The engravings on this ivory dial with a very unusual herring-bone grain are filled with red and black colour.
The outer surface of the upper leaf is laid out as a relief carving of St. John the Baptist.
The inner surface of the upper leaf is laid out as a vertical string gnomon dial for latitude circa 48?, the latitude of Nuremberg. The hours numbered anticlockwise VI to XII to VI.
The inner surface of the lower leaf contains a horizontal string gnomon dial The hours are numbered IIII to XII to VIII.
In the centre is an empty compass well. The lower part bears a simple geometrical pattern.
The outer surface of the lower leaf is plain.
The instrument was presented by A.W. Franks in 1877 and is described and illustrated in F. A. B. Ward, A catalogue of European Scientific Instruments in the Department of Medieval and Later Antiquities of the British Museum (London, 1981), p. 35, no. 76 (with plate X). See also P. Gouk, The Ivory Sundials of Nuremberg, 1500-1700 (Cambridge, 1988), pp. 28 ff.