The paper describes the author's witnessing of images projected from an eighteenth-century solar microscope made by John Dollond, now at the Deutsches Museum in Munich. Peter Heering facilitated this session as part of his research on the solar microscope. A rectangular mirror, the length of a hand, mounted outside a museum window caught the sunlight and directed it indoors into the microscope's optical tube with its specimen. Astonishing detail was displayed in the resulting image projected onto a screen at human height. Crisply delineated scales patterned the image cast by a historical specimen of a butterfly wing. Observers interacted fluidly with these images in the very dark room. In sharing what we noticed, questioned and conjectured, we contributed to a temporary community. These participant interactions relate to Steven Shapin and Simon Schaffer's notion that, in the seventeenth century, Robert Boyle used witnessing as a ‘collective act’. Here, the ‘collective act’ spanned participation across history. For example, Robert Hooke's 1665 Micrographia inspired Philip and Phylis Morrison's workshop during my college years and their collaboration with the Eames Office on a film depicting travel through ‘powers of ten’, based on Kees Boeke's 1957 picture book. Personal memories were extended and informed by historical experiences, both for Robert Hooke's subsequent interpreters and for Peter Heering's participants.

Thomas Salusbury's Life of Galileo (1664) was the first substantial biography of Galileo Galilei (1564–1642) in any language. All copies but one were destroyed in the Great Fire of London in 1666. The surviving copy was lost in the library of the Earls of Macclesfield at Shirburn Castle in the mid-nineteenth century. With the auction of the library in 2004–7, it temporarily re-emerged. This essay presents a preliminary description of the copy and its contents. It argues that to understand the existence and nature of the book we need to explore the social relations governing the control of information in early modern Europe. It is shown that Salusbury's project was launched in the face of social and political information blockades and in direct competition with other similar ventures. In particular, rumours of the future publication of an official biography by Vincenzo Viviani (1622–1703) and continuing negotiations over the memory and reputation of Galileo in Italy presented insurmountable barriers to the successful completion of his project. Despite these problems Salusbury's biography, produced on the margins of the emerging Royal Society, presents a spirited portrait of Galileo. Moreover, nearly four hundred years after the event, it offers a new and provocative explanation of the famous trial.

Solar microscopes and their techniques attracted particular attention in the second half of the eighteenth century. This paper investigates the grounds for this interest. After a general introduction to the solar microscope, it discusses the use of original instruments to gain access to the visual culture of solar microscopes and the issues raised by these re-enactments. Experiences involved in this process serve as a basis for reassessing the original source materials. Thence emerges a different account of the meaning of the solar microscope in the eighteenth century and possible reasons for its popularity.

Francis Hauksbee (1660–1713) is well known for his double-barrelled air-pump. However, the origin of this pump, and Hauksbee's background, are often described as a mystery. This text seeks to dispel the riddle. It is argued that Hauksbee's competence as an exceptional maker of air-pumps was developed between 1699 and 1703 as a result of his experiences with the construction, manufacturing and sale of cupping-glasses. His cupping utensils embodied a new design, where syringes were used to evacuate the glasses, instead of the traditional way by fire or mouth suction. These syringes, which in fact were small air-pumps, were perfected between 1699 and 1701. A larger syringe, introduced in 1701, served as a transition from the cupping-syringe to his first air-pump for use in natural philosophy. This syringe was described as a ‘combined engine’, which could serve as an air-pump, a condensing engine and a syringe for injecting air, wax or mercury into pathological specimens. Hauksbee's first air-pump was a single-barrelled model introduced in 1702, based on the combined engine. Its various features, such as easy and convenient leak-tightening, exact pressure measurements by an in-built barometer and an air-inlet function for readmission of air into the receiver, are discussed. Finally, it is shown that these activities gave Hauksbee the reputation of being an outstanding instrument-maker, years before the double-barrelled air-pump was in sight.

Using a striking example from the history of applied psychology, the concept of accident proneness, this paper suggests that historians of science may still find viable the idea of simultaneous discovery or construction of a scientific idea. Accident proneness (Unfallneigung) was discovered independently in Germany and in Britain during the period of World War I. Later on, in 1926, the idea was independently formulated and named in both countries. The evidence shows not only striking simultaneity but true novelty and commensurateness of the two formulations that crystallized at the same time in parallel, but distinctly separate, settings.

This paper discusses the theory of motion of the philosopher Honoré Fabri (1608–1688), a senior representative of early modern Jesuit scientists. It argues that the consensus prevailing among historians – according to which Fabri's theory of impetus is diametrically opposed to Galileo's or Descartes' concept of inertia – is false. It shows: that Fabri carefully constructed his concept of impetus in order to easily incorporate the principle of linear conservation of motion (designated here as “limited inertia”), by adopting formal (rather than efficient) causality between impetus and motion and by allowing impetus to act only along straight lines; that he explicitly deemed Aristotle's famous “inertial paradox” not as a paradox at all; and that linear conservation of motion was not limited to “counterfactual” circumstances but played a significant part in his discrete theory of free fall and constituted an integral component of his general physical (and even mathematical) philosophy. However, the paper also shows that Fabri's notion of inertia was restricted to one dimension only, and therefore should indeed be considered “limited.” In his analysis of horizontal projectiles, Fabri explicitly rejected Galileo's important principle of superposition, and thus revealed significant constraints to his “inertial” thinking.

The eighteenth-century natural histories of Paraquaria, a Jesuit province in South America ranging from the tropical forest to Río de la Plata (the River Plate), constitute a rich and consistent tradition of nature writing. The way the material is organized, the frequent use of lists of aboriginal names, and the focus on naming, all attest to the missionaries' preoccupation with language, understandable given that they were engaged in writing dictionaries and thesauri of the native tongues. During the nineteenth and twentieth centuries, this body of work went through a series of appropriations, reflecting the various intellectual programs that contributed to the making of the national tradition in Argentina. While these natural histories are still often interpreted in terms of Argentina's national history, science, and literature, I will argue that they should be considered a product of a mixed culture oriented toward the practical and religious goals that are characteristic of most of Jesuit missionary culture, the result of the missionaries' attempt at organizing their experience of the wilderness and their encounter with the aboriginal peoples.

“The Case of Ellen West” was published by the Swiss psychiatrist, Ludwig Binswanger, in 1944–1945. The case-history depicts the illness and suicide of a young woman who was his patient twenty years earlier. It came to be considered one of the paradigmatic studies of the newly established discipline of Daseinsanalyse, an attempt to synthesize existential philosophy and therapeutic practice. This paper analyzes the case-study, employing newly uncovered archival material to expose important details regarding the treatment of Ellen West (a pseudonym) and the posthumous writing of her case-history. The richness of the archival sources and the various historiographical characteristics they exhibit raise methodological questions about the potentialities and limitations of historical representation. The new data will thus serve as a platform from which to explore and discuss more generally the problems involved in historical reconstruction – of both subjective experience and clinical knowledge – and the questions of authorship and intertextuality in the genre of the case-history.

The history of ballooning has received considerable attention from historians examining the technological innovations behind it as well as from scholars interested in aeronautical anecdotes concerning launches and disasters. The cultural importance of this new machine, however, remains less fully analyzed. This essay explores one facet of that history through a discussion of the commodification of launches in France and Great Britain. These two countries, which have larger middling classes as well as a higher degree of commercialization in general, provided a fertile environment for aeronauts seeking to instruct and entertain an audience willing to fund ballooning. Balloonists had to invent ways to market this scientific discovery and determine how best to attract paying customers. The audience was entertained while simultaneously empowered to act as witnesses to what balloonists presented as a scientific experiment.