From Rocks to Roll.

Chapter 3: 

 

As we talked about Wheels last time, the thought grew deeper, no matter how important invention the wheel was, alone it was useless. The wheel is more like the 'Jack of all trades and Master of None'. We have an existence of wheel since early stages of Stone Age, but the use of the wheel as a mode of transportation dates back to 4200-4000 BC.

 

One of the first applications of the wheel to appear was the Potter's wheel, used by prehistoric cultures to fabricate clay pots. The earliest type, known as "tournettes" or "slow wheels", were known in the Middle East by the 5th millennium BC. One of the earliest examples was discovered at Tepe Pardis, Iran, and dated to 5200–4700 BC. These were made of stone or clay and secured to the ground with a peg in the center but required significant effort to turn. True potter's wheels, which are freely-spinning and have a wheel and axle mechanism, were developed in Mesopotamia (Iraq) by 4200–4000 BC. The oldest surviving example, which was found in Ur (modern-day Iraq), dates to approximately 3100 BC.

 

Evidence of wheeled vehicles appeared by the late 4th millennium BC. Depictions of wheeled wagons found on clay tablet pictographs at the Eanna District of Uruk, in the Sumerian civilization of Mesopotamia, are dated between 3700–3500 BC. In the second half of the 4th millennium BC, evidence of wheeled vehicles appeared near-simultaneously in the Northern Caucasus (Maykop culture) and Eastern Europe (Cucuteni–Trypillian culture). Depictions of a wheeled vehicle appeared between 3500 and 3350 BC in the Bronocice clay pot excavated in a Funnelbeaker culture settlement in southern Poland. In nearby Olszanica, a 2.2 m wide door was constructed (2.2 wide doors were constructed) for wagon entry; this barn was 40 m long and had 3 doors. Surviving evidence of a wheel–axle combination, from Stare Gmajne near Ljubljana in Slovenia (Ljubljana Marshes Wooden Wheel), is dated within two standard deviations to 3340–3030 BC, the axle to 3360–3045 BC. Two types of early Neolithic European wheel and axle are known; a circumalpine type of wagon construction (the wheel and axle rotate together, as in Ljubljana Marshes Wheel), and that of the Baden culture in Hungary (axle does not rotate). They both are dated to 3200–3000 BC. Historians believe that there was a diffusion of the wheeled vehicle from the Near East to Europe around the mid-4th millennium BC.

 

The mechanical advantage of a simple machine like the wheel and axle is computed as the ratio of the resistance to the effort. The larger the ratio the greater the multiplication of force (torque) created or distance achieved. By varying the radii of the axle and/or wheel, any amount of mechanical advantage may be gained. In this manner, the size of the wheel may be increased to a convenient extent. In this case, a system or combination of wheels (often toothed, that is, gears) are used. As a wheel and axle is a type of lever, a system of wheels and axles is like a compound lever.

 

Got a bit, sorry, a lot technical didn't I. Bear with me for another chapter, as we have now got the wheel rolling. And as they say, " Life.....it keeps rolling on."


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