Convert from douzieme [print] to royal foot

Unit Definition (douzieme [print])
The douzième is a traditional unit of distance used in watchmaking. The word is French for "twelfth," and a douzième is equal to 1/12 Swiss ligne, about 188 micrometers (microns) or 7.4 mils.

Unit Definition (royal foot)
The royal foot is a French pied de roi, also called the Paris foot in English.