Just above Marie and Pierre Curie is this imposing machine: a double electrostatic generator based on the Van de Graaff model. Made by André Lazard, the device was installed at the Palais de la Découverte during the 1937 Universal Exhibition in Paris – the event where The Spirit of Electricity was inaugurated.

The electrostatic generator allows a demonstration of the Faraday cage principle: two volunteers are placed in the generator’s two spheres, each 3 metres in diameter and set on 14-metre-high pillars. An impressive 10,000-volt flash of lightning erupts between the two spheres – and the volunteers emerge perfectly unharmed.

This generator can still be found at the entrance to the Palais de la Découverte.