Week 3 Summary Essay

              This week, I learned about the pencil, the stethoscope, the tunneling shield, and paved roads. Most people don’t think of these things when they think of inventions. However, these four inventions are massive solutions to this world, so I’ll tell you a bit about them.

              The first thing I learned about this week was the pencil and how it was invented. Before pencils were invented, many countries in Europe used clay tablets for writing, and some areas, like Rome, Greece, and China used erasable tablets made of beeswax. Then a graphite mine was discovered in England around 1500 A.D. The graphite could break apart and make marks, so this made it easier to draw. And Italian couple started using wood to cover the graphite instead of cloth. During the French Revolution, most countries in Europe cut off France’s supply of goods, including graphite. A man named Nicolas-Jacques Conte had the idea of mixing powdered graphite with clay and putting it in between two half-cylinder, hallow pieces of wood. Later, around 1820, a man named John Thoreau began manufacturing pencils in Massachusetts. Pencils are one of the most important tools ever to be made, because they made it easier to write and were erasable. We still use pencils in our everyday lives.

              Next, I learned about the stethoscope. It was invented by Rene Laennec in 1816. His idea for the stethoscope came from watching children play with hollow sticks held up to their ears. He had a patient that had heart problems, but because she was overweight, he could not hear or feel her heartbeat. So, he rolled up a piece of paper and held it to her chest. He was able to hear her heartbeat through the paper tube. This then led to the stethoscope, which comes from the Greek words stethos (chest) and skopos (examination). It quickly gained popularity through Europe and the rest of world. The stethoscope is commonly used today to not only listen to the heart, but also the lungs, stomach, parts of the brain, and blood flow, etc.

             Next is the tunneling shield. While miners were building Thames Tunnel in London, there were many problems, like cave ins. As a solution for this, Mark Brunel invented a tunneling shield that could be made bricks, concrete, cast iron, or steel. It prevented rocks and dirt from falling from the sides of the tunnel onto the miners while they were working. It could be moved forward with jacks as the miners completed a section. This invention was used to help build many tunnels underground and below rivers throughout the world.

             The last invention of the week was paved roads. Originally, road building used Pierre-Marie-Jerome Tresaguet’s method which involved three layers of stones laid by hand with side ditches to drain water off the road. Thomas Telford used Tresaguet’s road building theories but believed the stones all had to be a certain size for each layer. Later, John McAdam developed the macadam road method, which used certain size stones, but without anything in between them. A fun fact is that the workmen would put the stones in their mouths to check the stone size for the road. Now roads are made using crushed up stones and tar mixed before they are laid. This invention helped motor vehicle travel on roads without having rocks damage the wheels.

              In conclusion, these inventions have helped millions of people, including us. They have shaped history as well as every other invention on this earth. The pencil improved communication, the stethoscope improved diagnosing disease, and both the tunneling shield and paved roads improved transportation. All of these are still very important even to this day.