Figure 78 is a reproduction of an engraving from an old source depicting an eighteenth-century experiment referred to as the electrical boy. The boy is suspended by silk ropes in a horizontal position with his shoes rubbing on a wheel that is being rotated by a person operating a crank mechanism. Next to the boy there is a girl standing on a tar covered barrel. The girl holds one of the boy's hands and positions her other hand over a plate of feathers. The feathers leap in the air as they are attracted to the girl's hand.