The image to the right is a " Jacob's Ladder ", star of thousands of mad scientist labs in B movies.

High voltage arcs across the air gap at the bottom, much like a big spark plug. If your voltage generator can sustain the arc, the heat ionizes the air above it, creating a longer but less resistant path for the arc. The arc then seems to "climb" the wires, until it can't jump the gap and the process starts anew at the bottom.

Interesting effect, but you need HIGH voltages. Exactly why most of these professionally built ones are isolated in thick glass tubes.

But hey, thanks to the internet,Simon Jansen will show you how to make your very own bare, high voltage ladder for fun.

So, if playing with > 100000 volts sounds like your kind of fun, get building.

P.S. - I'm simply relaying info here, if you do get killed by this, the only thing your family will get from me is a nomination for this year's Darwin Awards.