In the West, 300 BC in ancient Greece the philosopher Aristotle in the mechanical problems, elaborate bronze or cast iron gear transmission rotation problems. Unearthed from ancient Greece gears la scholar Aristotle and Archimedes studied gear, Greece gudixibiaosi, famous inventor in circular plate evenly on the edge of the table top pin inserted, so that it pins gear, he applied to such institutions on the leak. This is about 150 BC. In 100 BC, and inventor Heron of Alexandria people invented the speedometer, odometer using gears. 1th century AD, Roman architects used also on the water wagon type milling machine of biduobisi made a gear. In 14th century, start using gears on the clock.