A. Sundial
B. Water Clock
C. Hourglass
D. Pendulum Clock
Answer: Water Clock
A. Sundial
B. Water Clock
C. Hourglass
D. Pendulum Clock
Answer: Water Clock
Additional Information: The ancient Egyptians used water clocks (clepsydras) to measure time by the flow of water.
Subjects: Inventions and Discoveries, General Knowledge