Time troubles: clocks and practices of precision in early eighteenth-century observatories.

In 1736/37, Joseph-Nicolas Delisle and Jean Jacques Dortous de Mairan communicated about the clocks that would enable the astronomers of the Saint Petersburg observatory to make highly exact observations. Delisle, who was in charge of the Saint Petersburg observatory, demanded old-fashioned clocks in the manner of Huygens. Mairan, well-versed in astronomy himself, recommended equation clocks. The article uses these seemingly inappropriate preferences to discuss eighteenth-century notions of accuracy and precision in clocks. It analyses the multiple factors that influenced expectations regarding the performance of timekeeping instruments, and draws attention to handling and monitoring practices. The latter reflected the individual user's purposes and experience, but also affected the clocks' going. Furthermore, the article presents the result of a statistical analysis, which serves to evaluate the historical performance of the Saint Petersburg observatory clocks and provides a foil against which Delisle's judgement of them is examined.

Timing the stars: Clocks and complexities of precision in eighteenth-century observatories.

In the eighteenth century, the sciences and their applications adopted a new attitude based on quantification and, increasingly, on a notion of precision. Within this process, instruments played a significant role. However, while new devices such as the micrometer, telescope, and pendulum clock embodied a formerly unknown potential of precision, this could only be realized by defining a set of practices regulating their application and control. The paper picks up the case of pendulum clocks used in eighteenth-century observatories in order to show the process of learning in the course of which the pendulum clock first became a precision instrument. By examining the results of an especially developed statistical analysis, conducted to compare the performance of eighteenth-century clocks, it highlights the diversity of conditions, attitudes, and manners of handling that are characteristic for the epoch. In this way, it underlines the necessity of standardization of timekeeping practices rather than exclusively focusing on the technological development of clocks. Ultimately, the paper discusses the role of makers and users in order to show the evolution of a "precision instrument."

[Mathematics - astronomy - astrology special library]. / Die mathematisch-astronomisch-astrologische Spezialbibliothek des Kurfürsten August von Sachsen.

About 1560 Elector August of Saxony created an unusual library--one distinguished within its period by both its specialization and location. Situated within the Kunstkammer this library was mostly dedicated to the mathematical sciences and related disciplines. It contained works by the most important authors on mathematics, astronomy, and astrology from the classical, medieval, and early modern periods. This essay traces the formation and composition of August's library, and examines its function: What kind of relationship existed between the library and the Kunstkammer? In what way did the library mirror the interests of the Elector, and to what extend does it permit inferences regarding the Elector's knowledge of mathematics? From the analysis August emerges not as a specialist with a deep understanding of mathematics, but as a particular aficionado of mathematical applications. As a practitioner and general follower of the mathematical arts he took part in a far-reaching intellectual network the center of which lay in the University of Wittenberg. Here, Melanchthon had effectively strengthened the importance of the mathematical disciplines within the university curriculum. He regarded mathematics as the foremost science, arguing that before all other disciplines its method enabled man to recognize the harmonic order of the world, and to discern divine providence. Thus, mathematics offered consoling stability and support in an often seemingly chaotic world torn by religious controversies. This kind of esteem for the mathematical sciences did not presuppose expert knowledge. Hence, the fact that August does not appear to have read the mathematical books he collected does not come as a contradiction. On the contrary, for August it sufficed to recognize the potential of the mathematical sciences, which he brought into life through the creation of a specialized library that developed a rhetoric of its own. The collection of his Kunstkammer library spoke of a harmonically ordered world while at the same time memorializing August as a lover of mathematics and an important figure within the group of mathematical experts and enthusiasts.