>What is the silver content of the Combe Martin lead ores?
>
Trevor,
There are as many assay figures as there days in the year - up to 1000ozs
per ton has been quoted in one case.
Unfortunately we do not have any run of mine assays from the 19th centurybut
the a prospectus for the Combmartin and North Devon Mining Co. in 1835 gives
the yield from one ton of ore as 14.5 cwt of lead and 54 ozs 7 dwt of
silver. That company was proposing working under the ancient bottoms, with a
considerable amount of ground having been taken away to surface by earlier
workers, ground which would have been in the oxidised zone above the water
table with an enhanced silver content.
>
>"From AD 361 each Roman soldier had an 'accession donative' (joining bribe)
of five gold Solidi and one pound of silver (327g) which must have stretched
the British silver production to its limits.
AD361 is quite late in the Roman occupation period - and the production
potential of British silver mines at that time is unclear - however any
payment to soldiers would be recycled in the economy and would not
neceassarily place is significant call on newly mined resources.
As to smelting / refining lead based ores with coal in the 4th century -
where does he get that idea from?? Iron smithing, yes, but not lead smelting.
Peter
______________________________________________
Peter Claughton, Blaenpant Morfil, 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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