Page from the Münster Chronick

This hand colored woodcut was once part of a copy of Cosmographia, a book on geography and astronomy by the German scholar Sebastian Münster (1488-1552). This publication was the earliest German description of the world and a major work in the revival of geographic thought in sixteenth-century Europe. It first appeared in print in 1544 and went through forty subsequent editions.

The Cosmographia included descriptions and maps of all parts of the earth known to Europeans at that time, and was accompanied by a discourse on cosmography. Texts were illustrated by intricate diagrams, such as the one depicted here, which could be used as tools to track the movements of the planets and stars, as well as to do specific calculations and measurements on distance or time.

This diagram from a French-language edition of the book was used to measure the length of days. The main circle symbolizes the earth, with its upper half lit by the sun and the lower half covered in darkness. The vertical line dividing the circle indicates the zenith, the highest point of the sun in the sky. To its left, six zodiacal signs, associated with the spring and summer months are represented. Parallel lines connect these signs with their counterparts, representative of autumn and winter.

The lower right quarter of the earth is centrally divided by a line that indicates the equinox, the moment in spring when the sun moves north across the celestial equator. It symbolizes the end of winter, as the days will start to get longer. The same happens in autumn, when around September 22nd, the sun again crosses the equator going south, and we are on our way to the winter solstice; the longest night.

Münster’s book was published at a time in which the astronomical sciences knew rapid development. Contemporary scholarship harked back to on the theories of the Greek astrologer Ptolomy, which were based on the principle of a geocentric planetary system, in which the earth formed the center of the universe. In 1543, just before Münster’s Cosmographia was published, Nicolas Copernicus (1473-1543) wrote his revolutionary De revolutionibus orbium coelestium, arguing that not the earth but the sun was the center of all things. It would take a long time before his idea of the heliocentric system would be widely accepted. Therefore, when Münster’s book appeared, the geocentric idea were still considered valid, and nothing prevented his publication from becoming a great success.