I remember seeing that as a kid, but it's been a long, long time ago. Not that I've grown up. I've just grown older.
That cylindrical device was an upright drum that had an abrasive coating on the vertical surface and a similarly coated rotating bottom. It basically sanded the peel off the potato by tumbling them against the abrasion (like those spray on truck bed liners).
From there a chute put them in a sink where they could be washed and hand cut in a cutter into another sink where they could be further washed. Then fried for a while (blanching) and then stored on a rack until final cooking.
Best fries ever.