This paper provides some history of Roentgen's famous discovery of x-rays, a technical review of radiation exposure units, and a history and overview of the risk associated from using or being near one of the earliest of x-ray applications, the x-ray shoe fitter.

While browsing through an antique store in Bethlehem, NH, I was asked by the owner if I needed any help. I made my usual query about the availability of red Fiesta Ware (the radioactive kind) or Vaseline Glass (also radioactive), and I got the usual response, "No, that stuff never stays here very long. You might try eBay." So I resigned myself to another 15 or 20 minutes of following my wife around, looking at high-priced items that I used to own, but had foolishly thrown away over the years (is the Corning Ware I got as a wedding present 24 years ago really antique?). Then I saw what I had only heard of previously through word of mouth. It was an x-ray shoe fitter. The machine, an essential fixture of successful shoe stores during the 1940s and 1950s, was in perfect condition (see Fig. 1). With the press of a button, you could look at a real-time x-ray image of your foot inside a pair of prospective new shoes. Always looking for a new way to present topics to excite students about physics, I realized the x-ray shoe fitter would both intrigue and surprise them as they were introduced to the concept of x-rays.

Figure 1.