Nor could they have made a rubber for the seal. They didn't have access to the plants (Nazi's tried to use the only source that would have been available at the

Nor could they have made a rubber for the seal. They didn't have access to the plants (Nazi's tried to use the only source that would have been available at the time to the Romans and failed [1]). Think of the supply chain required to get rubber plants from Asian or the Congo to a Roman city. Carthage would have had a hard time too. Even if they had rubber in enough quantity, they'd have to vulcanize [2] it to make it work. That was years, centuries beyond them. 1 - https://en.wikipedia.org/wiki/Natural_rubber https://en.wikipedia.org/wiki/Natural_rubber 2 - https://en.wikipedia.org/wiki/Vulcanization https://en.wikipedia.org/wiki/Vulcanization Edited for the vulcanization.