Pendulum

The pendulum is one of the oldest and most frequently used means of divining and fortune-telling since it has always been available to everybody. A ring or key fixed on a ribbon or string could easily be used as a pendulum, but people also made use of sieves and various other objects. 
A detailed map becomes necessary if the pendulum is used in order to locate a certain place or a vein of water. The pendulum can also be helpful for detecting troublesome elements that could affect the floor plan of a house or apartment.

Some doctors or healers use the pendulum to detect diseases, either on the patient him- or herself or on a blood or urine sample. Once again, I'd like to emphasize the fact that we do believe that the pendulum can be used as an additional means of diagnose, but you really should have a careful look at the person as well as his or her references. In no case should a diagnose be made on the sole basis of pendulum movements. If your complaints persist of even get worse, you should immediately consult traditional medicine and modern means of diagnose.

If you want to follow our advise and warnings when testing your sensitivity with a pendulum, you are now sufficiently instructed to go ahead.
You can find further readings in most bookshops. The titles mentioned below are only some possibilities you have to get deeper into the topic.
Further references

Divining Rod by Michael Knight

The Bit and the Pendulum: How the New Physiscs of Information is Revolutionizing Science - by Tom Siegfried

Pendeln ist elernbar. Ein methodisch aufgebautes Lehrbuch zum Pendeln und Ruteln - von Gertrud I. Hürlimann - M u. T Verlag, Zürich, DM 45.--

Pendel und Wünschelrute. Das große Praxisbuch - von Christiane Denryck - Ariston-Verlag, München, DM 39.80

Der richtige Platz - von Eva-Maria Mülle-Tschopp, Eric Tschopp - AT Verlag, Aarau, DM 39,90