Ritter Intra-Oral Stereoscope (ca. early 1930s)
This device was used to generate three dimensional images of dental/oral X-rays. According to one source, this improved the dentist's or physician's ability to localize "foreign bodies and supernumerary teeth. Odontomas and maxillary cysts also will be better visualized."
The patent was applied for in 1927 and awarded in 1931. Since the label on the base states"Patent Applied For," I am guessing that this particular unit dates from the early 1930s. Nevertheless, these were in use at least into the 1950s.
Size: ca. 14" high
Kindly donated by the Health Physics Society.
U.S. Pat. No. 1,808,176. June 2, 1931. "Stereoscopic View Box."