On Sat, 14 Nov 1998 22:30:00 +0000 Mike Yates 
<[log in to unmask]> wrote:

> You might be interested in Peter Schmitt's work in Tanzania. There is
> very little evidence there too as to how far back bellows were used, but
> the archaeology does indicate a very slow rate of change in technology.
> He demonstatrated that the valve-less bellows used in East Africa up to
> the beginning of this century are actually advantageous because air is
> better pre-heated by being occillated in the tuyeres. He found that the
> longer tuyeres and more simple bellows, than those used in Europe in the

The longer tuyeres might be true, but there is no evidence 
as to whether British Iron Age bellows had valves or not.

> BC era, apparently produced better blooms at much higher temperatures.

This statement was debated at the time of the conference 
that produced the book. 

The whole thesis seems to be based around the idea that 
there was a higher carbon content in the some of the 
African iron and that European iron was low carbon. 

Recent work presented at the Conference "Early Ironworking 
in Europe, archaeology and experiment" last year showed 
that there was high carbon steel in Europe in Iron Age 
Europe (http://users.ox.ac.uk/~salter2/plas/Contents.htm)
and the experimental shows that it is relatively easy to 
produce steel blooms. The experimental work also would 
seem to show that it is not so easy to retain the carbon 
content to the finished artefact. 

This undermines the main basis of the advanced african 
smelting technology theory, which was on dubious ground as 
far as the thermodynamics was concerned, but in turn may 
suggest that there were differences in smithing 
techniques, the way in which the metal was distributed, 
and in the archaeological sampling in Britian and 
Sub-Sahara Africa. 




Chris Salter

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