There isn’t a shortage of good pages to find out about this machine. Here is a page detailing restoration.
Here is a recent bloggingheads episode featuring a Wimshurst and a good explanation of how it works.
It’s a pretty low rent venture here, so you’ll have to click here for a simple diagram and here for photos. Apologies.
Does anyone know where I can get one at a good price?
See also: Electrostatic induction, Leyden Jars, Van De Graaff, Tesla Coil, Singing Tesla Coil
Addition: Here’s a good page for direct current electrostatic devices.
Addition: New bloggingheads this week has a Ruhmkorff coil and a De La Rive tube demonstration. Er…yes, Ruhmkorff and De La Rive.
Best explanation I’ve of how a Wimshurst works here.