Paul OESTERGAARD, geographer and inventor - Colombus duo ERD Globus - Berlin Stuttgart Illuminated world map on a graduated arched upright and a circular metal and wood base. Signed in the Indian Ocean. German work circa 1950. H. 34.5 cm Minor wear Note: The "Columbus Duo ERD Globus" was manufactured first in Berlin and then near Stuttgart, using the DUO principle invented by Columbus: two maps displayed depending on whether the globe is illuminated or not.