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.

Searching for precision: Lorenz Eichstadt's Tabulae harmonicae coelestium motuum (Stetin 1644) and astronomical prediction after Kepler.

In the century between the creation of the first large, European astronomical observatory by Tycho Brahe in the 1580s and the national observatories of France and England in the 1660-1670s, astronomers constructed ever more sets of tables, derived from various geometrical and physical models, to compute planetary positions. But how were these tables to be evaluated? What level of precision or accuracy should be expected from mathematical astronomy? In 1644, the Stetin astronomer and calendar-maker Lorenz Eichstadt published a new set of tables, mostly cobbled together from earlier tables, which include a running commentary on how his tables might be expected to match 'observed' planetary positions. His earlier works also often display a rhetoric of 'exactitude' and 'error'. Eichstadt thus offers a case study of explicit discussions of 'precision' in mid-seventeenth astronomy. Although some tables could generate positions to arcseconds, Eichstadt argued that a regime of five arcminutes should be enough for most table users who were, presumably, computing horoscopes.

'Si te omnimoda delectat precisio': early astronomical instruments with scales and the multiple meanings of precision in the sixteenth century.

This paper explores the various meanings of precision during the early modern period in Europe. In contrast with existing literature focused on assessing the precision of early instruments, this study delves into the intended significance of the term 'precision' as understood by historical figures such as J. Stöffler, P. Nunes or F. Mordente. By analysing a selection of instruments equipped with scales, both in their physical form and as they are described in instrument texts, several facets of precision emerge. Some findings demonstrate that the precision of scales can be enhanced through corrections obtained from tables. In other cases, visual estimation is substituted with a method for obtaining values of multiple sexagesimal places. Furthermore, certain instruments designed to represent theoretical concepts achieve greater precision by incorporating the most intricate details of these notions. This investigation into lesser-known meanings of precision underscores the need of comprehensively exploring the concepts, the practices and the terminology surrounding precision that were in use over the fifteenth and sixteenth centuries.

"All manner of gymnastic evolutions" for science: Dorothea Klumpke (1861-1942) and a life in astronomical research.

In this article, the extraordinary life of the astronomer Dorothea Klumpke (1861-1942) is described in detail for the first time, focussing on the four phases of her career, in which she researched various astronomical questions both as an amateur and as an employee of an observatory and as one half of a couple in science. For this reason, Klumpke's biography provides insights into the cornucopia of research approaches in astronomy at the time, in which professional and amateur astronomers explored the heavens in observatories, on field trips to exotic countries, in their own backyards, or aboard hot air balloons, using telescopes, gazing through the lenses of cameras and spectroscopes, or based on mathematical reasoning. By comparing her life to biographies of other contemporary women, including Klumpke's sisters, among them the famous neurologist Augusta Klumpke-Déjerine, the criteria that women had to fulfill in order to pursue an academic career in the long nineteenth century will be discussed at the same time. In this, particular attention will be paid to factors over which women themselves had no influence, also to show that before the middle of the twentieth century, many stars had to align in order to have such an unusual career as Dorothea Klumpke.

Knowledge and power: the role of astronomy in the territorial expansion of Chile, 1883-1890. / Conocimiento y poder: el papel de la astronomía en la expansión territorial de Chile, 1883-1890.

The article analyzes the role played by the National Astronomical Observatory (Observatorio Astronómico Nacional) in the territorial expansion of Chile at the end of the nineteenth century, through the relationship with three geographical explorations associated with this process. It is proposed that the Observatory played a central role in these geographic explorations, helping to obtain precise geographic coordinates to produce accurate maps of the territories annexed to the north and south of Chile. The results allow us to affirm that the National Astronomical Observatory provided strategic services during territorial expansion, and geography was an important part of its institutional scientific work.

El artículo analiza el rol que jugó el Observatorio Astronómico Nacional en la expansión territorial de Chile a fines del siglo XIX, a través de la relación que sostuvo con tres exploraciones geográficas asociadas a este proceso. Se propone que el Observatorio cumplió un papel central para estas exploraciones geográficas, ayudando a obtener coordenadas geográficas precisas en pos de producir mapas exactos de los territorios anexados al norte y sur de Chile. Los resultados permiten afirmar que el Observatorio Astronómico Nacional fue una institución que prestó servicios estratégicos durante la expansión territorial y, a su vez, que la geografía fue parte importante de sus trabajos científicos institucionales.

Astrology in the crossfire: the stormy debate after the comet of 1577.

The new star of 1572 and the comet of 1577 had a major impact on the ways in which astronomical research developed in the late sixteenth and early seventeenth centuries. Behind this gradual but significant change there was an extended epistemological reform which placed increasing emphasis on reason and experience and strove to exclude arguments from Scripture and authority from scientific debate. This paper argues that the humanist debate on astrology after 1577, which was initiated by highly prestigious members of a supraconfessional Republic of Letters, can be seen as an element of this process. Unlike earlier detractors of astrology, these new critics chiefly employed philosophical and scientific arguments concerning the legitimation of the entire art. By analysing a variety of accounts, this paper will reveal how great and complex the stakes in the debate over astrology were. They concerned not only the crucial problem of predestination and God's interventionalism (hence also the possibility of miracles), but also the idea of science, the concept of the human mind, and ultimately the humanist ideal of the virtuous, rational, and responsible citizen.

The spring of order: Robert Main's management of astronomical labor at the Royal Observatory, Greenwich.

During the early nineteenth century the Royal Observatory, Greenwich, significantly increased the number of individuals it employed. One of the new roles created was the position of First Assistant, who oversaw the management of astronomical labor at the observatory. This article examines the contribution of Robert Main, who was the first person employed in this role. It shows that, through Robert Main's duties and tasks, the observatory appears as a hybrid site embodying aspects of the other institutions that formed part of its operational network. Moreover, it demonstrates that the transformation of the observatory during the nineteenth century was driven by his rigorous maintenance of discipline in relation to the daily operations of the site.

Aurora borealis systems in the German-Russian world in the first half of the eighteenth century: the cases of Friedrich Christoph Mayer and Leonhard Euler.

We are interested in the case of Friedrich Christoph Mayer, who in the 1720s, while at the Imperial Academy of Sciences in St. Petersburg (in Latin Academiae scientiarum imperialis Petropolitanae), developed a system of the aurora borealis, as well as a mathematical method for calculating the height of the aurora from the geometrical characteristics of the auroral arc. Mayer, encountering a major contradiction in his system which placed the aurora at the height of the clouds, whereas his mathematical method led to an altitude a hundred times higher, never applied his method to concrete cases to deduce the height of the aurora, and quickly lost interest in their detailed description, a task that was nevertheless assigned to him at the St. Petersburg Observatory. Jean-Jacques Dortous de Mairan suggests that Mayer's abandonment was due to his lack of confidence in observations. We set Mayer's case against that of Leonhard Euler who, working with Mayer and being aware of the great height of the aurora, later developed a system of the aurora borealis that was compatible with the observational fact. We put forward possible hypotheses to explain Mayer's disinterest in observing the aurora and in the mathematical method he himself had developed.

Edward Gresham's Astrostereon, or A Discourse of the Falling of the Planet (1603), the Copernican paradox, and the construction of early modern proto-scientific discourse.

This paper investigates the functioning of the 'Copernican paradox' (stating that the Sun stands still and the Earth revolves around the Sun) in the late sixteenth- and early seventeenth-century England, with particular attention to Edward Gresham's (1565-1613) little-known and hitherto understudied astronomical treatise - Astrostereon, or A Discourse of the Falling of the Planet (1603). The text, which is fully appreciative of the heliocentric system, is analysed within a broader context of the ongoing struggles with the Copernican theory at the turn of the seventeenth century. The article finds that apart from having a purely rhetorical function, the 'Copernican paradox' featured in the epistemological debates on how early modern scientific knowledge should be constructed and popularised. The introduction of new scientific claims to sceptical audiences had to be done both through mathematical demonstrations and by referring to the familiar concepts and tools drawn from the inventory of humanist education. As this article shows, Gresham's rhetorical techniques used for the rejection of paradoxicality of heliocentrism are similar to some of the practices which Thomas Digges and William Gilbert employed in order to defend their own findings and assertions.

On the censorship of Tycho Brahe's books in Iberia.

It is known that throughout the seventeenth century the world system proposed by Tycho Brahe (1546-1601) assumed a preponderant position in the Iberian cosmological debate, according to many opinions the one showing the best agreement to empirical evidence. Moreover, the Tychonian model (or variants thereof) did not present the difficulties of apparent contradiction with scriptures, as the heliocentric system of Nicolaus Copernicus (1473-1543) did, since it kept the earth fixed at the centre of the world. However, Tycho, as a Lutheran author, was targeted by the Inquisition. Passages of various works of the Danish astronomer were included in the Spanish Indices of 1632, 1640 and 1707, although the formal condemnation of the Roman Inquisition never materialized. In the network of the Society of Jesus a seemingly informal censorship also circulated, apparently based on Tridentine determinations, published in 1651 in the influential work of Giambattista Riccioli (1598-1671) Almagestum novum. In this paper I will discuss the scope, effects and limitations of the censorship of Tycho's scientific books in Portugal and Spain, through the analysis of several annotated copies, preserved manly in Iberian libraries, with a special attention to books with a well-established provenance in past Jesuit colleges.

Newtonianism and information control in Rome at the wake of the eighteenth century.

This paper offers an opportunity to ponder the way the Catholic Church and its methods of information control reshaped, and paradoxically even enabled, the dissemination and practice of science in early modern Italy. Focusing on the activities of Newtonian scholars operating in Rome in the First half of the eighteenth century - especially the Celestine monk Celestino Galiani (1681-1753) and prelate Francesco Bianchini (1662-1729) - I will argue that major contributions to the spread of Newtonianism in Italy came from individuals operating within the Church, acting more-or-less independently from the Church's oversight. These scholars realized they were witnessing an inexorable transition and that the medieval scholastic cosmology and physics could not survive. In order to rescue the Church - and to avoid further embarrassment, especially after the Galileo Affair - renewal was needed. Counterintuitively, the dissemination of Italian Newtonianism was largely a Catholic effort.

Methodological issues in the Indo-European debate.

The Indo-European debate has been going on for a century and a half. Initially confined to linguistics, race-based anthropology and comparative mythology, it soon extended to archaeology, especially with the discovery of the Harappan civilization, and peripheral disciplines such as agriculture, archaeometallurgy or archaeoastronomy. The latest entrant in the field, archaeogenetics, is currently all but claiming that it has finally laid to rest the whole issue of a hypothetical migration of Indo-Aryan speakers to the Indian subcontinent in the second millennium BCE. This paper questions the finality of this claim by pointing to inherent limitations, methodological issues and occasional biases in current studies as well as in the interpretation of archaeological evidence.

Re-examining the impact of European astronomy in seventeenth-century China: a study of Xue Fengzuo's system of thought and his integration of Chinese and Western knowledge.

During the late Ming and early Qing period, Jesuit missionaries introduced European science into China, and thereby profoundly influenced the later development of Chinese astronomy. Not only did European astronomy become the official system of the Qing dynasty, but the traditional way to 'attain up above' by connecting the study of astronomy and Yi learning gradually fell into disuse. However, the astronomers in this period expressed different views on these two processes. As one of the most important early Qing astronomers, Xue Fengzuo's case presents a distinctive and important example. Firstly, under the influences of both Chinese tradition and European science, Xue Fengzuo rebuilt the way to 'attain up above' based on his three-fold 'calendrical learning', i.e. calendrical astronomy, astrology and related pragmatic applications, through which he could realize the highest Confucian ideal. Secondly, he integrated Chinese and Western knowledge for all three aspects of his 'calendrical learning', instead of ceding the dominant position to Western methods. From Xue Fengzuo's example, many of the complex effects of the encounter between different cultures and the process of knowledge transfer can be revealed.

Henry Bate's Tabule Machlinenses: the earliest astronomical tables by a Latin author.

The known works of the medieval astronomer/astrologer Henry Bate (1246-after 1310) include a set of planetary mean motion tables for the meridian of his Flemish hometown Mechelen. These tables survive in three manuscripts representing two significantly different recensions, but have never been examined for their principles of construction or underlying parameters. Such analysis reveals that Bate employed an unusual value for the length of the tropical year (c.365 1/4 - 1/112 days), which was probably derived by comparing ancient and contemporary observations of the vernal equinox. In addition, there are clear signs that Bate kept revising his parameters for the mean motions of Venus and the three superior planets, none of which can be traced back to earlier sources. Together with some of Bate's preserved statements, these findings support the conclusion that the Tabule Machlinenses were unique among the astronomical tables produced in medieval Latin Christendom for using independently derived parameters that were the result of new observations. Bate's achievement connects him to a wider milieu of astronomers operating in late-thirteenth-century Paris, who put an increased emphasis on observation and the critical examination of received data.