A phenomenon similar to water divining and dowsing in which a small pendulum is used instead of a forked twig. The pendulum is made by suspending a weight of any material, for example a finger ring, on a chain or thread. Without any conscious effort on the part of the operator, the weight when suspended is said to start swinging in one of many ways: in straight lines back and forth or sideways, or in clockwise or counterclockwise circles or ovals. Depending on the context and the questions to be answered, these motions are interpreted differently.
The term “radiesthesia” was coined by a Swiss priest, the Abbe Mermet, in the 1920s, but the pendulum is thought to have been used in Europe as early as the 18th century. The system was used by the abbe initially as a method of medical diagnosis; the term actually means “sensitive to radiation” and denotes a concern with disharmonies in energy patterns in the body. The motion of the pendulum, when hung over a patient, was believed to detect, diagnose, and even cure an ailment. The pendulum was also put to use to find the growing places of wild plants for herbal medicine. Many even wilder claims on the power of the pendulum have been made; for example, the device was used to find lost objects and the locale of buried treasure. As a follow-up to this, it was put to use in archaeology, where it was alleged not only to find sites but also to locate, describe, and date artifacts before they were even unearthed. Later, the pendulum came to be used on all occasions where previously the dowsing rod was utilized, as for example in finding underground water and mineral deposits. There were also forensic claims as in detecting criminals and in authenticating paintings.