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Mercurymotor 485
Here’s a simple motor you can make, if you happen to have a large quantity of mercury laying around, which you probably don’t have, so check out how it works from our pals at Popular Science – “Mercury used to be lots of fun–before we knew that it could kill you. In this simple electric motor, current running through the wire into 60 pounds of mer­cury causes the wire to revolve around a magnet…”Link.


  • HOW TO – Make the simplest electric motor – Link.
  • HOW TO – Make a simple electric motor – Link.
  • HOW TO – Simple DC Motor Controller – Link.

Phillip Torrone

Editor at large – Make magazine. Creative director – Adafruit Industries, contributing editor – Popular Science. Previously: Founded – Hack-a-Day, how-to editor – Engadget, Director of product development – Fallon Worldwide, Technology Director – Braincraft.



  1. robertadams1 says:

    A friend and I built something similar when were were living in London. Since we couldn’t find any mercury in our flat, we just used salt water, and we got the motor to work pretty well, using a 12V 1A wall-wart power supply. It ran, albeit slowly.

  2. Lenore says:

    This is very similar to our magnetohydrodynamic demonstration. The main difference is that the wire is held still, so it is the salt-water that moves.

    I wish I had 60 lbs of mercury to play with.

  3. rdarlington says:

    This is extremely similar to the first electric motor. This was a nearly identical setup, however the wire was fixed. A steel plug/cyllinder floated on the mercury and revolved around the wire instead.

  4. the_steven says:

    I wonder if home made ferofluid could take the place of mercury?

  5. JohnKit says:

    I used to have about a pound of mercury (don’t ask), I built one of these and was quite impressed at how well it worked. It was fun stuff, let’s hear it for the use of heavy metals in mining!

  6. dansdata says:

    Theodore Gray rocks.

    You could make the motor work with quite a small puddle of mercury – the amount you can harvest from the average old blood pressure meter would probably do for a small demonstration unit.

    Do the experiment outside to avoid excessive fume inhalation and/or tiresome cleanups.

    (The salt-water idea’s a neat one too, though!)

  7. ehrichweiss says:

    I was just thinking that salt water should work since the mercury is only used as a conductor in this instance(or so it seems anyway). Maybe I’ll give this a shot.

  8. supertim says:

    According to an episode of NOVA I recently saw, this is how Michael Faraday confirmed experimentally that electricity and magnetism were coupled.

  9. Triggur says:



    Mercury is just so amazingly toxic even in small quantities that I won’t have anything to do with the stuff.

    I saw a mercury fountain in the Miró museum in Barcelona. Think water fountain– except mercury shooting all over. Fortunately it was enclosed in a sealed glass chamber.