Peter,
Surely wherever in the world there was a need to crush ore, the technology
for the crazing mill was already in place. The flour or grist mills worked
on exactly the same principle of a circular stone rotating on a fixed stone
and centrally fed, as did their predecessor the rotary quern which can be
traced back to the Iron Age. These and crazing mills were both used to crush
small particles into powder. Perhaps then it is a case of technology
adaptation rather than diffusion. Other examples are the incorporating mill
used in gunpowder works in the 19th century which are similar to cider mills
for crushing apples in the UK and olive oil pressers used in the
Mediterranean which I believe can be traced back to the Greeks.
In tin producing areas, evidence for crazing mills is much scarcer than that
for stamping mills, and it is usually assumed they were fairly early in the
mechanising process, used either to reduce pure fine-grained stream tin or
to finish crushing material from stamps in the days before wet stamping. It
seems that the more efficient wet stamping process made them redundant. On
Dartmoor where at least 60 buildings have been recorded where stamping took
place in the medieval and post-med periods, evidence for only 3 crazing
mills have been recorded, all of these were found at stamping mill sites.
Unfortunately nobody at the time recorded the introduction of the crazing
mill so we are in the dark as to precisely when they were introduced but
their demise in Cornwall was recorded by Carew in 1602 who wrote 'howbeit of
late times they mostly use wet stampers and so have no need of Crazing Mills
for their best stuff'
Phil Newman
Archaeological Investigator
English Heritage Research and Standards
-----Original Message-----
From: Peter Claughton [mailto:[log in to unmask]]
Sent: Sunday, October 19, 2003 6:35 PM
To: [log in to unmask]
Subject: The diffusion of technology - the crazing mill for ore
preparation
Recently, whilst considering the diffusion of mining technology in Western
Europe during the late medieval / early modern periods, the use of the
crazing mill for ore preparation came to mind.
It is a technology, probably rooted in antiquity, which is only applicable
to certain sectors of non-ferrous metal mining. I am aware of its use on tin
ores, where a finely crushed concentrate was required to separate the waste
before smelting, but not certain as the date it was introduced. I might have
expected it to be used in the preparation of silver rich lead ores but have
no documentary evidence for its use in Devon prior to 1500. There is,
however, good archaeological evidence for its use at Pampailly, in central
France, in the mid 15th century (Benoit, Paul. La Mine de Pampailly
XVe-XVIIIe siècles Brussieu, Rhône, Documents d'Archéologie en Rhône-Alpes
No. 14, (Lyon, 1997)). Its use at Pampailly was on a marginal deposit
exploited during the bullion crisis when the demand to new sources of silver
was at its greatest. Perhaps the heighten demand for silver stimulated
experimentation with new crushing techniques but is there any link with the
introduction of the mill into the tin industry in the south-west of England?
Peter
______________________________________________
Dr Peter Claughton,
Blaenpant Morfil, nr. Rosebush, Clynderwen, Pembrokeshire, Wales SA66 7RE.
Tel. 01437 532578; Fax. 01437 532921; Mobile 07831 427599
University of Exeter - School of Historical, Political and Sociological
Studies
(Centre for South Western Historical Studies)
E-mail: [log in to unmask]
Co-owner - mining-history e-mail discussion list.
See http://www.jiscmail.ac.uk/files/mining-history/ for details.
Mining History Pages - http://www.exeter.ac.uk/~pfclaugh/mhinf/
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