Edited by Josefina Rodríguez-Arribas, Charles Burnett, Silke Ackermann and Ryan Szpiech
Contributors are Silke Ackermann, Emilia Calvo, John Davis, Laura Fernández Fernández, Miquel Forcada, Azucena Hernández, David A. King, Taro Mimura, Günther Oestmann, Josefina Rodríguez-Arribas, Sreeramula Rajeswara Sarma, Petra G. Schmidl, Giorgio Strano, Flora Vafea, and Johannes Thomann.
The subject of this article is the treatise on the astrolabe ring (1492/1493) by Bonetus de Latis (Jacob ben Immanuel Provenzale). The treatise belongs to a four-centuries-old tradition of Jewish treatises on the astrolabe, written mainly in Hebrew and more rarely in Judaeo-Arabic, Judaeo-Spanish, Spanish, and Latin, and produced mostly in southern Europe and Turkey. Bonetus’s text is the second treatise written in Latin by a Jew, following Abraham ibn Ezra’s treatise on the planispheric astrolabe (Rouen 1154). My purpose is to compare it with other contemporary treatises on similar instruments and with a little earlier treatise on the astrolabe in Hebrew (by Eliyahu Cohen of Montalto, fifteenth century) in order to understand the contribution of this instrument and why the treatise was so highly regarded among Bonetus’s contemporaries. The instrument depicted in Bonetus’s booklet can be considered one of the last contributions of Jewish culture to the history of the astrolabe; these contributions stretch back to the first Hebrew writings on the instrument in the twelfth century. The Latin text and the English translation are included at the end of the article together with the Latin text and translation of the longest version of the introduction to the treatise. The contents of the treatise are exactly the same in all editions of Bonetus’s text, but there are two versions of the introduction and one is longer and more complete than the other. I have used both versions in my study, the one in the version printed, among others, in 1557 (shorter) and the one in the version of the treatise printed, among others, in 1507 (longer).
The main topic of this article comprises four unpublished Arabic texts on astrolabe-like instruments for showing the conditions of eclipses. They are the earliest technical descriptions of eclipse computers in any language. The first text is a treatise by ʿAlī ibn ʿĪsā (ninth century) on a special astrolabe for lunar phases and eclipses. The second text is an anonymous redaction of the first text with some omissions and additions. The third text describes a similar instrument with a different design, which was invented by Muḥammad ibn Muḥammad Nasṭūlus al-Asṭurlābī in the year 893/894 CE. The fourth anonymous text describes a plate for a graphical solution of the size of a lunar eclipse. In the concluding part, later Arabic descriptions of eclipse computers are summarized, some traces of these texts on real astrolabes are mentioned, and finally some comparable medieval Latin texts are referred to. Four Appendices contain an edition of the Arabic texts and English translations.
The astrolabe of Petrus Raimundi, made in Barcelona in 1375, occupies a significant position in the set of medieval Spanish astrolabes with Latin inscriptions, as it is the only one signed and dated that has survived to the present day. A full description and study of the astrolabe is presented in the context of the support given to the manufacturing of scientific instruments by King Peter IV of Aragon. Although the astronomical and time reckoning features of the astrolabe are fully detailed, special attention is given to its artistic and decorative features. The relationships between Petrus Raimundi’s astrolabe and those manufactured in al-Andalus, the region under Islamic rule within the Iberian Peninsula in the Middle Ages, are highlighted, as well as the links with astrolabe production in other European Christian kingdoms. The role played by astrolabes in medicine is considered and first steps are taken towards discovering the identity of Petrus Raimundi.
Josefina Rodríguez-Arribas, Charles Burnett and Silke Ackermann
Laura Fernández Fernández
This article analyses the relationship between text and image in one of the most important scientific manuscripts commissioned by Alfonso X the Learned, El Libro del saber de astrologia (Ms. 156 BH Complutense University, Madrid). The main topic deals with the depiction of astrolabes in the four treatises devoted to this instrument in the codex, and the connexion established between the real astrolabes, the depicted ones, and the written sources used by the Alfonsine team.