Making a Chinese compass
Early Chinese compass
On a sunny day, you can begin by making a sun compass. In the morning, find a stick and stick it in the ground pointing up. Place a stone at the end of the shadow it casts. Come back in the afternoon (after you're done making the needle compass) and place another stone at the end of the new shadow. Put your right foot on the first stone, and your left foot on the second stone. Now you are facing south (reverse this if you are in the southern hemisphere). Behind you is north. Your left hand is pointing east, and your right hand is pointing west.
But suppose you wanted to carry the compass around with you? That's what people in China figured out how to do.
What you'll need: a source of heat (a fire, or a cookstove, or a Bunsen burner), a needle, anything that floats, and a small container of water (like a yogurt container) big enough at the top for the float to spin around freely. And you need to know which way is north.
Or, if you don't want to bother with heat, you can use any magnet to magnetize the needle, like a refrigerator magnet. Just hold the needle by one end and rub the other end along the magnet about 60 times. Be sure to always go the same direction, not back and forth! That should also magnetize the needle. One end will point north.
A model of a Chinese compass
by kids at Laurelhurst School, Portland
If that's north, which way is east? West? South? Can you use the Internet to find out why iron works to make compasses but not copper? If you try it with copper wire, does it work?
Would the world seem different to you if you pointed your compass south instead of north? Try looking at a world map upside-down.
What are compasses good for? What can you do if you have a compass that you couldn't do before?
Can you use these compasses to make a treasure map where you have to go this far north, this far east (or whatever) to find the treasure? Can the other children use your map to find the treasure?