Tabulae directionum et profectionum (Tables of Directions and Profections) and Tabella sinus recti (Table of Sines)

Tabulae directionum et profectionum (Tables of Directions and Profections) and Tabella sinus recti (Table of Sines)

Johannes Müller von Königsberg (1436–76), better known as Regiomontanus, was a Central European astronomer whose peripatetic career brought him into dialogue with some of the key humanist thinkers and patrons. He was one of the founders of modern observational astronomy and exerted a profound influence on Nicolaus Copernicus. His works were even used by Christopher Columbus and Vasco da Gama as navigational aids. Regiomontanus completed his Tabulae directionum et profectionum, a series of tables that allowed for the positions of celestial bodies to be determined mathematically with unprecedented accuracy when compared to the existing Alphonsine Tables that had been developed at the court of Alfonso X of Castile in the mid-thirteenth century. Regiomontanus’s tables, as copied in the present manuscript, continue the Ptolemaic system of their predecessors, but with added tables of tangents and sines that allowed for a much higher degree of predictive accuracy.

Author: Regiomontanus (Johannes Müller von Königsberg ); Scribe: Johannes de Kuppferperg

ca. 1467

Manuscript on paper, 95 fols.

University of Pennsylvania, Lawrence J. Schoenberg Collection, LJS 172

Bratislava (?)