Charles Burnett ( is Professor of the History of Islamic Influences in Europe at the Warburg Institute (University of London) and is part of the research group working on astrolabes in medieval Jewish society. He is an expert in the diffusion of Arabic knowledge into Latin and is also interested in the role of Jews as mediators in this transfer. He has an impressive record of publications on the subject of this transmission and its cultural context, as well as editions and translations of several of the key manuscripts involved in the amazing transfer of knowledge and ideas that took place in western Europe.

Our question for him is to explain the cultural context in which astrolabes emerged in Europe. This is his answer:

We have the first indications of the introduction of the astrolabe into Christendom towards the end of the tenth century in Catalonia, the provenance of the earliest astrolabe to be inscribed with Latin inscriptions, and of the earliest Latin texts. These were based on Arabic texts, some of which have been identified. But a Latin scholar added an elaborate preface, which, after emphasising the importance of the knowledge of astronomy, advertises the significance of the new instrument—the astrolabe–in the following words: ‘Among the other famous instruments of this art provided by him (Ptolemy), he invented  a certain instrument, both most useful for learners and a great miracle for those looking at it, than which among all inventions nothing is more eminent for the intimate investigations of doctrines and the arts of mathematics, and nothing is more useful for investigating the whole of that higher machine and for all astronomical studies and the science of geometry. It is the Wazzalcora, obtained by a divine mind, which in Latin means “flat sphere”, which also by another name is called “the astrolabe of Ptolemy”. In this Wazzalcora, the whole form of the celestial sphere is described by a natural reasoning according to the roundness of the sphere, and all things are noted correctly by the architectonic reasoning of celestial figurations, which I will describe a little more clearly afterwards. How useful this is, both what follows will demonstrate and the truth of the matter will prove’. From this time onwards the astrolabe gained a prominent place in Western European science, as a teaching instrument, as an instrument of observation, and as a symbol of the universe, and of the power of the ruler who owned that symbol. Adelard of Bath addressed a work on the astrolabe to Henry Plantagenet (the future King Henry II of England), pointing out that it was a guide to the universe; for just as the householder should know the house that he lived in, so the dweller in the universe should know his dwelling place, or else be cast out of it. Peter Abelard and Heloise named their son ‘Astrolabius’, perhaps as an indication that he pointed the way to the heavens. Works on the construction and use of the astrolabe featured prominently in the translation programmes from Arabic into Latin of the mid-twelfth century. Through the astrolabe the positions and the names of the most prominent fixed stars in the sky became known. No astronomer or astrologer could be without his astrolabe, and even the schoolboy was expected to know how to use the instrument, as we see from Chaucer’s English text on the astrolabe addressed to his son Louis.

(Sources: José-Maria Millàs Vallicrosa, Assaig d’història de les idèes fisiques i matemàtiques a la Catalunya medieval, Barcelona, 1931; Arianna Borrelli, Aspects of the Astrolabe, Stuttgart, 2008; Geoffrey Chaucer, A Treatise on the Astrolabe Addressed to his Son Lowys A.D. 1391, ed. W. Skeat, London, 1872).


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