Before the compass was invented, life could be very tricky. Not only did people have to do without a reliable direction indicator, but they also had to do without street lights, torches, road maps and satellite navigation. This must have meant a lot of dark nights lost in the woods.
First Star on the Right. A compass uses a magnetized needle that aligns itself with the magnetic north of the Earth. It sounds simple, but people had to find their way without it for thousands of years.
Around 200 BC, the Chinese used a magnetic metal pointer like a compass, but not for navigation: it was for working out lucky days for special events.
But we do have the Chinese to thank for the earliest compass (well, probably): an early form of compass was used in China during the 11th century. It was a magnetic needle floating in a bowl of water.
The more familiar form of a compass, a needle inside a box, appeared in Europe at the end of the 1200s. No one knows who invented it, or whether it came from a Chinese idea or was developed independently in Europe.
When it was clear, people used the stars to guide them at night. But of course lots of places tend to be a bit cloudy for at least some of the year. So the compass made getting about a lot easier. It also meant that people could explore new lands and have a much greater chance of getting home again. It’s an invention we’d be lost without.
MAKE YOUR OWN COMPASS
Imagine being lost in the woods without any idea of how to get out. What you need is a compass – but what if you don’t have one? Here is a simple way to make your own compass with the help of a few things you can find in your rucksack.
The most important part of any compass is the needle. Every compass needle points north due to forces of magnetism caused by the Earth’s molten iron core near the North Pole. Anyone know which way north is?
WHAT YOU NEED
a needle, a magnet, a cork, a bowl of water. Ff you don’t have any of these, you could try these alternative items:
Alternative needle: a paper clip or nail
Alternative magnet: silk or hair
Alternative cork: a plastic bottle top
Alternative bowl of water: a puddle
The first thing you need to do is turn your needle (or piece of metal) into a magnet. The easiest way to do this is by using a magnet. Stroke the magnet down the length of the needle about 30 times to make the needle magnetic.
If you have no magnet, you can stroke the needle in one direction down your hair or a piece of silk or synthetic material, but you’ll have to stroke it about 100 times to magnetize it.
Stick the needle through a small piece of cork and place the cork in the center of the bowl of water, away from the sides.
You now have a very simple compass. Keep the water as still as possible and your compass in the center of the water. You should find that your compass, if properly magnetized, will turn to the north/south position, depending which pole is closer Now you can escape from the woods!
Poles apart: The magnetic North Pole that compasses point to and geographical North Pole are very nearly the same but not quite – it’s still good enough for most purposes, though. It’s a very handy coincidence that they happen to be so close.