Amongst the most ancient -and most essential- technologies developed since the rise of modern Homo Sapiens, the wheel is an invention that quite literally makes the world go ’round. The word “wheel” in our language is derived from the Old English “hweol,” which was in turn derived from even older roots in Proto-Germanic and Proto-Indo-European languages (Online Etymology Dictionary).
The earliest examples of wheels discovered by archaeologists appear around 3500 BC in Mesopotamia, near the Black sea (Thinkquest.org). The first recognizable wheels in Eurasia were of a peculiar design, composed of longitudinally-cut boards that were attached together and shaped into a disk, through which an axle was mounted. This design was necessary due to the internal structure of wood; simple slices of a tree trunk would be unable to support any considerable weight (Diamond 255).
This initial design was eventually improved during the 2nd millennium BC, when the spoked wheel was developed in what is today Western Siberia. The spoked wheel offered a number of advantages over the older wheel design, including improved structural stability and considerably reduced weight. Since spoked wheels contained less material to construct, they also proved to be more economical to build. The invention of the spoked wheel allowed for the use of horse-drawn chariots in the classical Greek and Roman cultures, thereby reshaping the face of tactics, and of history, irrevocably. Additional innovations, such as the use of metal rims and the invention of tires, have refined the original idea without reinventing the wheel.
The invention of the wheel likely took place in what is now Iraq during the 5th millennium BC, where it was used as an early potter’s wheel rather than as a means of conveyance and load-bearing. The earliest confirmed discovery of a wheel used for vehicular purposes, as mentioned above, was around 3500 BC in Mesopotamia. Art of the period, frequently found on ceramics, illustrates the use of carts – the earliest known example of this is the Brononice Pot, a Polish ceramic container which dates back to 3500 BC (bronocice.dzialoszyce.info).
There is some evidence that the wheel was independently invented elsewhere, in addition to the prominent rise of wheel use in Mesopotamia. In pre-Columbian Mexico, for example, archaeologists have uncovered simple ceramic wheels that were used in children’s toys and small models. Larger wheels may never have been developed there, due to the lack of large mammals, such as horses or cattle, to pull a cart (Diamond 248). Some archaeologists have made claims to an independent development of the wheel in the Far East, but solid evidence for such a development has yet to emerge.
The invention of the wheel itself was most likely the result of a long process of observation and gradual improvement, rather than a sudden inspiration. There is evidence to suggest that the earliest cultures moved heavy burdens by dragging them rather than lifting them. Somewhere along the line, it was discovered that objects were often easier to drag along the ground with the assistance of a sled or runner, which would prove to be the precursor of a cart bed. It is likely that many of the earliest megalithic sites were constructed with the assistance of these sleds; Stonehenge’s massive bluestones are perhaps the most recognizable candidate for this sort of movement.
Eventually, the sled was combined with rolling logs or sticks to form what is called a sledge, allowing for even heavier burdens to be moved more easily than before. The mass was moved by rolling the sled atop the round logs. While this allowed for a much greater ease of movement, it was inefficient because the logs had to be continually placed in front of the mass in order to roll the mass.
Continued evolution of the log-rolling idea eventually resulted in simple axles as the movers noticed that it was easier to move a weight after a log became grooved by the burdens; the weight would rest on the grooved section, while the rest of the log would retain its original circumference. The weight would therefore move farther with less effort expended. A simple axle had been invented.
It was not long before this idea was expanded upon, and the wheel was made independent of the axle. Larger wheels allowed for more effective motion. The first raised carts were the direct result of this discovery. It was not long before the axle was permanently fixed to the cart bed itself, so that only the wheels were rotating. With relatively minor modifications, this design is the exact same idea that allows for automobiles and other modern wheeled devices.
References:
Diamond, Jared. Guns, Germs, and Steel: The Fates of Human Societies. New York: Norton. 1997.
