Fourwinds: I agree entirely that's it's a blend of elements and not just the rods. I've actually dowsed without rods or any other equipment, in fact, and I've met other people doing the same. I haven't tried Steve Gray's method, though. Thanks, Steve. I'll try that if I feel something but I'm not clear what and I want to explore it further.

Regarding water: yes, it's often possible there's another channel at a different level. As with all these cases, I think it's a matter of probability.

Water may be an explanation at some sites, and similarly there may be other explanations such as the ones suggested by Fourwinds.

But when you come to phenomena such as the ones I've encountered at Avebury, for example, water and similar underground phenomena seems very unlikely.

For example, I dowsed the line of stones that runs from the Repaired Stone and which includes the Barber Stone. No way does an underground stream or similar phenomenon approach each stone and presumably sink on the other side. There's a strong reading on the inner side of the circle and a weaker one on the other side. With one single stone it could be water, but not with a whole row of them.

Littlestone: Fourwinds has really answered this one for me. I'd also add overhead wires to his list.

What is really adds up to is dowsing at many different sites, and also returning to the same sites on several occasions so as to compare findings. If something may be, say, buried cables at one site but almost certainly isn't at another, that helps to build up a picture of what may be being picked up.

I suppose the difference between good sense and credulity is that good sense only posits an unknown form of energy if it seems reasonable to discount any others, while credulity jumps to the conclusion that there's an unknown form without taking other explanations into account.

Steve: The thermal theory is interesting. I really don't know one way or the other. Presumably it would be possible to verify that using detecting equipment, though, which would be an interesting line of research. It may or may not be relevant, but I suffer from hayfever, which is sometimes triggered by changes in temperature. Sometimes that would be due to pollen being released at those times, but I don't think that's necessarily always the case, and it seems likely that temperature changes can trigger a body reaction. I wonder if much more slight changes may be detectable, and whether people with hayfever may be more apt to spot them? It's just a thought, but it may connect with what you've suggested.

As nomadrush says, it makes sense to be sceptical but to try it out.

It's nice to visit a site where people are duly cautious and sensible.