The shoe fitting fluoroscope was a common fixture in
shoe stores during the 1930s, 1940s and 1950s. A typical unit, like the machine shown here, consisted of a vertical wooden cabinet with an opening near the bottom into which the feet were placed. When you looked through one of the three viewing ports on the top of the cabinet (e.g., one for the child being fitted, one for the child's parent, and the third for the shoe salesman or saleswoman), you would see a fluorescent image of the bones of the feet and the outline of the shoes.
According to Williams (1949), the machines generally employed a 50 kv x-ray tube operating at 3 to 8 milliamps. When you put your feet in a shoe fitting fluoroscope, you were effectively standing on
top of the x-ray tube. The only “shielding” between your feet and the
tube was a one mm thick aluminum filter. Some units allowed the operator
to select one of three different intensities: the highest intensity for
men, the middle one for women and the lowest for children.