This is my summary of the inventions I learned about in lessons thirty-one through thirty-four. Lesson thirty-one was about the invention of the combine harvester. When John Hascall moved to Michigan, he moved next door to Hiram Moore. John Hascall had lots of crops to harvest, but no fast way to harvest them. He told Moore about the dream his wife had about a large machine that could harvest fields of crops quickly, which led his neighbor to build his combine to take care of Hascall’s harvesting problem. The combine harvester combines several stages of the harvesting process: the reaping, the threshing, and the winnowing.

In lesson thirty-two, I learned about the invention of the solar compass. William Austin Burt- the inventor of the solar compass- grew up on a farm in Massachusetts, and developed an interest in sailing from a young age. He was an inventor, and invented many things, including the typewriter and the solar compass. He invented the solar compass as an alternative to the magnetic compass, and it didn’t rely on the earth’s magnetic field to work.

In lesson thirty-three, I learned about the invention of the screw propeller. Like William Austin Burt, Francis Pettit Smith grew up on a farm and became interested by boats. He was especially fascinated by boat propulsion. At the time, boats used paddlewheels, but Smith experimented with other ways. Eventually, he invented the screw propeller in 1835. The screw propeller was lighter and more efficient than the paddlewheel, as well as cheaper to install.

Last of all, lesson thirty-four was about the mechanical computer. Charles Babbage invented the idea of the mechanical computer, though he never saw it built.