This is my summary of the inventions I learned about in lessons eleven through fourteen. Lesson eleven was about the pencil. If you took 4th grade History, you might have read my summary of this invention when I learned about it for the first time. However, I studied the pencil again this week, so I’ll have to summarize it again.

Before the pencil, multiple writing instruments were used in ancient times, starting with clay tablets. After more ancient versions of writing tools, the first pencil came around: the British discovered graphite mines, and made pencils by gluing a wooden case around a stick of the mineral. They were the world’s pencil producers, so when France’s trade routes were blocked due to war, France didn’t have any pencils. To solve this dilemma, France invented an alternative pencil. They mixed their powdery graphite with clay to strengthen it, then called it the Conte pencil after its inventor.

Lesson twelve was about the stethoscope. Rene Laennec, who was a French physician, invented the first stethoscope at a hospital in France. He got the idea of the stethoscope from watching children play a game in which they used tubes to make small sounds louder. In a moment of genius, Laennec rolled up a piece of paper to better listen to a lady’s heartbeat, and the stethoscope was invented. The stethoscope provides an easy way of knowing what’s going on inside our bodies without being cut open.

In lesson thirteen, I studied the tunneling shield. More space was needed in Great Britain, so several attempts to tunnel under the river Thames were made. Unfortunately, they failed. So, in 1818, Marc Isambard Brunel patented the tunneling shield. The tunneling shield was inspired by the shipworm, a small worm that bores holes through wood. The tunneling shield protects tunnel diggers from cave-ins that would otherwise kill them.

Lastly, lesson fourteen was about the invention of paved roads. Rome built sturdy roads, but they were very expensive to build. In the 1700’s, roads were beginning to improve, but they were still expensive. In 1816, John McAdam invented the paved road. Today, the paved road is called the Macadam road, and consists of a few of gravel. The Macadam road is both durable and efficient.