How Does Roman Way of Reading a Sundial Work?

A Roman sundial tells time by using sunlight and a shadow, just like when you use your hands to tell what time it is in the playground.

Imagine you have a stick planted in the ground, like a flagpole. When the sun shines down on it, it casts a shadow on the ground. The shadow moves as the sun goes across the sky, like how your shadow gets longer when you walk away from the light.

The Romans made special tables with numbers and lines around their stick (called a gnomon) to show what time it was based on where the shadow fell. It’s like having a clock face that changes depending on where the sun is.

If you stand in one spot all day, your shadow moves from one side of you to the other, just like how the shadow on the sundial moves across its numbers. When the sun is high up, the shadow is short, and when it’s low, the shadow is long.

The Romans watched this movement and used their tables to know what hour it was, just like we use a clock today!