Dowsing involves the use of a forked tree branch (“dowsing rod”) to find underground water. Sometimes a pair of metal rods are used, and sometimes oil, minerals, and metal objects are claimed to have been found. When the dowser feels sudden jerks from the dowsing rod, he knows he is standing over a source of water (or oil, etc.). The practice depends on the hypothesis that water exerts some kind of magnetic influence over the rod or engages the psychic abilities of the dowser (or both). Design an experiment to test for the existence of this phenomenon. (See the references to dowsing in Randi, 1982a.)

Design or perform the following experiments, as directed.