In the grain trade, a grain elevator is a tower containing a bucket elevator or a pneumatic conveyor, which scoops up grain from a lower level and deposits it in a silo or other storage facility. In most cases, the term "grain elevator" also covers the entire elevator complex, including receiving and testing offices, weighbridges, storage facilities etc. It may also mean organizations that operate or control several individual elevators, in different locations. In Australia the term grain elevator refers to the lifting mechanism only (See "usage" below). Prior to the advent of the grain elevator, grain was usually handled in bags rather than in bulk (large quantities of loose grain). The elevator was invented by a merchant named Joseph Dart and an engineer named Robert Dunbar during 1842 - 43, in Buffalo, New York. Using the steam-powered flour mills of Oliver Evans as their model, they invented the marine leg, which scooped loose grain out of the hulls of ships and elevated it to the top of a marine tower. Early grain elevators and bins were often constructed of framed or cribbed wood, and were prone to fire. Grain elevator bins, tanks and silos are now usually constructed of steel or reinforced concrete. Bucket elevators are used to lift grain to a distributor or consignor, from where it falls through spouts and/or conveyors and into one of a number of bins, silos or tanks in a facility. When desired, silos, bins and tanks are emptied by gravity flow, sweep augers and conveyors