Thorney Computus

Digital Bodleian digitized manuscript

1. Text: Headings in red, mostly in rustic capitals. Texts introduced and divided by arabesque initials of various sizes, in red, green, and text ink. A variety of decorative figures to set off text runover, esp. plant stems and leaves and animal forms (dogs and wyverns). || 2. Illustrations: In the calendar (item 10), drawings of four signs of the zodiac and sketch of a fifth, readily visible only under ultraviolet light (fols. 16rv, 18, 19, 20: Aquarius, Pisces, Gemini, Leo, and Libra, the last the sketch). Another drawing, a king (or God) with a cup (fol. 27v); and a further dim sketch, a grieving male figure (fol. 36, the margin). Text magnificently illustrated with tables in multiple colours. These include: 1. Fol. 5vb: Rotae of easter termini, three separate systems for calculating the date ('Dionisivs', 'Victorivs', 'latenlus secundum antiochos'), above a T/O map, the rim giving times of sunrise/sunset for four major days. 2. Fol. 6: another T/O map. 3. Fol. 6: A ferial table. 4. Fol. 7: a table headed 'Divisio phylosophye', the legends in its circles from ISIDORE, Etymo1ogiae 2.24.10—16, 2.24.3—8. 5. Fol. 7v: 'Byrhtferth's diagram'. 6. Fol. 8ra: tidal rota, around a T/O map, to indicate the relation between the age of the moon and the tides. 7. Fol. 8rb: the sphere of Petosiris, a device for diagnosing the outcome of a patient's illness by arithmetical operations. 8. Fols. 8—12: thirteen compotus tables, with three textual additions, a logic square (fol. 11va) added text (d) above, and two computistical mnemonics (fol. 12). 9. Fols. 22—37: see item 10 above. 10. Fol. 40v: a diagram showing the names of the winds. 11. Fol. 41: two prognostic diagrams, the ‘sphere of PYTHAGORAS’ and a diamond diagram now cut out. 12. Fols. 41v—2: an abacus table, with associated tables and a poem explaining the Arabic names for the symbols (fol. 42). 13. Fol. 56v: three further diagrams on the use of the abacus. Fol. 57 is blank, and the repeated tables associated with item 16 follow on fols. 57 v—8.; Dark brown calf, 16th or 17th c., over medieval wooden boards (probably not original, but from a rebinding associated with the thirteenth-century scribes), with gold-stamped centrepiece on both boards and a thin gold fillet. On each board, five metal bosses, those at the corners with plates, and a single large round central boss. Two intact clasps in the lower board, the straps now missing, although grooves for them remain in the upper board. '17' in gold at the head of the spine, 'old' in black ink on the leading edges.; Digital Bodleian completeness: complete; 376 digitized image(s); Fols. vi + 177 + v (foliated s. xvii), representing an original 170 fols., since BL, MS Cotton Nero C.vii, fols. 80-4 have been removed from their place here, following fol. 143; and fols. 144-55 are an addition of s. xiii.; Overall 340 mm x 250 mm, in a variety of formats, especially given the number of diagrams.; Shelfmark: St John's College MS 17 [1997 images]; vellum