The Romans developed cement from raw materials available to them. There was nothing crude about it. (We’ve only recently been able to analyze their formula.) This group was introduced as on a level from 10,000 years ago. IMHO we won’t see that statement again.
The Romans developed cement from raw materials available to them. There was nothing crude about it. (We’ve only recently been able to analyze their formula.) This group was introduced as on a level from 10,000 years ago. IMHO we won’t see that statement again.