The Radium Room

Here's a photo taken inside the Elgin watch factory, about 1930.  The caption reads:

APPLYING "EVENING MAKE-UP" TO THE FACE OF A WATCH.  The Radium Room.  Radium occupies a department of its own, that people are not allowed to visit.  The room is finished entirely in white enamel, well lighted, and the air is changed every seven minutes to keep it clean and fresh.  Exhaust pipes which carry away all impurities can be seen in front of each girl.  Only a small potion of radium is mixed at a time, and all stock is held in lead containers, as is the daily mixture.  A common pen is used to place the radium on the hands and numerals of the dial.  Each girl is provided with a smock, and compelled to leave it in the department.  Every Precaution is taken so that no part of the radium reaches the operator.

From Elgin National Watch Co