The use of bitumen as mortar and pavement has helped waterproof the otherwise fragile Sumerian mud - bricks, ensuring that the structures endured for millennia. ”
Bituumen, mida kasutati mördina ja teesillutiste rajamisel, tegi muredad Sumeri savitellised veekindlamaks, tänu millele pidasid tookordsed rajatised vastu aastatuhandeid. ”