Popular Posts

Popular Posts

Pages

Total Pageviews

Thursday, April 19, 2012

Early inventions that changed the history of mankind.

Invention of the Wheel



Wooden WagonInvention of the Wheel


Aryan ChariotModern Car


Up till now, it is still a mystery as to who invented the wheel and when the wheel was invented. According to archaeologists, it was probably invented in around 8,000 B.C. in Asia. The oldest wheel known however, was discovered in Mesopotamia and probably dates back to 3,500 B.C.






This wheel was believed to have been made by the Sumerians. It was made of planks of wood joined together. The picture above briefly describes the stages of development of the wheel.



Stage one: Early men placed rollers beneath heavy objects so that they could be moved easily.






Stage two: Early men began to place runners under a heavy load, which they discovered would make it easier for the load to drag. This was the invention of the sledge.






Stage three: Men began to combine the roller and the sledge. As the sledge moved forward over the first roller, a second roller was placed under the front end to carry the load when it moved off the first roller. A model of a sledge with such rollers is in the Smithsonian Institution.






Stage four: Soon, men discovered that the rollers which carried the sledge became grooved with use. They soon discovered that these deep grooves actually allowed the sledge to advance a greater distance before the next roller was needed to come on!






Thus, in Stage five: The rollers were changed into wheels. In the process of doing so, wood between the grooves of the roller were cut away to form an axle and wooden pegs were fastened to the runners on each side of the axle. When the wheels turn, the axle turned too in the space between the pegs. The first wooden cart was thus made.






Stage six: A slight improvement was made to the cart. This time, instead of using pegs to join the wheels to the axle, holes for the axle were drilled through the frame of the cart. Axle and wheels were now made separately.






The wheel was furthered improved on later by the Egyptians, who made wheels with spokes, which could be found on Egyptian chariots of around 2000 BC. Over in Ancient India, chariots with spoked wheels dating back to around 1500 B.C. were also discovered. The Greeks too, adopted the idea of wheel-making from the Egyptians and made further improvements to it. Later, during the time of the Roman Empire, the Romans too engaged themselves in wheel-making and produced the greatest variety of wheeled vehicles. They had chariots for war, hunting, and racing, two-wheeled farm carts, covered carriages, heavy four-wheeled freight wagons and passenger coaches.






Today, we see that the wheel has indeed undergone a drastic transformation from a simple one made of wood to the pneumatic rubber tyres that we see on vehicles today. What do you think are the advantages of using rubber tyres instead of wooden wheels?






















A wagon on wooden wheels.










Chariots belonging to the Aryans of ancient India










A modern cart which uses rubber tyres instead.










A Another Example of a vehicle using rubber tyres










Car on pneumatic rubber tyres