Well, maybe the captain of the ship has been to this port many times and already knows the way!

But, more likely, even if the captain has been there before, he or she will use maps to help set a course for the ship and make sure it arrives safely at the right place.

Your parents probably use maps when they drive somewhere new. Maybe you used a map on your summer vacation. (Or maybe you didn't and got lost instead!) And maybe you have used maps to find your way around your school or to follow a hiking or biking trail.

You will probably not be surprised to learn that people have been creating maps for thousands of years.

They often drew maps on whatever material was available. Some old maps were carved onto clay tablets. Others were included in weavings. Some were painted on silk or other fabric. And, of course, many were drawn or painted on paper.

Maps made long ago covered only the places the cartographers, or map-makers, knew. A map would have a lot of detail about the lands and seas and rivers near the cartographer's home. But it might just have blank space - or even crazy, mistaken ideas - instead of the places farther away.

In fact, on some maps created hundreds of years ago, cartographers wrote the phrase, "Here there be dragons," to mark the end of the safe places they knew about. That phrase was a kind of warning to sailors or explorers who traveled farther than the world that was known at that time.

Of course, people have always wanted to explore. And therefore the known world that we include on our maps has grown and grown over the centuries.

Maps today are different in some ways from the maps of long ago. The Global Positioning System (a space-based system that includes 24 satellites circling the earth) lets cartographers map just about every inch of the Earth's surface. The GPS satellites give cartographers up-to-date information about changes on the Earth's surface due to floods or earthquakes or other events. And then cartographers can use their computers to quickly change their maps to reflect the new conditions.

Maps today don't usually say, "Here there be dragons" on them. But even though they are different from maps of long ago, they serve the same purpose: to help people find their way from place to place.

Would you like to try to be a cartographer? Work with your teacher to create a map of your classroom. You can do this with pencil and paper, or, if you have access to a computer and a drawing program, you can create a computerized map.

Here is more information about reading and making maps.

Check out past Trade Topics entries!