oval ivory diptych sundial
Date: circa 1585
Inventory Number: 7830
Classification: Sundial
Dimensions:closed: 1.3 x 5.6 x 7 cm (1/2 x 2 3/16 x 2 3/4 in.)
DescriptionBlack, red, and blue coloring. Brass wire clasps on I and II, hanging loop and four bun feet on II. Compass needle and glass intact. Plate II is made from two slices of ivory glued together. The exterior of II is cracked in several places, and I is split lengthwise.
Black, red, and blue coloring. Brass wire clasps on I and II, hanging loop and four bun feet on II. Compass needle and glass intact. Plate II is made from two slices of ivory glued together. The exterior of II is cracked in several places, and I is split lengthwise.
la) Standard German lunar volvelle with stamped brass rotating disc (2.3 cm) with index. Scales numbered 1-12 twice (inner and middle) and 1-29 (outer). Lunar phase indicated in red and blue under disc. Man- in-the-moon motif on volvelle. Outer circle labeled "PLENIP. VNIVM," "PRIMA QVARTA," "NOVIL. VNIVM," and "VLTIMA QVARTA" [full moon, first quarter, new moon, last quarter]. Two brass pbtc, in the shape oflunar crescents hold ivory together.
lb) Holes for string gnomon at 42°, 45°, 48°' 51°' and 54°. "vn HOC COMPASS LICET UBIQVE VT DE INSTRVCTIONE EIVS EX LIBELLO PERCIPIAS" [It is possible to use this compass anywhere, so observe the instruction from the booklet] and "IMPONE FILVM FORAMINI QVOD LOCI TV! POLVM INDICAT ET HORA HABEBITVR IN CIRCVLO QVI EODEM NUMERO POLAR! INSCKIBITVR" [Place the string into the hole which corresponds to your latitude and the time will be indicated in the circle which is inscribed with the same latitude].
Ila) Horizontal dial with five scales, middle and outer scales labeled 4-12-8 and inner scale labeled 5-12-7, marked for latitudes 54° (outer), 51°, 48°, 45°, and 42° (inner). Compass needle and glass intact. Compass points labeled s, ORIENS, M, and OCCIDENS and extraneous gilt indicator in compass bowl (added later?). Magnetic declination 6° east ofnorth. Initials "HT" with crowned snake maker's mark in between.
Latitudes labeled "ELEVATIO POLI 42 45 48 51 54" [elevation of pole (latitude) 42° 45° 48° 51° 54°].
llb) Scale reading 4-12-8, with gilt indi- cator (attached to the one in the compass bowl). This indicator is apparently a useless replacement for the original brass volvelle
used to convert between large and small hours. Scale for length of the day reading 8-16 labeled "TAG LENG" and "WINTER" and "SVMMER," with four zodiacal symbols. Image inverted for legibility.