Pile of weights weighing 50 marcs, known as ‘Charlemagne’s pile’

While there was a certain uniformity in measurement units during the Gallo-Roman period, the extreme fragmentation of medieval France’s territories led to the coexistence of a wide variety of units in the late 18th century. The same denomination could mean several things – the foot was longer in Lyon than in Paris – and this posed enormous problems in trade and in administrative and fiscal controls, becoming a recurrent source of discontent. Units often had picturesque names: the point (truchet point), ligne (line), pouce (inch), pied-de-roi (foot) and toise (fathom) for lengths (in Paris, a pied-de-roi measured 12 pouces or 325 millimetres); the pinte, velte and muid for liquids (the pinte is the equivalent of 930 centilitres); the litron, boisseau and setier for grain and dry commodities; the grain, denier, gros, once, marc and livre des poids de marc for weights (the livre weighs 489.5 grams). The museum has ‘Charlemagne’s pile’, a copy of an ancient set of weights now lost. The weights are piled on top of each other and weigh a total of 50 marcs (slightly more than 12 kilograms).