I'm refering specifically to what TC Lethbridge wrote about it.
He used a pendulum rather than rods and was theorising about energy resonances of all objects - not specific to leylines, water or anything.
Apparently you can dowse for absolutely anything you like, as long as you have a sample of what you are looking for, in order to 'tune' the pendulum to the right length.
He makes it sound so very easy. Just wondering if it is.