Ancient Impossible

"Ancient Einsteins" [1.04]:
His [Ctesibius's] goal was to invent for the first time something that would accurately tell the time.  Sundials were useless at night or when it was cloudy.  And for the Greeks, it was most important to measure time inside, especially in the law courts.  Justice depended on giving lawyers equal amounts of time. 27 July 2014, 10:07 P.M. Eastern Daylight Time