Paolo Brenni ( 1954 – 2021 )

Paolo Brenni’s untimely passing in the night between December 3 and 4, 2021, caused such deep and widespread emotion as to make a serene reconstruction of his intense scientific career extremely difficult.1 The gratitude of his colleagues for the generosity with which he always shared his knowledge exacerbates the emptiness we feel around us. In any event, it would be impossible to produce an exhaustive biography by merely offering a chronological commentary on the massive bibliography of his scholarly writings, or by describing the countless collections of historical scientific instruments that he helped to reorganize, catalogue, and restore. Paolo’s intellectual qualities were truly inseparable from his physical presence. This exceptionally rare harmony between intellect and manual dexterity was the key to his unique ability to tackle the history of scientific instruments. Indeed, Paolo exercised his superb skills above all with his hands—assembling, taking apart, repairing, and restoring the most complex scientific instruments, whose origin and function he was nearly always able to figure out, as in a conjuring trick. This outstanding

bining history of science and history of scientific instruments into a coherent whole, Nuncius was perfectly in tune with Paolo's vision.
In 1984, thanks to funding from the Province of Florence, Paolo was tasked by the Museo Galileo with restoring and cataloguing the collection of old scientific instruments held at the Istituto Tecnico Salvemini (formerly Istituto Tecnico Toscano), which became the Fondazione Scienza e Tecnica (fst) in 1987.9 This important collection, centered on nineteenth-century experimental physics, became a full-scale scientific laboratory for Paolo. Until his death, he worked with Anna Giatti on cataloguing, restoring, and reinstalling the collection, as well as on launching innovative projects focused on educational experiments and on training experts in scientific instrument conservation. The first result of this long-term commitment was the publication of the catalogue of acoustical instruments as early as 1986, followed by volumes on optics (1995) and electricity and magnetism (2000). 10 In 1987, with the sponsorship of the Museum in Florence and the Italian Ministry for Cultural Heritage, Paolo took part-with Mara Miniati and other instructors-in the first, pathbreaking practical and theoretical course on the identification, restoration, and cataloguing of old scientific instruments. The course was attended by 15 registered students and 12 auditors, many of whom would turn what they had learned into their profession.
In [1985][1986], with Mara Miniati, Paolo began a census of the scientific collections of historical interest in Tuscany. The project revealed the extraordinary richness of a heritage scattered across schools, institutions, private collections, and other locations where instruments unused for centuries had been miraculously preserved nearly intact. 9 Paolo worked for this institution for over 30 years, providing a highly valuable scientific and cultural contribution that gave the Fondazione unprecedented visibility. Its President is appointed by the Board of Directors and the Mayor of Florence and, in recent years, choices have been dictated by political considerations more than by scientific criteria. In 2015, the appointment of a person with no connection to the history of the institution and its instruments entailed its gradual decline and, in January 2020, the end of cooperation with the Italian National Research Council (cnr), leading to Paolo's departure. This incomprehensible break, underscored by the resignation of Mara Miniati, then Chairwoman of the Scientific Board, generated bitterness and disappointment. Fortunately, Paolo was immediately welcomed back to the Museo Galileo, a friendly institution that had never ceased to value his exceptional scientific and human qualities. 10 Paolo Brenni, Gli  Also in 1986, and again with Mara, Paolo organized the vi Scientific Instrument Symposium under the aegis of the Scientific Instrument Commission. In this same extremely active period, he took part in two exhibitions also curated by the Museo Galileo (Dal cembalo scrivano alla scrittura elettronica (1985)11 andOcchiali da vedere (1985)12), in the restoration and cataloguing of the instruments on display at the Misura d 'uomo show (1986),13 and in the cataloguing of the lenses, prisms, and optical games exhibited at the L'età di Galileo exhibition (1987).14 In 1987, Paolo was also involved in the reinstallation of the Museo Galileo, a project completed two years later. He helped to catalogue lenses, prisms, and optical games; mechanical instruments; meteorological instruments, with Stefano Casati; and weights and measures, with Mara Miniati.15 Twenty years later, he contributed to the new reinstallation inaugurated in 2010, curating five rooms of the section devoted to the Lorraine collection.16 This intense activity crammed into a very short period channeled Paolo's interests in directions that remained constant in later decades: the interest in instrument collections and in showcasing their historical significance; a prosopographic attention to instrument makers; an emphasis on instrument restoration as a complement to cataloguing; the production of exhaustive catalogues of high scientific quality; a focus on exhibition projects that could provide a historical and narrative dimension to often technically complex artifacts; the interaction between history of instruments and history of science; and, last but not least, an abiding concern to share with colleagues and young researchers all the skills he had acquired in the field. In all of these areas, Paolo-from the late 1980s on-developed a personal profile that soon made him an eminent figure in the international history of science community. Paolo's stay in Florence sharpened his historiographical and museological approach, which matured in the following decades. Another crucial step was his appointment by the French National Center for Scientific Research (cnrs) to the Centre de Recherche en Histoire des Sciences et des Techniques at the Cité des Sciences et de l'Industrie in Paris (1988Paris ( -1991. This experience put him contact with institutions and colleagues that broadened his research horizons and deepened his interest in the history of electricity and French makers of precision instruments. From the late 1980s on, Paolo incorporated Paris and France into his sphere of action. In the 1990s and 2000s, he worked on major projects with the Musée des Arts et Métiers; in 2006, he became a member of the scientific advisory board of the national project for the conservation and promotion of France's scientific heritage of the second half of the twentieth century. However, these important collaborative ventures never took Paolo away from Florence and Italy. Between 1992 and 2000, with funding from the Italian National Research Council (cnr), he served as research fellow at the Museo Galileo and, from 2001 to his retirement in May 2021, as cnr research fellow appointed to the Fondazione Scienza e Tecnica, also in Florence. These research positions had two benefits: first, they gave him academic recognition for scientific expertise that was hard to classify in the conventional categories of disciplines recognized in European university systems; second, they gave him a very broad freedom to conduct his work wherever he was attracted by the presence of collections or relevant projects.
It would certainly be most useful-as with his bibliography-to compile a complete list of all the collections and projects in which he was involved during his career, but they are so numerous and their documentation is still so fragmentary that I cannot provide a full account of them. In addition to formal contracts for the study and restoration of collections, Paolo was often contacted by auction houses, antique dealers, private collectors, and government agencies for advice on collections or single instruments. While this activity generated some highly interesting discoveries, its history is extremely hard to reconstruct. As with his official research, Paolo prepared detailed accounts of these investigations and, whenever possible, photographing the instruments submitted to his scrutiny.
What follows is merely a description of the projects that Paolo mentioned in a résumé sent to the University of Bologna in late 2019 ahead of the planned reorganization-completed a year later-of the Augusto Righi collection in the Physics and Astronomy Department.
In the 1990s, Paolo restored and catalogued many Italian collections including the Liceo Prati in Trento, the Liceo Foscolo in Pavia, the University Museum in Pavia, and the Liceo Visconti in Rome. He studied old instruments of spe-cial note such as the Jesse Ramsden circle at the Astronomical Observatory in Palermo17 and the Angelo Secchi meteorograph in the Astronomical Museum at Monte Porzio. At the international level, he partnered with the Conservatoire des Arts et Métiers in Paris, the Museum for the History of Science at Oxford, the Museum Boerhaave in Leiden, the Museo de la Ciencias in Madrid and, from the early 2000s, with the French astronomical observatories of Lyon, Haute Provence, and Nice. Paolo was also one of the founders of the universeum association, an assiduous participant in aseiste (Association de Sauvegarde et d'Études des Instruments Scientifiques et Techniques de l'Enseignement), and a generous provider of answers to historical queries submitted to the rete mailing list.18 This dense network of high-level working relationships led to Paolo's election as President of the Scientific Instrument Society (from 2005 to his death), President of the Scientific Instrument Commission (2003Commission ( -2013, and Vice-President of the International Union for History and Philosophy of Science-Division of History of Science and Technology (2009)(2010)(2011)(2012)(2013). Between 1999 and2003, Paolo helped to catalogue Volta's instruments in two locations: the University of Pavia and the Tempio Voltiano in Como. Also in 2003, he oversaw the restoration of the instruments at the Liceo Volta in Como and of a group of devices at the Ufficio Centrale di Meteorologia Agraria (ucea) in Rome and the Liceo Paolo Sarpi in Bergamo.
Between 2009 and 2011, he disassembled, restored, and reassembled the large refractor telescope built by Joseph von Fraunhofer in 1823, used by the astronomer Friedrich Georg Wilhelm Struve, and kept at the Tartu Observatory (Estonia).
In 2016, he began restoring a series of instruments at the Museo Caffi in Bergamo and cataloging and reorganizing the scientific instrument collection of the Museo Civico in Modena.
In 2011, Paolo's work at the Fondazione Scienza e Tecnica in Florence and the new displays there prompted him to produce a series of historical-educational videos to explain the functioning of old scientific instruments. The series was prepared with Anna Giatti and the video maker Antonio Chiavacci. Released on YouTube,19 it proved an instant success, winning attention and praise not only from the Foundation staff but also from schools and students. 17 And in 2012, he also restored the Merz refractor telescope on the same site. 18 The Paolo's educational creativity was unleashed whenever he was invited to give a lecture or a course. He showed and shared his knowledge without ever acting professorial, and he would invite attendees to take an active part in the event. Indeed, his university courses were almost always accompanied by experimental demonstrations that illustrated the topic in a novel and participative way. His university career included the appointment to the Sarton Chair of History of Science at the Ghent University (Belgium) for the academic year 2000-2001. His attention to the young had made him aware of the institutional difficulties they face when choosing such an uncertain career. In 2017, for example, he wrote: Today it is very hard to find career opportunities in Italy. Cuts in research funds and the niche status of history of science make it difficult for a young researcher to embark on a rewarding career. I know young and extremely able researchers who are forced to spend their time looking for research grants or fixed-term contracts in order to survive.20 I am sure that he would have viewed the Museo Galileo's decision to give his name to a post-doctoral fellowship in the study and restoration of scientific instruments as a fitting recognition of the attention he consistently devoted to training young people.
Back in 1999, Paolo and I, under the auspices of Dominique Ferriot, had developed a project to catalogue the instruments that had belonged to the French chemist Antoine-Laurent Lavoisier, most of which are held at the Musée des Arts et Métiers in Paris. However, it was only in 2015, thanks to Catherine Cuenca, that the right circumstances came together to make the project possible. As we both used to say, this became our most demanding task. We began in 2017 and consigned the final, revised version of the catalogue in late November 2021, just days before Paolo's death. The Lavoisier collection poses an especially difficult challenge because, as is well known, he commissioned the making of instruments-many of which he personally designed-that are unique and cannot be compared with other contemporary productions. This challenge, relating to so prominent a figure in history of science, came to us at a time when we had both perhaps acquired enough experience to take it up with some hope of success. Given the number of difficulties and obstacles Brenni, "Filming Nineteenth Century Physics Demonstrations with Historical Instruments," in Historical Scientific Instruments in Contemporary Education, ed. Elizabeth Cavicchi and Peter Heering (Leiden: Brill, 2021), 34-49. 20 Lorefice, "Il lavoro 'nascosto' di un illustre ticinese," 7. encountered, we were all the more relieved to have been able to complete the project. Our inability to celebrate its publication together will be a source of deep and permanent sorrow for me. These years of working together gave me a first-hand opportunity to appreciate Paolo's exceptional talents. In his hands, pieces and fragments of all sortspreviously inventoried and described without a clear understanding of what they were-became recognizable instruments. Clumsy tampering and previous restorations (not always satisfactory) were rapidly put right, bringing the Lavoisier collection gradually back to life. I believe I am not mistaken in stating that the famous gasometers built by Mégnié in 1788 are now in their best condition since their acquisition by the Conservatoire National des Arts et Métiers (cnam) in 1866. Other instruments, whose purpose long remained a mystery, have now been positively identified. The assurance and ease with which Paolo handled these instruments were such as to surprise even the most experienced curators, while the younger ones, more than once, feared that his handling would cause breakage. Not only did this never happen, but, in Paolo's hands, the instruments came back to life; whenever he could, he demonstrated this by making a device work again with surprising speed. For him, the repetition of an experiment had to be as quick and spectacular as those of Jean-Antoine Nollet, an author on whom he was one of the foremost experts. The enthusiasm that prevailed in these wonderful reconstructions spread to the Museum's curators and restorers. From the outset, this created an exciting atmosphere that we shared with many staff members at the professional and human level. We conducted much of our research at the Museum's reserves in Saint-Denis outside Paris. With its tens of thousands of instruments, machines, and artifacts of all kinds sitting on open shelves, the facility was, for Paolo, an enchanted place. Our lunch breaks would turn into guided tours, either to focus on a single instrument that interested him or to lose ourselves in an entire collection. His inexhaustible curiosity was backed by an extremely solid scientific training that, over time, was enhanced by a surprising close attention to the cultural history underlying the production of instruments and machines. This working method effectively revealed his personality as a nineteenth-century savant-as he often liked to define himself-a learned and enthusiastic admirer of scientific and technical achievements. However, this nostalgic sympathy for the Belle Époque was more a personal taste than an actual personality trait, for Paolo was a man fully immersed in his time, who could feel at ease in conversations with people regardless of age, background, social class or gender. Indeed, beyond his manual dexterity, Paolo was a most delightful conversationalist, capable of addressing a wide variety of topics with a rare blend of seriousness and humor.
His multifarious scientific career earned him many prizes and awards, most notably the Paul Bunge Prize from the H. Jenemann Stiftung for studies on scientific instruments and material culture (2002), the Scientific Instrument Society Medal (2005); and the Marc-Auguste Pictet Medal from the Committee of the Société de Physique et d'Histoire Naturelle in Geneva for his contributions to history of science and instrument restoration.
While the study of scientific instruments was his passion, it did not rule out many other interests, for which he displayed equal curiosity and-in a good many instances-expertise. Art history, technology, industry, museums and universal exhibitions, cinema, and industrial archeology were all subjects that captivated him deeply.
Paolo was also a gifted draftsman, and on several occasions he showed me watercolors of industrial landscapes drawn with precision but always with a style that revealed his characteristic vision of the world.
Notwithstanding his fondness for Italy, Paolo loved Switzerland and in particular his native town, Mendrisio. Like many of his fellow citizens, he celebrated August 1 by flying the red flag with the white cross from the window of his villa. During our conversations, he proudly reminded me that Mendrisio had been, in the late nineteenth century, one of the first towns in the Ticino to be electrified-hence its possibly apocryphal nickname of ville lumière of the Ticino-and that, a few kilometers from the town center, stood one of Europe's largest gold refineries. For me, with my Milanese roots, these displays of affection for his native land offered opportunities for good-natured bantering that drew on the vast repertoire nurtured by the historical, linguistic, and cultural ties between the Lombard capital and the neighboring Swiss Ticino. Despite a friendship of over thirty years, we would still refer to each other as "il Brenni" and "il Beretta"-a typical form of self-identification in an idiom that was and still is very popular in our part of the world.
While his passion for his work was a characteristic trait of his personality, Paolo had no shyness in expressing deep love for his family-his wife Andrea, his daughter Camilla, and his son Oliver. To them go my thoughts of heartfelt affection. obituary Nuncius 37 (2022)