- Pencil
- Stethoscope
- Tunneling Shield
- Paved Roads
Pencil
Ancient Times: Clay Tablets Are Used To Write.
Ancient Romans And Greeks: Wax Tablets Are Used To Write. They can be erased
Middle Ages: Feather Pens Dipped In Ink And Written On Early Paper Is Used
1500’s: Pencil is invented in England and the English gain a pencil monopoly because they have good graphite.
1789: The French Revolution Begins and English Pencils cannot be imported. That Brings Us To Today’s Lesson.
A french government official asked a man named Conte to invent a different kind of pencil with a different kind of lead. France had access to powdered graphite, but not solid graphite like England. Conte mixed clay with this powdered graphite, and got sturdy graphite that could be made into rods. Different kinds of marks could be made depending on how much clay you mixed in. Henry David Thoreau re-invented the Conte pencil in America in the 1820’s. Conte is still a pencil brand today even.
1822: The Mechanical Pencil Is Invented In England.
2007: Smart Pen Is Invented In The United States Of America For Computers, Smartphones, And Tablets.
For Information on the pencil from another lesson, click on the link below
Stethoscope
Laennac invented the stethoscope in France while working at a hospital. He got inspiration from watching children playing a game. One would hold a hollow stick to his/her ear, and the other would scratch a pin on the other end of the stick; The result was that the scratching of the pin would be amplified in the first child’s ear. His first stethoscope was a rolled up newspaper, but he later made one out of a hollowed out wood tube. He used it to identify an issue with the body and later his nephew used the stethoscope diagnose Laennac with Tuberculosis, which he died from not long after. The stethoscope spread rapidly, and now it is a symbol of hospitals and doctors internationally.
Tunneling Shield
London was a growing city in the 1700 and 1800’s, resulting in a need to travel under the Thames River, rather than over it. Marc Brunel invented the tunneling shield to help accomplish this. Brunel was inspired by a ship worm that ate through wood. The tunneling shield is a structure that is dropped into a hole and used to hold the dirt above the workers. You go in the tunneling shield, dig some of the dirt out, push the tunneling shield forward, and lay down bricks as a permanent support structure. Cave-ins became less common due to the tunneling shield. More modern tunneling shields were made, and also a tunnel under the English channel between England and France was built.
Paved Roads
John McAdam, after having become wealthy during the American Revolution, invented the paved road we have today in 1816 in Britain. The Interstate was invented, and that is what holds our economy together. Paved roads were made of gravel and later tar.