This is my summary of the inventions I studied in lessons sixteen through nineteen. In lesson sixteen, I learned about the invention of portland cement. When Rome fell, their method for making cement and concrete fell, too. But after the 1750’s, attempts were made to discover a new recipe. Joseph Aspdin was the one to find the perfect method of making cement. Joseph Aspdin patented portland cement, which resembles portland stone. Portland cement is very strong and durable, so it’s the most used version of cement in the world.

In lesson seventeen, I studied the invention of the electromagnet. William Sturgeon invented the electromagnet after learning of Hans Christian Oersted’s discovery about the link between electricity and magnetism. The electromagnet was invented in the 1820’s, and uses the magnetic field from electric currents to turn ferromagnetic materials into super strong materials.

Lesson eighteen was about the invention of the passenger rail. The first rails were wooden and were used to transport carts to and from mines. George Stephenson grew up working in the mines, and invented the passenger rail after spending years working on railroad lines. The main benefit of the passenger rail is that it’s a quick and efficient way to transport people from one place to another.

Lastly, lesson nineteen was about matches. Chinese alchemists invented an early version of the match, which was based on the chemical that ignited a flame with friction. Western alchemists were soon experimenting with chemicals, and it was discovered that certain chemicals can create a flame.

John Walker wanted to be a surgeon, but he couldn’t stand all the blood. Not wanting to waste his knowledge and experience, he became a pharmacist instead. Walker then wanted to figure out an easier way to make a fire than by crushing a glass bottle, which was was the method at the time. So, during an experiment with chemical-coated sticks, Walker accidentally discovered the match. Matches are a simple, convenient way to start a fire.