Part of a celestial globe, signed 'Guilhelmus Ianssonius Blaeu' and dated 1603. The globe is derived from the observations of Tycho, supplemented by those of Frederik de Houtman made in the southern hemisphere during the first Dutch voyage to the East Indies. Blaeu had worked under Tycho at Uraniborg and has included a portrait of him on the globe (see also next image).