52 - Libros del Saber de Astronomia del Rey Alfonso X de Castilla, 5 Volumes, compiled and annotated by

Libros del Saber de Astronomia del Rey Alfonso X de Castilla, 5 Volumes, compiled and annotated by Manuel Rico y Sinobas. published in Madrid by Don Eusebio Aguado, 1863–1867). (5) The Libros del saber de astronomía, "book[s] of the wisdom of astronomy [astrology]", is a series of books of the medieval period, composed during the reign of Alfonso X of Castile. They describe the celestial bodies and the astronomical instruments existing at the time. The collection is a group of treatises on astronomical instruments, like the celestial sphere, the spherical and plane astrolabe, saphea and universal plate for all latitudes, for uranography or star cartography that can be used for casting horoscopes. The purpose of the rest of the instruments, the quadrant of the type called vetus, sundial, clepsydras, is to determine the time, which was also needed to cast the horoscope. The king looked for separate works for the construction and use of each device.