The Watchers comprises 6 small stepper motors with doll heads attached.
The heads survey back and forth at slightly different speeds.
When a Watcher detects an object it trys to localize it by retracing
at a slower scan speed. It also sends a signal to another Watcher
which will speed up and try to find the object, and in turn
signal yet another Watcher.
The same sort of scanning speed synchronization as that of the
is used here to cause the Watchers to scan at different speeds.