Some think the Earth is spherical, others that it is flat and drum-shaped.
For evidence they bring the fact that, as the sun rises and sets, the part concealed by the Earth shows a straight and not a curved edge, whereas if the Earth were spherical the line of section would have to be circular …
… but in eclipses of the moon the outline is always curved: and, since it is the interposition of the Earth that makes the eclipse, the form of this line will be caused by the form of the Earth’s surface, which is therefore spherical.
Aristotle. “On the Heavens”. Written 350 B.C.E.
Kabanikhin, Sergey I. Inverse and Ill-Posed problems