Hello again Sébastien, and everybody else,
I do recognize the object at your picture. There's at least
one similar object from Helgö, see http://hem.passagen.se/anders.sberg/9890.jpg
This is an end-piece from a ceramic package from some
metallurgical process where the iron object to be treated was
wrapped in a protecting clay package before treatment. There
are probably several processes where clay was used in this way,
and I know two that so far have been identified - case
hardening and brazing (usually of padlocks and bells) - and
probably there may be a package-welding process around as well,
but the ceramic remains from such a process haven't yet been
identified.
The "Propfen" could represent end pieces from treating tubular
iron objects, as suggested at left in the picture 9890.jpg -
perhaps from soldering together/brazing small bells.
There are a few more examples from Bosau: check "Gebers, W.
1981. Bosau, Untersuchung einer Siedlungskammer in
Ostholstein. V:1, Der slawische Burgwall auf dem
Bischofswarder. Teil 1: Katalog. Sackau, H. (red) Neumünster.",
tafel 22, page 120.
Picture 4, 5 and 6 show similar end pieces. Moreover, picture
1, 2 and 3 show exellent fragments from brazing padlocks, with
visible imressions of the locks, and pictures 8-16 show
different examples of tubular packages, probably deriving from
case hardening.
Anders
>----Ursprungligt meddelande----
>Från: [log in to unmask]
>Datum: 18-11-2009 21:18
>Till: <[log in to unmask]>
>Ärende: Re: Ang: Re: slag rods/tubes on archaeological sites
>
>An image is avaible here: http://www.zoyd.info/public/bouchons.jpg.
>These two examples are from a large gallo-roman rural smithy
in
>Etagnières/Switzerland. As far as I can remember, some other
pictures
>were published in the monographs of Haithabu (viking/Germany)
and
>Dietikon (roman/Switzerland), but I don't have them at hand
right now;
>however, besides of the section, all of these items look quite
similar.
>I might put some other photographs online, if useful.
>Cheers, Sébastien
>
>Anders Söderberg a écrit :
>> It would be most interesting to see a few pictures of those
>> "Propfen". Are there any available somewhere?
>>
>> Anders
>>
>>
>>
>>> ----Ursprungligt meddelande----
>>> Från: [log in to unmask]
>>> Datum: 18-11-2009 16:10
>>> Till: <[log in to unmask]>
>>> Ärende: Re: slag rods/tubes on archaeological sites
>>>
>>> Dear all,
>>>
>>> I guess we may be talking of different things, but I
thought
>>>
>> I might use
>>
>>> this occasion to query about some slightly similar pieces
for
>>>
>> which I don't
>>
>>> find any satisfying explanation. We repeatedly found some
clay
>>>
>> rods a few
>>
>>> centimetres long in slag assemblages of gallo-roman
smithies
>>>
>> in Switzerland
>>
>>> (I know of at least 6 individuals from three sites in
>>>
>> Switzerland). The
>>
>>> surfaces are blackish and slagged on a very shallow
surface.
>>>
>> They have an
>>
>>> oval or rectangular section of perhaps three or four
>>>
>> centimeters; one
>>
>>> extremity generally shows a slight bulge. The pieces are
>>>
>> altered on all
>>
>>> surfaces of this extremity, which was obviously exposed to
a
>>>
>> certain heat,
>>
>>> although the alteration is restricted to the surface. One
of
>>>
>> these pieces
>>
>>> was analysed some time ago by Marianne Senn; the surface
was
>>>
>> strongly
>>
>>> enriched in iron, and the clay seemed to be similar to
that
>>>
>> used for crucibles.
>>
>>> Similar pieces have been found in quite large numbers in
the
>>>
>> Viking site of
>>
>>> Haithabu, and two or three others are known from two French
La
>>>
>> Tène sites. I
>>
>>> guess there might be many others, but they are quite
difficult
>>>
>> to identify
>>
>>> in large slag assemblages; besides of the particular
>>>
>> morphology, the
>>
>>> material looks just like the usual sandy-clayey slags;
like
>>>
>> these, they are
>>
>>> probably quite friable.
>>>
>>> The pieces I know of are always clearly associated to
smithies
>>>
>> in sites
>>
>>> devoid of smelting activities. In german, they have been
>>>
>> called "Propfen" or
>>
>>> "Zapfen". Obviously, they were used to block some
rectangular
>>>
>> or ovoid
>>
>>> opening (an air inlet?) on one side of the hearth exposed
to
>>>
>> the fire; but
>>
>>> why would there be a need to block an air inlet in a
smithing
>>>
>> hearth (and
>>
>>> what is more, from the inside)? Although they seem to be
very
>>>
>> rare, I find
>>
>>> it astonishing to find such pieces all over the time from
Iron
>>>
>> Age to
>>
>>> medieval times. I just can't figure out to what particular
>>>
>> practice they
>>
>>> could be associated; I wonder if somebody could come up
with
>>>
>> some
>>
>>> explanation for these objects?
>>>
>>>
>
>--
>Sébastien Perret
>Mineralogy and Petrography, Department of Geosciences
>University of Fribourg, Chemin du Musée 6, CH-1700 Fribourg,
Switzerland
>phone: +41 (0)26 300 89 40
>mail: [log in to unmask] <mailto:[log in to unmask]
ch>
><http://www.unifr.ch/geoscience/mineralogy/archmet>>
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