Gisella's School

This week in history I learned about the vapor compression theory, Oliver Evans, percussion ignition system, and the canning process.           

First, the vapor compression theory came when people’s houses got hot in the summer. Imagine walking into a hot house after a long day of work outside. That was why the vapor compression theory was invented. At first it was used to cool down houses but then it improved and was used to create the refrigerator. The vapor compression theory works by putting a liquid called refrigerant into some small pipes at the back which makes the refrigerator.

Second, Oliver Evans invented the air conditioner and the refrigerator. He invented the air conditioner because houses got too hot and when houses get hot the people in them get uncomfortable! After he invented the air conditioner he wanted to also cool food. He then invented the refrigerator.

Third, I learned about the percussion ignition system. In France, there was a war and they needed weapons so they started using guns. However, the guns were really slow to fire. When the percussion ignition system came out France was able to hit their targets a lot easier. The percussion ignition system ignites the gun powder by hitting an explosive (like mercury), then a little fire ball travels to the bullet and shoots the casing the other way.

Fourth, I learned about the canning process. The canning process helped soldiers in battle because preserved food helped them keep their energy up. The canning process is when you put food in glass jars and boil them to seal the jars from contamination.

Air conditioning and the light bulb both helped people in their homes, despite all the push back from those who lost their jobs because of advancements in technology.

In History 5 this week I learned about things that helped people have more food, comfort, and safety.