Benjamin Franklin, however, walked the Earth as a polymath in an era of polymaths, a self-made printing magnate who spent his spare time inventing and making scientific discoveries long before entering the world political scene.
In between creating bifocals and urinary catheters, Franklin ruminated about the size of the atom, tracked hurricanes, and studied climate change. Tying into the latter, Franklin theorized that dust, gas, and rock thrown into the air from a volcanic eruption could play a role in changing the climate thousands of miles a way by blocking the amount of sunlight that reaches the surface of the earth. Franklin made this connection on a jaunt to Paris in 1784 that followed a series of eruptions at Lakagígar, a volcanic fissure in Iceland.
Full size The fluid theory of electricity While Franklin's fateful date with a kite and key is debated, Benjamin Franklin is the first person to correctly suggest the positive and negative nature of electrical charge. In Franklin's Fluid Theory of Electricity, he posited that electricity acted as a fluid moving through the planet. The theory called for "electrical fluid" to move through the ether as a single substance and not two completely different fluids per the contemporary belief of the time.
Franklin's mid-18th Century theory called for a neutral equilibrium of electrical fluid, with electricity flowing from an area of electrical excess to areas lacking the electrical "fluid". Franklin deemed the areas of excess "positive" - a flipped viewpoint from our current scientific understanding wherein electron rich areas likely hold an overall negative charge or dipole.