Hand Truck

A hand truck, also known as a hand trolley, dolly, stack truck, sack barrow, or two-wheeler among other names, is an L-shaped device with handles at the top, wheels at the base, and a small ledge for holding a load. To use it, a person tilts a load forward, slides the ledge underneath it, and tilts the load back so its weight balances over the wheels, letting the hand truck act as a first-class lever that makes moving a heavy or bulky object far easier than carrying it by hand. The device originated in the eighteenth century, when it was used on docks so that young boys, who could not lift large sacks of spices by hand, could move them at adult efficiency. Hand trucks later spread into industries such as brewing and moving, and specialized versions exist today for tasks including transporting gas cylinders, serving as airport and train station baggage carts, and, in a curved form, tilting pianos. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/