View of a machinist at the Pontiac Motor Division operating a grinding machine, while looking into a mirror. Label on front: "American ingenuity at work. A dime store mirror attached to the end of his grinding machine enables this Pontiac Motor Division machinist to be in two places at once. Watching the reflection he is able to tend the machine and at the same time observe its action on the end of the long anti-aircraft cannon barrel." Handwritten on back: "Workers--Unusual."
