Source: Mechanix Illustrated, Oct, 1938 (from blog.modernmechanix.com )
Builds Remote Control Lawn Mower Device
Attaching two electric – motors, an old paint can, a wooden mixing bowl from a kitchen, sundry gears, wires and drive belts to a regulation lawn mower, Alvin Lodge, an unemployed mechanical engineer of Millersville, Pa., constructed a device that enables him to mow his lawn by remote control. As rigged up for its trial run, the mower successfully operated along a cable guide for a distance of 100 feet from the stationary control box shown being manipulated by the inventor.
See other early remote-controlled and robotic lawn mowers here.