Earliest forms of writing were on clay tables, Greeks and Romans used wax tables they were erasable. A unique graphite mine was discovered in England in 1500 AD. England gained a monopoly over pencil-making. Nicolas Jacques Conte invented the modern pencil as an alternative to Britain’s. Pencils are graphite rods encased in wood. Pencils make durable markings. They are cheap to make and use. Pencils offered benefits to artists. Conte pencil dominated Europe. But it didn’t spread to America. John Thoreacu manufactured pencils in Massachusetts in the 1820s. His pencils were inferior to Conte’s. John’s son, Henry independently invented the same pencil that Conte had 15 years earlier.
Rene Lannec was born in 1781 in France, he was sick as a child. He trained under great French doctors, he had several interests related to sound. He invented the stethoscope in a Eureka! Moment in 1816. Stethoscopes let us listen to sounds inside our body. The chest piece captures a sound wave. They traveled through air tubes into our eardrums. Electronics enhanced stethoscope features. We can listen to heartbeat, blood flow, and lunges. Laenec used his stethoscope with autopsies. He published a book in 1819. Lanennec wasn’t roo critical of the existing (inferior) methods. His invention spread quickly throughout Europe. The modern design emerged in 1852.
Marc Isambard Buried, was born in France in 1769, he fled to France to escape the murderous reign of Robespierre. Gained engineering experience in New York City in 1793. He returned to England in 1799 to mass produce pulley blocks. He patented a tunneling shield in 1818. Tunneling shields protect men digging tunnels. Brunel Sank, an acces ring into earth. The Shield contained worker compartments. He excavated 8-12 feet per week. He Negotiated with Russia For bailout. Brunel leveraged competition with Russia to escape British debtor’s prison. Began digging the Thames tunnel in 1825. Financial trouble struck by 1828.
John McAdam was born in Scotland in America as a prize agent. He returned to Scotland and got involved in road-building. McAdam began experimenting with new roads. He invented the Macadam paved road in 1816. MacAdam is a paved road made up of layers of gravel. 30 feet wide, 3-inch rise towards the center. The stones were crushed manually with hammers. More durable and economic than other kinds. The macadam road spread quickly. They rooted out corruption because they were so quick to build. McAdam’s promoted his design through a book. Books spread ideas rapidly, The first macadam road completed in America in 1823.