Front view of a Wimshurst machine, a mechanical device used to generate static electricity, photographed in operation. Electrostatic charges are induced on the perimeter of 2 parallel, circular plates (appearing like windmill blades) which rotate in opposite directions when turned by a handle at bottom. Charges are collected by a system of pointed combs & stored in the tubular sections: when sufficient charge has built-up, static discharge occurs across the small metallic spheres (top) in the form of a blue spark.