First Page
Posted 03/10/2014 3:40 pm
My Two Cents: it would be essential, as part of the "proof", to have a statistically meaningful calibration of the analysis. I. e. test a group of what we know are pre 1810 coins (say, like the hoard from Haiti I handled 6 or so years ago of about 1000 pieces) and see whether those results are ok with the documentation and consistent within themselves. The pool of pieces to calibrate "pre-1810" readings has to be substantial.
Other points:
- the Madrid and Mexico mints carried fineness testings that were accurate at the time, and records of those still exist. If our (your) tests of coins that are provingly pre 1810 do not match those historical tests, then there is a problem with the methodology.
- Do post 1787 8 Reales show the decrease in fineness that is to be expected from the secret royal ordinance of 1786?
- edge mills are not entirely similar between them. The Lima pieces have a characteristic edge, entirely different from the Mexico and Potosi pieces.
Sometimes modern results are not reliable or not easy to interpret. I recently catalogued a couple of rare 1646 Necessity Florins from the Dutch Brazilian series. Historical records show that these were indeed struck from gold that came in a vessel coming from Africa which presumably was bringing gold from the ducth controlled mines there. But modern testing of those coins showed that the metal was different from the Islamic coins struck with gold of the period and region.
The authors concluded that the coins were NOT struck from african gold.
But in my opinion, this was a mistake: either the tests had methodological errors, or their initial hypothesis (that the Islamic coins were indeed struck from the same African gold) was flawed: if the historical records state clearly that the gold used came from gold carried by those vessels, I have no reason whatsoever to doubt it. So either that gold (from the vessel) did not came from those African mines, or the comparison test of Islamic coins was flawed.
Other points:
- the Madrid and Mexico mints carried fineness testings that were accurate at the time, and records of those still exist. If our (your) tests of coins that are provingly pre 1810 do not match those historical tests, then there is a problem with the methodology.
- Do post 1787 8 Reales show the decrease in fineness that is to be expected from the secret royal ordinance of 1786?
- edge mills are not entirely similar between them. The Lima pieces have a characteristic edge, entirely different from the Mexico and Potosi pieces.
Sometimes modern results are not reliable or not easy to interpret. I recently catalogued a couple of rare 1646 Necessity Florins from the Dutch Brazilian series. Historical records show that these were indeed struck from gold that came in a vessel coming from Africa which presumably was bringing gold from the ducth controlled mines there. But modern testing of those coins showed that the metal was different from the Islamic coins struck with gold of the period and region.
The authors concluded that the coins were NOT struck from african gold.
But in my opinion, this was a mistake: either the tests had methodological errors, or their initial hypothesis (that the Islamic coins were indeed struck from the same African gold) was flawed: if the historical records state clearly that the gold used came from gold carried by those vessels, I have no reason whatsoever to doubt it. So either that gold (from the vessel) did not came from those African mines, or the comparison test of Islamic coins was flawed.
