Silver pocket sundial/compass. BUTTERFIELD" model for the inventions of Michael Butterfiel (1635-1724). Hexagonal plate engraved with the latitudes and its folding ruler called "à l'oiseau", round compass, engraved on the back with twenty French towns. Dimensions: 5 x 4.5 cm. Circa 1722/1727. Gross weight: 19.9 g. With a non-original case.