Archaeological evidence for modes of air supply into iron smelting furnaces in the African Great Lakes region

One of the themes that have attracted archaeologists’ attention is the mechanism by which iron smelting furnaces were supplied with air. Earlier studies on this theme were largely undertaken using expensive laboratory and experimental methods. Unfortunately, insufficient attention was paid to ethnographic and archaeological data while reconstructing air supply modes. This paper presents and discusses archaeological field evidence for determining modes of air supply into smelting furnaces. The archaeological evidence was gathered through survey and through ethnographic and excavation methods. The paper argues that beyond the almost unheard of survival of bellows in the archaeological record and laboratory and experimental methods, it is possible to establish the modes of air supply employed in iron smelting furnaces using flared and non-flared tuyère proximal ends, frequent evidence for multiple tuyères being fused together, furnace size and height and tuyère-mould slags. It is therefore vital for archaeologists to search for clues about furnace air supply while doing fieldwork in order to identify techniques of precolonial metal production and thus explain the reasons for such technological choices.