Water clocks measured time by letting water drip steadily from one vessel to another.

The longer version

A vessel with a small hole drains at a rate set by the water pressure above it, so the level in a second vessel shows how much time has passed. Makers shaped the container or adjusted the hole to keep the flow even, since pressure falls as the vessel empties.

These devices worked at night and indoors, where a sundial is useless, and they were used to time speeches, court sessions and night watches. Cold, evaporation and dirt in the water all changed the rate, so someone had to refill and check them, and they were never very accurate.

Where this entry sits

This set looks at ancient civilizations, old inventions, trade routes, calendars, and the ordinary objects people once used every day. Nothing here is advice or opinion, just short notes about how daily life used to be organised long ago. The full list sits on the History page, where every entry is listed in order.