 The context for Bacon’s writing on topics from the Meteorology of Aristotle came from the presence in Paris of the new translation of this work from Greek into Latin. With the recent critical edition of the Aristoteles Latinus version of the Meteorology, it is clear that Bacon is deliberately offering a criticism of William of Moerbeke’s translation. Bacon contends that the translations are not adequate and that the translator did not know the required sciences, especially Perspectiva, proposing instead a more accurate mathematical analysis of the phenomenon of the rainbow.