11. However, the most common type of public and palace timekeeping device was the inflow clepsydra . 12. Unlike the clepsydra , the motion of the ship while sailing did not affect the hourglass. 13. Today, in Beijing's Drum Tower an outflow clepsydra is operational and displayed for tourists. 14. A water clock, also known as a clepsydra , uses a flow of water to measure time. 15. They introduced several types of the inflow clepsydra , one of which included the earliest feedback control system. 16. Before very long, however, Gaffney is exposed as the murderer of Clepsydra when attempting to interrogate Dreyfus. 17. Water clocks or clepsydra measure a gain or loss of water by using drops of uniform size and frequency. 18. The explanation of a " clepsydra " or water clock was a popular topic in the Middle Ages. 19. This was used alongside a clepsydra clock and waterwheel to power a rotating armillary sphere in representation of astronomical observation. 20. In both Greek and Roman times, this type of clepsydra was used in courts for allocating periods of time to speakers.
