Improvised coke bottle compass

First you need to collect your materials you will be needing
1 About 2 meters of insulated wire
2 A 2 litre drink bottle
3 piece of mild steel wire or a nail

4 cotton thread is optional
5 small amount of water
5 power source her i use 4 d cell connected in series to provide 6 volts
A automotive starter battery is just as suitable
6 heat source

Heat up the end of wire in order to push it through the top
of plastic bottle cap a candle is satisfactory for this

you can see how i have pushed the wire through the top of the bottle cap

wind the 2 meter insulated wire around the mild steel wire or nail
because you are now going to need to magnetise it you can
also achieve this by rubbing with a permanent magnet if you have one
make sure to leave enough tail to connect to the power source

connect wires to power source for only 5 seconds
you have now created a small magnet which has north and south poles

connect the cotton thread to the middle of the wire or nail
it will need to be balanced while suspended and while floating in water

here you can see the bottle cap with the wire floating
inside the drink bottle the cotton thread is just taught enough
to prevent the needle from touching the sides of bottle
the cotton thread is connected to the neck of the bottle by
having a small stick across the neck i cut a hole in the side to
get the needle inside the bottle

the completed compass with a test compass