Inspired by a museum show on electricity I viewed while on Christmas vacation, I set about to build a small Wimshurst machine. If you know me well, you will know that I like bigger and better and more dangerous, etc., so this small machine is only a prelude to the large machine I intend to build. I hope to achieve 2 to 3 inch sparks. Heh heh heh.
Anyhow, this machine works by using two counter-rotating discs to gather and transfer static electricity into a capacitor called a Leyden jar. Once the charge in the Leyden jar is high enough, the electricity bridges the spark gap with a loud SNAP and some really cool sparks. The sparks produced from this machine are very short but are about as bright as lightning. The machine is quite fun to use.
Watch the video to see it in action! Be warned, though, that the video does not truthfully depict the sparks. They look much better in real life.