timekeeper

noun [专属名词]计时员；钟表；工作时间记录员

Once known, it spread rapidly, driving out water clocks but not solar dials, which were needed to check the new machines against the timekeeper of last resort.
一旦被人所知，它就迅速传播开来，替代了水钟，但却没有替代日晷，日晷被用来将新机器与原来的计时方法进行对照检查。