A 17th century double-hemisphere world map as a volvelle

A sketch map of the world in two hemispheres on a polar projection, each overlaid with a rotating map disk and one arm for showing longitude and latitude and another for the horizon. In the Northern Hemisphere California is depicted as an island. Under the spheres are the title on a pedestal and two more pointers. It was published in Coronelli's ''Epitome Cosmografica, o Compendiosa Introduttione all'Astronomia, Geografia, & Idrografia'', a guide to Astronomy, geography and hydrography, and the use of globes, astrolabes and maps.