Convert from carat [UK] to tonneau [France]

Unit Definition (carat [UK])
The carat [UK] is a unit of mass used for diamonds and other precious stones. In the U. S. and Britian, the diamond carat was formerly defined by law to be 3.2 troy grains, which is about 207 milligrams.

Unit Definition (tonneau [France])
The tonneau is the traditional French ton, equal to 2000 livres or about 979 kilograms (1.079 U.S. ton). The tonneau was also used as a measure of volume equal to 42 cubic pieds (50.84 cubic feet, or about 1440 liters). In the wine trade, the tonneau was a shipment of 100 cases, or 1200 bottles (about 900 liters of wine).