How do the compasses work on the equator?

north of the Equator. A magnetic compass with a freely spinning needle in the Northern Hemisphere. (Photo: Chris King). The same Northern Hemisphere magnetic compass photographed in the Southern hemisphere (Brisbane, Australia). (Photo: Chris King). The second photograph shows the white end of the compass needle jammed down against the base of the compass, so that the needle can’t rotate freely and it doesn’t work. read more

Because the compass needle will follow the lines of force, and these lines dip into the earth, compasses designed for use in the N hemisphere will have a small counter balancing weight to bring the needle to level. read more

When a compass is in the northern hemisphere, the north end of the needle is pulled down towards the Earth, so the south end must be counterweighted to balance it. If a northern-hemisphere compass is used south of the equator, the south end of the needle is pulled down instead. read more