Steampunk Workshop has a great tutorial by Jake Von Slatt on building your very own Wimshurst Influence Machine!
Influence machines were an early type of Electrostatic Generator that operated by way of two vertically-mounted rotating discs (each rotating in a different direction), two crossbars with metallic combs, and a spark gap formed between two metal spheres.
As Von Slatt says:
These machines that create high voltage charges don't have the familiar coils of copper wire, permanent magnets, and commutators of conventional generators. They are made from brass, glass, and wood, and look more mechanical then electrical. But the coolest thing about electrostatic machines is that you can feel them working. As you begin to crank a Wimshurst machine you will hear it start to crackle and hiss with energy, you will smell the sharp scent of ozone produced and you'll feel the hair on your arm stand up as the Leyden jars charge.