This article attempts to generalize various observations accumulated by many researchers. However, it mainly deals with the issues that most of the general studies on Ptolemy’s Geography usually pass over in silence. The article pursues three goals: (1) to clarify the relations between Ptolemy’s Geography and the work of his immediate predecessor Marinus of Tyre, (2) to reconstruct the rough framework underlying Ptolemy’s map (at least preliminarily), (3) to detect traces of transformations which his map underwent at early stages of its development.
Key words: ancient geography, Claudius Ptolemy, Marinus of Tyre, Hipparchus, Eratosthenes, Marcus Vipsanius Agrippa
Keywords: Ptolemy, GIS, digital archaeology, history of cartography, ancient Arabia
Summary: In this paper we provide updates and enhancements to the mathematical method for translating ancient coordinates from Ptolemy’s Geography into coordinates that can be used in modern GIS tools, such as ArcGIS and Google Earth. We also expand our coverage from In-dia to Arabia, another historically important peninsular subcontinent of Asia. The enhance-ments we have made include novel techniques for identifying duplicates and handling tenta-tively identified points, instead of just known and unknown ones, surrounding the region of interest by known points from adjacent regions, and modifications to our two primary under-lying models, triangulation and flocking. We compare the precision of reconstruction achieved for Ptolemy’s Arabia with the precision that we had computed earlier for his India before the Ganges. We also provide improved validation and comparison amongst the methods applied. The combination of these enhancements with the expansion of our coverage to Arabia as de-scribed by Claudius Ptolemy represents a novel contribution to understanding of our cultural cartographic heritage by improving our ability to explore the ancient world using familiar and accessible GIS tools.
Keywords: Claudius Ptolemy, ancient geography, GIS analysis, historical cartography, georeferencing
The multifaceted and challenging problem of reconstructing Claudius Ptolemy's map of ancient West Africa from the numeric coordinate data and other information found in his seminal 'Geography' and visualizing the results in modern projections using popular and powerful GIS tools, such as ArcGIS and Google Earth, is addressed by the authors iteratively. We apply a combination of several old and new techniques ranging from traditional toponymic analysis to novel modifications of cluster analysis. Our hybrid human-machine method demonstrates that Ptolemy-s information on West Africa is a compilation of data from three or more sources, including at least one version or derivative of The Periplus of Hanno.
The newest iteration adds data for three more provinces of Ptolemy's Libya - Mauretania Caesariensis, Africa and Aethiopia Interior - to Mauretania Tingitana and Libya Interior investigated in an earlier, unpublished version of the work that the late Lyudmila Filatova had contributed to as the founder of our multi-year project The surviving co-authors used their newest digital analysis methods (triangulation and flocking with Bayesian correction) and took into account their recent finds on Ptolemy's Sinae (Guinea/Senegal, where Ptolemy had placed fish-eating Aethiopians). We discuss some of the weaknesses
and fallacies of the earlier approaches to the problem Our revised digital reconstruction will help modern history of cartography researchers and the general public improve their understanding of what West Africa was like in the distant past.