What is "keraunography"

Keraunograph \Ke*rau"no*graph\, n. [Gr. ? thunderbolt + graph.] A figure or picture impressed by lightning upon the human body or elsewhere. -- Ker`au*nog"ra*phy, n.

Keraunography or keranography refers to the belief that lightning, when striking an object (generally a human body), can leave behind markings which constitute a photographic image of surrounding objects. At present, it is generally believed to be a myth.