Benjamin Franklin's Fluid Theory of Electricity

Benjamin Franklin is best known as a Founding Father of the United States, with historians often referring to the Boston-born Franklin as the First American.

Franklin lived in era where men and women wore many hats, with a lucky few spending their free time uncovering the mysteries of life and nature. Amidst time spent as a publisher, politician, and inventor, Franklin constructed one of the early theories interpreting the behavior of electricity, with parts of his theory informing our modern view of electricity.

Top image via snowpeak/Flickr.

Benjamin Franklin's Fluid Theory of Electricity

The polymath hobbyist
My view of Ben Franklin is often informed solely by HBO's John Adams series - the annoying guy living it up in France most of the time, wearing a fur hat and wooing old ladies.

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.

Benjamin Franklin's Fluid Theory of Electricity

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 a negative dipole.

The previous theory of Franklin's day called for two competing fluids, one vitreous and one resinous, that flowed through the air. Franklin also suggested that deposits of excess electrical fluid repelled each other, in line with the positive-positive repulsion of charges. While the idea of a fluid may sound unusual, it is a quite good approximation for the time, as Faraday's electric field theory would not surface for decades.

Benjamin Franklin's Fluid Theory of Electricity

Lightning rods
Benjamin Franklin championed the use of lightning rods in cities to divert strikes and decrease fires. Franklin kept a lightning rod on the top of his house, but for a completely different reason. The Founding Father used the rod to perform to draw lighting to his house for the purpose of experimental observation, with a series of bells connected to a grounding wire signalling a successful strike.

During 1816, a year marked with a bizarrely cold summer and snow falling in July, quizzical citizens used Franklin's own Fluid Theory to blame the deceased founding father for the change in climate. Individuals linked the unusual climate to Franklin's curious experiments with lightning decades prior, particularly those using a metal rod to divert lightning.

Citizen scientists of the day suggested the influx of lightning rods placed near houses and businesses at the behest of Franklin forever changed this flow and damned humanity to a reversal of the season. Apparently, one can invent, make scientific discoveries, and help draft the Declaration of Independence, but one can't prevent people from heaping world-ending blame on their shoulders decades after death.

The portrait of Benjamin Franklin by David Martin is within the public domain and on display at the White House. Carbonic alloy engraving of Benjamin Franklin is also in the public domain, drawn by C. N. Cochin and engraved by A.H. Richie. Lightning rod image via m.gifford/Flickr. Sources linked within the article.