A New Controlled Dowsing Experiment Putting the president of the American Society of Dowsers to the test Michael Martin I have taught a course at Boston University for several years entitled "Philosophy of Science and the Occult." Each student in the course is re­ quired to do a project in which some claim of the occult is subjected to critical scrutiny. In the spring of 1981, one of my students, Perry Flint, designed and performed a controlled dowsing experiment. The subject of the experiment was Paul Sevigny, president of the American Society of Dowsers and an experienced dowser. Before the actual experiment was performed, Mr. Sevigny gave an informal talk to some of my students and demonstrated the use of dows­ ing apparatus. Perhaps the most notable feature of this talk was the sweeping claims Sevigny made about dowsing. We learned that dowsers could not only determine the depth of underground water and the direc­ tion of its flow, but could locate water at a distance by seeing where the dowsing rod dipped on a map. Sevigny said that by using a dowsing rod members of his organization could locate missing persons, predict the sex of babies still in the womb, and locate the position of our nuclear sub­ marine fleet on a world map. After Sevigny's talk, we moved across the hall to a room in which Flint, with the help of my graduate-student teaching-assistant, Paul Krustapentus, had set up the experiment. It was quite simple in design and inexpensive to perform. It might well serve as a model for others who wish to test the powers of dowsers. Briefly, the experiment set up was this. Four plastic water-hoses ran from one plastic trashcan on one side of the room to another trashcan on the other side of the room. A water pump was attached to one of the four hoses and water was pumped from one can to the other. The pump, the person who operated it, and the trashcan containing water were all hid- Michael Martin is a professor of philosophy at Boston University. 138 THE SKEPTICAL INQUIRER, Vol. 8 den from the view of the dowser and the audience by a screen. The four hoses that ran across the floor were covered with a rug. The position of the four hoses underneath the rug was indicated by large pieces of paper on the floor with the numerals 1, 2, 3, 4 written on them. The operator behind the screen chose one of the four hoses, attached the pump, and pumped water through the hose from one can to the other. The choice of hose was determined by an inexpensive battery- powered randomizer commercially available for ESP experiments. In order to help eliminate the possibility that the dowser would pick up auditory clues from the water flowing through the hose, a loud electric drill was activated when the water pump was in use. During most of the experiment Sevigny, with dowsing rod in hand, walked back and forth over the rug attempting to determine which hose had water flowing through it. Occasionally he sat on a chair and attempted to dowse from a distance by asking the rod questions, for example, "Is it hose number one?" A dip of the rod was interpreted as a positive answer. He used the standard forked dowsing-rod most of the time, but on occa­ sion he used two L-shaped rods, one held in each hand. After Sevigny called out his guess, the operator behind the screen pushed a revolving drum stationed on a table alongside the screen. This drum swung around toward the audience and on it was pinned a piece of paper bearing the number of the hose the water was in fact flowing through. (The operator had pinned the paper on the drum before the pump was activated.) Sevigny's guesses and the correct answers were then written on a blackboard in the front of the room and independently recorded by a student on a piece of paper. Forty trials were run. If nothing but chance had been operating, then one would have expected about ten correct guesses in the forty trials. Sevigny got nine correct guesses in forty trials. The difference between Sevigny's performance in a controlled exper­ iment and his claims in the informal discussion beforehand was quite remarkable. What was Sevigny's explanation? He did not seem upset; in fact he laughed and joked about his bad performance. But he maintained that this experiment meant nothing; it was "just a game." He said that, if he had to find water under serious conditions, then he would be successful. The contrast between the claims made in the discussion and the per­ formance in the experiment was a good lesson for the students. From the standpoint of raising skeptical doubts in students' minds, there is perhaps nothing better than being able to compare for oneself a person's claim to possess allegedly occult powers and his or her failures in actual practice. Aside from the pedagogical impact of the negative results of this experiment, it should be noted that the results are completely in keeping with both the review of the evidence for dowsing provided by Vogt and Hyman (1979) and the recent experiment of Randi (1979) published in Winter 1983-84 139 this journal. The available evidence can be succinctly summarized: When dowsers perform under controlled conditions, they do not do better than one would expect by chance. References Randi, James. 1979. A controlled test of dowsing abilities. Skeptical Inquirer 4(1): 16-20. Vogt, Evon Z., and Ray Hyman. 1979. Water Witching USA, 2nd ed. Chicago: University of Chicago Press. • We* Zealand Listener "The practice of astrology took a major step toward achieving credibility today when, as predicted, everyone born under the sign of Scorpio was run over by an egg lorry." THE SKEPTICAL INQUIRER, Vol. 8 .