" rabdomanzia (= rabdomancy, I suppose)
This is not fortune telling, but has the same kind of root. In fact, there are people that pretend to be
able to guess where the water is in the underground, by walking and holding in their hands aY-shaped
stick: when the stick "moves", it should be a good place to drill a well."

Rhabdomancy

Amazing what some people will believe. A long time ago the Boston Herald columnist Bill Cunningham had a friend who was such an accomplished "dowser" that he was able to locate a place to dig a well in Bermuda by pointing his dowsing rod at a map of Bermuda Now, that's a remarkable skill.