Can a European compass be used in Australia?

Discussion in 'Weapons, Equipment & Rations' started by Mark The Convict, Aug 24, 2011.

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  1. Generally speaking, can a compass that's calibrated for use in the Northern Hemisphere be used with reasonable accuracy in Australia? A net search has yielded much varied and unhelpful opinion. Although fairly competent in nav (except for that one time), I know nothing about this, because we didn't need to know it, so it wasn't taught.

    I ask because I'm thinking of buying a Silva 54B, and object mightily to being gouged $250-$300 for a compass that's about 60 quid on Ebay UK. Obviously, I can't go to the Q Store and be told to '**** off, it's a starred item!', so I might as well be told to **** off here instead.:blowkiss:

    Am not keen on GPS, largely because of Murphy's Law, battery replacement, signal strength, potential for damage etc. etc.


  2. Wah.
    No the needle is thrown off by being repelled by any cans of piss weak Australian Lager in the vicinity.
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  3. Aren't hand compasses counterweighted for whichever hemisphere you happen to be in?

    Which means they won't work in the wrong one.

    Just found this
    So the answer is no your compass won't work properly.
  4. wedge_cadman

    wedge_cadman War Hero Reviewer Book Reviewer

    There are northern-hemisphere and southern-hemisphere compasses. The magnetic field lines to which a compass needle aligns point into the earth at the north and south magnetic poles. So in the northern hemisphere, the north end of the needle is pulled downwards and so the south end is counter-weighted to balance the needle.
    If you were to use a northern hemisphere compass in the southern hemisphere then the south end of the magnet is pulled downwards by the magnetic field and is also heavier, due to the counterweight, 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.

    Mostly nicked off the tinterweb
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  5. Compass Technical Information - Document #313 - EZ Facts Safety Info - Lab Safety Supply

  6. Thanks everyone. Travelgall, the beer-like fluid is used for needle damping, being unfit for human consumption (except for a few excellent beers that I'm not going to tell you about)
  7. I'm sorry but there's no difference in compasses for the Northern and Southern Hemispheres except a small weight on the needle that you're paying an extra $45AUD for the privelege. Otherwise ships would all have different compasses with the words North and South underneath them and captain Cook would have got lost shortly after passing Equatorial Guinea. What is different is the Magnetic Variation which is on your map which is used to adjust your compass. It could be argued that due to magnetic flux lines you could get a sticking needle due to the vertical dip, the solution to this is to hold the compass at an angle so it doesn't stick or buy a compass with an allowance for a fairly large vertical play in the needle.
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  8. And what would happen when ships crossed the Equator? There'd be carnage! Plus there's that water-swirling-down-the-plughole thing (Cooper's and Malt Shovel Brewery are quite good)
  9. I think as you cross the equator, you've just got to turn it upside down.
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  10. A ships compass is a somewhat different construction than a handheld silva.

    And what makes you think that Captain Cook et al had any idea where they were?
    Columbus and India springs to mind here :)
  11. And the French beat him anyway, depending on who you listen to.
  12. You'll fall off the bloody edge before you get there anyway. Turn back now!
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  13. It's turtles all the way down...
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  14. But in which direction do they swirl around the pan?