Thomas Birch Marcos Martinón-Torres

Abstract

An assemblage of post-medieval iron bars was found with the Princes Channel wreck, salvaged from the Thames Estuary in 2003. They were recorded and studied, with a focus on metallography and slag inclusion analysis. The investigation provided an opportunity to explore the use of multivariate statistical techniques to analyse slag inclusion data. Cluster analysis supplemented by principal components analysis revealed two groups of iron, probably originating from different smelting systems, which were compared to those observed macroscopically and through metallography. The analyses reveal that the bars were formed from raw blooms, and all were made with iron produced by the direct process. The outward uniformity of the bars is at odds with the variable quality of iron displayed within and between bars.

##plugins.themes.bootstrap3.article.details##

Keywords
References
Aitchison J, Barceló-Vidal C and Pawlowsky-Glahn V 2002, ‘Some comments on compositional data analysis in archaeometry, in particular the fallacies in Tangri and Wright’s dismissal of logratio analysis’, Archaeometry 44(2), 295–304.
Awty B G 2006, ‘The elusive Walloon finery forges of Liège’, Historical Metallurgy 40(2), 129–37.
Awty B G 2008, ‘The Austrian lift-hammer - its probable Walloon origin’, Historical Metallurgy 42(1), 12–2.
Auer J and Firth A 2007, ‘The ‘Gresham Ship’: an interim report on a 16th-century wreck from Princes Channel, Thames Estuary’, Post-Medieval Archaeology 41(2), 222–241.
Baxter, M 2003, Statistics in Archaeology (London).
Blakelock E, Martinón-Torres M, Veldhuijzen H A and Young T 2009, ‘Slag inclusions in iron objects and the quest for provenance: an experiment and a case study’, Journal of Archaeological Science 36(8), 1745–57.
Björkenstam N 1982, ‘ Technology, production, costs’, in G Pipping (ed), Iron and Steel on the European Market in the 17th Century: a contemporary Swedish account of production forms and marketing (Stockholm).
Buchwald V F 2005, Iron and Steel in Ancient Times (Copenhagen).
Buchwald V F and Wivel H 1998, ‘Slag analysis as a method for the characterization and provenancing of ancient iron objects’, Materials Characterization 40, 73–96.
Charlton M, Crew P, Rehren Th and Shennan S J 2010, ‘Explaining the evolution of ironmaking recipes – an example from northwest Wales’, Journal of Anthropological Archaeology 29, 352–367.
Cleere H and Crossley D 1985, The Iron Industry of the Weald (Leicester).
Coustures M P, Béziat D and Tollon F 2003, ‘The use of trace element analysis of entrapped slag inclusions to establish ore-bar iron links: examples from two Gallo-Roman iron-making sites in France (Les Martyrs, Montagne Noire, and Les Ferrys, Loiret)’, Archaeometry 45(4), 599–613.
Desaulty A-M, Dillman P, L’Héritier M, Mariet C, Gratuze B, Joron J-L and Fluzin P 2009, ‘Does it come from the Pays de Bray? Examination of an origin hypothesis for the ferrous reinforcements used in French medieval churches using major and trace element analyses’, Journal of Archaeological Science 36, 2445–2462.
Desaulty A-M, Mariet C, Dillman P, Joron J-L and Fluzin P 2008, ‘A provenance study of iron archaeological artefacts by Inductively Coupled Plasma-Mass Spectrometry multi-elemental analysis’, Spectrochimica Acta Part B 63, 1253–1262.
Dillman P and L’Héritier M 2007, ‘Slag inclusion analyses for studying ferrous alloys employed in French medieval buildings: supply of materials and diffusion of smelting processes’, Journal of Archaeological Science 34(11), 1810–1823.
Elban W L and Goodway M 2003, ‘Inclusions in 19th-century American wrought iron structural cable wires’, Historical Metallurgy 37(2), 106–19.
Evans C and Rydèn G 2007, Baltic Iron in the Atlantic World during the eighteenth century (Leiden).
Gordon C 1997, ‘Process deduced from ironmaking wastes and artefacts’, Journal of Archaeological Science 24, 9–18.
Hart C 1971, The Industrial History of Dean (Newton Abbot).
Hayman R 2005, Ironmaking: the history and archaeology of the iron industry (London).
Hedges R E M and Salter C J 1979, ‘Source determination of iron currency bars through analysis of slag inclusions’, Archaeometry 21(2), 161–75.
Hildebrand K-G 1992, Swedish Iron in the Seventeenth and Eighteenth Centuries Export Industry before the Industrialization (Stockholm).
Humphris J, Martinón-Torres M, Rehren Th and Reid T 2009, ‘Variability in single smelting episodes – a pilot study using iron slag from Uganda’, Journal of Archaeological Science 36, 359–369.
King P 1996, ‘Early Statistics for the iron industry: a vindication’, Historical Metallurgy 30(1), 23–46.
King P 2003, ‘The iron trade in England and Wales, 1500–1815: the charcoal iron industry and its transition to coke’, unpublished PhD thesis, University of Wolverhampton.
King P 2005, ‘The production and consumption of bar iron in early modern England and Wales’, Economic History Review, 57(1), 1–33.
van Laun V 1979, ‘17th century ironmaking in south west Herefordshire’, Historical Metallurgy 13(2), 55–65.
Mackenzie R J and Whiteman J A 2006, ‘Why pay more? An archaeometallurgical investigation of 19th-century Swedish wrought iron and Sheffield blister steel’, Historical Metallurgy 40(2), 138–49.
Nef J U 1987, ‘Mining and Metallurgy in Medieval Civilisation’, in M M Postan and E Miller (eds), The Cambridge Economic History of Europe (Cambridge), 735–56.
Pagès G, Long L, Fluzin P and Dillman P 2008, ‘Réseaux de production et standards de commercialisation du fer antiqueen Méditerranée: les demi-produits des épaves romaines des Saintes-Maries-de-la-Mer (Bouches-du-Rhône)’, Revue Archéologique de Narbonnaise 41, 261–283.
Pipping G (ed) 1982, Iron and Steel on the European Market in the 17th Century (Stockholm), 200–260.
Rostoker W and Dvorak J 1990, ‘Wrought irons: distinguishing between processes’, Archeomaterials 4(2), 153–66.
Shennan S 1997, Quantifying Archaeology (Edinburgh).
Sigurðardóttir K H 2004, ‘Provenance studies of iron from Iceland’, in G Guðmundsson (ed), Current Issues in Nordic Archaeology. Proceedings of the 21st Conference of Nordic Archaeologists 6-9 September 2001 Akureyri, Iceland (Reykjavik), 119–124.
Smith T 1997, ‘The Jernkontoret 250th anniversary conference’, Historical Metallurgy 31(1), 36–41.
Starley D 1999, ‘Determining the technological origins of iron and steel’, Journal of Archaeological Science 26, 1127–33.
Tangri D and Wright R V S 1993, ‘Multivariate analysis of compositional data: applied comparisons favour standard principal components analysis over Aitchison’s loglinear contrast method’, Archaeometry 35(1), 103–12.
Tholander E 1989, ‘Microstructure examination of slags as an instrument for identification of ancient iron-making processes’, in R Pleiner (ed), Archaeometallurgy of Iron. International Symposium of the Comite´ pour la Siderurgie Ancienne de L’UISPP, (Prague), 35–41.
Tylecote R F 1962, Metallurgy in Archaeology (London).
Tylecote R F 1976, A History of Metallurgy (London).
Tylecote R F 1987, The Early History of Metallurgy in Europe (London).
Tylecote R F 1991, ‘Iron in the Industrial Revolution’, in R F Tylecote and J Day (eds), The Industrial Revolution in Metals (London), 200–260.
Wessex Archaeology 2005, Princes Channel Wreck, Thames Estuary, Phase III Summary Report, unpublished report 57330.01.
Williams A R 1990, ‘Slag inclusions in armour’, Historical Metallurgy 24(1), 69–80.
How to Cite
The iron bars from the ‘Gresham Ship’: employing multivariate statistics to further slag inclusion analysis of ferrous objects. (2021). Historical Metallurgy, 48(1 & 2), 70-79. https://hmsjournal.org/index.php/home/article/view/92
Section
Articles