Convert from fother [lead] to uncia [Rome]

Unit Definition (fother [lead])
The fother is a traditional English unit of weight for lead. The fother, equal to 30 fotmals, was always a little smaller than a (long) ton. The original version seems to have been equivalent to 2160 avoirdupois pounds, and the version still being used in the nineteenth century was equal to 19.5 hundredweight or 2184 pounds.

Unit Definition (uncia [Rome])
The uncia is the Roman ounce, equal to about 27.2875 grams of 0.9625 ounce avoirdupois. There were 12 ounces in a Roman pound, and the word uncia means a 12th part; its name gives us the ounce, of course, and also the inch.