Dowsing is a type of divination specifically for the location of objects, most notably water or treasure of some sort, but any item can be the subject of dowsing.
Dowsing may be done with a “dowsing rod” or “divining rod” (Latin Virgula Divina, German Wünschelrute). The rod is usually a Y-shaped forked branch, the forks making a sort of handle and the branch they join to serving to point the way toward the hidden object. When the rod is pointing in the right direction or moves over the area where the desired object is, it will twitch.
Different types of trees may provide a suitable branch for dowsing. hazel, witch hazel, willow, and peach are popular. Some modern dowsers use metal rods or bent coat hangers.
Other objects may be used as well. Pendulums are occasionally used for dowsing. A stalk of goldenrod may be used to find objects by observing the way the flower head nods.
While it’s not clear when the practice originated but it seems to have first appeared in Germany in the early 1500s and was at that time most employed to help miners decide where to dig. It is discussed in the 1556 De Re Metallica, written by Georgius Agricola, “the father of mineralogy” and a woodcut image of a man with a dowsing rod can be found in Sebastian Münster’s Cosmographia printed in 1550. In 1518, Martin Luther condemned dowsing as a sin. Other clerics continued to condemn the practice for the next century or so but France saw fit to use dowsing to track down heretics in the 17th century.
Other words and phrases that refer to this process include: doodlebugging, divining and water witching, willow witching