A huge copper bell is hanging at the top of Beijing Bell Tower called "the King of Ancient Bells". The sound it makes is bright, mellow and powerful, which can be heard from a long distance away. How was it cast? It is said that a long time ago, there was an iron bell in the tower, but it was not resonant enough. So the emperor called all the artisans together and ordered them to cast another magnificent bell. However, three years past and the artisans still hadn’t finished it. The emperor was so annoyed that he beheaded the supervising eunuch and ordered the artisans to finish the bell within 80 days, or they would all be beheaded.