Astronomical Observatories and Chronometry, 18th-20th Century

Gianenrico Bernasconi is an research professor in the history of technology at the University of Neuchâtel. His main field of research are the history of technology, the history of material culture, and the food history. His current research concerns more particularly the cultures of time measurement (18th-20th centuries). He is the PI of two SNSF-funded projects: The Cantonal Observatory of Neuchâtel (1858-1948): Cultures of Precision, Economy of Quality and the "Commodification" of Time (2018-2022) and Timekeeping, Chemistry, and Kitchen: The Formalization of Practices, 17th-18th Century (2020-2023). He is the author of Objets portatifs au Siècle des Lumières (Paris 2015), the co-editor (with S. Thürigen) of Material Histories of Time: Objects and Practices, 14th-19th Centuries (Berlin-Boston 2020), the co-editor (with G. Carnino et al.)  of Les Réparations Dans l’Histoire (Paris 2022), and the co-editor (with Marco Storni) of Early Modern Fire: Science, Technology, and the Urban Space (Leiden-Boston, 2025).Ileana Chinnici is an astronomer at the INAF-Palermo Astronomical Observatory. Her main field of research is the history of astronomy and she is the author of many publications in this field. From 1996-2004 she was curator of the astronomical museum of the Observatory and is presently scientific advisor for its historical collections. Her interests are focused on the history of astronomy and astrophysics in the 19th century, especially exploiting archival resources. The 2021 Osterbrock Book Prize has been awarded to her biography of Jesuit scientist Angelo Secchi (1818-1878). She is currently member of the board of advisors of the Italian Astronomical Society, adjoint scholar of the Vatican Observatory and incoming President of the Scientific Instrument Commission of the International Union of History ad Philosophy of Science and Technology.Marco Storni is a postodoctoral fellow at the Université libre de Bruxelles. After completing his PhD at the École Normale Supérieure of Paris and the University of Bologna, he has been a postdoctoral fellow at Ca' Foscari University of Venice and at the University of Neuchâtel. His research focuses on the history of science and of philosophy of science in the early modern period. He is the author of Maupertuis. Le philosophe, l'académicien, le polémiste (Paris 2022; winner of the Prize of the Fondation Del Duca-Institut de France 2023) and the co-editor, with Gianenrico Bernasconi, of Early Modern Fire: Science, Technology, and the Urban Space (Leiden-Boston 2025).

• Introduction: Observatory Time.- Synchronising Paris in the Eighteenth Century? Henry Sully’s Meridian Line at Saint-Sulpice: Astronomy, Clockmaking, and Timekeeping.- Instructions and Time Measurement at the Paris Observatory (1667-1789).- The Chronometry Collection of the Palermo Astronomical Observatory.- “Hour by Hour, Day and Night”: Splitting Time between the Astronomical and Physical Observatories.- Timekeeping and Time Balls at the Hamburg Observatory.- Determining Time, Eliminating the Personal Equation and Introducing Quartz Clocks: The Neuchâtel Observatory’s Operating Chain in 1954.- The Nineteenth-Century Marine Chronometers of the Royal Astronomical Observatory of the Spanish Navy in San Fernando.- The Certification of Chronometers at the Neuchâtel Cantonal Observatory. Setting up and Renewing Equipment and the Legal Framework for Certification (1858-1912).- Astronomy and Chronometry: Institutions for Testing Chronometers after the Foundation of the German Empire in 1871.- On the Accuracy of Celestial and Terrestrial Clocks: The Merit of Felix Schmeidler’s Half-Century Monitoring of Two Riefler Clocks at Munich Observatory.- “Who Put That Hole In The Telescope?” The Development of the World’s Most Accurate Timepiece.- Observatories, Marine Chronometers, and Terrestrial Applications: From Chronometric Longitude Expeditions to Observational Efficiency.- Astronomy and Chronometry: Experimental Practices to Improve Hydrography during the Early Nineteenth Century.- Colonial Time Machines: Chronometry and the Personal Equation between Europe and South Asia.- Paolo Brenni Scholar, Educator and Artisan.- Beyond the Written Word. Paolo Brenni’s Foundational Contribution to the Conservation of Scientific Instruments.