A Roman shipwreck, dating to the third century AD, has revealed signs of smuggling. [Sebastiano Tusa]
So, poor government regulation of a product resulted in a black market for that product, and people willing to risk life and limb to supply it.
Who'd have guessed that would happen?
They need to find and punish those smugglers now. lol
I’m not quite getting it. These tubes interlocked to do what? Build a stay-in-place form for a masonry arch?
Smuggeling or just old fashioned small scale capitilism?
Dang, they beat Leif Erikson over here!
Link to picture of how they were used for vaulting. Scroll down to drawing.