Hemisferium Miniature AstrolabeThe Astrolabe, considered as the mathematical jewel of the Medium Age, was to the end of 17th century, the most used instrument in the whole history of Astronomy. It is still occasionally used today because it allows us to understand celestial mechanics and the apparent movement of the stars in a clear and simply way. Astrolabe, from the Greek, star searcher, was introduced to Europe by the Arabs in the early 12th century. It became a vital tool for