Like the original instrument, the replica bears the signature: "Georgivs Hartman Noremberge faciebat anno MDXXXI" (Georg Hartmann from Nuremberg made (it) in 1531). Georg Hartmann von Eggolsheim (1489 - 1564) worked as a skilled and famous instrument maker in Nuremberg and made sundials, astrolabes, armillary spheres, globes and other instruments.
Between 1525 and 1548, Hartmann built at least 22 astrolabes, as can be concluded from the surviving specimens. His instruments have diameters between 130 and 160 mm. Hartmann's astrolabes have a special style: Early instruments still have some numbers in fracture (4, 5, 7). Typical is the Hartmann rete with stepped east-west stripe and the arches bearing 25 bird's head-like star points (on the original instruments 27 star positions).
On the back there is often a double-headed eagle, as on this replica. On the outside, the back shows the scale with 4 x 90°, ecliptic, the calendar circle (0° Aries = 11 March), the shadow square, and the unequal hours diagram.
Hartmann's astrolabes usually have 3 inlay plates for the geogr. latitudes 39°, 42°, 45°, 48°, 51° and 54°. Our replica contains 2 plates for the latitudes 30°, 40°, 50° and 60°, each with 3° altitude circles (almucantarats), 10° azimuth lines, unequal hours (temporal hours), astrological house boundaries and twilight line (- 18°). The almucantarats 15°, 30°, 45°, 60° and 75° are highlighted.
The complete description of the instrument as PDF for download
