Convert from flask to rebah

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 (rebah)
The rebah is an ancient Hebrew unit of weight or mass equal to 1/4 shekel. The word means "quarter" in Hebrew.