Hi Snap. I've never gone and tried to dowse at any stones. I don't suppose many people have. It's easy to think it's rubbish because it doesn't fit in with generally held ideas about the material world which most people have in our culture in the 21st century. Part of me is very scientific and rational, the bit that poo-poohs it so I feel too embarrassed to to and dowse at a stone. But there's another bit of me that's very fortean and thinks people shouldn't dismiss people (like you)'s experiences so lightly. (it's not really the point, but it relates to why I am intrigued by experiences (and stories) of fairies and suchlike) because what are such experiences based on? Maybe they serve a purpose in a culture, and maybe they're based on real experiences based on the way our brains work.
I really like 'needles of stone' and reread it recently. It's easy to say 'dowsing is rubbish and doesn't work' and that may be true. But to the people doing it, they are experiencing Something are they not? (not all of them can be pretending..) And what's that Something?
Also. It's not so hard to put things in straight lines - the Romans were very good at it and they just had their low-tech 'groma's.
there's more things in heaven and earth etc.. and the best way to find out the truths of things is to experiment. Which is like wot you are doing.
I know some people will think opening your mind too far lets your brain fall out. But I know as I keep learning about science, social science, art etc my outlook on things has altered, and I think it's good to shake your brain up and see things from a new perspective sometimes.