> As the other comment here says, this isn't a mystery. It's just extremely labour-intensive.
And as I said there, I don't find that kind of blaise response as convincing or substantial. Labour intensive way of lifting and lapping 140 tonne rocks?
https://en.wikipedia.org/wiki/Lapping#Two-piece_lapping
As the other comment here says, this isn't a mystery. It's just extremely labour-intensive.