> As I understand it, the compass needle is magnetized so that it will point to the large iron deposit in the earth, the magnetic north pole, which is near the earth's true north pole. <br><br>Close, except it's not a "large iron deposit" it's an elecromagnetic field generated by molten metallic materials in the earth's mantle (the molten layer beneath the crust), at least that's according to the latest scientific evidence. (Or at least, according to Time magazine :-0 ) As such, it moves around - on a daily basis, I understand, it moves in an ellipse about 60 miles across, and is currently (no pun intended) moving northward at the rate of about 10-15 miles per year. <br>(see http://www.geolab.nrcan.gc.ca/geomag/e_nmpole.html)<br>But the bottom line is, the earth is a giant magnet (or electromagnet) and the compass needle lines up with the lines of magnetic flux that the earth creates; hence the compass needles points north (or south).<br><br>I can actually outdo the original poster - I had a cheap dashboard-mounted compass that I bought for my car, and I was using it to demonstrate to a group of cadets how to find North. Well, all the other methods we were using said N was *that* way, and my dashboard compass said N was *this* way, 180 degrees out. I concluded that the thing was hooped and threw it out (it only cost a couple of bucks). Only later did I realize that the compass was designed to be read from the side, not the top. Thus, when you were facing N, the "N" would be facing you - i.e. the "N" pointed South, not North. <br><br>This may not make sense unless you buy one and see for yourself. But trust me - if the compass you're using is designed to be read from the side (as most small airplane compasses are), don't try reading it from the top, even if you can, because chances are you'll be 180 degrees out.<br><br>That mistake could result in a very bad day; I'm truly thankful that I figured it out while teaching cadets and not trying to navigate my way to safety after a plane crash.
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"The mind is not a vessel to be filled but a fire to be kindled."
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