Steel meter housed in a walnut case with two locks and two keys. The length of this specimen measured from end to end slightly exceeded the official standard value — showing how difficult it was to manufacture metric bars to the exact desired length. The construction of the meter was assigned to French chemists in 1789. By applying the findings accumulated in a significant series of experiments on the dilatation of metals, they succeeded in obtaining a result that approximated the intended standard. This meter was probably acquired from France in 1798 during the international metrology congress in Paris, attended by Giovanni Fabbroni, deputy director of the Museo di Fisica e Storia Naturale of Florence.