Nocturnal (instrument)

A nocturnal is a special kind of instrument that sailors used back in the olden days to help them find out where they were when they were sailing their ships at night.

Imagine that you're on a ship in the middle of the ocean and it's dark outside. If you wanted to know where you are and which direction you're going, you can't just look at a map like we do today. That's why they used the nocturnal.

The nocturnal has two parts. The first part is round and has a hole in the middle. This part is called the "calculator." The second part is a long stick that is connected to the calculator. This is a "gnomon."

To use the nocturnal, you have to look up at the sky and find a star. Then, you stick the nocturnal's gnomon straight up in the air and point it at the star. The calculator part of the nocturnal has some special markings on it that will tell you where other stars are in the sky, even if you can't see them.

By using the nocturnal to measure the angle between the star you can see and the angle of the sky, sailors back then could figure out their latitude, which is their position on the earth north to south. They used this information to help them chart their course and figure out where they needed to go.

The nocturnal was a very important tool back in the days of sailing ships, and it is just one example of how people can use tools to help them navigate through the world.