Attributed to Jean Fusoris, 102 mm, circa 1410
An astrolabe of museum quality
Case: brass, engraved. Dial: rete with 20 flame pointers with Latin inscriptions, ecliptic plane, calendar scale with Latin names of the Zodiac signs; tympan with altitude and azimuth, zenith, horizon, equator and hours; the mater shows twice 12-hour chapters mit radial Roman numerals, back with month and day ring, Latin Zodiac signs, "Ordo Planetarum" with planet symbols, "Umbra versa" and "Umbra recta" shadow square. The front hand and the sight vane on the back are missing.
There are seven known astrolabes that were created by Jean Fusoris. The relatively small exemplar at hand has a characteristic unadorned form of suspension. With its fine design of the flame-shaped clockhands it is similar to the astrolabe kept at the Adler Planetarium and Astronomy Museum in Chicago, which is also attributed to him.
Jean Fusoris was born in Giraumont in the Ardennes region of France ca. 1365. His father was a pewterer. Jean Fusoris studied arts and medicine, attaining the bachelor's degree in 1379, returning after learning his father's craft for his master's degree which was attained in 1391, and served as one of the master's regents in Paris until 1400. Fusoris established a school and opened an instrument workshop in Paris making astrolabes, clocks and other instruments, but he continued to study theology.
Jean Fusoris was elected a member of the French embassy in England in 1415, where he met Richard of Courteny, Bishop of Norwich. Norwich bought an astrolabe from Fusoris but did not pay for it. When Fusoris returned to England in an attempt to collect the debt, war broke out between France and England and he was arrested as a suspected spy when he returned. He was exiled to Mezieres-sur-Meuze and later to Reims where he continued to accept and fill commissions for instruments. He died in 1436. In addition to his instruments, Fusoris wrote a treatise on the astrolabe in which he detailed the improvements he incorporated into his instruments and other tracts on mathematics and astronomy.
Source: "Astrolabe by Jean Fusoris", http://astrolabes.org/pages/fusoris.htm, as of 01.04.2015
Dial: very good, worn, lacking elements, slightly worn