One of the works of Eratosthenes (ca. 276 B.C. – ca. 195 B.C.) was entitled “On the measurement of the Earth”. Interpretation of this geographical data depends on a knowledge of the unit of distance employed by its author. This was the stadion. In the article under review the author concludes that the stadion unit used by Eratosthenes was of the order of 166.7 m, and would have been related to the foot termed “Italic” by Heron of Alexandria.