The ability to find people, artefacts or substances by use of maps, pictures or physically being in a place are currently the most popular applications of Dowsing. Most dowsers use two 'dowsing rods' and/or a pendulum. The rods, traditionally known as 'Wishing Rods', are formed into an L shape and are usually made of copper although the oldest known material was wood, usually forked Hazel branches along with Apple, Beech and Alder. (It is said that metal coat hangers work just as well!). One rod is held in each hand and you have located what it is you are looking for when the rods cross.
dowsing is sometinmes used to help find broken pipes underground.