Cyanometer

Do you know what the sky looks like sometimes? Sometimes it's really blue like a beautiful blue crayon. Other times it's not so blue, maybe it's more gray or white. A long time ago, people wanted to know how blue the sky was, so they made a special tool called a cyanometer.

The cyanometer is a small circle with different shades of blue on it. When they held it up to the sky, they could compare the color of the sky to the colors on the cyanometer and figure out what shade of blue it was.

People still use cyanometers today to measure the color of the sky. Scientists also use them to study things like air pollution and the atmosphere.

So, the cyanometer is like a tool that tells us how blue the sky is using different shades of blue colors.