4500 BC: Wheels, our greatest invention
THE WHEEL is often described as the most important invention of all time – it had a fundamental impact on transport and later on agriculture and industry.
The wheel-and-axle combination was invented around 4500 BC and was probably first used for a potter’s wheel.
The idea was quickly adapted for other uses – in particular on wagons and chariots.
For thousands of years, people used sledges to drag heavy loads.
At some point, they realised that placing logs underneath the sledges enabled them to move along more easily.
The wheel, fixed to the sledge, is an expansion of that idea.
On the earliest carts, the wheels were heavy, solid, and attached to the axle so the whole assembly turned together.
Soon, it became common for the wheels to turn around a fixed axle.
Wheels with spokes, first made around 2000 BC, were lighter, enabling vehicles to move faster.
Wheels were initially useful on carts and chariots pulled by oxen or horses.
But humans discovered that a wheel powered by people, animals, wind or flowing water can be put to many other uses.
Foot-powered spinning wheels appeared around 500 BC, water-wheels in the first century BC and windmills in the seventh century AD.
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.
During the 17th and 18th centuries, water-wheels powered huge machines in cotton mills.
Eventually, the steam engine became the preferred source of power to turn the wheels of industry.
There are many candidates for the most important invention of all time. Many of them – including the wheel – were developed in early civilisations.
Instead of hunting and gathering, they farmed the land and kept animals.
As settlements grew, people had more time to wonder about how the world works and to develop new technologies and techniques such as metalworking.
Stone gave way to bronze – a hard mixture of copper and tin – and the Stone Age became the Bronze Age.
Several of the most important early civilisations were in Mesopotamia, a large area between the Tigris and Euphrates rivers covering much of what is now Iraq.
Historians often call Mesopotamia the ‘cradle of civilisation’.
The city-states of this region had governments and laws, they had mathematicians and astronomers, and their inhabitants developed calendars, writing and systems of measurement.
The wheel was invented in Mesopotamia, and bronze was first used there.
Other early civilisations also grew up around big rivers. In Ancient Egypt it was the Nile; in Ancient India, the Indus; in China, the Huang He (Yellow River).
All of them flood every year, making low-lying areas dependably fertile.
Major technologies that developed in all these early civilisations include primitive timekeeping (water clocks and sundials), metalworking and glassmaking.
In Bronze Age Britain, people settled in small tribes, not a widespread, organised civilisation.
Travellers from civilisations abroad introduced new technologies, including the wheel.