At Avebury two weeks ago I watched a girl dowse by the 'alter' stone. The rods crossed at a certain point as she walked. She got chatting to a young couple walking past and showed them, then gave the rods to the chap, and he tried. They crossed for him too!!! Wow!
We had a pair of rods with us, so after they left I couldn't wait to try that spot. I've always been interested in dowsing but remain unconvinced. It had never worked for me . . but I like the idea. . you know?
Anyway, they left, I tried EXACTLY the same spot. . no result. Zilch. So . . I dunno. But I'd love someone to teach me or show me that it works.
(I assume that you are talking about 'Earth mysteries' and l*y lines type of dowsing rather than finding water).