museum-of-artifacts:Spherical Astrolabe, Museum of the History of Science, 1480 - 1481. This astrola
museum-of-artifacts:Spherical Astrolabe, Museum of the History of Science, 1480 - 1481. This astrolabe is made of brass with the inscriptions, hour-lines, meridians and circles of altitude in silver; the rotating star map is made of brass, laminated with silver on the ecliptic and equatorial circles -- source link