Walls are defined as a barrier, physical or nonphysical, that separates two different amounts of space on one plane from each other. The common wall is usually made of bricks, stone, wood, metal, or any other materials that are plentiful in the area. Walls are made for one of three main reasons:
- To keep things in, such as zoo walls keeping in animals
- To keep things out, such as the Great Wall of China, which kept invading Mongols out.
- To do both reasons 1 and 2, such as the Berlin wall, which separated part of Berlin from traveling to the other.
Long ago, before any standard forms of government or currency were ever made, a man could make a large surplus of resources (preferably food and water), and some less fortunate or disrespecting neighbors would try to take them for themselves. So these men had to build walls around where they were protecting, whether it were houses, cities, or countries. Walls have been continued being made to this day, as walls surround conjoining countries when they commonly have conflict between each other, walls surround military bases to keep enemies out, walls are made in houses to divide rooms and to protect against natural elements, and walls are built on borders such as the border of Mexico and USA, so that Mexicans don't illegally enter the United States of America.
Many walls are made of bricks. This is considered the easiest way. The bricks set on each other are most of the time set so that each edge is halfway farther to the left (or right) of its size than the bottom brick. This technique is used so that heavy bricks that aren't supported by paste mixtures between each other don't fall down as easily.
Other walls are made in simpler ways. Medieval walls were made with whatever stones were found, put in the most logical place they could think of. Many walls (especially in the north) were wooden and made of giant logs stacked neatly on each other. Egyptian or Mesopotamian walls were made with mixtures of mud from their rivers formed into bricks. Fences were built by medieval people for the first time, and were simply built to keep something that barely had any means of combat. Fences were single stakes of wood sticking up with more wood connecting them near the top. Although they have evolved up to now, they still are no match for armies in conflict with the owner.
Walls that were made for defense eventually evolved a great deal. Cannons, pillboxes, or Anti-Aircraft Guns were placed on or next to walls to increase defense of the area.
Types of Walls
There are many different types of walls that are notable. For instance, there is the defensive wall that is built entirely for the purpose of keeping out enemies.
Other types of walls are walls for simply keeping something inside that the owner does not want to leave or to be stolen. This ranges from fences that keep herds of sheep inside to the cages of zoo animals and to the bars of a jail cell. Depending on what it is they're keeping in, they may not need much defense or may need plenty of defense. Otherwise we could put fences up in jails to keep dangerous, insane criminals inside.
Another type of wall that's commonly used is the wall of a dwelling that has been carried on since ancient times. Today, they are usually covered in rooves for protection against bad weather. Walls could wall in heat or cold, depended on what was wanted, but it wouldn't be as powerful thousands of years ago. Today, our households can practically seal ourselves away from the elements using strong walls and thermostats.
There are all sorts of walls that deserve mention.
For example, the Great Wall of China is the longest wall ever built, and can be viewed from outer space. As previously stated, it was built to stop Mongols from invading the South part of the Chinese Empire.
Jericho is possibly the first recorded walled city ever. The first mention made of it is found in Numbers 22:1 of the Bible:
"Then the Israelites traveled to the plains of Moab and camped along the Jordan across from Jericho."
The only evidence that it had a wall, which seemed to be sort of metaphoric, states:
"By faith the walls of Jericho fell, after the people had marched around them for seven days." -Hebrews, 11:30
Some people choose not to believe this was the first walled city, because either they don't believe in the power of God and therefore this city couldn't have been destroyed or have existed in the first place, or because there are other cities that weren't described enough for us to know.
- The Pink Floyd album The Wall was about a man who had a mental disability to socialize with others without panicking. This disability was in the metaphorical form of a Wall between him and everyone else.
- There was a movie based on the The Wall.