[skepsel]

For that matter it's not unknown for unexploded shells from the US Civil War to turn up on old battlefields, still filled with black powder and still dangerous.

skepsel

[CrazyIvan]

Living in a farm area of the Midwest, I'd always known that solid objects rose to the surface of fields over time. Mr. Webster explains why in the book, and says that the really large artillery shells are just surfacing.