In antiquity, sundials served mainly for timekeeping, but were only functional under consideration of the respective geographical latitudes. Furthermore, different types of sundials have been distinguished, such as conical, spherical, cylindrical or planar. Even smaller, portable specimen exist.
The research project aims to re-analyze as many as possible of the 550 to 600 known Greek or Roman sundials using modern analytical methods such as 3D modeling. Modern technologies allow insights into the level of ancient knowledge and its dissemination in the ancient world. The sources allow to derive more precise classifications of ancient sundials and to decipher their design or construction principles.
The descriptions of the sundials so far used in this context regarding materials and dating are based - at least in part - on the research literature of the respective objects. As a result, different terms may be used for identical objects. These terms will be harmonized in the long term.
Rinner, Elisabeth, Bernhard Fritsch, and Gerd Graßhoff. "Die unvollendete Sonnenuhr von der Agora der Italiker auf Delos." eTopoi. Journal for Ancient Studies (2013).