This is my summary of the inventions I learned about in lessons forty-six through forty-nine. In lesson forty-six, I studied the invention of the electric clock. Alexander Bain grew up in Scotland and apprenticed to a clockmaker. He later moved to the city of London to sell his skills. He attended public scientific lectures, and learned about electromagnetism.

Bain combined his skills as a clockmaker with his knowledge of electricity to invent the electric clock in 1840. Electric clocks are more compact than older types of clocks, and are generally perfect in their timekeeping.

In lesson forty-seven, I learned about the invention of the blueprint. An English scientist named John Herschel invented the blueprinting process in 1842. Herschel inherited an astronomical interest from his father, who discovered Uranus. This led Herschel to take a trip to South Africa with his wife so he could study the night sky from the southern hemisphere. While there, he experimented with various forms of drawing and copying. He invented the sienna typing process, which is the base for making blueprints.

To make a blueprint, you first coat a piece of paper in a certain chemical. Next, you put an image drawn on a transparent material onto the paper and expose it to ultraviolet light. The ultraviolet light turns the chemical blue, but the parts covered by lines of the original drawing are blocked from the exposure and stay white. Blueprinting makes it easy to produce accurate reproductions of architectural designs.

Lesson forty-eight was about the invention of the stapler. Samuel Slocum grew up in New York City. he was introduced to the man who invented the pin with a round head, and worked in a pin manufacturing company in Great Britain. He invented a machine to make pins, then moved back to America and opened a factory to produce them.

However, Slocum needed a way to ship the pins. In solving that problem, he invented the stapler in 1841. His solution was a machine that punched pins through paper, and that was the stapler. Staplers make it quick and easy to bind several sheets of paper together.

Last of all, I studied the invention of the grain elevator in lesson forty-nine. After the Erie Canal was built, grain trade and production in Buffalo, NY increased. However, loading and unloading grain was still a long and tedious process. A businessman living in Buffalo named Joseph Dart saw an opportunity to make money in the grain industry by creating a way to solve this problem, and did so with the help of an engineer in 1842. Grain elevators quickly remove and store grain from ships sand other transports, and can dispense it as well.