It is interesting to note that one of the Cwm Heisian mines built a Plant
for gold, but it was, seemingly, at the end of the day, more successful in
recovering the zinc from the lode! (about 23 tons resulted - it is
interesting to note they received a bit more for that ore than was normal for the
day) - not quite the success that the Dirs. and shareholders wanted... but
there we go!
It is my firm belief that - anywhere pre 1890 - the only way to achieve a
good product was by hand sorting. The only way beyond this was by jigs
dedicated firstly to lead, so to remove as much of that product as possible,
and secondly jigs to take the zinc. Therefore, in the first instance little
evidence of lead there will be: in the second, well, there should be
negligible lead and less of zinc. A somewhat thankless task, and not easy to
interpret, since all will depend on how successful the plant was and how good
the Floor Mgr. managed the process.