[HAÜY (René-Just)]. Instruction sur les mesures déduites de la grandeur de la Terre, uniformes pour toute la République, et sur les calculs relatifs à leur division décimale: par la Commission temporaire des Poids & Mesures républicaines. Paris, De l'Imprimerie nationale exécutive du Louvre, An II de la République. In-8, bradel red half-chagrin, smooth spine decorated with double fillets and a Phrygian cap at head and tail (Modern binding). First edition of this instruction defining the metre as the unit of measurement in France, illustrated with a fold-out plate. [...] it is this length that has been adopted as the unit of measure, or the principal measure to which all others are related, & it has been given the name of metre, which itself signifies a measure (p. 17). A fine copy. Small paper restoration on the edge of the title page. Mottling on the plate.