Ancient tech: Rolling lantern

The rolling lantern is a unique device used in Chinese folk dances from areas along the Qiantang River, Zhejiang Province. On the outside, the spherical lantern is made from bamboo ribs covered with paper. However, the true tech lies inside: A candle on a platform is suspended by string in a way that, much like a gyroscope, remains upright no matter how the outer sphere spins. This enables dancers to jump, twist and run with the lantern - even roll it on the ground - without its candle going out!