A metrological and historical perspective on the stadion and its use in ancient geography: A metrological and historical perspective on the stadion

The stadion is the unit of length by which distances are reported in ancient Greek geographical sources. The itinerary indications in stadia can be found in several texts, but no specific unit values are given in the ancient geographers’ surviving works. However, the notion of a vaguely quantified, non-metrological itinerary unit is contradicted by the presence, since Hellenistic times, of road marker stones bearing distance indications along major ancient roads. The key assumption in this study is that, whatever the unit involved, main roads were actually measured to the best of capabilities, and distance measurements in ancient works did refer to some specific metrological system. Some well-known Greek languagecxesst sources are analyzed with the support of archeologic information obtained from a small number of pre-Roman road markers, and from modern reports of investigations about ancient roads and sites. Based on the evidence, it is shown that two different stadion values were most often used as itinerary units in the Greek and Hellenistic world, namely 177 m and 210 m, that can be traced respectively to the so-called Attic foot and Philetaeric (Ionic/Samian) foot. Conversion among units did also occur, and this may offer explanations for supposed textual inconsistencies that have so far proved hard to understand.