The first person to make a significant scientific examination of dowsing. A professor of physics in the Royal College of Science, Dublin, Barrett published his theories in The Divining Rod (1926). He suggested that clairvoyance by the dowser stimulated an involuntary muscular reaction that caused the dowsing rod to turn. Barrett was involved in psychic research and his explanation hovered between the physical and the psychic. On the one hand, he thought that the dowser’s involuntary reaction that flipped the rod might be the result of auto-suggestion that arises from cues picked up from the surroundings. On the other hand, he suggested that some kind of clairvoyance might be involved, the dowser receiving signals from the hidden water.
Although Barrett’s basic theory of the movement of the dowsing rod is today generally accepted, his own ambivalence on the subject is mirrored in the two prevailing views. The skeptics hold that the explanation lies in the dowser picking up clues that trigger the involuntary muscular action; the other party will not accept that, maintaining that the dowser receives some paranormal information that triggers the muscular action.