Observatoire de Paris, salle du conseil
January 21-22, 2021
Org. Nicholas A. Jacobson
The workshop will be organised online, link will be sent to participant shortly before the workshop sessions. If you want to participate please email Nick.Jacobson@obspm.fr
Rationale
A central component of the ERC-funded ALFA research project at the Paris Observatory is the study of procedure texts, known as canons, which were designed to instruct readers in the use of astronomical tables in the Alfonsine tradition. The canons sit at the intersection between the theoretical discipline of astronomy and its practical applications in astrology, medicine, cartography, and timekeeping. Due to their status as texts providing the “know-how” for using tables to perform calculations in these practical pursuits, they have sometimes been treated as distinct from other astronomical writings of the period – something of a bridge between two broadly construed domains of knowledge designated by the terms theorica and practica. Within such a framework – where theorica sought to establish the unchanging principles of knowledge, while practica strove to use this knowledge to produce a thing or realize a goal – canons do not fit neatly within either category. On the one hand, the rich astronomical theory of Ptolemaic astronomy lies behind the mathematics of the tables, which the canons instruct the reader in using. Thus, elements of theorica persist in these texts, even if in an attenuated form. On the other hand, the goal-oriented language and the simplified operations described in the canons appear to constitute a distinctly practical mode of astronomical writing.
After holding several internal seminars in which we have discussed these features of procedure texts within the Alfonsine tradition, ALFA would now like to host a workshop where scholars from around the world can come together to discuss the practices, contents, and boundaries of similar procedural sources as they were written in the late medieval and early modern periods. In doing so, we would also like to broaden our horizons beyond just canons in Alfonsine astronomy to include other domains of knowledge within an expanded chronology. For this reason, this workshop seeks to maintain an open attitude toward canons and procedural texts more broadly construed: seeking to identify commonalities across scientific disciplines that may help us to define a genre of practice/practical knowledge, while also allowing for the possibility that these practical texts share important connections with theoretical works, tables, diagrams, as well as physical objects and instruments.
In recent years, historians of science have rekindled an interest in exploring the role of practice and practical knowledge in the development of the sciences from the fourteenth to the seventeenth centuries. The categories that scholars use today to tell this history are inspired, in large part, by the historical actors themselves who considered practical knowledge to be an essential component of the learned scientia tradition of the universities. But scholars have also tried to move beyond normative definitions of scientific knowledge formally presented by historical actors in order to look at how they actually behaved when they engaged in scientific activities. The study of procedural texts allows the historian the opportunity to recreate workflows using material evidence available to us so as to put medieval and early modern practices back into action.
Contributions to this line of scholarship, moreover, have encouraged us to pay due attention to institutional contexts out of which such knowledge was produced. These include courts of the nobility, networks of religious orders, artisanal guilds, and mercantile schools. For instance, as just one salient example, if we shift our perspective to look at the interplay between university learning and craft production, distinctions between learned and artisanal practitioners become manifest. In this way, historians of science have usefully drawn up boundaries between textual knowledge and craft knowledge while still seeking out where practitioners in these two spheres interacted and when they might have had the opportunity to engage in both cultures. Identifying such areas of interplay may well help to clarify the commonalities and differences of various procedural texts. So too will our openness to the continued importance of university learning during these interesting moments of boundary-crossing.
In closely analyzing the content of these textual witnesses, as well as tracking their development and circulation, this workshop will contribute to the history of practice and practical science in the late medieval and early modern periods. Seeking to define the contours of a genre, we encourage papers that focus on the conventions adopted by the authors of procedure texts, paying close attention to language and vocabulary, organizational structure, page format (mise-en-page), annotations, cross-chapter instructions, and ostensive directions referring the reader to other practices, diagrams, and objects beyond the manuscripts and printed works themselves.
Thus, we hope that this workshop can help to generate and refine a number of questions for ongoing research in this field, including the following. Do the many examples of procedure texts found in the late medieval and early modern periods amount to a distinct genre of writing? Do they emerge out of shared or distinct communities of practice? In preparing canons and similar procedural works, which actions and skills were called upon explicitly in the text, and which remained tacit? How were steps, which were designed to effect an action or realize a goal, organized hierarchically? How did material technologies – such as manuscripts, tools, or instruments – accommodate or constrain the practitioner, and how was this made visible in the procedures themselves? What technical vocabulary was invented to present the constructions, recipes, or algorithms of a procedure? And how were actions and skills encoded into language in such ways that served to consolidate, expand, or constrain a practice? In sum, we would like to explore multifarious aspects of this flourishing period of practical science in medieval and early modern Europe with a focus on the codification of practical knowledge through procedural language, and with due attention to the individuals and communities out of which they emerged.
Participants: Alberto Bardi, James Barnes, Matthieu Husson, Nicholas Jacobson, Richard Kremer, Tillmann Taape, Michael Shank, Samuel Gessner, Camille Bui, Eleonora Andriani, José Chabas, Ségolène Albouy, Tristan Dot, Leni Gauffier
Program
Thursday, January 21st
Session 1
4:00 PM – 8:00 PM (break 6:00 PM – 6:30 PM)
Matthieu Husson
Welcome
Nicholas Jacobson
The Role of Estimating Procedures in Canons: Tracking Planetary Cycles and their Connection to Professional and Craft Production
James Barnes
Disguising Theory as Practice: Christopher Borri and the “Aula de Esfera,” 1624-1631
Tillmann Taape
Distilling Process: Artisanal Skill and Alchemical Thought in Early Printed Distillation Books
Michael Shank
Commentary
Friday, January 22nd
Session 2
4:00 AM – 8:00 PM (break 6:00 PM – 6:30 PM)
Alberto Bardi
Writing and Reading the Heavens in Tabular Form: Conventions and Formats of Byzantine Canons on Astronomical Tables
Matthieu Husson
Mercury Equations Procedures in John of Lignères Tables and Instrument Works
Richard Kremer
Canons for Making Planetary Almanacs: A Comparative Analysis of ‘Labor Saving’ in Medieval Computational Astronomy
Nicholas Jacobson
Commentary and Closing Remarks
Abstracts
Alberto Bardi
Writing and Reading the Heavens in Tabular Form: Conventions and Formats of Byzantine Canons on Astronomical Tables
This talk focuses on the practice of writing and reading canons in Greek and Latin on astronomical tables, produced in Constantinople and the Eastern Mediterranean in the fourteenth and fifteenth centuries. By examining manuscripts and analyzing procedural texts of the canons, such as the several commentaries to the so-called Persian Tables, this paper deals with the following areas of inquiry on the edge between theory and practice in the history science: conventions scholars used when writing the canons; implicit or explicit boundary between astronomy and astrology; institutional or private context; given/implicit knowledge; relationship between the format of the manuscript and the mathematical practice.
James Barnes
Disguising Theory as Practice: Christopher Borri and the “Aula de Esfera,” 1624-1631
The “Aula da Esfera” ran continuously at the Colégio de Santo Antão from 1590 to 1759, and was viewed by instructors and Portuguese authorities as bridging the gap between experts trained in natural philosophy—cosmology and astronomy in particular—and a lay public. Taught in Portuguese rather than Latin, instructors were charged first and foremost with educating pilots and navigators bound for service in the royal navy. The course content of the “Aula da Esfera” was notable for its idiosyncratic nature, often shifting from year to year to reflect the shifting interests of its instructors and the presentation of new natural discoveries. This dynamism notwithstanding, the course nonetheless maintained a consistent core of material, most notably Sacrobosco’s eponymous Sphere and Euclid’s Elements. It is within this context that Christopher Borri, instructor at the “Aula da Esfera” from 1627 to 1628, produced Arte de Navigar (1628). A practical work on navigation, this text was at once a junction between theory and practice as well as natural philosophy and practical mathematics. Soon after, Borri published the second half of Arte de Navigar under the separately titled Collecta Astronomica (1631), in which Borri proposed a new method for finding longitude at sea. Evidence suggests that Borri’s brief tenure at the “Aula da Esfera” was aimed at preparing a class of navigators to test Borri’s novel methods at the request of the Portuguese crown, and while it appears that Borri enjoyed substantial, if not tenuous, support from the Portuguese court, the theoretical claims Borri expressed in Collecta Astronomica were sufficient to delay publication of the text and precipitate Borri’s eventual departure from the Society of Jesus. Christopher Borri, his Arte de Navigar, and the “Aula da Esfera” consequently provide a unique opportunity to explore how practical texts could serve as vehicles for theoretical argument, and in Borri’s case, as a way for scholars to assert theoretical claims that might otherwise be impermissible due to traditional institutional boundaries.
Matthieu Husson
Mercury Equation Procedures in John of Lignères Tables and Instrument Works
In the 1320’s and 1330’s, John of Lignères produced, around Paris university, different tabular, instrument and theoretical works dealing with planetary procedures. Among them, I single out the Priores astrologi, the Multiplicis philosophie, the Quia nobilissima scientia astronomie and the Fiat primo regula. The first two are texts related to tables while the laters are related to a type of planetary instrument called equatoria. These different texts show how John of Lignères is working with the tabular and geometrical models of planetary motions and correlatively the type of procedures one can follow to manipulate them. Focusing on the specific case of Mercury, I will explore how an analysis of these procedures and their contrasts can provide clues on the kind of astronomical work John of Lignères is developing with respect to planetary motions with these different tools.
Nicholas Jacobson
The Role of Estimating Procedures in Canons Tracking Planetary Cycles and their Connection to Professional and Craft Production
Defining the precision that users should adopt in their tabular calculations was a common concern among authors of astronomical canons within the Alfonsine tradition. This issue sometimes arises when determining which place value one should take for the true position of a planet. It comes up even more frequently, however, when defining the temporal bounds of periodic cycles, such as the moment of true syzygy, the precise moment of the Sun’s entrance into Aries, or the times of significant planetary conjunctions, all of which require the reasoned judgment of calculators to know when to estimate the beginning of an event and when to be satisfied with the value that results from their efforts. In many important studies of the historiography of Alfonsine astronomy, questions of calculative precision are often defined in terms of the user-friendliness of procedures and the concomitant labor-saving techniques that privileged certain methods over others. In this paper, I would like to investigate how estimating procedures in tabular canons may have been tied to the final products the creation of which these calculations were tailored. I will look, in particular, at canons for determining synodic periods and periods of gestation found in Laurentius de Laurentiis (Florence, BNC, Convent. soppr. J. VIII. 28; Cod. Can. Misc. (Bodl.) 357) and Johannes de Sancto Archangelo (Ambrosiana MS D28 Inf). The language of estimating values and confirming accurate results in canon procedures will be seen to have a mutually influencing effect on the techniques and products of the professional medical astrologers who used them.
Richard Kremer
Canons for Making Planetary Almanacs: A Comparative Analysis of ‘Labor Saving’ in Medieval Computational Astronomy
Most canons accompanying medieval astronomical tables instruct readers on problems of spherical astronomy and on the use of tables to compute planetary positions, conjunctions, eclipses, and astrological tasks like houses, aspects or revolutions of the year, i.e., practical tasks involving a celestial configuration for one particular event or date. A few canons are known, however, that consider the more computationally laborious task of preparing daily planetary positions over long expanses of time. This presentation will offer a preliminary investigation of 6 such canons, including a text that circulated with the 13c Toledan Tables; Chapt. 27 of the Castilian Alfonsine Tables and the related Chapt. 44 of John of Lignères’s Priores astrologi; the anonymous ‘De compositione almanac’ in BnF Lat. 7346; and single chapters in the canons of Nicolaus de Aequaductu (1410), John Killingworth (1444) and Laurentius de Laurentiis (late 15th c.). Each of these texts offers procedures for reducing the labor of making daily almanacs; considered together, they let us explore the meanings of “labor saving” in medieval Latin mathematical astronomy.
Tillmann Taape
Distilling Process: Artisanal Skill and Alchemical Thought in Early Printed Distillation Books
Distillation books were one of the earliest printed how-to genres. As such, they grappled with the challenges of codifying a process that was informed by alchemical matter theory and also heavily reliant on embodied skill in handling materials and specialist equipment. This project gained import and momentum as distillation became one of the most important processes for understanding and manipulating nature. This paper investigates how this process was codified in print and explores the relationships it wrought—between artisanal and learned forms of knowledge, between the natural and the artificial, and between heavens and earth, as a process that could channel the material perfection of celestial substances in the sublunar world. Finally, it takes these procedural texts about distillation as an opportunity to explore what it means to historicise not only materials and objects, but the process itself.
Selected Bibliography
Christy Anderson Anne Dunlop, and Pamela Smith, eds., The Matter of Art: Materials, Practices, Cultural Logics, c. 1250-1750 (Manchester: Manchester University Press: 2015).
Guy Beaujouan, “Réflexions sur les rapports entre théorie et pratique au Moyen Age,” in J. E. Murdoch and E. D. Sylla, eds., The Cultural Context of Medieval Learning (Dordrecht, 1975): 437-484.
Karine Chemla and Jacques Virbel, eds., Texts, Textual Acts and the History of Science (Springer Interational, 2015).
Jens Høyrup, “Old Babylonian Mathematical Procedure Texts: A Selection of ‘Algebraic’ and Related Problems with Concise Analysis,” Max-Planck-Institu für Wissenschaftsgeschichte (1994): 1-60.
Pamela Long, Artisan/Practitioners and the Rise of the New Sciences, 1400-1600 (Corvallis: Oregon State University Press, 2011).
Matthieu Ossendrijver, ed. Babylonian Mathematical Astronomy: Procedure Texts (SpringerInternational, 2017).
Emmanuel Poulle and Owen Gingerich, “Les positions des planètes au Moyen Age: application du calcul électronique aux tables alphonsines,” in Comptes rendus des séances de l’Académie des Inscriptions et Belles-Lettres 111.4 (1967): 531-548.
Pamela Smith, “In the Workshop of History: Making, Writing, and Meaning,” in West 86th 19.1 (Spring-Summer 2012): 4-31.
Matteo Valleriani, ed., The Structures of Practical Knowledge (Springer International, 2017).