Wheel

A wheel is a circular block, usually made of a hard and durable material. In the centre of the wheel is a hole for an axle, about which the wheel rotates. Wheels are usually fixed below an otherwise static object to help it move. They are commonly an element of a means of transportation, such as for cars and bicycles, but have uses in agriculture, manufacturing, mechanical engineering and beyond.

History
In the Stone Age, humans realized round objects were easier to move than irregular ones. If a cylindrical object such as fallen tree was placed underneath a large object that needed moving, the job was made far easier. However it wasn’t until around 3500BC that humans began to make their own wheels. The first were potter’s wheels and hundreds of years later wheels were used to make chariots and later for animal-drawn carts and carriages.

More than one thousand years later, the Egyptians began to create spoked wheels to improve speed and maneuverability and another thousand years later, Celtic people began using iron rims for greater strength.

The wheelbarrow first appeared in ancient Greece somewhere between 600 and 400BC, saving construction workers days of labour.

Around 600AD the wheel was first used to create modes of transportation, even though it was being used for irrigation, milling and pottery.

Around the 19th century the pneumatic tyre was invented This was a rubber wheel of compressed air, a design that paved the way for the car and bicycle tyres we use today. Wire spoked wheels combined with pneumatic tyres allowed wheels to be both stiff and light.

Impact
The wheel is one of the most important invention of all times, having a fundamental impact on transport and later on agriculture and industry. Use of the wheel has continued to revolutionize travel and transportation through to the present day. It is used in trains, cars, bicycles and motor-bikes. The wheel was fundamental to the creation of the propeller and jet engine.

Its use in agriculture is almost as important as its use in transportation. For centuries, waterwheels and windmills helped irrigate fields or remove water from flooded areas; they drove grinding machines to produce flour; they powered bellows and hammers in metal workshops.