Dowsing is an extreemly interesting and curious subject. People who learn this skill are able to detect a variety of hidden objects (See Below).
1) Buried artifacts.
2) Underground streams.
3) Mineral deposits.
4) Buried pipes.
5) Energy lines (Leylines)
6) etc......etc
What really captured my attention on the subject was to learn that some "Dowsers" can detect objects using a map. Now this really blew my mind. Being able to detect items in an open field is in itself bizarre, given that it's scientifically impossible. But to find treasure for instance, from many miles away using nothing but a map and pendulum really wetted my appetite. Dowsers say that their sub-conscious minds can detect the items for which they are searching. The proceedure normally followed is for a dowser to ask questions of the tool he/she is using. These questions are directed to the subconscious mind and should be very precise to avoid any ambiguity. Prior to any "in the field" use of the tools below, a user/student would learn (or program) the response that the tools will provide to questions asked. It is not the tools that detect say the dowsers - it is the user and a (question verses response) understanding must be set up and understood prior to any practical work being undertaken. A simple way to program a "Tool" would be to use it above an upturned playing card and then asking the L-Rods or Bobb the question, "Is the card red" and so because the colour of the card is visible, you can match a response with an answer and build up a vocabularly with your instument. The answers you will recieve are as simple as the question asked and you will get a straight forward YES/NO or maybe MAYBE. eg: For an L-Rod session the question could be "is there water below" and a crossed wire response will be YES. It might be that your rods "open up" instead of crossing for a YES. This is entirely dependent on your own personal rapor with the tool. Now L-rods can give you a NO or MAYBE response but most users are simply looking for an item and only require a YES when it is detected so I'll not expand on L-rods further here.
Some of the tools used by Dowsers
L-RODS A BOBBER (OR WAND)
PENDULUMS V-ROD
L-Rods
L-rods are easily made from a wire coat hanger. For the handles you can use the plastic tube of a ball point pen. Simply hold the rods in the ready position and proceed across country until your YES (or found ) response occurrs.
Bobbers (Wands)
Bobbers are best made from a thinner guage metal than the coat hangers diameter. I found that metal-welding braising wire was ideal as purchased from my local "sell-anything DIY" type outlet. The material needs to be (as the name Bobber suggest) - a little springy. For the handle I used 2 wine bottle corks and the coiled area is readlity formed by winding the wire around a circular object. On the far end of my bobber I simply added a blob of "Blu-tack" of the right proportions just to give the tool some bounce. In the diagram below is a view looking along the shaft of the Bobber. As with all dowsing tools it's up to the user to decide which movements match which responses based on initial programming of the tool.
V-Rods
Sorry I've never made a v-rod and am unable to find any manufacturing instructions at this time. Also having never used one I'm not confident in giving advice on this tools functionality.
Pendulums
All dowsing tools are very personal to the user who either made or programed them. Many different capabilities of these devices are claimed and I don't doubt any of them. The science at the roots of their uses is unknown but has stood the test of time. Indeed Many dowsers are still employed to source hidden gas pipes or to find oil resources etc. If large companies are paying for their services, then this can only confirm that an ancient practise really does stack up to scrutiny. The motion of pendulums can be clockwise or anti-clockwise for YES/NO. Alternatively a back and forth motion could = YES or NO or you may choose a left or right motion. I prefer to use a forward and back swing as my ready position. having then asked a question of the pendulum I wait for the swing to mutate into a circular pattern. Its entirely up to the user to choose the question/ response language. With pendulums, some experts have fine-tuned their skills and by experimentation they have learned to alter and calibrate the length of string being used to enhance the detection of different materials. For example a 6" string may be ideal for one person to find silver with 8" better for copper perhaps. Also advanced dowsers can use pendulums of different weights and may use semi-precious stones, gold rings or even clothes buttons as the weight itself.
Footnote
Most dowsers believe that our subconcious mind has senses that are able to detect hidden objects etc. and that our concious minds tap into that information. I believe that the subconcious mind exists solely to perform automatic functions and life responses to ease the "running load on our conscious minds. There is a 3rd component to any human being and this is the immortal superconscious mind which is part of a greater universal conciousness. So in my view each human has a conscious, sub-consious and super-conscious mind. The super-concious mind can communicate with the subconcious mind but not with the conscious mind. As the sub-conscious mind has a two way link with the concious mind it, can transmit information coming from super-conscious sources directly to our conscious minds. So I think that dowsing is a skill owing it's insight to an all knowing collective super-conciousness. Perhaps the diagram on this link will clarify this paragraph a little. Diagram of Human Consciousness
Further reading and kit suppliers