The Eratosthanes thing is not valid because, assuming he even performed the purported experiment, even according to Black Science Man it wouldn’t have proven the earth weren’t flat because there were only two data points and the same results would have been obtained if the sun were closer and smaller than it is now believed to be by mainstream science. And flat earthers don’t believe the sun is the size or distance that we have been told. As for the other figures, I’m either not familiar enough or don’t know which specific writings you are referring to.