Unloading and storing from cars is accom plished as follows: The grain-laden cars are usually run up along the side of the building so that each car is placed directly under an ele vator leg. Two men in each car, operating shovels by ropes from a steam-driven shovel shaft, shovel the grain into the pits of the elevator leg, and thus fill the buckets of the conveyor, which, operating continuously, carries it up to the cupola, where the buckets are tipped over automatically and their contents dis charged into the turnhead spouts. From these the grain passes by gravity into the garners, thence into the hoppers of the weighing ma chines, thence to the cleaners if desirable, and finally through a system of spouts to the storage bins.
When transferring grain from ships to rail way cars the elevator legs are swung out side the house and their feet lowered into the hold of the vessel through the hatchways. The conveyors carry the grain to the turnhead spouts from which it passes to the storage bins, and thence through the floor valves of the bins to the cars placed beneath them. Under such con ditions they are called "marine elevators? and when the mechanism is mounted on a barge or float to permit of its being moved from place to place, it is commonly known as a "floating elevator? A carload of 1,200 bushels is delivered in about three minutes.
To load grain from an elevator into 1...e grain-carrying vessels of the Great Lakes, the vessel is made fast alongside the house, and its hatches being removed, the grain is poured by gravity in a perfect torrent into its hold through great spouts which extend to the hatchways from the floor valves of the bins. The discharging capacity of these spouts ranges from 12,000 to 60,000 bushels per hour and load vessels of the greatest capacity in two or three hours. In the largest elevator, where the work ing house is separate from the storage house, the grain is spouted from the bottom of the bin on to a belt conveyor by which it is carried to the top of the working house where it is weighed and then delivered to the loading spouts.
The loading and storing capacities of indi vidual elevators vary greatly according to their location. Innumerable small structures capable of handling only a few thousands of bushels each are located along the of railway traversing the grain-bearing regions of the Western States. These are owned and operated by the railroads. But at the large centres of flour manufacture and grain transportation, such as Minneapolis, Duluth and Chicago, are elevators of mammoth proportions, with indi vidual capacities ranging from 500,000 to 5,000,000 bushels. One of the medium-sized elevators at Duluth is 285 feet long, 85 feet wide and 150 feet high. Nine belt conveyors driven by a 200 horse-power steam engine lift the grain to a height of 145 feet to the turn head spouts. Each belt carries 125 buckets having a capacity of one peck each, so that the total load at any working instant is about 270 bushels or 15,000 pounds, representing an un loading capacity of 12,000 bushels per hour. The cleaning machines have an individual capacity of 3,000 bushels per hour, and the dryer house passes 2,000 bushels per hour. In many • of these larger elevators the motive power is electricity, each machine having its own special motor.
Throughout the grain-producing regions of the West the co-operative elevator has become a very considerable factor in the handling of the country's grain crops. The movement be gan to take on substantial proportions in the year 1900. Since then these farmers' co-opera tive elevator associations have steadily in creased until at the present time it is estimated that they handle nearly 40 per cent of the grain sent to market. These elevators are all small, but pay their owners dividends, which range up to 7 per cent, although the average would be nearer 3 per cent. Consult Grain Dealers' Journal 'Plans of Grain Elevators' (Chicago 1913); Ketchum, M. S., 'The Design of Walls, Bins and Grain Elevators' (New York 1911); Zimmer, P. G., 'Mechanical Handling of Materials' (New York 1905).