กก The stone sundial, an ancient "clock" donated by the Class of 1920, stands at the southern end of Tsinghua's grassy quadrangle. At the base of the sundial is an inscription in Chinese that translates into: "Action speaks louder than words." The Latin version of this famous phrase is beneath the Chinese characters, together with the date the sundial was erected.

กก People in ancient China used sundials as a simple way to count the hours on sunny days, with time indicated by the location of the shadow of the dial on the face of the "clock." For example, when the sun is due south, the shadow falls due north - at the hour of 12 (noon).