POLYHEDRAL DIALS

HANS HOLBEIN: THE AMBASSADORS (National Gallery)

HANS HOLBEIN: NICHOLAS KRATZER (Louvre)

MUSEO GALILEO . FLORENCE

CENTRAL DIAL by Stefan Buonsignori,

NICHOLAS KRATZER: POLYHEDRAL DIAL

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. This was a typical conjunction of astronomical and cosmographical interests. Born in Munich and educated at the universities of Cologne and Wittenberg, Kratzer was an instrument-maker, who brought the craft practice of astronomy to England in about 1517, arriving, according to a contemporary account, bearing astrolabes and armillary spheres. (Science Museum)