I must have missed the earlier post about locating graves so this may be off track - I just wanted to clarify that my daughter-in-law is an anthropologist and when they use a rod to locate burials, the rod is hollow; when it is brought up there is a 'tube' of soil inside. A scientist trained in geology, such as she is, can tell from this whether the soil has ever been disturbed, i.e., if there has ever been a grave dug there. I don't think they send it down quite far enough to hit the remains of a coffin. Which would feel like nothing because 100-yr old wood would probably not be there anymore. LaWanda