Benjamin Franklin is famous for his experiment with a key and a kite — but that's not his only lightning innovation. The famous inventor loved lightning so much, he actually invented a kind of alarm system to let him know when a thunderstorm was about to kick off.

And you can make one, too! Find out how to make a set of Franklin's Bells.

The alarm that Franklin made was fairly simple. He first set up three known insulators as a stand for the whole contraption. Then, from the far right insulator he hung a metal bell. The bell connected to a wire, that went up to a lightning rod on the roof. On the far left stand he hung another bell. This one was electrically collected to the ground. On the stand in between he hung a small metal ball, that could swing like a pendulum between the bells.

When a lightning storm approached, and a lot of charge was whipped up in the air, it would dump a surplus of electrons into the bell connected to the lightning rod. Electrons repel other electrons, so the electrons in the bell repelled the electrons in the center ball. The electrons in the ball moved to the far left to get away from the negative charge to their right. Heading to the left turned out to be a self-defeating move on the part of the electrons, because it left a lot of protons exposed on the right side of the ball. Protons and electrons attract, and so the entire ball flew over and knocked against the bell. As soon as the bell and the ball made contact, many of the extra electrons in the bell jumped over to the ball and the charges equalized. The ball dropped back to its original position. The ball's extra electrons were now irresistibly attracted to the grounded bell, and the ball zoomed over, ringing again. The electrons in the ball jumped into the bell, and from there into the ground.

The same set up can be done in any modern day house — but if you want to see a ball dance without having to install a lightning rod, there is a simpler way. Grab two empty soda cans, a couple of electric leads, a plastic pen, a string, and some aluminum foil. Suspend the pen between the two cans. Tie the string to it, and dangle a ball of foil between the cans. Connect one lead to a can and ground it. Connect the other lead to the other can and attach the other end to some foil that you've put over the screen of your tv. As you've noticed, tv screens build up a lot of static. The foil will collect it, the can will accumulate it, and the ball of foil will zoom between the two cans. They'll ring out as long as the TV is on. Just as a safety tip — do not touch the set-up until you've turned off the tv again.


If you find you like the sound, but would like it more if it rang out at random times and brought electricity into your home, feel free to set up a more official set of bells.

Image: Fir0002/Flagstaffotos

Via Arcs and Sparks and RM Cybernetics.