Resetting a magnetic Compass

AP said:
well -- sort of ... there is magnetic north, true north and grid north. Since most folks are using a map to navigate... you need to compensate for the difference between magnetic north and grid north (not true north - although maps will tell you the variation between grid and true north)... anyway the Silva 'Ranger' and it's derivatives gained their original popularity because you could mechanically (and quickly) adjust the compass to reflect the total 'declination' from mag North to grid North ...and forget about using a paper and pencil once you had it dialled in. Was very quick to use compared to the old prismatics - although not as absolutely accurate. As an aside - with the prismatics - for absolute accuracy - you also had to know - and adjust for - the individual compass imposed deviation from mag North.
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Fixed it.
 
FLHTCUI said:
Is that a compass for use in the Southern Hemisphere?
Rob
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Nope; one's to go hunting with and the other is to get you back home.:d Compasses that point north are fine if you want to go north.


I've never forgiven the southern hemisphere for having the noon day sun in the north sky. That throws my internal compass right out of whack.
 
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Technically all compasses are backwards, because the poles on magnets are named backwards. Back in the day they named the north pole of a magnet north because they noticed that the one side pointed north. Somewhat later when they discovered that whole opposites attract thing, there was an awkward pause before deciding that maybe nobody would notice that it must be the south pole of their compass that was pointing at the (magnetic) north pole.
 
I think this thread has reached a state of major confusion. Lets simplify it.
There are two magnetic fields on this planet, a north and a south. The compass needle is a little rod, magnetized to point at whichever of the two magnetic fields it is in the range of. You can make your own compass by magnetizing a sewing needle, pushing it through a small cork and letting it float on water. With no other magnetic interference the needle will point at whichever pole you magnetized it for. The same with a compass. The only way the direction can be changed is by re-magnetizing it in the other direction. The compass can not change direction by itself.
So put the thing in your pocket and go hunting with it.
 
geologist said:
The north end still points to the magnetic north pole with a southern hemisphere balanced compass.
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Yes, it is just the declination is all reversed...
Guess we will see how the Op does coming hunting season..
Then again , all those who wander may not be lost ;)
Carry a back up and know how to use it...directed to the new users of such hi teck equipment.
Rob
 
H4831 said:
I think this thread has reached a state of major confusion. Lets simplify it.
There are two magnetic fields on this planet, a north and a south. The compass needle is a little rod, magnetized to point at whichever of the two magnetic fields it is in the range of. You can make your own compass by magnetizing a sewing needle, pushing it through a small cork and letting it float on water. With no other magnetic interference the needle will point at whichever pole you magnetized it for. The same with a compass. The only way the direction can be changed is by re-magnetizing it in the other direction. The compass can not change direction by itself.
So put the thing in your pocket and go hunting with it.
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For accuracy sake the planet (Earth) actually has only one magnetic field. But it does have two magnetic poles.
 
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