tracing veins. These are simple rods bent into the shape of an "L"; when the dowser walks over the water vein, they either open out or cross each other. As with any tool, the movement depends on what the dowser expects. The final tool, a pendulum, is not quite as useful for finding water, but it is perhaps the easiest tool for a beginner to master. The dowser attributes a "yes," "no," and a neutral to each of the pendulum's movements (back and forth, clockwise and counterclockwise) and uses it to answer simple yes-and-no questions—such as whether the gallonper- minute flow is 20 or 30, whether it is worthwhile to divert a vein back into an old