Wheel

Roll, roll, roll.

• Wheels are generally circular in shape, and rotate, primarily on an axis, and are said to be one of the most important inventions of all time.
• A basic standard wheel has a rim which is the outside of the wheel, spokes that attach to the rim and go to the centre of the wheel, and a central hub where the spokes meet and the axle is held.
• Wheels are most commonly found on transport, which allow the vehicle to move, although they are used in many other applications including machinery.
• Modern wheels are made from metal, although they were originally made from wood, and they often have a rubber tyre on the outside of the rim of the wheel to protect the metal wheel and to reduce shock from bumps, holes and rocks on the ground.
• Wheels are often used in transportation, farming and industry machines, as well as on moving toys.

• The idea for the wheel is said to have come from the process of moving heavy items by sitting them on logs or similar, and this process was developed further by having a platform that sits on the logs, which eventually became a basic cart.
• Other inventions such as propellers, jet engines and wind turbines were derived from the idea of the wheel moving on an axis.
• Evidence of the use of a wheel, a potter’s wheel, dating back to 3500 BC, has been found in Mesopotamia (modern day Iraq).
• Other significant types of wheels throughout history include spinning wheels, water wheels, cogwheels (toothed wheels), steering wheels and grinding wheels.
• Hub-less wheels do exist and are very eye-catching, although they are not widely used due to their practical limitations and expensive manufacturing process.

Bibliography:
Wheel, 2013, Wikipedia, <http://en.wikipedia.org/wiki/Wheel>