when street cleaning reminds you of tape recording...

"funny, i just thought of an odd analogy... know those dizzy rear-steering wire-brush-and-spray street cleaners you see in big cities, zooming along next to the curb, scooping all the dirt and debris, lightly sprayed with water, into a central hopper? well, those wire brushes, striking sparks (and making your spine shiver sometimes) are "scanning" the street surface somewhat in the fashion of rotating heads on a passing tape (especially, a helical-scan videotape!). they manage collectively with many fast moving steel wires, to cover a vast mileage of asphalt at a very high sweep speed, though the machine moves along the tape - i mean, the street - at a relatively slow pace. the wires and the brushes do an overlapping job that is supposed to contact all the "information" - i.e., dirt and debris - at a properly vigorous sweep frequency..."

edward tatnall canby, in audio magazine, march 1966