* An unofficial New Silmarillion Outline *

[Findegil]

Humanity knew that the world was round since (at least) the time of Eratosthenes.

True, but it was forgotten and even cartographer in the middle ages considered the world round and with a rim where you could fall of. More so 'historians' writing about pre-historical times or mariniers.

But again: it does not matter. In our version the world is flat until the fall of Númenor then it becomes round. So the Númenorens could be as learned as you wish them to be or more, they would still report that their world had been flat before Valinor was removed, because that is inside the story a 'historical' fact.

Respectfully
Findegil