The original instrument is one of the oldest surviving astrolabes from Europe. It was made in the 14th century: The shape of the rete with arabesques and four-leaf ornamentation is remarkable. Arabic numerals are already used, although the numerals for 4, 5 and 7 differ from those used today.
This instrument was obviously still very close to the Arab culture. Thus, with few exceptions, the names of the stars are of Arabic origin. However, "Vultur cadens" ("falling vulture") was also a common name in European astronomy for Vega, the brightest star of the constellation Lyra.
The two insert discs (tympana) for the geographical latitudes 36°/40°/44°/48° contain 5° almucantarats, 10° azimuth lines, twilight line (-18°) and the unequal hours (temporal hours). The rete has 17 star positions. Regulus = Leo 21°.
The reverse shows on the outside the 4 x 90° scale for measuring altitude, then the zodiac and calendar circle with the vernal equinox on 13 March, the shadow square, and on the inside the 28-year cycle of Sunday numbers (first Sunday of the year: 7 = 7 January, 1 = 6 January, 2 = 5 January, 3 = 4 January etc.).
The complete description of the instrument as PDF for download
