A rare late 16th century German oval ivory diptych-dial, the upper inner leaf with tangent circles and inscribed 1593, the lower leaf (lacking its glass cover and string gnomon) housing a dry-card paper compass, beneath hour lines marked with Roman numerals, the upper outer leaf with a brass nocturnal, a small external catch keeps the lid open when in use, probably Nuremberg, width 39mm depth 48mm length 48mm CONDITION: Ivory stained and discoloured particularly in two patches to the underside and dirty to the top, metal mounts evenly oxidised, compass dial rubbed and looks like it was once glazed but this is now lacking.