http://www.zimbio.com/pictures/L-oY6KeqzmT/Hidden+World+London+Underground+Night+Shift/GOTEeHxLthr
which shows wonderfully atmospheric images of night workers and explains the work they do.
Smith’s photographs of working-class Britain were published, including three shots of the South Wales valleys. In a documentary made by BBC Wales, Professor Dai Smith traced a miner who described how he and two colleagues had met Smith on their way home from work at the pit and had been instructed on how to pose for one of the photos published in Life magazine. (http://www.masters-of-photography.com/S/smith/smith_articles1.html)