layer of less dense slag .However experimental reconstruction of copper smelting has shown that regular plano-convex ingots are difficult to form within the smelting furnace producing only small ingots or copper prills which need to be remelted (Merkel 1986, Craddock 1995.) The high purity copper bun ingots from the found in Late Bronze Age Britain and the Mediterranean seem to have undergone a secondary refining procedure between The metallographic structure and high iron compositions of some plano-convex ingots suggest that they are the product of primary smelting (Roman 1990.) Tylecote has suggested that Roman plano-convex copper ingots may have been formed by tapping both slag and copper in one go into a mould or pit outside the furnace (1986, 22-5.) A similar process was described by Agricola in book IX of his De Re Metallica (Hoover and Hoover 1950) and has been replicated experimentally (Bamberger and Wincierz 1990, 133.) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Plano-convex ingot」の詳細全文を読む スポンサード リンク
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