The astronomer Guo Shoujing helped restore the Beijing Ancient Observatory beginning in 1276, where he crafted a water-powered armillary sphere and clock with clock jacks being fully implemented and sounding the hours.
O astrónomo Guo Shoujing axudou a restaurar o antigo observatorio de Pequín en 1276, onde se deseñou unha esfera armilar con funcionamento hidráulico con tomas de reloxo aplicadas plenamente e facendo soar as horas.