An illustration of the structure and appearance of a waterspout, from an article on 'Waterspouts and Whirlwinds' by Benjamin Franklin (1706-1790). A waterspout is a meteorological phenomenon similar to a tornado, that forms over water. It is a rapidly rotating vortex of intense low presure, extending from the base of a cloud to the surface of the water. The spout does not actually consist of water sucked up from the surface, but is in fact water vapour condensing in the core of the vortex. Franklin, one of the Founding Fathers of the US Constitution, pursued interests in many areas of the sciences. In meteorology he is probably best remembered for his invention of the lightning conductor.
© Science Museum / Science & Society Picture Library