Hist. Geo Space Sci., 11, 31–51, 2020 https://doi.org/10.5194/hgss-11-31-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. The configuration of the Pontus Euxinus in Ptolemy’s Geography Dmitry A. Shcheglov S.I. Vavilov Institute for the History of Science and Technology, St. Petersburg, Russia Correspondence: Dmitry A. Shcheglov (
[email protected]) Received: 5 July 2019 – Revised: 22 January 2020 – Accepted: 20 February 2020 – Published: 1 April 2020 Abstract. This article aims to explain how Ptolemy could have constructed a map of the Pontus Euxinus (Black Sea), as described in his Geography, under the assumption that his sources were similar to those that have come down to us. The method employed is based on the comparison of Ptolemy’s data with corresponding information from other ancient sources, revealing the most conspicuous similarities and differences between them. Three types of information are considered as possible “constituent elements” of Ptolemy’s map: latitudes, coastline lengths, and straight-line distances. It is argued that the latitudes Ptolemy used for the key points determining the overall shape of the Pontus (Byzantium, Trapezus, the mouth of the Borysthenes and the Cimmerian Bosporus, the mouth of the Tanais, etc.) were most likely inherited from earlier geographers (Eratosthenes, Hipparchus, and Marinus). In exactly the same way, Ptolemy’s data on the circumference of the Pontus and the length of the coastal stretches between the key points (from the Thracian Bosporus to Cape Karambis, Sinope, Trapezus, and the mouth of the Phasis, etc.) closely correlate with the corresponding estimates reported by other geogra- phers (Eratosthenes, Artemidorus, Strabo, Pliny, Arrian, and Pseudo-Arrian), which implies that Ptolemy drew on similar coastline length information.