Passage:
While both the gnomon-based sundial and the clepsydra, or water clock, were essential timekeeping devices in the ancient Mediterranean, they operated under entirely different physical constraints. The sundial, which measured the position of the sun to cast a shadow across calibrated lines, was highly dependent on clear skies and daylight, rendering it useless at night or during overcast conditions. In contrast, the clepsydra measured time through the regulated flow of water from one vessel to another. This mechanism allowed the clepsydra to function continuously regardless of weather or the hour of the day. However, whereas the sundial required no mechanical maintenance beyond initial calibration, the clepsydra demanded constant supervision to prevent sediment from clogging the narrow drainage aperture and altering the flow rate.
According to the passage, how does the maintenance required for a sundial compare to that required for a clepsydra?
- AThe sundial needs frequent adjustments to track the sun during overcast weather, whereas the clepsydra remains functional without any ongoing maintenance.
- BThe sundial operates continuously without any calibration, whereas the clepsydra must be manually refilled with water every hour.
- The sundial requires no mechanical upkeep after its initial calibration, whereas the clepsydra requires regular monitoring to prevent blockages.Answer
- DThe sundial requires constant supervision to clear debris from its face, whereas the clepsydra requires only initial setup to function.