Arundel MS 66, ff 48r-248v

Guido Bonatti, Decem tractatus astronomiae:(ff. 53r-248v), preceded by a table of contents (ff. 48r-52r); rubric: 'In nomine domini amen. Incipit liber introductorius ad iudicia stellarum...'; incipit: 'In nomine domini nostri Jesu Cristi misericordis et vere dei et veri hominis.'

Guido Bonatti divided his work in 10 treatises which formed 6 parts (treatises 1-5 formed Pars 1). The divisions and order of treatises in Arundel MS 66 differ from the tradition that informed the first printed editions: the Decem tractatus Astronomiae (Erhard Ratdolt, Venice, 1491) and Guidonis Bonati Forliviensis Mathematici de astronomia tractatus X (Basel, 1550). The order of treatises in Arundel MS 66 is as follows (see Fronska 2013, Appendix 1):

ff. 53r-57r: Tractatus primus 'Ad ostendendum utilitatis quas possumus sequi de astronomia.'

ff. 57r-65r: Tractatus secundus 'De divisione orbis signorum.'

ff. 65r-73v: Tractatus secundus, 3rd part (here: Tractatus tertius).

ff. 73v-80r: Tractatus tertius, 1st part 'De naturis septem planetarum' (here: Tractatus quartus).

ff. 80v-85v: Tractatus tertius, 2nd part (here: Tractatus quintus).

ff. 86r-88r: Tractatus quartus 'De consideratione quarundam coniunctionum' (here: Tractatus sextus).

ff. 89r-128v: Tractatus sextus 'Super iudiciis astrorum'.

ff. 129r-147v: Tractatus septimus 'De electionibus' in two parts: 'Tractatus de electionibus primo universaliter' (129r-137r), and 'tractatus 2 de electionibus particularibus' (ff. 137r-143v); imperfect; includes an extract from Haly ibn Ragel [‘Ali ibn abi ’r-Rijal], De iudiciis astrorum (ff. 143v-147v).

ff. 148r-186v: Tractatus nonus 'De nativitatibus' in 4 parts.

ff. 187r-200v: Tractatus quintus 'De considerationibus.'

ff. 201r-243v: Tractatus optimus 'De revolutionibus annorum mundi' in 2 parts.

ff. 243v-248r: Tractatus decimus 'Tractatus de imbribus et aeris'.

Decoration:

Historiated initials: f. 148r: 'C'(um) of the Nativity ('Tractatus de nativitatibus'); f. 155v: 'F'(acta) of a man with a coffer of coins ('Tractatus de nativitatibus', part 4); f. 201r: 'R'(evolucio) of a king (Henry VII?) assisted by his courtiers and a bishop showing a book to a French ambassador ('Tractatus de revolutionibus').

Zoomorphic initials: f. 57r: 'S'(cias) of a dragon ('Tractatus secundus'); f. 129r: 'R'(adix) of a dragon whose breath pierces the trunk of a crowned tree ('Tractatus de electionibus'). Three types of decorated initials at the beginning of other treatises and major divisions: 1. Initials in gold on blue and rose grounds (ff. 52r, 65r, 73v, 80v, 86r, 89r), some decorated with a sunbursts (ff. 65r, 80v) or a crown with a sunburst (f. 86r). 2. Foliate initials in colours and gold, large at the beginning of part 2 of the Tractatus de electionibus (f. 137r) and small, at the beginning of parts of the Tractatus de nativitatibus (ff. 149v, 152v). 3. Initials in colours and gold with flowers at the beginning of chapters on the 12 houses in the Tractatus de considerationibus and the 'Tractatus de imbribus et aeris' (ff. 159r, 163v, 165r, 166v, 167v, 170v, 173v, 174v, 176v, 179v, 180v, 187r, 243v). Full borders of red and white roses, at the beginning of the 'Tractatus primus' and the 'Tractatus de Revolutionibus' (f. 53r: with a peacok and an eagle with a scroll 'vyve le roy'; and 201r). Pen-flourished initials in gold and blue, some with figural penwork decoration (ff. 97v, 98v, 110r, 111r, 113v, 120v, 125r, 126r-127r, 128r, 156r, 185v, 156v, 201r, 220r, 222v, 228v).

Diagrams: Zodiac (ff. 63v, 158v); cardinal directions (f. 65r), and horoscope charts (ff. 89r-90r, 91v, 111r, 111v, 144v, 184v). Space left for a chart (f. 232r).

Marginal images: a die (f. 143r); Venus in the rays of the sun, in gold (f. 203r).