September 2014
Page 40

Unexpected Aspects of Anniversaries, or: Early sundials, widely travelled

Links the 500th anniversary of Rheticus' birth (Copernicus's publisher) to early sundials. Discusses a lost coloured stone gnomon ordered by Bishop Giese from Nicholas Kratzer in London (c. 1520), and Georg Hartmann’s ivory cross dial (1541) now in the British Museum, suggesting Hartmann’s paper cut-out cruciform dial (1529) may be the earliest of its type.
Dials: Portable, Construction Projects, Historical Dials

Helmut Sonderegger