Benjamin Franklin’s Science
Bolt of Fate: Benjamin Franklin and His Electric Kite Hoax. Tom Tucker. xx + 297 pp. Public Affairs Press, 2003. $25.
An Entertainment for Angels: Electricity in the Enlightenment. Patricia Fara. vi + 177 pp. Columbia University Press; first published in the United Kingdom by Icon Books in 2002. $19.50.
Draw the Lightning Down: Benjamin Franklin and Electrical Technology in the Age of Enlightenment. Michael Brian Schiffer. xiv + 383 pp. University of California Press, 2003. $34.95.
America is rediscovering Benjamin Franklin. Stroll through any Barnes and Noble and you might find five recent Franklin biographies crowding the shelves next to perhaps a dozen old standbys. With so much written about the man, one might think that there was little left to say about the great patriot printer from Philadelphia. Not so. Although these works speak volumes about Franklin the revolutionary, they pay woefully scant attention to Franklin the scientist.
It’s a scandal, because Benjamin Franklin was, without a doubt, the greatest scientist of his age. Although he receives almost no credit for it today, Franklin’s theory of electricity lies at the heart of modern electrostatics. Through his invention of the lightning rod, Franklin was the first person to prove that pure science could benefit ordinary people. And that realization gave a bigger kick in the pants to the Enlightenment than any philosophical discourse penned by Voltaire.
Franklin was first to suggest how to size the atom, first to realize that the Earth’s climate could change, first to track a hurricane and first to chart the Gulf Stream. He won every major scientific honor his world bestowed, including the Royal Society’s highly prestigious Copley Medal (the Nobel Prize of its day); election to the Royal Societies of England, France and Germany; and numerous honorary degrees. Moreover, it was Franklin’s scientific achievements that raised this self-made tradesman into the lofty sphere of international politics. Simply put, Franklin the statesman never would have stepped onto the world stage had Franklin the scientist not first cleared the way. Despite all this, few people know anything of Franklin’s science beyond the lightning rod, bifocals and a newfangled stove. Oh yes, and wasn’t he the guy who flew that kite in a lightning storm?
Unfortunately, even those few books about Franklin’s science don’t always shed light on the significance of his accomplishments. Some writers try to build up their own reputations by tearing down those of great men and women who are no longer around to defend themselves. Ben Franklin has long presented a tempting target to these drive-by historians. One was a Harvard professor named Alexander McAdie, who in 1925 published an article questioning whether Franklin ever actually performed his most famous experiment—drawing electricity out of a thundercloud. McAdie’s intellectual descendants are still trying to shoot down Franklin’s electric kite, although they have never managed to convince most Franklin scholars.
The latest to take aim is Tom Tucker, an English instructor at Isothermal Community College in North Carolina. To Tucker’s credit, Bolt of Fate: Benjamin Franklin and His Electric Kite Hoax is the best-researched polemic of its kind. Tucker even attempted to replicate Franklin’s experiment. With that background, he could have delivered an erudite treatment of what every historian agrees was a bizarre affair in American history. Unfortunately, he chose to go for Franklin’s jugular, and as a result Bolt of Fate reads more like sophistry than serious history.
Like a prosecuting attorney arguing every possible angle to get a conviction, Tucker splits historical hairs, spins the written record and dismisses eminent antiquarians by selectively citing writers of deservedly lesser stature. Tucker makes his case in part by subtly shifting the meanings of words that appear in historical documents. For example, historians have long questioned why Franklin permitted only his son to witness the kite experiment. Joseph Priestley’s account, which he got directly from Franklin, explains it this way: “But dreading the ridicule which too commonly attends unsuccessful attempts in science, he communicated his intended experiment to no body but his son.” Tucker quotes this accurately but then spins the meaning. “Priestley explains,” says Tucker, “that Franklin did the experiment in secrecy because he was afraid of being embarrassed if the experiment failed,” and then Tucker argues that Franklin wasn’t prone to embarrassment. But ridicule and embarrassment are not at all the same thing. Embarrassment is a completely personal feeling. Ridicule, however, is an expression of public disdain and is something that every politician is quite right to dread. Tucker has altered the record here to slip a pry bar beneath Franklin’s perfectly reasonable explanation. Clearly, Tucker knew what conclusion he wanted to reach.
Then, there’s the heavy-handed hype: In a P. T. Barnum-esque bit of hucksterism, the book’s jacket claims that Tucker has proved “that Franklin never flew the kite at all.” Tucker never equivocates on Franklin’s guilt in the text (saying, for example, that “The kite experiment was [Franklin’s] scientific hoax”), but he eventually admits that “There’s no proving Franklin never flew his kite. It will always remain possible.” Unfortunately, this admission is hidden in an endnote, right next to another surprise: a description of Tucker’s attempts to replicate Franklin’s experiment. As Tucker’s most direct evidence, this material should be front-and-center, but instead it sits tucked away in the back of the book. Tucker reports that he tried to get a Franklin-style kite aloft, but it failed to fly even in a 20-mph wind. The exculpatory fact that three NASA aerodynamics experts studied Franklin’s kite design and saw it as “feasible” is also buried here in the notes.
Oddly, Tucker failed to test what he calls the “most convincing evidence against the kite story.” Had Franklin not electrically isolated himself from the kite string, his experiment would have failed, because any charge collected by the kite would have traveled through Franklin’s body to ground. That’s why Franklin held a silk ribbon that he had tied to that famous key. Wet silk is, of course, a conductor. So to keep the silk dry, Franklin took cover inside a shed and flew the kite out a door or window. But Tucker insists that that wouldn’t have worked. “The kite line,” he states, “is above the insulating silk ribbon. When the rainwater moistens the twine and moves down it, the water will continue freely over the surface of the silk.” This problem, Tucker insists, must have foiled Franklin’s result.
Tucker might be right. But any kite flyer knows that the string sags considerably and presents a surprisingly shallow angle at the hand. Tucker doesn’t say just how vertical a hemp string has to be for water to flow along it. Also, couldn’t other circumstances, such as the key deflecting any water stream, have protected the silk? Tucker doesn’t mention the possibility. Indeed, self-skepticism, the process of putting your own ideas to the critical test, is Bolt of Fate’s most glaring omission and the primary reason that it fails. So long as his antagonists lack such skepticism, Benjamin Franklin’s scientific reputation will be ever secure.
Franklin’s science also figures prominently in Patricia Fara’s new work, An Entertainment for Angels: Electricity in the Enlightenment. However, her subject is much broader. Fara, a historian of science at the University of Cambridge, presents an overview of the science behind the Enlightenment.
Sadly, An Entertainment for Angels disappoints. Written at about the level of a senior thesis, the work reads as if its author had mastered neither the history nor the science of the Enlightenment. The text contains many small errors. For instance, referencing the dangers of some early experiments in atmospheric electricity, Fara notes that “one fatality” took place “when adventurous experimenters clambered about on rooftops trying to record a charge.” This unfairly makes serious scientists sound like the Keystone Kops; moreover, the only person killed while conducting these experiments was Georg Wilhelm Richmann, and he wasn’t clambering about on a rooftop at the time. Rather, he was standing still, carefully reading a delicate instrument inside his apartment, when lightning struck an iron rod outside to which the electrometer was connected.
In addition, several omissions mislead the reader. For example, on reading Fara’s chapter titled “Robert Boyle and the Air-pump,” one might infer that Boyle invented the first hand-cranked vacuum pump. In fact, Boyle’s device was merely an improvement on a two-man pump demonstrated by Otto Von Guericke about 20 years earlier. Von Guericke receives not a mention, even though he had become quite famous for performing spectacular demonstrations of the power of his pump.
What’s more, Fara’s analysis of the complex interplay among the genius, personalities, and scientific and political philosophies that lay at the heart of the Enlightenment is disquietingly clichéd and superficial. Also, her viewpoint is colored by biases that historians often bring to their studies of science. One of the worst of these is the tendency to portray all competing theories as equals, even when one clearly trumped its rivals at explaining the experiments of the day. For example, consider how Fara compares Franklin’s theory of electricity with that of Jean-Antoine Nollet, his chief rival. With the concept of the electric field still 100 years away, Franklin tried to develop a mechanical model to explain electrical action-at-a-distance. That part of his model was wrong. Yet the essence of Franklin’s single-fluid theory, that all matter contains vanishingly small charged particles and that charge is conserved, lies at the foundation of modern electrostatics. In contrast, Nollet’s quasi-magical two-fluid theory retains no toeholds in science today. Nevertheless, Fara implies that no one could tell at the time which way history was going to go. For instance, she states that “Neither side had completely convincing evidence to support its case, but immediately interpreted any new results to lend weight to its own arguments.”
True enough. But by 1755 most of the world’s electricians had become self-professed Franklinists, because Franklin’s theory explained important phenomena, such as electrostatic induction, that Nollet’s model could not. Referring in part to Franklin’s theory, Fara says, “Eighteenth-century electrical theories are often hard to understand because they use poorly defined terms (such as ‘atmosphere’ and ‘fluid’) and gloss over inconvenient results that don’t fit in.” Although that is true of Nollet’s theory, the statement is horribly unfair to Franklin. By tossing both theories together into the same dustbin, Fara creates the impression that the two models were equivalent because they were equally flawed. Not so. Franklin was by far the better scientist, and most fair-minded skeptics of his day realized that, despite its shortcomings, Franklin’s single-fluid model was fundamentally sound.
In short, An Entertainment for Angels is one book that is best left on the shelf.
In contrast, Draw the Lightning Down: Benjamin Franklin and Electrical Technology in the Age of Enlightenment, by Michael Brian Schiffer, is an engaging work of quality scholarship. Schiffer, a professor at the University of Arizona, presents this subject from the perspective of a seasoned anthropologist. And although the field of anthropology has its own biases, they are quite different from those that pollute the work of some historians. Instead of focusing on personalities or ideas, Schiffer is interested in the physical artifacts that people leave behind, and so he follows the evolution of technologies.
First, like any good anthropologist, he divides the people he studies, namely Enlightenment electricians, into communities: the electrophysicists, who tried to understand how electricity worked; electrotherapists, who tried to use it to heal the sick; electrochemists, who tried to use electricity to study the structure of matter; and so on. Then he focuses on the equipment they constructed to drive their fields forward. He elaborates on many marvelous but strange contrivances, such as the electric pistol, the electric harpsichord, “electrovegetometers” and Volta’s electric lamp. Since the fledgling field of electricity is what binds these communities together, Schiffer does not skimp on Enlightenment science.
Draw the Lightning Down offers the reader a novel, and downright refreshing, viewpoint on the science and technology that were most central in bringing about the Enlightenment. Physicists may quibble with Schiffer on some of the fine points of electrostatics, but the man certainly knows his history. Draw the Lightning Down presents the reader with a wonderfully researched and delightful voyage into the past. This one is well worth taking.