The escapement mechanism in Chinese chronometer, a transition between clocks based on the first and second principle, is discussed as a technical preparation for the invention of machine clock.

• 指出中国天文钟上的擒纵机构为机械钟的发明提供了技术准备，天文钟是基于自然现象的时钟和基于机械结构的时钟之间的过渡。