Benjamin Franklin invented swim fins, bifocals, the lightning rod, the Franklin stove, the mechanized glass armonica and the "long arm" for reaching books. He created the first map of the Gulf Stream and improved the odometer and the catheter. He also posited the theory that lightning is electricity.
At age 11, Franklin invented swim fins that attached to a swimmer's hands and allowed for faster swimming. He later invented bifocals, a type of eyewear with the upper half for seeing into the distance and the lower half for reading. He also invented the lightning rod to divert lightning to the ground rather than striking houses.
His invention of the Franklin stove, a cast iron furnace, heated colonial homes more effectively. His armonica was an instrument played on a series of different sized glass goblets to create different musical tones. Franklin also created the "long arm," which was a wooden pole he invented to reach books from higher shelves. Stemming from his curiosity about why eastward journeys across the Atlantic Ocean were faster than westward trips, he theorized and was the first to map the Gulf Stream.
Franklin modified the odometer to attach to carriage wheels and calculate distance. He updated the urinary catheter, which drains urine from the bladder, to be flexible and more comfortable. He also discovered that lightning is electricity and that it is fluid, moving between "positive" and "negative" charges.
In addition to his many inventions and discoveries, Franklin was one of the Founding Fathers and helped write the U.S. Constitution. He was a musician and a writer, and he also founded the first library, the first post office and the first college in Pennsylvania.