Giovanni Dondi dell'Orologio (c. 1330 – 1388), also known as Giovanni de' Dondi, was an Italian physician, astronomer and mechanical engineer in Padua, now in Italy. He is remembered today as a pioneer in the art of clock design and construction. The Astrarium, which he designed and built over a period of 16 years, was a highly complex astronomical clock and planetarium, constructed only 60 or so years after the very first all-mechanical clocks had been built in Europe, and demonstrated an ambitious attempt to describe and model the planetary system with mathematical precision and technological sophistication. Source: Wikipedia (en)