Pencil, Stethoscope, Tunneling Shield, Paved Roads

Ancient people, like the Egyptians, used writing instruments. Ancient Egyptians used writing instruments for writing on clay tablets. The Egyptians' writing system was called hieroglyphics. Today, we use a writing instrument called the pencil. The American pencil was invented by Henry David Thoreau. Thoreau worked at his father's factory. He wrote a book saying he hated inventions. Pencils are cheap to make and easy to use.

The first hospital was built in France in 651 A.D. The invention of the stethoscope was a turning point in medicine. Hospitals were built by churches to provide charity for the sick and needy. Charity is a free gift. "The stethoscope is an acoustic medical device for auscultation or listening to the internal sounds of an animal or human body." The stethoscope provides a non-intrusive way of investigating the inside of our body.

Marc Isambard Brunel was born in France in 1769. He patented a tunneling shield inspired by the shipworm. Shipworms are called "termites of the sea". A tunneling shield protects men who are digging tunnels. Brunel was most famous for building the Thames Tunnel.

John McAdams was born in Scotland in 1756. John McAdams invented the Modern Paved Road method in 1816. The Ancient Romans built the best roads. John McAdam began experimenting with new road-building ideas. "improvements in road building led to the modern interstate system which is the backbone of our modern economy."