National Geographic : 1917 Aug
Westinghouse ELECTRIC MOTORS AND CONTROLLERS The Power Behind King Steel Nowhere can one gain a more vivid impression of tremendous forces than in a modern steel plant The massive structure of a blooming mill, the ease with which it shapes the ponderous ingot, are amazing to the layman. Yet, strangely enough, the force that drives the mighty mill is confined within the slender wire windings of the electric motor. More surprising still, that force is created simply by the swift revolution of one part of the motor within another. The revolving part, or rotor, moving in obedience to a magnetic pull that operates through the air gap between the two elements of the motor, turns a massive shaft and rolls out the white-hot steel.