Lesson 11-15

Hello! Today we are going to be learning about the pencil, stethoscope, tunneling shield and paved roads. Let get into it!

Pencil (Lesson 11)

Earliest forms of writing were on clay tablets. Greeks and Romans used wax tablets. England was the first to make pencil. pencils make durable markings. They are cheap to make and use. Pencils often have benefits to artists. Conte pencil dominated Europe, but it didn’t spread to America.

Stethoscope (Lesson 12)

Rene Laennec was born in 1781 in France. He was sick as a child. Trained under great french doctors. He invented the stethoscope in a Eureka (moment in 1816). We listen to heart beats, blood flow and lungs though stethoscopes. The modern design emerged in 1852. He publish a book in 1819.

Tunneling Shield (Lesson 13)

Marc Isambard Brunel was born in France in 1769. He invented tunneling shield in 1818. Tunneling Shield protects men digging in Tunnels. The shield contained worker compartments. Brunel sank in access ring into the Earth. Brunel leveraged competition with Russia to escape British debtors prison. He began digging Thames tunnel in 1825.

Paved Roads (Lesson 14)

John McAdam was born in Scotland in 1756. He built fortune in America as prize agent. McAdam began experimenting with new roads. He invented the Macadam paved roads in 1816. Macadam is a paved road in made up of layers of gravel. The macadam road spread quickly. McAdam’s promoted his design though books.