How Do I Make A Compass?

[inkleberry]

I have a bowl of water, a magnet, and a needle. How can I make a compass out of these objects? I tried the “leave eye of needle on magnet for a few minutes, rub on nose, float on water” method, but the needle just kinda floated aimlessly and then sank. Where did I go wrong? I am compass ignorant. Please help correct this.

[Captain_Amazing]

First, stroke the needle with the magnet, starting with the head, and down to the point. Do this repeatedly, for for about a minute. It’s not enough just to rest the head on the magnet.

Now you’ve got a magnitized needle. Your next job is to make sure it won’t sink. So attach it to a piece of cork or styrofoam. Then put the styrofoam supported needle in the bowl of water.

[inkleberry]

@Captain Amazing

First, stroke the needle with the magnet, starting with the head, and down to the point. Do this repeatedly, for for about a minute. It’s not enough just to rest the head on the magnet.

Now you’ve got a magnitized needle. Your next job is to make sure it won’t sink. So attach it to a piece of cork or styrofoam. Then put the styrofoam supported needle in the bowl of water.

can I just pierce the foam with magnetized needle?

[mittu]

IIRC I have seen people make compasses by piercing a cork (from a bottle of wine) so the needle was exposed at both ends, or simply by balancing the needle on a flat leaf.

[Q.E.D]

@inkleberry

can I just pierce the foam with magnetized needle?

Yes. Also, you can add a small amount of alcohol (doesn’t matter what kind) to the water, to break the surface tension and reduce friction so the needle moves more easily. Incidentally, if you want to guarantee that the point of the needle points to magnetic North, then determine which of the larger magnet’s poles is South, and stroke the needle with that end as outline above by Captain Amazing

[Stan_Doubt]

And when you’re ready to try it out, make sure to keep a good distance from any electric motors, computers, etc. that might screw it up.

[Elvez]

I remember something about being able to use silk instead of the magnet.

…so I checked google and found this really fun link: http://tinyurl.com/5k2vd

[inkleberry]

@Stan Doubt

And when you’re ready to try it out, make sure to keep a good distance from any electric motors, computers, etc. that might screw it up.

:smack: :smack: :smack: :smack:

Sigh

Oh, nevermind. Took it across the room, worked a charm.

[SavageNarce]

…and if you have really, really steady hands (and maybe a bit of patience) you can float the needle right on the surface of the water; it will be held up by the surface tension alone.

I am assuming we are talking a sewing needle here, and not a knitting needle…

[Q.E.D]

@SavageNarce

…and if you have really, really steady hands (and maybe a bit of patience) you can float the needle right on the surface of the water; it will be held up by the surface tension alone.

A dinner fork helps tremendously here. Lay the needle across the tines, and put the fork in the water until the surface just touches the needle. Then, very slowly let the fork sink under the needle. With patience and a bit of luck, the needle will be left floating.

[Xema]

You could try treating the needle with some of that goop that fly fishermen use on their dry flies - should make it float a bit better.