Whenever I see this, I think of an Encyclopedia Brown story. I don't remember the whole story, but somehow culpability for the crime he was investigating was proven by initials that had been carved in a tree long ago and thus were now high up on the tree, as it had apparently grown considerably in the interim.

He proved that this was fraudulent, as trees grow from the top rather than the bottom, so the initials would have been at roughly the height at which they were initially placed.

edit: Grammar.