You will need this for the compass-making exercises that follow.
Making a magnet.
Sewing pins and needles are often made of iron, which can be
magnetised, but some of them are made of brass. You need a strong bar magnet to
magnetise a pin, and it will help you choose suitable pins, or needles. Just
dip the magnet in the pin dish, and use some of the ones that stick to the
magnet.
All you need do is
to stroke a pin or needle about 20 times, always using the same end of the
magnet, and always going in the same direction. Why does this work? The
official answer is magnetic domains:
look this phrase up.
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