How did people tell the time before clocks were invented?
At first, the ancient people looked up at the sun and could tell it was the middle of the day when the sun was directly overhead in the sky. They also knew when it was morning or evening.
Later, the Egyptians used sticks. These sticks measured (测量) time during the day. The sun shone on the tall stick and the stick made a shadow (阴影). As the sun moved across the sky, the position (位置) of the shadow changed. This would let people tell what time it was.
Over time, the Chinese first used sundials instead of shadow sticks. The sundial has a type of shadow stick on it. As the sun shines on it, a shadow appears on the numbers. Each number stands for an hour of the day. But sundials don't work at night or on a cloudy day! There are no shadows unless the sun is out.
Water clocks used water to measure time at night. Water dripped (滴落) slowly from one bowl into another. The level of the water in the bowls showed the time.
People also used sandglasses. You may have seen one. Some games still use sandglasses. The sand falls from the top of the sandglasses to the bottom. It measures short amounts of the time. The more sand falls, the more time has passed. When the sand has finished falling, you have to turn the sandglasses over.
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