Rule, complete with case, consisting of a square-section wooden rod with a gilt brass collar. One side carries divisions into inches and feet, the other a meridian line and a shutter concealing a housing for the sights and, perhaps, a plumb bob (now missing). There is a black wooden rod with brass sights and a short brass graduated rod made of two jointed sections. The instrument was used for measurements and ballistic computations. Provenance: Medici collections.