Convert from flask to quartern

Unit Definition (flask)
The flask is a commercial unit of weight formerly used to measure liquid mercury (or quicksilver, as it was called). The flask was equal to 76.5 pounds avoirdupois, which is equivalent to almost exactly 34.7 kilograms.

Unit Definition (quartern)
The quartern is a traditional English unit of weight equal to 1/4 stone, 3.5 pounds, or about 1.5876 kilogram.