Benjamin Franklin was a printer, postmaster, diplomat and a Founding Father, but he was also an inventor. He created bifocal glasses, the library stepstool (a chair whose seat folded down to become a small step ladder), and the glass harmonica.
In his experiment with lightning he proved that lightning is electricity. He also patented a pointed lightning rod that he affixed to buildings to direct strikes.
1. Bifocal Glasses
As he grew older, Franklin developed presbyopia—or the inability to focus on near and distant objects. He grew tired of constantly changing between distance and reading glasses, so he asked his optician to cut the lenses of two pairs of glasses in half and glue them together, resulting in his first pair of bifocals.
Having both a lens for distance viewing and a lens for close-ups was a game-changer for him, as he could now read his newspaper in the morning, work at his desk, then go out to the tavern to meet friends without having to change glasses.
During his lifetime, Ben penned dozens of books and letters, created the Library Stepstool, the Franklin stove, and the glass harmonica (which sounds way more complicated than it actually is). He also founded an organization called the Junto—a group that encouraged self-improvement through meetings that included lectures and group discussions. In addition, he is credited with many other inventions including a urinary catheter and a bifocal lens.
2. The Franklin Stove
Benjamin Franklin was always looking for a better way to do things. His curiosity and boundless optimism allowed him to see potential in everything.
During one of his diplomatic trips abroad, Franklin saw a group perform what they called “singing glasses.” The musicians wet their finger and carefully ran it along the rims of the wine glass, causing them to sound musical notes. The idea fascinated Franklin, who fashioned a device he called the “long arm” that helped him reach books on high shelves without using a ladder.
In 1742, perhaps fed up with cold Pennsylvania winters, Franklin figured out a way to heat rooms more efficiently. His metal-lined fireplace, known as the Franklin stove, stood a few inches away from the chimney and used an inverted siphon and a hollow baffle to extract more heat with less smoke.
He also invented a urinary catheter to remove urine more quickly and an odometer that could measure distance along the colonial roads used by postal routes.
3. The Lightning Rod
In a time when most people thought lightning was “fire from heaven,” Franklin’s research revealed that thunderclouds contained electrical charges, and the pointed rods he attached to buildings aimed to conduct those electrical discharges to ground. The discovery that thunderstorms contain electricity revolutionized our perception of the natural world, and was one of Franklin’s many contributions to science.
In 1750, he began thinking about protecting people and buildings from lightning. This grew into his idea for a lightning rod, an iron rod 8 or 10 feet long that was sharpened to a point at the end.
Ben waited to conduct his experiment until the steeple of Christ Church in Philadelphia was finished, but then he got impatient and decided that a kite would be able to get close enough to the storm clouds for his purpose. At first he tried using a metal key, but later changed to an insulating ribbon for the knuckles of his hands.
4. Swimming Fins
Franklin loved the water and regularly promoted the healthful benefits of swimming in his writings. A lifelong avid swimmer, he figured out a way to swim faster when he was just 11 years old by inventing a pair of fins that he strapped to his hands. Shaped like lily pads or an artist’s paint pallet, the fins helped swimmers increase speed with each stroke.
While these may not be as exciting as the lightning rod or bifocal glasses, they show that Franklin was truly a man of many talents. He was a political figure, a trend setter, an inventor, a writer and more. He even designed a pulley system to help him reach books on high shelves at the library he founded.
He also invented the armonica, a musical instrument made of dozens of glass hemispheres that sit atop a wooden stand and create different notes when rubbed with moist fingers. And he was responsible for inventing the urinary catheter, prompted by his brother’s kidney stones.