Invention of Wheel
Wheels help an automobile to ove. Can you imagine the world without wheels? There would be no cars, buses, motorcycles, and scooters.
Wheel is one of the greatest mechanical inventions for the benefit of mankind. Before the invention of wheel, people carried load on their backs and shoulders. Later they used sledges to carry loads. Sledges were pulled by people or domesticated animals. Probably sledges were the first system used to transport heavy loads before the invention of wheel. People realised that tree trunks could be made round like rollers. These rollers were laid under the sledge at each stage and so very slowly it moved along. As the sledge rolled further the rollers were picked up behind it and laid down again in front of the sledge. The wheel probably developed using this technique.
The earliest known wheels were found in Mesopotamia (modern day Iraq) between 3500 and 3000 BC. The earliest picture of a wheel is seen in the Standard of Ur, a mosaic which depicts ancient civilisation in Mesopotamia around 6000 years ago. The picture shows procession of heavy war wagons rolling along on wooden wheels.
Early wheels where either slices of wood cut across a log (tree trunk) with a hole for the axle in the centre or made of three planks of solid wood. The three pieces were held together with wooden struts or strips of leather. But such wheels had to be sawed into shape. They could not be made until people learned to use metal tools.
The first wheeled vehicles were farm carts, war chariots and sacred wagons of Gods. These wheeled vehicles made the transport of heavy goods quicker and easier.
The invention of wheel was made in the late Neolithic Age (New Stone Age) around 5000 years ago. The invention of wheel is seen with other technological advances that gave rise to the Bronze Age.
Wheels first used for transportation in 3200 BC in Mesopotamia. In Indian mythology also, we get evidences of use of wheels in chariots dating around 3000 BC. In the Harappan civilization of the Indus valley and north western India, toy cart wheels made of clay were found. These wheels had painted or engraved spokes. Some seals of the second half of the third millennium BC had symbol of the spoked wheel in the script. In reality, the spoked wheels were invented more recently. Spokes are the rods radiating from the centre connecting the hub with the round surface. The Andronova culture is often credited with the invention of the spoke-wheeled chariots around 2000 BC. In Egypt, people started using chariots fixed with spoked wheels around 2000 BC. In China, wheeled vehicles appeared in the second millennium BC.
The wheels went to evolve and the first wheels with iron rims were seen in the Celtic chariots around 1000 BC.
Jawablah pertanyaan-pertanyaan di bawah ini menggunakan informasi yang tercantum di dalam bacaan di atas!
Kepustakaan:
Jha SN, Banerjee S, Jain N. (2013). A Textbook of Automobile Technology: For Class 9 (Level 1). New Delhi: Goyal Brothers Prakash Educational Publishers. hal. 1-4, 18.
