This is my summary of the inventions I learned about in lessons one hundred eleven through one hundred fourteen. In lesson one hundred eleven, I studied the invention of riveted blue jeans. In the 1800’s, the growing work industry made work clothes with higher durability a necessity. Pants especially were wearing out faster than ever before.

Two men invented the riveted blue jeans: Levis Strauss and Jacob Davis. Strauss was a dealer in the dry goods business, and sold fabric to Davis – who was a tailor. One day, Davis got an order for the strongest pants he could make, so he created riveted blue jeans. He couldn’t patent it on his own, so he called up his fabric producer and they patented the new pants together in 1873. The rivets are placed so they reinforce weaker spots, making them more durable. The indigo die that gives the jeans their color also makes the jeans more comfortable after they’re washed.

In lesson one hundred twelve, I learned about the invention of the fire sprinkler. Fire extinguishers were just fine for small fires, but if a fire broke out in a factory, it was much harder to put out. A new method of fire-fighting was needed, and it came in the form of the fire sprinkler. The first fire sprinkler was invented in 1812, but you had to manually turn it on. It just didn’t catch on. However, Henry Parmalee’s automatic version did.

Henry Parmalee invented the automatic fire sprinkler in 1874. Parmalee was motivated to invent the fire sprinkler because he owned a piano factory. Pianos are very expensive, and he didn’t want to have to replace one if it was destroyed in a fire. However, he also didn’t want to pay for insurance, which was quite an expensive option as well. Fire sprinklers work by detecting heat. When a it gets hot enough, the fire melts off the cap holding back pressurized water, which then sprays water over everything.

In lesson one hundred thirteen, I studied the invention of the QWERTY keyboard. Before the QWERTY keyboard layout, typewriters would get jammed easily. If you typed two letters that were next to each other too quickly, they would get stuck. You then had to spend a while unjamming them, and it would take quite a long time to get something typed.

Christopher Latham Sholes invented the QWERTY keyboard in 1878. He was bent on making a more efficient typewriter layout so you wouldn’t have to stop every minute to unstick the keys. It spaces out the most commonly used keys, so it was less likely to jamm.

Lastly, lesson one hundred fourteen was about the invention of the dental drill. When people think about the “good ol’ days”, they don’t stop to think about what dental service was like back then. Before the modern dental drill was invented, for example, drills were cranked manually. This meant they were less accurate and much more painful, since the faster the head of the drill turns, the easier it cuts away small bits of tooth at a time.

George Green invented the electric dental drill in 1875. The drill could turn faster when powered with electricity rather than your hand, so dental procedures were immediately much less painful. Today, the dental drill is called the handpiece, since it sounds less frightening.