Contents of the Manuscript
and its relation to the Discorsi

The Codex 72 of the Galilean Collection (Collezione galileiana) in the Biblioteca Nazionale Centrale in Florence is a miscellaneous manuscript comprising 241 folios of various sizes, carrying folio numbers from 1 to 196. The first 32 folios of the codex contain several different writings not included in this electronic representation.

The bulk of the manuscript (from folio 33r to folio 194r), which is covered by the electronic representation, holds drafts (texts, drawings and calculations) written by the hand of Galileo or of his disciples Mario Guiducci and Niccolò Arrighetti, mostly pertaining to the theorems on motion published in the Discorsi. The texts and translations of these theorems and their proofs are included in the electronic representation (translation of Henry Crew and Alfonso de Salvio, Macmillan, New York 1914). They are accessible through a list of propositions containing also links to all folio pages related to the respective theorems. Within the translations of the proofs links are added indicating deductive conditions used by Galileo at the respective places.

The fragments on motion and mechanics are neither dated nor does their order in the Codex correspond to the chronological sequence of their composition. Galileo's notes belong to very different periods of his life, the earliest dating from around 1600, the latest from the period in which he prepared the Discorsi for their publication in 1638. The selection and order of the folio pages in the present Codex 72 of the Galilean Collection is a result of the complex history of the manuscript.

Besides the fragments on motion, this part of the manuscript also includes three short letters to Galileo.