1) Work by Ptolemy
Found on
https://www.crosswordclues.com/clue/planisphaerium
The Planisphaerium is a work by Ptolemy. The title can be translated as `celestial plane` or `star chart`. In this work Ptolemy explored the mathematics of mapping figures inscribed in the celestial sphere onto a plane by what is now known as stereographic projection. This method of projection preserves the properties of circles. ==Publication...
Found on
http://en.wikipedia.org/wiki/Planisphaerium
No exact match found.
