Eric M. Ramírez-Weaver, A Saving Science: Capturing the Heavens in Carolingian Manuscripts. University Park, PA: The Pennsylvania State University Press, 2017, pp. 312, 75 b/w ill. + 35 color ill.
In 809, Carolingian prelates under the direction of Adalhard of Corbie convened at Aachen to discuss, among other pressing issues, the state of the knowledge of computus in the realm. The ability of churchmen to reckon the exact day when Jesus was crucified, the age at which he died, and the correct date to celebrate Easter, a moveable feastday, were of vital importance for the Carolingian program of correctio. The product of their meeting was a practical treatise of computistical, calendrical, and astronomical information known to scholars as the Handbook of 809. Culled from ancient and Christian authorities and lavishly illustrated with a total of forty-six diagrams and star pictures, the Handbook of 809 served as an important pedagogical tool for Carolingian intellectuals, who sought a Christian understanding of the heavens.