Convert from palm [US, Roman major] to league [ancient Celtic]

Unit Definition (palm [US, Roman major])
A palm, when used as a unit of length, is usually four digits or three inches, i.e. 7.62 cm (for the international inch). The width of an adult human male palm is indeed about 10 centimetres.In English this unit has mostly fallen out of use, as do others based on the human arm: digit (¼ palm), finger (7/24 palm), hand (4/3 palms), shaftment (2 palms), span (3 palms), cubit (6 palms) and ell (15 palms).

Unit Definition (league [ancient Celtic])
League is a unit of distance long common in Europe and Latin America, although no longer an official unit in any nation.