Early Travelling

Humans realized that heavy objects could be moved easier if something round, for example a fallen tree log, was placed under it and the object rolled over it. Humans also realized a way to move heavy objects, with an invention archeologists call the sledge. Logs or sticks were placed under an object and used to drag the heavy object, like a sled and a wedge put together.Humans thought to use the round logs and a sledge together.Humans used several logs or rollers in a row, dragging the sledge over one roller to the next.

With time the sledges started to wear grooves into the rollers and humans noticed that the grooved rollers actually worked better, carrying the object further. This was simple physics, if the grooves had a smaller circumference than the unworn parts of the roller, then dragging the sledge in the grooves required less energy to create a turning motion but created a greater distance covered when the larger part of the log roller turned.The log roller was becoming a wheel, humans cut away the wood between the two inner grooves to create what is called an axle.

Wooden pegs were used to fix the sledge, so that when it rested on the rollers it did not move, but allowed the axle to turn in-between the pegs, the axle and wheels now created all the movement. These were the first carts.Improvements to the cart were made. The pegs were replaced with holes carved into the cart frame, the axle was placed through the hole. This made it necessary for the larger wheels and thinner axle to be separate pieces. The wheels were attached to both sides of the axle.

Next, the fixed axle was invented, where the axle does not turn but is solidly connected to the cart frame. Only the wheels did the revolving by being fitted onto the axle in a way that allowed the wheels to rotate. Fixed axles made for stable carts that could turn corners better. By this time the wheel can be considered a complete invention.

Source : inventors.about.com/od/wstartinventions/a/wheel.htm

Early Days Life

In early days, human life was very hard. They spent their life in caves, wrap animal skin and tree leaves over their body and hunt animals for food. With time, they discovered many good things like fire, tools, farming etc. that made their life better than earlier. But these changes in early human’s life had taken a very long time.

Early humans lived in jungle and were afraid of bigger and stronger wild animals. Earlier they had no house to live in and they spend their time on the trees or hide themselves behind the bushes. But it could provide them security from wild animals, rain, winter and sun heat. So, they started living in caves.

As food and clothes is the basic necessity of humans, they started wrapping tree leaves and animal skin over their body to protect themselves from cold and heat. But they needed food also to live. They do not know how to grow crops in fields and finding food was not easy. In search of food, they had to go from one place to another. Earlier, they used to eat fruits from tree or roots of plants. Then they started hunting animals for food.

In start, early man started killing small animals for food. But they could not kill large animals with their bare hands. So, they used sharp edged stones to kill animals. Probably, this was the first tool he had started using for his need. They kept on improving their tools with time and requirements. They found that if they tied a sharp stone to a long piece of wood, they could throw it to a wild animal at a longer distance and they did not require go near to kill it. This was the invention of a spear. Later, on they improved it by making with bones and started using tools not only for hunting but also for cutting, digging and sewing.

Source : www.studyvillage.com/resources/3366-essay-early-human-s-life.aspx