RADIO MOTOR:
Another scheme of the rotary type, perhaps even better adapted to the distant control of large motors, is a small synchronous radio motor driven by power carried by radio from the broadcasting station to the receiving stations. It is, of course, rotated partly by radio power from the distant station, and partly by local current, just as a loudspeaker is operated. These small motors, rotating in synchronism with the motor at the sending station, control the rotation of a larger motor in each receiving camera, and so all stations keep in step.