The 16th-century English bibliophile, Robert Cotton, sometimes bound together unrelated manuscripts. This one contains 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 scientific textbook comes from two types of sources. First, an early medieval natural science tradition began in the treatises of Isidore of Seville and Bede, and was later expanded at Fleury, most notably by Abbo of Fleury, who lived at Ramsey in the 10th century. The second part of it is a copy of a late Roman version of Cicero's latin translation of the poem by the Greek writer Aratus on the constellations, known as the 'Aratea' and which probably had a long tradition of illustration.Monks and churchmen used the textbook in their theological training. Annals in another part of the book 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. The constellation of Canis Major (Greater Dog) contains Sirius, the brightest star in the sky of the northern hemisphere. In Greek mythology Canis Major was one of Orion the hunter's dogs (another was Canis Minor). The inscription within the figure of the dog tells of its role in mythology and describes the number and positions of stars within it. This part was a later addition to Cicero's translation and was always written within the pictures, which usually were not outlined.