This is my summary of the inventions I learned about in lessons twenty-one through twenty-four. In lesson twenty-one, I learned about the invention of the microphone. The microphone was invented in 1827 by Charles Wheatstone. The main benefit of the microphone is that it converts sound waves into electric signals, which can then be stored, amplified, and transmitted. Much of technology would not be possible without the microphone.

In lesson twenty-two, I studied the invention of the of the typewriter. William Austin Burt invented the typewriter in 1829. Typewriters allow people to write faster than with a pen or a pencil, as well as neater. Burt’s typewriter wasn’t commercially successful, but the American company Sholes and Glidden released a typewriter in 1874 that was.

Lesson twenty-three was about the Braille writing system. During the Napoleonic War in France, Captain Charles Barbier invented a coded system of writing that consisted of bumps. This allowed soldiers to read messages in the dark with feel alone.

Louis Braille became blind at the age of three, which led him to later invent an improved version of Barbier’s system. Louis Braille was a very good student despite this disability, and attended the very first school for the blind. He then realized a better way was needed for the blind to read and write.

That was how Louis Braille came to invent the Braille writing system. Braille uses different combinations of six raised dots to make up the alphabet, and enables people who are blind to read as quickly as people who aren’t.

Lastly, in lesson twenty-four, I learned about the invention of the sewing machine. In France, Bart Thimonnier invented the sewing machine in 1829. The sewing machine makes sewing high-quality clothes quick and easy.