The geographical data which can be attributed to Eratosthenes’ is available to us through the text of Strabo’s “Geography”. Unfortunately Strabo was neither a geographer nor a mathematician, but more a social historian, preferring to write mostly about that subject. However, we can glean from the text sufficient geographical data to enable a reasonable reconstruction of Eratosthenes’ world, and confirm some of the distance measures utilised.

The size of the world, 252000 Stadia (of unconfirmed) length is analysed, and then the length of the Stadion determined from the data collated. The metrology for determining the inter-distances from place to place is examined, and conclusions drawn that will require cartographic history to be updated.

8 A4 pages and 11 full colour diagram maps

Strabo’s “Geography” Book 17, chapters 1 to 4 discuss Egypt and in particular the River Nile. The data is primarily that of Eratosthenes, but, even though Strabo has sailed the Nile it is still mis-understood and obviously the text is later corrupted by copyist errors.

This paper analyses the River Nile measurements, determines that as Eratosthenes knew of them he had no necessity to rely on the “Aswan Well” phenomenon to determine the degree of Latitude and hence the world circle. The fact that “Egyptian Cord-Stretchers” had obviously measured or determined the world circumference centuries before Eratosthenes is then illustrated.
Finally the length of the Stadion utilised by Eratosthenes, illustrated first in Text Es1, is confirmed and the breadth of the Oikoumene discussed.
8 A4 pages and 5 full colour diagram maps