African Iron Production: A Review of Recent Publications
The Culture and Technology of African Iron Production
Iron Technology in East Africa: Symbolism, Science, and Archaeology
reviewed by
D. Dungworth This is an interesting time to be researching traditional iron working in Africa. The
topic has long attracted interest from Western academics (both in terms of its
technology and its symbolism), but there has been a notable increase in the pace of
research in the last decade or two. In addition, there is something of a
theoretical/methodological realignment going on. Whereas most early research
examined just technological or just symbolic elements, recent ethnographies have
included thorough studies of complete 're-enactments' of traditional techniques. In
many cases, this work has only been possible through interdisciplinary co-operation.
The subject is of considerable importance to archaeologists for the light it sheds on the
technology, social organisation, and symbolism of early metalworking in Africa and
beyond. These two books represent all that is best in the current re-examination of
African iron working. African iron working has been the subject of Western ethnographies for well over a
century. The earliest work was often undertaken by missionaries and colonial
administrators. The aspect of this industry which provoked the most interest amongst
Westerners was the role of magic and symbolism. The often tacit assumption was that
African iron working was 'held back' by the ritual surrounding production. This
formed part of a wide-ranging 'project' to portray Black African achievements as
inferior compared to those of the West. Africans were assumed to be intellectually
inferior, and the 'superstition' surrounding iron working was seen as a clear example
of this. Some of the early ethnographies were rather perfunctory, with most emphasis
on interviews rather than actual observations of smelting and smithing practice. As traditional African iron working (in particular smelting) declined economically in
the twentieth century, so ethnographies became less frequent. The topic has undergone
something of a renaissance in the last few decades, however, due in part to the
emergence of archaeometallurgy. In particular, the archaeological and scientific study
of early iron working in Europe and elsewhere has benefited greatly from an
examination of recent practice in Africa. Almost all iron production in Europe before
the Middle Ages was carried out using the bloomery (or direct) process in which the
iron was obtained from the ore as a solid (rather than as a liquid, as is modern
practice). In Europe, the bloomery process declined after the development of the blast
furnace. By the later twentieth century there were some metallurgists who doubted
that iron could be regularly obtained by a direct process. Tylecote's (1965) survey of
some of the early ethnographic accounts showed that the technique was widely used in
Africa in the nineteenth century. The furnaces, metal and waste products described
were all clearly produced by the direct process. Tylecote and his contemporaries,
however, showed little or no interest in rituals associated with iron working. Attention
was directed exclusively on technological aspects. Archaeological interest in metal working also focused on the social organisation of
metal working and the social standing of the smith. This derived in large part from
Childe's influential model of European Bronze Age society (Childe 1942). Childe
suggested that smiths in Bronze Age Europe were mobile; they had few social ties and
so could travel between different social groups, selling their wares across wide areas.
The idea that smiths could operate 'outside' society in such a way received a
substantial blow with the publication of Rowlands (1971) survey of the social standing
of smiths in African societies (taken from a survey of the then available literature). The last two decades have seen an enormous increase in interest in traditional iron
working in Africa. This recent interest differs from that seen previously in the ways
that the research is carried out and how the subject is conceptualised. Despite the
decline of traditional African iron working a number of researchers (e.g. Avery,
Barndon, Celis, Childs, David, de Barros, de Maret, Echard, Fowler, Goucher,
Herbert, Killick, McNaughton, Schmidt, and van der Merwe) have successfully
persuaded indigenous groups to carry out iron smelting and smithing (in many different
locations across sub-Saharan Africa). In many cases, smelting ceased only a generation
or two ago, but by drawing on the knowledge of those who smelted in their youth, as
well as the knowledge of younger smiths, it has been possible to smelt ore and produce
bloomery iron and steel according to traditional methods. The core of recent field
work on traditional iron smelting and smithing has been the direct observation of the
processes. This has often been enriched by the co-operation of specialists from many
different academic fields (especially ethnography and metallurgy). This ethnography is
extremely important as much of the detailed technological and ritual knowledge of
traditional African iron working (especially smelting) is dying out with its last
practitioners. In a sense, this is 'rescue ethnography'. The ethnography which is carried
out is sophisticated, however, and does not attempt to reconstruct iron working as a
'timeless' practice free from outside (especially Western) influence. Many of the recent
ethnographic surveys of iron working have explicitly addressed the changes in metal
working forced by changing social and economic conditions in recent centuries. The Culture and Technology of African Iron Production (hereafter Culture and
Technology) contains a series of papers on African iron working: some are taken from
a conference in 1988, while other are reprints or updates of important papers published
elsewhere. Schmidt's introduction places the various papers within a wider context
which ranges over changes in how iron working in Africa has been conceptualised by
Western scholars, including the role of technology and ritual. De Maret and Thiery
review the available evidence for 'How old is the Iron Age in Central Africa?'. The
increased excavation of archaeological sites in Africa and the availability of
radiocarbon dating has meant that data relevant to this question have burgeoned in
recent years. When very little data were available the answer to this question was
straight forward. As more data become available the picture is (at least initially) less
clear. It seems that iron working was underway in the Gulf of Guinea and the
interlacustrine area by the middle of the first millennium BC. There are a few earlier
dates (second millennium BC) but these are regarded sceptically at the moment. The
next three papers describe iron smelting in two different African societies. In each case
local people are persuaded to reconstruct iron smelting technologies which have been
abandoned in the last generation or two. Such rescue ethnography may involve
imperfectly remembered practices, but it is still important, as it may be impossible to
reconstruct in a few generations. Goucher and Herbert present a study of Bassari
smelting which was on a sufficient scale to be described as 'proto-industrial' on the eve
of colonial conquest. Research on Bassari iron smelting has been relatively intense (e.g.
two recent University of California at Los Angeles doctorates). The technology and rituals of iron smelting amongst
the Bassari were adapted to achieve high levels of production (e.g. natural draught and
a relaxation of many of the taboos against female participation). Barndon describes
how the part-time iron smelters of Ufipa in western Tanzania used a complex
technology involving tall forced-draught furnaces for the initial reduction, with a much
smaller furnace for bloom purification and consolidation. Barndon pays particular
attention to how the technological solutions to Fipa iron smelting are embedded within
their culture. The explanations of the symbolic power of rituals draw on associations
and relationships found in other contexts of the society. Schmidt's chapter on the
Barongo provides a fascinating study of a group who seem to have emerged as a result
of social and economic upheaval in the wake of the slave trade. The Barongo survived
as iron smelters in western Tanzania longer than many other smelting groups because
of the abundant local resources (especially ore and wood) and their remoteness from
imported scrap iron and steel. Schmidt argues that many aspects of Barongo iron
smelting technology and ritual are drawn from a variety of different sources, reflecting
the varied origins of the Barongo themselves. Schmidt employs the concept of
bricolage to help explain how Barongo iron smelters select solutions from a wide range
of technological and ritual options (a theme which is explored in more depth in Iron
Working in East Africa). The chapter by David and Robertson offers a welcome examination of iron smithing
rather than smelting. The ways in which Montagnard and Muslim smiths in northern
Cameroon have responded to changes in the economic landscape (in particular the
introduction of cheap imported scrap iron and steel) are explored in great detail. Childs
and Dewey examine the ways in which iron was smithed in ancient and modern Zaire
and Zimbabwe. Blooms were extensively hammered to produce a series of distinctively
shaped axes, some of which were utilitarian while others were invested with
considerable symbolic meaning (in particular political power). A series of papers follows which discusses the extent to which a distinctive and
innovative iron smelting technology developed in north-western Tanzania. The idea
that placing the greater part of tuyères inside the furnace allowed the air
introduced to the furnace to be pre-heated (and so increasing the temperature reached
inside the furnace) was first put forward by Schmidt and Avery in a 1978 article in
Science. This is reprinted here with a few extra clarifications. This is followed by an
updated version of a 1985 article by Schmidt and Childs on the excavation of early iron
working sites along the western shores of Lake Victoria (originally published in
African Archaeological Review, 1985). A critique of the 'pre-heating hypothesis' by
Rehder and a reply by Avery and Schmidt from the Journal of Field Archaeology
(1985) are reprinted here as a single chapter.
This is followed by further criticisms by Killick and defence by Avery and Schmidt.
Schmidt and Avery propose that a technologically advanced mode of iron smelting
arose in north-western Tanzania in the first millennium BC. Archaeological evidence
from the early Iron Age sites at Rugomora Mahe and Kemondo Bay indicate that iron
smelting slags were formed at temperatures of at least 1350°-1400° C.
This is at least 100° C higher than that implied for European bloomery furnaces.
The appearance of the tuyères from these sites (reduced and vitrified on the
outer surfaces) suggested that the greater part of the tuyères had been placed
inside the furnace and thus allowed the air being forced in to be pre-heated. Pre-heating allowed higher temperatures to be attained, which ensured more efficient
reduction with less use of fuel, as well as the reduction of relatively poor ores. A
bloom was also excavated from one of the Kemondo Bay furnaces. It was placed in
what must have been a ritual context in a small pit dug into the base of the furnace.
Metallography showed that this bloom was of steel rather than iron. The pre-heating
hypothesis put forward by Schmidt and Avery explained the nature of the used
tuyères, how the slags were formed and why steel rather than iron was formed.
Schmidt and Avery were aware that their findings had considerable ramifications for
the way in which iron and steel production in Africa was viewed: they demonstrated
that Africans were capable of considerable technological achievement. Schmidt and Avery chose to test their pre-heating hypothesis in an authentic
environment by observing traditional iron smelting in north-western Tanzania. By
observing Haya iron smelting, Avery and Schmidt hoped that many technological
aspects of iron smelting may have remained unchanged in the area over two millennia
or more. The Haya proceeded to smelt with a furnace, into which were placed the
tuyères. Avery and Schmidt measured high temperatures inside the furnace -- in
excess of 1820° C at one point. Schmidt and Avery's pre-heating hypothesis is
controversial; it overturns many pre-existing and deep-seated notions about the
development (or lack of development) of African technology. Rehder's criticism of the
pre-heating hypothesis is based primarily on a mathematical model using
thermodynamic theory and data. Rehder argues that Haya pre-heating could amount to
little more than an extra 10° C, which would have little or no effect on the slags
or metal produced. Avery, Schmidt, Rehder, and Killick argue the pre-heating
hypothesis backward and forward. It is clear that there are serious technical and
practical impediments to the accurate measurement of air temperatures inside
tuyères and furnaces and to the production of thermodynamic models of the
chemical and physical reactions which take place. In particular, thermocouples placed
inside tuyères may be heated more easily than the air flowing past them and so
may indicate a higher degree of 'pre-heating' than is actually the case. Attempts to
model pre-heating thermodynamically (both by Rehder and by Avery and Schmidt) are
less than satisfactory as the valveless bellows lead to an unsteady and turbulent forced
draught. On balance, the nature of the slag and the tuyères indicate that pre-heating did occur. Rehder's and Killick's criticisms deserve careful consideration but
are not powerful enough to disprove the pre-heating hypothesis. In the final chapter in the book, Childs presents the detailed scientific examination of
ores, slag, and metal from ancient and recent iron smelting in north-western Tanzania.
The study of the microstructure of the ores and slags provides support for Schmidt and
Avery's interpretation of Haya and earlier smelting procedures. Childs also recognises
that, while many blooms are made from steel (containing significant levels of
phosphorous and carbon), finished artefacts are usually made from phosphoric iron.
She suggests that the difficulties of working phosphoric steel led smiths to decarburise
the blooms regularly (but not exclusively) before working. The second book reviewed here, Iron Technology in East Africa; Symbolism, Science,
and Archaeology, covers some of the same topics discussed in Culture and
Technology, but the approach is somewhat different. I knew this book was rather
special as soon as I got it; a quick flick through showed that it managed to do justice
to complex features of both the technology and the symbolism of African iron
working. This is exemplified by the use of clear photomicrographs and the use of terms
such as bricolage to explain the wide variety of sources drawn upon in the
development of ritual. Iron Technology in East Africa represents several decades of research by Schmidt and
others amongst the Haya of north-western Tanzania. The book provides a detailed
account of the 'experimental ethnoarchaeology' conducted to determine how the Haya
smelted iron and specifically tests the pre-heating hypothesis. This book is about much
more as well. Schmidt had already used archaeological and ethnohistorical methods to
reconstruct Iron Age settlement and history around Lake Victoria. In Iron Technology
in East Africa, Schmidt draws on his considerable knowledge of the local cultures to
place iron smelting in its specific milieu. In doing so, Schmidt provides a particularly
'thick' (Geertz 1973) account of iron smelting as a technological, social, and symbolic
process. The first three chapters introduce the subject and provide a discussion of Haya history
and the history of Western study of African iron smelting. Schmidt is at pains to stress
that he wants to use a critical methodology to 'deconstruct Western representations
about African iron technology' (4). The fourth chapter 'Ethnoarchaeology and
bricolage' provides a detailed ethnography of Haya iron smelting based on the re-enactment of iron smelting. The Haya had conducted iron smelting regularly until the
1950s, and Schmidt managed to persuade some elders who had smelted in their youth,
as well as some younger iron smiths, to conduct smelts for him. Schmidt admits that
the results were 'interactive performances conducted in an environment far removed
from experience, routine, and memory' (12), but shows sufficient sympathy for
technological, social, and symbolic aspects of the process to yield a detailed and
reflexive account of iron smelting. Some of the difficulties which Schmidt had to
negotiate illustrate how easily one might form a simplistic model of 'traditional' iron
smelting. Since iron smelting had been abandoned more than a generation before, there
was initially, at least, very little local interest in the project. The smelters were reticent
about rituals associated with smelting, primarily because they were associated with
traditional religions which were disapproved of by the local Christian church. Schmidt's most distinctive insight into the Haya smelting process is the way in which
the smelters had a variety of technological and ritual solutions, or 'protocols', which
could be deployed when the process was not as successful as expected. Schmidt
identifies the process whereby smelters chose some protocols and not others as
bricolage (expanding on Lévi-Strauss and Lemonnier). The technological and
the ritual protocols were often so closely bound together that they could not be
separated easily. Altering ritual aspects of a smelt often altered the technology of the
smelt. In this way, ritual may actually have had a liberating effect, as opposed to the
traditional notion that African iron smelting (and technology in general) was held back
by 'superstition'. Following this are three chapters which provide a detailed scientific analysis of the
smelting process, its waste materials and its primary product, as practised by the Haya
and as seen from the excavation of early Iron Age sites in the area. This is based in
large part on the metallographic work of Terry Childs with some input from Donald
Avery. The construction and performance of the tuyères (seen as crucial in the
'pre-heating hypothesis') are discussed at some length. Chapter eight draws on an analysis of the spatial organisation of Haya smelting and
smithing to develop a 'middle-range theory' for the interpretation of archaeological
features on early Iron Age smelting and smithing sites. Chapter nine explores
structuring principals in Haya song and myth in order to aid in understanding the
symbolism of iron and iron working. Iron has long been associated with power and
fertility in Bantu-speaking Africa. By drawing on his already considerable knowledge
of Haya history, Schmidt is able to construct a detailed analysis of the relationships
between iron, iron production, human sexual reproduction, social reproduction, and
social power. Such relationships have recently been explored by Herbert (1993), but
Schmidt's account benefits from examining a restricted geographical and social space,
and thus does not 'smooth out' regional differences, and attempts to see how symbolic
relationships are manipulated over time, rather than construct some idealised
ethnographic present. In chapter 10, Schmidt examines some of the more
comprehensive ethnographic accounts of iron smelting from elsewhere in sub-Saharan
Africa. This and the last chapter help to produce a coherent picture of the employment
of technological and ritual protocols in smelting, which appear to have a considerable
history in the region. In particular, ritual offerings are sometimes placed in a tiny pit
within both Haya and early Iron Age smelting pits. The rituals associated with iron
working can now be seen as an essential part of the search for technological solutions
and as integrated into wider attempts to explain the relationships between people and
their social and natural environment. These two books together provide an excellent insight into African iron working. It is
clear that the emerging picture of African iron working is a complex one. This is
achieved by employing sympathetic ethnographic accounts based on actual practice
and indigenous explanations of that practice, as well as rigorous scientific analysis of
the practice and its products. Such approaches show that the technology employed
was sophisticated and also place that technology within a wider symbolic and social
context. We can also now see that African iron working is subject to significant
regional and chronological variation. The scope of these two books is almost breath-taking. If they represent the current state of archaeometallurgy and in particular its
relationship with ethnography, then the discipline has definitely come of age. I have no
hesitation in recommending both of these books to anyone interested in
archaeometallurgy, ethnography, the history of technology, African archaeology, and
related disciplines. Works cited
Geertz, C. 1973. The Interpretation of Cultures. London: Fontana Press.
Herbert, E.W. 1993. Iron, Gender and Power. Rituals of Transformation in African
Societies. Bloomington and Indianapolis: Indiana University Press.
Rowlands, M.J. 1971. The archaeological interpretation of prehistoric metalworking.
World Archaeology, 3: 210-223.
Tylecote, R.F. 1965. Iron smelting in pre-industrial communities. Journal of the Iron
and Steel Institute, 203: 340-348.
About the reviewer
Copyright © D. Dungworth 1998
by
P.R. Schmidt (ed.)
University Press of Florida, Gainesville, FL, 1996
338 pp. (bibliography, index)
ISBN 0-8130-1384-4
£40.00 (cloth)
by
P.R. Schmidt
Indiana University Press, Bloomington, IN, 1997
328 pp.(bibliography, index)
ISBN 0-8130-1384-4
£40.00 (cloth), £12.96 (paper)
Childe, V.G. 1942. What Happen in History. Harmondsworth: Penguin Books.
Dr David Dungworth is a Teaching Fellow in Glass and Metals at the Department of
Archaeology and Prehistory, University of Sheffield. He completed a degree in Ancient
History and Archaeology at the University of Birmingham in 1991 and was awarded a PhD
by the University of Durham in 1995 for research on Iron Age and Roman copper alloy use.
This research has now been published online in issue 2 of Internet Archaeology.
He may be reached by e. mail at the following address: <D.B.Dungworth@sheffield.ac.uk>.
Copyright © assemblage 1998