Medieval English manuscript. Illuminated folding almanac on vellum, southern England, c.1425. In Latin, written in a small legible bookhand in brown and red ink on 6 vellum leaves (folded dimensions approx. 135 x 40 mm, each except perhaps f. 5 opening ideally into six panels, dimensions when opened 270 x 120 mm), ruled in brown ink, prick-marks in margins, all leaves stitched together at foot and attached to alum-tawed leather thong, retaining but detached from original silk-lined leather covering (probably deerskin), a few small holes, mainly to intersections of folds.
Contents and illumination:
ff. 1-3: calendar of saints' days for March-September (i.e. only half of f.1 extant, lacking the half with January-February on flesh and hair sides respectively, leaf for October-December not present), divided into columns showing times of sunrise and sunset, sun's position in the Zodiac, Dominical letters for days of the week, and saints' days and festivals, illustrated with a total of 7 illuminated initials in gold on red and blue ground (20 x 15 mm; one for each month extant), one panel of each leaf with headings in red or brown ink incorporating decorative initials in blue amid penwork surrounds in red,
ff. 4-5: tables of solar and lunar eclipses, with 64 diagrams in red, blue and gold (each approx. 16 mm in diameter), one panel of each leaf with headings as above,
f. 6: large illuminated miniature of the Zodiac man (image rubbed and marked, leaf retaining only two panels apparently of six, but with only minor loss of image, the three missing upper panels presumably containing text only) (qty: 1)

Provenance: available on request.

An extremely rare survival, one of perhaps 30 examples of an English folding almanac known to be extant, nearly all of which are confined to major institutional collections; intended for practical use by physicians, who used astrological calculations to establish prognoses and the most auspicious timings for medical interventions, their form allowed them to be suspended from the waist for quick reference, hence the alternative name of 'girdle book'.

'From an analysis of the saints' days and festivals it would appear that [the present] calendar was made for use in the Canterbury diocese (thus confirming the south England emphasis of the astronomical calculations' e.g. St Augustine of Canterbury, in red, on 26th May, the Translation of the relics of St Thomas on 7th July, St David 1st March, St Chad, 2nd March (both of whose feasts were made obligatory in 1398), St Dunstan, on 19th May, St John of Beverley on 7th March [sic: really 7th May], and other English saints' (J. P. Harthan, Assistant Keeper of the Library, Victoria & Albert Museum, typescript description, 1960, provided with the lot).

'Folded almanacs must have been common in later medieval England; however, few still exist, because of their small size and the wear and tear caused by folding and unfolding them. Most of those that do survive seem to have been intended for physicians, yet others seem to have been produced for less sophisticated users ... Astrology had a vital role in medieval medicine, because an understanding of the stars was believed to be essential to determine the best timing for various medical procedures' (Pamela Robinson, 'A "very curious Almanack": the gift of Sir Robert Moray FRS, 1668', Notes and Records of the Royal Society (2008), Vol. 62, pp. 301-314).

Further reading: Cornelius O'Boyle, 'Astrology and Medicine in Later Medieval England: The Calendars of John Somer and Nicholas of Lynn', Sudhoffs Archiv 2005), Vol. 89, No. 1, pp. 1–22; C. H. Talbot, 'A Mediaeval Physician's Vade Mecum', Journal of the History of Medicine and Allied Sciences, Vol. 16, No. 3 (July, 1961), pp. 213-233.