27. Polyhedral dial by Nicolaus Kratzer, London, c.1525 Type: instrument Inv. No. 54054 Source: MHS The dial is unsigned but was made for Cardinal Wolsey (bearing his arms, the arms of York Minster and two representations of a cardinal’s hat), almost certainly by Nicholaus Kratzer. He was lecturing at Corpus Christi College, Oxford in the 1520s, under Wolsey’s patronage, on elementary astronomy, the construction of the astrolabe and Ptolemy’s geography.
Astrolabe with geared calendar, ca.1221/22. This 13th-century Persian astrolabe is the oldest complete device with cog wheels known. On the front side it is an astrolabe, linked to the calendar by a gear train. On the back, the disc shows the phases of the Moon | Oxford, Museum of the History of Science