The book under review results from an interdisciplinary research project aimed at identifying, by means of computer-based geodetic-statistical methods, the places given in the coordinate lists of Ptolemy’s Geography. Two of the authors, Marx and Lelgemann, are geodesists, while the third, Kleineberg, is a classicist. A first volume was dedicated to the northern and central parts of Europe, described in the second book of Ptolemy’s Geography (Germania, Gallia Belgica, Raetia et Vindelicia, Noricum, and Thule, corresponding to Geog. II,9.11–13 and II,3,32),1 while the book discussed here deals with the remaining regions treated in Geog. II, roughly covering northwestern, western, and parts of southeastern Europe (for more details see below). In the meantime, a third volume on book III of Ptolemy’s Geography has been published, addressing southern and eastern Europe.2
The general structure of the book is very similar to that of its predecessor volume on Germania. A short Introduction is followed by eleven chapters, each of which treats a region – Hibernia, Albion, Hispania Baetica, Hispania Lusitania, Hispania Tarraconensis, Gallia Aquitania, Gallia Lugdunensis, Gallia Narbonensis, Pannonia Superior, Pannonia Inferior, Illyricum – in close correspondence to the second book of Ptolemy’s Geography, where the same regions are treated chapter by chapter ( Geog. II,2–8.10.14–16). An appendix on the transformation units (“Transformationseinheiten”, pp. 202–6), a very brief acknowledgement, a list of abbreviations and symbols, an index of place names, and a map section close the volume.
The first part of the Introduction (pp. 1–11) gives a very general summary of Ptolemy and his time, of the Geography, its sources and its transmission, and of its second book in particular. The second part (pp. 11–19) introduces the methodical approach, the geodetic rectification of the Ptolemaic coordinates (“geodätische Entzerrung der ptolemäischen Koordinaten”, p. 11), an analytical method especially developed by this team of researchers for Ptolemy’s Geography, in order to correct the distortion of Ptolemy’s coordinates. According to the authors, the calculational results show shifts of single groups of places with regard to each other. They assume that the reason for these shifts was inaccurate or erroneous positions for the places of reference upon which the position of surrounding places was dependent, so that the error for a place of reference was transferred to its surrounding places, too.3 These errors, together with systematic errors of scale, due to Ptolemy’s oversized longitudinal extensions of the oikoumenē, and accidental or gross errors, can be identified and rectified, the authors argue, by their analytical method, which aims to define what they term “transformation units”, i.e. groups of places with homogeneous distortion. This procedure makes it possible to insert the rectified coordinates into a modern geographical reference system and hence to identify the places in question, or at least to provide possible identifications for them. The authors emphasize that, in addition to the values calculated by statistical-geodetic methods, topographical and toponomastic information, archaeological evidence, and ancient texts have to be considered as well. The last part of the Introduction (pp. 19–23) consists of a directory to the following eleven chapters and a short bibliography.
Each of these eleven chapters starts with a brief account of the geographical region in question, focusing on its historical development up to Ptolemy’s time, and is then divided into three sections. The first section (“Koordinaten und Identifizierungen”), arranged in tabular form, lists Ptolemy’s toponyms, their respective Ptolemaic coordinates, their modern place names (provided that the ancient toponyms are identifiable), the coordinates of the respective modern places, the differences between “transformed Ptolemaic” coordinates and modern coordinates, the transformation units, the identification categories (i.e., means of identifying a Ptolemaic site), and the sources for the Ptolemaic coordinates. Regarding the identification categories, the authors stipulate six ways of identifying Ptolemy’s sites, the most remarkable of which is that based exclusively on the transformational function. This method of analysis suggested new identifications for 119 places (or about 12 percent) out of a total of 964 places. The second section (“Anmerkungen”) specifies the sources for the modern identifications and Ptolemy’s sources for the places, and gives additional data as well. Each chapter ends with a bibliography (“Literatur”).
The twelve maps in color at the end of the book (one map for each chapter/region, with Hispania Tarraconensis split into two maps) are a helpful annex. They show the places listed by Ptolemy (labeled with their modern names) as well as their corresponding transformation units, indicated by different symbols.
The data collected and developed in this volume undoubtedly constitute a handy and useful tool for future research. From a philological point of view, however, there is an important problem in the data used in the analysis: not infrequently, the manuscript tradition provides more than one variant of longitude and/or latitude for a place. In these cases, the authors adopted the variant which produced a coherent result in their analysis (“die sich anhand der Analyse als stimmig ergab”, p. 20; see also p. 15 on the investigation, through the analytical method, of the “mutmaßlich korrekte bzw. genauere antike Koordinatenvariante” out of different values testified in the manuscripts). This approach seems random and unsystematic. The authors give the sources for their choice of a particular Ptolemaic coordinate, but one wonders according to which rules or criteria they made this choice in each case. As “sources” they indicate both textual recensions of the work, which they gathered from the most recent edition,4 alongside various other editions of Ptolemy’s Geography (see pp. 8 and 20). It is doubtful whether the value for a longitude or latitude that best fits the results of the analytical calculations is the most ‘authentic’ Ptolemaic value.
As a classicist, I have to leave to specialists the assessment of the statistical-geodetic methods, of their applicability to Ptolemy’s Geography, and of the outcome obtained. The non-specialist in geodesy misses illustrative examples demonstrating the five steps of the analytical method, which the short and general account on pp. 17–18 and formulas do not provide.5 The reader has to be content with brief general statements like “Mit Hilfe statistischer Tests können grobe Fehler identifiziert werden” (p. 15).
Whereas the first volume on Germania (see note 1) caused something of a sensation on account of its new, but not undisputed, identifications of Ptolemaic localities with modern places, and was even discussed in various German daily newspapers, Europa in der Geographie des Ptolemaios does not seem to have had the same impact, despite its ambitious subtitle ( Die Entschlüsselung des “Atlas der Oikumene”) and the publisher’s breathless book announcement.6 Exploring and understanding Ptolemy’s coordinate lists by modern technical means, in recent times also undertaken by others,7 is a welcome and stimulating approach to Ptolemy’s cartographic work. It is, however, questionable to what extent these approaches can accommodate his system, his methods and his concept of spatial perception and representation.
Notes
1. Kleineberg, Andreas, Christian Marx, Eberhard Knobloch and Dieter Lelgemann, Germania und die Insel Thule. Die Entschlüsselung von Ptolemaios’ “Atlas der Oikumene”. Darmstadt: WBG (Wissenschaftliche Buchgesellschaft), 2010, second edition 2011.
2. Marx, Christian, and Andreas Kleineberg, Die Geographie des Ptolemaios. Geographike Hyphegesis Buch 3: Europa zwischen Newa, Don und Mittelmeer. Berlin: epubli GmbH, 2012.
3. Indeed, Ptolemy’s suggestion to “give priority … to the [features] that have been obtained through the more accurate observations, as foundations, so to speak (καθάπερ θεμελίους)”, and to “fit [the features] that come from the other [kinds of data] to these, until their positions with respect to each other and to the first [features] stand as much as possible in agreement with those reports that are less subject to error,” supports this observation ( Geog. I,4,2 [translation by Berggren, J. Lennart, and Alexander Jones, Ptolemy’s Geography. An Annotated Translation of the Theoretical Chapters. Princeton NJ: Princeton University Press, 2000, p. 63]). However, shifts of local areas have already been pointed out by others, see e.g. Cuntz, Otto, Die Geographie des Ptolemaeus. Galliae, Germania, Raetia, Noricum, Pannoniae, Illyrcium, Italia. Handschriften, Text und Untersuchung. Berlin: Weidmannsche Buchhandlung, 1923, pp. 99.114.116.160 et al.
4. Klaudios Ptolemaios, Handbuch der Geographie. Griechisch-Deutsch. Ed. Stückelberger, Alfred, and Gerd Graßhoff. 2 vols. Basel: Schwabe, 2006.
5. A more detailed description of the method of analysis is given by Marx, Christian, “Rectification of the ancient geographic coordinates in Ptolemy’s Geographike Hyphegesis,” History of Geo- and Space Sciences, 3 (2012) 99–112, found at here.
7. See, e.g., Rinner, Elisabeth, Zur Genese der Ortskoordinaten Kleinasiens in der Geographie des Klaudios Ptolemaios. Bern: Bern Studies in the History and Philosophy of Science, 2013.