A self-sufficient electrostatic induction machine. It was used to achieve high uninterrupted voltages through opposite charge polarization. The two disks are rotated using a crank handle so that friction is produced via two diametric, perpendicular rods. This movement generates two charges of equal intensity, one positive and one negative. These charges are collected by combs and stored in two Leyden jars placed at either side of the disks. Wimshurst machines were the most common kind of power generator found in physics cabinets in the late 19th century. They were popular despite not being the most efficient machine, as the manual mechanism meant it was hard to achieve a steady movement and a stable voltage. They were also very sensitive to changes in temperature and humidity. They were used as a teaching resource to study physics, and this piece is from the Doña Godina Teachers and Resources Center for a school in Zaragoza (Centro de Profesores y Recursos de La Almunia de Doña Godina).