Convert from firkin [butter, soap] to hyl

Unit Definition (firkin [butter, soap])
The firkin [butter, soap] is a traditional unit of weight for butter and soap, equal to 4 stone or 56 pounds (about 25.40 kilograms).

Unit Definition (hyl)
The hyl is an obsolete MKS unit of mass. One hyl is the mass that is accelerated at one meter per second per second by one kilogram of force (kgf). Since 1 kgf = 9.806 65 newtons, the hyl is equivalent to 9.806 65 kilograms. The name of the unit comes from an ancient Greek word for matter.