In his well-known measurement of the Earth, and according to Cleomedes, Eratosthenes estimated in 5000 stades the distance between Aswan and Alexandria. Modern accounts state that he calculated the distance from the time taken by caravans (improbable, as the Nile was navigable all the way, downstream from Aswan, so caravans weren't needed) or that he hired walking surveyors for that task. For example, in https://www.aps.org/publications/apsnews/200606/history.cfm

enter image description here

I've been unable to confirm this in old, Greek or Latin accounts.

Any comments?

  • 5
    $\begingroup$ The main sources are Cleomedes and Strabo, and neither of them is reliable, so basically we do not know what Eratosthenes actually did. And not just for the distance, see How did Eratosthenes determine that Alexandria and Syene were on the same meridian? $\endgroup$ – Conifold Mar 28 at 10:41
  • 1
    $\begingroup$ There is no evidence that he specially hired someone to measure this distance. He probably relied on travelers accounts. $\endgroup$ – Alexandre Eremenko Mar 28 at 12:04
  • 2
    $\begingroup$ Martianus Capella, VI, 598 hs-augsburg.de/~harsch/Chronologia/Lspost05/Martianus/… $\endgroup$ – sand1 Mar 28 at 20:23
  • $\begingroup$ @sand1 It's an interesting text, but I can find no mention to the distance between Alexandria and Aswan/Syene... However, the fact that there were royal surveyors that had worked out the distance between Meroe and Syene is a valuable indirect clue... $\endgroup$ – xxavier Mar 29 at 16:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.