Unusually Big Sparks With A Ridiculously Simple Electrophorus
    Hopefully you have seen the web pages at the Exploratorium or The University of Rochester  about the electrophorus. There is a lot in print about this device as well. My earliest experiences with an electrophorus used a disposable pie pan and a foam plate. I was pleased with the consistency of  sparks, but they were always very small. After a little research, I decided to give the electrophorus another try. To my surprise, I found I could get big, visible sparks from a device that is both easy to make and takes up very little space. 

If you want to do this here's what you'll need:

    A feature of the standard electrophorus is an insulating handle on the metal part. We will skip that step for now. The pan will do do nicely as it is.
    Start by finding a flat surface that is grounded. Lay down your plastic sheet and charge it up by rubbing it with fur, or wool, or whatever works best. You should notice signs of electricity, like hearing sparks, as you rub.
    Next, pick up the cookie sheet and hold it 4 or 5 inches above the plastic sheet. Drop it. Now, If you draw your finger near the pan's edge, you will get a spark. Using a rounded metal object for this is less painful (don't use a pointed metal object, the rounder, the better).
    You have only just begun. Pick up the pan again and drop it the same way. You can now take another spark off of it. The kinetic energy of picking up the pan is transformed partly into electrical energy. You can do this over and over again.
    Here's where I tell you how to make an inch long spark, instead of 1/8 inch sparks: Start over and charge the plastic by rubbing it. Drop the pan on it as before. Now, carefully  pick up the ENTIRE apparatus, keeping your fingers as far from the edges of the pan as you can. While holding it up in the air, discharge the pan by bringing a rounded metal object near its edge . This method produces amazingly long sparks, considering how simple it is.
    The sheet of plastic must be larger than the pan. This is so you can pick it up and still keep your fingers some distance from the edge of the pan. It also has to be somewhat rigid, so it stays flat when you pick it up. The sheet also needs to be "chargeable." Before you go in search of a new sheet of plastic make sure that you have tried charging it with a variety of materials. I was lamenting over a sheet of Plexiglas that I couldn't charge by rubbing, but found it will charge with a rubber roller.
    I've also found that it's important not to dawdle between picking up the electrophorus and taking the spark off it. The longer you wait the smaller the spark will be (usually).

    The sparks you get from an electrophorus may not always be as bright and loud as those you get off a charged Leyden jar, but they can be long, indicating very high voltage. If you want more visible (and audible) sparks you can use this device to charge a Leyden jar. Here's how: Instead of taking the spark off with your finger or a round metal object, take it off with the terminal ball on a Leyden jar. Repeat that a dozen times or so, then discharge the jar. Yowza!

    So, does anyone know the plural of "electrophorus"?

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P.S.- If you use this page to do an experiment, science fair, or other project, send me an e-mail and tell me how it went. I need feedback to be sure I've included all the information needed to make an impressive spark!