[Tractorfan]

Hi,
I remember seeing them in Lewis's department store in Liverpool as a kid in the 60s. (As well as noticing the unusual twin gang 'Walsall' type mains sockets at the base of each stone column!)
The cameras had five lenses, including one that pointed straight down looking at the floor. They had two red flashing lights and were hemispherical, instead of the later hexagonal shape. OI presume they had something like a 1" vidicon camera within.
They moved round and scanned the area before reversing back again.
Of course, no one knew which was the real camera.
Cheers, Pete.