[JJ_BPK]

Originally Posted by Longstreet

What has confused me is that it offers two geographical balancing zones so the compass can be used anywhere in the world. Has anyone heard of this before? I have always been under the impression that all compasses can be used anywhere in the world. Am I missing something or is this just a sales gimmic? And with that said, the 'original' Silva Ranger (which came highly recommended by several QP's) is it usable throughout the world or limited to a certain area? Please help. Thanks.

Here is a quick explaination:

http://www.williams.edu/Biology/Facu...g/compass.html

Assuming that the compass is held flat, the red end points to north, and the white end to south.

An interesting detail is that there are northern- and southern-hemisphere compasses.

This has to do with the fact that the magnetic field lines, to which a compass needle aligns, point into the earth at the north and south magnetic poles.

In the northern hemisphere the north end of the needle is pulled downwards, and the south end is counterweighted to balance the needle.

When you use a northern hemisphere compass in, say, Australia, the south end of the magnet is pulled downwards by the magnetic field, and is also heavier than the north end - resulting in a needle that catches and drags on the bottom of the compass housing when the compass is held horizontal.