Benjamin Franklin Inventions

Benjamin Franklin is widely known for his inventions. He set up the first volunteer fire department and he came up with the idea of the public library; but he was not only a thinker.

With his own hands he created the numerous Benjamin Franklin inventions.


Benjamin Franklin was always faced with a problem of vision. He was constantly having to switch his glasses, or spectacles as they called them, every time he needed to look at something at a different distance: one pair for reading, one pair for things farther away.

Benjamin Franklin by George S. Stuart Gallery of Historical Figures
Used with permission from Wikimedia Commons

On, off, on, off, he was always switching, switching, switching … until he was so fed up he decided to find a way around it.

With a glass cutter, he cut the lenses of both pair of spectacles in half. He then placed half of each in his frames. VoĆ­la, he created the bifocals.

The solution to Benjamin’s problem is still widely used today.


Among the Benjamin Franklin inventions was an improvement to the catheter.

(A catheter is a tube that can be inserted in a person for drainage. They are generally used with urinary tract or kidney problems.)

The first catheter was a hard metal tube. As you may have guessed, this was not very comfortable to the patient and in severe cases could be very painful.

Benjamin Franklin’s brother John was subjected to this torture, so Ben decided to help him out. He created a pain-free model by making a thin. flexible tube. This tube could move as needed, in order to cause less pain. Modern doctors still use the tube Franklin designed.

Franklin Stove

Another Benjamin Franklin invention was the “Franklin Stove”, also known as the wood stove or furnace stove. It was made to avoid using open flame to heat homes during the frigid American winters.

In Franklin’s day, houses were made of just wood, which was not adequate for insulation, allowing cold air in. To keep warm, people would build very dangerous, open fires in their houses. Ben did not like the idea of such a danger in his house, so he decided to fix it.

He built a cast iron box to put his fire in. As a result, the iron would heat up and create more heat than the open fire. This way he heated his house with less risk, and with less wood. Benjamin Franklin had invented the first iron furnace.

Glass Harmonica

Another Benjamin Franklin invention was the glass harmonica.

When Franklin was a delegate for the continental congress, he was sent to many places to do business. On one of these trips, he was invited to a show. Toward the end, some performers came out with what they called singing glasses. They played music on the edge of a wine glass by wetting their finger and running it along the edge of the glass.

Benjamin was enthralled with this. When he went home, he wanted to make an instrument with this art.

He took a large amout of wine glasses, removed the legs, and drilled a hole in the bottom. When he finished with that, he ran one long stick through all of them. He then mounted the stick to a wheel that could be spun with the foot. He played this instrument by wetting his finger and running it over the spinning glasses.

Lightning Rod

Contrary to popular opinion, Benjamin Franklin did not invent or discover electricity. One famous Benjamin Franklin invention, however, was the lightning rod.

Franklin was fascinated with electricity as soon as he entered the field of science. When he realized the shocking amount of electricity in lightning, he decided to test it. He wanted to know if he could tame it. That is when he did his very dangerous experiment with the key on the kite.

Benjamin Franklin draws electricity from the sky by Benjamin West
Courtesy of Wikimedia Commons, public domain

He then discovered that lightning is attracted to metal. That is when he invented the Lightning Rod. The Lightning Rod was just a long, iron rod that extended high in the air. This would attract the lighning during storms, and when it struck the rod, it would be channeled around the house and into the ground. This kept houses, and people, safe from being struck during lightning storms. 


One of Ben’s many jobs was postmaster. Out of concern for fast and efficient service, Ben decided to measure the distances of each route. For this purpose, Benjamin Franklin invented the first road odometer, which was affixed to the wheels of a carriage and counted rotations.

The source for this image is unknown. It’s already found on web sites all over the internet, so we used it, but please let us know if you know this is copyrighted.

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