Beschreibung:

A rare 16th-Century German ivory diptych book dial, signed 15HT88 [i.e. Hans Tucher] around the maker's mark (Gouk p. 117, figure 104, number 3) Face Ia, upper leaf, outer face: lunar volvelle (lacking disc) , with moon phase diagram in red and blue, surrounded by scales graduated [12] - 12 and 1 - [29] , within compass rose, surrounded by the legend HIC MARINVS COMPASSVS SEMITANM TERRA MARIQVE OSTENDIT , compass viewing aperture Face Ib, upper leaf, inner face: pin gnomon dial (lacking pin) showing the length of the day, graduated 8 - 16 and showing the symbols of the houses of the zodiac, surrounded by inscription in red ILLA CVSPIS INDICAT INCREMENTVM ET DECREMENTVM DIEI ET DVODECIM SIGNA , six fixing holes for the later string gnomon, marked in red 54 , 51 , 48 , 45 , 42 and 39 , with inscription in red below die löchlein sein die polus heh der land und stett das schnurlein thu in das löchlein des lands polus grad , with further inscription in black below IMPONE FILVM FORAMINI QVOD LOCI TVI POLVM INDICAT ET HORA HOBEBITVR IN CIRCVLO QVI EODEM NVMERO POLARI INSCRIBITVR , three brass eyes to edges Face IIa, lower leaf, inner face: outer hour scale graduated in red 4 - 12 -8 and labelled in black 54 , surrounding five concentric scales marked 51 , 48 , 45 , 42 and 39 , with the names LAPSIA , UNGAR , VENET , ROMA and LISBOA scratched beside by a later hand, the inner scale graduated in red 5 - 12 - 7 , surrounding the compass with replacement brass-capped, blued-steel needle and bezel, three lines for magnetic variation scratched into the bowl by a later hand, legend below compass ELEVATIO POLI. 54 . 51 . 48 . 45 . 39 . GRAT. , three brass clips and brass support strut to edges Face IIb, , lower leaf, outer face: gilt brass volvelle with legend RVCK DAS SPITZ LEIN AVF DIE TAG LENG SO VERKLEICHT SI DIE GROS VHR GEGENT DER KLEIN to convert between large and small hours, graduated 8 - 24 - 0 running over a scale graduated in red 4 - 12 - 8 , with diagram showing the length of the day at different times of the year and the symbols of three houses of the zodiac, surrounded by inscription MOVE ORBICVLVM CVM INDICE IN LONGITVDINEM DIEI TVMC COMPARAT SE MAIOR HOROLOGIVM CVM MINORI HOROLOGIO , maker's mark, four gilt bun feet the hinged edges of the two leaves worked to resemble a book binding with raised bands -- 3.7/8in. (9.7cm.) long See Colour Illustration and Details