Astronomical Tables of Alfonso X and Regiomontanus

The oldest printed book on astronomy in the University of Turku Library contains two medieval astronomical works bound together in the same covers.

Alfonso X King of King of Castile, León: Tabulae astronomicae
Venetsia: Erhard Ratdolt, 1492.

Alfonso’s Tables is named after Alfonso X (1221-1284), King of Castile and Leon, who commissioned a new version of the astronomical tables used to calculate the orbits of celestial bodies. The tables were supplemented by a new version written in Paris in the 14th century, which was widely distributed and on which the printed versions of the work are based.

Johannes Müller: Tabulae directionum et profectionum
Augsburg, 1490

Johannes Müller (1436-1476), mathematician and astronomer from Königberg is also known as Regiomontanus. His astronomical tables were based on those of Alfonso, and he also included an explanatory section to help novice astronomers interpret the tables. Regiomontanus was also a printer, especially of astrological works.

The incunable (an early printed book) in the collections of the University of Turku Library contains the works of Alfonso and Regiomontanus bound between the same covers. The works can be consulted in more detail through digitised versions produced by the Bayer National Library.

• Digitised version of Tabulae astronomicae Munich Digitization Center.
• Link to digitised version of Tabulae directionum et profectionum Munich Digization Center.