(; in Italian: Le Meccaniche) The Operations of Geometrical and Military Compass (1606; in Italian: Le operazioni del compasso geometrico et militare) The Starry Messenger (1610; in Latin: Sidereus Nuncius) Discourse on Floating Bodies (1612; in Italian: Discorso intorno alle cose che stanno in su l'acqua, o che in quella si muovono, "Discourse on Bodies that Stay Atop Water, or Move in It") History and Demonstration Concerning Sunspots (1613; in Italian: Istoria e dimostrazioni intorno alle macchie solari; work based on the Three Letters on Sunspots, Tre lettere sulle macchie solari, 1612) "Letter to the Grand Duchess Christina" (1615; published in 1636) "Discourse on the Tides" (1616; in Italian: Discorso del flusso e reflusso del mare) Discourse on the Comets (1619; in Italian: Discorso delle Comete) The Assayer (1623; in Italian: Il Saggiatore) Dialogue Concerning the Two Chief World Systems (1632; in Italian: Dialogo sopra i due massimi sistemi del mondo) Discourses and Mathematical Demonstrations Relating to Two New Sciences (1638; in Italian: Discorsi e Dimostrazioni Matematiche, intorno a due nuove scienze) Personal library In the last years of his life, Galileo Galilei kept a library of at least 598 volumes (560 of which have been identified) at Villa Il Gioiello, on the outskirts of Florence. Under the restrictions of house arrest, he was forbidden to write or publish his ideas. However, he continued to receive visitors right up to his death and it was through them that he remained supplied with the latest scientific texts from Northern Europe. With his past experience, Galileo may have feared that his collection of books and manuscripts would be seized by the authorities and burned, as no reference to such items was made in his last will and testament. An itemized inventory was only later produced after Galileo's death, when the majority of his possessions including his library passed to his son, Vincenzo Galilei, Jr. On his death in 1649, the collection was inherited by his wife Sestilia Bocchineri. Galileo's books, personal papers and unedited manuscripts were then collected by Vincenzo Viviani, his former assistant and student, with the intent of preserving his old teacher's works in published form. Unfortunately, it was a project that never materialised and in his final will, Viviani bequeathed a significant portion of the collection to the Hospital of Santa Maria Nuova in Florence, where there already existed an extensive library. The value of Galileo's possessions were not