Canones vel op[er]ationes in op[er]ando quadrante (Instructions for the Use of the Astrolabe Quadrant)

Canones vel op[er]ationes in op[er]ando quadrante (Instructions for the Use of the Astrolabe Quadrant)

This manuscript consists of an otherwise unknown treatise in thirty-five chapters on the Astrolabe quadrant, a simplified version of the medieval instrument reduced to a quarter circle. The quadrans novus was cheaper and simpler to make, yet could still perform most of an Astrolabe’s functions— namely, the measurement of altitude, latitudes, and longitudes, and the calculation of the time of day and night. The text is illustrated with meticulous diagrams and tables describing the use of the instrument. The binding, which consists of a bifolium from a twelfth-century copy of Augustine’s Commentary on the Gospel of John, is written in rare Beneventan script. A southern Italian localization is bolstered by textual references to the island of Diomedes off the coast of Puglia (now the Isole Tremiti) and by the watermark, which is similar to one employed in Naples later in the sixteenth century.

1502

Manuscript on paper, 28 fols.

University of Pennsylvania, Lawrence J. Schoenberg Collection, LJS 497

Southern Italy