Convert from vara [South America] to douzieme [watchmaking]

Unit Definition (vara [South America])
Vara is an old Spanish and Portuguese unit of length. Varas are a surveying unit that appears in many deeds in the southern United States, and varas were also used in many parts of Latin America. It varied in size at various times and places; the Spanish unit was set at about 835.9 mm in 1801. At some time value of 33 in (838 mm) was adopted in California, and 33 1/3 inches (847 mm) in Texas.

Unit Definition (douzieme [watchmaking])
The douzieme 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. This is about 188 micrometers (microns) or 7.4 mils.