Wheelbarrow
A wheelbarrow is a small one or two-wheeled cart designed to be pushed by a single person using two handles to the rear. They are designed to ease the transport of heavy, often loose, loads (see lever) and are common in the construction industry and in gardening.
A two-wheel type is more stable, a one-wheel type has better maneuverability.
Modern designs are usually single wheel, with a pneumatic tyre. Common designs are all metal with a separate frame and tray. The noise generated by all metal designs in loading and moving means that for domestic use polypropylene trays are more common (as are solid tyres) being lighter and quieter but less tough.
History
Despite the development of wheeled carts from around around 5,000 years ago, the invention of the wheelbarrow is usually traced to China, where there are a number of competing claims. Invented around the 3rd century AD it is usually credited to Zhuge Liang, advisor to the Shu-Han Dynasty from 197 to 234, who had it developed as a transport for military supplies. The design was with a large single central wheel around which a wooden box was constructed but it was soon adapted to a design with two handles for pulling. The first indications of wheelbarrows in Europe are from illustrations in the 13th century. It was in Europe that the design was reversed with the wheel moving from the centre to the front of the box and the motive power to the rear.