But intrigued by the challenge, he returned to Edinburgh and tried dowsing for himself. Reddish's article and a positive new report by a German physicist have rekindled a long and sometimes acrimonious dispute. For millennia, humans have scouted for underground aquifers and other natural resources with the help of dowsing rods. More recently, diviners have expanded their efforts by looking for buried utility lines. Throughout dowsing's long and colorful history, people have wondered what might explain it.
Skeptics frequently ascribe it to charlatanry or the practitioner's imagination.
But critics and believers generally agree that whatever the cause, the rod serves only as a vehicle for signaling an effect produced on or by the diviner. Indeed, it's the explanations for what a dowser's body might be responding to and how unimpeachable the scientific evidence of dowsing's efficacy is that divide skeptics and dowsers. Robert R. Humphris happened into dowsing 20 years ago, when his teenage son came home from a summer job and began pacing up and down the driveway with a pair of coat hangers, trying to copy what he had seen plumbers doing earlier in the day. But he said, try it yourself. After that, I was hooked.