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Posted 08/01/2012 09:30 am
Quote:
As I said--there were a lot of problems with die hardening in the 1870s, and they did a lot of hardness tests in the denticles.
As I said--there were a lot of problems with die hardening in the 1870s, and they did a lot of hardness tests in the denticles.
It should be understood that these tests were actually done on the edge of the unhubbed die and not in the denticals themselves. After the die was hubbed it would be put on a lathe and the diameter turned down to the proper diameter. The date traces are from where the tests got in a little too far from the edge and they overlapped the area where the denticals were later impressed.
Of course this does not explain those MPD which are found closer to the center of the die in the devices themselves. All I can suppose is that they thought that traces of the tests would be wiped out by the hubbing.
One thing I find interesting is that the MPD's are always down close to the area of the date. If it was just hardness testing I see no reason why they would always take care to make sure that test area was in the press so the date would be in that same place. I suppose that the reason that all the MPD are in the actual date area is because that is the natural place where everyone looks for them. I think in the future eventually MPD's will be discovered in the denticals in other areas around the edge coin.
