The outer part of the upper leaf has a wind rose with 32 directions, brass index arm and compass viewing hole, and two bun feet. The cardinal points are marked 'NORT' [with a fleur-de-lis], 'OST', 'SVID' and 'WEST'.The inner part of the upper leaf has a pin gnomon dial for the length of the day numbered from 8 to 16 and engraved 'QVANTITAS DIEI' and the declination of the sun indicated by the symbols of the zodiacal signs. The string gnomon dial is adjustable for latitudes 42?, 48?, 54?. At the bottom of the leaf is the inscription 'IMPONE FILVM HORAMINI QVOD LOCI TVI POLVM INDICAT ET HORA HABEBITVR IN CIRCVLO QVI EODEM NVMERO POLARI INSCRIBITVR ?1 ?6 ?00 ?' ('put the string in the slot which represents the latitude of your location and the hour is to be had in the circle which is inscribed with the same latitude number').
The inner part of the lower leaf has a compass with cardinal points indicated 'S' [with a fleur-de-lis], 'ORI ENS', 'M', 'OCCI DENS' and a string gnomon dial for common hours numbered from 4 to 12 to 8 for the latitudes above mentioned. In the centre is the maker's mark (a serpent) and the date '?1 ?6 ?00'. Below is a scaphe dial with Italian hours numbered in red from 8 to 24, and a 16-leaf flower motif at the bottom.
The outer part of the lower leaf has a pierced lunar volvelle with the inscription 'NACHT VHR' and around it 'COMPASSVS PROPE FERRVM NON RECTE ASSIGNARE POTEST' ('the compass cannot point properly next to iron'), the maker's mark (a serpent) and two bun feet.
See P. Gouk, The Ivory Sundials of Nuremberg 1500-1700 (Cambridge, 1988).
Ilaria Meliconi