To generate high electrostatic potentials.
Cranking the handle rotates the two plates in opposite directions, generating a large electrostatic potential. The Leyden jars can be charged to increase the intensity of the spark between the two balls on the arms mounted above the Leyden jars. This machine can also be used for other demonstrations requiring high potentials. This gizmo may go up as high as 500,000 volts.
Markus Zahn, Richard L. Goslin, Larry F. Wicks, Self-Excited, Alternating, High-Voltage Generation Using a Modified◙Electrostatic Influence Machine, AJP 42, 289-294, (1974). ◙Hobart Mason, A text-book on Static Electricitiy, McGraw Publishing Co., 14-23, 120-135, New York, (1904). ◙Instructions: Wimshurst Static Machine, Stansi Scientific. ◙Catalog Description, 78780 Static Machine, Wimshurst, Cenco Scientific Co.