Galileo’s Almagest : New evidence from the Magliabechiana collection in Florence

The Magliabechiana collection of the National Central Library in Florence preserves a copy of the Almagest, printed in Basel in 1551, that is densely annotated (BNCF, Magl. 5.1.133). The purpose of this article is to set out the full range of evidence—paleographical as well as textual and contextual—demonstrating that Galileo Galilei was the annotator. It is likely that the majority of the annotations were written by Galileo before he moved to Padua in 1592. An Appendix to the article includes a transcription and an English translation of an extensive annotation on Chapter 7 of Book V of the Almagest, illustrating the technical nature of the marginalia.