ESHS/HSS Annual Meeting

Gerard of Cremona and the Toledan Tables

• In Event: Tabular Practices and the Cross-cultural Exchange of Knowledge in Ancient in Medieval Astronomy 3

English Abstract

The name of Gerard of Cremona has long been associated with the history of the transmission of the Toledan Tables. The Toledan Tables are a set of astronomical tables that were originally compiled in Arabic in al-Andalus at the end of the eleventh century by a group of astronomers, including the renowned Ibn al-Zarqālī (d. 1100). Despite the fact that no Arabic manuscript witness of the Toledan Tables has survived, their Latin translation was widely disseminated across medieval Europe and is preserved in well over a hundred manuscripts. As is typical of a zīj, the Toledan Tables comprise a comprehensive set of canons that detail the utilisation of the various astronomical tables they encompass. In the Latin translation, these canons manifest in three distinct versions, identified and designated as canons Ca, Cb, and Cc by their modern editor Fritz S. Pedersen. Canons Cb are the most prevalent set of canons, being present in the vast majority of manuscript witnesses. Gerard’s name has historically been associated with the translation or revision of these prevailing canons Cb, as they include two explicit textual references and an oblique ascension table that all refer to the city of Cremona, from which Gerard hailed. In this talk I will analyse the computational scenario underlying the oblique ascension table for Cremona in comparison to the canonical table for Toledo. I will argue that the table was not derived by Gerard, but by someone in Cremona, and, for example, was well-known and adopted in Northern Italy by the later astronomer Giovanni Bianchini in Ferrara.

Author

• Stefan Zieme, Humboldt University Berlin