Corona bij volledige zonsverduistering (1860) by Albert Schutze, P Angelo Secchi and Georg Westermann https://www.rawpixel.com/image/13758260/image-paper-book-moonFree Image from public domain licenseProtuberansen op de oppervlakte van de zon (1871) by Albert Schutze and Georg Westermann https://www.rawpixel.com/image/13758179/image-paper-frame-bookFree Image from public domain licenseSchematische doorsnede van de zon (1870 - 1872) by Albert Schutze and Georg Westermann https://www.rawpixel.com/image/13757947/image-paper-art-circleFree Image from public domain license