Keywords: Ole Rømer at work.jpg en Ole Rømer at work in his home observatory at t Kannikestræde in Copenhagen Cipperplate engraving intended for a never published work by Rømer After his death it was published in Peder Nielsen Horrebow's Basis Astronomiæ 1735 Horrebows Basis Astronomiæ author 1735 PD-old-100 Ole Rømer |