Determining the scale and map projection of Stjepan Glavač’s map from 1673

ABSTRACT

The uniqueness and detail in the depiction of Croatian regions gives Glavač's map exceptional importance as part of the Croatian cultural heritage. Since Glavač left behind as written evidence of map creation only its title and an exhaustive dedication, other information about the map remains unknown. The appearance of the cartographic network indicates that it is a normal aspect of cylindrical projection. From the relationship between the coordinates from the map, we concluded that Glavač used the equidistant cylindrical projection with the equator as a standard parallel. After that we have calculated that the ratio of the radius of the Earth's sphere to the scale of the map is 2292.7. The numerical scale of the map can be determined from a graphical scale and from the calculated ratio of the radius to the map scale. Since there were several attempts to determine the Earth's dimensions at the time of Glavač's map, there are several possible radii of the Earth's sphere. At the end of the paper, calculating the interval of the numerical scale of the map enabled us to refute and/or accept the theses of other authors who cited different scales of Glavač's map in their works.

Le fait d'être unique et détaillée dans la description des régions Croates donne à la carte de Glavač une importance exceptionnelle dans le patrimoine culturel Croate. Dans la mesure où Glavač n'a laissé comme trace écrite de la création de la carte que son titre et une dédicace détaillée, les autres informations concernant cette carte restent inconnues. La représentation du réseau cartographique indique qu'il s'agit d'un aspect normal de projection cylindrique. En se basant sur les relations entre coordonnées de la carte, on en déduit que Glavač a utilisé la projection cylindrique équidistante avec l'équateur comme parallèle standard. Après, nous avons calculé le rapport du rayon de la sphère terrestre, qui est à l'échelle de la carte de 2292,7. L'échelle numérique de la carte peut être déterminée à partir de l'échelle graphique et du rapport calculé du rayon à l'échelle de la carte. Dans la mesure où il y avait diverses tentatives de détermination de la dimension de la Terre à l'époque de Glavač, il y avait également plusieurs rayons possibles de la sphère terrestre. En fin de l'article, le calcul de l'intervalle de l'échelle numérique de la carte nous a permis de réfuter et/ou d'accepter les thèses d'autres auteurs qui ont proposé différentes échelles de la carte de Glavač dans leurs travaux.

KEYWORDS:

• Map projection
• Stjepan Glavač
• cylindrical projections
• map scale
• 17th century

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Marina Viličić

Marina Viličić is a postdoctoral researcher at the Faculty of Geodesy, University of Zagreb, where she teaches students and does her research mainly in the field of digital cartography and map projections. In her doctorate, she worked on a complete cartographic analysis of Stjepan Glavač’s map from 1673.

Miljenko Lapaine

Miljenko Lapaine graduated from the Faculty of Science, University of Zagreb, in the field of Theoretical Mathematics. He received his PhD from the Faculty of Geodesy of the University of Zagreb with a dissertation Mapping in the Theory of Map Projections. He has been a professor emeritus since 2018 and has published more than 1000 papers. He is the Vice-Chair of the Commission on Map Projections of the International Cartographic Association, the President of the Croatian Cartographic Society and the Editor-in-Chief of the Cartography and Geoinformation journal.