A few weeks ago in this thread there was a link to another book the contents of which was posted online. Although it was not favorable to dowsing, it accepted the proposition that dowsing can/does "work", and the author included a lot of carefully researched and reasoned critique of the subject. Not that I agree with all the author's reasoning and conclusions, but it was a darn good read. Sorry, I don't remember the name of the book itself or of the author.
Unfortunately the post disappeared, I'm guessing that a mod deleted it because the author was coming from a Christian perspective which theoretically could have turned it into a sectarian religious battle. I have no dog in that fight myself.
I'm hoping that whoever posted that link will do so again, preferably in its own thread. And I hope that the moderators will let it stand as long as the people posting in the thread can discuss the thing on its merits (and otherwise) as a discourse on dowsing, resisting the temptation to turn it into a war over religion which this website isn't about.
--Toto