The Re-Examination

Abstract This chapter examines the evidence for the use of a stade 180 m in length by Eratosthenes by using the innovative approach of using modern satellite mapping software to compare the distances between various locations that are recounted by Eratosthenes in the ancient source material. These distances were recorded by the professional surveyors (bematists) accompanying the army of Alexander the Great in the fourth century BC, were recounted by Eratosthenes, and later by Strabo. The unit of measure employed by the bematists in these measurements then formed the basis for Eratoshtenes’ works on geography and his calculation of the circumference of the Earth.

Interestingly, the application of the 180 m stade to Eratosthenes’ calculations leads to an incorrect result. However, by critically analysing the available literary evidence, the chapter concludes by demonstrating how this value was altered by the next generation of astronomers, and determining the ‘true’ result of Eratosthenes’ calculation of the size of the Earth.