Ritter Model A Dental X-ray Machine Serial No 300. This antique X-ray machine was manufactured by Ritter Dental Company in Rochester, New York. It comes in two parts: the X-ray machine and the display cabinet. It comes with a description on the cabinet that reads, "In the late 1880s, Mr. Frank Ritter established his mark in the dental world by creating the first dental chair. In what was known as the golden years of the Company between the early 1900s and late 1950s, the company introduced the first dental operating unit (1917) and the model-A dental x-ray unit (1920) that is displayed here. This new device gave the dental profession its most effective instrument for making dental diagnoses. To adapt the machine for use with the various voltages and frequencies of the era, two separate groups of transformers were used. What looked like a huge battery inside of the door of the cabinet was the source of power, a large high-voltage transformer. Both patient and operator had to stay further than 12 inches from the high voltage wire which ran outside the arm from the transformer cabinet to the x-ray head. Even with the operating guidelines at that time, exposure to the x-rays produced was viewed as an occupational hazard and little was done to protect the operator or the patient." The case measures 48 x 26 5/8 x 80 inches, and the X-ray machine measures 22 x 18 x 70 inches.