Apprentice turner at the lathe, Berlin, c. 1900

Alfred Kelly.  The German Worker.  Working-Class Autobiographies from the Age of Industrialization.  University of California Press, 1987.

Photography was still pretty new in 1900, so it must have been an intimidating experience for this young apprentice when someone decided to set up the bulky camera to take this photo.  No one smiled for photos back then.