This dial in the form of a book has coloured figures on both the outer faces: on the upper leaf, St. Helena holding a cross in her right hand, and on the lower leaf, Constantine (Helena's husband, father of the Emperor Constantine). The colours used are red and green. Constantine is depicted as a bearded man in Roman armour, and holds a pennant in his right hand. The mark of Hans Troschel is punched on this side of the lower leaf.The inner face of the upper leaf has a pin gnomon dial (pin missing) for Italian (marked from 13 to 24) and Babylonian hours (marked in red from 1 to 11). Below is the inscription 'SIC TRANSIT GLORIA MUNDI: AD LATITUD GRAD?51?MI?30?ANNO DOMINI?M D L X X X V I?'.
The lower leaf has a compass (needle, ring and glass missing) with cardinal points marked 'SE', 'OR', 'ME', 'OC', and two horizontal string gnomon dials marking common hours from 4 (a.m.) to 12 (noon) and from 12 (noon) to 8 (p.m.). The edges are decorated with a geometrical motif and there are two conical holes for stowing the pins.
See P. Gouk, The Ivory Sundials of Nuremberg 1500-1700 (Cambridge, 1988).
Ilaria Meliconi