The Trembling Tower

A windowless experimental room of a research institute in Menlo Park, California, smooth pale walls with dark baseboard strips, evenly lit by ceiling fluorescent tubes, a large pale wooden box and a low wooden ramp on a smooth grey floor, in the open doorway a wheeled robot one and three-quarter metres tall, a flat chassis of bright metal with a black rubber bumper ring, thin wire feelers, two wheels with blue hubs, above it a black-framed box with grey side panels and ventilation slots, a small green box on top, a swivelling aluminium head with a television camera, lenses and a rangefinder, crowned by a translucent red disc, every panel plain and unmarked.