Peter Hutchison wrote:

> .....
>
> I am sure the authors had a great time finding out how to do it. They don't
> seem to have expected to find out anything about how it was done in the
> past, and I don't think they have.

I think they have and I hope that fun and science are not factors excluding
eachother. Despite the fact that the details of the experimental reduction
process may not be directly comparable to archaeologically well described cases
(how few do we have and which experiment is really identical with which method
of the ancient metallurgists ?).
At least it has something to do with archaeometallurgy  : The observations
about the distribution of differently carburized metal relativ to its position
to the tuyere and the behaviour of  iron sponge with  variable contents of slag
during heating and hammering are most interesting, as well as the fact that
some sort of "analysing" can be done by "only" carefully observing the
behaviour of materials during processing them.

Which has been the lining and total wall thickness in antiquity ? According to
HINGST and the Scharmbeck model, in theses cases the total wall thickness
including lining would only have been approximatively 6 to 8 cm, despite the
fact, that much of the lining will participate in the slag formation
("normally"). During the Sandbjerg conference I did not yet recieve a
satisfying answer on this question.

Slagpits and the iron accumulation level under ground level, is this not
insulation ?

The  role of preheated air has been discussed concerning African smelting
processes and may perhaps be one of the essentials of the Matacam process
(David KILLICK ?).

If we take R.PLEINER (1987):Lovosice as it is (Radomir Pleiner confirmed, that
it is really reduction and not smithing) with ca. 16-18 % CaO in the slag we
have evidence that lime flux was used in antiquity. Not quite normal, indeed.
Fe-Pyroxen normativ slags should not be iron reduction slags but
kirschsteinite-slags may be possible at least under certain conditions, a
question of the relativ height of the silica content and not yet definitively
answered in every detail.


Ingo Keesmann
__________________________________________________________

Arbeitsgruppe Archaeometallurgie
Institut fuer Geowissenschaften
Johannes Gutenberg-Universitaet Mainz
D-55099 Mainz (Germany)
Telefon (+49) 6131 39 3 0181
Telefax (+49) 6131 39 2 3070
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http://www.uni-mainz.de/FB/Geo/Geologie/archaeo/




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