Hartmann's Astrolabe - Key Ring featuring a compass and cotton

featuring a compass and cotton shadow line

The Spanish astronomer and mathematician Juan de Rojas presented to the European public the Orthographic Projection (1550)

anyone who wishes to become engaged with the interactions of the Earth

Miniature nautical astrolabe

Hartmann's Astrolabe - Key Ring featuring a compass and cottonPlanispheric (Catholic or European) astrolabe, set for 50 North latitude. Stars and other features updated to make it functional. This beautiful astrolabe is based on the work of Georg Hartman a sixteenth century astronomer from Nuremberg, Germany. The astrolabe is an astronomical calculating device used from ancient times into the eighteenth century. It's used by measuring the height of a star using the back of the instrument, and knowing the