The picture is of a wheel. Click here for the link.
The wheel
The Mesopotamians' most important and notable invention was the wheel. The earliest examples of this date back to 3500 B.C.E. Sumerian potters used the wheel to shape clay into pots. The potter's wheels would spin on an axle, with the flat side of the wheel facing upward. The Sumerians made further improvements with the wheel when they discovered that if it was flipped onto its edge, it could be rolled. They used this discovery to create chariots for the army and wheeled carts for farmers. The Mesopotamians clamped pieces of wood together to create the wheel. The wheel really improved daily life in Mesopotamia because before, people dragged their goods on sledges, or flat-bottomed carts that often got stuck in the mud. Sledges could not move goods over long distances or support heavy loads. Wheels made these things possible. Another invention was the arch.