Convert from fotmal [lead] to pennyweight [troy]

Unit Definition (fotmal [lead])
The fotmal is a traditional English unit of weight for lead. In medieval England the fotmal was equal to 70 "mercantile" pounds, which is equivalent to 72 avoirdupois pounds.

Unit Definition (pennyweight [troy])
The pennyweight is a unit of weight in the traditional troy system, equal to 24 grains or 1/20 troy ounce. One pennyweight is approximately 1.5552 gram.