This section contains the following items:
One of the most significant features of Bede's De temporum ratione was the manner in which it fused a manual of Christian time-reckoning with a survey of astronomy and cosmology. This marriage is announced in the opening sentence of the book, where Bede states that his new work will bring supercede both De temporibus (his first computus treatise, composed about 703) and De natura rerum, his re-working of Isidore's work of the same title (
De temporum ratione
, Praefatio 263.1-6). The tendency of computus to expand into an encyclopedic filing-cabinet for all kinds of information - mathematical, philological, geographical, astronomical and medical - is certainly evident in the structure of MS 17 as a whole, and of many other computus manuscripts. But Bede's strong sense of form led him to restrict this proliferation to two domains: cosmology and history. The former was the indispensable astronomical basis of time-reckoning; Bede dealt with this in his chapters on the movements of the Moon (chs. 24-29) and Sun (30-33), on the climatic zones of the Earth, and the seasons (ch. 34-35). The latter, articulated in the great universal chronicle of ch. 66 and its projection into the apocalyptic future in the closing section of the book, elevated the Dionysian Paschal cycle into a tool for comprehending the plan of salvation.
Bede's decision to absorb lunar and solar astronomy and basic cosmology into computus furnished Carolingian schoolmasters with a Christian and clerical vehicle for conveying information about the physical world, as well as a convenient framework for storing newly recovered or freshly appreciated materials such as the works of Macrobius. Carolingian computus manuscripts tended to expand into generous encyclopedias.
For example, Cologne 83 II contains a cosmographical suite whose shape closely reflects that of MS 17: a section of tables on lunar months and solar years on fols. 80v-81v (comparable to MS 17's fols 35v-37r), followed by texts and diagrams on the structure of the universe, the earth and the winds on fols. 82r-84r (analogous to MS 17's fols. 37v-40v). An important family of Carolingian manuscripts actually organizes this material into a monumental formal structure, endowed with numerous illustrations.
The first section of Vatican City BAV Reg. lat. 309 contains the capitula for one such compilation, which is mirrored, if not exactly replicated, in the contents of the manuscript as a whole.
Book 1 contains tables and texts directly related to the calendar; Book 2 comprises formulae for computus reckoning; Book 3 discusses the year (especially the problem of leap-year); Book 4 the Moon and Paschal reckoning. With Books 5 and 6, however, we pass into the realm of pure astronomy and cosmography: the positions of the stars and planets, their movement through the zodiac, eclipses, meteorology, and the size of the Earth. Book 7 is Bede's De natura rerum.
This Carolingian encyclopedic impulse, and its Bedan roots, are reflected in this section of MS 17. Like De temporum ratione, it confines itself to explications of the movements of the Moon and Sun in relation to time, the basic architecture of the cosmos and Earth, and some elements of meteorology, notably the winds. But like the Carolingian compilations, it is richly endowed with illustrations. The presence of astronomica by Abbo of Fleury within this anthology strongly suggests a Fleury exemplar. There are numerous examples of Carolingian computi from Fleury ( Paris, BNF lat 5239; Paris BNF lat. 5543; Paris BNF nouv. acq. lat. 1615; London British Library Harley 3017...) but the cosmographical anthologies in these manuscripts are of a distinctive type, comprising extracts from Pliny's Natural History, Martianus Capella's De nuptiis, and Macrobius' Commentary on the Dream of Scipio. There is a strong possibility that this conglomerate was available to the compilers of MS 17, for it is found in its sibling manuscript, the Peterborough computus
(Tiberius fols. 21v-42v), where it is paired with Cicero's Aratea. Nonetheless, MS 17's compilers chose a different array of materials: (1) a suite of tables on solar and lunar reckoning; (2) Isidore of Seville's De natura rerum 23.1-4 on the planets; (3) Abbo's two tracts on solar, lunar and planetary motion; (4) Isidore on the four elements; (5) an extract from Macrobius on "gravity"; (6-7) two extracts (the first from Isidore of Seville) on the five climates; and (8) Isidore on the twelve winds. All these materials are found in the Peterborough computus, but divided between two locations: (1) and (4)-(6) in Tiberius fols. 6v-12v, and (3) in Harley fols. 8v-10v. Since the Harley section of the Peterborough computus
is gathering XXI, and the Tiberius folios lie within gathering VIII, this puts some considerable distance between Abbo and the rest of the cosmographical material. It is noteworthy that Abbo's computus compilation in Berlin 138 also includes almost all this material, minus Abbo's own treatises, sandwiched between the last of the computus tables on fol. 35v, and the opening of a suite of materials on the Paschal table on fol. 40r. While Berlin 138 omits Abbo's own treatises, it does include some of the diagrams and texts which Abbo drew on for these works. All of this adds up to strong presumptive evidence that the cosmographical anthology in MS 17 was derived from a Carolingian-type computus, edited by Abbo. However, the Thorney scriptorium seems to have made two deliberate decisions with regard to this material. First, it omitted the Pliny-Macrobius-Martianus suite; and secondly, it decided to integrate Abbo's own treatises into the cosmographical ensemble. For further discussion of the latter, see commentary on Abbo's summary of planetary astronomy (fol. 37v-38r).
1 Wallis 1999, lxiii-lxxi.
2 Barbara Obrist, "Les tables et figures abboniennes dans l'histoire de l'iconographie des recueils de comput," in
Oriens-Occidens2004 , 146-157; Barbara Obrist, "La cosmologie à Fleury," in
Lumières de l'an mil
3 Arno Borst, "Alkuin und die Enzykopädie von 809," in
Science in Western and Eastern Civilization in Carolingian Times
53-75; Anton von Euw, "Die künstlerische Gestaltung der astronomischen und komputistischen Handschriften des Westens," in
Science in Western and Eastern Civilization in Carolingian Times
251-269; Wallis 1999, xci-xcii.
4 Published by Saxl 1915, 60-62.