Convert from fotmal [lead] to tahil [China]

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 (tahil [China])
The tahil is a traditional unit of weight used throughout eastern Asia. During the colonial period, the tahil was more or less standardized throughout the region at 4/3 ounce avoirdupois (1/16 catty, 1/12 pound, or about 37.8 grams). In Japan, however, the tahil was identified with a slightly smaller traditional unit and is considered equal to 1.323 ounces (37.51 grams). The tahil is usually considered equal to the Chinese liang.