English folding almanac in Latin.

A folding almanac in Latin, containing a calendar (three months per leaf) and astrological tables and diagrams. Produced in England c.1415-1420 (the calendar includes the feast of John of Beverley, whose cult was proclaimed by Henry V after victory at Agincourt on 7 May 1415). It follows the Kalendar ad meridiem Oxonie of John Somer (1380), and contains data for the four Metonic cycles starting in 1387, 1406, 1425 and 1444, with lists of solar eclipses between 1384 and 1462 and lunar eclipses between 1387 and 1462. Like the other twenty-nine folding almanacs known to be extant, it contains data that enabled medical practitioners and others to diagnose and prognosticate, as well as to obtain information about religious feasts and other key moments in the calendar. Nonetheless, this example, with its silk binding and fine illustrations, may have been a luxury object that did not see practical use.