Polyhedral sundials with hexagonal and square faces. A different type of sundial (horizontal, vertical or inclined), complete with gnomon (the part that casts the shadow), is marked out on each face. The compass (held in the top) served to orient the instrument towards the local magnetic meridian. Made by Stefano Buonsignori in Florence toward the end of the 16th century. On display at the Museum of the History of Sciences in Florence, Italy.