Benjamin Franklin is long-gone, but as a world-famous inventor, some of his theories are still at work in the palm of your hand. He greatly added to the world’s understanding of electricity in his own time, creating ideas that can be found today in smartphones and other devices.
Contrary to the oft-told and largely apocryphal tale of his amateurish discovery of electricity while being shocked by a bolt of lightning, Franklin, who lived before the creation of the word “scientist,” was a well-respected “natural philosopher,” as scholars of science were known at the time. Franklin accumulated honors from organizations on both sides of the Atlantic; he was world famous long before he became a renowned diplomat. And at home in the American colonies for more than a quarter century, he had made a name for himself as a publisher and as the ghostwriter for the Poor Richard’s Almanack.
For centuries before Franklin lived, students of the natural world suspected that lightning was a form of electricity, but it was Franklin who proposed a way to prove that hypothesis. What later evolved into the idea of using a kite began with a plan to attract lightning’s electricity from a tall church steeple.
Other experimenters followed Franklin’s road map to prove the electric nature of lightning even before he put his own ideas into practice. And when he did seek to prove his theory, he received only a tiny shock from his kite-flying adventure; however, a Swede, Georg Wilhelm Richmann, was killed in 1753 while trying to duplicate Franklin’s scenario without being grounded.
A new case exhibit, “The Electric Dr. Franklin,” newly on view at the Smithsonian’s National Museum of American History, breaks down the smartphone components that owe a debt to Franklin’s ingenuity. The display reveals the ongoing impact of the 18th-century inventor’s work and features a deconstructed smartphone, a radio capacitor and a broadcast microphone, as well as devices employed in Franklin’s era.
“We’re using the smartphone as a hook,” says curator Harold D. Wallace Jr., who says he hopes it will invite more visitors to engage with Franklin’s story. Wallace sees Franklin’s greatest contribution to the study of electricity in the inventor’s use of capacitors, devices used to store electricity. In Franklin’s time, Leyden jars served that purpose, and he played a key role in identifying how they worked, and why. Today, capacitors contribute to the functionality of smartphones in multiple ways. “They’re built into the computer chips,” says Wallace, and they often contribute to smartphone microphones as well. Leyden jars, including one on display in the museum’s showcase, are glass containers lined with foil to hold electrical charges. Franklin found that positive charges resided on one side of the glass, while negative charges could be found on the other side. From that realization, he understood that “with the idea of attraction and repulsion, you could get rotary motion,” Wallace says.
Franklin theorized that linking several jars could increase the size of the charge they could hold. He called these linked jars a “battery,” and became the first to use that term to describe an electrical device, although the first real battery as we know them today wasn’t invented until almost a decade after his death. When he was trying to figure out how Leyden jars work, Franklin realized that he didn’t need a jar: “You can stack some glass plates together and get the same capacitor effect,” says Wallace.
So, did Franklin fly a kite? Yes, he apparently did, although there is some question about that because he didn’t announce the event until months after the experiment reportedly occurred. What he announced was that he had verified that lightning represented a discharge of electricity; however, he merely verified the electrical charge. And he was not hit by lightning himself.
Given his many tests and theories about electricity, biographer Carl Van Doren concluded that Franklin “found electricity a curiosity and left it a science.”
Franklin also developed “the doctrine of points,” which concluded that electricity was attracted to pointed objects. This led him to the development of lightning rods to spare structures from being struck by lightning. The rooftop rods garnered popularity in both Europe and England’s colonies in North America.
Some objected that the lightning rod interfered with the will of God, but Franklin flatly rejected the assertion. Writing to botanist and New York politician Cadwalader Colden, he argued that “surely the Thunder of Heaven is no more supernatural than the Rain, Hail or Sunshine of Heaven, against the Inconveniencies of which we guard by Roofs and Shades without Scruple.”
The lightning rod was just one of Franklin’s many famous inventions, including the well-known Franklin Fireplaces, the first flexible urinary catheters and bifocal eyeglasses, although it has been claimed that others share credit for bifocals. He also is credited with the beginning of weather prediction because he speculated about how heat rising through the air in southern colonies spawned low pressure systems in northern states. He and Colden shared ideas about topics as diverse as blood’s circulation, perspiration, comets and many other scientific topics.
Franklin’s work was part of an international effort to untangle the threads of electrical theory. His frequent correspondent Peter Collinson took responsibility for publishing many of Franklin’s theories in Europe. Wallace believes that while the lag time in communications sometimes left Franklin in the dark about new discoveries, it may have helped his scientific study because it allowed him “to really play around with experiments and think things through without immediate criticism.”
Otherwise, Wallace points out, he might have moved on, concluding that his ideas were “not part of the accepted wisdom of the current theory.” At the time of his own kite test, for example, Franklin did not know that his theory had already been validated by scientists in Europe, so he went through with the experiment himself with the help of his son, William, in June 1752.
In 1751, Collinson published the first series of letters from Franklin in an 86-page booklet entitled Experiments and Observations on Electricity, Made at Philadelphia in America, by Mr. Benjamin Franklin, and Communicated in several Letters to Mr. P. Collinson, of London, F.R.S. In subsequent years, supplemental collections of letters were issued to be added to the original publication.
These works augmented Franklin’s reputation as an expert in the study of electricity and lifted Philadelphia’s Poor Richard into the panoply of experts in the study of the natural world. Franklin was celebrated internationally as one of the great minds in science and as a figure who stimulated an age of great discovery.
In 1753, both Yale and Harvard gave him honorary degrees, and London’s Royal Society awarded to him the Copley Medal, the world’s oldest scientific prize for achievement. He was the first recipient to live outside of Britain. Other winners of the medal have since included Charles Darwin, Albert Einstein and Stephen Hawking.
Franklin’s study of electricity decreased when he went to England in 1757 where until 1776, he represented the colonists’ interests at the Court of St. James. Working in France the following year, he established a wartime alliance with that country. (The National Museum of American History holds a three-piece silk suit Franklin wore in 1778 when he helped to negotiate the Treaty of Alliance with France during the revolution.) After the American Revolution, as a representative of the young United States, he negotiated a treaty with the British in 1783.
The admiration he received while traveling abroad in the second half of the 18th century shocked him. He was received by the French monarch Louis XV during his first tenure in England. By the early 1770s, when his book of theories was in its fourth edition, the Marquis de Condorcet, a top mathematician in France, wrote to Franklin: “To you it is given to enlighten human minds with the true principles of the electric science, to reassure them by your conductors against the terrors of thunder and to sweeten their senses with a most touching and suave music.” Franklin told his family, “My picture is everywhere, on the lids of snuff boxes, on rings, busts. The numbers sold are incredible. My portrait is a best seller, you have prints, and copies of prints and copies of copies spread everywhere.”
In 1799, nine years after Franklin’s death, Alessandro Volta of Italy created the first working battery in the modern sense. It was Volta’s invention. However, Wallace notes that conversations with Franklin helped to inspire and influence Volta.
“He stacked alternating disks of dissimilar metals between saltwater-soaked pads and generated a steady electrical current, and that’s the origin of the modern battery,” says Wallace. Then, the wave of change spread with the 19th-century work of Michael Faraday and Hans Christian Oersted, both of whom contributed to scientific understanding of electromagnetism, and Samuel Morse who was able to build the first useful, and battery-operated, telegraph.
As both a scientist and a statesman, Franklin was a game changer. The leading French economist of the era, Anne Robert Jacques Turgot would honor his many contributions, writing: “He snatched the lightning from the sky and the scepter from the tyrants.”
"The Electric Dr. Franklin" is on view on the second floor of the Smithsonian's National Museum of American History in Washington, D.C.