1) Ancient Greek mathematician
Found on
https://www.crosswordclues.com/clue/ctesibius
[crater] Ctesibius is a small lunar impact crater that is located near the equator, on the far side of the Moon. It lies between the larger crater Abul Wáfa to the west and the slightly smaller Heron to the east. The outer wall of Ctesibius is wide and sharp-edged, with little erosion. A low ridge is attached to the southern rim, and curve...
Found on
http://en.wikipedia.org/wiki/Ctesibius_(crater)
No exact match found.
