Nautical Astrolabe Key Ring

The nautical astrolabe, a simplification of the planispheric astrolabe, was one of the greatest innovations from the Age of Discoveries. It allowed sailors to measure the altitude of the celestial objects to determine the ship´s location.

In the beginning it looked like the back of the planispheric astrolabe, but with the sailor´s experience it acquired a new form. It ceased to be made of a metal sheet or wood and began to be fused in copper alloy, so that it is heavier and more adapted for the motion of the ship.