Book Summary: Elemental
Author: Tim James
Substory: Stephen Gray’s Tragedy
It is a crying tragedy that the man who discovered electricity is usually forgotten. The Greek scientist Thales (the one who fell down the pit) had already made the discovery that rubbing pieces of amber with wool caused them to gain a crackly property, which sparked under the right circumstances, but the discovery of what we think of as electric current goes to an English experimenter named Stephen Gray.
One of the reasons why Gray’s work was overlooked is that he made the mistake of asking another scientist to help him develop it. That scientist was John Flamsteed, who happened to be a mortal enemy of Sir Isaac Newton.
Newton was a socially cruel, even malicious character who used his position as head of the Royal Society to discredit and bury the work of people he disliked, including Flamsteed.6 Consequently, much of Flamsteed and Gray’s achievements were ignored. It has to be said that while Newton was one of the greatest minds in history, he was also a jackass sometimes. So, let’s redress the balance and give Stephen Gray his due.
Born in 1666, Gray worked as a dyer for most of his life and only indulged science as a hobby. He discovered electricity one night in his bedroom at the age of forty-two while playing with a crude instrument used to generate static—a tube of glass.
Static generators had been around since 1661, invented by the German politician Otto von Guericke, but Gray didn’t have the money for such lavish equipment. He had to make do with rubbing a glass rod on rabbit fur and tapping it on whatever was around in the hopes of creating a shock.
Gray was curious about the fact that if you put the rod on the ground after rubbing it, it seemed to lose its electricity and wouldn’t shock anything again until recharged.
On this particular night he decided to jam the end of the rod into a piece of cork and discovered that when he tapped the cork-tip against a pile of feathers, it sparked. The glass had been rubbed but the cork was somehow able to transfer the electricity through itself. Whatever electricity was, it could flow.
Excited by this result, Gray built a silk harness from his ceiling so objects wouldn’t touch the ground, and began testing things to see if they would transfer electricity. After trying vegetables, string, coins, and anything else he could find, Gray began dividing everything into two categories: insulators, which wouldn’t transfer electricity, and conductors, which would.
The best conductors turned out to be metals, located on the left side of the periodic table. These were so good at electric transfer that Gray was able to pass a shock down nearly 250 meters of wire suspended from his bedroom window.
Metals even conducted when pointing upward, which meant that whatever electricity was, it wasn’t influenced by gravity. Electricity would still go into the ground, of course, but it’s obviously not because of gravitational attraction. Instead, the planet itself was a conductor, which electricity will flow through given the chance.
Even more surprising among Gray’s results was the fact that humans conducted electricity. By suspending a young boy from his silk harness, Gray was able to charge him and generate sparks from his face. This became the basis of a popular sideshow exhibit called “The Flying Boy” in which spectators could tap the floating youngster’s fingertips and receive a shock. All in the name of science.
The secret to this exhibition is that human skin is usually coated in a fine layer of saltwater in the form of sweat, allowing electricity to zap across its surface. When the spectators, who were connected to the ground, touched the charged boy, the electricity would flow over their skin and into the earth, creating the shock effect.