E-rays (from German Erdestrahlen, earth-rays) are believed to originate within earth and penetrate the crust to form invisible square lattices. Local circumstances such as underground streams, rock crevices, mineral ores, etc. also cause fields to radiate from the ground. These fields are believed to affect health, animal behavior, 'human auras', plant growth, and many other things. In addition, the fields can easily be detected by the use of the dowsing rod, and, to this day, by the dowsing rod only"

Found here: http://www.lysator.liu.se/~rasmus/skepticism/dowsing.html

E-rays are something currently new to science, as far as I can tell, and are a bit of a mystery. However, they are one of the more scientific theories that revolve around dowsing rods & how they work. If they can pick up on energy, and these e-rays bounce off of the surface differently when coming into contact with water, and also change in accordance to the amount, speed, or depth of the water...this means that by the time the e-rays penetrate the surface of the earth to where the dowsing rods can detect them, they will have been affected by the underground obstacles enough to the point where the way they have changed can tell you what is below the surface & how deep/fast it goes, etc. Because dowsing rods can pick up on energy, they will react to the e-rays, and the way they react is how you determine what you've found.

Generally speaking, the stronger the EM field, the more the rods will cross. At the strongest point they may cross over each other as far as possible. This is why they don't cross until you've entered a field of energy. The field is strong enough that it begins to pull the metal rods closer to one another until they cross. Once they cross, you are in an EM field. If you've ever used rods you'll notice that if they start to cross, and you continue in the direction of the center of that field, then they will continue to cross further along the length of the rod. I'm assuming that this is because once they have crossed, that point of crossing is directly over the center of the EM field.

Now, with the wooden "Y" dowsing rods this works differently. You have one hand (palm up) on each branch of the Y, and you create tension by pushing the branches out as you hold them. Now if you can imagine this situation, you'll realize that it's probably difficult to keep the branch from wobbling. However, once you've gotten used to holding it steady with the tension you're putting on it, you'll find it easier to use. If you are able to hold it steady with the tension, then you can probably imagine that it take quite a bit of concentration to do so. With this in mind, lets say you are holding it steady, but you begin to enter a field where the e-rays are slowly becomming more prominent. Because the e-rays bounce off of the more solid obstacles underneath the surface, you can imagine that they would also bounce off of the underside of your branch. This is what causes the branch to wobble; the stronger the wobble, the the higher the number or speed of the e-rays there are penetrating the earth's surface. Now you can imagine that with all the effort you've made to keep it steady that you would feel the slightest wobble. I think the reason this style is so effective is because of the way you hold the branch while putting tension on it; it makes it very unstable, but once you've learned to keep it stable you will feel the slightest movements it makes.

E-rays are like X-rays (they're everywhere! lol); we still don't know exactly what they are, but we somehow managed to find them & eventually learned to use them to our advantage through trial & error. We eventually realized that concentrated amounts of X-rays were bad & we found out that lead could prevent penetration. We still don't know what X-rays actually are, or what causes them, but they've been here all along. It's the same thing with E-rays, aside from the fact that they've been pretty much ignored by science thus far.

Then there's the use of dowsing rods for divining, but I've come to learn that when you program the rods for any form of divining, the answers you get are really coming from within yourself. Whether it simply answers coming forward from your subconscious, or you using your mind to tap into your abilities to get answers (even if you don't realize it); things like intuition, etc. The divination aspect is really just the person tapping into other areas of their mind that will translate the correct answer into the corrosponding muscle twitches that will cause the tool to give you the correct answer in accordance with your programming of it. Basically you program your mind to twitch certain muscles to move the tool a certain was for yes/no, and when it finds the answer (in old memories/esp/intuition/whatever) it translates it back to muscle twitches to move the tool.

More on Dowsing Rods can be found at: www.sdanet.org/atissue/ books/dowsing/d02a.htm