A Collection of Astonomical and Mathematical Treatises
Medium: Ink and pigments on vellum
By the 13th century when this manuscript was made, European astronomers had access to information on planetary movements and other observations of the heavens that had been compiled by Arab astronomers in 11th-century Spain. This knowledge, with its methods of observation and emphasis on the natural world, was part of an intellectual revolution taking place in the late middle ages. Christian theologians responded to the new knowledge by integrating it into the church's doctrine. Monasteries provided the intellectual environment where the latin translations of arabic books were copied and studied. This manuscript of astronomical treatises belonged to St Augustine's, Canterbury.
Ptolemy, the ancient Greek philosopher, wrote the 'Alamagest' in which he explained the movements of the planets by saying that the other planets orbited around the earth in perfect circles, some of them moving in epicycles or orbits within orbits to explain the 'irregularities' that we now know are due to eliptical orbits. Writings on the planets and their orbits were often wrongly believed to have been Ptolemy's, such as one called the 'Centilogium'. It in turn has a commentary by a writer who may have been an Arab astronomer in Spain. This page shows diagrams of the sun and moon orbiting the earth, with the sun casting shadows upon the other two.