National Geographic : 1917 Aug
Photograph byHugh Kennedy A QUARTER OP A MILION TONS OF PIG IRON AT BUFFALO This mountain of metal was handled by an electro-magnetic crane. It is interesting to watch such acrane loading acar. The lifting arm goes out over the pile, the cable drops the magnet down into contact with the "pig," a little lever is moved, and theinert magnet takes unto itself invisi ble power as great as that of steel grappling hooks. Then the cable pulls up the magnet and its tons ofadhering "pigs," thearm swings around, the magnet is let down into the car, the current is turned off, and the invisible hold released. Carsare loaded toexact quantities, and thefinishing process reminds one of the grocer weighing out a bag of sugar. The man at the scales calls out, "One thousand short." The craneman thereupon cuts off a tiny bit of current and a corresponding number of "pigs" drop into the car. Now there isslightly toomuch, and thecraneman adds more "juice" to the magnet, which picks up a pig or two and the scales balance.