The 17th-century English bibliophile, Robert Cotton, sometimes bound together separate manuscripts which were otherwise unrelated, creating books of miscellaneous contents, this book being a good example. It is made of a fragment of an early 12th-century English scientific textbook from Peterborough and an 11th-century pontifical (manual of services conducted by a bishop), part of which was probably made in France but to which additions were made at Sherborne Abbey in Dorset. The page shown comes from the scientific textbook which itself comes from two types of sources. One is the 'natural science' tradition of the early middle ages which begins in the treatises of Isidore of Seville and Bede, is later expanded by Abbo of Fleury, who lived at Ramsey in the 10th century. To these books belong a tradition of diagrams which incorporate Christian doctrine into classical theories on the structure of the heavens and earth. The second part of it is astrological, on the zodiac and planets. It would have been a textbook for monks and churchmen in their training as theologians. Annals in another fragment of the book (also in the British Library) giving the death dates of Peterborough abbots and the handwriting's similarity to that of the Peterborough Chronicle (at the Bodleian Library, Oxford) place the manuscript's origin at that monastery. These diagrams complement an excerpt about the parts of the world from Isidore of Seville's 'De natura rerum' ('On the nature of things'). The larger diagram shows simultaneously the four elements (Fire, Water, Air, Earth); four seasons (Winter, Summer, Autumn, Spring); and so on. These are juxtaposed with the four essences (Hot, Cold, Wet, Dry), so, for example, 'Summer' and 'Fire' at the top, are between 'Hot' and 'Dry', while 'Winter' and 'Water' at the bottom are between 'Wet' and 'Cold'. In the centre, the words MUNDUS, ANNUS, HOMO ('world, year, man') underscore the micro- and macrocosmic harmony of the structures of physical nature, the seasons and man, who had four humours and whose anatomy was structured in sets of opposing pairs.