Ileana Chinnici is an astronomer at the INAF-Palermo Astronomical Observatory. Her field of research is the history of astronomy and she is the author of many publications in this field. In 1996-2004 she was curator of the astronomical museum of the Observatory and is presently in charge of its historical collections. Her interests are focused on the history of astronomy and astrophysics in the 19th century, especially exploiting archival resources. She is currently a member of the Organizing Committee of the Commission C3 (History of Astronomy) of the International Astronomical Union.Brother Guy Consolmagno SJ is Director of the Vatican Observatory. He is a native of Detroit, Michigan, received SM and SM degrees from MIT, and earned his PhD in Planetary Sciences from the University of Arizona in 1978. His scientific research explores the physical properties of meteorites and their connection with origin and evolution of asteroids and planets. Along with more than 200 scientific publications, he is the author of six popular astronomy books. In 2014 he received the Carl Sagan Medal from the American Astronomical Society Division for Planetary Sciences for excellence in public communication in planetary science.

Preface.- Chapter 1. Introduction.- Part 1. The Context.- Chapter 2. Jesuits and Science: A Long Tradition .- Chapter 3. Science and Theology in the Nineteenth Century.- Chapter 4. Angelo Secchi: A Man of his Time.- Part II. Angelo Secchi's Scientific Contributions.- Chapter 5. The New Collegio Romano Observatory.- Chapter 6. Angelo Secchi and the Development of Spectroscopy.- Chapter 7. Planetary Observations by Angelo Secchi.- Chapter 8. Angelo Secchi: Natural Philosopher and Instrument Innovator.- Chapter 9. Angelo Secchi and Meteorology in Italy.- Chapter 10. Something New about Angelo Secchi's Meteorographs.- Chapter 11. Angelo Secchi's Book on The Unity of Physical Forces.- Chapter 12. The Measurement of the Geodetic Base at Via Appia.- Chapter 13. The History of the Secchi Disk.- Chapter 14. Terrestrial Physics in Italy.- Chapter 15. Angelo Secchi and Gnomonics.- Part III. Some Later Issues.- Chapter 16. The Unachieved Angelo Secchi Monument.- Chapter 17. Astronomy in Italy after Angelo Secchi.- Chapter 18. The Specola Vaticana: Jesuit Astronomy Today.- Chapter 19. Astronomy in Rome after Angelo Secchi, and his Heritage at the Rome Astronomical Observatory.- Part IV. Current Resources.- Chapter 20. Angelo Secchi Archives.- Chapter 21. An Angelo Secchi Portal by INAF.- Chapter 22. GATE (Gregorian Archives Texts Editing): An Online Resource for Angelo Secchi Correspondence.- Index.