From Alternative History

Although most of the world now use the metric system, efforts made to have it adopted by the URP have so far come to nothing

and the provinces still use the traditional measuring system of pre-revolutionary France.

[edit] Distance

2 grain	= 1 ligne
12 lignes	= 1 pouce
12 pouces	= 1 pied
6 pieds	= 1 toise
3 toises	= 1 perche
10 perches	= 1 arpent
84 arpents	= 1 lieue