A rainy Halloween's afternoon, while television shows only a derrick episode in original version and you have just received your bills, Be careful boredom and depression could come quickly…but well what can I do? empty the fridge? count bathroom's floor slabs? learn by heart the phone book just for fun? organize a Mikado tournament with my dog? So so… Ho no but I can make a compass instead! So I will finally know if my toilet door is exposed north, south… Since that time I asked to myself this important question, now it's time to find an answer!
1) Gear used
We need a sewing needle, a bowl or soup plate, a magnet, a small piece of thin cardboard, a battery of 4,5 volts like square batteries used for old torches, and if you have it in your surroundings a little enamelled copper wire(it can be found into an old radio set for example, it is a copper wire with an isolating varnish on).
2) How it goes
First the bowl is filled with water(with a less dense liquid like oil it works better but water is enough), then we take the needle and the magnet. We will then rub the needle with the magnet but always in the same direction(no go and back, we rub from the head to the bottom, from the head to the bottom…)for 5 minutes and then we put the needle on the cardboard, and cardboard on the water in the middle of the bowl. After a moment the needle will stop turning on itself and stabilize in the north/south axis(very efficient to chat up in nightclub).
By rubbing this needle from head to pic, the pic side of the needle indicates the south.
We can also magnetize the needle if it's wrapped with a varnish copper wire, then we connect 2 wire's ends with terminals battery(do not forget to sand the varnish at the wire's ends to make it work, if the battery heats after a short time then it works)but with a magnet it's more easy for the same result.
3) With a neodymium magnet
The most efficient thing is the use of a neodymium magnet instead of the needle. Very quickly he will move until the north/south axis.
The neodymium magnet is so powerful that you can even forget water's bowl, by maintaining it balanced on the thumbnail it will turn and come into the north / south axis alone(David Copperfield could be impressed!).
(Notice: If you apply this method and you can simultaneously see Polaris Star, you will be able to find the declination of your place without gps or compass, okay it's not very useful but at least it has kept you busy for the evening…)
Thank you for this article, I made in trying to do the same with a magnet recovered in a hard disk just for curiosity, I do not float but I do not know why moves?
So I do not really know, maybe the magnet in the disk is not powerful enough? In the small section is neodymium, basically it is better to let his fingers between two magnets like this… Otherwise it feels alright! Maybe for a compass with a recovered magnet in a computer less powerful or you must use a less dense liquid other than water…kind of oil for example, or ethanol? A less viscous liquid to facilitate movement of the magnet
From what I have read and experienced , magnets hard drives are also neodymium . Thank you
Ha ok I did not know, may be the shape of the magnet while its dimensions or?
Good in all ca!
north or south of the toilet door?
lol for once this is not spam for pumps, handbags and other pills “firming”! it faces west, it allows contemplation in a relaxed and serene sunset!