Compas de proportion dit demi-pied de Roy FRENCH... Lot 129

Compas de proportion dit demi-pied de Roy FRENCH WORK FROM THE EIGHTEENTH CENTURY Roy's half-foot proportional compass in engraved brass. Note: Until the French Revolution, there was a wide variety of units of measurement, hence the expression "Avoir deux poids, deux mesures" ("to have two weights, two measures"). Units of length were based, for example, on feet, inches...this object is a demi-pied du Roy (a pied du roi equals more or less 30 cm) L : 17 cm